| With the rapid development of the automobile industry,the possessing capacity of global automobile had reached 1 billion in 2017,although,the rapid development of automobile industry facilitates people's lives,the risen environmental and energy consumption problems are receiving wide social attention,therefore,how to effectively save fuel consumption and reduce environmental pollution has become a hot spot in the contemporary word,nowadays.The thermoelectric generation(TEG)technology is a green technology that can utilize TEG material to convert thermal energy into electric energy directly,for that there is a large amount of exhaust heat in the automobile exhaust system which can be used to generate electric energy with TEG technology,it not only can improve the utilization rate of automobile fuel but also can achieve the effect of energy conservation and emission reduction.This paper made research on the automobile exhaust heat recovery system equipped with thermoelectric generator,firstly,the paper analyzed the inner heat of engine system and the distribution of exhaust heat,temperature and pressure in the exhaust system,Secondly,based on the analysis of the contributory factors to TEG with heat of high temperature exhaust and the consideration of continuous operating temperature limit of TEG material hot end,adaptability of engine working conditions and effect on the exhaust system,and then,proposed the structure of exhaust heat flow diversion control thermoelectric generator and designed the exhaust heat flow diversion control strategy.This paper established the fluid-solid coupling system,the three-dimensional and steady-state calculation model between exhaust and thermoelectric generator with CATIA and ANSYS software,as well,considered the continuous operating temperature limit of TEG module hot end,the distribution uniformity of temperature and the effect on the back pressure of exhaust system,and then,simulated and optimized on the structure of heat-collecting box.The results show that: the optimal dimension structure of heat-collecting box is 400mm(length),100mm(width)and 110mm(height),when the engine operates at normal and high-speed steady working condition respectively,the maximum temperature of the TEG module hot end reaches 169? and 201? respectively;the distributions of temperature are uniform,so that,it can adapts to the engine working conditions when compared to the selected TEG material(continuous operating temperature limit of hot end is 200?);and the back pressure in the thermoelectric generator reaches 16.81 kPa and 13.89 kPa respectively,so that,the change of back pressure and the effect on the exhaust system are both small after refit;the average output power of a single TEG sheet reaches 3.3W and 4.65 W respectively.This paper built the simulated test table based on the refit of JAC Refine A60 exhaust pipe,the experiment simulated and analyzed the influence of valve opening degree on the temperature of hot end,cold end and the output power of TEG module when the engine is at idle,start-stop,normal,around city and high-speed working condition respectively,and then discussed the effective ways to improve the output power of thermoelectric generator.The results show that: the temperature of the TEG module hot end can reach the continuous operating temperature limit of the TEG material at the special working conditions,however,the impact of the special working conditions can be avoided with the designed flow diversion control strategy;with the gradual increase of simulated exhaust inlet heat,the optimal valve opening degree shows a gradual upward tendency,at the same time,changing the distribution of exhaust heat flow through the thermoelectric generator by controlling the valve opening degree can improve 6%~22% total output power of the thermoelectric generator,however,with the gradual increase of the simulated exhaust inlet heat,the additional increase of output power shows a tendency of increase at first and then decrease. |
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