| 摘要: |
| 建立了无墙面阻碍和有墙面阻碍情况下低环境温度空气源热泵六列四行的阵列物理模型，对以261.15 K为名义工况下的空气源热泵外环境流场进行三维数值模拟。对比研究不同水平风速下蒸发器换热面入口空气温度和换热量，分析冷风回流现象对低环温空气源热泵传热性能的影响，指出最恶劣工况机组的位置。环境风存在阻碍风机出口冷空气的扩散，使风机出口偏转角增大，导致冷空气在风机上部堆积，阵列内部以及背风侧的机组冷风回流现象更加明显。结果表明：当机组横向间距为0.6 m时，水平风速分别从0 m/s增至5 m/s，阵列机组最低入口空气温度比环境温度低2.44～3.69 K，平均换热量下降1%~6.2%，平均入口空气温度比环境温度低0.78~1.57 K；当机组距墙间距为0.6 m时，水平风速分别从0 m/s增至5 m/s，阵列机组最低入口空气温度比环境温度低3.51～4.14 K，平均换热量下降5.9%~11.5%，平均入口空气温度比环境温度低1.29~1.98 K。在此基础上对不同横向间距、不同距墙间距下阵列空气源热泵进行模拟，结果表明：增大横向间距或距墙间距均能改善阵列低环温空气源热泵机组的换热。当横向间距增至1.2 m，阵列机组平均换热量可达原来机组换热量的96.5%以上；距墙间距增至1.2 m，阵列机组平均换热量可达原来机组换热量的91.3%以上。横向间距或距墙间距为1.2 m为较好安装间距。 |
| 关键词: 低环温空气源热泵阵列 数值模拟 冷风回流 环境风场 |
| DOI： |
| Received:February 16, 2023Revised:June 29, 2023 |
| 基金项目:国家自然科学基金（51776075, 51976063）资助项目 |
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| External Flow Field Simulation of Low Ambient Temperature Air-source Heat Pump Array |
|
Tan Qingpeng1, Liu Jinping1,2, Chen Jianxun1, Chen Xiao1, Chen Ziyu1
|
| (1.School of Electric Power, South China University of Technology;2.Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization) |
| Abstract: |
| In this study, physical models of six-row and four-row arrays of a low-ambient-temperature air-source heat pump with and without wall obstruction are established. A three-dimensional numerical simulation of the ambient flow field of the low-ambient-temperature air-source heat pump under nominal working conditions at 261.15 K is carried out. In this study, the inlet air temperature of the evaporator surface and the heat transfer rate of the low-ambient-temperature air-source heat pump under different horizontal wind speeds are investigated. The location of the unit under the worst conditions is determined, and the influence of cold air backflow on the heat transfer performance is analyzed. The ambient wind hindered the diffusion of cold air at the fan outlet and increased the deflection angle of the fan outlet, resulting in the accumulation of cold air in the upper part of the fan, and the cold air reflux phenomenon in the unit was more obvious inside and on the lee side the array. The results showed that when the horizontal distance between the units was 0.6 m, the horizontal wind speed increased from 0 to 5 m/s. The lowest inlet air temperature of the array unit is 2.44–3.69 K lower than the ambient temperature; the average heat transfer decreases by 1%–6.2%, and the average inlet air temperature is 0.78–1.57 K lower than the ambient temperature. When the distance between the unit and wall is 0.6 m, the horizontal wind speed increases from 0 m/s to 5 m/s, respectively; the lowest inlet air temperature of the array unit is 3.51–4.14 K lower than the ambient temperature; the average heat transfer rate decreases by 5.9%–11.5%, and the average inlet air temperature is 1.29–1.98 K lower than the ambient temperature. On this basis, an array air-source heat pump was simulated under different lateral spacings and distances from the wall. The results showed that increasing the lateral spacing or distance from the wall enhanced the heat transfer of the array low-ambient-temperature air-source heat pump unit. When the lateral spacing increases to 1.8 m, the average heat transfer rate of the array unit can reach more than 96.5% of the baseline heat transfer rate of the array unit. When the distance from the wall is increased to 1.8 m, the average heat transfer rate of the array unit can be more than 91.3% that of the baseline unit. A horizontal spacing or a spacing from the wall of 1.2 m is a better installation spacing, which provides a theoretical basis for on-site installation. |
| Key words: low ambient temperature air-source heat pump array numerical simulation cold air backflow ambient wind fields |
