Heat Transfer, look for a fluid mix calculation?

Question

I am looking for a way to calculate the temperature of a fluid (oil) when three different amounts are entering a vessel and at different temps and flowrates. I would like to know the temp of the mixture after the flows have combined. Does anyone have any ideas??

Answer 1

Calculate the enthalpy of the oil at a certain temperature. You have two choices, either you use the specific heat at constant pressure and for that temperature or you use a vapor chart for the oil you want to know.

Then you multiply the enthalpy per the mass flow like this

h1m1+h2m2+h3m3=htotal*total mass flow

you get the total mass flow buy adding

m1+m2+m3 = total mass flow

when you get the htotal, go back to the vapor chart and check what temperature the oil should have with that enthalpy or you can do it too with the Cp.

Hope this helps.