为研究水-酒精混合蒸气浓度对板式换热器换热器换热系数的影响,自行搭建高气密性实验台,在压力30 k Pa,混合蒸气流量6 kg/h实验工况下,获得了局部凝结换热系数随蒸气干度、流道长度、混合蒸气浓度的变化关系。实验过程中,采用了在板片焊接热电偶的测温方法,实现了气侧板片壁面温度的直接测量。结果表明,凝结换热系数随着蒸气干度增加而增加;换热系数随板长方向上无量纲长度增加而减小;与纯水蒸气比较,1%、2%浓度混合蒸气的传热系数值较高,且浓度为1%时的传热系数高于浓度为2%时的传热系数;5%、10%、20%浓度混合蒸气的传热系数均低于纯水蒸气传热系数,且传热系数随混合蒸气浓度增加而减小。
In order to study the effect of ethanol water vapor concentration on the heat exchanger heat transfer coefficient,a self-built high air tightness test bench was made. Under the experimental conditions of 30 k Pa pressure,and 6 kg / h mixed vapor flow,the local condensation heat transfer coefficient was obtain with variance of vapor variation degree,channel length,mixed vapor concentration. During the experiment,the measurement method of welding thermocouple in the plate was used to achieve a direct measurement of the gas side plate wall temperature. The results show that of heat transfer coefficient increases with the increase of the vapor quality,and increases with the increase of the length of path. Compared with pure water vapor,the values of heat transfer coefficient under concentrations of 1%,2% are higher,and when the concentration is 1%,the heat transfer coefficient is higher than that of 2%. The heat coefficients under 5%,10%,20% concentrations of vapor mixture were lower than pure water vapor,and heat transfer coefficient decreases with the increase of mixed vapor concentration.