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Post by silverdragon on Jan 14, 2016 10:25:01 GMT
I have one to ponder on.. running an engine on Oxygen.
We all know the 14:1 air/fuel mix, and the maths are not that hard to work out what %age of air is oxygen.
But has anyone ever tried running an engine on pure bottled oxygen?... no air intake?...
Yep I know, it cant be that easy, the huge amount of Oxygen required, for even a small journey.
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Post by GTCGreg on Jan 14, 2016 14:31:27 GMT
I have no doubt it could be done. It should lower the required "air"-fuel mixture by about 80%. If fact, I believe that's why in racing they inject nitrogen oxide (NOX). It's a strong oxidizer like oxygen but easier to handle. It allows them to burn more fuel with less air.
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Post by the light works on Jan 14, 2016 15:31:02 GMT
the nitrous oxide has two functions: it increases the amount of oxygen in the mixture and it also raises the pressure (or reduces the vacuum) in the intake manifold. I would guess since it is delivered to the orifices as a pressurized gas, it also cools the intake as a not very noticeable side effect. - all of which means more oxygen = more fuel = more expanding gases per cylinder.
I have a small vested interest in the concept, because I used the concept in a story I wrote some years back - in which the bad guys used oxygen as a power booster at the cost of higher engine strain and rapid degradation of engine components due to higher combustion temperatures.
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Post by GTCGreg on Jan 14, 2016 15:47:39 GMT
the nitrous oxide has two functions: it increases the amount of oxygen in the mixture and it also raises the pressure (or reduces the vacuum) in the intake manifold. I would guess since it is delivered to the orifices as a pressurized gas, it also cools the intake as a not very noticeable side effect. - all of which means more oxygen = more fuel = more expanding gases per cylinder. I have a small vested interest in the concept, because I used the concept in a story I wrote some years back - in which the bad guys used oxygen as a power booster at the cost of higher engine strain and rapid degradation of engine components due to higher combustion temperatures. Right, when you take an engine designed to deliver 200 HP and force feed it to deliver 400 HP, it tends degrade the engine's useful life a little. |
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Post by the light works on Jan 14, 2016 16:13:25 GMT
the nitrous oxide has two functions: it increases the amount of oxygen in the mixture and it also raises the pressure (or reduces the vacuum) in the intake manifold. I would guess since it is delivered to the orifices as a pressurized gas, it also cools the intake as a not very noticeable side effect. - all of which means more oxygen = more fuel = more expanding gases per cylinder. I have a small vested interest in the concept, because I used the concept in a story I wrote some years back - in which the bad guys used oxygen as a power booster at the cost of higher engine strain and rapid degradation of engine components due to higher combustion temperatures. Right, when you take an engine designed to deliver 200 HP and force feed it to deliver 400 HP, it tends degrade the engine's useful life a little. as I tell people, I used to have a windup car. I could wind it tighter and make it go faster, but one day I would it too tight and it broke. |
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Post by silverdragon on Jan 15, 2016 7:27:16 GMT
Well, I was considering this as use for being able to run the engine underwater, but I suppose someone was going to drag race it at some point.
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Post by GTCGreg on Jan 15, 2016 13:25:23 GMT
Well, I was considering this as use for being able to run the engine underwater, but I suppose someone was going to drag race it at some point. I'd opt for a snorkel. |
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Post by the light works on Jan 15, 2016 15:37:01 GMT
however, as a theoretical question, it makes it that you want some sort of rebreather system for an internal combustion engine - and when you consider that you can make a rebreather that humans can survive using as long as everything is adjusted properly, you should be able to make a rebreather for an ICE; which is not subject to poisoning from getting the gas mixture incorrect.
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Post by GTCGreg on Jan 15, 2016 16:20:15 GMT
however, as a theoretical question, it makes it that you want some sort of rebreather system for an internal combustion engine - and when you consider that you can make a rebreather that humans can survive using as long as everything is adjusted properly, you should be able to make a rebreather for an ICE; which is not subject to poisoning from getting the gas mixture incorrect. Well, it will die. Just not permanently. |
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Post by the light works on Jan 15, 2016 16:27:21 GMT
however, as a theoretical question, it makes it that you want some sort of rebreather system for an internal combustion engine - and when you consider that you can make a rebreather that humans can survive using as long as everything is adjusted properly, you should be able to make a rebreather for an ICE; which is not subject to poisoning from getting the gas mixture incorrect. Well, it will die. Just not permanently. but the engine will either run good or run bad - as compared to a human which can, if you get the wrong mixture, show no adverse effects until it abruptly stops breathing. |
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Post by GTCGreg on Jan 15, 2016 18:39:10 GMT
Well, it will die. Just not permanently. but the engine will either run good or run bad - as compared to a human which can, if you get the wrong mixture, show no adverse effects until it abruptly stops breathing. Ever adjust the carb on an old pre injected engine? Yep, get it too far wrong and it will stop breathing. Although it will usually show some adverse effects first. |
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Post by the light works on Jan 16, 2016 1:19:11 GMT
but the engine will either run good or run bad - as compared to a human which can, if you get the wrong mixture, show no adverse effects until it abruptly stops breathing. Ever adjust the carb on an old pre injected engine? Yep, get it too far wrong and it will stop breathing. Although it will usually show some adverse effects first. AKA run bad. |
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Post by wvengineer on Jan 16, 2016 3:21:56 GMT
My first concern would be the amount of oxygen needed to get it to run for any length of time. If you look at it this way, a small, 1.5L engine (Naturally aspirated) running at an idle speed of 1200 RPM needs 900L of air per minute at ambient pressure to run. Okay, if I am doing my math right... If you had a 7" gas bottle that held 150 Ft^3 of air compressed to 3000 PSI, that would be enough air to run the above engine with air at sea level pressure for 953 minutes or just over 16 hours. So not that bad, but that is idle. It drops to 7.7 hours of run time at a 2500 RPM speed. Things would be different with oxygen. Pure O2 would burn hotter, so you don't need as much gas to get the same amount of expansion of gas, however, if you have too small of a volume of O2, then you don't have enough gas volume to generate a pressure difference to drive the engine. So somewhere in there is the sweet spot that replicates the performance of air. Attachment Deleted |
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Post by the light works on Jan 16, 2016 3:27:53 GMT
My first concern would be the amount of oxygen needed to get it to run for any length of time. If you look at it this way, a small, 1.5L engine (Naturally aspirated) running at an idle speed of 1200 RPM needs 900L of air per minute at ambient pressure to run. Okay, if I am doing my math right... If you had a 7" gas bottle that held 150 Ft^3 of air compressed to 3000 PSI, that would be enough air to run the above engine with air at sea level pressure for 953 minutes or just over 16 hours. So not that bad, but that is idle. It drops to 7.7 hours of run time at a 2500 RPM speed. Things would be different with oxygen. Pure O2 would burn hotter, so you don't need as much gas to get the same amount of expansion of gas, however, if you have too small of a volume of O2, then you don't have enough gas volume to generate a pressure difference to drive the engine. So somewhere in there is the sweet spot that replicates the performance of air. View Attachmentthat's why I was thinking of some sort of rebreather. there would be challenges designing the intercooler to make it work (filling the cylinder with hot expanded gases wouldn't gain much) then your oxygen bottle could provide oxygen for combustion, and a portion of the combustion gases could be cooled and returned to the intake to provide volume. |
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Post by ponytail61 on Jan 19, 2016 7:33:29 GMT
It looks like in the early 70's when the Gov't was implementing pollution standards for cars a few people had the idea of pure oxygen as a way to get a clean burn from the fuel. Here's a patent for Pure oxygen supply to an internal combustion engineThere are more listed under Patent Citations near the end. Looks like they all used a chemical and heat source for the oxygen production as bottled gas wouldn't get ya too far as stated by SD. |
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Post by silverdragon on Jan 19, 2016 9:20:32 GMT
It looks like in the early 70's when the Gov't was implementing pollution standards for cars a few people had the idea of pure oxygen as a way to get a clean burn from the fuel. Here's a patent for Pure oxygen supply to an internal combustion engineThere are more listed under Patent Citations near the end. Looks like they all used a chemical and heat source for the oxygen production as bottled gas wouldn't get ya too far as stated by SD. Nice find. I was worried about the idea of having to carry all that bottled Oxygen... after all, what a risk... even something slightly warm can catch a HUGE fire if all that oxygen went off pop?... |
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Post by silverdragon on Jan 19, 2016 9:24:01 GMT
Erm, Ok, I dont know the chemistry, but I have had a thunk.
May its a stupid think, maybe not....
LPG.
Liquid Petroleum Gas.
Can that be mixed with liquid Oxygen in a stable way?...
And then just inject the mix into the cylinder.....
This is born from the idea that many good ideas ignored the thought process of "You cant do that" and asked "why not?.." and then looked for proof.
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Post by the light works on Jan 19, 2016 15:43:34 GMT
Erm, Ok, I dont know the chemistry, but I have had a thunk. May its a stupid think, maybe not.... LPG. Liquid Petroleum Gas. Can that be mixed with liquid Oxygen in a stable way?... And then just inject the mix into the cylinder..... This is born from the idea that many good ideas ignored the thought process of "You cant do that" and asked "why not?.." and then looked for proof. best to have injectors for both inside the cylinder. keep in mind in a pure oxygen environment, petroleum's autoignition temperature drops below room temperature. |
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Post by GTCGreg on Jan 19, 2016 16:08:12 GMT
Erm, Ok, I dont know the chemistry, but I have had a thunk. May its a stupid think, maybe not.... LPG. Liquid Petroleum Gas. Can that be mixed with liquid Oxygen in a stable way?... And then just inject the mix into the cylinder..... This is born from the idea that many good ideas ignored the thought process of "You cant do that" and asked "why not?.." and then looked for proof. best to have injectors for both inside the cylinder. keep in mind in a pure oxygen environment, petroleum's autoignition temperature drops below room temperature. You wouldn't need a spark plug. Kind of like a diesel. |
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Post by the light works on Jan 19, 2016 16:24:07 GMT
best to have injectors for both inside the cylinder. keep in mind in a pure oxygen environment, petroleum's autoignition temperature drops below room temperature. You wouldn't need a spark plug. Kind of like a diesel. but you don't want that happening outside the cylinder. |
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