Professional Engineering

Hydrogen-powered vehicles are set to be an eco-friendly way that drivers will one day soon confidently choose to travel, and businesses will use them for their deliveries, in a bid to reduce carbon emissions. 

Sheffield firm ITM Power, which develops hydrogen systems for both niche and mass-market applications, is the latest company to take the next step in getting these vehicles on to UK roads. The company has helped to integrate hydrogen tanks into two vans, which will be test-driven by numerous firms and organisations across Britain in the next few years. 

Each van holds three hydrogen tanks. A refuelling station produces hydrogen from water and dispenses the gas to the vans via a mass flow meter. Hydrogen gas comes with serious health and safety issues. So the vans and tanks have had to meet strict safety standards to certify that they are suitable to travel on UK roads. To make sure these standards are met, the hydrogen tanks have been put through a series of tests, while computer-aided engineering (CAE) simulations have been used to test impacts on the vans themselves. In addition, the vans’ performance, when run on hydrogen, has been benchmarked against gasoline and diesel variants using a series of automotive test procedures. 

Canadian firm Dynatech designed and manufactured the vans’ hydrogen tanks and supplied them to ITM Power. The tanks have been put through a series of gruelling tests at Dynatech’s testing facility to make sure they are safe to use in the vans and won’t, for instance, get damaged or burst in the event of a crash or fire. These tests included drop, bonfire, pressure, penetration, ballistic and temperature tests. 

The ballistic test is conducted to test the tanks’ strength and their resistance to rifle fire. It involves firing a rifle at the tank, during which time the tank must not explode. With the drop test, large masses are dropped on the tanks from heights of up to 10m to establish their impact resistance, while the bonfire test involves the tank being put on a propane fire for 20 minutes, during which time it must not burst. The tanks must also not burst during a pressure test, in which they are put in a pool and, using a hydrostatic pump, subjected to around 2.25 times working pressure.  

Revolve Technologies of Brentwood, Essex, has built the vehicles. At the company’s facility, tests have been conducted to simulate crash scenarios utilising CAE. This involved side-impact testing using a one-tonne barrier mass. Side impact was tested because there is less space between the tanks and the side of the vehicle, compared with the front and the back.

Steve Hallett is ITM Power’s project leader and hydrogen applications engineer, and has been involved in integrating the tanks and hydrogen system into the vans. He says: “Essentially there cannot be any deformation of the tank or otherwise. There is a large crash space in the front of the vehicle and a large crash space in the rear of the vehicle, so the highest risk comes from side impact.”

In addition to the safety tests on the hydrogen tanks, the vehicles have been tested to assess their performance on the road. These tests took place at Millbrook proving ground in Bedfordshire. During the testing, the vehicles are driven on a chassis dynamometer against typical road loads. A sample of the emissions they produce during this drive cycle is taken and analysed by various gas analysis equipment.