安全儀表系統(tǒng)簡介ppt課件-在線瀏覽
2025-03-07 08:18本頁面
【正文】 ersible) S3 Potential for one or more lost time injuries S4 Potential for minor injuries, or irritation Eamp。I SIS 6 Example: Eamp。I SIS 7 Failures of a . ? Active error – triggers off the safety function for no reason – plant is switched back to safe operation – reduction of production availability ?有源故障 無緣無故觸發(fā)安全功能 裝置切回到安全運(yùn)行 生產(chǎn)運(yùn)行可用率降低 ? Passive error 無源故障 – inhibits the required safety function – plant continues operation although it should be switched off – impacting the process safety adversely affecting the safety function 對安全功能產(chǎn)生不利影響 no adverse effect on the safety function 對安全功能無不利影響 Failure 故障 Timeaveraged probability for a passive fault : PFD “Probability of Failure on Demand” 無源故障的時間平均可能性 : PFD”指令故障的可能性“ 20220428 Commissioning test of Eamp。I SIS 9 Passive Faults of sensors and actuators 傳感器和致動器的無源故障 mass flow meter after pressure pulse 壓力脈沖下游的 質(zhì)量流量計(jì) lost control valve plug control valve plug, damaged by cavitation restriction orifice, deformed by flow 限流孔板 限流孔 限流孔板 , 流量造成的變形 調(diào)節(jié)閥閥塞 ,空穴造成的損壞 20220428 Commissioning test of Eamp。I SIS 11 PFD – Probability of Failure on Demand PFD—指令故障概率 Probability Pf(t) for finding equipment in dangerous fault state after time t has passed since last functional test 自上次功能試驗(yàn)以來經(jīng)過時間 t 后 ,發(fā)現(xiàn)設(shè)備處在危險(xiǎn)故障狀態(tài)的概率 . Pf (t) = (1 – el t ) time average 時間平均值 PFD Probability of Failure on demand PFD—指令故障概率 PFD depends on failure rate of equipment AND test interval. PFD取決于設(shè)備 AND試驗(yàn)間隔的故障率 20220428 Commissioning test of Eamp。I SIS 13 Calculation of PFD – the problems… PFD的計(jì)算 —問題 … ? PFD data for field instruments usually not very reliable (not experimentally verified for chemical environment). 用于現(xiàn)場儀表的 PFD數(shù)據(jù)通常不是很可靠 (對于化學(xué)環(huán)境未經(jīng)試驗(yàn)驗(yàn)證 ). ? Contribution to Failure Probability (PFD):對故障概率的影響因素 ? ? calculated values for PFD: often not very accurate. ? PFD計(jì)算值 : 經(jīng)常不太準(zhǔn) Field Instruments 85 % 現(xiàn)場儀表 Logic Solver (fai
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