High-pressure Tank Research Articles

Методические аспекты унификации цельнометаллических шар-баллонов высокого давления для сжатых и сжиженных газов

Методические аспекты унификации цельнометаллических шар-баллонов высокого давления для сжатых и сжиженных газов

Dynamic water behaviour due to one trapped air pocket in a laboratory pipeline apparatus

Trapped air pockets may cause severe operational problems in hydropower and water supply systems. A locally isolated air pocket creates distinct amplitude, shape and timing of pressure pulses. This paper investigates dynamic behaviour of a single trapped air pocket. The air pocket is incorporated as a boundary condition into the discrete gas cavity model (DGCM). DGCM allows small gas cavities to form at computational sections in the method of characteristics (MOC). The growth of the pocket and gas cavities is described by the water hammer compatibility equation(s), the continuity equation for the cavity volume, and the equation of state of an ideal gas. Isentropic behaviour is assumed for the trapped gas pocket and an isothermal bath for small gas cavities. Experimental investigations have been performed in a laboratory pipeline apparatus. The apparatus consists of an upstream end high-pressure tank, a horizontal steel pipeline (total length 55.37 m, inner diameter 18 mm), four valve units positioned along the pipeline including the end points, and a downstream end tank. A trapped air pocket is captured between two ball valves at the downstream end of the pipeline. The transient event is initiated by rapid opening of the upstream end valve; the downstream end valve stays closed during the event. Predicted and measured results for a few typical cases are compared and discussed.

Overpotential Analysis in High Pressure Water Electrolysis

To store or transport hydrogen (and optionally oxygen) in high pressure tanks or pipelines pressures up to 1000 bar are needed. Pressurized polymer electrolyte electrolyzers are typically operated at around 30 bar to reduce downstream mechanical compression and gas drying stages. Interestingly, often the cell voltage does not show the expected thermodynamic voltage increase [1,2]. Consequently beneficial influences are compensating the compression work, at the expense of higher faradaic losses due to increased gas crossover. In this work we analyze cell voltages at gas pressures up to 100 bar as function of temperature up to 70 °C and current densities up to 4 A/cm2, considering the three main overpotentials (ohmic, kinetic, mass transport) using a zero-order analysis based on the Tafel kinetics model. As expected, the ohmic overpotential is mainly a function of temperature and almost independent from pressure. Therefore the overpotential gains with increasing pressure, observed for current densities above about 0.8 A/cm2, stem from the kinetics and/or the mass transport. Both overpotentials decrease with increasing pressure, but over a wide current density region kinetics contribute about two thirds to the voltage gain. The improved kinetics can be attributed to an increased apparent exchange current density, whereas the increased mass transport might be related to smaller gas volumes or velocities resulting in an improved two-phase flow in the porous structures. Literature: [1] S.A. Grigoriev, V.I. Porembsky, V.N. Fateev, Pure hydrogen production by PEM electrolysis for hydrogen energy, Int J of Hydrogen Energy, 31 (2006) 171-175. [2] P. Millet, R. Ngameni, S.A. Grigoriev, N. Mbemba, F. Brisset, A. Ranjbari, C. Etiévant, PEM water electrolyzers: From electrocatalysis to stack development, Int J of Hydrogen Energy, 35 (2010) 5043-5052.

Micro-distillation system for formaldehyde concentration detection

A micro-distillation system is presented for formaldehyde concentration detection in food products. The proposed system consists of a micro-distillation device, a micro-condensed device, micro-distillation chip, a high-pressure steam tank, a temperature controller, and a cooling system. The distillation chip is fabricated on polymethylmethacrylate (PMMA) substrates using a CO2 laser system and comprises three distilling chambers, a condenser micro-channel and a cooling micro-channel. In the proposed system, the formaldehyde sample is injected into the distillation chip and a high-pressure steam supply is used to vaporize the formaldehyde and carry it to the condenser region of the chip. The formaldehyde vapor is condensed under the effects of the low-temperature cooling channel and is transported to the collection region of the device. Finally, a colorimetric detection process is performed to measure the formaldehyde concentration of the collected sample using a commercial spectrophotometer. The validity of the proposed system is investigated using a control sample with a formaldehyde concentration of 6ppm. It is shown that a distillation efficiency as high as 98% can be obtained given a steam pressure of 4bar. The real-world applicability of the proposed micro-distillation system is demonstrated by measuring the formaldehyde concentrations of 18 commercial Chinese herb samples.

Experimental study of pressure dynamics, spontaneous ignition and flame propagation during hydrogen release from high-pressure storage tank through 15 mm diameter tube and exhaust chamber connected to atmosphere

Hydrogen is expected to be a promising fuel in the future. However, high-pressure hydrogen is extremely easy to leak, after which spontaneous ignition may occur and causes serious hazards. For the purpose of collecting data to assess the risks and develop mitigation measures, high-pressure hydrogen release through a tube with a diameter of 15mm and length of 360mm and subsequent spontaneous ignition and flame propagation are experimentally studied in this work. Piezoelectric pressure transducers and light sensors are employed to detect shock waves and spontaneous ignition inside the tube, respectively. A high-speed video camera is used to record the flame propagation outside the tube. It is found that the pressure in the tank does not decrease immediately after high-pressure hydrogen release. The pressure depletion rate in the tank increases at first and decreases afterwards. Spontaneous ignition of pressurized hydrogen has a tendency to occur with higher burst pressure in the tube with a diameter of 15mm and minimum pressure for spontaneous ignition in a 15mm tube is between 3.30MPa and 4.09MPa (previous experiments were performed in tubes with diameters of 5 and 10mm - this is new information). Initial flame detection time of spontaneous ignition is defined and it is shorter for the case with higher burst pressure. The velocity of the flame moving downstream outside the tube decreases at first and then remains approximately constant after the flame splits into two parts. In addition, the flame appears earlier and lasts longer with higher burst pressure. For the cases where spontaneous ignition successfully occurs, the pressure inside the exhaust chamber increases twice and oscillates with a larger amplitude. The pressure does not increase again and it oscillates with a smaller amplitude in other cases.

Development of Zr[sbnd]Fe[sbnd]V alloys for hybrid hydrogen storage system

The combination of unstable hydrogen storage materials with a high pressure tank provides a potential solution to on-board hydrogen storage system for fuel cell vehicles. However, none of the available solid-state materials can fulfill all the requirements. In this work, ZrFeV-based alloys were systematically investigated for the possible use in such kind of hybrid storage devices.Among these alloys studied here, the composition (Zr0.7Ti0.3)1.04Fe1.8V0.2 shows the best overall properties with a reversible hydrogen capacity of 1.51 wt%, and a hydrogen desorption pressure of 11.2 atm at 0 °C. Besides, this alloy also shows excellent stability without obvious capacity loss even after 200 hydrogen absorption/desorption cycles. Calculated results show that the gravimetric density of the hybrid storage system combining a 35 MPa high pressure tank with (Zr0.7Ti0.3)1.04Fe1.8V0.2 alloy is 1.95 wt% when the volumetric density reaches 40 kg/m3.

Modelling heat transfer in an intumescent paint and its effect on fire resistance of on-board hydrogen storage

This paper describes a 1-D numerical model for the prediction of heat and mass transfer through an intumescent paint that is applied to an on-board high-pressure GH2 storage tank. The intumescent paint is treated as a composite system, consisting of three general components, decomposing in accordance with independent finite reaction rates. A moving mesh, that is employed for a better prediction of the expansion process of the intumescent paint, is based on the local changes of heat and mass. The numerical model is validated against experiments by Cagliostro et al. (1975). The overall model results are used to estimate effect of intumescent paint on fire resistance of carbon-fibre reinforced GH2 storage.

A new approach to battery powered electric vehicles: A hydrogen fuel-cell-based range extender system

Sometimes technology and development of society run slightly different roads. This situation is now happening in the case of hydrogen as an energy carrier in the automotive world. In the article presented here, the authors propose a change in the structure of the power plant of Battery Electric Vehicles (BEV). The objective is that these vehicles can be presently used until the development of an electric and/or hydrogen recharge/refuel network allows being useful with the current status. In this paper a new concept of Extended Range Electric Vehicle (EREV) based in a Fuel Cell Electric Vehicle (FCEV) set model is presented. A study is then developed in order to determine the working conditions that will lead to better efficiency and performance, referring to capacity of both energy sources: electricity stored in a Lithium-Ion battery and hydrogen gas in high pressure tanks. The possibilities here shown open the door to strategic advantages and innovation for car designers in the future.

Blast wave from a high-pressure gas tank rupture in a fire: Stand-alone and under-vehicle hydrogen tanks

This study addresses one of knowledge gaps in hydrogen safety science and engineering, i.e. a predictive model for calculation of deterministic separation distances defined by the parameters of a blast wave generated by a high-pressure gas storage tank rupture in a fire. An overview of existing methods to calculate stored in a tank internal (mechanical) energy and a blast wave decay is presented. Predictions by the existing technique and an original model developed in this study, which accounts for the real gas effects and combustion of the flammable gas released into the air (chemical energy), are compared against experimental data on high-pressure hydrogen tank rupture in the bonfire test. The main reason for a poor predictive capability of the existing models is the absence of combustion contribution to the blast wave strength. The developed methodology is able to reproduce experimental data on a blast wave decay after rupture of a stand-alone hydrogen tank and a tank under a vehicle. In this study, the chemical energy is dynamically added to the mechanical energy and is accounted for in the energy-scaled non-dimensional distance. The fraction of the total chemical energy of combustion released to feed the blast wave is 5% and 9%, however it is 1.4 and 30 times larger than the mechanical energy in the stand-alone tank test and the under-vehicle tank test respectively. The model is applied as a safety engineering tool to four typical hydrogen storage applications, including on-board vehicle storage tanks and a stand-alone refuelling station storage tank. Harm criteria to people and damage criteria for buildings from a blast wave are selected by the authors from literature to demonstrate the calculation of deterministic separation distances. Safety strategies should exclude effects of fire on stationary storage vessels, and require thermal protection of on-board storage to prevent dangerous consequences of high-pressure tank rupture in a fire.

Current Status and Future Outlook of Fuel Cell Vehicle Development in Toyota

Fuel Cell Vehicle (FCV) offers one of solutions to the issues in energy and climate change. It is well known that FCV is zero-emission and hydrogen can be made from a variety of energy resources. FCV has such environmental friendly features but the recent FCV also has useful features in cruising range of more than 500km, startability under subzero condition and about 3 minutes refueling time. Furthermore, it shows attractive drivability in excellent response under lower vehicle speed cruising; another feature is that it can be used as emergency power supply, that roughly estimated to supply a household for one week by FCV, and a shelter for several hundred people for about five days by Fuel Cell Bus (FC bus) with fully fueled condition. It is considered that FC system is applicable to from small vehicle to large bus since it has longer cruising range and shorter refueling time compared to EV which is more popular than FCV now. However, both FCV and EV need years before these vehicles will be widespread because of higher cost and lack of infrastructures. For the moment, HV or Plug-in HV are considered to be major vehicle in next generation because of advantages in cost reduction and infrastructure development. FCV will increase gradually in the market according to progress of its development. Toyota started the development of FCV in 1992. After several model changes and market experiences with limited market introduction in 2002, the model “FCHV-adv” in 2008 shows excellent performances in drivability under subzero condition, cruising range and durability. These performances are reaching the levels of gasoline vehicle. Toyota announced to start selling commercial FCV “MIRAI” in December 2014 in Japan. The system uses Toyota-developed components including the Toyota FC Stack, FC boost converter, and high-pressure hydrogen tanks. Toyota FC Stack The new Toyota FC Stack achieves a maximum output of 114 kW. Electricity generation efficiency has been enhanced through the use of 3D fine mesh flow channels, which ensure uniform generation of electricity on cell surfaces, providing compact size and a high level of performance, and a power output density of 3.1 kW/L. The amount of water on fuel cell electrolyte membranes has a substantial influence on electricity generation efficiency. Control of the amount of water is carried out using an internal circulation system for circulating the water created when generating electricity, meaning the Toyota FC Stack is a system that, unlike systems used in all other previous Toyota fuel cell vehicles, does not require the use of a humidifier. FC Boost Converter A new compact, high-efficiency, high-capacity converter has been developed to boost power generated in the Toyota FC Stack to 650 volts. Increasing the voltage has made it possible to reduce the size of the electric motor and the number of Toyota FC Stack fuel cells, leading to a smaller, higher-performance Toyota Fuel Cell System, thereby reducing system costs. High-pressure Hydrogen Tanks Tanks with a three-layer structure made of carbon fiber-reinforced plastic and other materials are used to store hydrogen at a very high pressure of 70 MPa (70 megapascals, or approximately 700 bars). Compared to the high pressure hydrogen tanks used in the Toyota FCHV-adv model, tank storage has been increased by approximately 20 percent while both weight and size have been reduced to achieve a world-leading 5.7 wt%.

Possibilities of the design estimates of the reliability of a high-pressure metal-composite tank

The problem of the estimation of the reliability of a metal-composite overwrapped pressure vessel for the electrojet engine unit of a satellite vehicle is considered. The functions of probabilities of failure-free performance according to impermeability and strength criteria are used as reliability characteristics. The peculiarities of the estimation of the mentioned probabilities of failure-free performance are studied for different stages of the service life of the tank.

Using autofrettage technology to decrease stresses in a girth welded joint of a high pressure hydrogen tank

A numerical model of a welded joint of the hydrogen storage tank was built. The stresses caused by inner pressure, welding, and autofrettage were investigated. Numerical results showed that complicated welded residual stresses were generated in the weld central line and heat affect zone, which made the stresses in the welded joint increase and fluctuate. In order to improve the stress distribution, the autofrettage process was used after welding. Comparison of stress distribution with and without autofrettage, showed that the autofrettage process caused stresses in the welded joint of the hydrogen storage tank to be more uniform along the wall, and decreased the influence of welding on the total stresses. Therefore, the safety of a high-pressure hydrogen storage tank is improved by the application of autofrettage.

Composition design of Ti–Cr–Mn–Fe alloys for hybrid high-pressure metal hydride tanks

(Ti0.85Zr0.15)1.1Cr1−xMnFex (x=0, 0.05, 0.075, 0.1, 0.15) alloys with a C14-type Laves structure have been investigated for potential application in hybrid high-pressure metal hydride tanks used for fuel cell vehicles. The effects of the partial substitution of Cr with Fe on the hydrogen storage properties of (Ti0.85Zr0.15)1.1CrMn have been systematically investigated. Results show that the desorption plateau pressure increases with increasing the Fe content in (Ti0.85Zr0.15)1.1Cr1−xMnFex alloys, whereas the hydrogen capacity decreases. Among these alloys, (Ti0.85Zr0.15)1.1Cr0.925MnFe0.075 has the best overall properties, with a hydrogen desorption pressure of 10.6atm and a reversible capacity of 1.54wt% at 0°C under the pressure range between 0.1atm and 120atm.

Long Plasma Jet Generated by DC Discharge in N<sub>2</sub> at Atmospheric Pressure: Impact of Trace Admixtures on Composition of Reactive Species in Far Afterglow

The object under study is a long plasma jet (up to 15 cm) generated by a steady-state dc discharge in N2 at atmospheric pressure. Successful usage of long afterglow plasma jet for distant treatment of 3-D object of a complicated shape with deep slots was demonstrated. This paper focuses on a role of trace impurities in plasma-forming gas on chemical composition of reactive species in far afterglow plasma. This role was studied numerically by example of the additives in high-purity nitrogen contained in high-pressure N2 tank. It is shown that small oxygen admixtures (at 10 ppm level) to N2 can be more effective in production of atomic oxygen than ambient air. Besides, trace admixtures of water vapor and hydrocarbons (at parts per million level) lead to full change in a composition of reactive species in far afterglow in comparison with the set of primary species generated by plasma source.

Advanced high-pressure metal hydride fabricated via Ti–Cr–Mn alloys for hybrid tank

Ti–Cr–Mn-based alloys with a C14-type Laves structure have been investigated for potential application in hybrid high-pressure metal hydride tanks for fuel cell vehicles. The effects of partial substitution of Ti by Zr, and of Cr by Mo and W, on the hydrogen storage properties of Ti–Cr–Mn-based alloys have been systematically investigated. Among these alloys, (Ti0.85Zr0.15)1.1Cr0.9Mo0.1Mn shows the best overall properties, with a hydrogen desorption pressure and capacity of 9.54 atm and 1.78 wt% at 0 °C. The kinetics and cycling stability are also discussed for on-board hybrid high-pressure metal hydride tank applications. According to calculations, the volumetric H2 density of the hybrid system can reach the Department of Energy (DOE) 2017 target, while its gravimetric density remains at a high value of 2.72 wt% when 28% of the inner volume in a hybrid hydrogen metal hydride tank is filled with this alloy.

Toyota Frees Fuel-Cell Patents

In a move to spur development and adoption of hydrogen-fuel-cell transportation, Toyota says it will make thousands of its own patents available for free to other automakers, fuel-cell parts suppliers, and fueling station companies. Toyota’s first consumer fuel-cell car, the Mirai, will go on sale this year. Successful launch of a first generation of fuel-cell automobiles will require “unconventional collaboration between automakers, government regulators, academia, and energy providers,” said Bob Carter, senior vice president of automotive operations at Toyota Motor Sales U.S.A., when he announced the initiative at last week’s Consumer Electronics Show in Las Vegas. “By eliminating traditional corporate boundaries, we can speed the development of new technologies.” Toyota owns 5,680 fuel-cell-related patents covering fuel-cell stacks, high-pressure hydrogen tanks, system control software, and hydrogen production and supply. Similarly, Tesla CEO Elon Musk said last June that the electric car industry woul...

Numerical Modeling of Supercritical CO2 Leaks and its Subsequent Dispersion in the Ambient Air

An integrated 3D CFD based model to calculate the leak rates of supercritical CO2 from high pressure tanks and pipelines and its subsequent atmospheric dispersion is developed. The first component of the model takes into account the transition flow of supercritical CO2 under the action of large pressure changes through small flow passages such as orifices and leaks in high pressure pipe walls. It considers steep changes in transport and thermodynamic properties using appropriate equations of state for the wide range of pressures involved. The second component of the model calculates the large scale dispersion through the ambient air. This model includes consideration of the formation of dry ice due to sudden expansion and subsequent sublimation of dry ice due to entrainment of relatively hot ambient air. It also takes into account the effects of surrounding wind field using an atmospheric boundary layer model. The first model is validated by comparing the computed mass flow rates with the experimental data for transition flow through short-tube orifices and then for a high pressure tank of CO2 emptied through a small orifice. The second model is validated by comparing the temperature and volume fractions of CO2 at different points in the downstream of the jet during dispersion with the measurements in the latter experiment.

411 6000系アルミニウム合金の水素挙動に及ぼす合金組成の影響(OS4-(3),OS4 オーガナイズドセッション≪材料・組織と加工≫)

The 6061 aluminum alloy is currently applied to liner or other members in a high-pressure hydrogen gas tanks for fuel cell vehicle since it has been used high-pressure gas tanks for other usages such as air tank for scuba diving and fuel tank for natural gas vehicle. For fuel cell vehicle, some other alloys with higher strength such as 6066 and 6069 aluminum are being demanded for cost and weight reduction. To use these new alloys, the behavior of hydrogen in 6000 series aluminum alloys must be understood in terms of alloy composition. In this study, we investigated the behavior of hydrogen in 6000 series aluminum alloys affected by alloy composition by means of hydrogen microprint technique with which hydrogen can be visualized with respect to the microstructure.

Screen Channel Liquid-Acquisition-Device Bubble Point Tests in Liquid Oxygen

This paper examines the key parameters that affect the bubble point pressure for screen channel liquid acquisition devices in cryogenic liquid oxygen at elevated pressures and temperatures typical of a high-pressure propellant tank. An in-depth analysis of the effect of varying liquid temperature, pressure, and pressurization gas type on the bubble point is presented. Testing of a and Dutch twill screen sample was conducted at the NASA John H. Glenn Research Center at Lewis Field in Cleveland, Ohio. Test conditions ranged from 92 to 130 K and 0.138 to 1.79 MPa. The bubble point is shown to be a strong function of temperature with a secondary dependence on the amount of liquid subcooling. The subcooling dependence is believed to be a function of the amount of evaporation and condensation occurring at the liquid–gas interface at the screen. Good agreement exists between the data and theory for normally saturated liquid, but the model generally underpredicts the bubble point in subcooled liquid. Using the liquid temperature at the screen as opposed to the bulk liquid temperature to determine the surface tension of the fluid results in better correlation with the data.

Analysis of the Principal Characteristics of the On-Board Throttle Cooling System of the IR Receiver on the Basis of a Tank with Cryogenic Fueling

In this paper, a new tank with cryogenic charging (liquid nitrogen) is introduced. On the basis of this tank it is proposed to create a throttle cooling system, which may have enhanced characteristics compared with a throttle cooling system based on high pressure tank. This article deals with first results of tests of a tank with cryogenic charging (liquid nitrogen), which have been made at level of pressure to 4 MPa. Also it is shown that the behavior of parameters in a tank on time corresponds to calculation model.