Study On The Fire Extinguishing Performance And Mechanism Of Chlorofluoroolefin Chemical Fire Extinguishing Agent

In recent years,with the phasing out of existing Halon alternative fire extinguishing agents,it is crucial to find a new type of Halon alternative fire extinguishing agent that can match the aircraft fire extinguishing system,and has both environmental friendliness and excellent fire extinguishing performance,which has become a hot topic in the field of fire protection.The molecular structure of Hydrochlorofluoroolefin compounds has unsaturated double bonds,which can easily react with the OH radical in the atmosphere.Therefore,the atmospheric lifetime is relatively short,the greenhouse effect value is low.It has the potential to become a new type of Halon alternative fire extinguishing agent.In this paper,two typical Hydrochlorofluoroolefin compounds,HCFO-1233zd(E)and HCFO-1233 xf,were selected as the research objects.Experiments and theoretical calculations are used to study their fire-extinguishing performance and mechanism.The potential of the new Halon alternative application is evaluated.First,this article studies the combustion characteristics of HCFO-1233zd(E)and HCFO-1233 xf.The minimum extinguishing concentration of two kinds of chemical extinguishing agents was measured by using the cup burner system.The action process of fire extinguishing agent on the flame was recorded by high speed camera,and the flame behavior was analyzed by MATLAB image processing technology.The laminar combustion velocity of the Methane/Air premixed flame after adding HCFO-1233zd(E)and HCFO-1233 xf was measured on the cup burner system,and the influence of volume fraction of fire extinguishing agent on the laminar combustion velocity was studied,which provides experimental basis for chemical kinetics software analysis.Secondly,the dynamic fire extinguishing mechanism of HCFO-1233zd(E)and HCFO-1233 xf is studied.It can be divided into two steps.In the first part,the pyrolysis characteristics of these two kinds of chemical fire extinguishing agents were studied by using the thermal decomposition system,and the pyrolysis products and conversion rates were analyzed with temperature.According to the pyrolysis products of HCFO-1233zd(E)and HCFO-1233 xf,the pyrolysis reaction paths are inferred.The decomposition pathways of two extinguishing agents were calculated by Gaussian 16 software package,and the fire extinguishing mechanism of HCFO-1233zd(E)and HCFO-1233 xf was discussed based on the experimental and calculation results.In the second part,through constructing the suppression kinetic mechanism of HCFO-1233 xf,the gas-phase kinetic software Chemkin 17.0 was used to simulate the HCFO-1233xf/Methane/Air premixed combustion system,and the influence of the addition of HCFO-1233 xf on the combustion rate was investigated.The main substances and elementary reactions in the combustion system are studied,the key reactions causing the ignition promotion/suppression effect were found out,and the reaction path of HCFO-1233 xf in the combustion system is analyzed in detail.Finally,the causes of combustion promotion and suppression by HCFOs extinguishing agents were summarized.The potential of Hydrochlorofluoroolefin compounds as fire extinguishing agent was evaluated.Then the disadvantages of the present research work were analyzed and the future research of HCFOs extinguishing agents were prospected.