| At present,my country’s automobile industry is developing rapidly,and the domestic automobile ownership is also rising.But at the same time,there is still the problem of low automotive thermal efficiency.Especially the exhaust of the car,which takes away 30%-45% of the total heat generated by the combustion of the engine fuel,causing the car to lose a large part of the waste heat and causing a waste of energy.The new energy technology of semiconductor thermoelectric power generation device can be used for waste heat recovery.It has very stable performance during operation,and has the advantages of no noise and long life.Thus received more and more attention.The traditional plate type thermoelectric device mostly adopts the structure that thermoelectric module is directly attached to the high temperature tail gas channel,large fluctuation of temperature at the hot end with the working conditions,poor generation consistency of each generating module and so on.This paper proposes a new type of gas-liquid phase change thermoelectric device,which uses The boiling and condensation of the intermediate medium transfer the residual heat of the tail gas,so as to separate the tail gas channel from the power generation module and improve the power generation performance.At the same time,an experimental system is built to simulate the heat transfer of high-temperature tail gas,which provides heat for the gas-liquid phase change thermoelectric device and the traditional plate thermoelectric device,and compares their power generation characteristics.The experimental results show that:1.Under the same air inlet condition,because the heat exchange between the flat type thermoelectric generator and the high temperature air is large,the power and efficiency of the generation are higher than that of the phase change thermoelectric generator,but with the increase of the air inlet temperature,the gap is gradually reduced.When the inlet air temperature is 250 ℃,the maximum power generation efficiency of the phase change thermoelectric generator and the flat type thermoelectric generator is 0.91%,1.01% respectively;2.Compared with different power generation modules in the device,it is found that when the inlet temperature is 250 ℃,the difference between the maximum voltage and the minimum voltage of different power generation modules in the phase-change type thermoelectric power generation device is only 0.04 V,which is better consistent than the maximum voltage difference of 0.32 v in the flat type thermoelectric power generation device.3.As the number of power generation modules in the device changes,the power generation voltage,power generation and efficiency will also change.If the number of thermoelectric generator modules is less than 2 or 4,the total power generation voltage of the phase change thermoelectric generator,the power generation voltage of a single module,the generated power and efficiency will be higher than that of the flat thermoelectric generator.When the number of modules reaches 6 or 8,compared with the flat-type thermoelectric generator,the total generated voltage,the generated voltage of a single module,the generated power and the efficiency will decrease,and the gap will gradually expand with the increase of the number of modules.With the gradual increase of the number of thermoelectric power generation modules,the heat exchange area between the high-temperature gas and the intermediate medium in the phase-change thermoelectric power generation device increases slowly,and for the flat thermoelectric power generation device,the heat transfer area increases with the number of modules.Corresponding to the increase,the amount of heat exchange increases by a large amount,and the power generation performance of the flat-plate thermoelectric power generation device is more improved than that of the phase-change thermoelectric power generation device.4.After the instantaneous shutdown of the heater,the open circuit voltage and the temperature of the intermediate medium of the phase-change thermoelectric power generation device did not decrease significantly in a short time due to its good heat storage performance,while for the flat thermoelectric power generation device,the open circuit voltage decreased rapidly with the inlet air temperature due to the lack of heat storage capacity. |
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