: The main production process of thermal power plants (taking coal-fired power plants as an example) is: the raw coal stored in the coal storage farm (or coal storage tank) is sent from coal storage yard to raw coal hopper from boiler by coal transport equipment, then sent to coal crusher by coal feeder to be crushed into pulverized coal. The pulverized coal is sent to the separator for separation, and the qualified pulverized coal is sent to the pulverized coal bin for storage (storage boiler). The pulverized coal in the pulverized coal bunker is sent to the burner of the boiler body from the pulverizer and is pulverized from the burner into the furnace for combustion (direct blown boilers separate the pulverized coal and send it directly to the furnace) . Burning pulverized coal releases a large amount of energythermal power to heat water in water-cooled wall tubes around the furnace and form a steam-water mixture. The mixture is separated by the steam-water separator in the boiler drum. The separated water is sent to the water-cooled wall tube through the downspout for additional heating. The separated steam is sent to the superheater and heated into superheated steam which meets the. specified temperature and pressure. Through the pipe Sent to the steam turbine for work. The superheated steam works in the steam turbine to drive the steam turbine to rotate, and the steam turbine drives the generator to produce electricity. The three-phase alternating current generated by the generator passes through the wire at the end of the generator and is conducted. to the electrical network via the transformer. The superheated steam which has finished its work in the turbine is cooled by the condenser into condensed water. The water coolsnsée is sent to the low pressure heater for heating via the condensing pump, then sent to the deaerator for deoxygenation, then sent to the high pressure heater for heating via the feed water pump, sent to the boiler to continue the thermal cycle. The reheating unit adopts intermediate reheating process, that is, the steam after the high pressure cylinder of the steam turbine has done its work is sent to the boiler heater to be reheated, so that the steam temperature is raised to a certain (or initial steam) and then sent to the medium pressure steam turbine. The cylinder continues to operate.
The production process of thermal power generation is as follows:
The thermal power plant consists of three main equipment: boilers, steam turbines, generators and corresponding auxiliary equipment, which are generated par pipelines or lines are connected to form the main production system, namely the combustion system, the steam and water system and the electrical system. The production process is briefly described as follows.
1. Combustion system (including boiler combustion part and coal transportation, ash removal and flue gas emission systems, etc.).
The coal is transported to the coal hopper of the boiler workshop by a belt, enters the coal crusher and is crushed into pulverized coal, then injected into the furnace for combustion with air preheated by the preheater, converting the chemical energy of the coal. The combustion gases are converted into thermal energy. Once the dust is removed by the dust collector, the combustion gases are extracted by the induced draft fan and discharged into the atmosphere through the large chimney. Slag and ashes endes at the bottom of the dust collector are evacuated to the ash park by the slag pump.
2． Steam and water system (including steam and water circulation and water treatment system, cooling water system, etc. consisting of boiler, steam turbine , a condenser and a feed water pump, etc.).
Water is heated in the boiler and evaporates into steam, which is then heated by the heater to become superheated steam with a specified pressure and temperature, then sent to the steam turbine via a pipeline. In the steam turbine, the steam continues to expand, flows at high speed, impacts the steam turbine rotor, rotates at the rated speed (3000 rpm), converts thermal energy into mechanical energy and drives the coaxial steam generator. turbine to produce electricity.
During the expansion process, the pressure and temperature of the vfear continues to decrease. Steam is discharged from the lower part of the turbine after work. The spent steam is called spent steam and is discharged into the condenser. In the condenser, the exhaust steam from the steam turbine is cooled by the cooling water and condensed into water. The condensed water in the lower part of the condenser is boosted by the condensate pump and then enters the low pressure heater and deaerator to increase the water temperature and remove oxygen from the water (to prevent corrosion of the oven tubes, etc.). The water is further boosted by the feed water pump and then enters the high pressure. The heater returns to the boiler to complete the water-steam-water cycle. The condensate water after the feed water pump is called feed water.
There is always some loss of steam and condensate in the steam-water system during the circulation process. Consequentlyuent, chemically treated water must be continually replenished with water. The feed water enters the deaerator and is driven into the boiler with the condensate water by the feed water pump.
3． Electrical systems (including generators, excitation systems, power plant electrical systems and booster substations, etc.).
The voltage and current across the generator vary depending on its capacity. The voltage is usually between 10 and 20 kV, and the current can reach thousands of amps at 20 kA. Therefore, the electricity generated by the generator is usually increased in voltage by the main transformer and then sent to the grid via high-voltage electrical equipment and transmission lines in the substation. A very small amount of electricity, after voltage reduction via the factory transformer, is supplied to various auxiliary equipmentsuch as fans, water pumps and factory lighting through factory power distribution devices and cables.
:The thermal power generation process is a process that uses chemical energy generated when combustible materials (such as coal) are burned to convert it into electrical energy. According to their functions, they can be divided into two categories, namely vapor condensing type and thermoelectric type. The former only provides electrical energy to users, while thermoelectricity not only provides electrical energy to users, but also provides thermal energy such as steam and hot water to users, which called “cogeneration of heat and electricity”. Thermal power plants have different capacities and different specific shapes, but their production processes are similar. The image aboveessus is a schematic diagram of the production process of steam condensing type and coal type.
Thermal power generation process from Baidu Encyclopedia