Numerical Validation of a New Analytical Solution for Helical (Earth-Basket) Type Ground Heat Exchangers

Christoph Reichl; Henk Witte

doi:10.3390/pr11051418

Numerical Validation of a New Analytical Solution for Helical (Earth-Basket) Type Ground Heat Exchangers

Christoph Reichl
, Henk Witte

Sustainable Thermal Energy Systems

Groenholland Geo Energy Systems

Research output: Contribution to journal › Article › peer-review

Abstract

In this paper, we show that an analytical solution based on the Finite Line Source and G-function approach is both sufficiently fast and accurate for design calculations of ground heat exchangers with a complex (spiral) geometry. Detailed validations were performed for the steadystate and transient responses of analytical models with different time scales (10 h and 250 h). A comparison with a detailed computational fluid dynamics model (Ansys Fluent) and the analytical method for different boundary conditions showed a very good agreement (maximum root mean
square error) smaller than 0.25 K.

Original language	English
Article number	1418
Number of pages	17
Journal	MDPI Processes
Volume	11
DOIs	https://doi.org/10.3390/pr11051418
Publication status	Published - 8 May 2023

Research Field

Former Research Field - Digitalisation and HVAC Technologies in Buildings

Keywords

shallow geothermal
spiral ground heat exchanger design
GHEX;
earth basket collector
computational fluid dynamics (CFD)
finite line source (FLS)
G-function
engineering tool

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10.3390/pr11051418Licence: CC BY

Cite this

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title = "Numerical Validation of a New Analytical Solution for Helical (Earth-Basket) Type Ground Heat Exchangers",

abstract = "In this paper, we show that an analytical solution based on the Finite Line Source and G-function approach is both sufficiently fast and accurate for design calculations of ground heat exchangers with a complex (spiral) geometry. Detailed validations were performed for the steadystate and transient responses of analytical models with different time scales (10 h and 250 h). A comparison with a detailed computational fluid dynamics model (Ansys Fluent) and the analytical method for different boundary conditions showed a very good agreement (maximum root mean square error) smaller than 0.25 K.",

keywords = "shallow geothermal, spiral ground heat exchanger design, GHEX;, earth basket collector, computational fluid dynamics (CFD), finite line source (FLS), G-function, engineering tool",

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year = "2023",

month = may,

day = "8",

doi = "10.3390/pr11051418",

language = "English",

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T1 - Numerical Validation of a New Analytical Solution for Helical (Earth-Basket) Type Ground Heat Exchangers

AU - Reichl, Christoph

AU - Witte, Henk

PY - 2023/5/8

Y1 - 2023/5/8

N2 - In this paper, we show that an analytical solution based on the Finite Line Source and G-function approach is both sufficiently fast and accurate for design calculations of ground heat exchangers with a complex (spiral) geometry. Detailed validations were performed for the steadystate and transient responses of analytical models with different time scales (10 h and 250 h). A comparison with a detailed computational fluid dynamics model (Ansys Fluent) and the analytical method for different boundary conditions showed a very good agreement (maximum root mean square error) smaller than 0.25 K.

AB - In this paper, we show that an analytical solution based on the Finite Line Source and G-function approach is both sufficiently fast and accurate for design calculations of ground heat exchangers with a complex (spiral) geometry. Detailed validations were performed for the steadystate and transient responses of analytical models with different time scales (10 h and 250 h). A comparison with a detailed computational fluid dynamics model (Ansys Fluent) and the analytical method for different boundary conditions showed a very good agreement (maximum root mean square error) smaller than 0.25 K.

KW - shallow geothermal

KW - spiral ground heat exchanger design

KW - GHEX;

KW - earth basket collector

KW - computational fluid dynamics (CFD)

KW - finite line source (FLS)

KW - G-function

KW - engineering tool

U2 - 10.3390/pr11051418

DO - 10.3390/pr11051418

M3 - Article

SN - 2227-9717

VL - 11

JO - MDPI Processes

JF - MDPI Processes

M1 - 1418

ER -

Numerical Validation of a New Analytical Solution for Helical (Earth-Basket) Type Ground Heat Exchangers

Abstract

Research Field

Keywords

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