Analysis Of Constant Temperature Difference Power Generation System Based On The Exhaust Heat

In recent years, chinese automotive industry developed rapidly. The demand forthe car increased, along with the development of the automotive industry also broughta series of problems: increased oil consumption, increased pollution emissions,therefore energy saving was putting on the important agenda. Many advancedtechnologies are constantly developed and used into the automotive industry.Thermoelectric power generation as an important technology was applied to the fieldof automotive exhaust residual energy recycle. Based on the situation of Fuelcombustion heat only30%to40%are used and most of the rest in the form of tail gasdischarged into the atmosphere because of restricted by the current engine technology.It will not only be able to convert the exhaust heat energy into electrical energy,achieve automotive exhaust residual energy recycle, improve energy efficiency, butalso can improve the environment, bring huge economic benefits.The current relatively mature power generation system is few in the area oftemperature difference power generation. As is known to all, automotive exhaust gasunder different conditions has pulsation, exhaust temperature is unstable and it can’tprovide a stable heat source. So it has a strong impact on the power performance ofthe thermoelectric power generation. Based on heat transfer theory and phase changeenergy storage technology, Phase Change Materials (PCM) can be endothermic orexothermic to storage or release energy, high thermal conductivity filler played as anenhanced heat exchanger intermediary exchanged heat power with thehigh-temperature exhaust, not only improved exhaust heat recovery powergeneration,also reduced the volume of the device. So this paper has launched a studythat combined with phase change heat storage technology and the temperaturedifference power generation technology to form a new type of phase change heatstorage temperature difference power generation system.The related content and the main work is as follows:1.Mastering temperature difference power generation theory of technology,having carried on the theoretical analysis to warts the tail gas waste heat powergeneration system power generation model, calculated the temperature difference power generation system of waste heat utilization. In the meantime realised the highperformance, high reliability temperature difference power generation technology andbought a temperature difference power generation components used in the experiment.and has set up a test platform for the temperature difference power generationcomponents. Mastered the different temperature, temperature difference underdifferent combination circuit topological structure of power generation. Received thefollowing conclusions:（1）The output voltage of monomer thermoelectric generator increased with theincrease of temperature, with the increase of test temperature, the growth rate ofoutput voltage decreases gradually, finally tends to be the same.（2）The output power of monomer thermoelectric generator module goes as theload increases first increases then decreases, when the load resistance matchingresistance to the power module resistance, the power module reached the maximumpower output.（3）Need to know power resistance and external load to decide what specificconnections more efficient in Multi-chip thermoelectric generators.The new phase-change thermal power generation system: a combination of phasechange thermal storage technologies and thermoelectric power generation technology,and filled with foam nickel as enhanced heat transfer medium. The phase changethermal storage is a key factor in the phase change thermal power generation system,the regenerative heat release rate affects the performance of the whole system.Therefore this paper established a mathematical model of the new accumulator andqualitative conditions, using Fluent software for phase change thermal storage deviceto simulate analysis. Studied exothermic characteristics of Phase Change Materialunder different conditions on different times in different storage location, meanwhileanalysied the rule of special type of phase change thermal storage with the influenceof different porosity metal foams. The results showed that:(1) Increasing the temperature difference and add foam metal can greatlyimprove the rate of phase change thermal storage heat.(2) As the distance from the inner wall of the heat source increases, the heattransfer rate of the phase change material successive decrease. (3) In the melting process, with the advancement of the time, the heat transferrate of PCM successive decreases in the solidification process, the heat transfer ratesuccessively reduced.(4)95%of the metal phase change material porosity complete the meltingprocess of the shortest, but the porosity affect the coagulation time of melting within5min.3.The shortest time to finish the melting process is the PCM of the95%metalporosity,but the porosity affect the coagulation time of melting is in5min.In order toverify the simulation results of phase change thermal storage device, carring out anickel foam filling phase change thermal storage experiment to verify the strengtheneffect of metal foam influenced on the PCM heat storage process.Designed a newphase change thermal storage, completed the filling of PCM， built an experimentalplatform for the regenerative heat experiments. Experimental results were as follows：（1）In the regenerative process: In contrast to the same longitudinal section,with a different cross-section1#and2#found that farther away from the inner wall.In contrast the same cross-section, a different longitudinal section1#and3#, can befound that the trend is substantially consistent with the temperature change goes as thetime goes.（2）The results of experiments and simulations has some differences。Indifferent conditions.Temperature measurement points of1#is almost unanimously, can be speculatedthat the simulation had basically the same in the proximal. The maximum temperatureand the temperature change of2#is not very consistent. However, the overall trend ofthe curve temperature changes is consistent, and analyzed the differences between testand simulation.