Misplaced Pages

#528471

69-672: Tenaga Nasional Berhad ( lit.   ' National Energy Limited ' , abbreviated as TNB ; TENA, MYX : 5347 ), also known as Tenaga Nasional or simply Tenaga , is the Malaysian multinational electricity company and is the only electric utility company in Peninsular Malaysia and also the largest publicly listed power company in Southeast Asia with MYR 204.74 billion worth of assets. It serves over 10.16 million customers throughout Peninsular Malaysia (except Sarawak ) and

138-451: A steam drum , and the furnace with its steam generating tubes and superheater coils. Necessary safety valves are located at suitable points to protect against excessive boiler pressure. The air and flue gas path equipment include: forced draft (FD) fan , air preheater (AP), boiler furnace, induced draft (ID) fan, fly ash collectors ( electrostatic precipitator or baghouse ), and the flue-gas stack . The boiler feed water used in

207-435: A vacuum of about −95 kPa (−28 inHg) relative to atmospheric pressure. The large decrease in volume that occurs when water vapor condenses to liquid creates the vacuum that generally increases the efficiency of the turbines. The limiting factor is the temperature of the cooling water and that, in turn, is limited by the prevailing average climatic conditions at the power station's location (it may be possible to lower

276-480: A TNB chairman/CEO and its president. The company's professional management team consists of 14 members. TNB Power Generation Sdn Bhd (TNB Genco) owns and operates thermal assets and hydroelectric generation schemes in Peninsular Malaysia. In the peninsula, it has a generation capacity of 16,283MW. Plans to expand its generation capacity include increasing hydroelectric generation by 2015 and commissioning

345-498: A combination of the two. The efficiency of a thermal power station is determined by how effectively it converts heat energy into electrical energy, specifically the ratio of saleable electricity to the heating value of the fuel used. Different thermodynamic cycles have varying efficiencies, with the Rankine cycle generally being more efficient than the Otto or Diesel cycles. In the Rankine cycle,

414-472: A demutualized exchange and was renamed Bursa Malaysia in 2004. It consists of a Main Board, a Second Board and MESDAQ (now ACE Market) with total market capitalization of ( USD $ 397.39 billion). On 7 May 2024, Bursa Malaysia hit RM2 trillion in market capitalisation for the first time. Thermal power station The majority of the world's thermal power stations are driven by steam turbines, gas turbines, or

483-660: A gas turbine, in the form of hot exhaust gas, can be used to raise steam by passing this gas through a heat recovery steam generator (HRSG). The steam is then used to drive a steam turbine in a combined cycle plant that improves overall efficiency. Power stations burning coal, fuel oil , or natural gas are often called fossil fuel power stations . Some biomass -fueled thermal power stations have appeared also. Non-nuclear thermal power stations, particularly fossil-fueled plants, which do not use cogeneration are sometimes referred to as conventional power stations . Commercial electric utility power stations are usually constructed on

552-442: A gas turbine. The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. Geothermal plants do not need boilers because they use naturally occurring steam sources. Heat exchangers may be used where the geothermal steam is very corrosive or contains excessive suspended solids. A fossil fuel steam generator includes an economizer ,

621-410: A generator on a common shaft. There is usually a high-pressure turbine at one end, followed by an intermediate-pressure turbine, and finally one, two, or three low-pressure turbines, and the shaft that connects to the generator. As steam moves through the system and loses pressure and thermal energy, it expands in volume, requiring increasing diameter and longer blades at each succeeding stage to extract

690-480: A large scale and designed for continuous operation. Virtually all electric power stations use three-phase electrical generators to produce alternating current (AC) electric power at a frequency of 50 Hz or 60 Hz . Large companies or institutions may have their own power stations to supply heating or electricity to their facilities, especially if steam is created anyway for other purposes. Steam-driven power stations have been used to drive most ships in most of

759-402: A network of state and area offices to purchase electricity from embedded generators, market and sell electricity, connect new supply, provide counter services, collect revenues , operate call management centres, provide supply restoration services, and implements customer and government relationships. Since its privatization, the corporate slogan of TNB is 'Penggerak Kemajuan Negara' or Powering

SECTION 10

#1732859499529

828-585: A partnership between its subsidiary TNB Power Generation Sdn Bhd and YTL PowerSeraya Pte Ltd. TNB is one of the 10 companies under Khazanah Nasional , Malaysian sovereign wealth fund and also one of the 13 Malaysian companies listed on the Forbes Global 2000 in 2018. TNB is ranked 16th globally in Brand Finance: Utilities 50 2021 Ranking and 230th globally in 2023 Bentley Infrastructure 500. The Lembaga Letrik Pusat (Central Electricity Board, CEB)

897-559: A set of tubes in the furnace. Here the steam picks up more energy from hot flue gases outside the tubing, and its temperature is now superheated above the saturation temperature. The superheated steam is then piped through the main steam lines to the valves before the high-pressure turbine. Nuclear-powered steam plants do not have such sections but produce steam at essentially saturated conditions. Experimental nuclear plants were equipped with fossil-fired superheaters in an attempt to improve overall plant operating cost. The condenser condenses

966-567: A single set of prices on both boards. The Malaysian Stock Exchange was formally formed in 1964, and in the following year, with the separation of Singapore from Malaysia , the stock exchange continued to function under the Malaysian and Singapore Stock Exchange (MSSE). In 1973, with the termination of currency interchangeability between Malaysia and Singapore, the SEMS was separated into the Kuala Lumpur Stock Exchange Bhd (KLSEB) and

1035-523: A specific type of large heat exchanger used in a pressurized water reactor (PWR) to thermally connect the primary (reactor plant) and secondary (steam plant) systems, which generates steam. In a boiling water reactor (BWR), no separate steam generator is used and water boils in the reactor core. In some industrial settings, there can also be steam-producing heat exchangers called heat recovery steam generators (HRSG) which utilize heat from some industrial process, most commonly utilizing hot exhaust from

1104-423: A stationary stator and a spinning rotor , each containing miles of heavy copper conductor. There is generally no permanent magnet , thus preventing black starts . In operation it generates up to 21,000 amperes at 24,000 volts AC (504 MWe) as it spins at either 3,000 or 3,600 rpm , synchronized to the power grid . The rotor spins in a sealed chamber cooled with hydrogen gas, selected because it has

1173-613: A steam power station in Bangsar with a capacity of 26.5 MW, a hydroelectric power station at Ulu Langat with a capacity of 2.28 MW, and various diesel powered generators with a total capacity of 11.1 MW. On 22 June 1965, Central Electricity Board (CEB) of the Federation of Malaya was renamed the Lembaga Letrik Negara (National Electricity Board, NEB) of the States of Malaya. By the 1980s,

1242-406: A trip-out are avoided by flushing out such gases from the combustion zone before igniting the coal. The steam drum (as well as the superheater coils and headers) have air vents and drains needed for initial start up. Fossil fuel power stations often have a superheater section in the steam generating furnace. The steam passes through drying equipment inside the steam drum on to the superheater,

1311-478: A typical late 20th-century power station, superheated steam from the boiler is delivered through 14–16-inch-diameter (360–410 mm) piping at 2,400 psi (17 MPa; 160 atm) and 1,000 °F (540 °C) to the high-pressure turbine, where it falls in pressure to 600 psi (4.1 MPa; 41 atm) and to 600 °F (320 °C) in temperature through the stage. It exits via 24–26-inch-diameter (610–660 mm) cold reheat lines and passes back into

1380-429: Is also dosed with pH control agents such as ammonia or morpholine to keep the residual acidity low and thus non-corrosive. The boiler is a rectangular furnace about 50 feet (15 m) on a side and 130 feet (40 m) tall. Its walls are made of a web of high pressure steel tubes about 2.3 inches (58 mm) in diameter. Fuel such as pulverized coal is air-blown into the furnace through burners located at

1449-473: Is expensive and has seldom been implemented. Government regulations and international agreements are being enforced to reduce harmful emissions and promote cleaner power generation. Almost all coal-fired power stations , petroleum, nuclear , geothermal , solar thermal electric , and waste incineration plants , as well as all natural gas power stations are thermal. Natural gas is frequently burned in gas turbines as well as boilers . The waste heat from

SECTION 20

#1732859499529

1518-474: Is limited, and governed by the laws of thermodynamics . The Carnot efficiency dictates that higher efficiencies can be attained by increasing the temperature of the steam. Sub-critical pressure fossil fuel power stations can achieve 36–40% efficiency. Supercritical designs have efficiencies in the low to mid 40% range, with new "ultra critical" designs using pressures above 4,400 psi (30 MPa) and multiple stage reheat reaching 45–48% efficiency. Above

1587-476: Is returned to the downcomers and the steam is passed through a series of steam separators and dryers that remove water droplets from the steam. The dry steam then flows into the superheater coils. The boiler furnace auxiliary equipment includes coal feed nozzles and igniter guns, soot blowers , water lancing, and observation ports (in the furnace walls) for observation of the furnace interior. Furnace explosions due to any accumulation of combustible gases after

1656-464: Is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace. Here the steam is superheated to 1,000 °F (540 °C) to prepare it for the turbine. Plants that use gas turbines to heat the water for conversion into steam use boilers known as heat recovery steam generators (HRSG). The exhaust heat from

1725-465: Is the air-cooled condenser . The process is similar to that of a radiator and fan. Exhaust heat from the low-pressure section of a steam turbine runs through the condensing tubes, the tubes are usually finned and ambient air is pushed through the fins with the help of a large fan. The steam condenses to water to be reused in the water-steam cycle. Air-cooled condensers typically operate at a higher temperature than water-cooled versions. While saving water,

1794-657: The Kerinchi Pylon located near Menara Telekom , Kerinchi , Kuala Lumpur . The National Grid is linked via 132 kV HVAC and 300 kV HVDC interconnection to Thailand and 230 kV cables to Singapore. TNB, through its subsidiaries, is also involved in the manufacturing of transformers , high voltage switchgears and electrical cables , consultancy services, architectural, civil and electrical engineering works and services, repair and maintenance services and fuel undertakes research and development, property development, and project management services. The Distribution division conducts

1863-786: The Manhattan Elevated Railway . Each of seventeen units weighed about 500 tons and was rated 6000 kilowatts; a contemporary turbine set of similar rating would have weighed about 20% as much. The energy efficiency of a conventional thermal power station is defined as saleable energy produced as a percent of the heating value of the fuel consumed. A simple cycle gas turbine achieves energy conversion efficiencies from 20 to 35%. Typical coal-based power plants operating at steam pressures of 170 bar and 570 °C run at efficiency of 35 to 38%, with state-of-the-art fossil fuel plants at 46% efficiency. Combined-cycle systems can reach higher values. As with all heat engines, their efficiency

1932-643: The Securities Commission of Malaysia , the stock exchange regulates the capital market in Malaysia and, through its facilities, upholds the duty to manage and maintain order in the trading of stocks, bonds and derivatives. Bursa Malaysia was established in 1930, when the Singapore Stockbrokers Association became an official organization of securities in Malaya . In 1937, it was re-registered as

2001-602: The Stock Exchange of Singapore (SES). Malaysian companies continued to be listed on SES and vice versa. A new company limited by guarantee, The Kuala Lumpur Stock Exchange (KLSE) took over operations of KLSEB as the stock exchange. In 1994, it was renamed Kuala Lumpur Stock Exchange. It also fully suspended the trading of CLOB (Central Limit Order Book) counters, indefinitely freezing approximately US$ 4.47 billion worth of shares and affecting 172,000 investors, most of them Singaporeans. Kuala Lumpur Stock Exchange (KLSE) became

2070-403: The critical point for water of 705 °F (374 °C) and 3,212 psi (22.15 MPa), there is no phase transition from water to steam, but only a gradual decrease in density . Currently most nuclear power stations must operate below the temperatures and pressures that coal-fired plants do, in order to provide more conservative safety margins within the systems that remove heat from

2139-552: The steam boiler is a means of transferring heat energy from the burning fuel to the mechanical energy of the spinning steam turbine . The total feed water consists of recirculated condensate water and purified makeup water . Because the metallic materials it contacts are subject to corrosion at high temperatures and pressures, the makeup water is highly purified before use. A system of water softeners and ion exchange demineralizes produces water so pure that it coincidentally becomes an electrical insulator , with conductivity in

Tenaga Nasional - Misplaced Pages Continue

2208-409: The vapor pressure of water is much less than atmospheric pressure, the condenser generally works under vacuum . Thus leaks of non-condensible air into the closed loop must be prevented. Typically the cooling water causes the steam to condense at a temperature of about 25 °C (77 °F) and that creates an absolute pressure in the condenser of about 2–7  kPa (0.59–2.07  inHg ), i.e.

2277-531: The 18th century, with notable improvements being made by James Watt . When the first commercially developed central electrical power stations were established in 1882 at Pearl Street Station in New York and Holborn Viaduct power station in London, reciprocating steam engines were used. The development of the steam turbine in 1884 provided larger and more efficient machine designs for central generating stations. By 1892

2346-743: The 20th century . Shipboard power stations usually directly couple the turbine to the ship's propellers through gearboxes. Power stations in such ships also provide steam to smaller turbines driving electric generators to supply electricity. Nuclear marine propulsion is, with few exceptions, used only in naval vessels. There have been many turbo-electric ships in which a steam-driven turbine drives an electric generator which powers an electric motor for propulsion . Cogeneration plants, often called combined heat and power (CHP) facilities, produce both electric power and heat for process heat or space heating, such as steam and hot water. The reciprocating steam engine has been used to produce mechanical power since

2415-525: The Board was supplying the whole peninsula with electricity, replacing the Perak River Hydro Electric Power company (PRHEP) and its subsidiary Kinta Electrical Distribution Co. Ltd (KED) in 1982, Penang Municipality in 1976, and areas supplied by Huttenbach Ltd in 1964, which included Alor Setar, Sungai Petani, Kulim, Lunas, Padang Serai, Telok Anson, Langkap, Tampin and Kuala Pilah. On 4 May 1988, Prime Minister Mahathir Mohamad announced

2484-787: The East Malaysian state of Sabah through Sabah Electricity . TNB's core activities are in the generation , transmission and distribution of electricity. Other activities include repairing, testing and maintaining power plants , providing engineering, procurement and construction services for power plants related products, assembling and manufacturing high voltage switchgears, coal mining and trading. Operations are carried out in Malaysia, (except Sarawak), United Kingdom , Ireland , Turkey , Kuwait , Saudi Arabia , Pakistan , India , Cambodia , and Australia . TNB also offers higher education through its university, Universiti Tenaga Nasional (Uniten). TNB also exports electricity to Singapore via

2553-780: The Nation. Since 2013, the company has adopt new corporate slogan campaign, 'Better. Brighter'. Bursa Malaysia Bursa Malaysia is the stock exchange in Malaysia . It is one of the largest bourses in ASEAN . It is based in Kuala Lumpur and was previously known as the Kuala Lumpur Stock Exchange (KLSE). It provides full integration of transactions, offering a wide range of currency exchange and related services, including trading, settlement, clearing and savings services. Along with

2622-632: The Stockbrokers' Association of Malaya, but it still did not trade public shares. In 1960, the Malayan Stock Exchange was formed and public trading started on 9 May that year. In 1961, a board system was introduced in two trading places, one in Singapore and one in Kuala Lumpur. The two trading rooms were linked by direct telephone lines into a single market with the same stocks and shares listed at

2691-554: The United States are about 90 percent efficient in converting the energy of falling water into electricity while the efficiency of a wind turbine is limited by Betz's law , to about 59.3%, and actual wind turbines show lower efficiency. The direct cost of electric energy produced by a thermal power station is the result of cost of fuel, capital cost for the plant, operator labour, maintenance, and such factors as ash handling and disposal. Indirect social or environmental costs, such as

2760-486: The air in the air preheater for better economy. Secondary air is mixed with the coal/primary air flow in the burners. The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining slightly below atmospheric pressure in the furnace to avoid leakage of combustion products from the boiler casing. A steam turbine generator consists of a series of steam turbines interconnected to each other and

2829-400: The atmosphere, or once-through cooling (OTC) water from a river, lake or ocean. In the United States, about two-thirds of power plants use OTC systems, which often have significant adverse environmental impacts. The impacts include thermal pollution and killing large numbers of fish and other aquatic species at cooling water intakes . The heat absorbed by the circulating cooling water in

Tenaga Nasional - Misplaced Pages Continue

2898-433: The boiler, where the steam is reheated in special reheat pendant tubes back to 1,000 °F (540 °C). The hot reheat steam is conducted to the intermediate-pressure turbine, where it falls in both temperature and pressure and exits directly to the long-bladed low-pressure turbines and finally exits to the condenser. The generator, typically about 30 feet (9 m) long and 12 feet (3.7 m) in diameter, contains

2967-443: The condenser tubes must also be removed to maintain the ability of the water to cool as it circulates. This is done by pumping the warm water from the condenser through either natural draft, forced draft or induced draft cooling towers (as seen in the adjacent image) that reduce the temperature of the water by evaporation, by about 11 to 17 °C (52 to 63 °F)—expelling waste heat to the atmosphere. The circulation flow rate of

3036-519: The cooling water in a 500 MW unit is about 14.2 m /s (500 ft /s or 225,000 US gal/min) at full load. The condenser tubes are typically made stainless steel or other alloys to resist corrosion from either side. Nevertheless, they may become internally fouled during operation by bacteria or algae in the cooling water or by mineral scaling, all of which inhibit heat transfer and reduce thermodynamic efficiency . Many plants include an automatic cleaning system that circulates sponge rubber balls through

3105-411: The distribution network operations and electricity retail operations of TNB. The division plans, constructs, operates, performs repairs and maintenance and manages the assets of the 33 kV, 22 kV, 11 kV, 6.6 kV and 415/240 volt in the Peninsular Malaysia distribution network. Sabah Electricity provides the same function in the state of Sabah . To conduct its electricity retailing business, it operates

3174-411: The economic value of environmental impacts, or environmental and health effects of the complete fuel cycle and plant decommissioning, are not usually assigned to generation costs for thermal stations in utility practice, but may form part of an environmental impact assessment. Those indirect costs belong to the broader concept of externalities . In the nuclear plant field, steam generator refers to

3243-472: The efficiency of the cycle is reduced (resulting in more carbon dioxide per megawatt-hour of electricity). From the bottom of the condenser, powerful condensate pumps recycle the condensed steam (water) back to the water/steam cycle. Power station furnaces may have a reheater section containing tubes heated by hot flue gases outside the tubes. Exhaust steam from the high-pressure turbine is passed through these heated tubes to collect more energy before driving

3312-535: The first nuclear power plant in Malaysia by 2025 if the government decides to include nuclear as an acceptable energy option. In 2021, Tenaga became part owner of the repowered Blyth Offshore Wind Farm in England. The TNB Group has a complete power supply system, including the National Grid which is energised at 132, 275 and 500 kilovolt (kV), with its tallest electricity pylon in Malaysia and Southeast Asia being

3381-421: The four corners, or along one wall, or two opposite walls, and it is ignited to rapidly burn, forming a large fireball at the center. The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. The water circulation rate in the boiler is three to four times the throughput. As the water in the boiler circulates it absorbs heat and changes into steam. It

3450-403: The gas turbines is used to make superheated steam that is then used in a conventional water-steam generation cycle, as described in the gas turbine combined-cycle plants section. The water enters the boiler through a section in the convection pass called the economizer . From the economizer it passes to the steam drum and from there it goes through downcomers to inlet headers at the bottom of

3519-785: The government's decision on a policy of privatisation . Two pieces of legislation were passed to replace the Electricity Act and to provide for the establishment of a new corporation. Tenaga Nasional Berhad (TNB) was formed in 1990 by the Electricity Supply Successor Company Act 1990, to succeed the National Electricity Board (NEB) of the States of Malaya. The board of directors is responsible for governing and setting policy for TNB, consisting of 13 members: 6 independent non-executive directors, 5 non-independent non-executive directors, an executive director,

SECTION 50

#1732859499529

3588-611: The highest known heat transfer coefficient of any gas and for its low viscosity , which reduces windage losses. This system requires special handling during startup, with air in the chamber first displaced by carbon dioxide before filling with hydrogen. This ensures that a highly explosive hydrogen– oxygen environment is not created. The power grid frequency is 60 Hz across North America and 50 Hz in Europe , Oceania , Asia ( Korea and parts of Japan are notable exceptions), and parts of Africa . The desired frequency affects

3657-428: The intermediate and then low-pressure turbines. External fans are provided to give sufficient air for combustion. The Primary air fan takes air from the atmosphere and, first warms the air in the air preheater for better economy. Primary air then passes through the coal pulverizers, and carries the coal dust to the burners for injection into the furnace. The Secondary air fan takes air from the atmosphere and, first warms

3726-450: The local economy by creating jobs in construction, maintenance, and fuel extraction industries. On the other hand, burning of fossil fuels releases greenhouse gases (contributing to climate change) and air pollutants such as sulfur oxides and nitrogen oxides (leading to acid rain and respiratory diseases). Carbon capture and storage (CCS) technology can reduce the greenhouse gas emissions of fossil-fuel-based thermal power stations, however it

3795-842: The low-pressure exhaust from the turbine enters a steam condenser where it is cooled to produce hot condensate which is recycled to the heating process to generate even more high pressure steam. The design of thermal power stations depends on the intended energy source. In addition to fossil and nuclear fuel , some stations use geothermal power , solar energy , biofuels , and waste incineration . Certain thermal power stations are also designed to produce heat for industrial purposes, provide district heating , or desalinate water , in addition to generating electrical power. Emerging technologies such as supercritical and ultra-supercritical thermal power stations operate at higher temperatures and pressures for increased efficiency and reduced emissions. Cogeneration or CHP (Combined Heat and Power) technology,

3864-417: The middle of this series of feedwater heaters, and before the second stage of pressurization, the condensate plus the makeup water flows through a deaerator that removes dissolved air from the water, further purifying and reducing its corrosiveness. The water may be dosed following this point with hydrazine , a chemical that removes the remaining oxygen in the water to below 5 parts per billion (ppb). It

3933-444: The nuclear fuel. This, in turn, limits their thermodynamic efficiency to 30–32%. Some advanced reactor designs being studied, such as the very-high-temperature reactor , Advanced Gas-cooled Reactor , and supercritical water reactor , would operate at temperatures and pressures similar to current coal plants, producing comparable thermodynamic efficiency. The energy of a thermal power station not utilized in power production must leave

4002-630: The plant in the form of heat to the environment. This waste heat can go through a condenser and be disposed of with cooling water or in cooling towers . If the waste heat is instead used for district heating , it is called cogeneration . An important class of thermal power station is that associated with desalination facilities; these are typically found in desert countries with large supplies of natural gas , and in these plants freshwater production and electricity are equally important co-products. Other types of power stations are subject to different efficiency limitations. Most hydropower stations in

4071-405: The range of 0.3–1.0 microsiemens per centimeter. The makeup water in a 500 MWe plant amounts to perhaps 120 US gallons per minute (7.6 L/s) to replace water drawn off from the boiler drums for water purity management, and to also offset the small losses from steam leaks in the system. The feed water cycle begins with condensate water being pumped out of the condenser after traveling through

4140-507: The remaining energy. The entire rotating mass may be over 200 metric tons and 100 feet (30 m) long. It is so heavy that it must be kept turning slowly even when shut down (at 3 rpm ) so that the shaft will not bow even slightly and become unbalanced. This is so important that it is one of only six functions of blackout emergency power batteries on site. (The other five being emergency lighting , communication , station alarms, generator hydrogen seal system, and turbogenerator lube oil.) For

4209-686: The simultaneous production of electricity and useful heat from the same fuel source, improves the overall efficiency by using waste heat for heating purposes. Older, less efficient thermal power stations are being decommissioned or adapted to use cleaner and renewable energy sources. Thermal power stations produce 70% of the world's electricity. They often provide reliable, stable, and continuous baseload power supply essential for economic growth. They ensure energy security by maintaining grid stability, especially in regions where they complement intermittent renewable energy sources dependent on weather conditions. The operation of thermal power stations contributes to

SECTION 60

#1732859499529

4278-460: The steam from the exhaust of the turbine into liquid to allow it to be pumped. If the condenser can be made cooler, the pressure of the exhaust steam is reduced and efficiency of the cycle increases. The surface condenser is a shell and tube heat exchanger in which cooling water is circulated through the tubes. The exhaust steam from the low-pressure turbine enters the shell, where it is cooled and converted to condensate (water) by flowing over

4347-420: The steam turbines. The condensate flow rate at full load in a 500 MW plant is about 6,000 US gallons per minute (400 L/s). The water is usually pressurized in two stages, and typically flows through a series of six or seven intermediate feed water heaters, heated up at each point with steam extracted from an appropriate extraction connection on the turbines and gaining temperature at each stage. Typically, in

4416-433: The temperature beyond the turbine limits during winter, causing excessive condensation in the turbine). Plants operating in hot climates may have to reduce output if their source of condenser cooling water becomes warmer; unfortunately this usually coincides with periods of high electrical demand for air conditioning . The condenser generally uses either circulating cooling water from a cooling tower to reject waste heat to

4485-455: The tubes as shown in the adjacent diagram. Such condensers use steam ejectors or rotary motor -driven exhausts for continuous removal of air and gases from the steam side to maintain vacuum . For best efficiency, the temperature in the condenser must be kept as low as practical in order to achieve the lowest possible pressure in the condensing steam. Since the condenser temperature can almost always be kept significantly below 100 °C where

4554-452: The tubes to scrub them clean without the need to take the system off-line. The cooling water used to condense the steam in the condenser returns to its source without having been changed other than having been warmed. If the water returns to a local water body (rather than a circulating cooling tower), it is often tempered with cool 'raw' water to prevent thermal shock when discharged into that body of water. Another form of condensing system

4623-432: The turbine was considered a better 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. After about 1905, turbines entirely replaced reciprocating engines in almost all large central power stations. The largest reciprocating engine-generator sets ever built were completed in 1901 for

4692-400: The water walls. From these headers the water rises through the water walls of the furnace where some of it is turned into steam and the mixture of water and steam then re-enters the steam drum. This process may be driven purely by natural circulation (because the water is the downcomers is denser than the water/steam mixture in the water walls) or assisted by pumps. In the steam drum, the water

4761-620: Was established and came into operation on 1 September 1949. The Board was to become heir to three major projects considered by the Electricity Department following its re-establishment in April 1946 which were the Connaught Bridge Power Station , Cameron Highlands Hydroelectric Project and the development of a National Grid . CEB eventually became the owner of 34 power stations with a generation capacity of 39.88 MW, including

#528471