ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
INTERMEDIATE TEMPERATURE SOLAR THERMAL COLLECTOR ENABLED BY NON-EVACUATED TRANSPARENT AEROGEL AND NON-TRACKING COMPOUND PARABOLIC CONCENTRATOR
Abstract
In this study, we present a stationary solar thermal collector capable of operating at intermediate temperatures
(120-220 °C) using non-evacuated transparent silica aerogel. The silica aerogel serves as a transparent insulator, which eliminates the need of evacuated tubes. The proposed collector includes a compound parabolic concentrator (CPC) which can provide ~2x concentration without diurnal tracking of the sun. A planar absorber made of selective surfaces absorbs the concentrated sunlight and converts it into heat. The harvested heat is then conducted
away by a heat transfer oil flowing through a conduit on the back side of the absorber. To reduce absorber heat
losses, an optimized monolithic transparent silica aerogel is placed on top of the absorber surface. The aerogel
layer allows the concentrated sunlight to pass while minimizing absorber heat losses to the environment via
conduction, convection, and radiation. A lab-scale collector prototype is built and tested using a high-temperature
heat transfer fluid loop at temperatures up to 210 °C. The results demonstrate the proposed collector can operate
at the desired temperature range without relying on active solar concentrator and evacuated tubes.