平行流冷凝器的数值分析研究及翅片结构的传热性能优化

发布时间：2018-07-07 07:10

本文选题：平行流冷凝器 + 有限体积法　；参考：《华中科技大学》2014年硕士论文

【摘要】：平行流冷凝器是一种新型高效紧凑式换热器，其优点有换热系数高、结构紧凑、制冷剂充注量少、铝制结构轻、成本低廉，是目前最有发展前景的换热器形式之一。本文采用了数值分析的方法对平行流冷凝器进行研究，得出了冷凝器的热分布，并且提出多种提高空气侧换热性能的方法。首先，选取空气侧的流动传热关联式，制冷剂侧过热区、两相区、过冷区的流动传热关联式；然后，利用FVM，将冷凝器划分为多个微控制体；其次，利用传热单元数法依次迭代算出每个控制体的出口参数；最后，就可以求出冷凝器的整体换热性能。然后将模拟结果和实验结果相对比，验证了仿真模型拥有较好的准确性和精度。根据建立的仿真模型，，给出T1工况和T3工况下的热分布。从流程角度，得出平行流冷凝器的第1第2流程在整个换热过程中占据很主要的地位，两个流程加起来的换热量超过了总换热量的60%；从相态角度，得出两相区是冷凝器的换热主力相区，其换热量占总换热量的比例在65%左右。最后对空气侧的换热性能进行研究，发现增加空气来流速度、减少翅片间距、增大百叶窗开口角度以及降低百叶窗长度都能提高空气侧的换热性能。本文的研究成果很好地给出了平行流冷凝器换热机理，并且能很好的提高换热器的整体换热性能，对以后的平行流冷凝器的设计给出相应的指导。
[Abstract]:Parallel flow condenser is a new type of high efficiency and compact heat exchanger. Its advantages include high heat transfer coefficient, compact structure, less refrigerant filling, light aluminum structure and low cost. It is one of the most promising forms of heat exchanger at present. This paper uses numerical analysis method to study parallel flow condenser and obtain the thermal separation of condenser. A variety of ways to improve the heat transfer performance of air side are put forward.
First, the flow and heat transfer association of the air side is selected, the heat transfer correlation of the refrigerant side superheating area, the two phase region and the supercooled zone, and then the condenser is divided into several micro control bodies using FVM. Secondly, the outlet parameters of each control body are iteratively calculated by the heat transfer unit number method. Finally, the overall change of the condenser can be obtained. Thermal properties.
Then the simulation results are compared with the experimental results to verify the accuracy and accuracy of the simulation model. Based on the simulation model, the thermal distribution of the T1 and T3 conditions is given. From the point of view, the first second process of the parallel flow condenser occupies a very important position in the whole heat transfer process, and the two processes are added together. The heat transfer is more than 60% of the total heat transfer. From the angle of phase, it is concluded that the two phase region is the main phase of the heat exchange of the condenser, and the proportion of the heat exchange is about 65%. Finally, the heat transfer performance of the air side is studied. It is found that the air flow velocity is increased, the fin spacing is reduced, the opening angle of the louver is increased and the louver is reduced. The length of the window can improve the heat transfer performance of the air side.
The research results of this paper give the heat transfer mechanism of the parallel flow condenser well, and can improve the overall heat exchange performance of the heat exchanger, and give the corresponding guidance to the design of the parallel flow condenser.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657

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