Investigation of evaluation models for geothermal resources and intermittent operation/cycle thermal storage mode in closed coal mines

IF 3.5 2区工程技术 Q3 ENERGY & FUELS

Geothermics Pub Date : 2025-02-26 DOI:10.1016/j.geothermics.2025.103294

Meng Wang , Pingye Guo , Cheng Fang , Mohua Bu , Xin Jin , Jiong Wang

{"title":"Investigation of evaluation models for geothermal resources and intermittent operation/cycle thermal storage mode in closed coal mines","authors":"Meng Wang , Pingye Guo , Cheng Fang , Mohua Bu , Xin Jin , Jiong Wang","doi":"10.1016/j.geothermics.2025.103294","DOIUrl":null,"url":null,"abstract":"<div><div>The geothermal utilization of closed mines has a positive role to play in the reduction of fossil energy consumption, the development of renewable energy sources and the proper disposal of closed mine. In this work, for a more accurate evaluation of the sustainable geothermal production in closed mine, based on Xuzhou Jiahe coal mine, a 3D numerical model coupling roadway and goaf is established, and compared with other two numerical models. After analyzing the water storage space, flow field, temperature field, recovery well outlet temperature and heat recovery stability under long operation time, the roadway and goaf (RG) model performs more prominently and the results are more realistic. Both intermittent operation and cycle thermal storage mode have a higher recovery well outlet temperature in winter operation period, it can keep the heat supply at a high level, and accordingly the operational life of closed mine geothermal utilization system can be extended. COP (Coefficient of performance) of the system in winter operation period with different operation modes are basically the same when the recovery flow rate is low. As the recovery flow rate increase, COP of the system in cycle thermal storage mode has a significant advantage. In summer operation period, the outlet temperature in thermal storage cycle mode remains lower than the recharged hot water temperature, and it has a good cooling effect under high recovery flow conditions in the summer, contributes to the temperature return of thermal reservoir, and COP of the system in summer operation increase with recovery flow rate.</div></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":"129 ","pages":"Article 103294"},"PeriodicalIF":3.5000,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geothermics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S037565052500046X","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

The geothermal utilization of closed mines has a positive role to play in the reduction of fossil energy consumption, the development of renewable energy sources and the proper disposal of closed mine. In this work, for a more accurate evaluation of the sustainable geothermal production in closed mine, based on Xuzhou Jiahe coal mine, a 3D numerical model coupling roadway and goaf is established, and compared with other two numerical models. After analyzing the water storage space, flow field, temperature field, recovery well outlet temperature and heat recovery stability under long operation time, the roadway and goaf (RG) model performs more prominently and the results are more realistic. Both intermittent operation and cycle thermal storage mode have a higher recovery well outlet temperature in winter operation period, it can keep the heat supply at a high level, and accordingly the operational life of closed mine geothermal utilization system can be extended. COP (Coefficient of performance) of the system in winter operation period with different operation modes are basically the same when the recovery flow rate is low. As the recovery flow rate increase, COP of the system in cycle thermal storage mode has a significant advantage. In summer operation period, the outlet temperature in thermal storage cycle mode remains lower than the recharged hot water temperature, and it has a good cooling effect under high recovery flow conditions in the summer, contributes to the temperature return of thermal reservoir, and COP of the system in summer operation increase with recovery flow rate.

查看原文本刊更多论文

封闭式煤矿地热资源评价模型及间歇运行/循环蓄热模式研究

封闭矿山地热利用对减少化石能源消耗、发展可再生能源、妥善处置封闭矿山具有积极作用。为了更准确地评价封闭式矿井地热可持续开采，本文以徐州嘉河煤矿为例，建立了巷道与采空区耦合的三维数值模型，并与其他两种数值模型进行了比较。通过对长时间开采条件下储水空间、流场、温度场、回采井出口温度和热回收稳定性的分析，巷道-采空区（RG）模型表现更为突出，结果更为真实。间歇运行和循环蓄热方式在冬季运行期间都具有较高的回采井出口温度，可以保持较高的供热水平，从而延长封闭式矿井地热利用系统的运行寿命。当回收流量较低时，不同运行方式的系统冬季运行期COP（性能系数）基本相同。随着回收流量的增加，循环蓄热模式下系统的COP具有显著的优势。在夏季运行期间，蓄热循环模式下的出口温度保持在低于回灌热水温度的水平，在夏季高回收流量条件下具有良好的冷却效果，有利于热储温度的回升，系统夏季运行COP随回收流量的增大而增大。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Geothermics 工程技术-地球科学综合

CiteScore

7.70

自引率

15.40%

发文量

237

审稿时长

4.5 months

期刊介绍： Geothermics is an international journal devoted to the research and development of geothermal energy. The International Board of Editors of Geothermics, which comprises specialists in the various aspects of geothermal resources, exploration and development, guarantees the balanced, comprehensive view of scientific and technological developments in this promising energy field. It promulgates the state of the art and science of geothermal energy, its exploration and exploitation through a regular exchange of information from all parts of the world. The journal publishes articles dealing with the theory, exploration techniques and all aspects of the utilization of geothermal resources. Geothermics serves as the scientific house, or exchange medium, through which the growing community of geothermal specialists can provide and receive information.