日本地熱学会誌
Online ISSN : 1883-5775
Print ISSN : 0388-6735
ISSN-L : 0388-6735
5 巻, 4 号
選択された号の論文の6件中1~6を表示しています
  • 糸井 龍一, 福田 道博, 世古口 言彦, 岩城 保
    1983 年 5 巻 4 号 p. 235-248
    発行日: 1983/10/10
    公開日: 2009/08/07
    ジャーナル フリー
    In order to evaluate the change in flow characteristics of a geothermal production well with increasing the drilling depth, two-phase flow analysis in a wellbore was carried out assuming the well inlet condition. Pressure at the well inlet was given by the vertical pressure profiles of saturated water whose water level was located at 0 m and -100 m, and inlet steam quality of x1=0 was used. The steam and water flow rates of a 3000 m deep well at a constant well head pressure (P2=10 ata) are estimated 194 t/h and 183 t/h respectively.
  • 境界要素法を用いて
    松林 修
    1983 年 5 巻 4 号 p. 249-257
    発行日: 1983/10/10
    公開日: 2010/02/05
    ジャーナル フリー
    地殼熱流量に及ぼされる地形の影響を正当に評価するための新しい方法として,熱伝導を表わすラプラス方程式を境界要素法によって解くことを提案する。現実にフィールドで測定された温度勾配のデータと,その坑井の存在する地形条件に合致するような地表面傾斜方向の相異に起因する地表面年平均温度の分布を考慮した数値解との比較を試みた。用いた坑井は仙岩地域の深度250mのH-3坑であり,実測された地温勾配は坑底に向かって下方へ減少しており,深部温度勾配として5.0×10-2℃/mを仮定した計算値と一致する。更に,部分的に観測値が数値解と一致しない区間についても考察を加えた。
  • 湯原 浩三, 山本 敏雄
    1983 年 5 巻 4 号 p. 259-276
    発行日: 1983/10/10
    公開日: 2009/08/07
    ジャーナル フリー
    Kurobe Jobu railway tunnel was accomplished in 1940, and the maximum wall temperature between Asobaradani and Sennindani was 165 °C. Since then, the tunnel has been considerably cooled by natural ventilation, but the present maximum wall temperature near small fumaroles or hot springs exceeds 90°C in places, and such a high temperature is supposed to be caused by thermal fluid flowing through fractures. Meteoric water which flows through fractures from the ground surface is assumed to extract and transport heat from the rock matrix above the tunnel to the wall of the tunnel and cause a high temperature near small fumaroles or hot springs. The assumption was evaluated by a simple mathematical model. The model consists of the cylindrical rock mass having a fracture through which water flows downward at the center. The differential equations govering the rock temperature were numerically solved by the finite difference method. Consequently in case many small fractures in the upper part of the rock mass join a single large fracture in the lower part, the temperature near fumaroles or hot springs can exceed 90 °C.
  • 由佐 悠紀
    1983 年 5 巻 4 号 p. 277-288
    発行日: 1983/10/10
    公開日: 2009/08/07
    ジャーナル フリー
    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.
  • 幾世橋 広, 京 宗輔, 石浜 渉, 田中 正三
    1983 年 5 巻 4 号 p. 289-303
    発行日: 1983/10/10
    公開日: 2009/08/07
    ジャーナル フリー
    Thermal properties of rocks at elevated temperature and high pressure have been highly concerned in geothermal energy development and in many fields of engineering. This paper describes development of a needle probe method -a transient hot wire method for simple and fast laboratory measurements of temperature and pressure dependence of the thermal conductivity of rocks and other poor conductors. A cylindrical sample of high purity fused quartz as a standard material of the thermal conductivity and samples of two granite are heated by a thin needle probe having 2.0 mm 0. D. and 80 mm effective length, the resulting temperature increase at the effective center point of the probe being monitored by a thermo-couple, a digital voltmeter and a pen recorder. The experimental temperature data to yield values of the conductivity is obtained in about fifteen minutes. Conductivity values of fused quartz and the granite specimens are presented in the temperature range 300-800°K. The absolute accuracy better than ±3.0 % verified by measurement of the standard sample for this method. The thermal conductivity of the granite specimens exhibitsaT-1 dependence on temperature, T, as expected for these type of rocks. Sample preparation is simple and not critical. The method described is well suited for measurement of the variation of thermal properties with temperature and pressure.
  • 幾世橋 広, 京 宗輔, 石浜 渉, 田中 正三
    1983 年 5 巻 4 号 p. 305-320
    発行日: 1983/10/10
    公開日: 2009/08/07
    ジャーナル フリー
    Hot Dry Rock technology requires a thorough knowledge of the variation of the thermal properties of rocks up to depth of the order of five kilometers. Temperature dependences of the thermal conductivity of 42 core samples from three test wells having 300 m depth at the field test site for the HDR technology in Yakedake geothermal area are presented in the temperature range 20-500°C. They are measured by a needle probe method. The thermal conductivity of the core sample exhibits θ1, θ0 and θ-1 dependences on temperature, θ, macroscopically. However, they are more complicatedly classified into θ10, θ-10and θ-11 dependences on θ in addition to above the three dependences, microscopically. In situ thermal conductivities of the rocks and terrestrial conduction heat flows at depths 110, 200 and 300 m in one of the test wells, HY well, are estimated by the obtained data.
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