Advantages of Thermal Power Plant

Advantages of thermal power plant is a tool in which we will focus on to the advantages of thermal power plant. Before we understand this it is important to understand the basic important concepts of thermal power plant.

Basically thermal power is the plant which utilizes the energy of the coal to produce electricity. The thermal power is governed with the laws of the thermodynamics. The thermal power is basically divided into two main parts, one is the complete set of the Boiler, Turbine and generator and other is its balance of plant which helps in executing the main parts of the boiler. Furnace is the most critical part of the boiler of thermal power plant, where actually the firing takes place. Inside the furnace the firing takes place and energy is transferred to water by three important processes. One of the processes is conduction, other important process is convection and last process is radiation. With all of these processes the energy is transferred and basically steam is produced. This steam is then passed to the turbine and this turbine has blades inside it.

Based on design requirements, sometimes to increase the efficiency, the steam turbine is divided into the sub parts such as high pressure steam turbine, intermediate pressure steam turbine and two other low pressure turbines. And the turbine is finally connected to the generator. And hence finally turbine gives drive to the rotor of the generator and finally the electricity is produced. This electricity is transmitted everywhere by the transmission lines with the help of transformers.

After understanding the basics of thermal power plant, now we will learn about the advantages of thermal power plant. The detailed advantages of thermal power plant is given below:
1) We know that the coal is the resource or fuel to produce electricity; it is easily available fossil fuel.  It means that the advantage of thermal power plant is that it uses coal as a fuel which is easily available in nature.
2) It produces more electricity in comparison to the wind and solar power plant. The size of the thermal power plant is up to 1000 MW. And most of the power producers are dealing with sizes 660 MW or higher, basically they are dealing with supercritical boilers. While the size of solar and wind power plant is always less than 100 MW.
3) Since it produces enough electricity, so it plays a major role in the development of the country. Because of this now villagers are also uplifting their living standards.
4) Like nuclear power plant, thermal power plant has no danger in passing the harmful radiations.
5) In comparison to all other types of power plant, the electricity produced by the thermal power plant is cheapest.
6) Thermal power plant requires lesser area in comparison to the other power plant. Nowadays because of the development, all compacted boiler and turbines are available which further reduces the area of the thermal power plant.
7) By the help of the chimney and ESP design, it fulfills the environmental pollution department requirements.

Hence we have seen that setting up a thermal power is directly related to the growth of the country.

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From Wikipedia

Thermal power station

A thermal power station is a power plant in which the prime mover is steam driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this is known as a Rankine cycle. The greatest variation in the design of thermal power stations is due to the different fuel sources. Some prefer to use the term energy center because such facilities convert forms of heatenergy into electrical energy. Some thermal power plants also deliver heat energy for industrial purposes, for district heating, or for desalination of water as well as delivering electrical power. A large proportion of CO2 is produced by the worlds fossil fired thermal power plants; efforts to reduce these outputs are various and widespread.

Introductory overview

Almost all coal, nuclear, geothermal, solar thermal electric, and waste incineration plants, as well as many natural gas power plants are thermal. Natural gas is frequently combusted in gas turbines as well as boilers. The waste heat from a gas turbine can be used to raise steam, in a combined cycle plant that improves overall efficiency. Power plants burning coal, oil, or natural gas are often referred to collectively as fossil-fuel power plants. Somebiomass-fueled thermal power plants have appeared also. Non-nuclear thermal power plants, particularly fossil-fueled plants, which do not use co-generation are sometimes referred to as conventional power plants.

Commercial electric utility power stations are most usually constructed on a very large scale and designed for continuous operation. Electric power plants typically use three-phase or individual-phase electrical generators to produce alternating current (AC) electric power at a frequency of 50 Hz or 60 Hz (hertz, which is an AC sine wave per second) depending on its location in the world. Other large companies or institutions may have their own usually smaller power plants to supply heating or electricity to their facilities, especially if heat or steam is created anyway for other purposes. Shipboard steam-driven power plants have been used in various large ships in the past, but these days are used most often in large naval ships. Such shipboard power plants are general lower power capacity than full-size electric company plants, but otherwise have many similarities except that typically the main steam turbines mechanically turn the propulsion propellers, either through reduction gears or directly by the same shaft. The steam power plants in such ships also provide steam to separate smaller turbines driving electric generators to supply electricity in the ship. Shipboard steam power plants can be either conventional or nuclear; shipboard nuclear plants are with very few exceptions only in naval vessels. There have been perhaps about a dozen turbo-electric ships in which a steam-driven turbine drives an electric generator which powers an electric motor for propulsion.

In some industrial, large institutional facilities, or other populated areas, there are combined heat and power (CH&P) plants, often called co-generation plants, which produce both power and heat for facility or district heating or industrial applications. AC electrical power can be stepped up to very high voltages for long distance transmission with minimal loss of power. Steam and hot water lose energy when piped over substantial distance, so carrying heat energy by steam or hot water is often only worthwhile within a local area or facility, such as steam distribution for a ship or industrial facility or hot water distribution in a local municipality.

History

Reciprocating steam engines have been used for mechanical power sources since the 18th Century, with notable improvements being made by James Watt. The very first commercial central electrical generating stations in the Pearl Street Station, New York and the Holborn Viaduct power station, London, in 1882, also used reciprocating steam engines. The development of the steam turbine allowed larger and more efficient central generating stations to be built. By 1892 it was considered as an alternative to reciprocating engines Turbines offered higher speeds, more compact machinery, and stable speed regulation allowing for parallel synchronous operation of generators on a common bus. Turbines entirely replaced reciprocating engines in large central stations after ab

Thermal pollution

Thermal pollution is the degradation of water quality by any process that changes ambient water temperature.

A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. When water used as a coolant is returned to the natural environment at a higher temperature, the change in temperature (a) decreases oxygen supply, and (b) affects ecosystem composition. Urban runoff--stormwater discharged to surface waters from roads and parking lots--can also be a source of elevated water temperatures.

When a power plant first opens or shuts down for repair or other causes, fish and other organisms adapted to particular temperature range can be killed by the abrupt rise in water temperature known as 'thermal shock'.

Ecological effects — warm water

Elevated temperature typically decreases the level of dissolved oxygen (DO) in water. The decrease in levels of DO can harm aquatic animals such as fish, amphibians and copepods. Thermal pollution may also increase the metabolic rate of aquatic animals, as enzyme activity, resulting in these organisms consuming more food in a shorter time than if their environment were not changed. An increased metabolic rate may result in fewer resources; the more adapted organisms moving in may have an advantage over organisms that are not used to the warmer temperature. As a result one has the problem of compromising food chains of the old and new environments. Biodiversity can be decreased as a result.

It is known that temperature changes of even one to two degrees Celsius can cause significant changes in organism metabolism and other adverse cellular biology effects. Principal adverse changes can include rendering cell walls less permeable to necessary osmosis, coagulation of cell proteins, and alteration of enzymemetabolism. These cellular level effects can adversely affect mortality and reproduction.

Primary producers are affected by warm water because higher water temperature increases plant growth rates, resulting in a shorter lifespan and species overpopulation. This can cause an algae bloom which reduces oxygen levels.

A large increase in temperature can lead to the denaturing of life-supporting enzymes by breaking down hydrogen- and disulphide bonds within the quaternary structure of the enzymes. Decreased enzyme activity in aquatic organisms can cause problems such as the inability to break down lipids, which leads to malnutrition.

In limited cases, warm water has little deleterious effect and may even lead to improved function of the receiving aquatic ecosystem. This phenomenon is seen especially in seasonal waters and is known as thermal enrichment.... An extreme case is derived from the aggregational habits of the manatee, which often uses power plant discharge sites during winter. Projections suggest that manatee populations would decline upon the removal of these discharges.

Ecological effects — cold water

Releases of unnaturally cold water from reservoirs can dramatically change the fish and macroinvertebrate fauna of rivers, and reduce river productivity. In Australia, where many rivers have warmer temperature regimes, native fish species have been eliminated, and macroinvertebrate fauna have been drastically altered.

Control of thermal pollution

Industrial wastewater
In the United States, thermal pollution from industrial sources is generated mostly by power plants, petroleum refineries, pulp and paper mills, chemical plants, steel mills and smelters. Heated water from these sources may be controlled with:

Some facilities use once-through cooling (OTC) systems which do not reduce temperature as effectively as the above systems. For example, the Potrero Generating Station in San Francisco, which uses OTC, discharges water to San Francisco Bay approximately 10°C (20°F) above the ambient bay temperature.

Urban runoff
During warm weather, urban runoff can have significant thermal

Solar thermal energy

Solar thermal energy (STE) is a technology for harnessing solar energy for thermal energy (heat). Solar thermal collectors are classified by the USAEnergy Information Administration as low-, medium-, or high-temperature collectors. Low temperature collectors are flat plates generally used to heat swimming pools. Medium-temperature collectors are also usually flat plates but are used for heating water or air for residential and commercial use. High temperature collectors concentrate sunlight using mirrors or lenses and are generally used for electric power production. STE is different from photovoltaics, which convert solar energy directly into electricity. While only 600 megawatts of solar thermal power is up and running worldwide in October 2009 according to Dr David Mills of Ausra, another 400 megawatts is under construction and there are 14,000 megawatts of the more serious concentrating solar thermal (CST) projects being developed.

Low-temperature collectors

Of the 21000000|sqft|m2 of solar thermal collectors produced in the United States in 2006, 16000000|sqft|m2 were of the low-temperature variety. Low-temperature collectors are generally installed to heat swimming pools, although they can also be used for space heating. Collectors can use air or water as the medium to transfer the heat to their destination.

Heating, cooling, and ventilation

In the United States, heating, ventilation, and air conditioning (HVAC) systems account for over 25 percent (4.75 EJ) of the energy used in commercial buildings and nearly half (10.1 EJ) of the energy used in residential buildings. Solar heating, cooling, and ventilation technologies can be used to offset a portion of this energy.

Thermal mass materials store solar energy during the day and release this energy during cooler periods. Common thermal mass materials include stone, concrete, and water. The proportion and placement of thermal mass should consider several factors such as climate, daylighting, and shading conditions. When properly incorporated, thermal mass can passively maintain comfortable temperatures while reducing energy consumption. A solar chimney (or thermal chimney) is a passive solar ventilation system composed of a hollow thermal mass connecting the interior and exterior of a building. As the chimney warms, the air inside is heated causing an updraft that pulls air through the building. These systems have been in use since Roman times and remain common in the Middle East.

Solar space heating with solar air heat collectors is more popular in the USA and Canada than heating with solar liquid collectors since most buildings already have a ventilation system for heating and cooling. The two main types of solar air panels are glazed and unglazed.

Glazed Solar Collectors are designed primarily for space heating and they recirculate building air through a solar air panel where the air is heated and then directed back into the building. These solar space heating systems require at least two penetrations into the building and only perform when the air in the solar collector is warmer than the building room temperature. Most glazed collectors are used in the residential sector.

Unglazed Solar Collectors are primarily used to pre-heat make-up ventilation air in commercial, industrial and institutional buildings with a high ventilation load. They turn building walls or sections of walls into low cost, high performance, unglazed solar collectors. Also called, "transpired solar panels", they employ a painted perforated metal solar heat absorber that also serves as the exterior wall surface of the building. Heat conducts from the absorber surface to the thermal boundary layer of air 1 mm thick on the outside of the absorber and to air that passes behind the absorber. The boundary layer of air is drawn into a nearby perforation before the heat can escape by convection to the outside air. The heated air is then drawn from behind the absorber plate into the building's ventilation system.

A Trombe wall is a passive solar heating and ventilation system consisting of an air channel sandwiched between a window and a sun-facing thermal mass. During the ventilation cycle, sunlight stores heat in the thermal mass and warms the air channel causing circulation through vents at the top and bottom of the wall. During the heating cycle the Trombe wall radiates stored heat.

Solar roof ponds are unique solar heating and cooling systems developed by Harold Hay in the 1960s. A basic system consists of a roof-mounted water bladder with a movable insulating cover. This system can control heat exchange between interior and exterior environments by covering and uncovering the bladder between night and day. When heating is a concern the bladder is uncovered during the day allowing sunlight to warm the water bladder and store heat for evening use. When cooling is a concern the covered bladder draws heat from the building's interior during the day and is uncovered at night to radiate heat to the cooler atmosphere. The Skytherm house in Atascadero, California uses a prototype roof pond for heating and cooling.

Active solar cooling can be achieved via absorption refrigeration cycles, desiccant cycles, and solar mechanical processes. In 1878, Auguste Mouchout pioneered solar cooling by making ice using a solar steam engine attached to a refrigeration device. Thermal mass, smart windows and shading methods can also be used to provide cooling. The leaves of deciduous trees provide natural shade during the summer while the bare limbs allow light and warmth into a building during the winter. The water content of trees will also help moderate local temperatures.

Process heat

Solar process heating systems are designed to provide large quantities of hot water or space heating for nonresidential buildings.

Evaporation ponds are shallow ponds that concentrate dissolved solids through evaporation. The use of evaporation ponds to obtain salt from sea water is one of the oldest applications of solar energy. Moder

Thermal conductivity

In physics, thermal conductivity, k, is the property of a material describing its ability to conduct heat. It appears primarily in Fourier's Law for heat conduction. Thermal conductivity is measured in watts per kelvin-metre (W·K−1·m−1, i.e. W/(K·m). Multiplied by a temperature difference (in kelvins, K) and an area (in square metres, m2), and divided by a thickness (in metres, m), the thermal conductivity predicts the rate of energy loss (in watts, W) through a piece of material. In the window building industry "thermal conductivity" is expressed as the [http://www.energystar.gov/index.cfm?c=windows_doors.pr_ind_tested U-Factor] measures the rate of heat transfer and tells you how well the window insulates. U-factor values generally range from 0.15 to 1.25 and are measured in Btu per hour - square foot - degree Fahrenheit (ie. Btu/h·ft²·°F). The lower the U-factor, the better the window insulates.

The reciprocal of thermal conductivity is thermal resistivity.

Measurement

There are a number of ways to measure thermal conductivity. Each of these is suitable for a limited range of materials, depending on the thermal properties and the medium temperature. There is a distinction between steady-state and transient techniques.

In general, steady-state techniques are useful when the temperature of the material does not change with time. This makes the signal analysis straightforward (steady state implies constant signals). The disadvantage is that a well-engineered experimental setup is usually needed. The Divided Bar (various types) is the most common device used for consolidated rock samples.

The transient techniques perform a measurement during the process of heating up. Their advantage is quicker measurements. Transient methods are usually carried out by needle probes.

Standards

  • IEEE Standard 442-1981, "IEEE guide for soil thermal resistivity measurements", ISBN 0-7381-0794-8. See also soil thermal properties. [http://ieeexplore.ieee.org/servlet/opac?punumber=2543]
  • IEEE Standard 98-2002, "Standard for the Preparation of Test Procedures for the Thermal Evaluation of Solid Electrical Insulating Materials", ISBN 0-7381-3277-2 [http://ieeexplore.ieee.org/servlet/opac?punumber=7893]
  • ASTM Standard D5334-08, "Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure"
  • ASTM Standard D5470-06, "Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials" [http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/D5470.htm?E+mystore]
  • ASTM Standard E1225-04, "Standard Test Method for Thermal Conductivity of Solids by Means of the Guarded-Comparative-Longitudinal Heat Flow Technique" [http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/E1225.htm?L+mystore+wnox2486+1189558298]
  • ASTM Standard D5930-01, "Standard Test Method for Thermal Conductivity of Plastics by Means of a Transient Line-Source Technique" [http://www.astm.org/cgi-bin/SoftCart.exe/STORE/filtrexx40.cgi?U+mystore+wnox2486+-L+THERMAL:CONDUCTIVITY+/usr6/htdocs/astm.org/DATABASE.CART/REDLINE_PAGES/D5930.htm]
  • ASTM Standard D2717-95, "Standard Test Method for Thermal Conductivity of Liquids" [http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/D2717.htm?L+mystore+wnox2486+1189564966]
  • ISO 22007-2:2008 "Plastics -- Determination of thermal conductivity and thermal diffusivity -- Part 2: Transient plane heat source (hot disc) method" [http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=40683]
  • Note: What is called the k-value of construction materials (e.g. window glass) in the U.S., is called λ-value in Europe. What is called U-value (= the inverse of R-value) in the U.S., used to be called k-value in Europe, but is now also called U-value in Europe.

Definitions

The reciprocal of thermal conductivity is thermal resistivity, usually measured in kelvin-metres per watt (K·m·W−1). When dealing with a known amount of material, its thermal conductance and the reciprocal property, thermal resistance, can be described. Unfortunately, there are differing definitions for these terms.

Conductance

For general scientific use, thermal conductance is the quantity of heat that passes in unit time through a plate of particular area and thickness when its opposite faces differ in temperature by one kelvin. For a plate of thermal conductivity k, area A and thickness L this is kA/L, measured in W·K−1 (equivalent to: W/°C). Thermal conductivity and conductance are analogous to electrical conductivity (A·m−1·V−1) and electrical conductance (A·V−1).

There is also a measure known as heat transfer coefficient: the quantity of heat that passes in unit time through unit area of a plate of particular thickness when its opposite faces differ in temperature by one kelvin. The reciprocal is thermal insulance. In summary:

  • thermal conductance = kA/L, measured in W·K−1
    • thermal resistance = L/(kA), measured in K·W−1 (equivalent to: °C/W)
    • heat transfer coefficient = k/L, measured in W·K−1·m−2
    • thermal insulance = L/k, measured in K·m²·W−1.

The heat transfer coefficient is also known as thermal admittance

Resistance

When thermal resistances occur in series, they are additive. So when heat flows through two components each with a resistance of 1 °C/W, the total resistance is 2 °C/W.

A common engineering design problem involves the selection of an appropriate sized heat sink for a given heat source. Working in units of thermal resistance greatly simplifies the design calculation. The following formula can be used to estimate the performance:

R_{hs} = \frac {\Delta T}{P_{th}} - R_s

where:

  • Rhs is the maximum thermal resistance of the heat sink to ambient, in °C/W
  • \Delta T is the temperature difference (temperature drop), in °C
  • Pth is the thermal power (heat flow), in watts
  • Rs is the thermal resistance of the heat source, in °C/W

For example, if a component produces 100 W of heat, and has a thermal resistance of 0.5 °C/W, what is the maximum thermal resistance of the heat sink? Sup


From Yahoo Answers

Question:

Answers:Most electric generation is thermal. The exceptions are solar, wind, and hydroelectric generators. Thermal plants use heat to generate high pressure steam to drive turbines efficiently. They are relatively cheap and can provide high levels of power output consistently. As opposed to renewable resources which require certain natural phenomenon and produce considerably less power. The disadvantages are pollution for fossil fuel plants. Nuclear plants need to maintain a nuclear reaction and store high level nuclear waste for generations. Geothermal steam vents are usually very corrosive, the equipment needs to be maintained and replaced and you can't just turn off the steam source.

Question:what are thermal power plants and what countires that have thermal powerplants?

Answers:In Iceland, a country in the North Atlantic, they use thermal energy to heat their homes as well as a lot of other things. Look up Iceland on the Internet. Advantages are that it has no negative effects on the earth's environment. Disadvantages may be costs of harnessing but that should be reconfirmed. The costs of finding oil and getting it up to the surface may be just as high plus we are polluting the planet which has an incalculable cost.

Question:Wat are the initial Steps to start a Thermal Power Plant.. From the very beginning till the completion of the plant.....

Answers:http://en.wikipedia.org/wiki/Thermal_power_station

Question:Hey all I am a B.E(EEE) graduate, who's planning to undergo a training in thermal engineering,which can fetch me a job. Now, can any seniors tell me how life is in thermal power plant n detail. Some suggest it's a boring and pity thea. Regards Prabagar

Answers:Depends if you will be in the operation or maintenance side. Both sides have their kicks and boring side. If you actually have to be on a shift, then, it can be pretty boring. If you have to be on the daily planning management side, then, it can be more exciting. If you are going to be on the maintenance end, then, the best part is controls and instrumentation. Substantial training is required for that.