ACKNOWLEDGEMENT
First of all we would like to thank all the respective persons of Soaltee Crowne Plaza, who have helped us throughout the attachment period. The success of the attachment is especially due to their kind cooperation and coordination. We are extremely thankful thankful to Mr. Shailesh Shailesh Kumar Jha Jha (Chief engineer,Soaltee engineer,Soaltee Crowne Crowne Plaz Plaza, a,Ta Taha hach chal al), ),
Mr. Mr.
Indr Indra a
Khad Khadka ka
(Tra (Train inee ee
Mana Ma nag ger, er,
Soal So alte tee e
Crow Crowne ne
Plaza,Tahachal ), Mr Bal Purushotam Shakya, Mr Sunil Rijal, Mr Madan Dawadi, Ram Dahal, Kendra, Hem , Prem Shakya. We would like to convey our thanks to the all those braches supervisors of Soalte Soa ltee e Crowne Crowne Plaza, Plaza, where where we visite visited. d. We are are genuin genuinely ely gratef grateful ul to our respected respected supervisor supervisor Mr. Santosh Santosh Chhetri Chhetri for his co-opera co-operation tion and guidance guidance throughout the site visiting period. Last but not the least we would like to thank all of our teachers and close friends who have directly and indirectly contributed for the successful completion of this Industrial attachment report.
ABSTRACT
This This report report is based based on the Indust Industria riall Attac Attachme hment nt done done at Soa Soalte ltee e Crowne Crowne Plaz Plaza a ,Tah ,Tahac acha hall as a requ requis isit ite e for for the the stud studen ents ts of Ba Bach chel elor or in Me Mech chan anic ical al Engineering IOE, Pulchowk (4th year 1st part). The report consists of the technical and manageri managerial al aspects aspects learnt during during the attachment attachment period period of 15 days.
The
report report also also provid provides es the infor informat mation ion about about the Engine Engineeri ering ng Depart Departme ment, nt, its respo responsi nsibil biliti ities, es, its functi functions ons and how it execu executes tes its work. work. The Engine Engineeri ering ng Depa Depart rtme ment nt is the the cent centra rall gove govern rnin ing g body body for for any any obst obstac acle les s rais raised ed in the the mechanical and electrical equipments all around the bodies of Soaltee Crowne Plaza. Mainly it handles the procurement, installation and maintenance of AC system, Boiler Plant, Filter Plant, diesel generators for backup power supply in load shedding hours. So, the report consists of various data and information about about the AC syste system m and its diff differe erent nt types types;; Boi Boiler ler Plant Plant and and its differ different ent accessories, Filter Plant and its different units and the diesel generator and its compo componen nents ts (mostly (mostly the engine engine part). part). Moreove Moreover, r, differe different nt types of oper operat atio ion n
at diffe iffere rent nt bran branch ches es like like Hima Himala laya yan n
ACs ACs in
Wing Wing,, Prin Prince ce ship ship Wing Wing
Jawalakhel branch and Regal Suites were observed. Management aspects of the Soaltee Crowne Plaza has been attempted to be drawn. Crisis management in the department was considered of utmost importance. Although Soaltee Crowne Plaza is a deluxe hotel, mostly dealing with hospitality and services, the attachment has helped understand an undergraduate student of mechanical engineering his/her scope in the very field.
ABSTRACT
This This report report is based based on the Indust Industria riall Attac Attachme hment nt done done at Soa Soalte ltee e Crowne Crowne Plaz Plaza a ,Tah ,Tahac acha hall as a requ requis isit ite e for for the the stud studen ents ts of Ba Bach chel elor or in Me Mech chan anic ical al Engineering IOE, Pulchowk (4th year 1st part). The report consists of the technical and manageri managerial al aspects aspects learnt during during the attachment attachment period period of 15 days.
The
report report also also provid provides es the infor informat mation ion about about the Engine Engineeri ering ng Depart Departme ment, nt, its respo responsi nsibil biliti ities, es, its functi functions ons and how it execu executes tes its work. work. The Engine Engineeri ering ng Depa Depart rtme ment nt is the the cent centra rall gove govern rnin ing g body body for for any any obst obstac acle les s rais raised ed in the the mechanical and electrical equipments all around the bodies of Soaltee Crowne Plaza. Mainly it handles the procurement, installation and maintenance of AC system, Boiler Plant, Filter Plant, diesel generators for backup power supply in load shedding hours. So, the report consists of various data and information about about the AC syste system m and its diff differe erent nt types types;; Boi Boiler ler Plant Plant and and its differ different ent accessories, Filter Plant and its different units and the diesel generator and its compo componen nents ts (mostly (mostly the engine engine part). part). Moreove Moreover, r, differe different nt types of oper operat atio ion n
at diffe iffere rent nt bran branch ches es like like Hima Himala laya yan n
ACs ACs in
Wing Wing,, Prin Prince ce ship ship Wing Wing
Jawalakhel branch and Regal Suites were observed. Management aspects of the Soaltee Crowne Plaza has been attempted to be drawn. Crisis management in the department was considered of utmost importance. Although Soaltee Crowne Plaza is a deluxe hotel, mostly dealing with hospitality and services, the attachment has helped understand an undergraduate student of mechanical engineering his/her scope in the very field.
1.0 BACKGROUND The work work of an engine engineer er is concer concerned ned with with develo developin ping g eco econom nomic ical al and safe safe solu so luti tion ons s to prac practi tica call prob proble lems ms,, by appl applyi ying ng math mathem emat atic ical al and and scie scient ntif ific ic knowl knowledg edge e while while consi consider dering ing techni technica call constr constrain aints. ts. As such, such, the engine engineeri ering ng profession is concerned to be the linked between art and science. The work of an engineer in a society is related to research and development, development, designing, testing, production, maintenance etc. One of the most valued qualities in an engineer is his managerial skills, which enhances his ability to lead and set an example for his followers. An Engine Engineer er might might need need to work work in variou various s worki working ng enviro environme nment nt and face number of problems. He/she then must be capable of solving the problems with full confidence, with a quick and right decision as far as possible. To be acquainted and be much more familiar with such engineering aspects of the society, we were demanded to work with a selected organization. For this we chose Soaltee Crowne Plaza, Tahachal, Kathmandu. The main objectives of our visit can be summarized as following: To visit and work under senior engineers and technicians To stud study y the the exis existi ting ng mana manage geme ment nt syst system em and and tech techno nolo logy gy of that that organization • •
•
•
To be fami famili liar ar with with vari variou ous s engi engine neer erin ing g aspe aspect cts s dema demand nded ed by that that particular organization To understand the role played by any engineer in a particular organization
2.0 Introduction Nestled in the Himalayas of Nepal, Soaltee Crowne Plaza is the leading five star deluxe hotels in Nepal offering a Resort atmosphere and is ideal for both business and leisure travel. Spread over 11 acres of lush green lawns, the hotel is located in the quiet green suburbs of the city with fabulous views of the mountain ranges. Kathmandu is proud to have many top-standard hotels and lodges to accommodate the numerous tourists coming to vacation here, and experience the magic and e xoticism that it seethes in. One of the most popular names among the 5 Star Hotels in Kathmandu is the Soaltee Crowne Plaza Hotel in Kathmandu, which draws a steady crowd of tourists with the promise of deluxe accommodation at affordable prices. Soaltee Crowne Plaza Hotel Hotel in Kathma Kathmandu ndu has made itself itself an acc accomm ommoda odatio tion n that that boasts boasts of the perfec perfectt melding of comfort and hospitality. Its suitable location, and a services and facilities arranged for comfort, the hotel is an ideal accommodation choice among the many Hotels in Kathmandu in Nepal. The Location of Soaltee Crowne Plaza Hotel in Kathmandu is chosen very carefully, and places the guests in an ideal locale, which is perfect for exploring the charms of the city. The Soa Soalte ltee e Crowne Crowne Plaza Plaza Hotel Hotel in Kathma Kathmandu ndu stands stands in the suburb suburbs s of Tahach Tahachal, al, cushioned by the majestic Himalayas. The Soaltee Crowne Plaza Hotel in Kathmandu is easily accessible, being just 15 minutes away from the Airport, making it easy for guests to get to it. The Room Facilities at Soaltee Crowne Plaza Hotel in Kathmandu are selected with care to ensur ensure e that that the the gues guests ts are are trea treate ted d to maxi maximu mum m comf comfort ort.. One One find finds s here here an arrangement which is shaped to rest the guests with the maximum comfort possible. 283 Superior, Deluxe and Crowne Plaza Club rooms, 8 Executive Suites and 7 Regal Suites, as well as Non-smoking rooms are available at the Soaltee Crowne Plaza Hotel in Kathmandu. To increase the comfort and give the guests a homelike experience, the Soaltee Crowne Plaza Hotel in Kathmandu has lined up a fine range of services and facilities. The Hotel Amenities and Services at Soaltee Soaltee Crowne Plaza Hotel in Kathmandu Kathmandu are allinclusive, and try to meet all the possible needs of the guests. The guests can see that all their needs are being catered to, what with the amiable and efficient staff of the Soaltee Crowne Plaza Hotel in Kathmandu working round the clock. Right from your dining needs, to your leisure and recreational desires, and your business requirements, all are superbly catered to by the conveniences offered by the Soaltee Crowne Plaza Hotel in Kathmandu. We were given various works to perform at different sections mainly air conditioning, boiler boiler,, filter filter plant plant sectio section n and generat generator, or, under under the supervi supervisio sion n of Engine Engineers ers and Technicians.
3.0
AIR CONDITIONING PLANT
3.1 Introduction Air conditioning refers to the cooling and dehumidification of indoor air for thermal comfort. In a broader sense, the term can refer to any form of cooling, heating, ventilation or disinfection that modifies the condition of air. An air conditioner (often referred to as AC or air con.) is an appliance, system, or mechanism designed to stabilize the air temperature and humidity within an area (used for cooling as well as heating depending on the air properties at a given time), typically using a refrigeration cycle but sometimes using evaporation, most commonly for comfort cooling in buildings and motor-cars. The concept of air conditioning is known to have been applied in Ancient Rome, where aqueduct water was circulated through the walls of certain houses to cool them. Similar techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season. Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by Willis Haviland Carrier. Early commercial applications of air conditioning were manufactured to cool air for industrial processing rather than personal comfort. In 1902 the first modern electrical air conditioning was invented by Willis Haviland Carrier in Syracuse, NY. Designed to improve manufacturing process control in a printing plant, his invention controlled not only temperature but also humidity. The low heat and humidity were to help maintain consistent paper dimensions and ink alignment. Later Carrier's technology was applied to increase productivity in the workplace, and The Carrier Air Conditioning Company of America was formed to meet rising demand. Over time air conditioning came to be used to improve comfort in homes and automobiles. Residential sales expanded dramatically in the 1950s. In 1906, Stuart W. Cramer of Charlotte, North Carolina, USA, was exploring ways to add moisture to the air in his textile mill. Cramer coined the term "air conditioning", using it in a patent claim he filed that year as an analogue to "water conditioning", then a wellknown process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories, controlling the humidity so necessary in textile plants. Willis Carrier adopted the term and incorporated it into the name of his company. This evaporation of water in air, to pro vide a cooling effect, is now known as evaporative cooling. The first air conditioners and refrigerators employed toxic or flammable gases like ammonia, methyl chloride, and propane which could result in fatal accidents when they leaked. Thomas Midgley, Jr. created the first chlorofluorocarbon gas, Freon, in 1928. The refrigerant was much safer for humans but was later found to be harmful to the atmosphere by ozone depletion in the stratosphere. The resulting biological
consequences included an increase in skin cancer, damage to plants, and the reduction of ocean plankton. Freon is a trademark name of DuPont for any Chlorofluorocarbon (CFC), Hydrogenated CFC (HCFC), or Hydrofluorocarbon (HFC) refrigerant, the name of each including a number indicating molecular composition (R-11, R-12, R-22, R-134A). The blend most used in direct-expansion home and building comfort cooling is an HCFC known as R-22. It is to be phased out for use in new equipment by 2010 and completely discontinued by 2020. R-12 was the most common blend used in automobiles in the US until 1994 when most changed to R-134A. R-11 and R-12 are no longer manufactured in the US, the only source for purchase being the cleaned and purified gas recovered from other air conditioner systems. Several non-ozone depleting refrigerants have been developed as alternatives, including R-410A, invented by Honeywell (formerly AlliedSignal) in Buffalo NY and sold under the Genetron (R) AZ-20 name it was first commercially used by Carrier under the brand name Puron. Innovation in air conditioning technologies continue, with much recent emphasis placed on energy efficiency, and improving indoor air quality. Reducing climate change impacts is an important area of innovation, because in addition to greenhouse gas emissions associated with energy use, CFCs, HCFCs and HFCs are potent greenhouse gases when leaked to the atmosphere. For example, R-22 (also known as HCFC-22) has a global warming potential about 1,800 times higher than CO2[10]. As an alternative to conventional refrigerants, natural alternatives like CO 2 (R-744) have been proposed. 3.2 Types of Air Conditioning Air conditioning engineers broadly divide air conditioning applications into comfort and process. Comfort applications aim to provide a building indoor environment that remains relatively constant in a range preferred by humans despite changes in external weather conditions or in internal heat loads. Comfort air conditioning makes deep plan buildings feasible. Without air conditioning, buildings must be built narrower or with light wells so that inner spaces receive sufficient outdoor air via natural ventilation. Air conditioning also allows buildings to be taller since wind speed increases significantly with altitude making natural ventilation impractical for very tall buildings. Comfort applications for various building types are quite different and may be categorized as: •
Low-Rise Residential buildings, including single family houses, duplexes, and small apartment buildings
•
High-Rise Residential buildings, such as tall dormitories and apartment blocks
•
Commercial buildings, which are built for commerce, including offices, malls, shopping centers, restaurants, etc.
•
Institutional buildings, which includes hospitals, governmental, academic, and so on.
•
Industrial spaces where thermal comfort of workers is desired.
In addition to buildings, air conditioning can be used for comfort in a wide variety of transportation including land vehicles, trains, ships, aircraft, and spacecraft. Process applications aim to provide a suitable environment for a process being carried out, regardless of internal heat and humidity loads and external weather conditions. Although often in the comfort range, it is the needs of the process that determine conditions, not human preference. Process applications include these:
Hospital operating theatres, in which air is filtered to high levels to reduce infection risk and the humidity controlled to limit patient dehydration. Although temperatures are often in the comfort range, some specialist procedures such as open heart surgery require low temperatures (about 18 °C, 64 °F) and others such as neonatal relatively high temperatures (about 28 °C, 82 °F). Clean rooms for the production of integrated circuits, pharmaceuticals, and the like, in which very high levels of air cleanliness and control of temperature and humidity are required for the success of the process. Facilities for breeding laboratory animals: Since many animals normally only reproduce in spring, holding them in rooms at which conditions mirror spring all year can cause them to reproduce year round. In both comfort and process applications the objective may be to not only control temperature, but also humidity, air quality and air movement from space to space. The air conditioning units visited by us is included in this category. They are basically used for better functioning of the sensitive equipments. Humidity control is not that much important.
3.2 Working of Air Conditioners The evaporative cycle of an air conditioning works as follows: 1. The compressor compresses cool refrigerant, causing it to become hot, highpressure refrigerant gas (left in the diagram shown below) 2. This hot gas runs through a set of coils so it can dissipate its heat, and it condenses into a liquid. 3. The refrigerant liquid runs through an expansion valve, and in the process it evaporates to become cold, low-pressure gas (right in the diagram above). 4. This cold gas runs through a set of coils that allow the gas to absorb heat and cools the air inside the building. Fig: A typical air conditioner(A-expansion valve;B-compressor)
3.3 Parts of air conditioning unit a. Air conditioning or heat pump compressor: It compresses low pressure refrigerant gas into a high pressure, high temperature gas. Usually the compressor is in the outdoor portion of an air conditioning or heat pump system. The compressor is basically a high pressure pump driven by an electric motor. The air conditioning compressor is usually packaged in the outdoor compressor/condenser unit.
b. A condenser or condensing unit: It is typically a condensing coil inside which high temperature high pressure refrigerant gas flows, and over which a fan blows air to cool the refrigerant gas back to a liquid state (thus transferring heat from the refrigerant gas to the air being blown by the fan). The condenser unit is basically a coil of finned tubing and a fan to blow air across the coil. Usually the condenser unit is in the outdoor portion of an air conditioning system, often packaged along with the compressor motor. The change of state of the refrigerant, from hot high pressure
gas to a liquid releases heat, including heat collected inside the building to the outdoors.
c. An evaporator coil or cooling coil: Typically the cooling coil is a section of finned tubing (it looks a lot like a car radiator) into which liquid refrigerant is metered and permitted to evaporate from liquid to gas state inside the coil. This state change of the refrigerant, from liquid to gas, absorbs heat, cooling the evaporator coil surface and thus cooling indoor air blown across the cooling coil. Usually the cooling coil is located inside the air handler. d. An air handler and blower unit: It provides a fan to blow building air across or through the evaporator coil. The air handler blower fan unit moves building air across the evaporator coil surface in order to condition building air by cooling it (and thus also by removing moisture from the cooled air).
e. A duct system: It distributes conditioned air from the air handler in to the occupied space (supply ducts), and which takes air from the occupied space and returns it to the cooling system air handler.
f. Air conditioner controls and features: It includes a room thermostat, electrical switches, fuses or circuit breakers, condensate handling system, and air filters.
3.4 AIR HANDLING UNIT: Air Handler Unit (AHU)
which
typically
includes
Fig. Air Filters of AHU
Condensate system: Water or condensate is produced when we cool warm moist air by blowing it over the evaporator coil. The condensate runs down the coil to a collecting pan which drains to piping used to route condensate to an approved drain for disposal Condensate pump on some air conditioning systems a small pump is used to collect
the
following
accessories:
and then pump condensate up to a building drain or other location for disposal. Condensate pumps are needed for systems which cannot dispose of the condensate by simple gravity flow down a drain line. Condensate overflow pan or tray is a container placed below the air handler when that unit is located in an attic or in other building locations where condensate leakage or overflow would otherwise spill onto building floors or into a building ceiling. The condensate overflow pan is a safety device intended to prevent unwanted spillage; normally it does not contain condensate. The condensate overflow pan should have either an independent drain to an approved location or a float switch to shut down the air conditioner should the pan become full. Blower fan in a blower compartment circulates building air into itself from the return ducts and return plenum, and moves that air across the evaporator coil and onwards to the supply plenum and supply ducts in the building. Blowers may be single speed, multiple speed, or variable speed, and may need to move air at different rates if the blower is used for both heating and cooling in the same duct system. Some air blowers are also rated for continuous operation. Evaporator Coil (also called the "cooling coil" is connected to high pressure and low pressure (suction) refrigerant lines. High pressure refrigerant liquid, released into the cooling coil by the thermal expansion valve changes state from a liquid to a gas, causing a drop in temperature of the refrigerant and thus cooling the evaporator coil so that when we move air across the coil the air will, in turn, be cooled. Return Plenum, connected to return duct system, is the air receiving compartment which provides air to the blower fan. Supply plenum connected to supply duct system, is the air collecting compartment to which building supply ducts are connected. Think of the return plenum and supply plenum as junction boxes to which return ducts or supply ducts respectively can be connected. Support system is the means by which an attic-mounted air handler is supported or held in place, for example by being suspended from the roof rafters (a quiet installation) or perhaps by being placed on supporting wood beams laid across ceiling joists. Thermal expansion valve in an air conditioner is a device located at the cooling coil and connected between the incoming refrigerant line and the refrigerant inlet to the cooling coil in the air handler. The air conditioning system thermal expansion valve or "TEV" is a metering device which regulates the flow of refrigerant from the incoming high pressure side (from the compressor/condenser) into the low pressure side (in the cooling coil). Air Filters located at the return duct air inlets, at one or more central return air inlets, or at the air handler unit itself are used to remove dust and debris from building air. Access ports to duct interior Commercial ducts and some residential duct systems may have inspection/cleaning access ports;
residential HVAC ducts may have plugs indicating that the ducts have been cleaned in the past. Ductless air conditioning systems, which may also be called "split A/C systems" may employ one or more wall mounted cooling units such as shown at right above. Return air ducts and registers collect warm moist air from the occupied space and return it to the air handler unit. Some air conditioning installations do not provide return air registers and ducts in every room and use one or more "central air return inlets" instead. Central air returns are most common on air conditioning retrofit installations (adding A/C to an existing building). Supply air ducts and supply air registers deliver cooled air to the occupied space. Supply registers have the dual function of spreading out and directing the air flow into a location and permitting the regulation of air flow by opening or closing the register. Some air conditioning duct systems use small-diameter, "high velocity" ducts to deliver conditioned air to the living space. Supply air balancing dampers, manual and motorized zone dampers may be installed inside the supply ducts at varying locations in to permit balancing the air flow among different duct sections and thus among different building areas. Thermostat(s) are used to turn the air conditioning on and off and to set the desired indoor temperature. One thermostat will be located in each different air conditioning zone and will control an individual air handler unit's operation. 3.5 Compressors: A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Compressors are similar to pumps, both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas. Liquids are relatively incompressible, so the main action of a pump is to transport liquids. Types of compressors The main types of gas compressors are illustrated and discussed below:
Reciprocating compressors
Fig: Reciprocating Compressor Unit
Reciprocating compressors use pistons driven by a crankshaft. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines. Small reciprocating compressors from 5 to 30 horsepower (hp) are commonly seen in automotive applications and are typically for intermittent duty. Larger reciprocating compressors well over 1 000 hp are still commonly found in large industrial and petroleum applications. Discharge pressures can range from low pressure to very high pressure (>5000 psi or 35 MPa). In certain applications, such as air compression, multi-stage double-acting compressors are said to be the most efficient compressors available, and are typically larger, noisier, and more costly than comparable rotary units. 1.
Rotary Compressors
In positive displacement rotary type compressors, the air is entrapped between two sets of engaging surfaces and the pressure rise is either by back flow of air (roots blower) or by both squeezing action and back flow of air (vane type). Rotary vane compressors consist of a rotor with a number of blades inserted in radial slots in the rotor. The rotor is mounted offset in a larger housing which can be circular or a more complex shape. As the rotor turns, blades slide in and out of the slots keeping contact with the outer wall of the housing. Thus, a series of decreasing volumes is created by the rotating blades. Rotary Vane compressors are, with piston compressors one of the oldest of compressor technologies. With suitable port connections, the devices may be either a compressor or a vacuum pump. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines. A rotary vane compressor is well suited to electric motor drive and is significantly quieter in operation than the equivalent piston compressor. Rotary screw compressors use two meshed rotating positive-displacement helical screws to force the gas into a smaller space. These are usually used for continuous operation in commercial and industrial applications and may be either stationary or portable. Their application can be from 3 hp (2.24 kW) to over 500 hp (375 kW) and from low pressure to very high pressure (>1200 psi or 8.3 MPa). There are various types of air conditioners like window air conditioner, split air conditioner, packaged air conditioner and central air conditioning system used in Soaltee Crowne Plaza.
3.6 Types of Air conditioning unit used in Soaltee Crowne Plaza are: Central air conditioning Central air conditionings commonly referred to as central air or air-con, are an air conditioning system which uses ducts to distribute cooled and/or dehumidified air to more than one room, or uses pipes to distribute chilled water to heat exchangers in more than one room. With a typical split system, the condenser and compressor are located in an outdoor unit; the evaporator is mounted in the air handler unit. With a package system, all components are located in a single outdoor unit that may be located on the ground or roof .
Central air conditioning performs like a regular air conditioner but has several added benefits. When the air handling unit turns on, room air is drawn in from various parts of the building through return-air ducts. This air is pulled through a filter where airborne particles such as dust and lint are removed. Sophisticated filters may remove microscopic pollutants as well. The filtered air is routed to air supply ductwork that carries it back to rooms. Whenever the air conditioner is running, this cycle repeats continually. Because the central air conditioning unit is located outside the home, it offers a lower level of indoor noise than a free-standing air conditioning unit. The main air conditioning system used in Soaltee Crowne Plaza is central air conditioning system.
Fig. Central A/C System and its Compressor
The one used is: Chilled water central air conditioning plant: This type of system is more useful for large buildings comprising of a number of floors. It has the plant room where all the important units like the compressor, condenser, throttling valve and the evaporator are housed. The evaporator is a shell and tube. On the tube side the Freon fluid passes at extremely low temperature, while on the shell side the brine solution is passed. After passing through the evaporator, the brine solution gets chilled and is pumped to the various air handling units installed at different floors of the building. The air handling units comprise the cooling coil through which the chilled brine flows, and the blower. The blower sucks hot return air from the room via ducts and blows it over the cooling coil. The cool air is then supplied to the space to be cooled through the ducts. The brine solution which has absorbed the room heat comes back to the evaporator, gets chilled and is again pumped back to the air handling unit. 1. Window and through wall AC units A window air conditioner unit implements a complete air conditioner in a small space. The units are made small enough to fit into a standard window frame. Many traditional air conditioners in homes or other buildings are single rectangular units used to cool all or a portion of an apartment, house, or other building. Air conditioner units need to have access to the space they are cooling (the inside) and a heat sink; normally outside air is used to cool the condenser section. For this reason, single unit air conditioners are
placed in windows or through openings in a wall made for the air conditioner; the latter Fig: The external section of a typical A/C unit type includes portable air conditioners. Window and through-wall units have vents on both the inside and outside, so inside air to be cooled can be blown in and out by a fan in the unit, and outside air can also be blown in and out by another fan to act as the heat sink. The controls are on the inside. A large house or building may have several such units. Should virtually every room be cooled with its own air conditioning unit, most of the day, it would be less expensive to use central air conditioning, though that may not be physically possible. They consist of following units: A compressor An expansion valve A hot coil (on the outside) A chilled coil (on the inside) Two fans A control unit The fans blow air over the coils to improve their ability to dissipate heat (to the outside air) and cold Fig: Window AC unit (to the room being cooled). • • •
•
• •
2.
Split-system AC Units
A split-system air conditioner splits the hot side from the cold side of the system. The cold side, consisting of the expansion valve and the cold coil, is generally placed into a furnace or some other air handler. The air handler blows air through the coil and routes the air throughout the building using a series of ducts. The hot side, known as the condensing unit is placed outside the building. ). Besides the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there is no difference between a split-system and a window air conditioner. In warehouses, businesses, malls, large department stores and the like, the condensing unit normally lives on the roof and can be quite massive. Alternatively, there may be many smaller units on the roof, each attached inside to a small air handler that cools a specific zone in the building. In larger buildings and particularly in multi-story buildings, the splitsystem approach begins to run into problems. Either running the pipe between the condenser and the air handler exceeds distance limitations (runs that are too long start to cause lubrication difficulties in
the compressor), or the amount of duct work and the length of ducts becomes unmanageable. Fig: Split system AC unit 3. Packaged Air Conditioners Packaged air conditioner models are used for medium sized halls and multiple rooms on the same floor. They are usually used for applications where air conditioning of more than 5 tons is required. They are used when central plant air conditioner cannot supply sufficient air. If you want to cool a number of rooms in your home, you will probably have to consult an HVAC designer for maximum cooling at the lowest possible cost, and they might suggest package air conditioners for your application. The package unit is used for cooling medium sized halls, hospitals, and multiple rooms, usually on the same floor. Installing multiple small window units or split units in the halls or multiple rooms may not be feasible; in such cases package units are recommended by the HVAC engineers. There are two possible arrangements of packaged unit: 1) In the first arrangement the compressor, condenser and the expansion valve, which make the outdoor unit, are all enclosed in a single large casing. Freon gas passes through the compressor, condenser, and expansion valve and gets chilled. This gas then passes through the evaporator or cooling coil. There is a large blower that sucks the hot returned room air and blows it over the cooling coil. This cool air is then supplied though ducts which are laid down in various rooms or various parts of the room or hall. The openings are provided in the ducts at various locations so that the cool air is evenly distributed as per the heat load in the rooms. 2) In the second possible arrangement, there are two parts of the package air conditioner similar to the split air conditioner. These are the outdoor unit and the indoor unit. The outdoor unit houses important parts of the air conditioner like the compressor and the condenser. The indoor unit houses other important parts of the air conditioner like expansion valve, the evaporator coil or the cooling coil and the blower. There can be multiple outdoor units or a single large outdoor unit. The indoor units are usually multiple units located in various rooms or at various places inside the large space, where the cooling effect is required. The indoor units are usually laid hanged over the ceiling. The blower of the indoor unit sucks hot returned room air from the various parts of large room. When this air is blown over the cooling coil, it gets cooled and it is supplied through the ducts to various parts of the room. 3.7 Refrigerants Until the 1990s, the refrigerants were often chlorofluorocarbons such as R-12 (CCl 2 F2). Its manufacture was discontinued in 1995 because of the damage that CFCs cause to the ozone layer if released into the atmosphere. One widely-adopted replacement refrigerant is the hydro fluorocarbon (HFC) known as R-134a(1,1,1,2-tetrafluoroethane). R-134a is not as efficient as the R-12 it replaced (in automotive applications) and therefore, more energy is required to operate systems utilizing R-134a than those using R-12. Other substances such as liquid ammonia, or occasionally the less
corrosive but flammable propane or butane, can also be used. Fig: Refrigerants
In residential and commercial applications, the hydro chlorofluorocarbon (HCFC) R-22 is still widely used, however, HFC R-410a does not deplete the ozone layer, but it is a powerful global warming gas and is nevertheless increasingly being used. Hydrogen, helium, nitrogen, or air is used in the Stirling cycle, providing the maximum number of options in environmental friendly gas. Hydrocarbons (HCs) and hydro fluorocarbons (HFCs) provide an alternative to fully halogenated CFC refrigerants. They contain no chlorine atom at all and, therefore, have zero OPD (Ozone Depletion Potential). Even hydro chlorofluorocarbon (HCFCs) which do contain chlorine atom/s, but in association with hydrogen atoms, have much reduced ODP. The association one or more H-atoms allow them to dissociate faster in the lower atmosphere of the earth. Chlorine thus released, gets absorbed by the rain water etc. so few chlorine atoms reach the ozone layer in the upper atmosphere. However HCFCs have a level of GWP (Global Warming Potential). The two most common refrigerants which have very high ODP are R11 and R12 (CFCs). R22 which is a HCFC has 1/20 th the ODP of R11 and R12. However all these have GWP. Nevertheless, R22 is found to be of greater use these days as it is being employed, not only in its existing R22 applications, but also as a substitute for R11 in very large capacity air conditioning applications either with screw or with centrifugal compressors. There are two AC plants used in Soaltee Crowne Plaza.The ACs used in Soaltee Crowne Plaza mainly uses R22,R123 as refrigerant. These refrigerants come in cans with different colour coding. Availability of R-22 The Clean Air Act does not allow any re frigerant to be vented into the atmosphere during installation, service, or retirement of equipment. Therefore, R-22 must be recovered and recycled (for reuse in the same system), reclaimed (reprocessed to the same purity levels as new R-22), or destroyed. After 2020, the servicing of R-22-based systems will rely on recycled refrigerants. It is expected that reclamation and recycling will ensure that existing supplies of R-22 will last longer and be available to service a greater number of systems. As noted above, chemical manufacturers will be able to produce R22 for use in new A/C equipment until 2010, and they can continue production of R-22 until 2020 for use in servicing that equipment. Given this schedule, the transition away from R-22 to the use of ozone-friendly refrigerants should be smooth. For the next 20 years or more, R-22 should continue to be available for all systems that require R-22 for servicing. Alternatives to R-22 in Residential Air Conditioning As R-22 is gradually phased out, non-ozone-depleting alternative refrigerants are being introduced. Under the Clean Air Act, EPA reviews alternatives to ozone-depleting substances like R-22 in order to evaluate their effects on human health and the environment. EPA has reviewed several of these alternatives to R-22 and has compiled a list of substitutes that EPA has determined are acceptable. One of these substitutes is R410A, a blend of hydrofluorocarbons (HFCs), substances that do not contribute to depletion of the ozone layer, but, like R-22, contribute to global warming. R-410A is manufactured and sold under various trade names, including GENETRON AZ-20(R), SUVA 410A(R), and Puron(R). Additional refrigerants on the list of acceptable substitutes include R-134a and R-407C. These two refrigerants are not yet available for residential applications in the U.S., but are commonly found in residential A/C systems and heat
pumps in Europe. EPA will continue to review new non-ozone-depleting refrigerants as they are developed. Equipment capacity: Most air conditioners have their capacity rated in British thermal units (BTU). Generally, a BTU is the amount of heat required to raise the temperature of one pound (0.45 kg) of water 1 degree Fahrenheit (0.56 degrees Celsius). Specifically, 1 BTU equals 1,055 joules. In heating and cooling terms, 1 "ton" equals 12,000 BTU. A Central air conditioner used in Soaltee Crowne Plaza is of 300ton capacity. The use of electric/compressive air conditioning puts a major demand on the electrical power grid in warm weather, when most units are operating under heavy load.
Problems in AC system
The ice or frost formed on a cooling coil Dirt-blocked air conditioner air handler fans Filters protect the blower assembly: The typical A/C system circulates air through the building duct work using a "squirrel cage" blower fan. It is very important for you to check and change air filters at least monthly when the system is in use to protect the blower fan from dirt clogging. Cupped fan blades can become blocked by debris: The blades of a squirrel-cage fan are cupped in order to cause the spinning cage to move air. Dirt accumulation on the blades fills-in this cupped area, ultimately changing the "cup" to a simple flat area. The fan will spin just fine. I've seen the cubic feet per minute of air conditioning air-flow literally double when a very dirty squirrel cage fan fan of this type was cleaned or replaced. Cleaning an air conditioner squirrel cage fan with compressed air.If the blower fan blades have significant dirt accumulation, you should have the system professionally cleaned. While this is a fairly costly ser vice call (requiring blower disassembly and removal for cleaning) it can make a dramatic improvement in system performance. Do not permit a simple "blow out" of the blower by compressed air if the air handler/blower are in the living area. Some HVAC service companies use a foaming cleaner for removing debris from an evaporator coil. That same material might assist in cleaning a squirrel cage fan. Otherwise we recommend removing the fan and cleaning it thoroughly outside. Clean the remainder of the fan cabinet and housing before returning the air handler to service.
4.0 BOILER PLANT A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.
Fig. Two types of Boiler
4.1 Fire-tube boiler A fire-tube boiler is a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water. The general construction is as a tank of water perforated by tubes that carry the hot flue gases from the fire. This has a cylindrical barrel containing the fire tubes, but also has an extension at one end to house the "firebox". The tank is usually cylindrical for the most part – being the strongest practical shape for a pressurized container – and this cylindrical tank may be either horizontal or vertical. The heat energy from the gases passes through the sides of the tubes by thermal conduction, heating the water and ultimately creating steam. Here, water partially fills a boiler barrel with a small volume left above to accommodate the steam ( steam space). This is the type of boiler used in nearly all steam locomotives. The heat source is inside a furnace or firebox that has to be kept permanently surrounded by the water in order to maintain the temperature of the heating surface just below boiling point. The furnace can be situated at one end of a fire-tube which lengthens the path of the hot gases, thus augmenting the heating surface which can be further increased by making the gases reverse direction through a second parallel tube or a bundle of multiple tubes; alternatively the gases may be taken along the sides and then beneath the boiler through flues (3-pass boiler). In the case of a locomotive-type boiler, a boiler barrel extends from the firebox and the hot gases pass through a bundle of fire tubes inside the barrel which greatly increase the heating surface compared to a single tube and further improve heat transfer. Fire-tube boilers usually have a comparatively low rate of steam production, but high steam storage capacity. Fire-tube boilers mostly burn solid fuels,
but are readily adaptable to those of the liquid or gas variety. There are three boilers in Soaltee Crowne Plaza. Among them, The bigger one can produce 3600kg of steam per hour and next can 2000kg of steam per hour. A fire-tube boiler is sometimes called a "smoke-tube boiler" or "shell boiler" or sometimes just "fire pipe". 4.2 Materials The pressure vessel in a boiler is usually made of steel (or alloy steel), or historically of wrought iron. Stainless steel is virtually prohibited (by the ASME Boiler Code) for use in wetted parts of modern boilers, but is used often in superheater sections that will not be exposed to liquid boiler water. In live steam models, copper or brass is often used because it is more easily fabricated in smaller size boilers. Historically, copper was often used for fireboxes (particularly for steam locomotives), because of its better formability and higher thermal conductivity; however, in more recent times, the high price of copper often makes this an uneconomic choice and cheaper substitutes (such as steel) are used instead. For much of the Victorian "age of steam", the only material used for boilermaking was the highest grade of wrought iron, with assembly by rivetting. This iron was often obtained from specialist ironworks, such as at Cleator Moor (UK), noted for the high quality of their rolled plate and its suitability for high-reliability use in critical applications, such as high-pressure boilers. In the 20th century, design practice instead moved towards the use of steel, which is stronger and cheaper, with welded construction, which is quicker and requires less labour. Cast iron may be used for the heating vessel of domestic water heaters. Although such heaters are usually termed "boilers", their purpose is usually to produce hot water, not steam, and so they run at low pressure and try to avoid actual boiling. The brittleness of cast iron makes it impractical for high pressure steam boilers.
Fig. Steam pump and non-returning valve
4.3 Fuel The source of heat for a boiler is combustion of any of several fuels, such as wood, coal, oil, or natural gas. The boiler in the Hotel soaltee crowne plaza uses furnace oil as fuel. The boiler used in Soaltee Crowne Plaza consumes 168 litres of furnace oil per hour. 4.4 Heat exchanger A heat exchanger is a device built for efficient heat transfer from one medium to another, whether the media are separated by a solid wall so that they never mix, or the media are in direct contact. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, and natural gas processing. One common example of a heat exchanger is the radiator in a car, in which the heat source, being a hot engine-cooling fluid, water, transfers heat to air flowing through the radiator [i.e. the heat transfer medium. Heat exchangers may be classified according to their flow arrangement. In parallel-flow heat exchangers, the two fluids enter the exchanger at the same end, and travel in parallel to one another to the other side. In counter-flow heat exchangers the fluids enter the exchanger from opposite ends. The counter current design is most efficient, in that it can transfer the most heat from the heat (transfer) medium. See countercurrent exchange. In a cross-flow heat exchanger, the fluids travel roughly perpendicular to one another through the exchanger. Shell and tube heat exchanger Shell and tube heat exchangers consist of a series of tubes. One set of these tubes contains the fluid that must be either heated or cooled. The second fluid runs over the tubes that are being heated or cooled so that it can either provide the heat or absorb the heat required. A set of tubes is called the tube bundle and can be made up of several types of tubes: plain, longitudinally finned, etc. Shell and Tube heat exchangers are typically used for high pressure applications (with pressures greater than 30 bar and temperatures greater than 260°C. This is because the shell and tube heat exchangers are robust Fig. A Shell and Tube heat exchanger due to their shape. 4.5 Calorifier An apparatus used for the transfer of heat to water in a vessel by indirect means, the source of heat being contained within a pipe or coil immersed in the water. Calorifier is a device utilizes the heat energy of steam to heat the water for heating and domestic purposes. There are two basic types of calorifier, the storage type, used to heat water for domestic purposes and the non-storage type designed to heat water for a means of central heating. The calorifier is sometimes used to provide heat to a drying room for linen. 4.6 Boiler fittings and accessories: Safety valve: It is used to relieve pressure and prevent possible explosion of a boiler. Water level indicators: They show the operator the level of fluid in the boiler, also known as a sight glass, water gauge or water column is provided. Bottom blowdown valves: They provide a means for removing solid particulates that condense and lay on the bottom of a boiler. As the name implies, this valve is •
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usually located directly on the bottom of the boiler, and is occasionally opened to use the pressure in the boiler to push these particulates out. Continuous blowdown valve: This allows a small quantity of water to escape continuously. Its purpose is to prevent the water in the boiler becoming saturated with dissolved salts. Saturation would lead to foaming and cause water droplets to be carried over with the steam - a condition known as priming. Hand holes: They are steel plates installed in openings in "header" to allow for inspections & installation of tubes and inspection of internal surfaces. Steam drum internals: A series of screen, scrubber & cans (cyclone separators). Low- water cutoff: It is a mechanical means (usually a float switch) that is used to turn off the burner or shut off fuel to the boiler to prevent it from running once the water goes below a certain point. If a boiler is "dry-fired" (burned without water in it) it can cause rupture or catastrophic failure. Surface blowdown line: It provides a means for removing foam or other lightweight non-condensible substances that tend to float on top of the water inside the boiler. Circulating pump: It is designed to circulate water back to the boiler after it has expelled some of its heat. Feedwater check valve or clack valve: A non-return stop valve in the feedwater line. This may be fitted to the side of the boiler, just below the water level, or to the top of the boiler. Top feed: A check valve (clack valve) in the feedwater line, mounted on top of the boiler. It is intended to reduce the nuisance of limescale. It does not prevent limescale formation but causes the limescale to be precipitated in a powdery form which is easily washed out of the boiler.
Problems in Boiler plant Foaming Foaming is a condition that occurs in boilers when there are high concentrations of soluble salts, suspended solids or organic matter. These create foam in the steam space of your boiler that actually look like the foam on a good glass of beer! Now foam on your beer is acceptable, foam in your boiler is not. When these little foam bubbles pop, they create a liquid that, in turn form slugs of water. Not only does your steam quality suffer, so may your entire system. Remember steam can reach velocities of over 80 miles an hour. Push a slug of water through at that speed and you can seriously damage turbine blades, piping systems and actuators.
Chemical carry over The most likely cause for chemical carryover is that the Total Dissolved Solids are too high (Boiler water Conductivity is another way to express TDS). TDS is controlled by the surface blow down and should be controlled to the recommendations of your chemical supplier (normally 4000 micro-mho plus/minus 400). Another possibility for chemical carryover is that you are dropping too big of a load too fast onto the boiler which drops boiler pressure suddenly causing the boiler to suddenly boil excessively and carrying over into the steam line. This is a bit harder to fix but can be done.
Accumulation of dirt in feedpump When water to produce steam is passed to the boiler through feedpump. The dirt present in water gets collected in feedpump causing it to block. Blockage of smoke As the fuel used in boiler is furnace oil, it is not as pure as petrol and diesel it contains lots of dirts and carbon. Thus continuous burning of this fuel causes carbon to stick onto the surface of the chimney causing blockage of smoke to passed through chimney. This is removed by cleaning and flushing the inner part of boiler regularly.
5.0 FILTER PLANT Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from raw water. The goal is to produce water fit for a specific purpose. Most water is purified for human consumption (drinking water) but water purification may also be designed for a variety of other purposes, including to meet the requirements of medical, pharmacology, chemical and industrial applications. In general the methods used include physical process such as filtration and sedimentation, biological processes such as slow sand filters or activated sludge, chemical process such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi; and a range of dissolved and particulate material derived from the minerals that water may have made contacted after falling as rain. The standards for drinking water quality are typically set by governments or by international standards. These standards will typically set minimum and maximum concentrations of contaminants for the use that is to be made of the water.
5.1 Sources of water in Soaltee Crowne Plaza Groundwater: The water emerging from some deep ground water may have fallen as rain many decades, hundreds, thousands or in some cases millions of years ago. Soil and rock layers naturally filter the ground water to a high degree of clarity before it is pumped to the treatment plant. Such water may emerge as springs, artesian springs, or may be extracted from boreholes or wells. Deep ground water is generally of very high bacteriological quality (i.e., pathogenic bacteria or the pathogenic protozoa are typically absent), but the water typically is rich in dissolved solids, especially carbonates and sulfates of calcium and magnesium. Depending on the strata through which the water has flowed, other ions may also be present including chloride, and bicarbonate. There may be a requirement to reduce the iron or manganese content of this water to make it pleasant for drinking, cooking, and laundry use. Disinfection may also be required. Where groundwater recharge is practised; a process in which river water is injected into an aquifer to store the water in times of plenty so that it is available in times of dr ought; it is equivalent to lowland surface waters for treatment purposes. Rainwater harvesting or fog collection which collects water from the atmosphere can be used especially in areas with significant dry seasons and in areas which experience fog even when there is little rain. 5.2
Treatment
The processes below are the ones commonly used in water purification plants. Some or most may not be used depending on the scale of the plant and quality of the water.
Pre-treatment: Pumping and containment: The majority of water must be pumped from its source or directed into pipes or holding tanks. To avoid adding contaminants to the water, this
physical infrastructure must be made from appropriate materials and constructed so that accidental contamination does not occur. Aeration: Aeration is a process of removing gases present in the ground water. In this process the collected ground water is first pumped upward in air (vertical direction).Then the contained gases is removed from it. Storage: Water from rivers may also be stored in bankside reservoirs for periods between a few days and many months to allow natural biological purification to take place. This is especially important if treatment is by slow sand filters. Storage reservoirs also provide a buffer against short periods of drought or to allow water supply to be maintained during transitory pollution incidents in the source river. Chlorination: Its compounds such as chloramine or chlorine dioxide. Chlorine is a strong oxidant that rapidly kills many harmful micro-organisms. Because chlorine is a toxic gas, there is a danger of a release associated with its use. This problem is avoided by the use of sodium hypochlorite, which is a relatively inexpensive solution that releases free chlorine when dissolved in water. Chlorine solutions can be generated on site by electrolyzing common salt solutions. A solid form, calcium hypochlorite exists that releases chlorine on contact with water. Handling the solid, however, requires greater routine human contact through opening bags and pouring than the use of gas cylinders or bleach which are more easily automated. The generation of liquid sodium hypochlorite is both inexpensive and safer than the use of gas or solid chlorine. All forms of chlorine are widely used despite their respective drawbacks. One drawback is that chlorine from any source reacts with natural organic compounds in the water to form potentially harmful chemical by-products trihalomethanes (THMs) and haloacetic acids (HAAs), both of which are carcinogenic in large quantities and regulated by the United States Environmental Protection Agency (EPA). The formation of THMs and haloacetic acids may be minimized by effective removal of as many organics from the water as possible prior to chlorine addition. Although chlorine is effective in killing bacteria, it has limited effectiveness against protozoans that form cysts in water (Giardia lamblia and Cryptosporidium, both of which are pathogenic). Airscoured Pressure Filter: Water exiting the storage basin may enter the Airscoured Pressure Filter, also called a clarifier or settling basin. It is a large tank with slow flow, allowing floc to settle to the bottom. The Airscoured Pressure Filter is best located close to the storage basin so the transit between does not permit settlement or floc break up. Airscoured Pressure Filters can be in the shape of a cylindrical, where water flows from end to end, or circular where flow is from the centre outward. Airscoured Pressure Filter outflow is typically over a weir so only a thin top layer - furthest from the sediment exits. The amount of floc that settles out of the water is dependent on the time the water spends in the basin and the depth of the basin. The minimum clarifier retention time is normally 4 hours. A deep basin will allow more floc to settle out than a shallow basin. This is because large particles settle faster than smaller ones, so large particles bump into and integrate smaller particles as they settle. In effect, large particles sweep vertically through the basin and clean out smaller particles on their way to the bottom. As particles settle to the bottom of the basin, a layer of sludge is formed on the floor of the tank. This layer of sludge must be removed and treated. For this, the filter should be back-washed twice a day. Once in two years, sand airscoured filter must be changed.
Granular Activated Carbon filter: After separating most floc, a form of activated carbon with a high surface area, adsorbs many compounds including many toxic compounds. Water moves vertically through sand which often has a layer of activated carbon or anthracite coal above the sand. The top layer removes organic compounds, which contribute to taste and odor. The space between sand particles is larger than the smallest suspended particles, so simple filtration is not enough. Most particles pass through surface layers but are trapped in pore spaces or adhere to sand particles. Effective filtration extends into the depth of the filter. This property of the filter is key to its operation: if the top layer of sand were to block all the particles, the filter would quickly clog. For this, the filter should be back-washed twice a day.
Fig. Activated Carbon Filter and Organic scavenger resin filter
Organic scavenger resin filter: Organic scavenger resin filter is a process in which water is clarified. Clarifying means removing any turbidity or colour so that the water is clear and colourless. Clarification is done by causing a precipitate to form in the water which can be removed using simple physical methods. Initially the precipitate forms as very small particles but as the water is gently stirred, these particles stick together to form bigger particles - this process is sometimes called flocculation. Many of the small particles that were originally present in the raw water absorb onto the surface of these small precipitate particles and so get incorporated into the larger particles that coagulation produces. In this way the coagulated precipitate takes most of the suspended matter out of the water and is then filtered off, generally by passing the mixture through a coarse sand filter or sometimes through a mixture of sand and granulated anthracite (high carbon and low volatiles coal).
Softener resin filter: Softener resin filters may be used where there is sufficient land and space as the water must be passed very slowly through the filters. These filters rely on biological treatment processes for their action rather than physical filtration. The filters are carefully constructed using graded layers of sand with the coarsest sand, along with some gravel, at the bottom and finest sand at the top. Drains at the base convey treated water away for disinfection. Filtration depends on the development of a thin biological layer, called the zoo Leal layer or Schmutzdecke, on the surface of the filter. An effective slow sand filter may remain in service for many weeks or even months if the pre-treatment is well designed and produces water with a very low available nutrient level which physical methods of treatment rarely achieve. Very low nutrient levels allow water to be safely sent through distribution system with very low disinfectant levels thereby reducing consumer irritation over offensive levels of chlorine and chlorine byproducts. Slow sand filters are not backwashed; they are maintained by having the top layer of sand scraped off when flow is eventually obstructed by biological growth. A specific 'large-scale' form of slow sand filter is the process of bank filtration, in which natural sediments in a riverbank are used to provide a first stage of contaminant filtration. While typically not sufficiently clean enough to be used directly for drinking water, the water gained from the associated extraction wells is much less problematic than river water taken directly from the major streams where bank filtration is often used. Through softening the calcium and magnesium salts in the water are exchanged for sodium salts that do not cause the disadvantages of hard water. The method is used in industries and institutions for treatment of water for steam boiler plants and district heating plants, laundries, cooling towers, rinse processes, washing, dishwashing etc. Backwashing: To clean the filter, water is passed quickly upward through the filter, opposite the normal direction (called backflushing or backwashing) to remove embedded particles. Prior to this, compressed air may be blown up through the bottom of the filter to break up the compacted filter media to aid the backwashing process; this is known as air scouring. This contaminated water can be disposed of, along with the sludge from the sedimentation basin, or it can be recycled by mixing with the raw water entering the plant. Some water treatment plants employ pressure filters. This work on the same principle as rapid gravity filters, differing in that the filter medium is enclosed in a steel vessel and the water is forced through it under pressure. Advantages: Filters out much smaller particles than paper and sand filters can. Filters out virtually all particles larger than their specified pore sizes. They are quite thin and so liquids flow through them fairly rapidly. They are reasonably strong and so can withstand pressure differences across them of typically 2-5 atmospheres. They can be cleaned (back flushed) and reused. Membrane filters are widely used for filtering both drinking water and sewage (for reuse). For drinking water, membrane filters can remove virtually all particles larger than 0.2 um—including Giardia and cryptosporidium. Membrane filters are an effective form of tertiary treatment when it is desired to reuse the water for industry, for limited domestic purposes, or before discharging the water into a river that is used by towns further downstream. They are widely used in industry, particularly for beverage preparation (including bottled water). However no filtration can remove substances that are actually dissolved in the water such as phosphorus, nitrates and heavy metal ions. • • • •
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5.3 pH adjustment Distilled water has a pH of 7 (neither alkaline nor acidic) and sea water has an average pH of 8.3 (slightly alkaline). If the water is acidic (lower than 7), lime or soda ash is added to raise the pH. Lime is the more common of the two additives because it is cheap, but it also adds to the resulting water hardness. Making the water slightly alkaline ensures that coagulation and flocculation processes work effectively and also helps to minimize the risk of lead being dissolved from lead pipes and lead solder in pipe fittings. If the water is alkaline, acid (HCl) or carbon dioxide (CO2) may be added in some circumstances to lower the pH. Having an alkaline water does not necessarily mean that lead or copper from the plumbing system will not be dissolved into the water but as a generality, water with a pH above 7 is much less likely to dissolve heavy metals than a water with a pH below 7. Here in Soaltee water use is underground so hardness of water should be checked. There are different reagents uses for checking pH of water for different uses. For example for the production of steam, water having less than 6 ppm hardness is considered. Similarly for swimming pool water, water of range 7-8.5 ppm is considered.
Problems in Filter Plant
Poor filter this problem arises as water is continuously passed or filtered for longer period of time. As water is continuously filters floc or mud gets settled down in at the top causing poor filter. This problem can be solved by backwashing. To clean the filter, water is passed quickly upward through the filter, opposite the normal direction (called backflushing or backwashing) to remove embedded particles. Prior to this, compressed air may be blown up through the bottom of the filter to break up the compacted filter media to aid the backwashing process; this is known as air scouring. This contaminated water can be disposed of, along with the sludge from the sedimentation basin, or it can be recycled by mixing with the raw water entering the plant. Some water treatment plants employ pressure filters. These work on the same principle as rapid gravity filters, differing in that the filter medium is enclosed in a steel vessel and the water is forced through it under pressure.
Backwash Problem There are a number of possible causes of hydrotreater feed filter fouling including: i) Fouling by asphaltenes may be countered by raising the feed temperature, and employing a filter system with an automatic solvent soak cycle. ii) Incompatible feedstocks (where more than one feed is used at a time) can cause severe asphaltene precipitation. Don't use incompatible feeds. iii) Fouling by gums. If hydrotreater feed is via tanks; ensure the tanks have adequate Nitrogen blanketing in place. This is especially important for cracked feedstocks. iv) Inconsistent filtration rating. Filters with non-fixed pore sizes or some slotted wire media may suffer reverse plugging during backwashing when particles bypass the filter media and are later driven into filter media during backwashing. Backwash fluid quality is known to vary considerably from plant to plant. Gas Assisted type backwash reduces the problems of reverse plugging and reduces backwash fluid generation. v) Filtration level too fine. Finer filters foul quicker than courser filters. 25um nominal is generally considered to be adequate to protect fixed bed rectors from fouling although
finer may be appropriate depending on the particle size distribution present. vi) Valve failure - mechanical problems have bee n known to reduce backwash efficiency and decrease effectiveness of regeneration. We would recommend an audit to be undertaken to under stand the root cause and define the solutions. Such consulting services are available from some experienced filter vendors.
6.0 Mechanical Workshop The principal role of the Technical Services Mechanical Workshop is the manufacture and maintenance of equipment and instruments.
Fig: Sketch of grinding machine
Services Provided The Workshop is comprehensively equipped with machines and tooling to manufacture a wide range of items in a variety of materials including metals and alloys. Specialized services offered by our qualified staff include: Precision fabrication (eg vacuum chambers, anti vibration tables) Sheet metal fabrication with stainless steel, aluminium, copper, brass and other mediums Welding: TIG, MIG, Spot, Gas, Electric Arc General fabrication (eg stands, benches, frames) Repairs and maintenance of mechanical equipment •
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Fig. Drilling Machine
7.0 ELECTRICAL WORKSHOP As a supervisor, he has to inspect test and modify the work done by skilled workers or artisans under hire. Sometimes he has to demonstrate the correct method and procedure of doing certain operations. So an electrical diploma holder must have conceptual understanding of the method of procedure and possess manual skills in addition to supervisory capability.
7.1 Objectives: To develop special skills required for repairing small electrical domestic appliances, making joints and carrying out work and detecting faults etc. in electrical equipments and circuits including generators.
7.2 Generator The diesel generator was a FIAT company generator and was one of the oldest generators being used by Soaltee Crowne Plaza. The engine model was B631-I and was a 625kVA capacity generator with power factor 0.8. This was a six cylinder engine. There were three diesel generator which works at power cutoff time. The various systems and their parts observed were as follows: 1) Cooling system Burning fuel in the engine produces heat and part of this heat generated needs to be taken away before it damages the engine parts. Thus cooling system is required in an engine to bring the engine up to normal operating temperature as quickly as possible. The parts of the cooling system seen were: i) Radiator : The radiator present in the engine was the down flow type of radiator. The radiator is a heat exchanger with two set of passages, one set is for coolant and other for the outside air. In radiator coolant loses heat to passing air. ii)Fan : A fan pulls or pushes outside air through the radiator. The fan is driven by a belt drive which links the fan pulley with the pulley driven by the crankshaft.
Fig: Radiator fan with belt drive
iii) Thermostat : A thermostat controls the coolant flow. When engine is cold thermostat closes to prevent coolant circulation to the radiator. As engine warms up the thermostat opens to allow coolant flow through the radiator. iv) Water pump : The water pump forces the hot coolant out of the water jackets and through the radiator. The water pump is driven by the engine through the fan belt drive. v) Water jackets These are the internal passages that surround the cylinder and combustion chamber through which the coolant flows. The coolant from water pump flows first through the block water jackets then the coolant flows up through the cylinder head water jackets and back to the radiator. vi) Drive belt The drive belt is a continuous loop of reinforced rubber used to transmit power between two shafts; the belt used was V-belt. 2) Engine Lubricating System The lubricating system supplies lubricating oil to all the moving parts in the engine. The lubricating oil does several jobs as it lubricates the moving parts to reduce wear, provides cooling effect by moving through the engine, fills the clearance between the bearings and rotating journals, forms a gas tight seal between the piston rings and cylinder wall, acts as cleaning agent by picking up the particles and dirt and carry them to oil pan. It is necessary to supply lubricant to most of the parts of the running engine so the lubricating system is essential in an engine. In a lubricating system The oil pump picks up oil from the oil pan and sends the oil through the oil filter and then to the oil galleries or passages. From these passages the oil distributes to the main bearings supporting the crankshaft and to the cylinder head. Some of the oil from the main bearings flows to the rod bearings through the holes drilled in the crankshaft. Through the oil spurt hole the oil is thrown to the lower part of piston and cylinder from the rod bearings then oil drops back to the oil pan. The oil flowing to the cylinder head flows through oil passages to lubricate the camshaft bearings and valve train parts. After oil circulates to all the engine parts it drops back down into the oil pan i) Oil pump Generally two types of oil pumps are used in automotive engines. The first one is the gear type pump and the second one is the rotor type oil pump. The type of oil pump present in the engine was the gear type oil pump. The oil pump is driven by the crankshaft through gear i.e. the pump was crankshaft driven oil pump. ii) Oil pressure sensor switch The oil pressure sensor switch is the switch which closed when engine oil pressure falls below a preset minimum and indicated the low pressure by lighting a light. The oil pressure switch is closed when the engine is not running, when ignition key is turned on the indicator light glows. As soon as the engine starts pressure builds up in the lubricating system this opens the pressure sensor switch and the light goes out.
iii) Oil filters The oil filters clean the oil received from the oil pump and then supply cleaner oil to the engine. The oil from the pump flows through the filter before reaching the engine bearings. The filter has a pleated paper filtering element which allows the oil to pass through while trapping particles of dust and carbon. iv) Oil drain system and oil indicator rod Oil drain system in case of the diesel generator was a hand operated pump and piping arrangement which could be used to drain out the oil to be changed from the oil pan. The pump was a reciprocating manually pump which was operated manually. The oil level indicator rod was dipped in the oil sump. Maximum and minimum allowable levels for oil were marked on the rod. The levels should be maintained between the two levels and checked manually by taking out the rod. Not only the rod showed the level of oil in the oil pan but also it was useful to check the condition of oil i.e. whether the oil has lost its proper viscosity, color. Thus the oil level indicator rod is a very reliable method to know whether the oil is to be changed or not. v) Oil cooler: The oil cooler is a heat exchanger fitted in the passage for oil flow. As the oil has to work under very high temperature produced by the engine it needs to be cooled down in order to prevent the loss of properties of the oil and the burning of oil. In oil cooler the oil passes through the outer fins of the oil cooler and cold water flows inside the conduit surrounded by the fins. As oil passes through the fins the oil loses its heat to the fins which transmit the heat gained to the water flowing through the conduit. In case of this engine the oil cooler was damaged causing the water flowing inside the pipe to leak through the fins and mix with the oil. This caused a huge loss of properties of the lubricating oil and finally led to engine seizure. 3) Fuel supply system Diesel engine burns diesel as fuel oil. Diesel fuel is more viscous than gasoline fuel and can self ignite under high temperature. The characteristics of diesel engine that differ it from the gasoline engines are: i) Diesel engines do not have throttle valve. ii) In diesel engines only air is compressed during compression stroke. iii) Heat of compression ignites the fuel as it is sprayed. iv) The compression ratio is higher. v) Have glow plugs to make starting easier. The diesel engine fuel supply system had the following parts: Fuel tank: The fuel tank is a airtight vessel which is the fuel reservoir for the engine. Two pipe lines are present in the fuel tank. One pipe line is for supplying the diesel fuel to the engine and the other is to receive back the excess fuel. Fuel supply pump: The fuel supply pump is a low pressure pump which supplies fuel from the fuel tank to the fuel injection pump. The fuel supply pump also has a hand operated priming pump which is operated manually if the fuel supply line contains air bubbles. This pump is driven by the camshaft.
Fuel filter and water separator: To prevent jamming of the injection pump and the nozzle and to prevent entering of water and impurities in the combustion chamber fuel filter with water separator is placed before the fuel injection pump. Injection pump: Diesel engines use one of the two types of fuel injection pumps available. One is an inline cam operated pump and the other one is the rotary distributor type of pump. The type present in the engine was the Inline type of pump. This pump has the barrel and plunger assembly for each cylinder. An injection line connects each barrel and plunger assembly to an injection nozzle. Low pressure fuel supplied by fuel supply pump flows through the inlet port into the space above the plunger. The plunger has a roller that rides on a cam present in the camshaft. When the camshaft comes up under the plunger the lobe raises the plunger this applies high pressure on the fuel trapped above the plunger. The fuel is forced through the tube to the injection nozzle in the cylinder where the piston is reaching the Top Dead Centre on the compression stroke. The amount of fuel injected is varied by varying the effective stroke of the plunger. The control rod connects by linkage through the governor to the accelerator. The linear movement of control rod provides rotation to the plunger varying the effective stroke. The governor of the pump was mechanical governor. Moving the control lever changed the setting of the governor which then controlled the amount of fuel injected. Without a governor a diesel engine can stall at low speeds or run so fast that it will be damaged. Injection nozzle: The injection nozzle is used to supply fuel spray to the combustion chamber in direct injection type of engine or in pre chamber in the indirect injection type of engine. The engine was a direct injection type of engine. The high pressure fuel from the injection pump comes out of the nozzle in form of finely atomized spray of fuel which burns due to heat of compression of combustion chamber. A spring holds the needle valve or nozzle valve closed until the high injection pressure is applied through the injection pipe. This forces the valve off its seat so fuel sprays out into the cylinder. As pressure drops the spring resets the valve and fuel injection stops. Different types of injection nozzles are present like single hole, multi hole, circumferential hole, pintle, pintaux etc. The type of nozzle used in the engine was the multi-hole type of nozzle where fuel was sprayed from a number of holes located at the sides of the tip of the nozzle. 4) Starting System For a diesel engine to start the crankshaft must turn fast enough for air to enter the cylinders. A starting motor does this job by rotating the flywheel through pinion flywheel gear assembly. The starting motor is driven by a battery. The electrical energy of the battery is converted to mechanical energy as rotation of flywheel and crankshaft. Fig: starter motor
Various types of starting motors are present and are used in various engines as required. If solenoid is present the starter motor is solenoid type and if solenoid is absent it is movable pole shoe type, starting motors may be with or without internal gear reduction and the gear reduction may be planetary gear reduction or more simpler type of gear reduction. Starting motors may also be classified as having permanent magnet or having an electromagnet. In case of this engine the starter motor was solenoid type of starter motor with internal gear reduction. The gear reduction increases the cranking torque.The starting motor solenoid had a plunger that connects by a shift lever to the overrunning clutch. When the ignition key is turned on, the current flows to
the solenoid which creates a magnetic field that pulls the plunger in. The attached shift lever pivots and pushes the pinion into mesh with the ring gear teeth through the reduction gear set. At the same time pinion movement moves the contact plate which closes the contacts in the solenoid switch. This connects the starting motor to the battery so the armature rotates and cranks the engine. Solenoid has two windings, a hold in winding and a pull in winding. The combined magnetic fields force the pinion into mesh with the ring gear. Then the pull in winding is disconnected since less magnetism is required to hold on the pinion in mesh than to engage it. 1. Transformers A transformer converts a high voltage source of 11kV to a low voltage of 380V. A 3phase, 4-wire 380V source is supplied through the main switch board. As the city supply is never certain, there is always problem of load shedding; an alternative power supply i.e. a standby generator is used. A change over switch is used to switch these two power sources as per requirement. 2. Batteries There are 3 batteries working in series to run the generator or to start the generator.
8.0 COOLING TOWERS: Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or rely solely on air to cool the working fluid to near the dry-bulb air temperature. Common applications include cooling the circulating water used in oil refineries, chemical plants, power stations and building cooling. The towers vary in size from small roof-top units to very large hyperboloid structures that can be up to 200 metres tall and 100 metres in diameter, or rectangular structures that can be over 40 metres tall and 80 metres long. Smaller towers are normally factory-built, while larger ones are constructed on site. An HVAC cooling tower is a subcategory rejecting heat from a chiller. Water-cooled chillers are normally more energy efficient than air-cooled chillers due to heat rejection to tower water at or near wet-bulb temperatures. Air-cooled chillers must reject heat at the dry-bulb temperature, and thus have a lower average reverse-Carnot cycle effectiveness. Large office buildings, hospitals, and schools typically use one or more cooling towers as part of their air conditioning systems. Generally, industrial cooling towers are much larger than HVAC towers. In a wet cooling tower, the warm water can be cooled to a temperature lower than the ambient air dry-bulb temperature, if the air is relatively dry. As ambient air is drawn past a flow of water, evaporation occurs. Evaporation results in saturated air conditions, lowering the temperature of the water to the wet bulb air temperature, which is lower than the ambient dry bulb air temperature, the difference determined by the humidity of the ambient air. To achieve better performance (more cooling), a medium called fill is used to increase the surface area between the air and water flows. Splash fill consists of material placed to interrupt the water flow causing splashing. Film fill is composed of thin sheets of material upon which the water flows. Both methods create increased surface area.
Fig. Cooling towers Generator and A/C Plant
There are three cooling towers in Soaltee Crowne Plaza; Two cooling towers are used for AC plant and one for generator.
Responsibilities of Engineering Department Engineering department in the hotel is responsible for operating and maintaining the entire building services systems. Around 1.5 to 3% of the total hotel financial turnover is spent for the engineering related Repair and Maintenance (R&M). The expenditure for engineering R&M includes AC fittings, dampers, ther mostat, refrigerant gases, carpentry, electrical items etc. The major portion, say around 15 to 20% of engineering R&M is spent for the Heating, Ventilation and Air Conditioning (HVAC). The role and mandate of any property engineering department is the protection of the building’s/owner’s assets; the structure from the façade or building envelope, to the integrity of the floors, walls, ceilings and all of the furniture, fixtures, and equipment (FF&E) contained therein. This includes the electrical transformers and the distribution throughout, the domestic water distribution and sewage, the heatingventilation-air conditioning system, (HVAC), the fire alarm system and fire safety components, the vertical transportation system (elevators), the property surroundings like parking and landscaping and pest control. Utility management such as electrical, gas, steam, water. Kitchen and laundry equipment. Lighting and sound systems and on and on. Hotels are much more extensive and demanding. The engineering department has the responsibility for everything in the building as well. Depending on the organizational structure of the hotel, some elements are assigned to other departments. The Security or Loss Prevention department may take on the task of fire systems but ultimately this is the responsibility of the engineering department as the building operators to monitor for regulatory compliance. Hotels have often been given the analogy of a cruise ship or a hospital in that the operation is 24 – 7. Twenty-four hours a day and seven days a week. When the guests are sound asleep the systems of the building continue to operate. The heating and ventilation units are running, the domestic hot water is being heated, the laundry may be operating, the night cleaners making their rounds, desk clerks and night auditors all
doing what they have to do. Behind the scenes, there is a flurry of activity, and everything has to work so that everyone can do their jobs and the guests are safe and comfortable. The following is the percentage break-up of energy consumption by various utility areas of engineering department. • • • • • • •
HVAC 25 – 30% Lighting 35 - 45% Kitchen 10 – 15% Lobby 10 – 15% Elevators 02 – 04% Banquets 02 – 04% Others 10 – 25%
SWOT Analysis of the Engineering Department
Service it provides
Human resources
Physical resources
Strength Certainty of work. Stable work ; not dynamic
Weakness
Opportunity Newer knowledge can be applied to do things differently.
Well organized & knowledgeable resource. Well motivated. Almost no turnover.
Trainings are being provided but more training is required.
Provided needed environment well trained and well informed resource can be developed.
Newer and advanced resources are being opted.
Lack of proper policy in procurement.
Proper policy can increase the quality of physical resources as per need.
Threat
Reliable older machines are fading out.
Environmental Impacts: To maintain the electrical, mechanical and plumbing system & equipment, the engineering department consumes enormous amount of resources and generates disproportionate amount of waste. These wastes has an adverse environmental impacts, some of them are listed below. Significant environmental aspects and impacts of engineering department Section
Various activities in Aspects Engineering operation
Environmental Impact
Generator
Operation of generator
Effluent Treatment Plant
Flow of effluent from Possibility of generation of Water Pollution kitchen to treatment plant oil & grease and the phosphates in the effluent for treatment
Cooling Tower
Operation of cooling tower Consumption of make up Resource water due to evaporation Conservation and other losses Potential
Condenser Pump
Operation of pump
Generation of noise
Boiler
Operation of boiler
Generation of combustion exhaust
Generation of heat, vibration Safety and health Generation of smoke, hazard Generation of emission suspended PM, CO2, CO, HC, SOX, NOX from the DG set Air Pollution
Noise pollution gas Air pollution
Natural Operation of the Possibility of leakage of gas Gas /LPG equipment by using the Equipment LPG/NG
Safety and health hazard
Maintenance There are three types of maintenance. They are described below. Maintenance
Improvement (IM)
Modification Retrofit Redesign Change order
Preventive (PM)
On-condition Condition Scheduled Self Monitor (SM) scheduled Statistical Periodic Machine cued Predictive Fixed interval Control limits Trend Hard time Types of Maintenance Description When Analysis Limits Program time Improvement deficientEfforts for the reductionSpecific or elimination As required maintenance Maintenance (IM)
Corrective (CM)
Unscheduled (UM) Breakdown Emergency Remedial Repair of the need for
Reliability engineering efforts need to emphasize the need for error elimination rather than maintenance Opportunity to pre-act rather than react Corrective Maintenance(CM)
Corrective (emergency, repair, remedial, unscheduled) Troubleshooting and diagnostic fault detection and isolation.
Preventive Maintenance (PM) (On-condition)
Maintenance carried out when equipment needs it. Uses human thought process, electronics and sensor technology, to detect if threshold limits of established standards have been exceeded in order to take most appropriate action. Use of statistics and probability theory for data generation and analysis to detect trends in causes of failure and therefore take appropriate measures for prevention.
Preventive Maintenance(PM) (condition monitor) Preventive Maintenance(PM) (scheduled)
Has to be used only if there is an opportunity for reducing failures, which cannot be detected in advance. Different from fixed interval inspection, this looks for threshold conditions.
Regular maintenance at intervals as required by machines/equipments is the key factor for long life. Records are kept properly and utilized as per need. Possible maintenance as described above is utilized as per time, condition and applicability.
Emerging challenges for the Soaltee Crowne Plaza i.
Ethics and social responsibility The decisions made by managers in organization have a broad reach inside and outside the organizations. Thus, managers must be concerned about ethics and social responsibility. Although ethical scandals in business are not really new, media attention focused on them in recent years have increased public sensitivity about them. Any late work or decisions in Power Department can lead to the service interruption which harms the reputation of the organization as a whole.
ii.
Empowerment Contemporary organizations have in recent years undertaken efforts to empower the employees. It is an effort to take advantage of human resources by giving everyone more information and control over how they perform their jobs. Various technologies and methods for empowerment range from participation in decision making to the use of integrated work teams. Managing empowered employees will be a challenge to the managing department.
iii.
Change Managers are facing more change than ever before. It is important to keep in mind that any change in organization or environment may have effects extending beyond that area. Thus, managers face the challenge of managing change. They must be aware of factors contributing to change and impact on practice of management.
iv.
Learning organization In an environment in which change takes place at an unprecedented rate, organizations will need to be learning organizations. A learning organization is one that has developed the capacity to continuously learn, adapt and change. Organizations that are continually learning are faced with changing and improving the way work is done.
Suggestion 1. Need of more lockers in Engineering Department 2. Separate Electrical Workshop 3. Newer and more advanced machines in Mechanical Workshop 4. Frequent training programme for all Engineering Staffs 5. More interaction between supervisors and their co-workers. 6. More specialized and automated instruments for maintenance. 7. Motivation programme for all technicians towards their works should be done periodically. 8. Technician should be introduced with the manual of the equipments they are going to use.
Conclusion Soaltee Crowne Plaza is the leading five star deluxe hotels in Nepal offering a Resort atmosphere and is ideal for both business and leisure travel. Soaltee Crowne Plaza Hotel in Kathmandu has made itself an accommodation that boasts of the perfect melding of comfort and hospitality. The main aim of this hotel is to provide warm and homely atmosphere, services and comfort facilities at affordable costs for this there requires varieties of services like providing cool temperature in rooms.
So a wide range of air
conditioning units of various capacities were installed to regulate the temperatures of different rooms and halls. Throughout our attachment period, we visited different plants like AC plant, Boiler plant, Filter plant and became familiar with various systems, its working principles components of an engine and analyzed the reasons of its failure and also the methodologies used in maintaining it. In the air conditioning section we analyzed air conditioning units of various capacities and types and also visited various sites. Apart from that we also helped technicians in performing their work easily. Thus, in this entire 15 days of industrial attachment period we got the basic idea of how engineers decide and work under various working circumstances. Apart from that we were acquainted with the fundamental knowledge of central AC system, its operation, AC maintenance, and boiler operation; its maintenance, generator operation,. generator maintenance. We also got ideas about the services it provides to its guests. The working of engineering department in that hotel.
