Fuel-Cell Race Car Relies on Bürkert Valve Technology

One of the most innovative cars at the starting line was the Forze V from the Delft University of Technology, the lurid coloured racer was green in more ways than one, as it was the only vehicle in the race to be powered by a fuel cell. The hydrogen / electric motive power was made possible by dedicated technology from fluid control specialist Bürkert.

With a weight of only 280 kg, a length of 3m, 18 kW of power (fuel cell only) or temporarily up to 60 kW (including regenerative braking power) and a speed of about 120 km/h – at first glance the performance data of the Forze V seems modest in comparison with conventionally fuelled race cars, however, this first impression is deceptive, as confirmed by the reaction of Ross Brawn, team leader of the Mercedes AMG Petronas Formula 1 team.

Ross Brawn, impressed by the engineering of the Dutch students, called the Forze V “an outstanding example of genuine innovation”. As so often in racing, the reason for this enthusiasm is under the bonnet: As opposed to the overwhelming majority of the race cars at the starting line in Silverstone, this one was powered, not by a combustion engine, but by an electric motor. Different again from all other electric vehicles in the race, it was powered by a fuel cell rather than a battery. By finishing in the midfield in Silverstone, the Forze Hydrogen Racing Team proved that it is possible to keep pace in motor sports by using hydrogen instead of petrol in the tank, and with zero emissions.

Lighter, stronger and faster.

The rules of the Formula Student stipulate that the teams must design and build a race car in one year, with which they then compete against each other in different events and races. The students are also responsible for the financing of the project, with the aid of industrial sponsors.

The team had already competed in 2011 with the Forze IV, the precursor of the current race car of the Delft University team. “We achieved good ratings in the design competition, but were unable to take part in the actual race due to technical problems,” Jan Jaap Treurniet, team manager of the Forze Hydrogen Racing Team recalls. That has changed with the Forze V in 2012. The new race car needed to be more powerful, faster, lighter and above all, more reliable than its predecessor. Since standard solenoid control valves and controllers from Bürkert were already in use on the car, the decision to contact the fluid technology specialist for fuel cell specific components and technology was a logical next step.

Racing fever in Ingelfingen

Johann Gunnesch is a motor sports enthusiast and an engineer at the Systemhaus of Bürkert Fluid Control Systems in Ingelfingen. He develops customised, highly specific system solutions for a wide range of applications requested by Bürkert customers throughout the world. When his Dutch sales colleague John van Loon approached him on behalf of the Forze Hydrogen Racing Team, he was quick to offer his assistance. After the Bürkert executive management agreed to provide the students with products and know-how from the Systemhaus, it was not long before racing fever broke out in
Ingelfingen.

After a preliminary meeting at Bürkert, the task was soon clear: The student team presented its flow plan for the fuel cell and explained the basic technical requirements. The goal was to find a solution for the hydrogen supply, which had to be as compact and lightweight as possible while making use of standard components from the Bürkert product portfolio. In the Bürkert Systemhaus Gunnesch and his team developed a proposal for an integrated solution. A compact aluminium block, which saved considerably on material, provided room for a safety valve, a solenoid control valve for controlling the hydrogen pressure, a mass flow meter, an overflow valve, as well as temperature and pressure sensors.

Johann Gunnesch explains the function of the low pressure block: “Coming from the tank, the hydrogen first passes a shut-off valve. An integrated excess pressure safety valve has to release the hydrogen in the event of a malfunction. A Type 2833 solenoid control valve meters the hydrogen for the fuel cell by controlling the pressure in the fuel cell. A Type 8711 flow meter measures the supplied quantity of hydrogen and sends this data to the vehicle’s electronic control system. The pressure and temperature are likewise monitored constantly by sensors that send their readings to the controller to enable the fuel cell to operate under optimal conditions at all times. Furthermore, there is a Type 6011 overflow valve, which can evacuate the entire system in case of emergency.”

After the design phase for the Forze V was completed, the block was adapted to the race car’s systems. There were also special requirements such as a mirror-inverted design or the 90° shift of a fitting. Finally, the low pressure block and a second, identical replacement block were manufactured in Ingelfingen and delivered to Delft. Shortly after came positive feedback: All systems go!

Slim and trim.

After having found an extremely compact and lightweight solution for the hydrogen supply, the Delft Racing Team became increasingly dissatisfied with the existing solution for the air supply. Although it functioned perfectly, the size and weight made it unsuitable for racing. The situation was addressed during a visit by Bürkert employees to the Delft University of Technology. “At first we had to pass,” Johann Gunnesch relates. “Our standard components for measuring the flow of gases are just as big and heavy as the components they were using.” But then – through a combination of racing fever and experimental spirit – the Bürkert team, after having found a solution for the hydrogen supply, joined forces with the students to tackle the air supply problem.

“Standard components were out of the question from the start,” Gunnesch emphasises. “What we needed was an ultra light, one-of-a-kind component.” This was based on a Bürkert flow meter for gases, which was reduced to the bare bones, and advanced sensor technology that is not yet available on standard products. The result was an ultra-compact solution for measuring the air flow in a compact design weighing several kilograms less than a solution using standard components. The Aerospace and Engineering Department at Delft tested the air flow meter and confirmed the excellent precision of the solution. Once it became clear that this solution was not only extremely lightweight but also functionally outstanding, the enthusiasm spread among everyone involved.

With the exception of the stack, the humidifier, the recirculation pump and the compressor, the rest of the fuel cell technology on the Forze V comes from Bürkert. “Thanks to the Bürkert solutions we were able to double the performance of the fuel cell in the Forze V in comparison with the Forze IV. At the same time, the weight of the vehicle was reduced by about 10% from 312 kg to 280 kg,” Forze team leader Jan Jaap Treurniet explains. “In motor sports, where fractions of seconds make a difference, that is a gigantic step forward.” And that is also exactly what Ross Brawn recognised when he visited the team during the Silverstone event. In an interview about the race, the Mercedes team leader called the Formula Student the most innovative racing class besides Formula 1. There are so many regulations for all the other classes that there is hardly room for genuine innovations.

The Forze V passed its baptism of fire in the Formula Student and cut a good figure in the race. “The Delft team race car shows what highly motivated students can achieve in the space of only one year,” praises Johann Gunnesch from the Bürkert Systemhaus. The race car – “green” in more than one sense – sprints from 0-100 km/h in less than five seconds and can run at full speed for about an hour on 600 grams of liquid hydrogen: in this case, 28 litres at 350 bar. The only “emissions” left behin