| Parallel flow heat exchanger has been widely used in the field of refrigeration and air conditioning because of its low cost, low refrigerant charge and high heat transfer coefficient. Previous studies have shown that one of the important factors that restrict the performance of this type of heat exchanger is that the refrigerant distribution is uneven between the tubes. In this paper, the theoretical analysis, numerical simulation and experimental research are used to study the influence factors of the uneven flow distribution. And the scheme to improve the uneven flow distribution is given.In this paper, several factors, such as the geometric parameters, the pressure drop in the tube and the refrigerant dryness, are studied for the parallel flow heat exchanger with end to side and side entry. The characteristics of refrigerant distribution under various geometric and geometric parameters are studied.The theoretical model of the flow distribution in the pipe is established by theoretical analysis, and the influence factors of the uniform distribution are analyzed by the correlation analysis. The Tae theory model and Lu model are compared and analyzed. The advantages and disadvantages of two different theoretical models are obtained.In this paper, the modeling and numerical calculation of the end to side parallel flow heat exchanger are presented. The reliability of the numerical model is verified by comparing the numerical results with the experimental data. The simulation data is analyzed, and the research direction is pointed out. By using numerical simulation method,respectively for the parallel flow heat exchanger pipe manifold, research and design the geometrical parameters of the splitter plate. The effects of different geometric parameters on the flow distribution are obtained. Based on the analysis of the flow field distribution in different parameter models, a scheme for improving the uniformity of flow distribution is put forward. In addition, the comprehensive influence of various factors on the flow distribution, given a set of optimal combination model and parameter setting. The numerical results show that the flow distribution uniformity is improved obviously.In this paper, a visual experimental platform is set up to visualize the flow and distribution of fluid in three typical geometric models. On the one hand, the experimental results verify the validity of the calculation results. On the other hand, we give detailed information about the flow and distribution of fluid in the pipe. The results show that the distribution of the pipe is the best when the splitter plate (No. 12) is added.The research in this paper is expected to provide reference for the design and performance improvement of parallel flow heat exchanger. |
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