Solar selective absorbers impact on thermoelectric generator efficacy

Autor: Zhi-Yu Lin, 林志俞
Rok vydání: 2011
Druh dokumentu: 學位論文 ; thesis
Popis: 99
This research employs solar selective absorbers and heat sink to provide the temperature difference needed by thermoelectric generator to produce electricity. This research starts by discussions on solar selective absorbers comprising three major components, ITO, A1N, and A1. The discussions proceed by elaborating on A1N, ITO+A1N, ITO+A1N+A1, and samples without coating. In respective experiments, A1N has a temperature rise of 29.2℃ to 42.8℃ (i.e. 46.5% rise) after 600s of sun exposure. ITO+A1N has a temperature rise of 30.7℃ to 45℃ (i.e. 46.5% rise) after 600s of sun exposure. ITO+A1N+A1 has the highest temperature rise of 28.7℃ to 46.1℃ (i.e. 60.6% rise) after 600s of sun exposure. With the same sun exposure time, ITO+A1N+A1 provides the best performance. On the voltage output, ITO+A1N+A1 demonstrates 21.8% higher output comparing with ITO+A1N and 53% higher output comparing with A1N. On the current output, ITO+A1N+A1 demonstrates 18.6% higher output comparing with ITO+A1N and 53.9% higher output comparing with A1N. Because ITO+A1N+A1 can provide the best temperature rising, this research presents system level thermal simulations with COSMOS and extends the sun exposure time to 4800s. Simulation results suggest the heat sink can provide the cooling demanded by ITO+A1N+A1. In other words, at the heat sink side, temperature is properly maintained and decorrelated with the temperature at the film side. Respective simulations on the amount of current and level of voltage are also presented. Experimental results suggest A1N layer absorbs solar radiation and effectively converts it to heat. ITO and A1 layer allows more energy to hit A1N layer. ITO layer achieves this by reducing reflection whereas A1 layer achieves this by making radiation reenter A1N layer through reflection.
Databáze: Networked Digital Library of Theses & Dissertations
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