Silicone oil envelope for enhancing the performance of nanofluid-based direct absorption solar collectors

Nanofluids inherently have high emissivity in the mid-infrared region making them unsuitable for satisfying the conditions of solar selectivity required for direct absorbers. In this study, a layer of silicone oil is located above nanofluid comprising of graphite nanoparticles and deionized water. S...

Full description

Saved in:
Bibliographic Details
Published in:Renewable energy 2020-01, Vol.145, p.2733-2740
Main Authors: Bhalla, Vishal, Beejawat, Sachin, Doshi, Jay, Khullar, Vikrant, Singh, Harjit, Tyagi, Himanshu
Format: Article
Language:English
Subjects:
Heat transfer
Nanofluid
Silicone oil
Solar energy
Stratified fluid
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Nanofluids inherently have high emissivity in the mid-infrared region making them unsuitable for satisfying the conditions of solar selectivity required for direct absorbers. In this study, a layer of silicone oil is located above nanofluid comprising of graphite nanoparticles and deionized water. Silicone oil layer is shown to act as a barrier against the infrared emissions from the nanofluid. High transparency of silicone oil in the visible solar spectrum and high absorptivity in the mid-infrared wavelength range made it an excellent candidate for this study. Solar selectively was achieved by using two different liquid layers (nanofluid and silicone oil) in direct thermal contact. Silicone oil layer on the top of the nanofluid resulted in an approximately 17% higher temperature rise in the nanofluid. [Display omitted] •Direct absorption solar collectors can withstand much higher flux.•Graphite nanoparticle have good solar absorption.•Silicone oil shows high absorption in IR regime.•The use of silicon oil layer leads to a temperature gain of 3 °C.
ISSN:0960-1481
1879-0682
DOI:10.1016/j.renene.2019.08.024