“DISEÑO ÓPTIMO DE REDES DE ENFRIAMIENTO”

Se presenta la formulación de un modelo MINLP para la optimización de redes de enfriamiento, cuya característica principal es que toma en consideración la optimización simultánea de los componentes de todo el sistema de agua de enfriamiento, a saber: la red de enfriadores, la torre de enfriamiento y el subsistema de bombeo. Como función objetivo se establece la minimización del costo total que resulta de la suma del costo de operación y de capital. El diseño de la red de enfriadores está basado en una superestructura que permite arreglos completamente en paralelo o en serie o una combinación de ambos, en tanto que el de la torre de enfriamiento se basa en el Método de Merkel y, en cuanto a la bomba, se utiliza un método corto para determinar su costo en función del flujo de agua a manejar. Las variables de optimización son: la temperatura de entrada (temperatura de salida de la red de enfriadores) y de salida de la torre de enfriamiento, la temperatura de salida del mezclador (temperatura de entrada a la red de enfriadores), la altura de la torre, la temperatura de salida del aire en la torre, la temperatura de salida del agua de enfriamiento en cada enfriador de la red, la temperatura de entrada a cada etapa en la red de enfriadores, la temperatura de salida de cada etapa en la red de enfriadores, la potencia de la bomba y del ventilador, así como el flujo de agua de enfriamiento y el área de cada uno de los enfriadores de la red

Optimal integration of organic Rankine cycle with industrial processes. Energy Convers

a b s t r a c t This paper presents a procedure for simultaneously handling the problem of optimal integration of regenerative organic Rankine cycles (ORCs) with overall processes. ORCs may allow the recovery of an important fraction of the low-temperature process excess heat (i.e., waste heat from industrial processes) in the form of mechanical energy. An integrated stagewise superstructure is proposed for representing the interconnections and interactions between the HEN and ORC for fixed data of process streams. Based on the integrated superstructure, the optimization problem is formulated as a mixed integer nonlinear programming problem to simultaneously account for the capital and operating costs including the revenue from the sale of the shaft power produced by the integrated system. The application of this method is illustrated with three example problems. Results show that the proposed procedure provides significantly better results than an earlier developed method for discovering optimal integrated systems using a sequential approach, due to the fact that it accounts simultaneously for the tradeoffs between the capital and operating costs as well as the sale of the produced energy. Also, the proposed method is an improvement over the previously reported methods for solving the synthesis problem of heat exchanger networks without the option of integration with an ORC (i.e., stand-alone heat exchanger networks)

Involving Acceptability in the Optimal Design of Total Integrated Residential Complexes Involving the Water-Energy-Waste Nexus

This work presents a multiobjective optimization model for the design of an integrated residential complex, which incorporates the proper use of available resources and wastes through recycling and reusing networks. The proposed model involves the proper use of water accounting for rainwater harvesting and the reuse of reclaimed water. The model also includes the design of a cogeneration system to satisfy electricity demands as well as hot water demands. The treatment of the produced solid waste is also incorporated through an incineration system, and an algae system is involved for sequestering the associated emissions. The proposed model aims to satisfy the energy, heat, and water demands and the treatment for the residues with the objective to minimize the associated cost and the associated emissions. Furthermore, the proposed model includes an objective function associated with the minimization of the damage to the health of the inhabitants

Optimal Design of Distributed Algae-Based Biorefineries Using CO₂ Emissions from Multiple Industrial Plants

This work proposes an optimization approach for capturing carbon dioxide from different industrial facilities to yield an algae-based biorefinery. The proposed approach is based on a distributed system to account for the economies of scale and includes site selection for the processing facilities. Additionally, the model considers optimization for the technologies used in the process stages and different technologies to yield several products. The algae oil that is obtained from each facility can be sent to processing hubs located in the same plant and/or to a central processing unit. The objective function is to minimize the total annual cost for the treatment of flue gases, including the capital and operating costs for the different processing stages and the overall transportation costs associated with the system minus the sales of products plus the tax credit for reducing CO₂ emissions. The results show several economic benefits