摘要 |
PROBLEM TO BE SOLVED: To provide a construction method of an underground heat storage device improvable in heat storage efficiency by enhancing water holding property of soil even with low water holding property containing a plenty of hard clayey soil, gravel, etc. to improve specific heat, and to provide the underground heat storage device and an underground heat storage method.SOLUTION: The construction method of the underground heat storage device includes a vertical hole excavating step (S110) opening a vertical hole 310 in the ground, a soil shearing step (S130) inserting a high pressure jet nozzle 360 into the vertical hole 310 and jetting a high pressure liquid A from the high pressure jet nozzle 360 toward soil 300 around the vertical hole 310 to shear the soil 300, and a heat storage section forming step (S140) holding moisture in the sheared soil 300 to form a water-containing layer B for heat storage. |