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Thermodynamics example in industry

  1. Nov 4, 2012 #1
    In thermodynamics, can give any example in industry that is involving the first law ,second law ,entropy ,third law ,compressibility,expansibility,I just want to know what is the point for me to study them~~~~
    One complicated example will do , thank you
    Last edited by a moderator: Feb 6, 2013
  2. jcsd
  3. Nov 4, 2012 #2


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    Staff Emeritus
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    Re: Thermodynamics

    Any heat engine?
  4. Nov 4, 2012 #3


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    Staff: Mentor

    Re: Thermodynamics

    Oy. For (presumably) an engineering student to be asking 'why do I have to study thermodynamics' is just....wow.
  5. Nov 5, 2012 #4
    Re: Thermodynamics

    The thermodynamic I have studied involve too many mathematics I really don't want to memorize, I totally don't know what is the point for me to do so, it makes me lost interest to study it without any reason, like why is it define the coefficient of expansibility =(1/V)(dv/dt)?, why do I need to study Cp-Cm for real gas?,how increasing entropy in universe will affect us? ...I have studied how refrigerator work and carnot engine which do not relate to the things I have mentioned.
    I just need an example of practised machine that involve all the things in thermodyna just , An example will do,I will find answer on my own.
    Thank you
  6. Nov 5, 2012 #5


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    Re: Thermodynamics

    I don't understand your question really. I mean, I do understand the question, but not the motive behind it. You want an example of a single machine that uses all the laws of thermodynamics so that you can understand why you need to learn thermodynamics? Dude, name practically any machine and you'll find thermodynamics in use. You may not find every single law and whatnot in every single machine, but so what?
  7. Nov 5, 2012 #6


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    Re: Thermodynamics

    The only question is why you study at all if it doesn't interest you.
  8. Nov 6, 2012 #7
    Re: Thermodynamics

    A chemical plant has chemical reactors, compressors, heat exchangers, distillation columns, cooling towers, evaporators, absorption columns, ion exchange columns, etc. Engineers need to use thermodynamics to design and improve all these operations and equipment.

    An automobile has heat exchangers (in the coolant system), chemical reaction and compression within the cylinders, gas dynamics in the intake and exhaust manifolds, fluid mechanics and heat transfer in the lubrication system, redox chemical reactions and equilibria in the battery, conversion of mechanical energy to electrical energy in the generator, etc., etc.

    These are only two examples. Watch the Science Channel program How Do They Make It? and see how many operations in industrial processes required understanding of Thermo for their design and operation.
  9. Nov 6, 2012 #8
    Re: Thermodynamics


  10. Nov 6, 2012 #9
    Re: Thermodynamics

    Internal combustion engine.
    Jet engine.
    Rocket engine.
    Air Conditioner.
    Nuclear power plant.
    Steam engine.

    I find thermo dynamics a bit challenging myself. It's not so much the math as the chicken and the egg thing. There are things that I have to, more or less, take on faith. For example, I believe that heat can't fow "uphill", but I can't prove it.

    The math can be a bit tricky. A good reason to learn the math is that you will strengthen your skills with partial derivatives. Something you will need in abundance.

    These might be helpful to you:

  11. Nov 7, 2012 #10
    Re: Thermodynamics

    Sorry about the mangled URLs. I couldn't get back to the site in time to fix them.

    I have to retract what I said about not finding the math difficult. I'm reading Feynman's chapters on thermodynamics, and it's not as easy as I remembered it to be. What makes it difficult is that there are multiple, interacting parameters.

    The problem of the chicken and the egg is there as well. Trying to keep the axioms and conclusions straight is a challenge at times.

    Here's an example of where thermodynamics can be applied to engineering. How much heat would be needed to cause the beams in WTC7 to "walk off" their supports and lead to the global collaps of the building?
  12. Nov 15, 2012 #11
    Re: Thermodynamics

    Thank everyone for help, although there are a lot of things you guys mentioned that I don't really understand ,I find thermodynamics more and more interesting.
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