A general distributed parameter model for ground heat exchangers with arbitrary shape and type of heat sources

Tian You, Baolong Wang, Xianting Li, Wenxing Shi, Hongxing Yang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

The heat and mass transfer simulation model of a ground heat exchanger (GHE) directly affects the design and operation performance of a ground-coupled heat pump system. The GHE models based on the response function (like the Green function and g-function) can achieve a fast calculation speed. However, the heat sources in these models are limited to points or whole boreholes, leading to low calculation accuracy in heat transfer during a short time period and limitation to a certain GHE. A general distributed parameter model for a ground heat exchanger (RF model) is proposed based on the principle of response factors in this paper. A sandbox experimental platform is then built to test the temperatures of typical points in the double-layered soil and to validate the RF model. After that, the calculation of the RF model is simplified by determining suitable positions for the soil boundaries and the numbers of sub pipes and sub soil boundaries. Finally, the RF model is applied in different scenarios to demonstrate its characteristics. The results show that: (1) the RF model is suitable for different kinds of GHEs with arbitrary shape and type of heat sources releasing heat in arbitrary time steps; (2) the RF model has only 0.01 °C and 0.23 °C temperature response errors compared to those from numerical solutions and experiments, respectively; (3) the general RF model has similar accuracy to the numerical solution in calculating the distributed temperatures of the borehole and pipes, heat transfer in the short term, and heat transfer of borehole groups and the energy pile.

Original languageEnglish
Pages (from-to)667-679
Number of pages13
JournalEnergy Conversion and Management
Volume164
DOIs
Publication statusPublished - 15 May 2018

Keywords

  • Distributed parametermodel
  • Ground heat exchanger
  • Ground-coupled heat pump
  • Response factor
  • Simulation

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

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