水源热泵回灌井悬浮颗粒运移和沉积物理特性试验模型研究

 针对地下水源热泵系统阻塞机制研究开发的砂层阻塞模拟试验系统，利用砾石颗粒作为多孔介质，以粉煤灰颗粒作为悬浮物，研究悬浮颗粒在砾石中运移和沉积时相对浓度与孔隙体积的关系。通过试验可知：(1) 在3种不同流速试验条件下，悬浮颗粒在砾石介质中的运移和沉积主要经历了浓度的增加、骤减和平稳段，总体趋势是相同的，主要区别在于浓度的峰值有所不同，流速越大所对应的峰值越大，反之亦然。(2) 给出的渗透率衰减模型对预见试验中悬浮颗粒的迁移所引起的孔隙率下降是有效的。(3) 把理论分析方法同试验曲线比较后发现，余尾效应在本次试验中并没有出现，试验值和理论值具有较好的吻合性。

TEST STUDY OF PHYSICAL PROPERTIES OF SUSPENDED PARTICLES MIGRATION AND DEPOSITION IN WATER SOURCE HEAT PUMP INJECTION WELL

For groundwater source heat pump system blocking mechanism study and development of sand blocking simulation test system，the gravel particles is used as porous media with the fly ash particles as the suspended solids. The relationship between relative concentration and pore volume of suspended particles is studied during the migration and deposition in gravel particles. The main conclusions are drawn as follows：(1) Under three different flow velocities，the migration and deposition of particles in gravel particles mainly experience three stages：increase，decrease sharply and stable stages of concentration. The overall trend is the same；and the main difference lies in different peak values of concentration. The greater the flow velocity is，the larger the peak value is；and vice versa. (2) The proposed permeability attenuation model of suspended particles is an effective tool to forecast test porosity decline caused by particles migration. (3) Through comparing theoretical analysis with test curve，it is found that tail effect did not appear in this test；and the test values are consistent with the theoretical ones.