Design of a low-concentration roof-mounted solar thermal collector for industrial heat production

This paper presents the design of a roof-mounted solar thermal system consisting of a CPC collector and evacuated tube receivers which utilise thermal oil as the working fluid. The design process employed in this work considers the transmission and absorption of solar energy, optical losses due to the receiver-reflector gap, heat transfer within the receiver, and the thermal losses. Impacts of collector module tilt and CPC acceptance angle on annual energy gain were also included. The collector system has a packaged height of 100mm, ensuring its appearance is similar to traditional flat-plate collectors when installed. The collector is intended to supply renewable process heat for applications with loads between 150°C-250°C, with a target thermal efficiency of 50% at 200°C. A prototype collector is currently in production and will be tested in the latter months of 2016 at the RMIT University solar test laboratory in Melbourne.