Research On Application Of Data Center Cooling System Combined Heat Pipes With Water Cooling

With the rapid development of information age, requirement of the data services has explosively increased, so the cooling mode of traditional data room cannot meet the needs of the IT services expansion and the deployment of high-density computer equipment. In order to solve high energy consumption, low energy utilization efficiency, insufficient cooling capacity and other problems in the current data center, a new cooling solution, which is composed of a data center system combined heat pipes with water cooling, is proposed. The cooling system accurately cools the data center by utilizing liquid cooling as the main cooling mode and wind cooling as the auxiliary cooling mode. Heat of the main heating element in the server can be discharged with water-cooled heat pipe radiator, and then the heat is dissipated to the cooling power by the plate heat exchanger which uses natural cooling source as refrigerant.Structures of the water-cooled heat pipe radiators, including heat pipes, cold plate and substrate, are designed for the two different servers(Sugon I620-G15 and Huawei Tecal RH2288). The selection and manufacturing technology of each component are analyzed. Grooved heat pipes with 8mm diameter, 68 tooth number and 0.5mm wall thickness, which uses water as working medium and with high permeability, are selected according to the analysis of working medium, wick structure and steam and liquid flow pressure drop. 6061 aluminum alloy is selected as material for cold plate, vacuum brazing technique is used in welding and then leak test is carried out. At last, heat pipes, cold plate and substrate of the water-cooled heat pipe radiator are welded by reflow soldering.Icepak is used to carry out numerical simulation analysis and comparison of server-class data center cooling system combined heat pipes with water cooling and air-cooled cooling system. In the case of inlet water temperature of 25℃and inlet velocity of 0.2m/s, the maximum temperature of CPU in the cooling system combined heat pipes with water cooling is less than 50℃. The temperatures of CPU, hard sink and memory reduce more than 20℃, 20℃and 10℃, respectively. A comparative test is done to further verify the feasibility and superiority of data center cooling system combined heat pipes with water cooling.From the aspect of process and influencing factor of the water-cooled heat pipe radiator, the relationships between heat transfer temperature difference between substrate and heat pipe, temperature difference between inlet and outlet water of the cold plate, CPU temperature and other factors such as environment temperature, CPU load, inlet water temperature and inlet flow are analyzed. The correlation formula between these parameters are deduced by mathematical modeling.Finally,an experimental data room utilized cooling system combined heat pipes with water cooling is set up. The energy consumption, PUE and economic benefits of the data center are analyzed. The results show that cooling system combined heat pipes with water cooling not only can remove heat island effect of the server but also enhance the average operating power up to 25 kW. The installed capacity of the machine increases more than 200%, the energy consumption of air conditioning system reduces about 19.2%-30.6% and PUE is less than 1.2.