| Author: | Wang, Sifan |
| Title: | The effect of groundwater advection in a non-homogeneous medium on spiral-coil energy pile |
| Advisors: | Yang, Hongxing (BSE) You, Tian (BSE) Lim, Grace (ELC) |
| Degree: | M.Eng. |
| Year: | 2018 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Heat exchangers Heat -- Transmission Heat pumps |
| Department: | Department of Building Services Engineering |
| Pages: | x, 80 pages : color illustrations |
| Language: | English |
| Abstract: | Recently, investigations have been widely conducted in the research area of "energy pile", which uses foundation piles not only to support the building structure, but also serve as underground heat exchangers. It is, however, hard to find relevant analytical models to describe the impact of groundwater seepage on the heat and mass transfer in a non-homogeneous ground environment. Therefore, this thesis proposes a new analytical solution to better describe the heat transfer process of pile geothermal heat exchangers with spiral coils (PGHE-SC) under the circumstances of groundwater flow. Due to the complexity in performing direct solutions on the energy governing equations for thermal response, the temperature field of point source was proposed by Green's function. Integrating point sources along the pile dimension and time period was then made for acquiring the spiral line heat source model to explore the heat transfer process in a semi-infinite medium. Then, the correction factor of velocity was used to highlight the impact of the non-homogeneous medium on temperature responses before modelling. Finally, other similar models were offered to present and support my original contributions. Other independent variables in the proposed model were also considered for sensitivity analysis. According to a series of simulation verifications and comparisons, the optimal analytical solution could have a relative desirable performance for both the simulation and design of the novel pile GHE. It was also found that the potential behavior of an energy pile was better understood in the novel model with coil pitch becoming the least importance. Consequently, a novel analytical solution for the heat transfer of a spiral-coil energy pile has been established, updating the research in the field of non-homogeneity. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991022168750703411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 1.37 MB | Adobe PDF | View/Open |
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