Ground Heat Exchanger Design Tool

A package with the novel capability of automatically selecting ground heat exchanger configurations based on polygonal land constraints. This package contains advanced methods that are the first of their kind. The results are validated against the world renowned GLHEPRO (Cook 2021).

The Ground Heat Exchanger Design Tool (DT) is a Python package that can quantify the short- and long-term thermal interaction in a ground heat exchanger (GHE). The long-term thermal response g-functions are computed live-time with pygfunction. The DT contains a fast monthly hybrid time step simulation for prediction of heat pump entering fluid temperatures over a design life. The DT can vary the size (or borehole height) of a specified borehole field to ensure the heat pump entering fluid temperature remains within specified bounds. DT contains a novel borehole configuration selection algorithm.

Novel Design Algorithms

DT contains a novel design methodology for automated selection of borehole fields. The advanced methodology performs optimization based on a target drilling depth. An integer bisection routine is utilized to quickly search over a unimodal domain of boreholes. DT can consider available drilling and no-drilling zones defined as polygons.

The selection process shown below is performed in less than half a minute on an 11th Gen Intel Core i9-11900K @ 3.50GHz. Refer to Cook (2021) for more information.

Requirements

ghedt requires at least Python 3.7 and is tested with Python 3.7 and 3.8, and is dependent on the following packages:

• pygfunction (>=2.1)
• numpy (>=1.19.2)
• scipy (>=1.6.2)
• matplotlib (>=3.3.4)
• coolprop (>=6.4.1)
• pandas (>=1.3.2)
• openpyxl (>=3.0.8)
• opencv-python (==4.5.4.58)

Quick Start

Users - Install ghedt via the package installer for Python (pip):

pip install ghedt

Developers - Clone the repository to via git:

git clone https://github.com/j-c-cook/ghedt

See installation for more notes on installing. See ghedt/examples/ for usage.

Citing the Design Tool

The Ground Heat Exchanger Design Tool and other related work is described in the following thesis:

Cook, J.C. (2021). Development of Computer Programs for Fast Computation of 
    g-Functions and Automated Ground Heat Exchanger Design. Master's Thesis, 
    Oklahoma State University, Stillwater, OK.

Here is an example of a BibTeX entry:

@mastersthesis{Cook_2021,
school = "{Oklahoma State University, Stillwater, OK}",
author = {Cook, J C.},
language = {eng},
title = "{Development of Computer Programs for Fast Computation of g-Functions 
and Automated Ground Heat Exchanger Design}",
year = {2021},
}

Questions?

If there are any questions, comments or concerns please create an issue, comment on an open issue, comment on a closed issue, or start a discussion.

Acknowledgements

The initial release of this work (ghedt-v0.1) was financially supported by the U.S. Department of Energy contract DE‐AC05‐00OR22725 through research subcontracts from Oak Ridge National Laboratory. Dr. Jeffrey D. Spitler was integral to the successful development, mostly through advice and feedback.