What is the method of steam pressure control in boiler drum?

Boiler steam pressure control refers to maintaining the steam pressure of boiler drum by adjusting the fuel control system. Its basic task is to adapt the heat provided by fuel combustion to the steam load of boiler drum. At the same time, it is necessary to ensure the safe and economic operation of boiler drum and meet the requirements of environmental protection. As another main parameter of boiler combustion control, the steam pressure of the boiler drum is too high, which will increase the stress of each pressure-bearing component, while the economy of the unit cannot be guaranteed if it is too low.

Boiler combustion process control system generally includes three sub-control systems, namely fuel control system, air supply control system and induced air control system. The fuel control system maintains the stability of steam pressure in boiler drum by adjusting the amount of fuel entering the furnace. The air supply control system maintains the air quantity needed for fuel combustion and the economy of combustion process by adjusting the air supply quantity into the furnace. The induced air control system balances the air supply and induced air volume by adjusting the induced air volume and keeps the boiler drum pressure stable.

When the boiler is in operation, steam continuously enters the steam space of the drum, on the other hand, steam continuously leaves the drum and is sent to external users. When the amount of steam generated is greater than the external demand, the steam pressure of the boiler drum will rise, and vice versa, the steam pressure of the boiler drum will decrease. Therefore, controlling the steam pressure of boiler drum is basically the adjustment of evaporation.