Clear-days operational performance of a hybrid experimental space heating system employing the novel mini-channel solar thermal & PV/T panels and a heat pump

Zhou, Jinzhi; Zhao, Xudong; Ma, Xiaoli; Du, Zhenyu; Fan, Yi; Cheng, Yuanda; Zhang, Xinghui

Abstract

The paper investigated a hybrid experimental space heating system that comprises the novel mini-channel solar thermal and PV/T panels, as well as a heat pump. The major advantage of the system lies in the multiple functions of providing energy for space heating in winter and domestic hot water in other seasons, and generating electricity annually to balance the electricity demand of the system. Compared to traditional flat-plate solar collectors, the mini-channel solar thermal and PV/T panels have the smaller cross-sectional area, higher fluid flow velocity and thus higher heat transfer rate between the heat-carrying fluid and panel walls, thus leading to enhanced solar thermal and electrical efficiencies. It is found that during the typical-day testing, the mini-channel thermal panels had average solar efficiency of 50.8%; while the mini-channel PV/T panels had average solar efficiency of 45.0% and the whole system had average Coefficient of Performance (COP) of 4.9. The system made use of solar and gas sources with the fractional solar consumption of 44%, while its operation was under the pre-set time schedule, i.e., solar panels on from 9:00 to 6:00, heat pump on from 18:00 and 20:00, and gas heater on from 22:00 to 9:00. Throughout the testing period, the room temperature was maintained at above 18 °C, thus enabling achieving the required thermal comfort. Concerning the complexity of such a system, a simplified system comprising the mini-channel thermal and PV/T panels and a heat pump was suggested. In brief, the research has produced fundamental data for the mini-channel-based solar thermal and PV/T panels and established a foundation for designing a simple and low-cost mini-channel based solar space heating system for rural houses in cold climatic regions of China, which will subsequently contribute to significant fossil fuel saving and carbon emission reduction in the global extent.

Citation

Zhou, J., Zhao, X., Ma, X., Du, Z., Fan, Y., Cheng, Y., & Zhang, X. (2017). Clear-days operational performance of a hybrid experimental space heating system employing the novel mini-channel solar thermal & PV/T panels and a heat pump. Solar Energy, 155, 464-477. https://doi.org/10.1016/j.solener.2017.06.056

• Journal Article Type: Article
• Acceptance Date: Jun 24, 2017
• Online Publication Date: Jun 29, 2017
• Publication Date: 2017-10
• Deposit Date: Feb 18, 2021
• Journal: Solar Energy
• Print ISSN: 0038-092X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 155
• Pages: 464-477
• DOI: https://doi.org/10.1016/j.solener.2017.06.056
• Keywords: Mini-channel; Solar thermal panel; PV/T panel; Heat pump
• Public URL: https://hull-repository.worktribe.com/output/551037
• Additional Information: This article is maintained by: Elsevier; Article Title: Clear-days operational performance of a hybrid experimental space heating system employing the novel mini-channel solar thermal & PV/T panels and a heat pump; Journal Title: Solar Energy; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.solener.2017.06.056; Content Type: article; Copyright: © 2017 Elsevier Ltd. All rights reserved.