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Question on making something cold any help?

  1. May 5, 2010 #1
    Ok, i need some serious help here....

    I need to cool air... this is something that involves motorsports, and i want to ask people that have knowledge way beyond me, so i found this forum, hoping someone here can help me...

    We are running air through a 3 inch diameter pipe... roughly 1800cfm of air... through a steel pipe for around 18 seconds in duration... The air pressurizes to around 50-60psi inside of this pipe. Now, what i would like to know, is there anyway possible to cool this air? Without adding water to it...

    Is there any sort of a chemical coating we could put on this pipe, or in this pipe to make it cold inside? or any sort of chemical that could be sprayed into it, to make it extremely cold? Right now over that 18 second time period, the air heats up to roughly 350-400 degrees... Is there any way possible to keep it cold? under 100 degrees? Any sort of coating we could put on this piping? or anything at all anyone here can think of?

    Please let me know if you have any ideas...

    Thanks in advance!
     
  2. jcsd
  3. May 5, 2010 #2

    alxm

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    Science Advisor

    Sounds like a very difficult problem.
    It's probably safe to say your air is heating up mainly due to the compression. Given that gas is a bad conductor of heat (and cold), I'm not sure you'd be able to cool it much at that flow rate, no matter how cold or conductive the pipe is (unless the pipe's a lot longer than I think it is).

    You could increase conductivity by increasing the surface area within the pipe for more heat-exchange, but at the cost of restricting flow. And do the same to the outside (flanges), although I'm not sure it'd help so much.

    The other option would be to add something colder to the air. Either an aerosol of some liquid which could evaporate - there are alternatives to water. Or you could inject another gas. air even, from a canister of compressed gas, thus cooling on expansion. CO2 and N2O get even colder on expansion. Of course, I don't know if you need the air to be pure air or not.
     
  4. May 6, 2010 #3
    Alex

    Thanks for the information. And maybe i didn't give out enough information about this. So i'm going to give you as much information as i possibly can here to help out.

    This pipe i'm talking about is between a turbo, and intake manifold on a diesel engine. The air is being compressed by the turbo to around 50-60 psi, and it's flowing around 1800 cfm. We also inject water into this pipe to help cool the engine, so our cylinder temps don't get to hot and burn down the aluminum pistons.

    Here's where i'm stumped... Recently there was a discovery of someone using ethyl glycol mixed with the water, and it was adding horsepower to engines by doing it. But we "supposedly" have our water tested to make sure it's pure water. They do this by specific gravity, and now using a "freeze" test. Since ethyl glycol won't freeze. Well, they started to figure it out after water samples won't freeze. Also they used some sort of other chemical or "masking agent" to make the water still have the same specific gravity as water normally would. Because adding the ethyl glycol would throw the specific gravity off.

    What i would like to know, is there any other way you could possibly add something to the water, or to the air that could make it cold, or to maybe make up the same kinds of results the ethyl glycol does, without being able to be detected in the water samples.

    We are only allowed to use diesel fuel, as our engine fuel, and water, as a cooling agent in the air. But i know from being involved in this so long, that it's only a matter of time before someone experiments with something like this. And i guess i'm just looking to find something better. Because according to the sanctioning body of this motorsport, they claim to have a test to detect this. But i have yet to see it. So is there a way to detect it? or is there a way to get around it or fool it? Or a better chemical or composition to use, that would be no way detectible? Or a way to somehow add more oxygen to this water?

    like my name on here says.. i'm a dumdum.... trying to get smarter with the help of people who have probably forgotten more about chemicals, and atoms than i'll ever know! :)
     
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