Thermodynamic Performance And Optimal Analysis Of Three-terminal Structure Thermoelectric Devices

In this thesis,some models of thermoelectric devices with three-terminal structure are proposed.Based on the models proposed,we derive the expressions of the related thermodynamic parameters including power,efficiency,cooling rate and coefficient of performance(COP).Furtherly we investigate the performance characteristics of the models and analyze their optimal performance.Some meaningful and important results are obtained.The detailed contents of the paper are listed as follows:In chapter 1,we introduce the research backgrounds and the advantages of three-terminal structure thermoelectric devices,explain the main methods and theories for our research,and analyze the common operational principle of the three-terminal structure thermoelectric devices.In chapter 2,we propose two symmetrical models of three-terminal hybrid driven thermoelectric refrigerator based on ideal resonant tunneling quantum dots.We derive the expressions of the cooling power and the COP of the models by using Landuaer formulas,and furtherly obtain the working region,the figures of performance characteristics and the range of optimal parameters.Finally,the influence of the energy level width on the optimal performance is analyzed.In chapter 3,we establish the model of hybrid driven quantum dots photoelectric refrigerator with three-terminal structure.By using master equation,we derive the expressions of the cooling rate and the COP,and obtain the upper bound of reversible COP;we plot the figures of the cooling rate and the COP varying in the working region,the curves of performance characteristics and obtain the range of optimal parameters when the nonradiative effects are taken into account;finally,we analyze and discuss the influence of nonradiative effects and applied bias voltage on the optimal performance of this model.In chapter 4,we investigate the performance characteristics and the optimal performance of the quantum dots photoelectric heat engine with three-terminal structure,derive the expressions of the power and efficiency,analyze the upper and lower bounds of the reversible efficiency,plot the figure of power and efficiency varying in the working region and the curves of performance characteristics,and particularly analyze the influence of energy level difference of the two quantum dots on the optimal performance of the engine finally.Finally,in chapter 5,we make conclusions to the main works and results of the thesis,discuss the shortcomings which exist in this paper,and give the further research direction.