HEAT TRANSFER FILLING MATERIAL, UNDERGROUND HEAT EXCHANGE DEVICE, AND FILLING METHOD OF HEAT TRANSFER FILLING MATERIAL

摘要

PROBLEM TO BE SOLVED: To eliminate a clearance in a heat transfer filling material, and thereby to provide a good a heat transfer between a heat exchange pipe and underground soil.SOLUTION: Iron powder 12C is added to bentonite 12B to form pellets 12A as the heat transfer filling material 12. Pellets 12A are thrown in a cut hole H provided in soil G, and water is supplied thereto. Hence the heat transfer filling material 12 is formed by swelling of the pellets 12A. Because the bentonite 12B becomes swellable by including water, and then by supplying water, the pellets 12A swells to bury the clearances among the pellets 12A. The clearances in the heat transfer filling material 12 is eliminated in this way, and the good heat transfer between an underground side heat transfer pipe 11 and the soil G is provided.