It is known that the directly affects the amount of services of external heating and cooling. In this sense, you are requested to economically and environmentally evaluate the integration considering a value equal to 10 C. Determine the following: a) Minimum amount of external cooling and heating services for the option of correspondent b) Heat exchange network for the value of c) Diagram of the feasible exchangers indicating the inlet and outlet temperatures for the currents of each proposed heat exchanger.

\begin{tabular}{cccc} Corriente & Tentrada (C) & Tsalida (C) & FCp(kcal/hrC) \\ \hline 1 & 120 & 50 & 6 \\ 2 & 100 & 20 & 9 \\ 3 & 20 & 150 & 12 \\ 4 & 20 & 90 & 10 \end{tabular}