某600 MW超临界空冷燃煤机组深度调峰运行热经济性研究

Study on thermal economy of a 600 MW supercritical air-cooled coal-fired unit for deep peak regulating operation

“双碳”目标下,以新能源为主体的新型电力系统正在加速构建。燃煤火电机组逐渐由电量主体转变为灵活性调峰电源。为探究大容量、高参数机组在深度调峰运行下的主要设备性能和热经济性,以超临界600 MW直接空冷燃煤机组为研究对象,对机组在不同深度调峰负荷下的锅炉、汽轮机性能、厂用电率、运行煤耗情况变化进行了试验研究。结果表明:机组从50%额定负荷深调至40%额定负荷时,运行发、供电煤耗分别增加6.18 g/(kW·h)和9.11 g/(kW·h)。机组从40%额定负荷深调至30%额定负荷时运行发、供电煤耗分别增加31.75 g/(kW·h)和51.33 g/(kW·h)。通过试验对比分析,超临界燃煤空冷机组深度调峰至40%负荷以下时,机组锅炉、汽轮机性能显著下降,机组热耗率、厂用电率和运行供电煤耗显著增加,运行经济性下降明显。在此基础上,分析了机组在不同负荷率和相同负荷率不同深调占比下机组全年平均供电煤耗的变化。当机组负荷率由65%下降至60%、55%负荷率时,机组纯凝运行全年平均供电煤耗分别升高6~7 g/(kW·h)和12~13 g/(kW·h)。在机组负荷率和全年计划电量不变时,当机组深度深调峰负荷占比为10%、20%和30%时,供电煤耗分别升高1~2 g/(kW·h)、2~3 g/(kW·h)和4~5 g/(kW·h)。研究结果可为超临界燃煤空冷机组深度调峰经济性调度和优化运行提供一定参考。

Under the goal of"double carbon",the construction of new power system with new energy as the main body is accelerating.Coal-fired thermal power units gradually change from the main body of electricity to flexible peak regulating power source.To explore the main equipment performance and thermal economy of large-capacity and high-parameter units under deep peak-shaving operation,the paper,which takes supercritical 600MW air-cooled coal-fired uni as an example,analyzes the changes of equipment performance,power consumption rate,operational coal consumption changes under different depth peak load.Through the analysis,When the unit is deeply adjusted from 50%rated load to 40%rated load,the coal consumption of operating generation and power supply increases by 6.18 g/(kW·h)and 9.11 g/(kW·h)respectively.When the load of the unit decreases from 40%rated load to 30%,the coal consumption of operating generation and power supply increases by 31.75g/(kW·h)and 51.33g/(kW·h)respectively.When the depth peaking of the supercritical coal-fired air cooling unit is below 40%load,The performance and operation economy of the main and auxiliary units decreased significantly.On this basis,The change of power supply coal consumption is analyzed under different load rate and different depth ratio of the same load rate.When the load rate of the unit decreases from 65%to 60%and 55%,The annual average power supply coal consumption of the unit during pure condensation operation increases by 6~7 g/(kW·h)and 12~13 g/(kW·h)respectively.When the unit's load rate and annual planned electricity are unchanged,the coal consumption of power supply will increase by 1~2 g/(kW·h),2~3 g/(kW·h)and 4~5 g/(kW·h),respectively,when the unit's depth and depth peak load account for 10%,20%and 30%.The research results can provide some reference for the economic scheduling and optimal operation of supercritical coal air cooling units.