Research on heat extraction performance of deep U-type borehole heat exchanger

doi:10.11949/0438-1157.20240666

Abstract

Abstract:

Based on the open-source numerical simulation software OpenGeoSys, a 3D numerical model is established, which fully considered the size characteristics of deep U-type borehole heat exchanger (DUBHE) and the distribution of complex geological parameters. The effect of factors affecting the hourly circulating temperature of the DUBHE and the long-term heat extraction performance are analyzed in this study. The thermal performance test results show that the outlet temperature of the DUBHE drops rapidly in the initial stage of operation, and gradually stabilizes in the later stage of operation. The sensitivity analysis shows that the geothermal gradient, drilling depth of the descending and ascending wells, and the length of the horizontal well have significant effects on the performance of DUBHE. The relevant conclusion will be conducive to guiding the project design and application.

Key words: renewable energy, deep U-type borehole heat exchanger, numerical simulation, heat transfer, heat extraction performance

摘要：

基于开源数值模拟计算软件OpenGeoSys建立了充分考虑中深层U型地埋管换热器尺寸特征与复杂地质参数分布的三维数值计算模型，开展了换热器长期取热过程逐时出口水温及取热性能影响因素分析。热性能测试分析结果表明，运行初期换热器出口水温快速下降，随着取热进程不断推进换热器出口水温逐渐平稳。敏感性分析表明，地温梯度、上下行井钻井深度及水平对接井长度对中深层U型地埋管换热器取热性能影响显著。相关研究结论可为中深层U型地埋管工程设计及技术应用提供参考。

关键词: 再生能源, 中深层U型地埋管换热器, 数值模拟, 传热, 取热性能

CLC Number:

TE 09

Jian HU, Jinghua JIANG, Shengjun FAN, Jianhao LIU, Haijiang ZOU, Wanlong CAI, Fenghao WANG. Research on heat extraction performance of deep U-type borehole heat exchanger[J]. CIESC Journal, 2024, 75(S1): 76-84.

胡俭, 姜静华, 范生军, 刘建浩, 邹海江, 蔡皖龙, 王沣浩. 中深层U型地埋管换热器取热特性研究[J]. 化工学报, 2024, 75(S1): 76-84.

Figures/Tables 15

Table 1 Regional geology of Hebei University of Engineering

岩土深度/m	热导率/(W/(m·K))	密度/(kg/m³)	比热容/(J/(kg·K))
0~420	1.8	1400	920
420~1000	3.5	1780	1379
1000~1580	2.6	2030	1450
1580~2000	2.6	1510	1300
2000~2500	2.6	2600	878

Table 2 Basic completion data of geothermal research project of Hebei University of Engineering

参数	数值
钻井深度/m	2500.0
对接井长度/m	684.0
下行井管径/mm	311.7
对接井管径/mm	168.3
上行井管径/mm	244.5
钻孔直径/mm	444.5
管材热导率/(W/(m·K))	41.0
回填材料热导率/(W/(m·K))	1.5

Fig.1 Compared results of deep U-type borehole heat exchanger between numerical results and measured data

Fig.2 Outlet water temperature of deep U-type borehole heat exchanger under different geotherml gradients

Fig.3 Heat extraction performance of deep U-type borehole heat exchanger under different geotherml gradients

Fig.4 Outlet water temperature of deep U-type borehole heat exchanger under different drilling depths of descending and ascending wells

Fig.5 Heat extraction performance of deep U-type borehole heat exchanger under different drilling depths of descending and ascending wells

Fig.6 Outlet water temperature of deep U-type borehole heat exchanger under different drilling depths of horizontal wells

Fig.7 Heat extraction performance of deep U-type borehole heat exchanger under different drilling depths of horizontal wells

Fig.8 Outlet water temperature of deep U-type borehole heat exchanger under different diameter specifications

Fig.9 Heat extraction performance of deep U-type borehole heat exchanger under different diameter specifications

Fig.10 Outlet water temperature of deep U-type borehole heat exchanger under different grout thermal conductivity

Fig.11 Heat extraction performance of deep U-type borehole heat exchanger under different grout thermal conductivity

Fig.12 Outlet water temperature of deep U-type borehole heat exchanger under different flow rate

Fig.13 Heat extraction performance of deep U-type borehole heat exchanger different flow rate

References 30

1	张海龙. 中国新能源发展研究[D]. 长春: 吉林大学, 2014.
	Zhang H L. Research on the new energy development in China[D]. Changchun: Jilin University, 2014.
2	Cai W L, Wang F H, Chen S, et al. Analysis of heat extraction performance and long-term sustainability for multiple deep borehole heat exchanger array: a project-based study[J]. Applied Energy, 2021, 289: 116590.
3	陈焰华, 於仲义. 从建筑碳排放达峰看地热能的技术特性[J]. 暖通空调, 2022, 52(1): 75-80.
	Chen Y H, Yu Z Y. Study on technical characteristics of geothermal energy from building carbon emission peak[J]. Heating Ventilating & Air Conditioning, 2022, 52(1): 75-80.
4	Wang R F, Wang F H, Xue Y Z, et al. Numerical study on the long-term performance and load imbalance ratio for medium-shallow borehole heat exchanger system[J]. Energies, 2022, 15(9): 3444.
5	鲍玲玲, 王雪, 刘俊青, 等. 基于岩土纵向分层的中深层U型地埋管换热器取热性能研究[J]. 地球物理学进展, 2022, 37(4): 1371-1378.
	Bao L L, Wang X, Liu J Q, et al. Research on heat extraction performance of U-shaped underground heat exchanger based on longitudinal layering of rock and soil[J]. Progress in Geophysics, 2022, 37(4): 1371-1378.
6	李俊岩. 中深层地热用深U型地埋管换热器取热特性研究[D]. 邯郸: 河北工程大学, 2021.
	Li J Y. Study on heat extraction characteristics of vertical deep-buried U-bend pipe heat exchangers for middle-deep geothermal[D]. Handan: Hebei University of Engineering, 2021.
7	Zhang Y P, Huang S P, Meng X Z, et al. Geothermal characteristics of two deep U-shaped downhole heat exchangers in the Weihe Basin, China[J]. IOP Conference Series: Earth and Environmental Science, 2020, 463(1): 012156.
8	王少锋, 申小龙, 赵真, 等. 黄陵地区中深层地热能赋存与U形井岩-水换热潜力分析[J]. 中国煤炭地质, 2022, 34(6): 40-45, 72.
	Wang S F, Shen X L, Zhao Z, et al. Medium deep geothermal energy hosting and U-shaped well rock-water heat transfer potential analysis in Huangling area[J]. Coal Geology of China, 2022, 34(6): 40-45, 72.
9	Li C, Guan Y L, Feng Y G, et al. Comparison of influencing factors and level optimization for heating through deep-buried pipe based on Taguchi method[J]. Geothermics, 2021, 91: 102045.
10	张育平, 刘俊, 王沣浩, 等. 中深层U型对接井取热能力影响因素显著性分析[J]. 可再生能源, 2022, 40(11): 1473-1480.
	Zhang Y P, Liu J, Wang F H, et al. Significance analysis on the influence factors of thermal extraction capacity of medium-deep U-shaped butted well[J]. Renewable Energy Resources, 2022, 40(11): 1473-1480.
11	Hu X C, Banks J, Guo Y T, et al. Effects of temperature-dependent property variations on the output capacity prediction of a deep coaxial borehole heat exchanger[J]. Renewable Energy, 2021, 165: 334-349.
12	姜静华, 高远, 张育平, 等. 中深层套管式地埋管换热器取热性能研究及经济性分析[J]. 西安建筑科技大学学报(自然科学版), 2021, 53(6): 851-859.
	Jiang J H, Gao Y, Zhang Y P, et al. Research on heat extraction performance of deep coaxial borehole heat exchanger and its economic analysis[J]. Journal of Xi'an University of Architecture & Technology (Natural Science Edition), 2021, 53(6): 851-859.
13	Chen C F, Shao H B, Naumov D, et al. Numerical investigation on the performance, sustainability, and efficiency of the deep borehole heat exchanger system for building heating[J]. Geothermal Energy, 2019, 7: 18.
14	Li M, Lai A C K. Review of analytical models for heat transfer by vertical ground heat exchangers (GHEs): a perspective of time and space scales[J]. Applied Energy, 2015, 151: 178-191.
15	Kolditz O, Bauer S, Bilke L, et al. OpenGeoSys: an open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THM/C) processes in porous media[J]. Environmental Earth Sciences, 2012, 67: 589-599.
16	Chen C F, Cai W L, Naumov D, et al. Numerical investigation on the capacity and efficiency of a deep enhanced U-tube borehole heat exchanger system for building heating[J]. Renewable Energy, 2021, 169: 557-572.
17	王雪. 中深层U型井下换热器热渗耦合传热性能研究[D]. 邯郸: 河北工程大学, 2022.
	Wang X. Study on heat transfer performance of medium-deep U-type borehole heat exchanger under the coupling condition of thermal permeability[D]. Handan: Hebei University of Engineering, 2022.
18	Gu F, Li Y W, Tang D Z, et al. Heat extraction performance of horizontal-well deep borehole heat exchanger and comprehensive comparison with the vertical well[J]. Applied Thermal Engineering, 2022, 211: 118426.
19	Liu J, Wang F H, Cai W L, et al. Numerical investigation on the effects of geological parameters and layered subsurface on the thermal performance of medium-deep borehole heat exchanger[J]. Renewable Energy, 2020, 149: 384-399.
20	Luo Y Q, Xu G Z, Zhang S C, et al. Heat extraction and recover of deep borehole heat exchanger: negotiating with intermittent operation mode under complex geological conditions[J]. Energy, 2022, 241: 122510.
21	Zhang W, Li W, Sørensen B R, et al. Comparative analysis of heat transfer performance of coaxial pipe and U-type deep borehole heat exchangers[J]. Geothermics, 2021, 96: 102220.
22	关春敏. 中深层U型井地源热泵的传热分析及系统优化[D]. 济南: 山东建筑大学, 2022.
	Guan C M. Heat transfer analysis and system optimization of the medium-deep U-type ground source heat pump[D]. Jinan: Shandong Jianzhu University, 2022.
23	Xia Z H, Jia G S, Ma Z D, et al. Analysis of economy, thermal efficiency and environmental impact of geothermal heating system based on life cycle assessments[J]. Applied Energy, 2021, 303: 117671.
24	王兴, 李超, 官燕玲, 等. 竖向U型深埋管建筑供暖连续及间歇运行的现场实验[J]. 区域供热, 2018(3): 8-12, 21.
	Wang X, Li C, Guan Y L, et al. In-situ experiment of continuous and intermittent operation of vertical U-bend deep-buried pipe to supply heat in buildings[J]. District Heating, 2018(3): 8-12, 21.
25	国家质量监督检验检疫总局, 中国国家标准化管理委员会. 石油天然气工业油气井套管或油管用钢管: [S]. 北京: 中国标准出版社, 2017.
	General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China. Petroleum and natural gas industries—steel pipes for use as casing or tubing for wells: [S]. Beijing: Standards Press of China, 2017.
26	李超, 官燕玲, 杨瑞涛, 等. U型深埋管固井层对埋管换热性能影响的研究[J]. 太阳能学报, 2021, 42(2): 267-273.
	Li C, Guan Y L, Yang R T, et al. Study on influence of cementing layer on heat transfer performance of U-bend deep-buried pipe[J]. Acta Energiae Solaris Sinica, 2021, 42(2): 267-273.
27	Liu J, Wang F H, Gao Y, et al. Influencing factors analysis and operation optimization for the long-term performance of medium-deep borehole heat exchanger coupled ground source heat pump system[J]. Energy and Buildings, 2020, 226: 110385.
28	Nian Y L, Cheng W L, Yang X Y, et al. Simulation of a novel deep ground source heat pump system using abandoned oil wells with coaxial BHE[J]. International Journal of Heat and Mass Transfer, 2019, 137: 400-412.
29	张哲菲, 刘洪涛, 刘攀峰, 等. 中深层地热地埋管实际运行影响因素研究[J]. 太阳能学报, 2022, 43(12): 503-509.
	Zhang Z F, Liu H T, Liu P F, et al. Study on actual operation and influencing factors of middle-deep geothermal buried pipe[J]. Acta Energiae Solaris Sinica, 2022, 43(12): 503-509.
30	王雪婷. 中深层U型埋管换热器传热性能研究[J]. 区域供热, 2021, (5): 20-24, 43.
	Wang X T. Research on heat transfer performance of medium and deep U-type buried tube heat exchanger[J]. District Heating, 2021, (5): 20-24, 43.

[1]	Xinyu DONG, Longfei BIAN, Yiyi YANG, Yuxuan ZHANG, Lu LIU, Teng WANG. Study on flow and heat transfer mechanism of supercritical CO₂ in inclined upward tube under cooling conditions [J]. CIESC Journal, 2024, 75(S1): 195-205.
[2]	Qirui GUO, Liyuan REN, Kang CHEN, Xiangyu HUANG, Weihua MA, Leqin XIAO, Weiliang ZHOU. Numerical simulation of static mixing tubes for HTPB propellant slurry [J]. CIESC Journal, 2024, 75(S1): 206-216.
[3]	Kuangxi LI, Peiqian YU, Jiangyun WANG, Haoran WEI, Zhigang ZHENG, Liuhai FENG. Flow analysis and structure optimization of micro-bubble swirling air flotation device [J]. CIESC Journal, 2024, 75(S1): 223-234.
[4]	Su TANG, Zi'ao ZHENG, Hanze WEI, Xiaoling XU, Xiaoqiang ZHAI. Preparation and thermal conductivity reinforcement of PMMA/PEG600/CNT composite shaped phase change materials [J]. CIESC Journal, 2024, 75(S1): 309-320.
[5]	Zhangzhou WANG, Tianqi TANG, Jiajun XIA, Yurong HE. Battery thermal management performance simulation based on composite phase change material [J]. CIESC Journal, 2024, 75(S1): 329-338.
[6]	Siyu QIN, Yijia LIU, Jiacheng YANG, Wei TONG, Liwen JIN, Xiangzhao MENG. Characteristics of gas-liquid two-phase heat transfer in a confined vapor chamber [J]. CIESC Journal, 2024, 75(S1): 47-55.
[7]	Dehui DU, Wei FENG, Jianghui ZHANG, Yanlong XIANG, Gaopan QIAO, Wei LI. Prediction model of flow boiling heat transfer in microfinned hydrophobic composite enhanced tube [J]. CIESC Journal, 2024, 75(S1): 95-107.
[8]	Guanyu REN, Yifei ZHANG, Xinze LI, Wenjing DU. Numerical study on flow and heat transfer characteristics of airfoil printed circuit heat exchangers [J]. CIESC Journal, 2024, 75(S1): 108-117.
[9]	Xinze LI, Shuangxing ZHANG, Guanyu REN, Rui HONG, Wenjing DU. Thermal performance of pulsating heat pipe for high power LED thermal management [J]. CIESC Journal, 2024, 75(S1): 126-134.
[10]	Yong YANG, Zixuan ZU, Yukun LI, Dongliang WANG, Zongliang FAN, Huairong ZHOU. Numerical simulation of CO₂ absorption by alkali liquor in T-junction cylindrical microchannels [J]. CIESC Journal, 2024, 75(S1): 135-142.
[11]	Junhao HUANG, Keliang PANG, Fangyuan SUN, Fujun LIU, Zhiyuan GU, Long HAN, Yanquan DUAN, Yanhui FENG. Influence of bell structure of coke dry quenching furnace on coke distribution [J]. CIESC Journal, 2024, 75(S1): 158-169.
[12]	Juhui CHEN, Tong SU, Dan LI, Liwei CHEN, Wensheng LYU, Fanqi MENG. Study on the heat transfer characteristics of microchannels under the action of fin-shaped spoilers [J]. CIESC Journal, 2024, 75(9): 3122-3132.
[13]	Shuyue LI, Huan WANG, Shaoqiang ZHOU, Zhihong MAO, Yongmin ZHANG, Junwu WANG, Xiuhua WU. Numerical simulation of hydrogen reduction of U₃O₈ in fluidized bed reactors using CPFD method [J]. CIESC Journal, 2024, 75(9): 3133-3151.
[14]	Chaowei CHEN, Yang LIU, Wenjing DU, Jinbo LI, Dakuo SHI, Gongming XIN. Flow and heat transfer characteristics of micro ribs channel with local hot spots [J]. CIESC Journal, 2024, 75(9): 3113-3121.
[15]	Shaojun DOU, Liang HAO. Mesoscale simulation of coupled gas charge transfer process in PEMFC catalyst layer [J]. CIESC Journal, 2024, 75(8): 3002-3010.