根据能量守恒和质量守恒定律,对板式蒸发式冷凝器中制冷剂、冷却水与空气之间的传热传质过程,建立了热质交换过程的二维数学模型,由此分析板式蒸发式冷凝器中冷却水温度、空气温度和空气含湿量等参数的分布规律,以及空气流速、干湿球温度、冷却水喷淋密度和冷凝温度对板式蒸发式冷凝器热流密度的影响,并将模拟结果通过实验进行了验证,两者之间的误差在10%以内。研究表明:板式蒸发式冷凝器的热流密度随进口空气流速的增加而增大,随湿球温度的升高而减小,几乎不受进口空气干球温度的影响;热流密度随着冷却水喷淋密度的增加逐渐增大,但增大至一定量后小再对热流密度有明显影响;冷凝温度越高,其热流密度越大。上述结论对板式蒸发式冷凝器的优化设计具有指导意义。
Two-dimensional mathematical model of the heat and mass transfer process among refrigerant, cooling water and air in the plate evaporative condenser was established on the basis of energy and mass conservation. Distributions of cooling water temperature, air temperature and air humidity ratio are obtained. And then studies on influencing factors of plate evaporative condenser heat flux, i.e., air flow rate, cooling water spray density, air dry bulb temperature, wet bulb temperature and the condensing temperature were conducted. Simulation results were verified through experiments, and the error was less than 10%. The results showed that heat flux increased with increasing air flow rate, increasing condensing temperature and decreasing air wet bulb temperature, and is not relevant to air dry bulb temperature. With the increasing cooling water spray density, heat flux gradually increased and then kept constant. These conclusions are instructive for ootimization design of olate evaporative condenser.