Experimental Study On Micro Thermoelectric Generator Driven By Hydrogen Catalytic Combustion

With the development of society,energy and environmental crises are becoming increasingly serious.At the same time,electronic equipment and the Internet of Things have also developed rapidly.The development of high energy density carbon free mobile power supply is an urgent problem to be solved.At present,the most commonly used portable power supply is the lithium battery system,but the lithium battery system has the disadvantages of low energy density,long charging time and high ambient temperature.Therefore,the long-term sustainability of new energy vehicles and UAVs is still a very serious problem.In order to develop a high-performance carbon free mobile power supply under the background of carbon neutralization,a thermoelectric generator with hydrogen catalytic combustion was designed and experimentally studied.The combustion chamber volume is 15.3 cm³.The thermoelectric generator is composed of multi-stage flame stabilizer,two cross ribbed pipe rings,four thermoelectric generator modules,two water-cooling modules and two platinum plated nickel foam blocks.The following conclusions are drawn from the experimental results.（1）In order to improve the hydrogen combustion efficiency of the catalyst,metal foam nickel based Pt/Ni catalyst（porosity 98%）was prepared.The combustion temperature of the catalyst is between 450～650℃,and the hydrogen conversion rate does not drop after 30 hours of operation.（2）The experimental results show that the diethylene glycol designed in this paper can run automatically without ignition at room temperature（20℃）,and the maximum power under the circulating cooling mode can reach 14.59 W,and the corresponding production efficiency is 1.74%.Under the condition of boiling water cooling,the maximum power is 20.7 W,and the maximum production efficiency is2.04%,which is higher than the value reported in the literature.（3）The influence of chemical equivalence ratio on power generation performance and the influence of input power on power generation performance are studied in detail.When the chemical equivalent is greater than the constant time,the output power increases with the increase of the input power.When the input power is constant,the power first increases and then decreases with the increase of chemical equivalence ratio.The optimum stoichiometric ratio is 0.75.When the stoichiometric ratio is less than 0.15,catalytic combustion can still be carried out normally,which has obvious advantages compared with traditional combustion methods.（4）The operation of a thermoelectric micro generator for catalytic combustion of hydrogen in cold regions was simulated experimentally.When the oxygen concentration is lower than 9%,the generator can still operate stably,the power is5.45 W,and the system efficiency is 1.30%when the chemical equivalence ratio is0.65.（5）The hydrogen catalytic combustion thermoelectric micro generator developed in this paper has the characteristics of environmental protection and pollution-free.The NOx content in the flue gas of micro hydrogen catalytic combustion thermoelectric generator is 1ppm（mechanical measurement error is5ppm）,which is far lower than the national standard 150ppm.No SO₂and CO_Xemissions,suitable for social and environmental protection.（6）The hydrogen catalytic combustion thermoelectric micro generator developed in this paper uses highly efficient conversion hydrogen catalytic combustion catalyst,multi-stage flame stabilizer,cross ribbed preheater and collector,and can collect 72.7%of the heat released from hydrogen catalytic combustion.The heat is generated by the heating module.This research has important theoretical significance for the development of zero carbon thermoelectric micro generator with high power density,and provides a new way for the development of hydrogen thermoelectric micro generator and the utilization of hydrogen energy.