Enhancing ground source heat pump performance : the role of phase change material integrated grouts in subsurface temperature control

Ahmed, Fawad (author), Massarotti, Nicola (author), Šarler, Božidar (author)

Ground source heat pump (GSHP) systems are increasingly being adopted for heating and cooling applications. However, their continuous operation can lead to thermal imbalances in the ground, which may impact overall system performance. This study investigates the thermal performance of a coaxial ground heat exchanger (CGHE) in a GSHP system, using different grouting materials: reference grout, enhanced grout, micro-encapsulated phase change material (MEPCM) grout, and shape-stabilized phase change material (SSPCM) grout. The effects of these grouts on the heat exchange efficiency and ground temperature variation are analyzed. Additionally, the integration of phase change materials (PCMs) into grouts is examined for its potential to improve thermal performance. Results show that the thermal conductivity of grout has a significant influence on system performance, affecting heat transfer. Among the grouts tested, the SSPCM-integrated grout outperformed others, achieving an average specific power of 5.72 kW/m for cooling and 4.06 kW/m for heating. Furthermore, the ground temperature with PCM-integrated grouts fluctuated between 20 °C and 23 °C, compared to 19 °C to 25 °C with ordinary grouts. Hence, PCM integration in grouts can enhance the stability of source and sink temperatures.

• Language: English
• Keywords: phase change material, enhanced grout, coaxial ground heat exchanger, numerical model
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 15 str.
• Numbering: Vol. 287, [article no.] 129419
• PID: 20.500.12556/RUL-176877
• UDC: 536
• ISSN on article: 1873-5606
• DOI: 10.1016/j.applthermaleng.2025.129419
• COBISS.SI-ID: 261088515
• Publication date in RUL: 12.12.2025

Record is a part of a journal

• Title: Applied thermal engineering
• Publisher: Pergamon Press
• ISSN: 1873-5606
• COBISS.SI-ID: 23195397

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: fazno spremenljiva snov, izboljšano polnilo, koaksialni zemeljski toplotni izmenjevalnik, numerični model

Projects

• Funder: Other - Other funder or multiple funders
• Funding programme: Italian Ministry for Universities and Research
• Project number: FSE REACT-EU CUP 165F21001390001
• Name: Doctoral Research Funding for Green Themes

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0162
• Name: Večfazni sistemi