Performance tests of an evacuated flat plate solar collector under a virtual image solar simulator

Abstract

An evacuated flat plate collector has been built and tested in a solar simulator. A vacuum of <0.1 Pa was used to eliminate heat losses through convection and gas conduction. CFD and stress calculations for the hydro-formed panels determined the material thickness and through-hole sizes. The simulator used a reflecting tube to generate uniform illumination via multiple virtual images of four halogen floodlights. Tests with and without vacuum over a range of illumination powers demonstrate the efficiency benefits of vacuum insulation when providing heat at elevated temperatures or with weak insolation.