A novel aftertreatment process for particulate matters (PM) emitted by a diesel engine was investigated in this study. This technique is based on electric precipitation but its collection electrode is covered with dielectric surface. In the process where PM is collected, the dielectric surface is charged by a weak discharge induced by the electrodes placed on the surface, while PM itself is charged with the opposite polarity by charging electrodes. In the decomposition process, PM deposited on the surface is oxidatively decomposed by oxidative active species generated in nonthermal plasma induced by dielectric barrier discharge (DBD). In a condition of optimal applied voltages, PM emission was reduced by around 40 % substantially.

Filtration of cutting oil W/O emulsion by using spiral cross flow was conducted, and the filtration rate and filtration ratio in different filtration conditions was evaluated. In the experiment, different kind of filters, such as ceramic filter and alumina filter was used and the insert material, such as spiral rod and static mixer, was also changed. To evaluated filtration performance of spiral cross flow, function group of filtrate was also analyzed by FT-IR. Cutting oil W/O emulsion was separated oil and water by the ceramic filter, and the filtration ratio of ceramic filter was more than 99%. However, the filtration rate of the W/O emulsion was extremely slow, and it was necessary to find a method for improving the filtration rate. Depending on filter type, filtration performance was different, and the alumina filter decreased both filtration rate and ratio. Static mixer did not effect on the filtration performance, and it was clarified the insert material did not influence on the filtration rate and filtration ratio, but filter type significantly influenced on the filtration performance.

Recently, heat island phenomenon due to expansion of artificial covering such as concrete and asphalt with higher heat capacity and to increase of anthropogenic heat becomes a remarkable environmental problem in many urban areas. As one of the mitigation measures, it is considered to pave the walking space with porous water retentive material. The aim of this countermeasure is to reduce sensible heat transfer on the urban surface related to increase of air temperature by absorbing solar radiation with latent heat of water included in the internal porous structure of the material. Shape of the water retentive material generally used on the street surface is cuboid block. Evaporation performance of the material with this shape tends to deteriorate in drying process, so applying granular porous media whose surface area per unit volume is larger than block shape media is considered. The effect of internal pore structure and particle size related to the inter-particle void structure on the evaporation performance of granular water retentive material are experimentally evaluated by drying tests with thermostat and wind channel.

Deformation behavior of ceramic thin film was studied due to drying-induced shrinkage. Hot air drying examination was carried out for a piece of kaolin thin film in the two patterns; both the faces of the sample piece were subjected to heating (both side heating and drying) and drying and only the top face was subjected to heating and drying (one side heating and drying). The drying characteristic curves showed preheating, constant rate and falling rate periods. However, the drying rate per unit drying area in the both side heating and drying was lower than that in one side heating and drying. The sample piece dried in one side heating and drying was warped upward due to drying-induced shrinkage caused by more nonuniform moisture content profiles. No crack was observed in the experiment conditions performed in this examination.

ESP has advantages such as high dust collection performance, low pressure loss, and easy maintenance. However, ESP which is usually used has a demerit that re-entrainment phenomenon in which particles once collected are discharged. The new hole-type ESP was developed to overcome the re-entrainment in the ESP. The particle flow into the hole by ionic wind. The Electric field of a collecting zone in the hole is zero. However, the internal phenomenon and the dust collecting mechanism of the hole-type ESP are not yet clarified. Therefore, this study aimed to elucidate the dust collection mechanism of hole-type ESP by simulation analysis of fluid flow and particle behavior using finite element method. Ionic wind blows from the discharge electrode toward the hole, blow up on the grounded electrode, and create a Karman vortex on the upstream of the discharge electrode. The validity of this simulation results was verified by comparison with experimental results using PIV.

During pulsed corona discharges, both negative and positive ions react with moisture to generated cluster ions. These cluster ions are considered to be useful for cleaning hazardous materials such as hazardous pollutants and allergen. In this paper, for such type of ions generation devices, numerical simulation is carried out on the cluster ions formation. The behavior of streamer evolution and cluster formations are simulated well, and it is clarified that the clustering progresses toward H₃O⁺(H₂O)₄ and O₂^-(H₂O)₄. Ions number densities obtained in the experiment are smaller than the calculated ones because some differences between the numerical model and experiment exit and the ions may be lost near in the path of the chamber.

Plasma-catalytic process received a great deal of interests in removal of NOx, SOx, and Volatile organic compounds(VOCs) processes. The efficiency of the above process will be improved in spouted bed. The purpose of this study is to figure out the effect of plasma on the behavior and surface changes of fine particles in an AC plasma jet spouted bed. Several parameters such as the height of fine particles, presence of plasma, plasma voltage, and working gases have been investigated. X-ray diffraction(XRD) has also been carried out to characterize the lattice structure changes. Results showed that the minimum spouted bed velocity (u_ms) presented the similar trend regardless of static bed height, however it decreased when the plasma applied. Fine particles maintained as fixed bed with a constant flow rate until plasma voltage high enough. In the higher flow rate (remain in fixed bed) conditions, lower plasma voltage is required for fluidization. The same trend was found in two plasma working gases, N₂ and Ar, that u_ms decreased by higher plasma voltage. The phases of the particles did not change in the plasma treated regardless of different gases.

Non-scanning 3D-CT(Computer Tomography) technique using a multi-directional quantitative schlieren system with flash light source is proposed to obtain instantaneous 3D density distributions of fuel jet and flame kernel. This "Schlieren 3D-CT" is based on (i) simultaneous acquisition of flash-light schlieren images taken from numerous directions, and (ii) 3D-CT reconstruction of the images by an appropriate CT algorithm. In this paper, with custom-made 20 directional schlieren camera, two types of instantaneous density distributions of flame kernels in practical fuel jets are reconstructed by the 3D-CT technique. First a flame kernel in a free jet of propane gas injected into ambient air is investigated. Next, a spark-ignited flame kernel in a direct-injection engine model is reconstructed. The engine model consists of a fuel injector, a guiding cavity and spark electrodes. The cavity has a shape of a hemispherical concave of 8 mm diameter.

Cement industry consumes a large amount of energy, and emits much carbon dioxide as well. Implementation to save energy and mitigate carbon dioxide emission is required immediately, and R&Ds on innovative technologies are carried out. A candidate among them is a low temperature calcination process, but it needs an in-situ accurate temperature measurement method of calcined clinker in the furnace to maintain a quality of the products. Radiation thermometers may be the most appropriate method, but the existence of dust suspended in the space in the furnace inhibits thermometers from measuring accuratly the temperature as the radiation emitted on the clinker is influenced during propergating to the senser due to absorption and scattering in the dust. In this study, the radiation properties of clinker dust under a high temperature were spectroscopically measured with a hot model. The radiation properties were evaluated in the term of extinction efficiency of the dust particle cloud suspended in hot gas stream. The extinction efficiency under the stream at 650°C was almost same as that at the room temeprature. However, the magnitude was resulted in being greater than that analyzed spectroscopically in the cold model by the nujol method due to any effect of scattering.

Activated cokes promote generation of microwave-induced plasma under low power. The plasma shows a significantly dynamic behavior and has a high reaction activity. The present study applied the plasma to non-catalytic methane synthesis from carbon dioxide and hydrogen. Methane yield was enhanced by increasing microwave power and/or the ratio of hydrogen to carbon dioxide in reaction gas stream and mixing preliminarily the reaction gases, and the maximum yield achieved at as high as 50% in the range of the experimental conditions performed here. It was resulted in implying that the methane synthesis may proceed by the following overall reaction when the yield was compared with conversion of the both gases:
CO₂ + 4H₄ → CH₄ + 2H₂O
In addition, little byproduct was not observed in this reaction, and these experimental data showed remarkably high selectivity of the methane yield.

Global warming is mainly due to carbon dioxide (CO₂). We need high efficiency and low cost of CO₂ processing technology. In this study we carried out basic experiments on reduction of CO₂ to CO using nonthermal plasma for the purpose of using CO as fuel. In the experiments we processed CO₂ at high concentration using circulating flow and absorbent, to obtain high efficiency. We should use absorbent several times to desorb CO₂ efficiently. In the experiments using the same absorbent for eight times, CO₂ desorption increases gradually. In further experiments, we change circulation flow rate at a desorption process. By reducing the flow rate, heat from the plasma reactor stayed in the absorbent chamber. Because desorption from absorbent is endothermic reaction, the amount of CO₂ desorption increased. As a result, the amount of CO increased simultaneously.

As a convenient, low cost and safe sterilization method, atmospheric pressure plasma has been studied. It generates chemical species such as reactive oxygen species and reactive nitrogen species which have high reactivity against microorganisms. However the sterilization mechanisms, which and how the chemical species affect, are not revealed completely. We succeeded in keeping high concentrated ozone circumstances using airtight vessel filled with pure oxygen gas while reducing the generation of nitrogen oxides significantly. A plasma system was applied dielectric barrier discharge (DBD) consisted of alumina plate electrode. The applied voltage was ±1.4 kV, and the frequency was 40 kHz. The bacteria spores were sterilized in 7 min for the case of air, and 25 min for the case of water. The maximum concentration of ozone was reached 35,000 ppm in 15 min for the case of pure oxygen gas. Also for the case of water, the concentration of ozone was reached almost 6.00 mg/L in 20 min. And we produced the existence of minute amount of nitrogen by controlling the flow rate of pure nitrogen gas to 1,000 ppm. It decreased the generation of ozone and took much sterilization time compared with only oxygen plasma.

Hydrothermal treatment of organic waste was conducted and the effect of hydrothermal treatment condition on ammonia behavior in the treated slurry was evaluated. In the experiment, sludge from sewage farm was used as organic waste. Sludge slurry was hydrothermally treated in different conditions, such as treatment temperature, treatment time, rate of temperature increase and slurry concentration, and the ammonia concentration in the treated slurry was measured. Ammonia concentration was varied significantly depending on the treatment condition. The treatment temperature influence on the ammonia concentration, and the highest ammonia concentration was measured at 493 K. Treatment time also affected on the ammonia concentration, 5min treatment showed the highest ammonia concentration and the ammonia concentration decreased with increasing treatment time. The ammonia concentration increased with increasing temperature rise rate, and it was clarified that slower heating in hydrothermal treatment could control ammonia production.

Calcium has been shown good decreasing in leaching concentration of several trace elements. In the term of suppressing material, based on the previous research, paper sludge ash (PS 3) conducted good influences in controlling As, Se and B leaching concentration from coal fly ash (FA H). Paper sludge ash is waste generated by the paper recycling industry which is consisting high calcium compound concentration and it is used as an additive in trace element leaching experiment. In order to make an improvement in decreasing of trace elements leaching concentrations, coal fly ash and paper sludge ash conducted in variant ratio and waiting time. One coal fly ash sample (FA C) has been tested with variant of paper sludge ash in order to ensure the effect of suppressing material. The result initiated that PS 3 and PS 8 had the good effect in decreasing the leaching of As, Se and B. PS 8 also tested into FAC in variant addition ratio and compared with the effect of Ca(OH)₂, the result showed that PS 8 showed very close effect to Ca(OH)₂, therefore it could be used as the single suppressing material or be combined with Ca(OH)₂ with the appropriate ratio. FA C also been tested with PS 8 in variant days of waiting time before the leaching process is carried out. The results shows that sample which directly carried out to leaching process without waiting time did not show the good decreasing in Se and B leaching concentration and samples which carried out after one day of waiting shows rapidly decreasing then almost constant for the next seven days.

Drying experiment with using a drying the accelerator was conducted, and the effect of drying the accelerator addition on drying rate was evaluated. In the experiment, drying the accelerator was added to sludge 0-20wt%, and the weight of the sludge samples during drying process are monitored. In order to evaluate physical and chemical properties of drying sample, the strength of the drying sample was measured by a particle strength measurement equipment, and the functional group of the sample was analyzed by using a FT-IR. By adding drying the accelerator to sludge, drying rate of sludge increased. There was a drying trend that a drying rate increased with increasing addition ratio of the drying the accelerator. The reasons of drying acceleration with adding drying the accelerator could be increment of surface are by small cracks inside of the particle and increase of water diffusivity associating to hydrophobic function group.

In this research, the authors try to optimize operation method of storage battery on an individual house of one day by bi-directional inverter for smart house system. In the proposed system, purchase from the commercial power system is minimized by optimal operation of the bi-directional inverter on the predicted data of the energy balance and solar radiation amount of the next day. In addition, surplus electric power obtained by solar power generation is sold to electric power company. The proposed system consists of solar cells, storage battery, bi-directional inverters and simulated load. A bi-directional inverter optimization algorithm is installed into the controller of the proposed system. The operation of the controller is optimized by the genetic algorithm (GA), and the objective function gives the minimization of the amount of purchase electric power per one day. As a result, compared to the conventional method (when the proposed system is not introduced), the purchase amount was reduced by 16.4%, 33.2%, and 13.7% in January, April and July. In addition, the electricity charges were reduced by 32.4%, 44.6%, and 56.1% in January, April and July.

Due to slow response of fuel cell, small capacity of battery used to assists the Proton Exchange-membrane Fuel Cell (PEFC) that suitable for residential applications, when power fluctuation occurs from renewable energy, electric, and heat demand load, as the aim of this study. In order to reach green microgrid concept for rural area, the hydrogen fuel which produced through the water electrolysis to support uninterruptible hydrogen supply for fueling the fuel cell stacks or store for further use were also analyzed. Moreover, A 40% exhaust heat of fuel cell stored in heat storage tanks used to meet the heat demand load. In addition to the propose concept, a concrete design of the system for a group of one hundred houses was presented and analyzed by using MATLAB/Simulink. The changes performance of the model examined by the real data of Sapporo-heat- electric demand load, solar radiation and wind speed. As a result, the analysis of this proposed system obtained around 14.42 [Nm³/h] of hydrogen fuel through the electrolyzer and finally revealed that an independent fuel cell microgrid contributes significantly to improve green-microgrid system.

In the dynamic ice storage system, ice slurry is used for air conditioning. However, there is a gap between melting point of ice and cooling water temperature, and the gap is 5～12°C. So, to settle the gap TBAB hydrate slurry which has good fluidity and larger latent heat of fusion has been noticed because its melting point can be adjusted to suitable temperatures for air conditioning by varying concentrations of TBAB solution. So, the melting point existing between 5 and 12°C can be realized. However, it can be expected that a strong adhesion force of TBAB hydrate to a cooling surface occurs during formation of TBAB hydrate slurry or its transport through a pipe. In this paper, adhesion forces of TBAB hydrate to the cooling copper surface at a fixed temperature were measured varying concentrations of TBAB solution, after which the measured values were quantitatively investigated by estimating mass of free water in the TBAB hydrate which varies according to concentration of TBAB solution.

The new solar tracking system technology using MH (La_0.55Ce_0.44Ni_4.61Co_0.73Mn_0.1) actuator of the solar-heat drive is proposed. A hydrogen storage capacity is found in the relation between the temperature of MH, and the equilibrium pressure of hydrogen. Therefore, if the heat transfer amount to the MH is controllable, a hydrogen storage capacity can be taken.Hydrogen is enclosed in the same two MH reactors in which MH is contained and the solar panel tracks the angle of direction due to the difference in hydrogen pressure in these MH reactors. The hydrogen pressure of each MH reactors and the pressure difference required for driving the actuator are investigated with the 3D-CAD thermal fluid solver. Also, investigating the effect of wind condition analysis on MH and assumed the location of Sapporo in April (middle season), August (summer) and December (winter). As a result, the minimum driving pressure difference could be obtained at any time of each month. However, it was also considered, that the actuator might be driven inversely depending on the condition and cooling effect of the wind.

Honeycomb solar air heating system is highly efficient as compared to conventional solar air heaters. Efficiency of solar air heating systems depends on high solar heat gain and higher heat transfer rate from the absorber plate to air. Honeycomb type absorbers are employed for high solar energy absorption rate. The air to be heated, passes through the honeycomb hole and sides of the honeycomb absorber. To maximize the absorption of solar thermal energy several dimensions and orientation of honeycomb are necessary to be considered. Maximizing the solar heat gain is also dependent on solar altitude angle and local coordinates. Optimization of honeycomb dimensions considering the solar angles, local coordinates, tilted surface radiation characteristics etc. has been discussed in this paper.

Solar air heaters, because of its simply structure, flexible and convenient characteristic, could be widely used for winter heating of the Non-central heating building. However, the existing heaters are either too inefficient or too costly, which seriously limits their practical application. Based on this, this study proposed an aluminum honeycomb solar air heater, which used aluminum honeycomb for radiation absorption and heat transfer. In order to explore and optimize the efficiency of aluminum honeycomb solar air heater, in this research, experimental and mathematical research have been down. The results show that: aluminum honeycomb heater have higher efficiency; In mechanical ventilation, when the aluminum honeycomb parameters for the diameter * depth is 6*10mm, heater efficiency is the best; The efficiency curve of the aluminum honeycomb solar air heater is increasing with the increase of wind speed, which is basically stable at 5m/s, with 78% efficiency.

The objective of this study is to evaluate the performance of the solar chimney installed in the warehouse by variation of directions and to visualize the air flow in the warehouse. The objective crop is orange in this study. The air flow rate inside the solar chimney increases by stack effect. The solar chimney is installed in 30 degree intervals from the South to the East. The performance of the system was investigated by a computational fluid dynamics method. The results showed that the more solar chimney lean to the East, the less the air flow rate decreases in the case of installing the solar chimney on the wall. Therefore, in the case of installing on the roof, the solar chimney can ventilate during the day. By installing solar chimney, the system can lower the temperature of orange by 1.3 degC.

Since renewable energy (RE) is influenced by weather conditions makes an unstable output power of the grid. So that, the number of introduction RE into the power system is limited by the load performance of the compensation power supply. Therefore a small scale distributed power supply network that uses coal gasification combined power generation (IGCC) capable of separating and recovering CO 2 for power compensation of distributed RE to the system as the proposed concept of this study. Furthermore, introduce a flywheel into the IGCC to adjust the inertia force of the proposed system and aim to suppress the frequency fluctuation of the system. As a result of a dynamic analysis model of IGCC that investigates by using numeric analysis, was possible to increases the introduction capacity of RE through increasing the inertial force of the system by using flywheel.

Thermosyphon utilizing vapor bubble pumping, which can realize the heat transfer without requiring the outside power, has been studied intensively. However, some problems have been left for the practical application. Especially, it has been clarified that the heat transfer, that is, the circulation of working fluid becomes intermittent in the condition with small solar heat in morning and evening by the demonstration experiment using model house installed in outdoor. Then, a control system of thermosyphon system for realizing the stable heat transfer, namely almost constant flow rate of working fluid is proposed. An analytical model is required in order to develop a control system. In this report, an analytical model for the experimental equipment of thermosyphon utilizing vapor bubble pumping is discussed.

CO₂ emissions of natural gas are lower than gasoline by 20% or more. On the other hand, since the charging of the electric vehicle (EV) is carried out at night when the coal-fired power is fully operated, if the spread of EVs is suppressed, the surplus power can be adjusted by reducing the coal-fired power. When calculating CO₂ emissions from EPA's fuel and electricity consumption label value, CO₂ emissions from coal-fired power to charge EVs considerably exceed that from cars using natural gas. Technologies for generating methane from renewable energy have also been put to practical use, and natural gas vehicles (NGV) are suitable for the next generation environment-friendly cars.

This study examined the performance of a photovoltaic system with flat mirrors and south-to-north direction sun tracking system. The proposed system is composed of flat mirrors and solar cells connected each other alternately, which can track the sun by expansion and contraction. The objectives are to find out the optimum operation of the inclination angle of the solar cell and to design the ratio of the length of the flat mirror to the solar cell by ray tracing simulations. According to the simulation results, the ratio of 2.5 gives the largest solar collection which is higher than the conventional PV system by 44%. Larger flat mirrors are advantageous to collect sunlight in winter while shorter mirrors are advantageous in summer. When the ratio is less than 2.0, the efficiency of land use is better than the conventional system. The ratio of 1.5 is considered preferable from the viewpoints of both annual performance and the efficiency of land use.

This paper describes about “Ultra Lightweight Vehicle (ULV) ” which is able to drive with smallest body size and the least energy. From recent automobiles social conditions, there is a high demand for a small size and environmental-friendly mobility. Then we examined equipping the air engine as a part of the development of ULV. The result of performance test of the compressed air engine, the maximum output was 341 W, the high output area was around 800 rpm. According to the results above, we developed ULV-Air (ULV-A) with the compressed air engine. The results of the running test, the maximum speed was 23.9km/h, and the distance was about 4km. Through the evaluation of the comprehensive energy utilization by exergy, we investigated for the performance improvement of air engine and ULV-A. ULV-A is expected to be used at the theme park in Nagano prefecture as one of the demonstration test, with production of air by woody-biomass generation system.

The objectives of this study are to design a mirror concentration system with an evacuated tube heat collector installed on walls and to evaluate its performance. The proposed system consists of a parabolic mirror combined with an involute curved mirror and an evacuated tube. Ray tracing simulation was employed to evaluate the performance of collecting direct sunlight. According to the simulation results, the proposed system collects 5.9 times as much sunlight as an evacuated tube collector does. The heat collecting performance was also investigated experimentally in December 2016 and January 2017. The results indicated that the heat collected by the proposed system was 3.1 times as much as that of single evacuated tube. The proposed system was estimated to have the efficiency of heat collection of 42%.

Recent drastic economy growth with rapid urbanization in China has caused severe problem in increase of energy consumption and air pollution represented as PM 2.5. In this circumstance, annual energy consumption reduction for households and public buildings especially energy consumption reduction for AC system are not only important challenges for China but world-wide. The solar energy the highest renewable energy source is consider as solution and commercialization of solar cooling and heating system based on water fired absorption chiller is desired in China where the solar thermal usage ratio is quite high.
In this research the system adaptability in Chinese market condition (climate, load profile) is examine based on comparison of several optimized auxiliary heat source system.

This study focuses on solid oxide fuel cell (SOFC) for commercial buildings. Although SOFCs have high power generation efficiency, it was predicted that SOFCs would not be adapted by buildings with low thermal demand such as office buildings. The objective of this study is to investigate the environmental and economic effects using optimization model when SOFCs are shared by two different types of commercial buildings. Primary energy reduction rate are used as the indicator of the environmental effect. In this study, 21 cases of combination of 7 kinds of buildings were analyzed. The results show that sharing SOFCs is effective for almost all cases. Especially in the combination of hotel and office, primary energy reduction rate is enhanced by 12% more than the case installing SOFCs to individual single building.

We hereby illustrate the principle and an applications example of absorption heat pumps. Absorption heat pumps can get high grade heat fluid by low grade heat source and supplying driving heat source. In the case of absorption heat amplifier applications, enthalpy of the high grade heat fluid output includes the low grade heat source input and driving heat source input. Nevertheless, the temperature of high grade heat fluid is lower than that of driving heat source. In the case of absorption heat transformer applications, temperature of the high grade heat fluid is higher than that of the driving heat source, but heat quantity of the high grade heat fluid shall be less than the heat that of the driving heat source because about a half of the driving heat source heat quantity is transferred to the low grade heat fluid.

A large amount of waste heat is exhausted in the industrial and commercial field. In particular, low temperature heat such as that below 80~90°C is not utilized enough. The single-effect double-lift absorption chiller is driven by hot water around 95°C and utilizes it until under a 55°C return (outlet) temperature. Therefore, it is expected to recover unused low temperature waste heat, and to utilize district hot water for cooling uses in the summer. This chiller is assumed to be useful mainly in European market. In this study, we developed a prototype and conducted its performance test. Consequently, we obtained a prospect that even more heat recovery can be realized by adopting parallel-flow cycle and two-step structure for the evaporator and absorber in this single-effect double lift absorption chiller.

The problem of global warming is possibly occurred due to a problem being in energy utilization of human beings. This report aims to develop a new education method on the energy utilization based on thermodynamics with an application of exergy. A problem in conventional education on energy utilization would be the luck of balance between an energy value in a demand and the energy consumption in supply system. We are mainly using two important energy forms of electricity and thermal energy. From a viewpoint of exergy, electricity can be treated as being exergy itself but the thermal energy should be treated carefully from a viewpoint of exergy value. This report proposes to use thermal exergy-indices in the case of assessment for energy systems. EB (Exergy Balance) evaluates the exergy balance between an energy demand and the consumption as well as EE (exhaust exergy) evaluates a thermal effect to the environment. If we can supply something by consuming the same exergy amount as that required in a demand side, EB=1 (100 %), which is the ideal case. When we exhaust thermal energy to the environment, whose temperature equals to the environmental one, EE=0 as the ideal case. Not only the index-proposal but also the currently working researches are introduced as the application examples.

Single-double-effect absorption chiller is a complex system that uses dual heat sources (solar energy and gas) at the same time for the conditions of large cooling capacity or insufficient solar energy. The operation performance of this system is affected by the solution mass flow rate and the solution distribution ratio toward the double-effect side. Hence, Control strategy using the solution mass flow rate and the solution distribution ratio plays an important role to keep the stability of cooling capacity and also to enhance system performance. The appropriate combination from both of them needs to be obtained to improve the system performance. The simulation results show the improvement of the system performance by adopting the appropriate control methods is around 12-53% compared to the operation performance of the double-effect side alone.

In recent years, the amount of carbon dioxide emissions in the civil service division has been increasing, and introduction of heat source systems using renewable energy is one of countermeasures. The purpose of this research is to measure the effect of a heat source system utilizing solar heat and geothermal heat. We are monitoring and evaluating the solar thermal and geothermal hybrid heat source system newly established in the small and medium-sized restaurant street in Honjo smart energy town in Honjo Waseda, Saitama prefecture. Specifically, we evaluated the performance of each device (solar collector, adsorption refrigerator, geothermal heat pump system) making up the heat source and constructed energy prediction formula (solar heat collection amount, cooling and heating load). As a result, it is possible to clarify the parameters when conducting the actual measurement and evaluation of solar heat and geothermal heat, and it becomes possible to utilize clarification the parameters for supporting planning of a new system.

An optimal structural design approach, using hierarchical combination of artificial immune system (AIS) and mixed-integer linear programming (MILP), is developed for energy supply networks using multiple power and heat supply devices. In the energy supply network, generated power and hot water are interchanged. The optimal structure of energy supply networks is determined in consideration of multi-period operation so that annual primary energy consumption may be minimized subject to partial satisfaction of capital recovery. The developed approach is based on two level-optimization considering hierarchical relationship between design and operation variables. In the upper level, multiple sets of design variables are searched using AIS. In the lower level, optimal operational planning problems, in which the design variables are fixed, are solved using MILP and parallel computation. The developed approach is then applied to the structural design of an energy supply network for a housing complex with four residences.

Demand response (DR) is a valuable tool for balancing supply and demand in power systems. Estimating DR potential is important to analyze the effect of DR implementation in power system. We conduct literature research into the DR potential studies mainly for air conditioner in commercial sector, and consider the key point of estimation method of DR potential.

This study estimates the performance of a single stage adsorption heat pump by collecting adsorption and condensation heat for hot water supply in winter. The adsorption heat pump gains heat from cooling water that circulates in the adsorber during the adsorption process and the condenser. Silica-gel is chosen for the adsorbent. Chilled water in the evaporator utilizes groundwater of 15°C while driving heat sources are assumed to be solar thermal energy which temperature ranges from 60 to 75°C. In this study, the effects of a flow channel of cooling water, temperature and mass flow rate of the external fluids and cycle time are investigated. The performance is derived by dynamic analysis that solves differential equations of energy balance and mass balance. The results showed the COP would be 1.52 and Specific Heating Capacity would be 1756W/kg when cooling water is 15°C and heat source temperature is 75°C.

A loop-tube type thermoacoustic refrigerator consists of a thermoacoustic engine, a thermoacoustic refrigerator and a resonance tube. The engine consists of a ceramic stack with thin tubes and two heat exchangers. The temperature profile inside the stack of a thermoacoustic engine is experimentally investigated. Air is introduced as a working gas. In order to enhance the performance of the thermoacoustic system, it is important to examine the influence of the configuration of each element on the system performance, as well as overall energy conversion efficiency. In this paper, the characteristics of the engine inside are examined for various heater input to the hot side of the stack. Here, the work intensity, that is the power intensity of the generated sound, is theoretically estimated using a two-sensor method from the experimentally obtained phase difference of the sound pressure inside a resonance tube. The characteristics of the temperature profiles inside the ceramic stacks are shown. The temperature gradient on the hot side of the stack is larger than the gradient average estimated from both stack edges. This tendency appears as the temperature difference between both edges increases.

Ionic wind generator systems have a special characteristic in that it does not have mechanical driving devices. This means that it can have a long operating life without maintenance and in a quiet environment. In this paper, the influence of shapes of electrode plates and their relative position of these plates on the direction and intensity of ionic wind are experimentally examined. A pair of electrodes is introduced in the experiment in order to examine the basic characteristics of the wind. A thin plate is introduced for the discharge electrode, and a thin plate or thin wire is chosen here for the grounding electrode. The experiment was conducted for the various relative plate positions and a voltage was applied to the pair of electrodes. When the plate electrodes are applied to both poles, the ionic wind generated by this system collides with the grounding electrode and flows along the plate. The grounding plate acts as a wind direction control plate of ionic wind. On the other hand, the ionic wind takes a direction to the wire and then passes through a wire in the case of a wire grounding electrode. The specific volumetric flow rates for unit plate length are also estimated from velocity profiles.

With an ultimate goal of enhancing the flow distribution within a microchannel heat exchanger, an experimental apparatus was designed and constructed. This study presented an initial evaluation and investigation of R410A distribution with mass flowrate of 40, 60, 80 kg/h or mass flux of 120, 180, 240 kg/m²s. The inlet vapor quality before the header was varied at 0.1, 0.2 and 0.6. The inlet flow entered at the bottom with a normal location towards the vertical header. 20 horizontal parallel flat tubes having microchannel holes were protruded half-width of the header where the flow was distributed. Individual pressure drop and flowrate were measured. Corresponding inlet vapor quality for each was calculated. Visualization was conducted for the observation of the flow behavior at the vertical header. Increase on the liquid level at higher mass flux and more homogeneous two-phase flow at lower quality were observed within the header, which yielded better distribution.

Mixing/diffusion enhancement is one of the key technologies in various aspects, and is needed in chemical reactors, heat exchangers, burners/combustors, air conditioners and so on. Jets are known to be useful for such mixing/diffusion enhancement. Most of past studies concern a circular jet, namely, the jet from a nozzle with a circular cross section. On the other hand, we have been recently focusing our interest upon non-circular jets, to achieve more efficient mixing/diffusion enhancements. Among such non-circular jets, a plane jet has fundamental and practical importance. We research the jet from an asymmetrical two-dimensional nozzles to one side of which a lip changing lip length. Experiments are conducted at Reynolds numbers of 1,000 3,000 and 6,000. The aspect ratio of the nozzle exit is fixed to 300. And, the lip length is 0, 2.0h, 3.3h, 4.0h, 5.0h, 6.0h, 8.0h and 10h, where h denotes the height of the nozzle exit. We show turbulence-intensity in addition to mean-velocity profiles at various downstream sections, in order to reveal fundamental characteristics of the jet.

The purpose of this paper is to analyze the characteristics of a gas-liquid two-phase flow passing through a thin tube that includes expansion and contraction junctions. The fluid is refrigerant R134a. The refrigerant evaporates with decreasing pressure while it is passing through a thin tube. The experiments are conducted in a flow visualization device that is 0.5 mm in a thin tube diameter, 10.0 mm in its length, and 1.0 mm or 2.0 mm in contraction and expansion tube diameter. The flow characteristics are evaluated concerning the expansion and contraction diameter and the local pressure in the thin tube, and the phase transition of refrigerant flow is quantitatively analyzed by visualization with a high-speed camera and luminance intensity profile. Then, flow patterns that are analyzed by visualization are compared with that of Rémi Revellin. As a result, the local pressure drop in a thin tube is influenced by inlet pressure and the contraction and expansion diameter ratio to the thin tube. From the luminance analysis, the refrigerant in the thin tube transitioned from a bubbly flow to an annular flow. These results are compared to the extended flow pattern diagram of Rémi Revellin

A numerical simulation model of a plate-fin and tube type heat exchanger, which can switch a three phase state model with superheat, saturation, and subcool states and a two phase model with superheat and saturation states in accordance with operational conditions, is developed. Three and two phase models consist of mass, momentum, and energy balance equations for working fluid and air and result in a set of nonlinear algebraic equations, which is solved using a Newton-Raphson method. The switching from a three phase model to a two phase model is conducted when the heat transfer tube length in the subcool region becomes shorter than a threshold value. The switching from a two phase model to three phase model is conducted when the specific enthalpy of working fluid at the outlet of the heat exchanger is smaller than that of saturated liquid. A steady-state performance analysis on an air-cooled condenser, employed in a vapor compression heat pump system, reveals effectiveness of the developed switching approach for the consideration of the phase region change.

As a working-fluid candidate for high-temperature heat pumps and organic Rankine-cycles (ORCs), isopentane is considered since its normal boiling-point temperature (300.96 K) is slightly lower than n-pentane. Although it is flammable, its negligible GWP (global warming potential) is important benefit to use large amount of the working fluid in industrial energy plants. The thermodynamic equation of state used for an estimation of the cycle performance was developed based on old experimental data especially in the gas-phase. In the present study, therefore, gas-phase PVT properties were newly obtained by using an apparatus with a magnetic levitation densimeter (MLD). The present authors measured 59 gas-phase PVT properties in a temperature range from (290 to 420) K and a pressure range up to 1.45 MPa.

For effective energy utilization, power plants using organic Rankine cycle and high temperature heat pump systems are expected. The working fluids for their systems are needed to have low GWP (Global Warming Potential). So HFC245fa, existing working fluids, should be substituted. HFO1234ze(Z) is one of alternative to HFC245fa because it has a low GWP value and thermophysical properties of HFO1234ze(Z) are similar to that of HFC245fa. However, the experimental data of critical parameters, which are key property of thermophysical properites, is limited for HFO1234ze(Z). In this work, critical parameters of HFO1234ze(Z) are measured using the optical cell.