Heat Loss Measurements on Parabolic Trough Receivers

Abstract

A measurement set-up to determine the heat losses of single parabolic trough receiver components at steady
\nstate conditions has been developed at Schott. This paper describes the functionality of the set-up and a
\ncomparative campaign with three Schott receivers of 7.0, 8.9 and 11.1% emittance (400°C) including test
\nstands at German Aerospace Center (DLR) and U.S. National Renewable Energy Laboratory (NREL). This
\ncampaign showed generally good agreement with deviations <10%.
\nAdditionally, results are compared to heat loss predictions derived from optical measurements of the absorber
\ncoating via a one-dimensional simulation. The general trend suggests good accordance with a systematical
\ndeviation at lower emissivities.
\nOverall, this non destructive measurement technique provides a good possibility to determine an important
\nreceiver specification, its heat loss.