油循环率对蒸发器内传热与工质流动的影响  

Effect of Oil Circulation Ratio on Thermal-hydraulic Performance in Evaporators

作　　者：李兆华 赵俊杰 沈浩 鲍鑫 周航 左吉 Li Zhaohua;Zhao Junjie;Shen Hao;Bao Xin;Zhou Hang;Zuo Ji(School of Mechanical Engineering,Yangzhou University,Yangzhou,225127,China)

机构地区：[1]扬州大学机械工程学院,扬州225127

出　　处：《制冷学报》2023年第3期119-125,共7页Journal of Refrigeration

基　　金：江苏省青年基金(BK20210820)项目资助

摘　　要：在VCR(蒸气压缩制冷)系统中,压缩机润滑油会发生泄漏,混入制冷剂后对制冷剂的流动性和传热产生负面影响。本文基于使用R1234yf的直线压缩机,建立蒸发器的数值模型。通过无油直线压缩机驱动的VCR系统进行实验测试获得系统制冷量与换热器压降,以此对无油工况下的数值模型进行实验验证,预测压降和制冷量的MAPE(平均绝对百分比误差)分别为3.9%和8.2%。结果表明:在冷凝温度为50℃,蒸发温度为2℃时,无油工况与OCR为2%和6%时系统制冷量相差可达4%和22%,OCR(油循环率)的增大降低了蒸发器内传热速率;在冷凝温度为50℃,蒸发温度为-11℃时,无油和OCR为4%时压降分别为6.17 kPa和9.92 kPa,含油制冷系统比无油制冷系统的压降高5%~82%,换热器压降随OCR的增大而增大。A leakage of oil lubricants affects the heat transfer and flow of refrigerants in vapor compression refrigeration(VCR)systems.In this study,a numerical model of a VCR system using a linear compressor and R1234yf as the refrigerant was developed.The proposed model was validated in terms of pressure drop and cooling capacity through experimental tests under oil-free conditions using a VCR system with an oil-free linear compressor.The mean absolute percentage error of the cooling capacity and pressure drop were 3.9%and 8.2%,respectively.The results showed that the discharge temperature wasinversely proportional to the evaporating temperature and the oil circulation ratio(ORC).The cooling capacitiesunder oil-free conditionswere 4%and 22%higher than those at 2%and 6%oil circulation ratio(OCR),respectively,at a condensing temperature of 50℃and evaporating temperature of 2℃in the VCR system.The pressure drop under oil-free and 4%OCR conditions were 6.17 kPa and 9.92 kPa,respectively,at a condensing temperature of 50℃and an evaporating temperature of-11℃.The pressure drop of the oil-containing system was 5%-82%higher than that of the oil-free system,and the pressure drop in the heat exchanger increased with an increase in the oil circulation ratio.

关 键 词：蒸气压缩制冷系统 传热系数 蒸发器 油循环率 

分 类 号：TB611[一般工业技术—制冷工程] TB657.5