• YAMADA Toshihiko, ISHII Toru, TAKAFUJI Makoto, ISO Yoshiyuki

The oxyfuel combustion boiler for CO2 capture is one of candidates as a CO2 Capture and Storage (CCS) system for the coal-fired boilers for electric power generation plants. Research and development activities and demonstration in this area have been conducted worldwide. IHI has participated in the Callide Oxyfuel Project in Australia and conducted various activities towards demonstration operation of the boiler plant. This report describes the study results, the prediction of combustion characteristics, and the stable and safe operation. These results will be applied to the demonstration plant and the design of the next commercial oxyfuel combustion boiler.

• SAKAMOTO Rie, KOBAYASHI Kazuyuki, IIJIMA Tooru, NISHIMURA Yoshihito, MIZO Yutaka

Manual metal-arc welding has mainly been applied to vertical joints in LNG storage tanks made of 9%Ni steel abroad. To shorten the construction period and improve welding efficiency, a new welding method using simple equipment and without using shielding gas has been required. IHI has developed a new vertical submerged arc welding method with small diameter wire and weave technique. Stable welding and quality have been obtained by developing welding equipment and new welding consumables. Deposition rate of the method is in the 50g/min to 80g/min range. This shows possibility of welding efficiency improvement using vertical submerged arc welding method.

• TANAKA Hiroshi, NARIAI Kentaro, NAKAMURA Shikou, SATO Kenji, MATSUZAWA Yoshiaki

Bioethanol, as an alternative for fossil fuels, is produced by fermenting sugar components of plant materials. It is important to bring the sugar-containing source material into efficient contact with condensed microorganisms to attain faster ethanol fermentation. In the study, high microbial concentration was achieved in a fermentation reactor using a flocculent strain of yeast. The yeast particles were continuously fluidized by upward current generated by the fermentation gas. During more than 30-day operation, high ethanol productivity was performed steadily. It was clearly demonstrated that the system is applicable to high-performance bioethanol production.

• TAMAKI Hideaki, UNNO Masaru, KAWAKUBO Tomoki, HIRATA Yutaka

High boost pressure is required to increase the specific output power of diesel engines. The pressure ratio of compressors for turbochargers has been increased to meet these engine requirements. IHI developed a new turbocharger, AT14 mounting a high pressure ratio centrifugal compressor, for 500kW class diesel engines. In high pressure ratio centrifugal compressors, it is expected that the complicated flow characteristics related to occurrence of shock wave will deteriorate compressor efficiency and operating range. To avoid these problems, several countermeasures were taken in the aerodynamic design of AT14 centrifugal compressor. Newly designed compressors were realized with the expected performance, stage pressure ratio, and efficiency. This paper outlines the aerodynamic design of the centrifugal compressor for AT14.

• KURE Hirotaka, MORI Hatsuo, WATANABE Osamu

We suggest a new design methodology for a multipurpose trade-off design and a risk management, called Total Design Management (TDM). TDM has two important concepts: "Set Based Design (SBD)" and "Model Based Risk management (MBR)." In SBD, designers firstly calculate the total set of design solutions and then narrow down the solutions complying with the design requirements or constraint conditions by a filtering method. SBD is very simple, transparent and practical process. In MBR, designers manage a design risk based on designers' non-confidence of the mathematical models which they make or calculate. In this paper, we also indicate effectiveness of this methodology with two examples: cantilever problem and impeller design.

• AYAME Yoshihiko