Experimental Studies And Numerical Simulation Of Plasma Burner Ignition Mechanism

During the course of pulverized coal boiler commissioning, cold start up and low load combustion stabilizition, need to consume a lot of oil. Plasma ignition technology is an efficient means that can decrease cost of ignition and operating in low load, and can save oil in the course of ignition and low load combustion stabilizition. Plasma ignition burner is one of the main equipment of the plasma ignition system, whose structure and ignition characteristics play the key role in the application of plasma ignition technology. The thesis studies the ignition characteristics of plasma ignition burner in the round.The thesis firstly introduces the basic characteristics of plasma, pyrogenation course and factors on the mixture of pulverized coal and primary air, and the combustion improving effect of reaction of plasma and pulverized coal. On this condition, the thesis studies the DLZ-200 plasma ignition system, and presents the theoretical calculation method of direct ignition quantity of pulverized coal.The thesis studies the plasma temperature field and its characteristics of DLZ-200 plasma producer, and presents the method of theoretical calculation temperature of arc plasma, then sets up relation test-rig to prove the theoretical calculation conclusion. The work provides good experience to decide the size of the plasma burner first stage barrel.The thesis sets up hot multi-stage ignition test-rig, and then studies the ignition characteristics of the plasma burners first stage barrel. The thesis gains the effect rule of the pulverized coal nature, primary air velocity, pulverized coal concentration, plasma burner power and the diameter and dimension of the first stage barrel on the ignition characteristics of plasma.The thesis sets up test-rig and studies the ignition course of pulverized coal and air mixture. The thesis gains that the factors such as pulverized coal quality, primary air velocity, the concentration board structure of burner entrance elbow, each stage barrel size(diameter and length), the concentration board structure of the stage barrel and so on, are how to effect the plasma ignition characteristics.The thesis presents the numerical simulation model and simulates the first stage barrel of plasma burners and multi-stage barrel plasma burners. By FLUENT software, thesis selects the hot test reference to modify relate parameter of burning model, and then presents plasma burners heat stage ignition model. This model can include all inner parameters of plasma burners, which will provide good reference for design plasma burners.The thesis sums up the above study result and experiment date, presents the method of optimizing plasma burner structure, and finds the basic rule of distribution of different stage coal quantity in multi-stage plasma burner, which provides the reference for design multi-stage barrel plasma burners.