Study Of Safety Analysis And Risk Assessment In Industrial Circulating Cooling Water Treatment System

With the safety accidents growing,our safety awareness is gradually strengthened.In industrial circulating cooling water treatment system,corrosion?scaling and microbial breeding are major obstacles to operation.The circulation water supply system is the most basic unit of the cold source,is essential to ensure the normal operation of other systems,although there is no dangerous medium in the device,the water quality is an important factor to the safe operation of the system.The corrosion and scaling of the system is closely related to the water quality.According to the statistics,more than 90%of the heat exchangers are corroded.Therefore,we need to adopt the idea of safety system engineering to make a comprehensive analysis and risk assessment of the hidden dangers of recirculating cooling water treatment system.In this paper,the risk assessment of recirculating cooling water treatment is studied by intrinsically safe design(ISD)and layers protection analysis(LOPA).(1)Corrosion risk analysis of circulating cooling water treatment systemThe paper selects 3 circulating cooling water system in use from 2016-2017 to track water quality analysis.It is found that the water quality indexes of the circulating cooling water in the A factory are all in accordance with the national standard.The water quality of the circulating cooling water in B and C factories is exceeding the standard,the stable operation of the system may exist in the hidden danger.Using A3 steel as experimental samples with electrochemical test and weight loss method to research the influence of corrosion factor(pH and concentration)on the circulating cooling water system,it is found that the lower pH,the higher concentration multiplier,the stronger the corrosion tendency of A3 carbon steel in the cooling water,and the greater the number of corrosion rate.(2)Essential safety analysis of circulating cooling water treatment systemFrom the perspective of intrinsically safe design,the risks in two aspects of water quality and water treatment process are analyzed.The fuzzy comprehensive evaluation method is used to evaluate the water quality risk.The evaluation results show that the grade of the water quality risk of the circulating cooling water in B factory is "moderate risk",and the risk grade of the circulating cooling water in C factory is "safe".The risk factors are identified,and the factors affecting the system security risk are analyzed,and the essential safety evaluation index system suitable for the circulating cooling water system is established.Through the analysis,8 risk scenarios,such as water quality,pressure,temperature difference and flow rate,are found.(3)Risk assessment of circulating cooling water treatment system based on LOPA methodHAZOP analysis is a widely applied risk assessment method.It can identify risk and maneuverability qualitatively,but this method has some limitations on quantifying the problem.Therefore,based on the HAZOP analysis,the LOPA method is applied to conduct quantitative risk assessment with combined protective layer of the circulating cooling water treatment system,to establish a risk assessment system applicable to the circulating cooling water treatment system.In this paper,"circulating cooling water pH is too low" is selected as the research scene.By increasing the protection layer,the risk level of the accident scene is reduced from high risk to low risk,which shows that this method is suitable for circulating cooling water system.