At Hannover Messe this week, Bosch Rexroth announced that it has developed a scalable portfolio of servohydraulic drives for compressors in the power range between 10 and 280 kW in partnership with others from the hydrogen industry.
Hydrogen produced from renewable energies plays a key role in achieving global climate targets. It is a CO2-free alternative to fossil fuels, especially for commercial vehicles. However, experience from the switch to electromobility shows how important a comprehensive charging infrastructure is if the new technology is to succeed.
Within the next six years, several thousand hydrogen filling stations will go into operation worldwide — with Europe leading the way — making an important contribution to the decarbonization of the mobility sector.
According to a decision by the European Union, hydrogen filling stations for cars and heavy commercial vehicles must be installed in all urban nodes and every 200 km along the trans-European transport network by 2030. The USA has set itself ambitious targets, too. The Fuel Cell and Hydrogen Association predicts that around 4,300 hydrogen filling stations will be needed in the USA in 2030. “With our new technical solutions and in close collaboration with partners from the hydrogen industry, we can provide outstanding support in achieving these goals,” said Dr. Steffen Haack, Chairman of the Executive Board of Bosch Rexroth AG.
Refueling with hydrogen is much more technically complex than with petrol and diesel filling stations or electric charging stations. The challenge: Hydrogen is stored on site either in liquid form at -253 °C or as a gas in tanks with various pressure levels. In order to refuel vehicles, the hydrogen must be compressed in a controlled manner to between 700 and 900 bar. Robust drives for the compressors are needed here.
The company relies on servohydraulic drive technology with an infinitely variable hydrostatic transmission. The robust hydraulics has a long service life. Long-stroke, ATEX-certified drive cylinders for compressors increase delivery rates thanks to end position-optimized control. The portfolio covers the power range between 10 and 280 kW as well as various applications.
New cryopump: 100 kg of hydrogen in 10 minutes
Bosch Rexroth developed the new electrohydraulically driven cryopump in collaboration with FirstElement Fuel, the market leader for the commercial operation of hydrogen filling stations in the USA. With a connection rating of 280 kW, it compresses liquid hydrogen to 875 bar for the direct refueling of heavy trucks. The aim is to refuel vehicles with 100 kg of hydrogen within 10 minutes. With direct refueling, there is no need for temporary storage tanks at filling stations. The first filling stations will be equipped with the new system from 2025.
Bosch Rexroth also offers variants developed together with partners for medium and smaller outputs. The 75 kW CytroCore compressor drive can be used to compress both liquid and gaseous hydrogen. In the lower output range of 10 kW, a ready-to-connect self-contained actuator CytroForce drives the compressor cylinders. No specific hydraulics know-how is required for either of the solutions.
Rexroth products in different performance classes cover a wide range of applications: From in-house filling stations for forklift trucks in logistics centers to car filling stations and filling stations for heavy HGVs. The drive systems for compressors can be installed in small spaces. Compared to previous electromechanical pump drives, they offer a significantly higher flow rate and are much more efficient. Designed for continuous operation, they can be used for several hundred refueling operations a day operating in start-stop mode.
Standard modules finely scalable in hardware and software
For optimum energy efficiency, Bosch Rexroth relies on displacement control. In contrast to throttle control which is used in most industrial hydraulic systems, position and force control is achieved by means of servohydraulic pump control. This control concept reduces energy consumption by approximately 75%. In addition, the drive systems for compressors require less than one square meter of installation space and are much quieter than conventional drive systems. After a one-off parameterization, they are ready for immediate use. They communicate with the control system for the hydrogen filling station via open interfaces. All modules continuously record operating data, thus putting in place the conditions for systematic condition monitoring and predictive maintenance for maximum availability with the digital service CytroConnect Solutions.
Bosch Rexroth can configure the standard drives in its portfolio in hardware and software to suit specific applications and thus precisely meet the requirements of users. The drive systems for compressors simplify the system architecture and operability of hydrogen filling stations and are suitable for both established companies in the hydrogen industry and newcomers.
Bosch is developing technologies for the production, compression, storage and use of hydrogen along the entire value chain. By 2030, Bosch aims to achieve a turnover of around five billion euros with this business segment. Between 2021 and 2026, the company will invest a total of around 500 million euros annually in the development and production of its H2 technologies.
Bosch Rexroth
www.boschrexroth-us.com
