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Question on Steam to Electric

Question on Steam to Electric

Question on Steam to Electric

(OP)
I have 80psi of excess steam that I would like to put to work.  is there any small turbine products/solutions to turn this into electrical energy?
Would i be better off using this for heating?

RE: Question on Steam to Electric

Just the pressure doesn't tell much.  You need to also know the steam temperature to determine how superheated you are (so you know how much energy you can get out of it before it condenses to water).  You'll also have to determine how much superheat you can produce per hour.

Don
Kansas City

RE: Question on Steam to Electric

Need quantity of steam (lbm/hr) also to determine capacity.

RE: Question on Steam to Electric

If your steam pressure is greater than you need, you may drop the pressure through a backpressure turbine and extract some energy.
If you have an excess of steam, use a condensing turbine.
If your excess steam quantity is too low for economical power generation, it may be possible to drive pumps or other mechanical loads with small turbines. Heating is, of course, another option.
respectfully

RE: Question on Steam to Electric

motorguyny
it would also be worth re-tracing the process of steam generation and looking at reducing the output of the original process as this will ultimately yield greater savings in energy.

RE: Question on Steam to Electric

(OP)
thank you for the tips.  I am looking to see if anyone has any sources for turbines of this size.  
Basically i am looking to take the 80 psi and have it turn a shaft. ie: i'd even be happy putting steam through an airmotor if possible!  Efficiency is not important (for anything is better than 100% waste)

RE: Question on Steam to Electric

Steam has a few important differences from air.  If the steam is superheated, it is dry (purely gaseous), just like air.  But when you pass it through a turbine you extract energy from it, and it can condense into water, which is something you don't have to worry about with air.  Most ordinary turbines (or air motors) don't like liquid and have no way to deal with it, since gravity makes it collect in the bottom and now your sloshing your blades down in it.

That's why I asked what temperature the steam is.  That will tell you how far it is superheated at a given pressure and how much energy per pound you can get out of it before it starts condensing.  

You're going to need to know this before you worry about where to buy a turbine.

Don
Kansas City

RE: Question on Steam to Electric

Again, you might revisit your steam generation to find out if you can reduce the excess.  While reclaiming the excess is admirable, the net savings is substantially poorer than not generating the excess in the first place.

Consider that you might have 30% efficiency in generating the steam and that your reclamation efficiency might also be 30%.  That's a net of 9% savings.  As you say, it's better than nothing, but eliminating the excess generation might net you more like 50% to 80%.

TTFN



RE: Question on Steam to Electric

You are going to have to find out what quantity of steam you have before you can get any real answers.
I have seen turbines rated at 25kw, 750 kw, and 1500 kw.
All ran on steam at 150 psig.
At 80 psig they would develop  13.3 kw, 400 kw and 800 kw.
As I remember the 1500 kw unit required 30,000 lbs. per hr. of steam.
That meant that 15 tons of water was boiled to steam, passed through the turbine and condensed back to water, each and every hour.
If you have no idea what the capacity of your boiler is, try to describe your installation and we may be able to help you.
I agree with the suggestion that it may be better to generate less steam, unless you are burning waste and your fuel cost is very low.
Your boiler controls are probably cutting of the fuel when the pressure reaches 80 psig. You would only be wasting energy if steam was continually blowing out the safety valve. If you add a load to the boiler such as a turbine, the controls will feed more fuel as needed to generate the extra steam demanded by the added load.
As sed2developer and IRstuff have suggested, reduce your steam generation.
Actually, I am pretty sure that your control system is doing that for you automatically right now. If it isn't it should be. If steam is not being released to the atmosphere at 80 psig, then you are probably not wasting any.
yours

RE: Question on Steam to Electric

You will probably get a better response to your question on one of the chemical engineering forums. This is commonly done with steam in chemical plants.

RE: Question on Steam to Electric

Or maybe forum666, the Devil's Forum, I mean Engine & Turbine Engineering. The quys there will ask the same questions regarding steam quality.

----------------------------------
  Sometimes I only open my mouth to swap feet...

RE: Question on Steam to Electric

The devil is in the details.

rmw

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