Steam Powered Electric Generator

minimum Steam Turbine 25 Kw , 3000 Rpm with a Boiler 5 bar with 450 C .

I doubt if you get usable amount of steam at 30Deg Even if it is in Celsius. Or Am I undersatnding you wrong? Please confirm.

Hi Rakesh, thank you for asking. I am trying to find a low scale power generator.

The black bodies, behind glass, in our sun make the water heat up to 120-130 degrees Celsius.

Not enough for practical steam.

After this, one or more stages are to come, but the heat we have collected already is very beneficial.

The idea is to find out if there is a win/win situation available.

In other words: will this system compete with e.g. the lower efficiency PV voltage panels?

I am trying to find a doable way to produce power out of heat from the sun.

To make it easy I suggested - additional energy - e.g. with diesel - while I also have parabolic or Fresnel collector systems in mind.

I also Do think sometime on smiler lines. But In such kind of projects one need to act instead of just making ideas. No idea is going to work in first go and there is very minimal you find in market as a standard Items. So one will will have to apply a full PDCA path many times before reasonable level of success.

Anyway I ll share some of the thoughts with you later on.

What about a sterling?

What is the temperature of the steam you want to work with? Black bodies are not THAT hot. + 30 celsius? You will need some dry steam far over 250 degrees I think. I found a company in India that produces steam engines up to 16 kW. Check "mini steam generators" - $2,000 - $15,000.

My experience in with Naval steam plants and 15Kw is microscopic in that world. From what you are saying you are only just making steam and I doubt that you would have enough pressure to produce much usable power. The plants I ran where 1200 psi and 850 degree super heated steam.

I understand for turbines you need that.

What about old western locomotives? What temp. and pressure they operated on? I remember having pretty dry steam at 160 Celsius @ 10 bar.

I'm not familiar with old western locos, but I am sure the Rankin cycle still applies!

You think there is hope?

YES

It's all about temperature, pressure and volume. Get enough of any one or two and you will get the amount of power you need.

According to the steam tables the temperature at 10 bar should be 184.13 deg.C and it will be saturated dry steam for process not for power driven turbines.

Should I keep the temperature lower then?

How'd iknow? ..when i'm unable to understand this

"The idea is to get the 20- 30 degrees to attain steam with electric power "

I pasted you how it is possible to generate power with 200F heat.

Suggest you do more study and research, put in practical use or whatever, thats your job.

http://en.wikipedia.org/wiki/Stirling_engine

thanks Ducon, Stirling looks good but besides some gadgets, doesn't seem to be produced and sold in usable power outputs. I went through the whole green story and many more.

10 bar and 184degre c was quite normal pressure for steam engine to drive sugar mill in sugar plant and sometime even for turbine drive

I have been working on this for a while now and have concluded that dry steam requires just too much energy to generate and have settled on a working fluid that is vaporized by hot water which itself is heated by the sun. There are too many issues with wet steam to deal with here. There are only two good ways to heat water to that temperature (the temp depends on your working fluid). One is a parabolic collector and the other is a dish concentrator focusing on a central point. If you need very hot water use the dish concentrator, you can get much higher temperatures than with the parabolic collector. If you use the internet you can find ideas for condensing turbines so that you will not loose the working fluid. Using a working fluid like hydrofluoroether which is kyoto approved will keep the EPA cops away. Or you can use any other hydro carbon of your choice. Every situation is different. There are generators available in that range, I see them all the time in home emergency standby generator systems. Well, I should say I have seen them is the lower range of your spec. I wish you success and suggest that the internet has proven a valuable tool for me. I have been impressed with the wealth of information available through google searches; or bing if that is your flavor.

Hello dvmdsc,

You have many good answers already, but I think you should consider the following: Around 30 years ago, I experimented with metalized Mylar film. I found that I could make very economical linear solar concentrators using half mil thick film shaped by low air pressure (about 5 inches w.c.). It made very pretty mirrors at a very low cost. With a 5 by 6 foot piece of film, I was able to produce a considerable amount of steam at midday in east Tennessee using a blackened piece of 0.5 inch diameter copper tubing supported at the focus of the cylindrical mirror. I believe we were getting about an 85 deg. C rise to the boiling point. The pipe was atmospheric, so the maximum steam pressure available remains an unknown. The 20-30 degree C rise you describe indicates that you are using flat plate type collectors.

You might want to consider using some concentrating solar collectors to "dry" the saturated steam made by your black body collector array. Feeding saturated steam into a steam turbine would result in rapid erosion of the turbine blades! Also don't waste good water vapor. Reuse it to make more steam and to save the sensible heat.

The aiming requirement for any form of concentrating solar collectors is their downside, but if you use E-W orientation of the cylindrical mirrors, you will only have to automatically adjust the black body tube closer to the mirror early and late in the day. The slow movement from solstice to solstice can be manually adjusted every few days by tilting the mirrors. This sounds like an excellent "Green" project, I would like to hear more about this project, please keep us informed.

Best regards,

Luther M

Does not appear to be workable at 15KW level. Steam engines even with condensers achieve about 25% efficiencies. You have to collect the equivalent of 60KW. This translates to about 120 Sq,Mtr. collector area at peak in tropical latitudes. More area will be needed for averaging out during daylight hours for angle variation. Lenses or mirrors can increase temperature but have no effect on colector area. If anything losses in these concentrators will further aggravte area. Then there is the nuisance of having to set up a sun tracking system.

http://www.spiritus-temporis.com/steam-engine/efficiency.html

Sterling Engine in Garths post a few posts back above would work with the narrow temperature fluctuations of 30 degrees between cool and hot water, but you would need probably 100 thousand of these individual sterlings to get the torque necessary to drive a generator to make the power needed. And that many in addition to not being economical would also work against themselves in the fact that all that mechanical friction would cause a loss of optimum output.

If you had a natural hot spring or other geothermic source that would be great for a steam powered electric generator. But from the sun as the power source to have steam power you would need to amplify the radiation to a surface area with mirrors to a black surface similar to the power plant in Arizona to achieve the radiant energy necessary to have the energy needed to make steam constant as the sun is up. You also would need a way to control the mirrors to change their angle as the sun passes across the sky due to earths rotation.