I'm performing a heat pinching analysis for the heat exchangers in my process flow diagram. Most of the streams are multicomponent. Hence I plan to use Hysys to obtain the Cp values by taking the average value between the inlet and outlet for each stream. However, I'm concerned about streams for which the Cp is sensitive to temperature change, or the temperature difference between inlet and outlet is huge such that the Cp value varies greatly. Would taking the average Cp value lead to a huge error for this case? Would it be better to divide the stream into segments of different Cp values, considering each one as a new stream?
So for example if "hot 1" has a variable Cp value for the link above, should I split it into "hot1a" and "hot1b" with their respective Cp values for the temperature ranges which "hot 1" was split into?