Steam Engine Thermodynamics
The following is a direct quote from Cyclone paper posted to internet circa 11 NOV 2009 taken from WAYBACK MACHINE web archive entitled “background.pdf”:
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In 1929 Prof. Stumpf stated the seven losses of the steam engine.
1. Surface loss
2. Clearance volume loss
3. Losses due to throttling or wire drawing
4. Friction loss
5. Loss due to leakage
6. Losses due to heat radiation and convection
7. Losses due to incomplete expansion
<OK, Stumpf was a genius, I have no problem with any of the above. Sheer logic. It is the part that now follows where reality gets twisted beyond recognition >
These have been dealt with by the Schoell Cycle Cyclone Engine
1. The engine is directly connected to the heat exchanger (boiler SC does not boil)
2. Using high compression uniflow with a variable compression where a constant SC can be maintained, high compression, as in a diesel, fills the clearance volume and adds to the expansion temperature.
3. The Cyclone has no throttle valve, as steam admission occurs at the head admission valve, where high density fluid of SC operation slows down the admission velocities, which minimizes wire drawing.
4. Friction losses are at a minimum because of only one throw on the crank and small pistons because of the high BMEP from the high pressure and slippery water lubrication
5. Leakage is at a minimum because the engine is at one with the condenser and the piston rings are of a special design where there is no metal to metal contact
6. Heat losses are at a minimum because the flame front travels towards the center where the flame is the coolest inward through the heat exchanger giving a very small surface exposed to the insulation. The engine can be run with hands on it.
7. High compression with high super heat eliminates saturation before
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Now let us examine the claim starting with number 2 above. Harry was absolutely right, high compression raises the temperature of the remnant steam mass at the end of expansion and this is achieved by tailoring the clearance volume to provide the correct degree of compression. Highest efficiency does occur when the compression is to exactly the pressure of the incoming steam.
OK, can anyone explain to me EXACTLY how this new rotary valve version of the Mark 5 can recompress to any great pressure with that long tube running from the cylinder head to the crankshaft mounted rotary valve?
Correct answer, IT CAN’T.
Now, how about point #4. It is claimed that friction losses are at a minimum because of slippery water lubrication. A simple question occurs: “Which creates a more dangerous trip hazard, water or oil?” ----mumble grumble----- EXACTLY RIGHT! That is why they put oil in engines.
Also on number 4, while it is true the radial engine has fewer main bearings, it has the same number of crank bearings and wristpins. Instead of one main bearing for each connecting rod, there are two rubbing/rolling contact points that causes the spider bearing to index as meant to do. Can anyone explain to us exactly why that that is such a huge improvement in friction reduction EVEN IF we ignore the whole issue of the less slippery water lubrication? Yeah, I didn’t think so.
Point #5. It is claimed that leakage is at a minimum because there is no metal-to-metal contact. Why does steam leaks around metal-to-metal joints so much easier than anything else? Smart boy, not even gonna touch that one. Since the engine allegedly uses steam at 3200 PSI , and I quote Cyclone’s own website:
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“High Efficiency • Super-Critical Liquid - Pressures in the range of 3200 psi with temperatures of about 1200°F cause super-critical vapor ...”
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How do these high pressures cause a minimum leakage across the piston rings? I think most of us figured the leakage INCREASED as the pressure went up. Hmmm…regarding that last video of the Mark 5, can we assume those white puffs of steam coming out of what appears to be the valve housing are proof that the unit is no longer leak-proof? For that matter, highly superheated steam doesn’t leave visible white puffs because the visible puffs are saturated water vapor.
How are they are maintaining supercritical pressure and superheated pressure and producing those white puffs? Or did they abandon it and give up on the high efficiency engine altogether.
If they've given up on high efficiency, exactly what is left of their original mission and why do they keep wanting to spend more money?
