板翅式蒸发器换热仿真研究

以板翅式蒸发器为研究对象,开发两相换热仿真模型。通过仿真分析的方法开展研究,构建了热平衡方程,给出了假设条件与计算流程,基于文献中试验结果进行了模型验证。以蒸发器冷却液出口温度为对比项,仿真值与实验值相对误差为6.58%~9.25%,模型准确性较好,可以满足工程计算需求。仿真分析了冷却液进口温度、制冷剂进口温度、冷却液流量、制冷剂流量等参数对于换热特性的影响,结果表明冷却液进口与制冷剂进口温差、冷却液流量对于换热性能具有较大影响,制冷剂流量对于换热性能的影响主要取决于其干度变化情况.蒸发器设计过程中应考虑冷热源参数的动态变化,合理确定设计点。

Simulation Study of Heat Transfer of Plate-fin Evaporator

The simulation model of two-phase heat transfer was developed, based on the research ob-ject of plate-fin evaporator in this paper. The research was carried out by method of simulation analy-sis. The heat balance equation was established. The assumed conditions and computing process were given. The model was validated with the experimental results in the reference. Compared to the cool-ant outlet temperature of evaporator, the relative errors between the simulation and experiment were6.58% ~9.25% . The accuracy of the model built was high and it could meet the demand of the en-gineering calculation. The effects of coolant inlet temperature , refrigerant inlet temperature, coolantflow rate and refrigerant flow rate on heat transfer performance were analyzed by simulation. The re-sults show that the effects of the inlet temperature difference of coolant and refrigerant and coolant flow rate on heat transfer performance were great. The effect of refrigerant flow rate on heat transferperformance depended on the change of refrigerant dryness. The dynamic change of the parameters of cold and heat source should be taken into account in the design process of evaporator. The designpoint should be determined reasonably.