liquid lpg injection on the new direct injection engines what are your 1

[sohoruel]

the new direct injection engines are being injected at very high presures wouldnt that allow lpg to be used on same system ?

 

[BrianPetersen]

I suppose the theoretical possibility exists, as long as temperatures in the system aren't beyond the critical temperature of the liquid fuel in question, but I've sure never seen it done ...

The high-pressure pumps in those systems generally rely on the fuel to act as a lubricant. Some of them have been having enough difficulty with this even using ordinary gasoline. I would imagine that LPG (propane, butane) has even lower lubricity than gasoline, which could be troublesome.

 

[sohoruel]

there are companies that make additives for lube on lpg systems.because some liquid lpg injection systems have pumps in thier tanks. and to aid the injectors.

 

[franzh]

DI HPLPFI (Direct Injection High Pressure Liquid Propane Fuel Injection) is a working system. Vialle, Icom, Prins, and others are in production. There is one platform nearing completion for the US market.

Franz

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[TDIMeister]

Any fuel system adapted for compression-ignited, DME (dimethyl ether)-fuelled engines will work for LPG. The physical properties of both (boiling point, CP, flash point) are similar, but DME works well as a CI fuel (high cetane number) while propane works well as an SI fuel (high octane number).

Search literature for direct-injected DME engines.

 

[PJGD]

Here is one ~500 bar DME common rail system:

http://www.altfueltechnology.com/

PJGD

 

[bcs5274]

and why aren't we using our plentiful natural gas to do this here and get our selves away from middle east oil???????????

 

[TDIMeister]

Yes it is being done. Cummins/Westport have ISB/ISX-based engines running on natural gas direct-injected with a Diesel pilot injection.

 

[dcasto]

because we do not have plentiful natural gas. By the time the EPA shuts down drilling, we are stuck with imported oil.

He is my question to everyone, why take a fuel like natural gas that we can burn and get 90+% efficiency and use it at say 40% efficiency?

 

[TDIMeister]

Because 90% efficiency for space heating is very different in terms of utility than 40% for useful mechanical work.

 

[TDIMeister]

Check out Boretti and Watson, SAE Paper 2009-01-1881: Development of a Direct Injection High Efficiency Liquid Phase LPG Spark Ignition Engine.