复杂地质条件下的地埋管换热孔成孔工艺措施

根据统计,贵州省土壤源热泵的利用情况远落后于其它省份,原因是由于贵州省特殊的地质条件造成地埋管换热孔施工难度及工程成本的大幅度增加造成的,故解决上述问题是在贵州省推广土壤源热泵系统的先决条件。本文针对贵州地区喀斯特地貌等复杂地质条件,特别是针对地下岩溶发育明显的石灰岩地区以及破碎、裂隙发育明显的白云岩地区,根据贵州当地的成功案例,提出了在岩溶发育明显的地区采用清水正循环回转钻进方式结合混合速凝剂的水泥浆回灌封孔固化后复钻的成孔处理工艺,以及在破碎、裂隙发育明显的地区采用添加火碱、纤维素、堵漏剂的混合泥浆作为护壁材料的正循环回转钻进方式,结合局部泥浆无法成功护壁的同时添加聚丙烯酰胺的成孔处理工艺。

Pore-forming Technology of the Ground-pipe Heat Exchanger under Complicated Geological Conditions

According to the statistics, the promotion of Ground Source Heat Pump (GSHP) in Guizhou is relative low comparing with other domestic provinces. The geological complexity in this area makes the construction of ground-pipe heat exchanger more dififcult and results in increase of costs. Therefore, solving the above problems is prerequisite to promote the application of GSHP system in Guizhou. According to successful cases in this area, the paper introduces new craft processes of pore-forming under complicated geological conditions such as karst topography in Guizhou, speciifcally for limestone area, where the development of subground karst is obvious, it needs to adopt a repetitive drilling method based on a normal-circulation rotary drilling method using clear water, combined with a recirculation technology applying the liquid cement mixed with accelerating admixture. Besides, in the area with obvious development of fracture and crack, this paper puts forward a pore-forming technology by a normal-circulation rotary drilling method using mixed slurry-supported wall, which is added by caustic soda, cellulose and plugging agent, polyacrylamide to mix slurry-supported wall when local slurries couldn’t support the wall of pore.