巻号一覧
9 巻 (1987)
- 4 号 p. 255-
- 3 号 p. 185-
- 2 号 p. 109-
- 1 号 p. 1-
9 巻, 4 号
選択された号の論文の4件中1～4を表示しています
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松木 浩二, 奥村 清彦, 杉本 文男1987 年 9 巻 4 号 p. 255-270
発行日: 1987/10/27
公開日: 2009/08/07
ジャーナル フリーScale deposition in wells and in pipes on the surface has been a serious problem for geothermal power plants as the effective method for removing the scales or for preventing the scales from being deposited has not been established yet. In this study, in order to clarify the performance of high speed water jets in removing geothermal scales, fundamental experiments were carried out for three kinds of geothermal scales, a calcium carbonate scale and two silica scales, which were deposited in transportation pipes. Slot cutting in water was conducted first to know the effect of driving pressure and standoff distance, and then removal of the scales with rotary nozzles was tested to clarify the effect of rotary speed, rate of feed and driving pressure. As a result, it is shown that high speed water jets can remove geothermal scales almost perfectly without damaging the pipe if sufficient driving pressure is employed, and that optimum rotary speed gives the largest rate of removal. The test results also show that the driving pressure required to remove the scales is roughly proportional to the tensile strength of the scale, and that larger size of 5 to 15 mm is predominant in particle size distribution of removed scales.抄録全体を表示PDF形式でダウンロード (9093K) -
新堀 雄一, 荻原 洋一, 千田 佶1987 年 9 巻 4 号 p. 271-283
発行日: 1987/10/27
公開日: 2010/02/01
ジャーナル フリー本論文は多孔質体における水一水蒸気流れに及ぼす相変化に関する基礎的研究を述べたものである。実験はガラスビーズ充填層を373K以上の恒温槽に水平に浸すことにより行われる。これらの結果は,非濡れ相の相対浸透率と飽和度の関係式において新たなフィッティングパラメータCを有する一次元二相モデルの計算結果と比較される。パラメータCは,濡れ相が多孔質体における支配的な流路における非濡れ相の流れを妨害しはじめる臨界点である。 本研究から次の結論が得られる。(1)多孔質内における相変化を伴う水一水蒸気流れにおいて,水と気泡の流れに及ぼす気泡の阻害効果であるJamin effectが存在する。(2)パラメータCを含んでいる非濡れ相の相対浸透率曲線はWyckoffら(1936)によって実験的に示された水飽和率とガスの相対浸透率の関係とおおよそ一致する。(3)提出された数字モデルは蒸気比が6.6より小さい範囲において,相変化を伴う水一水蒸気流れを表す。抄録全体を表示PDF形式でダウンロード (2032K) -
1次元流れの数値解析糸井 龍一, 福田 道博, 神野 健二, 横山 拓史, 清水 晨1987 年 9 巻 4 号 p. 285-306
発行日: 1987/10/27
公開日: 2010/06/17
ジャーナル フリーA mathematical model which simulates the previously reported experimental results on permeability decrease of porous media is proposed. In the model, the silica deposition rate is proportional to the product of the degree of supersaturation of dissolved silica in geothermal water with respect to amorphous silica solubility and the surface area of porous media exposed to the water. In addition, the effect of the previous-ly deposited silica on silica deposition should be considered because it accelerates the silica deposition. Unknown deposition rate coefficients, β1 and β2, are determined using trial and error method so as to fit the measured flow rates. The calculated profiles for the amount of deposited silica and permeability are then compared with the experimental data. The optimum values for the deposition rate coefficients are obtained by assuming that a very small quantity of excess silica in the water can deposit along the porous media. For instance, at the inlet of the porous media, it is only 2 ppm, although the concentration of excess silica in the water is as high as 201 ppm. The deposition rate coefficients determined are β1=3.5x10-4 cm/s and β2=4.0x103∼5.0x103抄録全体を表示PDF形式でダウンロード (2694K) -
湯原 浩三, 江原 幸雄, 原 幸, 藤光 康宏1987 年 9 巻 4 号 p. 307-355
発行日: 1987/10/27
公開日: 2009/08/07
ジャーナル フリーInfrared measurements by a helicopter-borne remote sensing system were conducted in the nineteen volcanic and geothermal fields in Kyushu, south western Japan. Heat discharges calculated from the thermal images by a method based on heat balance of the ground surface range from 2.0 × 105 cal/sec (for a weak steaming ground) to 2.1 x 107 cal/sec (for a crater of an active volcano). Finally, it is found that average heat fluxes are approximately constant, 104 HFU.抄録全体を表示PDF形式でダウンロード (35321K)
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