| Plate heat exchangers have been widely used in different industrial applications for nearly a century. This type of compact heat exchanger provides a number of advantages over other heat exchangers, such as high effectiveness, compactness, easy cleaning, etc. However, due to the complexity of the flow channel shape, the investigation to the plate heat exchangers has little improvement for a long time. In addition, there are little heat transfer and pressure drop correlations of PHE. In order to simplify the simulation of the refrigeration system and the design of PHE, the evaporation and condensation heat transfer coefficient and pressure drop for refrigerant R22 flowing in a plate heat exchanger were investigated experimentally in this study.The main research contents of this thesis are as follows:1. Summarize the development history of plate heat exchangers, and also the significance of this research. A series of correlations suitable for this study are selected from the literatures.2. A steam boiling and condensation test rig of plate heat exchanger are set. Each heat transfer and pressure drop characteristics of one kind of typical operation condition in PHE are obtained. The process of steam boiling and condensation in PHE is analyzed in detail based on the data processing of experimental points.3. A steady distributed parameter model is established to fit the correlation equation of the plate heat exchanger as an evaporator and a condenser. The program is compiled by Visual Basic. Based on the model, the correlation equation of evaporator and condenser are obtained, which can be the design basis for similar board type heat exchangers. In addition, it is possible to improve the performance and design of the exchanger.4. Compared the correlation equation results with the experimental data to determine the correctness of the correlation equation.5. Summarize the research work and suggestions to improve the system, which can be useful for the coming studies.
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