The Analysis And Calculation Of SIS Based On S-Zorb

The safety instrument system has become the key equipment of safe production,and the conventional equipment can reduce the occurrence probability of accidents through its safety instrument function.At present,security integrity level analysis has been a hot topic in the field of control research and industry.A availability evaluation method of system is proposed based on Markov model.The improved redundant structure grouping is proposed point at the increase of the complexity of the redundant structure of the SIS leads to the increase of the total failure probability.The safety and reliability analysis of the specific desulfurization device is carried out and the results are obtained.It is mainly studied from the following aspects:A system availability evaluation method is proposed,which is based on markov model in this paper.By differentiating the discrete markov model,we can obtain the change curve of the redundant structure and the test cycle and the availability.The operator can choose redundant structure accurately according to this method to determine the test cycle,so as to greatly reduce the equipment installation cost.This method solves the determination of the test cycle of the safety instrument system and the selection of redundant structure is only by the manual experience.Based on the algorithm proposed,the corresponding calculation software is developed,which can realize the calculation of the safety efficiency and the dangerous inefficiency.The increase of the complexity of the redundant structure of the security instrument system leads to the increase of the total failure probability,and the improved redundant structure grouping is proposed.Point at the disadvantages of the total failure correction factor,which increases with the increase of redundant structure,we improves the construction method of the SIS.Under the premise of valves in the system did not increase,modify the valve configuration mode,improve the way of build redundant,whcih can adopt the existingequipment so as to save the cost of equipment and material costs at the same time to eliminate the potential risk of the introduction of new instruments are introduced.According to the important SIF in the SIS of desulfurization device,the security reliability analysis is carried out,and the feasible rectification measures are put forward through the comparison between the actual SIL and the target SIL.The calculation results show that the huge influence of SIF on SIS is the sensor and actuator part,and the influence of logic control is small.If the equipment tend to improve the reliability of the SIS,it is necessary to attach importance to the reliability of the actuator part and take full consideration in the determination of the instrument valve and the function test cycle.The algorithm and structure of the paper are analyzed in the desulfurization device,and it works well.