平行流换热器管内换热的数值模拟研究

Numerical Simulation Incestigation of Heat Transfer Per Fofmance in Parallel Flow Heat Exchanger Tuber

平行流蒸发器由于其良好的换热性能而广受关注，但目前用在低温下的平行流蒸发器较少，且流场温度均匀性较差。本文采用COMSOL中的广义传热模型和不可压缩N-S方程对其二维模型进行模拟，研究了在相同R134a制冷剂充注量下，8根与10根管平行流蒸发器在孔径大小不变时，调整进口制冷剂流量和管间距后温度场的变化情况；研究了在模拟工况与实验工况一致的情况下，平行流蒸发器降温速率的差异；为改善管内流量的均匀，优化换热器的传热性能提供了参数依据。

Parallel flow evaporator enjoys great popularity with its favorable heat exchange properties, but it＇s used in low temperature is less and flow temperature uniformity is poor. The thesis simulates a two-dimensional model by applying the generalized heat exchange mould and incompressible Navier-Stokes equations in COMSOL. Under the same R134a refrigerant charge amount, when 8 and 10 parallel flow evaporators remains the same size, changes of temperature fields after regulation imported refrigerant flow rates and inter-tubular distances have been studied in this dissertation; Studied in simulated conditions consistent with the experimental condition, the different rate of parallel flow evaporator cooling; In order to improve the uniform rate of the flow, optimize of heat transfer performance of heat exchanger providing the foundation for parameters.