The need to reduce emissions and comply with stricter public regulations is today a major concern, which naturally explains why more and more equipment manufacturers (OEM) seriously look at the options offered by hydrogen. Although a large part of the market is still focusing on the potential of vehicles powered by battery, hydrogen fuel cell vehicles offer a viable supplement which, at least for the moment, is more suitable to offer longer autonomies and faster supplies.
However, hydrogen presents its share of challenges, and manufacturers must carefully reflect on the design modifications necessary to make to their on -board fuel power systems to meet the additional hydrogen needs. Here are some of the most important factors to take into account when you decide to change your fuel source.
More ecological options
Today, there are more green energy sources than ever to supply transport vehicle parks. In this context, each equipment manufacturer and operator of vehicle fleet must determine the option best suited to a specific application. This means that you have to choose between natural gas (sometimes also called methane) or hydrogen. (For the needs of this article, we focus on compressed hydrogen (and non -liquid), because more and more equipment manufacturers use compressed natural gas (GNC) rather than liquid gas and, to date, the compressed hydrogen market is greater than that of liquid hydrogen.)
GNC and hydrogen are gases usable in an internal combustion engine (MCI) which are cleaner than diesel. However, the GNC still contains carbon. Only hydrogen represents a “zero emission” solution. On the other hand, hydrogen has less energy density. You must therefore store a larger quantity, at a much higher pressure, to reach an equivalent autonomy. While vehicles in the GNC generally maintain natural gas to pressures of approximately 3,600 psi, hydrogen vehicles store their fuel at pressures between 5,000 and 10,000 psi. This higher pressure has challenges in terms of safety and exploitation.
Increasingly strict standards
All the components of the power system, including seals, fittings and filters, must be compatible with fuel to avoid premature failures or potentially catastrophic leaks, and guarantee the sealing of the system.
Many components present on a hydrogen vehicle can be HGV3 approved. 1 or compliant with the ISO 19887 standard, which should be published soon. The CE-79 regulations, which is gradually removed and replaced by the ISO 19887 standard, is a certification created by the EU which guarantees the safety and performance of the equipment operating for hydrogen for different pressures and under different electrical, mechanical and thermal conditions.
This concerns the ability to contain the pressure, performance and safety characteristics of new components of compressed hydrogen fuel systems intended to be used on vehicles.
Components that do not comply with these stricter standards may not bear the higher pressures associated with hydrogen vehicles.
A weakening phenomenon occurs when a metal absorbs hydrogen and loses ductility. Hydrogen atoms being small and subjected to enormous pressure, they can enter solid metals. Once absorbed, hydrogen reduces the constraint levels necessary for the creation and propagation of cracks in metal, resulting in weakening.
Learn from the past
If you plan to pass the whole or part of your fleet of hydrogen vehicles, the task may seem colossal at first glance due to all the changes necessary in the design of systems as well as considerations concerning the compatibility of the materials of the components.
However, be aware that you don’t need to start completely from scratch, because if you already use GNC to a certain extent, you have probably already solved some of the problems related to the use of hydrogen. For example, there are already sealing solutions designed to withstand higher pressures.
Parker’s SEAL-LOK ™ fittings and adapters, for example, have been specially designed for on-board and GNC fuel systems. The design of Seal-Lok fittings is approved for use with pressurized hydrogen at 700 bar (10,000 PSI) and GNC up to 250 bar (3,600 psi). These fittings offer an improved flat -plane sealing surface as well as toric joints whose material meets the requirements for using high pressure gases. Overall, the toric joints are more effective than the “metal/metal” fittings to maintain perfect seal despite the additional vibrations linked to road trips.
Whether you use natural gas or hydrogen, you need a filtration system suitable for eliminating particles, oil, water or other contaminants that could damage the engine or fuel cell.
For more than 20 years that the GNC has been used on garbage trucks, we have learned to transport, control and effectively filter fuel. In addition, we have learned to safely store fuel in the vehicle to high pressures, often using specific pipes and assemblies of united stainless steel tubes that have proven themselves for this purpose.
Advantages of fuel cells
One of the main differences lies in the quantity of nitrogen oxide released during the fuel combustion reaction in an internal combustion engine (MCI). Fuel batteries directly convert the chemical energy of hydrogen into electricity, with pure water and, potentially, useful heat as the only by-products. With a fuel cell, there is no combustion; The chemical reaction generates electricity which loads the on -board battery, so that the only emission consists of water.
Hydrogen fuel cells can increase autonomy, as they work more effectively than internal combustion engine, with more than twice higher yield than conventional combustion technologies.
Allow the transition to “zero emission” thanks to hydrogen
The technologies linked to renewable energies have reached a level of maturity which allows an effective renewable electricity production worldwide, a prerequisite for a production of competitive green hydrogen in terms of costs. However, hydrogen engines and hydrogen fuel cell technologies experience different levels of maturity. From the point of view of equipment manufacturers and operators of vehicle fleets, the transition to an internal combustion engine (MCI) operating to hydrogen is by reusing a common set of parts and technologies. This reduces the initial cost of the transition to hydrogen. A hydrogen fuel cell electric vehicle has the additional cost and complexity of an on -board battery and a thermal management system.
However, this type of vehicle and internal hydrogen combustion engines are not competitors. The development of some supports that of others, because all require a common infrastructure suitable for hydrogen. These are complementary technologies, which are part of a progressive transition to reduced emission vehicles. “When we have fully entered the era of green energies, the internal hydrogen combustion engine will open the way to the use of electric battery -free electric vehicles without emissions, by taking full advantage of the infrastructure that will have been created for hydrogen,” says Steve Duricky.
Find the right partner makes all the difference
Getting to convert fuel systems on board hydrogen is not a decision to be taken lightly. System design changes and components upgrades are necessary. In some cases, you may also have to train your teams in maintenance protocols and procedures.
Choosing the right partner can help you take up these challenges more easily. Make sure your suppliers have already worked specifically with hydrogen. Parker, for example, has been working on hydrogen -related applications for over 60 years. We offer a full range of products that have obtained CE-79 certification, and many of them will soon be approved in accordance with the most recent standards. Moreover, our teams actively participated in the development of new standards. This means that you can trust with confidence an effective, safe and waterproof ecological fuel supply system with Parker by your side.
About Parker Hannifin
Parker Hannifin is one of the 250 world leaders in the field of movement and control technologies. For more than a century, the company has contributed to technological advances leading to a better world. For more information, see the site www.parker.com/fr or Our LinkedIn account Parker Hannifin France.
Author’s biography:
Steve DurickyGlobal Platform Manager, Fluid Connectors Group, Parker Hannifin Corporation.
Expertise: Fluid products and channels on various mobile and industrial markets. 33 years of experience in the sector.
Based in the United States, Steve has spent the last 15 years identifying world market trends and developing products that meet the needs of growing segments, especially that of clean substitution fuels. Engineer in training mechanics, Steve operates in the transport and construction markets, with vehicle parks, integrators and equipment manufacturers, to increase the use of substitution fuels. After working on GNC and LNG fuel systems, Steve today helps to help customers in the construction and transport sectors to engage on the hydrogen route.
