Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How much reduction in temperature can be achieved?

  1. Sep 28, 2016 #1
    I want put here an imaginary, but close to reality scenario. We have 3 MW power plant here having 1800 kg/hr or 0.5 kg/sec steam flow and the exhaust will be steam at 1 bara pressure and 100C temperature. If a cooling system of 2000 ton capacity is fitted to the Condenser, how much it can reduce the temperature in the Condenser?
  2. jcsd
  3. Sep 29, 2016 #2


    User Avatar
    Science Advisor

    It's not really close to reality, you'll end up with a lot of very very cold ice.
    2000 cooling tons is about 7 MW - a lot of cooling power.
  4. Sep 29, 2016 #3
    2000 ton of ice means extracting 2000X80X1000 kCal 16 million kCal of heat in a single day. In fact, I want to mean the cooler can convert 2000 kg or 2 ton of water to ice every hour and that means 48 tons of refrigeration. That by my calculations, it will take around 250 kW. Sorry for the mistake!
    Last edited: Sep 29, 2016
  5. Sep 29, 2016 #4


    User Avatar
    Science Advisor

  6. Sep 29, 2016 #5


    User Avatar
    Science Advisor
    Gold Member

    This is the kind of problem worked through by someone who's taken a college-level course in Thermodynamics. Based on your interests over the past weeks, have you considered taking a course and/or purchasing a text book to increase your knowledge in this area?
  7. Sep 29, 2016 #6
    I wouldn't mean that this system will just remove 250 kW of heat from the steam, but rather to get this 48 ton of refrigeration, the power consumption would be 250 kW.
  8. Sep 29, 2016 #7


    User Avatar
    Science Advisor

    48 tons of cooling is only 170 kW.

    How much power your cooling system requires to achieve this cooling is irrelevant.

    It makes no sense to use a refrigeration cycle to condense steam at a power plant. We just dump the waste heat directly to the atmosphere, river or lake.

    I second mech engineer's suggestion, I'd recommend Thermodynamics by Cengal and Heat and Mass Transfer, also by Cengal.
    Or at least start by reading this:
  9. Sep 29, 2016 #8
    The purpose of this process is to lower the temperature of the Condenser so that efficiency and output can be increased.
  10. Sep 29, 2016 #9


    User Avatar
    Science Advisor

    If it worked we'd already be doing it.
  11. Sep 29, 2016 #10
    That can be said about any new innovative idea.
  12. Sep 29, 2016 #11


    User Avatar

    Staff: Mentor

    The condenser uses a process (probably either direct air or water to air heat exchanger) that requires less input power than a mechanical chiller, so adding a mechanical chiller would reduce the efficiency and output, not increase it.

    It is nice that you are trying to think of ways to make existing systems more efficient, but I agree that it would be better if you started by learning how they work by taking a thermodynamics class. It will save you a lot of wasted effort.
    That's true, but unfortunately you don't have any way to know if your ideas are new, innovative or even functional. Most are just wrong. People don't like hearing this, but it is the truth: new/innovative ideas almost never come from people who don't understand the subject they are investigating. So please do yourself and us a favor and make your time more productive by starting with more rigorous study of thermodynamics instead of continuing with all of this pointless idle speculation.

    Thread locked.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook