| 摘要 |
PROBLEM TO BE SOLVED: To cut installation cost of an underground heat exchanger buried in the ground vertically to a ground surface.SOLUTION: An underground heat exchanger 10 according to the present invention includes: a metallic underground pipe 11 temporarily storing therein a heat accumulation/discharge fluid R circulated via a heat pump device 2; a fluid inlet pipe 14 feeding the heat accumulation/discharge fluid R into the underground pipe 11 via the heat pump device 2; and a fluid delivery pipe 15 for reflow of the heat accumulation/discharge fluid R stored in the underground pipe 11 to the heat pump device 2. A large-area spiral blade plate 20 is fixed to an outer circumferential surface of the underground pipe 11. Since the spiral blade plate 20 can contribute to increasing an underground contact area of the underground pipe 11, an underground depth of the underground pipe 11 can be made smaller. An underground auxiliary pipe 30 for rotatably inserting the underground pipe 11 deep underground is often connected to an upper portion of the underground pipe 11. |
