Research On Development And Productization Of Dual-loop Coupled Refrigeration System

With the improvement of living standards,consumers’ refrigerator/freezers(RFs)consumption habits are gradually changing.Consumers concern about not only the energy consumption of the RFs,but also the form,function,etc.Currently,trend of development of the RFs have advanced from simple low temperature storage to high-capacity,multi-temperature zone,high temperature control accuracy,energy saving,environmental protection and other high-quality aspects.In order to capture the market quickly and enjoy high profits,it is vital for each manufacturers to design and produce RFs that meet consumer needsWith significant energy-saving effect and high temperature control accuracy,double-compressor dual-loop system has great potential for application.However,the high initial cost and low efficiency of small compressors limited its application in the market.Apply the cooling transformer technology to double-compressor dual-loop system,and a dual-loop coupled system is proposed.The coefficient of performance(COP)improved significantly in the new system,without compromising temperature control accuracy,which greatly promotes the application of the double-compressor system in the market.On the basic of the previous research,the novel dual-loop coupled RFs are constructed,and systematical studies are carried out from the aspects of theoretical analysis,simulation calculation and experimental test.The detailed research results are as follows:1.The theoretical analysis and calculation between double-compressor dual-loop system and conventional single-cycle system were carried out.The results showed that the COP of double-compressor system was higher than that of traditional single-cycle system,and dual-loop coupled system could achieve higher energy-saving potential than traditional double-compressor system.2.The overall structure and arrangement of the RFs were designed,the heat load calculation and thermal calculation of the system were completed.Based on all of these,the components of the RFs were selected and designed,and the dual-loop coupled RF prototypes were constructed.3.The temperature and coupling running combination control scheme was presented,and the control effect was analyzed and verified by means of computer simulation and experimental tests.The results showed that the synergy control between compartment temperature and coupling running of RF system were achieved.4.By comparing the experimental results of two typical RF prototypes,the influences of running conditions on the operating parameters of the refrigerator subsystem and freezer subsystem were analyzed.5.The standard energy consumption tests of dual-loop coupled RFs were carried out,the results showed that the energy consumption of dual-loop coupled prototype was 1.15 kW·h/24h,which met the Level 1 of energy efficiency standards and was significantly lower than that of same model single-cycle system RFs.Finally,the shortcomings of the existing research work and the ideas of further research are briefly described.