tailieunhanh - Marine_Structural_Design Episode 15

Tham khảo tài liệu 'marine_structural_design episode 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 538 Port Y Risk Assessment Install Fire and Blast Barriers Escalation caused by explosions can be limited by fire and blast barriers between modules and areas. However the barriers themselves may cause problems for keeping ventilation and introduce more blocks. The construction repair of such barriers may involve extensive hot work. This measure is therefore more effective in the early design stage. Active Deluge on Gas Leakage Leakage may be deluged out without causing any explosions or fires. Deluge may be particularly effective in preventing so-called runaway flame accelerations. It may also lead to a reduction of the peak overpressure. The most critical aspect in the use of deluge is that it must be triggered prior to ignition . on detection of a gas leak. Modeling of ignition has shown that the most likely interval between release and ignition is two to three minutes. Thus deluge activation has to be within the first half minute in order to be effective. Improve Resistance of Equipment and Structures The last possibility of reducing an explosion consequence is to improve the resistance of equipment and structures to blast loads. However it is not cost-effective to design structures for the worst explosion case. Therefore this approach may be quite expensive. Fire Risk In the offshore risk assessment usually two types of fire risk are considered the topside fire and the fire on sea. The following sections mainly deal with the topside fire. Further the smoke effect analysis and the structural response under the fire are normally integrated into the fire risk assessment. The distinction between what is classified fire and what is called explosion is relatively subjective. The total loss of the fixed platform Piper Alpha was initiated by a small explosion but the damage was primarily due to fire. Fire Frequency Fire frequency analysis is very similar to explosion frequency analysis. The overall fire frequency can be expressed as Ppp Ppeak P j .