新能源车用CO_(2)空调系统泄漏特性仿真研究

Simulation Research on Leakage of Vehicle CO_(2) Air Conditioning System

CO_(2)作为一种安全、高效且环境友好的自然工质,是未来汽车空调制冷剂替代方案的重要选择。考虑到CO_(2)系统制冷剂泄漏导致乘员舱气体体积分数超标的舒适及安全问题,本文使用三维仿真软件STAR-CCM+搭建乘员舱CO_(2)制冷剂泄漏仿真模型,仿真分析两种不同泄漏速率和泄漏圆孔孔径下乘员舱乘客面部测点CO_(2)体积分数的动态变化情况。在50 g/s的高CO_(2)泄漏速率下,面部CO_(2)体积分数在泄漏完成时能够达到9%以上,需要切换送风模式提供新风来降低乘员舱内CO_(2)体积分数;在0.1 g/s的低CO_(2)泄漏速率下,泄漏完成时面部CO_(2)体积分数不超过3%,处于呼吸安全区范围。

As a safe,efficient,and environmentally friendly natural working fluid,CO_(2)is the primary choice for future automotive air conditioners.To consider the comfort and safety problem of an excessive CO_(2)volumetric concentration in the passenger cabin caused by refrigerant leakage,the 3D simulation software STAR-CCM+was used to build a CO_(2)refrigerant leakage model in the passenger compartment.Simulations and analyses of the dynamic changes in CO_(2)volumetric fraction in the passenger compartment facial measurement points for two different leakage rates and leakage orifice diameters were performed.At a high CO_(2)leakage rate of 50 g/s,the CO_(2)volumetric fraction on the face can reach more than 9%when the leakage is completed.The air supply mode must be switched to provide fresh air and reduce the CO_(2)volumetric fraction in the passenger cabin.At a low CO_(2)leakage rate of 0.1 g/s,the facial CO_(2)volumetric fraction does not exceed 3%,which is safe for breathing,when the leakage is completed.