Research On Water System Optimization Design And Algorithm Simulation In Petrochemical Enterprises

With the increasingly serious pollution of water resources,the global freshwater resources are increasingly scarce,and the problem of water waste is becoming more and more prominent.All industries in the world are facing water problems,and China is no exception.China’s industrial water consumption accounts for a high proportion in the total water consumption of the country,and in the industrial water,the water consumption of the refining and chemical industry is relatively large,and the water reuse is relatively small.Compared with the developed countries,there is still a large gap of the level of water saving and emission reduction.In this society of conservation,how to save water and reduce waste water emissions in the refining and chemical industry has become the main research direction.Therefore,adopting appropriate technologies or methods to optimize the water system of refining and chemical companies are important for improving the water-saving capacity and sustainable development of refining and chemical companies.This topic was carried by combining theory,field investigation and mathematical simulation.Firstly,to understand the laws and regulations,management systems,water-saving measures and technologies,relevant standards and norms related to joint water by consulting a large number of documents,and a relatively complete use evaluation index system of a refinery and chemical company was established;Secondly,took a refinery and chemical company as an example to comprehensively sort out its drainage situation,and analyzed the water level and water saving potential of the refinery through a water balance test;Then,the water pinch technology was used to determine the location of fresh water pinch by concentration combination curve and concentration interval chart,and the minimum amount of fresh water was obtained.At the same time,the grid graph in the concentration interval design method was used to design an initial water consumption that can achieve the minimum fresh water consumption and the minimum wastewater discharge Network block diagram,the optimized water network diagram was obtained by disconnecting the circuit;Finally,the Python language programming was combined with the Excel file,and the optimization algorithm process was simulated and applied to the refinery and chemical enterprise to obtain certain results.Firstly,a large fuel-chemical refinery company was selected to sort out its drainage situation,and after passing the water balance test,the company’s entire plant water balance diagram was drawn.It was calculated that the company’s fresh water flow was 2663.80t/h,and the desalinated water flow was 1027.52t/h,the flow rate of softened water was 89.60t/h,the flow rate of purified water was142.13t/h,and the amount of wastewater generated was1648.93t/h;Then the water use evaluation indicators of the refinery and chemical enterprises were calculated,and compare them with the national regulations.Comparing the standard values of water-saving enterprises,it was concluded that the comprehensive leakage rate of fresh water pipe network of 7.39%(≤7.0%)and the reuse rate of purified water of 46.58%(≥60%)and the waste water reuse rate of 48.25%(≥50%)were lower than the national water-saving enterprise standard.Then 5 typical water operation units were selected to optimize the water pinch point technology,use the concentration combination curve and the concentration interval chart to obtain the pinch point A(4.8,50)of fresh water,and further calculate the minimum flow of fresh water,the result was 96.0 t/h,which was less than the206.0t/h required when there was no water reuse,so it can be concluded that the fresh water flow after the water pinch technology was optimized which was reduced by 53.40%;At the same time,based on the above research,according to the determined concentration combination curve and the fresh water pinch point position,an optimized water network diagram with 5 water operation units was designed;Finally,the optimization process was simulated by using Python language algorithm programming combined with Excel files,and the fresh water pinch point concentration was 50 ppm,the minimum flow of fresh water was95.2t/h,which is basically consistent with result obtained by the above method(96.0t/h),and its relative error was about 0.83%,which simplifies the entire data calculation and processing process and improves work efficiency.