Consider a simple double-pipe heat exchanger where a liquid stream is being heated by condensing leaves (z L) at TL(L. t). Heat transfer takes place between the steam (TS and the wa (T nd then is a "lumped" variable, Ts.
a) Develop a mathematical model to determine the dynamics of wall temperature Tw as function of time.
b) Develop a mathematical model to determine the dynamics temperature TL of Liquid.