循环冷却水系统是石化行业重要的公用工程,其用水量占工业用水量的80%左右,是石油化工领域用水量最大的系统。循环水系统节水状况的好坏,将严重影响整个工业水系统的节水程度。针对炼油企业循环水系统能耗大、运行不经济等实际问题,分析了炼油企业循环水用水网络优化的影响因素,根据循环冷却水系统的超结构建模原理,以循环水用量最小为目标,综合考虑水流量平衡、热量平衡、水冷器进出口温度、水冷器温差、整数变量、现场实际条件等因素,建立循环水用水网络优化的数学模型,并采用优化建模工具Lingo建模求解,以获得循环水量最小、网络结构简单的循环水用水网络。以某炼油企业蜡油加氢装置循环水系统为实例,验证模型的可靠性。分析结果表明,优化模型充分考虑了蜡油加氢装置循环水用水网络的特点,获得了循环水用量最少且网络结构简单的循环水用水网络,有效降低了循环水系统的运行成本。优化前后该装置各水冷器用水量对比显示,循环水系统优化后,每小时节约循环水152.09t,占现行冷却水总量的40.9%,按循环水价格0.3元/t计算,每年节约水费39.97万元。 Circulating cooling water system is an important public utility in the petrochemical industry. Its water consumption accounts for about 80% of the industrial water consumption, and is the system with the largest water consumption in the petrochemical industry. Circulating water system, water quality is good or bad, will seriously affect the water level of the entire industrial water system. Aiming at the practical problems such as large energy consumption and uneconomical operation of circulating water system in oil refining enterprises, the influencing factors of circulating water network optimization in oil refining enterprises are analyzed. According to the principle of superstructure modeling of circulating cooling water system, Considering the factors such as water flow balance, heat balance, inlet and outlet temperature of water cooler, temperature difference of water cooler, integer variables and actual field conditions, the optimization mathematical model of circulating water network is established and solved by Lingo modeling, Access to the smallest amount of circulating water, the network structure of simple recycled water network. The recycle water system of wax refinery hydrogenation unit was taken as an example to verify the reliability of the model. The analysis results show that the optimization model fully considers the characteristics of recirculating water network of the wax hydrotreating unit and obtains the recirculating water network with the least amount of recirculating water and simple network structure, which effectively reduces the running cost of the recirculating water system. The comparison of the water consumption of each water cooler before and after the optimization shows that after the optimization of the circulating water system, the circulating water is saved by 152.09t per hour, accounting for 40.9% of the total amount of the current cooling water. According to the circulating water price of 0.3 yuan / t, the annual water saving 399,700 yuan.