多周期石化企业水系统平衡模型与评价

Multi-period water system balance model for petrochemical enterprises and its evaluation

石化企业用水量和废水排放量巨大,因而节水减排至关重要。企业的水平衡测试是节水减排的工作基础,因此其研究意义重大。本文研究了石化企业水系统网络,基于水平衡测试的数据,建立水系统平衡模型,并进行单周期/多周期的水系统平衡计算和用水指标评价。以某大型石油炼化企业的用水系统作为案例分析,结果表明该企业加工吨原油取水量基本达到了节水型企业的标准,但各周期变化较大,水重复利用率较高,各个周期都在97.5%以上。随着水重复利用率的增加,加工吨原油取水量吨油耗水量明显降低。此外,废水回用率较低,基本在35%左右,尚未达到节水型企业的要求。

With the considerable huge amount of freshwater and discharged wastewater in petrochemical complexes, water conservation and wastewater minimization has been indispensable. Water balance test of an enterprise is the basis of water conservation and waste- water minimization, which plays a significant role in the research. On the basis of data of water balance test, the water system balance model is constructed, and the single/multiple period water system balance and the water usage index evaluation are performed. The wa- ter system of a petrochemical complex is taken as case study, the results show that flowrate of the quantity of water intake per ton crude oil in each period varies dramatically. Although it reaches the requirement of the water-saving enterprise standard, it has certain gap compared with international advanced level. Water reuse rate is high in each period at approximately 97.5%. In the meantime, the higher water reuse rate is, the lower the quantity of water intake per ton crude oil will be. Moreover, reused wastewater ratio in each period is around 35%, which cannot reach requirement of the water-saving enterprise standard.