The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform

Yohsuke Tamura - One of the best experts on this subject based on the ideXlab platform.

  • The residual strength of automotive hydrogen cylinders after exposure to flames
    International Journal of Hydrogen Energy, 2019
    Co-Authors: Yohsuke Tamura, Koji Yamazaki, Kiyotala Maeda, Kenji Sato
    Abstract:

    Abstract Fuel cell vehicles and some compressed natural gas vehicles are equipped with carbon fiber reinforced plastic (CFRP) composite cylinders. Each of the cylinders has a pressure Relief Device designed to detect heat and release the internal gas to prevent the cylinder from bursting in a vehicle fire accident. Yet in some accident situations, the fire may be extinguished before the pressure Relief Device is activated, leaving the high-pressure fuel gas inside the fire-damaged cylinder. To handle such a cylinder safely after an accident it is necessary that the cylinder keeps a sufficient post-fire strength against its internal gas pressure, but in most cases it is difficult to accurately determine cylinder strength at the accident site. One way of solving this problem is to predetermine the post-fire burst strengths of cylinders by experiments. In this study, automotive CFRP cylinders having no pressure Relief Device were exposed to a fire to the verge of bursting; then after the fire was extinguished the residual burst strengths and the overall physical state of the test cylinders were examined. The results indicated that the test cylinders all recorded a residual burst strength at least twice greater than their internal gas pressure for tested cylinders with new cylinder burst to nominal working pressure in the range 2.67–4.92 above the regulated ratio of 2.25.

  • Study of a post-fire verification method for the activation status of hydrogen cylinder pressure Relief Devices
    International Journal of Hydrogen Energy, 2017
    Co-Authors: Koji Yamazaki, Yohsuke Tamura
    Abstract:

    Abstract To safely remove from its fire accident site a hydrogen fuel cell vehicle equipped with a carbon fiber reinforced plastic composite cylinder for compressed hydrogen (CFRP cylinder) and to safely keep the burnt vehicle in a storage facility, it is necessary to verify whether the thermally-activated pressure Relief Device (TPRD) of the CFRP cylinder has already been activated, releasing the hydrogen gas from the cylinder. To develop a simple post-fire verification method on TPRD activation, the present study was conducted on the using hydrogen densitometer and Type III and Type IV CFRP cylinders having different linings. As the results, TPRD activation status can be determined by measuring hydrogen concentrations with a catalytic combustion hydrogen densitometer at the cylinder's TPRD gas release port.

Ke Sun - One of the best experts on this subject based on the ideXlab platform.

  • Mitigation measures for intended hydrogen release from thermally activated pressure Relief Device of onboard storage
    International Journal of Hydrogen Energy, 2020
    Co-Authors: Ke Sun
    Abstract:

    Abstract Vehicular high-pressure hydrogen tanks are commonly required to install thermally-activated pressure Relief Device (TPRD) to prevent tank catastrophic rupture. However, the intended hydrogen release from TPRD may pose fire hazards to drivers, passengers and people outside the vehicle. This paper develops mitigation measures to reduce the risks of hydrogen fire introduced by TPRD. New rotatable design of the pressure Relief Device allows the system to actively adjust the hydrogen release direction towards void open space outside the vehicle to minimize the risks of hydrogen fires. To determine when and where to rotate, a monitoring system with infrared sensors, ultrasonic radar and temperature sensors, is designated to collect the indoor and outdoor information. A control strategy is also proposed to operate the safety system in an appropriate way. The cost-benefit analysis results show that the new mitigation can significantly reduce the risks of intended hydrogen releases from onboard pressure Relief Devices with total cost increasing by less than 1% of the vehicle's price, making it a cost-effective engineering solution.

Koji Yamazaki - One of the best experts on this subject based on the ideXlab platform.

  • The residual strength of automotive hydrogen cylinders after exposure to flames
    International Journal of Hydrogen Energy, 2019
    Co-Authors: Yohsuke Tamura, Koji Yamazaki, Kiyotala Maeda, Kenji Sato
    Abstract:

    Abstract Fuel cell vehicles and some compressed natural gas vehicles are equipped with carbon fiber reinforced plastic (CFRP) composite cylinders. Each of the cylinders has a pressure Relief Device designed to detect heat and release the internal gas to prevent the cylinder from bursting in a vehicle fire accident. Yet in some accident situations, the fire may be extinguished before the pressure Relief Device is activated, leaving the high-pressure fuel gas inside the fire-damaged cylinder. To handle such a cylinder safely after an accident it is necessary that the cylinder keeps a sufficient post-fire strength against its internal gas pressure, but in most cases it is difficult to accurately determine cylinder strength at the accident site. One way of solving this problem is to predetermine the post-fire burst strengths of cylinders by experiments. In this study, automotive CFRP cylinders having no pressure Relief Device were exposed to a fire to the verge of bursting; then after the fire was extinguished the residual burst strengths and the overall physical state of the test cylinders were examined. The results indicated that the test cylinders all recorded a residual burst strength at least twice greater than their internal gas pressure for tested cylinders with new cylinder burst to nominal working pressure in the range 2.67–4.92 above the regulated ratio of 2.25.

  • Study of a post-fire verification method for the activation status of hydrogen cylinder pressure Relief Devices
    International Journal of Hydrogen Energy, 2017
    Co-Authors: Koji Yamazaki, Yohsuke Tamura
    Abstract:

    Abstract To safely remove from its fire accident site a hydrogen fuel cell vehicle equipped with a carbon fiber reinforced plastic composite cylinder for compressed hydrogen (CFRP cylinder) and to safely keep the burnt vehicle in a storage facility, it is necessary to verify whether the thermally-activated pressure Relief Device (TPRD) of the CFRP cylinder has already been activated, releasing the hydrogen gas from the cylinder. To develop a simple post-fire verification method on TPRD activation, the present study was conducted on the using hydrogen densitometer and Type III and Type IV CFRP cylinders having different linings. As the results, TPRD activation status can be determined by measuring hydrogen concentrations with a catalytic combustion hydrogen densitometer at the cylinder's TPRD gas release port.

Jinyang Zheng - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Studies on Discharge Characteristics of the Typical Thermally-Activated Pressure Relief Device Used for High-Pressure Hydrogen Storage Cylinder in Different Fire Conditions
    Volume 5: High-Pressure Technology; Rudy Scavuzzo Student Paper Symposium and 27th Annual Student Paper Competition; ASME Nondestructive Evaluation Di, 2019
    Co-Authors: Jinyang Zheng, Gu Chunlin, Zhao Baodi, Qianghua Huang, Binbin Liao
    Abstract:

    Abstract Thermally-activated pressure Relief Devices (TPRD) with glass bulbs or fusible alloy are applied to high-pressure hydrogen storage cylinders (HHSC), in order to release hydrogen gas from the cylinder in fire accidents. In this paper, cylinders with different TPRDs were tested in two groups using different bonfire test methods. In group A, the fire was set exactly under the TPRD. While in group B, the fire was set 80 mm beside the TPRD. The result shows that TPRDs with glass bulb and fusible alloy acted in a similar way when the fire was under the cylinder and the TPRD. However, they acted in a quite different way when the fire was only under the cylinder and beside the TPRD. In group A, hydrogen was released continuously from TPRD both for glass bulb and fusible alloy. In group B, hydrogen was released continuously from the TPRD using glass bulb which was similar to the group A. However, for TPRDs using a fusible alloy, hydrogen was released in several stages taking much more time. The results are instructive for the design and selection of TPRDs on HHSC.

  • Experimental and numerical investigation of localized fire test for high-pressure hydrogen storage tanks
    International Journal of Hydrogen Energy, 2013
    Co-Authors: Jinyang Zheng, Zhengli Hua, Yongzhi Zhao, Bing Han
    Abstract:

    Abstract Vehicle fires may cause localized fires on on-board high-pressure hydrogen storage tanks. To verify the safety performance of such tanks under localized fire exposure, a localized fire test was proposed in the Global Technical Regulation for Hydrogen Fuel Cell Vehicles. However, practicality and validity of the proposed test still require further verification. In this paper, this new fire test was experimentally investigated using the type 3 tanks. Influences of hydrogen and air as the filling media were studied. A three-dimensional computational fluid dynamics model was developed to analyze the effects of filling pressure and localized fire exposure time on the activation of thermally-activated pressure Relief Device (TPRD). The experimental results showed that temperature distribution on the tank surface was uneven around the circumference. The rising temperature of internal hydrogen or air contributed little to TPRD activation. The simulation results indicated that TPRD activation time was slightly affected by the variations of the filling pressures, but it increased when the localized fire exposure time was extended.

Ganwei Cai - One of the best experts on this subject based on the ideXlab platform.

  • Influence of the Nonlinear Stiffness Parameter of the Vibratory Stress Relief Device on Strong Nonlinear Superharmonic Resonance
    IEEE Access, 2021
    Co-Authors: Lifang Zhao, Li Yanzhou, Ganwei Cai
    Abstract:

    Nonlinear superharmonic vibratory stress Relief (VSR) is an effective way to solve the resonance problem of a high stiffness workpiece. However, strong nonlinear factors are present, and superharmonic resonance is relatively complicated when the entire Device is a strongly nonlinear system. Choosing the best nonlinear stiffness parameter of the spring to allow the superharmonic resonance to generate a sufficient amplitude and sufficient dynamic stress becomes difficult. To solve this problem, it is necessary to explore the effect of the stiffness parameter on the system resonance: First, the nonlinear vibration situation of the VSR Device is analysed, and the effect of the stiffness parameter on the vibration characteristics is explored under the action of the strong nonlinear system. Then, a simulated vibration table is used to verify the rule that the stiffness parameters affect the superharmonic resonance. It was shown that strong nonlinear theory provides a theoretical basis for simulating vibration table experiments, and the relationship between the spring stiffness parameter and amplitude satisfies a certain relationship, which provides a useful reference for the application and research of the VSR Device for nonlinear superharmonic resonance.