Experimental performance of borehole heat exchangers and grouting materials for ground source heat pumps

2011 ◽  
Vol 36 (13) ◽  
pp. 1238-1246 ◽  
Author(s):  
Johan Desmedt ◽  
Johan Van Bael ◽  
Hans Hoes ◽  
Nico Robeyn
Keyword(s):  
Heat Exchangers ◽  
Heat Pumps ◽  
Ground Source Heat Pumps ◽  
Experimental Performance ◽  
Ground Source ◽  
Grouting Materials ◽  
Borehole Heat Exchangers

scholarly journals Ground-Source Heat Pumps with Horizontal Heat Exchangers for Space Cooling in the Hot Tropical Climate of Thailand

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1274 ◽  
Author(s):  
Arif Widiatmojo ◽  
Sasimook Chokchai ◽  
Isao Takashima ◽  
Yohei Uchida ◽  
Kasumi Yasukawa ◽  
...  
Keyword(s):  
Economic Growth ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Life Cycle Cost ◽  
Heat Pumps ◽  
Ground Source Heat Pump ◽  
Ground Source Heat Pumps ◽  
Air Source Heat Pump ◽  
Ground Source ◽  
Space Cooling

The cooling of spaces in tropical regions, such as Southeast Asia, consumes a lot of energy. Additionally, rapid population and economic growth are resulting in an increasing demand for space cooling. The ground-source heat pump has been proven a reliable, cost-effective, safe, and environmentally-friendly alternative for cooling and heating spaces in various countries. In tropical countries, the presumption that the ground-source heat pump may not provide better thermal performance than the normal air-source heat pump arises because the difference between ground and atmospheric temperatures is essentially low. This paper reports the potential use of a ground-source heat pump with horizontal heat exchangers in a tropical country—Thailand. Daily operational data of two ground-source heat pumps and an air-source heat pump during a two-month operation are analyzed and compared. Life cycle cost analysis and CO2 emission estimation are adopted to evaluate the economic value of ground-source heat pump investment and potential CO2 reduction through the use of ground-source heat pumps, in comparison with the case for air-source heat pumps. It was found that the ground-source heat pumps consume 17.1% and 18.4% less electricity than the air-source heat pump during this period. Local production of heat pumps and heat exchangers, as well as rapid regional economic growth, can be positive factors for future ground-source heat pump application, not only in Thailand but also southeast Asian countries.

scholarly journals A numerical study on heat transfer performances of horizontal ground heat exchangers in ground-source heat pumps

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250583
Author(s):  
Hang Zou ◽  
Peng Pei ◽  
Chen Wang ◽  
Dingyi Hao
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Heat Pumps ◽  
Working Fluid ◽  
Total Heat Transfer ◽  
Ground Source Heat Pumps ◽  
Spiral Coil ◽  
Ground Heat Exchangers ◽  
Ground Source ◽  
Heat Transfer Capacity

Horizontal ground heat exchangers (HGHEs) have advantages such as convenient construction and low cost; however, their application and popularization are restricted owing to traditional linear HGHEs occupying large space and presenting low total heat transfer capacity. Spiral-coil and slinky-coil HGHEs have been proposed, but currently a comprehensive comparison and evaluation for these types of HGHEs are still needed. In this study, a three-dimensional heat transfer model of the three types of HGHEs for ground source heat pumps (GSHPs) was established. Based on the simulation results, the long-term heat transfer performances were investigated, including the temperature field of surrounding energy-storage soils, outlet working fluid temperature, coefficient of performance (COP) of units, and surplus temperature of the energy-storage soils. A new concept named heat transfer capacity per heat-affected area was proposed in this paper. It is found that the spiral-coil HGHEs have the best performances in terms of working-fluid outlet temperature, unit COP, total heat transfer capacity, heat transfer rate heat-affected area. The linear HGHEs shows the best performances in terms of mitigating heat imbalance risk and heat transfer rate per length. The results provide a reliable basis for selection of HGHE types in engineering practice and improvement guide in the future.

scholarly journals Experimental work over borehole filling material to reinforce characterization and model validation of Ground Heat Exchangers

2021 ◽  
Vol 19 ◽  
pp. 109-114
Author(s):  
A.J. Extremera-Jiménez ◽  
◽  
D. Eliche-Quesada ◽  
C. Guitérrez-Montes ◽  
F. Cruz-Peragón1
Keyword(s):  
Experimental Work ◽  
Heat Exchangers ◽  
Heat Pumps ◽  
Thermal Capacity ◽  
Filling Material ◽  
Ground Source Heat Pumps ◽  
Ground Heat Exchangers ◽  
Ground Source ◽  
Consistency Results ◽  
Air Conditioning Systems

Ground Heat Exchangers (GHE) are part of Ground Source Heat Pumps (GSHP), employed as a renewable source in air conditioning systems. Models implemented are quite in tune to the real behaviour, enabling reliable designs and optimization, once several thermal properties of the surrounding soil and borehole are known. Since some values of those properties are evaluated from experiments, other ones are selected and approached from data base, leading sometimes to poor reproductions, due to the lack of their specific knowledge. This work demonstrates the effectiveness of the experimental evaluation of the filling material properties in a vertical GHE, to guarantee more reliable values to model its thermal behaviour: moisture content, density, and both thermal capacity and conductivity. Experiments must be easy and fast to perform, because their values must be known previous to the GSHP design. In addition, an identification process over a numerical model has been developed. In order to check its consistency, results have been compared with those determined experimentally. As well as a high model accuracy, it has been demonstrated the importance of the presented assays to be included in the previous experimental work to the design step of a GSHP system, providing a valuable borehole characterization.

scholarly journals Laboratory thermal conductivity measurements on gravel sample

2018 ◽  
Vol 7 (3) ◽  
pp. 67-70
Author(s):  
Antonio Galgaro ◽  
Matteo Cultrera ◽  
Giorgia Dalla Santa ◽  
Fabio Peron
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Heat Exchangers ◽  
Heat Pumps ◽  
Conductivity Measurements ◽  
Ground Source Heat Pumps ◽  
Ground Source

Modern Ground Source Heat Pumps (GSHPs) systems must be designed by taking into account the ground thermal properties, in order to properly plan the capability of the heat pumps to transfer calories through the Ground Source Heat Exchangers (GSHE) to the subsoil (and vice versa). [...]

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