【作者】 黄银盛；

【导师】 朱冬生；

【作者基本信息】 华南理工大学 ， 化学工程， 2011， 硕士

【摘要】 随着全球能源需求的不断增长,全球性的能源危机和环境恶化问题日益突出。倡导低碳经济运行,加大对新能源及绿色环保技术的开发利用已成为社会的强烈要求。太阳能作为可再生绿色能源,具有储量大、清洁环保、利用经济等优点,被普遍认为是理想的新能源。太阳能发电及相关技术研究是目前各国关注的焦点。温差发电是利用热电转换材料将热能直接转化为电能的一种能量转化技术,在利用太阳能等低品位热源上有着明显优势。太阳能温差发电把太阳辐射热能直接转换为电能,具有无运动部件、无噪音、无磨损、无污染物排放、体积小、重量轻、可靠性高等特点,是绿色环保的发电方式。利用太阳能发电,人们的研究多集中于太阳能光伏发电,基于温差发电技术的太阳能发电方式的研究则比较少。本文以温差发电理论及热传递机理为基础,采用理论分析、数学建模和实验测试相结合的方法,对一种新型太阳能温差发电系统的性能进行了研究。主要研究工作包括以下几个方面:1、在对温差发电基本原理基础上,推导出温差发电的性能参数及其计算公式,探讨了影响温差发电性能的因素,分析了电偶臂的几何尺寸、接触效应、模块内阻对温差发电性能的影响机理,为太阳能温差发电的结构设计和优化提供理论依据。2、搭建了温差发电的性能测试平台,通过实验对商用温差发电组件进行了测试,深入研究了单个温差发电组件的输出特性,并以此为基础对其串、并联的输出特性作了进一步探讨。实验结果表明,该温差发电组件的开路电压随着冷热端温差的增大近似呈线性增大趋势,当负载电阻接近发电器总内阻时可获得相应的最大输出功率。温差发电组件作为电源,其串、并联性能和普通直流电源的串、并联基本相同,为实现温差发电系统的大功率输出提供了有益的结论。3、对于选定的温差发电组件,外部传热的不可逆性对温差发电系统的性能有显著的影响。本文根据传热学理论,采用热网络分析法对温差发电的传热特性进行了理论分析与实验研究。研究结果表明,温差发电组件冷端散热热阻是整个温差发电器的关键热阻,当热源热流量恒定,与空气自然对流相比,采用强制风冷和水冷散热方式能明显降低发电器冷端的热阻和温度,发电器的输出功率可提高20%~30%,随着热源热流量的增大,这种改善的效果越明显。4、根据复合抛物面聚光器的光学原理,设计并搭建了复合抛物面太阳能温差发电装置。对该装置的聚光性能与电输出性能进行了实验研究,结果表明该集热器集热温度均匀,集热板最高温度与最低温度之差不超过3℃。该温差发电装置的开路电压随着冷热端温差的增大而增大,当负载电阻与发电模块总内阻相匹配时输出功率最大。当热端平均温度基本稳定在80℃,冷却水流量为340 L/h时,当负载电阻接近130 ?时获得36个温差发电组件串联后的最大输出功率为7.1 W。更多还原

【Abstract】 With the high-speed develoment of industrialization, global environmental deterioration and energy have become increasingly prominent. Governments of all countries have paid attention to research and usage of green environmental protection technology. The solar energy, as a renewable energy, has advantages such as abundance, economy and non-pollution, and attracts lots of attention. Thermoelectric generation can directly conver the solar power to electricity power. It has the advantages of high reliability, non-pollution and peaceful operations with immovable parts. It is a green and environmentally friendly technology and has a distinct advantage in the use of solar energy.Solar photovoltaic and solar thermal power have been discussed for a long time. The research on solar thermoelectric generation is few. So it is necessary to conduct a much further study on it. Based on the TEG theory, the electricity generating and heat transer performance are investigated by the means of theoretical analysis, mathematical modeling and experimental testing in this paper. The main works and conclusions include the following:(1) The performance parameters and their calculation formulas were given based on the theoretical derivation. The working performance of thermoelectric generator is analyzed on the base of size of TE couple, contact effect and internal resistance. This relationship provides a foundation for optimizating output power and conversion efficiency.(2) The platform for testing the performance of thermoelectric generator has been built. Further study was done through experiments on the output characteristics of single thermoelectric generation module. When the load resistance is close to the total resistance of TEG, the maximum output is obtained. Based on the output characteristics of single power module, futher study was done on two modules with series connection and parallel connection. The result shows that the characteristics of two modules with series and parallel connection are the same as DC power supply. Some useful conclusions about high-power output is obtained.(3) For the selected thermoelectric generator, the external heat transfer has a significant impact on the performance of the TEG. Based on heat transfer theory, the heat transfer characteristics of the TEG was theoretical and experimental researched by the means of thermal network analysis. The results inducat that the thermal resistance on the cold side is the key thermal resistance. When the heat flux of heating source is constant, forced air cooling and water cooling can significantly reduce the thermal resistance or temperature of cold side, and the output power can be increased by 20% to 30% compared with the air natural convection. The larger heat flux of heating power is, the more significant the improvement is.(4) The Compound Parabolic Concentrator (CPC) was designed based on the optical principle. The performance of the solar collecting and the power output performance of the TEG were experimental investigated. The results show that the temperature of the collector is uniform. The maximum temperature difference is no more than 3℃. The open circuit voltage of the device increased with the temperature difference between the cold side and hot side. When the load resistance matches the total internal resistance, the maximum output power can be obtained. When the average temperature of hot side reaches 80℃, and the cooling water flow is 340 L/h, we can obtain the maximum output power of 7.1 W with the matching load resistor of 130 ?.更多还原