Research On The Way Of Recovery Of Air-cooled Waste Heat In Thermal Power Plant Based On Temperature-Protected Power Generation

In northern China,most thermal power units use air cooling to recover the exhaust steam from steam turbine work.The process of using air cooling also causes waste of waste steam heat and heat pollution to the atmosphere.In view of the wide adaptability of thermoelectric generation theory to energy grade and the practice of thermoelectric generator in industrial waste heat recovery an d application,this paper provides a new method and new idea for direct air cooling unit exhaust steam waste heat recovery with the help of thermoelectric conversion technology according to the energy supply demand of wireless monitoring node of air cooling unit,which is of great significance to the research on power supply of wireless monitoring node in air cooling system.Based on the Seebeck effect in the principle of thermoelectric power generation,the thermoelectric conversion of waste steam and waste heat can be realized.Firstly,the basic and additional effects of thermoelectric effect are introduced to provide theoretical support for the subsequent derivation of efficiency formula.Through the introduction and analysis of the working environment of the direct air cooling system of thermal power units and the temperature field of the air cooling unit,the overall layout and distribution scheme of the thermoelectric generator in the air cooling unit is designed.At the same time,based on the actual structural characteristics of the air cooling unit,the mechanical structure design scheme of the thermoelectric generator is formulated,and the energy supply demand of the low-power wireless monitoring node is analyzed.Based on the above overall scheme research,the efficiency and power formulas of thermoelectric power generation are derived by characterizing the main performance parameters of thermoelectric power generation,and the factors affecting its power generation efficiency and efficiency and output power are studied.According to the comparison between the actual structural parameters of air cooling units and the thermal conductivity of materials,the hot end installation structure and cold end heat dissipation structure of thermoelectric generators are designed.At the same time,the heat dissipation effect of radiator structure changes is simulated,Finally,the overall mechanical structure of the thermoelectric generator is designed,and the selection of the power management system is determined in combination with the energy supply requirements of the wireless nodes.The thermoelectric unit of thermoelectric power generation is simulated and analyzed to study the influence of its structure change on the output performance.Three dimensional models of three different p/n junction logarithm thermoelectric slice are built by using three-dimensional modeling software.Through finite element analysis,the temperature and voltage distribution within the model are simulated and comprehensively analyzed,and the influence law of different p/n junction logarithm and temperature difference on the power generation performance of thermoelectric module is studied.The results show that the series connection of the thermoelectric generator can increase its output voltage,and the parallel connection mode can increase its output current,but its output power and output efficiency are the same under the two operation modes.Finally,by making the experimental prototype of the thermoelectric generator,the test platform for the output performance of the thermoelectric power generation system is built,and the performance parameters related to the thermoelectric conversion of the thermoelectric power generation system under the similar working conditions of air-cooled exhaust gas are verified.Combined with the experimental data,the charging and discharging effects of lithium batteries and the energy supply of wireless nodes are evaluated and analyzed.The experiment shows that the theoretical research of the thermoelectric power generation system is basically consistent with the experimental test.The thermoelectric power generation system can convert the waste heat of the air cooling unit into electric energy,effectively prolong the discharge working time of the lithium battery,and provide a research basis for the realization of wireless node power supply on the air cooling system by using the waste steam waste heat.