燃煤电厂超低排放系统能耗关键因素分析

Study on Key Factors Influencing Energy Consumption of Ultra-low Emission System in Coal-fired Power Plant

以东南沿海某660 MW超临界燃煤机组为研究对象,分析其超低排放系统改造前后各环保设备的厂用电率变化、烟道阻力变化、管式GGH(气-气再热器)辅助蒸汽消耗情况,得出:管式GGH的辅助蒸汽消耗使供电煤耗增加1.38 g/kWh,是影响超低排放系统能耗的关键因素。根据管式GGH的运行数据分析了辅助蒸汽消耗的原因是烟气冷却器和再热器的热量不平衡,提出了管式GGH热媒水旁路节能方案,可降低供电煤耗约0.16 g/kWh。

Taking a 660 MW supercritical coal-fired generating unit in the southeast coastal area as a research object,the paper analyzes the changes of environmental equipment in auxiliary power consumption rate,resistance in flue gas and consumption of auxiliary steam in tubular GGH(gas-gas heater)after transformation of the ultra-low emission system.The results showed that auxiliary steam consumption in tubular GGH increased the net coal consumption rate by 1.38 g/kWh,which is a key factor influencing energy consumption of the ultra-low emission system.According to the operation data of tubular GGH,the reason for auxiliary steam consumption is the heat unbalance between the flue gas cooler and reheater.The paper presents an energy-saving scheme of tubular GGH heating medium water bypass,which can reduce the net coal consumption rate by 0.16 g/kWh.