1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculating Rate of Heat Transfer for Refrigerator Evaporators

  1. Aug 25, 2013 #1
    Dear all,

    I am a bit stuck trying to find out how heat is transfered through an evaporator in a refrigerator. I was using Newton's law of cooling before I realised there are more complexities in the equation as the refrigerant is in a mixture of saturated liquid and saturated gas in the evaporator.

    Newton's Law of cooling (heat transfer from a solid surface to a fluid):

    QL=UL*AL*LMTD
    where
    QL= heat transfer
    UL= overal heat transfer coefficient
    AL= external surface area of the evaporator
    LMTD= log mean temp different over the evaporator tube. i.e. The average temperature difference between the solid surface and the fluid (air in this case) across the evaporator inlet and outlet.

    My Question

    Is Newton's Law of cooling applied to refrigerator evaporators and/or condensers with this equation, for a simplified calculation? Or would the results be so far from correct that calculations must always take into consideration the boiling and condensing of the refrigerant?
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: Calculating Rate of Heat Transfer for Refrigerator Evaporators
Loading...