Study On Energy Saving Optimization Of Circulating Water System In Petrochemical Enterprises

In the petrochemical industry,circulating water system is an important public engineering system,and it is also a public system with high energy consumption.The energy and water consumption of the circulating water plant in the refinery are very large,which has great energy saving potential.Therefore,it is of great significance to improve the utilization efficiency of circulating water system for improving the economic benefits of petrochemical refineries.There is a large amount of low-temperature heat to be cooled in the process of petrochemical enterprises.Circulating water cooling is the most important cooling mode in petrochemical enterprises.The circulating water system is the auxiliary system with the largest energy consumption in petrochemical enterprises.The circulating water circulating capacity of the whole refinery can reach 50000 t / h and the annual power consumption is nearly 100 million kwh.In view of the low efficiency of the circulating water system in the petrochemical refinery,which results in the sky high water consumption and power consumption of the circulating water plant,this paper puts forward a series of measures for the energy-saving transformation of the circulating water system by optimizing the heat exchange network and power consumption equipment.First of all,the pinch technology is used to analyze the heat exchange logistics,the device is optimized and improved by using the "three link of energy use" model,and the unreasonable heat exchange network is simulated and optimized by using the process simulation software such as Aspen Plus and Pro II,so as to save a lot of circulating water while optimizing the heat exchange network.Secondly,the energy-saving purpose is achieved by optimizing the energy consumption equipment such as circulating water pump and cooling tower unit.The main results are as follows:(1)By optimizing the heat exchange network,5045 t / h of circulating water can be saved,and the water saving rate is 10.97% ?(2)The difference between the design condition and the actual condition results in the state of "using a steam-hammer to crack nuts".Therefore,the pump has a surplus flow of 1205 t / h in the design.By optimizing the circulating water pump,matching with the actual working condition can save 1.79 million kwh / year.(3)After the optimization of the heat exchange network of the water cooling process,the consumption of circulating water is reduced by 660 t / h,and the actual working condition of the circulating water pump is changed at the same time.Through the matching of the actual working condition,the optimization is achieved,and the power consumption is saved 0.882 million kwh / year.(4)9.728 million kwh/year of power consumption can be saved by optimizing the circulating water pump and cooling tower,power saving rate is 21.4%...