空冷凝汽器验收考核实验中的几个原则

对空冷凝汽器进行性能测试,以考核是否达到验收标准,对于我国火电站空冷岛的设计、生产和运行都具有重要意义。从空冷凝汽器传热模型出发,分析了VGB-R131Me验收考核实验导则中存在的缺陷。针对我国直接空冷机组运行中存在的诸如夏季满负荷高背压运行,冬季防冻等问题,指出了单纯增加空冷凝汽器传热面积以满足设计要求的不足,建议制定不同工况不同容量机组的考核传热系数值。空冷凝汽器验收考核应在设备供应商提供凝汽器传热性能,即传热关联式的基础上,由用户计算不同轴流风机转速,不同凝汽器饱和蒸汽凝结量和不同进口空气温度条件下的凝汽器传热系数并进行实验测试,只有当该传热系数大于考核传热系数之后,才能绘制凝汽器性能曲线以检验是否达到设计要求。

Principles of Acceptance Test Measurements for Air-cooled Condensers

It is useful for the designing,manufacturing and operation of direct air-cooled units to make the acceptance test measurements for air-cooled condensers in power plant.The shortcomings of VGB-R131Me guideline are discussed based on the heat transfer model of air-cooled condensers.The disadvantages of increase in heat transfer area to satisfy the designing demand are analyzed by investigating the operation problems such as the high exhaust steam pressure in hot summer and the freezing prevention of condensers in cold winter.The acceptance heat transfer coefficients are suggested for different capacity units in different operation conditions.The supplier of air-cooled condensers should provide the performance of condensers,that is,the correlation of heat transfer of condensers.The heat transfer coefficients of air-cooled condensers should be calculated and tested at different fan speeds,saturated exhaust steam flow rates and inlet air temperatures.Only this coefficient is larger than the acceptance heat transfer coefficient can the performance diagram be drawn to test whether the performance meets the designing demand or not.