动态非均匀热流密度下热电器件的热—应力—发电性能研究

发布时间：2018-01-15 04:37

本文关键词：动态非均匀热流密度下热电器件的热—应力—发电性能研究　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：温差发电技术作为一种新能源技术,各方面的理论研究和应用已开展了近一个世纪,可以作为缓解能源危机的有效手段;同时,由于温差发电技术具有无噪音,无介质泄漏、零排放的优点,决定了其对环境的友好。此外,温差发电器还具有移动方便、使用寿命长、维护成本低、重量轻、无磨损、体积小等优点,故近年来已引起广泛关注。本论文主要建立热电发电器的热-电-应力耦合模型,分析了热电发电器在不同工况下的电能输出和应力特性,同时分析了对热电器件电能输出和应力分布特性的影响因素。首先建立热电器件的传热-发电-应力耦合数学模型,分析了热电材料物性参数随温度变化对输出特性的影响,热辐射对输出特性的影响。然后分析了非均匀热流密度对输出特性的影响,基于相同热流量下分析不同的热流集中度的影响。通过选取模块不同的横截面可以看到在非均匀热流密度下模块内部的温度云图,进一步分析非均匀热流密度对其效率产生影响的原因。研究了热电器件的启停特性。研究稳态输出特性后又研究了其非稳态输出特性,观察了物性参数、热辐射对温度和输出电压影响的过程,同时对比非均匀热流密度的施加方式,高斯热流密度和非均匀热流密度。其次研究了热电器件的热应力结果,从热应力模拟结果云图可得到该模块热应力最大节点,结果表明模块最大热应力节点在铜板和热电材料接触直角处,追踪该节点进行非稳态分析,得到从开始到稳态过程该节点热应力变化。通过选取模块内的一系列截面,得到模块热应力形成过程以及最有可能发生热应力破坏的区域,观察其热应变云图和位移云图。同时还通过非稳态分析的云图结果得到其热应力形成过程。然后研究了铜板厚度和聚热层厚度对热应力大小的影响,以及对发电稳定性,应力稳定性的影响,以及热流密度,温度和热应力之间的相位关系。
[Abstract]:As a new energy technology, thermoelectric power generation technology has been studied and applied in various fields for nearly a century, which can be used as an effective means to alleviate the energy crisis. At the same time, the thermoelectricity technology has the advantages of no noise, no medium leakage, zero emission, which determines its environmental friendliness. In addition, the thermoelectric generator also has the advantages of convenient movement, long service life and low maintenance cost. Because of its advantages of light weight, no wear and small volume, it has attracted much attention in recent years. In this paper, the thermoelectric-stress coupling model of thermoelectric generator is established. The characteristics of power output and stress of thermoelectric generator under different working conditions are analyzed. At the same time, the influence factors on the characteristics of power output and stress distribution of thermoelectric devices are analyzed. Firstly, the coupled mathematical model of heat transfer, power generation and stress of thermoelectric devices is established. The influence of the physical parameters of thermoelectric materials with temperature on the output characteristics and the effect of thermal radiation on the output characteristics are analyzed, and then the effect of non-uniform heat flux on the output characteristics is analyzed. The influence of different heat flux concentration is analyzed based on the same heat flux. Through selecting different cross sections of the module, we can see the temperature cloud map of the module under the non-uniform heat flux. The influence of non-uniform heat flux density on its efficiency is further analyzed. The starting and stopping characteristics of thermoelectric devices are studied. After studying the steady output characteristics, the unsteady output characteristics are studied, and the physical parameters are observed. The process of influence of thermal radiation on temperature and output voltage, at the same time, compared with the application of non-uniform heat flux density, Gao Si heat flux and non-uniform heat flux. Secondly, the thermal stress results of thermoelectric devices are studied. The maximum thermal stress node of the module can be obtained from the cloud diagram of the thermal stress simulation results. The results show that the maximum thermal stress node of the module is located at the right angle between the copper plate and the thermoelectric material, and the unsteady state analysis of the node is carried out. Through selecting a series of sections in the module, the forming process of thermal stress and the region most likely to occur thermal stress failure are obtained. The thermal strain cloud diagram and the displacement cloud diagram are observed. The thermal stress formation process is also obtained by the results of the unsteady analysis. Then the influence of the thickness of copper plate and the thickness of the thermal accumulation layer on the thermal stress is studied. And the effects on generation stability, stress stability, and phase relationship between heat flux, temperature and thermal stress.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM913

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