HEAT TRANSFER MODEL AND THERMAL RESPONSE RADIUS CALCULATION OF ENERGY PILE CONSIDERING PILE-SOIL DIFFERENCE

Ou Xiaoduo; Huang Zhongzheng; Qin Jinxi; Jiang Jie; Lyu Zhengfan

doi:10.19912/j.0254-0096.tynxb.2021-0304

PDF(2074 KB)

Acta Energiae Solaris Sinica ›› 2022, Vol. 43 ›› Issue (10) : 386-394. DOI: 10.19912/j.0254-0096.tynxb.2021-0304

HEAT TRANSFER MODEL AND THERMAL RESPONSE RADIUS CALCULATION OF ENERGY PILE CONSIDERING PILE-SOIL DIFFERENCE

Ou Xiaoduo, Huang Zhongzheng, Qin Jinxi, Jiang Jie, Lyu Zhengfan

Author information +

History +

Abstract

In order to solve the problem of error caused by treating pile and soil as the same medium in heat transfer analysis of energy pile, an unsteady heat transfer model of U-shaped buried pipe energy pile is established, which can consider the thermophysical properties difference between pile and soil. The accuracy of the model is verified by comparing with the linear heat source model. On this basis, the approximate simplified expression of thermal response radius of energy pile is obtained by series expansion. Finally, the heat exchange per unit pile length, the thermal diffusion coefficient, pile diameter and the soil type are analyzed, and the "heat storage ratio" is used to evaluate the influence of the above parameters on the heat transfer process of the energy pile. The results show that： compared with the linear heat source model, the model can describe the heat transfer process of energy pile more accurately, which can effectively avoid the problems of underestimating the excess temperature of pile wall in the initial stage of heat transfer and overestimating the pile temperature in the stable stage of heat transfer; in the typical operation cycle of energy pile, the error of the calculation method of thermal response radius proposed in this study is within 0.1 ℃, which meets the engineering requirements; during the heat transfer process of energy pile, the heat storage ratio of soil increases with the decrease of the heat capacity of pile and the relative difference of thermal diffusion coefficient between pile and soil; the excess temperature of pile wall and the heat storage ratio of soil decrease with the increase of pile diameter; with the increase of heat transfer time, the excess temperature difference of pile wall corresponding to different pile diameter increases gradually, and the difference of heat storage ratio of soil decreases gradually; under the same heat transfer power, the change rate of excess temperature of energy pile wall hardly changes with the increase of heat transfer time; after 90 days of heat transfer, the pile diameter has little effect on the distribution of energy transfer.

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

Ou Xiaoduo, Huang Zhongzheng, Qin Jinxi, Jiang Jie, Lyu Zhengfan. HEAT TRANSFER MODEL AND THERMAL RESPONSE RADIUS CALCULATION OF ENERGY PILE CONSIDERING PILE-SOIL DIFFERENCE[J]. Acta Energiae Solaris Sinica. 2022, 43(10): 386-394 https://doi.org/10.19912/j.0254-0096.tynxb.2021-0304

References

[1] LYCSSE L, ALICE D D.Understanding the behavior of energy gco-structures[J]. Civil engineering, 2011, 164(4): 184-191.
[2] 江强强, 焦玉勇, 骆进, 等. 能源桩传热与承载特性研究现状及展望[J]. 岩土力学, 2019, 40(9): 3351-3362, 3372.
JIANG Q Q, JIAO Y Y, LUO J, et al.Review and prospect on heat transfer and bearing performance of energy piles[J]. Rock and soil mechanics, 2019, 40(9): 3351-3362, 3372.
[3] INGERSOLL L R, ZOBEL O J, INGERSOLL A C.Heat conduction with engineering, geological and other applications[M]. New York: USA McGraw-Hill, 1954.
[4] MAN Y, YANG H, DIAO N, et al.A new model and analytical solutions for borehole and pile ground heat exchangers[J]. International journal of heat and mass transfer, 2010, 53(13/14): 2593-2601.
[5] CUI P, LI X, MAN Y, et al.Heat transfer analysis of pile geothermal heat exchangers with spiral coils[J]. Applied energy, 2011, 88(11): 4113-4119.
[6] 黄光勤, 杨小凤, 庄春龙, 等. 新型圆台型螺旋能量桩传热模型与换热性能[J]. 太阳能学报, 2019, 40(3): 695-702.
HUANG G Q, YANG X F, ZHUANG C L, et al.Heat transfer model and performance of novel truncated cone helif energy pile[J]. Acta energiae solaris sinica, 2019, 40(3): 695-702.
[7] 刘耶军. 能源桩传热数值模拟暨热响应半径研究[D]. 杭州: 浙江工业大学, 2019.
LIU Y J.Numerical simulation of heat transfer and thermal response radius of energy piles[D]. Hangzhou: Zhejiang University of Technology, 2019.
[8] 刘汉龙, 黄旭, 孔纲强, 等. 桩芯介质对管式能量桩换热效率的影响[J]. 中国公路学报, 2019, 32(1): 1-11.
LIU H L, HUANG X, KONG G Q, et al.Influence of pile core medium on heat transfer efficiency of tubular energy pile[J]. China journal of highway and transport, 2019, 32(1): 1-11.
[9] YANG J, YAN Z G, LI X X, et al. A unified model and analytical solution for borehole and pile ground heat exchangers[J]. International journal of heat and mass transfer, 2020, 152: 119559.1-119559.11.
[10] BOURNE W P, AMATYA B, SOGA K, et al.Energy pile test at Lambeth College, London: geotechnical and thermodynamic aspects of pile response to heat cycles[J]. Geotechnique, 2009, 59(3): 237-248.
[11] 赵篙颖, 蒋大伟, 宋晓东. 能量桩储热技术材料选取研究[J]. 吉林建筑大学学报, 2013, 30(6): 32-35.
ZHAO S Y, JIANG D W, SONG X D.The research on materials selection about heat accumulation technology of energy pile[J]. Journal of Jilin Jianzhu University, 2013, 30(6): 32-35.
[12] 白丽丽, 裴华富, 宋怀博, 等. 相变能量桩段模型传热模拟[J]. 防灾减灾工程学报, 2019, 39(4): 684-690.
BAI L L, PEI H F, SONG H B, et al.Heat transfer simulation of phase change energy pile[J]. Journal of disaster prevention and mitigation engineering, 2019, 39(4): 684-690.
[13] ROQUC B T, PABLO P M, DANICL C F, et al.Study of different grouting materials used in vertical geothermal closed-loop heat exchangers[J]. Applied thermal enginccring, 2013, 50: 159-167.
[14] 王哲, 刘耶军, 张正威, 等. 能源桩全生命周期热响应半径简化计算方法[J]. 中南大学学报(自然科学版), 2020, 51(2): 514-522.
WANG Z, LIU Y J, ZHANG Z W, et al.Simplified calculation method of thermal response radius of energy pile in its whole life cycle[J]. Journal of Central South University (science and technology), 2020, 51(2): 514-522.
[15] 李国能, 方佳, 郑友取. 层流脉动流中平行圆柱体的温度边界层[J]. 热科学与技术, 2015(3): 208-213.
LI G N, FANG J, ZHENG Y Q.Thermal boundary layer of parallel cylinder in laminar pulsating flows[J]. Journal of thermal science and technology, 2015(3): 208-213.
[16] 刘俊. 地源热泵系统地下换热过程几个基础问题的探讨[D]. 上海: 同济大学, 2010.
LIU J.Study on several basic problems ofunderground heat transfer process of ground source heat pump systems[D]. Shanghai: Tongji University, 2010.
[17] KIM J Y, JANG J C, KANG E C, et al.Verification study of a GSHP system manufacturer data based modeling[J]. Renewable energy, 2013, 54(6): 55-62.
[18] 李方政, 夏明萍. 基于指数积分函数的人工冻土温度场解析研究[J]. 东南大学学报(自然科学版), 2004, 34(4): 469-473.
LI F Z, XIA M P.Study on analytical solution of temperature field of artificial frozen soil by exponent-integral function[J]. Journal of Southeast University (natural science edition), 2004, 34(4): 469-473.
[19] 张正威, 赵石娆, 李晓星. 竖直埋管换热器热响应半径简化计算方法[J]. 太阳能学报, 2016, 37(9): 2338-2343.
ZHANG Z W, ZHAO S R, LI X X.The simplified calculation method of thermal response radius for vertical borehole heat exchangers[J]. Acta energiae solaris sinica, 2016, 37(9): 2338-2343.
[20] 陈乐, 王尔觉, 郭易木, 等. 竖直埋管及桩基内埋换热器传热模型研究进展[J]. 防灾减灾工程学报, 2017, 37(4): 557-564.
CHEN L,WANG E J, GUO Y M, et al.Review of analytical models for vertical-borehole ground heat exchangers and energy piles[J]. Journal of disaster prevention and mitigation engineering, 2017, 37(4): 557-564.
[21] GB 50011——2010, 混凝上结构设计规范[S].
GB 50011——2010, Code for design of concrete structures[S].
[22] 闫振国, 张正威, 杨军. 考虑桩身热容的能量桩传热性能分析[J]. 防灾减灾工程学报, 2019, 39(4): 599-606.
YAN Z G, ZHANG Z W, YANG J.Analysis of heat transfer performance of energy pile considering heat capacity of pile body[J]. Journal of disaster prevention and mitigation engineering, 2019, 39(4): 599-606.
[23] LI M, LAI A C K. Review of analytical models for heat transfer by vertical ground heat exchangers(UHES):aperspective of time and space scales[J]. Applied energy, 2015, 151: 178-191.