Plasma Ignition System to Start Up Pulverized Coal Boilers: Experimental Simulation and Full-Scale Test

The conditions of coal ignition and combustion with application of plasma ignition system have been studied experimentally. Research on plasma ignition of coal fuel flow was carried out on a pilot setup. The conditions were close to the industrial ones used for start-up of coal boilers. The operating range of the velocities of pulverized coal flow in the electric arc unit has been determined. It has been established that a stable process of ignition and further combustion of coal is possible at these flow velocities in the electric arc unit. The experimental setup was started up from a cold state and heated to a temperature of 1000°C; the start-up time did not exceed 200 s. Based on the obtained experimental results, an industrial prototype of plasma ignition system (PIS) was designed and tested with a TP-10 boiler with a capacity of 220 tons of steam per hour. The boiler was started up from a cold state by means of the PIS technology without use of fuel oil; the start-up time was 5 hours. After the pass of pulverized coal through the PIS, stable ignition and combustion of pulverized coal flame with a temperature of 1350°C was observed in the boiler. For the first time, a technology for ignition of pulverized coal boilers without use of fuel oil was created and implemented on the basis of a starting burner with plasma ignition of fuel. The technology features positive economic and environmental parameters in comparison with the widespread technology of starting up coal-fired boilers with liquid fuel combustion.