Among some types of catalysts in a reactor, one of the popular configurations is a surface catalyst, in which a catalyst layer is coated on the channel plate. The phenomenon within the channel with the surface catalyst is complicated because of the boundary layers for temperature and concentrations in gas phase. Furthermore, the profiles of concentration within the catalyst layer must be taken into account. In this study, the models of reaction kinetics which includes the internal diffusion within a catalyst are proposed and confirmed through the experiment of steam methane reforming with different thickness of catalyst layer.

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Li-air battery has attracted much attention because of its large theoretical capacity. Aqueous type has an advantage of avoiding an issue pore clogging because the reaction products are water soluble. Detailed assessments of material behavior in the battery are important to make practical. We have not however got the knowledge because of complexity structure at porous media of cathode side. In this study, we made a numerical simulation using Lattice Boltzmann Method (LBM) to calculate a distribution of Li^+(Cl^-), electric potential and O_2. Interpretations between the transport/reduction of Li^+ and O_2 are made in detail.

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The vanadium redox flow battery (VRB) has emerged as a viable grid-scale energy storage technology that offers energy storage solutions for renewable energy applications. In this study, we focus on the effect of material transport and electrolyte concentration distribution on cell performance. The original cell was specially designed for measurement of current density distribution, and the analysis method was established. In the method, the measured values just after the start of discharge were used to identify the non-uniform contact resistances, and the current density distribution unaffected by the measurement devices can be estimated. The measurement results showed that the current density decreases along the electrolyte flow, and the range of the current density and the cell performance are improved by increasing the electrolyte flow rate.

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Electrolyte solution is often encountered in many energy related devices, i.e., Li/Air batteries and electrolyzers. However, mass transport phenomena of Li/Air batteries are not completely clarified. We visualized mass transport phenomena in an aqueous solution of lithium chloride as an electrolyte of a Li/Air battery by using MRI. We visualized ionic transportations in the electrolyte by measuring water molecules' transportations. We electrolyzed LiClaq using a pair of carbon electrodes and a pair of copper electrodes. When LiClaq was electrolyzed using carbon electrodes, the convection like Benard cells was observed. Similarly, when we used copper electrodes, the density induced convection by copper ions was observed.

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To clarify the degradation mechanism of the perfluorinated polymer electrolytes in polymer electrolyte fuel cells, we studied the decomposition process of the end group of these polymers using the first-principles molecular dynamics method. We successfully clarified that the polymer end model of CF_3CF_2CF_2OH reacts with a hydroxyl radical to generate a water molecule and CF_2O. After CF_2O was desorbed, polymer end model became CF_3CF_2・. CF_3CF_2・reacts with another hydroxyl radical to reproduce the hydroxyl end group. Therefore, it was revealed that cyclic degradation reactions like the unzipping mechanism occur when CF_3CF_2CF_2OH reacts with hydroxyl radicals. Furthermore, it was revealed that the CF_2O desorption reaction is inhibited by surrounding water molecules, while the HF desorption reaction from CF_3CF_2CF_2OH is promoted.

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A PtRu alloy nano-particle attracts attention as an anode catalyst in a polymer electrolyte fuel cell because of its higher tolerability for CO poisoning than a Pt nano-particle. To reveal the mechanism of the high tolerability for CO in the PtRu alloy nano-particle, we investigated adsorption process of a CO molecule on the Pt and PtRu alloy nano-particles by first-principles calculation. The results show that the bond length of the CO molecule adsorbed on the PtRu alloy nano-particle is longer than that on the Pt nano-particle. This indicates that the PtRu alloy nano-particle oxidizes a CO molecule to a CO_2 molecule more easily than the Pt nano-particle. In addition, the CO molecule is more difficult to adsorb on the Pt atom in the PtRu alloy nano-particle than that in the Pt nano-particle.

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To investigate the effect of the chemical species transport and temperature distribution on the electrochemical reaction kinetics in catalyst layer, two-dimensional two-phase unsteady-state PEFC model was developed. Gas diffusion layer (GDL), the cathode catalyst layer (CL), and cathode MPL were calculated in the model. In this model, catalyst layer was treated as spherical aggregates model made with Pt, carbon particles and the polymer electrolyte. Electrochemical reaction, heat transfer and transport of chemical species (electrons hydrogen, oxygen, nitrogen, water vapor, liquid water, and the proton) were considered in this model. Prediction of temperature distribution in the cell showed that the occurrence of liquid water affected. And it indicated that the existence of MPL affects liquid water transport.

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One of the technical problems for the commercialization of FCV is a sub-zero performance improvement. During 0℃ to -30℃, generation water in channel and GDL freezes. Therefore, gas supply is obstructed and diffusion overvoltage increases. The solution has been solved by the optimization of the purge condition and the improvement of the heater. On the other hand, under the extremely low temperature less than -30℃, the water even in polymer electrolyte membrane freeze, the conductivity of the proton decreases and the operation of PEFC cannot start. This problem does not have a solution. The key to the solution is to make clear the drop mechanism of the proton conductivity due to the solidification of the generation water. This paper investigates the transport property of the proton under sub-zero degree.

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To achieve the high performance of PEFC, understanding generated water phase (liquid and gas) in it is an important issue. In this study, we try to clarify the phase through open circuit voltages (OCVs) for a cell. We experimentally investigated the OCVs under the pressure of 1 atm and temperature of 40℃, with changing the humidity of supplied gases and compared theoretical potentials estimated by the Nernst equation, with considering hydrogen crossover and cathode Pt oxidation. The measured OCVs decreased with increasing the relative humidity. This characteristic corresponded to the prediction by the theory. However, the quantitative agreement between them was not obtained. This considered to be caused by the dynamic change of OCVs.

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Flooding is one of the problems to be solved for practical use of PEFC. In this study, the numerical simulation using the lattice Boltzmann method (LBM) was developed to elucidate the liquid water behavior in a gas diffusion layer. In the equal density LBM code developed by the authors, there is a problem that setting value of water flow rate was not ensured. This paper explains the applied improvements for setting the inlet boundary conditions, keeping the fast calculation for the large-scale simulation, and the improved results. The instability of simulation, however, still remains as an unsolved issue, and the cause is also discussed.

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Microporous layer (MPL) has a dramatic effect on the durability and water management of polymer electrolyte fuel cell (PEFC). In this paper, the visualization and quantitative analysis of the liquid droplet behavior at the GDL/channel and MPL/GDL interfaces of an operating fuel cell were performed using a digital microscope, and the effect of MPL addition on the liquid water transport in the cathode electrode was investigated. It was found that the MPL addition effectively suppresses the liquid water accumulation at the cathode CL/GDL interface.

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In order to measure humidity inside PEFC, we developed flexible and thin film capacitive humidity sensor by micro-electro-mechanical-systems (MEMS) technology. The sensor consists of parylene and Ni. Parylene was selected as an electrical isolating material and also sensing material. Ni electrodes was deposited thinly to obtain water vapor permeability to the sensing material. Sensing area and thickness of the sensor are 4mm^2 and 6.51μm respectively. By the calibration measurement, the sensor has high sensitivity of 31.8%. It means that the sensor has a high reproducibility and small error. Furthermore, the sensor demonstrated a very small hysteresis in the range from 60%RH to 100%RH.

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This study aims to investigate the impact of CO_2 reactivity on soot reduction in O_2/CO_2 combustion. As a result, unburned hydrocarbons (CH_4 and C_2H_2) in O_2/CO_2 combustion were found to be lower than those in air combustion. Calculations also showed that CO_2 reactivity plays an important role in the PAH (Polycyclic Aromatic Hydrocarbons) reduction in O_2/CO_2 combustion. Calculated PAH concentration in O_2/CO_2 combustion was almost half of that in air combustion when gas temperature and inlet O_2 concentration were the same. It was shown that O_2/CO_2 environments were suited to reduce soot concentration from the viewpoint of CO_2 reactivity.

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Combustion properties of coal gasification gas with CO_2 dilution were investigated for an IGCC power generation system with CO_2 capture. In this system, the gasification gas which consists of H_2 and CO, is burned under high CO_2 concentration atmosphere. The turbulent burning velocities and flame shapes were examined for outwardly propagating stoichiometric CO_2 diluted H_2/CO flames under the condition of constant flame temperatures of 1300 and 1700 degrees Celsius. The model of turbulent burning velocity was proposed.

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Experimental and numerical studies on Pt-catalytic combustion were carried out in order to investigate the characteristics of it in highly concentrated CO_2. In the experiment, flue gases were analyzed by gas chromatography. In the numerical calculation, catalytic surface reactions were revealed by using two-dimensional axial symmetric simulation. As a result, intermediate products such as CO and H_2 were highly exhausted at rich mixture condition (Φ=1.5〜2.5), and those amounts were reduced in comparison with that in N_2 mixture. These characteristics were interpreted with the reaction temperature, the reactivity and the desorption rate on the catalyst.

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The Fuel-NO_x concentrations under the conditions of high CO_2 concentration have been experimentally investigated with a tubular flame burner. At first, flame stability limits are examined for CH_4/O_2/CO_2 mixture with a tubular flame burner for non-preheating conditions as well as 300℃ preheating conditions. Results show that, for CO_2-dilution mixture, although a tubular flame can be established in wide range of Φ even under the 21% O_2 concentration condition, the stability limits can be further enhanced with the preheating of the unburned mixture. The results of NO_x measurement showed that the preheat temperature affects little on the Fuel-NO_x concentration under the fuel lean condition of Φ=0.8. The difference of the NO_x concentration for various preheat condition is within 10% for all experimental conditions.

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Direct numerical simulation (DNS) of methane-air turbulent jet premixed flame has been conducted to clarify characteristics of local burning velocity. A detail kinetic mechanism including 49 reactive species and 279 elementary reactions is used to represent the methane-air reaction. In this study, we investigate effects of definition of flame front and fluid velocity on local burning velocity. The calculated displacement speed at flame front is strongly affected by the definition of fluid velocity. It is difficult to describe dynamic characteristics of turbulent premixed flame in strong turbulence by the flamelet concept.

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By this experiment, I controlled the jet flame with coaxial type DBD plasma actuator. The flow rate of propane and air is adjusted, mixed in the experiment, and it is gushed from the nozzle. The induced flow by a coaxial type DBD plasma actuator was given to the jet flame. The observation flow rate is 1.2 L/min-9.8 L/min. Volume density is 16.7 % 55.6 %. As a result, when the impressed voltage is increased, the flame pattern changes. Moreover, the burner flame can be maintained by increasing the impressed voltage in a wide area of flow rate and concentration.

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Direct numerical simulations of autoignition have been conducted to clarify effects of length scale in flow and temperature field and initial temperature fluctuations on turbulent combustion mechanisms in homogeneous charge compression ignition engines. Methane-air mixtures at high pressure with spatial inhomogeneity of temperature are investigated by considering a detailed kinetic mechanism. For the case with lower temperature fluctuations, local autoignition starts later at smaller length scale due to larger effects of turbulent and molecular diffusion before the autoignition, while effects of length scale is relatively weak for high temperature fluctuations. Lagrangian fluid particle tracking method is conducted to identify combustion regimes under the different length-scale conditions.

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For practical application of high carbon number biofuel, experiments of propanol isomers and propane turbulent premixed flame using OH-PLIF measurement were performed in a high pressure environment. The local flame surface density, Σ_<local>, for each fuel was analyzed from instantaneous turbulent flame images of cross-section. The results of Σ_<local> analysis indicated differences of intrinsic flame instability for 1-propanol, 2-propanol and propane. In addition, numerical simulations of propanol and propane laminar premixed flames using CHEMKIM-PRO were carried out to clarify the relationship between chemical reaction and flame instability. It was presumed that turbulent flame structure is affected by the diffusive thermal effects related to concentrations of the intermediate species, C_2H_2 and C_2H_4, depending of fuels and differences in dissociation reaction pathway.

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In this paper, a feasibility study of energy recovery from such exhausted gas from industrial devices and smoke of woodstove in domestic heating usage was conducted. In this system, organic Rankine cycle (ORC) system with latent heat thermal storage (LHTS) is used as an energy recovery. The LHTS would be a good thermal buffer for stable running of the ORC system and also as a quick heat supply for air conditioning. The PCM used in this study was chosen to be fit the evaporating temperature of R245fa. Numerical analysis of the ORC system showed that performance of primal heat exchanger was most important and further improvement of heat transfer would be required.

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There is a Stirling cooler in one of the refrigerating machines which mechanically obtain low temperature. This cooler becomes a compact system, and can electrically control cooling temperature in the easiness. However, the responsibility of temperature control is inferior. In the meantime, there is a thermoelectric conversion module of which heating and cooling are electrically possible without a moving part. This module is excellent in the responsibility of the temperature control. However, the cooling of the waste heat from the heat radiation side is difficult. In this study, each problem is overcome by combining a Stirling cooler with a thermoelectric conversion module, and the new system which can control cooling temperature is proposed.

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In the present study, effects of inner diameter on generated work and efficiency of single tube oscillating steam engine are experimentally investigated. Larger work can be obtained at higher frequencies for smaller inner diameter tubes. In addition, maximum efficiency is achieved at higher frequencies for smaller diameter tubes. However, larger diameter tubes give higher maximum efficiency than smaller diameter tubes. In a smaller tube, most heats are not effectively used to generate work but transfer to the cooling section because of its high heat-transfer performance. High heat transfer can decrease efficiency of the engine with small size tubes at lower frequencies.

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A Low-grade Thermal Energy Conversion (LTEC) is refocused as one of the renewable energy. For the LTEC and Refrigerator/Heat Pump, it is very important to enhance on the heat transfer of heat exchanger though the available temperature deference is smaller than conventional thermal system. On last our study, by using micro fabrication surface on plate evaporator, heat transfer coefficient of HFC245fa is enhanced. In this paper, the experimental performance test as evaporator is evaluated on comparison with various Freon. The results show the boiling heat transfer coefficient of HFC134a was larger than that of another Freon. Heat transfer coefficient of these working fluids is estimated using Lockhart-Martinelli parameter.

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The thermal efficiency of Low-grade Thermal Energy Conversion (LTEC) system is theoretically small. Therefore it is necessary to enhance on the thermal efficiency of the LTEC system. The Multi-Stage cycle was proposed aiming at optimizing the power output from low-temperature heat sources such as geothermal or waste heat. In this paper, it is shown on an influence of the heat source flow rate on the maximum power of Multi-Stage cycle that has independent equipment respectively. As a result, the maximum power output increases with an increase of the heat source flow rate. The maximum power output ratios of Multi-Stage cycle to Single-Stage cycle are almost same at any heat source flow rate conditions.

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Compact brazed heat exchangers (BHEs) are used in many industrial products, e.g., in refrigerators and heat pumps. Many studies have been conducted on the boiling in BHEs employing Freon or carbon dioxide as the working fluid. Moreover, a thermal conversion system that works using the small temperature difference has attracted attention as a renewable source of energy e.g., ocean thermal energy conversion. These systems mostly employ ammonia as a working fluid. For miniaturizing this system, the use of BHEs as heat exchangers is suggested. However, the boiling characteristics of ammonia in BHEs have not been clarified. Therefore, the overall heat transfer and boiling heat transfer coefficient of ammonia are measured in this study. In addition, the heat transfer performance of the BHE is clarified under varying experimental conditions.

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The thermoacoustic engine can convert heat energy into acoustic energy. Heat energy cannot superpose while acoustic energy can superpose. Superposing acoustic energy that several thermoacoustic engines generated leads to the effective utilization of energy. This study tried superposing acoustic energy that double thermoacoustic engines generated. Those engines consist of engine part that form a parallel line cylinder and resonator part. As a result, superposing acoustic energy could not happen because those engines were in the opposite phase. Therefore the jointed part division plate was inserted. In consequence, superposing acoustic energy could happen because those engines were in the coordinate phase.

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In recent years, ebullient cooling and forced-circulation cooling is applied to cooling system for power conversion equipment of high capacity. However, problems of precipitous temperature fluctuation, correspondence to large area, and usage restrictions of the coolant are held in cooling system for the power conversion equipment. This study examined the natural circulation cooling system which canceled the demerit of both the above-mentioned cooling system for the coolant of high environmental performance. The objects of coolant are HFE-7200 and PFK-649. Heat transfer characteristics and natural circulation flow characteristics of the coolant concerned were verified by changing heat flux using an experimental apparatus. Moreover, the effect installed check-valve in the test loop was also made applicable to verification. As a result, we found that flow fluctuation can be reduced from 30 to 50% by the effect of check-valve in any of two kinds of coolants case.

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A new type of heat pipe, called BACH (Bubble-Actuated Circulating Heat pipe), was revised so as to be capable of both top-heat mode and bottom-heat mode by valve switching. In this research, heat transport characteristics of the BACH between underground and ground surface were measured experimentally. The working fluid was R134a. The obtained results show that at bottom-heat mode, BACH can transport heat of 200W maximum, while it can transport heat of 300W maximum at top-heat mode. The heat transport characteristics were affected by underground length and cooling method of intermediate cooled section, and in general the underground length 4m was optimal.

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Experimental study has been conducted to clarify the heat transfer characteristics of emulsified fuels composed with hydrocarbon and water with a small amount of surfactant and additional component. The focus is mainly paid on the effect of additions of ethanol and fatty acid methyl ester (i.e. FAME) produced from biomass on the heat transfer coefficient and its hysteresis. Heat transfer coefficient was determined using an electrically heated horizontal Pt wire, which is 0.2 mm in diameter and 100 mm in length for various ambient emulsions temperature. It is concluded that heat transfer coefficient increase in the higher emulsion temperature conditions, which occurred by the changes in its viscosity of test emulsions. The effects of alcohol and FAME additives on heat transfer coefficient of water in fuel emulsions were also revealed.

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Heat transfer performance of dropwise condensation is higher than filmwise one due to droplet removal from the condensed surface. In order to further enhancement of its performance, removal of microscale droplet is a key issue. However, condensation mechanism at microscale on hydrophobic-hydrophilic hybrid surface is not understood, although all surfaces are consisted with those combinations. In this study, we conducted condensation experiments on a graphite surface at 0℃ and 550 to 600 Pa by using environmental scanning electron microscope (ESEM). Nanoscale step-terrace structures on graphite surface are obtained by using an atomic force microscope (AFM) before ESEM experiments. It was found that condensed droplets with diameter of 150 to 300 nm are lined up along step edges at over 150 nm intervals. In addition, we found that most droplets are on the steps of height of 1 nm and shorter droplet intervals are induced by higher steps and shorter terrace width. Our results were analyzed by an extended nucleation theory and we found that water molecules attracted on steps play an important role for droplet condensation.

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In the frost formation process, the growth of the frost layer and crystallization of frost depend on several factors such as: the cooling surface temperature where the frost is formed, the temperature and humidity of the humid air, air velocity, pressure, cooling surface's shape, dimensions, orientation, roughness and wettability, and the time elapsed since the start of frost formation. In this study, the effects of cooling surface's shape and dimensions on frosting phenomena were investigated.

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Since frosting to a cooling surface has often caused the loss of equipment performance, it is important to investigate the method for efficient removal of frost crystals from the cooling surface. Thus, authors focus on frosting from generation to the primary stage of growth because the scraping force of frost crystals on the cooling surface until the primary stage is expected to be weak. However, considering the dimensions of frost crystals until the primary stage, it is essential to measure frost crystals dimensions/distribution and scraping force in micro scale field. In this paper, using a scanning probe microscope (SPM), dimensions/distribution and scraping force of forest crystals until the primary stage were measured by authors' proposed method, varying humidites. And then, the correlations among them were clarified, comparing influences of the humidity with those of the surface temperature.

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We carried out experiments on the ice growth and temperature profiles of aqueous solution flow of winter flounder antifreeze protein in a mini-channel. The solution was cooled by an electronic device. We mesured temperature field in the flow using a near-infrared camera. It was found that concentration of solution and flow rate affect temperature field. The temperature dropped near the interface when the concentration of solution was high. The temperature gradient became large when the flow rate was high. The concentration of solutions was highly related to the ice growth suppression by the antifreeze protein.

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To discuss the uniformity of ice nucleating activity of solid/water interfaces, ice nucleation in water droplets prepared on glass surfaces was investigated for various droplet sizes from micrometer to sub-millimeter. When the interfacial area between water and the glass surface was larger than 1×10^<-8> m^2, the ice nucleation temperature showed large scatter, suggesting that the ice nucleating activity was no longer uniform. When the classical nucleation theory (CNT) is used to analyze surface-induced ice nucleation, the uniformity of interfaces that contribute to ice nucleation must be carefully considered, because CNT cannot be directly applied to non-uniform interfaces.

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This study describes water freezing phenomena around heat transfer tubes mounted in ice thermal energy storage systems. In this report, we perform the numerical analysis for predicting the water freezing by using commercial spreadsheet software. The freezing around the heat transfer tubes are calculated by solving the 2-dimentional heat conduction equation and simulated by using the enthalpy method. It is found that the developed spreadsheet can predict the amount of the generated ice accurately when natural convection around the tubes is inhibited by the dimensions of the vessel.

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Oil tankers carrying high viscous oil are usually equipped with the cargo-oil heating system. For design of oil heating system, three dimensional numerical analysis of unsteady flow and heat transfer was conducted to grasp the influence of heat loss from cargo-oil tank on natural heat convection in rectangular cargo-oil tank during heating up as fundamental study. From the numerical analysis, typical flow pattern and distribution of oil temperature in oil tank when heated were obtained. Additionally, the relations between the minimum oil temperatures in tank and the overall heat transfer coefficient for walls were discussed.

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This study describes a relation of combustion chamber deposit (CCD) generated on a piston of two-stroke cycle engine and flow influences of lubricant oil. Generation of the CCD is influenced by temperature, pressure, gas flow conditions and retention period of lubricant oil in a cylinder. In this report, we especially focused on a relationship among CCD streaks (CCDS) and an influence of flow on the deposit formation. In the results, (1) CCDS on a piston surface flows to the average direction of gas flow on there, (2) CCDS formed on the inclined heated plate along the flow lines of the lubricant oil has a pattern of the inclination angle and the generated length, (3) the viscosity of the lubricant oil becomes lower when the oil is heated up. However, when the oil deteriorates, the viscosity sometimes become higher.

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Air conditioning in greenhouses contributes to improvement of quality and quantity of crops. This study proposed a combined heat pump and desiccant air conditioning system to control temperature and relative humidity in greenhouses. The performance of dehumidification in the desiccant was verified by experiment under winter conditions. It was found that desorption and adsorption ratio 2:3, achieved the largest dehumidification rate.

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Shallow geothermal resources can be used as both heat source in winter and heat sink in summer. In order to utilize shallow geothermal energy, U-tube downhole heat exchanger is used as the most common method. Because a U-tube downhole heat exchanger has advantage that is the simplicity of construction and cost effective. However, a U-tube downhole heat exchanger has disadvantage that is difficult to increase heat transfer area. Therefore, a downhole heat exchanger with multi-pipe which has larger heat transfer area has been invented. The objective of the present study is to reveal heat extraction characteristics of a downhole heat exchanger with multi-pipe by numerical simulation.

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CO_2 geological sequestration is considered as one of the effective technology to mitigate global warming by reducing CO_2 emission into the atmosphere. A new storage method that is using micro or nano scale CO_2 was proposed to realize stable capillary trap in aquifer; however, detail of the mechanism is not clarified. In this study, we employed Lattice Boltzmann Method (LBM) to investigate the two-phase flow in the porous media. In order to realize simulation of micro-scale CO_2, stabilization methodology of two-phase separation was discussed from the view point of chemical potential. As the result, LBM of micro-scale CO_2 in the porous media was performed stably.

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In recent years, the power conversion using oil pressure attracts attention as measures against global environment problems. Although a hydraulic system motor is effective in oil pressure-power conversion, these are designed for high pressures such as several 10 MPa. So apparatus suitable for the oil pressure-power conversion of low-pressure is needed from now on. Authors made the property evaluation equipment for the power recovery which built into the closed circuit used the multi-vane type liquid circulation pump, and performed evaluation examination about the power recovery from the circulating oil of sveral MPa.

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Emission of greenhouse gases into atmosphere is becoming an international concern. Therefore, greenhouse-gas-emission reduction is a pressing subject. In particular, it is assumed that large plants diffuse the major quantity of gas emissions. A large amount of biogas is also emitted by methane fermented in sewage disposal plants. As methane and carbon dioxide with high greenhouse effect in biogas are 60% to 40%, respectively, reduction is indispensable. In this study, bubble-free gas dissolution apparatus is utilized to separate methane and carbon dioxide in the digestion gas, using methane as a fuel product while dissolving carbon dioxide into seawater is used for algae culturing, and then carbon dioxide is immobilized through the photosynthesis algae culturing. This process proposes a system to reduce and digestion gas and utilize it for algae industrial use.

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A porous media approach based on the volume-averaging theory has been proposed to investigate spiral-wound reverse osmosis processes. A set of the governing equations, namely, the continuity, momentum and concentration equations, are derived for three distinctive phases, namely, brine, permeate and membrane phases, exploiting a volume averaging approach. An analytical expression is derived for the permeate salinity, flow rate and pressure drop in spiral-wound reverse osmosis modules. Available experimental data and numerical results based on a finite difference method are found to agree well with the present analysis. The present model can be used to design an efficient spiral-wound reverse osmosis desalination system, without resorting to extensive finite difference calculations.

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This paper has the objective of developing an interconnected system using tidal, wind and solar generation in order to supply the total demand of Kitami City, in the Hokkaido Island. In addition, this paper proposes a seasonal energy shifting strategy by using an energy storage technology that employs organic chemical hydride using hydrogen as a medium, including an optimal equipment design planning. Results show that the optimal sizes of the equipment is composed of 95 sets of tidal turbines, 7.8×10^5 m^2 of solar farm, 400 to 500 sets of wind turbines, 0.1 to 0.5 GWh of NaS battery and 5.0×10^6 to 7.5×10^6 m^3 of hydrogen storage of organic chemical hydride.

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