Calculating Steam Demand

[vargthewanderer]

Is it possible to calculate the steam demand of an engine? I would guess that it would involve cylinder displacement and RPM I want to run it at x(number of cylinders), as well as pressure, but that's when I get fuzzy.

I'm very new at this, but I'm going to go out on a limb and guess that if you are running 60psi in on the intake line the actual pressure in the cylinder at BDC is less than that, so how do you calculate that?

Can you calculate that?

And if you can't, how do you figure out how big of a boiler you need?

Thanks,
Varg

 

[aonemarine]

It can be calculated, but I can't do it. Go to the steam automobile club of America form, a bunch of real steam nuts there that will help you out. Search the site first before asking for help, they hate repeating themselves over and over......

 

[Charles Lamont]

1) As you say, you can calculate the swept volume per revolution of all the cylinders and multiply by the speed to get a steam consumption. This ignores things like early cut-off, leakage, and condensation but is a reasonable stab at it.

2) From steam tables, if you know the working pressure, you can look up how much water you need to evaporate to provide the required steam. Again, you err on the safe side if you ignore superheat.

3) Sources such as Model Boilers & Boilermaking by K N Harris will give guidance as to the evaporative capacity that could be expected of various boiler designs, in terms of water boiled per unit of heating surface area, per unit time. Decide on a boiler type and work out the necessary heating area. In fact, I should have just replied saying 'buy this book' as it explains the whole thing.

4) Design your boiler.

 

[Entropy455]

Your question is similar to, “how much gasoline will my engine consume?

The answer is depends – it depends on engine displacement, engine RPM, and the very important engine loading. The type of engine is also an important variable. Is it a piston engine, rotatory engine, gas turbine engine, etc?

The steam demand of an engine can most certainly be calculated. I would be happy to run the calculations for you, and explain how I obtained the results. However you need to limit the scope of the problem a bit, and provide some specific engine parameters (displacement, loading, cutoff-ratio, single stage,or multi stage, RPM, etc). I also need to know the temperature of the saturated steam you intend to run.

 

[aonemarine]

Your question is similar to, “how much gasoline will my engine consume?

The answer is depends – it depends on engine displacement, engine RPM, and the very important engine loading. The type of engine is also an important variable. Is it a piston engine, rotatory engine, gas turbine engine, etc?

The steam demand of an engine can most certainly be calculated. I would be happy to run the calculations for you, and explain how I obtained the results. However you need to limit the scope of the problem a bit, and provide some specific engine parameters (displacement, loading, cutoff-ratio, single stage,or multi stage, RPM, etc). I also need to know the temperature of the saturated steam you intend to run.

Judging by the screen name you a serious steam nut, who are you??

 

[Entropy455]

The entropy portion of my user name traces back to thermodynamics – which was my favorite class in college. The 455 represents my all-time favorite engine – the Pontiac 455.

 

[aonemarine]

LOL Pontiac??? boat anchor, the ony person I know that can get one to run is Neil Owens....... this is a test and only a test LOL

 

[Entropy455]

I have a 1974 Firebird, with 455 and TH-350 automatic transmission. The car will consistently run 12.9 at 110 MPH in the quarter, on Walmart-special street tires. It’s pretty respectful, considering the engine is running 8.6:1 compression, and the car weighs over 4300 pounds with me in it.

While the Pontiac 455 is my favorite engine, I find that I’ve collected more than a few Caddy 500 engines lately. . . . .

I also picked up a fully functional W-670 Radial engine (668 cid, WWII vintage). I have no idea what I’m going to do with it - it’s pretty darn cool though. . . The radial is sitting on the top-shelf within the pic linked below.

 

[Lopezmike]

Well, if you decide you aren't going to have time to deal with that old Continental, the owners of Stearman biplanes and Cessna 190's are always looking. Also I think the PT-17 trainer used them. Depends on whether it's rear or front exhaust. Convertible, I think. Not sure.
Mike

 

[Maryak]

An interesting diagram for your consideration.

Best Regards
Bob

 

[aonemarine]

12.9 is respectable. Im only joking on the boat anchor part, Im a car nut in general, all makes and models, working on a 40 ford coupe at the moment. Neil Ownes is a local drag racer that has had some great sucess with the pontiac 455's 8.5 at over 160 mph in the 1/4 in a 91 trans am full body and interior (as I best remember. ) but thier blocks are weak and split from the mains to the cam once over 800 hp. Also just got done building a 400 pontiac with ram air 4 cam 9.5:1 cr and a quadrajet carb to boot for a 67 lemans I painted for my dads friend. sounds pretty tough and is a joy to drive. Dont see many 500 caddy engines any more, and thier a real bugger for performance parts, best bet is to get some 472 heads and bolt on the 500 to get the cr up and have some fun. Id love to drop that radial on a street bike LOL!!!
[ame]http://www.youtube.com/watch?v=_hE9mnbAMWc[/ame]

Sorry for the tread jack guys......