Operational Optimization of Large-Scale Parallel-Unit SWRO Desalination Plant Using Differential Evolution Algorithm

Jian Wang,Aipeng Jiang,Shu Jiangzhou,Xiaolong Wang,Ping Li

doi:10.1155/2014/584068

Jian Wang, Aipeng Jiang + Show 3 more

Open Access

https://doi.org/10.1155/2014/584068

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Abstract

A large-scale parallel-unit seawater reverse osmosis desalination plant contains many reverse osmosis (RO) units. If the operating conditions change, these RO units will not work at the optimal design points which are computed before the plant is built. The operational optimization problem (OOP) of the plant is to find out a scheduling of operation to minimize the total running cost when the change happens. In this paper, the OOP is modelled as a mixed-integer nonlinear programming problem. A two-stage differential evolution algorithm is proposed to solve this OOP. Experimental results show that the proposed method is satisfactory in solution quality.

Highlights

The shortage of fresh water has become a bottleneck of the economic development in many countries
A kind of large-scale parallel-unit seawater reverse osmosis (SWRO) desalination plant, which is composed of multiple parallel Reverse osmosis (RO) units, has appeared
The RO units are still opening at these time periods, so that the total running cost (TRC) under manual operation cannot get its optimal value; (3) the optimal operation takes full use of its advantage in global optimization, so at times 8, 13, and 18, the sum of generated freshwater reaches its local peaks before the time-of-use electricity price gets higher

Summary

Introduction

The shortage of fresh water has become a bottleneck of the economic development in many countries. A kind of large-scale parallel-unit SWRO desalination plant, which is composed of multiple parallel RO units, has appeared. This kind of plant has huger capital cost and more complicated operation processes. Before it is built, an optimal design is made to select the suitable devices and system performance to match the operating condition [4,5,6,7,8]. A mathematical model of operational optimization problem (OOP) for a large-scale parallel-unit SWRO desalination plant, which includes objective function and constraint functions, is made. The simulating results show that the TSDE is excellent in searching ability than basic DE and genetic algorithm (GA)

Problem Description and Formulation

Two-Stage Differential Evolution

Experimentation

Comparative Study

Findings

Conclusions