THE BI-FUEL SYSTEM
The Bi-Fuel System operates by blending diesel fuel and natural gas in the combustion chamber. This is achieved using a pilot-ignition, fumigated gas-charge design, whereby natural gas is pre-mixed with engine intake-air and delivered to the combustion chamber via the air-intake valve. The air-gas mixture is ignited when the diesel injector sprays a reduced quantity of diesel fuel into the chamber. This diesel "pilot" acts as the ignition source for the primary air-gas combustible. Because of the high auto-ignition temperature of natural gas, the air-gas mixture will not ignite during the compression stroke, as there is not enough heat present to facilitate combustion.
Because the OEM air-intake and diesel injection systems are utilized by the Bi-Fuel System, no engine modifications are required for installation. The various components of the Bi-fuel System are installed externally of the engine, and at no time is the engine disassembled during installation. All OEM engine specifications for injection timing, valve timing, compression ratio, etc., remain unchanged after installation of the Bi-Fuel System.
The Bi-Fuel System requires a low pressure natural gas supply (approximately 2-5 psi) with a flow rate of approximately 8 scfh/kW (i.e. 500 kW=5,000 scfh).
The primary components of the Bi-Fuel System include: