Experiment And Numerical Research On Compression/injection Hybrid Refrigeration Cycle In Household Refrigerators

In the 21^sh Century energy crisis,energy-saving of household refrigerator is very important for economic development,environmental protection and energy security. This dissertation is to study compression/injection hybrid refrigeration cycle system on the basis of previous studies,optimiz the design of refrigerator-ejector.The results manufactured refi-igerator-ejector sample and refrigerator prototype into superior energy-saving effect according to the requirements of the system performance.To achieve the objectives,theoretical study and experiment on compression/injection hybrid refrigeration cycle system of refrigerator were carried out respectively,the results conclude that:(1) For the compression/injection parallel hybrid refrigeration cycle system,two refrigerator experimental prototypes' energy consumption are 0.775 kWh/day and 0.748 kWh/day respectively,which fail to reflect on the energy-saving advantages.(2) For the compression/injection series hybrid refrigeration cycle system,two refrigerator experimental prototypes with different capillary flow energy consumption are 0.760 kWh/day and 0.768 kWh/day respectively,similarly there are disadvantages of low energy consumption.(3) For the compression/injection heat-exchange hybrid refrigeration cycle system,the loss of heat in the throttle processing can be effectively decreased,the refrigerator experimental prototype's energy consumption is 0.655 kWh/day,with reducing energy consumption by 7.75%.The numerical simulation on the performance of refrigerator-ejector was studied, the results show that:(1) In the outlet of nozzle,there are two vortices on the center line for the axis of symmetry.(2) In thermodynamic parameters,there is one optimal pressure of primary fluid,i.e.P_popt=0.06612 MPa,corresponding to the maximum entrainment ratioμ=0.568,and one optimal pressure of secondary fluid,i.e. P_Hopt=0.04837 MPa,corresponding to the maximum entrainment ratioμ=0.564.(3) In geometric parameters,being one optimal throat area ratioΨ_opt=6.25,corresponding to the maximum entrainment ratioμ=0.561,there is one optimal cross-section distance of nozzle exit between mixing chamber entrance X_copt=14.78,corresponding to the maximum entrainment ratioμ=0.563,the angle of mixing section has a negligible effect on the performance of refrigerator-ejector and entrainment ratio has no noticeable change which maintains a relatively high value withθ=5°～10°.The modified suction(or discharge) booster energy-saving devices were used, the refrigerator can reduce energy consumption by 3.36%～8.0%,what's more,the refrigerator with the discharge booster energy-saving device has advantage in reducing energy consumption than which one with the suction booster energy-saving device.