摘要
针对跨临界CO2汽车空调系统制冷性能较差的问题,分析了回热器大小对系统性能和运行参数的影响,在汽车空调测试环境实验室中搭建了一个可变回热量的跨临界CO2制冷系统实验台,在35、38和41 ℃环境温度下,保持压缩机转速为3500 r/min,通过旁通阀调节回热量,测量了不同排气压力下全回风系统的稳态性能,分析了回热量对系统制冷量和能效比的提升作用,以及对压缩机运行参数的影响。结果表明:排气压力为10 MPa时,35、38和41 ℃下,使用回热器后系统的最大能效比分别提高了14.2%、23.3%和33.2%,制冷量也增加了14.3%~33.3%;使用回热器可以改善换热器压力损失,但同时会引起排气温度升高;相同温度下,系统最大回热度一般随环境温度升高而减小;回热器的使用可以有效提高系统性能,但也会引起压缩机压比增大和排气温度的上升。在跨临界CO2制冷循环的回热器大小设计时,需要兼顾性能和安全。
To solve the problem of the bad cooling performance,an experimental setup of the transcritical CO2 refrigeration system with an adjustable heat exchanger is set up in a mobile air conditioning calorimeter facility to investigate the effects of the internal heat exchanger on the performance and operation parameters of transcritical CO2 air conditioning system used in electrical vehicles.The experiments are conducted at the ambient temperature of 35,38 and 41 ℃with the compressor speed at 3500 r/min,and the steady results are measured under variable discharge pressure and heat flux of the internal heat exchanger.The effects of the internal heat exchanger on the improvement of cooling capacity and COP of the system and the influence on the operation parameters of the compressor are analyzed.The results show that when the exhaust pressure is 10 MPa,the COP of the system increases by 14.2%,23.3%and 33.2%respectively after using the internal heat exchanger under the three ambient temperatures,and the cooling capacity increases by 14.3%to 33.3%.Meanwhile,the pressure reduction in the heat loss was reduced.But using an internal heat exchanger would result in the increase of discharge temperature.The higher the ambient temperature is,the smaller an internal heat exchanger allowed is when operating at same discharge pressure.The use of the internal heat exchanger can effectively improve the system performance,but it will also cause the increase of the compressor pressure ratio and the rise of the discharge temperature.So,the performance enhancement and the security must be both considered in the design of the size of the internal heat exchanger for a transcritical CO2 refrigeration cycle.
作者
方健珉
王静
孙西峰
殷翔
曹锋
FANG Jianmin;WANG Jing;SUN Xifeng;YIN Xiang;CAO Feng(School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;Dongfeng Motor Corporation Technical Center, Wuhan 430000, China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2020年第6期155-160,共6页
Journal of Xi'an Jiaotong University
基金
国家科技重大专项资助项目(2017-Ⅲ-0010-0036)
国家自然科学基金资助项目(51976153)。
关键词
回热器
二氧化碳
电动汽车空调
internal heat exchanger
CO2
electric vehicle air conditioning
