Three-dimensional transient heat transfer from a buried pipe—I. Laminar flow

doi:10.1016/0009-2509(93)85006-B

Chemical Engineering Science

Volume 48, Issue 20, October 1993, Pages 3507-3517

https://doi.org/10.1016/0009-2509(93)85006-B Get rights and content

Abstract

A model is presented for heat transfer from a fluid in laminar flow inside a buried horizontal pipe. The top surface of the soil in which the pipe is buried is horizontal and flat and is kept at a temperature lower than the soil and the liquid temperatures. The problem is modelled as a transient three-dimensional process in cylindrical geometry. The solution is obtained using a string-intersected-boundary formulation and a three-level alternating-direction implicit finite difference method. The resulting equations were solved on a CDC Cyber 205 supercomputer. The validity of the numerical scheme has been verified by comparison with an analytical solution for a simplified problem.

References (12)

H.H. Bau et al.
Heat loss from a fluid flowing in a buried pipe
Int. J. Heat Mass Transfer
(1982)
K. Himasekhar et al.
Thermal convection associated with hot/cold pipes buried in a semi-infinite, saturated, porous medium
Int. J. Heat Mass Transfer
(1987)
W.W. Martin et al.
Bounds on transient temperature distribution due to a buried cylindrical heat source
Int. J. Heat Mass Transfer
(1978)
P.L.T. Brian
A finite-difference method of high-order accuracy for the solution of three-dimensional transient heat conduction problems
A.I.Ch.E. J.
(1961)
H.S. Carslaw et al.
E.R.G. Eckert et al.
(1972)

There are more references available in the full text version of this article.

Cited by (21)

Comparative performance analysis of building foundation Ground heat exchanger
2020, Geothermics
Citation Excerpt :
The first of these is the Kelvin Line Source Theory and the other is the Cylinder Source Theory. Only the symmetrical soil temperature distribution around the pipe can be obtained by using these source theories (Gu and O’Neal, 1995; Hastaoglu et al., 1995; Lei, 1993; Mukerji et al., 1997; Negiz et al., 1993, 1995; Chiasson, 1999; Mei, 1991). In the analytical model proposed by Metz (1983), the temperature distribution in the soil was obtained by dividing the soil into blocks around the coil by making some changes in the Line Source theory.
The aim of this work is to improve the performance of Ground-Source Heat Pumps (GSHPs) by placing the heat exchanger pipes in the soil under the building foundation and in the building foundation reconstructed in Turkey. In this scope, firstly, experimental studies have been performed on horizontal parallel pipes buried in soil under the foundation of the 2400 m² Central Laboratory building, which was newly built at Yıldız Technical University. A comparison between the results of the experimental and newly developed numerical model is presented. Then, a full-scale numerical model for a shopping mall is developed based on the pipe location (soil and concrete layer), Numbers of Parallel Tube (NPTs) and different condensation temperatures in the heating season. The results show that the COP of GSHP when the pipes are buried in the soil under the building foundation is greater than when the pipes are buried in the building foundation. Furthermore, considering capital investment and operational costs, a reference function is defined as an optimization parameter. The effects of the pipe location, increasing rates in electricity prices and NPTs on reference function are investigated. For higher NPT values, locating the pipes in the foundation gives higher values of the reference function while for lower NPT values it is vice versa.
Energy and exergy analysis of horizontal ground heat exchanger for hot climatic condition of northern Tunisia
2015, Geothermics
Citation Excerpt :
Eicker and Vorschulze (2009) showed, in numerical study, that direct cooling of a building by using a GHE is possible but only if the temperature of the soil adjacent to the intake pipe is lower than the desired temperature of the indoor air. More complicated model for heat transfer of buried pipes was performed, Negiz et al. (1993, 1995), for petrol transferring pipes, Thiers and Peuportier (2007) and Bi et al. (2002) with a two-dimensional cylindrical coordinate system. Demir et al. (2008) simulated heat transfer of horizontal parallel pipe GHE, using alternating direction implicit finite difference formulation, including all meteorological and surface conditions.
This paper deals with the energy and exergy analysis of horizontal ground heat exchanger (HGHE) for hot climatic condition of northern Tunisia. The HGHE consists of 50 m of length buried at 1 m of depth. The ground temperatures at several depths were measured, the overall heat transfer coefficient (overall HTC) was determined, the heat exchange rate was quantified. In addition, the effects of various parameters such as the HGHE length and diameter and the mass flow rate of circulating water were inspected analytically. The results showed that the energy and exergy efficiencies are found to range between 52 and 18% and 36 and 12%, respectively. For a tested room with 12 m² of surface area, the GHE system allowed to cover 65% of its total cool requirement.
In-field performance analysis of ground source cooling system with horizontal ground heat exchanger in Tunisia
2013, Energy
Citation Excerpt :
Better energy efficiency of ground coupled heat pump systems in comparison with traditional applications leads to continued growth in the number of installations for space conditioning [17]. In the open literature, many research works have been conducted, modeling and testing of ground coupled heat pump systems [18–25]. Recently, in simulation study using TRNSYS, Entchev et al. [26] proved that the GSHP and a hybrid GSHP/fuel cell systems achieved significant overall energy savings of 39% and 24% respectively, compared with conventional system with boiler/chiller.
GSHP (Ground source heat pump) system is a promising technology for cooling and heating building in the world. Regrettably, this technology is still not available in Tunisia and it is time to test the GSHP systems in our country. For this purpose, two experimental systems are performed at the Research and Technology Center of Energy (CRTEn), in Borj Cédria, northern Tunisia. Firstly, to evaluate optimal parameters of the GHE (ground heat exchanger), the performance of the GHE with horizontal configuration was analyzed experimentally and analytically. The effect of various parameters such as mass flow rate of circulating water, length, buried depth and inlet temperature of the GHE on the heat exchange rate were examined. Second, water-to-water GSCS (Ground Source Cooling System) with HGHE (Horizontal Ground Heat Exchanger) was performed. The results obtained from this experimental study, are used to evaluate the COP_hp (coefficient of performance of the heat pump) and the COP _sys (coefficient of performance of the overall system) of the GSCS, which are ranged between 3.8–4.5 and 2.3–2.7, respectively. The results showed that the utilization of the ground source heat pump is appropriated for cooling building in Tunisia, which is characterized by a hot climate.
Simulation analysis of thermal influential factors on crude oil temperature when double pipelines are laid in one ditch
2013, Advances in Engineering Software
Citation Excerpt :
Therefore, it is meaningful to investigate and gain a deep understanding of thermal influential factors on crude oil temperature drop when double pipelines are laid in one ditch, and it is important to provide technical support to ensure operation safety and at last, really save energy and investment. Extensive studies have been carried out to investigate the thermal characterization of hot crude oil pipeline [7–12], while few researches are about double pipelines laid in one ditch. Ling et al. [13] and Yu et al. [14,15] had simulated the temperature field of double pipelines system and analyzed the effect of pipeline interval and diameter combination on thermal impact.
Crude oil pipeline laid with products pipeline in the same ditch is a new technology to save investment and protect environment. In order to provide reference to construction and operation optimization, the majority of this paper investigates the thermal influential factors affecting the crude oil temperature in double pipelines system using the computational fluid dynamics methodology. A two-dimensional rectangular region including the two pipelines is selected as computational domain in this investigation. Heat transfer models are proposed to obtain the temperature field distribution and the crude oil temperature drop. The impacts of pipeline interval, crude oil temperature at the outlet of heating station, diameter of crude oil pipeline and atmosphere temperature have been reasonably captured and analyzed in details.
Experimental study of heat transfer of buried finned pipe for ground source heat pump applications
2009, International Communications in Heat and Mass Transfer
Ground heat exchangers have vital importance for ground source heat pump applications. Various configurations tried to improve heat transfer in the soil. A new kind of aluminium finned pipe buried in the soil for this aim. In order to compare effectiveness of the Al finned pipe over the traditional PPRC pipe an experimental study carried out. The experimental GSHP system was installed at Yıldız Technical University Davupasa Campus on 800 m² surface area with no special surface cover. Temperature data were collected using thermocouples buried in soil horizontally and vertically at various distances from the pipe center and at the inlet and the outlet of the ground heat exchanger. Experimental results were compared with results from analytical study. To compare effectiveness of the Al finned pipe and PPRC pipe a new parameter defined as transferred amount of heat per unit mass of working fluid per unit time for this aim. It is found that Al finned pipe has higher heat transfer values than the traditional PPRC pipe.
Heat transfer of horizontal parallel pipe ground heat exchanger and experimental verification
2009, Applied Thermal Engineering
The ground heat exchangers (GHE) consist of pipes buried in the soil and is used for transferring heat between the soil and the heat exchanger pipes of the ground source heat pump (GSHP). Because of the complexity of the boundary conditions, the heat conduction equation has been solved numerically using alternating direction implicit finite difference formulation. A software was developed in MATLAB environment and the effects of solution parameters on the results were investigated. An experimental study was carried out to test the validity of the model. An experimental GSHP system is installed at Yıldız Technical University Davupasa Campus on 800 m² surface area with no special surface cover. Temperature data were collected using thermocouples buried in soil horizontally and vertically at various distances from the pipe center and at the inlet and the outlet of the ground heat exchanger. Experimental and numerical simulation results calculated using experimental water inlet temperatures were compared. The maximum difference between the numerical results and the experimental data is 10.03%. The temperature distribution in the soil was calculated and compared with experimental data also. Both horizontal and vertical temperature profiles matched the experimental data well. Simulation results were compared with the other studies.

View all citing articles on Scopus

¹: A. Negiz is currently at the Chemical Engineering Department, Illinois Institute of Technology, Chicago, Illinois, U.S.A.

View full text

Three-dimensional transient heat transfer from a buried pipe—I. Laminar flow

Abstract

Int. J. Heat Mass Transfer

Int. J. Heat Mass Transfer

Int. J. Heat Mass Transfer

A finite-difference method of high-order accuracy for the solution of three-dimensional transient heat conduction problems

A.I.Ch.E. J.