高温采空区地热抽采方法及抽采效果控制因素研究

Study on geothermal extraction method and control factors of extraction effect in high temperature goaf

为合理利用矿井采空区地热资源,提出了一种采空区取热系统及采空区抽采回注地热利用的方法。建立了采空区热储的温度—渗流场数值模型,确定了影响抽采效果的控制因素,揭示了抽采过程中采空区温度场变化规律。采用正交试验—方差分析法,分析了各影响因素对抽采效果的影响程度。研究结果表明:采空区温度场冷锋首先由大孔隙率区域发展至抽采井附近,而小孔隙率区域降温较慢;各因素对抽采效果的影响程度顺序为注射流量>注射温度>抽采井长度>抽采压力。

In order to rationally utilize the goaf geothermal resources,a goaf heat extraction system and a goaf extraction and injection geothermal utilization method were put forward.The numerical model of temperature-seepage field of goaf was established.The controlling factors affecting the effect of extraction were determined,and the variation law of temperature field in goaf was revealed in the process of extraction.Orthogonal experiment-variance analysis was used to analyze the influence degree of each influencing factor on the extraction effect.The results show that the cold front in the temperature field of the goaf firstly develops from the area with high porosity to the area near the extraction well,while the temperature drops slowly in the area with small porosity.The order of influence degree about each factor on extraction is injection flow rate>injection temperature>pumping well length>pumping pressure.