Study On The Performance Of The R404A Gravity Cooling System About The Area Of Evaporator

Gravity for liquid cooling played an important role in the refrigeration industry.Gravity for liquid cooling bases on the thermal siphon principle. In the gravity feed liquidcooling system for liquid method is super times for liquid. This method can make the liquidrefrigerant in the evaporator greater than evaporation evaporator. Since the supply of therefrigerant liquid in the evaporator is greater than the amount of evaporation, thatguarantees the evaporator pipe remain fully wetting condition, improving the flow rate ofthe refrigerant in the evaporator tube, thereby strengthening the convective heat transfer ofrefrigerant and improving the thermal efficiency of evaporator.Evaporator is an important part of the refrigeration system. Improving the thermalefficiency of the evaporator has a very important role for the refrigeration system. Thethermal efficiency of the evaporator is mainly related to the heat transfer coefficient andheat transfer temperature difference. Therefore, increasing the heat transfer coefficient andheat transfer temperature difference of the evaporator can improve the thermal efficiency ofthe evaporator. There are two methods to improve the heat transfer coefficient of theevaporator. One is the tube refrigerant, another is the tube outer air side. Increasing the flowrate of the refrigerant can also improve the thermal efficiency of the evaporator.The mathematical model is established. The simulation calculation for theevaporator of the gravity feed liquid cooling system is carried on. Decreasing theevaporator area increases the heat transfer coefficient and temperature difference of theevaporator. In order to select the evaporator which can match with the cold storage, fivedifferent areas of the evaporator was simulated. The five kinds of evaporator area is basedon the original area of evaporator, respectively90%,85%,80%,75%,70%. Throughsimulation selects the most suitable evaporator used in the experiments and processing outthe evaporator. Through the experimental study and the comparison of the experimentalresults and the simulation results, we can find that the evaporator area for the original75%can match with the cold storage.In this experiment, there are three comparison, respectively experimental comparisonof original evaporator and new evaporator, the simulation results and experimental results,and experimental comparison of new evaporator for liquid height in different situations.And another study is the new evaporator temperature field. Through analysis concluded thatreducing the area of the evaporator can improve the heat transfer coefficient and heattransfer temperature difference. Simulation results and experimental results are similar.That can show that the simulation of gravity for liquid cooling system can make predict andguide for the evaporator. The most suitable liquid height for the gravity of cooling system is 900mm. Uniformity of the temperature field distribution inside the evaporator remains tobe further improved.