Environmental problems worsens, and a change of a personal lifestyle are demanded. In this study, we suggest LSA (Life Style Assessment) as technique to evaluate environmental load quantitatively of a lifestyle by applying LCA (Life Cycle Assessment) method, and aimed at performing examination to contribute to advancement and the spread of the methods. In this report, we expanded the evaluation targets, paid attention to the eating habits and a mobile telephone. We compared environmental load of eating out with cooking at home in the eating habits and evaluated environment load from production stage to use stage with a mobile telephone. In addition, we developed LSA software to do ELP (Environmental Load Point), our own LCA valuation method, calculation of the whole lifestyle easily and enabled that we grasped environmental load of the whole life quantitative and visual.

View full abstract

The writers suggested ELP (Environmental Load Point) as LCA (Life Cycle Assessment) valuation method to evaluate environmental load quantitatively. ELP is classified into "Panel Method" and we carried out questionnaire for estimating category weight with some questions about LCA for the purpose of getting an indicator for practical use of future LCA technique and development. Then, we take a surge of interest to environmental problems of these days, we try to research the category weight by doing the questionnaire above. The targets are students, domestic public, environment experts. We conpared with a questionnaire result of the past in that and examined how the consciousness change for environmental problems with times.

View full abstract

A latent heat storage and transportation system that collects low temperature waste heat (less than 200℃) generated from a waste incinerator or other sources and supplies it as thermal energy by transportation was licensed from Germany. It is an epoch-making system for using of untapped energy sources and reducing CO_2 emission. The technology has already been put to practical use in foreign countries. We started corroborative studies in FY2004 under the "Global Warming Prevention Tecnology" program of the Ministry of the Environment. PCM of 13.5 ton was heat transported with 20 feet container and the performance of 1.06MWh was confirmed. We would like to execute the examination corresponding to the air-conditioning demand in the future.

View full abstract

Effective utilization of waste heat from municipal solid waste incineration plants and biomass power plants has become very important to reduce CO_2 emissions. But it is difficult to use waste heat on site or very near by. Because waste heat from municipal solid waste incineration plants is too many value to use for heating and cooling applications on site. We need the method to transport waste heat to heating and cooling applications of other site. Kobe Steel Ltd. and Kobelco Eco-Solutions Co., Ltd are developing latent thermal energy storage equipment for this transport system. The erythritol of phase change material (PCM) and direct contact heat transfer technology are being used for this equipment. Direct contact heat transfer technology is thermal energy storage method of contacting heat medium to PCM directly. The advantages are high performances of heat input and heat output, light weight equipment by no heat exchanger. This time, in order to study the applicability as a heat source to the absorption refrigerator of this system, the experiment which used thermal energy storage cassette and absorption refrigerator was carried out. As a result, stable operation of this system and the effect of fuel consumption reduction were obtained.

View full abstract

The aim of this study intends to investigate the potential for H_2 rich synthesis gas production from the catalytic gasification of refuse plastic and paper fuel (RPF). Gasification experiments were conducted in a bench scale two-stage reactor with using a composite catalyst of Ni-based catalyst (G-90LDP) and CaO in the reforming process under a range of 923K to 1123K, where conversion characteristics of H_2 and the trace of impure matters, as well as the effects of main operating factors were examined. With the comparison between a non-catalytic gasification and a catalytic gasification with using G-90LDP, it indicated that the performance of reforming catalyst could be significantly improved by integrating with CaO. The highest H_2 concentration of 59vol% containing synthesis gas and the maximum H_2 yield of 49 mole/kg of RPF were generated with using the composite catalyst at 1023K. It is demonstrated that H_2 content is mainly affected by temperature, however, H_2 yield strongly affected by both temperature and steam addition. An additional advantage can be achieved in efficiently decomposing light hydrocarbons, VOC, particularly tar by the complex of the catalyst with CaO. Moreover, it also proved that through neutralization reactions, H_2S and HCl could be efficiently removed from gas product by CaO, furthermore dioxins be eliminated to a considerable low level.

View full abstract

Hydrogen production from biomass raw materials and RPF (Refuse Paper and Plastic) using fluidized bed pyrolysis gasifier were investigated. Oxygen and steam were used for gasification and fluidizer. Ni based catalysts (G90LDP, ISOP) were estimated for tar cracking and hydrogen productivity. Tar concentration in pyrolysis gas decrease with increasing pyrolysis temperatures. In the case of using Ni based catalysts, 40〜70wt% tar materials in pyrolysis gas were decomposed into volatile mater, and the H_2 content in the pyrolysis gas is 45〜70vol%, dry base.

View full abstract

This study is devoted to clarifying the effect of Ca additive on biomass gasification characteristics in a lab-scale fluidized bed gasifier coupled to a pneumatic char combustor. Addition of about 5.0wt.% CaO into the fuel increased likely the fuel conversion, but the increment degree is distinctively different depending on the addition method. While physical mixing of CaO into the fuel resulted in a very slight improvement, impregnation of the same amount of Ca onto the fuel not only elevated the fuel conversion for about 20% but also decreased the tar evolution with the product gas for more than 60%. These distinctive good catalytic effects of the impregnated Ca on fuel gasification are relative to Ca's high dispersion over the fuel matrix.

View full abstract

The possibility and availability of thermal recycling of recycled plastic resin have been investigated by supplying plastic resin powder as an auxiliary fuel to a proposed industrial twin-fueled burner. The preceding studies clarify the necessity of a series of fundamental investigations such as high-speed microscopic observations of heating and burning processes of a micro plastic resin particle under abrupt heating. In this paper the single mini-puff generator is first devised to extinguish the flame around the micro particle and to cease the heating and burning processes at an arbitrary timing after abrupt heating. The dependency of internal and external appearances of the micro plastic particle on the heating time is then analyzed to clarify the processes of melting, thermal decomposition and gasification, by combining the devised mini-puff generator and the high-speed microscopic observation system.

View full abstract

The possibility and availability of thermal recycling of recycled plastic resin have been investigated by supplying plastic resin powder as an auxiliary fuel to the proposed industrial twin-fueled burner. The preceding studies clarify the necessity of a series of fundamental investigations, such as high-speed magnifying observations of ignition and burning processes of frying micro plastic particles passing through combustion zone of the two-dimensional premixed flame. In this paper the tracking system composed of a pair of synchronized rotating plane mirrors is first devised to pursue simultaneously some micro particles in their long paths through the flame zone. By combining the devised tracking system with the high-speed video camera and by taking account of the flow patterns measured by the PIV/PTV system, effects of the particle diameter, the particle frying speed, and the relative velocity between the particle and gas velocity on the ignition and burning processes of macro particles are examined.

View full abstract

Calorie of the waste to be burnt has been increased comparing to the original design value at an existing MSW incineration plant. Incineration capacity and quality of the flue gas exhausted from the plant could be improved by adapting of Water-cooled stoker system with keeping the flue gas amount within the maximum original design value. By the improvement of the plant, total expenses of the waste treatment operation were reduced including of the initial modification cost. The overall improvements of the facilities by adapting Water-cooled stoker and other related systems contribute to reduce the maintenance cost very much and could be confirmed as a technology to be able to satisfy both in environmentally and economically.

View full abstract

We have developed a new exhaust-gas cleaning system using ceramic filters and a sodium reactant that removes particulates and acid gases in the temperature range of 300℃. This system has been applied to a kiln-type pyrolysis gas melting plant for MSW (70t/24h×2 units). As the heat source for the pyrolysis, the exhaust gas from burning the combustible gas generated by the pyrolysis process is used in this plant. This new filtration system has been applied to this exhaust gas in the temperature range of 300℃ for the removal of acid gases and the particulates. The filter element is made of ceramic (produced by Kyocera Co.) and is stronger than those made of fabrics. This plant put into operation with load in June of 2005. The dust-collection efficiency of the ceramic filter has been over 99.8% with the pressure loss of roughly 2.2kPa at a filtration speed of 1.5m/min. To prevent the corrosion of the heating pipes that carry the combustion exhaust, the HCl concentration after the exhaust-gas cleaning was set at 15ppm by controlling the reagent feed rate, enabling a stable operation within the corrosion-free state.

View full abstract

We have developed such thermal waste treatment systems for MSW (municipal solid waste) as incineration technology (mechanical stoker furnace, fluidized bed furnace), melting technology (sludge and ash melting furnace) and thermal cracking technology (kiln furnace, fluidized bed furnace). These systems are able to realize recovery of resources and effective use of energy from waste and further recycling of ash, reduction of flue gas, prevention of environmental pollution. We got the first order from Kushiro Koiki Rengou Kumiai in October 2003 and constructed the plant in October 2005. When guaranteed values (HCl≦50ppm, SOx≦50ppm, NO_x≦50ppm, CO≦30ppm and DXN≦0.1ng-TEQ/m^3N) were not only achieved but the molten slag was cleared the soil environment requirement, this plant was delivered in the end of March this year. This plant has been smoothly working now.

View full abstract

JFE developed a new slag cooling method suitable for molten slag from the ash vitrification process using an electric-resistance furnace. The system consists of twin drum type copper rolls cooled indirectly by coolant flowing inside. Slag is poured between the turning twin rolls and solidified. This paper describes the practical application of Twin-roll type slag indirect cooling equipment. The operating result shows that this method solves the conventional problems of space and water treatment.

View full abstract

The proper processing technology of hydrocarbon refrigerant isobutane (R600a) is required to prepare for recycling of the refrigerator. Isobutane extracted from the refrigerator compressor is diluted with air below the flammable range, is oxidized to CO_2 and H_2O by using a palladium catalyst. This paper describes the prototype isobutane oxidation system and its oxidation characteristics. In order to maintain the catalytic conversion efficiency highly, it is required to keep the catalyst inlet gas temperature more than 623K. Exhaust gas recirculation is effective for preheating of gas temperature.

View full abstract

Fluorinated compounds (such as CFC, HCFC, HFC, PFC and SF_6) had been used widely because of excellent features and safety for human health. However, once they are discharged into the atmosphere, they cause destruction of ozone layer and greenhouse effect of the earth, which led to restrictions in the production and use of fluorinated compounds discussed internationally in Vienna (1985), Montreal (1987), and Kyoto (1997). In Japan, fluorocarbons recovery and destruction law was enacted, and appropriate procedures for its destruction are also stipulated in the law. TSKE (Tsukishima Kankyo Engineering Ltd.) has developed a highly efficient fluorinated compounds destruction system based on the technologies accumulated over many years of experience in the destruction of chlorinated organic compounds. The first plant was constructed for destruction of by-product of fluorinated organic material production unit in 1992, before the Third Conference of Parties (COP3) agreement in Kyoto. Up to now, 13 plants in Japan and 5 plants overseas have been constructed. In 2004, this technology was awarded the "Chairman prize of the Japan Society of Industrial Machinery Manufacturers", and also was awarded the "Ministry of Economy, Trade and Industry" prize in 2005.

View full abstract

Mitsui Engineering & Shipbuilding Co., Ltd. has developed the detoxification technique for dioxins-contaminated soils and sediments by indirect-heating oxidation & decomposition method (registered as Diobreaker). We conducted the detoxification experiments of the actual soils and sediments contaminated by dioxins using the rotary-kiln type test facilities with the treatment capacity of 10 to 20kg/h (bench scale) and 70 to 150kg/h (pilot scale). As the test results, we confirmed that the dioxins in the soils and sediments were decomposed more than 99% and the dioxins that vaporized into the vent gas of the rotary-kiln was very small in its balance against the input dioxins.

View full abstract

A reductive heating treatment test using pilot scale equipment was carried out to develop an on-site decontamination process for POPs in polluted soil at lower temperatures. The pilot-scale test confirmed the reduction of BHCs from 2,354 μg/kg to 0.31 μg/kg for contaminated soil, namely removal rate of 99.99% at 550℃ for one hour under an oxygen deficient atmosphere. The content of Dioxins in treated water and gas from the reductive heating equipment also met the Japanese regulations.

View full abstract

To construct the Sustainable Society, the importance of consideration to 3R (Reduce, Reuse, Recycle) in the design phase increases in various industrial products. Concerning Reuse and Recycle, the improvement of the disassembly property is important. Then we develop the quantity disassembly property assessment method Disassembly Property Index (DPI), one of the DfE (Design for Environment) supporting tool. In this paper, we pay attention to bicycles. Recently, bicycles are produced and wasted in large quantities, therefore, it is hoped to be sustainable. Then, we examine the consideration of 3R. about bicycles. And also, we develop Disassembly Supporting Software which support the disassembly process of used products by showing disassembly flow and 3D animation

View full abstract

In recent years, global environmental problems become aggravated, and the shift to the sustainable society is required. The quantitative environmental load assessment is necessary to achieve the sustainable society. Though various LCA (Life Cycle Assessment) method is developed for such a demand, it is pointed out that there are a lot of problems in existing LCA. To solve such problems, Eco-Efficiency Potential Assessment (E2-PA) is developed. E2-PA is based on the concept of "Eco-Efficiency" and the "Potential Assessment". In this research, we pay attention to "Utility", the numerator element of the E2-PA, of the products. Utility is the quantitative index means the essential factors of products in terms of consumers. We propose a method to quantify the Utility, which is the great merit of E2-PA. The targets in this paper are notebook computers. The case study of Utility assessment and calculation of Total Index (TI), which is the integration index of E2-PA. is shown.

View full abstract

While the membrane filtration technology is installed into small-medium scale purification plants, its application to a large scale plant is also studied and incorporated. In this study, an experiment was performed to solve possible problems, using a high density immersion type hollow fiber MF membrane unit developed for large scale filtration plants. As a result, 1) experiment of the high density immersion membrane was performed and a stable operation result was obtained. 2) By using a filtration membrane for backwashing waste water, the system with the recovery rate of 99.9 to 99.95% was established. 3) In case study, estimated footprint of membrane process is less than half of conventional method but another 50% electricity is needed.

View full abstract

It is important to monitor the treated water quality at drinking water production system where membrane filtration units are installed. In this study, a new sensing system is developed which can identify the damaged membrane module quickly with high sensitivity. The developed system measures electrical resistance change if air bubbles are passed through the sensing region in the permeate water line when the membrane module has some damaged portion and air leakage is anticipated by air pressurizing. This membrane damage sensing technique is not affected by the water quality and is more sensitive than conventional systems such as high sensitivity turbidity or particle meter. The simple mechanism of the developed sensor also makes it economically feasible for installation at each membrane module.

View full abstract

Recent developments in the precision grinding technology of advanced ceramics and silicon wafer have been remarkable. However, ceramics swarf floating in grinding fluids causes scratches on the ground surface, deteriorating the surface finish. Ceramic swarf is extremely fine hard nonmagnetic substance and this shape is relatively particulate with low specific gravity. Therefore, the removal of ceramic swarf by the conventional filtration system becomes very difficult. In this report, the experimental analysis of the cross-flow microfiltration of grinding fluids was examined and the flactional void of cake layer in cross-flow microfiltration was clarified. The influences of filtration pressure, abrasive grain diameter on the fractional void was examined.

View full abstract

This paper describes fundamental characteristics of bioremediation for the purpose of in-situ remediation of oil-contaminated soil. The decomposition characteristic for the every oil was examined. It was confirmed that decomposition rate of heavy oil might be higher than that of lubricant. It is guessed that the lubricant contained an antiseptic etc. and consisted of substances with more carbon than heavy oil. Moreover, the oil decomposition characteristic for the every soil was examined. It was confirmed that kuroboku soil might have higher remediation potential than loam and sand. It is guessed that more microorganisms are contained in the kuroboku soil than loam and sand.

View full abstract

The decomposition of trace phenol in the solution, using a liquid-phase nonthermal plasma, which has been investigated by many researchers, results in extremely high power consumption. Therefore, we have investigated the phenol decomposition, using gas-phase plasma applied above the surface of the solution. However, the phenol decomposition was insufficient because the chemical reaction took place only at the surface of the solution. Then, gas bubbling was employed to enlarge the solution contact area, which resulted in significant improvement in terms of phenol decomposition in solution. Furthermore, the air mixed with argon (Ar) and hydrogen peroxide (H_2O_2) were investigated. The removal efficiency with air mixed with H_2O_2 bubbling was about twice as high as that with air bubbling alone, due to the generation of hydroxyl (OH) radical in solution.

View full abstract

The double diffusive natural convection at Freezing in aqueous solution was studied numerically. The dimensionless parameters for the calculation were the Prandtl number Pr=13, the Lewis number Le=100, the Rayleigh number Ra_0=10^6 and the buoyancy ratio N_0=1 or 10 at the salt water solidification, and Pr=13, Le=100, Ra_0=10^6 and N_0=-1 or -10 at alcohol solution solidification. At salt water solidification, salt fingers and salt-curtain were formed and developed with time. Then the solute accumulated effectually near the bottom. At alcohol solution solidification, many fingers occurred upwardly and the solute accumulated near the top surface of the enclosure. The finger pattern depends on the buoyancy ratio.

View full abstract

For the destruction of freons in formed plastics using as insulation materials for buildings, the key technology is effective defoaming and low-cost decomposition of freons. The basic study of the deforming from the polyurethane form and destruction of freons in the fluidized bed combusion of deformed residuehas been conducted. Effective recovery method of lead contained in the form from the combution gas and dioxin formation amounts are also studied.

View full abstract

A destruction equipment system for fluorocarbon compounds such as chlorofluorocarbons, which are known to be both ozone depleting and global warming substances, has been developed. This system destructs fluorocarbon compounds with a dry process using solid alkali, and has the feature without necessitating a liquid waste treatment process. Four kinds of fluorocarbons such as CFC12, HCFC22, HFC134a and SF_6 were destructed with practical scale treatment. These fluorocarbons were destructed quiet enough with the system, and the experimental results were quite satisfied with the national criterion. The destruction treatment temperatures of the system were lower than those using combustion, which was typical destruction method for fluorocarbon compounds.

View full abstract

Waste lubricating oils generally contain metallic compound impurities, which result from various additives mixed into fresh lubricating oils and wear grits generated during machine operations. To remove these metallic compounds and other impurities from waste lubricating oils for recycling as base oil, refining process with brown coal has been studied. Several steps, such as water addition, heating, adsorption with brown coal particles and solid-liquid separation (centrifugation) are included in this process for removal of impurities in various chemical forms. Then, to improve the removal performance with this process, exact chemical forms of metallic compounds and their removal mechanisms should be specified. In this study, experimental investigations were conducted to determine what mechanism happens to metallic impurities in each step and then which step would be effective to remove these impurities. Elemental composition analyses of oil samples after several processing described above showed that many kinds of elements could exist in close relation with moisture in waste lubricating oil. Some of metallic impurities separated out as depositions by a dehydration of waste oils during heat treatment. Water addition showed a stimulating effect on coal adsorption of some metallic impurities.

View full abstract

The objectives are to elucidate homogeneous mechanisms of mercury oxidization in high temperature and study the important factors on mercury oxidization in the homogeneous reaction. The mercury oxidation experiments were carried out by injecting Hg gas with HCl or Cl_2 gas, using an electrically heated horizontal reaction tube. Additionally, chemical equilibrium and chemical kinetics analyses were also conducted for studying the main mercury elementary reaction scheme theoretically. The results show that HCl has little possibility of mercury oxidation. For Cl_2 addition case, however, the mercury oxidization is enhanced more.

View full abstract

In order to control emissions of sodium compounds during coal combustion, the sorbent injection technology is tested under the coal combustion condition. Kaolin is selected as the sorbent to absorb vapors of sodium compounds evolved from the coals. In the combustion experiments, the kaolin is physically mixed with coal. Two types of coal, which have the similar coal properties, are burned. Combustion tests are conducted, using an electrically heated drop tube furnace, to study effect of kaolin addition on the capture characteristics of sodium compounds. As a result, the kaolin can effectively capture the vapor of sodium compounds even under the actual coal combustion condition. The capture efficiency depends on the coal type. The sodium compounds for the coals, which produce many fine particles with size of less than 1μm, tend to be effectively captured by the kaolin.

View full abstract

Electrical discharge process using corona is effective in reducing particulate matter (PM), nitrogen oxides (NO_x) and total hydrocarbon (THC) contained in diesel engine exhaust. We experimentally evaluate the application of DC corona discharge reactor to reduce the PM, NO_x and THC from diesel exhaust. Particulate trapping in a corona reactor can be accomplished by electrostatic precipitation. The accumulated PM on a nichrome electrode of reactor can be regenerated by the controlled burning process. In a corona reactor, NO is oxidized to NO_2 and NO_2 reacts with H_2O contained in exhaust. NO_x decreases as a result of HNO_3 formation in a reactor, and successively HNO_3 is neutralized on the filter paper contained alkali. A corona reactor consists of cylindrically-shaped outer electrode made of stainless steel and central electrode made of rolled nichrome wire. In this study, the effects of corona voltage, current and the space velocity of reactor on soot collection efficiency, NO_x removal rate and THC reduction rate are investigated. Also discussed is the particle size distribution of soot collected by a reactor.

View full abstract

The ozonizer combined with the chemical hybrid reactor is investigated using a 479cc (5.5kW) power generation diesel engine. The PM deposited on the diesel particulate filter can be incinerated by ozone and NO_2 and evaluated for various gas temperatures. The NO is oxidized to form NO_2 by ozone and produced NO_2 is reduced by the 3 mass% Na_2SO_3 chemical reactor. Furthermore, a new ozone circulation system for DPF regeneration is proposed. As the results, PM deposited on both metal and ceramic filters are successfully removed even at ambient temperature. With the use of 10L/min with 2% ozone concentration, 82% of NO is oxidized to NO_2 and 78% of NO_x is removed. The operating cost is approximately 25% of the conventional SCR.

View full abstract

We experimentally evaluate a performance and exhaust emissions of a four stroke direct injection diesel engine operating on water-fuel emulsions. Two types of water emulsified fuels are produced after the suitable selection of emulsifier. The ratio of water to fuel oil was volume of 20%. We use JIS #2 Gas oil, Gas oil containing 50% volume waste food-oil (Blend 50), Blend 50 emulsified fuel whose water particulate are 12μm (Emu) and 3μm (Emu-Hi) as tested fuels. The combustion characteristics and emissions such as NO_x, CO, HC, HCHO, O_2, CO_2 and smoke, particle size distribution are compared with the case of diesel fuel. We found that (i) the CO emissions of Emu-Hi are higher than Emu especially in the low load range. (ii) the NO_x emissions of Emu-Hi are as same as Emu in the almost load range, and smoke of water-emulsified fuels are lower than Base fuel Blend 50. (iii) fuel consumptions of engine operating on water-emulsified fuels are lower than original fuel at the high load conditions.

View full abstract

Air pollution around heavy traffic road is a major environmental problem especially in urban area. For the determination of appropriate road structure and/or for the application of some kind of air purification system to prevent serious pollution in the vicinity of the road, it is necessary to know the details of turbulent diffusion process of vehicle exhausts within the roadway. In this study, a series of numerical experiments was executed to estimate vehicle-induced turbulence and its influence on pollutant dispersion. Movement of each vehicle was represented by numerical grids explicitly. Patterns of mean velocity, turbulent intensity and mean concentration distributions within the roadway were compared between one-way and two-way facing traffic cases. Comparison was also made for some crosswind cases. In the lee side of roadway, vertical dispersion coefficient estimated in our simulation showed good agreement with that of stability-D value in Pasquill-Gifford classification.

View full abstract

As a control system to reduce the residual hydrogen after utilization as hydrogen energy, we proposed a fluidized-bed catalytic combustion system and confirmed the performance. Cousequently, we obtained the following conclusions ; hydrogen combustion rate is dependent on the bed temperature which suggests that the combustion rate is 100% over 100℃, the combustion rate is considerably decreased with less than 4% of hydrogen concentration the fluidized bed can promote the effective combustion to reduce the completely amount of expensive catalyst, the cooling tube in the fluidized bed can control the bed temperature.

View full abstract

Combustion process in stoker type incinerator consists of two steps so that complete combustion is achieved. Through the combustion processes, the flue gas including environmental pollutant is exhausted, and the reduction of the emission is required to decrease environment load. In this paper, numerical computations assuming the secondary combustion in waste incinerator are made of axisymmetric laminar jet diffusion flames, which flows air from round tube nozzle into the high temperature reducing condition assumed burnt gas from primary combustion. The effects of the flow velocity and the temperature of the air, and burnt gas composition after primary combustion given to the flame structure and NO_x formation characteristics are evaluated.

View full abstract

In order to obtain the fundamental data for deodorization of livestock excreta, effects of DME adding on the decomposition of ammonia was investigated in electric furnace and heat-exchange-type deodorizer. The results show that DME adding decreases the reaction temperature at which ammonia decomposes. Numerical analysis based on elemental reaction kinetics indicates that DME has the same effect as CH_4 by producing CO and H_2 during reaction.

View full abstract

The partial load performance tests of multi-type package air-conditioner for buildings, the rated cooling performance of which was 56kW, were carried out by using the air-enthalpy method testing apparatus. The annual energy consumption measured by those tests was closely compared with that estimated from the current calculating method. It was found that the current calculating method could not reproduce the deteriorations of COP that appeared under the low thermal load condition in both the cooling and heating seasons. As a result it seriously underestimated the annual energy consumption ; the error amounted to as large as about 20% of the measured annual electric power consumption.

View full abstract

In the field of data communication, broadband services that make use of high speed bi-directional data flow are expanding and the trend in IT equipment such as large-capacity routers and blade servers is toward higher density and greater heat generation. This creates various problems concerning the air conditioning of the data centers in which this high-heat-generating equipment is installed. We developed the "Data Center Air Conditioning System" with the objectives of reducing power consumption and eliminating local regions of high temperature in data center. It is based on four techniques: 1) design methods of raised-floor panels which have various vent hole sizes, 2) air flow design methods, such as volume of air flow in the vicinity of high heat generating equipment, 3) development of a task air conditioner and its design method and 4) development of a high-efficiency ambient air conditioner. Application of this system makes it possible to provide a good room temperature environment while reducing the air conditioning operating power by 50%.

View full abstract

In recent years global environmental problems become aggravated, and various energy-saving function and method have been introduced in vending machine. However, it is reported that useless energy is consumed because the amount of power consumption changes greatly by the installation environment in actual operation. Then, it aimed to achieve efficient conservation of energy by managing operational information on the vending machine, we did the monitoring investigation to the vending machine in the university premises. When the conservation of energy setting matched to the use state was given, the amount of power consumption of about 17.8% was reduced to 8 vending machines selling cans and PET bottles, and about 17.3% was reduced to 3 machines selling cartons. We also developed a tool which is called Best Available Allocation Supporting tool. By using this tool, we plan to propose people who operate vending machines to save vending machines energy consumption without dropping off sales.

View full abstract

Heating tower system, which is used for both cooling and heating by using water-cooled heat pump chiller, is not so widespread up to now because of the reasons as follows ; necessity of complex defroster, large space required for installation, and expensiveness. Therefore, we developed the compact and economical closed-type heating tower with the simple built-in defroster. The efficiency of the developed heating tower system is on the highest level in various air-conditioning methods.

View full abstract

This paper presents the study of a monitoring and assessment for energy supply system of public facility with Co-Generation System (CGS). Recently, CGS is expected as one of the measures for global warming. However, there are many cases that the actual operation conditions of the energy supply system, like CGS are uncertain to practice to the energy saving at the facility. Then, we focus to public facility with CGS, and investigate the energy supply system. A monitoring and assessment are done in a certain hospital CGS. Concretely, total energy available efficiency of CGS is calculated by monitoring the heat balance in CGS. And we showed the comparison result with measurement value by applying various CGS assessment method and standard.

View full abstract

Conservation of energy consumption is a pressing issue all over the world, especially for office buildings where the energy consumption has continued increasing. Cogeneration system is expected to play an effective role in energy conservation. We researched energy consumption and operation situation of gas engine cogeneration system at Keio University Shonan Fujisawa Campus from November 1, 2004 to October 31, 2005. The energy consumption at the campus is caused mainly by electricity and air-conditioning. The central system with gas-fired absorption heater chillers is the major air-conditioning system of the campus, and exhaust heat of the gas engine is effectively reused in the system by a heat exchanger in winter or an absorption chiller in summer. The effectiveness of the cogeneration system was examined taking the influence on grid power and the gas-fired absorption heater chillers into consideration, and found that the effectiveness varies seasonally depending on air-conditioning demand.

View full abstract

The Life Cycle Impact Assessment methodology is applied to specific co-generation energy systems consisting of gas turbines or gas engines, and then used to minimize the CO_2 emissions, environmental impacts and running costs during system operation. These results are compared with those of non-combined heat and power systems. The energy demands of various facilities, including hotels, hospitals, office buildings and condominiums, are analyzed. The energy balance conditions for each energy demand are formulated for the co-generation system and for the respective system components. The algorithms applied here are the well-known simplex and branch-bound methods to seek optimized eco-operation solutions from objective functions in linear programming. In this paper, an approach to select the type, capacity and configuration of co-generation systems suitable for the energy demand is proposed, and the advantages and disadvantages for the introduction of co-generation systems are examined from ecologically and economically conscious standpoints.

View full abstract

Refrigerator and Air-Conditioner Combined System improves Coefficient of Performance of the system during year and achieves diffusion of risks. This system has two refrigerating cycles and two plate heat exchangers. The case is divided into two and it is controlled systematically by connecting both cases with pipes and the signal line. This system has 27% energy saving effect by waste heat recovery heating, and 11% energy saving effect by waste heat recovery cooling, and 17% energy saving effect during year.

View full abstract

We have developed the refrigerator and air-conditioner combined system for convenience store. The heating COP of air-conditioner is improved by using exhaust heat of refrigerator. The subcooling degree of the refrigerator is increased by the air-conditioner, so that high efficiency is performed. As compared with the conventional system, it is expected to reduce the annual power consumption about 13.8% through the field test at the convenience store. Non-stop defrost of the air-conditioner can be performed by bypassing the discharge refrigerant of the compressor. Therefore, the temperature drop in the store at the time of defrost is prevented, and amenity is improved.

View full abstract

A new heat exchanger with branch structure generated easily high temperature air. This exchanger consists of rings with a diameter of about 30mm and a height of 100mm. Rings were also connected with straight tubes to the rings. The heat exchanger was set in an electric furnace and water bath adjusted to 100℃ or 600℃. Air was supplied to the top ring, and was drained from the bottom ring, repeating collosions at branch points. Air of 80℃ or above was generated, when the heat exchanger was installed in a water bath of about 100℃. High tempreture air of 500℃ or above was generated, when the furnace temperature was 600℃. Heat exchange was observed only for a short time in the spiral type exchanger without branch points. The outlet air temperature increased with the number of branch points, suggesting that the air collision at branch points stimulates the heat exchange.

View full abstract

A room temperature magnetic refrigerator deserves our attention as a refrigerator without having to use environmentally hazardous fluids, since magnetic materials showing a giant magnetocaloric effect at room temperature have been developed in the last few years. We have been investigating a performance of a magnetic refrigerator that uses water as a coolant. In the present study, we clarify the influence of heat exchanging period and water flow rate on the refrigerator performance.

View full abstract

The purpose of this study is to understand the optimum operating condition of magnetic refrigerator at room temperature for direct air-cooling. The basic components of the target system are a magnetic circuit including two permanent magnets, a test section, an air blower, and an associated instrumentation. A test cell consists of a packed bed which enclose gadolinium particles as a magnetic working substance in a prescribed packing rate. In order to understand a fundamental system performance, an experimental study have been carried out for the variety of conditions such as a volumetric flow rate of air, a packing rate of the magnetic working substance, and a shape of the magnetic working substance. The results reveal that the pressure loss during magnetization process is lower than during demagnetization process.

View full abstract

The energy demands are predicted by using multiplication Autoregressive Integrated Moving Average (ARIMA) model in consideration of the application of the optimal operation plan to the energy supply system. The ARIMA model is identified to reduce the vibration and the fluctuation of the predicted values in addition to the minimization of the error margin of the predicted values and the measured values based on it. The prediction of energy demands and the optimal operation planning are held, and the effectiveness of the identified model is confirmed.

View full abstract