Performance investigation of a finned tube evaporator under the oblique frontal air velocity distribution

The performance evaluation of the finned tube evaporator under different frosting boundary conditions is of great importance to the refrigeration industry. This paper presents a set of equations, which can be used to predict the performance parameters of an evaporator, when there is an oblique angle between the inlet air velocity and frontal face of the evaporator. In order to calculating the performance, a simulation model for predicting the performance of a plate-fin tube evaporator, on which frost formation occurs, has been presented. This model adopts different numerical algorithms according to different flow conditions including laminar, transitional and turbulent flow patterns. An experimental setup is built to verify the validity of this model. Then a comparison between the model's predictions and laboratory test data is provided. After correction, the numerical program based on this model is used to predict relationship between the oblique angel of the inlet air velocity and performance parameters (including frost weight, pressure drop and refrigerating capacity of the evaporator). At the end of this article, the degree of performance degradation is described by a set of equations that is obtained through regression analysis.