-
Manabu NAKAGAWASAI, Naoya KANO, Michiko MANIHA, Shigeaki INADA
Article type: Article
Session ID: S0601-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
There is a trade-off relation between sterilization of the food and the quality (nutritional value, color, shape and smell, etc.). Presently, the main priority is the guarantee sterilization of the food at the sacrifice of the quality. In this study, the practical effect of the sterilization was verified using a low-temperature plasma in which a sterilization process was achieved without damaging the quality of the food material. For sterilization of porous food such as Hijiki and Zenmai, a boiling heat treatment was usually required, but the non-heating sterilization was realized by the plasma exposure. Also, the hydrophilicity groups formed on the surface of the porous food such as Hijiki and Zenmai, using oxygen or air plasma irradiation process. In the aqueous cleaning after the plasma exposure process, it was proven that the microorganism which inhabits the inside of the food was effectively removed with a rinse using regular tap water. It was confirmed that the absorbency of the Hijiki by the oxygen plasma treatment was more effective than that of the air plasma treatment.
View full abstract
-
Tadahisa HAYASHI, Kiyoshi NODA, Hisashi KUDO, Takaharu TSURUTA
Article type: Article
Session ID: S0601-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
We have developed a new microwave drying system which can perform the sterilization process as well as the room-temperature drying process. A wet heating sterilization is carried out after the first stage of the microwave vacuum drying. The system pressure at the sterilization process is a little lower than the atmospheric pressure and the steam is at the superheated state. After the sterilization for a several minutes the second stage of drying starts. It was confirmed that neither color nor function of food had deteriorated. We also found that the number of the bacteria (aerobic mesophilic bacteria), the endospore (bacillus) and the coliforms decreased to 1/852000, 1/108 and 1/254000 by this method.
View full abstract
-
Nurkholis HAMIDI, Kazuaki UEDA, Takaharu TSURUTA
Article type: Article
Session ID: S0601-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Effect of thawing rate on the food quality has been studied by using the mackerel. The samples were frozen at temperature -20℃ and -80℃. Three different conditions were supplied for the thawing, i.e. microwave irradiation of 100W, warming by room temperature at 25℃ and in the refrigerator at 8℃. The results indicated that drip production decreases with the decreasing thawing rates. The microwave pre-dehydration can also reduce the drip loss. The microscopic observation indicated that the muscle fibers were melted first then followed by the melting of the external ice. The melted ice (water) gradually was absorbed by the muscle fibers. The results give evidence to hypothesis that the thawing conditions affect the amount of drip loss because the cells need time for re-absorption of the extracellular water.
View full abstract
-
Yukio TADA, Yoshiaki SATOU, Akira TAKIMOTO, Hajime ONISHI
Article type: Article
Session ID: S0601-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A method to actively controlling crystallization is one of promising technique for cryopreservation. The object of this paper is to study the effects of ultrasonic irradiation on ice formation during freezing of biological materials with supercooling. In the experiments, agar gel was frozen under irradiation of ultrasound at frequency of 28kHz. The results suggest that higher degree of ultrasonic irradiation can release supercooling state, but also lower degree of ultrasonic irradiation would enhance supercooling dgree during freezing process. It was also found that the size of ice crystal decreased with increasing ultrasonic power under constant supercoling degree. The method to setting sample as possible as near the ultrasonic horn was useful for reducing ice crystal size.
View full abstract
-
Kunito OKUYAMA, Shoji MORI, Michito KISHI, Mikako TANAKA
Article type: Article
Session ID: S0601-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A simple method for the production of superheated steam using a porous ceramic block is proposed. As soon as a fine wire heater, which is set up to contact spirally with the hole surface of a porous ceramic impregnated with water, is powered, superheated steam flows out of the hole within several seconds. Efficiency of energy utilization is higher than 90% at steady state. The micro-channel heat transfer inside the dried region of the porous ceramic that forms in the proximity of the heating wire, is shown to be significant for superheating of generated steam from the temperature measurement of vapor flowing out of the micro-pores. The depth of the dried region is estimated to be at least within 1 mm from the temperature distribution in the block that was measured using micro-thermocouples.
View full abstract
-
Shogo ISSHIKI, Hiroyuki IYOTA, Tamotsu INOUE, Junko YAMAGATA
Article type: Article
Session ID: S0601-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A method for measuring a steam mole fraction at the temperature of around 80 - 300℃ and the steam mole fraction of hot air to superheated steam as the objects of heating devices for cooking, and so on, was considered in this study. The temperatures of spherical wet materials (brick and gauze) were measured in a flow system wherein the temperatures and humidity were regulated by heaters and by balancing the flow rate of steam and air, respectively. The steam mole fraction was calculated from the wet material temperatures by two methods, based on adiabatic saturated temperature and on heat and mass transfer model in boundary layer. These calculation results were in good agreement with the set values of the experimental flow conditions. The psychrometric chart for a wide temperature and humidity range including superheated steam was proposed as well. In addition, error factors of between the measured temperatures of wet material and the adiabatic saturated temperature were investigated.
View full abstract
-
Junko YAMAGATA, Hiroyuki IYOTA, Shogo ISSHIKI, Nobuya NISHIMURA
Article type: Article
Session ID: S0601-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A steam convection oven can heat a large amount of food using steam generated from a small boiler. To measure the changes in the humidity of the gas in heating chamber, we set a wet spherical gauze in the chamber during heating with and without steam.In the case of heating with steam, the steam mole fraction of chamber reached 100% after approximately 3min, the material temperature increased faster, and lesser water evaporated than in the case of heating without steam. Furthermore, it is shown that the amount of food in the chamber is effected on the humidity increasing rate during heating without steam. We show that the humidity of the gas in oven chamber affects the material temperature, the mass of evaporated water, and the time required for heating, all of these facters are important for good cooking.
View full abstract
-
Toshikazu YANO, Takahiro ORIKASA, Satoru SUGINOME
Article type: Article
Session ID: S0601-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In order to realize one fifth of Green-House Gas (GHG) on 2050, the food industry is not an exception in the reduction of GHG. The environmental evaluations are also needed against the food industry, such as agriculture, fishery, food production, distribution, consumption, disposal and recycle, by utilization of Life Cycle Assessment (LCA) and Carbon Foot Print (CFP). Moreover, the estimation and revolution of technology by thermal engineering will contribute the reduction of GHG and the food industry toward sustainable low carbon society, by the utilization of renewable energy, evaluation of environmental impact, plant factory, food production, processing and cooking food.
View full abstract
-
Tanio SUGANO, Takao YOKOYAMA
Article type: Article
Session ID: S0601-2-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Mitsuo HIGANO, Masato AKAMATSU
Article type: Article
Session ID: S0601-2-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The effect of vacuum drying of steamed rice on sake taste was studied. Aspergillus oryzae grown up on steamed sake rice was used to make Japanese Sake. Drying of steamed sake rice by vacuum technique was done instead of traditional drying. The taste of Japanese Sake made by this vacuum drying was drastically changed in comparison with that of traditional sake.
View full abstract
-
Nobushige TAMAKI, Takashi YAMAJI
Article type: Article
Session ID: G0701-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Atomization of spray and spray characteristics of aero-engine air-blast atomizer affect to improve combustion characteristics, that is, combustion efficiency, emission performance and flame stability. Air-blast atomizer is widely used atomizers for aero-engine due to the benefits such as high-dispersion of spray, generation of smoke is little under high-load condition. However, droplet of spray increases with decreasing in atomizing air flow rate. The purpose of this study is to develop the air-blast atomizer, which excellent spray with uniform and small droplets are obtained under low atomization air flow rate. Hence, the effects of supply methods of atomizing air, existence of swirling flow and atomizer design on atomization of spray were investigated.
View full abstract
-
Keiya NISHIDA, Seoksu MOON, Yuhei MATSUMOTO
Article type: Article
Session ID: G0701-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Measurement was made of the ambient gas flow field induced by the D.I. Diesel spray by means of the particle image velocimetry combined with laser induced fluorescence (LIF-PIV) technique. The Diesel fuel spray was injected into the constant volume vessel where the fluorescent tracer particles were well dispersed. The fluorescent light images from the tracer particles illuminated by the double-pulsed Nd:YAG laser sheet were only captured by a CCD camera by installing the long-pass filter in front of the camera lens. The tracer particle images were analyzed by the PIV system to obtain the ambient gas flow field. It was found that the region with the strong entrainment flow into the spray appears in the region of the upstream nozzle side and its vectors increase at the end of fuel injection. Then the vectors decreases and the region moves in the down stream direction as time proceeds.
View full abstract
-
Nobuaki MOTEGI, Mikiya ARAKI, Hideshi YAMADA, Hisao NAKAMURA, Seiichi ...
Article type: Article
Session ID: G0701-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Effects of pressure atomization using a jet engine fuel injector with wall impingement on the atomization characteristics have been investigated. In the present study, combustion test using the injector was conducted. Effects of nozzle diameter D on combustion characteristics were investigated. It is shown that when equivalence ratio φ = 0.60〜1.00, SMD is from 40 to 213 μm. Atomization mode is Air-Blasting Atomization mode. It is also shown that when equivalence ratio φ = 0.60〜0.80, El(NO_x) decreases with the increase in SMD. It is also shown that when equivalence ratio φ = 0.80〜1.00, El(NO_x) is almost constant regardless of nozzle diameter D.
View full abstract
-
Minoru SATO, Sho SHIRAGA, Masato KURAHASHI, Kazuhiko KAWAJIRI
Article type: Article
Session ID: G0701-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A multistep NO_x reduction system that set up the catalysts and the plasma equipment is developed to purify the lean-burn engine exhaust gas. The plasma equipment converts the unburnt fuel in exhaust gas into the aldehyde, and converts the nitric monoxide into the nitrogen dioxide. NO_x conversion efficiency of the NO_x selective reduction catalyst is improved by the effect of plasma equipment. Ag catalyst is used for the NO_x selection reduction catalyst, and Pt catalyst is used to purify the hydrocarbon(HC) and the carbon monoxide(CO). The conversion efficiency of the exhaust gas is obtained 75% or more in NO_x and 99% in HC and CO as the result of using these catalysts with the plasma equipment.
View full abstract
-
Shinichi MORITA, Tomohiko FURUHATA, Masataka ARAI
Article type: Article
Session ID: G0701-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Six-stroke diesel engine proposed here has six processes in one cycle, i.e. intake, 1st compression, 1st combustion, 2nd compression, 2nd combustion and exhaust. By the direct EGR in the 2nd combustion process, NO emission could be expected to decrease. However, much soot was exhausted by a weak mixing in the 2nd combustion process. In the case of pre-mixed combustion with early injection in the first combustion process, NO was reduced in the first combustion and Soot was also reduced. However, the indicated torque was decreased and CO was increased. The objective of this study is to investigate the effect of compression ratio and valve timing on the characteristics of the six-stroke diesel engine. The result obtained in this study showed that reducing compression ratio caused increases of Soot and CO emission, and indicated torque decreased. Also Soot and CO emission could be reduced by delaying the valve timing.
View full abstract
-
Ryota NAKASHIMA, Tadashige KAWAKAMI
Article type: Article
Session ID: G0701-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Nowadays, the global environmental problems, such as air pollution and global warming, and the global energy problems, such as drain of crude oil, become very serious. Internal combustion engines are main causes of these problems. So, it is necessary to achieve low emissions and low fuel consumption for internal combustion engines. Especially, in automotive diesel engines, low-particulate and low-NO_x emissions are very much needed by using blend fuels and emulsified hydrocarbon fuels. As the first step in this study, experiments have been carried out to determine the influence on combustion characteristics and NO_x, CO, CO_2 emissions for small diesel engines by using emulsified vegetable-light oil. The main conclusions are as follows: 1) The maximum burning pressure of emulsified vegetable-light oil is higher than that of blend fuel. 2) The CO emission of emulsified vegetable-light oil is lower than that of emulsified light oil. 3) The NO_x emission of emulsified vegetable-light oil is lower than that of light oil.
View full abstract
-
Hiroyuki KAMOSHIDA, Hiroshi KON, Naotake FUJITA, Michio KITANO
Article type: Article
Session ID: G0701-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper reported on combustion chamber deposits (CCD) in small two-stroke engines. As already known, the CCDs cause increased in octane number requirement and NO_x. CCDs are known to be harmful to the engine performance. To inhibit the formation of combustion chamber deposits, we can prevent the deterioration of engine performance. Using separated a piston crown and a cylinder head, the characteristic properties of deposited sediments in the combustion chamber were surveyed and analysed.
View full abstract
-
Hidekazu SUZUKI, Tsuneaki ISHIMA, Tomio OBOKATA, Yasukazu BABA
Article type: Article
Session ID: G0701-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Oil film on the piston skirt area has significant effects on friction loss, oil consumption and piston slap noise. Therefore, it is important to form necessary and sufficient oil film on the skirt. In order to clarify the oil supply mechanism to the piston skirt, the oil film behavior was visualized and observed through a sapphire cylinder. The following results were obtained: (1) Oil film on the piston skirt area was affected by adhered oil thickness to the cylinder liner. (2) Blow-by gas-dragging caused oil flow into the skirt bearing area. (3) In some cases, oil flowed from the oil drain holes at the oil ring groove into the skirt bearing area.
View full abstract
-
Tatsuya Ishimuro, Akihiko AZETSU
Article type: Article
Session ID: G0701-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A new measurement technique of liquid film thickness, such as oil film thickness, proposed by one of the authors, was developed in this study. In this technique, a fluorescent dye was dissolved in the liquid film and excited by a laser light of Nd-YAG Laser. The light beam with spectrum corresponding to a liquid film thickness was emitted perpendicular to the liquid film by stimulated emission of radiation. Through the systematic experiments, it is confirmed that the dispersion angle of the light beam is around 30 degrees which allows the optical sensor system can be set easily.
View full abstract
-
Toshihiro OZASA, Yoshinari Kawahara
Article type: Article
Session ID: G0701-3-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The authors propose a measuring method of friction in main journal bearings of an engine under construction or assembly. A crankshaft supported by main bearings in crankcase joined to a rotary encoder in one side and combined with an eccentric flywheel in the other side. A crankshaft was rotated by an electric motor and then separated from it. The angular acceleration is measured from the pulses of the rotary encoder. The moment of inertia of crankshaft is calculated from the angular acceleration and the known values of the eccentric flywheel, those are the moment of inertia and the center of gravity. Friction torque was measured with the moment of inertia of the crankshaft and angular deceleration after the crankshaft was rotated by the electric motor and then separated from it. The friction torque was measured in the different bearing numbers.
View full abstract
-
Mitsuhiro Soejima, Shingo Sakaguchi
Article type: Article
Session ID: G0701-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Regarding the tribotechnology to improve the performance and reliability of engines by solving the friction, wear and scuffing problems in the valve train, the past, present and future studies have been reviewed, considered and foreseen, so that the research and development points, namely the design concepts for the cam and follower, have been investigated and summarized as follows. (1) For the cam follower with sliding contact, the hard materials combination, the surface finish, roughness and coating are effective to better the running-in and lubricating properties. (2) The tribo-reacted layer formation on the contact surface by blending additives in engine oil is also effective. (3) The effect of the rolling contact between cam and follower on the tribotechnology becomes large under the low camshaft rotation speed.
View full abstract
-
Hirotsugu HAYASHI, Hidekazu Furuno
Article type: Article
Session ID: G0701-3-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this paper, it is clarified by using simultaneous bearing analysis that effects of balance weight on performance such as journal orbits of piston pin boss bearings and small end bearings & big end bearings of connecting rod are small as compared with result of main bearings. The four new approximate analyses considering balance weight are proposed for main bearings and influences of balance weight on main bearings are shown in good agreements of results by simultaneous analysis. Engine bearing analyses considering balance weight are established.
View full abstract
-
Hirotsugu HAYASHI, Yuta Komatsu
Article type: Article
Session ID: G0701-4-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
For scientific engine analyses, authors proposed a simultaneous and approximate analyses for connecting rod big end bearings, for piston pin bearings and for crank shaft main bearings. However, to save computation time for engine bearing analysis, it is better to innovate new iteration methods to introduce solutions of partial differential equations in finite width bearing theory. In this paper, some kinds of Runge-Kutta methods are proposed by using variable step methods with inherent algorithm of engine bearings, and the characteristic of variable step's Runge-Kutta methods in engine bearing analyses are clarified.
View full abstract
-
Hirotsugu HAYASHI
Article type: Article
Session ID: G0701-4-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
It is purpose in this paper to investigate dynamic oil film observation in journal bearings of Engine because it is important to make dear boundary conditions in engine journal bearings. More accurate apparatus of multi-purpose journal bearings is developed., and oil film behaviors in steady state are observed by using two high speed video cameras and the results are discussed.
View full abstract
-
Ryuta NAKAMURA, Akira IWABUCHI, Michimasa UCHIDATE, Sayaka KUBOTA
Article type: Article
Session ID: G0701-4-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The frictional test was examined by dry condition and lubricated condition by using the cast iron, which is known as wear resistance material and used for piston ring and cylinder liner, etc. The S45C steel was examined as a comparison material. The seizure was evaluated from viewpoints of temperature rise, coefficient of friction, wear, and surface damage. As a result, the existence of the boundary lubricating film was confirmed. For lubricated condition, seizure was defined when coefficient of friction increased to 0.3. The critical load, the critical temperature and the amount of the critical heat generation were obtained, when seizure occurred. Moreover, the difference on the wear surface before and after the seizure was detected by the surface observation using SEM, AFM and nano-indenter.
View full abstract
-
Toru NAKATSUKA, Hiroyuki YOSHIDA, Kazuyuki TAKASE
Article type: Article
Session ID: G0801-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In the thermal hydraulic design of supercritical water-cooled reactor, it is required to establish a thermal hydraulic design method which can precisely predict heat transfer deterioration of supercritical water as the core coolant. Assessments of applicability of turbulence models used in design methods have not been sufficiently performed, since the mechanism of heat transfer deterioration has not been clearly figured out yet. Japan Atomic Energy Agency has started developing prediction method of heat transfer deterioration with large eddy simulation to improve the thermal hydraulic design accuracy. In the present study, preliminary results of surveys on models and parallel computing methods are reported.
View full abstract
-
Momoko SAKAMOTO, Yosuke NAKADA, Yoichi TAKEDA, Akio OHJI
Article type: Article
Session ID: G0801-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A micro gas turbine (μGT) and a solid oxide fuel cell (SOFC) hybrid cycle power generation is considered as one of the distributed energy supply sources. Additionally, Dimethyl ether (DME), which is attracting fuel as a clean and economical alternative fuel, has the advantage of the fuel portability and easy application. In this investigation, a thermal performance analysis of the μGT SOFC system fueled by DME was performed. Dependence of the major parameters on the total heat efficiency was obtained. Higher efficiency was obtained when the system was used for the micro grid and the emergency power supply.
View full abstract
-
Shigehiko KANEKO, Kazuki IIJIMA, Tatuo WATANABE, Yudai YAMASAKI
Article type: Article
Session ID: G0801-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, to establish the methodology for controlling the rotational speed of two shaft axial micro gas turbine generator system, modeling strategy of static and dynamic characteristics of the system based on nonlinear model is proposed. This model is constructed based on the combination of measured data and correction factors and does not rely on compressor and turbine map, which yields better prediction results with higher accuracy. To investigate the stability and robustness of the system, H infinity algorithm is employed as a system controller. The difference on controller performance designed based on the dynamical modeling of the target system and the measured data is discussed.
View full abstract
-
Ken-ichi FUNAZAKI, Takeshi HORIUCHI, Keita FUJIMURA
Article type: Article
Session ID: G0801-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper deals with experimental and computational studies on heat transfer characteristics of high-pressure turbine nozzle vanes with endwall film cooling under the influence of purge flow. Main goal of this study is to reveal the behavior of upstream leakage flow upon film-cooled endwall. This study presents measurement of film effectiveness and heat transfer coefficient on the endwall of first vane. The experiment is conducted using heated air as secondary air. The experimental technique is a transient method monitoring surface temperature rise using thermochromic liquid crystal coating on the surface. The experimental results show that film effectiveness increases the leading edge region of the endwall by increasing mass flow rate from 0.8% to 2.0%. However, the coolant cannot come at downstream region of the endwall.
View full abstract
-
Yuki MATSUMOTO, Akiko KANEKO, Yutaka ABE, Kenji YAMANE
Article type: Article
Session ID: G0801-1-5
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The objective of the present study is to elucidate the influence of water flow on CO_2 hydrate film thickness. The models are developed based on the heat transfer and the mass transfer to estimate the film thickness. By the heat transfer model, the calculated hydrate film thickness increase as increasing of water flow. On the other hand, by the mass transfer model, the calculated hydrate film thickness decrease as increasing of water flow. These results indicate that the more investigation is needed to elucidate the dominating factor of initial hydrate film thickness changing with flow rate. For this reason we construct the experimental apparatus to be able to generate water flow on the hydrate film to measure the hydrate film thickness experimentally.
View full abstract
-
Shinji KUBO, Kaoru ONUKI, Masaaki NAITO, Yukio TACHIBANA
Article type: Article
Session ID: G0801-1-6
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Merits of open-cycle thermochemical processes are characterized -as compared with closed-cycle thermochemi-cal processes to make water-splitting- by unnecessity of high-temperature equipments, acceptable low thermal efficiency than water electrolysis to produce hydrogen, and conversions of unwanted materials into valuable ma-terials. This study focuses a open cycle process to produce hydrogen and sulfuric acid from water and sulfur dioxide which is obtained from sulfur of general industry wastes. Improvement of hydrogen iodide decomposition rate by absorptions of reactant of iodine into active carbon was adapted to measure thermal burden on hydrogen production section and to utilize low temperature waste heat ranged 200-400℃. A heat requirement to drive a hydrogen production reactor with active carbon was estimated to be 194 kJ/mol-H_2, thereby heat input of total process was reduced from 6380 without active carbon to 1480 kJ/mol-H_2 with that.
View full abstract
-
Firdaus BASRAWI, Takanobu YAMADA, Kimio NAKANISHI
Article type: Article
Session ID: G0801-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This study shows basic performance analysis and challenge of cogeneration system (CGS) operated by micro gas turbine (MGT) at sewage treatment plant of cold region. Especially, when biogas produced by the fermentation process in the facility is assumed to be used as fuel, whereas tendency of excess biogas is shown in summer, shortage energy for heating is shown in winter. In this study, as a one solution to the unbalance occurred, excess biogas is assumed to be stored by the methane hydrate (MH) storage method which is integrated with the whole system. While adopting an actual data as a part of the calculation procedure, results of the performance analysis are shown in this paper.
View full abstract
-
Matsunori Nara, Keisuke Akanuma
Article type: Article
Session ID: G0801-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, the biomass ethanol production using grain is done. On the other hand, the sudden rise of fodder and the fertilizer happens because grain was used for the bio-ethanol production, and the review of the raw material is being requested by the society. Then, it aimed at the bio-ethanol production that used unused woods such as the abolition woods and thinned woods in this study. We experimented on the method of the decomposition of wood that used solar energy and the photocatalyst without using a chemical oxidative decomposition of a past sulphuric acid method etc. As a result, the wood flour was decomposed to lignin and the holocellulose by the reaction of ultraviolet rays and the photocatalyst. In addition, sugar was obtained by the cellulose's that had been obtained here being similarly decomposed. However, the improvement of the treatment efficiency is future tasks in this method.
View full abstract
-
Takuya ARAIKAWA, So MANABE, Takuto ARAKI
Article type: Article
Session ID: G0801-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Polymer Electrolyte Fuel Cell (PEFC) is expected to be used in many fields as future power sources. Polymer electrolyte membrane, which is inserted in PEFC as a electrolyte, has proton conductivity that depends on its water content. It is important for improving the cell performance to keep suitable wet condition within the cell and grasp water concentration, diistribution, and its effect. It is said that the voltage response of PEFC is effected by condensed water, so in this study, we predicted the voltage response at the conditions with/without condensed water, and compared the results with experimental data. Both numerical and experimental results had relatively good agreement, and appropriateness of analytical model might be comfirmed.
View full abstract
-
Kenji OHORA, Kouichi OHTA, [in Japanese], Takuto ARAKI
Article type: Article
Session ID: G0801-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The heat and mass transport characteristics of gas diffusion layer have strong influence on Polymer Electrolyte Fuel Cell (PEFC) performance. In this study, we measured thermal conductivity of GDL by steady state method and discussed about diffusive characteristics of GDL. Little difference was observed in diffusive resistances of GDL with or without PTFE. Measured diffusive resistances can be organized by (u/l)^<0.5>
View full abstract
-
Satoshi NISHIMURA, Tomonari KOGA, Izumi KINOSHITA
Article type: Article
Session ID: S0803-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
4S (Super-Safe, Small and Simple) is a sodium cooled fast reactor with non-refueling core, aiming to play a local energy supplier. The core is very tall and has a dense arrangement of thick fuel pins in order to achieve a long life. Since previous thermal hydraulic data is limited to thin fuel pin bundles with larger pin-to-pin gap, we have conducted experimental studies focusing on the thermal hydraulics for such a unique fuel subassembly. The present paper addresses water experiments with an enlarged sector model.
View full abstract
-
Nobuyuki KIMURA, Jun Kobayashi, Hideki KAMIDE
Article type: Article
Session ID: S0803-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Hot and cold fluids are mixed at the core outlet of sodium cooled fast reactors. The temperature fluctuation causes high cycle thermal fatigue in structural components. The temperature fluctuation at the core outlet region has not a sinusoidal waveform but an irregular spike waveform. In the study, the evaluation method for the high cycle thermal fatigue was investigated against the spike waveform of temperature fluctuation. It was found that the combinational method between the peak-to-peak value of temperature fluctuation and the frequency response function of structure could evaluate the fatigue damage in structure.
View full abstract
-
Kei ITO, Tomoaki Kunugi, Hiroyuki OHSHIMA, Takumi Kawamura
Article type: Article
Session ID: S0803-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
To evaluate the gas entrainment (GE) phenomenon in sodium-cooled fast reactors, two methods are proposed in this study. One is a CFD-based prediction method and the other is a high-precision numerical simulation method for interfacial flows. In the CFD-based prediction method, a theoretical flow model is applied to the CFD result obtained on a relatively coarse mesh to determine the indicators of the GE phenomenon, e. g. interfacial dent. This method was validated by evaluating the occurrence condition of the GE phenomenon in the full-scale testing of a fast reactor. On the other hand, several numerical algorithms were developed to achieve the high-precision numerical simulation of interfacial flows. In the development, physics-basis formulations were derived to improve the simulation accuracy on interface tracking. As a result, it was confirmed that the developed numerical simulation method can reproduce the GE phenomenon observed in a simple GE experiment.
View full abstract
-
Hiroyuki OHSHIMA, Tomoyuki UWABA, Akihiko HASHIMOTO
Article type: Article
Session ID: S0803-1-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Adoption of higher burn-up core can be considered as one of effective methods to enhance economic competitiveness for the commercialization of sodium-cooled fast reactors and it becomes possible with evaluating and confirming structural integrity of fuel assemblies under high bum-up conditions. A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency (JAEA) in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies under various operating conditions. In this paper, an analysis method of thermal-hydraulics in a wire-wrapped and deformed fuel pin bundle using two kinds of component programs of the numerical simulation system and its application to an irradiated fuel assembly analysis are described.
View full abstract
-
Yoshihisa NISHI, Yuzuru EGUCHI, Takashi NISHIHARA, Izumi KINOSHITA, Ka ...
Article type: Article
Session ID: S0803-2-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In measurement of an ultrasonic flowmeter, the flow rate in piping is obtained using some measurement signals along the "chord" of the circular cross section of the piping. As for the "Chordal type ultrasonic flowmeter", the flow rate is obtained by four (or eight) "chords". The wall roughness influences the velocity profile. To evaluate the influences of roughness change on the measurement using four velocity points, a water test was performed. In the wall where sand of 0.1mm diameter was pasted, no difference in the velocity profile with the smooth wall was observed. A change in the velocity profiles appeared in the rough surface pipe where sands of 0.6mm and 0.2mm diameter has been pasted. It was suggested that the change could be diagnosed by the surveillance parameter VSLR when the inside surface of pipe roughness changed. It was found that the Reynolds number dependency of the measurement and the sensitivity of the roughness are small.
View full abstract
-
Kimitoshi YONEDA, Ryo MORITA, Kazutoshi FUJIWARA
Article type: Article
Session ID: S0803-2-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Flow Accelerated Corrosion (FAC) requires considerable attention in plant piping management, for its potential of catastrophic pipe rupture of main piping systems. For rational management dealing with FAC, besides present wall thickness measurement, quantitative prediction method is willing to be introduced for pipe residual lifetime evaluation, in parallel. In this study, FAC prediction model was investigated by re-constructing Sanchez-Caldera's method with single-oxide film based mechanism. The model's applicability was verified by adapting FAC experiment data.
View full abstract
-
Akio Takota, Yuji Kuroda, Masashi Tatematsu, Masaya Kondou, Yoshiyuki ...
Article type: Article
Session ID: S0803-2-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Contributing the establishment of technical basis for advanced codes and standards for the management of flow accelerated corrosion (FAC)-induced pipe thinning. 3D PIV measurements on orifice downstream flow including the global flow patterns and the influence of forced swirl was performed. There is some correlation between the large-scale motion and the velocity gradient close to the wall. This result shows that the large scale motion has some effect on the pipe thinning mechanism.
View full abstract
-
Masaya KONDO, Yuji KURODA, Akio TAKOTA, Yoshiyuki TSUJI, Yutaka KUKITA
Article type: Article
Session ID: S0803-2-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The mass transfer from the pipe wall to the bulk water is electrochemically estimated to study the effect of pipe flow on pipe wall thinning induced by FAC. The estimation shows that the mass transfer from the pipe wall surface to the bulk water varies with the 〜0.3 and 〜0.6 power of Reynolds number at laminar flow condition and turbulent flow condition.
View full abstract
-
Akira FUKUICHI, Yutaka ABE, Akiko KANEKO, Tadashi NARABAYASHI, Chikako ...
Article type: Article
Session ID: S0803-3-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Supersonic steam injector is a passive jet pump without rotating machine and high efficient heat exchanger because of the direct contact condensation between the supersonic steam and the subcooled water jet. It is considered that flow behavior in the steam injector is governed by the direct contact condensation and complicated turbulent flow with large shear stress induced by velocity difference between the steam and water. However, the studies about the turbulent flow under the large shear stress with direct contact condensation are not enough. Especially mechanisms of the momentum and the heat transfer are not clarified in detail. Objective of the present study is to investigate the turbulent behaviors of the water jet and the interface between the supersonic steam and the water jet. Interfacial wave in the mixing nozzle is observed by using a high speed camera. It is suggested that there are some correlations between the interfacial wave propagation velocity and heat transfer of water jet in the mixing nozzle.
View full abstract
-
Yuta SANO, Yutaka ABE, Akiko KANEKO, Fumitoshi WATANABE, Kenichi TEZUK ...
Article type: Article
Session ID: S0803-3-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The evaluation of coolant flow at a lower plenum of an advanced boiling water reactor (ABWR) is very important because there are a lot of structures such as control rod guide tubes. The simulation results by a CFD (Computational Fluid Dynamics) code can predict such complicated flow in the lower plenum. It is required to establish the database of flow structure in lower plenum of ABWR experimentally for the benchmark of CFD code. In the model of the lower plenum, we measured velocity profiles by LDV and PIV with a high-speed video camera. Velocity and turbulent energy profile are obtained from experiment and numerical simulation. Average velocity profiles were qualitatively good agreement in both experiment and simulation.
View full abstract
-
Tetsuaki TAKEDA, Akira HONMA, Yuta SUGAI
Article type: Article
Session ID: S0803-3-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The objective of this study is to investigate heat transfer characteristics by forced or natural convection of porous materials inserted into a rectangular channel with high porosity. In order to obtain the heat transfer characteristics of the one-side heated vertical rectangular channel inserting the porous material, an experiment was carried out. From the results obtained in this experiment, it was found that an amount of removed heat by forced convection using porous material (porosity > 0.996) was about 10% higher than that without the copper wire. Furthermore, the ratio between the amounts of heat removed of the rectangular channel with the porous material and without the porous material increases with increasing temperature of the channel wall. It was found that there is possibility to enhance the heat transfer by not only forced convection bet also natural convection.
View full abstract
-
Tomohisa KURITA, Toshimi TOBIMATSU, Shinji KUBO, Mika TAHARA, Yuka SUZ ...
Article type: Article
Session ID: S0803-3-4
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A mitigation system which can keep core melt stable aftter a severe accident is necessary to a next generation BWR design. TOSHIBA has been developing a compact core catcher to be placed at the lower drywell in the containment vessel. This paper summarizes flow dynamics and heat removal capability in a inclined cooling channel of core catcher when cooling water flows by the natural circulation.
View full abstract
-
Takashi Homma, Mitsuhiro Ishikawa, Nobuyuki Sawada
Article type: Article
Session ID: S0805-1-1
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Heat pump is paid attention to energy conservation equipment that obtains the thermal energy more than the electric energy. However, frost is caused in the outside heat exchanger while heating or hot water supplying, it becomes impossible to take heat from air. And, the defrosting driving interrupts heating, it causes the decrease in the amenity and efficiency. In this study, we examined fin and tube heat exchanger to take heat from air and a suitable fin pitch for the cold region. As a result, we understood that the effective fin pitch is 1.6mm.
View full abstract
-
Tatsuya YOHIDA, Keisuke SHIOMI, Kenji YOSHIDA, Isao KATAOKA
Article type: Article
Session ID: S0805-1-2
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The frost surface plays an important role as an interface of heat and mass transfer between air-flow and ice-air composite solid layer. The water vapor in the humid atmosphere reaches the cooling surface and changes the supercooled water droplet. And then it freezes and the frost grows by sublimation. The frost layer surface consists of ice and air. It is rough and any specific definition of the frost layer thickness is not found. The frost layer thickness is usually measured by observation. But measured values may be different by observers. So this study proposes how to measure the frost layer height by using a Laser Focus Displacement Meter and reports about frost layer growth and its structure.
View full abstract
-
Shuichi UMEZAWA, Kenji WATANABE, Haruo AMARI, Takayuki TSUJII
Article type: Article
Session ID: S0805-1-3
Published: September 12, 2009
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This paper reports the development of a steam generator in case of low temperature difference between generated steam and heat resources. A steam generator was designed employing a method of vaporization using falling films on evaporation tubes. The tubes were set in a steam generating chamber with a layout of three lines and twenty layers. An electric heater was equipped in each of the tubes as a heat source. While water was fallen on the surface of tubes and evaporated, temperatures of the surfaces and steam were measured. Mother experiment of vaporization by pool boiling was also carried out. As a result, the heat transmission coefficient of the surface evaporation was the largest under the condition of low heat flux. On the other hand, deterioration of the heat transmission coefficient was observed under a condition of high heat flux. Considering these experimental results, development requirements and possibility of the steam generator will be discussed.
View full abstract
