Abstract:The biggest problem of post combustion decarburization is the efficiency loss of coalfired power unit. This paper conducted an optimization study on the performance of coalfired power unit with a megaton class post combustion decarburization device. Aimed at increasing the power generation efficiency and supply efficiency, this paper proposed an optimized integration scheme of waste heat utilization, which used depth recovered waste heat of flue gas to preheat boiler air, and used waste heat of flue gas and decarburization to heat condensation water. This study found that the power generation efficiency and supply efficiency of unit with a megaton class post combustion decarburization device declined about 1.78% and 2.98% respectively before optimization, and the main reasons were the generating capacity reduction caused by decarburization regeneration steam extraction and the power consumption of decarburization auxiliary engine. After adopting the optimized integration scheme, power generation efficiency and supply efficiency increased about 0.74% and 0.73% respectively. Based on the optimized integration scheme, the ultimate optimized integration scheme, which was added a superheating cooler for decarburization regeneration steam extraction, the power supply efficiency of unit could be further increased about 0.04%.

Keywords:coal fired power unit, post combustion decarburization, performance optimization, energy consumption