Project link: SimScale Login
Can I know if this heat exchanger in this simulation is a qualified heat exchanger?
Because I saw the hot fluid is not cooled down.
If I may ask, what do you mean by “qualified heat exchanger”?
I mean the heat exchanger able to cool down the hot fluid.
Because only the temperature of cool fluid increase 32 °C. And the temperature of hot fluid only decrease 0.3 °C.
If this is unexpected, I would suggest double checking your boundary conditions.
You have approximately 200x more flow rate for the hot inlet when compared to the cold inlet at the moment 
Cheers