低层住宅群空调冷凝器送风及换热的数值研究

Numerical study of air flow and heat transfer at condensing units of split-type air-conditioners installed at low-rise residences

近年来 ,随着分体式空调的广泛应用 ,对分体式空调的研究也日趋广泛。合理的流场和温度场可以提高空调机组的制冷效率 ,节约能源。本文采用CFD商用软件对五种不同结构的香港小型住宅群中空调冷凝器的送风与换热进行了数值模拟。计算中我们采用标准k -ε湍流模型 ,在动量方程中引入附加的阻力和体积力 ,在能量方程中引入附加源项来模拟冷凝器 ,并且引入了Boussinesq假设来考虑自然对流的影响。计算得出了五种不同情况下住宅冷凝器附近的温度场、速度场 ,并且对五种情况在制冷效率 (COP)进行了比较。

A computational fluid dynamics(CFD)simulation for analyzing the air flow and heat-transfer at the air-cooled condensers installed at low-rise residences of Hong Kong is presented in this paper.In recent years with the wide spread use of split-type air-conditioners,more and more investigations have been denoted to study their energy performance.In the current study,a commercial software CFX4.2 has been used to simulate the airflow and heat - transfer conditions of five different design cases. The standard k-ε model was adopted, with flow resistance and body force added to the momentum equations to represent the condenser fan operation,volumetric heat added to the energy equations to represent the condenser heat rejection,and the Boussinesq hypothesis used to bring into consideration natural convection.The predicted on-coil temperature data was used to evaluate the energy performance of these five selected cases.The work gives good guidance on the installation of air-conditioning units in low-rise residences.