Re: GAS-L: Internal Combustion with Producer Gas

[Reedtb2@cs.com]

Dear Mike, Prof. Parikh et al:

Mike said...
<<  PS. The increased efficiency of the diesel engine compared to the
 > spark-ignition engine is due to primarily to the higher compression
 > ratio.  The reduced pumping loss has an important, but smaller effect on
 > the engine efficiency.

Certainly the theoretical efficiency of the diesel engine increases linearly 
with compression ratio in the range 6-15, but tapers off with friction losses 
below that.  

However, I have also heard that the higher efficiency of diesel engines is 
doe to the lack of throttling loss, a major loss in spark engines.  Is this 
true??

I have also heard that the high flame velocity of hydrogen (2.83 m/s in air 
compared to 0.46 m/s for propane) causes a "knock" which makes burning 
hydrogen in engines difficult in the conventional mode.  

However, the wide flamability range of hydrogen permits burning hydrogen in a 
semi-diesel mode with open throttle and variable air-fuel ratio.  

This may then permit a higher efficiency for hydrogen combustion in spark 
engines.  

NOW, producer gas contains a lot of hydrogen.  How does this affect all of 
the above.  
The Gasification List is sponsored by
USDOE BioPower Program http://www.eren.doe.gov/biopower/
and PRM Energy Systems http://www.prmenergy.com
Other Sponsors, Archives and Information
http://www.crest.org/renewables/gasification-list-archive
http://solstice.crest.org/renewables/biomass-info/gasref.shtml
http://www.crest.org/renewables/biomass-info/
http://www.crest.org/renewables/biomass-info/carbon.shtml