Research On Conversion Efficiency Of Solar Temperature Difference Power Generation System Based On Micro Heat Pipe Array

Nowadays,petroleum,natural gas and other fossil resources are still the main ways of energy utilization.The fossil resources are not only polluted seriously,but also the reserves at this stage can not meet the long-term consumption of human beings.In order to alleviate this situation,the research and utilization of renewable resources,represented by solar energy,is imminent.Solar thermal power generation technology can effectively utilize the characteristics of strong solar energy dispersion and low energy flow density to obtain low-temperature heat source.Based on the analysis of the research status of thermoelectric power generation system at home and abroad,it is found that the power generation efficiency per unit area is very low because the collector covers too large area.In order to improve the efficiency of thermoelectric power generation in unit area,a solar thermoelectric power generation system based on micro heat pipe arrays is proposed.This kind of thermoelectric power generation device is essentially a comprehensive utilization of optics,thermodynamics,thermoelectric power generation,control technology and other technologies.Firstly,the Sebeck effect,Palter effect,Thomson effect,Joule effect and Fourier effect of thermoelectric materials are introduced.The Sebeck coefficient,conductivity,thermal conductivity,working principle of heat pipe and convective heat transfer of fluid working substance in heat pipe are explained.A solar thermal power generation system based on micro-heat pipe array is built by selecting micro-heat pipe array,RLHY-2337 solar selective absorption coating and SP1848-27145 SA thermoelectric chip.In order to analyze the performance of thermoelectric power generation system,a test platform based on thermoelectric power generation system is built.Secondly,the photothermal conversion efficiency and thermoelectric conversion efficiency of thermoelectric power generation system based on micro heat pipe arrays are analyzed respectively.In the analysis of the photothermal conversion efficiency of the system,the photothermal conversion efficiency is analyzed from the composite heat transfer of the system and the instantaneous thermal efficiency of the system.In the analysis of the thermoelectric conversion efficiency of the thermoelectric power generation system,the ideal thermoelectric efficiency is explained first,and then the thermoelectric conversion efficiency is analyzed considering the heat dissipation of the system.In order to improve the thermoelectric conversion efficiency of thermoelectric power generation system,the distributed,centralized and hybrid control strategies are compared.Finally,the hybrid control strategy is selected to control the thermoelectric power generation system.Finally,simulation and experiment are carried out for the factors affecting the efficiency of thermoelectric power generation system.Through field test,the instantaneous thermal efficiency and heat loss of thermoelectric power generation system are analyzed and explained.A threedimensional simulation model is established by ANSYS to analyze the influence of thermoelectric units on the ground.Then,the effects of temperature difference at the cold and hot ends,load resistance and series-parallel connection of thermoelectric units on the thermoelectric conversion are emphatically studied through experiments.