贵州岩溶疏干区浅层地热能地埋管施工技术

贵州省浅层地热能资源丰富,开发潜力巨大,但碳酸盐岩地层分布广、浅表岩溶裂隙极为发育,浅层地埋管施工难度大。以贵州仁怀妇幼保健院浅层地温中央空调地埋管工程为例,采用偏心潜孔锤跟管钻进、潜孔锤钻进、简便除尘器除尘、固结封堵和圆木封隔溶洞、提吊法下管等技术措施,解决了在由于溶蚀和断裂构造及河流深切割作用造成的局部岩溶发育以及地埋管埋置深度内无水的岩溶疏干区进行地埋管施工面临的松散浅表回填及岩溶软弱层成孔困难、全孔段无液面潜孔锤钻进粉尘污染环境、溶洞跑管(PE管)等技术难题,在保证了工程质量、安全的同时提高了施工效率,为类似工程提供了施工经验。

Placement of shallow geothermal heat pipes in the dewatered karst area of Guizhou province

Guizhou province is rich in shallow geothermal resource with huge exploitation potential.However,widespread carbonate strata and well?developed karst fractures in shallow formation cause great difficulties in placement of shallow underground heat pipes.In the case of placement of the underground heat pipes for the shallow low ground temperature central air conditioner of Maternity and Childcare Hospital of Huairen,Guizhou,various technical measures,including eccentric DTH(down?the?hole)hammer drilling with simultaneous casing,DTH hammer drilling,dust removal by the simple dust remover,sealing off karst caves with cement and logs,RIH of pipes with the auxiliary winch,have been adopted to solve the technical problems such as difficulty in borehole completion,environmental pollution by dust from DTH hammer drilling without underground water over full holes,laying the heat pipes(PE pipe)through karst caves due to presence of loose shallow backfilling and karst weak formation encountered in placement of underground heat pipes in the dewatered karst area characterized by local karst development and water shortage(produced by dissolution,rupture structure,and deep cutting by the river)over the length of the underground heat pipes.This not only guarantees project quality and safety,but also improves construction efficiency,providing construction experience for similar projects.