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Forum Index : Other Stuff : Steam powered electricity
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hllrhd Newbie Joined: 01/07/2010 Location: United StatesPosts: 1 |
Anybody out there messing with steam? I was wondering if you could run steam through a compressor and turn the electric motor to produce electricity? 20 years ago I was messing with a wankle rotory engine and blowing steam through it. I could really get it reving but I never hooked it up to anything. Nursing school, getting married, raising a family all got in the way. I've seen where others had the same idea. The prob with that is the seals get eaten up. They had that prob. with internal combustion too. They don't mind that much because dead Mazdas are plentiful. I had a hard time finding the one I was using, it's long gone and I can't find one locally. I want to be able to generate electricity from wood heat. I heat my home with a woodstove exclusively. A lot of calories or BTU's get wasted. I'd like to capitalize on that. Firewood is plentiful here and the way things are going I'd like a way to power my home using it. I don't believe that public utilities are going to be available reliably in the near future. Neither will gasoline be redily available, and I can't afford to store enough to make a real difference. I'm also interested in woodgas generation and it is very complicated. Parts left out cost nothing and never need replacement |
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Robb Senior Member Joined: 01/08/2007 Location: AustraliaPosts: 221 |
Your going to need something with timed valves or a turbine. Compressors just use air pressure to work the valves. Did you read VK4AYQ's second post here? Still try explaining that to the power company I'v done the electrical bit. It works but is not viable with the petrol engine I was using but proved the concept.. |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Hllrhd I like your Idea and started to build one years ago however a shift to a warmer climate made it impractical. It was from an old set of plans I got from a English magazine published in the 1930's I think, it was a fire place with a double skin that acted as a boiler and hot water heater, with a small steam engine that produced 700 watts at 32 volts into a battery pack for off grid house, it even had plans to build your own batteries. It worked at 30 psi with a condenser to improve power 6" Bore and Stroke from memory, I did build the steam engine with some mods to update to modern bearings and balanced valves, it worked well producing 10 hp on higher pressure. In your climate and circumstances it would be a good project but I don't think a air compressor would be suitable or have a long life due to oil contamination. If you have exposed hot surfaces on your stove you should try peltier cells, the high power ones I tried gave a 16 watt output per cell 4" square, so a gang of them and a small circulation pump to circulate the cold from outside to the cold side would be a good project, and a lot cheaper than building a steam engine. The peltier plate I had powered 3 x 5 watt led lights at 15 volts tried 4 but voltage sagged to 11 volts. However not as much fun as there is nothing like a steam engine ticking over, its better to watch than TV. All the best Bob Foolin Around |
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Tim_the_bloke Senior Member Joined: 15/11/2009 Location: AustraliaPosts: 105 |
My interest in alternate energy is due to my family's hobby farm off grid. Cooking is done on a wood stove. The wood stove also heats our hot water. In winter you keep it burning all the time, this results it our hot water tank boiling out unless we have long showers. On cold nights we keep the fire fueled up and can hear the overpressure valve on the hot water tank continually releasing steam outside. It would be great to harness this wasted heat and turn it into electricity. So, please you experienced and wise backshedders, advise away... |
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Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Do a google and youtube search for Tesla Turbine, they are relativly easy to make and reasonably efficient for steam. Or you could use the heat directly on a stirling engine. A lot safer than steam, and you dont need to top up the water. Search for Stirling Engine, or Rider Ericsson Engine. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Tim How about putting a small hot water pump on the HWS to circulate the hot water through some built up radiators through the house instead of over firing the stove as it only heats one room, you could also circulate the hot water through the Stirling engine as Gizmo suggested as the temp differential to outside would be close to 100 degrees. All the best Bob Foolin Around |
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matt down south Regular Member Joined: 20/10/2007 Location: AustraliaPosts: 50 |
hi Bob so are the peltier plates in cooler/warmer fridges suitable and whats the max temp they can cope with till the magic smoke gets out? matt |
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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
The peltier plates off ebay are rather cheap and would be worth a try. Also do a search for a test done in Sweeden i think it was on doing exactly what you are thinking. It was a test conducted by the govenment there, on recovering power form heater/stoves. Some peltier plates data sheets have a temp rating and also the temp differance from one side of the plate (hot) to the other side of the plate(cold) to give maximum output. So basically the greater the temp differance the higher the output. When i looked into it it was only somewhat practical if you used something like a wood stove to get a large enough differance across the plate. Pete. Sometimes it just works |
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MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
[Quote=hllrhd]I'm also interested in woodgas generation and it is very complicated. I've messed around with this (40+ years ago) and while it's not all that complicated, an even easier thing to do is "destructive distillation" of (dry) wood chips. I used concentrated solar (Florida, USA) but a wood fire would work just as well. All you do is cook dry wood chips inside a sealed (from air) vessel and let the exhaust gasses flow down a water-jacketed tube. There's stuff in the smoke that condenses and drips out the end and what you have is methyl alcohol, which can be burned inside an internal combustion engine. Couple the engine to a generator and you're in business. Of course, there's a catch (always a catch, eh?). The catch is you don't want to come into contact with the methyl alcohol at all. Don't breathe the fumes and don't get it on your skin. It'll soak right through your skin and poison you on the spot. If you get it into your eyes, be sure a loaded M1911 is handy! It's pretty brutal stuff, but in this case, it's free. You might want to Google "still" and see how to make a water-jacketed flu pipe if you decide to go this route. All it is, is a copper tube with smaller copper tubing wound around its outside. You pump cold water through the small tube and it sinks the smoke's heat away, condensing the methyl alcohol. Be careful! Oh, and did I mention this? BE CAREFUL . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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matt down south Regular Member Joined: 20/10/2007 Location: AustraliaPosts: 50 |
Mac i'll stick with the peltier plates that other way sounds like a sure fire way of ending up in a pine box and at 51 im to young matt |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Matt The peltier plates I got from ebay rated at 400watt input where about $20 from memory, rated at 100 C Temp differential, I tried them on a black metal plate in the QLD sun at ambient on the cold side with a finned heat sink with a fan and got 16 watts, if you piped the southern cold inside with a small pump they would be more efficient, the ebay cells worked OK but there are High temp cells available with more output, but a lot more expensive. I think with a hot stove it would pay to mount them in a separate plate and use the radiant heat to heat it, rather than direct mounting oh the stove, adjust the air gap to adjust the temperature. Doing it this way would make it a lot easier to make and manage. The cold side needs to have a supply of cool antifreeze pumped or thermo -siphoned for Max effect. I think Alm RHS would work well. If I had a heater / stove I would be setting up some, as I read an article from a guy in Canada with a setup that replaces his solar panels in winter. He used the high temp direct contact cells that are all ceramic, the ones I tried only have ceramic faces and the rest is plastic, so the need to use the low temp side to get the best effect. Havnt seen the Hi temp cells on ebay but available from a supplier in Taiwan. All the best Bob Foolin Around |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hy Mack Playing with stuff there that's more dangerous than high voltage DC, All the best Bob Foolin Around |
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MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
VK4AYQ You're one to talk; with brown snakes living in your hobby shed! Still, that's why I got away from it; too dangerous. For the amount of bother as well as danger, it's just better to buy gasoline and use a lawnmower engine. A friend and I actually built a thing that made "producers gas" out of wood chips burning without oxygen. It's the same way charcoal is manufactured. The gasses given off are volatile and will run an engine. My hunch is un-condensed much of the gas produced by this method is methanol. Edit: Forgot a word! . . . . . Mac Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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nofear Newbie Joined: 20/07/2010 Location: AustraliaPosts: 11 |
Hi Everyone, I too am interested in possible steam power /stirling / heat power as we will be in a cold winter climate and have lots of wood to burn for heating /cooking and hot water, but also want to utilise some of the heat for electricity generation /top up.. I stumbled upon this website www.greensteamengine.com I invite comments. Anyone know of anyone who has built one of these or dealt with the company? [URL=http://greensteamengine.com steve a widely held belief is not necessarily a fact |
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davef Guru Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Steve, I had seen this previously, but thanks for the reminder. I would be interested in comments as well, as we are similar position, ie trees to burn and cooler climate. The process of actually getting the steam in a safe manner that doesn't require expensive certification is for me the bigger hurdle. Any comments about that issue? Good luck. Dave |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Dave I did an experiment years ago using an old McDonald diesel motor 5hp it was a hopper cooled engine, so I insulated the hopper and cylinder block and fed oil that was heated to 250C into the hopper this came from my trough collector I was using for another experiment. The McDonald engine has a low pressure injection system so I was able to use that to inject the superheated water direct into the engine, it did run but wouldn't self start as it is a single cylinder engine. The cam was modified to make it fire and exhaust on every stroke making it a two cycle engine. the normal governor regulated the amount of water injected and maintained normal rpm. To super heat the water the injector pipe was diverted to the hot oil in the hopper, so it flashed directly into steam on injection plus absorbed the heat from the heated block to augment expansion. I tried it with just the hot water injection but it was no good as the steam condensed in the cylinder giving no pressure expansion. Problems with the idea, the oil was diluted by the condensate coming past the piston, and the injector pump was prone to corrosion, as it was a simple plunger pump I made one out of SS and made SS valves no corrosion but wore out quicker SS was to soft, the oil condensation was solved by feeding the heated oil through a heat exchanger in the oil sump to keep the temperature high enough to boil the condensate out of the oil. It was an interesting exercise but in reality produce less than half the power from the heat absorber compared to a conventional double acting steam engine. It was good fun at the time but never went further with it as I concentrated on a freon 22 engine with closed loop energy system. All the best Bob Foolin Around |
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nofear Newbie Joined: 20/07/2010 Location: AustraliaPosts: 11 |
Hi Dave "The process of actually getting the steam in a safe manner that doesn't require expensive certification is for me the bigger hurdle. Any comments about that issue?" very good point there! NZ, sadly, is about as over-regulated as one can get...and to think I'm moving back there in a few months lol. Just watched a re-run of Top Gear and the Flying Scotsman....man did they burn some coal in that run!...mind you it wasn't fuel consumption that was said to be the problem with steam automobiles...it was the time required to get the car up to steam before being able to drive it. steve a widely held belief is not necessarily a fact |
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davef Guru Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Thanks for the comments guys. I'll have to talk to a few local experts to see what they say. Maybe, if you keep the pressure under a certain value, there is no certification requirement. Cheers, Dave |
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VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi All If you use a radiator cap as a pressure release device no pressure boiler license needed, and then 10 lb vacuum on the condenser, giving a 25 lb pressure in the engine, that's the way the old fire hearth system worked, a 6" bore and 6" stroke steam engine made over 700 watts 32 volt. The Stanley steamer used a flash boiler no pressure vessel license needed and got steam up in a minuet. Fuel consumption was high something like 12 mpg on kero. All the best Bob Foolin Around |
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davef Guru Joined: 14/05/2006 Location: New ZealandPosts: 499 |
Bob, I have been Goggling around for steam engines driven off a fire hearth system and seem to only get commercial system for generating large amounts of low pressure steam. Is this what you are referring to or could you suggest a few more appropriate key words? Something like a wet-back in a wood stove, which has a boiler for central heating, but running at a higher temperature?? 100-200Watts/hour would be enough to supplement low solar energy in the winter months. Cheers, Dave |
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