加装低压省煤器对汽轮机相对内效率的影响

Effect of Low Pressure Economizer on Relatively Internal Efficiency of Steam Turbine

摘要:

加装低压省煤器是火电厂节能减排的重要措施之一,以350 MW汽轮发电机组为对象,分析了该系统加装低压省煤器对汽轮机热经济性指标的影响.低压省煤器加入热力系统分串联和并联2种模式,降低烟气温度25 ℃,若汽轮机抽汽点蒸汽参数按等熵规律变工况,其串联和并联2种模式对汽轮机相对内效率的影响分别为-0.012 9%和-0.007 2%,使循环热效率分别增大0.606 2%和0.656 7%,相应的汽轮机绝对内效率分别增大0.615 2%和0.691 8%;若汽轮机抽汽点蒸汽参数按照等温规律变工况，其串联和并联2种模式对汽轮机相对内效率的影响分别为0.020 6%和0.042 7%,使循环热效率分别增大0.602 5%和0.651 4%,相应的汽轮机绝对内效率分别增大0.645 2%和0.736 5%.

Abstract:

Assembling low pressure economizer is one of the important measures for energy-saving and emission reduction in power plants.An analysis is made of the 350 MW Unit installed with low pressure economizer,which consists of two linking models,series and parallel way.As exhaust gas temperature is lowered by 25 ℃,and steam state changes according to isentropic process in extraction hole,the relative internal efficiency decreases by 0.012 9% in series and 0.007 2% in parallel,and the cycle efficiency increases by 0.606 2% and 0.656 7%,respectively,and absolute internal efficiency 0.615 2% and 0.691 8%,respectively.As the extraction hole steam state is in isothermal process,the relative internal efficiency relative increases by 0.020 6% in series and 0.042 7% in parallel;cycle efficiency increases by 0.602 5% and 0.651 4% respectively,and absolute internal efficiency by 0.645 2% and 0.736 5%,respectively.