单缸低参数汽轮机末级排汽湿度的热力分析  

Thermodynamic Analysis of the Last-stage Exhaust Steam Wetness of a Single-cylinder Low-parameter Steam Turbine

作　　者：田瑞峰[1] 

机构地区：[1]哈尔滨工程大学核科学与技术学院,黑龙江哈尔滨150001

出　　处：《热能动力工程》2009年第6期705-709,814-815,共5页Journal of Engineering for Thermal Energy and Power

摘　　要：采用VB语言,通过动态链接库的调用,编制了低参数单缸汽轮机热力计算程序。应用此程序,在不同设计参数下,针对无抽汽除湿、级间抽汽除湿和除湿级除湿3种方案,研究了机组末级湿度的变化。结果表明,进汽压力、进汽温度和排汽压力三者对末级湿度的影响不同,进汽温度对末级湿度的影响最大,进汽压力次之,排气压力最小。在本研究所提参数条件下,满负荷运行很难保证末级出口湿度要求,需采用有效的内部除湿措施。研究也表明,在不同位置抽汽除湿和除湿级除湿对机组末级湿度影响较大,在相同的设计参数下,在机组的第四级后抽汽除湿对机组末级湿度的影响最大。在相同的除湿效率下,除湿级位置每向后移动一级,使末级湿度降低约1%,随除湿级位置后移,除湿效率对末级湿度的影响增大。By adopting VB language and using a dynamic-link data base,designed was a thermodynamic calculation program for low-parameter single-cylinder steam turbines.By employing this program,the change of the last-stage wetness of the turbine unit for the following three versions of wetness removal was studied at various design parameters:namely,(1) without any steam extraction,(2) by extracting steam between stages and(3) by adopting a wetness removal stage.It has been found that the inlet steam pressure and temperature as well as the exhaust steam pressure can affect the last-stage wetness in different ways,and the inlet steam temperature exercises a maximal influence on the last-stage outlet wetness with consecutively less influence being exerted by the inlet steam pressure and the exhaust steam pressure.Under the given parameter condition of the present study,it is difficult for a full-load operation to meet the requirement for the laststage outlet wetness,making it necessary to take effective inner wetness removal measures.The research results also indicate that the wetness removal by extracting steam at different locations,and by using a wetness removal stage exercises a relatively big influence over the last-stage wetness of the unit.At the same design parameters,the wetness removal by extracting steam after the fourth stage of the unit can maximally affect the last-stage wetness of the unit.At an identical wetness removal efficiency,when the location of the wetness removal stage shifts one stage backwards each time,it will lower the last-stage wetness by about 1%.With the location of the wetness removal stage moving backward,the influence of the wetness removal efficiency on the last-stage wetness will increase.

关 键 词：单缸汽轮机 热力设计 除湿级 除湿效率 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]