DBR Efficiency

A great deal of energy is lost through each cycle of a traditional piston driven engine. With that understood, the DBRE works to minimize these energy losses:

1) The power output of a DBRE is continuously variable. With conventional engines power is constant in relation to the RPM. When driving at a constant speed the engine will be producing a specific amount of power, and consuming a specific about of fuel, regardless if it is needed or not. On the other hand the DBRE’s output can be changed on the fly to meet power demands. In almost an instant output can change from 40 to 400HP!

This is accomplished by varying the packets of air and fuel. As the packets get smaller, less horse power is produced but with greater burn efficiency. Excessive compression is not built up, but instead an “ultra lean” condition is achieved. A side advantage to this ultra lean mix is lower combustion temperature and NOX emissions.

2) Conventional engines suffer from a ‘pumping loss’ where the pistons are working against themselves as well as forcefully sucking and blowing gasses. This is the main reason why engines must waste fuel idling - which is neither efficient nor environmentally friendly. By dynamically metering the power stroke gases, the DBRE is fed just what is needed and the so-called pumping losses are eliminated. Fuel can be metered down to a pilot flame or even stopped. Once stopped, the DBR can be turned by releasing high-pressure air from an accumulator.

There is no need to idle and waste fuel while stopped in traffic. Full power is available from zero RPM. Stored compression and fuel are simply introduced again and ignited. In the final analysis, this really does represent the epitome of the efficient and environmentally friendly “stop and go” engine.

4) Regenerative braking can have a tremendous impact both on fuel efficiency and environmental impact. While slowing or stopped, even the ultra lean fuel consumption can be stopped. Compression produced by braking, is stored in an accumulator which can later be used to motor the engine for short periods completely on air or instantaneously boost intake pressure like a turbocharger.

5) Each cycle can be treated as a separate process and optimized for thermodynamic efficiency. External combustion can be better controlled. Heat recovered from exhaust gases can preheat the compression gasses, while the compression gasses simultaneously cool the hot section. This is common inter-stage heat recovery used in turbines.

6) Further efficiencies are possible with designs that are unheard of in piston engines but evident in the DBRE: Pulsed modulation of combustion gas can be shortened; effectively lengthening the power stroke to extract more work [heat] before it is exhausted. Variable compression ratios are possible.