Research on Heat Exchange Law and Structural Design Optimization of Deep Buried Pipe Energy Piles

Chen, Zhi; Wang, Bo; Zheng, Lina; Xiao, Henglin; Wang, Jingquan

doi:10.3390/en14206449

Cited by 10 publications

(5 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(3) The thermal property of the reinforcement in the pile foundation is the same as that of concrete; (4) Rock and soil temperature around the pile foundation are uniform; (5) The effects of the pipe wall on heat transfer are ignored; (6) The pile-soil contact surface is regarded as rigid unit contact; (7) It is assumed that soil is an ideal elastoplastic model.…”

Section: Basic Assumptionsmentioning

confidence: 99%

“…At the same time, the DBP-EP enables the heat-exchange pipe to pass through the pile end to achieve an ideal depth for heat transfer. Furthermore, the deep buried pipe energy pile (DBP-EP) has a more flexible structure that the design of the pile body, and the relevant size of the deep well can be achieved according to the heat-transfer demand in practical applications, which is a further optimization of the inside buried pipe energy pile (IBP-EP) and the GSHP in the pile [5,6]. Furthermore, this realizes the efficient and economic utilization of geothermal resources as an efficient and feasible idea for the development of low-carbon buildings.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study on the Thermomechanical Response of Deep Buried Pipe Energy Piles under Temperature Load

et al. 2022

Self Cite

View full text Add to dashboard Cite

A deep buried pipe energy pile (DBP-EP) is a composite structure that integrates ground-source heat pump (GSHP) systems and inside buried pipe energy piles (IBP-EP) to effectively achieve the improvement of heat transfer efficiency and quantity. Utilizing this technology in building a pile foundation can contribute to reducing carbon emissions. This paper studies the variation rules of the thermomechanical response of DBP-EP under temperature load via field testing and numerical simulation. The results show that, under heating and cooling conditions, the DBP-EP temperature variation within the pile is substantial, while there is no significant change in the temperature field at the bottom of the pile. This is different from the internal temperature change of the temperature distribution of IBP-EP. The minimum axial average strain of the DBP-EP under the cooling condition is significantly smaller than that under the heating condition. However, the additional axial average strain under the temperature load is significantly larger than that in the heating condition, resulting in larger additional axial stress when the pile is cooled. The connection between the pile and foundation must considered in design due to the large settlement of the pile top under cooling conditions. When only under the temperature load, the maximum axial average pressure increments of the pile in our test during heating and cooling are –85.3 kN/°C and 99.4 kN/°C, respectively, suggesting that the additional load cannot be ignored.

show abstract

Section: Basic Assumptionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Study on the Thermomechanical Response of Deep Buried Pipe Energy Piles under Temperature Load

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is found that the existence of water in soil has a great role in promoting the efficiency of energy piles [9,[12][13][14]. It is also concluded that the pile diameter ratio, pile spacing, the diameter of the heat exchange tube in the pile, the water flow velocity in the pipe, the inlet water temperature, and the properties of the strata around the energy pile will affect the working efficiency of the energy pile [15][16][17][18][19][20]. In terms of the long-term working performance of the energy pile, the thermal cycle of the energy pile will lead to a decrease in the soil moisture content around the pile, resulting in a decrease in the thermal conductivity of the soil around the pile, which will increase the temperature around the energy pile and reduce the heat exchange efficiency of the energy pile [21,22].…”

Section: Introductionmentioning

confidence: 99%

Study on Thermodynamic Properties of Spiral Tube-Encapsulated Phase-Change Material Energy Pile

Liu,

Zhang,

Yang

et al. 2024

Buildings

View full text Add to dashboard Cite

Based on the research status of phase-change material (PCM) energy piles, this paper proposes a new type of PCM energy pile-spiral tube-encapsulated PCM energy pile. In order to study the related properties of the energy pile, this study designed and processed the relevant test equipment and built an indoor scale model experimental system. The thermodynamic performance of the spiral tube-encapsulated phase-change energy pile under summer conditions was studied by the test system. Through the indoor scale model test, it is found that compared with the traditional energy pile, the spiral tube-encapsulated PCM energy pile improves the heat exchange capacity of the unit pile body in the early and middle stages of operation, and reduces the surface temperature of the pile body and the heating rate of the surface temperature of the pile body. The upward displacement of the energy pile top is reduced. The heat exchange capacity of the unit pile depth is increased by 6.52 W/m, the maximum pile surface temperature difference is 0.62 °C, and the maximum pile top displacement difference is 0.005 mm. In addition, the total heat transfer of the spiral tube-encapsulated PCM energy pile during the whole operation period is 3.38% higher than that of the traditional energy pile. However, during the whole operation period, the surface stress value of the spiral tube encapsulated PCM energy pile is higher than that of the traditional energy pile. The maximum difference between the two is 9.84 kPa and the maximum difference is 10.8%. The difference between the two is finally stabilized at 1.4 kPa with an increase in time, and the final difference is only 8.8%.

show abstract

“…The appearance of energy piles provides a new opinion for the extensive application of ground source heat pump, which has been widely used because of overcoming the shortcomings of traditional ground source heat pumps. At present, domestic and foreign scholars have carried out a large number of studies on energy piles, covering various aspects such as heat transfer mechanisms, heat exchange enhancement, thermal structural response, and group piles effects [1][2][3][4][5][6][7]. As one of the core components of the energy pile, the circulating working liquid carries heat and circulates in the heat exchanger under the working condition in summer, to release heat into the soil, and absorbs heat from the soil as it flows under the winter condition.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Enhancement of Energy Pile with Nanofluids as Heat Carrier

Wang,

Yin,

et al. 2023

Advances in Civil Engineering

View full text Add to dashboard Cite

As one of the core components of the transport medium in the energy pile system, the circulating working fluid is crucial for the enhancement of its heat transfer efficiency. In this study, based on the heat transfer enhancement theory of nanofluids, deionized water was used as the base solution to prepare the corresponding 0, 0.5, 1, and 1.5 vol% nanofluids by introducing nanoparticles SiO2, Al2O3, CuO, and Cu. The laws of thermal conductivity and specific heat capacity with the volume fraction of different nanofluids are studied by the comparison. The results of thermal conductivity research illustrate that the specific heat capacity of nanofluids decreases linearly with the increase of the volume concentration of nanoparticles, but the thermal conductivity increases linearly. The fluid with the highest thermal conductivity and specific heat capacity is Cu–water nanofluids. In addition, it is proposed to directly apply all kinds of nanofluids with 1 vol% as circulating fluid to self-made miniature model box of energy pile to simulate the working conditions in summer. The influence laws of the nanofluids on the flow rate and heat transfer efficiency in the energy pile were calculated through the temperature difference between the inlet and outlet of the heat exchange tube. The results reveal that the nanofluids used in the experiment exert a optimization influence on the heat transfer of energy pile but the mass flow rate of the nanofluids during the circulation is decreased compared with that of the deionized water circulation liquid. Among them, the temperature difference between inlet and outlet of Cu–water nanofluid is the largest, which has the best effect on improving the heat transfer efficiency of the energy pile but its mass flow loss is also the largest. The research results can provide a reliable reference for the improvement of heat transfer efficiency of energy pile engineering in the future.

show abstract

Research on Heat Exchange Law and Structural Design Optimization of Deep Buried Pipe Energy Piles

Cited by 10 publications

References 23 publications

Study on the Thermomechanical Response of Deep Buried Pipe Energy Piles under Temperature Load

Study on the Thermomechanical Response of Deep Buried Pipe Energy Piles under Temperature Load

Study on Thermodynamic Properties of Spiral Tube-Encapsulated Phase-Change Material Energy Pile

Heat Transfer Enhancement of Energy Pile with Nanofluids as Heat Carrier

Contact Info

Product

Resources

About