Research On Output Characteristics Of Semiconductor Thermoelectric Generator

With the increasing of energy crisis and environmental pollution,people have been paid more and more attention to the recovery and utilization of dissipated energy.Thermal power generation technology can recycle and reuse dissipated energy,which not only improves the energy utilization rate,produces huge economic benefits,but also reduces environmental pollution.Semiconductor thermoelectric technology has attracted more and more attention due to its nonpollution and high reliability in power generation process,but its poor output performance limits its wide use.This paper analyzes the mechanism of thermoelectric power generation technology and the material properties of semiconductors by summarizing the thermoelectric power generation technology.In view of the low output power of the current thermoelectric generator,the research on the output characteristics of the thermoelectric generator is carried out by comparing and analyzing the loading pressure,the size of the cold source structure and the thermal conductive silicone grease.The loading pressure is increased,the output voltage and output power of the thermoelectric generator increase,and the increasing amplitude is smaller and smaller;when different cooling structures are used to dissipate heat to the thermoelectric generator,the smaller the cooling structure unit,the corresponding output The voltage and output power are larger;when the thermal grease is added to the contact surface of the hot and cold end,the air gap between the thermoelectric module and the cold heat source is filled with the thermal grease,so that the contact resistance of the contact surface is reduced,and the temperature difference of the thermoelectric module is increased,and further Improved output performance of thermoelectric generators.However,the output characteristics of thermoelectric generators are influenced by many factors.In order to make a more comprehensive analysis of thermoelectric generators,an output model of thermoelectric generators is established based on the structure and working conditions of thermoelectric generators.The output voltage of thermoelectric generators is obtained by using the model to analyze the temperature at the cold and hot ends,the external load of the contact resistance at the cold and hot ends and the internal contact resistance.There is a linear relationship with the temperature of cold and heat sources,and the different temperature of cold and heat sources will lead to different output voltages at the same temperature difference;the contact resistance at the cold and hot ends will affect the output performance of thermoelectric generators,and the output performance will become worse and worse with the increase of the contact resistance at the cold and hot ends;the existence of the contact resistance will reduce the output performance,but the output voltage will increase with the increase of the load resistance.With the increase of load resistance,the output power increases first and then decreases.In this chapter,based on the response test design method,the external conditions of thermoelectric power generation are optimized,and the influence degree of external factors on thermoelectric power generation is explored.At the same time,the best combination of external conditions is found.It is concluded that the temperature of hot and cold end,contact resistance and load resistance have different effects on the output results.The temperature of hot end has the most significant effect on the output voltage and maximum output power.With the increase of the temperature of hot end,the output voltage and maximum output power increase greatly;the load resistance takes the second place,with the increase of load resistance,the output voltage and maximum output power increase first and then decrease;The temperature and contact resistance have little effect on the results because of the small range of variation.With the increase of cold end temperature and contact resistance,the output voltage and maximum output power decrease,and the reduction range is relatively small.Combined response surface analysis with cost consideration,the optimal results are obtained as follows: hot end temperature 195 C,cold end temperature 15 C,load resistance 3.5?,contact resistance 0.3?.