| 摘要: |
| 利用EES软件对直接膨胀式地源热泵系统中U形埋管换热器内含油制冷流动状态进剂行了模拟分析。模拟分析结果表明：含油制冷剂压力沿U形埋管先缓慢增加后减少；温度沿U形埋管先增加后减少，进入过热区后急剧增加；在U形埋管上升管段中含油制冷剂不存在泡状流，以弹状流和环状流形式存在，且以环状流为主；最小回油速度随U形埋管管径的增加而增加。计算结果和实验结果的对比表明实验系统能够正常回油。 |
| 关键词: 工程热物理 地源热泵 数值计算 U形管换热器 最小回油速度 |
| DOI： |
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| Numerical Analysis of Refrigerant/Oil Mixture in a Vertical U-tube |
| Cao Xiaolin,Zeng Wei,Chen Hui,Cao Shuangjun,Wang Fangfang |
| (School of Energy Science and Engineering, Central South University) |
| Abstract: |
| EES software was used to simulate the flow of refrigerant and oil in underground U-tube of the Direct Expansion Ground Source Heat Pump. The results show that: the pressure of refrigerant/oil mixture first increases and then decreases along the U-tube;the temperature of refrigerant/oil mixture increases firstly and then decreases, in superheat region, the temperature rises sharply; the refrigerant/oil mixture exits in U-tube mainly as annular flow; the minimum refrigerant/oil return velocity is increasing when the U-tube diameter increases; comparing the simulation results with the experimental results find that the oil in the U-tube of the experimental system can return normally. |
| Key words: Engineering thermophysics Ground source heat pump Numerical analysis U-tube heat exchanger Minimum oil return velocity |
