Power plant on every truck
“60-70% of all the energy a truck produces is lost as heat. That’s a huge waste of energy. Using the same principle as an electric power plant we can make some of that heat useful again. Using this technique earlier studies show that in theory you could make an engine 10-20% more energy efficient. We want to see what is really possible in practice to make an electric power plant on every truck.
Chris Criens (29) started working for TMC only two months ago, but he talks about his role at the Flanders' Mechatronics Technology Centre (FMTC) in Leuven, Belgium, with the passion of someone who has been working with the team for years. “One of my projects here is a new Waste Heat Recovery System. The 60-70% wasted heat in engines is lost through the exhaust and the cooling system. Our intention is to develop a system that can re-use that waste heat and make trucks more energy efficient.”
Before working for TMC he studied Dynamics & Control at the Technical University in Eindhoven, Netherlands, and also did his PhD there on a new dynamic setup for Exhaust Gas Regulation to improve both fuel consumption and emissions in heavy-duty diesel engines. It is no surprise then that his new job at FMTC also has to do with dynamic systems. “My job right now on this project of a new Waste Heat Recovery System is to investigate useful works in the scientific literature. The theory is pretty simple. You use the heat from the exhaust to boil a liquid in a high-pressure evaporator. When you release this pressure, you can get an expander (e.g. a turbine) moving. This movement can be used to make electricity, or you can connect it to a drive shaft and produce extra power for the truck.”
Getting the theory to work in practice is always more difficult. Chris explains: “The literature already has proven this system could work, but we have a lot more work to do before the prototype is market-ready. The challenge is to make an efficient system that isn’t too big or heavy. The truck has to be able to carry something other than just the Waste Heat Recovery System, of course, and it can’t be too heavy or you’ll lose all of the energy benefits.”
Chris says there are a lot of choices to be made: “The system also needs to work at low temperatures. So what kind of liquid should we use? The liquids in refrigerators are commonly available, but they don’t meet all the constraints in terms of temperature, pressure, eco-friendliness and legislation. The next generation of these liquids is very interesting, but what exactly are their qualities in this kind of system? What is their boiling point? What kind of expander should we use? All of these considerations have a big impact on the size of the system and its efficiency. And with all these types of engines around the world, every 0,1% of making these engines more energy efficient has a significant economical and environmental impact.”
The project ‘Energy Conscious Design – Waste Heat Recovery’ is a project by Flanders’ DRIVE in cooperation with: Bosal, DANA, FMTC, LMS, Punch Powertrain & Voxdale. The project is financially supported by the Flemish Government.