巻号一覧
17 巻 (2000)
- 4 号 p. 413-
- 3 号 p. 203-
- 2 号 p. 105-
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17 巻, 4 号
選択された号の論文の11件中1～11を表示しています
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Shoichiro FUKUSAKO, Yoshiyuki KOZAWA, Masahiko YAMADA, Masayuki TANINO2000 年 17 巻 4 号 p. 413-437
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーIn this paper, a brief review for fundamental researches and developments on fine crystalline ice slurries in Japan has been made. The present paper essentially consists of two parts. In the former part of the present paper, the fundamental studies on the basic components, namely, the production, the transportation, and the melting of ice slurry were presented. Furthermore, as an example for the application of these basic researches, the computer simulation on the cold thermal storage system has been performed to study the effects of such as the operation mode on the system performance. In the latter part, the state of the art of ice slurries, which is applied to development of ice storage systems for air conditioning uses in Japan, has been described. The types of ice storage system were categorized into five groups by the way of ice manufacturing. Furthermore, the performance of ice storage system was also discussed.抄録全体を表示PDF形式でダウンロード (1542K) -
Adsorption Heat Pumps柳 秀治2000 年 17 巻 4 号 p. 439-452
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーThe use of waste heat of low temperatures is an important problem from the environmental considerations. Notice that adsorption cycles have a distinct advantage over other systems of their ability to produce cooling by using low waste heat as 60 to 80°C and also being absolutely benign for the environment. However the present available adsorption chillers are still heavier and larger in size. Hence their compactness and cost reduction as well as higher efficiency are urgent tasks for wider use. This review discusses recent development on adsorption heat pumps as well as forthcoming applications. The sources are mainly papers and discussions at the IEA Annex 24 Workshop in Turin, Italy (1999), FOA6 (Fundamental of Adsorption) Conference in Presquile de Giens, France (1998) and ISHPC (International Sorption Heat Pump Conference) in Munich, Germany (1999).抄録全体を表示PDF形式でダウンロード (809K) -
長野 龍彦, Kang Yong tae, 秋澤 淳, 柏木 孝夫2000 年 17 巻 4 号 p. 453-459
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーThe objectives of the paper are to visualize the bubble shape and to investigate the characteristics of the bubble behavior for an1monia-water absorption process. Tbe orifice dian1eter, liquid concentration and vapor velocity are considered as the key parameters. The initial bubble diameter increases with increasing the liquid concentration. A transition vapor Reynolds number is introduced, which is defined as Reynolds number at a sudden change of ratio of the initial bubble diameter to the orifice diameter. The transition Reynolds number increases with increasing the liquid concentration, and it significantly influences the bubble shape. Heat transfer additive (n-octanol) makes bubble more hemispherical. The departing bubbles tend to be spherical for a surface tension dominant flow, and the bubbles tend to be hemispherical for an inertial force dominant flow. This study presents an experimental correlation of initial bubble diameter with &±20% error band. The correlation can be used to calculate the interfacial area in the design of ammonia-water bubble absorber.抄録全体を表示PDF形式でダウンロード (364K) -
小山 繁, 李 相武2000 年 17 巻 4 号 p. 461-471
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーThis paper deals with a prediction method for the condensation of a multi-component refrigerant mixture inside a horizontal smooth tube. The present method is obtained by extending our prediction method for a binary zeotropic refrigerant mixture to multi-component one. The governing equations for the local heat and mass transfer characteristics are derived based on the some reliable assumptions such as the phase equilibrium is established only at the vapor-liquid interface. In order to demonstrate the present method, the local heat and mass transfer characteristics of ternary zeotropic refrigerant mixtures composed of HFC32/HFC125/HFC134a, including R407C, are evaluated for a counterflow double-tube condenser cooed by water. Then, the local values of vapor quality, thermodynamic states at bulk vapor, vapor-liquid interface and bulk liquid, heat flux and condensation mass flux are obtained. The effects of the composition of HFC32/HFC125/HFC134a on the total pressure drop and the heat transfer characteristics are also examined.抄録全体を表示PDF形式でダウンロード (534K) -
梁取 美智雄, 大平 昭義2000 年 17 巻 4 号 p. 473-480
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーThis paper deals with the pressure drop in cold water flow in the beds packed with crushed ice. 1n each case, ice-packed beds were filled with sevral kinds of crushed ice, and friction-loss coefficients were examined. The following results were obtained. (1) The friction factor of rectangular-type ice-packed beds is smaller than that of ideal sphere beds by about 1/4 to 1/2. (2) The friction factor of small-stone-type ice-packed beds is about twice as large as that of ideal sphere beds. (3) It is difficult to compare the flow model of water in restricted channel of particle-type ice-packed beds with that of ideal packed beds.抄録全体を表示PDF形式でダウンロード (434K) -
本田 博司, 高田 信夫, 高松 洋, 金 正植, 宇佐見 敬一郎2000 年 17 巻 4 号 p. 481-487
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーExperimental results are presented that show the effect of fin geometry on condensation of refrigerant R134a in a staggered bundle of horizontal fined tubes. Two kinds of conventional low-fin tubes and three kinds of three-dimensional fin tubes were tested. The refrigerant mass velocity ranged from 8 to 23 kg/m2s and the condensation temperature difference from 1.5 to 12 K. In most cases, the highest performance was obtained by one of the three-dimensional fin tubes. In the case of high mass velocity and high film Reynolds number, however, the highest performance was obtained by one of the low-fin tubes. The results were compared with previous experimental results for bundles of smooth tubes and low-fin tubes.抄録全体を表示PDF形式でダウンロード (349K) -
狩野 直樹, 斯波 波, 横山 良平, 伊東 弘一2000 年 17 巻 4 号 p. 489-499
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーIn planning an air conditioning system, supply water and air temperatures are important factors from the viewpoint of energy saving and cost reduction. For example, lower temperature supply water and air for space cooling reduce the coefficient of performance of a refrigeration machine, and increase the thickness of heat insulation material. However, they enable larger temperature differences, and reduce equipment sizes and power demand. It is also an important subject to evaluate the effect of the supply water and air temperatures on energy saving and cost reduction on the annual basis by considering not only cooling but also heating loads. The purposes of this paper are to propose an optimal planning method for an air conditioning system with large temperature difference, and to analyze the effect of supply water and air temperatures on the long-term economics through a numerical study for an office building. As a result, it is shown that the proposed method effectively determines supply water and air temperatures, and the influence of the cooling to heating load ratio on the long-term economics is clarified.抄録全体を表示PDF形式でダウンロード (632K) -
本田 博司, 高田 信夫, 高松 洋, 金 正植, 宇佐美 啓一郎2000 年 17 巻 4 号 p. 501-509
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーRow-by-row heat transfer data were obtained during condensation of downward-flowing refrigerant mixture R407C in a staggered bundle of horizontal finned tubes. Two kinds of conventional low-fin tubes with flat-sided annular fins and three kinds of three-dimensional fin tubes were tested. The refrigerant mass velocity ranged from 4 to 23 kg/m2s, and the condensation temperature difference from 1.5 to 12 K. At a low to medium film Reynolds number(⟨2000), the highest heat transfer coefficient was obtained by one of the three-dimensional fin tubes. At a high film Reynolds number(⟩2000), on the other hand, the highest performance was obtained by one of the low-fin tubes. For all tubes tested, the heat transfer coefficient decreased with decreasing mass velocity. On the basis of previous results for R134a, consideration was given to the characteristics of vapor phase mass transfer of R407C.抄録全体を表示PDF形式でダウンロード (459K) -
森 英夫, 柿本 益志, 大石 克巳2000 年 17 巻 4 号 p. 511-520
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーThe present paper reports an investigation of the dryout quality for refrigerants flowing in horizontal evaporator tubes. Experiments were made for the flow of boiling HFC-134a and HCFC-22 inside smooth tubes and a spirally grooved (micro-fin) tube. At given conditions, dryout proceeded over a certain quality range. Therefore two dryout qualities were defined; dryout inception quality at which the circumferentially averaged (axially local) heat transfer coefficient began to decrease rapidly, and dryout completion quality at which the decrease in the heat transfer coefficient ended. Based on the experimental data, the characteristics of both dryout qualities were clarified, and thereby the dryout qualities were classified into three characteristic regimes for the smooth tube and two regimes for the micro-fin tube. A dimensionless correlation of each dryout quality, which can reproduce the measurement successfully, was developed for the respective tubes.抄録全体を表示PDF形式でダウンロード (482K) -
森 英夫, 吉田 駿, 柿本 益志, 大石 克巳, 福田 健一2000 年 17 巻 4 号 p. 521-528
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーStudies of the post-dryout heat transfer were made based on the experimental data for HFC-134a flowing in horizontal smooth and spiral1y grooved (micro-fin) tubes and the characteristics of the post-dryout heat transfer were c1arified. The heat transfer coefficient at medium and high mass flow rates in the smooth tube was lower than the single-phase heat transfer coefficient of the superheated vapor flow, of which mass flow rate was given on the assumption that the flow was in a thermodynamic equilibrium. A prediction method of post-dryout heat transfer coefficient was developed to reproduce the measurement satisfactorily for the smooth tube. The post dryout heat transfer in the micro-fin tube can be regarded approximately as a superheated vapor single-phase heat transfer.抄録全体を表示PDF形式でダウンロード (398K) -
笹口 健吾, 石川 昌稔, 牟田 健二, 芳野 清隆, 林 寛子, 馬場 敬之2000 年 17 巻 4 号 p. 529-540
発行日: 2000年
公開日: 2012/03/14
ジャーナル フリーIn the present study, the authors propose the use of a low concentration aqueous solution as phase change material for static-type ice-storage-vessels, instead of pure water commonly used today. If an aqueous solution with low concentration is used, even when a large amount of solution (aqueous ethylene glycol in this study) is solidified and bridging of ice developed around cold tubes occurs, the pressure increase could be prevented by the existence of a continuous liquid phase in the solid-liquid two-phase layer (mushy layer) which opens to an air gap at the top of a vessel. Therefore, one can continue to solidify an aqueous solution after bridging, achieving a high ice packing factor (IPF). First, experiments using small-scale test cells have been conducted to confirm the present idea, and then we have performed experiments using a large vessel with an early practical size. It was seen that a large pressure increase is prevented for the initial concentration of the solution C0 of 1.0%, and IPF obtained using the solution is much greater than 0.65 using pure water for which the solidification must be stopped before the bridging.抄録全体を表示PDF形式でダウンロード (708K)
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