Efficient ground energy systems for deployment in diaphragm walls under challenging application scenarios

• Grant number: 22/11675-8
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2023
• End date: October 31, 2026
• Field of knowledge: Engineering - Civil Engineering - Geotechnical Engineering
• Agreement: EPSRC, UKRI
• Principal Investigator: Cristina de Hollanda Cavalcanti Tsuha
• Grantee: Cristina de Hollanda Cavalcanti Tsuha
• Principal researcher abroad: Fleur Loveridge
• Institution abroad: University of Leeds, England
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: Alberto Hernandez Neto

Abstract

The project tackles heating and cooling of buildings, which is a key priority for meeting NetZero targets. Thermal energy solutions that can deliver against cooling and heating demands urgently need to be developed. In the UK, heat pump deployment is not progressing as fast as is required, while in Brazil, there is an absence of demonstrator projects showing local feasibility. Heat pumps are suited to both heating and cooling, with ground source heat pumps (GSHPs) offering high efficiencies. Inclusion of heat transfer pipes within sub-structures, so-called energy geostructures, is one way to reduce costs of GSHP systems. This project aims to tackle the problem of developing embedded retaining walls for application in thermal energy. Currently, their use is restricted to retaining the ground, but they could be built to have dual-purpose by incorporating them in a GSHP system. This project will equip them with the appropriate design tools and knowledge to incorporate highly efficient and optimized energy retaining walls into GSHP systems. We will construct a controlled field study site at the EESC/USP in Brazil that will include an instrumented retaining wall system with different pipework geometries to allow a wide variety of wall operation modes to be studied. This will create an important data set specific to the local climate and unsaturated soil conditions. Scaled physical models will be fabricated at the University of Dundee and tested on a geotechnical centrifuge to investigate different parameters that cannot be easily controlled on site and test deeper walls and ground conditions ground conditions similar to brownfield land development in the UK. The University of Leeds will use the data and insights from the field and physical model studies to develop thermal analytical tools for design of these structures. This will result in fast run transient solutions for energy walls that can work in a variety of ground conditions and be integrated with existing building energy modelling software. Development of these tools will then be available for practical design of more efficient embedded retaining wall GSHP systems and remove barriers to adoption. (AU)