Source: Wang Zhiyun, et al. Brother Bao
For a 300 MW steam turbine unit with this heating method, the regulation characteristics of the medium-pressure valve were studied by experiments under the conditions of electric load of 250 MW and heating and steam extraction capacity of 52.20~53.94 t/h. When the minimum opening of the medium pressure valve is 24.97%, the inlet steam pressure of the medium pressure cylinder is 3.44 MPa, and the pressure of the heating exhaust mother pipe is 3.13 MPa, the maximum pressure ratio of the high-pressure cylinder decreases with the decrease of the opening of the medium-pressure control door, the maximum value is 3.13, the minimum value is 2.65, and the exhaust temperature of the high-pressure cylinder increases with the decrease of the opening of the medium-pressure regulating door, and the maximum value is 331.76 °C, the lowest value is 312.97 °C, with the decrease of the opening of the medium pressure control door, the efficiency of the medium pressure cylinder gradually decreases, from 93.37% to 84.78%; with the decrease of the opening of the medium pressure adjustment door, the steam enthalpy drop of the high-pressure cylinder and the medium-pressure cylinder does not change much, but the first stage of the pumping pressure and the exhaust pressure of the high-pressure cylinder increase, the flow rate of the high and medium pressure cylinders decreases, and the power of the high and medium pressure cylinders decreases, resulting in a decrease of 9.79 MW of the electric load of the unit.
