Multi-objective Optimization Of Thermoacoustic Engine

Thermoacoustic machinery is a new type of power conversion device with high reliability and flexibility.It shows great potential in civil science and technology,military,aerospace,electronic information technology,biomedical and other aspects.At the same time,in view of low-grade energy utilization and environmental friendliness,it can significantly reduce the dependence of today's society on petroleum energy,thereby effectively alleviating air pollution.On the basis of previous work,this paper applies the finite-time thermodynamics theory to the multi-objective coordinated optimization of thermoacoustic engine.The efficiency,output power and entropy yield are included in the multi-objective optimization category,in order to find the best compromise of thermodynamic parameters of thermoengine,and the cycle performance of low-grade energy-solar-driven thermoacoustic engine is discussed.Its main contents are as follows:1.Aiming at the multi-objective optimization of thermoacoustic microcirculation under ideal conditions,the relationship between output power and efficiency of irreversible heat engine microcirculation model is analyzed in limited time.The relationship between profit margin,ecological objectives and oscillation temperature and longitudinal temperature gradient was discussed.The optimal operating conditions of thermoacoustic microcirculation under ideal cycle and the optimal coordination point between power and entropy production were found by using intelligent optimization algorithm.2.Aiming at the multi-objective optimization of thermoacoustic microcirculation including linear process,the analytical formulas of output power and efficiency of the actual irreversible heat engine microcirculation model in limited time are derived,and the relationship between profit margin,the volume ratio of ecology target to constant pressure endothermic volume ratio and cycle pressure ratio is deduced and analyzed.The coordinated equilibrium between input rate,output rate,power rate and entropy rate is sought through profit rate and ecological objective,and the influence of irreversibility on the performance of heat engine is discussed.The multi-objectiveoptimization function is established by weighting method,and the optimal coupling effect between output power and cyclic entropy yield is analyzed.3.Aiming at the multi-objective optimization of thermoacoustic cycle,the thermal relaxation factor is introduced to establish the optimization model of irreversible Carnot thermoacoustic motor under complex exponential heat transmission standard.The rate of work target and the exergy capacity factor target under the complex exponential heat transmission standard are deduced.The coupling analysis is carried out by introducing the intermediate function Z target.The multi-objective coupling optimization of the Z target and the ecology E target of the heat engine is carried out by using the minimum-maximum method.The results show the combined optimization performance of the output power,the efficiency and the entropy yield.4.Aiming at the optimization of thermodynamic performance of solar-powered thermoacoustic engine,the optimal analytical expressions of output power and total efficiency of the thermoacoustic engine with complex exponential heat transfer under solar radiation heat model are derived,and the effect of internal irreversibility on the performance of the engine is discussed.The influence of temperature ratio factor on single thermal efficiency is analyzed.The influence of collector temperature on the thermal efficiency of the whole machine is discussed.The optimum working temperature of the collector end is summarized.