Research On The Influence Of Coupled Operation On The Freezer Of Dual-loop Refrigerator/freezer

Previous research has shown the large energy-saving potential of coupled dualloop refrigeration system.However,test revealed that the coupled operation of the system reduced the freezer's discharge pressure.Part of condensation process took place in the subcooler,which degraded the performance and limited the energy-saving potential of the coupled dual-loop system.Aiming at the problem,this research investigated the effect of coupled operation on the freezer system by theoretical analysis and experiments,revealed the reason of discharge pressure reduction and proposes some feasible solutions.The main outcomes are as follows:1.The freezer of coupled dual-loop refrigeration system is modeled.The experimental platform is designed and implemented based on a BC/D-108 freezer;2.It is shown that the migration of refrigerant from condenser to the evaporator directly lead to the discharge pressure reduction.And the original problem is that the required refrigerant charge of the coupling operation is greater than that of the independent operation;3.The experiment and analysis results indicated that coupled operation will reduce the discharge pressure.The greater the coupled heat exchange is,the lower the pressure will be.The model could describe the change of the operation parameters well within the scope of this study.It is also shown that in our installation,the COP of coupled operation is lower than that of independent operation when the coupled heat exchange is over 20W;The charge difference between coupled operation and independent operation is about 10 g.4.Adding an accumulator between the condenser and the subcooler of the freezer could prevent the reduction of the discharge pressure.However,the feasibility of this method in actual refrigerator products requires further study.