并联型水冷散热器

重庆大学硕士学位论文ABSTRACTWith economic boom of China,especially the rapid development of high-speed railindustry,various power electronic devices have been applied more and more widely tolocomotives.Particularly,high-power IGBT modules have already become increasinglysignificant in high-speed rail.All these power electronic devices develop toward thehigh-power,miniaturization,integration and high-performance direction.The problemfollowing it is that the increasing calorific value of these devices renders that heat fluxof system also increases quickly.However,this equipment has to work at a certaintemperature range.If the temperature exceeds the maximum allowable workingtemperature,the reliability of the equipment may be dramatically reduced and even theequipment be burned down.As a result,the study on cooling the devices in locomotiveshas become necessarily significant.At present,the water-cooling radiator has predominated in locomotives.Channelsin traditional water-cooling radiators are mostly connected in series.The problem is thatthe temperature of cooling water will continue to rise along the flow direction,whichwill result in uneven distribution of temperature on the radiator.In order to deal withabove-described problem,this paper focuses on the water-cooling radiator whosechannels are connected in parallel.The main contents of this paper are as follows:1Physical and mathematic model of the parallel water-cooling radiator has beenestablished and numerical simulation was applied to the model.Then,variousparameters of the performance of the radiator were obtained and the calculated resultswere analyzed,too.A method for measuring the uniformity of temperature distribution,which is determined by the uniformity of flow distribution,has been proposed.Moreover,by comparing different flow rate of the cooling water,it was concluded thatthe uniformity of temperature distribution would first increase and then decrease as flowrate increase and there exists a critical flow rate that can make the temperatureuniformity achieve the optimal value.2 Because of the sophistication of the radiator's model and huge grid,an effectivesimplified model method has been proposed to reduce the computation cost and shortencomputation time.In addition,the feasibility of the model has been verified.3 In order to improve the performance and temperature and flow rate uniformityof the radiator,structure optimization is carried out.Four different channel structures,