Study On Flow And Heat Transfer Characteristics Of Micro Channel Cold Plate Heat Exchanger

As the size of electronic components gradually dwindles,the traditional heat exchanger can not meet the requirements of miniaturization and the high efficiency of miniaturized electronic components.Since the microchannel cold plate heat exchanger has the advantages of small structure,light weight,easy to carry,low pollution,high heat exchange efficiency and high precision,it has become a development trend of scientific research and engineering application.However,the experimental technology of liquid flow and heat transfer in the current microchannel cold plate heat exchanger is not mature,and the technology and theory of the common size heat exchanger are not verified.In this paper,the main study is to use simulation methods under the microscale liquid flow state,from space with microchannel cooled heat exchangers in the fluid flow and heat transfer are two aspects to find factors that influence the flow and heat transfer characteristics of different function is used to guide and microchannel structure optimization,open the microchannel cold plate heat exchanger in practical bottlenecks in the use of science and engineering.To shape size is 100 mm x 100 mm x 20 mm of space studied experimentally using microchannel heat exchanger in deionized water in different dimensions of channel flow using FLUENT simulation software to study the physical properties of the water in the stress under different conditions with the temperature and the change rule of rectangular cross section aspect ratio,the length of microchannel and equivalent diameter of the change of the flow channel the internal friction resistance coefficient are analyzed,and the results show that under certain conditions can be studied experimentally to improve micro channel heat exchanger by improving the flow of the heat transfer effect;The simulation results are compared with the experimental results of similar models and empirical formulas in conventional flow to verify the accuracy of the method and model.According to the simulation results,the flow and heat transfer performance of the 24 sets of calculation models were optimized.Variable physical properties of microchannel flow through the fluid heat transfer law shows that the influence of microscale water can't be ignored the influence of physical parameters,within a certain range of pressure can be ignored the influence of other factors on the physical parameters.Simulation study of the rectangular cross section micro channel height to width ratio,the length and the equivalent diameter of the influence of flow and heat transfer,introduced some set of space using microchannel heat pipes of different channel cross section structure size,in the same boundary conditions,by comparing the equivalent diameter,the channel section height to width ratio,the length of the three geometric structure size under various numerical example flow between friction coefficient and the rule of variation of nusselt number,it can be seen that the channel section equivalent diameter of Dh,aspect ratio H/W and channel length and the equivalent diameter ratio L/Dh,not all as influence channel water flow and heat transfer performance of geometric parameter.The flow friction resistance coefficient and nusselle number decrease with the increase of the channel length,and the model should satisfy the channel length greater than 32 mm.Through heat flux and heat transfer efficiency curve along with the change of height to width ratio,determine when microchannel ratio of high to width of rectangular section 20,equivalent diameter of 0.436 mm,channel section height is 4.58 mm,width is 0.2289 mm can ensure that the larger the average heat flux and at the same time when the larger heat transfer efficiency.