Bill Bianchi wrote: If I weld a lid onto a pot and it's air tight, then put that pot over a fire, it will eventually explode. The bigger the pot and fire, the greater the volume of hot air and pressure, the bigger the explosion. This suggests a greater volume of heated air has a greater amount of energy. First, am I correct in this assumption? Does a greater volume of air have more potential energy than a smaller volume? This seems like a common sense question, but I want an answer anyway. Maybe I'm wrong and a sealed thimble explodes with the same force as a sealed cooking pot.
Bill Bianchi wrote: If I took that same pot and welded a pipe on it that lead to the small cylinder and piston of the size we currently see in most heat motors, would the expanding air from the pot transfer pressure to the cylinder and drive the piston, assuming the cylinder is not too far from the pot? If the answer is yes, would the hot air from the pot over the fire drive the piston harder than a candle beneath the little sealed cylinder we usually see?
Bill Bianchi wrote: If I used a larger pot over a bigger fire with that exact same cylinder, would more horse power result? Yes or no. Save the possibility of blowing the piston for later, if there is a later with this discussion.
Bill Bianchi wrote: I see current heat motors using a very small area to heat. Yes, I'm aware this is for efficiency. I'm wondering if the HP can be upped my heating a greater volume of air, basically. I've been told it will not and that just goes against the way it seems things should work. I would like to understand why it wouldn't, if that's the case. I'm honestly not going to argue, just trying to understand this question about increased volume as pertains to HP.
Bill Bianchi wrote:To increase surface area, lets say I fill the pot with metal shavings, which will heat up inside the pot. This should, in theory, heat a greater volume of air inside the pot, increasing pressure and driving the piston with greater force, or HP. In theory.
Bill Bianchi wrote:For the sake of a clear answer to this question of volume vs HP, lets not get into efficiency or fuel usage just yet. If I'm wrong in my thinking, those things will not matter, anyway. I just want an answer to the question about a greater volume of heated air equalling greater horse power. Does it?
Bill Bianchi wrote:Also, I don't understand where the continued pressure would come from in the pot. The piston would relieve/exhaust some of the pressure with each stroke. It seems like the air inside the pot is already expanded. So, where would the pressure for another stroke come from? Wouldn't cooler air be required in there so it can be expanded for more pressure? Or, does the air inside the pot constantly cool and expand as it comes in contact with the surface area, leading to constant pressure as the fire burns? I mean, with steam engines, water has to be added to the boiler because the level lowers as the water is turned to steam to drive the steam engine. What about the air in a sealed cylinder or pot? Doesn't it need to be replentished if the piston relieves some of the pressure with each stroke? I realize this is probably a stupid question, or extremely basic to some of you. Good news is if I can understand the answer, I won't ask again.
Bill Bianchi wrote:Again, I'm not saying anything needs to change or that anyone is doing anything wrong with the current methods or that this is a better idea or that this hot sealed pot idea is even possible. I'm just trying to better understand something about the Stirling that's been nagging me.
Bill Bianchi wrote:If you find this question annoying, wait till I post a question about flash steam engines. That'll be loads of fun.
Bill Bianchi wrote:Seems like a valve on the pipe leading to the cylinder would help, if it cuts the pressure on the return stroke and opens to push the piston again after its all the way back in the cylinder. That would be a lot of opening and closing, though. Don't know if a reliable valve like that exists. It would at least address the flywheel working against the pressure on the return stroke. If the valve also opened the cool chamber at the same time only on the return stroke, maybe it would help "suck" the piston back into the cylinder as the hot gas cools and contracts?
Bill Bianchi wrote:The cool chamber, where the hot air exhausts into, looks like another challenge. How the heck do you cool that without expending more energy or overwhelming the cooling the cooling agent used to cool the working fluid?
Bill Bianchi wrote:This may be another stupid question, but has anyone tried using ammonia as the working fluid in a Stirling, a mixture like that found in an absorbsion refrigerator? To a newb like me, the thinking goes like this. The ammonia liquid gets heated, expands, drives piston forward, exhausts into an unheated chamber where it condenses. That second chamber should get ice cold as it condenses, providing a wide temperature difference, which should help the engine run more efficiently.
Bill Bianchi wrote:That seems like a good idea, but there's probably a ton of legistics that would have to be overcome, if its even workable. Maybe the ammonia corrodes the crap out of the piston and cylinder.
Bill Bianchi wrote:On that note, could the same ammonia mixture be used on a thermal electric generator to heat one side, then condense on the other plate and cool that side?
I'm thinking 2 connected containers, one on each plate of the TEG. Heat one tank, which also heats that TEG plate on the hot ide, route the ammonia gas to the second tank on the other plate, where it condenses back to liquid and turns ice cold before going back over to the hot tank to repeat the cycle.
Again, sounds nice, but lots to figure out for a demonstration model. I like it, though, because the heat applied would, in theory, also power the cold side, enhancing energy output through extreme differences in temp without having to add more input energy than normal. In theory, which is all any of this is.
Bill Bianchi wrote:We can get into possible heat sources next, if I'm not being too boring with this thought experiment. Just trying to look at possibilities. I need to know what's possible for a fiction book I'm writing.. I'm not going to try to build one, but I need to understand this if I'm to present it as a viable method.
Bill Bianchi wrote:Fiction, as in a fictional novella. I'd like to show characters using alternative energy technologies that a lot of the reading public may not be knowledgable about yet. But, I don't want to show something generating energy in the story that won't work in the real world.
Gasification is one I intend to show the characters using. It's fairly unknown to a lot of people, so it'll be new or exotic to them. I'm looking for more technologies like that.
Bill Bianchi wrote:I thought absorption refrigerators removed heat from the inside, which keeps food cold, by heating the liquid, which turns to gas and travels up the tube, then condenses back to liquid, absorbing heat from the box, then drains back down the tube where it will be reheated to a gas to repeat the cycle.
Bill Bianchi wrote:Are you telling me that the condensing of the gas will not remove heat from the area where it condenses? How do those icy balls get cold after heating?
Bill Bianchi wrote:My thought was that if the heat can be removed from the other side of a TEG, there would be a wide temperature difference between the heated side and the refrigerated side, increasing electric output.
You're telling me it's not possible to use the absorption cycle to heat one side of a TEG and cool the other side?
Or, that it's not possible to use the absorption cycle to refrigerate the cool chamber of a Stirling?