摘要
在对包含低温省煤器(低省)系统的汽轮机进行性能试验时,由于运行参数的波动性、环境因素所产生的不确定性,导致低省运行边界条件无法完全与设计条件相同,这使得试验测量的汽轮机热耗率、低省节能量无法直接与设计值进行比较。本文针对一台典型的带低省机组,提出了3种不同试验目的下汽轮机及低省性能修正计算方法。针对试验目的 1包含低省的汽轮机性能考核试验,提出了7种修正计算方案,对比结果表明采用5种有效方法计算得到的汽轮机热耗率最大值与最小值的偏差为12.4 kJ/(kW·h),偏差较大,反映出设备买卖双方在试验前应对低省的修正计算方法予以协商确定;针对试验目的 2低省节能量验收试验,提出通过将烟气流量及烟气比热容的乘积定义为系数λ实现对低省运行参数进行修正,计算示例结果表明低省设计吸热量、节能量分别为36.28 MW、29.0 k J/(kW·h),实测值分别为14.93 MW、4.9 kJ/(kW·h),但修正后分别为27.92 MW、19.2 kJ/(kW·h),其修正值和设计值之间的偏差反映出低省换热特性未达到设计要求;针对试验目的 3低省无法退出时的汽轮机本体性能试验,采用本文修正计算方法得到的汽轮机热耗率与退出低省工况试验得到的试验结果相对偏差仅为0.002 6%,满足工程应用需要。本文研究结果可为带低省的火电机组热力性能试验提供参考。
During performance test for steam turbine with low temperature economizer, the operating boundary conditions of the low temperature economizer cannot be completely the same as the design values due to the uncertainty caused by fluctuation of operation parameters and environmental factors. As a result, the measured heat rate of the steam turbine and energy saving of the low temperature economizer cannot be directly compared with the design values. In this paper, against a typical thermal power unit with low temperature economizer, three methods for performance correction calculation of the steam turbine and low temperature economizer with different test purposes were proposed. For purpose one which is acceptance performance test of steam turbine with low temperature economizer, seven correction precepts are proposed. The comparison results show that, there are five feasible methods to calculate heat rate of the steam turbine, in which the maximum deviation between the maximum and the minimum value is 12.4 kJ/(kW·h), which is larger, indicating that the buyer and the seller of low temperature economizer should determine the correction calculation method before the test. For purpose two which is acceptance performance test of energy saving of low temperature economizer, the coefficient λ, product of flue gas flow and specific heat capacity, is proposed to correct operation parameters of the low temperature economizer. The example results show that, the design values of heat absorption and energy saving are 36.28 MW and 29.0 kJ/(kW·h), and the measured values are 14.93 MW and 4.9 kJ/(kW·h), but the corrected values are 27.92 MW and 19.2 kJ/(kW·h) respectively, the deviation between the corrected values and design values indicates the heat transfer characteristics of the low temperature economizer do not meet the design requirements. For purpose three which is performance test of steam turbine body when the low temperature economizer cannot be cutting out. The results show that, the deviation between the heat rate of steam turbine obtained by the corrected calculation method in this paper and measured by the low temperature economizer cut-out performance test is 0.002 6%, which meets the needs of engineering application. The results of this paper can provide reference for performance test of thermal power units equipped with low temperature economizer.
作者
薛志恒
陈会勇
何欣欣
王伟锋
赵杰
吴涛
付昶
XUE Zhiheng;CHEN Huiyong;HE Xinxin;WANG Weifeng;ZHAO Jie;WU Tao;FU Chang(Xi'an Thermal Power Research Institute Co,Ltd,Xi'an 710054,China)
出处
《热力发电》
CAS
CSCD
北大核心
2021年第2期89-96,共8页
Thermal Power Generation
关键词
低温省煤器
性能试验
汽轮机
修正计算
火电机组
热耗率
节能效果评价
low temperature economizer
performance test
steam turbine
correction calculation
thermal power unit
heat rate
evaluation of energy saving effect
