Study On Mapping Method And Optimization Strategy For Fire And Gas System Detector Of PP Plant

Fire and combustible gas hazard is a typical hazard in process industry production.As a result,fire and gas system has been installed in the related facilities to detect,in some cases,and automatically mitigate the hazard.Fire and gas system includes fire alarm and gas(combustible gas and toxic gas)detection.It plays a very important part in preventing fire and ensuring the safety to the facility and is an integral part to establish safety system for chemical plants.In addition,fire and gas system is also the safety critical equipment,so it must be designed in a robust manner.Currently,domestic fire and gas design is still at initial phase,the application is not wide either,and there is no clearly-defined and mandatory performance-based requirement.Furthermore,the generic designer and user don't have distinct concept.Basically,fire and gas system is not as safety system independently designed and deployed.Instead,the common civilian-type or industrial-type fire alarm is applied.Subsequently,gas detection and alarm are carried out through distributed control system(DCS).Therefore,the fire and gas mapping after design still needs to be improved regardless of coverage and effectiveness.This thesis begins with analysis for the 2 existing flaws that are commonly seen(firstly,fire and gas system is unable to detect hazards due to an insufficient number of or poorly located detectors;secondly,fire and gas system has a relatively high frequency of spurious activation)of fire and gas system to assess the original fire and gas design of polypropylene(PP)plant in Tianjin by means of semi-quantitative analysis methodology and corresponding consequence calculation in combination with the advanced overseas fire and gas mapping software from aspects of basic fire and gas design principle,fire and gas zone grading,and fire and gas performance target,find significant amount of issues and shortcomings that need to be addressed from perspective of fire and gas design after comparing the achieved results with the original design for fire and gas by the designer,and put forward feasible and plausible calculation optimization strategy for fire and gas mapping based on the actual circumstances,so as to provide technical support for the fire and gas mapping.