耦合化工过程的废热回收废水脱盐系统的优化

Optimization of waste heat-driven wastewater desalination process in chemical process

为了解决化工过程余热回收和废水反渗透脱盐的问题,提出深度耦合于背景过程的废热回收驱动的废水脱盐系统。利用Duran-Grossmann模型、Peng-Robinson状态方程和质量传递-扩散方程对耦合系统的有机朗肯循环(ORC)驱动的废水反渗透脱盐(RO)单元进行建模,考察废水进料温度的不确定性对系统最优操作参数的影响。研究结果表明,提出的设计方案能够有效地节省费用和回收废热,在年最低气温、年平均气温、年最高气温3种工况下的单位产水成本分别可降低至0.191、0.129和0.135$×m-3。与同等规模的反渗透装置的单位产水成本(0.3~0.4$×m-3)相比,具有较好的经济性和抵御环境参数不确定性的能力。

A waste heat driven wastewater desalination system with process heat integration was proposed to enhance the waste heat recovery and wastewater desalination in chemical process.Duran-Grossmann model,Peng-Robinson equation of state and mass transfer diffusion equation were applied to develop the model of wastewater reverse osmosis(RO)desalination unit driven by organic Rankine cycle(ORC)in the process.The effect of the uncertainty of wastewater feed temperature on the operating parameters of the integrated process was investigated.The results of an industrial case show that the integrated system can effectively recover waste heat and reduce desalination cost.The optimal unit product costs(UPC)are 0.191,0.129 and 0.135$×m-3 under the coldest temperature,average temperature and hottest temperature,respectively.Compared with industrial RO with UPCs of 0.3 to 0.4$×m-3,the integrated process has better economy and ability to resist the uncertainty of whether conditions.