Details of a Researcher - Kobayashi, Hiromichi

Papers - Kobayashi, Hiromichi

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High Temperature Air Combustion Boiler for Low BTU Gas

K.Kawai, K.Yoshikawa, H.Kobayashi, J.S.Tsai, M.Matsuo and H.Katsushima

Energy Conversion and Management (Elsevier Science) 43 ( 9-12 ) 1563-1570 2002.06

Research paper (scientific journal), Joint Work, Accepted

A new concept boiler where fuel can be efficiently combusted by high temperature preheated air is proposed and experimental demonstration is done. This boiler is suitable for low BTU gas derived from gasification process of coal and wastes with no dioxin emission. This boiler is characterized by the following features; uniform heat flux field, augmentation of heat transfer, reduction of combustion noise level, suppression of NOx emission and compactness. Preliminary experiments using natural gas as a fuel demonstrate above distinct performance as well as good agreement with three-dimensional numerical simulation.

高温空気燃焼ボイラの熱特性に関する研究（第１報，実験による検討）

小林宏充，吉川邦夫

日本機械学会論文集Ｂ (日本機械学会) 67 ( 633 ) 2877-2882 2001.11

Research paper (scientific journal), Joint Work, Accepted

A new concept compact boiler using high temperature air is proposed and experimental demonstration is done. In the boiler, high temperature air combustion is realized. Fuel can be efficiently burned by high temperature preheated air of about 800C-1000C under low oxygen content ( < 5% ). The temperature distribution in the furnace is very uniform and there is no hot spot, so that low NOx emission ( < 40ppm) and relatively high average temperature in the furnace can be achieved. Thermal efficiency of more than 90% is accomplished including waste heat recovery of exhaust gas. This boiler is useful to partial load operation, because the response of thermal output is linear. This boiler is also suitable for low calorific value gas derived from gasification process of coal and wastes with no dioxin emission. Simulated low calorific value gas made from natural gas diluted with argon can be burned with low NOx emission.

凍結希ガスプラズマを利用したディスク形MHD発電機の性能数値計算

小林宏充，佐藤幸正，奥野喜裕

電気学会論文誌Ｂ (電気学会) 121 ( 8 ) 1023-1028 2001.08

Research paper (scientific journal), Joint Work, Accepted

MHD electrical power generation with frozen helium plasma (FHP) is examined numerically. The FHP can be initiated by pre-ionized helium without the alkali metal seed at the generator inlet. Since the three-body recombination coefficient of helium ions is low at the electron temperature above 5000K, the ionization degree can be kept almost constant in the entire region of the generator channel. The r-theta two-dimensional numerical results show that the performance of the FHP MHD generator is comparable to that of the seeded plasma MHD generator, if the additional power consumed to pre-ionization is ignored. In the FHP MHD generator, the ionization degree at the inlet should be controlled precisely, as well as the seed fraction in the seeded plasma MHD generator. Under the adequate inlet ionization degree for sustaining the FHP plasma, the plasma maintains the uniform structure. On the other hand, a slightly excess ionization degree causes the strong Lorentz force in the upstream region of the generator, then the generator performance is deteriorated.

The Performance of Dynamic Subgrid-Scale Models in the Large Eddy Simulation of Rotating Homogeneous Turbulence

Hiromichi Kobayashi, Yutaka Shimomura

Physics of Fluids (American Institute of Physics) 13 ( 8 ) 2350-2360 2001.08

Research paper (scientific journal), Joint Work, Accepted

The performance of dynamic subgrid-scale models is numerically examined in the large eddy simulation (LES) of rotating homogeneous turbulences in comparison with the corresponding filtered data of the direct numerical simulation (DNS). The examined dynamic SGS models are: the dynamic Smagorinsky model (DSM), the dynamic mixed model (DMM), the dynamic Clark model (DCM), and the dynamic two-parameter Clark model (DTCM). All models are mathematically reformulated in a rotating frame from the corresponding expressions in an inertial frame. It is shown that the DSM and the DMM are not consistent with the constraint of asymptotic material frame indifference, but the DCM and the DTCM are consistent. All models except the DSM show similar decays of the grid-scale turbulent energies both in non-rotating and in rotating frames; they agree well with the DNS in the non-rotating case, but they are slightly less dissipative than the DNS in the rotating case. The DSM underestimated the GS energy dissipation in the non-rotating case, though there is no major difference from other models in the rotating case. However, the DSM in a rotating frame, which takes a different form from that in an inertial frame, leads to an unphysical fluctuating decay for a homogeneous turbulence suddenly submitted to a rotation.

MHD(電磁流体力学)発電機内におけるプラズマ流の3次元数値シミュレーション

小林宏充

慶應義塾大学日吉紀要 (慶応義塾大学出版会) ( 28 ) 39-46 2000.09

Research paper (bulletin of university, research institution), Single Work

Feasibility Study on Frozen Inert Gas Plasma MHD Generator

Hiromichi Kobayashi, Yoshihiro Okuno

IEEE Transactions on Plasma Science (The Institute of Electrical and Electronics Engineers) 28 ( 4 ) 1296-1302 2000.08

Research paper (scientific journal), Joint Work, Accepted

The feasibility of an MHD generator with frozen inert gas plasma is examined numerically. The frozen inert gas plasma is produced by pre-ionizing helium of inert gas without alkali metal seed at the generator inlet. Since the three-body recombination coefficient of helium ions is low at
the electron temperature more than 5000K, the ionization degree of inert gas is kept almost constant in the entire region of the generator channel and the relation between the electron temperature and the electron number density deviates from the Saha equilibrium. In a small scale disk shaped generator, the enthalpy extraction ratio of 22.7% and the isentropic efficiency of 54.8% are obtainable for the load resistance of 3.0Omega and magnetic flux density of 4T under the pre-ionization degree of 4.79x10^{-5}. The auxiliary power to sustain the pre-ionized plasma corresponds to about 2% of the thermal input. For high magnetic flux density, the generator performance can be improved as well as a conventional seeded plasma MHD generator.

CIP法によるMHD発電機内プラズマ・流体の３次元シミュレーション

小林宏充，奥野喜裕，椛島成治

数値流体力学会誌 (数値流体力学会) 8 ( 3 ) 130-136 2000.04

Research paper (scientific journal), Joint Work

高温空気を用いた石炭・廃棄物ガス化発電システム

小林宏充，吉川邦夫，塩田進

日本機械学会論文集Ｂ (日本機械学会) 66 ( 641 ) 235-240 2000.01

Research paper (scientific journal), Joint Work, Accepted

A new concept of gasification power generation systems fueled by coal, RDF and various kinds of wastes using high temperature air is proposed. Cycle analyses of these IGCC and boiler systems are done. The calculation shows that heating value of syngas almost doubles when we increase the gasification air temperature from 25C to 1000C. More than 45% thermal efficiency is obtainable both for coal and RDF by employing the new high temperature air blown IGCC system. This IGCC system is applicable to various wastes including low grade wastes such as sludge.

亜音速非平衡ディスク形MHD発電機内の流れと発電性能

名原啓博，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 119 ( 8/9 ) 931-936 1999.08

Research paper (scientific journal), Joint Work, Accepted

入口スワールをもつ非平衡ディスク形MHD発電機内プラズマ・流体の三次元構造

清水和弥，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 119 ( 7 ) 828-833 1999.07

Research paper (scientific journal), Joint Work, Accepted

Three-Dimensional Simulation of Plasma and Flow in a Disk MHD Generator by Using CIP Method

Hiromichi Kobayashi, Yoshihiro Okuno, Shigeharu Kabashima

Computational Fluid Dynamics JOURNAL (Intern'l Society of CFD) 8 ( 1 ) 50-55 1999.04

Research paper (scientific journal), Joint Work, Accepted

非平衡ディスク形MHD発電機における放電構造と発電性能に及ぼす背圧の影響

藤野貴康，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 119 ( 1 ) 97-102 1999.01

Research paper (scientific journal), Joint Work, Accepted

熱入力100MW非平衡ディスク形MHD発電機におけるプラズマ・流体の三次元構造

清水和弥，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 119 ( 1 ) 103-108 1999.01

Research paper (scientific journal), Joint Work, Accepted

Three-Dimensional Structures of MHD Flow in a Disk Generator

Hiromichi Kobayashi, Yoshihiro Okuno, Shigeharu Kabashima

IEEE Transactions on Plasma Science (The Institute of Electrical and Electronics Engineers) 26 ( 5 ) 1526-1531 1998.10

Research paper (scientific journal), Joint Work, Accepted

亜音速ディスク形CCMHD発電機の部分負荷運転特性

名原啓博，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 118 ( 9 ) 1041-1046 1998.09

Research paper (scientific journal), Joint Work, Accepted

非平衡MHD発電におけるプラズマ擾乱の三次元挙動

村上貴裕，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 118 ( 5 ) 587-592 1998.05

Research paper (scientific journal), Joint Work, Accepted

亜音速ディスク形CCMHD発電機の電圧－電流特性

小林宏充，桑子奈津子，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 118 ( 3 ) 302-307 1998.03

Research paper (scientific journal), Joint Work, Accepted

空間的なシード不均一下での非平衡ディスク形MHD発電機内プラズマの挙動

村上貴裕，小林宏充，奥野喜裕，椛島成治

電気学会論文誌Ｂ (電気学会) 117 ( 5 ) 665-670 1997.05

Research paper (scientific journal), Joint Work, Accepted

Three-Dimensional Simulation of Nonequilibrium Seeded Plasma in Closed Cycle Disk MHD Generator

Hiromichi Kobayashi, Yoshihiro Okuno, Shigeharu Kabashima

IEEE Transactions on Plasma Science (The Institute of Electrical and Electronics Engineers) 25 ( 2 ) 380-385 1997.02

Research paper (scientific journal), Joint Work, Accepted

ディスク形ＣＣＭＨＤ発電機の性能に与える入口圧力変動の影響

Kobayashi Hiromicih, Okuno Yoshihiro, Kabashima Shigeharu

電気学会論文誌Ｂ (電気学会) 116 ( 6 ) 718-723 1996.06

Research paper (scientific journal), Joint Work, Accepted

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