低β值喉部取压喷嘴直接测量给水流量比对试验  

Comparison experiments of direct measurement of feed water flow rate by throat-tap nozzle with low β value

作　　者：江浩 施延洲[3,2] 王兴平 

机构地区：[1]西安西热节能技术有限公司,陕西西安710054 [2]西安热工研究院有限公司,陕西西安710054 [3]苏州西热节能环保技术有限公司,江苏苏州215153 [4]上海发电设备成套设计研究院,上海200240

出　　处：《热力发电》2018年第2期120-124,共5页Thermal Power Generation

基　　金：中国华能集团公司总部科技项目(HNKJ15-H10)~~

摘　　要：与以凝结水流量为基准通过热平衡计算给水流量相比较,直接测量给水流量使汽轮机性能试验更加简单方便,目前我国已有机组尝试采用低β值喉部取压喷嘴测量给水流量。为验证其直接测量给水流量的可信度,按照ASME PTC6热耗率试验的方法和要求,在某超超临界660 MW机组上进行了分别以给水流量和凝结水流量为基准流量的比对试验。结果表明二者具有良好的重复性,在75%THA以上负荷偏差为-0.5%~0.2%,在THA负荷偏差仅为±0.2%左右,当负荷低至50%THA时,偏差也仅约1.2%,说明直接测量给水流量具有较好的测量精度,可满足汽轮机性能考核试验、大修前后试验要求。另外,一些喷嘴出现的差压测量一致性差问题,是由于差压变送器安装、投运不规范造成,而喷嘴表面结垢问题尚需进行长期观察。Compared with calculating the feed water flow through heat balance based on the condensate flow, measuring the feed water flow directly makes the steam turbine performance tests more simple and convenient. At present, some units in our country try to measure the feed water flow by the throat-tap nozzle with low β value. In order to verify the reliability of this method, according to the method and requirement of the ASME PTC6 heat rate tests, the comparison experiments were carried out of the water flow and the condensate flow at an ultra-supercritical 660 MW unit respectively. The results show that both of them have good repeatability. When the load is above 75% THA, the deviation is-0.5%-0.2%, the deviation of THA load is only about ±0.2%. And when the load is as low as 50% THA, the deviation is only about 1.2%. This results indicate that these two methods have good measurement accuracy, which can meet the turbine performance requirement of assessment tests, pre-overhaul tests and overhaul tests. Some nozzles appear poor consistency in the differential pressure measurement, which is because of the nonstandard installation and operation of differential pressure transmitter. And the nozzle surface fouling problems need long-term observation.

关 键 词：低β值喉部取压喷嘴 给水流量 基准流量 ASME PTC6 测量精度 比对试验 

分 类 号：TK26[动力工程及工程热物理—动力机械及工程] TK313