二次再热机组不同抽汽过热度热能利用方案性能比较

Performance Comparison of Thermal Energy Utilization Schemes of the Extractions Superheating Degree for a Double Reheat Coal-fired Power Plant

针对二次再热机组回热抽汽过热度偏高的问题,对机组加装两级外置式蒸汽冷却器(方案1)和集成回热式汽轮机(方案2)这两种降低抽汽过热度的方案进行比较研究。对变工况下两种方案中各级抽汽的过热度进行对比分析,并基于单耗分析理论计算和分析了两种方案机组的能耗分布。结果表明:方案2可以有效降低多级抽汽的过热度;在不同负荷下,方案2机组的单耗均低于方案1,THA工况时机组单耗低至256.095 g/kWh。

In view of the problem that the superheating degrees of regenerative steam extractions are too high in double reheat unit,the comparison study on two system schemes between double reheat unit equipped with two outer steam coolers and integrated with regenerative steam turbine in order to reduce the regenerative extraction superheating degree is conducted.And their regenerative extraction superheating degrees and energy consumption contributions are compared and analyzed under off-design conditions.The research results show that scheme 2 could effectively reduce multistage regenerative extractions superheating degrees,and the fuel specific consumption of scheme 2 is lower than that of scheme 1 in any working condition,especially at THA condition it goes down to 256.095 g/kWh.