620℃超超临界煤电机组能耗指标动态计算与分析

Dynamic Calculation and Analysis on Technical-Economic Index of a 620℃ Ultra-Supercritical Coal-Fired Power Generation Unit

为分析再热汽温620℃超超临界机组的日常连续运行实际能耗,以某电厂设计蒸汽参数为28 MPa/600℃/620℃的1 000 MW超超临界湿冷机组为研究对象,基于机组运行大数据,开展了长周期的能耗指标动态计算与分析。研究表明:额定负荷下,锅炉热效率达到了保证值,汽轮机组热耗率比设计值高32 kJ/(kW·h),厂用电率优于设计值,修正后的机组供电标准煤耗率基本达到设计值;随着负荷率的降低,锅炉热效率降低,汽轮机组热耗率升高,厂用电率升高,机组发、供电标准煤耗率增加,机组发、供电效率降低;当负荷率由100%降低至50%时,修正后锅炉热效率降低1.09%,汽轮机组热耗率升高380 kJ/(kW·h),厂用电率升高1.84%,机组供电标准煤耗率增加23.63 g/(kW·h),机组供电效率降低3.53%。

In order to analyze actual energy consumption under daily continuous operation of ultra-supercritical power generation units with reheat steam temperature of 620℃,with a 620℃ ultra-supercritical coal-fired power generation unit as the research object,long-period dynamic calculation and analysis were conducted based on the operational big data.Results showed that,under rated load,boiler efficiency has reached the design value,while steam turbine heat consumption rate is higher than the design value,at 32 kJ/(kW·h),auxiliary power ratio is lower and the standard coal consumption rate after correction basically reaches the design value.With the decrease of load rate,boiler efficiency decreases,steam turbine heat consumption rate increases,auxiliary power ratio increases,standard coal consumption rate increases,and unit efficiency decreases.When the load rate reduces from 100% to 50%,boiler efficiency after correction has a decrease of 1.09 percentage points,heat consumption rate of steam turbine after correction has a increase of 380 kJ/(kW·h),auxiliary power ratio has a decrease of 1.84 percentage points,the standard coal consumption rate after correction has a increase of 23.63 g/(kW·h),and the unit efficiency after correction has a decrease of 3.53 percentage points.