基于CFD分析的汽车空调EAPI优化设计

EAPI optimization design of automotive air-conditioning based on the CFD analysis

以计算流体力学(CFD)为基础,采用SST两方程模型,建立了汽车空调的数值仿真模型。利用某型空调总成制冷量对蒸发器单体制冷量利用率低的空调,以重庆三电蒸发器通风面速度均匀性指标(EAPI)为评估标准,通过数值仿真分析指导空调箱结构优化设计。研究结果表明:数值计算结果与试验结果吻合较好,其风量偏差为1.29%;EAPI指标非常合理且重要,指标由43.93%增加到83.54%时,总成制冷量对单体制冷量的利用率由77.59%提高到91.70%;蜗壳扩压段对风机性能影响较大,扩压段有效扩压会增加风机风量;蒸发器进气前段结构分区域调整(台阶与挡风筋)是优化蒸发器通风面速度均匀性的有效方式。

Based on the computational fluid dynamics(CFD),the numerical-simulation model of automotive air-conditioning is worked out with the aid of the SST two-equation model.With the low utilization ratio of the evaporator monomer’s refrigerating capacity to the air-conditioner’s refrigerating capacity assembly,Chongqing Sanden’s evaporator performance indicator(EAPI)is adopted as the standard to conduct the simulated analysis on the air-conditioner’s structural optimization.It’s shown that the CFD results are in line with the experimental data,and the deviation of air volume is 1.29%.When EAPI,which is extremely important and reasonable,increases from 43.93%to 83.54%,the utilization ratio of the evaporator monomer’s refrigerating capacity to the air-conditioner’s refrigerating capacity assembly will rise from 77.59%to 91.70%.The volute‘s expansion section has great influence on the fan’s performance,and the effective expansion will increase its air volume.The sectional adjustment of the evaporator’s front inlet(step and windshield)ensures a higher standard of evaporator performance.