A boiler refers to a closed device that uses various fuels, electricity or other energy to heat the contained liquid to certain parameters and withstand a certain pressure. Its scope of application is defined as a pressure steam boiler with a larger or larger volume. equal to 30L; outlet water pressure is higher than hot water boilers under pressure equal to 0.1 MPa (gauge pressure) and rated power greater than or equal to 0.1 MW of organic heat transfer boilers (heating boilers are special equipment as long as they meet the above requirements; Boilers are classified as follows: A. Power plant boilers are classified by use: used for electricity generation, mainly large capacity and high parameter boilers and furnaces. Combustion, high efficiency, the output working fluid is voverheated fear. Industrial Boilers: Used for industrial production and heating. They are mainly low pressure, low temperature and small capacity boilers. Most of them are firebed combustion, with low thermal efficiency. The output working fluid is an industrial steam boiler. The output working fluid is heat. The water is called a hot water boiler. Marine Tank Device Locomotive Boiler Steam Injection Boiler: Used for steam injection thermal recovery of heavy oil in oil fields. The working fluid produced is usually high pressure wet steam. b. Fire tube boilers are classified according to their structure: flue gases circulate through fire tubes, which are generally boilers of small capacity and low parameters. The oven has a low thermal efficiency, myis has a simple structure, low water quality requirements, and is easy to transport and maintain. Water Tube Boiler: Steam and water flow through tubes, which can be made into boilers with small capacity and low parameters. It can also be transformed into a boiler with large capacity and high parameters. Power plant boilers are usually water tube boilers with high thermal efficiency but poor water quality. Operational level requirements are also higher. vs. Classify by circle. Natural circulation drum boiler, multiple forced circulation drum boiler, low speed circulation boiler, single pipe boiler, combined cycle boiler d. Classified according to the pressure of the working fluid at the boiler outlet. Low pressure boiler: the general pressure is less than 1.275 MPa. Mo boileryenne pressure: the general pressure is 3.825 MPa. High pressure boiler: the general pressure is 9.8 MPa. Ultra high pressure boiler: the general pressure is 13.73 MPa. Subcritical pressure boiler: the general pressure is 16.67 MPa. Supercritical pressure boiler: the general pressure is 22.13 MPae, classified according to the combustion mode. Combustion boiler: mainly used in industrial boilers, including fixed grate boilers and boilers. Composite grate stove, etc. Combustion Chamber Combustion Boiler: Mainly used in power plant boilers to burn liquid fuel and gas. Oil fired boilers and pulverized coal boilers are combustion chamber boilers. Fluidizing Furnace: The air flow sent to the grate is high, causing large coal particles to burn on the grate. The surface of the boiled bedlonnant stirs and burns, and small particles of coal rise with the air. Then burn. Classified by fuel or energy used. Solid fuel boilers: burn solid fuels such as coal; liquid fuel boilers: burn liquid fuels such as heavy fuel oil; gas-fired boilers: burn natural gas and other gaseous fuels; Waste heat boilers: use waste heat from metallurgy, petrochemicals and other industries. heat sources; atomic boilers: use nuclear reactors. The thermal energy released acts as a heat source for the steam generator. Biological organs; waste heat boiler: A boiler that uses trash, bark, liquid waste, and other waste as fuel. Furnaces; other energy boilers: steam generators or water heaters using geothermic, solar and others. g. Classified by slag discharge method. Solid slag boiler, liquid slag boiler h, negative pressure boiler according to the furnace flue gas pressure: the furnace pressure is maintained at negative pressure, it is a coal boiler with blowing machine and induced draft fan. The main type of oven; micro positive pressure boiler: furnace surface pressure 2-5kpa, without induced draft fan, it is easy to suffer from hypoxia. Combustion; I. Classification according to the arrangement of drums The number of drums of the boiler is generally one or two, and the drums can be arranged vertically or horizontally. Modern drum power plant boilers all use a single drum type, and industrial boilers use them. Drum or double drum. j.Classification by furnace type There are many types of boilers, including the U-type iinverted type, tower type, box type, T type, U type and N type. Type, l type, d type, a type, etc. Type d and type a are used in industrial boilers and other boilers. Type A is generally used in power plant boilers. k, classified according to the type of boiler room. Boilers can be located in the open, semi-open, indoors, underground or in caves, and are used for industrial purposes.
1. According to the boiler flue gas flow in the boiler: water tube boiler, furnace shell boiler (fire tube boiler) and hybrid fire tube and water boiler.
2. Place the pot according to the method: vertical pot, horizontal pot.
3. Depending on its use: domestic boilers, industrial boilers, power plant boilers.
4. Depending on the fluid: steam boiler, hot water boiler, sparkling water boiler, calop boilerorganic ortor.
5. According to the installation method: quick installation boiler, assembly boiler, bulk boiler.
6. Depending on the fuel: coal boilers, oil boilers, gas boilers, heat recovery boilers, electric boilers, biomass boilers.
7. According to the key points of water circulation: natural circulation, forced circulation and mixed circulation.
8. Pressure: normal pressure boiler, low pressure boiler, medium pressure boiler, high pressure boiler, ultra high pressure boiler.
9. According to the number of boilers, they are divided into: single-drum boilers and double-drum boilers.
10. Depending on the internal or external combustion part of the boiler: internal combustion boiler, external combustion boiler.
11. According to the flow mode of the working fluid in the evaporation system, it can be divided into circulation boilers nnatural, forced circulation boilers and single-pass boilers.
12. Classification by manufacturing quality: Class A, Class B, Class C, Class D, Class E (depending on manufacturing boiler pressure)
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Working principle of power plant boiler:
The function of the boiler is to convert the chemical energy of fuel into thermal energy and use the heat to The water in the boiler is heated to become superheated steam of sufficient quantity and quality (steam temperature and pressure) to be used by the steam turbine.
At present, boilers of thermal power plants have large capacities, high parameters, complex processes and high levels of mechanization and automation. Therefore, the fuel is mainly coal. Coal is firstd transformed into pulverized coal. before burning, then sent to the boiler for combustion. Releases heat into the oven. Generally speaking, the operating process of a boiler mainly involves fuel combustion, heat transfer, water heating and vaporization, and steam superheating.