صلاحيت ادامه سرويس آسيب ترك HIC در مخزن تحت فشار

Fitness For Srevices of HIC crack damage in pressure vessel

صلاحيت ادامه سرويس (Fitness For Services ) براي اثبات يكپارچگي ساختاري يك تجهيز معيوب، در حال سرويس و يا بهره برداري در شرايط عملياتي كه ميتواند منجر به از كار افتادگي آن گردد، انجام مي‌شود. تجهيز مورد بررسي بر اساس اطلاعات موجود دچار آسيب هيدروژني (HIC) شده است. جنس بدنه تجهيز مذكور SA-516-70 N و تكنيك بازرسي غيرمخرب مبتني بر امواج فراصوتي (PAUT - TOFD) مي باشد. سطح 1 و 2 ارزيابي به دليل نزديكي فاصله ي HIC تا ناپيوستگي‌هاي ساختاري Lmsd مورد پذيرش واقع نگرديد و پس از آن سطح سوم استاندارد API 579-1/ASME FFS-1 بر اساس نرم افزار آباكوس انجام شد. نتايج پس از تهيه مدل سه بعدي، تحليل تنشي مخزن بدون عيب، تحليل تنشي ترك روي بدنه استوانه اي مخزن، تحليل تنش عدسي هد مخزن داراي ترك HIC و همچنين محاسبه ميزان انتگرال-J صورت پذيرفت كه نشان دهنده اطمينان از صلاحيت ادامه سرويس اين مخزن مي باشد.

Fitness for services is a quantitative engineering evaluation that is performed to prove the structural integrity of a defective equipment, in service or operation in operational conditions that can lead to its failure. The investigated equipment is the V-1000 (Pressure Vessel) in the Ilam Gas Refinery, which has suffered hydrogen damage (HIC) based on the available information. The body material of the mentioned equipment is SA-516-70 N and the non-destructive inspection technique is based on ultrasonic waves (PAUT - TOFD). The 1st and 2nd levels of the assessment were not accepted due to the proximity of the HIC distance to the Lmsd structural discontinuities, and then the third level of the API 579-1/ASME FFS-1 standard was performed based on Abaqus software. The results after preparing the three-dimensional model, the stress analysis of the tank without defects, the stress analysis of the crack on the cylindrical body of the Pressure Vessel, the lens stress analysis of the Pressure Vessel head with HIC crack and considering the isostatic internal pressure of 9 MPa and continuing up to the pressure of 15 MPa and also after Calculating the amount of integral-J output of the indicated cracks shows the qualitative accuracy of the crack energy calculation method and ensuring the eligibility of the continued service of this Pressure Vessel.