Condensates - condensate pump - shaft plus - bottom plus - degasser - feed water pump - top plus - economizer - steam drum - downcomer - water wall - steam assembly (steam and water separation) - superheater (ceiling, screen, low temperature, final stage superheater, etc.) - turbine high pressure cylinder - high pressure cylinder exhaust - heater (sieve heater, wall heater, final heater, etc.) ——Medium pressure cylinder of steam turbine—Low pressure cylinder of steam turbine—Condenser—Condensed water
It is the main process of boiler steam and water system
Parameters of 300 MW unit Water consumption rate for electricity production How much?
Depending on the flow power and circulation mode and characteristics of the working fluid circulating through the surface of evaporative heating, the water circulation mode of the boiler can be divided into:(1) Natural circulation boiler.
The flow power of the working fluid in the evaporative heating surface of a natural circulation boiler is the density difference between the unheated downflow and the heated upflow. A natural circulation boiler is characterized by a drum, which constitutes a fixed separation point between the evaporative heating surface and the superheater. Its main features are a simple flow pattern, stable hydrodynamic characteristics and reliable operation. It has been widely used in the past in subcritical pressure boilers.
(2) Multiple forced circulation boilers
In the evaporative heating surface of multiple forced circulation boilers, the flow power of the working fluid mainly depends on the difference density between steam and water. mixture and water. It depends on the height of pression of the circulation pump installed downstream of the boiler circulation loop. The circulation pump on the descent constitutes the main difference with natural circulation. Multiple forced circulation boilers are mainly used in subcritical pressure boilers.
(3) Single-pass boiler
The flow power of the working fluid in the evaporative heating surface of the single-pass boiler is the pressure head of the boiler feed water pump. A once-through boiler has no drum and the working fluid in the evaporative heating surface is forced to flow only once. This is the main difference with a natural circulation boiler. The applicable pressure range is very wide, especially for boilers with supercritical parameters.
(4) Compound circulation boiler
The basic characteristic of the ccompound circulation boiler is that a circulation pump is also installed in the middle. The circulation pump only operates at low load, which allows. Part of the water to pass through The recirculation pipeline recirculates into the evaporative heating surface to completely cool the evaporative heating surface and stops working when the load is high, automatically switching to a boiler working state at single pass. Compound cycle boilers are mainly used in boilers with supercritical parameters.
0.6 kg/kWh
The power generation water consumption rate of the unit parameter of 300,000 kilowatts should refer to the rate of water consumption of the unit 300,000 kilowatts of the unit. thermal power plant, excluding hydraulic ash removal, auxiliary equipment cooling water, coal yard water, waterdomestic, etc., but refers to the normal water replenishment of the unit's circulation cooling system and the boiler water replenishment.
Therefore, according to the requirements of 14.1.4 of “Technical Regulation DL 5000-2000 for the design of thermal power plants”, the rate of water consumption for electricity production should not exceed design regulations. However, in the actual production process, based on various production management factors, the water consumption rate for power generation generally evolves towards the first-rate thermal power plant management indicators. According to relevant reports, the water consumption rate of the best water-saving generator per unit of electricity generation can reach 3.Below 6kg/kWh, this is of course related to the type of unit.
Detailed information
Shanghai Heavy MAchinery Factory Co., Ltd. and others are responsible for high and medium pressure cylinder trial production, forming fusion, casting, heat treatment, welding repair, etc. Complete production process, the product was used in a 600MW steam turbine.
After many failures in the development of high-voltage rotors, we finally solved the problem of smelting high-alloy low-silicon and aluminum steels, developed under-slag remelting technology Nitrogen protected electric and successfully tested- produces one high voltage rotor, two rotors for the product in production. Austenitic stainless steel pipe is developed by the special steel branch of Baoshan Iron and Steel Co., Ltd. and participated by Shanghai Boiler Works Co., Ltd. The metallurgical quality of the domestic pipe is equivalent to the level of imported materials, and the durable strength can reach 99 MPa ata high temperature of 650°C.
High temperature and high strength materials for blades and bolts developed by Shanghai Steam Turbine Co., Ltd. and others have been industrialized, with an annual production of around 600 tons. Generators installed with this component in power plants such as Huangdao in Shandong and Suxian in Anhui have been put into normal operation. The high-strength screw material for turbine generators developed by Shanghai Xinmin Heavy Forging Co., Ltd. and others has been used successfully in 1000 MW generators.
According to expert estimates, once the project is completed, the cost of ultra-supercritical units could be reduced by half. The outline of China's "eleventh five-year plan" proposes "to optimize the development of thermal energy by emphasizing large-scale, high-efficiency and environmentally friendly units."ment, and to build large ultra-supercritical power plants and large-scale air-cooled power plants. The “Medium and Long-Term National Science and Technology Development Plan” clearly lists energy as a priority development area and clearly proposes technologies such as high-parameter ultra-supercritical units under the theme “Clean and Efficient Development and Utilization ". Coal, Liquefaction and Polygeneration".
Baidu Encyclopedia-Ultra-supercritical unit