Theoretical And Experimental Research On A Subcooled Evaporation Combined Absorption-Compression Refrigeration Cycle

With the energy crisis growing increasingly, governments are paying more attention to the development and utilization of the low grade energy, such as solar energy, geothermal energy, industrial waste heat and so on. In this process, combined absorption-compression refrigeration cycle which could be driven by low temperature heat source and has high performance has been brought up to the public’s interest. However, the general combined absorption-compression refrigeration cycle used the same work medium, which had influence on the efficiency of absorption and compression refrigeration cycle to a certain extent respectively. So a theoretical and experimental research on a new combined absorption-compression refrigeration cycle has been taken in this article. The research content mainly includes:(1) Firstly, the research background has been expounded and the development history of absorption refrigeration technology has been reviewed in this article. According to the developing status of absorption refrigeration technology, conclusion can be made that combined absorption-compression refrigeration cycle is fit for the development and utilization of the low grade energy. Meanwhile, brief introduction of the research status of the combined refrigeration cycle at home and abroad has been presented.(2) Secondly, a program compiled by the Visual Basic language is used to do simulated computation on performance of this new combined absorption-compression refrigeration cycle. The effect of generation temperature, evaporation temperature, condensation temperature, heat flux, refrigeration capacity on the performance of new combined cycle have been obtained. Also, its performance compared with that of a conventional compression refrigeration cycle is presented.(3) Based on the thermodynamic calculation, structure designing and selection Calculating on components of the new combined refrigeration system have been described. Anew combined refrigeration experimental system has been constructed.(4) Finally, in order to obtain the performance characteristics of this new combined absorption-compression refrigeration system futher and verify the model computation results, some experiments have been carried out. The experimental part includes:research on the performance of traditional absorption refrigeration system, new combined absorption-compression refrigeration system and traditional compression refrigeration system. In the end, comparision of the performance of this new combined refrigeration system and traditional compression refrigeration system has been made.The model computation and experiment results prove that the absorption subsystem cycle of this new combined refrigeration cycle produces refrigeration capacity to subcool the refrigerant of the compression subsystem cycle, which makes low grade refrigeration capacity produced by absorption subsystem cycle transform into high grade refrigeration capacity exported by combined cycle. Consequently, under the same power consumption of unit refrigerant flow, the refrigeration capacity of new cycle is more than that of traditional compression cycle. The COP of the new cycle is also higher than traditional compression cycle. Setting regenerator in the new cycle helps to reuse the waste heat of compressor exhaust partly and reduces the heat requirement of the new cycle, which improves cycle’s performance effectively. In addition, compared with traditional absorption refrigeration cycle, temperature required for driving heat source in the new cycle has been lowered. During the experimental process, when hot water’s inlet temperature has been lowered to64.4℃, the new cycle still could work normally.To sum up, it is clear that the new cycle not only could greatly reduce air conditioning load, but also provides technical support for the development and utilization of the low grade energy.