Basic composition of industrial boilers
The main components and functions of the boiler are as follows:
1. Furnace to ensure that the fuel is burned out and the temperature of the flue gas at the outlet is cooled to a value where the convection heating surface can work safely.
2. The combustion equipment sends the fuel and the air required for combustion to the furnace and makes the fuel ignite stably and burn well.
3. The boiler drum is the closure of each heating surface of the natural circulation boiler, which connects the heating surfaces of the boiler together and forms a water circulation loop with the water wall and downcomer. Steam and water are stored in the drum, which can adapt to load changes. There are steam and water separation devices inside to ensure the quality of steam and water. The once-through boiler has no drum.
4. Water-cooled wall is the main radiation heating surface of the boiler and absorbs the radiant heat of the furnace to heat the working medium. It is also used to protect the furnace wall, and the thinning part of the rear water wall tube is called the slag tube to prevent the superheater from slagging
5. Superheater Heat the saturated steam to the rated superheated steam temperature. Steam boilers and hot water boilers producing saturated steam have no superheaters.
6 Reheater Heat the exhaust steam from the high-pressure cylinder of the steam engine to a higher temperature, and then send it to the medium-pressure cylinder of the steam turbine to expand and do work. It is used in large power plant boilers to improve the thermal efficiency of power plants.
7. The economizer uses the heat of the flue gas at the tail of the boiler to heat the feed water to reduce the temperature of the exhaust gas and save fuel.
8. Air preheater Heat the air used for combustion to enhance ignition and combustion; absorb waste heat of flue gas, reduce exhaust gas temperature and improve boiler efficiency; provide dry blasting agent for pulverized coal boiler pulverizing system.
9. Furnace wall It is the protective casing of the boiler, which plays the role of sealing and heat preservation. Heavy furnace walls in small boilers also serve to support boiler components.
10. Frame Support and fix the various parts of the boiler and maintain their relative positions.
Boiler auxiliary equipment and its function
1. Fuel supply equipment storage and transportation of fuel.
2. Coal grinding and pulverizing equipment: Coal is ground into coal powder and input into boiler combustion equipment for burning coal powder.
3. Air supply equipment The air is sent to the air preheater by the blower to be heated and then sent to the furnace door and coal grinding device for use.
4. Induced air equipment The flue gas discharged from the boiler is sent to the atmosphere by the induced draft fan and the bacon.
5. Water supply equipment The feed water treated by the water treatment equipment is sent to the boiler by the feed water pump.
6. Deslag removal equipment removes ash and slag from the boiler and transports it away.
7. Dust removal equipment Remove fly ash in boiler flue gas and improve environmental sanitation.
8. Automatic control equipment automatic detection, program control, automatic protection and automatic adjustment.
9. Safety accessories Safety valves, pressure gauges, water level gauges, high water level alarms, sewage devices, steam and water pipes, instrument valves.