An Engineering Analysis Method for Deep Geothermal Energy
type: CreativeWork
description: At present there are already many deep geothermal projects allowing us to have a better understanding of deep geothermal energy. However, there are still many issues to be solved for more reliable use of deep geothermal energy. This thesis proposes an engineering analysis method to assess the performance of a typical deep geothermal system, which is a doublet system with one injection well and one extraction well. A convective heat transfer boundary between the aquifer and overburden layers is applied for the axisymmetric problem based on the Lauwerier model for the first time. A new analytical solution is deduced using a series of Laplace transforms. The interaction between the injection well and extraction well is first neglected. Compared with other relevant analytical solutions, this new analytical solution comprehensively includes both heat conduction and heat advection in the aquifer and the heat flux between the aquifer and overburden layer. As long as the relevant parameters are obtained, the new analytical solution can intuitively illustrate the temporal and spatial temperature distribution within the aquifer. It can be used to determine the location of the extraction well and to evaluate the extracted geothermal power of the hot water aquifer. The convective heat transfer boundary at the interface does not only reflect the actual heat transfer process at the interface, but also models the heat transfer process in the overburden layer. It is shown that the dimensionless equivalent heat transfer coefficient is expressed as a function of the dimensionless injection rate and the dimensionless thermal conductivity of the overburden layer so the new analytical solution effectively incorporates the properties of the overburden layer. A series of FE simulations are conducted, and the analytical model is curve fitted to the FE results to evaluate the values of the dimensionless equivalent heat transfer coefficient. Based on the results of the curve fitting exercise…
abstract: At present there are already many deep geothermal projects allowing us to have a better understanding of deep geothermal energy. However, there are still many issues to be solved for more reliable use of deep geothermal energy. This thesis proposes an engineering analysis method to assess the performance of a typical deep geothermal system, which is a doublet system with one injection well and one extraction well. A convective heat transfer boundary between the aquifer and overburden layers is applied for the axisymmetric problem based on the Lauwerier model for the first time. A new analytical solution is deduced using a series of Laplace transforms. The interaction between the injection well and extraction well is first neglected. Compared with other relevant analytical solutions, this new analytical solution comprehensively includes both heat conduction and heat advection in the aquifer and the heat flux between the aquifer and overburden layer. As long as the relevant parameters are obtained, the new analytical solution can intuitively illustrate the temporal and spatial temperature distribution within the aquifer. It can be used to determine the location of the extraction well and to evaluate the extracted geothermal power of the hot water aquifer. The convective heat transfer boundary at the interface does not only reflect the actual heat transfer process at the interface, but also models the heat transfer process in the overburden layer. It is shown that the dimensionless equivalent heat transfer coefficient is expressed as a function of the dimensionless injection rate and the dimensionless thermal conductivity of the overburden layer so the new analytical solution effectively incorporates the properties of the overburden layer. A series of FE simulations are conducted, and the analytical model is curve fitted to the FE results to evaluate the values of the dimensionless equivalent heat transfer coefficient. Based on the results of the curve fitting exercise…
author: Lu, Xiaoyu
language: en
keywords: geothermal, fracture flow, heat transfer coefficient, advection, conduction, Analtical solution, fault, Numerical solution, deep geothermal energy, doublet, Lauwerier model, Finite Element Analysis, temperature distribution, injection well, extraction well
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/f644f230-15a2-4233-b3a5-79d77413cfa0/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2020-03-21
date modified: 2026-07-22T22:24:16Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.50101