Temperature measurement of gas explosion flame based on the radiation thermometry

摘要

In order to obtain more detailed temperature information from images photographed with a high speed camera located at the transparent window of explosion pipeline, a method of calculating the two-dimensional temperature distribution field of premixed gas explosion flame is put forward based on the radiation thermometry. Also, the calculation results of the upside and downside flame temperature are modified according to the different emissivity of gases at the upside and downside zone and the temperature isotherms of gas explosion flame are depicted. The calculated average temperature of explosion flame is compared with the experimental results measured by thermocouples and both are close, which can testify that the method of calculating temperature is correct and feasible. The results show that there is a sharp increase of the temperature at the flame front, then the increase rate of the flame temperature slows down gradually until the maximum temperature and then the temperature declines. The results also indicate that chemical reaction is the most intense at the flame front, but the time of maximum temperature reached lags behind the front. This phenomenon may be attributed to that reactants fail to react completely and aggregate in groups at the flame front due to large numbers of ions. By this method the temperature field of gas explosion can be attained from flame images. So the retrospective study can be done by this method and more information can be obtained. This method can be used widely in the field of explosion flame propagation and provide the theoretical foundation for investigating the rules of gas explosion.