intercooler concept
06-11-2014, 02:43 AM
#16
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Location: Austin TX, drinking beer in the garage
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My reference to thermal loss was more a comment about thermal energy lost to the cylinder head, water cooling system, oil, and block. You wont be able to recover this energy and it is a significant amount. Not trying to shoot down your idea, as admiralkhole said I'm one of the crazier guys arouns here and I lovs innovation, just clarifying my statementz.
06-11-2014, 02:56 AM
#18
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Hmm...i sincerely doubt there is more energy in the cooling system than the exhaust, I would have to crunch the numbers. I was just bringing to light the fact that with respect to my aforementioned back of the napkin calculations concerning energy, although the energy "is there" it is not all in one place and easy to obtain to do useful work.
06-11-2014, 03:09 AM
#19
Pro
Thread Starter
well with the one guys idea of running the refrigeration intercooler, L2A, after a normal A2A to further cool the intake tempature any amount of free additional cooling would help...
even after the point where colder air doesn't make more power it would still allow you to turn boost up higher and higher because of detonation reduction..
even after the point where colder air doesn't make more power it would still allow you to turn boost up higher and higher because of detonation reduction..
06-11-2014, 07:28 AM
#20
Nordschleife Master
ptuomov
wow.. i never thought of running this after an A2A intercooler to further cool the intake air... very interesting..
but this system uses no glycol what so ever, no compressor, very simple system with no moving parts at all...
i like it, a normal A2A and then a direct ammonia evaporator to air instead of water to air..
oh and no storage tanks or nothing of that sort, that's just extra weight..
these things continue to cool 24 hours after heat application.. that means its going to be cooling all night and still be cold when you go turn your key in the morning and apply more heat..
wow.. i never thought of running this after an A2A intercooler to further cool the intake air... very interesting..
but this system uses no glycol what so ever, no compressor, very simple system with no moving parts at all...
i like it, a normal A2A and then a direct ammonia evaporator to air instead of water to air..
oh and no storage tanks or nothing of that sort, that's just extra weight..
these things continue to cool 24 hours after heat application.. that means its going to be cooling all night and still be cold when you go turn your key in the morning and apply more heat..
Most likely, any system that you build will not be able to refrigerate the intake charge much in full power stead state. Therefore, you need some sort of "cool reservoir" that the system is cooling constantly, including low power states, and that gets used up in full power states.
Glycol tank is one such "cool reservoir." That is what the "Lighting" system used.
Another idea for cool reservoir is to use "'phase change materials heat storage." For example, paraffin wax was suggested in this article: http://www.autospeed.com/cms/article.html?&A=110772 . You could use the refrigeration to turn the wax into solid at low power states, and then in full power states the specific heat of fusion would keep the intake charge cool until all of the wax has melted.
06-11-2014, 08:21 AM
#21
Addict
Rennlist Member
Rennlist Member
The only thing that would really work IMO is NatureFridge style system cooled with nitrogen.
natureFridge is the most efficient, emission free, silent running cryogenic refrigeration system for trucks and trailers. The components of the system can be grouped into five subsystems: Supply, Control, Cooling, Safety and Power.
The natureFridge system works by releasing vaporized nitrogen into the load area from an under slung tank with a capacity of up to 1000-litres. The nitrogen goes through an expansion chamber that transforms the liquid into a gas that is then released into the freezer truck or trailer as an almost invisible vapor.
The natureFridge has virtually no moving parts, therefore it is almost maintenance free, thus reducing maintenance costs and downtime.
For more information visit our web-site: http://www.naturefridge.com
The natureFridge system works by releasing vaporized nitrogen into the load area from an under slung tank with a capacity of up to 1000-litres. The nitrogen goes through an expansion chamber that transforms the liquid into a gas that is then released into the freezer truck or trailer as an almost invisible vapor.
The natureFridge has virtually no moving parts, therefore it is almost maintenance free, thus reducing maintenance costs and downtime.
For more information visit our web-site: http://www.naturefridge.com
06-11-2014, 10:43 AM
#22
Race Car
I like the way you think! Love the creativity going on there. I'd encourage you to run out this.....but only on paper, not on a real application.
So put some numbers to it. And that is what ideaola was trying to help you do. He understands it isn't an energy consuming system, but his points were two-fold:
1. The potential gain is not very big
2. The benefit would only be realized for a very short period of time
Furthermore, your estimates on how much waste heat goes through the exhaust are way off. Thermal efficiency alone of an engine is higher than 25%. Will typically be above 30%. Of the at most 70% that is left, a good chunk of it, say 30% will be lost in mechanical inefficiencies, leaving about 40% of indicated power left. Of that 40%, only a portion makes its way into the exhaust system, a good deal of heat will be lost through the walls of teh combustion chamber - the piston, cylinder walls, head, and valves. Leaving the chamber, more will be lost through the exhaust ports. Now we are at the flange to the header. Your EGT's are say maybe 1000 degrees C after all of those losses. Now, I've never quantified what portion of heat is lost up to that point, but I would bet that AT LEAST half. That leaves you with 20%. A lot of heat is lost on its way to the turbo. Then some of that energy is used to turn the turbo. After the heat lost through the turbo, you are probably in the 275 degree range, only an estimate. So of the 20% left, you have maybe 550/1275 (degrees Kelvin) available in the exhaust. So that is a little over 40% of the 20%.....meaning your potential heat for recovery is likely closer to 8%. So from your example of a 200bhp engine, that would mean 800hp indicated, and you have 8% of that available. That is 64 horsepower at most.
Now let us look at what it would take to make this work. At 6,000 RPM at 1 bar of boost, you are looking at 60 RPS*1/2*~5L, or 150L/s of air to cool. To cool that down a single degree C would require about 200 Watts. Since this has to be an enclosed system, you need to pull the temperature down probably 125 degrees C (assuming from 150 to 25). That is 25,000 Watts. 1hp = 746 Watts. So that means you need 33 horsepower just to get it back down to where the stock intercooler had it. That is half of your potential, which sounds like plenty of reserve, but the system will be most efficient at its hottest, and you are trying to effectively "supercool" it relative to the baseline, meaning it gets harder and harder to do so.
The next step would be to determine how big the system would need to be to first extract heat from the exhaust, and second to convert that to usable heat to remove from the intake system. I suspect a system capable of making that kind of power would be absolutely ENORMOUS. I think our refrigerator at home draws about 10 amps of current, which makes it 1200 Watts, or under 2 horsepower. Your system will need to be more than 20 times as big. Why more? Because you don't have a mechanical device to create the pressures needed to run a compact refrigerant system.
So, I don't really think it will work, personally. Guess I kind of just did most of the running it out for you. Seriously, though, back when I used to do this kind of stuff for a living, I used to do all kinds of hairbrained stuff like this, but of course you have to run it out. You may come up with 20 ideas that don't make sense for every one that will work. Again, love the creating thinking, don't get too attached to any idea or thought, just run them out. But also consider that virtually everything that does not rely on technology was figured out in the first couple of decades. One of my mentor's favorites references was a book that was published in 1929.
A much, much, much better way to improve a system would be to use a liquid injection system, which relies of phase transformation, which is orders of magnitude more efficient than trying to use just heat capacities to cool down a system.
So put some numbers to it. And that is what ideaola was trying to help you do. He understands it isn't an energy consuming system, but his points were two-fold:
1. The potential gain is not very big
2. The benefit would only be realized for a very short period of time
Furthermore, your estimates on how much waste heat goes through the exhaust are way off. Thermal efficiency alone of an engine is higher than 25%. Will typically be above 30%. Of the at most 70% that is left, a good chunk of it, say 30% will be lost in mechanical inefficiencies, leaving about 40% of indicated power left. Of that 40%, only a portion makes its way into the exhaust system, a good deal of heat will be lost through the walls of teh combustion chamber - the piston, cylinder walls, head, and valves. Leaving the chamber, more will be lost through the exhaust ports. Now we are at the flange to the header. Your EGT's are say maybe 1000 degrees C after all of those losses. Now, I've never quantified what portion of heat is lost up to that point, but I would bet that AT LEAST half. That leaves you with 20%. A lot of heat is lost on its way to the turbo. Then some of that energy is used to turn the turbo. After the heat lost through the turbo, you are probably in the 275 degree range, only an estimate. So of the 20% left, you have maybe 550/1275 (degrees Kelvin) available in the exhaust. So that is a little over 40% of the 20%.....meaning your potential heat for recovery is likely closer to 8%. So from your example of a 200bhp engine, that would mean 800hp indicated, and you have 8% of that available. That is 64 horsepower at most.
Now let us look at what it would take to make this work. At 6,000 RPM at 1 bar of boost, you are looking at 60 RPS*1/2*~5L, or 150L/s of air to cool. To cool that down a single degree C would require about 200 Watts. Since this has to be an enclosed system, you need to pull the temperature down probably 125 degrees C (assuming from 150 to 25). That is 25,000 Watts. 1hp = 746 Watts. So that means you need 33 horsepower just to get it back down to where the stock intercooler had it. That is half of your potential, which sounds like plenty of reserve, but the system will be most efficient at its hottest, and you are trying to effectively "supercool" it relative to the baseline, meaning it gets harder and harder to do so.
The next step would be to determine how big the system would need to be to first extract heat from the exhaust, and second to convert that to usable heat to remove from the intake system. I suspect a system capable of making that kind of power would be absolutely ENORMOUS. I think our refrigerator at home draws about 10 amps of current, which makes it 1200 Watts, or under 2 horsepower. Your system will need to be more than 20 times as big. Why more? Because you don't have a mechanical device to create the pressures needed to run a compact refrigerant system.
So, I don't really think it will work, personally. Guess I kind of just did most of the running it out for you. Seriously, though, back when I used to do this kind of stuff for a living, I used to do all kinds of hairbrained stuff like this, but of course you have to run it out. You may come up with 20 ideas that don't make sense for every one that will work. Again, love the creating thinking, don't get too attached to any idea or thought, just run them out. But also consider that virtually everything that does not rely on technology was figured out in the first couple of decades. One of my mentor's favorites references was a book that was published in 1929.
A much, much, much better way to improve a system would be to use a liquid injection system, which relies of phase transformation, which is orders of magnitude more efficient than trying to use just heat capacities to cool down a system.
06-11-2014, 11:44 AM
#23
Burning Brakes
If the math doesn't end up working out to make an appreciable difference for cooling the intake air, a setup might still be valuable to racers as a no-loss A/C system for keeping the cabin cool. Heck, it would be useful for anyone with an NA car that doesn't want to give up any precious horsepower.
06-11-2014, 12:20 PM
#24
Race Car
06-11-2014, 04:08 PM
#25
Pro
Thread Starter
If the math doesn't end up working out to make an appreciable difference for cooling the intake air, a setup might still be valuable to racers as a no-loss A/C system for keeping the cabin cool. Heck, it would be useful for anyone with an NA car that doesn't want to give up any precious horsepower.
I cant quite remember but it was some college in conjunction with GM or Chrysler that made this system in the early 80's but never implemented into regular use for some reason, but it is a proven concept...
witch proves this can work in a somewhat unstable environment "sloshing"..
however I myself have little to no interest in creature comforts, I just want to make things go fast.....
take it, run with it, if its a success don't forget little ol' me..
Last edited by fasteddie313; 06-11-2014 at 05:20 PM. Reason: uh.. why not? cause i can... had an afterthought..
06-11-2014, 04:59 PM
#26
Pro
Thread Starter
Furthermore, your estimates on how much waste heat goes through the exhaust are way off. Thermal efficiency alone of an engine is higher than 25%. Will typically be above 30%. Of the at most 70% that is left, a good chunk of it, say 30% will be lost in mechanical inefficiencies, leaving about 40% of indicated power left. Of that 40%, only a portion makes its way into the exhaust system, a good deal of heat will be lost through the walls of teh combustion chamber - the piston, cylinder walls, head, and valves. Leaving the chamber, more will be lost through the exhaust ports. Now we are at the flange to the header. Your EGT's are say maybe 1000 degrees C after all of those losses. Now, I've never quantified what portion of heat is lost up to that point, but I would bet that AT LEAST half. That leaves you with 20%. A lot of heat is lost on its way to the turbo. Then some of that energy is used to turn the turbo. After the heat lost through the turbo, you are probably in the 275 degree range, only an estimate. So of the 20% left, you have maybe 550/1275 (degrees Kelvin) available in the exhaust. So that is a little over 40% of the 20%.....meaning your potential heat for recovery is likely closer to 8%. So from your example of a 200bhp engine, that would mean 800hp indicated, and you have 8% of that available. That is 64 horsepower at most.
Now let us look at what it would take to make this work. At 6,000 RPM at 1 bar of boost, you are looking at 60 RPS*1/2*~5L, or 150L/s of air to cool. To cool that down a single degree C would require about 200 Watts. Since this has to be an enclosed system, you need to pull the temperature down probably 125 degrees C (assuming from 150 to 25). That is 25,000 Watts. 1hp = 746 Watts. So that means you need 33 horsepower just to get it back down to where the stock intercooler had it. That is half of your potential, which sounds like plenty of reserve, but the system will be most efficient at its hottest, and you are trying to effectively "supercool" it relative to the baseline, meaning it gets harder and harder to do so.
The next step would be to determine how big the system would need to be to first extract heat from the exhaust, and second to convert that to usable heat to remove from the intake system. I suspect a system capable of making that kind of power would be absolutely ENORMOUS. I think our refrigerator at home draws about 10 amps of current, which makes it 1200 Watts, or under 2 horsepower. Your system will need to be more than 20 times as big. Why more? Because you don't have a mechanical device to create the pressures needed to run a compact refrigerant system.
So, I don't really think it will work, personally. Guess I kind of just did most of the running it out for you. Seriously, though, back when I used to do this kind of stuff for a living, I used to do all kinds of hairbrained stuff like this, but of course you have to run it out. You may come up with 20 ideas that don't make sense for every one that will work. Again, love the creating thinking, don't get too attached to any idea or thought, just run them out. But also consider that virtually everything that does not rely on technology was figured out in the first couple of decades. One of my mentor's favorites references was a book that was published in 1929.
A much, much, much better way to improve a system would be to use a liquid injection system, which relies of phase transformation, which is orders of magnitude more efficient than trying to use just heat capacities to cool down a system.
those numbers look quite promising to me actually
ok lets say that this thing is only has the potential to almost match the performance of an intercooler, maybe 75%...
if you were to run this after an A2A intercooler that is already bringing the intake temps down from (assuming from 150 to 25).
A2A= 150-25=125 C drop
75%= 125C drop X .75 = 93.75C drop
125C drop + 93.75C drop = 218C drop
150C start + 218C drop = -68C intake tempature....
-68C INTAKE TEMPS??? NOW THATS COLD...
I don't think we need anything near that cold of intake temps.. so lets cut that in half..
125C drop + (93.75C X .5 = 46.875C) drop = 171.875C drop
150C start + 171.875C drop = -21.875C intake temps
so if this thing can even do (75% X .5 = 37.5%) 37.5% the work our original A2A is doing then combined we get our intake temps below -20C...
so lets take whats theoretically available
you have 8% of that available. That is 64 horsepower at most.
8% X .375 = 3%
so we only need to capture just over a third of the 8% waste and we get
intake temps in the -20C or -7F range
now that is some cold dense air with excellent detonation resistance...
remember this thing will go far below ambient air temps ..
A2A can only bring temps down close to ambient, this will be able to get you negative below ambient temps...
I think intake temps of 0C or 32F would be a good goal and were already well past that...
time for algebra..
150C start - 125C A2A + X = 0C X = 25C drop
25/125= 20%
now we only need to get this thing to do 20% as much work as our A2A to get temps to freezing point 0C or 32F
now how much energy does it take to bring your volume of air from 25C to 0C?
compared to useable waste heat?
06-11-2014, 08:21 PM
#27
Pro
Thread Starter
ok I found a ratio of 5.86 kw/ton efficiency..
and 1 RT = 3.5168525 kW
so that means 5860 watts of heat in and 3517 watts of cold out...
so an efficiency factor of about .6
still looking good
exhaust 45,000 watts in and 27,000 cold watts out..
but were gonna lose some.. cut it in half... no a third to be generous...
1/3= 15,000 watts in and 9,000 watts out
9,000 divided by 200 watts per degree C gets us a 45 degree C drop in temp at 150 liters per second of air...
so after our A2A intercooler getting us down to 25C an additional 45C drop gets us -20C intake temps
and that's estimating being able to use only a third of the available heat energy in the exhaust...
so.... numbers crunched... numbers work....
if it fits under the hood its worth putting under the hood...
now to find out if it fits
and 1 RT = 3.5168525 kW
so that means 5860 watts of heat in and 3517 watts of cold out...
so an efficiency factor of about .6
still looking good
exhaust 45,000 watts in and 27,000 cold watts out..
but were gonna lose some.. cut it in half... no a third to be generous...
1/3= 15,000 watts in and 9,000 watts out
9,000 divided by 200 watts per degree C gets us a 45 degree C drop in temp at 150 liters per second of air...
so after our A2A intercooler getting us down to 25C an additional 45C drop gets us -20C intake temps
and that's estimating being able to use only a third of the available heat energy in the exhaust...
so.... numbers crunched... numbers work....
if it fits under the hood its worth putting under the hood...
now to find out if it fits
06-11-2014, 11:13 PM
#28
Burning Brakes
Although not suggesting the OP idea lacks merit, seems to me that it might be more efficient and much cheaper to:
1.) Straighten out the convoluted plumbing of the stock intercooler, which surely has about twice as much piping as needed, plus a bunch of nasty internal kinks which impede flow, and;
2.) The stock air inlet for the cooling air coming into the car nose is good, but Porsche seems to have completely forgotten to make an efficient exit path for that cooling air. Sort that out and the stock intercooler would be way more efficient.
Do both 1 and 2 above, plus properly vent the engine bay to shed unwanted heat from exhaust manifold and turbo, and there might be no need for further enhancements to the intercooler, etc.
1.) Straighten out the convoluted plumbing of the stock intercooler, which surely has about twice as much piping as needed, plus a bunch of nasty internal kinks which impede flow, and;
2.) The stock air inlet for the cooling air coming into the car nose is good, but Porsche seems to have completely forgotten to make an efficient exit path for that cooling air. Sort that out and the stock intercooler would be way more efficient.
Do both 1 and 2 above, plus properly vent the engine bay to shed unwanted heat from exhaust manifold and turbo, and there might be no need for further enhancements to the intercooler, etc.
06-11-2014, 11:29 PM
#29
Pro
Thread Starter
Dash01
good points for sure for a 951 but I am trying to work out a concept that would work with all internal combustion engines, even n/a would benefiet from intake temp cooling below ambient temps...
for my Porsche im working on im 99.9999% sure that its going to get nothing more than a regular A2A as it comes with no intercooler in the first place..
when I get to that stage with that car ill have to decide between a top mount A2A between ITBs and the brake booster with a hood scoop
(http://924board.org/viewtopic.php?t=39763&highlight=)
witch I guess nobody found interesting enough to reply to...
or a standard 951 FMIC....
good points for sure for a 951 but I am trying to work out a concept that would work with all internal combustion engines, even n/a would benefiet from intake temp cooling below ambient temps...
for my Porsche im working on im 99.9999% sure that its going to get nothing more than a regular A2A as it comes with no intercooler in the first place..
when I get to that stage with that car ill have to decide between a top mount A2A between ITBs and the brake booster with a hood scoop
(http://924board.org/viewtopic.php?t=39763&highlight=)
witch I guess nobody found interesting enough to reply to...
or a standard 951 FMIC....
06-11-2014, 11:53 PM
#30
Burning Brakes
While we're on the general topic of intercoolers, has anybody insulated the IC pipes so they don't needlessly heat soak from engine bay heat?
All that convoluted plumbing gets hot from the engine bay and so heats up the air flowing through it, defeating the whole purpose of an intercooler.
All that convoluted plumbing gets hot from the engine bay and so heats up the air flowing through it, defeating the whole purpose of an intercooler.