Method for designing recycle hydrogen heating furnace gas pressure safe instrument system

Abstract

The invention discloses a design method of a gas pressure safety instrumented system used in a circulating hydrogen heating furnace. The design method comprises the following steps: analyzing functions of the safety instrumented system based on a risk matrix to determine a required safety integrity SIL level; computing the SIL levels of an original system (1001) and a system (1002) which is provided with a redundancy unit by a Markov modeling method; and verifying whether the improved system reaches the required SIL level. The safety instrumented system has the following advantages that: 1) the SIL level required by the system is determined according to the risk matrix, and taken as the basis for improving the system, which has good generality, visual and understandable property, and facilitates document establishment and routine maintenance; 2) the SIL levels of the original system and the system which is provided with the redundancy unit are computed by a Markov model, which can reflect a static relation among the devices and dynamic changes of the system, and has high-precision quantitative analysis of reliability; and 3) the SIL level of the system is computed by the Markov modeling method, which is not affected by a dependency relationship among the devices, wherein, the model can comprise a plurality of failure modes of the devices, and a plurality of reliability indexes such as PFS, MTTFS, PFD and MTTFD can be obtained by a single modeling.

Description

technical field [0001] The invention relates to a design method of a gas pressure safety instrument system of a circulating hydrogen heating furnace, in particular to an analysis and design method of a safety integrity level based on risk matrix and Markov modeling. Background technique [0002] Hydrocracking in the petrochemical industry is one of the main processes for the deep processing of heavy distillate oil, and an important means for mass production of high-quality middle distillate oil and adjustment of oil product structure. The hydrocracking unit uses vacuum gas oil as raw material to produce various high-quality products such as light naphtha and jet fuel through hydrodesulfurization, dehydrogenation, olefin saturation and hydrocracking reactions. The device is installed in some key parts: such as the new hydrogen compressor, circulating hydrogen heating furnace, high-pressure feed pump, cold high-pressure separator and other parts are equipped with a safety inst...

AI Technical Summary

Problems solved by technology

At present, most domestic software in this area adopts fault tree modeling, and the development is not very mature.

The disadvantage of the fault tree modeling is that the reliability quantitative analysis accuracy is not high; only one reliability index can be obtained in one modeling, and the flexibility is not enough; it cannot reflect a series of dynamic changes of the system from startup to failure to normal operation

The discrete-time Markov model is easy to calculate by computer; the continuous-time Markov model is difficult to solve the state transition matrix in a multi-state complex system

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