The Vuilleumier (VM) cycle machine is realized as a regenerative and external-combustion machine in the same way as a Stirling (ST) cycle machine. In the VM cycle, heat enters the cyc1e from hot and cold temperature heat sources and is delivered to an intermediate temperature heat source by a working gas. In consequence of the theoretical cycle, output power is not produced. The VM cycle machine is made of the same elements as the ST cycle machine and also closely connected with the ST cycle machine in its working principle. By means of analysis using an isothermal model, it is found that the VM cycle machine is internally divided into a ST engine and a ST refrigerator. In addition, the calculated results by a simulation model based on a so-called 3rd-order method clarify that the VM cycle machine has different featuers from the ST cycle macine with regard to the working gas behavior, the energy flow and the performance depending on the revolution speed. Application of the VM cycle machine to a heat pump for heating and cooling takes effect on the environment and energy problems arising on a terrestrial scale. In reacent years, research and development have been making on the VM haet pumps.

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There is a lack of information about vapor-liquid two-phase flow patterns determined using void signals in high temperature generator of absorption chiller/heater. Sensing void fraction has been hampered because lithium bromide aqueous solution of strong alkalinity is employed as working fluid at high temperature and high level of vacuum.
New void sensor applicable to such difficult conditions was developed. The void Fractions at 48 locations in a high temperature generator were measured simultaneously in both cooling and heating operations.
Analysis of void signals detected reveals that the most violent boiling occurs at the upper part of rear plate of combustion chamber and the first line of vertical tubes located in the flue. The flow patterns are strongly affected by the system pressure difference between the cooling and heating operations: there appear bubbly, slug and froth flows in the cooling operation, but only bubbly flow in the heating operation.

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Experiments have been performed to investigate the effect of air-flow rate in clearance between the insulation and the wall on the temperature distribution, moisture accumulation, and heat flux. Glass-wool, whose thickness is 100mm and whose density is 16kg/m³, is adopted as a testing material, and the heating surface of the glass-wool and cooled-wall temperature are 25 and -15°C, respectively.
The clearance between surface of glass-wool and cooling walls is 20mm, and inlet air velocity ranges from 0.2 to 1.0m/s. A s a result of the present investigation, it is observed that an increase in both air velocity and cooled-wall temperature causes the decrease in moisture accumulation and heat flux within the glass-wool and that inlet air temperature become very important for evaluating performance of insulation.

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Enhancement of evaporation heat transfer is required for saving energy and making compact evaporators of air conditioners. Although internal grooves are widely used as means to improve the heat transfer performance of tubes, their optimum shape and spiral angle have not been clarified. In our long-term research program, a rectangular channel is used instead of circular tube because this geometry will allow for a better control of the groove shape in future studiesu. In this paper as a first report, characteristics of the evaporation heat transfer and pressure drop inside a rectangular channel with smooth surface have been studied by using HCFC22 as a working fluid. The experimental results are compared with experimental results for a smooth tube and with already existing equations. The rectangular channel, 10mm in width, 5mm in height, and 300mm in 1ength, was set horizontally, and the upper and lower surfaces were heated electrically with Nichrome heaters. Evaporating pressure was 0.49MPa, vapor quality was varied from 0.1 to 0.9 mass velocity was varied from 86 to 345kg/(m²s), and heat flux was varied from 2.33 to 9.30kW/m². Average heat transfer coefficient of the upper and lower surfaces compared well with the predicted values except for low mass velocity region where the heat transfer coefficient of the upper surface was much lower than that of the lower surface. Pressure drop of the rectangular channel was found to be close to that of the smooth tube for a given mass velocity.

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An anlytical and experimental study was performed to determine the characteristics of marine icing on a horizontal circular cylinder immersed in a cold air stream with seawater droplets. The formation of the ice-accretion formed on the cylinder were extensively observed. Considering heat, mass, and salt concentration balances, an analytical model was determined based on the observation of icing phenomena. Experiments and calculations were carried out under a variety of parameters such as air temperature and air velocity. It was found that the analytical results were unexpectedly in good agreement with the experimental ones under conditions that air velocity was smaller than 10m/s.

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This research was to investigate numerically the effect of temperature distribution due to natural convection on appearance of ice in water independent of the heat transfer surface. Two kinds of models were chosen and compared. One was a model without convection which illustrates the case of cooling from the top of the water container. The other was with natural convection which illustrates the case of cooling from the side. Cooling from the side was chosen since it accelerates the heat transfer and gives stratified temperature distribution.
Comparatively with the case of cooling from the top (without natural convection), it was found that, in the case of cooling from the side, if the geometric aspect ratio is low the water near the surface having a higher degree of supercooling diffused away from the surface and caused to reduce the probability of ice appearance in water. In contrast with the above result, in the case of aspect ratio between 2.0 and 8.0, the probability was increased. This phenomenon was due to the acceleration of heat transfer and temperature stratification, as mentioned above.

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To predict performance of a refrigerating cycle it is effective to use a computer simulation program which employs mathematical models of the cycle components. This paper describes a mathematical model of a rotary compressor which can expersses transient behavior of the compressor with variable operting speed. The compressor is divided into two control volumes and two control bodies, and the model is expressed by six governing differential equations on specific enthalpies of refrigerant in the control volumes, mass flow rates of refrigerant delivered from the volumes and temperatures of the bodies. Simulation results and experimental data are favorably compared for transient behaviors of the compressor under wide operating speed range. The model developed will be effectively integrated into cycle simulation of dynamic responses of inverter driven heat pumps.

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As for the automotive air conditioner, (1) to keep the automotive cabin temperature in a comfortable region, (2) to improve driving feeling, (3) to drive the air conditioning system economically through all seasons, are universally required. Recently, from these points, compressors with variable capacity control mechanism for automotive air conditioners have been remarkably requested. We have developed a scroll comoressor with variable capacity control mechanism. The capacity control mechanism, which changes the channel area of the bypass hole continuously, according to the suction gas pressure and the discharge gas pressure, has been developed.
In this report, we describe the mechanism of variable capacity control and the performance simulation program that has been developed for the scroll compressor.
Further, we describe the measuring results of cylinder pressure behavior, the results of energy loss analysis and the effect of comfort, drivability, power saving in the refrigerating cycle using the developed capacity control compressor.

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The paper describes measurements of the vapor pressure for the solutions of HCFC-123 and naphthenic base oil. The vapor pressure has been measuered for the range of temperatures from 293.15 K to 353.15 K and pressures up to 0.49 MPa. The composition of HCFC-123 in the liquid phase ranges from 28.6 wt% HCFC-123 to 100 wt% HCFC-123. The uncertainty of the measurements is estimated to be ±10 mK in temperature, ±5 kPa in pressure and ±0.82 % in composition, respectively. The results have been correlated in two different ways for practical use. The measurements reveal that the solutions of HCFC-123 and naphthenic base oil have no phase separation within the range concerned here.

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The cryoprotective effect of sorbitol (0.5M) and monosodium glutamate (0.3M) was examined on the freeze denaturation of carp myosin B filaments by observing the morphological changes in electron microscopy. Myosin B in the presence of 0.1 or 0.6M KCl was stored at -8°C that was higer temperature than the eutectic point of KCl and provided the concentrated KCl solution for causing the filamentous structure to deform. In the case of frozen storage in 0.1M KCl, the deformation of myosin B filaments was protected with both cryoprotectants. In the case of 0.6M KCl with monosodium glutamate, the deformation of the filaments was prevented. However, the granular matters deformed from myosin B were observed to some extent in 0.6M KCl with sorbitol. Morphological changes of the filaments in the electron microscopy agreed with the changes in biochemical properties of myosin B.

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