平行流热管换热器传热传质特性的数值模拟研究

Numerical Simulation of Heat and Mass Transfer in a Parallel Flow Heat Exchanger

建筑排风冷能回收是降低建筑能耗的重要手段。本文基于Fluent提供的VOF模型,编写蒸发冷凝相变的UDF程序,对用于建筑排风冷量回收的平行流热管内部的蒸发和冷凝特性进行了数值模拟,计算结果揭示了平行流热管内的气液两相流特性以及复杂相变传热传质的演变过程。结果表明:蒸发主要发生在液池内部,冷凝主要发生在冷凝段和绝热段的近壁面部位;相变传质过程是保证热管高效换热的关键因素。本文结果为设计平行流热管换热器提供理论依据。

Building exhaust air cold energy recovery is an important means to reduce the building energy. Based on the VOF model provided by computational fluid dynamics software Fluent and the UDF program of evaporation-condensation phase transformation written, numerical simulation of heat and mass transfer in a Parallel flow heat pipe used for the exhaust air cold energy recovery is carried out in this paper. The results revealed the characteristics of gas-liquid two phase flow and the complicated heat and mass transfer process in a Parallel flow heat pipe. Evaporation mainly occurs in the liquid pool, and condensation occurs mainly on the near wall of the condensation section and adiabatic section, the mass transfer with phase change is the key factor to ensure the efficient heat transfer of the heat pipe. The results of this paper provide a theoretical basis for the design of parallel flow heat exchanger.