Research On Safety Analysis Of In-Service Hydrogen Absorber

Hydrogen absorber is a typical pressure vessel under fatigue load, using in oil refining, chemical industry, metallurgy and other fields. For bearing complex loads and adsorption medium which is inflammable and explosive easily, Hydrogen absorber is dangerous and fatigable due to the high frequency of accidents. Based on high requirement for research on reliability, safety and fatigue life of hydrogen absorber, this paper mainly studies10sets hydrogen absorbers using in the process of hydrogen production for PSA device. Considering10years has been used already, and cycle number has approached its design life (3×105cycle), theory stress analysis, the actual stress measurement, safety assessment and fatigue life estimation were carried out on in-service hydrogen absorber, the dangerous areas were obtained, it’s important to prolong service life, cut down operation cost, increase the economic benefit and prevent safety accidents.The numerical simulations on hydrogen absorber using ANSYS software were completed in this paper. The larger stress areas were found distributed in the take over zone, transition zone and the lower skirt over zone. The dangerous section of hydrogen absorber located under the inner corner of the nozzle and the head of the transition according to the actual stress level measurement and verification by pasting the strain gauge in the hydrogen absorber. And the safety assessment and fatigue life of in-service hydrogen absorber were estimated. Given the fatigue strength condition, the hydrogen absorber can satisfy the6×105cycle index which means the device can continue to use10years. Meanwhile, this paper analyzes how the surface cracks infect the fatigue life of hydrogen absorber, assume there was a2mm deep,8mm long semi-elliptic surface crack in the inner corner section of nozzle and head transition of the in-service hydrogen absorber, the calculation of fatigue assessment containing crack condition was executed to discover the research result that hydrogen absorber would fail after4.5years according to GB/T19624-2004. Therefore general inspection every four years was conducted to ensure the safe operation of the equipment.