| In recent years,our vehicle industry has been developed fastly.Nowvehicles are our important tracffic tools in daily life.Due to the increaseof vehicle gross in our country,the consumption of fuel that provided tovehicle is immense,which result in the environmental pollution caused byvehicle emissions can not be ignored.In response to these series ofquestions,many governments in the world continue to improve laws andregulations on environmental pollution that caused by vehicles.Everyadvanced vehicle technology research organization has invested a lot ofmoney and research efforts to develop new energy conversion devices.The thermoelectric power generation system which recycle theautomotive waste heat has became a hot focus of major companies,universities and their research institutes, the waste heat in automobileexhaust emissions can be coverted to electrical energy,it is a effectivesolution to improve the use rate of the fuel combustion energy.In theanother hand,it can be considered to improve the fuel efficiency of thevehicle, and increase the inlet gas temperature,so some kinds of theharmful exhaust emissions can be decreased,it has a good prospect and important social value.Based on the analysis of relevant research about LNGV at home andabroad, the liquefied natural gas (LNG) vehicles as a new energy vehiclesare promoted by governments, but the automobile exhaust waste heatpower generation system has many defects such as a low output power,conversion efficiency and so on, but LNG as the cold source ofthermoelectric power generation that provides good conditions for theapplication of thermoelectric power generation and increases the outputpower of thermoelectric power generation,but the reliability andperformance of LNG vehicles must be analyzed.Firstly,thestream-structure coupling analysis of heat exchanger which closelyrelated the use rate of waste heat is needed, simulation can be done toimprove the thermoelectric power generation module installation surfacetemperature distribution through a variety of ways,and analysis its impacton traditional exhaust system.To find an effective way to increase thetemperature difference between the hot and cold side of the powermodule. Using UG establish three-dimensional model of three differentinternal structure heat exchangers of the internal structure,thenconducting multi-physics coupling analysis by ANSYS Fluent,where theautomobile exhaust high-temperature gas flow and heat transfer processin the heat exchange channel can be analyzied.By means of analysiscorrelation search methods to obtain the finite element model and the boundary conditions.Through calculation the three heat exchangerstemperature,pressure and flow field simulation results areobtained,comparing with heat exchanger with smooth surface,"one" finand "person" fin,analysis these kinds of heat exchanger simulation resultsto obtain the best among these heat exchanger structures.At last,saving itsthermoelectric power generation module mounting surface temperaturecontours,then a reasonable module installation pattern should be decided,it provides the basic conditions for the subsequent simulation,andconsidering the impact of the contact resistance on the moduletemperature distribution,conducting the contact heat transfer optimizationfrom the thermal contact resistance aspect.In addition,the heat-solid and heat-electricity coupling analysis ofthermoelectric power generation device on the automobile exhaust systemare conducted,the temperature load that caculated in fluid couplinganalysis is loaded,then stress and strain analysis of thermoelectric powergeneration unit are caculated,and compared with the simulation results ofthermoelectric power generation unit which take cold water as coolsource,the results show that the automobile exhaust thermoelectric powergeneration unit meet the requirements,and provides a reference for thefuture research. |
PDF Full Text Request