巻号一覧
19 巻 (2002)
- 4 号 p. 301-
- 3 号 p. 211-
- 2 号 p. 101-
- 1 号 p. 1-
19 巻, 3 号
選択された号の論文の9件中1～9を表示しています
- |<
- <
- 1
- >
- >|
論文
-
高松 洋, 山城 光, 高田 信夫, 中山 武, 本田 博司2002 年 19 巻 3 号 p. 211-221
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーHeat and mass transfer in a vertical in-tube absorber is studied experimentally using LiBr aqueous solution. The water vapor is absorbed by the liquid falling inside a smooth copper tube (16.05 mm I.D.,400 mm long) that is cooled on its outside with water flowing counter-currently. The presented results include the effect of solution flow rate, solution subcooling and cooling water temperature on the heat transfer rate, absorption rate and pressure drop in the absorber. Discussion is also presented on the heat and mass transfer coefficients that are defined by estimated temperature and concentration at the vapor-liquid interface.抄録全体を表示PDF形式でダウンロード (648K) -
マランゴニ対流の発生·成長機構の解明と吸収促進効果の簡易評価法西村 伸也, 野邑 奉弘, 伊輿田 浩志, 川上 隆一郎2002 年 19 巻 3 号 p. 223-235
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーEffects of an addition of surfactant to a lithium bromide aqueous solution have been investigated experimentally. N-octanol was used as a surfactant. The Marangoni convection occurred at/beneath the solution surface in the very beginning of steam absorption was observed both by a real-time type laser holographic visualization and by temperature measurements with extremely fine gauge thermocouples. Generation and growth of the Marangoni convection were both observed and evaluated quantitatively by the flow visualization. Furthermore, solution's surface temperatures with and without addition of the surfactant were measured minutely. Cell's formation pattern and migration speed at the surface were measured varying the initial surfactant's concentration ranging from 0 to 50000 ppm and the shallow liquid layer thickness ranging from 2 to 5 mm. And spacio-temporal scales of the Marangoni convection were determined. Also solution temperature changes at the surface were compared. Temperature increases when the surfactant was added to its solubility limit became almost double than that case of no surfactant. From these temperature differences, effects of the surfactant on absorber's performances were estimated by a calculation quantitatively with diffusion coefficient as an evaluation value.抄録全体を表示PDF形式でダウンロード (910K) -
寸法効果寺西 恒宣, 小澤 貴敬, 瀧本 昭2002 年 19 巻 3 号 p. 237-244
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーAs a basic research for the development of a high-performance and environment-friendly thermal energy recovery system, detailed experiments have been conducted to investigate the mechanism of the enhancement of condensation heat transfer by the counter-current moist air flow in a vertical tube. From the results of visual observation of the phenomena by using a high-speed video recorder and the measurement of condensate rate respectively from an upper and a bottom end of a cooled tube, in which various humidity vapor of air and water flowed upward or downward, the dynamic behavior of liquid film condensed on cooled surface and moist air flow was classified into four distinctive patterns in quality and quantity. Further, the effect of the scale and the operating condition such as the diameter and the length of tube, the vapor concentration and the moist air temperature, on the condensation rate of counter-current wavy flow was clarified in relation to the pattern and condition of occurrence of the wavy flow of liquid film and flooding due to the shear forces between the interface of liquid and moist air flow.抄録全体を表示PDF形式でダウンロード (494K) -
下村 信雄, 熊田 雅弥, 儲 仁才, 水野 敏之2002 年 19 巻 3 号 p. 245-254
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーPurposes of this study are unsteady evaluation of thermal performance of heat exchanger with frosting and decision of optimal defrosting cycle. Thermal performance characteristics were examined. The density distribution in the height direction of the frost layer on the flat plate exists under the forced convection. The structure of the frost can't be regarded as homogeneous. The friction coefficients can be arranged by Reynolds number and the equivalent diameter ratio within ±12%.Dependence of Reynolds number is different on the experiment condition, but there are no relations in the experiment condition, and equivalent diameter ratios are almost arranged by the constant value. As for the time variation of the mass and heat transfer, reverse tendency is shown, and analogy isn't concluded. The reason is that: 1) The leading edge becomes the quadrant-shaped projection caused by the frost growth, that is made to enhance heat transfer. 2) Due to the temperature rise and partial melting of the leading edge, the infiltration of the water vapor into frost is blocked, and mass transfer doesn't increase.抄録全体を表示PDF形式でダウンロード (666K) -
一宮 浩市2002 年 19 巻 3 号 p. 255-262
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーThis paper presents the experimental results on the impingement heat transfer by 4-circular nozzles arranged in square type. Experiments were performed for the dimensionless space H(= h/D)=0.5-8,the Reynolds number Re(= VoD/v)=3000-40000, and the dimensionless pitch Pi(= pi/D)=8. The two-dimensional behavior of the local Nusselt number was corresponded to the flow visualization by oil film method on the impingement surface. The average Nusselt number was expressed by the geometric function and Re2/3. The maximum average Nusselt number was obtained at the dimensionless nozzle-impingement surface spacing H=2 for constant Reynolds number.抄録全体を表示PDF形式でダウンロード (466K) -
臨界表面張力の小さな壁面材質の熱抵抗が製氷過程に与える影響について中川 慎二, 岡田 昌志, 土田 大輔, 姜 〓東, 松本 浩二, 川越 哲男2002 年 19 巻 3 号 p. 263-272
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーA water-oil emulsion which is the mixture of silanol-aqueous solution and silicone oil was frozen in a vessel with stirring under various cooling temperatures. The cooling surfaces of the vessels were PTFE or PF A whose critical surface tension is relatively low. The effects of the wall thermal resistance on ice formation process were investigated. The relationship between the state of formed ice and cooling heat flux during freezing was c1arified. When the critical surface tension of the inner wall of the cooling surface is fixed, a smaller thermal resistance of wall enables the ice formation without ice adhesion to the surface at a higher ice formation rate. Ice can be formed without adhesion at the lower cooling temperature by using the vessel with a larger thermal resistance although the maximum cooling heat flux is relatively small. The maximum cooling heat flux decreases when the ratio of wall thermal resistance to overall thermal resistance before freezing is more than one half. It was shown that there were proper conditions to increase the cooling heat flux and that ice could be formed with high IPF under the proper conditions.抄録全体を表示PDF形式でダウンロード (739K) -
冷却性能の特性川口 清司, 岡本 義之2002 年 19 巻 3 号 p. 273-279
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーIn recent years, semiconductor devices have become faster and more highly integrated, and their capacity has increased. Accompanying this there has also been the increase in the rate of heat generation of devices. We have developed the boiling refrigerant type cooling unit for high power electric controller. The main features of this cooling unit is high cooling performance, low noise, and low electric power. In this study we clarified the influence of cooling air velocity and the number of rows of heat exchanger on the cooling performance of this cooling unit. And it was found that the boiling refrigerant type cooling unit for electric power controller had low noise and low electric power performance compared with conventional air-to-air type cooling unit by testing the two kinds of cooling units.抄録全体を表示PDF形式でダウンロード (527K) -
第1報:理論モデル濱本 芳徳, 岡島 次郎, 松岡 文雄, 秋澤 淳, 柏木 孝夫2002 年 19 巻 3 号 p. 281-292
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーThe study aims at clarifying the performance of desiccant rotor, and at obtaining the design aspects of high efficient desiccant rotor and systems. In the paper, theoretical analysis is performed for rotary dehumidifier and humidifier. The validity of the model is confirmed by comparison between experimental data and calculation. The influences of several complex factors such as adsorption/desorption time ratio, air flow path patterns and air conditions on rotor performance are examined. It is clarified that there is an optimum angle of adsorption, desorption and purge zone becoming a maximum amount of humidifying And also, there is an optimum desorption side air flow rate. It is confirmed that air flow rate and air temperature influence significantly the amount of dehumidifing and humidifing. Furthermore, it is suggested that heat transfer enhancement of the rotor is efficient in the mass transfer enhancement at the beginning of desorption process.抄録全体を表示PDF形式でダウンロード (617K) -
笠井 一成, 藤野 宏和, 吉岡 俊, 蛭子 毅2002 年 19 巻 3 号 p. 293-299
発行日: 2002年
公開日: 2011/09/08
ジャーナル フリーThis paper presents a new method for predicting evaporating and condensing heat transfer coefficients of refrigerants flowing inside a new type herringbone heat transfer tube which is developed for the use of an air-conditioning machine. Not until recently has there been sufficient quantitative explanation about the heat transfer enhancement mechanism of the new tube, the present prediction assumes that the heat transfer coefficient is simply governed by the circumferential local thickness of an unique liquid film layer formed inside the tube. The developed semi-empirical prediction method agrees with the experimental data within the deviation of 30% for both evaporation and condensation.抄録全体を表示PDF形式でダウンロード (400K)
- |<
- <
- 1
- >
- >|