地学前缘 ›› 2020, Vol. 27 ›› Issue (1): 185-193.DOI: 10.13745/j.esf.2020.1.20

• 地热开发利用模拟和实践 • 上一篇    下一篇

基于开挖的增强型地热系统概述

亢方超,唐春安   

  1. 1. 大连理工大学 海岸和近海工程国家重点实验室, 辽宁 大连 116023
    2. 大连理工大学 深地工程研究中心, 辽宁 大连 116023
  • 收稿日期:2019-06-01 修回日期:2019-10-12 出版日期:2020-01-20 发布日期:2020-01-20
  • 作者简介:亢方超(1984—),男,博士研究生,工程师,岩土工程专业。E-mail:fangchaokang@126.com
  • 基金资助:

    国家自然科学基金项目(5167804)

Overview of enhanced geothermal system (EGS) based on excavation in China

KANG Fangchao,TANG Chun’an   

  1. 1. State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116023, China
    2. Deep Underground Engineering Research Center, Dalian University of Technology, Dalian 116023, China
  • Received:2019-06-01 Revised:2019-10-12 Online:2020-01-20 Published:2020-01-20

摘要:

地热能赋存于地球内部岩土体、流体和岩浆体中,是一种永久的、可再生的、储量丰富的清洁能源。地热能的开发,尤其是干热岩的开发利用,有可能成为解决人类未来能源危机的重要途径。目前采用的干热岩开采方法被称为增强型地热系统(EGS)。热储地质环境的复杂性和水力化措施对天然裂隙的依赖性,造成多数的EGS项目存在热储体积和换热面积不足、工质流量小、终端温度低,以及诱发地震风险等局限性,致使干热岩开发始终未能大规模商业化。基于开挖的增强型地热系统(EGSE)的提出为突破传统EGS的技术弊端和规模局限提供了新思路。文章在其概念模型的基础上,从系统原理、工程构想、技术优势等方面对EGSE进行了更详尽的阐述。EGSE采用开挖、爆破、崩落等采矿技术,形成了独特的热储致裂系统和热能交换系统,能够大幅度降低地质环境对热储质量的限制,具备构建定制的热储空间、形成充足的换热面积,维持稳定的工质流量与温度及减少诱发地震风险等优势,为干热岩开发的商业化提供了新的解决方案。

关键词: 地热能, 干热岩, 深层地热开发, 增强型地热系统

Abstract:

Geothermal energy is a permanent, renewable, inexhaustible and clean energy stored in regosol, fluid and magmatic bodies in the Earth’s crust. Its exploitation and utilization, mainly hot dry rock (HDR), may become a meaningful way to solve the future energy crisis. The enhanced geothermal system (EGS) is the primary method used in the exploitation of HDR up till the present time. Because of the complexity of geological environment and dependency of hydraulic measures on natural fissures, most of EGS projects have many technical shortcomings, such as insufficient thermal storage volume and heat transfer area, low working fluid flow rate, low terminal temperature and induced earthquake risk, making largescale commercialization of DHR unachievable. The prospects of the enhanced geothermal system based on excavation technology (EGSE) inspired us to find breakthroughs  overcoming the technical difficulties and limitations of EGS. In this paper, we discussed EGSE in great detail on its operation fundamentals, engineering principles and technical advantages based on a conceptual model. By adopting mining technologies, such as excavation, blasting and caving, EGSE can significantly overcome geological environmental restrictions on thermal storage quality to form a unique fracturing system of geothermal reservoir as well as a special thermal energy exchange system. It has the advantages of building up customized thermal storage, forming sufficient heat transfer areas, maintaining stable working fluid flow rate and temperature, and reducing earthquake risks, thus provides a brandnew scheme for the commercialization of HDR geothermal energy.

Key words: geothermal energy, hot dry rock, deep geothermal exploitation, enhanced geothermal system

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