Transactions of the Japan Society of Refrigerating and Air Conditioning Engineers
Online ISSN : 2185-789X
Print ISSN : 1344-4905
ISSN-L : 1344-4905
Volume 8, Issue 2
Displaying 1-7 of 7 articles from this issue
Review Article
  • Manabu KITAMIKADO, Keiko YOSHIOKA
    1991 Volume 8 Issue 2 Pages 93-102
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    In Japan fresh fish has a much higher market price than that for frozen-thawed fish. However, a large number of frozen-thawed fish are sold without being differentiated from fresh fish. We discuss here the differentiation methods described in literatures and our works in the search for such a method.
    We used the opacity of crystalline lens and the destruction of red blood cells as the index for the differentiation, in addition to the activity of neutral β-N-acetylglucosaminidase in blood. Thus, a fluorometric method and a rapid paper test method were developed based on measurement of the activity of this enzyme. This enzyme, found in fish red blood cells, was inactive in intact cells but was activated when cells were disrupted by freezing, and thawing. Both methods were applicable for testing most commom edible fish prior to filleting and required about 20 min using a UV-lamp.
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Papers
  • Hiromichi KAWABE, Teimi TANAKA, Shoichiro FUKUSAKO
    1991 Volume 8 Issue 2 Pages 103-110
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    An experimental study has been performed to investigate the heat-transfer characteristics in a concentric-tube closed thermosyphon in which boiling and free convection take place. The outer tube of the thermosyphon used in this study was 100mm in diameter with 3420mm in height, which consisted of both some individual electrical heating copper tubes of 330mm in length and lucite tubes of 60mm in length. On the other hand, inner copper tubes of 41.3mm and 66.6mm in diameter with 3270mm in length were adopted. Experiments were carried out under the constant wall surface temperature conditions and refrigerant R-11 was utilized as a testing fluid. Out of a number of possible controlling valiables, the effect of the heat flux, the void fraction, the ratio of heating length to the total test section length, and the diametric ratio of the concentric tube on the heat-transfer performance were determined.
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  • Makoto TAGO, Shoichiro FUKUSAKO
    1991 Volume 8 Issue 2 Pages 111-122
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    An experimental study has been performed to investigate the ice-layer transition phenomena observed in a channel which has a lower cooled wall kept less than the freezing temperature of water. The rectangular test channel with cross-sectional dimensions of 50mm by 19mm was used in the present measurements. The velocity distribution and the turbulence intensity in a flow passage were measured using the Laser Doppler Velocimeter setup on the two-dimensional traversing device. The freezing experiments were carried out under the condition of constant amount of flow even after the ice-layer developed in the channel. It was found that onset of the ice-layer transition might be closely related to the increase of the turbulence intensity in a flow along the developing ice-layer surface.
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  • Analysis of Ideal Rankine Cycles for Multistage Systems
    Kentaro KIKUCHI, Akira YABE
    1991 Volume 8 Issue 2 Pages 123-130
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    Three heat pump ideal cycles of two stage compression with two stage expansion, three stage compression with single stage expansion and three stage condensation systems, all of which are considered as the performance improvement methods, are analyzed by introducing the evaluation formula of COP, and the physical property of working fluids. Temperature lift, condensation temperature, COP, working fluids and cycle name are taken as the analysis parameters. No losses for compressors, evaporator and condenser are assumed for ideal cycles. Analytical results are processed for graphical presentation and data bases are made for the performance comparison and evaluation of multistage systems.
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  • Simulation Analysis and Experiments of Two Stage Compression System
    Kentaro KIKUCHI, Akira YABE
    1991 Volume 8 Issue 2 Pages 131-140
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    Computer simulation analysis was made for theoretical thermal characteristics of double stage compression double stage expansion cycle, which is one of the multistage heat pump system, and the steady state solution of convergence was obtained, component characteristics being replaced by simplified experimental models. Also, experiments were performed by cycle simulation system using R22 as a working fluid and the steady results of measurements were obtained. Useful information for the design and estimation of multistage heat pump systems were obtained, by the consideration of the effect of the change for the performance parameter of condensation temperature, working fluids, intermediate temperature on the cycle characteristics.
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  • Akio SAITO, Hiki HONG, Osamu HIROKANE
    1991 Volume 8 Issue 2 Pages 141-150
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    In direct contact melting, it is clear that one of factors that affect the heat transfer is the size of heat transfer surface. This indicates that the shorter the path through which the liquid between the heat transfer surface and the solid PCM is rejected outside, the thinner the liquid melt, which decreases the thermal resistance between source and PCM. In the present work, it was investigated how the heat transfer can be promoted by machining slots on the disk-type heat transfer surface and dividing it into lots of sector-shaped sections, through theoretical analysis and numerical simulation. Numerical simulation, which includes only the effect of heat conduction in liquid layer, shows a good agreement with experiments reported in other literature. Also, it was turned out that prediction equation yielded by theoretical analysis gives not only the qualitative explanation of the increase of heat flux, but also the quantitative prediction on the heat flux with an adequate accuracy. Summarizing those results, the enhancement of heat transfer can be apparently achieved according to the number of splits.
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  • Akio SAITO, Seiji OKAWA, Hiroshi UNE, Ken'ichi TANOGASHIRA, Akira TOJI ...
    1991 Volume 8 Issue 2 Pages 151-160
    Published: 1991
    Released on J-STAGE: October 11, 2011
    JOURNAL FREE ACCESS
    In relation to the problem of supercooling for ice storage devices, various kinds of experiments were carried out to find some factors which control the supercooling phenomenon. Convection due to rotating solid in water, stirring, vibration, shock, rubbing glass with glass in water and collision of solid in water were selected as outer factors. It was found that factors such as convection, stirring, vibration, non-contacting shock have no effect on freezing supercooled water. They seem to be just adding some positive energy to water. On the other hand, collision or rubbing between solids or solid and liquid surface helps supercooled water to freeze. We believe that making water molecules closer to each other, whose motion were restricted by solid or liquid surface, induce the growth of ice embryo.
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