While near-surface geothermal energy applications for the heating and cooling of buildings have been in use for decades, their practical adoption is limited by the energy transport rates through soils. Aquifers provide a means to use convective heat transport to improve heat transfer between the building and the aquifer. However, the solid matrix in the aquifer is carbonaceous in nature, and calcification prevention techniques in the heat exchangers for the building also lead to dissolution of the aquifer matrix. Due to the Arrhenius nature of the reaction, dissolution rates may decrease with increasing temperature. An effective medium model is derived for the energy, calcium species, and fluid transport through a dynamic calcite porous medium which undergoes a reaction between the matrix and fluid. To better discern how these competing phenomena affect thermal transport in the aquifer, a two-dimensional Cartesian system is considered, where the vertical axis is parallel to the borehole axis, and flow is in the horizontal direction. An effective medium model is derived for the energy, calcium species, and fluid transport through a dynamic calcite porous medium which undergoes a reaction between the matrix and fluid. Since the fluid velocity decays algebraically with radial distance from the borehole axis, two flow regimes are considered. In one regime, far from the borehole where flow rates are small, conductive thermal transport acts faster than the species transport, leading to a case where precipitation dominates and regions of the smallest porosity contract to limit energy recovery. In regions with larger porosity, moderate advection of the species is sufficient to prevent significant pore closures over the time scale of exploration. The second regime, closer to the borehole, larger flow rates reduce species concentrations sufficiently to dissolve the solid phase between pores. In this second regime, Taylor dispersion effects in both energy and species transport compete, but thermal conduction acts more slowly than advection, promoting dissolution. The critical limitation in modeling the long-term evolution of the aquifer structure is the in situ dissolution rate.

尽管近十年来用于建筑物加热和冷却的地表热能应用已经使用了数十年，但它们的实际采用受到通过土壤的能量传输速率的限制。含水层提供了一种利用对流传热的方式来改善建筑物与含水层之间的热传递。然而，含水层中的固体基质本质上是碳质的，并且用于建筑物的热交换器中的防止钙化的技术也导致含水层基质的溶解。由于反应的阿累尼乌斯性质，溶解速率可能随温度升高而降低。得出了一个有效的介质模型，用于能量，钙物质和流体通过动态方解石多孔介质的传输，该多孔方解石在基质和流体之间进行了反应。为了更好地识别这些竞争现象如何影响含水层中的热传输，我们考虑了二维笛卡尔系统，其中垂直轴平行于井眼轴，而水流沿水平方向。得出了一个有效的介质模型，用于能量，钙物质和流体通过动态方解石多孔介质的传输，该多孔方解石在基质和流体之间进行了反应。由于流体速度随着距井眼轴线的径向距离而代数衰减，因此考虑了两种流动形式。在一种情况下，远离井眼的流速很小，传导热传输的速度比物质传输的速度快，从而导致以降水为主且孔隙率最小的区域收缩以限制能量回收的情况。在孔隙率较大的地区，物种的中等对流足以防止在勘探的时间范围内出现明显的孔隙封闭。第二种方案，更靠近井眼，较大的流速降低了物种浓度，足以溶解孔之间的固相。在第二种状态下，泰勒在能量和物质传输中的分散作用相互竞争，但热传导的作用比对流慢，从而促进了溶解。在模拟含水层结构长期演化过程中的关键限制是原位溶解速率。泰勒在能量和物质传输中的分散作用相互竞争，但热传导的作用比对流慢，从而促进了溶解。在模拟含水层结构长期演化过程中的关键限制是原位溶解速率。泰勒在能量和物质传输中的分散作用相互竞争，但热传导的作用比对流慢，从而促进了溶解。在模拟含水层结构长期演化过程中的关键限制是原位溶解速率。