Operational cost minimization in heat exchanger network under milk fouling

Milk pasteurization processes in dairy industries, carried out in heat exchanger network (HEN), undergo severe fouling because of the complex biological composition of milk. The formation of fouling gradually reduces the heat transfer capacity requiring to maintain the performance of a HEN by its periodic cleaning for fouling, which not only involves very high cleaning cost but also leads to production loss due to shutdown of the production process during cleaning. Hence, the HEN needs to be scheduled in a way to minimize the cleaning cost satisfying different process conditions as well as avoiding loss in the net production. In this work, the problem is formulated as a single-objective optimization problem for minimizing operational cost and then it is solved using a genetic algorithm. Further, along with the economic criteria, the effects of energy consumption and heating medium flow rate in the process are also discussed.