凝汽式汽轮机相对内效率在线监测的一种近似计算方法

针对汽轮机热力试验条件与正常运行条件间的差别 ,指出正常运行中汽轮机并不具备热力试验所要求的完全隔离的条件 ,同一电厂中各机组间总有一定的汽 (水 )联系。因此 ,对于正常运行的汽轮机 ,无法采用常规热力试验所采用基金项目 :国家电力公司重点科技资助项目 (SPKJ0 13 0 7)。的求解汽轮机质量和能量平衡方程的方法在线求解排汽焓 ,从而使在线准确确定汽轮机相对内效率存在一定的困难。文中提出一种在线计算汽轮机相对内效率的热力学近似方法 ,该方法基于汽轮机热力循环的基本原理 ,采用一些容易测量的参数来推算汽轮机的相对内效率 ,避开了常规的求解排汽焓的难题。通过与汽轮机热力试验结果的比较 ,证明该方法足以满足工程上对计算精度的要求。最后给出该方法在某 10 0MW汽轮机相对内效率在线监测中的应用情况。

AN APPROXIMATE METHOD OF ONLINE MONITORING RELATIVE INTERNAL EFFICIENCY FOR CONDENSING STEAM TURBINE

To counter the difference of the usual operation modes and the thermal test modes of steam turbine, the viewpoint is pointed out that steam turbines in usual operating don't possess the condition of being isolated from each other that is required in the thermal test. Steam turbines in the same power plant are jointed by water or steam crossover pipes. So the exhaust steam enthalpy for steam turbine in usual operation modes can't be online obtained by the methods of solving the mass and energy equations that is used for thermal test modes, and this makes online monitoring relative internal efficiency very difficult. This paper gives an approximate thermodynamics method of online monitoring relative internal efficiency for condensing steam turbine. Based on the basic principle of steam turbine thermodynamic cycle, this method obtained relative internal efficiency by some parameters that are easily measured, and this thermodynamics method can avoid the difficulty of fixing the exhaust steam enthalpy for steam turbine in usual operating. Compared with results of thermal test, it is proved that the thermodynamics method can satisfy the needs of engineering for calculating precision. Finally, the application of this method in online monitoring relative internal efficiency of 100?MW steam turbine is given.