套管式中深层地埋管换热器传热建模及取热分析

Transfer modeling and heat extraction analysis of coaxial tubes deep borehole heat exchanger

为了研究无干扰换热条件下,中深层地热能的实际取热性能,文章通过数值模拟方法模拟计算了套管式中深层地埋管换热器的名义取热量。模拟结果表明,套管式中深层地埋管换热器的名义取热量随着钻孔深度、大地热流、循环水流量、当地大气年平均温度的增加而增加。套管式中深层地埋管换热器周围土层的地质条件分布也影响着中深层地埋管换热器的名义取热量,具体表现为浅层土层的导热系数越小,中深层地埋管换热器的名义取热量越大;深层土层的导热系数越大,中深层地埋管换热器的名义取热量也越大。通过调整地埋管换热器的相关参数,并选择合适的地埋管埋设地点等优化措施,可使套管式中深层地埋管换热器达到可观的名义取热量。

Under the condition of non-interference heat exchange,in order to study the actual heat extraction performance of the deep geothermal energy,the paper simulates and calculates the nominal heat extraction of coaxial tubes deep borehole heat exchanger by numerical simulation method.The results show that the nominal heat extraction of coaxial tubes deep borehole heat exchanger increases with the increase of the drilling depth,the earth heat flow,the circulating water flow and the annual average temperature of the local atmosphere.The distribution of geological conditions of the soil layer around the sleeve-typecoaxial tubes deep borehole heat exchanger also affects the nominal heat extraction of coaxial tubes deep borehole heat exchanger:the smaller the thermal conductivity of the shallow soil layer,the greater the nominal heat extraction ofcoaxial tubes deep borehole heat exchanger;the greater the thermal conductivity of the deep soil layer,the greater the nominal heat extraction of the mid-deep buried heat exchanger.By adjusting the parameters of the buried pipe and choosing the location of the buried pipe reasonably,the coaxial tubes deep borehole heat exchanger can achieve considerable nominal heat extraction.