Use of thermal wheel in a gas turbine
During the automotive industry’s interest in gas turbines for vehicle propulsion (around 1965), Chrysler invented a unique type of rotary heat exchanger that consisted of a rotary drum constructed from corrugated metal (similar in appearance to corrugated cardboard). This drum was continuously rotated by reduction gears driven by the turbine. The hot exhaust gasses were directed through a portion of the device, which would then rotate to a section that conducted the induction air, where this intake air was heated. This recovery of the heat of combustion significantly increased the efficiency of the turbine engine. This engine proved impractical for an automotive application due to its poor low-rpm torque. Even such an efficient engine, if large enough to deliver the proper performance, would have a low average fuel efficiency. Such an engine may at some future time be attractive when combined with an electric motor in a hybrid vehicle owing to its robust longevity and an ability to burn a wide variety of liquid fuels.