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mechanics of intercooler heat-exchange rates.

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Old Jul 27, 2002 | 08:29 PM
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mechanics of intercooler heat-exchange rates.

All the talk to date about intercoolers has failed to satisfy one of my basic questions. That is, what is the maximum heat exchange capable? For example, if one was to fabricate an intercooler that was refrigerated like an air conditioner evaporator maintaining about a 38 deg. F. core temp, what sort of intake air temp reduction COULD take place? Simply put, how are the factors of ambient air temp, core size, and intake air temp all related? I was also curious if the boosted air from the turbos is essentially always the same temp, regardless of outside ambient temp, prior to hitting the I/C, and if so, what IS that temp?

I have been playing with some venturi air chillers at work recently. These things are cool, and come in all sorts of sizes. One of the ones I have messed with is about 8 inches long, and it will chill incoming air at 100 deg. to about 42 degrees. The venturi effect actually cools the air to produce chilled air. No moving parts.
You hook an air line to the damned thing, and very cold air comes out one place and very hot air comes out another....it is sort of freaky in its simplicity.
There is a muffled exhaust that, naturally has very HOT air coming out of it....whatever the heat exchange is, you will get that heat into the exhaust. I have toyed with the idea of using something like the stock airpump to generate a flow of air to a venturi chiller coupled to a custom I/C. I am pretty sure that there is at least SOME merit to further investigation.
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Old Jul 27, 2002 | 09:17 PM
  #2  
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There is some good info on IC theory here - http://www.scuderiaciriani.com/rx7/i...olers.html#THE but I don't know if it answers all your questions.

Obviously when you compress the air it's temperature increases and my educated guess is that the temp increase is constant and linear as the pressure increases. But starting with colder air will obviously lead to lower post-turbo pre-IC charge temps.
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Old Jul 29, 2002 | 10:00 AM
  #3  
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Re: mechanics of intercooler heat-exchange rates.

Originally posted by bajaman
All the talk to date about intercoolers has failed to satisfy one of my basic questions. That is, what is the maximum heat exchange capable? For example, if one was to fabricate an intercooler that was refrigerated like an air conditioner evaporator maintaining about a 38 deg. F. core temp, what sort of intake air temp reduction COULD take place? Simply put, how are the factors of ambient air temp, core size, and intake air temp all related? I was also curious if the boosted air from the turbos is essentially always the same temp, regardless of outside ambient temp, prior to hitting the I/C, and if so, what IS that temp?

I have been playing with some venturi air chillers at work recently. These things are cool, and come in all sorts of sizes. One of the ones I have messed with is about 8 inches long, and it will chill incoming air at 100 deg. to about 42 degrees. The venturi effect actually cools the air to produce chilled air. No moving parts.
You hook an air line to the damned thing, and very cold air comes out one place and very hot air comes out another....it is sort of freaky in its simplicity.
There is a muffled exhaust that, naturally has very HOT air coming out of it....whatever the heat exchange is, you will get that heat into the exhaust. I have toyed with the idea of using something like the stock airpump to generate a flow of air to a venturi chiller coupled to a custom I/C. I am pretty sure that there is at least SOME merit to further investigation.
Your question is pretty detailed...you'd probably be best off getting a thermodynamics book and reading that. In general, the theoretical best that an air to air/water to air intercooler could do would be to get the incoming air down to ambient temps. The best that a refridgerated intercooler could do would be to get the boosted air down to the IC core temp. However, keep in mind that you are going to take a hp hit to run the chiller.

"I was also curious if the boosted air from the turbos is essentially always the same temp, regardless of outside ambient temp, prior to hitting the I/C, and if so, what IS that temp?"

If only life were that simple. Compressor outlet temp is a function of ambient (inlet) temperature, inlet pressure, and outlet pressure and follows this equation.....

T2/T1 = (P2/P1)^(.4/1.4)

You may want to check that because it was off the top of my head.

Also, your description of the chiller confused me...you're saying that the air magically gets cooled with no work put into the system? If so, show me how someone managed to violate the laws of physics.
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Old Jul 29, 2002 | 11:12 AM
  #4  
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From: UK
If my memory recall is not too bad..I saw a programme where there were using the venturi effect to heat water with air. the air is seemed to be spun in a loop and then split...one end gives hot air the other gives cold...can;t remember how exactly it worked, but no power was added to the system except for the air being pumped into the vessel.

maybe somebody else can explain the details.
cheers
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