Superheated steam temperature control system is an indispensable part of the unit, its performance and reliability has become an important factor to ensure the safety and economy of the unit. When the superheated stea...Superheated steam temperature control system is an indispensable part of the unit, its performance and reliability has become an important factor to ensure the safety and economy of the unit. When the superheated steam temperature is high, the thermal efficiency of the unit is relatively high. However, when the superheated steam temperature is too high, the metal material of the steam turbine cannot bear it. If the temperature is too low, the efficiency of the unit will be affected. The stability of superheated steam temperature is very important for the safe and economic operation of the unit, so there are higher requirements for its control. In the whole control system of power plant, there are many factors affecting superheated steam temperature, including steam flow disturbance, flue gas flow disturbance and desuperheating water disturbance. The spray desuperheating method is widely used at present, which is beneficial to the safe operation of superheater. Combined with the operation characteristics of the 300MW unit in Diaobingshan power plant, this paper studies and analyzes the superheated steam temperature control strategy, designs a set of control scheme under all working conditions, sets the relevant control parameters, and verifies its effect through simulation. The superheated steam temperature is regulated by two-stage spray desuperheating, and the first stage desuperheating is arranged at the inlet of platen superheater for coarse regulation of steam temperature. The secondary desuperheater is arranged at the inlet of high temperature superheater for fine adjustment. The superheated steam temperature at the outlet of the boiler is maintained at the set value by adjusting the water spray quantity of the primary and secondary superheaters.展开更多
文摘Superheated steam temperature control system is an indispensable part of the unit, its performance and reliability has become an important factor to ensure the safety and economy of the unit. When the superheated steam temperature is high, the thermal efficiency of the unit is relatively high. However, when the superheated steam temperature is too high, the metal material of the steam turbine cannot bear it. If the temperature is too low, the efficiency of the unit will be affected. The stability of superheated steam temperature is very important for the safe and economic operation of the unit, so there are higher requirements for its control. In the whole control system of power plant, there are many factors affecting superheated steam temperature, including steam flow disturbance, flue gas flow disturbance and desuperheating water disturbance. The spray desuperheating method is widely used at present, which is beneficial to the safe operation of superheater. Combined with the operation characteristics of the 300MW unit in Diaobingshan power plant, this paper studies and analyzes the superheated steam temperature control strategy, designs a set of control scheme under all working conditions, sets the relevant control parameters, and verifies its effect through simulation. The superheated steam temperature is regulated by two-stage spray desuperheating, and the first stage desuperheating is arranged at the inlet of platen superheater for coarse regulation of steam temperature. The secondary desuperheater is arranged at the inlet of high temperature superheater for fine adjustment. The superheated steam temperature at the outlet of the boiler is maintained at the set value by adjusting the water spray quantity of the primary and secondary superheaters.
