engine stats and effort/horsepower math?

[Mattybock]

If I know the operating pressure and overall size of a stationary boiler, exactly what else can I determine or guess about in regards to what that boiler, or an engine attached to it, is capable of in terms of horsepower?

If I have a boiler making 10 liters (about 5gl) of water into 10 kilograms (5lbs) steam per hour, at 1.5kg/cm sq of pressure (20psi), spinning a 20kg (40 lb) flywheel at 60rpms, what can I calculate or guess about the newtons/horsepower of the entire boiler and engine assembly?

Please don't hold me to any of these figures, they're just stand-ins.

[redneckalbertan]

These sites can probable answer your question better than I can:

http://en.m.wikipedia.org/wiki/Horsepow ... horsepower
http://www.engineeringtoolbox.com/boile ... _1061.html
http://www.johnstonboiler.com/T_BoilerFormulas.php

[dnevil]

You may find what you need in Winton Brown's Engineering Data:

http://ibls.org/mediawiki/index.php?tit ... ering_Data

Happy steaming!
Daris

[James Powell]

All of those will allow you to figure out IHP.

IHP=PLAN/33000

P=Mean Effective Pressure
L=Length of stroke (ft)
A=Area of Cylinder (sq ft)
N=Number of strokes/min (remember, double acting here...)

So, for instance, {15 PSI MEP (probably high for a 20 psi boiler), with a 3" stroke (1/4), and 3" bore (Pi*(1.5^2)*120strokes/min}/33000=around 1/10th HP indicated

Boiler HP is much trickier. It depends on specific consumption- you could work backwards if the boiler above is big enough to supply steam for the above engine, I think it will be. (220 lb water/hp/hour would be quite high...figure 30 lb/hr is high for a 1000 hp engine, and it can be quite low (12 lb/hr) for as small as a 70 hp engine.

James

[Fred_V]

A number I keep hearing about our boilers is 8 lb. per hour of steam per 1 sq. ft. of heating surface. This is for locomotive boilers of conventional build and may not apply to a smaller pot boiler.