水圧破砕された乾燥高温岩体からの熱抽出を予測するための簡便法

抄録

To predict heat extraction from hot dry rock by water circulation through a thin hydraulic circular fracture, a simple methematical scheme is presented. As the scheme does not treat complicated phenomena occurring in the fracture, it has an advantage of calculating the extracting water temperature for a long period easily. Calculations are carried out for the single fracture system made along the middle vertical plane of a rectangular rock body surrounded by thermally insulated planes; the size of the rock is 400m×307m×400m, the initial rock temperature is 250°C, the injection water temperature is 20°C and flow rates are 6 to 6001Jmin. Examples of calculations show that the single fracture system extracts the heat stored near the fracture and that the flow rate may be limited if one expects to get the high temperature water, though the water with the almost constant temperature can be taken out for a rather long period.