深部含水层储热系统的数值模拟研究

Numerical Modeling of the High-temperature Thermal Energy Storage System in Deep Aquifers

深部含水层储热系统,是一种以深部含水层介质为载体的“地热+”多能互补储/供能系统。该系统可将各种形式的能量储存于地下并按需求取出加以利用,能够弥补能源供需的时空分布的不平衡,是综合利用多种可再生能源,实现节能减排的有效途径。深部含水层储热是一种水热型地热资源开发利用的新方式。传统的水热型地热资源开采,受限于地热尾水回灌导致的热突破,热田寿命有限。而利用深部含水层储能,不但可以增强热储能力,而且能够延长热田寿命。本研究通过数值模拟研究表明,与传统的水热型地热系统相比,通过采取深部含水层储热技术,在相同开采流量下,可以提升单井供热能力20%。其储热效率可以达到60%~90%,能够保证更高的地热能提取率;同时,与传统水热型地热井寿命受限于热突破时间的情况不同,深部含水层储热系统可以延长地热井寿命,实现可持续开采。通过参数敏感性分析的方法进一步评估了不同参数对深部含水层储热性能的影响。通过参数研究发现,储层渗透率和储热温度等是影响储热能力和效率的关键参数。本研究为后续开展深部含水层储热系统工程的设计与优化提供科学参考。

Deep aquifer thermal energy storage(deep-ATES)technology is a“Geothermal Plus”multi-energy complementary storage/supply system based on the deep aquifer medium.The system can store various forms of energy underground and take them out for utilization according to the demand,which can be used as the imbalance of energy supply and demand in time and space.It is an effective way to comprehensively utilize a variety of renewable energy sources and to realize energy saving and emission reduction.Deep aquifer thermal storage is a new way to develop and utilize hydrothermal type geothermal resource.Exploitation of the traditional hydrothermal geothermal resources by thermal breakthrough is limited due to the geothermal tail water reinjection reducing the lifetime of geothermal fields.Not only can the use of deep aquifer thermal energy storage enhance the geothermal resources,but it can also extend the life of the geothermal field.Our numerical simulation shows that,compared with the traditional hydrothermal geothermal system,deep aquifer thermal energy storage technology can enhance the single well heating capacity by 20%with the same production flow rate.Moreover,its heat storage efficiency can reach 60%-90%ensuring a high extraction rate of geothermal energy.Unlike the traditional hydrothermal geothermal well life,which is limited by the thermal breakthrough time,the deep aquifer thermal storage system can ensure that no thermal breakthrough occurs in the reinjection wells and achieve sustainable exploitation.While evaluating the influence of different parameters on the thermal storage performance of deep aquifers by sensitivity analysis,reservoir permeability and injection temperature were found as the key parameters affecting heat storage capacity and efficiency.This study aims to provide a calculation method and reference for deep aquifer energy storage technology.