-
奈良林 直
原稿種別: 本文
2009 年 75 巻 751 号 p.
387-
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
-
池本 一郎, 佐藤 幹夫
原稿種別: 本文
2009 年 75 巻 751 号 p.
388-390
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
IPCC 4th assessment report (AR4) published in 2007 concluded that the global warming is unequivocal and is very likely due to the increase in anthropogenic breenhouse gas (GHG) concentrations. Because the global warming is predicted to accelerate by increase in energy consumption and population in the developing countries from now, the drastic reduction of GHG emissions is necessary on worldwide scale. This paper describes the indications of AR4 and what kinds of power and energy are expected to mitigate the global warming in the future.
抄録全体を表示
-
大内 全, 阪井 一郎, 牧野 武史
原稿種別: 本文
2009 年 75 巻 751 号 p.
391-393
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Hokkaido Electric Power Company, Inc. (HEPCO) supplies electricity to almost all area of Hokkaido. Its service area accounts for about one-fifth of Japan's area, on the other hand, the population of the service area only accounts for 4.4% of the nation. This means Hokkaido's nature is precious, and one of HEPCO's missions is to protect such environment, with providing stable electricity. Therefore, nuclear power, which does not emit greenhouse effect gas for generation, is becoming more important. HEPCO's operating nuclear power stations are Tomari No. 1 unit and No.2 unit. Their generation capacty is 579MW respectively. Now, No.3 unit is under construction. Its generation capacity is 912MW and it will be operational in December 2009. In Hokkaido, about one fourth of electricity is now produced by nuclear power, however, after Tomari No.3 is completed, more than 40% of electricity will be produced by nuclear. So, Tomari No.3 unit will contribute stable supply of electricity in the first half of 21st century and prevent global warming in Hokkaido. This paper describes the present status of Tomari No.3 unit construction with major specifications and our efforts to prevent global warming.
抄録全体を表示
-
佐藤 育男, 岩本 隆志
原稿種別: 本文
2009 年 75 巻 751 号 p.
394-396
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Currently, nuclear power is reevaluated as clean energy to reduce greenhouse gas emission in worldwide and so called Nuclear Renaissance. At the start or under planning of construction of new nuclear power plants, it is important to turn round the development and manufacturing of large integrated forgings to improve the safety and reliability of components. In order to support the Nuclear Renaissance, it is necessary to increase the manufacturing capability for forgings.
抄録全体を表示
-
山本 泰, 武内 豊, 白川 健悦, 師岡 慎一
原稿種別: 本文
2009 年 75 巻 751 号 p.
397-399
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In the envisioned high-power density core plant, the degradation of stability is concerned that is attributed to the shortening of rod heat conduction time constant upon the dense fuel grid and the increment of pressure drop caused by the wall friction. Under power and flow oscillating conditions, the two-phase flow behavior might be different from that under the steady conditions. Therefore, the thermal-hydraulic test using the rod bundle under oscillating conditions were performed to obtain the verification data for the analysis code. In this paper, the test results were described. It was found that the critical power decreased under flow oscillating conditions compared with under steady conditions, and the power oscillation had a little effect on the critical power.
抄録全体を表示
-
野崎 謙一朗, 大川 富雄, 堀田 亮年
原稿種別: 本文
2009 年 75 巻 751 号 p.
400-402
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In the envisioned high-power density core plant, the degradation of stability is concerned that is attributed to the shortening of rod heat conduction time constant upon the dense fuel grid and the increment of pressure drop caused by the wall friction. To confirm the influence of such degradation on the fuel soundness, the bundle geometry critical power test was held under flow-power oscillation condition which envisages the unstable phenomenon occurring under in the flow transient event. This paper describes the analysis results of the cited test with sub-channel code NASCA, and the discussion of the mechanism of boiling transition under flow-power oscillating condition.
抄録全体を表示
-
大森 修一, 奈良林 直, 森 治嗣, 渡邉 史紀
原稿種別: 本文
2009 年 75 巻 751 号 p.
403-405
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
A Steam Injector (SI) is a simple, compact and passive pump. We are developing this innovative concept by applying the SI system for core injection system in emergency core cooling systems (ECCS) to further improve the safety of nuclear power plants. Passive ECCS in nuclear power plants would be inherently very safe and would prevent severe accidents by keeping the core covered with water (Severe accident-free concept). The passive core injection system (PCIS) driven by high-efficiency SI is a system that, in an accident such as a LOCA, attains a higher discharge pressure than the supply steam pressure used to inject water into the reactor by operating the SI. This report describes the experiments and the analytical simulation on a SI-driven PCIS for innovative-simplified nuclear power plant. In addition, we conducted the analytical simulations of SI, which grew in size for the actual nuclear power plant.
抄録全体を表示
-
内田 誠, 桶谷 浩一郎
原稿種別: 本文
2009 年 75 巻 751 号 p.
406-407
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
The recent worldwide "Nuclear Renaissance" is encouraging the globalization of our nuclear business and making us aware of the increasing importance of the human education and trainings for it. The basic concept of MHI's human resource development and its improvement is "The improvement in the skills and motivation of each employee leads to the strengthening of the company-wide technology base". Under this concept we are improving our job efficiency continuously by means of information technology, institutionalizing the means to improve the individual skills and motivation and investing for the effective succession of the skills. In order to take real advantage of those efforts for maintaining, strengthening and effectively handing down the nuclear technology base, it is imperative to keep the volume of actual jobs. So, we have to keep in mind that having actual business continuously is extremely important to keep the sound and solid technology base.
抄録全体を表示
-
有馬 博, 小川 雪郎, 佐川 渉
原稿種別: 本文
2009 年 75 巻 751 号 p.
408-409
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Due to environmental concerns such as global warming, needs for nuclear power is increasing. However, many expert engineers and technicians are now entering a period of retirement. And due to weak demands of new plant construction for long years, opportunity for technology learning/experience had been lost. Therefore, to secure human resource and to develop their ability are urgent issues for nuclear industries. Hitachi nuclear division continues efforts for technology transfer and human resource training. This paper describes the following two activities. (1) Improvement of common technical basis, and implementation of PDCA cycle, (2) Development of supporting tools to accelerate technology transfer through OJT (On the Job Training).
抄録全体を表示
-
班目 春樹
原稿種別: 本文
2009 年 75 巻 751 号 p.
410-412
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In order to make the inspection of nuclear facilities more effective, mutual understanding and respect between the regulatory body and the licensees, and a frank, open and yet formal relationship, shall be fostered. Thus the Research Section on Optimization of Nuclear Safety Regulation was established at JSME in 2005, where academic, regulatory and industrial members have frankly discussed for the improvement of inspection system. Agreed on the necessity of system renovation, the optimal inspection system was discussed. Suitable plant shutdown interval for the preventive maintenance was evaluated considering the current monitoring technique. At the same time, the U.S. and European inspection systems were reviewed to learn a lesson. The useful conclusions were published so that each member makes efforts for the effective inspection system. Some of the results have already been referred by the governmental task force on the inspection system improvement, and contributed to the system renovation.
抄録全体を表示
-
野間 格
原稿種別: 本文
2009 年 75 巻 751 号 p.
413-415
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
As a part of the study group's work on Optimization of Nuclear Safety Regulation of JSME, we studied the current experience and information about Containment Leakage Rate Testing (CVLRT) in the U.S. and European countries. After that, we compared their methods with the methods of CVLRT used in Japan. The results of our studies were summarized as follows: 1) In the U.S., NRC de-regulated the CVLRT methods so that the utilities could select the most efficient and the safest method. 2) In France and Belgium, the OLM (Online Leakage Monitoring) is used.
抄録全体を表示
-
大山 健, 水町 渉, 岡本 孝司, 奈良林 直, 高木 敏行
原稿種別: 本文
2009 年 75 巻 751 号 p.
416-418
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
During recent years, Nuclear Power Plants in U.S.A. have achieved high performance both in plant capacity factor and safety operation indices. Such high performance has come from Licensees' strong initiative towards safety operation supported by US NRC. This paper describes regulatory activities by US NRC Region III Office based upon 2nd JSME Delegation Visit to U.S.A., which provides us with some useful information to comprehend the above said high performance.
抄録全体を表示
-
小林 正英
原稿種別: 本文
2009 年 75 巻 751 号 p.
419-421
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Risk informed regulation for Nuclear Power Reactor is adopted widely in the U.S. In the U.S., reactor core damage frequency (CDF) is used as risk information. An acceptable value is prepared in the increment of a risk (CDF), and various actions such as online-maintenance or RI-ISI are permitted within the acceptable value. The permission time (AOT: Allowed Outage Time) when a plant can carry out continuous operation when one line of a redundant system breaks down can also utilize and search for risk information. In this report, the contents examined by the NUPEC (Nuclear Power Engineering Corporation) are reported about the evaluation method of AOT which utilized risk information, and it proposes about future practical use.
抄録全体を表示
-
根井 寿規, 班目 春樹
原稿種別: 本文
2009 年 75 巻 751 号 p.
422-424
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In order to make the inspection of nuclear facilities effective, mutual understanding and respect between the regulatory body and the licensees, NISA has been made considerable efforts open and yet formal relationship shall be fostered. For example, Inspection and optimization of Nuclear Safety Regulation meeting has been held at NISA from 2005, where academic, regulatory and industrial members, such as JSME had frankly discussion for the improvement of inspection system. Based on the agreed on the necessity of system renovation, the optimal inspection system, suitable plant shutdown interval for the preventive maintenance was evaluated considering the current monitoring technique. The useful conclusions were published so that each member makes efforts for the effective inspection system. And this year, NISA will start the new maintenance system, and inspection that is improved not also during outage but also the startup and rated operation.
抄録全体を表示
-
野田 満靖, 高橋 茂
原稿種別: 本文
2009 年 75 巻 751 号 p.
425-426
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In the nuclear power plant, many small-bore piping are near vibrational sources like pumps, and it is important to evaluate vibrational stress of the piping efficiently to prevent the fatigue failure. We developed a new method to evaluate vibrational stress using displacements measured by multiple contactless displacement sensors. The purpose of this study is to verify the applicability of the proposed method by vibration tests with a pipe. In these tests, the stress evaluated by this method was compared with the stress measured by strain gauges. As the results, the evaluated stress was in good agreement with the measured stress, but this method has some errors which are negligible comparing to endurance limit of failure. Therefore the method we developed is applicable to measure vibrational stress of small-bore piping.
抄録全体を表示
-
米田 公俊, 稲田 文夫, 森田 良, 古谷 正裕
原稿種別: 本文
2009 年 75 巻 751 号 p.
427-428
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Flow Accelerated Corrosion (FAC) requires considerable attention in plant piping management, for its potential of catastrophic pipe rupture of main piping systems. In view of fluid dynamics, the most essential factor to be considered is mass transfer at the inner surface of the pipe. Mass transfer coefficients are determined by fluid properties and piping geometry, however, no universal correlation exists, which is adaptable to various types of piping elements with strong turbulence. In this study, the modeling of mass transfer coefficient was progressed based on Chilton-Colburn analogy and utilizing "effective friction velocity" from the hydraulics in the viscous sub-layer along the wall. FAC experiments with PWR condensate water condition and CFD for the flow were conducted with a contracted rectangular duct. By considering the turbulent velocity of the viscous layer into the mass transfer coefficient, the correlation with the FAC thinning rate improved, effectively.
抄録全体を表示
-
黒崎 裕一, 高木 愛夫
原稿種別: 本文
2009 年 75 巻 751 号 p.
429-430
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Recently, wall-thinning problems of piping in power plants induced by high temperature water or a two-phase (high temperature water and steam) flow attract attentions. Since the wall thinning mechanism was not fully understood, a new test facility was constructed to evaluate a long-term wall thinning of piping under two-phase flow conditions. Using this facility, the wall-thinning tests of carbon steel pipes was carried out. The changes in wall thickness during the test period were realtime monitored using an ultrasonic sensor for high temperature applications. During the two months of the test period, the monitored pipe thickness kept decreasing steadily. The difference between the monitoring result and the actual thickness measured after testing was confirmed to be small. It is concluded, therefore, that this monitoring system is effective for wall thinning monitoring of high temperature piping.
抄録全体を表示
-
山本 敏弘, 高木 敏行, 内一 哲哉
原稿種別: 本文
2009 年 75 巻 751 号 p.
431-433
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
The remote field eddy current testing (RFECT) is usually used for inspection of ferromagnetic small tubes with inner coils. The aim of this study is to clarify the precise characteristics of RFECT for inspection of flat plates with pancake coils, which has rarely appeared in the literature. The study was performed by actual experiments and computations based on electromagnetic analysis to evaluate the capability of RFECT to detect a defect and estimate the shape of a defect. This paper introduces some of the results obtained from these computations for a simple probe configuration having only one excitation and one pick-up coils. The results shows even this simple configuration enables RFECT to detect local wall thinning and roughly estimate its shape.
抄録全体を表示
-
寺前 哲夫, 鈴木 俊一
原稿種別: 本文
2009 年 75 巻 751 号 p.
434-435
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
It is well known that the internally pressurized pipe shows the mechanical ratchet phenomenon when it is subjected to cyclic axial secondary membrane stress. This phenomenon is the main failure mode when the power plant pipes are subjected to the seismic load. In this paper, the authors show the theoretical method to calculate the shakedown limit and the hoop ratchet strain for elastic-perfectly plastic material.
抄録全体を表示
-
三浦 直樹, 曽根田 直樹
原稿種別: 本文
2009 年 75 巻 751 号 p.
436-438
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
The fracture toughness Master Curve is a universal relationship between the median of fracture toughness and temperature in the ductile-brittle transition temperature region of ferritic steels. The Master Curve approach specified in the ASTM standard theoretically provides the confidence levels of fracture toughness in consideration of the inherent scatter of fracture toughness. In this study, fracture toughness tests for Japanese reactor pressure vessel steels, with various specimen sizes and shapes were conducted. The differences in test temperature, evaluation method, and specimen size and shape did not affect the Master Curves, ascertaining that the Master Curve approach could be well applied to these classs of steels. The adequacy of the lower bounds based on the ASTM standard was also verified by comparing with experimental fracture toughness data.
抄録全体を表示
-
町田 秀夫
原稿種別: 本文
2009 年 75 巻 751 号 p.
439-441
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
For the revised edition of the Fitness-For- Service (FFS) Codes of JSME, establishment of crack growth rate due to stress corrosion cracking (SCC) is one of the principal subjects. In order to define the crack growth rate based on the data obtained from experiments, it is important to know the influence of the crack growth rate on the reliability of the components. In this study, the influence of setting of the crack growth rate due to SCC in FFS Codes on the reliability of primary loop recirculation system piping was evaluated using a probabilistic fracture mechanics analysis code. The proposal for establishment of the crack growth rate in FFS Codes was summarized based on the analytical results.
抄録全体を表示
-
岡本 孝司, 奈良林 直, 高木 敏行
原稿種別: 本文
2009 年 75 巻 751 号 p.
442-444
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
The Niigataken Chuetsu-oki earthquake attacked the Kashiwazaki-Kariwa Nuclear Power Plant (NPP) of Tokyo Electric Power Company on July 16th in 2007. The three units under normal operation and one unit under startup stage were safely shut down. The other three units are in refueling and maintenance outage. Althogh the NPP were safely controlled, even in the very strong earthquake, there were several unexpected events and many troubles. In order to investigate the influence of the earthquake on the NPP, the Research Committee had been started in the Division of Power and Energy System in JSME. This note summarizes the activities of the Research group.
抄録全体を表示
-
秋月 輝男, 岡本 孝司, 奈良林 直
原稿種別: 本文
2009 年 75 巻 751 号 p.
445-446
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Due to the Niigataken Chuetsu-oki earthquake on 16 July 2007, Tokyo Electric Power Company's Kashiwazaki-Kariwa Nuclear Power Plant (NPP) suffered from quakes exceeding design basis. The plants consisting of seven reactors and related facilities performed its essential functions required in the nuclear safety design such as "stop", "cool", and "confine" as designed, no matter whether in operation or in outage. The fact our group found through surveys in the site tells us that the experience of the Kashiwazaki-Kariwa NPP provides all NPPs with very important scientific findings.
抄録全体を表示
-
水町 渉, 小林 正英
原稿種別: 本文
2009 年 75 巻 751 号 p.
447-449
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Conventionally, the design of a nuclear reactor has been performed from a viewpoint of a safety function and the importance on earthquake-proof on the basis of not giving off the mainly included radioactivity outside. In this Niigataken-Chuetsuoki earthquake, there is almost no damage to the system, components and structure on safe also in the earthquake beyond assumption, and the validity of the design was checked. But, the situation peculiar to a big earthquake was also generated. The emergency plan room which should serve as a connection center with the exterior was not able to open a door and use at the beginning. Fire-extinguishing system piping fractured and self-defense fire fighting was not made. And so on. Discussion from the following three viewpoints was performed. (1)The importance from a viewpoint which should maintain a function also with the disaster in case of an earthquake like an emergency plan room etc. (2)In the earthquake, since the safe system and un-safe system was influenced, the importance from a viewpoint which may have influence safely inquired when the un-safe system broke down. (3)Although it was not directly related safely, discussion from a viewpoint which influences fear of insecurity, such as taking out smoke, for example, was performed.
抄録全体を表示
-
宮野 廣, 高木 敏行, 酒井 信介
原稿種別: 本文
2009 年 75 巻 751 号 p.
450-452
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
According to Chuetsu-oki earthquake in 2007, there is no significant damage on Kashiwazaki-Kariwa Nuclear Power Station's components, even though over size earthquake compare to design use had happened. This paper describes outline how to design a nuclear plant and evaluate its seismic safety, then try to make clear what safety margins there are and how much they are. Safety margins are in Safety factors apply to Load under seismic and Strength of materials covering uncertainty, Modeling of seismic integrity analysis, Damping factors, Strain-Stress diagram, and others. Recently the design method of LRFD (Load Resistance Factor Design) is studied to apply to structural design instead of traditional method.
抄録全体を表示
-
高木 敏行, 岡本 孝司
原稿種別: 本文
2009 年 75 巻 751 号 p.
453-455
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
This paper describes technical issues for the seismic safety of nuclear power plant components and also shows preliminary roadmaps for the solution of the issues. After the Chuetsu-oki earthquake of July 2007, research committees were established in JSME and AESJ for the discussion of the effect of the earthquake on NPP components. Ten technical issues due to the earthquake are pointed out and the discussion concerning the roadmaps has started to solve each issue. The goal of the activity is for the advanced design methodology with seismic safety.
抄録全体を表示
-
笠井 滋, 岡本 孝司, 秋月 輝男
原稿種別: 本文
2009 年 75 巻 751 号 p.
456-457
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
When the Kashiwazaki-Kariwa Nuclear Power Plant (NPP) of Tokyo Electric Power Company was attacked by the Niigataken Chuetsu-oki earthquake on July 16th in 2007, three units were in operation, one in start-up and the other three in refueling and maintenance outage. It is important to learn lessons from this event for improvement of the design, operation and management of nuclear power plants. In this presentation, we evaluated the experience and lessons learned from technical viewpoints, and selected good practices for disseminating and sharing them among various industries not limited to nuclear.
抄録全体を表示
-
濱本 和子, 奈良林 直, 小林 正英, 秋月 輝男, 大西 英俊
原稿種別: 本文
2009 年 75 巻 751 号 p.
458-460
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
As for the influences of Chuetsu-Oki Earthquake on Kashiwazaki-Kariwa Nuclear Power Station, we can conclude that "the safety function of the nuclear power station, that is, "Shutdown", "Cooling down" and "Isolating" functioned as per designed even against an earthquake beyond assumption, and fundamental nuclear safety could assured". Nevertheless, it is said that one of the causes that harmful rumor had spread was due to mass communication media. In the press reports on some nuclear power station when affected by an earthquake and on trouble in the nuclear power station in the future, we will propose that the publication should be really useful for habitants and citizens and be promoted in the positive and expected direction, in order not to make the same mistake as this time. JSME should aim at implement the above-mentioned proposal under cooperation with other academic societies and organizations.
抄録全体を表示
-
内堀 昭寛, 大島 宏之
原稿種別: 本文
2009 年 75 巻 751 号 p.
461-463
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
A numerical analysis method for melting/solidification phenomena has been developed to evaluate feasibility of the several candidate techniques in the nuclear fuel cycle. Our method is based on an extended finite element method, which has been developed for moving boundary problems. The basic idea of the method is to incorporate a signed distance function into a finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. This technique makes it possible to simulate movement of the solid-liquid interface without the use of a moving mesh. Construction of the finite element equation has been discussed in this study. The technique of quadrature and the method to solve the governing equations have also been constructed. The numerical solutions of the basic problems were compared to the approximate solutions or to the existing experimental data. Through these verifications, validity of the newly developed numerical analysis method has been demonstrated.
抄録全体を表示
-
大野 修司, 大木 裕, 菅原 章博, 大島 宏之
原稿種別: 本文
2009 年 75 巻 751 号 p.
464-465
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Three-dimensional thermal-hydraulic analyses of thermal stratification phenomena have been carried out in order to validate simulating ability of a single-phase thermal hydraulic code AQUA and commercial CFD codes STAR-CD and FLUENT. The analyses of thermal stratification water experiments demonstrated that the codes reproduced temperaure gradient and upward movement of the stratification interface in the case of utilizing appropriate discretization method and computational mesh arrangement for gravitational direction. No remarkable difference was observed between the calculated results with three codes. It was also shown that three turbulence models of the standard k-ε model, the RNG k-ε model and the RSM predicted fairly well the fundamental stratification behavior observed in the experiments.
抄録全体を表示
-
伊藤 啓, 功刀 資彰, 大島 宏之, 河村 拓己
原稿種別: 本文
2009 年 75 巻 751 号 p.
466-467
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
To evaluate directly gas entrainment (GE) phenomena in fast reactors, a numerical simulation method based on a high-precision volume-of-fluid (VOF) methodology have been studied. Unstructured meshes to subdivide simulation domains have been employed because exact modeling of complicated geometries is necessary for GE simulations. In this note, formulations of each calculation procedure in the high-precision VOF methodology on unstructured meshes are briefly presented. Calculation procedures of surface tension forces are also presented. In addition, unphysical behaviors of velocity distributions near gas-liquid interface induced by inappropriate formulation of pressure gradient are addressed and an appropriate formulation is presented considering proper balance conditions between pressure and surface tension forces. Finally, the improved simulation method is applied to the basic GE experiment. The simulation results show that the GE phenomena occur in the same mechanism with the experimental results.
抄録全体を表示
-
青山 卓史, 伊藤 主税, 岡崎 幸基, 原野 英樹, 渡辺 賢一, 井口 哲夫
原稿種別: 本文
2009 年 75 巻 751 号 p.
468-470
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In a sodium-cooled fast reactor, highly sensitive technology is required to detect a sodium leak from the cooling system piping or components. Conventional sodium leak detectors have difficulty in measuring small amounts of sodium leak because of the presence of salinity in the atmosphere. In order to overcome this problem, an innovative technology has been developed to selectively detect the radioactive sodium of the primary cooling system using Laser Resonance Ionization Mass Spectrometry (RIMS). This research and development program consists of investigating the detection process of sodium aerosol by RIMS, manufacturing the prototype sodium detection system, and testing its function using an actual radioactive sodium sample, which will be taken from the experimental fast reactor Joyo. The conceptual design of the prototype system and the results obtained from fundamental experiments are shown in this paper.
抄録全体を表示
-
白川 昌和
原稿種別: 本文
2009 年 75 巻 751 号 p.
471-473
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
This paper proposes an intelligent start-up schedule optimization system for a thermal power plant. This system consists of a neural network, a genetic algorithm, and an interactive multi-objective programming technique. The features of this system are as follows. (1) The start-up schedule can be optimized based on multi-objective evaluation and (2) an optimal and flexible start-up schedule can be determined with a reasonable computing time and calculation accuracy through interaction between human beings and computers.
抄録全体を表示
-
網 健行, 梅川 尚嗣, 小澤 守, 三島 嘉一郎, 齋藤 泰司
原稿種別: 本文
2009 年 75 巻 751 号 p.
474-475
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Critical Heat Flux (CHF) in a non-uniformly heated tube is very important factor in designing boiling two phase flow system. Although many investigations of CHF have been conducted under uniform heat flux and vertical upward flow condition, water tubes are affected by non-uniform heat flux distribution under inclined orientation in actual boiling system. In this series of studies, the non-uniform heat flux distribution has been realized by using the Joule heating and CHF was measured under several inclination angles, i.e. 15, 30, 45 and 90 degree. The CHF characteristic was depended on a combination of the tube orientation and the location of the maximum heat flux along the circumferential direction.
抄録全体を表示
-
横野 泰之, Debasish BISWAS, 神保 智彦, 新関 良樹
原稿種別: 本文
2009 年 75 巻 751 号 p.
476-478
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Numerical studies of 3-D incompressible viscous flow within a turbine stage based on a high order LES (Large Eddy Simulation) approach were carried out. In this work, 3-D unsteady flow was visualized to investigate the flow characteristics around the stator and the rotor. Computations were carried out for quarter cycle of a turbine stage consist of 22 stator and 19 rotor blades in order to examine the unsteadiness due to the blade number difference. The visualization of the simulation results indicated that a secondary vortex core was formed due to the interaction with the blade surface and the hub wall in the stator region. This vortex core flowed into the rotor blade. A landscape vortex at the leading edge and a large scale separation at the suction face were observed in the rotor region. The rotor wake indicated a complex 3-D structure of rolls with axis in blade height direction.
抄録全体を表示
-
小川 英之
原稿種別: 本文
2009 年 75 巻 751 号 p.
479-481
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Innovations to improve thermal efficiency, to reduce exhaust gas emissions, and to utilize alternative fuels in diesel engines are necessary to prevent global warming, to save energy resources, and to reduce the impact on the environment. Introduction of the latest materials and technologies for control and sensing is essential to achieve the innovations, including concepts which could not be realized previously but can be at present. The diesel engine will remain as the main power source of automobiles in the long term as they have superior efficiency, performance, and cost. This overview will detail the development and prospects of diesel engine technologies and alternative fuels, including bio-diesel fuels, dimethyl ether (DME), and gas to liquid (GTL) fuels.
抄録全体を表示
-
山崎 由大, 菅野 雅信, 西澤 幸紘, 永田 裕樹, 金子 成彦
原稿種別: 本文
2009 年 75 巻 751 号 p.
482-484
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Auto-ignition and combustion characteristics of biomass gas were investigated experimentally. Mock biomass gas consisted of H_2, CH_4, CO, N_2 and CO_2, was used assuming a wood pyrolysis gas. A test engine was a 3-cylinder 1.6L gas engine modifying compression ratio from 9.5 to 24 and equipping the intake air heating system. Experiments were carried out by varying equivalence ratio and fuel composition. The engine could realize auto-ignition and combustion at higher thermal efficiency with mock biomass gas, IMEP was 0.28Mpa and indicated thermal efficiency was 37% at 600rpm. The knock did not cause at higher equivalence ratio over 0.4, because the fuel had much dilution components, which made combustion speed slower like as EGR. Higher hydrogen content caused the combustion speed to be high, but it did not influence on the ignition timing. On the contrary, the high carbon monoxide content retarded ignition timing, but it did not influence on the combustion speed. Auto-ignition temperature of biomass gas was from 1000K to 1050K as same as hydrocarbon fuels.
抄録全体を表示
-
西澤 幸紘, 山崎 大輔, 永田 裕樹, 山崎 由大, 金子 成彦
原稿種別: 本文
2009 年 75 巻 751 号 p.
485-487
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
In order to use biomass resources efficiently, a small-size gas engine in a small-distributed generation system is one of the effective methods. However, existing gas engines for energy generation are too big to use in small-distributed generation systems and very expensive. So, diverting automotive engines is sensible solution because of their low cost. On the other hand, the composition of biomass gas generated from gasification plants is affected not only by the source and the gasification method but also by the gasification condition. Therefore, we aimed to develop a low cost and small size biomass gas engine by diverting an automotive engine with original control system. The intake system of the automotive gasoline engine was changed to two throttles in order to control both fuel and air flow rate respectively. The control system was constructed by assuming to use various fuels whose composition can fluctuate. Operational test was carried out by using real biomass gas from the gasification plant. As results, engine speed and air fuel ratio were stably controlled and the engine output achieved 19kW.
抄録全体を表示
-
岡田 幸順, 飯島 一樹, 山崎 由大, 金子 成彦
原稿種別: 本文
2009 年 75 巻 751 号 p.
488-489
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
The micro gas turbine (MGT) system for the biomass gas has been constructed. This system consists of MGT power generation system, mock biomass gas supply system and control system. The features technologies in this system are two-stage combustor and H infinity system controller. The combustor achieves both higher combustion efficiency and lower NO_x emission, in which a stable tubular flame combustion of the first stage supplies burned gas to the second stage and causes stable ignition and combustion of biomass gas and air pre-mixture. H infinity algorithm is employed as a system controller for its robustness for disturbances like as unpredictable fuel component fluctuation. By using this MGT system, operation test was carried out with mock biomass gas. Rotational speed of the power turbine could be kept constant with both fermentation gas and pyrolysis gas, and NO_x emission was low. The speed could be also kept constant, even when the fuel composition or load changed.
抄録全体を表示
-
河崎 澄, 山根 浩二, 森 慶太
原稿種別: 本文
2009 年 75 巻 751 号 p.
490-492
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
The aim of this study is to clarify the appropriate reaction condition for the thermal decomposition of the glycerol, in order to utilize wasted glycerol produced as a by-product of biodiesel fuel. The effect of the reaction temperature on decomposition products were examined by the experiment and the chemical equilibrium simulation. Also, the effects of steam addition and partial oxidation on thermal decomposition were investigated. Results shows that both steam addition and partial oxidation are effective to improve the gasification ratio with relatively low reaction temperature, while the heat value of product is decreased when the partial oxidation is adopted.
抄録全体を表示
-
金木 裕一, 井上 真二, 吉田 壮貴, 山越 幸康, 田村 修二
原稿種別: 本文
2009 年 75 巻 751 号 p.
493-495
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
FAME manufacturing tests with calcium oxide catalysts was carried out. Long reaction time and much calcium oxide addition gave high quality FAME. FAME content was more than 90% on practical plant. Glycerin concentration of by-product glycerin made with calcium oxide catalyst (85%) was much grater than that made with potassium hydroxide catalysts (73%) and it was greater than standard value of JIS K 3351 (2nd grade crude glycerin for industrial use, 80%). In addition, it was able to utilize as additive to bioplastics.
抄録全体を表示
-
行本 正雄, 中島 江梨香
原稿種別: 本文
2009 年 75 巻 751 号 p.
496-498
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
DME (Dimethyl Ether) attracts now big attention worldwide as a clean and economical carrier of alternative energy. It can be synthesized from various resources, such as natural gas, coal, wasted plastics, and biomass. Furthermore, because of its properties similar to propane, it has many potential uses such as electric power generation, household and diesel engine fuel. In this paper, we designed the hybrid system of DME and electric power generation using coal, natural gas and biomass for a rural area and evaluated the system of LCA and economics. The analysis shows that the system using bark cannot be brought difficult to realization economically. The system using both bark and waste plastics reduces CO_2 emission in comparison with already existing system, and is economically possible because of inverse onerous contract of disposed packed plastics. This is not restriction of the scale of plant, the distance of conveyance of ingredient or circulation income of energy.
抄録全体を表示
-
須崎 光太郎, 山田 裕之, 手崎 衆, 後藤 雄一
原稿種別: 本文
2009 年 75 巻 751 号 p.
499-501
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
High thermal efficiency is established by increasing the compression ratio while the engine is operated in SI mode. In order to suppress knocking, the octane number of the fuel is raised by partially cracking the hydrocarbon molecules. When the cracking is carried out in an onboard fuel reforming system utilizing waste heat produced from the engine, it is further effective on the thermal efficiency improvement. In this study, a prototype fuel reformer was constructed and the fuel composition was analyzed with GC-MS. The primary reference fuel 90 (PRF90) was used as the test fuel. It was found that the fuel was partially cracked into small size hydrocarbons such as iso-butene and propene, which are effective in knock suppression due to their high octane number. This fuel was supplied to the test engine, which was a 4-cylinder, 2-litter, turbo gasoline engine and the compression ratio was modified to be 12. The fuel consumption decreased by approximately 4〜6%.
抄録全体を表示
-
北川 敏明, 中原 崇志
原稿種別: 本文
2009 年 75 巻 751 号 p.
502-503
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Outwardly propagating hydrogen-air turbulent flames were studied at the equivalence ratios from 0.6 to 1.0 and the initial pressures from 0.10 to 0.50MPa. Turbulence intensity, u' was set to 0.80 to 1.59m/s. The Markstein number decreased for increasing pressures and for small equivalence ratios. The ratios of turbulent to unstretched laminar burning velocities at a constant Peclet number increased with increasing turbulence Karlovitz number and decreasing Markstein number at a constant pressure. This burning velocity ratio increased with increasing pressure at the equivalence ratios of 0.6 and 0.8. At the equivalence ratio of 1.0, however, the burning velocity ratio did not increase with increasing pressure although the Markstein number reduced with pressure.
抄録全体を表示
-
中園 徹, Khandoker Abu RAIHAN, 西村 章広
原稿種別: 本文
2009 年 75 巻 751 号 p.
504-506
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Recently DME is focused as alternative fuel because DME could be made from natural gas, biomass gas and coal. Now DME is investigated fuel for Diesel engine because Cetane number of DME is almost as same as light oil. On the other hand, DME can be blended with LPG because characteristic of DME is similar as LPG. LPG is usually used as gas fuel for small gas engine, cooking equipment and stove. LPG small gas engine drives generator and heat pump system. If mixture fuel of DME and LPG can be used instead of LPG in the market, energy security will be safe in the world. However, the knocking limit of DME is very low comparing LPG because the auto ignition temperature of DME is almost as same as light oil. This research is investigated on knocking limit of mixture fuel of DME and LPG on each ratio of DME. The test engine is natural aspirated small spark ignition gas engine which is used for micro cogeneration system. The bore size of test engine 88mm and stroke is 96mm. The displacement of the test engine is about 1.6 liter. The engine speed is 1500min^<-1>. The result showed that the knocking limit using DME mixture fuel could be improved by retarded ignition timing and A/F ratio under the limit of blend ratio without EGR is less than 30%. The limit of DME blend ratio should be less than 40% by retarded ignition timing and controlling EGR ratio in improvement of knocking limit.
抄録全体を表示
-
薦田 哲男
原稿種別: 本文
2009 年 75 巻 751 号 p.
507-509
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
This system consists of a 1MW class gas engine of which generating efficiency is 42.5% LHV, that is the best level of this class in the world, and HRSG (Heat Recover Steam Generator) with reburning system to expand heat/power ratio. The total thermal efficiency of this system is 10-20 points higher than that of conventional variable heat and power gas turbine systems or current gas engine systems in combination with independent package boiler in a range of heat/power ratio of 0.5-1.5. In this paper, features of this gas engine system which is eco-friendly and has high electrical efficiency and moderate steam output, and the energy saving effect of this system based on a field test result in some mining factory for two years are described.
抄録全体を表示
-
梅沢 修一, 渡辺 健次, 甘利 治雄
原稿種別: 本文
2009 年 75 巻 751 号 p.
510-512
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Reduction of CO_2 emissions and energy saving are the urgent issues for many fields of industries at present. Steam, occupying considerable energy consumption rate in the whole industry, is generally generated using combustion gas being higher than 1000 centigrade at boilers. However, the temperature loss is large at boiler process in the case of generated steam of 100 something centigrade. Therefore, we thought that energy saving could be accomplished if steam could be generated using low temperature heat resources. This presentation reports the development of steam generator in the case of low temperature difference between generated steam and heat resources. The steam generator was designed employing method of vaporization using falling films on heat transfer tubes, so that the size of the generator became compact. The size was calculated in the case of generated steam flow late being 2000kg/h. The development requirements and the possibility will be discussed.
抄録全体を表示
-
中垣 隆雄, 大橋 幸夫, 高橋 武雄, 山中 矢, 佐藤 純一, 笹部 和宏, 渡邊 恒典
原稿種別: 本文
2009 年 75 巻 751 号 p.
513-514
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Chemically Recuperated Gas Turbine (CRGT) is an advanced GT cycle that can increase power generation efficiency by recovering the exhaust heat with endothermic reaction of steam reforming. The CRGT fueled by Dimethyl Ether (DME) was demonstrated using 30kW Micro GT (MGT) and accomplished both 10% reduction of fuel consumption compared with steam injected GT cycle and NO_x emission level of less than 10ppm. Alternative fuel nozzle had concentric double pipe, one of which was designed to burn DME directly with diffusive combustion, and the other was premixed combustion of low-BTU reformed gas. The reformer, which was designed to fit into the MGT consisted of 96 SS 316-tubes filled with Pt catalyst and alumina balls, top and bottom headers and rectangular duct, recovered 15.3kW heat from exhaust gas and increase heating value by 7.9%.
抄録全体を表示
-
桜井 毅司, 芳賀 誠, 湯浅 三郎, 村山 元英
原稿種別: 本文
2009 年 75 巻 751 号 p.
515-516
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
An annular-type micro combustor was developed for a several hundred W-class micro gas turbine. Propane which is a liquid fuel having a large vapor pressure of 0.8Mpa at room temperature was used. A lean-premixed combustion method was applied to realize low NO_x emission. To prevent flash back when using premixture, the fuel was injected directly into the upstream region of the combustion chamber and formed the premixture. An orifice was located in the chamber to promote the fuel/air mixing and the flame stability. The flame stability limit showed enough wide operation regions including design point. The CO concentrations were less than 70ppm at the equivalence ratios over 0.42. The NO_x emission was around 20ppm (@16%O_2) at the design point. The combustor attained the high space heating rate of 800MW/(m^3・MPa) and the high combustion efficiency more than 99.5%.
抄録全体を表示
-
天谷 賢児, 村山 元英, 深井 雅宏, 黒木 唯文
原稿種別: 本文
2009 年 75 巻 751 号 p.
517-518
発行日: 2009/03/25
公開日: 2017/06/09
ジャーナル
フリー
Micro gas turbine systems have been developed as a portable power supply and the utilization of kerosene spray with pre-vaporized system was investigated for the combustor of the gas turbine. However there were few investigations about the spray characteristics with pre-vaporization. In this study, the characteristics of the kerosene spray with fuel vaporization on a hot wall were investigated experimentally. Twin fluid atomizer was used for the spray formation. Heating block, which has a straight hole, was set at the nozzle exit of the atomizer. The wall temperature of the hole was changed from 292K to 433K. Effect of the wall temperature on mean diameter of spray droplets was investigated. Spray structure was visualized by the YAG laser system. As a result, mean diameter decreased when the wall temperature was around 360K. This temperature was close to a maximum vaporization temperature of the fuel.
抄録全体を表示