How can I bridge thermodynamics theory to practical heat exchanger design?

[BrianS]

I'm a mechanical engineering student struggling to conceptually bridge the gap between the theoretical laws of thermodynamics and their practical application in designing a simple heat exchanger for a class project. I understand the equations for entropy and enthalpy on paper, but visualizing the real-world energy transfers and inefficiencies is challenging. For engineers who use these principles daily, what mental models or analogies helped you develop an intuitive grasp of thermodynamic systems, beyond just solving textbook problems?