Thermal means heat, power means the energy energy or electric electricity, ity, so so in a layman’s layman’s language language we can say that a thermal power plant is a place where the heat energy (here coal) is converted to power or electricity. We know the power plants through their capacity as MW where it stands for the Megawatts of power generated. In a thermal power plant the coal is burnt to generate heat and this heat is used to change the water to steam and this steam is required required to run/rotate run/rotate the turbines which in turn are connected connected to a generator which converts the mechanical motion of the turbine to electrical energy. This generated generated electrical electrical energy comes to our homes through a set of Electrical Electrical Structures to our homes.
THERMAL THERMAL POLLUTIONPOLLUTION- Thermal Thermal pollution pollution is the harmful harmful increase increase in water
temperature in streams, rivers, lakes, or occasionally, coastal ocean waters. Thermal pollution is caused by either dumping hot water from factories and power plants or removing trees and vegetation that shade streams, permitting sunlight to raise the temperature of these waters. Like other forms of water pollution, thermal pollution is widesp widesprea read, d, affecti affecting ng many lakes and vast vast number numbers s of streams streams and rivers rivers in the various parts of the world. A temperature increase as small as 1 or 2 Celsius degrees (about 2 to 4 Fahrenheit degrees) can kill native fish, shellfish, and plants, or drive them out in favor of other species, often with undesirable effects. SOURCES OF THERMAL POLLUTION-The major sources of thermal pollution
are electric power plants and industrial factories. In most electric power plants, heat is produced when coal, oil, or natural gas is burned or nuclear fuels undergo fission to release huge amounts of energy. This heat turns water to steam, which in turn spins turbines to produce electricity. After doing its work, the spent steam must be cooled and condensed back into water. To condense the steam, cool water is brought into the plant and circulated next to the hot steam. In this process, the water used for cooling warms 5 to 10 Celsius degrees (9 to 18 Fahrenheit degrees), after which it may be dumped back into the lake, river, or ocean from which it came. Similarly, factories contribute to thermal pollution when they dump water used to cool their machinery.
The second type of thermal pollution is much more widespread. Streams and small lakes are naturally kept cool by trees and other tall plants that block sunlight. People often remove this shading vegetation in order to harvest the wood in the trees, to make room for crops, or to construct buildings, roads, and other structures. Left unshaded, the water warms by as much as 10 Celsius degrees (18 Fahrenheit degrees). In a similar manner, grazing sheep and cattle can strip streamsides of low vegetation, including young trees. Even the removal of vegetation far away from a stream or lake can contribute to thermal pollution by speeding up the erosion of soil into the water, making it muddy. Muddy water absorbs more energy from the sun than clear water does, resulting in further heating. Finally, water running off of artificial surfaces, such as streets, parking lots, and roofs, is warmer than water running off vegetated land and, thus, contributes to thermal pollution.
Coal combustion in power plants in India produces large quantities of coal-related wastes, e.g. fly ash and bottom ash. Indian coals used in power stations are of high ash content, thus resulting in the generation of large amounts of fly ash (~100 million tons/year). Combustion of coal results in enhanced concentration of most radionuclides found in waste materials.
IMPACTS
Sudden death of aquatic life due directly to increased temperature. An increased predation rate, due to changes in avoidance reactions induced by
temperature changes. Decrease in swimming speed and stamina, etc. Increased susceptibility of aquatic organisms to chemical or physical toxins .Disruption of normal biological rhythms.
Disruption of migration patterns.
Decreased oxygen concentrations in heated waters at the same time as the
organisms Increase in anaerobic organisms with putrefaction of sludge, etc. Increase in rooted plant growth leading, for example, to decreased flow rates,
increased siltation, and a total disruption of the biosystem. Increased susceptibility to pathogenic organisms.
Decreased spawning success and decrease in survival of young fish .
CONSTRAINTS OF THERMAL POWER- The
constraints of thermal power are(1) serious pollution and ecological hazards associated with it.(2) complicated thermal equipment.(3) poor industrial relations in generating stations.(4) complicated operation and maintenance of thermal plants CONTROLLING MEASURES- Thermal pollution from power plants and factories
is relatively easy to control. Instead of discharging heated water into lakes and streams, power plants and factories can pass the heated water through cooling towers or cooling ponds, where evaporation cools the water before it is discharged. Alternatively, power plants can be designed or refitted to be more efficient and to produce less waste heat in the first place. In a process called cogeneration, the excess heat energy from generating electricity can be used in another manufacturing process that needs such energy. Where homes or other buildings are located near industrial plants, waste hot water can be used for heating CONCLUSION-Thermal
wastes from the current generation of large, nuclear power generating stations are immense in quantity and can cause drastic changes in the bodies of water involved. There is little hope for a spectacular breakthrough which would significantly improve the thermal efficiency of light-water nuclear reactors. Even if fast breeder reactors prove safe enough for general use, the thermal efficiency would be only slightly improved over the present reactors. If the past performance of the nuclear industry. is taken as representative of what to expect, there will be vast quantities of radioactive wastes discharged both at nuclear power plant (reactor) sites and at fuel-fabricating and fuel reprocessing plants. Even without the catastrophic releases of radioactive wastes which would result from a major accident, the introduction of these radioactive wastes in normal operation poses a major threat not only to the current generation but also to the future of the human race. Perhaps the genetic effects which would result from the wastes of the nuclear industry can be tolerated.and perhaps they cannot. It is a dangerous game to play, trading potential death and mutation for minor immediate economic gain.
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