Thermal Energy Storage System
Operations Manual
Project: Pune Central,
Pune
•r" s / I:MS
Cristopia Energy Systems (I) Pvt. Ltd.
Village Umrikheda, 12, KM Indore-Khandwa Road Indore - 452020 (M.P.) Ph: 0731-2874434 / 55, 2874686 / 87, Fax: 0731-2874432 Email: cris_indiafajsancharnet.in
Index 1)
Introduction to Thermal Storage System
2)
General Information on Cristopia Thermal Storage System 3)
Design Data and System
Selection 4) System Description 5)
Technical Data
6)
P 8s I Diagram
Sheets
7) Histogram 8)
Guidelines
for Operation (Operation
Logic) 9) Monthly Operation Strategy * * * * * * * * *
1.0 INTRODUCTION At the time when we talk more and more about ecological risks and the rationalisation of energy use, the thermal energy storage represents a technical solution adapted to industrial cooling and air conditioning systems. Classical systems are designed for peak demand, even if we use the chillers at 100 % for only a few days or few hours every year. Thermal storage by latent heat allows a reduction in chiller capacity. This storage provides shortfall of the energy when demand is higher than the chiller capacity. Thus chiller operation is continuous and its efficiency at maximum. The STL allows real management of the cooling energy according to the demand. Also significant savings can be made on running costs using off peak electrical tariffs. The reduction in the chiller size also reduces the quantity of refrigerant used, a point that is more and more important with the new restrictive laws on CFC's. The STL improves system reliability and offers a safer mode of operation for processes or back-up systems. Cristopia, a manufacturer of latent heat thermal storage systems present in this document the basic principles of thermal storage. Additionally we detail the fundamental elements for installation, operations and maintenance of thermal Energy Storage System. The Cristopia team is always at your disposal to assist you.
2..0
GENERAL INFORMATION.
2.1:
ENERGY STORAGE. 2.1.1
WHY STORE ENERGY?. Until now, it has not been possible to store reasonable quantities of heat or cold and as a result, chillers have been sized to satisfy maximum design load conditions ; much of this capacity being used for only a few hours per day (or even year). Daily thermal storage allows the use of smaller chillers. During low demand periods the store is charged, then during high demand the energy stored is released. For cyclic loads, Thermal Energy Storage permits smaller chillers to operate on a near continuous basis; storing energy during off peak (usually cheaper) periods for use during peak hours.
Z1.2 HOW IS ENERGY STORED ? •
SENSIBLE HEAT Principally, we consider water as the storage medium for sensible energy. As well as being available cheaply and in abundance, water has a volumetric heat capacity of 1.16 kWh/m10C ; greater, for instance, than iron or stone. However, there are limitations to its use especially when used with large temperature differentials. In cooling applications, a practical maximum of only 6 kWh/m3can be achieved.
.
LATENT HEAT Latent heat is the name given to the energy either stored or liberated when a substance changes phase.
Example : ice changes to water, water to gas or steam. These changes occur at constant temperature. The energy absorbed or released during phase change is rather more significant than the energy required to decrease or increase the PCM (Phase Change Material) temperature (sensible heat).
Daily consumption
1
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
To melt a material we require a quantity of energy. For instance to melt one gram of ice require 80 calories at constant temperature. This energy is released when the material is cooled down and returns to solid phase. Different materials have different fusion points. For Thermal Storage we use different materials to satisfy the requirements of a wide range of applications. These materials are called PCMs (Phase Change Materials). Latent heat storage presents us with two significant advantages : • •
high thermal densities can be achieved, energy is released at almost constant temperature.
STORAGE APPLICATIONS When considering potential applications for Latent thermal storage it is necessary to examine the energy source being used. Where cooling is generated by electricity through a thermodynamic machine (chiller), the attractiveness of storage is significantly increased since reduced auxiliary loads result in significant savings in electrical consumption. Where two part tariff (Maximum demand + unit charges) and / or Time Of the Day tariffs (lower unit charges during off peak and / or high unit charges in peak periods) are applicable, the energy cost is further getting reduced. In industrial cooling and air conditioning systems, the process requirements do not permit large temperature differentials across the circuit. Thus, sensible energy storage which requires very large storage volumes is generally unsuitable and CRISTOPIA STL systems are most appropriate.
Ihe high cost of the chillers makes the reduction ot installed power attractive. Industrial process cooling and air conditioning aw tavourable applications tor the use of LATENT HEAT STORAGE. tfelovy are listed some typical applications for Thermal Energy Storage
• • • • •
Air Conditioning Office building Hospital Banks Conference centres Museums
• • • • • • • •
Recording studios Theatres Department stores Supermarkets Airports Cinemas Sport centres Hotel
Process Cooling <----------------n in . I . I ■imin mm.
..............
i i J l
• Dairy industries • Slaughter houses • Cold stores • Central kitchens • rharmdceutK.il industries • Bottling plants • Breweries • Skating rinks • Meat industries
_____________
• • • • •
Back-up _______________ Computer rooms Clean rooms Operating Theatres Telephone exchanges Cold storage
• TV studios • Explosive storages
The advantages of thermal storage are : • • • • • •
a reduction of chiller size (50 to 90 %), a reduction of costs, a reduction in energy consumption. an increase in reliability, simplified maintenance, refrigerant load reduction (CFC, HCFC, ammonia) (50 to SO %).
Thermal storage is an efficient system for optimising a i r conditioning and refrigeration plant.
According to the application a significant installed chiller capacity reduction of 50 to % % can be achieved. Also other components (transformer, cooling tower, etc..) are reduced in the same proportions and the servicing of equipment is simphlied. Also it allows the reduction of maximum demand and use ot electncitv at night to take advantage of Time Of the Dav tariff.
2.2
STL SYSTEM STL - STorage of Latent Heat The STL is composed of a tank filled with "nodules". The tank has upper manholes to allow the filling with nodules. A lower manhole allows emptying. Inside the tank two diffusers (inlet and outlet) spread the heat transfer fluid along the tank. The pressure drop through the tank is 2.5 mWG. The inlet in charge mode must be via the lower diffuser in order to ensure the natural stratification. The tanks are manufactured in black steel (test pressure between 4.5 to 10 bar), are delivered empty and positioned on site or, if the access to site is impossible, constructed on site. Concrete tanks can also be used. The nodules are spherical with a diameter of 77 mm, 78 mm or 98 mm (depending on the nodule type). The spherical plastic nodules contain the Phase Change Material (PCM). The mechanical and chemical characteristics of the nodule shell (manufactured in polyolefin) are well adapted to the conditions encountered in Air Conditioning or Refrigeration systems. The use of modern technologies permits quality control. The materials used are completely neutral to the phase change materials and heat transfer fluid. The phase change materials used by CRISTOPIA Energy Systems, and also the nodules, have been laboratory tested in France and abroad. This product development work has led to a very high reliability of the STL. Once filled with PCM the nodule plugs are sealed by ultrasonic to ensure perfect water-tightness. The nodules are delivered in bags. Tanks are filled on site. The filling is regular and homogeneous. CRISTOPIA Energy Systems offers a range of temperatures: -
33°C to + 27°C The STL has been conceived for hydraulic applications. Please consult CRISTOPIA Energy Systems for any other application. 2.3
SYSTEM COMPONENTS
The quantity of energy stored for each type of nodule is proportional to the storage volume. The number of nodules in a system determines the heat exchange rate between the nodules and the heat transfer fluid. 2.3.1
Terminology : How to understand the terminology:
STL -00 -15 00: phase change temperature in °C 15: tank volume in cubic metres STL - N15 - 50 N: negative temperature 15: the phase change temperature in °C 50: tank volume in cubic metres STL - AC - 100 AC: the phase change temperature of 0°C (the nodules have a diameter of 96 mm) 100: tank volume in cubic metres 2.3.2 The nodules: The envelope: High Strength special plastic material chemically neutral towards eutectics and heat transfer fluid thickness 1.5 mm : no migration of the heat transfer fluid exterior diameter: • •
96 mm : 77 mm :
exchange surface
Air conditioning Industrial Cooling
Plug Air pocket Phase Change Material (PCM) Blend of polyolefines
1CS N o d u le Operating temperature ,,QC thP nndules Storage Te c h a ra c te rist limite^C_______ 1 The table hereafter Phase change — —------------------" temperature gi ---------__ = = = = = = = = = =°C N o d u le type __------------------------- ------__
-33
. . -------------------------------------------------------------------------------------------------------------------■--------------------------------------------------------------------------------
SN.33 SN.29 SN.26 SN.21 SN.18 SN.15 SN .12 SN.10 SN .06 SN .03 S.OO
COO SC27
2.3.3
-28.9 -26.2 -21.3 -18.3 -15.4 -11.7 -10.4
- 5.5 - 2.6
-40°C a +60°C
0
0 + 27
THE TANK AND TANK INSULATION: The horizontal cylindrical tank is made of black steel. As standard, the test pressure is 4.5 bars. Two upper manholes allow the tank to be filled with nodules. Two connections are fitted on the manhole covers for filling air bleed valves and manometers.
The dimensions of the standard tanks are give in the table below. The tank can be also vertical with a skirt (see drawing VA). For systems working at atmospheric pressure is possible to use rectangular tanks (in steel or concrete).
According to the space available we can modify the diameter and length to fit the tank to the site. The tank is manufactured according to plant requirements.
INSULATION ( old storage: Insulation is essential and has two objectives : •
to reduce thermal losses, • to avoid condensation. «i,,,,« Theinsu.ation wil. be of Sty— type, injected m,nera>, etc... as common.^ in A/C or refrigeration. *w,,ah the The insulation includes two vapour barriers to avo.d water migrate through the insulation. , Tanks s,ted outdoors must have external waterproof cladding to protect the tank. Hot storage: The insulation will respect the same rules as for water storage.
•
>.3.4
In both cases: • it is necessary to allow insulation between cradles and tank. This insulation must withstand the tank weight (-1500 kg/m 3 ) Options included high density neoprene or equivalent. HEAT TRANSFER FLUID The heat transfer fluid must be compatible with all the hydraulic network components, and with the operating temperatures.
For "hot storage" (temperatures higher than 4°C) the heat transfer fluid must respect classical heating plant network conditions (the heat transfer fluid is water + additives). • For cold storage, water alone can not be used. It is necessary to use a brine or glycoled water. • In the food industry, the heat transfer fluid must be compatible with foodstuff. 3.5
EXPANSION
• I!)!^^!^™
tank must take
**> account the maximumand at
lZT^C
F
f r°
r USUal te
*Wre differences
the loops (20-25 C maximum) and for normal heat transfer fluid volume ""
^
fO
"OWing
M
"
• 3 % for atmospheric STL tank, • 5 % for pressurised STL tank (maximum 10 bars). 13.6
SIX PRESSURE PROP . i he SI L consists of a tank filled with nodules. The flow * J^^^very tank by the diffusers. Ins.de the tank the heat * a ^J3
j£7 s almost low, and the flow is laminar. The pressure drop due to nodules nil. The pressure drop is only due to the diffusers.
. Typically, for an usual flow rate of 2.5 mVh per ^ of tan* the pressure drop of a STL is 2.5 mWG. Before manufacturing the tank it is important determine the maximum flow rate and the pressure drop wanted. From this information (maximum flow rate and maximum pressure drop), the diameter and the number of holes per diffuser are calculated. Ihis calculation is done by the Technical Department of CRKTOPIA Energy Systems. At the order, it is then important to indicate the maximum flow rate and the pressure drop wanted. 2.3.7
PUMPS For parallel lay-out two pumps are required to ensure circulation of the heat transfer fluid (charge pump and distribution pump).
S
•
Charge pump
The charge pump flow rate depends on chiller capacity and Delta T. The heat transfer fluid characteristics must be taken into account •
Distribution pump
The distribution flow rate depends on the maximum demand and Delta T. The heat transfer fluid characteristics must also be taken into account. 2.3.8 THREEWAY VALVE The 3-way valve must be a modulating type. For systems below 0°C allow for a spindle element heater. For selection, see manufacturer's documentation.
2.4
STORAGE STRATEGIES
600 500 400
Daily consumption 300
(kW)
200 100 0
1
3
5
7
9
11
13
15
17
19
21
23
STL manages the cooling energy according to designer's requirements, here are various strategies that can be adopted. 2.4.1
PARTIAL STORAGE (REDUCED CHILLER CAPACITY)
1
The chiller capacity is reduced to 30 to 60 e n erg y isstOre.
2.4.2
D u rin g d ay vZ Z V l
Durin
LOW SEASON DISCHARGE
P(kW) 6001 500400 300 200
ZZZ
Discharge
Charge
100
Charge
ire
ro( uc< ion
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
A partial storage in high season can be easily transformed into a total storage or time of day storage during low season in order to increase the running costs savings.
13 14 15 16 17 18
5 0
1
8 P(kW) 600
19 20 21 22 23 P(kW) 600 -,
■//
500
Charg e
D
Charge
400 300
200
I
2
3
4
5
6
7
8
9
'<> »
12
13
14
15
'
During the air conditioning period « Kfillers are stopped a*d ail the cooling energy is provided only by the STL. 2.4.5 BACK-UP P ( k W ) 6 0 0 1 500-
400-
3 0
200100-
C
Discharge
hours
The STL is used as back-up only when it is necessary. It replaces the main cooling system in case of failure. The STL is regularly recharged to compensate for standing losses. " to
Design Data and System Selection
3-1 . Design Data :
1. Ambient Conditions 40 °C 26.1 °C
Dry Bulb Wet Bulb
2. Chilled Water Inlet Temperature Chilled Water Outlet Temperature
12 °C 7 °C
3. Condenser Water Inlet Temperature : 32 °C Condenser Water Outlet Temperature : 36°C 3 - 2 . System Selection :
Peak Load Chillers
: 730 TR
Thermal Energy Storage System: 225 TR x 2 Nos. : 1048 TRH (62 CUM) x 1 No. 505 TRH (30 CUM) x 1 No.
Plate Heat Exchanger
: 365 TR x 02 Nos.
System Description ste m for Pune Centra! has * »*«& %*£ reduced ChUler Capacity for Peak Load of 73O Sy
with
Entire building sha.1 havecon, mon g have 2 Nos. of 62 tu Chillers of 225 TK compressors , 2 Nos. thermal PHE pumps, p storage system CUM respectively, primary, secondary , condenser and gasket heat exchanger 2 Nos x 365 TR .
225 TR x 2 Nos. Screw Chillers are connected in Parallel with Two Thermal Storage Systems of 62 Cum & 30 Cum Capacities and are sufficient to meet Peal Load of 730 TR. Thermal Energy Storage System is used to optimize the installation. Instead of selecting the chillers for peak cooling rating, the use of Thermal Energy Storage system allows selection of chillers for average capacity.
Screw energy
Thermal Energy Storage System uses the latent heat of crystallization and fusion to provide a compact and controlled storage. The system consists of storage nodules filled in the exchanger vessel. During period of low load, the eutectic salt filled in the storage nodules freezes thereby absorbing cooling power and when the cooling demand exceeds, the filled eutectic salts melt to release the additional cooling power
•
Reduction of chiller size
•
Reduction of installed power and plant room space
•
Reduction of operation and maintenance costs.
•
Peak 'shaving' or lopping' of cyclic loads
Optimization of electrical resources ( Generator set and Electrical installation )
•
S Reduction in use of refrigerant S Increases system reliability S Better energy management (off-peak electricity) S Availability of Back-up during off peak months S Reduction of electrical consumption . 5.
Technical Data Sheets : Enclosed
6. P & I Diagram : Enclosed Piping and instrumentation diagram is enclosed . 7. HISTOGRAM : Peak Month Load Histogram is enclosed herewith
CUM]
1
_ _ _ -------------------------------------------------------------------------- Air conditioning _------------------------_
2
Service________________________■
-----------
34
Type
Cristopia_______________________.- - - --------------------~~
56
Make
AC00____________________________-
___—_____________"
~~
._______________—------
Thermal Stnrage capacity
______________1048 TRH_______
____.--------._
_____________8 Hours_________.__
Averaqe time for full chargjnfljromful!)^^
25 % MFH water solution_______
Heat transfer medium_____________--------7
Bnne Entry temperature_____________________.----------------■--------
8
Brine leaving temperature___________________.---------.----------------
9
Chiller shutt-off Temperature
10
Phase change temperature
11
Pressure drop across storage tank_____________________________—
12 13
Tank material Insulation material
14
Insulation Thickness
■----------------------------------------------------------------------------------------------------"
---------------------------------
_____________-5DegC___________ -1.8 Peg C____ -6.5 Peg C____ OPeqC _______________________ ' -------- 2.5 MWG__________________I
__------------------------------_----- ---------
-------------------------------------
Carbon Steel IS2062, Grade 'B' Thermocol 100 mm
Tank dimensions 15 Dia Length
3.5 M 6.955 M
Empty Weight
10600 Kgs
Service Weight
72600 Kgs
Page 5
T e c h
n i c a l S e e c l l i c a t i o n s PHE for isolation of Glycol Water, 2 _
_
_
-------------------------------■
Nos. -
___________
,____________________________________________________________________________________ ■
Secondary side (Water)
--------------------------------------------------------------------
Description
________
-------------------
Primary Side (25% Ethylene
___________________________
—
Glycol) __ TR_____________________-------
.----------------------------------■ —
.--------------------------------------■
--------------------------------------------------
Entering Temp. ( C ) ExchangeWater Capacity--------Leaving Water Temp. ( C )
________
—_________12
7
—
------------------------------
Water flow rate (CUM/Hr.)
220.76
________________40 ________________9.5
__________
232.41 ,-----------------------------------------------------------------------------------------------------------------------------------------■-----------------------------------------------------------------------------------------------------
Water Pressure Drop ( MWG)
4.85
6.0
Rated Pressure ( Bar)
7 Bar
7 Bar
Page 7
T e c h n i c a l S e e c l l i c a t i o n s PHE for isolation of Glycol Water, 2 _
_
_
-------------------------------■
Nos. -
___________
,____________________________________________________________________________________ ■
Secondary side (Water)
--------------------------------------------------------------------
Description
________
-------------------
Primary Side (25% Ethylene
___________________________
—
Glycol) __ TR_____________________-------
.----------------------------------■ —
.--------------------------------------■
--------------------------------------------------
Entering Temp. ( C ) ExchangeWater Capacity--------Leaving Water Temp. ( C )
________
—_________12
7
—
------------------------------
Water flow rate (CUM/Hr.)
220.76
________________40 ________________9.5
__________
232.41 ,-----------------------------------------------------------------------------------------------------------------------------------------■-----------------------------------------------------------------------------------------------------
Water Pressure Drop ( MWG)
4.85
6.0
Rated Pressure ( Bar)
Page 7
G u i d e
7 Bar
7 Bar
l i n e s f o r O p e r
a ti o n ( O p e r a ti o
n L o gi c)
si* -
9 ¥
k
•#
8. _Gm deiin esJbr _OEe ratio n_:
-
A. HVA C Instal lation consi sts of: 1. Wate r Coole d Scre w Chill ers: 225 TR x 2 Nos
2
^: ^ S X ^ ^ ^
^e ^ and ON prior Ch ille r O N. . f
,,
nnP
t in g pu m ps Al so pu m p ca n be sta nd by by sel ect ra
in g an y of th e op er ati ng P
thr ou gh sta nd by arr an ge m en ts
3. Secon dary Pump s for HVA C Work ing + 1 Stan dby On e pu mp
sha ll be op era tio nal thr ou gh VF D an d VF D wil l get co m ma nd fro m pre ssu re tra ns du cer . In cas e of VF D fail ure the pu n
can be cha ng ed ov er to D OL sta rti ng. Ea ch op era tin g pu mp mu st D ON as soo n as loa d de ma nd on lo w sid e is ava ila ble .
Ho we ver sta nd by pu mp ca n be sel ect ed fro m an y of the op era tin g pu mp thr ou gh sel ect or swi tch . 4. Conde nser Water Pumps 2Wor
king + 1 Stand by Ea ch op era tin g pu mp mu st be for par tic ula r ma chi ne an d O N as so on as its Ch ille r pu mp is O N, Al so pu mp
ca n be sta nd by by sel ect ing an y of the op era tin g pu mp s thr ou gh sta nd by arr an ge me r 5. PHE Pumps -1 Worki ng + 1 Stand by Ea ch
ope rati ng pu mp mu st be ON as soo n as coo lin g is req uir ed A pu mp can be sta nd by by sel ect ing an y of the op era tin g pu mp s thr o sel
ect or swi tch. 6. Motori zed valves:
M: Valv es for 62 M3 STL Char ging and load meet ing
STL.
ge and port A clos B. System
operation is categoriz ed In two Modes.
1. 2.
Night mode. Day mode.
1. Niftht Mode:
Operation selection will be on time base and time must be adjustable. Charging : Timings 10:00 PM to 06:00 AM. Both chillers will be at -ve set point (auto select through timer) BOTH CHILLER SET POINT
= - 4°C, Chiller Inlet Control.
As soon as charging is selected before chiller start-up, following sequence of operations must be performed: Sequence I : For STL charging with Both Chiller Valve MV1, MV2 Open Port A of valve Vmdl & Vmd2 close Primary Pump ON, Condenser Pump ON, Cooling Tower Fans ON. Sequence II As soon as charging complete Chiller is switched OFF, following equipment must be OFF. Condenser Pump, Cooling Tower Fans, Primary pumps OFF. Valve MV1, MV2,- Close. II Day Mode:
Load Meeting and STL Discharge
Operation selection will be on time base and time must be adjustable. STL discharging & Load Meeting: 10:00 AM to 10:00 PM. Set Point of Chillers will be changed from -ve to +ve as below: Chiller I = + 9°C Chiller Inlet Control.
Chiller II - + 8°C Chiller Inlet Control. However, before starting of chillers, following sequence of operations must be performed.
Valve MVl, MV2 - Closed Valve MV3 of Chiller I open when CHW return temp. T2 > 12 O Valve MV4 of Chiller II open when CHW return temp. T2 > 14°C Valve MVl open when CHW return temperature T2 > 13° C As soon as return Temperature is <12°C , VI Closes Valve MV2 open when CHW return temperature T2 > 15° C As soon as return Temperature is <12°C , V2 Closes VMdl 8s VMd2 - 3 WMV - Modulates at +7 °C. Primary Pump ON, Condenser Pump ON, Cooling Tower Fans ON Secondary Pump ON through VFD. As soon as any Chiller is switched OFF, following equipment must be Urr.
It's Condenser Pump, Cooling Tower Fans, Primary pump - OFF. Secondary Pump OFF, PHE pump OFF
C. Seasonwise Operations shall be as under :-C.I Summer : (March to June) Day Mode : 10:00 AM to 10:00 PM Load Meeting and STL Discharge Normally both the Chillers alongwith STL Discharge shall operate to meet the peak load from 10 AM to 10 PM . In peak hours from 12 Noon to 8 P.M., both the chillers shall run on 100% capacity. However for remaining hrs. (10 AM to 12 Noon & 8 PM to 10 PM) , Two circuits of One Chiller & One circuit of another chiller + t>i ^ discharge shall be normally sufficient to meet the Loads. Both the Chillers operate at +ve set point. Chiller I Set point : + 9°C Chiller II Set Point : + 8°C MV of both the STL senses CHW return temperatures & operate as under 62 Cum STL Motorized valve MV1 : Open > 13°C & Close at 11°C 30 Cum STL Motorized valve MV2 : Open > 15°C & Close at 13°C
Both the 3WMV modulates at + 7°C .0 Night Mode: 10:00 PM to 06:00 AM Operation selection will be on time base and time must be adjustable. Charging : Timings 10:00 PM to 06:00 AM. Both chillers shall operate on Charging Mode & will be at -ve set point (auto select through timer) BOTH CHILLER SET POINT
= - 4°C, ChiUer Intlet Control.
As soon as charging is selected before chiUer start-up, foUowing sequence of operations must be performed:
Valve MV1, MV2 - Open Port A of valve Vmdl & Vmd2 close Primary Pump ON, Condenser Pump ON, Cooling
Fans QN
Sequence II As soon as charging complete Chiller is equipment must be OFF. Condenser Pump, pumps - OFF. Valve MV1, MV2,Close
T
,
C.2 Winter : (November to February) Day Mode : 10:00 AM to 10:00 PM Load Meeting and STL Discharge Normally One Chiller alongwith STL Discharge shall operate to meet the peak load from 10 AM to 10 PM . In peak hours from 12 Noon to 8 P.M., One chiller shall run on 100% capacity. However for remaining hrs. (10 AM to 12 Noon & 8 PM to 10 PM) , One circuit of One Chiller + STL discharge shall be normally sufficient to meet the Loads. Chiller II shall be Normally OFF during the day time. Both the Chillers operate at +ve set point. (Inlet Control) Chiller I Set point: + 9°C Chiller II Set Point : + 8°C MV of both the STL senses CHW return temperatures & operate as under 62 Cum STL Motorized valve MV1 : Open > 13°C & Close at 11°C 30 Cum STL Motorized valve MV2 : Open > 15°C 8B Close at 13°C Both the 3WMV modulates at + 7°C .0 Night Mode: 10:00 PM to 06:00 AM
Operation selection will be on time base and time must be adjustable
Charging : Timings 10:00 PM to 06:00 AM. Charging ; Both chillers shall operate on Charging Mode (auto select through timer) BOTH CHILLER SET POINT
&
will be at -ve set point
= - 4°C, Chiller Inlet Control.
As soon as charging is selected before chiller start-up, following sequence of operations must be performed: Sequence I for STL charging with Both Chiller Valve MV1, MV2 - Open Port A of valve Vmdl 85 Vmd2 close Primary Pump ON, Condenser Pump ON, Cooling Tower Fans ON. Sequence II As soon as charging complete Chiller is switched OFF, following equipment must be OFF. Condenser Pump, Cooling Tower Fans, Primary pumps OFF. Valve MV1, MV2,- Close C.3 Monsoon : (July to October) Day Mode : 10:00 AM to 10:00 PM Load Meeting and STL Discharge Normally One Chiller alongwith STL Discharge shall operate to meet the peak load from 10 AM to 10 PM . In peak hours, One chiller shall run on 100% capacity. However for remaining hrs. (10 AM to 12 Noon & 8 PM to 10 PM) , One circuit of One Chiller + STL discharge shall be normally sufficient to meet the Loads Chiller II shall be Normally OFF during the day time For the Month of October, both the Chillers + STL discharge shall meet 10 act. Both the Chillers operate at + ve set point. (Met Control) Chiller I Set point : + 9°C Chiller II Set Point : + 8°C
tne
MV of both the STL senses CHW return ^^^ V1 O > 13 C & Ctoae at MV of both the STL senses C ^ ^ 62 Cum STL Motorized valve MV1 : Open > 13 C & 30 Cum STL Motorized valve MV2 : Open > 15 C & Close at Both the 3WMV modulates at + 7°C .0 Night Mode: 10:00 PM to 06:00 AM Operation selection will be on time base and time must be adjustable. Charging : Timings 10:00 PM to 06:00 AM Charging Both chillers shall operate on Charging Mode & will be at -ve set point (auto select through timer) BOTH CHILLER SET POINT
= - 4°C, Chiller Inlet Control.
As soon as charging is selected before chiller start-up, following sequence of operations must be performed: Sequence I for STL charging with Both Chiller Valve MV1, MV2 Open Port A of valve Vmdl & Vmd2 close Primary Pump ON, Condenser Pump ON, Cooling Tower Fans ON. Sequence II As soon as charging complete Chiller is switched OFF following
Monthly Operation Strategy
Project: Koncord Pune HOURLY LOAD
Central Month wise Operating Strategy
Month: Ja
oad Considered ' 428 TR
Night Operations : 22 hrs to 06 AM- Charging STL Charging : Both Chillers in Charging Mode with -4°C set point. Chillers Valves VM3 & VM4 open, STL Valves VMl & VM2 Open, 3 WMV MVdl & MVd2 Port A Close. Following is the sequence before Chiller Startup. Both Primary Pumps, Condenser Pumps, C.T. fans ON
Day Operation : 06 Hrs. to 22 Hrs - Load Meeting 9 Am to 12 Noon & 18 to 22 Hrs. : During this period Load shall be met by STL discharge. Both the chillers shall be OFF to take the advantage of T.O.D. tariff rates. Primary pumps, Cond. Pumps, C.T. fans OFF. Chillers Valves VM3 & VM4 Close. STL Valves VMl & VM2 Open 3WMV MVdl : Port A Open at CHWR > 13°C , Close at 12°C MVd2 : Port A Open as CHWR > 14°C , Close at 13°C 10 AM to 18 hrs : Load meeting with both Chillers & STL discharge. 1 & XA chiller alongwith STL discharge shall meet the load during this period. Chiller I set point: (+) 9°C Chiller II set point: (+) 8°C Primary Pumps, Cond. Pumps. C.T. fan :ON 3 WMV MVdl & MVd2 modulates Chiller valves VM3 & VM4 Open, STL valves : VMl open at CHWR > 13°C & VM2 open at CHWR >14°C Histogram for the Month of January enclosed.
Month Night Operations : 23 hrs to 06 AM- Charging STL Charging : Both Chillers in Charging Mode with -4°C set point. Chillers Valves VM3 & VM4 open, STL Valves VMl & VM2 Open, 3 WMV MVdl & MVd2 Port A Close. Following is the sequence before Chiller Startup. Both Primary Pumps, Condenser Pumps, C.T. fans ON
Day Operation : 09 Hrs. to 22 Hrs - Load Meeting
9 Am to 10 Noon & 20 to 22 Hrs. : During this period Load shall be met by STL discharge. Both the chillers shall be OFF to take the advantage of T.O.D. tariff rates. Primary pumps, Cond. Pumps, C.T. fans OFF. Chillers Valves VM3 & VM4 Close. STL Valves VMl & VM2 Open 3 WMV MVdl : Port A Open at CHWR > 13°C , Close at 12°C MVd2 : Port A Open as CHWR > 14°C , Close at 13°C 10 AM to 20 hrs : Load meeting with both Chillers & STL discharge. Both the chillers alongwith STL discharge shall meet the load during this period. Chiller I set point: (+) 9°C Chiller II set point: (+) 8°C Primary Pumps, Cond. Pumps. C.T. fan :ON 3 WMV MVdl & MVd2 modulates Chiller valves VM3 & VM4 Open, STL valves : VMl open at CHWR > 13°C & VM2 open at CHWR >14°C Histogram for the Month of March enclosed.
;:\M y D o c u m e n ts W o g e S T L F eb - V ariant4 4
% of Energy (STL) 100
S T L S tr a te g y C o
Capacities (tons) 494 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 fflbase liildirect productiorHMdischarge ^charge Hover charge % of Energy (STL)
