一种评价低压给水加热器运行热经济性的方法  

A Method for Evaluating Thermal Economic Performance of Low-pressure Feedwater Heaters

作　　者：李勇[1] 马广辉[1] 

机构地区：[1]东北电力大学能源与动力工程学院,吉林省吉林市132012

出　　处：《中国电机工程学报》2012年第20期20-26,134,共7页Proceedings of the CSEE

基　　金：吉林省科技发展计划项目(20080523)~~

摘　　要：加热器端差受入口温度、汽轮机负荷等因素的影响,实测端差值并不能直接用来评价加热器热经济性。采用传热学原理及热平衡理论,考虑到加热器入口水温、汽轮机负荷等对传热系数的影响,提出采用低压加热器上、下端差应达值的计算方法。以某300 MW汽轮机为例,对其经过大修后的低压加热器传热系数及上、下端差进行计算。结果表明:加热器上、下端差的计算值与相应的测量值吻合较好,证明了该方法的有效性。最后,将加热器上、下端差的实测值与应达值进行对比,利用二者的偏差程度对加热器的运行经济性状态进行评价,评价结果得到了试验验证,说明提出的低压加热器运行热经济性评价方法可实现加热器性能降低的早期发现。The terminal temperature difference of heater is affected by many influence factors,such as the heater tube inlet temperature,the turbine load,etc.So the measured value of temperature difference can not evaluate the heat economy of the heater directly.Heat conduction theory and the thermal equilibrium theory were used,the influences of the tube inlet temperature,turbine load were considered,calculating methods of target values of terminal and drain cooler approach temperature difference were put forward.Taking a 300 MW unit for example,the heat transfer coefficient,terminal temperature difference and drain cooler approach temperature difference of the low-pressure heater after general repair were calculated.It demonstrates the efficiency of the proposed calculating method that the calculated values agree well with the measured values of terminal and drain cooler approach temperature difference.Finally,the heat economy of heater’s actual operation was evaluated by using the deviation degree of measured value and target values,and the evaluation was supported by experiment.It means that the suggested low-pressure heater operation heat economic evaluation method can be used for the early detection of heater performance degradation.

关 键 词：汽轮机 低压加热器 端差 热经济性 应达值 

分 类 号：TK267[动力工程及工程热物理—动力机械及工程]