The Characteristic Simulation And Structure Optimization Of High Heat Flux Electronic Components Using Phase-change Cooling Method

The high heat flux cooling requirements of electronic components is to ensure that its operating temperature within the normal range,it has become an new hot emphasis on the study, the traditional approach of single-phase flow cooling methods can no longer satisfy the increasing demands of heat flux.The vaporization latent quantity of cold quickly absorpt the heat and achieve the purpose of cooling efficiently.Casing structure of phase-change cooling method is simple and small-volume,it's an effective way to solve the high heat flux of laser crystal.According to the external working entironment and the heat transfer requirements, Casing heat exchanger structure(phase-change cooling pipe)is selected as the suitable form,and then the materials'expression of property parameters is educed by programmed calculation using Matlab.The internal heat transfer process simulation model is established using FLUENT fluid-solid coupling model,and the boiling heat transfer are solved appropriately by UDF programmer.Meanwhile the settings and operations in FLUENT are discussed in detail.The performance of casing pipe's heat transfer characteristics is simulated and analyzed by FLUENT.First,the inner surface of the crystal temperature are calculated under the situations of the same mass flow, different inner tube diameter din(0.002m, 0.003m, 0.004m)and different inlet velocity u.In addition,when the inner cylinder diameter is 0.003m,and different ln2 inlet velocity u (1.5m/s～2.1m/s), different heat transfer surface structure,low-temperature water cooling,the temperature distribution of laser crystal's inner face is calculated,and also at the situation of 2 different pre-cooling temperature,the time when its temperature reaches steady after working are Calculated.Analyzed the influence of the cooling, the dimensionless quantity h/d and the baffle diameter to the whole system.The results show that the sleeve-type phase-change cooling system can be an effective solution to high heat flux laser crystal's cooling requirements. when the jet distance is certain,the heat transfer coefficient of small jet diameter is better thanlarge-diameter's.when the fluid-filled volume is within the range of 1.75～1.84m/s,the maximum temperature of the surface can be controlled within 263～283K,reached the conclusions that the more cavity on the boiling surface,the greater rate of vaporization of liquid nitrogen.When the laser crystal is precooled to 260K\265K,they respectively need 0.3881s\0.39s to reach steady temperature state.Analized the simulation results,and compared with the researchs of domestic and foreign scholars, the trend is consistent with with the theory and the scholars's results. Finally, proposed the structural optimization strategy of the cooling system , and the new cooling method ,the cold prospect of recycling as well.