| 摘要: |
| 在VCR（蒸气压缩制冷）系统中，压缩机润滑油会发生泄露，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，预测压降和预测制冷量的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 ℃，蒸发器度为2 ℃时，无油工况与油循环率（OCR）为2%和6%时系统制冷量相差可达4%和22%，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出5%~82%，换热器压降随油循环率的增大而增大。 |
| 关键词: 制冷系统 传热系数 蒸发器 油循环率 |
| DOI： |
| Received:April 28, 2022Revised:September 03, 2022 |
| 基金项目:江苏省青年基金(BK20210820)项目资助。 |
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| Effect of Oil Circulation Ratio on Thermal-hydraulic Performance in Evaporators |
|
Li Zhaohua, Zhao Junjie, Shen Hao, Bao Xin, Zhou Hang, Zuo Ji
|
| (School of Mechanical Engineering, Yangzhou University) |
| Abstract: |
| 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 was inversely proportional to the evaporating temperature and the oil circulation ratio (OCR). The cooling capacities under oil-free conditions were 4% and 22% higher than those at 2% and 6% oil circulation ratio, 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 61 kPa and 99 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. |
| Key words: vapor compression refrigeration system heat transfer coefficient evaporator oil circulation ratio |
