Hydrogen emission in enclosed volume (tunnel for mobility)

Fuel cell vehicles and trains (FCVs) are seen as a viable alternative to fossil fuel-powered vehicles, with the potential to help the automotive and transport industry grow sustainably. Because of their zero emissions, great efficiency, and diverse hydrogen sources, they are an ideal solution to climate change and the global energy issue. In this study, the simulation of releasing hydrogen from a moving vehicle inside a tunnel has been done. For this purpose, two scenarios have been considered. In the first one, it assumed that hydrogen propagates inside a tunnel without ignition and in the second approach, hydrogen released considered to be combusted. The effect of this combustion on the tunnel and train wall has been investigated. For this goal, two different mass flow rates of hydrogen were considered and results were compared together. Moreover, pressure contours have been shown to represent the overpressure phenomenon and it is resulted that in the area of hydrogen dispersion, there will be high pressure.

Evidence for Energetic Neutral Hydrogen Emission from Solar Particle Events

We report the probable detection of energetic neutral hydrogen atoms (ENAs) at >0.8 MeV in several large solar energetic particle events observed between 1997 and 2004. The low Earth orbiting SAMPEX satellite detected transient increases of quasi-trapped equatorial protons beginning typically ∼3 hr after the X-ray flare and lasting for up to several hours. Since the magnetic cutoff rigidity is >10 GV at the magnetic latitude where the particles were observed, we interpret the signal as due to ENAs that penetrate Earth’s magnetic field and charge exchange in the upper atmosphere, whereupon the charged particles may become trapped. One event outside our survey period (2006 December 5) had previously reported solar flare ENAs, the only example of this phenomenon of which we are aware. Although the statistics are limited, the events we report suggest that the ENAs are produced as the flare-associated coronal mass wjection moves through the corona, as concluded previously for the 2006 December 5 event. The finding of ENAs emitted in conjunction with large solar flares opens a new avenue to understanding these events.

Research on Economic and Operating Characteristics of Hydrogen Fuel Cell Cars Based on Real Vehicle Tests

With the increase of the requirement for the economy of vehicles and the strengthening of the concept of environmental protection, the development of future vehicles will develop in the direction of high efficiency and cleanliness, and the current power system of vehicles based on traditional fossil fuels will gradually transition to hybrid power. As an essential technological direction for new energy vehicles, the development of fuel cell passenger vehicles is of great significance in reducing transportation carbon emissions, stabilizing energy supply, and maintaining the sustainable development of the automotive industry. To study the fuel economy of a passenger car with the proton exchange membrane fuel cell (PEMFC) during the operating phase, two typical PEMFC passenger cars, test vehicles A and B, were compared and analyzed. The hydrogen consumption and hydrogen emission under two operating conditions, namely the different steady-state power and the Chinese Vehicle Driving Conditions-Passenger Car cycle, were tested. The test results show the actual hydrogen consumption rates of vehicle A and vehicle B are 9.77 g/kM and 8.28 g/kM, respectively. The average hydrogen emission rates for vehicle A and vehicle B are 1.56 g/(kW·h) and 5.40 g/(kW·h), respectively. By comparing the hydrogen purge valve opening time ratio, the differences between test vehicles A and B in control strategy, hydrogen consumption, and emission rate are analyzed. This study will provide reference data for China to study the economics of the operational phase of PEMFC vehicles.

HYDROGEN EMISSION CHARACTERISTICS OF Zr0.9Ti0.1Cr0.6Fe1.4 ALLOY UNDER DIFFERENT TEMPERATURE AND LOADING CONDITIONS

The hydrogen emission characteristics of a hydrogen storage alloy operating system employing the Zr[Formula: see text]Ti[Formula: see text]Cr[Formula: see text]Fe[Formula: see text] alloy were analyzed under different temperatures and loading conditions for application in a rehabilitation system for motion assistance for the aged and disabled. After activating 8.56[Formula: see text]g of a Zr[Formula: see text]Ti[Formula: see text]Cr[Formula: see text]Fe[Formula: see text] alloy under a 5.5[Formula: see text]MPa hydrogen atmosphere, operation tests were conducted in the temperature range of 25–80∘C under the loading conditions of 5–45[Formula: see text]kg. The lightest load of 5[Formula: see text]kg was lifted by 150[Formula: see text]mm when the system was heated from the initial test temperature of 25–80∘C and a 40[Formula: see text]kg load was lifted by 12.5[Formula: see text]mm at 80∘C, while a 45[Formula: see text]kg load could not be lifted under any of the temperature conditions. The hydrogen storage alloy operating system developed in this study is expected to be useful in motion assistance for the socially underprivileged, as a rehabilitation tool for the hand, wrist, and elbow, as supplementary equipment, and in rehabilitation systems for daily life.

Evidence of chromospheric molecular hydrogen emission in a solar flare observed by the IRIS satellite

We have carried out the first comprehensive investigation of enhanced line emission from molecular hydrogen, H2 at 1333.79 Å, observed at flare ribbons in SOL2014-04-18T13:03. The cool H2 emission is known to be fluorescently excited by Si iv 1402.77 Å UV radiation and provides a unique view of the temperature minimum region (TMR). Strong H2 emission was observed when the Si iv 1402.77 Å emission was bright during the flare impulsive phase and gradual decay phase, but it dimmed during the GOES peak. H2 line broadening showed non-thermal speeds in the range 7-18 $\rm {km~s}^{-1}$, possibly corresponding to turbulent plasma flows. Small red (blue) shifts, up to 1.8 (4.9) $\rm {km~s}^{-1}$ were measured. The intensity ratio of Si iv 1393.76 Å and Si iv 1402.77 Å confirmed that plasma was optically thin to Si iv (where the ratio = 2) during the impulsive phase of the flare in locations where strong H2 emission was observed. In contrast, the ratio differs from optically thin value of 2 in parts of ribbons, indicating a role for opacity effects. A strong spatial and temporal correlation between H2 and Si iv emission was evident supporting the notion that fluorescent excitation is responsible.

Study on hydrogen emission performance of FCEV

Hydrogen leakage and emission will bring adverse effects to the environment and human health. When it enters a certain concentration range, it will bring the potential explosion. Hydrogen emissions from fuel cell vehicles can be divided into two sources: normal operation of the system and leakage under abnormal circumstances. This paper mainly uses the flowmeter method to measure the hydrogen emission from fuel cell electric vehicle（FCEV）. The different emission characteristics of different types of FCEV under idle and steady cycle conditions were analyzed. The hydrogen emission levels of different types of FCEV under idle and cycle conditions were verified by analyzing and processing the experimental data through a certain amount of hydrogen emission tests of FCEV.