| 摘要: |
| 本文利用稳态分布参数法对冷风机建立仿真模型，并利用冷风机性能实验台对冷风机样机进行实验研究，利用实验研究与数值模拟相结合的方法，对冷风机换热性能进行分析研究。在校准箱内温度为﹣25 ~0 ℃范围内，循环倍率在2~5范围内变化时，冷风机总换热系数随着校准箱温度的升高而增大；制冷工质为CO2时冷风机的制冷量明显高于制冷工质为NH3时，在校准箱内温度为0 ℃时高42%，﹣20 ℃时高26%；管内侧压降随着循环倍率的增大而增大；换热系数随着循环倍率的增大先增大后逐渐减小，在循环倍率为3左右时，换热系数达到最大。仿真结果与测试结果趋势相同，但存在一定误差。模拟计算得出NH3换热系数值与测试结果的误差约为16%，CO2换热系数值与测试结果的误差约为8%。 |
| 关键词: 换热系数 管内压降 校准箱温度 循环倍率 |
| DOI： |
| 投稿时间：2016-11-02
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| 基金项目: |
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| Simulation and Experimental Study on Heat Transfer Performance of CO2 Air Cooler |
|
Shen Jiang, Bian Yujun, Huang Bing
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| (Refrigeration Key Laboratory of Tianjin, Tianjin University of Commerce) |
| Abstract: |
| In this study a cooling-fan simulation model was established using the steady-state distributed parameter method, and the performance of a cooling-fan prototype was tested in an air-blower performance test rig. Further, a cooler heat transfer performance analysis was conducted based on the experimental data and numerical simulation. For a temperature calibration of ?25-0 ℃ and a circulation rate varying in the range of 2-5, it was found that the total heat transfer coefficient increases with increasing calibration-box temperature. When the refrigerant is CO2, the cooling capacity of the cooling fan is obviously higher than that for an NH3 refrigerant. Further, the cooling capacity is 42% higher when the temperature in the tank is 0 ℃ and 26% higher for a tank temperature of ?20 ℃. The pressure drop of inner side of the tube increases with increases in the circulation rate. Further, the heat transfer coefficient first increases and then decreases with increases in the circulation rate. The circulation ratio is approximately 3, corresponding to the maximum change in the thermal coefficient. The simulation results exhibit the same trend as the test results, but some errors exist. The error of heat transfer coefficient between the numerical and test results is approximately 16% for the NH3 system, and approximately 8% for the CO2 system. |
| Key words: heat transfer coefficient calibration temperatures pressure drop inside the tube circulation rate |
