Abstract:

High-temperature aquifer thermal storage (HT-ATES) can be used to solve the problem of inter-seasonal thermal energy storage in solar heating, but low heat recovery efficiency seriously affects its efficient and sustainable operation. Taking the HT-ATES system as the research object, a flow heat exchange model was constructed, and heat losses evaluation indexes were defined. Based on quantitative analysis of the heat losses in various parts of the formation, the main factors affecting recovery efficiency (R) and formation heat losses (Q_s,m) were revealed. The simulation results indicated that R and Q_s,m were more sensitive to permeability, reservoir thermal conductivity, and flow rate. Reservoir permeability decreased from 4.5D to 0.5D and thermal conductivity decreased from 2.5W/(m·K) to 1.8 W/(m·K), which could reduce Q_s,m by 4.9% and 6.6% respectively, and increase heat extraction by 3% and 2.4%, thereby rising R by 1.8% and 1.7% separately. Magnifying porosity of the reservoir from 0.15 to 0.25 and capacity from 830J/(kg·K) to 1030J/(kg·K) could increase heat storage capacity of reservoir by 2.1% and 3.1% respectively, and decrease thermal effect range by 1.64m and 2.18m separately. The rise of temperature and flow rate of the injection fluid led to a 0.5% decrease and a 5.6% increase in R, respectively, and appropriately growing flow rate and reducing injection temperature could maximize thermal storage capacity and recovery efficiency of the HT-ATES system. Quantitative analysis of heat losses in HT-ATES system provided scientific basis for reservoir selection and optimal development strategy formulation.

Key words: high-temperature aquifer thermal storage (HT-ATES), recovery efficiency, formation heat losses, sensitivity analysis, heat losses quantitative analysis

摘要：

高温含水层储热（HT-ATES）可解决太阳能供暖跨季节储热难题，但热回收效率低，影响其高效、可持续运行。以HT-ATES系统为研究对象，构建了流动换热模型，提出了热量损失评价指标。基于对地层各部分热损失的定量分析，揭示了影响热回收效率（R）和地层热损失（Q_s,m）的主要因素。模拟结果表明，R和Q_s,m对渗透率、储层热导率和流量更为敏感。储层横向渗透率由4.5D降低至0.5D、热导率由2.5W/(m·K)降低至1.8W/(m·K)，可使得Q_s,m分别减少4.9%、6.6%，采热量分别增加3%、2.4%，R分别提高1.8%和1.7%。储层孔隙度由0.15增大至0.25、比热容由830J/(kg·K)增加至1030J/(kg·K)，可将储层储热量分别提高2.1%、3.1%，并使热影响范围分别缩小1.64m、2.18m。注入流体温度和流量的增加分别导致R下降0.5%和提高5.6%，适当提高流量并降低注入温度可实现HT-ATES系统储热量和热回收效率的最大化。量化分析HT-ATES系统热损失为储层的选择以及最佳开发方案的制定提供了科学依据。

关键词: 高温含水层储热, 热回收效率, 地层热损失, 敏感性分析, 热损失定量分析