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Post by silverdragon on Jan 29, 2016 8:57:09 GMT
Steam engine re-invent....
I have a crazy idea I want to run past you lot and see just how crazy it may be.
Take a traditional steam engine, and make it tougher, thicker steel, because it needs pressure.
Fill the boiler with OIL.
Heat the oil to maybe 200degC....
Throw in some water.....
Instant flash-over to high pressure steam?...
Am I just crazy or has anyone ever tried this before?.
I am also playing with the idea of introducing cold water directly into the piston after the power stroke as a spray to condense the steam back to water to get two power strokes, on of pressure one of vacuum...
Of course that will need an exhaust that drains the water, but the idea is that the water is then scavenged and your not wasting it as waste steam.
Why?.
I am working on a way to use waste heat from industrial plants and recycling the energy some way, and steam generators seam a logical idea to this.
All you need is water.
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Post by GTCGreg on Jan 29, 2016 13:50:07 GMT
I don't understand the oil concept. Are you just using the oil to store thermal energy? If that's the case, just use the water already in the boiler. That's how steam boilers work now. The water stays in liquid form until there is a reduction in pressure and then flashes to steam. That's how energy is stored in the boiler.
As for the vacuum on the discharge stroke of a steam engine, that's what a condenser is for.
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Post by the light works on Jan 29, 2016 16:39:28 GMT
in all honesty, it sounds like a huge complication for not much benefit. consider how long it took to cool the railcar for the railcar episode. using oil for a thermal mass in the boiler sounds like a rather good idea - but adding the water directly to the oil sounds like a recipe for disaster.
the real issue with steam engines is that they are already more complex to maintain and run than diesels.
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Post by GTCGreg on Jan 29, 2016 16:53:27 GMT
in all honesty, it sounds like a huge complication for not much benefit. consider how long it took to cool the railcar for the railcar episode. using oil for a thermal mass in the boiler sounds like a rather good idea - but adding the water directly to the oil sounds like a recipe for disaster. the real issue with steam engines is that they are already more complex to maintain and run than diesels. And they have already been refined to perfection. Back in the 1940's. |
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Post by the light works on Jan 29, 2016 17:08:36 GMT
in all honesty, it sounds like a huge complication for not much benefit. consider how long it took to cool the railcar for the railcar episode. using oil for a thermal mass in the boiler sounds like a rather good idea - but adding the water directly to the oil sounds like a recipe for disaster. the real issue with steam engines is that they are already more complex to maintain and run than diesels. And they have already been refined to perfection. Back in the 1940's. well, I'm sure modern constructions techniques and process controls would refine them more, but they are still limited by the expansion rate of steam. - and the golden age was the height of their beauty. |
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Post by GTCGreg on Jan 29, 2016 19:21:05 GMT
And they have already been refined to perfection. Back in the 1940's. well, I'm sure modern constructions techniques and process controls would refine them more, but they are still limited by the expansion rate of steam. - and the golden age was the height of their beauty. I'm sure boiler and steam turbine technology has advanced, but I don't think there's much to improve on reciprocating steam engines. |
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Post by the light works on Jan 30, 2016 2:06:07 GMT
well, I'm sure modern constructions techniques and process controls would refine them more, but they are still limited by the expansion rate of steam. - and the golden age was the height of their beauty. I'm sure boiler and steam turbine technology has advanced, but I don't think there's much to improve on reciprocating steam engines. no, not going to improve design much - better materials, and better control systems, maybe. |
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Post by silverdragon on Jan 30, 2016 8:28:17 GMT
The idea of the oil is as you suggest to "store" the heat.
It will take a lot more heat to warm up, and as we have an "unlimited" supply being its waste heat from an industrial process, storing it in water required a lot more water, unless its heavily pressurised....
If its oil, it can store above 100degc without pressurisation....
Then add water to run an engine "as required".
Weather I run water directly into the oil, maybe not, but use a radiator inside the oil, that I havnt decided.
What I have is a "free" heat source going to waste and the opportunity to turn that to power.
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Post by the light works on Jan 30, 2016 8:57:59 GMT
The idea of the oil is as you suggest to "store" the heat. It will take a lot more heat to warm up, and as we have an "unlimited" supply being its waste heat from an industrial process, storing it in water required a lot more water, unless its heavily pressurised.... If its oil, it can store above 100degc without pressurisation.... Then add water to run an engine "as required". Weather I run water directly into the oil, maybe not, but use a radiator inside the oil, that I havnt decided. What I have is a "free" heat source going to waste and the opportunity to turn that to power. ah, that is an additional factor in the equation. using oil as a higher temperature storage medium allows you more heat storage with less mass - but it also leaves more waste heat, since you can only harvest heat above the temperature of your storage medium. a multistage heat exchanger might be a better option for that - possibly using heat that escapes the oil accumulator to preheat the water. |
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Post by silverdragon on Jan 31, 2016 10:29:46 GMT
The heat is escaping as waste anyway, keep it simple, just use what you can, this thing doesnt need to be economical anything, its making use of waste?...
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Post by GTCGreg on Jan 31, 2016 12:22:23 GMT
The heat is escaping as waste anyway, keep it simple, just use what you can, this thing doesnt need to be economical anything, its making use of waste?... Sometimes an unrelated secondary process is added to a manufacturing plant to make use of the waste heat. Like making pudding. |
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Post by the light works on Jan 31, 2016 15:04:21 GMT
The heat is escaping as waste anyway, keep it simple, just use what you can, this thing doesnt need to be economical anything, its making use of waste?... It needs to be economical enough to produce more than it consumes, though. And you know us - half the fun of having something is making it work better. |
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Post by GTCGreg on Jan 31, 2016 15:35:09 GMT
It needs to be economical enough to produce more than it consumes, though. And you know us - half the fun of having something is making it work better. Or at least be eligible for government subsidies. |
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Post by c64 on Feb 14, 2016 10:26:29 GMT
Steam engine re-invent.... I have a crazy idea I want to run past you lot and see just how crazy it may be. Take a traditional steam engine, and make it tougher, thicker steel, because it needs pressure. Fill the boiler with OIL. Heat the oil to maybe 200degC.... Throw in some water..... Instant flash-over to high pressure steam?... Am I just crazy or has anyone ever tried this before?. I am also playing with the idea of introducing cold water directly into the piston after the power stroke as a spray to condense the steam back to water to get two power strokes, on of pressure one of vacuum... Of course that will need an exhaust that drains the water, but the idea is that the water is then scavenged and your not wasting it as waste steam. Why?. I am working on a way to use waste heat from industrial plants and recycling the energy some way, and steam generators seam a logical idea to this. All you need is water. Just look into the history books! There were steam-storage engines in service for many decades.  www.bahn-express.de/berichte/be176.htmIt has a large tank of water and no boiler. The trick is that the storage drum is 80% filled with water. At the factory, process steam with high pressure is pumped into the storage drum. The steam condenses under pressure and heats up the water way past 100°C. When steam is used by the engine, the hot water will boil to steam maintaining the pressure. Except for heat energy leaking out into the environment you get all of the steam back. This system isn't used any more since modern factories don't waste a lot of energy you can just take for free before it is blown into the environment. |
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Post by c64 on Feb 14, 2016 10:44:00 GMT
Now for the condensation stroke. First generation steam engines actually used the vacuum since pressurized systems tended to blow up. James Watt didn't invent the steam engine at all. He just stopped the vacuum nonsense and used the pressure of the steam itself. When the first steam engines were used, technology and materials science didn't exist. Pipes and boilers couldn't be made to last. Metal fatigue and corrosion was normal so pressurized boilers tended to blow up for sure after a relative short time of usage. The vacuum steam engines filled the cylinder with steam which was then cooled down creating a vacuum. Cooling was done just as you have suggested by injecting water. There are many problems: - The cylinder needs to be reheated before the steam doesn't condense when put in. To prevent hydro-locks, the cylinder had to be vigorously flushed with steam wasting a lot of steam.
- Cooling the cylinder and piston and reheating causes problems with heat expansion. If the cylinder cools down by too much, the still hot piston gets stuck. To solve this the piston must be very small and needs a (leather) seal to be air tight. This only works when the system operates very slow and the seal wears out quickly.
- Heating and cooling causes metal fatigue
- Even with a perfect vacuum, the environment atmosphere is ~ 1 bar (14.7 PSI) and this is your absolute maximum differential pressure driving the piston. You need a very huge piston to have enough surface to create a reasonable force. A common steam engine operates at 15 bar, even a perfect vacuum would just add 1/15 of the power. In reality it would be a gain of less than 1% with all the disadvantages listed above
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Post by silverdragon on Feb 14, 2016 13:06:55 GMT
We have come a long way with engines.
Use modern engines of the high rev variety just using steam instead of combustion....
Dont have a full-stroke piston that "almost" touches the cylinder head to prevent hydro-lock, and have pressure release valves in the cylinder head to allow escape of water should that happen.
To go back to the technology used "in the day" and try and start again from back then ignoring how far the humble piston engine has come since that time, to NOT try to use a multiple bore engine, to not use "All the toys" to control that steam, well,then your just getting back to the ultimate steam engine.
The reasons they abandoned steam were exactly that, they had got as far as they possibly could.
They didnt have anywhere to go.
That doesnt mean that the resultant 50 yrs since steam started to go have not produced a lot better engine technology....
Think of it this way.
Shorter stroke engine steam injected under pressure then use a 'fuel injector' type nozzle to quickly condense the steam to create the vacuum return stroke without excessively cooling the cylinder walls that then flushes out the water content thus a 2-stroke type power on multiple pots.
That COULD be done on a multi-valve piston engine "upside down" to use gravity to ease flushing the condensed water out?..
The inlet valve open all of the power stroke, close that, quick water injection, open the exhaust valve to flush water just before the piston gets to full back stroke, then restart the steam injection again.
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Post by c64 on Feb 14, 2016 14:08:59 GMT
Not much gain, too much effort.
The steam engine is "dead" because of the high maintenance costs and all the bulk (power to weight and size ratio) made them not economic. The latest steam engines are very efficient under certain circumstances.
A steam engine needs continuous work to be efficient. Anything else is a great waste of resources and you need to schedule everything. Diesel engines are fired up and running full power in minutes.
With steam engines, you need to know how much power you need hours ahead, with diesel you simply stomp the accelerator.
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Post by silverdragon on Feb 15, 2016 7:30:54 GMT
Not much gain, too much effort. The steam engine is "dead" because of the high maintenance costs and all the bulk (power to weight and size ratio) made them not economic. The latest steam engines are very efficient under certain circumstances. A steam engine needs continuous work to be efficient. Anything else is a great waste of resources and you need to schedule everything. Diesel engines are fired up and running full power in minutes. With steam engines, you need to know how much power you need hours ahead, with diesel you simply stomp the accelerator. I dont believe you. Even under diesel, a diesel fired hot water generator, think hot water power washer, can create steam in seconds, and why wait all that time when instant hot is new technology. If you use a solar generator, the hot part can be kept hot and store heat indefinitely as long as you have sunshine. |
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Post by GTCGreg on Feb 15, 2016 14:28:41 GMT
While the steam engine itself may be approximately the same size as a diesel engine, the energy storage and steam generator is going to be considerably larger and adds to the complexity of the overall system.
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Post by wvengineer on Feb 15, 2016 15:58:37 GMT
I am also playing with the idea of introducing cold water directly into the piston after the power stroke as a spray to condense the steam back to water to get two power strokes, on of pressure one of vacuum... Of course that will need an exhaust that drains the water, but the idea is that the water is then scavenged and your not wasting it as waste steam. The Very first steam engines operated like that. Cold water was sprayed on the cylinder to condense the steam and cause the stroke to reverse. The problem is that over time, the water acts to cool the cylinder too much. The cylinder eventually get so cold that when you introduce fresh steam, it hits the cold cylinder walls and condenses too soon, causing a reduction in power. The problem is that the amount of cold water needed to get a usable amount of steam condensation is enough that you can't completely reheat the cylinder on the next cycle. It is always a net loss. What James Watt is really known for was inventing methods of doing condensing outside the cylinder that make the steam engine practice. Add to this you have a constant rapid heating and cooling of the cylinder metal. This results in a lot of thermal stress and will weaken the metal. If you have access to it, James Burke's Connections series talks about this in one of the episodes. It is episode 6 "Thunder in the Skies" of the original 1978 series. |
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