Method of test for burning velocity measurement of flammable gases and results

摘要

This article describes a test method for measuring the burning velocity of flammable gases with air used as oxidant. Burning velocity is a physical property enabling the classification of flammable refrigerants. A safety standard committee, such as ASHRAE 34 SSPC, requests information about methods of tests capable of improving the classification of flammable refrigerants. The burning velocity is a function of the flammable gas concentration in the total mixture with air, and it can be measured at concentrations ranging from the lower propagation limit (LPL) of the flame in the tube to the upper propagation limit (UPL). The burning velocity reaches a maximum in the vicinity of the stoichiometric concentration. The test method is based on the initiation of the combustion of the gas, or blends of gases, in a homogenous mixture with air contained in a vertical cylindrical tube, and the observation and the recording of the flame propagation. Results for R-290, R-152a, R-717, R-32, and R-143a are presented using the tube method as described and performed at the Center for Energy and Processes.