This paper describes the system study of the air turbine power generation system using high temperature air for working fluid. In the field of biomass power generation, the application of power generation using waste or biomass especially for high efficient type applied to small capacity level is delayed. Air turbine power generation system achieves high electric efficiency and high economic characteristics by the adoption of the regenerative cycle which utilize the turbine exhaust heat into the externally firing furnace and the adoption of the simple component arrangement. One of the study results shows that the electric efficiency of more than 25 % can be obtained by using biomass pellet to the 20kw level of the hot air turbine system. This study is performer by one of the subjects of the governmental project "The Countermeasures for CO_2 Emission Reduction" under the Ministry of Environment(MOE),.which has been performed for three(3) year program starting 2013.

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It is necessary for thermal power plant to achieve high heat efficiency and to use an alternative energy source because of global warming and exhaustion of fossil fuels. Heat efficiency of latest thermal power plants reaches to 60% and researches to achieve more high heat efficiency are done, for example, rising burning temperature and pressure ratio. However these measures can improve heat efficiency only few points. In this study, we try to get jumping raise of heat efficiency by reducing compression work of air compressor. To reduce compression work, we devise new system which liquefies air by using cool heat of liquid hydrogen and we propose to use liquid oxygen as the oxidizer. In this paper, we explain about this new system and calculated results which reaches 73% of heat efficiency.

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CCS is expected as countermeasure for global warming but it deteriorates efficiency of power stations. It is so important to ensure high efficiency that we are carrying out a project to develop innovative CO_2 capture power generation system whose efficiency is higher than 40%. In this project we gasify coal with a mixture of O_2 and recirculated exhaust gas, similarly to oxy-fuel combustion. As exhaust gas is mainly composed of CO_2, CO_2 capture unit is not required and in-house power is saved. Moreover CO_2 gas acts as a gasifying agent, thus gasifier performance will be improved. CRIEPI confirmed this effect using pressurized entrained flow coal gasifier. And experiments on a hot gas clean-up system have been carried out to develop countermeasures for carbon deposition in high-CO-concentration syngas. Other considerations are done to make this system feasible to construct appropriate steps toward commercialization. This paper introduces latest status of the project.

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The authors have tried to evaluate the effect of local flow field on flow accelerated corrosion (FAC), employing mass transfer rate as an evaluation parameter. In this study, corrosion rates of elbow pipe were measured using the electric resistance method. The diameter of pipe was 50 mm, and the temperature of water was controlled within ±1 at 150deg-C. In these measurements, we carried out the measurement of FAC rate of elbow pipe. We didn't use the orifice upstream from an elbow pipe. In these results, the FAC rates of an elbow pipe were higher than those of upstream and downstream from it, and those of the outside wall of an elbow pipe were higher than those of the inside wall of it.

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Flow Accelerated Corrosion (FAC) is one of the issues to be noticed considerably in plant piping management. For the integrity and safety of the plant, the wall-thinning and thinning rate due to FAC should be predicted, and we hope to construct the model to predict the wall thinning rate. We have studied FAC from the view point of flow dynamics. The mass transfer coefficient is measured by the electrochemical method with the point electrode. In this study, we evaluate the effect of concentration boundary layer on the point electrode.

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Flow accelerated corrosion (FAC) is one of the causes for wall thinning mechanisms in carbon steel pipes. We suppose that the corrosion is caused by the mass transfer diffusion of ferrous ion from the wall. In order to simulate the mass transfer coefficient in pipe flow, we adopt the analogy between mass transfer and heat transfer, and calculate the unsteady temperature field using the Large Eddy Simulation. In this paper, we study the effect of flow field on the mass transfer coefficient in an INSS elbow which added the short straight pipe in the middle of 90 degree elbow. At a Reynolds number of 15000, mass transfer coefficient is increased around outside wall surface of elbow section caused by mean flow and increased around inside wall surface of short straight section caused by unsteady flow.

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Flow Accelerated Corrosion (FAC) is one of the issues to be noticed considerably in plant management. From the previous study, it is expected that FAC can be predicted by measuring mass transfer coefficient, k. The mass transfer coefficient is measured by the electrochemical method with the point electrode and calculated by computer fluid dynamics. As a result of our simulation, the development of concentration field is different from velocity field. This result predicts that we have to improve the electro chemical method to study a mass transfer rate measured by point electrode in a complicated flow field.

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Residual seismic performance has to be evaluated in tall buildings and important structures, such as nuclear power plant, after striking earthquakes. Because of lowering brittleness of structural materials, added plastic deformation is important material characteristic to be measured, although most non-destructive tests cannot. In this study, we introduce the method to evaluate added plastic deformation in certain period by using asymptotic approach of residual magnetization to anhysteresis curve under applied stress. We show some experimental results and mechanism of this phenomena. Since external magnetic field affect the amount of residual magnetization, measurement should be limited into most deformed area. Comparing between deformed and undeformed area, we can prevent misjudgments from degradation of magnetization over time and can improve its reliability. Since ferromagnetic steels themselves plays the role of sensors and memories, this can be cheap and easy nondestructive test to clarify seismic performance of the structures.

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加圧水型原子力発電所の原子炉容器等の管台のNi基合金異材継手溶接部, あるいは1次冷却材配管材料であるステンレス鋳鋼は, 材料の音響異方性等により超音波探傷が困難と言われている. これらのNi基合金溶接部内のSCC, 及びステンレス鋳鋼内の疲労き裂について, 実機の検査で適用されるパルス反射法に基づく従来法と異なる, 高調波超音波法により探傷を行い, これらの割れの検出・画像化と寸法測定を試みた結果について報告する.

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It is well known that cavitation occurs in seawater pipes of electric power plants. Lining materials for seawater pipes suffers the damage from erosion. In this paper, we examined the relationship between the mechanical properties and the erosion rate of a chloroprene rubber and a number of polyethylene materials of different production methods. We carried out the cavitation erosion tests by using a flowing apparatus as specified in the ASTM G134-95. Power plants are used for a long period of time. The erosion rate of the aged lining material was also discussed by comparing it with the rate of new material.

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More efficient preventive maintenance and repairing techniques are required because many nuclear power plants are aging. Especially, management of Stress Corrosion Cracking is important. We have developed Laser-Peening as a preventive maintenance technique and Underwater Laser Welding as a repairing technique. In this study, we propose a new repairing technique combined local laser heating and hot wire feed device. This local laser has oblong energy distribution in heating area. A wire is heated using Joule heat in the feed device. We focused on "Laser scanning velocity", "Heating current" and "Feeding velocity", and optimized these parameters. As a consequence, we confirmed that the combination of this local laser heating and the hot wire feed device is efficient to expand repairing area.

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When a heat transfer tube is failed in a steam generator (SG) of a sodium-cooled fast reactor (SFR), pressurized water and/or water vapor leaks into liquid sodium surrounding the tube and forms a reacting jet with high temperature and high alkali. This reacting jet might cause the secondary failure of adjacent heat transfer tubes due to wastage or over-heating tube rapture resulting in undesirable failure propagation. Therefore, the sodium-water reaction phenomenon (SWR) is one of the most important issues for the design and safety assessment of SFRs. The authors have carried out systematic experiments for the elucidation of SWR and developed a new multi-physics numerical simulation system which is based on mechanistic and theoretical modeling of SWR rather than empirical modeling and can contribute to detailed and quantitative evaluations of SWR in any types of SGs. This paper summarizes the results of four years' R&D activities.

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Wastage phenomena on adjacent tubes (target-wastage) arise from water/steam leak in steam generators of sodium-cooled fast reactors. Target-wastage is likely to be caused by liquid droplet impingement erosion (LDI) and flow-accelerated corrosion (FAC) in an environment marked by high-temperature and high-alkali (reaction jet) due to sodium-water reaction. The author carried out flow-accelerated corrosion experiments as a part of phenomena clarification experiments for target-wastage by using tube material under high-temperature sodium-hydroxide and sodium monoxide conditions which are mainly generated by sodium-water reaction. New wastage correlations were derived from LDI and FAC data based on influencing factors which were formed on the periphery of an adjacent tube, and were confirmed those applicability to water leak event in this report.

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Corrosion may occur on the tube surface due to chemical reaction between sodium and water (self-wastage) if water/steam leak proceed through the penetrating crack caused in the steam generator tube of sodium-cooled fast reactor. When the self-wastage goes along up to inside wall of tube, water leak rate will be larger and it will be likely to spread the affected area caused by sodium-water reaction. It is very important to clarify the self-wastage behavior for locally affected region and detection of the water leak in real plant. In this study, we performed the self-wastage experiments under high sodium temperature condition to evaluate the effect of wastage form/geometry and water leak rate on self-wastage rate in the pinhole type micro crack.

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A mechanistic computer program called SERAPHIM to calculate compressible multicomponent multiphase flow with sodium-water chemical reaction has been developed as one of the numerical evaluation methods for heat transfer tube failure accident in a steam generator of sodium-cooled fast reactors. In this study, applicability of the SERAPHIM program was investigated through the analysis of the experiment on vertical water vapor discharging into liquid sodium under the actual condition of the steam generator. The water vapor underexpanded jet reacting with the ambient liquid sodium appeared in the numerical result. The high-velocity region of the entrained liquid droplets was formed around the jet. The impingement position of the liquid droplets on the target tube located above the water vapor discharging tube agreed with the position of the wastage mark confirmed in the experiment. The temperature distribution measured around the reacting jet was also successfully reproduced by the SERAPHIM program.

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In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes in a steam generator. Therefore the study on sodium-water chemical reactions is of paramount importance for safety reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. The sodium-water, sodium-oxygen and sodium-hydrogen counter-flow reactions were measured using laser diagnostics such as Raman, absorption and photo-fragmentation spectroscopies. The measurement results show that the main product of the sodium-water reaction is NaOH. The sodium-water reaction rate is slower than that of the sodium-oxygen reaction and hydrogen does not react noticeably with sodium.

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For countermeasure against sodium leak, structural concrete is protected by steel liner in a sodium-cooled fast reactor (SFR). However, if considering severe and unexpected accidental condition such as breach of steel liner by intensive sodium leak, the reaction of concrete with liquid sodium potentially may occur. For the purpose of elucidating the mechanism of sodium-concrete reaction in SFR, kinetic study of the sodium-hydroxide (NaOH)-silica (SiO_2) reaction was carried out by Differential Scanning Calorimetry (DSC). The parameters, including melting point of NaOH, phase transition temperature of NaOH and SiO_2, and NaOH-SiO_2 reaction temperature were identified from DSC curves. From visualization test, sample eruption was observed during reaction. It was found that rate of NaOH-SiO_2 reaction was quite fast from DSC curves, which was similar with that of the reaction between NaOH and aggregate of practical concrete. Thermal analysis results indicated that NaOH-SiO_2 reaction could occur in the timeframe of sodium-concrete reaction.

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It is quite likely that a complex turbulent flow field and large pressure fluctuation induced by separation vortex shed from the intrados of the elbows are seemed to appear in the cold leg piping of the primary cooling system of Japan Sodium-cooled Fast Reactor. This study researched the influence of the inflow condition upon the flow separation especially in the 3rd elbow. In this study, the inflow condition to the 3rd elbow was imposed by changing the distance between the 2nd and 3rd elbows from 6.4D (original design) to 9.4D. The visualization experiment showed that the flow separation appeared in the intrados of the 3rd elbow as was the case with the original design and the separated regions became larger than that in the original one. This is because a swirling flow observed at the inlet of the 3rd elbow became weaker than that in the original case.

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A Shutdown Heat Removal Test (SHRT) conducted using the EBR-II reactor at Argonne National Laboratory (ANL) in the U.S.A. was proposed by International Atomic Energy Agency (IAEA) in June 2012 as a benchmark problem. The SHRT-17 test is loss-of-flow (LOF) test, and the SHRT-45R is an unprotected loss-of-flow (ULOF) test. We use the plant system code NETFLOW++ and the neutronics code ERANOS to analyze the two tests. The SHRT-17 test is calculated using only the NETFLOW++ code because it is a purely thermal hydraulic problem. To calculate the SHRT-45R test, we should have delayed neutron data and reactivity coefficients calculated by the ERANOS code. These parameters are used in the NETFLOW++ code to conduct a neutronics - thermal hydraulic coupled calculation. In the present work, major parameters of the plant are predicted with good accuracy. But we overestimated the peak temperature of coolant because of the slightly weak reactivity feedback coefficient for sodium density change in the fuel region. When the reactivity feedback coefficient is adjusted, good agreement of the peak coolant temperature is obtained.

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Thermal-hydraulics analyses of the reactor upper plenum of Monju, Japanese prototype of FBR, were performed in IAEA/Monju-CRP from 2008 to 2012. However, detail temperature and flow rate conditions of the inlets were required for an accurate analysis. In this paper we re-evaluated the inlet boundary condition (subassembly outlets) and performed another thermal-hydraulics analysis with Star-CCM+. The surface of the structures in the upper plenum was precisely modeled. The structures included a fuel transfer machine, in-vessel racks, flow-guide tubes, etc. The result was following: the structure didn't have large influence to the temperature distribution, and the analysis result of the temperature distribution on the thermocouple plug had some difference from the test result.

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Monju is a sodium-cooled, loop-type prototype fast breeder reactor with three primary cooling loops which can supply 280 MW of electricity. If Station blackout occurs in Monju, the decay heat removal by natural circulation is required, because the power was lost for operating circulation pumps and blowers. The pressure losses of air flow path are very important factors for evaluating of the cooling ability by natural circulation because the air cooler is the ultimate heat sink and the pressure loss characteristic of air side in air cooler affects the temperature of cooling loop greatly. Therefore, the analytical model of the pressure loss characteristic of air side in the plant dynamic analysis code Super-COPD was improved for accurate simulation of natural circulation flow in this study.

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In the present work, a passive decay heat removal system for light water reactors (LWRs) based on a new concept is studied referring to an air cooling system (ACS) of the fast breeder reactor Monju. The present study will contribute to the reduction of severe accident risks of nuclear power plants. In this system, a blower for an air cooler (AC) is operated using the rotation of a small steam turbine by generated steam in order to cool heat transfer tubes by forced convection of air. The purpose of the present work is to investigate the plant transient caused by a station blackout (SBO) using the plant system code NETFLOW++ and decay heat removal characteristics. A calculation model is the Advanced Boiling Water Reactor (ABWR) in Japan.

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This paper discusses two different thermal management systems for nuclear reactor during emergency situation. First system will provide safer and reliable heat pipe based emergency core cooling system (ECCS) for nuclear-reactor, with initial 10 sec gravity feed water for accelerated cooling response. The designed loop type heat pipe ECCS is composed of cylindrical evaporator with 62 vertical tubes, each 150 mm diameter and 6 m length, mounted around the circumference of nuclear fuel assembly and 21 m x 10 m x 5 m naturally cooled finned condenser installed outside the primary containment. Proposed ECCS will be able to cool down core after reactor shutdown from 282 ℃ to below 250 ℃ within 4.3 hours of shutdown thereby providing safer environment to nuclear power plants. Second system proposes debris cooling system for nuclear reactor chamber, based on open air Bryton cycle. Such a system will provide cleaner and safer system for the nuclear reactor chamber after accident.

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In this study, we aimed to quantitatively evaluate cooling capacity of isolation condenser (IC) for core cooling in Fukushima Daiichi Nuclear Plant Unit 1. In order to evaluate cooling capacity, decay heat emitted from fuels in reactor core was calculated. We used the data of nuclear fuel and rated thermal power which is released by TEPCO. We analyzed IC with TRAC code. We made an experiment in order to check IC's input data. Because analysis data is close to experimental data, we made sure validity of input data. We analyzed IC under conditions which are recorded when IC started up and tsunami rushed toward plant. As a result of analysis, we confirmed that cooling capacity exceed decay heat under both conditions. In conclusion, IC had a capability to prevent core meltdown accident in Fukushima Daiichi Nuclear Plant Unit 1.

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This study deals with heat transfer characteristics in a blazing plate heat exchanger used as a condenser in heat pump hot water heater. In this report, experiments of single channel heat exchanger were carried out by using a pump driven two-phase flow loop. The test section has one path for each fluid, refrigerant and water. The effects of mass flow rate of refrigerant and water, wave height of plate, and setting arrangement, vertical with downward refrigerant flow or horizontal, were examined. HFC134a was used as the refrigerant. Superheated vapor was supplied to the condenser, and heated water. Water was flowing in the counter flow direction. The wall temperature distribution of the refrigerant path was measured by an infrared camera. As a result, it was shown that the lateral temperature distribution for the horizontal arrangement was affected by the wave pattern while that for the vertical arrangement was uniform.

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With the domestic energy picture changing, geothermal energy as renewable energy attracts attention. The temperature of the underground less than 100m depth will be constant by geothermal energy throughout the year. Such the ground source heat can be used as a heat sink of a heat pump. A ground source heat pump (GSHP) system offers the attractive heating and cooling system, because it is higher energy efficiency compared with conventional systems. This paper describes the experimental results obtained by using the GSHP system which is installed at University of Yamanashi. The effects of the filled material on heat exchange are evaluated. Coefficient of performance (COP) of the GSHP system is 2.3 (silica sand) and 2.6 (water) in the average.

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The objective of this study is to investigate a heat exchange performance of ground source heat pumps (GSHPs) that use the direct expansion method. This paper described an experimental result of the coefficients of performance of the GSHP system. A depth of a borehole is 30 m. The refrigerant was R410A. The experiment of heating mode was performed continuously over 48 hours. A preset value of a room temperature was changed after 24 hours from the running. Thermal performance was evaluated by a ratio of the amount of heat transferred at the indoor unit to electric power consumption of the compressor. Pressures and temperatures in the primary loop were measured when the preset value was changed during the day. The coefficients of performance of heating mode was about 4 and 7.5 when the preset value was 23℃ and 20℃, respectively.

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To reduce CO_2 emission causing global warming, it is necessary to use and expand natural renewable energy sources and to promote energy conservation. One approach is to retrieve unused energy. There is a lot of waste warm water from steelworks and petrochemical process at less than 373 K, which is not being used. We have been proposing the adsorption heat pump using zeolite to retrieve steam from warm water. We develop for practical realization. In this study, we studied a form of the steam generator based on experiments with the equipment which is able to visualize steam generation and regeneration phenomenon at the packed bed. As the results, the thickness of the packed bed is decided at 180 mm for generating steam at 423 K, and the thinner thickness of the packed bed is needed in the regeneration. Moreover we suggest the form of steam generator with line splitting.

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Drying process consumes great amount of energy, but, by attaching the evaporation-dehydration system called VCC (Vapor Compression and Condensation), energy consumption can be reduced significantly. VCC is an open-type heat pump cycle uses water. ln this study, authors take up a granulating-drying system for sewage disposal process. It is called as case-A as a reference. The adaptability of the VCC to the system is evaluated by comparing two sets of process, case-B and C. Case-B is the cascading combination of the VCC and the granulating-drying system. VCC preprocess the dehydrating process in order to relaxing the drying-load of existing centrifugal hydro-extractor. Then, to enhance the energy recovery in the process, the integrated process was derived by pinch method; that is case-C. These three cases are compared with primary energy consumption. As a result, compared with Case-A, primary energy consumption of Case-B is reduced 42.8%, and Case-C is reduced 50.5%.

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Japanese iron and steel manufacturing industries consume a lot of expensive imported coking coal and its consumption reduction is great challenge for the industry. In this paper, we proposed in-plant CO recycling system which supplements and alternates coking coal as a gaseous reducing agent in the blast furnace. Process flow diagrams including blast furnace with CO recycling, coke oven and hot stove were built by Aspen Plus and the effect of CO recycling on coal conservation and exergy efficiency was quantitatively evaluated. By using the CO gas separated from the BFG (Blast Furnace Gas), the coke oven gas, and the converter gas which are normally used to generate electric power, the coal consumption and the CO_2 emission decreased by 13.6 % and 7.3%, respectively, and consequently, the input exergy decreased by 10.4% while the effective output exergy from the system also decreased due to composition change of BFG.

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The subject of this study is to plan the operation of residential energy system with uncertain parameters based on ex-ante decision before uncertain parameters are realized. This paper applies a scenario-based stochastic programming framework to the operational planning problem having uncertain energy demand as parameters. Based on predicted energy demand scenarios, the operational strategies, which indicates the prime mover's start-stop status and the level of hot water tank, are decided. The decided operational strategies and realized values of energy demand are input to optimal control problem, which is formulated by dynamic programming. Finally we consider the operational performance of dynamic programming using the decided operational strategies based on predicted demand scenarios. As a result, the proposed stochastic programming framework decided the optimal strategies, and showed that effectiveness.

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Nowadays, PEFC-CGS is getting attention as a distributed energy system. It has high efficiency, and a lot of studies of PEFC-CGS were reported. But almost of them didn't consider energy prediction error. In this study, in order to evaluate energy-saving performance of PEFC-CGS for residential use with energy prediction error, I made PEFC-CGS control low input optimal operational plan based on energy prediction value. Consequently, operational plan to start PEFC-CGS in the morning or avoiding unneeded power runup and low load operation of PEFC-CGS can make control low of PEFC-CGS improved.

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The deployment of energy saving and fuel substitution is affected by the mechanism of boiling and heating systems selection by household. This study developed the Conjoint Analysis to deal with the simultaneous selection of boiling and heating apparatuses, and analyzed the mechanism of boiling and heating systems selection by household living in rented houses in Sapporo by using conditional logit model. The result shows that the households in Hokkaido place more importance on initial cost than fuel cost when choosing boiling and cooling apparatuses. As the households using gas boiler and oil heater, about 50% of them selects gas boiler when they buy their houses, but the selection of heaters is not affected by present fuel types. About the half of households select the high efficient apparatuses, such as electric heat pumps and heat recovery-type boilers, without subsidies.

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One of the methods to cover the change of the output by renewable energy subject is construction of micro-grid. In micro-grid the change of output of renewable energy is controlled by distributed generation. This study was performed to develop the algorithm that determines the number of gas engines and the amount of battery about several demands to use micro-grid optimally considering environmental load with genetic algorithm. In this study system that consists of photovoltaic, gas engines and battery is supposed. Evaluation functions are the emission of CO_2, system efficiency and generation cost. According to this study, variables are determined with respect to generation cost and the emission of CO_2. However, system efficiency is not taken into consideration. Furthermore evaluation of population of optimal solutions is performed. In population of optimal solutions, by investment ten thousands yen in system 25〜35 tons of the emission of CO_2 is cut.

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We are developing a highly efficient thermoacoustic system that is capable of using industrial waste heat efficiently and aim at resolution of the overheating phenomenon of a pipe. That is why we develop analysis model of thermoacoustic system by CFD. In this study, we analyze a small stack tube of thermoacoustic refrigerator by FLUENT. With thermoacoustic system, heat exchange is made between a wall pipe and oscillating flow. We measured the heat exchange by a T-S curve. The result of this study, we measured that the T-S curve is drawing the circumference. For the future, we see the relation between heat exchange and frequency.

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We are developing a highly efficient thermoacoustic system that is capable of using industrial waste heat efficiently. In this study, we have designed a taper stack, for the thermoacoustic system, in which the cross sectional area increases toward the axial direction. Theoretically, the smaller the taper ratio, the prime mover efficiency improves compared with the efficiency of a straight prime mover. The efficiency of thermoacoustic energy conversion was examined for a taper prime mover and cooler with a taper ratio of 0.75. The specific Carnot efficiency of prime mover improved to 1.85 times whereas that for a straight by experiment.

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The "dream pipe" is the name of a heat transport device that was first proposed by Kruzweg and Zhao. Their dream pipe has hot and cold liquid-reservoirs connected by a capillary bundle. If the liquid columns in the bundle reciprocate with a tidal-displacement amplitude smaller than the bundle length, the heat flow rate from the hot to cold reservoir increases remarkably depending on the amplitude and frequency of the oscillatory liquid flow. In previous studies of dream pipes, liquid working fluids were used, but their operating temperature ranges were limited in the liquid state, and one cannot apply a higher operating frequency until around 10 Hz. We propose overcoming this disadvantage using a gas working fluid. In this paper, we choose air as a working fluid, and study experimentally whether the same high heat transport process is present as for liquids.

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The purpose of our study is to develop a compact adsorption refrigeration system. Use of high pressure refrigerants, such as hydrofluorocarbons (HFCs) or CO_2 is one of approaches to reduce a system size because the volume flow rate of refrigerant can be significantly reduced. In our previous studies, adsorption equilibrium of activated carbon-R32 pair and activated carbon-R1234ze pair were measured and theoretical adsorption cycles were investigated. In the present study, we attempted to obtain kinetics of activated carbon-R32 pair from time series data of adsorption uptake. The paper reports the time constants of adsorption for activated carbon-R32 pair.

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Operating conditions play an important role in order to achieve the maximum performance for an adsorption cooling system. Therefore, in this study the performance of an adsorption cooling system using activated carbon powder/ethanol pair has been experimentally investigated by varying the heat source temperatures ranging from 70 to 90℃. From the theoretical calculations, it was shown that increasing the heating source temperature gives significant results on the adsorption heat value. The experimental study revealed heat losses that would cause degradations in COP in the actual system.

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The objective of this study is to investigate the technological feasibility of heat transportation based on ammonia absorption cycle named STA. STA recovers discharged steam from waste power generation to convert it into cooling and heating supply. An optimization model was employed to analyze technological selection wity the criteria of minimizing total system cost. The results indicate STA is adopted when the heat transportation distance is 3-6 km, which implies that heat utilization in addition to power generation is effective for waste incineration plants.

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In this study, experiment that snow melting utilization waste heat recovery of boiler with heat pipe BACH was carried out. BACH is operation principle different from conventional heat pipes. In the experiment, 50% ethylene glycol solution were enclosed in BACH and thermocouples were attached to snow melting plate and BACH, and temperature of snow melting plate and BACH when the boiler is running were recorded with date logger. Consequently, operation of the top heat BACH using the high-temperature waste heat boiler and snow melting could be confirmed. When thermal insulation material was attached to intermediate cooled section, temperature of intermediate cooled section is higher than 30 degrees without thermal insulation material. Also, amount of heat radiation on the snow melting plate was calculated. Result of calculation, amount of heat radiation was 142W. Assuming that the entire plate is snow melting possible area, heat radiation amount per square meter was 300W.

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Feasibility of a new incineration power generation combined with solar thermal energy with conventional type waste power generation has been investigated by a simulation from the viewpoint of mitigation of city thermal environment At first, performance characteristics of conventional incineration power plant to the environmental temperature were analyzed by using waste incineration plant annual operation data. A trend of decrease in power generation amount as outdoor air temperature increase was found out. Next, constitutions of the proposed new incineration power generation facility were determined by a turbine outlet steam temperature and a selection of low boiling point medium. Finally, influences of an addition of solar thermal energy against an incineration power generation were evaluated quantitatively by calculation results of both power generation capacity and power generation efficiency.

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Numerical simulation of oscillation flow steam engine is carried out. Simulation model calculates the movement of gas liquid interface, thermal conduction and phase transition. Though there are some difference between simulation results and experimental results, basic characteristics such as dependence on frequency and tube diameter can be predicted. Sensible heat is not used for phase transition but transfers from the heating section to the cooling section, which is considered to be the major cause of energy loss. Amount of liquid injection and heat transfer from cooling water have optimal values, and lower thermal conductivity material should be used for the adiabatic section.

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Low-grade Thermal Energy Conversion(LTEC) is operated using waste energy, hot spring energy, ocean themal energy as low temperature heat source under 150℃. The thermal efficiency of LTEC systems is lower than that of the conventional thermal power and nuclear power generation. Multi-stage cycle has been proposed for improving performance of the LTEC systems. Double-stage cycle(D-C) is one of Multi-stage cycle. It is clear that the maximum power output of D-C is higher than that of Single-stage cycle(S-C) by theoretical study. However, the maximum net power output is not clarify enough. LTEC can't ignore the influence of the heat source pump power. So, it is necessary to define the evaluation method of maximum net power of D-C. The purpose of this paper is to propose the evaluation method of maximum net power and compare maximum net power of D-C to S-C. In this study, it is examined that the increase of the maximum net power output of D-C theoretically in comparison with the S-C.

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We describe an exergy analysis for thermoelectric (TE) generators used as a topping cycle on top of Rankine cycle steam turbines. The TE generators are stilized to effectively convert the available heat at higher temperature than the temperature range the steam turbine uses in current power plants. The destroyed exergy flow by adding TE generators are a function of the thermal resistances. The balance between the TE power generation and the available energy for the bottoming cycle needs to be considered. We also investigate the performance per investment cost [W/$] for the topping. TE generator and the waste heat recovery TE as a comparison. Higher exergy utilization with the thermal resistance across the boiler wall improves the system efficiency by approximately 6%. Adding the topping cycle results in relatively better efficiency but significantly lower cost compared to the waste heat recovery of the flue gas of the boiler.

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