Design And Study Of35kW Composite Air Conditionin Module With Heat Pipe For Data Center

Aimed at the cooling requirements of high performance computer and electronic integrated system with high heat flux, a design of composite refrigeration unit which combines traditional vapor compression refrigeration and separate type heat pipe has been proposed based on the target of energy saving, high reliability and easy to adjust. Operating mode of the composite refrigeration system can be switched among vapor compression refrigeration, vapor compression/heat pipe composite refrigeration and heat pipe refrigeration according to heat load and the temperature difference between indoor and outdoor. Shielding pump has been used in the heat pipe system to drive the working substance cycle. When outdoor temperature is below the temperature set which is based on the needs of environment controlled, usage of heat pipe not only can reduce the energy consumption greatly, but also can avoid the reliability problem occurred in vapor compression refrigeration system during the very cold season. The main contents are as follow:(1) Technology and application of heat pipe were studied according to the relevant technology materials and papers collected. Through investigating the characteristics of heat load of the object controlled and the technical requirements of user, design basis of the air conditioning module has been proposed.(2) A design of composite air conditioning module was put forward according to the cooling requirements of a particular high performance computer.(3) Operating performance of heat pipe unit under different working conditions was simulated based on the mathematical model of heat pipe unit developed.(4) The thermodynamic cycle, heat-exchanger, pump and accumulator of35kW composite air conditioning module with heat pipe were designed in this thesis. Gradual study results are as follow:(1) A design of composite air conditioning system with heat pipe owning independent intellectual property right has been proposed. The operating temperature range of heat pipe is widened due to the usage of mechanically driven separate type heat pipe which can take benefits of outdoor natural cold source more fully. And the energy consumption of system can be reduced greatly.(2) The air conditioning system is designed to be a module which is convenient for large-scale production and can reduce the producing cost. The number of module is determined by the heat load.(3) The refrigerant flow channels of refrigeration unit and heat pipe unit are independent in the composite air conditioning module with heat pipe. The two units are combined in the evaporative condenser.(4) Operating performance and cyclic process of heat pipe system was analysed through simulation. The way to adjust the cooling capacity of heat pipe unit has been proposed. Annual energy consumption of35Kw composite air conditioning module with heat pipe has been calculated through simulation. It shows that vapor compression/heat pipe composite refrigeration mode can widen the working temperature range of heat pipe and improve the annual comprehensive COP of the air conditioning system greatly. Composite air conditioning system with heat pipe is very suitable for the all-weather cooling requirements of high performance computer and electronic integrated system with high heat flux because of its advantages of wide operating temperature range, high reliability and effectively energy saving. Compared with the traditional vapor compression refrigeration system, energy saving rate of the composite system can be more than40%.