以乙醇溶液为冷却工质的开式喷雾冷却系统实验研究

在开式循环喷雾冷却系统上研究质量分数分别为10%、20%、30%、50%、70%、99%的乙醇溶液对喷雾冷却效果影响,结果表明:热沉表面热流密度和传热系数先随乙醇水溶液浓度的增大先增大,当乙醇质量分数为50%时达到最大值,随后随乙醇浓度的增大而减小。体积流量0.944 46L/min,乙醇质量分数为50%时,喷雾冷却传热系数为6.41 W/(cm~2·K),热流密度为216.04W/cm~2,较之纯水传热系数增加了34.95%,热流密度增加了24.9%。结果表明使用乙醇溶液作为冷却剂的喷雾冷却系统能同时满足高热流密度和低换热表面温度的要求,具有良好、稳定的换热冷却能力。推导了反映介质喷雾特性和蒸发强度对换热影响的光滑表面量纲一换热准则方程,涉及的物理参量较少,因此可方便用于工程设计。

Experiment study on spray cooling of an open system with ethanol as coolant

Experiments were conducted to study the effects of ethanol mass fraction of 10％ 、20％ 、30％ 、50％ 、70％ 、99％ on heat flux and heat transfer coefficient of spray cooling.The experimental results show that the heat flux is the largest when mass fraction is 50％.The heat flux and heat transfer coefficient are 216.04 W/cm2 and 6.41 W/(cm2 · K)repectively with the volume flow rate of 0.944 46 L/min and the mass fraction of 50％,which increases by 24.9％ and 34.95％ respectively comperred with distill water.The results of experiments indicate that ethanol has a stable heat cooling capacity as a spray cooling refrigerant and meets the requirement of high heat flux with low temperature of cooling surface.