British company Clean Power Technologies is working on a novel new type of hybrid powertrain. They are taking advantage of the fact in an internal combustion engine upwards of thirty-five percent of the energy in the fuel goes out the exhaust pipe in the form of heat in the exhaust gases and a similar amount is dissipated by the cooling system. Clean Power wants to recapture that lost heat energy and store it in the form of steam.
So far that seems like a good idea, the problem is that in the confined space of a car utilizing steam can be problematic. The hot exhaust and cooling system are used to produce the steam which is stored in an accumulator. Power plants use steam to drive turbines and generators. A car would be unlikely to generate enough steam flow to keep a turbine running. Instead Clean Power is using a pair of Mazda RX-8s to develop their system. They have modified the Wankel rotary so that one rotor runs normally on gasoline while the other is driven by steam.
Over the next year they will be modifying the RX-8s and testing them. It will be interesting to see if the steam system can add enough power to the drivetrain to overcome the extra weight or whether it will be better than just a smaller displacement engine of similar efficiency. We'll be keeping an eye on this unique new approach.
[Source: Clean Power Technologies]