Experimental And Simulative Study On Performance Of Micro-channel Backplate Heat Pipe In Data Centers

With the explosive demand in mobile Internet,networking,cloud computing and rapid development in IT technology,traditional cooling method in data center could not satisfy the requirement for heat dissipation in modern data center as numerous issues would inevitably occur such as increased energy consumption,low energy utilization efficiency,high value in PUE.Moreover,local hotspot might easily occur in cabinet content,causing the server downtime even damage.With regard to high flux in data center,micro-channel heat exchanger is adopted to cool data center cabinet in this study.And both experimental and numerical studies have been conducted on evaluating thermal performance of the micro-channel backplane heat pipe(MCBHP)cabinet cooling system.Initially,experimental set-up has been established and thermal performance of the MCBHP is experimentally studied based on the enthalpy difference testing platform.The effects of the filling ratio on hear transfer rate,energy efficiency,refrigerant pressure and temperature evolution of MCBHP system has been analyzed,meanwhile,influence of air volume on hear transfer rate of MCBHP system is also evaluated.The ultimate objective of this study is to identify the optimal filling ratio and heat transfer rate.The results indicate that the maximum heat transfer rate and EER are 7.9 kW and 7.9,respectively,the optimal filling ratio is between 65.3%and 74.6%.Moreover,experiments in different cases have also been conducted to investigate the effects of air volume on hear transfer rate as well as the minimum outlet air temperature.When the air volume decrease from 2000m3/h to 600m3/h,hear transfer rate of MCBHP system decrease from 8.6kW to 3.2kW which is dropped by 62.8%,the minimum outlet air temperature also reduce from 22.4℃ to 20.8℃.Then,the steady state model of MCBHP has been established based on the law of conservation in momentum,energy and mass.The developed numerical model is validated by experimental data,and it turn out that the numerical model match well with our experimental data with the relative error 4.5%in heat transfer rate and 8.6%in mass flow rate.According to the results generated by our model,effects of the filling ratio on heat transfer performance parameters such as evaporator heat transfer coefficient and evaporator Reynolds number is investigated.And heat transfer rate and air flow characteristics are analyzed with different indoor air temperature,CDU inlet water temperature and air volume under steady simulation.Based on our model,effects of structural parameters of MCBHP such as fin height,fin pitch,louver pitch,flat tube height and the height difference between evaporator and CDU on heat transfer of MCBHP and flow resistance have been also analyzed,which would provide reference for the design optimization of the system.