Heat Exchanger by F.D. Drake, 1988

      An energy balance combined with steam property calculations serves to
determine the flow rate of fluid 1 to achieve a desired cooling or heating 
effect on fluid 2.  Fluid 1 can be water with or without phase change
or any other fluid without phase change.  The properties of fluid 2 can also
be specified by the user.  The mass flow rate of fluid 1 is calculated by:
  .   .
  m = Q/(h    - h     ) 
   1      1,in   1,out
  .   .
  Q = m (h     - h    )
       2  2,out   2,in

     All inlet and outlet states and the mass flow rate of fluid 2 have to
be specified.

"Evaluating Cogeneration Options for a Campus Heating and Cooling Plant"
Drake F.D.  M.S. Thesis 1988