The k-ε algebraic stress model was systematically compared with the Mellor-Yamada model to verify its possibility in atmospheric applications. Both were applied to the Lagrangian particle transport simulation over the complicatedly undulated terrain in Kyoto (60×60×3km). The k-ε algebraic stress model reflected the complicacy of the terrain and evaluated the mixing layer height and the turbulent energy flux higher than the Mellor-Yamada model.

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One of the calculating methods for the estimation of the collection efficiency of a cyclone dust collector is basing upon the cut sixe Xc and the particle size distribution R (Xp). In order to consider the separation process of the fine solid particles in the centrifugal flow field, it is necessary to estimate not only the particle size XB on the mechanical equilibrium state of the solid particle between the centrifugal force Fc and the Stokes drag force Rd but also the radial distribution of the particle concentration. Then in this paper, the correlation between the experimental results of the particle concentration and the calculated results of the diffusion equation of the particle concentration by finite difference method with explicit technique was discussed in detail. The diameter of the cyclone was D1=290mm, the test dust was fly-ash of the mean diameter X50=17.5μm and the mean inlet velocity Vo in the tangential inlet pipe of the diameter Do=50mm was Vo=5.0,9.0 and 15.0m/s, respectively.

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A cyclone dust collector is very simple construction and it is easy to maintain and control. Therefore it is used widely in many industries. In this paper the collection efficiency depended on the feed particle concentration and the presser drop of pure gas flow ware investigated for the Potential Flow Type in axial flow cyclone dust collector with fixed guide vanes. The boss shape of potential flow type is calculated with complex potential flow functions. The feed particle was fly-ash of the mean size Xp50=5.59 (μ m). The feed particle concentrations ware Co (g/m3)=2.5 5.0 7.5 and 10.0.

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Uni-flow cyclone dust collector is applied to the separation of particles from air and gases. This equipment could not be expected a high collection efficiency. So in this report, effect of secondary jet was investigated to promote separation efficiency. And its collection efficiency and the pressure drop depended on the velocity of secondary jet as a variable were measured. Velocity V_2 of secondary jet was determined as 13.7,18.5,23.8,27.0 28.4 (m/s), and velocity V_1 of main flow was determined as 3.0,6.0,9.0,12.0,15.0 (m/s). Therefore in this report, the boss diameter was Db=47 (mm), the form of guide vane was plate type of fixed guide vane. and dust was used Fly-Ash, the average particle diameter was X_<50>=5.57 (μ m). and the dust was measured by Andreasen pipette method, This experiment was acted the condition.

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A method to making ice slurry is one of key technology for cold-energy storage system. This study has been conducted to clarify the production of ice slurry by utilizing constitutional supercooling promoted by mixing of two aqueous solutions whose solute concentrations are different. In this technique, fine ice crystals are made under volume-catalyzed nucleation without heat transfer surface. In the experiments, cooled sucrose solution and water were mixed in the cylindrical vessel, and the ultrasonic vibration was applied to promote nucleation in the supercooled solution. It is found that the ice making process is classified into three characteristic pattern; stable ice making, concentration stratified type ice making, and no ice making. The characteristics of ice making were discussed with the mixing ratio and total flow rate of solutions.

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Dynamic-type of ice-making cold thermal energy storage systems using water-silicone oil emulsion with an additive, (C_2H_5O)_3SiC_3H_6NH_2,has been proposed. Two kinds of heat exchanger were examined and the performances were compared. One type of heat exchanger was a spiral tube and it was immersed in a low temperature thermostatic bath. The other was coil-shaped double tube heat exchanger using two tubes. The emulsion was circulated to make ice continuously. These systems were operated under various cooling conditions (flow rates of the emulsion and brine temperatures). The effects of the tube materials (fluororesin and non-fluororesin) and thickness were also examined. Slurry ice can be formed continuously without adhesion of ice to the cooling wall under certain conditions. Using the fluororesin tube prevents ice from the adhesion and make it wide that the range of the cooling conditions under which slurry ice was formed continuously. Furthermore, making thickness of a tube thin and accelerating heat transfer enable to make ice continuously without lowering rate of ice formation at a higher brine temperature.

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Freezing phenomenon of the water in which air dissolves has been investigated experimentally. Ice layer formed depends on the freezing rate and was divided into three patterns; ice layer involving many small bubbles, ice layer involving muscle-shaped bubbles and transparent ice layer. The effect of additives on trapped and swept phenomenon of air bubbles due to freezing from the viewpoint of electric interactive force. It was found that the critical freezing rate (the maximum freezing rate that air bubbles are swept from the frozen layer) rapidly increased with increasing the concentration of the water solution of [CH3(CH2)15N(CH3)3]Cl. From these results, it became clear that the critical freezing rate strongly depends on the electric double layer force.

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Melting process in packed beds of ice particles (with 0.2mm mean diameter) which were formed from supercooling ethylene glycol aqueous solution (2wt%) was investigated experimentally and numerically. The packed beds had the circular passage of 38mm diameter at first. The ethylene glycol aqueous solution was sprayed on water layer above the beds. The solution flowed downward in the passage and melted ice at the surface of the passage. The temperature of the solution at the outlet of the passage and the shape of the passage were measured as a function of time for different flow rates (2.0L/min and 3.0L/min). The time average value of local heat transfer coefficient was estimated. From the experiment, it was found that the local heat transfer coefficient had a maximum at upside of circular passage. Comparison between the experimental and numerical results indicated that actual area of heat transfer surface is about ten times larger than the surface area of the smooth passage because of the increase in the contact surface between the solution and ice particles.

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A new district cooling system utilizing ice/water slurry (new DCS) has been proposed and it may take the place of the usual district cooling system utilizing cold water only. In this work, a pilot plant of the new DCS was built using the elemental apparatuses developed so far and, performance tests were made. It is important to take out ice of the tank at a desired rate irrespective of the Ice Packing Fraction (IPF) in the tank, and to keep the ice fraction constant through the pipeline network in the DCS so that high quality and high density cold energy is supplied to the users. After some improvements of the form of the ice storage tank, ice fraction control system and so on, the continuous operation test of the pilot confirmed that the cold energy is supplied steadily to the demand side by the ice/water slurry system.

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According to the popularization of air conditioners, maximum power consumption in summer is increasing year by year. Ice thermal storage system is expected to level the "maxmums". SANYO Electric Air Conditioning Co., Ltd. And Tokyo Electric Power Company cooperatively developed ice thermal storage commercial air conditioning system ECO ice mini "ECO mini guppy". The feature of the system is integrated outdoor unit which conventional outdoor unit and thermal storage tank are combined into one unit. Since the unit was improved, it is as easy as ordinary commercial air conditioner in installing the unit. By using new refrigerant R410A, the unit is environmental friendly. Comparing with non-ice thermal storage system, the unit is energy-saving and can decrease about 35% of rated power consumption in cooling operation.

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In recent years, the penetration of air conditioners and office automation facilities increase the electric power demand disparities among seasons and even for daytime and nighttime uses in Japan. Thus, the ice thermal storage air conditioners have been rapidly spreading to level the annual power load. Also, the needs of the HFC refrigerant, which has zero ozone depletion potential, are increasing from a viewpoint of ozone layer protection. The ice thermal storage multi-split system air conditioner utilizing the HFC refrigerant, R407C, has been developed to contribute power load-leveling and energy saving. In this paper, the technical features of the new ice thermal storage multi-split system air conditioner are clarified.

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In order to clarify the cooling heat transfer characteristics of CO_2 at a supercritical pressure condition, experimental approach was carried out. The experimental conditions were 9.5MPa for the system pressure and 20 to 70 ℃ for the fluid temperatures. Heat transfer coefficients were measured under the temperature range, and then it was found that the maximum value existed at the fluid temperature of about 45℃. Furthermore, CO_2/Oil mixture was also employed as the experimental fluid. the experiments revealed the heat transfer coefficient decreased by existence of lubricant oil. In order to understand the effect of the lubricant oil on the heat transfer coefficient, flow visualization was achieved through the view section made of acrylic resin tube. It was also clarified that the distribution of the oil changed with varying the fluid temperature, in other words, the flow property of CO_2.

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Desalination by solar stills is one of the most cost-effective methods for producing freshwater from seawater or wastewater. For enhancing the freshwater production rate, a transparent film coated with titanium oxide was applied to the condensing cover of the solar still. A comparative experiment using a solar still applied with the film as the cover and a conventional one with glass was conducted from November 2001 to January 2002 at Osaka. The water production rate of the solar still with the film averaged 750g-water/m^2/day, equivalent to 1.2 times higher than that of the conventional one, even in the winter season. This improvement could be explained by higher transmission coefficient for solar radiation and higher hydrophilicity of the film than that of glass.

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Recently a great deal of waste PET bottles has been accumulated in the stock yards without any management. In the other hand in the ceramic kiln furnace commercial grade LPG is generally employed as a gaseous fuel and used simply as a heat source. It is very useful and important to replace a part of gaseous propane with an alternative fuel such as PET-resin powder from the view point of energy saving and low environmental impact. In this paper based on physical and chemical properties of PET-resin powder, construction and dimensions of a ceramic burner suitable for twin fuel combustion are then designed to burn PET-resin powder as an auxiliary fuel, while gaseous propane is employed as a main fuel. By varying equivalence ratio under a constant combustion loading, combustion characteristics of the proposed ceramic burner are experimentally examined and analyzed by optical observation and measurements of temperature and composition.

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Recently, Construction of the waste processing system corresponding to resources circulation type society is demanded. In the inside of the framework, when the local governments draw up a waste processing master plan, they need to perform quantitative evaluation of environmental load. Then, we created the software that can perform evaluation by the TLCA method that our laboratory proposes. And the analysis result of the exhaust gas processing technology in an incineration institution is described.

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The life cycle inventory (LCI) of the electric power generation plays a vital role on LCIs of the industrial products. The objective of this study is to introduce life cycle assessment (LCA) method for Indonesian's electric power generation systems and to establish LCI for electricity grid mix of Indonesia, which would be databases for further LCA study. In this study, the main data are obtained from the Electricity Generating Authority of Indonesia (Perusahaan Listrik Negara, PLN), and the Independent Power Producers (IPPs) during fiscal year 1999 from April 1999 to March 2000. The result of this study could be useful for further LCA research on Indonesia.

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Life Cycle Assessment (LCA) has been gradually considered for its effectiveness in evaluation of environmental impacts LCA assesses environmental impacts over the entire life cycle of any products, process, or activities. The research focused on the LCA evaluation of grid electricity thermal power plant and hydro power plant in Thailand. The power plant inventory database has been developed and LCA-NETS method is used to analyze environmental impact of power plants in Thailand. Assessments indicate power plant performance and propose possibility to reduce environmental effect. The results could be useful for further development of Eco-Power generation systems in Thailand.

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The ELV (End-of-Life Vehicle) problem is one of important issue in Japan. Recycling ratio of the ELV is very low in the present. Therefore we proposed a new ELV inverse manufacturing plants where ELVs are efficiently dismantled and assorted into green parts according to the type of material. And we evaluated the whole ELV's LCA environmental impact including the plant by using the LCA-NETS method that we proposed. The results revealed that the inverse plant has much lower environmental load than conventional plants and that separating parts for recycling have a large effect on remarkable reduction environmental load.

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We developed Eco-Efficiency Potential Assessment Method, which assesses the sustainability of products or services by evaluating their environmental impacts and benefits, so that it would contribute to establishment of the sustainable society. It can integrate various environmental impacts into a single indicator in accordance with the concept of eco-efficiency. Its assessment policy, 'Potential Assessment', makes it possible to assess total environmental performance by using only manufacturing phase's data, ie. inputs to the produsts. These characteristics of the method will be a great advantage for users. We believe it is promising as a tool to support decision-making with its capability of extensive application from products to technologies for recycling and plants etc. As a case study, we conducted an assessment of electric rice cookers.

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Life Cycle Assessment (LCA) has been greatly paid attention to its effectiveness in evaluating environmental impacts through the lifecycle of any industrial products. In this paper we are focusing the evaluation of metal processing such as stamping, welding etc. during manufacturing process. The LCA-NETS method is used to analyze the environmental load of the process. As a result we propose optimum ecological manufacturing process of industrial products in manufacturing process, and develop Quality Function Development for Environment (QFDE), using NETS values as points of reference tor further development and refinement.

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"World Econo Move" is the event competing for the driving distance with the battery under an equal condition. We improved on the car in preparation for that event. As a result, we could increase the mileage at 1.3km compared to the last year. After than event, reviewing the way of the putting in hot water to heat battery up, the electric capacity increased about 3.0%. So we will increase the mileage at 2.0km compared to this year.

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In these years, there are many attempts at saving the impact on the environment in various fields. And we also need to be considerably improved the impact in private sector, including our everyday life. But, compared with the industrial sector, there are few effective approaches in the private sector because of unestablished assessment method. In this study, we attempted to suggest LSA (Life Style Assessment) as an assessment method to reduce the environmental load in our everyday life. We evaluated the environment load of individual's action using ELP (Environmental Load Point). And we examined environmental load curtailment effect of action improvement in everyday life.

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The recycling method of a plastic is evaluated as the applied usage of environmental utility potential evaluation technique E2-PA. The three kinds of the recycling method is energy recovery, material recycling, and oil-izing and those are compared. Supposing that a plastic for recycling is the mixture of PE and PVC, The renewable-resource intensity by each recycling method is computed and measured. As mentioned above, material recycling is advantageous when accuracy sufficient by machine sorting is acquired. However, considering the user-friendliness and the case where manual sorting is required, the profitableness of energy recovery or oil-izing is also fully considered.

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In environmental utility potential evaluation technique E2-PA, it is the quantitative evaluation technique of the environmental load which pursued and developed the standard nature as a decision-making support tool for a plan and a designer, and convenience. Comparison examination in consideration of the life cycle of the product which took part reuse, renewal, material recycling, etc., and the product which has not been taken in was performed. Moreover, the existing LCA technique also estimated the copying machine and it was compared with the evaluation result of E2-PA. As mentioned above, the validity of an inverse-system and the justification as the evaluation technique of E2-PA have been checked.

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The authors have already proposed a chemical heat pump using CaO/H_2O/Ca(OH)_2 reaction dryer (CHPD) for energy saved drying and confirmed that the CHPD unit produce hot dry air effectively in the heat-release step. In this paper, we examined the condensation heat utilization of the decomposed water vapor in the high temperature chemical heat-storage step to Ca(OH)_2 reactant bed. The results show that the refined CHPD system including the condensation heat utilization enhances the efficiency of drying process especially from the viewpoint of exergy.

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The energy consumption and resultant CO_2 emission of a commercial ice thermal storage unitary air conditioner are calculated by a simple simulation program which is based on its performance data released by its manufacturer, and hourly averaged cooling load and outdoor temperature data for an average office building in Tokyo. The result shows that the cooling mode of operation utilizing nighttime ice thermal storage is not energy saving in comparison with the conventional cooling mode of operation without thermal storage. This fact is also shown by discussion of energy consumption based on a criterion derived in this study.

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The ice thermal storage system has influence on energy consumption, especially the amount of one. In order to survey this effect, the amount of energy consumption was measured concerning two systems, the ice thermal storage system and the conventional one, in office building. As a result, the ice thermal storage system consumed 55% more energy in comparison with the conventional one. It is caused by the lower COP of the ice thermal storage system which drives under the condition of lower evaporating temperature than the conventional one. Through this actual survey, it became clear that the ice thermal storage system was not effective to energy conservation.

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The transport process of heat and water between air and soil surface was studied by a laboratory experiment and a one-dimensional multi-layer soil model. An insulated column (φ200mm, depth650mm) packed with soil (sand16.0%, silt33.8%, clay50.2%) was set up in an indoor laboratory. Soil characteristics needed for numerical simulations, such as matric potential, hydraulic and thermal conductivity, were preliminarily measured. Radiation influx to the soil surface was kept at a constant 155(Wm)^<-2> and wind speed was set at 0.8(ms)^<-1>. Air temperature was 10-15℃ in the 7-days experiment. Temperature and volumetric water content in the soil column at 30,45,60,100,160,260,460,and 650-mm depth were monitored. The experiment and numerical simulation showed that temperature and water content at the surface ranged from 11.5 to 13.5℃ and from 0.296 to 0.308m^3m^<-3>, respectively, depending on air temperature and humidity. While those at 460-mm depth remained constant at 11.0-12.5℃ and 0.301-0.308m^3m^<-3>. The average evaporation flux from soil to air was estimated to be 1.5×(10)^<-5>(kgm)^<-2>s^<-1>.

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There found many places where the concentrations of nitrogen dioxides (NO2) exceed the environmental air quality standard. The main sources of NO2 emission in urban area are the automobile mainly heavy duty trucks and the concentrations are high at main road intersections, underground parking lots and, bus terminal etc. To improve the air quality at these areas active air cleaning system are required. The Acid Gas Eliminator removes nitrogen dioxides at an efficiency as high as 80%, and simultaneously. It is also able to remove smoke and soot. To examine the efficiency of the compact gas purification system, numerical simulations of airflow and pollutant diffusion in a road were carried out for two dimensional and three dimensional numerical model. The simulated results show that the gas purifier works to improve the road side environment under low wind condition.

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The air pollution in a city region has not been improved fully yet. Especially, the rate of achievement of environmental quality standard achievement of NOx or SPM cannot yet grasp the tendency of an improvement in an urban area where the heavy traffic roads and the highways are concentrated. For this reason, autonomy and road administrator are planning to introduce air purifiers and investigating the effect of such facilities. This research aims to clarify suitable placement, performance assessment and improvement of compact air purifier (act as denitrification and dust precipitator). In this study, simulation of wake flow induces by a truck and automobile emitted NO transport and diffusion were numerically simulated by two dimensional model.

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For the optimization of arc ash melting process, the present study has proposed the new numerical model to consider the arc flow boundary conditions without using experimental data and also the complex interactions between the arc flow and molten soil interface with phase change. Next, the effects of arc current, electrode gap, inlet gas flow rate and cathode vertex angle on the thermofluid field of arc-molten soil system are clarified by numerical simulation to provide the fundamental data for optimum operating conditions and melter configuration of arc ash melting process.

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A numerical method for simulating aerosol transport in mesoscale atmospheric weather conditions considering actual geography is being developed in our laboratory. It is based on the GIS (Geographical Information System) and CFD (Computational Fluid Dynamics). Three-dimensional compressible full Navier-Stokes equations and a condensation model are solved by the high-order and high-resolve FDM coupled with the preconditioning method. In this paper, the outline of the numerical method is introduced and a preliminary result of aerosol transport in 60km×40km at Sendai-Yamagata region is presented.

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This paper describes the assessment of thermal environment in an urban street canyon under the urban heat island condition. First, the latest field observation result of ambient temperature is shown. Next, computer simulations for a radiant environment in an urban street canyon are conducted, and the results of simulations are discussed. Three-dimensional radiation model of urban street canyon is used for these simulations. The simulation results show that the characteristics of radiant environment in an urban street canyon.

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In recent years, the needs of the risk assessment to increasing chemical substances such as trichloroethylene tetrachloroethylene, benzene, etc are required. The chemical substances are mainly discharged in the atmosphere from the exhaust pipes or the stacks attached to the factory houses. The pollutants emitted from low stacks are affected by near buildings or the building on which exhaust pipes are attached and sometimes it causes high level pollution in neighbouring area. Moreover, the discharge to the water system occur through the river, via a water pipe or a sewer from the exit of drainage processing equipment. In this study, atmospheric diffusions of chemical substance emitted from a low chimney on the roof buildings were studied numerically for various buildings and chimney conditions. And compared with the results of the analytical model METI-LIS.

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In order to simulate the indoor environment in the commercial kitchen with the ceiling exhaust system, the plume above the cooking stove was modeled based on the measurement of temperature, velocity, concentration of CO_2 and SF_6 (as a tracer of contaminant die to cooking). Turbulent kinetic energy and length scale of turbulence. Gas cooking stove and IH cooking stove were tested. Gauss distribution was adapted to horizontal distribution of temperature, velocity and gas concentration, and the turbulent kinetic energy was modeled to be in proportion to the square of mean velocity. The length scale of turbulence was determined by CFD simulation when different values of length scale were assumed as parameter.

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We have modified original code for prediction of the thermal environment of rooms which was based on Computational Fluid Dynamics (CFD) and have developed Macro Model using perfect mixed model of air in rooms for prediction of room air temperature and heating/cooling loads. The characteristic of this Macro Model is consideration for reflectance of short-wave and long-wave radiation at walls and thermal comfort. It is possible to evaluate thermal environment and thermal loads of rooms. In this paper, the comparative examinations of CFD and Macro Model, and the results of prediction for heating/cooling loads of a passive solar house are reported.

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Authors developed two kinds of simple and low cost apparatus for fermentation of dairy manure slurry using solar energy. One (A type) of them is made in pipe frame construction covered by transparency film as a greenhouse; another (B type) is having wooden walls faced on north side, east and west side for thermal insulation and storage like a log house type. Thermal analysis for two type fermentation apparatus was done by simulation calculation. Consequently, the temperature of fermentation bag of the type A was kept over 113 days above 30℃, on the other hand, the fermentation bag temperature of type B was kept over 160 days above 30℃, and kept over 113 days above 35.℃ It was made clear that wooden wall type was excellent in the effect of thermal insulation and storage.

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A large pressure loss of the refrigerant flow occurred at the direct expansion type photovoltaic and thermal hybrid panel, which was adopted in the heat pump for an experimental (resaech)^<1)>. In this study, a new panel, which was a modification of the original panel, was made to reduce the pressure loss. Then, the thermal performance of the heat pump which used either one of the two types of the panels at a time was examined and the results were compared with each other. For the convenience, the panels without photovoltaic modules were used for the experiments. The pressure loss of the new panel decreased one fourth of that of the original panel. The increase of the COP of the heat pump with the new panel from the COP of the heat pump with the original panel was not so large as it could be seen clearly from the experimental results. The increase was estimated to be about 5 to 10%. The new panel would be suitable for commercial use.

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This study aims at evaluating the possibility for market penetration of solar water heaters to utilize solar energy as thermal energy. Japanese government planet to introduce four times as many solar heaters as present plants. However, stable oil price in recent years results in decrease of solar heaters. The study investigated optimal setting of solar collector as well as energy saving per detached house, It was aggregated over three regions to estimate total possible energy saving in Japan. Because installing solar heater depends on the judgement by household from economic point of view, the acceptability function is assumed with respect to payback year. It was found that present cost condition resulted in no additional installation while 20% cost reduction would amplify the installation so as to achieve the governmental target in 2010.

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The nonimaging Fresnel lens has been developed for advanced solar concentration systems as thermal concentrator or for photovoltaics generation of electricity. Nonimaging flat Fresnel lens was designed based on the Edge ray principle and manufactured. The geometrical concentration ratio of the lens is 19.3. The lens needs to track the sun by one axis. The lens was evaluated by ray tracing method and by experiments under the sun. Result of the simulation and the experiment show that flux density changes according to incidence angles and that the optical concentration ratio is 15.2. The optical efficiency is 79.1% under normal incidence. The lens is capable of concentrating solar ray in a wide range of wavelength.

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Since fossil fuel like petroleum, coal, and natural gases will sooner or later run out in this or next century, natural energy like solar, wind, and biomass will rise as one of alterative energy sources. Most of the conventional solar thermal electric systems utilize high-temperature difference. In the present paper, an advanced solar Rankine cycle system with CPC (Compound Parabolic Concentrator) collector and steam accumulator of phase-change type was newly proposed. And the new steam turbine (expander) was invented and designed under the "Concept of Superposition". This paper reports experimental results of the proposed system under heat stored accumulator conditions.

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Vertical axial cross flow type of wind turbines are considered to have superior characters in comparison with the conventional propeller type of HAWT, especially in combined with outer static guide vanes. One benefit is to operate for all directions of the wind without the mechanism of yaw drive systems, which lead to simple structures and low costs. Others are the safety against the dangerous rotating body and the considerable increasing the output because of having the outer static guide vanes installed, subsequently be suitable for setting to the park/street for small units. In this paper, aerodynamic performance characteristics of the cross flow type of wind turbine combined with outer static guide vanes were studied experimentally by small scale model under the condition of open-type wind tunnel restricted with max wind stream velocity 4.5m/s and outlet duct's dia. 0.88mφ. The free stream velocity at the outlet of the wind tunnel was regulated from 0.8&acd;4.5m/s by a 1200mm dia. propeller driven by a 400W inverter controlled induction motor. The mechanism of the cross flow model employed in this experiment are involved the rotor with 0.32mφ dia. and 0.3m wide comprised of flat and curved plate blades with pitch angle 60 degree and the number Z=8/16 and the length 1=40&acd;80mm, and static flat guide vanes with outer and inner dia. 0.64mφ and 0.32mφ, setting angle 30 degree and the number Z=8. The aerodynamics characteristics of the turbine obtained by experiment were discussed, correlated by the tip speed ratio and power and torque coefficients C_p, C_q for various parameter combinations, and cleared to be optimiged design parameters of rotar blades number Z and blade width acting as significant roles.

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In this study, a series of experiments have been performed to clarify the heat transfer characteristics of a multi layer type of gas-to-gas heat exchanger. The present heat exchanger is composed of two, three, four or five porous medium sections separated by opaque solid walls; that is, the low and high temperature sections in a two layer type system and the low, first and second high temperature sections with the first and second heat recovery sections in a five layer type system for instance. The key parameters in the present experiments are selected as follows; inlet gas temperature of the high temperature section : 300&acd;700℃(573-973 K), optical thickness of the porous medium : 0 (without porous medium) and 7.7,flow rate of low and high temperature gases : 0.35 (Nm)^3/min, flow direction of low temperature gas in the low temperature section : approaching flow.

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The efficient cooling on semi-conductors of the electronic devices has been becoming important in recently developed computer industry. This paper describes the cooling problem on heat generating semi-conductor components (DC source) in electronic-luminescence board (LED) used as the destination indicator in JR station, to make a level up of the reliability and durability of the devices. The cooling approaches employed here are involved the natural/forced convection of air in the opened duct covering with the radiator fins enclosed in the board, backside of which is the DC sources. Particularly, fan motor on-off control cooling system is introduced depending on the temperature of the bimetal sensing. Cooling characteristics of the heat generating DC source semiconductor device by the present approaches are cleared.

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The study aims at clarifying the local heat and mass transfer in the desiccant rotor, and at obtaining the design aspects of high efficient desiccant rotor and operation method. In the paper, theoretical analysis is performed for rotary dehumidifier. Both surface diffusion and mass transfer coefficient are considered in the model. The local temperature, humidity and the amount of adsorbed water vapor are calculated. It is examined that temperature and humidity of air in the rotor change clockwise between each inlet air condition on the psychrometric chart. The reason that the system has the optimum adsorption and desorption rate. It is attributed to the increase of mass transfer coefficient and surface diffusivity.

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The study reports a calculated performance of proposed desiccant air conditioning system, which is driven by air cycle refrigerator and evaporative cooler. The system has such characteristics that (i) safe material of air and water are used as a refrigerant, (ii) waste heat from air cycle refrigerator performs the regeneration of desiccant material for energy saving. The system can operate for wide range cooling load with a fraction control of evaporative cooling. This paper presents the influences of the ratio of air intake flow rate to the supply air for air conditioning room, and the temperature difference of heat exchanger on the system performance. The system performance drops with the increase of the ratio, and drops with the increase of temperature difference. Furthermore, it is found that the system of ventilation mode can not operate in the temperature difference of above 15 K.

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The study develops exergy analysis of the desiccant dehumidification augmented air conditioning systems. The air cooling system is absorption or vapor compression cooling system. The performance of systems is evaluated for varied ambient condition. The calculation results are described on psychrometric chart. The results show system performance, which depends on out-door condition, mainly in hot-humid climates and on system operation modes. The performance of the systems for the East Asian regions and Tokyo in Japan is also evaluated. The desiccant dehumidification-absorption hybrid air conditioning system has a high potential of energy saving. The desiccant hybrid system has exergy loss reduction or exergy efficiency improvement and coefficient of performance for hot and humid climate regions.

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Adsorption refrigeration cycle is driven by waste heat at near ambient temperature, but performance of this cycle is low. Therefore, For improvement of COP and cooling capacity, adsorption refrigeration cycle with vapor recovery process was studied by Pons (1999). In this process, adsorber is connected to desorber, therefore, the adsorbate continues moving from desorber to adsorber to their equilibrium levels. Pons applied this cycle to zeolite-water pair, but silica gel-water was suitable for regeneration at low temperature. COP and cooling capacity were calculated with computational analysis and compared with conventional single stage cycle. An evaluation of this cycle with vapor recovery process is presented.

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Despite the fact that an absorption refrigerator is required to improve its efficiency, even the optimum design point of the absorption cycle has not been clarified. This research discusses the optimum design method of a double-effect absorption refrigerator, which has spread generally. The objects of the analysis are the three typical double-effect absorption cycles, series, reverse and parallel flow. COP is the evaluation function. Some constraints to drive the absorption cycle normally exist. As the analysis technique, the exterior-point-penalty-function method, which can analyze nonlinear optimization problems with constraints, and the applying-trial-and-error method are adopted to seek the optimum point. As a result, optimum COP for each flow at the point of 90% temperature efficiency were, series 1.47,Reverse 1.49 and parallel. 50.

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In absorption systems, the performance of heat and mass transfer can be significantly enhanced by adding heat transfer additives to the working solution pairs. The small addition of heat transfer additives changes the magnitude of surface tension, which causes interfacial turbulence by the Marangoni effect leading to a higher heat and mass transfer performance. The surface tension of working solution has a significant effect on not only heat and mass transfer characteristics but also the flow mechanism. In this study, it was found that addition of the heat transfer additive beyond the solubility limit assisted Marangoni convection occurrence, but should not be a criterion for Marangoni convection inducement.

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