2014 Vol.46 No.2
IHI ENGINEERING REVIEW
2014 Vol.46 No.2
Ocean currents, such as the Kuroshio Current, are expected to be effectively used as marine renewable energy in order to supply sustainable energy and reduce greenhouse gas emissions. IHI is aiming to realize power generation using an ocean current and is working toward development of a floating type ocean current turbine system.
In our technical training center, which is independent from other organizations and has been renovated in terms of equipment, facilities, and training programs, young welders are trying hard to learn skills from veteran welders and veteran welders are aiming for world-class welding skills.
2. Technical Papers
SHIMADA Takahiro, SHIMAMURA Kazuo, SHIONAGA Ryosuke, YAMAGISHI Kenjiro, SAITO Hiroyuki, ITO Akio
The lesson learned from the tsunami disaster of the Great East Japan Earthquake (March 11, 2011) prompted the Central Disaster Prevention Council to present a guideline that city planning should be improved to the extent that a place of refuge can be accessed within about 5 minutes on foot. However, no effective way of implementing this guideline has been found for areas that do not have large-scale refuge accommodations such as hills or tsunami refuge buildings, or for nursery schools, kindergartens, or elderly people. Given this situation, Shikoku Transport & Tourism Bureau organized an investigation committee to study the possibility of creating a tsunami lifeboat. This paper describes the development and design process of the prototype tsunami lifeboat carried out as a part of the research of this investigation committee. The results of some examinations for proving that the prototype tsunami lifeboat has sufficient structural strength to withstand collisions and is sufficiently stable are included in this paper.
SHITO Motoaki, INUZUKA Ittetsu, AMAYA Ichiro, SAITO Hiroyuki, KURATA Junji
Extensive damage caused by the 2011 off the Pacific coast of Tohoku Earthquake triggered demands for a variety of tsunami assessment methods. These are described in this paper, including numerical simulations of tsunami propagation, wave impact load and drifting, and hydraulic experiment techniques to generate the long wavelengths that are characteristic of tsunami. The simulations and experiments were carried out on run-up tsunami acting on the tank and the barrier effects of tsunami breakwaters located in the bay mouth.
ISHIKAWA Atsushi, IMAI Ryoji, TANAKA Takahiro
This study focuses on evaluating constitutive equation of two-phase flow drift flux model under horizontal tube bundle. In two-phase flow, liquid to gas density ratio is one of the most important parameters to simulate the flow structure. Sulfur hexafluoride (SF6) gas and water were used to simulate water-vapor two-phase flow behavior of PWR steam-generator at ambient temperature and low pressure under 1MPa. The test section consists of a 360mm high rectangular channel of 150.9×160mm with square pitch horizontal tube bundle of 8 rows of 5 tubes. Each tube has 22.23mm outer diameter and arranged in line with a pitch of 32.54mm. Pitch-to-diameter ratio P/D is 1.46. The experiments were conducted at 0.4 to 0.6MPaabs and ambient temperature. The superficial velocity of SF6 gas and water at the tube gap were changed in the range jG=1.5 to 13.5m/s and jL=1.2 to 2.4m/s, respectively. Time averaged void fraction and interfacial gas velocity was measured using Bi-Optical Probe (BOP). These results were compared with the values generated by previous empirical equations to verify soundness of this facility and measurement method.
HAYASHI Eri, MIZUNO Masayuki, NAGAO Takahisa, YOKOMINE Takehiko
In order to predict and evaluate the erosion to products that accompanies particle-gas flow, an erosion simulator has been developed. The simulator comprises the following components: (1) an erosion prediction model; (2) a basic erosion test; and (3) particle movement analysis with CFD. In this research, the equations of Finnie and Bitter have been adopted for the erosion prediction model. The experimental fixed values in the model have been obtained with a centrifugal erosion tester. In order to ascertain the validity of this method, the simulation was compared with erosion test data for the erosion depth of a 12×4 tube array. The results showed that the analysis generally agrees with the erosion depth experimental results for the tube array, demonstrating the simulator is able to estimate the characteristics of tube array erosion.
IZAWA Jun, OMI Soichiro, INAMOTO Tomoyuki, KUBOTA Nobuhiko
We are developing a system for the remote monitoring of CO2 across wide areas (several kilometers) using laser technology. We have measured atmospheric CO2 and that contained in combustion gases using our compact and portable test system. We were successful in measuring atmospheric CO2 and that contained in exhaust gases from a combustion plant over a distance of 130 meters by using our original system that is based on a commercial laser. In this paper, we provide an outline of CO2 monitoring using a laser system, and describe its innovativeness and characteristics, together with the results of CO2 measurements using it.
YAMAMOTO Yuichi, KAIFUKU Shinji, KAWABATA Satoshi, TOKUCHI Tomonobu, IDANI Tatsuya
"Binh Bridge," located in Hai Phong City, Vietnam, is a cable-stayed bridge with composite girders that was completed in 2005. In July 2010, parts of the main girder and several stay cables of the bridge suffered serious damage after three ships washed away by typhoon No.1 collided with it. Rehabilitation works on the bridge were awarded to IIA in March 2012 following a collaborative emergency investigation within the IHI Group (IHI, IIS, IIA). This is the first time IHI undertook cable replacement works and the complex stress distributions in the composite girder necessitated extensive planning. This report describes the rehabilitation works carried out on the bridge, in particular the main girder repair and stay cable replacement.