Degrees of freedom for Liquid to liquid heat exchanger

Degrees of freedom for Liquid to liquid heat exchanger

Degrees of freedom

The degrees of freedom of a process define the maximum number of independently acting automatic controllers that can be placed on a process 

Degrees of freedom = number of variables – number of equations

Liquid to liquid heat exchanger

In this case there are six process variables and one defining equation is 

[ CpF(Th1-Th2) = CpcFc(T2c-T1c)]

Six process variables are four temperature and and two flow variable 

hence the number of degrees of freedom of that process is five. 

Thus, a maximum of five automatic controllers can be placed on it.