Experimental Study On Fluid Distribution And Simulation Of Back-plate Heat Pipe Air Conditioning System

Heat pipe,which is also called "superconducting hot body",is a highly efficient heat transfer component.Compared with the same size of the solid metal conductors(such as copper,silver),its heat transfer efficiency is several times higher than the solid metal conductors,even nearly one thousand times,and it has the advantages of low cost,simple structure and reliable work.The working principle of the heat pipe is the heat transfer device which relies on the phase transformation process of internal working substance and completing the circulation through the density difference of gas-liquid phase.In recent years,it has been widely used in energy conservation,development and utilization of new energy.In this paper,by combination of experimental research,theoretical analysis and numerical technology,the problem of fluid distribution with the back plate heat pipe air conditioning system are studied.The heat transfer performance of air conditioning system with back plate is effectively improved.The research results will provide a theoretical foundation and practical experience for further study of the heat pipe air conditioning system.The research contents are shown as the following aspects:(1)First of all,the back plate type heat pipe air conditioner is selected as the research object in the air conditioning system.Based on the enthalpy difference experimental platform of enthalpy difference,The effects of the filling rate of working materials on the air conditioning performance of the system,the effects of the filling rate on the refrigerant temperature and the effects of different indoor and outdoor temperature differences on the heat exchange performance were respectively studied.And the influences of various factors on the heat transfer performance of back plate heat pipe air conditioning are analyzed.The best state of back plate type heat pipe air conditioning is obtained.Then the air conditioning system is taked as the research object,the influence of fluid distribution on the heat transfer performance of the air conditioning system is analyzed,and it is concluded that the heat transfer performance of air conditioning system is greatly reduced when the fluid distribution is not uniform.(2)FLUENT software was used to build the pipeline simulation model of the system.Under the same experimental conditions,the uniformity of fluid distribution in the pipe was simulated.Then compared with the pressure value measured in the experiment,the error between the two is obtained in the range of 10%.The accuracy of the model is verified,and the distribution rule of fluid in the pipe is obtained under four different inlet speeds of 0.5m/s,1m/s,1.5m/s and 2m/s.(3)After the cause of the system fluid distribution non-uniform is analyzed,the pipeline structure of the system has been improved according to the basic theory of uniform fluid transmission and distribution.Then the fluid distribution uniformity of the improved conical structure pipe is simulated and analyzed.The results show that the unevenness of the fluid distribution in the pipeline decreases obviously after the improvement,and it was concluded that the inlet velocity of the pipeline had a great influence on the uniformity of the fluid distribution in the system pipeline.