Boiler steam system

Soda systemg2CBoiler Burner

During the whole process of steam generation, the working medium goes through three heating stages in the boiler.First, the boiler feed water is heated to saturated water, then to saturated steam and steam with a certain overheating temperature.These three processes are usually performed in the economizer, the water wall, and the heating surface of the superheater.g2CBoiler Burner

When the boiler is in operation, after water treatment and deoxygenation, the feed water will flow through the high-pressure heater after being pressurized by the feed water pump and enter the inlet header of economizer.In general, the water is heated to saturated water in a economizer.But actually different boilers have different conditions.For example, the use of cast iron economizer low pressure small industrial boiler, generally will not heat the feed water as saturated water;For medium pressure boiler, the working medium at the outlet header of economizer may be required to have up to saturated steam content.For boilers above subcritical pressure, it may be required that the working medium of economizer outlet header is unsaturated water with a large enthalpy deficit.The working medium flows from the economizer outlet header into the drum through a catheter. In this process, the working medium flows under the forced action of the feed pump.After entering the drum, the working medium flows into the lower header along the descending pipe, and is then distributed to each water wall pipe (i.e. the ascending pipe) into the furnace to be heated, and forms the soda mixture to return to the drum.This flow is maintained by the density difference between the soda mixture in the descending tube and the ascending tube.After the soda mixture is returned to the drum, it is separated by the steam separation device in the drum. The steam is concentrated in the steam space of the upper half of the drum, and the water enters the water space of the lower half of the drum.For high pressure boilers, the water in each cycle usually evaporates into saturated steam.g2CBoiler Burner

After the saturated steam in the drum is separated, it is introduced into the superheater through a catheter for overheating.When superheated steam is heated to the rated temperature, it is sent to the turbine for work.The boiler shown in the picture has a reheater in its convection flue.The steam from the outlet of the high-pressure cylinder of the steam turbine is diverted to a reheater for reheating.When the required temperature is reached, the reheated steam is reintroduced into the steam turbine's middle and low pressure cylinders through the reheated steam outlet for expansion work.g2CBoiler Burner