In this study, we analyze factors affecting the explosion limits of flammable refrigerants. We conclude that any method used for measuring flammable refrigerant explosion limits has its conditional restrictions. Flamm...In this study, we analyze factors affecting the explosion limits of flammable refrigerants. We conclude that any method used for measuring flammable refrigerant explosion limits has its conditional restrictions. Flammable refrigerants in the atmosphere can also explode under certain conditions, when the concentration is approaching the explosion limits. An experimental study on the explosion limits of six kinds of flammable refrigerants is carried out with a mixture of refrigerant and combustible refrigerant, which has a similar effect to a flame retardant. An experimental apparatus was designed to test the explosion limits of mixtures made from three different nonflammable refrigerants and six different flammable refrigerants. Two practical models were developed to estimate the critical concentration for inhibiting explosion of refrigerant mixtures: one was made up of two flammable components with one nonflammable component, and the second was made up of one flammable component with two nonflammable components.展开更多
A series of plate impact experiments on alumina was conducted using a light gas gun in order to further investigate Hugoniot elastic limit(HEL)and failure properties of alumina under shock compression.The velocity int...A series of plate impact experiments on alumina was conducted using a light gas gun in order to further investigate Hugoniot elastic limit(HEL)and failure properties of alumina under shock compression.The velocity interferometer system for any reflector(VISAR)was used to record the rear-free surface velocity histories of the alumina samples.According to the experimental results,the HELs of tested alumina samples with different thicknesses were measured,and the decay phenomenon of elastic wave in shocked alumina was studied.A phenomenological expression between HEL and thickness of sample was presented,and the causes of the decay phenomenon were discussed.The propagation of failure wave in shocked alumina was probed.The velocity and delayed time of failure wave propagation were obtained.The physical mechanism of the generation and propagation of failure was further discussed.展开更多
文摘In this study, we analyze factors affecting the explosion limits of flammable refrigerants. We conclude that any method used for measuring flammable refrigerant explosion limits has its conditional restrictions. Flammable refrigerants in the atmosphere can also explode under certain conditions, when the concentration is approaching the explosion limits. An experimental study on the explosion limits of six kinds of flammable refrigerants is carried out with a mixture of refrigerant and combustible refrigerant, which has a similar effect to a flame retardant. An experimental apparatus was designed to test the explosion limits of mixtures made from three different nonflammable refrigerants and six different flammable refrigerants. Two practical models were developed to estimate the critical concentration for inhibiting explosion of refrigerant mixtures: one was made up of two flammable components with one nonflammable component, and the second was made up of one flammable component with two nonflammable components.
基金supported by the Science and Technology Development Foundation of China Academy of Engineering Physics (Grant No. 2014B0101009)the National Natural Science Foundation of China (Grant No. 11502258, 11272300)
文摘A series of plate impact experiments on alumina was conducted using a light gas gun in order to further investigate Hugoniot elastic limit(HEL)and failure properties of alumina under shock compression.The velocity interferometer system for any reflector(VISAR)was used to record the rear-free surface velocity histories of the alumina samples.According to the experimental results,the HELs of tested alumina samples with different thicknesses were measured,and the decay phenomenon of elastic wave in shocked alumina was studied.A phenomenological expression between HEL and thickness of sample was presented,and the causes of the decay phenomenon were discussed.The propagation of failure wave in shocked alumina was probed.The velocity and delayed time of failure wave propagation were obtained.The physical mechanism of the generation and propagation of failure was further discussed.
