Study Of Characteristic Of Methane/Air Premixed Laminar Flame Interacted With Water Mists

Due to the fine dispersity, high heat capacity, and ease of evaporation, water mists have got widely used and concerned about as the substitute of the haloalkane extinguishing agent. Flammable gas flame acceleration is the universal phenomena in fires and explosion industrial hazards, such as coal mine gas explosion, oil vapor explosion in the ship machine space, flashover and backdraft in building and so on. It indicated that certain condition water mist could be available to inert the flammable gases and inhibit the gas explosion in the gas or vapor congregated location. The corresponding researches are mainly about the mechanism of the methane/air premixed gas inerting and the mitigation of premixed gas laminar flame propagation by water mist. The kernel and fundamentals of flammable gas inerting and inhibition by water mist are interactions of water mist and premixed flame. This paper would try to explore the influence and mechanism of inerting and inhibition of premixed flame by water mist, by the experiments of the combustion characteristic on the influence of water mist. The main works and achievements in the paper contain the following sections.1. The original experimental equipments of the bigger aperture tube burner with coflow water mist were designed and setup.With this experimental equipment the interaction of large size distribution water mist (water mist diameter distributed within 30μm～150μm) and methane/air premixed flame were studied. Compared with the present classical tube burner and the Fuss burner whose burner nozzle diameter was 5.4mm and the water mist size was 10μm, this burner equipment can be applied more widely.According to the design theory of the tube burner, the calibration and error analysis were carried out. And the LDV/APV system was employed to study the water mist characteristic along the axis outside the burner nozzle of the tube burner. The effects of coflow inlet gases flux on the droplets movement were analyzed. In addition, the water mist characters and the tow-phrase flow of the tube burner with different coflow conditions were also studied in theory.