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Volume 2 (1985)
- Issue 3 Pages 155-
- Issue 2 Pages 71-
- Issue 1 Pages 1-
Volume 2, Issue 3
Displaying 1-8 of 8 articles from this issue
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Toyohiko MIURA1985 Volume 2 Issue 3 Pages 155-168
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSThe thermal comfort of air conditioned indoor environment for workers depended, of course, on metabolic rate of work, race, sex, age, clothing, climate of the district and state of acclimatization. The attention of the author was directed to the seasonal variation and the sexual difference of comfortable temperature and a survey through a year was conducted on the thermal comfort, and health conditions of workers engaged in light work in a precision machine factory, in some office workers. Besides, a series of experiments were conducted for purpose of determinning the optimum temperature of cooling in summer time in relation to the outdoor temperature.
It seemed that many of workers at present would prefer somewhat higher temperature than those before the World War II. Forty years ago the average homes and offices were not so well heated as today, and clothing worn on the average was considerably heavier.View full abstractDownload PDF (837K) -
Tetsu FUJII, Shigeru KOYAMA, Masao GOTO, Hiroshi TAKAMATSU1985 Volume 2 Issue 3 Pages 169-178
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSFrom the point of view of the application of non-azeotropic mixed refrigerants to heat pump and refrigeration cycles, literatures on condensation and evaporation are surveyed and future problems to be studied are extracted. All researches on the relevant problems are recently started and still in developing way except for condensation on a single horizontal tube. Particularly, the studies for condensation and evaporation of mixed Freon refrigerant in a horizontal tube, which are the most important in practice, are far backward in comparison with single component refrigerant in every point of heat transfer characteristics, flow pattern and theoretical analysis.View full abstractDownload PDF (489K) -
Akira MATSUDA, Tetsuo IDE, Keiji YUKINO1985 Volume 2 Issue 3 Pages 179-188
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSExperiments on evaporation for water and lithium bromide (LiBr) aqueous solution were made in a externally heated wetted-wall column under reduced pressures. For water, evaporation rate increased slightly as feed rate decreased. The heat transfer coefficients of falling film agreed with those for filmwise condensation. For LiBr solution, evaporation rate decreased and outlet temperature of LiBr solution increased as feed rate decreased.
The equations of continuity, diffusion and energy which assume that only water moves to the surface and LiBr doesn't move through falling film of LiBr solution were solved numerically. Calculated values of evaporation rate and outlet temperature of solution agreed with experimental results.
The results of this work were compared with pool boiling data reported previously, and it was shown that falling film heater is superior to pool boiling heater concerning heat transfer.View full abstractDownload PDF (504K) -
Yoshifumi KUNUGI, Tomihisa OUCHI, Sanpei USUI, Tamio FUKUDA1985 Volume 2 Issue 3 Pages 189-196
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSExperimental studies on heat transfer performance of absorber for lithium bromide-water absorption refrigerating machine are presented in this paper. Experimental apparatus for 35 kW evaporator and absorber, and outer grooved tubes are used.
As a result, over-al1 coefficient of heat transmission of absorber has a maximum value, in the case of heat transfer area ratio of absorber to evaporator, is about 0.8. Heat transfer rate of absorber is increased by 60% by using the outer grooved tube compared with the plane surfaced tube.View full abstractDownload PDF (363K) -
Masahiro YOSHIWARA, Yoshiro KATTO1985 Volume 2 Issue 3 Pages 197-202
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSAn experimental study for convective heat transfer between a cavity wall surface and the external main stream has been made in the range of Reynolds numbers from 10 4 to 105. The temperature distribution in a cavity of which both width and depth are 25mm is almost uniform except a thin portion immediately adjacent to the wall surface of a cavity. The representative mean temperature of the fluid in a cavity is used for the following treatment. Convective heat transfer between a cavity wall surface and the external main stream is treated by the following two phenomena; one the heat transfer related to the temperature difference between the wall surface and the fluid in a cavity, and the other the heat transfer related to the temperature difference between the fluid in a cavity and the external main stream. Experimental data obtained for the foregoing dimensions almost coincide with existing data obtained for a cavity of 50mm in width. Approximate dimensionless correlations are described for the foregoing two phenomena.View full abstractDownload PDF (326K) -
Eiji KUWAHARA, Masaya YAMAZAKI, Toshiaki KAWAMURA1985 Volume 2 Issue 3 Pages 203-212
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSMethods to shorten the defrost time have been studied on a heat pump air conditioner. The experiment has been carried out using a 0.75kW heat pump and the energy balance during defrosting has been analyzed. We have found that the following methods are effective to shorten the defrost time; (1) Increase in power inqut to the compressor during defrosting, (2) Utilization of the compressor for thermal energy storage, (3) Reduction of the water left on the outdoor heat exchanger fins.
The heat pump with the new defrosting system has been made on an experimental basis. lts defrost time is 1 minute and 55 seconds under the defrost condition of the Japanese Industrial Standard.
The defrost time of a conventional heat pump is about 4 or 5 minutes.View full abstractDownload PDF (444K) -
Tomohiro NOMURA, Hisamoto WAKABAYASHI, Tsutomu HYODO1985 Volume 2 Issue 3 Pages 213-222
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSEffects of the sizes and the arrangements of the insulated fabrics (shell plates, frames and beams) and the boundary conditions of the shipside fabrics, on the insulation performances of the insulated walls of refrigerated cargo hold have been investigated. The coefficient of the overall heat transmission, the inside temperature distribution, the isothermal line and the heat flow through the insulated wall, which are calculated by numerical procedures using the Finite Element Method, were adopted in order to evaluate the degree of the influence on the insulation performance.
By performing the experiments with the refrigerated wall models, by the measurements of the insulation performances, with the practical refrigerated cargo holds, and by the simulation regarding the insulation performance, the effects of the variations in all the individual items given above as well as the hardwears such as lug pieces, steel pieces and fitting bolts were clarified quantitatively. In addition to these results, it was shown that the coefficient of the overall heat transmission of insulated wall with the complicated construction in the directions of three dimentions can be calculated numerically by applying the two dimensional FEM to the some divided cross sections of the wall.View full abstractDownload PDF (450K) -
Yozo SAWAKI, Namie YASUDA, Susumu OHSHIMA, Tadashi KAWASAKI1985 Volume 2 Issue 3 Pages 223-230
Published: 1985
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSIn order to evaluate the fatigue strength of brazed part of copper tube for refrigerant piping use, experimental study has been carried out on the specimens, 1) having different grain sizes produced by heat treatment in furnace, 2) socket jointed copper tube, and 3) flange joint type, prepared by different brazing conditions such as torch brazing and furnace one, with different filler metal.
It is found that the fatigue strength decreases with the increase of grain diameter. And linear corelation is obtained between the fatigue strength and the reciprocal square root of the grain diameter. The reduction of fatigue strength of brazed part, can be explained successfully by both effects of the grain growth due to brazing and the stress concentration induced by the geometrical change in dimension at the drazed part.View full abstractDownload PDF (400K)
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