摘要
以NZK660-24.2/566/566机组为例,建立了可减少汽轮机冷源热量、增加发电量的蒸汽-有机工质联合循环发电模型.为了筛选出适合新模型的工质,根据工质性质设定新模型的运行参数,通过采用排汽温度为55.3℃及35℃的原机组及新模型的热经济性指标对9种有机工质的热力性能进行了分析.结果表明:与原机组在排汽温度为35℃时相比,当机组热耗相同时,新模型的发电热效率提高,不同工质的发电效率提高幅度不同,而且空冷面积变小;随着工质临界温度的升高,低压缸2的进口压力和排汽压力呈下降趋势;新模型采用环保工质R365MFC时,低压缸2的进、出口压力较为适宜,且排汽未通过湿蒸汽区,可获得较高的热效率.
Taking the NZK660-24.2/566/566 unit as an example,a steam-organic fluid combined cycle power generation model has been established so as to reduce the heat loss of cold source and increase the capacity of power generation for the steam turbine.To select suitable working fluids for the new model,operation parameters are set according to fluid properties,while the thermodynamic properties of 9 organic fluids analyzed based on thermal economic indicators of both the new model and the original unit with exhaust temperature of respectively 55.3℃ and 35℃.Results show that comparing with the original unit with exhaust temperature of 35℃,the new model has a higher thermal efficiency of power generation and smaller air-cooled areas,under same conditions of heat consumption;different working fluids produce different improvement degrees on power generation efficiency.As the critical temperature of working fluid rises,the inlet and outlet pressure of LP cylinder 2 follow a downtrend,which are found to be appropriate when environmental fluid R365MFC is adopted for the new model.Furthermore when R365MFC is used,the exhaust steam won＇t go through the saturated steam area,therefore high thermal efficiency can be obtained for the unit.
出处
《动力工程学报》
CAS
CSCD
北大核心
2012年第1期72-77,共6页
Journal of Chinese Society of Power Engineering
关键词
有机工质
热力特性
热经济性指标
冷源热量
联合循环模型
organic fluid
thermal property
thermal economical indicator
cold source heat
model of combined cycle unit
