Research On Heat Transfer Mechanism Of Micro-groove Plate Heat Pipe And Micro-channel With Electronic Devices Cooling

With the electronic devices branching out into high-density and high-power, the chip heat flux is made so density that the space for heat dissipation decrease. The traditional way of cooling electronic technology may not meet the growing demands of electronic technology. The research and development of microchannel plate heat pipe becomes a hot spot because of its broad application prospects in cooling device in the electronics field.Although the structure of microchannel plate heat pipe is simple, the physical process taking place within them are complex. Experts have not yet reached a consensus on some mechanism. In this paper, the author summarizes and synthesize former research results on microchannel plate thermal theroy, and conduct a more in-depth study on the microchannel plate rectangular slot heat pipe.This paper consists of four major parts:Part one is about the design elements of flat heat pipe and its manufacturing process. In this part, the author points out:In the process of design, attentions should be paid to the compatibility of woking qulity and shell material; in manufacturing, the key process of cleaning, leak detection and filling should be strictly monitored in order to ensure the production quality. Also, a disscussion is given about the limits on heat transfer of heat pipe. Part two deals with that having fully considered the vapor-liquid interfacial shear force within the channel, how to establish the mathematical model of a micro heat pipe flat rectangular slot; By iteration method, how to calculate refrigerant mass flow rate, the average velocity of fluid and steam, the meniscus radius of vapor-liquid interface, and their pressure distribution pattern along the groove. An experimental study is also made on the micro rectangular copper used in experiments---a horizontal plate heat pipe. The result shows that the heat pipe has a good start feature; its best charge ratio is 1.3; the gravity can assit the heat pipe in exchanging heat and improve the heat transfer performance; the improvement of cooling ability of the condensing section can effectively raise the heat transfer performance. In Part three, the author compares the calculation results of the surface temperature of the heat pipe wall with the experimental results, and find that both are basically the same values. Meanwhile, the tests of simulation are carried out by using thermal analysis software_ANSYS. The temperature of the center surface of the heat pipe calculated by iteration method and the simulation results are compared, and the error is only 5.27%.The results prove that the mathematical model bulit is in line with the actual one and it has directive significance on the theoretical analysis of heat pipe. Finally, some simulations are conducted with three kinds of microgroove plate heat pipes (rectangular, trapezoidal' and triangular). The author makes a comparision with the focal point temperatures of micro-groove plate heat pipes under the conditions of the heating power being respectively 30w,40w and 50w. At last, three-dimensional numerical simulation is carried on the heat transfer and flow characteristics of rectangular micro-channel, and the theoretical reference could be provided for designing and study the performance of micro-channel by analyzing the model.Obtained by this study:The cooling of electronic devices using micro-channel plate heat pipe built by the mathematical model is basically consistent with the actual situation, and can truly reflect the heat transfer and flow characteristics of micro-channel plate heat pipe; It has help for theoretical analysis of the heat pipe; Flat trapezoidal groove heat pipe has much better heat transfer performance.; The model of rectangular micro-channel can be more truly reflect the heat flow charateristics. At the end of this paper, a further in-depth study on electronic devices and heat pipe is viewed.