摘要
利用计算流体动力学(CFD)仿真分析技术,研究了动车组空调系统中以CO_(2)作为制冷工质的翅片管蒸发器空气侧的换热性能。选取空气出口温度、压降、传热因子j、阻力因子f等作为目标函数,同时在空气流道中设置监测点,实时监测湍流场和管壁压力变化。研究显示,该CO_(2)蒸发器的制冷量最高可达29.76 kW,满足动车组空调系统所需的换热量。为提高蒸发器的换热效果,分别改变空气进口流速、蒸发器换热管管径和翅片间距进行仿真优化。结果表明:随着空气进口流速的增大,蒸发器制冷量增大,换热管面积优化因子j/f值随之增大,换热效果提升;但当空气进口流速ve>2.2 m/s时,继续提高流速对换热效果影响较小;适当减小换热管管径可降低风阻,提高j/f值,进而增强蒸发器的制冷能力;随着翅片间距的增大,流道内的湍流运动得以充分发展,j/f值的变化存在峰值;最佳翅片间距为1.6~1.7 mm,此时空气侧平均湍动能较大且湍流耗散率较小。
The heat transfer performance of the air side of the finned tube evaporator using CO_(2) as the refrigerant in the air conditioning system of the EMU was studied by using the computational fluid dynamics(CFD)simulation analysis technology.The air outlet temperature,pressure drop,heat transfer factor j,and resistance factor f were selected as the objective functions,and monitoring points were set in the air flow channel to monitor the changes of the turbulent field and the tube wall pressure in real time.The research shows that the maximum cooling capacity of the CO_(2) evaporator can reach 29.76 kW,which can meet the heat exchange requirements of the EMU air conditioning system.To improve the heat transfer effect of the evaporator,the simulation optimization was carried out by changing the air inlet velocity,the diameter of the heat exchange tube and the fin pitch respectively.The results show that with the increase of the air inlet velocity,the cooling capacity of the evaporator increases,and the j/f value of the heat exchange tube area optimization factor increases,and the heat transfer effect improves;but when the air inlet velocity ve>2.2 m/s,further increasing the velocity has a small impact on the heat transfer effect;appropriately reducing the diameter of the heat exchange tube can reduce the wind resistance,increase the j/f value,and thereby enhance the cooling capacity of the evaporator;with the increase of the fin pitch,the turbulent motion in the flow channel is fully developed,and the j/f value change has a peak;the optimal fin pitch is 1.6-1.7 mm,at which the average turbulent kinetic energy on the air side is large and the turbulent dissipation rate is small.
作者
张洋
苏晓钶
崔洪江
高洁
ZHANG Yang;SU Xiaoke;CUI Hongjiang;GAO Jie(CRRC Dalian Locomotive and Rolling Stock Co.,Ltd.,Dalian 116022,China;CRRC Zhuzhou Locomotive Co.,Ltd.,Zhuzhou 412001,China;Zhan Tianyou College(CRRC College),Dalian Jiaotong University,Dalian 116028,China;Dalian Traffic Technician College(The Vocational School of Dalian Transportation and Port),Dalian 116033,China)
出处
《大连交通大学学报》
2025年第6期86-94,共9页
Journal of Dalian Jiaotong University
基金
辽宁省教育厅基本科研项目(LJKFZ20220203)。
关键词
动车组空调
翅片管蒸发器
CO_(2)工质
CFD
传热性能
air conditioning for bullet trains
finned-tube evaporator
CO_(2) working medium
CFD
heat transfer performance
