# Calculate refrigerant temp inside evaporator based on exit temp and pressure

1. ### bobboviking

6
Hi guys,

I'm stuck on some thermodynamic calculations and I would really appreciate some help!

I'm trying to calculate the refrigerant temperature inside of an evaporator (two-phase lumped parameter model) based on the exit temperature of the evaporator and the pressure.
I've understood that the refrigerant temperature in phase 1 (fluid) may be expressed as
Tr1 = T(Pe) (temperature as a function of evaporator pressure)

and the refrigerant temperature in phase 2 (vapor) may be expressed as
Tr2 = T(Pe,he2) (temperature as a function of evaporator pressure and enthalpy in the second region)

But I'm not quite getting how to do that after measuring the exit temperature and evaporator pressure (I'm assuming constant pressure in the evaporator). I've got a refrigerant table (see attachment) but I'm not sure how to use it.

I would really appreciate if you could point me in the correct direction!

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Last edited: Sep 12, 2011