Operational optimization of SWRO process with the consideration of load fluctuation and electricity price

摘要

In this work, the operational optimization of seawater reverse osmosis (SWRO) process is studied to reduce the energy cost. Effects of load fluctuation and electricity price change were considered, and storage tanks were used to adjust the water production and balance the freshwater demand. Based on comprehensive first-principles, a detailed and accurate mathematical model with spiral-wound membranes, water storage tanks and water demands is developed and validated by plant data and the ROSA9.0 simulation package. The operational optimization problem with the form of DAEs was solved with simultaneous approach and IPOPT solver. Computing results of real SWRO plant were then investigated. It is shown that, compared with conventional operation and operation with constant water level, about 27.88% and 24.17%of energy cost, respectively, can be saved by optimizing both feed flowrate and feed pressure within normal range. Optimal profiles of key performance states were analyzed and future work for operational cost saving are described.