Performance Analysis And Safety Assessment Of The Hot-Wall Hydrogenation Reactor

Hydrogenation reaction chamber is essential and dangerous equipment in the petroleum refinement process. So it is always an important topic for specialists that how to guarantee the safe operation of hydrogenation reaction chamber. Base on the inspection and finite element analysis and according to the standard of BS7910 and GB/T 19624-2004("safety assessment on in-service hydrogenation reactor with flaw"), the safety analysis was carried out for the crack in the head and nozzle of hot-wall hydrogenation reactor which imported from Japan.The comprehensive analysises were made for the safety performance of the hot-wall hydrogenation reaction chamber which include wall-thickness measure, non-destructive inspection, metallographic examination, hardness measurement and analysis of chemical components. The inspecting results show that the safety condition of the hydrogenation reaction chamber is in the third grade through the ultrasonic examination completely.. There are four welded seam out of six which have the problem of inadequate penetration and the extreme depth is 3mm. The other inspection data are reasonable.Applied to three types of vessels connectted pipe which included two kinds of computation operating modes respctively, finite element method was used to calculated the stress concentration coefficient in high stress area and consequently provided the reference for security evaluates. Finite element analysis was carried out with ANSYS program on the non-flaw stress at angular weld of connectted pipe. The results indicate that the maximum stress exists in inner corner of main body axially, and its value is 318.5MPa which is 3.22 times of the average stress value. In the hydrostatic test, the stress which parallelled to the axis of connector in weld root is 52.7MPa, and this value would act as the stress of crack location in safety assessment.After safety evaluating the cracks in the head and nozzle of hot-wall hydrogenation reactor, the fracture mechanics assessment results show that the crack length is less than the critical length. Meanwhile, the extending life of fatigue crack was estimated and the residual life was calculated.The results show that the reactor can be used safely for more than 8 years in theory though there are cracks and troubles of security in practice.