Integrated analytical modeling of transient heat transfer inside and outside U-tube ground heat exchanger: A new angle from composite-medium method

A vertical U-tube ground heat exchanger can be utilized to exchange heat with the soil in ground source heat pump systems. The outlet temperature of the working fluid through the U-tube not only accounts for heat transfer capacity of a ground heat exchanger, but also greatly affects the operational efficiency of heat pump units, which is an important characteristic parameter of heat transfer process. It is quantified by defining a thermal effectiveness coefficient. The performance evaluation is performed with a three dimensional numerical model using a finite volume technique. A dynamic simulation was conducted to analyze the thermal effectiveness as a function of soil thermal properties, backfill material properties, separation distance between the two tube legs, borehole depth and flow velocity of the working fluid. The influence of important characteristic parameters on the heat transfer performance of vertical U-tube ground heat exchangers is investigated, which may provide the references for the design of ground source heat pump systems in practice.

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Heat Transfer Performance Analysis of Horizontal Ground Heat Exchanger under the Artificial Lake

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.516-517.316 ◽

2012 ◽

Vol 516-517 ◽

pp. 316-321

Author(s):

Zhong Yi Yu ◽

Yan Hua Chen ◽

Xiao Liang Tang ◽

Jian Ping Lei

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Transfer Performance ◽

Simulation Method ◽

Transfer Performance ◽

Ground Heat Exchanger ◽

Loop Formation ◽

Artificial Lake ◽

Pump System ◽

Heat Pump System

According to the application conditions of horizontal ground heat exchanger(HGHE) under artificial lake, this paper uses numerical simulation method to do dynamic simulation research of the heat transfer performance of HGHE, analyzes the effect of connection mode and pipe flow velocity on heat transfer performance of HGHE in detail，puts forward efficient HGHE loop formation mode，and will provide effective technical support for ground-source heat pump system design with HGHE.

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Reduced dimension model for heat transfer of ground heat exchanger in permafrost

Journal of Physics Conference Series ◽

10.1088/1742-6596/937/1/012056 ◽

2017 ◽

Vol 937 ◽

pp. 012056

Author(s):

M Vasilyeva ◽

S Stepanov ◽

I Sirditov

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Ground Heat Exchanger ◽

Reduced Dimension

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Case study of heat transfer behavior of helical ground heat exchanger

Energy and Buildings ◽

10.1016/j.enbuild.2012.06.019 ◽

2012 ◽

Vol 53 ◽

pp. 137-144 ◽

Cited By ~ 41

Author(s):

Hyunku Park ◽

Seung-Rae Lee ◽

Seok Yoon ◽

Hosung Shin ◽

Dae-Soo Lee

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Ground Heat Exchanger ◽

Heat Transfer Behavior ◽

Transfer Behavior

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Simulation on Ground Temperature Change of GSHP System in Severe Cold Regions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.945-949.2820 ◽

2014 ◽

Vol 945-949 ◽

pp. 2820-2824 ◽

Cited By ~ 2

Author(s):

Li Bai ◽

Peng Xuan Wang

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Temperature Change ◽

Heat Pump ◽

Ground Heat Exchanger ◽

Ground Source Heat Pump ◽

Cold Regions ◽

Ground Source ◽

Ground Coupled Heat Pump ◽

Operation And Management

For the case of ground-source heat pump in severe cold regions in winter, the heat transfer situation of the ground and ground heat exchanger was dynamically simulated according to the statistics of a project in Changchun to analysis the change of the ground heat, which provided references for the initial design and operation and management of the ground-coupled heat pump in severe cold regions.

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Mathematical Modeling of Fluid Flow and Heat Transfer in Petroleum Industries and Geothermal Applications

Energies ◽

10.3390/en13061344 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1344

Author(s):

Mehrdad Massoudi

Keyword(s):

Mathematical Modeling ◽

Heat Transfer ◽

Porous Media ◽

Fluid Flow ◽

Heat Exchanger ◽

Ground Heat Exchanger ◽

Special Issue ◽

Flow And Heat Transfer ◽

Convection In Porous Media

This Special Issue of Energies is dedicated to all aspects of fluid flow and heat transfer in geothermal applications, including the ground heat exchanger, conduction, and convection in porous media [...]

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Transient Heat Transfer in a Vapor-Heated Heat Exchanger With Arbitrary Timewise-Variant Flow Perturbation

Journal of Heat Transfer ◽

10.1115/1.3687085 ◽

1964 ◽

Vol 86 (2) ◽

pp. 133-142 ◽

Cited By ~ 9

Author(s):

Wen-Jei Yang

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Heat Exchanger ◽

Transfer Coefficient ◽

Heat Exchangers ◽

Amplitude Ratio ◽

Perturbation Technique ◽

Transient Heat Transfer ◽

Coolant Temperature ◽

Flow Perturbation

An analysis is made of transient heat transfer in a vapor-heated heat exchanger with an arbitrary timewise-variant flow perturbation. The heat-transfer coefficient between the tube and coolant is assumed to vary like the n power of the coolant velocity. Results are obtained through the use of the perturbation technique. General relations are presented in closed form and their application is illustrated by carrying out some typical examples: step, linear, exponential, and sinusoidal transients in the coolant flow velocity. The influence of the system parameters on the variation of the coolant temperature is investigated. A phenomenon of resonance in the amplitude-ratio and phase-shift is disclosed for the oscillating flow transient. This phenomenon is explained by analyzing the enthalpy change of the coolant particle in the heat exchanger. The results are also compared with the analyses that have assumed a constant heat-transfer coefficient. Heat exchangers to which these results apply include the double-pipe and shell- and-tube type heat exchangers.

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