Japan
Exchange Current Density of Reversible Solid Oxide Cell Electrodes
Mar 2022
Publication
Reversible solid oxide cells (r-SOCs) can be operated in either solid oxide fuel cell or solid oxide electrolysis cell mode. They are expected to become important in the support of renewable energy due to their high efficiency for both power generation and hydrogen generation. The exchange current density is one of the most important parameters in the quantification of electrode performance in solid oxide cells. In this study four different fuel electro Read More
Hydrogen Technologies and Developments in Japan
Jan 2019
Publication
The successful development of hydrogen-energy technologies has several advantages and benefits. Hydrogen energy development could prevent global warming as well as ensure energy security for countries without adequate energy resources. The successful development of hydrogen would provide energy for transportation and electric power. It is a unique energy carrier as it can be produced from various energy sources such as wind fossil fuels and Read More
Dynamic Crush Test on Hydrogen Pressurized Cylinder
Sep 2005
Publication
It is necessary to investigate cylinder crush behavior for improvement of fuel cell vehicle crash safety. However there have been few crushing behaviour investigations of high pressurized cylinders subjected to external force. We conducted a compression test of pressurized cylinders impacted by external force. We also investigated the cylinder strength and crushing behaviour of the cylinder. The following results were obtained.The crush force of hi Read More
Heuristic Design of Advanced Martensitic Steels That Are Highly Resistant to Hydrogen Embrittlement by ε-Carbide
Feb 2021
Publication
Many advanced steels are based on tempered martensitic microstructures. Their mechanical strength is characterized by fine sub-grain structures with a high density of free dislocations and metallic carbides and/or nitrides. However the strength for practical use has been limited mostly to below 1400 MPa owing to delayed fractures that are caused by hydrogen. A literature survey suggests that ε-carbide in the tempered martensite is effective for str Read More
The New Facility for Hydrogen and Fuel Cell Vehicle Safety Evaluation
Sep 2005
Publication
For the evaluation of hydrogen and fuel cell vehicle safety a new comprehensive facility was constructed in our institute. The new facility includes an explosion resistant indoor vehicle fire test building and high pressure hydrogen tank safety evaluation equipment. The indoor vehicle fire test building has sufficient strength to withstand even an explosion of a high pressure hydrogen tank of 260 liter capacity and 70 MPa pressure. It also has enough s Read More
Quantitative Evaluations of Hydrogen Diffusivity in V-X (X = Cr, Al, Pd) Alloy Membranes Based on Hydrogen Chemical Potential
Jan 2021
Publication
Vanadium (V) has higher hydrogen permeability than Pd-based alloy membranes but exhibits poor resistance to hydrogen-induced embrittlement. The alloy elements are added to reduce hydrogen solubility and prevent hydrogen-induced embrittlement. To enhance hydrogen permeability the alloy elements which improve hydrogen diffusivity in V are more suitable. In the present study hydrogen diffusivity in V-Cr V-Al and V-Pd alloy membranes was investigat Read More
Mach 4 Simulating Experiment of Pre-Cooled Turbojet Engine Using Liquid Hydrogen
Jan 2022
Publication
This study investigated a pre-cooled turbojet engine for a Mach 5 class hypersonic transport aircraft. The engine was demonstrated under takeoff and Mach 2 flight conditions and a Mach 5 propulsion wind tunnel test is planned. The engine is composed of a pre-cooler a core engine and an afterburner. The engine was tested under simulated Mach 4 conditions using an air supply facility. High-temperature air under high pressure was supplied to the engine co Read More
Development of High-pressure Hydrogen Gas Barrier Materials
Oct 2015
Publication
We prepared several gas barrier resins based on amorphous PVA derivative that has the T1C (13C spin-lattice relaxation time) of a long time component in amorphous phase. We confirmed it was important to control state in amorphous phase of gas barrier resin in order to achieve both moldability and good gas barrier property. Polymer alloy was designed to improve flexibility. Polymer alloy made of amorphous PVA and elastomer resin showed good hydro Read More
Dispersion Tests on Concentration and its Fluctuations for 40MPa Pressurized Hydrogen
Sep 2007
Publication
Hydrogen is one of the important alternative fuels for future transportation. At the present stage research into hydrogen safety and designing risk mitigation measures are significant task. For compact storage of hydrogen in fuel cell vehicles storage of hydrogen under high pressure up to 40 MPa at refuelling stations is planned and safety in handling such high-pressure hydrogen is essential. This paper describes our experimental investigation into disper Read More
Fundamental Safety Testing and Analysis of Solid State Hydrogen Storage Materials and Systems
Sep 2007
Publication
Hydrogen is seen as the future automobile energy storage media due to its inherent cleanliness upon oxidation and its ready utilization in fuel cell applications. Its physical storage in light weight low volume systems is a key technical requirement. In searching for ever higher gravimetric and volumetric density hydrogen storage materials and systems it is inevitable that higher energy density materials will be studied and used. To make safe and co Read More
Leakage-type-based Analysis of Accidents Involving Hydrogen Fueling Stations in Japan and USA
Aug 2016
Publication
To identify the safety issues associated with hydrogen fuelling stations incidents at such stations in Japan and the USA were analyzed considering the regulations in these countries. Leakage due to the damage and fracture of main bodies of apparatuses and pipes in Japan and the USA is mainly caused by design error that is poorly planned fatigue. Considering the present incidents in these countries adequate consideration of the usage environment Read More
Numerical Investigation of Vented Hydrogen-air Deflagration in a Chamber
Oct 2015
Publication
This paper shows numerical investigation related to hydrogen-air deflagration venting. The aim of this study is to clarify the influence of concentration gradient on the pressure histories and peak pressures in a chamber. The numerical analysis target is a 27 m3 cubic chamber which has 2.6 m2 vent area on the sidewall. The vent opening pressure is set to be gauge 10 kPa. Two different conditions of the hydrogen concentration are assumed which are Read More
Numerical Investigation on the Self-ignition Behavior of High Pressure Hydrogen Released from the Tube
Sep 2017
Publication
This paper shows the numerical investigation on the self-ignition behavior of high pressure hydrogen released from the tube. The present study aims to clarify the effect of parameters on the behavior and duration of self-ignition outside the tube using two-dimensional axisymmetric numerical simulation with detailed chemistry. The parameters in this study are release pressure tube diameter and tube length. The strength of the spherical shock wave to Read More
Energy-efficient Conversion of Microalgae to Hydrogen and Power
Jun 2017
Publication
An integrated system for H2 production from microalgae and its storage is proposed employing enhanced process integration technology (EPI). EPI consists of two core technologies i.e. exergy recovery and process integration. The proposed system includes a supercritical water gasification H2 separation hydrogenation and combined cycle. Microalga Chlorella vulgaris is used as a material for evaluation. The produced syngas is separated to produce Read More
Security Risk Analysis of a Hydrogen Fueling Station with an On-site Hydrogen Production System Involving Methylcyclohexane
Sep 2017
Publication
Although many studies have looked at safety issues relating to hydrogen fuelling stations few studies have analyzed the security risks such as deliberate attack of the station by threats such as terrorists and disgruntled employees. The purpose of this study is to analyze security risks for a hydrogen fuelling station with an on-site production of hydrogen from methylcyclohexane. We qualitatively conducted a security risk analysis using American Petrole Read More
Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage
Oct 2017
Publication
Hydrogen has a very diverse chemistry and reacts with most other elements to form compounds which have fascinating structures compositions and properties. Complex metal hydrides are a rapidly expanding class of materials approaching multi-functionality in particular within the energy storage field. This review illustrates that complex metal hydrides may store hydrogen in the solid state act as novel battery materials both as electrolytes and el Read More
A Review for Consistent Analysis of Hydrogen Permeability through Dense Metallic Membranes
Jun 2020
Publication
The hydrogen permeation coefficient (ϕ) is generally used as a measure to show hydrogen permeation ability through dense metallic membranes which is the product of the Fick’s diffusion coefficient (D) and the Sieverts’ solubility constant (K). However the hydrogen permeability of metal membranes cannot be analyzed consistently with this conventional description. In this paper various methods for consistent analysis of hydrogen permeability are review Read More
3D Real Time Monitoring of H2 in FCV Applications
Sep 2019
Publication
In order to monitor a trace amount of Hydrogen in millisecond portable H2 sensor (Sx) was made by using mass spectrometer. The method of monitoring the hydrogen pulse of millisecond in exhaust gas is the increasing needed. Determining H2 concentration both inside and outside of the Fuel Cell Vehicle (FCV) for the optimized operations is becoming a critical issue. The exhaust gas of Fuel Cell Vehicle H2 consumption flushing and disposal around Fuel cell th Read More
Techno-economic Analysis on Renewable Energy Via Hydrogen, Views from Macro and Micro Scopes
Mar 2019
Publication
This paper addresses from both macro- and micro- areal coverage in introducing hydrogen system in terms of cost and performance where the produced hydrogen from surplus photovoltaic (PV) power is stored. Feed-in tariff in Japan had successful achievement for great expansion of renewable energy systems (RES) causing problematic operation due to excess power by overcapacity of RES. One of the candidate approaches to overcome this sur Read More
Hydrogen-enhanced Fatigue Crack Growth in Steels and its Frequency Dependence
Jun 2017
Publication
In the context of the fatigue life design of components particularly those destined for use in hydrogen refuelling stations and fuel cell vehicles it is important to understand the hydrogen-induced fatigue crack growth (FCG) acceleration in steels. As such the mechanisms for acceleration and its influencing factors are reviewed and discussed in this paper with a special focus on the peculiar frequency dependence of the hydrogen-induced FCG acceleration. Fu Read More
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