Looks like Turbo compound for diesel trucks is becoming off the
   shelf.

   http://www.voithturbo.de/vt_en_paa_road_motorenkomponente_turbocompound.htm


   "TurboCompound
   According to the European Exhaust Gas Norm Euro 5, from October
   2009, the
   borderline value for the emission of soot particles from heavy
   commercial
   vehicles will be set at 0.02 g/kWh. Nitric oxide emissions must not
   exceed a
   value of 2 g/kWh. It is assumed that from 2012, regulations will be
   even
   stricter with the introduction of Euro 6. Engine-related measures
   aiming at
   meeting this Euro 6 norm lead to increased fuel consumption. By
   utilizing the
   thermal energies occurring within the exhaust fumes, TurboCompound
   systems help
   to save up to 3 percent fuel. Consequently, CO2 emissions also drop.
   Voith Turbo
   supplies hydrodynamic couplings and pre-assembled systems for such
   TurboCompound
   systems."

   The 3% is an under estimation. DD claims 5%. Voith is not making the
   turbine
   apparently.

   Note the trade off between Nitric oxide emissions and fuel consumption.

   Nitric oxide never hurt anybody :) OK send me the proof!

   Like CO2 plants probably love it :)

   Also I'll bet that particle filter adds back pressure.

   Paul Lamar


For the record, NOx is a big family of related compounds, some of which
are quite toxic and irritate lungs; it can be somewhat dangerous to
infants and folks that have lung problems.  The biggest environmental
problem is that it reacts with other pollutants in sunlight which result
in ozone, smog, and acid rain.

Do you know what is in the blue drum- some kind of clutch or converter?

MICHAEL D PARKER

That is hardly the record. What specific NOX compound comes out of an engine?
Please cite your exact references.

It takes two to tango. Both Hc and NOX are required to form smog.
Eliminate the Hc alone and you eliminate smog.

"better combustion also results in more combination of nitrogen with oxygen, producing NOx' The nature of operation of the Otto-type internal-combustion engine, used in almost all cars in the world, precludes eliminating both hydrocarbons and NOx' Now the reader may reasonably ask this question: If the smog is caused by the combination of NOx and hydrocarbons, why is it necessary to get rid of both of them? That is an excellent  question."

"The father of smog, Professor Haagen-Smit, said "the Muskie bill passed last December [1970] without Congress understanding that emissions in 1970 vehicles had already been controlled 70 to 80 percent." He described the EPA air quality standards for hydrocarbons as "absurd."".

B. Bruce Briggs 1973 "The War Against the Automobile" Page 83.
I highly recommend anybody interested in engines read this book.

What is in the blue drum is a hydrodynamic coupling that isolates severe diesel
torque variations from being applied to the turbine. Detroit Diesel does it better putting the coupling closer to the crank shaft in the train of gears. However the efficiency of these devices is about 97% or worse. In other words 3% of the HP recovered by the turbine is thrown away in this device. It would be better to come up with a purely mechanical device to damp the torque pulses such as a one way clutch or belt drive. So far the truck guys are copying the scheme used in the R3350 TC.

It is encouraging and ironic that now that we have people building turbo compound engines we are now discussing the best way to do it.

Paul Lamar