JCB unveiled their clean-sheet hydrogen combustion engine, the 448 ABH2, at CONEXPO 2023 in Las Vegas. The company is touting their engine as a zero-emissions solution for construction and agricultural equipment.
JCB chairman Anthony Bamford said in a statement “The JCB engineering team has made enormous strides in a short space of time to develop a hydrogen internal combustion engine. As the first construction equipment company to develop a fully working combustion engine fueled by hydrogen, I’m delighted we are now able to present this technology on the international stage.”
JCB has a team of 150 engineers is working on hydrogen combustion engines and claims that over 50 prototypes have already been manufactured at the company’s U.K. engine plant. The prototype engines are currently powering a backhoe loader and Loadall telescopic handler machines. JCB also reportedly installed one of their H2 engines in a 7.5-ton Mercedes truck to test its potential for on-highway use.
The case for hydrogen combustion
Though JCB believes that battery electric powertrains are suitable for small machines, the company feels that energy requirements for larger machines are not practical for implementation of battery-based powertrains.
JCB also investigated the use of H2 fuel cells and unveiled a prototype fuel cell powered excavator in 2020, the 20-ton 220X. However, JCB studies concluded fuel cells are too expensive, too complicated and not robust enough for construction and agricultural equipment.
“Machines powered by fuel cells are simply not robust enough to handle the rigors of site dust and G forces,” said Tim Burnhope, chief innovation and growth officer for JCB. “They are also too expensive for customers due to the cost of platinum and the power electronics and are far too complicated for the market they serve.
JCB states that a hydrogen fuel cell machine could cost as much as triple as its diesel counterpart. Because of these findings, the company decided to begin development on their hydrogen combustion engine as a zero-emissions fuel solution. “If employed in an affordable and practical way, they hydrogen is a perfect solution for our industry,” said Burnhope. “Our customers are demanding a carbon-free mobile fuel which delivers maximum uptime. We believe hydrogen is that fuel.”
Back to basics
During their presentation, JCB stressed that the engineering team had gone back to first principles in designing their hydrogen combustion engine. The team reportedly studied 76 different technical papers on the subject and identified four key technical challenges: achieving a perfect mix of air and hydrogen, increasing the volume of air, achieving a clean spark ignition, and managing steam output.
Ryan Ballard, JCB powertrain engineering director, explained some of the challenges the team encountered. “When most hydrogen engines were developed in the early 2000s, they were large capacity naturally aspirated engines,” he said. “Today, engines work on lower capacities with powerful turbochargers.
Ballard also explained the operating principles behind JCB’s engine based on their research into past designs. “What we noticed in earlier (hydrogen) engines is most people ran them in a way that produced a lot of NOx. That’s really different to what we’re doing. We run the engines at a much lower temperature and pressure, which essentially does not create NOx emissions. Its not a problem anymore.”
“We discovered that there’s a certain temperature you can burn air at where its incredibly clean,” said Burnhope. “However, if you go over that temperature, its awful. In the past, people tried to hydrogen combustion using a gasoline engine with hydrogen fuel. So they were working at the wrong temperatures and pressures and the result was awful outputs in terms of emissions and efficiency.”
Something that was completely new to JCB for this engine design was spark ignition. The company reportedly drew on expertise from the auto industry to integrate spark plugs into their engine and provide the right amount of spark for H2 combustion.
According to Ballard, the first generation of JCB’s 448 ABH2 engine features a port fuel injection system for speed to market and because PFI systems are very robust. There is also no aftertreatment system required. The 4.8-L inline-four engine features a single turbocharger with a variable vane design due to the high airflow requirements of H2 engines.
In addition to powering their own machines, JCB stated that they are open to selling their engine to external suppliers in the future. The company also plans to address the infrastructure concerns of H2 refueling in innovations such as their mobile refueller that can deliver hydrogen directly to the jobsite that the machines are working in.Continue reading »