The experimental evaluation and improvements of a novel thermal diode pre-heat solar water heater under simulated solar conditions

• Published in: Renewable energy 2018-06, Vol.121, p.116-122
• Main Authors: Smyth, M., Quinlan, P., Mondol, J.D., Zacharopoulos, A., McLarnon, D., Pugsley, A.
• Format: Article
• Language: English
• Subjects: ICSSWH; Pre-heat; Solar simulation; Thermal diode
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2017.12.083

This paper presents the development through experimental performance characterisation of a pre-heat Integrated Collector Storage Solar Water Heater using a novel thermal diode operation to reduce ambient heat loss during non-collection periods. Using a solar simulator facility at Ulster University, the novel prototype pre-heat Mark IV unit was tested and evaluated. The concept has been designed and developed to be a sustainable pre-heat alternative to other types of solar water heating systems traditionally used in domestic hot water installations. The highest 6 h collection efficiency was 36.17% under solar simulated conditions. The lowest system ‘U’ value was 0.98 Wm−2K−1 with no draw-off conditions. When the current prototype ICS units are compared with other conventional ICS systems, particularly in terms of thermal retention during non-collection periods, an improved performance is clearly demonstrated. The measured thermal losses were approximately 40% less than other similarly measured systems. •Experimental performance characterisation of a pre-heat ICSSWH.•A novel thermal diode operation to reduce ambient heat loss during non-collection periods.•Experimental evaluation via a solar simulation test facility.•6 hour collection efficiency of 36.17%.•System ‘U’ value was 0.98 W m−2K−1.