| 摘要: |
| 本文总结了现具有较高认可度且具有相当预测精度的空气侧换热特性的理论预测模型，选用常规平直铝翅片铜管换热器在典型的空调工况（空气干球温度为27 ℃，湿球温度为19.5 ℃，换热器迎面风速为1~4 m/s，入口水温为7~13 ℃，流速为1.8 m/s）下，对现有模型在低气压环境（40~100 kPa）下的适用性进行分析研究。实验研究表明：在试验工况下，随着换热器所处环境压力的降低，常压模型预测值与实验值的偏差急剧增加至127.4%~-36.6%，且常压模型预测值普遍偏大。同时低气压环境下管排数的影响依然存在，且更加明显。基于本文实验数据对3个常压模型进行环境气压修正后，预测精度大幅提高：在试验工况下，最大偏差分别降至32.63%、24.91%和21.74%，平均偏差为1.79%、-2.90%和-8.59%，在±20%的误差带内修正模型预测精度比分别达到90.97%、93.75%和88.96%。 |
| 关键词: 传热因子 环境压力修正 空气换热 翅片管换热器 |
| DOI： |
| 投稿时间：2018-10-23 修订日期：2018-12-29
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| 基金项目:上海市部分地方院校能力建设专项计划(16060502600）资助。 |
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| Applicability Study of Air Side Heat Transfer Model of Fin-tube Heat Exchanger in Low Ambient Pressure |
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Zhang Jiawen, Liu Jianhua, Zhang Liang, Liu Qi
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| (School of Energy and Power Engineering , University of Shanghai for Science and Technology) |
| Abstract: |
| The applicability of popular air-side heat transfer models of a flat fin-tube heat exchanger with high prediction accuracy are summarized in this paper. Their performance in a low ambient pressure (40–100 kPa) is analyzed under typical air conditioning conditions (air dry bulb temperature 27 oC, wet bulb temperature 19.5 oC, approach velocity 1?–4 m/s, inlet cooling water temperature 7–13 oC, and water flow rate 1.8 m/s). To check the applicability of these models, three heat exchangers with different tube rows (2/3/4) were tested. Experimental results showed that the data with large deviation appeared in the cases with a low ambient air pressure and the deviation could be +127.4%-–-36.6%. The predictions with models under atmospheric pressure were generally greater than the test results as the influence of atmospheric pressure on the Re number of the air side heat transfer was not considered. The effect of the number of tubes under a low-pressure environment on the heat transfer remains there and is more apparent. A correction term of ambient pressure was proposed based on the experimental data in this study. There was a substantial improvement of these three models’ prediction accuracy after this correction as follows: under the experimental conditions, the maximum deviation dropped to 32.63%, 24.91%, and 21.74% respectively; the average deviation was 1.79%, -2.90%, and -8.59% respectively; and the error range of ±20% covered 90.97%, 93.75%, and 88.96% respectively of the experimental values. Furthermore, pressure correction makes the models applicable to a more extensive range of ambient pressures. |
| Key words: heat transfer factor ambient pressure correction airside heat transfer fin-tube heat exchanger |
