Because of the phase-out CFC Freon series required by Montreal Protocal, the conversion to HFC alternatives for vapor compression refrigeration system have been in progress. The each component design of these system should need to be reassessed, however, to improve the performance and compactness of the evaporator, an influence of the refrigerant oil on the refrigerant side heat transfer remains as an important and unsolved subject.
In this article, the previous research progresses on the thermophysical properties, two-phase flow regimes and heat transfer in evaporator tube of refrigerant and oil mixture are briefly reviewed and the ability of these results to the combination of the alternative refrigerant and oil system is discussed.
According to the review, the limited quantitative agreements were obtained from the perfect miscible refrigerant and oil mixture and, in particular, the much detailed research on the heat transfer mechanisms are required in future.

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Life and death judgement of a clam by appearance is in a great difficulty. This paper describes an measurement of an electrical pulse generated from clam heart and makes a catch of it on the shell surface of clam.

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The present work investigates the cold heat-release characteristics of the solidified oil droplets (tetradecane, C₁₄H₃₀, freezing point 278.9 K)/water solution emulsion as a latent heat-storage material having a low melting point. An air bubbles-emulsion direct-contact heat exchange method is selected for the cold heat-results from the solidified oil droplet-emulsion layer. This type of direct-contact method results in the high thermal efficiency. The diameter of air bubbles in the emulsion increases as compared with that in the pure water. The air bubbles blown from a nozzle show a strong mixing behavior during rising in the emulsion. The temperature effectiveness, the sensible heat release time and the latent heat release time have been measured as experimental parameters. The useful nondimensional emulsion level equations for these parameters have been derived in terms of the nondimensional emalsion level expressed the emulsion layer dimensions, Reynolds number for air flow, Stefan number and heat capacity ratio.

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In the recent years double effect cycles have gathered a lot of attention because of their good efficiency particularly fitting with preoccupation of energy saving and with recent environmental problems. Simulation studies on double effect absorption cycles for refrigeration purposes have been performed for H₂O/LiBr fair. The purpose of this study is the objective for evaluating the possibilities of effectively utilizing waste-heat as a secondary heat source for the low temperature generator. The efficiency of the different cycles have been studied and the simulation results show that higher coefficient of performance could be obtained for standard parallel cycle (TYPE PA). The optimum designs and operating conditions were determined based on the operating conditions and the coefficient of performance. The effectiveness of introducing a waste-heat source of about the same temperature level as the low temperature generator is demonstrated. If the cycles are assisted by fuel cell waste-heat, the input of waste-heat to low temperature generation parallel cycle (TYPE PB) yields highest COP.

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The evaporation of HCFC141b, HFC152a and HFC23, and non-azeotropic refrigerant mixture used at the very low temperature refrigeration system is experimentally studied in a horizontal spirally grooved tube with corrugation.
The experiments were conducted at 0.03 to 0.47MPa of boiling pressure, 100 kg/(m²s) of mass flux, 1 to 15 kW/ m² of heat flux, -26 to 21 °C of refrigerant temperature and 11.4 mm of average inner diameter.
It is concluded that boiling heat transfer coefficients of single-refrigerant are higher than these of non-azeotropic refrigerant mixture. And dimensionless correlation of the heat transfer coefficirnts, i.e. Lockhart-Martinelli parameters agreed with equation (10) within the limit of ±40 percent. Pressure drops of these refrigerant mixture depend on its liquid density and flow pattern.

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An experimental study has been performed to investigate the freezing characteristics of an aqueous binary solution droplet on a cooled wall. Pure water, ethylene-glycol aqueous solutions of 1to 10 mass%, and NaCl aqueous solutions of 1 to 15 mass% in concentration were adopted as the testing solutions. The droplet was frozen under a variety of cooling conditions such as wall temperature, air temperature, air velocity, and solute concentration in both the static atmosphere and the cold air flow. The observations on both the freezing characteristics and the morphologies of the droplet were extensively carried out. In addition, the inside flow of the droplets were observed. It was found that the morphology of the droplet on the cooled wall varied markedly depending on the solution, which appears to be mainly caused by the difference in the surface tension of the solution. On the other hand, under the conditions with a cold air flow, initial freezing point of the droplet was found to be mainly owing to the cooling rate between the cooled wall and the cold air.

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Supercooling characteristics of three kinds of organic water solutions (D-Sorbitol, Glycerol, Glucose) in a forced flow were investigated experimentally. The critical condition of ice nucleation in a cooled circular tube was examined for concentration of water solution and cooling temperature under various Reynolds numbers. It was found that the flow velocity and cooling temperature conditions in a laminar flow region. However, in a turbulent flow region, the critical degree of supercooling was influenced by the flow velocity and cooling temperature. As a result, non-dimensional correlation equations for the critical condition of ice formation were derived in the laminar and turbulent flow region as a function of some non-dimensional parameters. While the ice making efficiency of D-Sorbitol water solution was measured under various Reynolds numbers and cooling temperature conditions on the stable supercooling condition. The ice making efficiency of supercooled organic water solution was influenced by the degree of the supercooling based on the mixed organic water solution temperature at the outlet of the inner tube.

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The passages of vapor flow and the returning liquid flow are perfectly partitioned in a separate type thermosyphon. Therefore the flooding limit can be eliminated and practicability based on its construction is highly evaluated. The carry-over of the liquid into the condensing section accompanied with the rising vapor flow should be avoided in the separate type thermosyphon, since it causes to decrease the heat transfer coefficient on the heat transfer surface in the condenser.
In the present work, the effect of liquid level, the heat input into the evaporating section, the charging rate of the liquid, and the dimension of the adiabatic section supposed on the generation of carry-over were studied experimentally.
The frequency of the bumping and the velocity of the vapor in the adiabatic section were examined as the function of the termination of the carry-over. The experimental correlation representing the relation among the elapsed time, the liquid temperature and the charging rate of the liquid were also derived.

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The protection of environment is becoming a grave problem nowadays and an absorption refrigerator, which does not use fleon as a refrigerant, is acquiring a close attention. Among the absorption refrigerators, a number of ammonia-water absorption refrigerators are being used in realm such as refrigeration and ice accumulation, since this type of refrigerator can produce below zero degree products.
It is essential to conduct an investigation on the characteristics of ammonia-water absorption refrigerator in detail by means of computer simulation in order to realize low cost, highly efficient operation. Unfortunately, there have been number of problems in order to conduct computer simulations. Firstly, Merkel's achievements of enthalpy diagram does not give the relational equations. And secondly, although relational equation are being proposed by Ziegler, simpler equations that can be applied to computer simulation are yet to be proposed.
In this research, simper equations based on Ziegler's equations have been derived to make computer simulation concerning the performance of ammonia-water absorption refrigerator possible-Both results of computer simulations using simple equations and Merkel's enthalpy diagram respectively, have been compared with the actual experimental data of one staged ammonia-water absorption refrigerator. Consequently, it is clarified that the results from Ziegler's equations agree with experimental data better than those from Merkel's enthalpy diagram.

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Although most of the absorption refrigeration/heat pump systems use LiBr/H₂O solution for absorbent/refrigerant pair, there exist only a limited number of reliable sets of data on the bubble-point pressures of LiBr/H₂O solution. The objective of the present study is to reveal the concentration and temperature dependence of bubble-point pressures of LiBr/H₂O solution over a wide range of parameters so as to provide more precise set of thermodynamic property data for advanced design of the absorption refrigeration/heat pump equipments.
A total of 44 bubble-point pressures have been measured along seven concentration isopleths of 20, 30, 40, 45, 50, 58 and 60 wt%LiBr solution which cover the range of temperatures 283-413 K and of pressures up to 300 kPa. The experimental uncertainties of temperature, pressure and concentration measurements were not greater than ±20mK, ±0.1 kPa and ±0.1wt%, respectively.

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This paper investigates a heterogeneous nucleation of supercooled water on a heat transfer surface. The ultra pure water in an acrylic tank is cooled by the upper side heat transfer disk and freezing temperatures are measured where the cooling rate and a material and a surface roughness of heat transfer surface are varied. The property of the heat transfer surface is known to be explained by a surface parameter. We assume that the supercooled water will freeze when the number of nuclei in the supercooled water reaches 1. Freezing temperatures are calculated using the surface parameters and the experimental results are compared with the calculated results. Freezing temperatures are dependent on the material and the surface roughness of the heat transfer surface, while the dependence of the cooling rate of the surface is very little. We will be able to predict the freezing temperature of the supercooled water by measuring the surface parameter of the heat transfer surface experimentally.

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This study presents a new adsorption material type humidifier for automobiles, in which the moisture in the outside air is adsorbed onto a solid desiccant material and the adsorbed water is then used as the humidifying source for the interior air of the car, that is, no additional water supply for humidification is required. The new humidifier was installed in a test car under actual conditions, and the humidification performance and the interior air quality, as determined by CO₂, O₂, dust concentration and SnO₂, output, were measured. A comparison between the data for the new humidifier and those for an ultrasonic humidifier showed that the humidification ability was adequate but the interior air quality was far better when the new humidifier was used. Finally, the results of longevity tests, repeated adsorption/desorption tests and acid-gas poisoning tests are presented.

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