Help me build a coal power plant!

[Doctor Jones]

Hi,

 

I'm thinking of constructing a miniature of a coal power plant for a school project to explain in practise and detail how it works and why it is a innefective method to produce electrical energy with. I'll use reliable methods aswell as material in my working process which will be oversimplified towards realities coal power plants.

 

But before I can get started I need help with my planning and eventual issues that might arise.

 

I'm thinking of using the following components in eneral to my coal power plant:

 

Steam turbine (Probably I'll build this my own if I can't find one in the right size, maybe a tesla turbine?)

Electricla generator (Have one!)

Pollution pipe

Coal

Water

Pipes

Drums

 

And here is a bad scetch i made recently (Took me 5 minutes, don't complain!):

http://yfrog.com/jtcoalpowerplantj

Forgot to draw the axe between the steam turbine and the electrical generator, but there is one

 

And here's some questions I've been figuring on:

Will it work or why won't it work?

What components should I add/change?

Could I place the components different to optimy the function of the power plant?

Will charcoal work?

How can I optimy the pressure of the steam when it reaches the turbine?

Which material should I use for the drums and pipes?

Is it anything else I could do?

Where could I find useful components on the web?

Will a cubic metre be enough space for the device?

I'll might update with pictures when the work gets going. And excuse me for my bad language, english is not my native language.

Thank you in advance,

Doctor Jones

 

EDIT:

I'll probably use a steam powered tesla turbine. The steam will come from a kettle with boiling water (this will compress the air enough after seeing this video:

) which will be heated with burning coal.

 

Question added:

Is there anyway I can use the CO2-gas to help power the tesla turbine? Can I connect the C02-pipe to the water steam pipe?

Edited August 9, 2010 by Doctor Jones

[rigney]

Hi,

 

I'm thinking of constructing a miniature of a coal power plant for a school project to explain in practise and detail how it works and why it is a innefective method to produce electrical energy with. I'll use reliable methods aswell as material in my working process which will be oversimplified towards realities coal power plants.

 

But before I can get started I need help with my planning and eventual issues that might arise.

 

I'm thinking of using the following components in eneral to my coal power plant:

 

Steam turbine (Probably I'll build this my own if I can't find one in the right size, maybe a tesla turbine?)

Electricla generator (Have one!)

Pollution pipe

Coal

Water

Pipes

Drums

 

And here is a bad scetch i made recently (Took me 5 minutes, don't complain!):

http://yfrog.com/jtcoalpowerplantj

Forgot to draw the axe between the steam turbine and the electrical generator, but there is one

 

And here's some questions I've been figuring on:

Will it work or why won't it work?

What components should I add/change?

Could I place the components different to optimy the function of the power plant?

Will charcoal work?

How can I optimy the pressure of the steam when it reaches the turbine?

Which material should I use for the drums and pipes?

Is it anything else I could do?

Where could I find useful components on the web?

Will a cubic metre be enough space for the device?

I'll might update with pictures when the work gets going. And excuse me for my bad language, english is not my native language.

Thank you in advance,

Doctor Jones

 

EDIT:

I'll probably use a steam powered tesla turbine. The steam will come from a kettle with boiling water (this will compress the air enough after seeing this video:

) which will be heated with burning coal.

 

Question added:

Is there anyway I can use the CO2-gas to help power the tesla turbine? Can I connect the C02-pipe to the water steam pipe?

 

Doc. ineffectual is a word characterizing a surgeon makes a mistake during an operation, an umpire, with a wrong decision; or a teacher instructing a class negativly. Using coal as a fuel, other than the atom is probably the most effective method we have of producing eletricity, since there isn't enough water or positive wind power to do the job. Rather than demean the process of using coal as a fuel, teach them the value of increasing their knowledge of its use.

[ydoaPs]

Doc. ineffectual is a word characterizing a surgeon makes a mistake during an operation, an umpire, with a wrong decision; or a teacher instructing a class negativly. Using coal as a fuel, other than the atom is probably the most effective method we have of producing eletricity, since there isn't enough water or positive wind power to do the job. Rather than demean the process of using coal as a fuel, teach them the value of increasing their knowledge of its use.

More energy reaches the Earth from the Sun in one hour than the entire Earth uses in one year. A properly managed solar infrastructure is the way to go.

[cypress]

A properly managed solar infrastructure is the way to go.

 

Perhaps some day it will be more than a dream.

[Moontanman]

Hi,

 

I'm thinking of constructing a miniature of a coal power plant for a school project to explain in practise and detail how it works and why it is a innefective method to produce electrical energy with. I'll use reliable methods aswell as material in my working process which will be oversimplified towards realities coal power plants.

 

Your basic premise is deeply flawed, coal is in no way an ineffective way to produce power, coal is a very effective way to produce power, it does have problems but most of them are centered around pollution from burning the coal and environmental problems from mining the coal not the effectiveness of producing power.

 

 

But before I can get started I need help with my planning and eventual issues that might arise.

 

See above... power plant efficiency whether it be coal or natural gas or nuclear power revolve around how much power is produced and how much is lost to waste heat, most new power plants are designed with very high efficiencies and loose the least amount of heat possible to waste, If you have problems with using coal as a power source I suggest you stick to environmental problems not the least of which is radioactive ash from coal....

[Doctor Jones]

Your basic premise is deeply flawed, coal is in no way an ineffective way to produce power, coal is a very effective way to produce power, it does have problems but most of them are centered around pollution from burning the coal and environmental problems from mining the coal not the effectiveness of producing power.

 

 

 

 

See above... power plant efficiency whether it be coal or natural gas or nuclear power revolve around how much power is produced and how much is lost to waste heat, most new power plants are designed with very high efficiencies and loose the least amount of heat possible to waste, If you have problems with using coal as a power source I suggest you stick to environmental problems not the least of which is radioactive ash from coal....

 

Sorry, I wrote wrong. Of course it is the pollution that is the problem and not the effeciency.

 

However, can you answer any of my other questions?

Edited August 9, 2010 by Doctor Jones

[Moontanman]

The first thing I notice in your drawing is that your coal needs air, our coal fired power-plant used powdered coal blown into a burner with air. with out air your coal will not produce smoke to go out your "pollution pipe" but more importantly the coal will not burn. I'm not real sure coal will burn in space small enough to be included in your meter cube. It takes quite a bit to get coal to burn, i grew up in a house that used coal fire places as a source of heat, it took a pretty good sized wood fire to get coal to burn, that why at DuPont we burned powdered coal and we used a very large hot natural gas flame to start it burning, getting a small amount of coal to burn in a tiny space will be difficult.

 

Other than the problem with burning coal and the large amounts of smoke it will produce I see no problem with your device, you have the basic steps about right.

[Doctor Jones]

The first thing I notice in your drawing is that your coal needs air, our coal fired power-plant used powdered coal blown into a burner with air. with out air your coal will not produce smoke to go out your "pollution pipe" but more importantly the coal will not burn. I'm not real sure coal will burn in space small enough to be included in your meter cube. It takes quite a bit to get coal to burn, i grew up in a house that used coal fire places as a source of heat, it took a pretty good sized wood fire to get coal to burn, that why at DuPont we burned powdered coal and we used a very large hot natural gas flame to start it burning, getting a small amount of coal to burn in a tiny space will be difficult.

 

Other than the problem with burning coal and the large amounts of smoke it will produce I see no problem with your device, you have the basic steps about right.

 

Thank you! I'll probably use a bellows or an open "coal oven" to solve the problem with the air. I've myself burned charcoal many times and I know it's a bit of process to get it burning, but I guess some charcoal lighter fluid should do the thing. However, I'll probably not be able to make "coal blown into a burner with air" due to the fact that I'll use small quantites. So do you think I still should use powdered coal? Maybe it's the easiest way whatsoever.

 

And also, should I use charcoal or bituminous coal?

 

Then I wonder if I can mix the CO2(g) which comes out from the pollution pipe, more correct the flue gas stack, with the H20(g) in order to run the tesla turbine?

[Moontanman]

Thank you! I'll probably use a bellows or an open "coal oven" to solve the problem with the air. I've myself burned charcoal many times and I know it's a bit of process to get it burning, but I guess some charcoal lighter fluid should do the thing. However, I'll probably not be able to make "coal blown into a burner with air" due to the fact that I'll use small quantites. So do you think I still should use powdered coal? Maybe it's the easiest way whatsoever.

 

 

Powdered coal can explode, we used a system that kept the powdered coal in constant suspension, if it settles out it will not burn, too much dispersal and it explodes, using small gravel sized chunks i think would be best...

 

 

And also, should I use charcoal or bituminous coal?

 

If you use charcoal it wouldn't really be coal... two completely different things... and charcoal lighter fluid will probably not light coal... it burns too fast and too cool to light up coal...

 

Then I wonder if I can mix the CO2(g) which comes out from the pollution pipe, more correct the flue gas stack, with the H20(g) in order to run the tesla turbine?

 

Now that I do not know the answer to...

[Mr Skeptic]

The main limits to efficiency for a coal plant are the maximum temperature reachable, and also that some heat is lost by exhaust gas. A nuclear reactor, for example, uses the same steam parts but its temperature is limited by safety and the melting point of materials.

 

Then I wonder if I can mix the CO2(g) which comes out from the pollution pipe, more correct the flue gas stack, with the H20(g) in order to run the tesla turbine?

 

If you did this, you'd have to waste tremendous amounts of energy cramming air into your burner. Note that the reaction C + O2 --> CO2 leaves the number of gas molecules unchanged, and so any increase in pressure is due to the change in temperature. For something as small scale as yours, there is no way that the gains will overcome the losses.

[rigney]

ydoaPs is 100% right if you are looking for the perfect fuel to power ratio. Then you'll want to use the sun. Cost?, Thats another question? But I believe you were interested in showing your class the negative side of using coal as a fuel? For the most negative method, use Bituminous coal. It's soft with a lot of impurities and oils in it, and it's messy. On the other hand, Anthracite is roughly 96-98 % pure, cleaner to work with and burns much hotter. The most efficient method for using anthracite is to grind it into a powder as fine as, or finer than flour. Then, using tubular air blowers; inject it into the fire box. In such a powdered form the dust can be quite dangerous and very explosive if dispersed into the air. In large generating systems the coal is powdered as needed so as not to have this liability. So don't keep more than a five pound bag of the stuff on hand at any time. Any of your engineering buddies can help with pre-ignition heating of the fire box before injection begins. Then it's just a matter of controls. Looks like fun.

[John Cuthber]

Don't forget that a badly designed coal burner will generate lots of carbon monoxide and poison everyone.

[rigney]

Don't forget that a badly designed coal burner will generate lots of carbon monoxide and poison everyone.

 

CO doesn't kill you per-se, but robs a body of its natural intake of oxygen. Just be careful where and how you vent your home.

Quote: If we have to buy coal from foreign countries, our energy rates will skyrocket. Millions of homes depend on U.S. coal for electricity. Are you worried that lost coal production will dramatically increase your electrical rates? How would your community be affected if tax revenue and salaries from coal are lost? Are you concerned about the thousands of good American jobs that will be go to foreign countries? We would love to hear your personal story and your answers to the questions asked above. Email your comments, along with your photo, to faces@myfacesofcoal.org.

Edited August 10, 2010 by rigney

[John Cuthber]

"CO doesn't kill you per-se, but robs a body of its natural intake of oxygen."

You still die.

[Doctor Jones]

Powdered coal can explode, we used a system that kept the powdered coal in constant suspension, if it settles out it will not burn, too much dispersal and it explodes, using small gravel sized chunks i think would be best...

 

 

 

 

If you use charcoal it wouldn't really be coal... two completely different things... and charcoal lighter fluid will probably not light coal... it burns too fast and too cool to light up coal...

 

 

 

Now that I do not know the answer to...

 

I see. Then I'll be heading for anthracite or bituminous coal in small gravel sized chunks, if I can find it.

 

The main limits to efficiency for a coal plant are the maximum temperature reachable, and also that some heat is lost by exhaust gas. A nuclear reactor, for example, uses the same steam parts but its temperature is limited by safety and the melting point of materials.

 

 

 

If you did this, you'd have to waste tremendous amounts of energy cramming air into your burner. Note that the reaction C + O2 --> CO2 leaves the number of gas molecules unchanged, and so any increase in pressure is due to the change in temperature. For something as small scale as yours, there is no way that the gains will overcome the losses.

 

That's true. But there will still be CO2 produced when the coal is heated, regardless if I use a bellow or not due to the fact that the burner will be open ion some way. Maybe I can compress the C02 in a separate tank and mix it when it reaches the same PSI as the steam.

 

But it seems dangerous. I'll se about this...

 

ydoaPs is 100% right if you are looking for the perfect fuel to power ratio. Then you'll want to use the sun. Cost?, Thats another question? But I believe you were interested in showing your class the negative side of using coal as a fuel? For the most negative method, use Bituminous coal. It's soft with a lot of impurities and oils in it, and it's messy. On the other hand, Anthracite is roughly 96-98 % pure, cleaner to work with and burns much hotter. The most efficient method for using anthracite is to grind it into a powder as fine as, or finer than flour. Then, using tubular air blowers; inject it into the fire box. In such a powdered form the dust can be quite dangerous and very explosive if dispersed into the air. In large generating systems the coal is powdered as needed so as not to have this liability. So don't keep more than a five pound bag of the stuff on hand at any time. Any of your engineering buddies can help with pre-ignition heating of the fire box before injection begins. Then it's just a matter of controls. Looks like fun.

 

I'm alone so I'll have to be pretty hard on the safety management and aswell my equipment is restricted. So I think I'll use small chunks instead.

 

Don't forget that a badly designed coal burner will generate lots of carbon monoxide and poison everyone.

 

Yepp, I'll test run it outside to prevent deaths.

 

 

Now I'm figuring on how to get this coal, maybe a visit to some sort of industry could do the thing?

 

And also I'm thinking of how to seal the top to the kettle. It must be strong enough to handle 3-5 bar, as that would be the pressure I'll use to be able to drive the tesla turbine at a reasonable rpm. Weld? Epoxy? I'll probably have to build some sort of wire safety cage around it if it would break

Edited August 11, 2010 by Doctor Jones

[Doctor Jones]

Here's a better sketch I made for the project:

 

http://img826.imageshack.us/img826/5476/powerplantoverview.jpg

 

I'll fix a blueprint later with measurements and maybe also a 3d model,

 

 

[engineer_norway]

First: You should use a safety valve on your system. If the pressure gets to high, you can be in for some nasty damage to your body!

 

Second: You have a point when you talk about using the energy in the exhaust (exhaust = CO2). Using the exhaust to run the turbine will not get you anywhere. There won't be nearly enough pressure in the exhaust to do that. If you want to use the energy in the exhaust you should use the heat, not the pressure. Using the heat in the exhaust to help heat the water will increase the effeiciency of your system. You can do this by letting the exhaust go through pipes which run through the "steam chamber" on its way out. Ideally, the temperature of the exhaust should be equal to the temperature in the steam when you release it into the atmosphere. I do not think you will be able to do this in your small system, but that is what you would do in a full scale system.

 

Good luck!

[CaptainPanic]

I agree with the above. Forget about using the CO2 for extra pressure. You can use it to heat the water though, if you run it through a tube through the water...

 

But my main question is to Doctor Jones: what are you trying to show with your project??

- Efficiency of coal powered plants: your small scale, low temperature, low pressure system won't come near the efficiency of the large plants. You'll be lucky to get half the efficiency. Therefore, any comparison with other sources, using your own results, is difficult.

- The workings of a coal powered plant are very simple. Essentially, it's just a steam engine without pistons, but with a turbine instead. The diagram here shows that there is a little more to it nowadays. There are 3 turbines (high, medium, low pressure). The steam is generated in many heat exchangers. The gas cleaning is ever more important. Research now focusses on turbine design (make them better), and the use of different fuels.

 

Will it work or why won't it work?

It will work, but it won't be efficient.

What components should I add/change?

Pressure relief valve. It's a piece of kit that lets out the pressure if it gets too high. You're actually trying to do something that's more dangerous than you may think.

Other stuff to add can be found in the same diagram I added above.

Could I place the components different to optimy the function of the power plant?

Not really. Optimizing your coal powered plant is tricky. Try not to lose too much heat, make sure the water gets hot. And don't blow yourself up if the steam gets pressurized.

Will charcoal work?

Yes. But charcoal will be easier, and gives you the same results in the end. Coal will burn hotter, but that's only relevant if you're really looking at efficiency. I'd be surprised if you can measure the efficiency accurately enough, and if you approach the reality near enough for this to be relevant.

How can I optimy the pressure of the steam when it reaches the turbine?

Hotter = higher pressure. Be careful!

Which material should I use for the drums and pipes?

Your question should simply be: what pressure do I want to achieve? The pressure is determined by the pressure drop of the turbine. Turbines are designed for certain pressures... and therefore your choice of turbine will determine the pressure.

 

Then, once you know the pressure, you make sure that your drums and pipes have the the right thickness. Thicker = stronger. Steel should be ok... but make sure it cannot corrode too fast.

 

If you intend to design the turbine yourself (good luck - that's really difficult), then I'd be surprised if you achieve any high pressure at all.

 

Is it anything else I could do?

Try to heat the water with the sun, using mirrors. That's essentially the same machine, but solar powered.

Where could I find useful components on the web?

Try Swagelok.com for all the pressurized piping you may need. Be warned, you're playing with expensive toys.

Will a cubic metre be enough space for the device?

Depends how big you want to make it. I've seen small steam engines that fit on a 30x30 cm area.

Your limiting factor for size is the area you need for a decent fire. Gas fires can be a lot smaller (think if a lighter or a small cooking fire), and therefore it will be easier (smaller) to build a gas power plant.

I'll might update with pictures when the work gets going. And excuse me for my bad language, english is not my native language.

 

Good luck!