Thermal design of Earth-to-Air Heat Exchanger. Part I a new transient semi-analytical model for determining soil temperature

Thermal design of Earth-to-Air Heat Exchanger. Part I a new transient semi-analytical model for... This article is the first in a series about the thermal design of Earth-to-Air Heat Exchanger, EAHE, using a new developed semi-analytical method. The temperature distribution in the soil surrounding the EAHE is studied in the goal to determine the soil radius as a function of the operation duration. This radius is the first distance from the pipe axis where there is no effect of heat from EAHE. For that, a new transient semi-analytical model is developed in particular to facilitate the thermal design of EAHEs. The main application of the developed model is to predict the deterioration in EAHE's thermal performance as a function of the duration operation. This deterioration can be caused by soil thermal saturation where the nearby subsoil temperature becomes almost equal to the inlet air temperature resulting in minimum heat transfer between air and soil. The analytical solution of the proposed model has been integrated by means of the Bessel function method, for a constant heat flux per unit of length at the pipe surface in the radial dimension and constant inlet air temperature. The model has been verified with several results obtained from the literature. In addition, an investigation of continuous operation of an EAHE is made on thermal performance of the EAHE in the soil of the region of Biskra (Southern Algeria) (34°47′N - 005°43′E) by applying extreme ambient air temperature (57 °C). Results show that the deterioration in thermal performance of EAHE is observed for longer duration in hot and dry climate. In the case of 6 h of continuous operation, the soil radius can reach 0.55 m from the pipe surface. The model proposed in this paper can be considered as the first of its kind which gives a formula for calculating the soil radius (thickness) as a function of the: i) duration of operation, ii) soil thermal diffusivity, iii) pipe diameter and iv) air temperature. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Cleaner Production Elsevier

Thermal design of Earth-to-Air Heat Exchanger. Part I a new transient semi-analytical model for determining soil temperature

Loading next page...
 
/lp/elsevier/thermal-design-of-earth-to-air-heat-exchanger-part-i-a-new-transient-7AnzPO95u4
Publisher
Elsevier
Copyright
Copyright © 2018 Elsevier Ltd
ISSN
0959-6526
D.O.I.
10.1016/j.jclepro.2018.02.089
Publisher site
See Article on Publisher Site

Abstract

This article is the first in a series about the thermal design of Earth-to-Air Heat Exchanger, EAHE, using a new developed semi-analytical method. The temperature distribution in the soil surrounding the EAHE is studied in the goal to determine the soil radius as a function of the operation duration. This radius is the first distance from the pipe axis where there is no effect of heat from EAHE. For that, a new transient semi-analytical model is developed in particular to facilitate the thermal design of EAHEs. The main application of the developed model is to predict the deterioration in EAHE's thermal performance as a function of the duration operation. This deterioration can be caused by soil thermal saturation where the nearby subsoil temperature becomes almost equal to the inlet air temperature resulting in minimum heat transfer between air and soil. The analytical solution of the proposed model has been integrated by means of the Bessel function method, for a constant heat flux per unit of length at the pipe surface in the radial dimension and constant inlet air temperature. The model has been verified with several results obtained from the literature. In addition, an investigation of continuous operation of an EAHE is made on thermal performance of the EAHE in the soil of the region of Biskra (Southern Algeria) (34°47′N - 005°43′E) by applying extreme ambient air temperature (57 °C). Results show that the deterioration in thermal performance of EAHE is observed for longer duration in hot and dry climate. In the case of 6 h of continuous operation, the soil radius can reach 0.55 m from the pipe surface. The model proposed in this paper can be considered as the first of its kind which gives a formula for calculating the soil radius (thickness) as a function of the: i) duration of operation, ii) soil thermal diffusivity, iii) pipe diameter and iv) air temperature.

Journal

Journal of Cleaner ProductionElsevier

Published: May 1, 2018

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off