Experimental and numerical investigation on a new type of heat exchanger in ground source heat pump system

Liu, Xichen; Xiao, Yimin; Inthavong, Kiao; Tu, Jiyuan

doi:10.1007/s12053-015-9324-8

Cited by 18 publications

(13 citation statements)

References 29 publications

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“…Experimental measurements and modeling have been carried out to investigate the performance of a single U-shaped tube, double U-shaped tubes, and the new 4-tube structure (3 inlet tubes and 1 outlet tube). The thermal resistance of the 4-tube structure was 15.8 and 31.1% lower than that of the single U-shaped tube and double U-shaped tubes, respectively [29]. Chang and Kim (2016) reported that the thermal resistance of BHEs reduced with an increasing heat transfer area either by using a larger diameter of tube or the insertion of more tubes [31].…”

Section: Innovative Borehole Heat Exchanger Structuresmentioning

confidence: 99%

“…The vertical BHE consists of a hole drilled in the ground and completed with different pipe geometries such as single/double or triple U-shaped tubes, co-axial, and multi-pipe configurations. Recent developments in ground BHEs have focused on the design of new innovative structures [28][29][30][31][32] and the use of thermally enhanced materials [33][34][35][36][37][38][39][40][41]. Figure 3 illustrates a variety of common and innovative BHE configurations.…”

Section: Innovative Borehole Heat Exchanger Structuresmentioning

confidence: 99%

See 1 more Smart Citation

A Critical Review on the Use of Shallow Geothermal Energy Systems for Heating and Cooling Purposes

Ahmed

Assadi

Mehrjerdi³

et al. 2022

Energies

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The reduction of CO2 emissions has become a global concern. In this regard, the EU intends to cut CO2 emissions by 55% by 2030 compared to those of 1990. The utilization of shallow geothermal energy (SGE) in EU countries is considered the most effective measure for decarbonizing heating and cooling. SGE systems utilize heat energy collected from the earth’s crust to provide secure, clean, and ubiquitous energy. This paper provides a literature review on the use of SGE for heating and cooling purposes. The latest advances in materials, new innovative structures, and techno-economic optimization approaches have been discussed in detail. Shallow geothermal energy’s potential is first introduced, and the innovative borehole structures to improve performance and reduce installation cost is outlined. This is followed by an extensive survey of different types of conventional and thermally enhanced collectors and grouts. Attention is mainly given to the techno-economic analysis and optimization approaches. In published case studies, the least economic break-even point against fossil fuel-based heating systems occurs within 2.5 to 17 years, depending on the local geological conditions, installation efficiency, energy prices, and subsidy. Ground source heat pumps’ cost-effectiveness could be improved through market maturity, increased efficiency, cheap electricity, and good subsidy programs.

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Section: Innovative Borehole Heat Exchanger Structuresmentioning

confidence: 99%

Section: Innovative Borehole Heat Exchanger Structuresmentioning

confidence: 99%

A Critical Review on the Use of Shallow Geothermal Energy Systems for Heating and Cooling Purposes

Ahmed

Assadi

Mehrjerdi³

et al. 2022

Energies

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“…Fused salts are also used as heat-exchanger fluids in some applications. The exchangers are used to recover heat between two streams in a process; these fluids may be single compounds or mixtures [7].…”

Section: Literature Reviewmentioning

confidence: 99%

Heat Lump in Different Pavement Layer Using Ethylene Glycol as A Solar Heat Collector

et al. 2016

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Abstract. Due to the hot weather in Malaysia, several studies being carried out regarding solar energy harvesting and use as a noble renewable energy. Therefore, researchers start developing various methods to utilize sun's heat as a renewable source of energy. Solar energy has been always concern researchers to develop most effective, durable and cheap methods and materials to be used as solar energy collectors in road pavements. Therefore, this study was conducted to determine the maximum heat area using ethylene glycol. The study was involved the field monitoring of the six samples of asphalt slab with stainless steel pipe with ethylene glycol and empty pipe act as the controlled sample. The pipe was arranged in three different depths of 50mm, 100mm and 150mm and keeping controlled the pipe diameter and the size of slab of 20mm and 300mm x 300mm respectively. These results show that the maximum heat extraction by the ethylene glycol was at a depth 150mm which was 51.2°C. The average percentage increments of the pipe with ethylene glycol for three days for pipe depth 50mm was 71%, while for pipe at depth 100mm and 150mm were 78% and 62% respectively. The ethylene glycol effect was more noticeable compare to the pipe without ethylene glycol and can store more heat. For the strength of pipe, the highest maximum load bearing capacity that can be supported by the stainless steel pipe was at depth 50mm and the second highest was at a depth 100mm while the third highest was at depth 150mm. So, the suitable depth to install the pipe with the consideration of both cases which was maximum heat gain and the maximum load that can be supported was at depth 50mm.

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“…The results showed that the borehole wall temperature increased with an increase in the duration of the TRT [16]. Liu et al (2015) suggested a new VGHE design with three inlet pipes and one outlet (3Itype) and compared its performance to the single and double U-Tube VGHEs. Experimental results showed that the thermal resistance of the 3I-type was 31% and 15.8% lower than the single and double U-Tubes, respectively [17].…”

Section: Introductionmentioning

confidence: 99%

“…Liu et al (2015) suggested a new VGHE design with three inlet pipes and one outlet (3Itype) and compared its performance to the single and double U-Tube VGHEs. Experimental results showed that the thermal resistance of the 3I-type was 31% and 15.8% lower than the single and double U-Tubes, respectively [17]. In an analysis of the influences of the different pipe material properties (copper and high density polyethylene pipes) on the performance of VGHEs, Ramadan (2016) found that the performance trend remains the same for both copper and high density polyethylene pipes in a ground heat exchanger [18].…”

Section: Introductionmentioning

confidence: 99%

Performance of Conventional and Innovative Single U-Tube Pipe Configuration in Vertical Ground Heat Exchanger (VGHE)

Eswiasi

Mukhopadhyaya

2021

Sustainability

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A ground source heat pump system (GSHP) with a ground heat exchanger (GHE) is a renewable and green technology used for heating and cooling residential and commercial buildings. An innovative U-Tube pipe configuration is suggested to enhance the heat transfer rate in the vertical ground heat exchanger (VGHE). Laboratory experiments are conducted to compare the thermal efficiency of VGHEs with two different pipe configurations: (1) an innovative U-Tube pipe configuration (single U-Tube with two outer fins) and (2) a single U-Tube. The results show that the difference between the inlet and outlet temperatures for the innovative U-Tube pipe configuration was 0.7 °C after 60 h, while it was 0.4 °C for the single U-Tube after the same amount of time. The borehole thermal resistance for the innovative U-Tube pipe configuration was 0.680 m·K/W, which is 29.22% lower than that of the single U-Tube. The heat exchange rate in the innovative U-Tube pipe configuration is increased by 57.95% compared to the conventional single U-Tube. Measured ground temperatures indicate that compared to single U-Tube pipe configuration, the innovative U-Tube pipe configuration has superior heat transfer performance. Based on the experimental results presented in this paper, it was concluded that increasing the surface area significantly by introducing external fins to the U-Tube enhances the heat transfer rate, resulting in increased thermal efficiency of the VGHE.

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Experimental and numerical investigation on a new type of heat exchanger in ground source heat pump system

Cited by 18 publications

References 29 publications

A Critical Review on the Use of Shallow Geothermal Energy Systems for Heating and Cooling Purposes

A Critical Review on the Use of Shallow Geothermal Energy Systems for Heating and Cooling Purposes

Heat Lump in Different Pavement Layer Using Ethylene Glycol as A Solar Heat Collector

Performance of Conventional and Innovative Single U-Tube Pipe Configuration in Vertical Ground Heat Exchanger (VGHE)

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