This paper deals with reviews for research and development of a dynamic-type ice thermal storage system. This system has three main features. First, the ice thermal storage tank and the ice generator are separate. Second, ice is transported to the tank from the ice generator by water or air. Third, the ice making and melting processes are operated at the same time. Outlet water temperature from the dynamic-type ice thermal storage tank remains low for a longer time. In this paper, dynamic-Type ice thermal storage systems are divided into three parts: the ice making part, the ice transport part, and the cold energy release part. Each part is reviewed separately.

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Heat and mass transfer coefficients during ammonia gas absorption into a falling liquid film formed by distilled water on a horizontal tube were obtained experimentally. The test absorber consists of 200 mm i.d., 600 mm long stainless steel shell, a 1 7.3 mm o.d., 14.9 mm i.d. stainless steel test tube with 600 mm working length mounted along the axis of shell, and a 12.7 mm o.d. pipe manifold of supplying the absorbent. In this paper, it was clear that heat and mass transfer coefficient could be enhanced by increasing the flow rate of absorbent and temperature difference between inlet absorbent and ammonia gas, also heat driven by the temperature difference have an effect on heat transfer of the fa1ling liquid film and mass transfer of vapor side. And the new correlation of heat transfer in dimensionless form was proposed by the temperature difference which was considered heat driven of vapor and liquid film side using a interface temperature of vapor and liquid phase. The new correlations of mass transfer on a interface of vapor and liquid phase in dimensionless form were proposed by using effect factors could be suppose from absorption phenomena.

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In recent years, the heating value of CPU has been increasing rapidly in proportion to the improvement of computer performance. Therefore computer industry is requiring the new cooling unit having high cooling performance for CPU adaptable to high heating value and high heat flux. In the past the cooling unit for CPU is used with air-cooling aluminum fin, but it can not be adaptable to high heating value. We have developed a new compact boiling refrigerant type cooling unit for CPU having high cooling performance in comparing with air-cooling aluminum fin. This paper described the cooling performance and pressure drop characteristics of the boiling refrigerant type cooling unit for CPU. The characteristics were clarified by testing the cooling unit under various test conditions, which were different Reynolds number, various sizes of cooling unit and various inclination angles. Furthermore the equations to predict cooling performance and pressure drop which are necessary on design of the cooling unit were proposed.

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This paper deals with the drag coefficient of solidified hexadecane particles and their free rising velocity in liquid. The drag coefficient was experimentally investigated in Reynolds number range of about 40-300. The present experimental results are summarized in the following; (1) the drag coefficient of solidified hexadecane particles formed in liquid coolant by direct contact cooling is higher than that of a smooth surface sphere, this high drag coefficient seems to be attributed to the non-smooth surface of the solidified hexadecane particles, (2) experimental correlation for the drag coefficient of the solidified hexadecane particles was proposed, (3 ) the measured rising velocity of the solidified hexadecane particle agrees well with the calculated one, (4) the drag coefficients of hexadecane particles that were made by pouring hexadecane liquid into a solid hollow sphere agreed well with the drag coefficient of smooth surface sphere.

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Energy-efficient adsorption systems, such as adsorption heat pump, desiccant cooling, humidity control system, and so on, are expected as a energy exchange process because they are able to utilize low temperature exhaust heat. As an adsorbent for such systems, materials with large adsorption capacity in the pressure range of practical operation are preferable. To enable the design and synthesis of materials with large heat storage capacity, the pore structure of adsorbents should be optimized for each systems. In this paper, we synthesized ordered mesoporous silica (MPS) with an arrow pore size distribution of around 2nm by a solvent evaporation method and evaluated their water adsorption properties. The adsorption isotherms for MPSs showed steep increase at a relative humidity corresponding to their pore size. Since MPSs have a large adsorption capacity than conventional materials in the relative humidity region of practical operation, they are expected for new adsorbents for energy-efficient adsorption systems.

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The relationship between the ice polycrystalline structure and the dielectric properties of a frozen gelatin gel were investigated. The Micro-Slicer Image Processing System (MSIPS) was applied to measure the diameter, the perimeter density and the number density of ice crystals. The dielectric property of frozen gelatin gel at various freezing rate was measured in the frequency range of 100Hz to 100kHz at –40°C. The characteristic value of dielectric property, σ₀ and ε₀-ε_∞ have good correlation with structural parameters of ice crystals, such as diameter, perimeter density and number density, while other characteristic value, the relaxation time, τ has no relation to the structure of ice polycrystalline. The resu1ts showed that the possibility of non-destructive measurement of ice structure by dielectric property.

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This paper shows an influence of evaporative cooler at the inlet of regeneration air stream of an adsorptive desiccant cooling process on the cooling/dehumidifying performance. This evaporative cooling was expected to cause humidity increase in regeneration air reducing the dehumidifying performance of the honeycomb absorber, while the evaporative cooling plays an important role to produce a lower temperature in supply air. Two different airs to be used for the regeneration of the desiccant wheel were considered. One was fresh outside air (OA mode) and the other was air ventilated from the room (RA mode). Experimental results showed that the amount of dehumidified water obtained at the process without water spray evaporative cooler was actually larger than that of process with water spray evaporative cooler. This behavior was mainly due to increase of humidity or relative humidity in the regeneration air as expected. However, temperature of supply air produced by the process with the evaporator was rather lower than that of the other because of the cooled return air, resulting higher CE value. Regarding the operating mode, the evaporative cooler at the OA-mode was no longer useful at higher ambient humidity because of the difficulty of the evaporation of the water in such high humidity. It was also found that its dehumidifying performance was remarkably decreased at higher ambient humidity and lower regeneration temperature since the effective adsorption capacity at the resulting high relative humidity of the regeneration air decreased.

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The pulse-tube cryocooler doesn't need moving parts in the expansion space and it is an advantage such as a low vibration and high reliability. On the other hand, in order that the pulse-tube cryocooler perform compression and expansion with a gas piston unlike other cryocoolers which have a solid piston, it is tended to influence the cryocooler performance by operating condition. When the low temperature part of the expander is in the top from the ambient temperature part, natural convection occurs by the influence of the gravity and a cooling capacity decreases greatly. We have developed the Stirling-type pulse-tube cryocooler ‘WE-SP2000’ with cooling capacity 4.6W at 77K for 200W input power for high-temperature superconductor devices and semiconductor sensors, but there have been demands a smaller size, a high efficiency and higher reliability and needed further improvement. This paper describes an examination that was done of the efficiency improvement due to the change in the pulse-tube size and 24% of a cooling capacity has improved as a result. Furthermore, the influence of the inclination exerted on the cooling capacity for differences in expander form was examined.

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