"Ω" Shaped Axial Micro Channel Heat Pipe Heat Transfer Characteristics And Its Heat Exchanger Design

A heat pipe is a sealed vessel which is used as a thermal conductance device. The heat pipe is filled with a work-ing fluid and the pipe is sealed. The micro heat pipe(MHP) is an effective device in various heat transfer, heat recovery, and heat exchanger applications, including biological and nanotechnology applications because of its high efficiency, reliability, and cost effectiveness. On the other hand, the interior physical mechanism in MHP has many differents from conventional heat pipes. The research work on the MHP has positive significance to promote other research in the field of microscale heat transfer. Axial "Ω" microgrooves heat pipe, as a new type heat pipe applied in the field of aerospace, showed the excellent performance of thermal conductivity and temperature characteristics. It can be used in safe, reliable and stable operation under the condition of microgravity, and also be expected to be used in the cooling of microelectronic elements, industrial equipments, and other fields.The liquid flow in MHP will be attached to the inside canal edge area formed by various geometric cross section of the channel.To this axial "Q" microgrooves heat pipe, this thesis analysed the flow characteristics to the internal working liquid in "Ω" shaped micro grooves at low load power firstly. Then analysed the flow rules of steam and liquid insides the heat pipe under the condition of high load power, build the mathematical model. Using the method of numerical simulation to the experimental heat pipe under specific working conditions to slove the steam and liquid flow velocity field. The purpose of the above content is to find the physical evidences to optimize the structure of the axial "Ω" microgrooves heat pipe. Numerical simulation analysis indicated that the contact angle between liquid working medium and the wall material, the geometry sizes in the axial "Ω" shaped micro groove heat pipe have great influence on the flowing of liquid at the microgrooves. Therefore, when designing this type of heat pipe, need to choose the wicking structure, the steam cavity structure size, and suitable working medium.Meanwhile, this thesis has carried on the experimental study to the completed production of aluminum-acetone axial "Ω" shaped micro groove heat pipe.Experiments show that the testing heat pipes’total thermal resistance is0.08-0.18K/W, equivalent coefficient of thermal conductivity is34000-34000W/(m K), about85-190times of copper’s. Heat pipe working at low temperature has good heat transfer performance, but under high temperature conditions, the heat transfer performance is weakened. Gravity has an important influence on the operation of this heat pipe. For this, the more deviating from the vertical state, the decrease of the performance are more severe. In horizontal condition, the heat pipe can operate normally, but which, in a negative angle condition, could not work properly. The startup/shutdown times of this heat pipe are greatly influenced by external factors.The last section of the thesis designs the corresponding water cooled heat pipe heat exchanger using the aluminum-acetone axial "Ω" shaped micro groove heat pipe for industrial zinc pot room. This design adopts185heat pipes which reachs a length of45cm, forking arrange according to the equilateral triangle structure. There are some fins at the heating side. The power rating of the heat exchanger can be up to15kw, which can cool down the zinc pot room’s temperature from80℃to40℃.