Investigation on the sustainability and efficiency of single-well circulation (SWC) groundwater heat pump systems. (January 2019)

• Record Type: Journal Article
• Authors: Wu, Qiang; Tu, Kun; Sun, Haizhou; Chen, Chaofan
• Is Part Of: Renewable energy. Volume 130(2019)
• Page Start: 656
• Page End: 666
• Publication Date: 2019-01
• Subjects: Shallow geothermal energy -- Groundwater heat pump (GWHP) -- Single-well circulation (SWC) system -- Long-term sustainability and efficiency -- Coefficient of performance (COP); Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2018.06.107
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Among various groundwater heat pump (GWHP) system configurations, the single-well circulation (SWC) groundwater heat pump system is totally different with other conventional GWHP systems. In recent years, the SWC system has gained increasing interest due to the fact that it is a cost-effective technology providing large quantities of heating and cooling to buildings. The performance of a SWC system is closely related to the hydrogeological and thermogeological properties. Also, the proper system design and installation are crucial to maintain long-term sustainability and efficiency. In this work, a series of scenarios were simulated to evaluate the influence of different parameters on the outlet temperature evolution and efficiency of a SWC system. It was found that the W-S mode with active cooling will be beneficial to the efficiency of the heat pump and the recovery of the subsurface. It is also demonstrated that the sealed section length plays the most influential role in the design of a SWC system. In addition, the present of groundwater flow will have positive effect on the system performance. In contrast to other factors, the thermal conductivity, volumetric heat capacity and porosity are considered to have a minor influence on the sustainability and efficiency of the system. Highlights: A numerical model was developed to perform a statistical sensitivity analysis. The benefit of groundwater flow and injection of excess heat is quantified. It was found that longer sealed section do not always lead to a better financial performance over 30 years. The economic analysis of SWC groundwater heat systems compared to the conventional system has been performed. Total cost of SWC groundwater heat pump systems depend heavily on interest rate and electricity price.