This paper presents thermal hydraulic analysis of the cross-flow finned tube heat exchangers for an out-door unit in residential air-conditioning and heat pump applications. Performance of heat exchangers affect significantly the system energy efficiency and size of the air-conditioning and heat pumps. The Navier-Stokes equations and the energy equation are solved for the three dimensional computation domain that encompasses multiple rows of the fin-tube heat exchangers. Rather than solving the flow and temperature fields for the outdoor heat exchanger directly, the fin-tube array has been approximated by the porous medium of equivalent permeability, which is estimated from a three dimensional finite volume solution for the periodic fin element. This information is essential and time-effective in carrying out the global flow field calculation which, in turn, provides the face velocity for the microscopic temperature-field calculation of the heat exchanger. The flow field and associated heat transfer for a wide range of face velocity and fin-tube arrangements are examined and the results are presented compared with experimental data. The predicted pressure drop and heat transfer rate for various inlet velocities are in excellent agreement with the measured data.

本文介绍了住宅空调和热泵应用中用于室外单元的错流翅片管热交换器的热力水力分析。热交换器的性能会显着影响系统的能效以及空调和热泵的尺寸。对于包含多排翅片管换热器的三维计算域，求解了Navier-Stokes方程和能量方程。除了直接求解室外热交换器的流场和温度场外，还通过等效渗透率的多孔介质来近似翅片管阵列，该多孔介质是根据周期性翅片元件的三维有限体积解来估算的。在进行全局流场计算时，此信息必不可少且具有时效性，而全局流场计算又为换热器的微观温度场计算提供了面速度。检查了各种面速度和翅片管布置的流场和相关的热传递，并将结果与​​实验数据进行了比较。各种入口速度下的预测压降和传热速率与实测数据非常吻合。