Compact Compression Ignition (CCI) Engine

The CCI Engine is a dual compression, dual expansion engine that uses an alternative architecture, high compression ratio and more efficient thermodynamc cycle in order to acheive the following characteristics:

• Brake thermal efficiency of 52%
• 1/4 the size of a conventional enigne of the same power
• Lower noise levels
• Less vibration
• Compression ignition of natural gas, diesel, biofuels, jet-A and JP-8

 

In the 3D model to the left, the blue section is the induction/precompression piston, the space between the opposed pistons is the combustion space and the red section is the expansion/exhast piston. The animation below shows the movement of the engine.

The reasons that the CCI engine has such tremendous performance are many. The alternative architecture of the CCI gives it the ability to have over a 40:1 compression ratio and a large bore to stroke ratio without the combustion shape and friction problems of the slider-crank. Additionally the constant pressure combustion and expansion to atmospheric pressure of the Brayton cycle bolster efficiency.

Animation of the CCI Engine

Thermodynamic Cycle: Unlike conventional piston engines which use the Otto Cycle or Diesel Cycle, the CCI Engine uses a modified Brayton Cycle - the same cycle used by gas turbine engines. At equal pressure ratios, the Brayton Cycle is inherently more efficient, but even more so at the extremely high 40:1 or greater compression ratio of the CCI engine. The Brayton Cycle advantage comes from expansion to ambient pressure and constant pressure combustion.

 

Engine Architecture: The architecture of the CCI Engine allows for a large intake bore and a short stroke without the problems of implementing this geometry in a traditional slider-crank engine. It allows for a very attractively shaped combustion chamber with a shape-factor closer to one, allowing for less heat-loss during combustion.

Compression Ratio: High compression ratio is key to extracting more efficienty from an engine. The CCI uses a 43:1 compression ratio compared to 12:1 for gasoline (Otto Cycle) engines and 18:1 for diesel engines.

 

 

Engine Architecture: Three sequential chambers allow for large bore compared to stroke enabling smaller engine size without compromising on combustion chamber shape or friction.

Themodynamic Cycle: The CCI Engine is a four-stroke engine, yet there is a power stroke every revolution like a two-stroke. This allows an engine that meets the strictest emissions standards while remaining compact and light.