SH3RL0CK Posted March 24, 2010 Posted March 24, 2010 (btw, technically you dont need energy to cool something down, you just need to let the molecules you are trying to cool to give their energy away to other molecules) One difficulty in this, of course, is to prevent these same molecules from receiving energy from other molecules at the same time...its not like heat transfer is a one way street. PV=nRT is a good equation to start with determining how to change the temperature of an ideal gas (either increase P or V; or conversely reduce the amount of gas present in the system n, to increase the temperature). In all practical cases, energy must be applied to force the molecules to do something they wouldn't have otherwise done.
lazygamer Posted March 24, 2010 Posted March 24, 2010 (edited) the system I am describing? the one that makes the nitrogen? or the kender engine? because the kender-engine will produce over 300MWh annually, and look here: 900 Watts, times 24 (hours in a day), equals 0,0216MWh, and a minimum of 4,5 liters of liquid nitrogen - nitrogen-machine ... you could infact produce 1642,5 liters of nitrogen with ease, and still only use 7,9MWh out of 300MWh (annually). not exactly a hugely fantastic technology, its actually very simple. @ Sh3rlock well heat-transfer is not a one-way street, no, but if a molecule with less kinetic energy (heat) hits one with more kinetic energy, the one with more will allways give kinetic energy to the one with less. Therefore you can allways make something very close to absolute zero (lets say 23 kelvin is very easy in this case) just by using the clever pressure-decreasing trick only a more elaborate setup, but you'll need alot of tubes and pipes and valves. btw, if you "reduce the amount of gas present in the system", don't you DEcrease the temperature? anyways, its not black magic, you just use the 14 psi's in our atmosphere, send it through a valve that decreases it to 1psi or something like that, then you cool the 14 psi pipe with the cooler gas, then you get cooler and cooler gas out of the 14 psi thing until it allmost stops (pressure decreases, it pulls in more air behind it, pressure increases and then decreases more etc until it begins to slow down because of excess heat from the surroundings), then you send the super-cool air through a small compressor and into a container-of sorts and divert the next batch of super-cooled air to cool the container down (the container is far more than 14 psi, so when you reach for example minus 150 degrees C like the super-cool air at only 14psi you release the gas in the container and get 200 minus, voilà). (or to the PhD's here, sort of ((AX-z)*(BY-z)) second per second (where A is pressure, 14psi, x is temperature of the gas in the A, B is 1psi and the subequent temperature of the gas in B after a decrease in pressure from 14 to 1 psi. Z is the fall in temperature since last cycle in the respective sides of the equation. for every second the temperature in A and B decreases)). Edited March 24, 2010 by lazygamer
Sisyphus Posted March 24, 2010 Posted March 24, 2010 the system I am describing? the one that makes the nitrogen? or the kender engine? because the kender-engine will produce over 300MWh annually, and look here: 900 Watts, times 24 (hours in a day), equals 0,0216MWh, and a minimum of 4,5 liters of liquid nitrogen - nitrogen-machine ... you could infact produce 1642,5 liters of nitrogen with ease, and still only use 7,9MWh out of 300MWh (annually). not exactly a hugely fantastic technology, its actually very simple. You don't even have to look at the mechanism to know it can't work according to these numbers, because that would be a perpetual motion machine. A "kender engine" powered by a temperature differential cannot generate more energy than is used to create that differential in the first place. There is an error in reasoning somewhere.
SH3RL0CK Posted March 24, 2010 Posted March 24, 2010 (edited) well heat-transfer is not a one-way street, no, but if a molecule with less kinetic energy (heat) hits one with more kinetic energy, the one with more will allways give kinetic energy to the one with less. Therefore you can allways make something very close to absolute zero (lets say 23 kelvin is very easy in this case) just by using the clever pressure-decreasing trick only a more elaborate setup, but you'll need alot of tubes and pipes and valves. and I suspect a much, much, much higher initial pressure than 14 psi... but regardless how do you "decrease the pressure" without applying some kind of energy to the system? if you "reduce the amount of gas present in the system", don't you DEcrease the temperature? PV=nRT. If PV is constant (and R is constant), then if n decreases, T must increase. Of course in the real world, removing some of the gas (decreasing n) without changing either the pressure or volume is going to be a trick. One way to do this is to increase the temperature by applying some energy that is external to the system If you wanted to decrease both n and T (or decrease T and keep n constant), then you will have to increase the pressure and/or volume. How do you propose to modify either the pressure or volume of a system without applying energy? anyways, its not black magic, you just use the 14 psi's in our atmosphere, send it through a valve that decreases it to 1psi or something like that, which requires energy to do then you cool the 14 psi pipe with the cooler gas, which results in the "cooled" gas heating up much more quickly than the "14 psi" gas. The reason being that there is much more gas at 14 psi than what was "cooled" through the valve. PV = nRT, in a closed system PV and R is constant so n must be reduced proportionally to T. When the numbers are run, I'm sure the energy input to force the pressure decrease to 1psi will equal the amount of cooling to the 14 psi gas, plus losses. In an open system, the "cooled gas" cannot cool down the gas at 14 psi since this is essentially an infinite amount of gas. Which means the following: then you get cooler and cooler gas out of the 14 psi thing until... doesn't happen. At least not in a way that any energy is gained. And since there is bound to be energy lost due to inefficiencies, this system just spends a lot of energy to do nothing. Edited March 24, 2010 by SH3RL0CK
Sayonara Posted March 24, 2010 Posted March 24, 2010 the system I am describing? the one that makes the nitrogen? or the kender engine? because the kender-engine will produce over 300MWh annually, and look here: 900 Watts, times 24 (hours in a day), equals 0,0216MWh, and a minimum of 4,5 liters of liquid nitrogen - nitrogen-machine ... you could infact produce 1642,5 liters of nitrogen with ease, and still only use 7,9MWh out of 300MWh (annually). What you are saying here is essentially that you can get free energy by piping cold gasses about. But to get a gas cold enough to be useful as you have described (i.e. in a production environment device) you have to physically invest more energy than the amount of energy you want to remove. Here is the critical assumption: that the 1642.5 litres of liquid nitrogen which the elan2 machine can produce by running constantly for a year will be sufficient to drive a turbine (engineered however you see fit), over the same period, to generate 300MWh. Care to fill in the blank in that reasoning? If your reasoning was sound, then the elan2 would have an optional add on called the "Liquid Nitrogen Free Energy Device". It doesn't.
lazygamer Posted March 24, 2010 Posted March 24, 2010 You don't even have to look at the mechanism to know it can't work according to these numbers, because that would be a perpetual motion machine. A "kender engine" powered by a temperature differential cannot generate more energy than is used to create that differential in the first place. There is an error in reasoning somewhere. ehm, no you :facepalm: (sensored because there probably are americans around). heat = kinetic freakin' energy that comes from the molecules moving. the sun shines on the planet all day long, for about 5 billion years into the future. If we had no atmosphere we'd have 380 kelvin on the surface of earth during day (over boiling point of water), that energy is distributed into our atmosphere, we take a substance with little energy and _trap_ it (you only have to refill it once or twice a year because of quantum mechanics, ie some molecules teleport now and again). then we heat it up by it just EXISTING in our atmosphere which holds loads of energy (288 kelvin or something average temperature), and the pressure increases, we send it through a turbine (and still keep it freakin' trapped) and thus the pressure decreases and it becomes just as cold as it was to begin with. and I suspect a much, much, much higher initial pressure than 14 psi... but regardless how do you "decrease the pressure" without applying some kind of energy to the system? how do we cool it? we release x amount of gas at room-temperature, into 10x amount of space and cut the pressure and temperature by alot (any box without gas in it is a freakin' vaccuum! and what do you think the 1/5 energy produced goes to? a compressor (compressor compresses the gas to 15 psi or whatever, and it comes out 200 psi or whatever at the other side, therefore you produce energy, there's many percents losses oh yeah like on everything else, that's why 20% of the energy is lost instead of just 10% (cus if there were far less losses due to all the gas-physics and mechanical stuff it would produce about twice the amount of energy but still only need the original compressor-energy)). If you wanted to decrease both n and T (or decrease T and keep n constant), then you will have to increase the pressure and/or volume. How do you propose to modify either the pressure or volume of a system without applying energy? release the gas into an artificially made low-pressure part, right where the compressor gets the gas it pumps back into the radiator. What you are saying here is essentially that you can get free energy by piping cold gasses about. But to get a gas cold enough to be useful as you have described (i.e. in a production environment device) you have to physically invest more energy than the amount of energy you want to remove. Here is the critical assumption: that the 1642.5 litres of liquid nitrogen which the elan2 machine can produce by running constantly for a year will be sufficient to drive a turbine (engineered however you see fit), over the same period, to generate 300MWh. Care to fill in the blank in that reasoning? If your reasoning was sound, then the elan2 would have an optional add on called the "Liquid Nitrogen Free Energy Device". It doesn't. the only thing you spend energy on is a small compressor that constantly keeps one area (or several) a little lower in pressure than the rest (on the nitrogen thing). then you just put a nozzle that releases just enough gas so its for example 1 psi at the output end when there's 14 psi at the input end. the kender energy isn't free either, you create cold air by using the heat. heat is energy, this is a heat engine, but you have to forget about that little nagging voice in the back of your head that is thinking "everything below the freezing point of H2O is zero energy or somehow a different type of temperature than any temperature above 273 kelvins". all heat above zero kelvin can be used if you just know how (though its difficult to get it really close to absolute zero since one photon would ruin it... cus its not the cooling that's difficult, its keeping the heat away from all the stars, planets and americans around it. though it must be said that if you managed to pump something at absolute zero into this thing, you'd create alooot of energy). btw, where the hell did all of you get the idea that the kender-folks were so stupid they made a machine that is dependant on a constant stream of nitrogen at the thousands of litres a year level? that would be like inventing the heat-pump I have in my home BEFORE the kender engine, oh wait the heat-pump people really did mess up that badly. (btw, a heat-pump gives back 300% more heat-energy than the energy you put in it, simply because there's so much energy in the heat allready in the air that its not difficult to use it, google it). just to clarify: THE NITROGEN DOESN'T GET RELEASED INTO THE ATMOSPHERE, it simply teleports like happens all the time, which is why your tyres go flat after a while etc. you don't have to drag a hose filled with air after your car do you? XD I'm staggered
SH3RL0CK Posted March 24, 2010 Posted March 24, 2010 how do we cool it? we release x amount of gas at room-temperature, into 10x amount of space and cut the pressure and temperature by alot (any box without gas in it is a freakin' vaccuum! and what do you think the 1/5 energy produced goes to? a compressor (compressor compresses the gas to 15 psi or whatever, and it comes out 200 psi or whatever at the other side, therefore you produce energy, there's many percents losses oh yeah like on everything else, that's why 20% of the energy is lost instead of just 10% (cus if there were far less losses due to all the gas-physics and mechanical stuff it would produce about twice the amount of energy but still only need the original compressor-energy)). release the gas into an artificially made low-pressure part, right where the compressor gets the gas it pumps back into the radiator. So if I understand you, you are saying it takes less energy to draw a vacuum in a box than you gain by filling the box up again? Lets assume a 100% efficient vacuum pump that uses 1J of energy to pull all the air out of the box. Applying PV= nRT, there is now an energy differntial of 1J of potential energy that can be gained by letting air back into the system, stored in the "n" component (fewer number of atoms) and "T" component (perhaps the overall temperature of the box dropped). So, now if we let gas back into this box, the system gains the 1J of energy from the box in the form of the "n" components (more gas in the box) and in the "T" component (perhaps the overall temperture increases once again). So where is the extra "free" energy coming from? Are you claiming that, assuming the box cooled and some energy is stored in the "T" component of the equation, you will let the external environment warm the box up to room temperature. Then the box will become warmer than room temperature once gas is released into this vacuum (PV= nRT and some energy added to the "T" part of the equation) and you will harvest this extra energy? If so, I would suggest the problems here would be 1) most of the energy is in the "n" part of the equation so there is very little "T" energy to reclaim by this method. 2) A real vacuum pump would have losses greatly exceeding this potential gain. 3) It would be necessary to harvest energy only during the warm up phase, otherwise you would lose this potential energy gain during the "cool down" when drawing the vacuum. I'm not sure how you could switch off a potential energy harvester like this but there could be ways to do this. 4) Even assuming 100% efficient pumping and energy harvesting, there is still energy losses associated with maintenance and repair of the valves, connections, pump, energy harvesting equipment, etc. that may exceed this energy gain (its going to be quite small). You would be much better off installing a windmill or solar panel to harvest the available energy in the environment.
lazygamer Posted March 24, 2010 Posted March 24, 2010 (edited) So if I understand you, you are saying it takes less energy to draw a vacuum in a box than you gain by filling the box up again? Lets assume a 100% efficient vacuum pump that uses 1J of energy to pull all the air out of the box. Applying PV= nRT, there is now an energy differntial of 1J of potential energy that can be gained by letting air back into the system, stored in the "n" component (fewer number of atoms) and "T" component (perhaps the overall temperature of the box dropped). no, you can choose to release the same psi back into it, or you can send the same amount, only with 200psi pushing it there instead of the original psi. (if you pump 15psi out of the box, and release the same amount of gas per second that the compressor can pump out, you create energy because you pump 15psi out, but the energy coming into the box is at 200 psi which pushes the gas into the box quicker m/s than you pump it out and with more force). think about it, you pump out 15 psi, and between the box and the box with the 200psi in it there is a turbine, the 200 psi gas pushes its way through the turbine at over 13 times the force or energy than what you need to pump it out of the box. So where is the extra "free" energy coming from? where don't you see what I see? 200psi - turbine - low-pressure zone - compressor (20psi to make it easier). heated - pushes - cools down and gets pumped out - re-heats. 200psi against turbine and mechanical stuff, around 50% effecient, so you get 5 times more energy than what you are using to pump it back at 20 psi. its not that difficult, I dont know how I can explain it simpler btw, a solar panel delivers aproximately 6 to 7 MW of power average annually if it has PV panels with a max capacity of 50MW, and you need square miles in space because you only get about 200 watts per square meter (or per 9 square feet aproximately), and you need direct sunlight, and you need it to be daytime. and with windmills you need wind, and that's usually way out 2 miles from the middle of nowhere, which you need to make a road to, then an electricity-wire to, then you need to put up the windmill, then you need to hope and pray that its windy when you need the energy the most. doesn't really sound like good technologies? (and btw, windmills are over 300 feet tall these days, and they produce 2,5MW then, a kender-engine would only take up aproximately 25 square meters at 2-3 meters tall, and it would produce energy independently of wheather-conditions and you can place it right where it is needed instead of spending just as much as you spend building the facility on making powerlines to just get the electricity out'a there) in comparison to wind and PV, the kender engine is in a different league, its just that you don't get it so you don't "believe" in it, even though fact is fact, it works (one test is better than a thousand expert-opinions, there's allways going to be sceptics (the day before they launched one of the apollo missions the story in Times magazine was that "the rocket couldn't work because there were no air to push against in space"), and you can't mix opinion into fact). Edited March 24, 2010 by lazygamer
SH3RL0CK Posted March 24, 2010 Posted March 24, 2010 (edited) no, you can choose to release the same psi back into it, or you can send the same amount, only with 200psi pushing it there instead of the original psi. (if you pump 15psi out of the box, and release the same amount of gas per second that the compressor can pump out, you create energy because you pump 15psi out, but the energy coming into the box is at 200 psi which pushes the gas into the box quicker m/s than you pump it out and with more force). think about it, you pump out 15 psi, and between the box and the box with the 200psi in it there is a turbine, the 200 psi gas pushes its way through the turbine at over 13 times the force or energy than what you need to pump it out of the box. Where did the 200psi gas come from? Under my scenario, I am going from 14psi (standard atmospheric) to a vacuum of 0 psi; then refilling at 14 psi. This was intentional to keep it simple. Adding a third pressure increases the complexity of your example. But lets take your example: where don't you see what I see? 200psi - turbine - low-pressure zone - compressor (20psi to make it easier). heated - pushes - cools down and gets pumped out - re-heats. 200psi against turbine and mechanical stuff, around 50% effecient, so you get 5 times more energy than what you are using to pump it back at 20 psi. For simplicity, lets have a closed system using an ideal gas. It takes energy to get to 200 psi. For the sake of argument, lets say 1J. Through the turbine, lets say we get the 1J back and the gas is at 14psi. You can't get more than the 1J back because that was all the energy input into the system, this energy was stored in the "P" part of the ideal gas equation then transfered to heat (T) and mechanical energy (V) by passing through the turbine. If its contains 1J of energy stored in the form of heat (1J of T), then we gained no energy from the turbine (0J of V). If we got all 1J of energy by harvesting it with the turbine (1J of V), then its not heated (0J of T). This is something you seem to be overlooking. In the formula PV=nRT, we harvest the energy in the PV part as the turbine in the form of mechanical energy. We either mechanically change PV (for an energy loss or gain) or change T (for an energy loss or gain). There is no free energy from this formula. If we DID gain all 1J back with the turbine, then what good would it do to put all 1J of energy into the gas to re-compress it to 200 psi? its not that difficult, I dont know how I can explain it simpler Neither do I know how to explain it simpler...where and how does PV=nRT give us free energy? Edited March 24, 2010 by SH3RL0CK
lazygamer Posted March 24, 2010 Posted March 24, 2010 WHAT??? ofcourse you wouldn't create energy by pumping the same darn pressure of gas in and out of a box!?!?! but where the heck did you think that was relevant? the kender engine uses the pressure at which the gas enters the radiator, the pressure it becomes from being heated up by the surroundings, and the pressure between the turbine and the compressor... its impossible to decrease the complexity of an example when the example needs the "complexity" to actually form a logical problem at which one can come with a conclusion to. if you just take out the number "1" out of binary in an example to simplify it all, its all pointless!
SH3RL0CK Posted March 24, 2010 Posted March 24, 2010 WHAT??? ofcourse you wouldn't create energy by pumping the same darn pressure of gas in and out of a box!?!?! but where the heck did you think that was relevant? the kender engine uses the pressure at which the gas enters the radiator, the pressure it becomes from being heated up by the surroundings, and the pressure between the turbine and the compressor... its impossible to decrease the complexity of an example when the example needs the "complexity" to actually form a logical problem at which one can come with a conclusion to. if you just take out the number "1" out of binary in an example to simplify it all, its all pointless! The Kender engine uses helium, therefore it must be a closed system as I am very certain I am breathing a combination of Nitrogen and Oxygen and other trace gases with virtually no helium. As a closed system, yes, we are simply pumping the gas around inside a box, or multiple boxes. By making it complex, we increase the chances (intentional or not) of introducing a mathematical fallacy. http://en.wikipedia.org/wiki/Mathematical_fallacy
lazygamer Posted March 24, 2010 Posted March 24, 2010 for the last time, you pump it into a box at x pressure, it increases in pressure to 10x because of the surroundings that are warmer. then you have 10 times as much pressure turning the turbine, generating 10 times as much energy, than what you need to pump it back at x pressure again. if you don't get it ......... I give up, go do whatever. (btw, why we don't have helium in our atmosphere is because the earth has too little mass to keep helium-molecules within our atmosphere. the same reason is why we dont have any pure hydrogen in our atmosphere)
Sayonara Posted March 24, 2010 Posted March 24, 2010 the only thing you spend energy on is a small compressor that constantly keeps one area (or several) a little lower in pressure than the rest (on the nitrogen thing). then you just put a nozzle that releases just enough gas so its for example 1 psi at the output end when there's 14 psi at the input end. So you think you are going to get more energy back from the gas expanding than you put into compressing it, right? That IS what you are saying, yes? the kender energy isn't free either, you create cold air by using the heat. The claim is that it is "free" because it uses only a freely available source of energy, and no other. That is what the debate in this thread disputes. You are not addressing any of the technical or physical issues that have been raised. heat is energy, this is a heat engine, but you have to forget about that little nagging voice in the back of your head that is thinking "everything below the freezing point of H2O is zero energy or somehow a different type of temperature than any temperature above 273 kelvins". That's not what my nagging voice says. My nagging voice says things like "no free lunch" and "it takes energy expenditure to do ANY work". btw, where the hell did all of you get the idea that the kender-folks were so stupid they made a machine that is dependant on a constant stream of nitrogen at the thousands of litres a year level? I didn't. I quite expressly said "the elan2 machine ... will be sufficient to drive a turbine (engineered however you see fit)". This was in reply to you talking about the annual energy output of the Kender engine and the nitrogen production rate of the elan2, between which you implied a causal route, so any connection you infer is down to your own argument. I asked you to fill in the blank in your reasoning. Are you going to try? I was specifically referring to the part where you imagined that because you have both the elan2 and your turbine running for a year that they somehow have a 1:1 input-output relationship.
Mr Skeptic Posted March 25, 2010 Posted March 25, 2010 heat = kinetic freakin' energy that comes from the molecules moving. Wrong! Heat is the flow of thermal energy. Oh and heat engines work on a flow of heat, and heat flows from warmer to colder, so to have an engine you need a heat source and a heat sink, and the heat source has to be warmer than the working fluid and the heat sink must be cooler than the working fluid. This supposed engine has no heat sink, and instead relies on people being too dumb to notice that there is no heat flow when expanding a gas (its a temperature change only).
lazygamer Posted March 25, 2010 Posted March 25, 2010 So you think you are going to get more energy back from the gas expanding than you put into compressing it, right? That IS what you are saying, yes? its not energy from the gas expanding, it turns a freakin' turbine at 200 pounds per square inch and you only need to compress it back to 15 or 20 pounds per square inch. The claim is that it is "free" because it uses only a freely available source of energy, and no other. That is what the debate in this thread disputes. You are not addressing any of the technical or physical issues that have been raised. heat is the freely avaliable source of energy, the average temperature on earth is over 280 kelvin above zero temperature. That's not what my nagging voice says. My nagging voice says things like "no free lunch" and "it takes energy expenditure to do ANY work". and you generate cold air from using the heat to expand a gas that pushes a turbine!!! colder air = spent energy from warm air. I asked you to fill in the blank in your reasoning. Are you going to try?I was specifically referring to the part where you imagined that because you have both the elan2 and your turbine running for a year that they somehow have a 1:1 input-output relationship. I mentioned the elan and its production-capability because you figured it took way more energy to create the nitrogen than what you can possibly produce from the kender engine. Wrong! Heat is the flow of thermal energy. and what is heat? heat is the kinetic energy of molecules when they bounce off other atoms because they are moving. its not magical powder that flows through everything like dark matter apparently is. Oh and heat engines work on a flow of heat, and heat flows from warmer to colder, so to have an engine you need a heat source and a heat sink, and the heat source has to be warmer than the working fluid and the heat sink must be cooler than the working fluid. This supposed engine has no heat sink, and instead relies on people being too dumb to notice that there is no heat flow when expanding a gas (its a temperature change only). nitrogen at 20 psi, 73 kelvin. it warms up to around 273 kelvin and around 200 psi. then you push a turbine at 200 pounds per square inch and loose about 50% of the generated energy to mechanical loss. the space behind the turbine makes the pressure go down aswell as the temperature. then you use 20% of the energy generated to pump the gas back into the radiator at 20 psi, 73 kelvin. Ask a proffessor within thermodynamics about it if you still claim there's no heat-sink or whatever.
Mr Skeptic Posted March 25, 2010 Posted March 25, 2010 and what is heat? heat is the kinetic energy of molecules when they bounce off other atoms because they are moving. its not magical powder that flows through everything like dark matter apparently is. Nope, what you are describing is called thermal energy. nitrogen at 20 psi, 73 kelvin. it warms up to around 273 kelvin and around 200 psi. then you push a turbine at 200 pounds per square inch and loose about 50% of the generated energy to mechanical loss. the space behind the turbine makes the pressure go down aswell as the temperature. then you use 20% of the energy generated to pump the gas back into the radiator at 20 psi, 73 kelvin. And then it stops working because when you compress it it heats up again. Yes, gas gets cold when it expands but it also gets warmer when it is compressed. They pretend that second part isn't true. They pretend that you are compressing it in a heat sink at 73 K, but they are not -- it is an adiabatic compression at best. If it isn't, where are they dumping the heat to maintain the temperature at 73 K? Ask a proffessor within thermodynamics about it if you still claim there's no heat-sink or whatever. Please do. Also look up what a heat sink is, and what direction heat flows. You seem to have things backward: if your gas is really cold, then you need an environment that is far colder if you want that environment to be a heat sink. If your gas is a heat sink to the environment, then the environment is a heat source. Thermal energy flows from hot to cold, not the other way around.
Sisyphus Posted March 25, 2010 Posted March 25, 2010 (edited) It seems like the main problem is that you seem to think that thermal energy = heat. It doesn't. http://en.wikipedia.org/wiki/Heat http://en.wikipedia.org/wiki/Thermal_energy You don't extract work from something just because it has a temperature. You extract work from a difference in temperature. And creating a difference in temperature takes work. More work than can be extracted from it. So, to take something which is warmer or colder than the air, there is a certain amount of energy which it has to gain or lose in order to be in thermal equilibrium with the air. That flow of energy is called heat. And that amount of energy is the most you can ever extract from the process. If it were otherwise, I could power my apartment with my refrigerator, instead of having to power it. (But I suppose that's exactly what you're claiming I could do!) Edited March 25, 2010 by Sisyphus
SH3RL0CK Posted March 25, 2010 Posted March 25, 2010 for the last time, you pump it into a box at x pressure, it increases in pressure to 10x because of the surroundings that are warmer. This is incorrect. If you pump it into a box at x pressure, it increases in pressure to X, not to 10X. Otherwise I wouldn't need an aircompressor to air up the tires on my car as I could do so by breathing into the tire. Now certainly a temperature change can modify the pressure, but we have already gone over why this doesn't work... then you have 10 times as much pressure turning the turbine, generating 10 times as much energy, than what you need to pump it back at x pressure again. No, you don't have 10X as much pressure unless you also apply a very considerable amount of heat energy in accordance with PV=nRT. if you don't get it ......... I give up, go do whatever. Certainly one of us does not seem to understand. (btw, why we don't have helium in our atmosphere is because the earth has too little mass to keep helium-molecules within our atmosphere. the same reason is why we dont have any pure hydrogen in our atmosphere) But you brought up the Kender engine and they specifically say they use Helium. Therefore their system must be a closed system, as I said, because our atmosphere is not helium.
lazygamer Posted March 25, 2010 Posted March 25, 2010 (edited) Nope, what you are describing is called thermal energy. idiot, http://en.wikipedia.org/wiki/File:Thermally_Agitated_Molecule.gif that is heat. the movement of the molecule, thus it hits other molecules, what you think of as "heat" is just the transfer of kinetic energy from one molecule to another (with radiation-heat through infrared included, in the "heat" definition), what I define as heat is kinetic energy, because anything that is transfered with photons is light-energy, and why I use thermodynamics is because and I quote: "In thermodynamics, the internal energy of a thermodynamic system, or a body with well-defined boundaries, denoted by U, or sometimes E, is the total of the kinetic energy due to the motion of particles (translational, rotational, vibrational) (...)". And then it stops working because when you compress it it heats up again. Yes, gas gets cold when it expands but it also gets warmer when it is compressed. They pretend that second part isn't true. They pretend that you are compressing it in a heat sink at 73 K, but they are not -- it is an adiabatic compression at best. If it isn't, where are they dumping the heat to maintain the temperature at 73 K? ehem, they release the gas into an somewhat empty box. I've gone through this many times now. (just to repeat: lower pressure = lower temperature, its just as low temperature at 20 psi before and after the process, because when you expand a gas the gas gets less kinetic energy, the heat doesn't have to "go" anywhere because the simple act of expanding the gas makes the molecules hit eachother less so they loose energy, ie heat (hit something going away from you and you get alot less energy bouncing back at you, its basic physics)) Please do. Also look up what a heat sink is, and what direction heat flows. You seem to have things backward: if your gas is really cold, then you need an environment that is far colder if you want that environment to be a heat sink. If your gas is a heat sink to the environment, then the environment is a heat source. Thermal energy flows from hot to cold, not the other way around. I meant for you to actually go see a professor, cus I ain't getting pay'd to teach and I'm really sure I'm not going to waste my spare time trying to teach you anything when there's others that might actually learn something around here. It seems like the main problem is that you seem to think that thermal energy = heat. It doesn't. http://en.wikipedia.org/wiki/Heat http://en.wikipedia.org/wiki/Thermal_energy You don't extract work from something just because it has a temperature. You extract work from a difference in temperature. And creating a difference in temperature takes work. More work than can be extracted from it. dont you see 73 kelvin written all over here? and its not the flow of heat you use (or you only use it to heat up the gas so it has more pressure), you use the pressure, even steam-engines and combustion-engines use pressure, not heat (the heat is there only to boil the water or explode the fuel so you get pressure). and as I said before, you define "heat" as the flow of heat, including light-transfered heat etc, I define heat as kinetic energy, and the radiation-heat etc as freakin' light, cus that's what it is. also, you dont use light-transfered heat primarily in this system, you take the kinetic energy of the air around the radiator, which bounces against the radiator, which transfers the kinetic energy through the metal, and then onto the gas molecules, which inturn make them hit eachother with more energy, which inturn creates more pressure. then, when you expand the gas, and the molecules start bouncing against molecules that are traveling away from themselves, they bounce back with less energy, and voilà, you've turned heat into pressure, which pushed a turbine, and turned the 273 Kelvin gas into gas at freakin' 73 Kelvin!!! So, to take something which is warmer or colder than the air, there is a certain amount of energy which it has to gain or lose in order to be in thermal equilibrium with the air. That flow of energy is called heat. And that amount of energy is the most you can ever extract from the process. if you didn't contain it, yes. but the thing about having a gas that's 200 kelvin below the temperature around the system, is that you will allways produce energy. and in return you TAKE energy from the air around the system. is that so darn difficult to comprehend? imagine a room filled with balls that bounce around in zero gravity with zero loss to due to friction (the laws of physics make sure the atoms bounce off eachother without loosing momentum because of changing shapes etc), at around 1000 miles per hour. then you introduce walls that also bounce around at a more energetic level than the balls inside the room. then the balls inside the room bounce harder and faster. then you have increased the pressure, then you double the size of the room, and the balls allmost instantly spread out and all of them get less momentum because they hit eachother when most are traveling away from eachother, therefore you just LOOSE heat, its GONE. that's why we aren't a super-heated quark-plasma right now like it was for a time after the big bang. the space increased, so all the particles bounced off particles that was traveling away from them, which made the heat go down, and made the temperature so low that today, the average temperature of the universe is just over absolute zero. If it were otherwise, I could power my apartment with my refrigerator, instead of having to power it. (But I suppose that's exactly what you're claiming I could do!) you really have no idea what you're talking about do you? R-134a, which is the gas they use in most refridgerators, boil at 247 kelvin, so its useless for anything else but to create an appliance according to what the electric power companies wanted people to buy so they used more electricity (they initially used poisonus gas, and then freon, which ruins O3 (ozone)). if the refridgerator-people wanted to make a cooling apparatus which generated electricity they would have invented something very similar (if not equal) to the kender engine. but they were out to create appliances which uses electricity instead, so that the power-companies would have a market. This is incorrect. If you pump it into a box at x pressure, it increases in pressure to X, not to 10X. Otherwise I wouldn't need an aircompressor to air up the tires on my car as I could do so by breathing into the tire. Now certainly a temperature change can modify the pressure, but we have already gone over why this doesn't work... No, you don't have 10X as much pressure unless you also apply a very considerable amount of heat energy in accordance with PV=nRT. Certainly one of us does not seem to understand. But you brought up the Kender engine and they specifically say they use Helium. Therefore their system must be a closed system, as I said, because our atmosphere is not helium. if the air you filled in your tire was gas-form nitrogen at 83 kelvins you'd only need a fraction of what you fill your car-tyres with at 293 kelvin or whatever the temperature is around where you live and you really misunderstand things, x + 200 kelvin = 10x you spanner, I figured you'd understand it with logic... from 73 kelvin to around 273 kelvin isn't a big temperature change? its 200 kelvins! water boil at 100 kelvin above solid form! 200 kelvins, from such a low temperature as 73 kelvins, is huge, do the thermodynamics calculation, same volume, different temperature, see what you get. and how the hell does us not having helium in our atmosphere have anything to do with "it must be a closed system"? its a closed system as in there are no holes in it, but kinetic energy (AKA HEAT) transfers through metal. its like saying because "Statement 1: Most of the green is touching the red. Statement 2: Most of the red is touching the blue.", and then say "Since most of the green is touching red, and most of the red is touching blue, most of the green must be touching blue.". this is however a stupid piece of unlogical thinking ( http://en.wikipedia.org/wiki/File:Logical_fallacy.svg ). you know what, my hypothesis, is that sherlock, shflssl or whatever, and sceptic, all consider yourself quite conservative, am I correct? Edited March 25, 2010 by lazygamer
Phi for All Posted March 25, 2010 Posted March 25, 2010 idiot, http://en.wikipedia.org/wiki/File:Thermally_Agitated_Molecule.gifthat is heat. Please drop the personal attack. Calling someone an idiot is a violation of the rules you agreed to when you signed up.
lazygamer Posted March 25, 2010 Posted March 25, 2010 k, but I won't be offended if they throw back. just felt it had to be said. won't happen again.
Phi for All Posted March 25, 2010 Posted March 25, 2010 k, but I won't be offended if they throw back. just felt it had to be said. won't happen again.It's not really about being offensive, although there are plenty of places on the net you can go to be insulted and we do like to be different in that regard. It's more that ad hominem is a logical fallacy in arguments. We try to aim our discussions at the ideas, not at the person who holds them.
Cap'n Refsmmat Posted March 25, 2010 Posted March 25, 2010 imagine a room filled with balls that bounce around in zero gravity with zero loss to due to friction (the laws of physics make sure the atoms bounce off eachother without loosing momentum because of changing shapes etc), at around 1000 miles per hour. then you introduce walls that also bounce around at a more energetic level than the balls inside the room. then the balls inside the room bounce harder and faster. then you have increased the pressure, then you double the size of the room, and the balls allmost instantly spread out and all of them get less momentum because they hit eachother when most are traveling away from eachother, therefore you just LOOSE heat, its GONE. No. The balls would not lose momentum. If there's no friction and collisions are elastic, momentum will be conserved. The total kinetic energy of the system will remain the same. If there's no friction losses, there's no waste heat created, so all energy remains either kinetic or potential. Since there's no gravity, there's no gravitational potential energy. Kinetic energy thus must be conserved. Momentum is always conserved anyway. Your understanding of physics is flawed.
SH3RL0CK Posted March 25, 2010 Posted March 25, 2010 if the air you filled in your tire was gas-form nitrogen at 83 kelvins you'd only need a fraction of what you fill your car-tyres with at 293 kelvin or whatever the temperature is around where you live and you really misunderstand things, x + 200 kelvin = 10x you spanner, I figured you'd understand it with logic... So, then, we are in agreement that PV=nRT is valid? Then you must also agree that in a closed system, there is no energy gain. Where, then, does the free energy you keep refering to come from? It seems to me this idea does not work and there is no energy gained by any contraption built to work in this manner. Your arguments in favor of the idea are not pursuasive to me. you know what, my hypothesis, is that sherlock, shflssl or whatever, and sceptic, all consider yourself quite conservative, am I correct? What would political leanings have to do with your idea? Nothing at all.
Mr Skeptic Posted March 25, 2010 Posted March 25, 2010 idiot, http://en.wikipedia.org/wiki/File:Thermally_Agitated_Molecule.gifthat is heat. the movement of the molecule, thus it hits other molecules, what you think of as "heat" is just the transfer of kinetic energy from one molecule to another (with radiation-heat through infrared included, in the "heat" definition), what I define as heat is kinetic energy, because anything that is transfered with photons is light-energy, and why I use thermodynamics is because and I quote: "In thermodynamics, the internal energy of a thermodynamic system, or a body with well-defined boundaries, denoted by U, or sometimes E, is the total of the kinetic energy due to the motion of particles (translational, rotational, vibrational) (...)". I know what thermal energy is. You can't go making up personal definitions. I don't care how you define heat, and it doesn't even matter how you define heat if you are using someone else's definition anyways (when talking about heat engines). This is what heat is: http://en.wikipedia.org/wiki/Heat In physics and thermodynamics, heat is the process of energy transfer from one body or system due to thermal contact, which in turn is defined as an energy transfer to a body in any other way than due to work performed on the body. ehem, they release the gas into an somewhat empty box. I've gone through this many times now. (just to repeat: lower pressure = lower temperature, its just as low temperature at 20 psi before and after the process, because when you expand a gas the gas gets less kinetic energy, the heat doesn't have to "go" anywhere because the simple act of expanding the gas makes the molecules hit eachother less so they loose energy, ie heat (hit something going away from you and you get alot less energy bouncing back at you, its basic physics)) Repeat it all you like, but please also listen to what I am saying. I understand that expanding a gas lowers its temperature. Here's how they fail: In phase 3, they talk of compressing the helium into the heat source, and claim that the compression and rise in temperature brings the helium back to its original pressure. This means that they are compressing the helium either back to the original pressure and allowing the temperature to rise while they do it (this process at best takes as much energy as they can get from expanding the gas in the turbine so it won't work), or they are compressing it while maintaining the temperature at -240 C, in which case this only will function in an environment at -240 C which does not exist on earth. So it won't work. I meant for you to actually go see a professor, cus I ain't getting pay'd to teach and I'm really sure I'm not going to waste my spare time trying to teach you anything when there's others that might actually learn something around here. Well if you are getting paid to teach elsewhere, I do hope you aren't teaching thermodynamics.
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