Steady state simulation for the de-bottlenecking of heat recovery networks

This work presents the use of a steady state simulator for the de-bottlenecking of heat recovery networks. It is shown how a heat exchanger network designed for fixed conditions can be de-bottlenecked when process streams undergo changes in operating conditions such as flow rate and supply temperature. A network is said to be flexible if it is capable of maintaining acceptable operation either during normal or under modified conditions. The de-bottlenecking of heat recovery networks can be considered as a special case of the design for improved flexibility. A simulation model for a single phase network of heat exchangers is presented. The model is based on the use of the thermal effectiveness (ε) parameter for heat exchangers. Any type of exchanger configuration and flow arrangement can be modeled by using the appropriate ε–number of transfer units relationships. A general methodology for improving network flexibility is proposed.