【摘要】 对发电厂空冷系统热回流产生的原因及其危害进行了分析,提出了定量分析热回流的评价标准.在直接空冷系统模型内导入恒温热水构成循环系统,在低速风洞中对直接空冷模型进行热效应试验研究,并在不同来流条件下,通过测量风机入口和翅片管束出口空气的温度,计算各测点回流率的大小,探求环境来流风速和风向的变化对空冷塔下回流率的影响,结果发现在实验风速范围内,空冷塔下平均回流率随着来流风速的增加而增加,不同来流风速下空冷塔下平均回流率随风向角变化趋势基本相同;实验风向角β=0时,空冷塔下平均回流率最大.更多还原

【Abstract】 The reasons of thermal recirculation formed in air cooled system of power plant and its hazards were analyzed so as to present the evaluation criteria of quantitative analysis for thermal recirculation.The hot water with constant temperature flows inside the model of direct air cooled system to form the circulating system.Then the model was put into the low velocity wind tunnel to carry out the experimental research on heat effect.The effect under the variation of inflow velocity of environmental wind and its direction on the recirculation ratio under air cooled tower was searched by calculating the recirculation ratio based on the air temperature measured at each point of fan’s inlet and fined tube’s outlet with different inflow conditions.It was found that the mean recirculation ratio under the air cooled tower grows higher with increasing of the inflow velocity within the range of testing wind velocity.The trends of the mean recirculation ratio under the air cooled tower varying with the wind direction angle under different inflow wind velocity are basically the same.The mean recirculation ratio under the air cooled tower reaches the highest value with the testing wind direction angle of β=0°.更多还原