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Post by the light works on Feb 15, 2016 16:17:23 GMT
sure you can have a system that flash heats the water to steam.
consider, in the US, we have flash water heaters and tank water heaters.
the flash heaters have a 3/4 inch gas line running at 2 PSI. the tanks have a 3/8 inch gas line running at 1 PSI.
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Post by GTCGreg on Feb 15, 2016 16:31:39 GMT
Gas? I though we were going to run this puppy on coal.
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Post by the light works on Feb 15, 2016 16:47:53 GMT
Gas? I though we were going to run this puppy on coal. we seem to bounce back and forth between this being a way to increase efficiency by capturing waste heat and being a way to make an engine more efficient by adding processes to it. |
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Post by c64 on Feb 15, 2016 18:39:14 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. The power hot water washers atomize the water, it is not steam, just tiny droplets of liquid water. Real steam is invisible. What you can see over a steaming pot of tea is condensation, water which isn't steam any more. "Wet steam" doesn't do much work at all. Efficient steam power plants use superheated steam which is invisible. The difference between an external combustion engine and an internal combustion engine is simple. The ICE converts the fuel to power the moment it is required. The ECE needs to burn fuel on suspicion in advance and power is lost before the energy reaches the actual engine. Of course you can boost efficiency of all kinds of machines. But this is either not economic or bad for someone or something else. For example, I do it all the time. My old car was rigged for "super fuel economy". VW did something on a small scale with their recent diesel engines - and VW was caught, I wasn't. My old car ran a lot faster on ~30% less fuel and was violating all existing emission standards and laws. If I do that, it is good for me. If you do that, it is good for you - but if everybody does it, it is real bad for everybody, especially in the long term! And this is why VW was seriously punished for a little tweak while I went as far as I possible could. Another example, due to bad luck I had water in the oil of my car. I could have been a good tree huger and changed the oil but I just had let the engine run real hot to it ingested the water. I had a efficiency boost which resulted in a nice power boost. The downside was that I pulled a white wall behind me like in the videogame "tron". Now imagine what happens if everybody creates a "James Bond smoke screen" in public traffic! Also the catalytic converter couldn't possibly stay functional doing this. There is a simple way to boost the efficiency of cars and industrial gear by 20%. Change back the environmental laws to 1960 ("none") and still use modern technology. China does it with great success:  It is all about economy and convenience. Whatever saves you money and doesn't interfere with your convenience becomes the norm. An SUV is the result of convenience winning against economy. There are many easy ways to conserve energy. I do that all the time. My flat is currently 11.7°C even if owning a caloric value furnace which could heat the place with half the fuel a conventional furnace would use. I don't turn on lights while taking a shower, watching TV or using my computer. To inconvenient for almost everybody else but it works fine for me. So if you want something where you can boost the efficiency for yourself, build one of those:  It is made of two heat sinks, a Peltier element, an USB DC/DC converter and a regular USB reading lamp. It boosts the efficiency of candles generating more light which is also really white. And for the pollution of manufacturing and shipping the parts all around the world, you can just plug in your regular reading lamp for many, many hours... |
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Post by silverdragon on Feb 16, 2016 7:59:36 GMT
I do know that already, but of you could manage to catch the water, its not cold, and considering the flow of water, I suppose thats the equivalent of heating a shower, its still instant heated water from a cold supply.
On the subject of adding extra processes, weight is not an issue, nor is size, because if this gets to the size of an old steam train, where I am planning to throw it, you could park a full sized truck no problems as they have the space.
I have already decided that the thing may need outside car park space as no roof would ever support it anyway, plus it going to need some form of maintenance?..
Bouncing back and forth may be helping.
We have heat, in abundance, can that be changed to steam, and can that run an engine.
Or maybe even a Turbine...
Why didnt anyone suggest that one?.
One moving part.
On that score, can there be such a thing as a vacuum turbine?..
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Post by GTCGreg on Feb 16, 2016 14:32:44 GMT
All heat is not created equal. While they may contain the same amount thermal energy, a large quantity of low temperature heat is a lot harder to deal with then a small quantity of high temperature heat. Yes, you can make steam from 101°C heat. But the quality of that steam is so low that it is almost impossible to extract mechanical energy from it. About all you can use it for is heating. That's why I suggested the solution to your problem is to somehow couple your low-quality heat to some process that can use it. Such as a food processing line of some type. Or maybe use it to heat the feedwater to a high-pressure boiler and then use the output of that boiler to produce your mechanical energy. But that would require adding additional energy to the system to make it useful.
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Post by the light works on Feb 16, 2016 15:30:03 GMT
I do know that already, but of you could manage to catch the water, its not cold, and considering the flow of water, I suppose thats the equivalent of heating a shower, its still instant heated water from a cold supply. On the subject of adding extra processes, weight is not an issue, nor is size, because if this gets to the size of an old steam train, where I am planning to throw it, you could park a full sized truck no problems as they have the space. I have already decided that the thing may need outside car park space as no roof would ever support it anyway, plus it going to need some form of maintenance?.. Bouncing back and forth may be helping. We have heat, in abundance, can that be changed to steam, and can that run an engine. Or maybe even a Turbine... Why didnt anyone suggest that one?. One moving part. On that score, can there be such a thing as a vacuum turbine?.. I have a vacuum turbine on my vacuum cleaner. it turns the brush on the furniture tool. and yes, we had already mentioned a turbine somewhere back there. as for bouncing back and forth - not helping all that much. if you want a system for utilizing waste heat, it does us little good to discuss a higher performance heat source. it's kind of like trying to design a motor for a rowboat. if your waste heat is not a whole lot over boiling, then pretty much the only viable machine you could run would be a big low pressure reciprocating engine. probably with a double action piston. trying to cool the cylinder for vacuum boost would probably use most of the power output from it, because letting the steam into a cold cylinder would draw too much heat from the steam and significantly reduce the expansion, although you could use a gated reed valve for the exhaust to capture any vacuum that happened anyway. this is an existing engine that may function in this manner. en.wikipedia.org/wiki/Uniflow_steam_engine |
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Post by GTCGreg on Feb 16, 2016 16:31:11 GMT
I do know that already, but of you could manage to catch the water, its not cold, and considering the flow of water, I suppose thats the equivalent of heating a shower, its still instant heated water from a cold supply. On the subject of adding extra processes, weight is not an issue, nor is size, because if this gets to the size of an old steam train, where I am planning to throw it, you could park a full sized truck no problems as they have the space. I have already decided that the thing may need outside car park space as no roof would ever support it anyway, plus it going to need some form of maintenance?.. Bouncing back and forth may be helping. We have heat, in abundance, can that be changed to steam, and can that run an engine. Or maybe even a Turbine... Why didnt anyone suggest that one?. One moving part. On that score, can there be such a thing as a vacuum turbine?.. I have a vacuum turbine on my vacuum cleaner. it turns the brush on the furniture tool. and yes, we had already mentioned a turbine somewhere back there. as for bouncing back and forth - not helping all that much. if you want a system for utilizing waste heat, it does us little good to discuss a higher performance heat source. it's kind of like trying to design a motor for a rowboat. if your waste heat is not a whole lot over boiling, then pretty much the only viable machine you could run would be a big low pressure reciprocating engine. probably with a double action piston. trying to cool the cylinder for vacuum boost would probably use most of the power output from it, because letting the steam into a cold cylinder would draw too much heat from the steam and significantly reduce the expansion, although you could use a gated reed valve for the exhaust to capture any vacuum that happened anyway. this is an existing engine that may function in this manner. en.wikipedia.org/wiki/Uniflow_steam_engineAnother option may be to use a Sterling engine. They can operate at a much lower temperature difference and don't require steam at all. Here's a modern Sterling engine used to convert heat from a solar farm to mechanical power to run a generator.  |
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Post by the light works on Feb 16, 2016 16:53:32 GMT
I have a vacuum turbine on my vacuum cleaner. it turns the brush on the furniture tool. and yes, we had already mentioned a turbine somewhere back there. as for bouncing back and forth - not helping all that much. if you want a system for utilizing waste heat, it does us little good to discuss a higher performance heat source. it's kind of like trying to design a motor for a rowboat. if your waste heat is not a whole lot over boiling, then pretty much the only viable machine you could run would be a big low pressure reciprocating engine. probably with a double action piston. trying to cool the cylinder for vacuum boost would probably use most of the power output from it, because letting the steam into a cold cylinder would draw too much heat from the steam and significantly reduce the expansion, although you could use a gated reed valve for the exhaust to capture any vacuum that happened anyway. this is an existing engine that may function in this manner. en.wikipedia.org/wiki/Uniflow_steam_engineAnother option may be to use a Sterling engine. They can operate at a much lower temperature difference and don't require steam at all. Here's a modern Sterling engine used to convert heat from a solar farm to mechanical power to run a generator. at that point, the oil could be used as the heat transfer medium and not bother with a steam process at all. |
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Post by wvengineer on Feb 17, 2016 11:15:23 GMT
I posted something but it seams to have failed to post. So here is re-typing it... 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. I should clarify that my previous post was in regard to piston steam engines. Water injection is also a problem with continuous flow (turbine) engines, but for different reasons. In a turbine, the speed of steam flowing though can be very high, up to several hundred miles per hour. With this, any condensation within the turbine can be very damaging. Water drops can be almost as corrosive as acid on the blades of the turbine. With a turbine, the ideal setup is to have your steam ext the turbine as low a pressure as possible and still be 100% pure steam. The actual condensation process of getting it back to liquid form is done in a separate condensing unit. |
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Post by c64 on Feb 17, 2016 20:23:25 GMT
I posted something but it seams to have failed to post. So here is re-typing it... 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. I should clarify that my previous post was in regard to piston steam engines. Water injection is also a problem with continuous flow (turbine) engines, but for different reasons. In a turbine, the speed of steam flowing though can be very high, up to several hundred miles per hour. With this, any condensation within the turbine can be very damaging. Water drops can be almost as corrosive as acid on the blades of the turbine. With a turbine, the ideal setup is to have your steam ext the turbine as low a pressure as possible and still be 100% pure steam. The actual condensation process of getting it back to liquid form is done in a separate condensing unit. Correct. The latest power plants also have a "wet steam" turbine which only produces a fraction of the total but saves some energy before it is lost in the cooling towers. Those plants reach an efficiency of around 43%. Of course there are power plants which claim to have a greater efficiency but those also count heat energy delivered for heating purposes, the electricity generation is much less than 40% since those plants can't have a wet steam turbine. A power plant or a steam engine works like this: A liquid medium - usually water - is heated past the boiling point so it creates a pressure due to increasing its volume. Releasing the steam creates a steam flow so the energy is converted into kinetic energy. This kinetic energy from the flow is then converted into kinetic energy in form of a rotating shaft by the turbine or using a system with pistons. A steam engine vents the steam into the environment so all the remaining energy is lost. The spent water is then replaced by cold water, e.g. from a tender. A power plant recycles the steam using cooling towers. The steam is condensed back to water which is still very hot, almost boiling. This water is then pumped back into the boiler so no extra energy to heat it towards the boiling point is spent. In both cases, the trick is pumping a low volume into the boiler which exits as high volume. This is how you can extract energy in the first place since you need to pressurize the water to the same pressure as the exiting steam. The difference in volume is what allows you to take energy out of the system. Pumping back the wet steam would cost more energy than you can harvest from the steam. This is where the major part of the energy gets lost, by using energy to pump and the energy wasted in the cooling towers. You don't really need to pass 100°C for the cycle. You can use all kinds of other media which boil at different temperatures. E.g. alcohol would do this at 30°C less. You can even do this at very low temperatures, e.g. using CO₂ (-70°C). The problem is that you need to cool the medium below its boiling point and since heating is easier than cooling, high temperatures are better and since water is not only environmentally friendly, it is also easy to obtain in large quantities almost for free. This is why they use water. A Stirling engine runs without a medium changing its aggregate phase. But you still need a heat flow through the engine. Without a medium changing its aggregate phase, it can't harvest much energy from a given heat flow so its output power is low for its size. It doesn't matter how you create the heat flow. Just like a water wheel works as long as you have flowing water, no matter how you make it flow. Usually you heat one side and keep the other side of the system at environmental temperature. You can also keep one side to environmental temperature and cool the other side e.g. using an ice cube. But heating is easier and more efficient than cooling. You could make a power plant using CO₂ which runs on environmental heat energy - but you need to cool the other side of the system below -70°C which is very expensive and would require more energy than the plant produces. This is the idea of a "ZPM", a "Zero Point Module". Imagine you have a can of "nothing", no energy inside, absolute zero temperature. Environmental heat is much higher and it flows inside. If you put a thermocouple or a sterling engine and generator between environmental heat and the "nothing" inside, you can harvest electricity - until the "nothing in a can" is used up. If you could invent a system which is 100% efficient, all the heat energy trying to reach the "nothing in a can" is converted and the can never spent so you can convert as much environmental energy to electrical energy as you want in any quantity. And the waste heat from using the electricity can keep powering the ZPM in a closed circuit. This is the holy grail of physics. |
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Post by silverdragon on Feb 19, 2016 7:46:46 GMT
Researching the Stirling engine.
May be useful..
Efficiency, yeah, maybe in an ideal world.
However, as pointed out, this heat to be used is waste.
Therefore, any benefit in energy produced by using up what otherwise is a waste from an industrial process, think an Iron foundry here, ANY energy reclaimed is 100% more than is currently reclaimed, so, no losses whatever is used?...
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Post by mrfatso on Feb 19, 2016 13:10:23 GMT
In some places waste heat from some industrial processes is used to heat local homes.
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Post by the light works on Feb 19, 2016 15:51:23 GMT
Researching the Stirling engine. May be useful.. Efficiency, yeah, maybe in an ideal world. However, as pointed out, this heat to be used is waste. Therefore, any benefit in energy produced by using up what otherwise is a waste from an industrial process, think an Iron foundry here, ANY energy reclaimed is 100% more than is currently reclaimed, so, no losses whatever is used?... however, if you fall into paying a dollar to reclaim 90 cents worth of energy, you are not getting any benefit. |
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Post by c64 on Feb 20, 2016 19:45:02 GMT
Researching the Stirling engine. May be useful.. Efficiency, yeah, maybe in an ideal world. However, as pointed out, this heat to be used is waste. Therefore, any benefit in energy produced by using up what otherwise is a waste from an industrial process, think an Iron foundry here, ANY energy reclaimed is 100% more than is currently reclaimed, so, no losses whatever is used?... however, if you fall into paying a dollar to reclaim 90 cents worth of energy, you are not getting any benefit. Correct, this is the problem. It's all about money. Sure, you can cut the amount of energy which is wasted easily but it costs money. Being environmentally friendly costs money. In Germany, there are high taxes on energy so you either keep wasting energy and give a lot of money to the government or you try to safe energy spending part of the money on more efficient machinery and processes. The trouble is that spending more money for the energy makes production more expensive so countries which keep wasting energy because it is cheaper can produce much cheaper. That's one of the reasons why China can produce much more cheaply than any other country. And the reason why 92% of their water is so badly polluted that it is rated as "highly poisonous" in all western countries. Also trying to safe energy can also be going the wrong way fast. For example, there was a large AM radio station in Germany. There were two buildings, one with the transmitter and one where the attendant of the transmitter lived. The waste heat of the radio tubes heated the whole place in winter. They figured that this is a waste of energy since the radio tube transmitter used up a lot of electricity. So they replaced it with a tiny solid state amp - and an oil furnace to keep the place warm in winter. Now in winter, the energy costs were about even. But in summer they had to install an A/C to prevent the semiconductors from overheating and the entire system used up more electricity than the original tube amp which didn't mid becoming real hot. So they wasted even more energy and money. |
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