> Haven't you noticed they operate near the
    > full load point a tiny fraction of their lives?
    > Hold the pedal down in a car and you get a speeding ticket long before
    > any TC efficiency payback.

    > Don Sherman

   ------------------------------------------------------------------

   Depends on the size of the engine. A Prius engine is flat out at 80 MPH.
   If the battery was charged to begin with it is soon dead or switched off
   before it is dead.

   The smaller the car engine the higher the duty cycle. Yes of course a 400 HP
   Corvette is using a tiny fraction of claimed HP. Using a smaller engine is
   called "down sizing" and yes indeed it does improve the MPG as the
   engine is
   more closely operating in the best BSFC island. First two charts.

   If the engine is 50 HP flat out to improve the BSFC by 10% all you need out of
   the turbine is 5 HP. At 100,000 RPM that is .26 foot pounds of turbine torque.

   If you take a look at this next chart you will notice that even a fully
   loaded truck is not using max power at a steady 70 MPH. California has a truck
   speed limit of 55 MPH in many places. At 55 MPH a fully loaded truck is using
   about 50% max power. Aerodynamic drag is a major factor.

   Next to the last chart is the BSFC chart for gas engines verses diesels as a
   percentage of max power.

   Paul Lamar
   -------------------------------------------------------------------------

   Paul, with all of your expertise, why don't you apply for some of the
   grant money being thrown around for energy and efficiency research projects?
   C. Smith

   -------------------------------------------------------------------------------

   I am too old to go back to work. I'll be glad to work with somebody for
   free if
   they decide to do that. I have already mentioned that to Eric at Rotamax as
   they
   have the credibility of already being a U.S. rotary engine manufacturer with a
   complete machine shop and dyno. So far no word on if or when this will happen.
   If Mazda did it I would also be glad to help.

   Due to a lack of exhaust valves the turbo compound rotary is potentially the
   most efficient internal combustion engine of all. A marriage of the best
   features of the intermittent and continuous internal combustion engines. Once
   the turbo compound rotary reaches 50% efficiency there is no point to an
   electric car or rail transport unless the nation switches to nuclear energy.
   The
   reason for this is the majority of electric energy generated in the U.S. is by
   power plants burning coal, oil or natural gas. Transmission lines are not 100%
   efficient.

   The maximum local efficiency of these power plants is about 50% this in the
   case
   of a bottoming cycle gas turbine.  A bottoming cycle gas turbine is sort of a
   turbo compound power plant where the waste heat from the gas turbine makes
   steam
   that is fed to a steam turbine. Most other electric generating power plants are

   not 50% efficient. Look it up in Marks "Standard Handbook for Mechanical
   Engineers".

   Paul Lamar


   Paul, I think the rotaryTC/hybrid idea is the best option for an automotive
powerpalnt as well. At Ford there is a website for posting ideas that could help
the company, and I did post a note about the rotary TC, and with Ford's ties to
Mazda, that could be the foundation for a joint project. An engineer replied
that it would be nicely suited in a hybrid, and we all know the reasons why. But
that's as far as it went as I can tell.

   August issue of Control Engineering, Page 36, article titled "The Hunt for
60+% thermal efficiency" Frank J. Bartos. speaks to your points precisely.

   go to www.controleng.com/archive <http://www.controleng.com/archive>.

   At any rate, I marvel at the degree of technical expertise discussed here
on this list, if only our politicians and the general public could grasp some of
the reality of the physics and technological challenges facing us while we seek
solutions to our energy  woes.

   C. Smith

-----------------------------------------------------------------------------------

That article was hard to find so here it is. Thanks C. Smith. PL

The hunt for 60+% thermal efficiency
Frank J. Bartos, P.E. -- Control Engineering, 8/1/2008

In this era of high concern for energy consumption, readily available energy-efficient motors top the 96% mark, electric drives reach 95%, and many appliances and consumer devices exhibit rising efficiency. What, then, makes 60% thermal efficiency so special?

It’s a much different scenario for power generation. Complex combustion and fluid-flow processes involved in power conversion limit thermal efficiency, despite application of the best engineering know-how. For example, a typical light-water reactor nuclear power plant offers thermal efficiency around 35%, while a modern coal-powered plant with super-critical boiler tops out at 44%.

However, one power technology, the gas turbine, has been pushing the efficiency envelope. These large, land-based (stationary) turbines—with 100s of megawatt (MW) output—draw on the advances in design, materials, and cooling techniques of their more numerous aircraft gas turbine cousins. The latest turbines offer thermal efficiencies in the 40% range, with a recent model reportedly obtaining 46%.

These values refer to simple-cycle operation, where turbine exhaust is not further used. Real advantage comes from gas turbine exhaust applied as input to a standard steam turbine in a combined-cycle power plant. This is where new-generation gas turbines can become the driving engine to obtain 60%+ overall thermal efficiency. Europe leads the way

Among stationary gas turbine suppliers, developments from two manufacturers are particularly noteworthy. GE Energy installed the first of its H systems (combined-cycle gas and steam turbine) at Baglan Bay power station in South Wales (U.K.). The plant went commercial in 2003 and, to date, has logged over 30,000 operating hours. Currently it runs at 480 MW, with capability for higher output, according to GE Energy.

Five other GE H turbines are in various stages of implementation; three are in Japan at Tokyo Electric Power Co.’s (TEPCO’s) Futtsu thermal power station. The first of these 50-Hz machines was initially fired in Dec. 2007, and is expected to be in operation in late summer 2008. H systems in TEPCO Units 2 and 3 are scheduled to run by mid-2010.

GE’s first H-class turbine in the U.S., also its first 60-Hz machine, was installed in 2006 at Inland Empire Energy Center—a natural gas combined-cycle power plant in Riverside County, CA. Two GE H systems will comprise this plant, which is designed for maximum net rated electrical output of 775 MW to domestic and business users. Inland’s two units are scheduled to go online later this summer.

Meanwhile, Siemens Power Generation is moving its H-class SGT5-8000H turbine toward commercialization. Installed at the Irsching 4 gas power plant near Ingolstadt, Germany, the first firing of the turbine occurred in Dec. 2007. First synchronization to the grid followed in March 2008 and full-load testing (simple-cycle mode) started in April 2008, notes Phillip Ratliff, director of next-generation gas turbines at Siemens.

Siemens’ 50-Hz machine outputs 340 MW, but is designed to produce 530 MW in eventual combined-cycle operation—with expected efficiency of more than 60%. “A 60-Hz turbine is being developed after further verification of the first design,” says Ratliff.

An extensive test and validation program will continue for the SGT5-8000H turbine until mid-2009. Then, build-out of the combined-cycle plant begins in phase 2 of the program, with transfer to the plant operator, E.ON Kraftwerke GmbH, expected in mid-2011.

The next couple of years look exciting for the gas turbine power generation arena.
For more information, visit:
www.ge.com/energy
www.powergeneration.siemens.com