Safety Interlock Design In LNG

Modern engineering projects are increasingly demanding for safety and risk handling.In the project,the raw material gas is transported to the main device area by pipelines,and the process steps of compression,dehydration,deacidification,mercury removal,drying,liquefaction,mixed refrigerant refrigeration,mixed refrigerant storage and the like are liquefied into liquid natural gas products and stored in dedicated storage.Within the tank,follow-up will undertake LNG product loading and transportation functional device area.There are many safety interlocks involved in this complete product line to ensure production and property safety throughout the entire installation area.This paper gives the idea and process of interlocking design work for this kind of product project,combining design principles and safety interlocking techniques,such as risk assessment,China Petrochemical Safety Instrum ent System design specification,and special requirements for process flow,etc.Many parts have designed safety interlock control,and the contents mainly include:1.Steps and important steps in designing safety interlocking:including determining the SIL level(up to the SIL for the entire proje ct,down to the SIL for each equipment segment),planning and purchasing the SIS system,and determining important commonly used logic structures(to achieve SIL)Based on the standard,to achieve the process requirements for the purpose),according to the actual project c onditions and national standards and other industry specifications arrange the details of the instrument and interlocking loop.2.Actual engineering cases concretely embody the operational fl ow and design results of the LNG safety interlock design during actual project design,using two typical interlocking conditions(compressor emergency stop and device tank outlet flow level control)as an example.The figurative illustration illustrates the safety interlock desig n.3.Summarize the technical focus and design flow of this article,and summarize some principles,technical foundations,and program choices that need attention in the design of safety interlocking.