The predictive methods of thermodynamic properties are discussed with respect to the halogenated hydrocarbons using as working fluids for refrigeration and heat pump cycles. The methods introduced into this paper can be calculated by the limited information; critical properties, normal boiling point and acentric factor. The results of prediction are compared with the experimental values of PVT property, vapor pressure and saturated liquid density. On the basis of these comparisons, Lydersen's method for predicting the critical properties, the generalized vapor pressure correlation by Ashizawa et, al., and Hankinson-Thomson's method for predicting saturated liquid density can be recommended. With respect to the equation of state, either Soave equation or Peng-Robinson equation is effective in calculating the thermodynamic properties except high density region.

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This paper concerns the development of a new plate-fin type evaporator and its heat transfer performance. This evaporator is characterized by the tank section at one side alone and 180-degree turn refrigerant path in each tube.
Experiments were conducted to determine the most suitable shape at the turn section for evaporative heat transfer performance. Some kinds of plate with V-shaped rib and X-shaped rib were manufactured by trial, then cooling performance and tube wall temperature distributions were measured. In addition, the refrigerant behavior in the tube was observed by the flow visualizing equipment.
As a result, it was found that evaporative heat transfer performance of the tube with X-shaped rib is superior to the tube with V-shaped rib, and the optimum turn clearance for heat transfer exists in the tube with X-shaped rib. The target of 15 % improved performance compared with the serpentine type and 8 % improved performance compared with the conventional plate-fin type was attained.

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The Present experiments were carried out on freezing of round type of yellowfin tuna / albacore to measure the internal pressure which causes gape and heave of frozen body during the CaCl₂ brine immersion freezing under outer pressure and to forstall these undue defects on frozen foodstuffs by the internal pressure. Both of the temperature and the internal pressure of yellowfin tuna / albacore were measured and recorded continuously by a temperature sensor and a pressure sensor during the freezing.
The results were that frozen body supported to resist against considerable pressure during the freezing under outer pressure and that gape of frozen body was created by the internal pressure during the freezing when the body had been coverd with many scales or could not be expanded during the freezing. The empirical result that the thick spherical body under outer and internal pressure like round type tuna stacked in a fish hold always caused gape and heave during freezing was theoretically supported. The internal pressure or stress of frozen bodies was released by a thermal equalizing process during freezing

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In order to get better heat transfer coefficient of absorption in actual apparatus, it is considered that the wettability of the surface should be high, and that the thickness of liquid film should not be too thin or too thick all over the surface. So, new conception of two-dimensionally constant curvature surface (CCS) for absorption heat transfer has been introduced for the first time by the authors.
First, theoretical CCS section curves of CCS tubes were calculated, and some of them were manufactured for the test.
The wettability of CCS is tested and compared to the other finned tubes (radial fin tubes of triangular and rectangular profiles). As may be seen from photographs and compared to the other finned tubes, on the CCS surface, the thickness of liquid has shown to be even all over the surface without creating paticulary thick or thin place, so that, liquid films are very wettable on the CCS surface.

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The following are concluded for the High Discharge Swirl Atomizer, through theoretically analyzing liquid film disintegration, analysis and experiment for a liquid immersion process, and the measurement of liquid film thickness.
(a) A new liquid immersion process is developed, presenting the method of determining a mean droplet diameter.
(b) Empirical formulae are given for the atomization characteristics and discharge characteristics with the figures of a swirl atomizer.
(c) Empirical formulae are derived from the film thickness-atomization characteristics, and atomization characteristics are summarized, proposing a mean droplet diameter nomogram widely applicable to a swirl atomizer.

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It is highly essential to create a high performance drying technology from the viewpoint of energy conservation. Recently the drying process using superheated steam has received a great attention for improving the energy efficiency of the conventional air drying processes. Many other advantages of this superheated steam drying include its inert atmosphere, enhanced drying rate, improved product quality and easier control.
This study presents a new concept of superheated steam drying in which the absorption temperature amplifier is effectively applied in order to recover the waste heat with high efficiency. A feature of this new drying system is that, owing to a closed circuit dryer, the consumption of heating energy decreases by approximately 50% of the conventional noncirculated one, and the superheated steam conventionally discharged so as to maintain the pressure of the dryer at an atmospheric one can be reused as heating energy for the generator of the absorption temperature amplifier. In the 1st report, thermal performances of this proposed system have been analyzed by a computer simulation developed for the solar-assisted absorption heat transformer model at the steady-state operating condition.
It may be fair to conclude that this drying system satisfies the desired operating conditions, although it involves some problems to be solved further in detail in future.

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In this study, a phase change process in heterogeneous composite materials which consist of water and coiled copper wires as conductive solid is investigated by four kinds of typical calculation models : 1) model-1 in which the effective thermal conductivity of the composite material is used, 2) model-2 in which a fin metal acts for many conductive solids, 3) model-3 in which the effective thermal conductivities between nodes are estimated and three-dimensional calculation is performed, 4) model-4 proposed by authors in the previous paper in which effective thermal conductivity is not needed.
Consequently, model-1 showed the phase change rate considerably lower than the experimental results. Model-2 gave the larger amount of the phase change rate. Model-3 agreed well with the experiment in the case of small coil diameter and relatively large Vd. Model-4 showed a very well agreement with the experiment in the range of this study.

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Experiments were carried out to examine the effects of a single porous-type roughness element on the insulated wall opposite the smooth heated plate for the heat transfer. Local heat transfer and drag coefficient depend on the porous diameter and the porosity. Local heat transfer coefficient takes a peak P1 under the porous element in laminar flow. On the other hand, in turbulent flow, it takes two peaks P1 and P2 under and after the element, respectively. The position of the peak P2 varies with the height of the element and the Reynolds number. The drag coefficient of the porous element is lower than that of the solid element. According to thermal performance this kind of element should be used in laminar flow. It is estimated that the porous element should be utilized in the composite effects of heat transfer in order to apply the element effectively.

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A closed-loop two-phase thermosyphon can transport a large amount of thermal energy with small temperature differences without any external power supply. A fundamental investigation of flow and heat transfer characteristics was performed experimentally and theoretically using water, ethanol and R113 as the working liquids. Heat transfer coefficients in an evaporator and a condenser, and circulation flow rates were measured experimentally. The effects of liquid fill charge, rotation angle, pressure in the loop and heat flux on the heat transfer coefficients were examined. The heat transfer coefficients in the evaporator and the condenser were correlated by the expressions for pool boiling and film condensation respectively. As a result, the heat transfer coefficients in the evaporator were correlated by the Stephan-Abdelsalam equations within a±40% error. Theoretically, the circulation flow rate was predicted by calculating pressure, temperature, quality and void fraction along the loop. And, the comparison between the calculated and experimental results was made.

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Vapor pressures of aqueous solutions of ethylene glycol are measured in the range of temperature from -10 to 60°C and concentration from 20 to 50wt%. In a low concentration range, the measured values of vapor pressure decrease according to the Raoult's law independent of temperature, while in a high concentration range, they show a trend to decrease towards the estimated values of freezing point with decreasing temperature. The following correlation equation is obtained for practical calculations on heating towers and the like.
log(p/P₀) = 5.351 - 6.4×10^-4y + (1817 + 0.008y(y + 10))/(t + 240)
where p, vapor perssure of aqueous solutions of ethylene glycol [kPa] ; P₀, atmospheric pressure [=101.325kPa] ; y, concentration [wt%] ; t, temperature [°C].

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