Enhancement of hydrogen storage performance in shell and tube metal hydride tank for fuel cell electric forklift

Novel metal hydride (MH) hydrogen storage tanks for fuel cell electric forklifts have been presented in this paper. The tanks comprise a shell side equipped with 6 baffles and a tube side filled with 120 kg AB₅ alloy and 10 copper fins. The alloy manufactured by vacuum induction melting has good hydrogen storage performance, with high storage capacity of 1.6 wt% and low equilibrium pressure of 4 MPa at ambient temperature. Two types of copper fins, including disk fins and corrugated fins, and three kinds of baffles, including segmental baffles, diagonal baffles and hole baffles, were applied to enhance the heat transfer in metal hydride tanks. We used the finite element method to simulate the hydrogen refueling process in MH tanks. It was found that the optimized tank with corrugated fins only took 630 s to reach 1.5 wt% saturation level. The intensification on the tube side of tanks is an effective method to improve hydrogen storage performance. Moreover, the shell side flow field and hydrogen refueling time in MH tanks with different baffles were compared, and the simulated refueling time is in good agreement with the experimental data. The metal hydride tank with diagonal baffles shows the shortest hydrogen refueling time because of the highest velocity of cooling water. Finally, correlations regarding the effect of cooling water flow rate on the refueling time in metal hydride tanks were proposed for future industrial design.     

Performance-based testing for hydrogen leakage into passenger vehicle compartments

International regulatory representatives have proposed the performance-based test methodology for hydrogen fuel cell vehicle (HFCV) fuel system integrity certification in a new global technical regulation (GTR). For this test method, vehicle certification depends on system performance during barrier/rollover crash tests. The GTR proposal specifies that the test is failed if within 1 h post-crash, hydrogen leakage rates exceed 118 L/min or flammable mixtures develop within the passenger cabin or trunk. An analysis of the capabilities necessary to detect the second failure mode was performed through exploratory in-vehicle leakage tests at SRI International’s Corral Hallow Experimental Site. Hydrogen concentrations were primarily derived from oxygen depletion sensor measurements, and were compared to directly measured concentrations from co-located hydrogen sensors. Close agreement between the two sensor technologies was observed. Since oxygen depletion measurements have the additional advantage that nonflammable gases can be used, helium was investigated as a surrogate due to its similar diffusion and jet spreading characteristics. The good agreement in overall dispersion trends for both gases highlights the flexibility of the indirect sensor method. While hydrogen mixture fractions strongly depended on release characteristics (e.g., rate, location, type), the results of an analytic examination indicated that pinhole leaks from moderate source pressures likely would produce unacceptably high in-vehicle hydrogen concentrations. The optimum sensor location for leak detection was determined to be high above the release point. Accordingly, sensor placement for crash tests involving vehicle rollovers must account for the final vehicle orientation.     

Review on studies of the emptying process of compressed hydrogen tanks

Compressed hydrogen tanks are now widely used for onboard hydrogen storage in fuel cell vehicles (FCVs). However, because of the high storage pressure and the low thermal conductivity of carbon fibre reinforced polymer (CFRP), the emptying of such tanks during driving or emergency release can cause a significant temperature decrease and result in an in-tank gas temperature below the low safety temperature limit of ?40 °C even in warm weather. Once the gas temperature within the tank is lower than ?40 °C, the sealing elements at the boss of the tank may fail, and glass transition of the polymer liner of the type IV tank may occur; both can cause hydrogen leakage and severe safety problems. In this paper, the heat transfer correlations, thermodynamic analyses, computational fluid dynamics (CFD) simulations, experimental studies, and thermal management methods associated with the emptying process of compressed hydrogen tanks are comprehensively reviewed. Future research directions on this topic are suggested.     

Theoretical investigation on heat leakage distribution between vapor and liquid in liquid hydrogen tanks

As a key factor affecting thermal behaviors of liquid hydrogen (LH₂) tanks, heat leakage plays an important role in accurate prediction of pressure build-up for safe storage and transportation of LH₂. Uniform heat flux between vapor and liquid in LH₂ tanks is widely adopted as thermal boundary condition in predicting pressure build-up process. However, a distribution of heat flux between vapor and liquid was observed during the self-pressurization process in the experimental test. In light of this, an analytically theoretical model of revealing the energy exchange process among the vapor, liquid and inner wall is proposed to investigate the heat leakage distribution ratio (HDR) between vapor and liquid in LH₂ tanks. The feasibility of the model is validated by the experimental results from NASA. In the whole self-pressurization process of 25,000 s, HDR reduces from 0.803 to 0.235 under a liquid fill ratio of 90% and a total heat leakage of 71.3 W. The results show that the existence of inner wall and different thermal properties between the vapor and liquid make the heat leakage flux non-uniformly distributed into the vapor and liquid. And the geometric structure of tank, thermal properties and initial states of the vapor and liquid have a significant effect on HDR. When coupling the model with thermal multi-zone model, the relative error in pressure prediction is reduced by 61.8% against experimental results. Benefiting from the coupled model, the relative error in pressure prediction caused by the uniform heat flux boundary condition reduces from 90.16% to 8.15%. The present work establishes theoretical foundation on analyzing heat leakage distribution between the vapor and liquid for LH₂ tanks, and provides useful guidance on modifying boundary conditions in accurately predicting thermal behaviors of LH₂ tanks.     

Study on hydrogen dynamic leakage and flame propagation at normal-temperature and high-pressure

Experiments of two nozzle diameters at three ignition positions under three initial pressure conditions were carried out. The dynamic leakage characteristics and the stagnation parameters of flame propagation under normal temperature and high pressure conditions were studied. Based on van der Waal's equation, a model for predicting stagnation parameters, jet velocity and flow rate of hydrogen leakage was proposed. Compared with the experimental results, it was found that the maximum error occurred when the initial pressure was 200 bar. Theoretical leakage time was 1.66 s, experiment leakage time was 1.84 s, the error was 9.8%. Background-Oriented Schlieren image technology was used to record the flame development and propagation process after ignition. For the same nozzle diameter and ignition location, the higher pressure caused the flame to propagate faster upstream and downstream. For the same initial pressure and ignition position, a flame with a large nozzle diameter propagated faster upstream and downstream. For the same initial pressure and nozzle diameter, the farther the ignition point was, the greater the slope of flame attenuation when propagating upstream. Due to the attenuation of hydrogen concentration and jet velocity, the flame propagation velocity to the downstream decreased linearly with the increase of distance from the ignition location.     

Effect of the position and the area of the vent on the hydrogen dispersion in a naturally ventilated cubiod space with one vent on the side wall

The design of ventilation system has implications for the safety of life and property, and the development of regulations and standards in the space with the hydrogen storage equipment. The impact of both the position and the area of a single vent on the dispersion of hydrogen in a cuboid space (with dimensions L x W x H = 2.90 × 0.74 × 1.22 m) is investigated with Computational Fluid Dynamics (CFD) in this study. Nine positions of the vent were compared for the leakage taking place at the floor to understand the gas dispersion. It was shown a cloud of 1% mole fraction has been formed near the ceiling of the space in less than 40 s for different positions of the vent, which can activate hydrogen sensors. The models show that the hydrogen is removed more effectively when the vent is closer to the leakage position in the horizontal direction. The study demonstrates that the vent height of 1.00 m is safer for the particular scenario considered. The area of the vent has little effect on the hydrogen concentration for all vent positions when the area of the vent is less than 0.045 m² and the height of the vent is less than 0.61 m.     

Thermal analysis of coupled vapor-cooling-shield insulation for liquid hydrogen-oxygen pair storage

The long-term storage of liquid hydrogen (LH₂)-liquid oxygen (LO₂) pair with extremely low heat leakage is essential for future deep space exploration. Vapor-cooled shield (VCS) is considered an effective insulation structure that can significantly reduce the heat penetration into the LH₂ tanks, however it is relatively ineffective for the LO₂ tanks. Novel coupled VCS insulation schemes for LH₂-LO₂ bundled tanks were proposed to achieve optimal performance not only for the LH₂ but also for the LO₂ tanks. A thermodynamic model had been developed and validated by experiments. The optimal VCS location, the temperature profile within the insulation, the heat leakage reduction contributed by the VCS, and the thermal performance versus scheme structural mass had been parametrically investigated. A comparison indicated that the proposed single integrated shield configuration can reduce the heat flux of the LH₂ and the LO₂ tanks by 64.0% and 54.8%, respectively compared with the non-VCS structure. In addition, the results also confirmed that zero boil-off storage of LO₂ can be achieved by only utilizing the exhausted hydrogen vapor, with no need for an extra cryocooler.     

Effect of thermal deformation on leakage clearance of claw hydrogen circulating pump for fuel cell system

The leakage clearance have a strong impact on the performance and reliability of hydrogen circulating pump in a fuel cell system, and the thermal deformantion is the most significant factor because of its high working temperature, small size. In this paper, the distribution of leakage clearance with different temperatures and rotors materials is obtained. The radial leakage clearance decreases with the increase of temperature in the working chamber. The axial clearance is increased by about 100  μm at rated working condition. When the material of rotors is aluminum alloy, the minimum radial clearance under rated working condition is about 8.5 μm, and the risk of interference is large. When the material of rotors is structural steel and titanium alloy, the radial clearance is maintained above 30 μm, and the risk of interference is small. The variation of leakage clearance leads to the variation of leakage area. The variation of total leakage clearance first increases and then decreases with the increase of angle. The minimum variation of total leakage area is 6.25  mm² at 0° and the maximum is 7.578  mm² at 84°. The total leakage area increased by 7.144 mm² on average. The results can be used as guidelines for the structural optimization of hydrogen circulating pump.     

Development of correlation equations on hydrogen properties for hydrogen refueling process by machine learning approach

The energy transition which refers to shift of the energy system from fossil-based resources to renewable and sustainable energy sources becomes a global issue to mitigate the progression of climate change. Hydrogen can play an important role in long-term decarbonization of energy system and achievement of carbon neutrality. Currently, the utilization of hydrogen in the energy system is focused on a road transportation sector as a fuel in a vehicle fleet.Compressing gaseous hydrogen is the most well-established technology for storage in hydrogen-fueled vehicles. The refueling hydrogen requires short filling time while ensuring the safety of storage tanks in a vehicle. However, a fast filling of hydrogen in high pressure leads to a rapid temperature rise of hydrogen stored in tank. Therefore, many numerical and experimental studies have been carried out to analyze the filling process. Various thermo-physical properties of gaseous hydrogen such as density, viscosity, and thermal conductivity are required for the numerical studies and the accurate hydrogen properties are essential to obtain reliable results.In this work, a polynomial equation is proposed with respect to temperature and pressure in ranges of 223.15 K < T < 373.15 K and 0.1 MPa < P < 100.1 MPa to present various hydrogen thermo-physical properties by adopting different coefficients. The coefficients are determined by a machine learning method to regress the equation using a great number of reference data. The equation is trained, tested, and validated using different datasets for each property. The order of the equation has been changed from 2 to 5. Then, the accuracies are estimated and compared with respect to the order. The average relative errors (REs) of the 5th order equation are assessed to lower than 0.3% except for molar volume and entropy. The accuracy of the equation is also examined with experimental data and other correlation equations for density, viscosity, and thermal conductivity which are required for numerical simulations of hydrogen refueling. The proposed equation presents better accuracy for viscosity and thermal conductivity than literature equations. In density calculation, a literature equation shows better performance than the proposed equation, but the difference between their accuracies is not so significant. In calculation time comparison, it is revealed that the proposed equation rapidly responses adequate to computational fluid dynamics (CFD) simulations.Results of the study can provide accurate and reliable hydrogen property values in a fast and robust means specifically for simulation of hydrogen refueling process, but not restricted only to the process. Correlation equations proposed in the present work can aid in optimizing a hydrogen value chain including production, storage, and utilization by providing accurate hydrogen property.     

Hydrogen sensors fabricated with sprayed NiO,NiO:Li and NiO:Li,Pt thin films

Hydrogen sensors have been prepared using NiO, NiO:Li and NiO:Li,Pt thin films deposited on alumina substrates by chemical spray deposition. X-ray diffraction indicates grain sizes of the order of 60 nm, which are in agreement with HRSEM images. The electrical response to hydrogen was studied at different work temperature (250 °C–450 °C) and at different hydrogen concentrations (3000–30,000 ppm). The NiO and NiO:Li sensors present maximum sensibilities in the range of work temperatures used, while the NiO:Li,Pt sensor has it at lower temperatures, promising to be a good hydrogen sensor at temperatures close to ambient. When tested at different concentrations the pure nickel oxide sensor and the sensor with platinum present a linear behavior, while the lithium-doped sensor presents a potential relation; in all cases, lithium-doped and with platinum on surface, sensitivity proved to be higher than that of pure nickel oxide. The use of platinum on surface sensors improves the response time from 6.6 min to 1.5 min.     

Hydrogen gas dispersion studies for hydrogen fuel cell vessels I: Vent Mast releases

We report modeling results for hydrogen releases associated with deploying hydrogen fuel cell technology on vessels. This first paper (I) considers hydrogen releases through the vessel Vent Mast from 250-bar hydrogen gas storage tanks, the type of tanks being used for the first hydrogen vessels. A manifolded 10-tank hydrogen storage system, holding 278 kg of hydrogen, can be emptied in ～10 min for maintenance purposes, with a pressure reduction to half the original pressure (125 bar) realized in 2 min if a rapid pressure reduction is needed, for example in the event of a fire. The time profile for filling a tank is also of interest so as not to exceed the tank thermal limits. The calculations show that a manifolded 10-tank array can be filled with hydrogen to 250-bar pressure in ～2 h from a 350-bar hydrogen refueling trailer without exceeding the 85 °C temperature limit typical of Type IV hydrogen tanks.Computational fluid dynamic (CFD) modeling shows that when the hydrogen is released out of the 10-tank array and into the Vent Mast in a 5-mph wind blowing horizontally, the effect of the wind on the hydrogen dispersion strongly depends on the hydrogen exit speed. For high release speeds (～800–900 m/s), the hydrogen flow is strongly momentum-driven, and there is modest cross-wind influence. For low hydrogen exit speeds (～10 m/s), the hydrogen is readily entrained in the wind flow and blown sideways, with the downstream flammable envelope rising at a positive angle to the horizontal due to buoyancy. To capture the influence of a wind with a downward component (e.g., created by a downdraft near a building), a calculation of a low-velocity (8.6 m/s) hydrogen release was performed with a 5-mph wind pointed downward at a 45° angle. The results show that despite the buoyancy of hydrogen, the wind blows the hydrogen substantially downward for low hydrogen speeds exiting the Vent Mast.     

Acceleration of hydrogen forced ventilation after leakage ceases in a partially open space

This paper treats the real-time sensing-based risk-mitigation control of hydrogen dispersion and accumulation in a partially open space with low-height openings by forced ventilation. A hunting-preventive control scheme that we previously proposed (Matsuura et al., Int J Hydrogen Energy, 2012;37(2):1972–84) has parameters such as the monitoring period of hydrogen sensors T_p, a unit increment in the exhaust flow rate per area from a roof vent α, and a threshold ε for the change in the exhaust flow rate. Through parametric simulations of the hydrogen exhaust after leakage ceases, we clarify the effects of the parameters on the rate of exhaust flow from the roof vent and the amount of hydrogen accumulating near the roof, which are critical for ventilation performance. With a selected combination of (T_p, α, ε) for which the ventilation system has a quick response and reasonable original performance, we first introduce two acceleration methods separately to the original hunting-preventive scheme to improve the ventilation performance after hydrogen leakage ceases. Ventilation performance employing the two methods is compared with that employing the original scheme. From the results, a hybrid method is finally proposed. The effectiveness of the proposed method is computationally validated for leak flow rates of 9.44 × 10⁻⁴, 4.72 × 10⁻⁴ and 2.36 × 10⁻⁴ m³/s.     

Two-dimensional thermal analysis of liquid hydrogen tank insulation

Liquid hydrogen (LH₂) storage has the advantage of high volumetric energy density, while boil-off losses constitute a major disadvantage. To minimize the losses, complicated insulation techniques are necessary. In general, Multi Layer Insulation (MLI) and a Vapor-Cooled Shield (VCS) are used together in LH₂ tanks. In the design of an LH₂ tank with VCS, the main goal is to find the optimum location for the VCS in order to minimize heat leakage. In this study, a 2D thermal model is developed by considering the temperature dependencies of the thermal conductivity and heat capacity of hydrogen gas. The developed model is used to analyze the effects of model considerations on heat leakage predictions. Furthermore, heat leakage in insulation of LH₂ tanks with single and double VCS is analyzed for an automobile application, and the optimum locations of the VCS for minimization of heat leakage are determined for both cases.     

Hydrogen storage – Industrial prospectives

The topic of this paper is to give an historical and technical overview of hydrogen storage vessels and to detail the specific issues and constraints of hydrogen energy uses. Hydrogen, as an industrial gas, is stored either as a compressed or as a refrigerated liquefied gas. Since the beginning of the last century, hydrogen is stored in seamless steel cylinders. At the end of the 60 s, tubes also made of seamless steels were used; specific attention was paid to hydrogen embrittlement in the 70 s. Aluminum cylinders were also used for hydrogen storage since the end of the 60 s, but their cost was higher compared to steel cylinders and smaller water capacity. To further increase the service pressure of hydrogen tanks or to slightly decrease the weight, metallic cylinders can be hoop-wrapped. Then, with specific developments for space or military applications, fully-wrapped tanks started to be developed in the 80 s. Because of their low weight, they started to be used in for portable applications: for vehicles (on-board storages of natural gas), for leisure applications (paint-ball) etc… These fully-wrapped composite tanks, named types III and IV are now developed for hydrogen energy storage; the requested pressure is very high (from 700 to 850 bar) leads to specific issues which are discussed. Each technology is described in term of materials, manufacturing technologies and approval tests. The specific issues due to very high pressure are depicted.     

Real-time microscopic monitoring of temperature and strain on the surface of magnesium hydrogen storage tank by high temperature resistant flexible integrated microsensor

Magnesium hydrogen storage tanks shrink and expand due to different states of hydrogen absorption and desorption, so it is important to monitor the body expansion, temperature change and stress change on the surface of magnesium hydrogen storage tank in real time. At present, commercially available temperature sensors and strain gauges are bulky, and the two sensors are not easy to be placed on the surface of magnesium hydrogen storage tanks for accurate measurement. Therefore, this study used micro-electromechanical systems (MEMS) technology to innovate and integrate micro-temperature sensor and micro-strain sensor, and make a small volume but high sensitivity high temperature resistant flexible integrated microsensor, which can be placed on the surface of the magnesium hydrogen storage tank to monitor the temperature, expansion and stress changes in real time, thus providing a reference for improving the optimal design of the magnesium hydrogen storage tank.     

Compressor speed control design using PID controller in hydrogen compression and transfer system

Hydrogen is an energy carrier which can be processed by high pressure compressor and they can be transported, stored and converted to electricity for later use. This paper proposes a hydrogen compression model development and modeling of hydrogen transportation between two tanks using MATLAB software version 22. The proposed model provides amount of hydrogen required in volumes (m³) and compressor power required in (KW) for compressor speed of 500 rad/s, 1000 rad/s and 1500 rad/s. This model provides hydrogen volume of 1 m³ and 10 KW compressor power requirement at 500 rad/s compressor speed. For compressor speed of 1000 rad/s, the proposed model provides hydrogen volume of 10 m³and 20 KW compressor power requirements and for 1500 rad/s this model provides volume of 30 m³and 30 KW compressor power requirements which indicates that the increase in compressor speed increases hydrogen volume generated and increase the power requirement also. For maintaining compressor speed at desired value, a PID (Proportional + Integral + Derivative) controller has been designed and the results were compared with Proportional (P), PI (Proportional + Integral), and PD (Proportional + Derivative) controllers. PID controller performance can be measured using the parameters delay time and settling time. Low values of settling time and delay time indicate the better performance of PID controller. P controller achieves the desired compressor speed with delay time of 228 ms; settling time of 1250 s. PI controller achieves the desired compressor speed with delay time of 210 ms, settling time of 1210 s. PD controller achieves the desired compressor speed with delay time of 185 ms, settling time of 1280 s. PID controller provides better speed regulation with low delay time of 110 ms and settling time of 1120 s when compared with P, PI, PD controllers. From the simulation results it is observed that PID controller can be a good option for slow process like hydrogen gas flow through pipeline for effective speed regulation.     

Numerical simulation of leakage and diffusion distribution of natural gas and hydrogen mixtures in a closed container

The transportation and utilization of hydrogen blended natural gas have received extensive attention. The dangerous characteristics of hydrogen such as high diffusivity and wide flammability/explosion limit also increase the leakage risk of hydrogen blended natural gas. In this paper, a numerical model is established for the leakage and diffusion of hydrogen blended natural gas in a closed container. The evolution of the distribution, diffusion law and flammable area of different proportions of hydrogen blended natural gas after leaking into a closed container is investigated. The results show that the flammable area with low hydrogen ratios (20% and below) will disappear within 2.7 s–11.1 s after the leakage, which is relatively safer, while the high hydrogen ratio (80% and above) reaches 3875 s–4555 s with a significant increase in risk duration. After the 50% hydrogen ratio leakage, the thickness of the flammable area is higher than 15.67% for the 80% hydrogen ratio and 30.25% higher than pure hydrogen at 120 s after leakage, and the risk is higher in a short time. Due to the difference in the diffusion rates between methane and hydrogen, hydrogen diffuses to the middle and lower part of the enclosed container faster, and the risk in the middle and lower part also deserves attention.     

Highly sensitive hydrogen sensor based on a new suspended structure of cross-stacked multiwall carbon nanotube sheet

In this research, we proposed a highly sensitive hydrogen sensor based on a new suspended structure of cross-stacked multiwall carbon nanotube (MWCNT) sheet. MWCNT sheet is a kind of CNT film which has a super-high CNT alignment and can be easily prepared by drawing from the spinnable CNT array in large scales. By stacking the sheets onto an electrode with a 1 × 1 cm hole in mutually perpendicular directions, sensors with suspended cross-stacked structure were realized. Afterwards, a two-side Pd functionalization was introduced. The effects of suspended structure, cross-stacked structure and two-side Pd functionalization were investigated respectively. It was observed that the sample with 2 + 1 layers of cross-stacked MWCNT sheet and two-side 3 nm Pd deposition showed the best gas sensing performance with a relative resistance change of 35.30% at 4% H₂. This result indicates that the proposed sensor is one of the best among all reported MWCNT based hydrogen sensors. The method demonstrated in this research gives a potential solution for the mass production of CNT-based sensors with high sensitivity and reliability.     

Development of efficient hydrogen refueling station by process optimization and control

Development of efficient hydrogen refueling station (HRS) is highly desirable to reduce the hydrogen cost and hence the life cycle expense of fuel cell vehicles (FCVs), which is hindering the large scale application of hydrogen mobility. In this work, we demonstrate the optimization of gaseous HRS process and control method to perform fast and efficient refueling, with reduced energy consumption and increased daily fueling capacity. The HRS was modeled with thermodynamics using a numerical integration method and the accuracy for hydrogen refueling simulation was confirmed by experimental data, showing only 2 °C of temperature rise deviation. The refueling protocols for heavy duty FCVs were first optimized, demonstrating an average fueling rate of 2 kg/min and pre-cooling demand of less than 7 kW for 35 MPa type III tanks. Fast refueling of type IV tanks results in more significant temperature rise, and the required pre-cooling temperature is lowered by 20 K to achieve comparable fueling rate. The station process was also optimized to improve the daily fueling capacity. It is revealed that the hydrogen storage amount is cost-effective to be 25–30% that of the nominal daily refueling capacity, to enhance the refueling performance at peak time and minimize the start and stop cycles of compressor. A novel control method for cascade replenishment was developed by switching among the three banks in the order of decreased pressure, and results show that the daily refueling capacity of HRS is increased by 5%. Therefore, the refueling and station process optimization is effective to promote the efficiency of gaseous HRS.     

Numerical simulation of hydrogen leakage diffusion in seaport hydrogen refueling station

Ningbo's seaport hydrogen refueling station was used as the research object. The effects of different leakage angles, wind direction, roof shape, leakage hole diameters, temperature, and humidity on the diffusion of hydrogen leakage were studied by numerical simulation. The influence of leakage angle on hydrogen leakage is mainly reflected in the presence or absence of obstacles. The volume of the flammable hydrogen cloud was reduced by 31.16%, and the volume of the hazardous hydrogen cloud was reduced by 63.22% when there was no obstacle. The wind direction can significantly impact hydrogen leakage, with downwind and sidewind accelerating hydrogen discharge and reducing the risk. At the same time, headwind significantly increases the volume of the flammable hydrogen cloud. Compared with no wind, the volume of the flammable hydrogen cloud increased by 71.73% when headwind, but the volume of the hazardous hydrogen cloud decreased by 24.00%. If hydrogen shows signs of accumulation under the roof, the sloping roof can effectively reduce the hydrogen concentration under the roof and accelerate the hydrogen discharge. When the leakage angle θ = 90°, the sloping roof reduced the volume of the flammable hydrogen cloud by 11.74%. The leakage process was similar for different leak hole diameters in the no wind condition. The inverse of the molar fraction of hydrogen on the jet centerline was linearly related to the dimensionless axial distance of the jet in different cases. Using a least squares fit, the decay rate was obtained as 0.0039. In contrast, temperature and humidity have almost no effect on hydrogen diffusion. Hydrogen tends to accumulate on the lower surface of the roof, near the roof pillars and the hydrogen dispenser. In this paper, a set of hydrogen detector layout schemes was developed, and the alarm success rate was verified to be 83.33%.