ABSTRACT
Pinch Technology is one of the best methods for designing a multi stream heat exchanger [MSHE] through a network; current pinch-based methods, however, lead to a larger and more complicated design problems. The major drawback of the current methods is they result in designs having more individual MSHE sections than essential, correspond to the enthalpy intervals on temperature vs. enthalpy diagrams or composite curves. In this paper, a new conceptual procedure for optimizing the entrance and exit points of each stream of a MSHE is proposed minimizing the number of sections required for a given duty. Moreover, Genetic algorithm [GA] is used to find the suitable fin type for making the heat exchanger dimensions consistent with manufacturing needs and the fully utilization of allowable pressure drops. Having applied the new design procedure in two industrial case studies, the results showed 11% and 7% cost reductions compared to the current method, respectively
ABSTRACT
Recirculating cooling water systems are consist of a cooling tower and heat-exchanger network which conventionally have a parallel configuration. However, reuse of water between different cooling duties enables cooling water networks to be designed with series arrangements. This will results in performance improvement and increased cooling tower capacity. Research on recirculating cooling water systems has mostly focused on the individual components. However, a particular design method represented by Kim and Smith accounts for the whole system interactions. In this study, the Kim and Smith design method is expanded and a comprehensive simulation model of recirculating cooling system was developed to account for the interaction between the cooling tower performance and the heat-exchanger network configuration. Regarding this model and considering cycle water quality through introducing ozone treatment technology, a modern methodology of recirculating cooling water system design was established and developed. This technique, called the integrated ozone treatment cooling system design, is a superior designed tool based on pinch analysis and mathematical programing. It also ensures maximum water and energy conservation, minimum cost and environmental impacts. Related coding in MATLAB version 7.3 was used for the illustrative example to get optimal values in cooling water design method computations. The result of the recently introduced design methodology was compared with the Kim and Smith design method