Development of direct energy conversion system from high temperature thermal radiation to electricity by solar themophotovoltaic system

热光伏发电被认为是一种新型的环保型发电系统。本研究以太阳能集热发电为主要能源，研究太阳能热光伏发电系统，即太阳能热光伏发电系统，是一种清洁可再生能源系统。该项目计划在日本进行首次太阳能TPV实验演示。本研究也探讨了太阳能集热器、太阳能热接收器、稀土选择性发射器、太阳能光伏电池等关键组件技术。本项目取得了以下成果。(1)我们已经建立了系统，这是由自动跟踪抛物面聚光器使用CCD相机。通过测量太阳热的空间分布来评估焦点处的太阳图像。利用这些数据设计了一个太阳能热接收器，并在真实的太阳能系统下进行了测试。在实验中，采用钼热屏，获得了1500K以上的接收器温度。此外，还发现选择性发射系统可以提高接收器的温度。这可以归因于窄的热辐射光谱。(2)本文研究了两种选择性散热器，这是提高TPV效率的关键技术。掺铒选择性发射极具有比NASA研制的选择性发射极高的辐射选择性和高达20OK的热稳定性。建立了钨金属衬底表面光栅结构的制作工艺。我们观察到清晰的发射峰对应的表面周期性。在本研究中，也获得了高温电阻W光栅。(3)光伏电池实验表明，TPV系统存在最佳的电池与散热器之间的距离。

Thermophotovoltaic (TPV) power generation is considered to be a new environment friendly power generation system. In this study, we have investigate the TPV system driven by concentrated solar thermal energy as the primary resource, which is called as solar-TPV and is the clean and renewable energy system. The first demonstrate of solar-TPV experiment in Japan is planned in this project. Several key component technologies, such as solar concentrator, solar thermal receiver, rare-earth selective emitter, and photovoltaic cell for TPV, are also investigated in this study. The following results are obtained in this project.(1) We have constructed the system, which was composed of the auto-tracking parabolic concentrator using CCD camera. A solar image at the focal point is evaluated by measuring the spatial distribution of solar heat. Using this data a solar thermal receiver is designed and tested under real solar system. From this experiment, we obtained receiver temperature more than 1500K by using Mo thermal shield. In addition to this, it is found selective emitter system boots the receiver temperature. This can be attributed to narrow thermal radiation spectrum. (2) Two kind of selective thermal radiators, which are a key technology to increase the TPV efficiency, are investigated in this study. Rare-earth (Er) doped selective emitter shows high selective radiation as compare as that developed by NASA and high thermal stability up to 20OK. The manufacturing process of surface grating structure on tungsten metal substrate is established. We observe the clear emission peak corresponding the surface periodicity. The high temperature resistive W gratings is also obtained in this study. (3) PV cell experiment revealed that the optimum distance between PV cell and radiator exist on TPV system.