压缩空气储能驱动反渗透海水淡化系统

A compressed air energy storage system driving reverse osmosis desalination system

为解决传统反渗透海水淡化系统高能耗、高成本等问题,利用压缩空气储能系统对电力资源削峰填谷的作用并依据其能量输出特点,进行能量配比分析,提出了绝热压缩空气储能与反渗透海水淡化集成系统新构型。建立了系统各部件的数学模型,以20 s为时间步长,对系统的不同设计工况进行了动态模拟,并采用经典龙格库塔算法进行求解,分析了储罐充能释能结束压力和季节变化对系统性能的影响,最后对系统部件的投资成本进行估算,获得了系统在不同设计工况点的淡水生产成本。结果表明,在所有的模拟工况点中,储罐释能结束压力在3~7 MPa内变化时,无论储罐充能结束压力在8~12 MPa内取何值,释能结束压力均存在最优值5 MPa,使系统淡水生产比能耗最低;相比于冬季低温环境,夏季高温环境淡水的生产比能耗能减少约30%;在所有的模拟工况点中,当充能结束压力为12 MPa,释能结束压力为5 MPa时,系统淡水生产成本最低,为1.72$/m^(3)。与传统反渗透海水淡化系统相比,本储能驱动的淡水生产成本最大能够降低4.4%,具有更好的经济效益。本研究有助于推动绝热压缩空气储能系统在反渗透海水淡化领域的应用,并为工厂的投资建设提供理论依据。

To solve the problems of high-energy consumption and the high cost of traditional reverse osmosis(RO)desalination systems,an innovative hybrid adiabatic compressed air energy storage system(ACAES)and RO desalination was proposed.The system was based on the improvement of adiabatic compressed air energy storage on the fluctuation of grid load and its output characteristics.The mathematical model of each part of the hybrid system was established,and the dynamic simulation of the system under different design conditions was carried out using 20 s time steps.The classic Runge-Kutta algorithm was used to solve the problem.Then,the effect of the storage pressure range and seasonal variation on the system's performance was analyzed.Meanwhile,the investment cost was estimated,and the economy of the hybrid system was evaluated under different design conditions.The results showed that,in all of the simulated working conditions,when the end pressure of discharge(EPD)changed within 3~7 MPa,regardless of whether the end pressure of charge(EPC)was within 8~12 MPa,the optimal value of the EPD was 5 MPa;this rendered the specific energy consumption(SEC)of freshwater production by the system the lowest.SEC in high summer temperatures could be reduced by approximately 30%compared to low temperatures in winter.In all simulated working conditions,when the EPC was 12 MPa and the EPD was 5 MPa,the SEC had a minimum value of 1.72 USD/m^(3).Compared with a traditional RO desalination system,the unit price for producing freshwater using this hybrid system could be reduced by a maximum of 4.4%,thereby achieving better economic performance.This study helps promote the application of A-CAES in the field of RO desalination and provides a theoretical basis for the construction of such a power plant.