Experimental Study On The Effect Of Marine Environment With High Humidity And High Salinity On The Harmfulness Of The Combustion Of Flexible Polyurethane Foam

In this paper,considering the characteristics of high humidity and high salt sea air,the combustion of flexible polyurethane foam（FPUF）commonly used in ship cabin is studied by cone calorimeter,steady tube furnace（SSTF）and small scale horizontal fire spreading experimental box.The combustion behavior and heat release rate（HRR）of FPUF with different densities were studied by cone calorimeter.The results show that:the HRR of FPUF with different density has different change rules,which shows single peak or double peak shape.With the change of irradiance,the combustion performance parameters of FPUF change,and the ignition time of FPUF with different densities decreases with the increase of irradiance;The maximum heat release rate（pk HRR）,average heat release rate（MHR）and total heat release rate（THR）increased with the increase of irradiance;under the same irradiance,the combustion time,ignition time,pk HRR,MHR and thr of FPUF materials increased with the increase of density.The results show that the heat release rate（HRR）curves of FPUF with different salinities are basically similar in either forced ignition mode or non forced ignition mode;in the case of no forced ignition mode,when the radiation intensity is large,the ignition time of FPUF increases with the increase of droplet salinity,and the highest peak value of HRR curve decreases with the increase of droplet salinity.The characteristics of flue gas components of FPUF during combustion in air with different salt and humidity were studied by using steady-state tubular furnace（SSTF）.The variation rules of HCN,CO,NO and CO₂in the flue gas were analyzed.At the same time,the toxicity changes caused by the formation of HCN and CO in the main asphyxiating gases were analyzed by the smoke toxicity assessment model.The results show that:the variation law of flue gas components in different salt humidity air is similar.The production of HCN and co increases with the increase of global equivalence ratio,while the production of NO and CO₂decreases with the increase of global equivalence ratioΦ.Compared with dry air,the production of HCN,NO and CO₂in air with different salt humidity is reduced,while CO is produced However,the amount of production increased slightly.Among them,HCN and CO production increased with the increase of experimental humidification solution salinity,on the contrary,NO and CO₂production decreased with the increase of experimental humidification solution salinity;the effective dose fraction fed value of flue gas toxicity evaluation parameter increased with the increase ofΦvalue,and increased with the increase of experimental humidification solution salinity;with the increase of experimental humidification solution salinity,Fed was in danger The results show that the increase of air salt humidity has a certain strengthening effect on the toxicity of flue gas produced by FPUF combustion.The horizontal fire spread characteristics of FPUF combustion in air with different salt humidity were studied by using a small-scale horizontal fire spread test box.The results showed that the average speed of horizontal fire spread and the mass change of FPUF combustion decreased with the increase of air salt humidity,which indicated that the increase of air salt humidity could delay the spread of horizontal fire;compared with the air humidity condition,the horizontal fire spread characteristics of FPUF combustion were improved The results show that the change of air salinity has little effect on the average speed of horizontal fire spread and the mass change of FPUF combustion.