Thermal power plants are abbreviated as thermal power plants, which are factories that use combustibles (such as coal) as fuel to produce electricity. Its basic production process is: when the fuel is burning, water is heated to generate steam, which converts the chemical energy of the fuel into heat energy. The steam pressure drives the steam turbine to rotate, and the heat energy is converted into mechanical energy. Then the steam turbine drives the generator to rotate and converts the mechanical energy into electrical energy.
The prime mover is usually a steam engine or a gas turbine. In some smaller power stations, internal combustion engines may also be used. They all generate electricity by using the pressure drop in the process of high-temperature, high-pressure steam or gas passing through a turbine into low-pressure air or condensate.
Composition and equipment
A modern thermal power plant is a large and complex factory that produces electricity and heat.
It consists of the following five systems: ① Fuel system. ② Combustion system. ③Soda system. ④ Electrical system. ⑤ Control system.
In the above system, the most important equipment is boiler, steam turbine and power generation
They are installed in the main building of the power plant. Main transformers and power distribution devices are generally installed in independent buildings or outdoors. Other auxiliary equipment such as water supply system, water supply equipment, water treatment equipment, dust removal equipment, fuel storage and transportation equipment, etc., are installed in the main building, and Others are installed in auxiliary buildings or in open spaces. The basic production process of a thermal power plant is that the fuel is burned in the boiler to release its heat and transfer it to the water in the boiler to produce high-temperature and high-pressure steam; the steam is converted into rotational power through the steam turbine to drive the generator to output electrical energy.
The production process of a thermal power plant
A thermal power plant is composed of three main equipments: boilers, steam turbines, generators and corresponding auxiliary equipment, which are connected by pipelines or lines to form the main production system, namely the combustion system, the steam and water system and the electrical system.
The main equipment of the combustion system includes: coal conveyor, coal mill, boiler, dust collector, induced draft fan, air preheater. The main equipment of the steam-water system includes: steam turbine, condenser, heater, condensate pump, feed water pump, circulating water pump, and water tank. The main equipment of the electrical system includes: generators, transformers, relays, power distribution cabinets, and control switches.
The working equipment of thermal power plants is more complicated, and at the same time it is required that these equipments must ensure good operation.
Daily maintenance is very important.
In order to improve the volumetric efficiency and isothermal compression efficiency of the vacuum pump within the entire suction pressure range, the 2BE1 series water ring vacuum pump adopts an automatically adjustable gas outlet and a reasonably-shaped exhaust distribution plate. Because there is a flexible polytetrafluoroethylene plate outside the exhaust distribution plate to cover the discharge port of the distribution plate when the gas pressure in the compression chamber of the impeller is lower than the pressure at the gas discharge port. When the impeller continues to rotate until the gas pressure in the compression chamber of the impeller is equal to the outside, the PTFE plate is opened to discharge the gas. In this way, the sucked gas must be discharged at a constant pressure, avoiding the power loss caused by gas over-compression. In addition, the pump also adopts a double-sided axial suction and exhaust structure. The impeller and the main shaft are thermally fitted. The shape of the impeller is that the middle of the hub is higher than the ends, which strengthens the mechanical strength of the blades. In order to prevent the packing from wearing to the shaft, a chrome steel protective sleeve is used. The shaft sealing device can either use internal water supply or external water supply. EVP water ring pump vacuum pump adopts internal water supply mode, that is, the shaft seal water is directly taken from the vacuum pump water ring, without any external pipelines and equipment. Regarding the vulnerable parts of the vacuum pump, Siemens believes that it is not necessary to replace the vulnerable parts frequently. Only the shaft seal packing is generally required to be replaced once a year due to wear. In addition, the main components of the EVP water ring vacuum pump, such as the impeller, pump body, front and rear distribution plates, front and rear side covers, can be selected from a variety of materials to make the vacuum pump resistant to corrosion.
Copyright: Shanghai EVP Vacuum Technology Co., LTD
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