Study On Warning Agent And Explosion Inhibitor Of Refrigerant R290

In the past decades,more and more attention was paid to environmental protection.The refrigerants of chlorofluorocarbons and hydrofluorocarbons are limited for environmental damage,while hydrocarbons show great potential and are known as the green refrigerant by the refrigeration industry due to its excellent refrigeration efficiency and environment-friendly performance.However,its flammable and explosive properties limited the further promotion in industrial applications.The safety performance of natural refrigerants R290 containing warning agents and suppressors was studied in this paper.The specific contents are as follows:The odor threshold values of the three kinds of warning agents were studied.The odor threshold value of the warning agents A,2-picoline and ethanethiol were 0.066 mg/m3,0.288 mg/m3 and 0.015 mg/m3 respectively.In addition,both warning agent A and ethanethiol have strong irritating smell,which possess a good alarm function.The odor of 2-picoline is more moderate,and the warning effect is relatively poor.The corrosion effects of warning agents on several kinds of common metal were studied under the limit conditions(alarm concentration is saturated vapor pressure at 80 °C).The results showed that the corrosion rate of ethanethiol to different metals was about 4～6 times to that of the warning agent A.The corrosion rates of 2-picoline to carbon steel,brass,copper and aluminum were less than 0.005 mm/a,2-methylpyridine can be considered as no corrosion to the above four metals.At room temperature,the corrosion rates of all four metals were lower than 0.05 mm/a in the lower concentration of warning agent A-petroleum ether solution.The effect of explosion suppression agent CF3I on the explosive properties of R290 was studied.The results showed that the explosion range of R290 hybrid system and the explosion hazard is obviously reduced as content of CF3I increases.When the volume ratio of CF3I to R290 is 1.0,the explosion limit is reduced by 91.02%,and the minimum ignition energy of the mixture is about 200 times higher than that of R290.The average detonation velocity at 1.6 m from the ignition end is reduced to 3.52 m/s and the explosion pressure is decreased by 37.12%.When the volume ratio of CF3I to R290 reaches 1.2,the explosion limit range is reduced to 0,the system is not explosive at this time.In conclusion,there is no obvious corrosion effect on the pipeline when the amount of warning agent A is less.The explosion suppression agent CF3I can significantly inhibit the explosion tendency of R290 and greatly improve the safety performance of the system.Both substances are expected to be used as additives in refrigerants.