2results about How to "Improve ignition stability" patented technology

This invention discloses a porous rectifying structure for the afterburner of a variable cycle engine, comprising a rectifying orifice plate installed in an annular channel between the turbine outlet and the flame stabilizer. The orifice plate is symmetrically arranged along its radial central axis, with the clogging area facing the turbine inflow and axially aligned with the heat shield inlet. The orifice plate height is 2 / 3 of the channel height between the central cone and the heat shield. The plate has uniformly distributed pores with an equivalent diameter of 10-20 mm along the radial direction, with a clogging ratio of 5%-25%. This invention forms a multi-stage mixing interface through the radially gradient porosity pore arrangement, promoting shear mixing of the high-temperature internal combustion gas and the external bypass gas. Simultaneously, the static pressure difference across the orifice plate drives the external bypass gas flow into the heat shield cooling channel, increasing the cooling flow rate, improving the uniformity of the upstream velocity field of the flame stabilizer, eliminating the recirculation zone inside the heat shield, reducing the thermal load on the casing wall, and controlling the total pressure loss to within 3%, achieving high-stability combustion and reliable thermal protection under a wide bypass ratio.

The invention aims to provide a W-shaped boiler burner based on pulverized coal particle size separation, belongs to the technical field of pulverized coal combustion, and can solve the problems that coarse pulverized coal particles are located on the periphery of the burner and fine pulverized coal particles are located in the center due to airflow rotation inertia of the W-shaped boiler burner; and the problems of delayed pulverized coal ignition, low combustion efficiency, high NOx emission and the like are solved. A vertical downward injection type structure is adopted, and a cross deflection flow guide structure is arranged in the combustor, so that pulverized coal is finally distributed at a contraction nozzle of the combustor in the mode of'centralized injection of center coarse powder and coating of outer layer fine powder '. By means of the structure, fine pulverized coal can be preferentially ignited in a hearth with the low temperature to establish a stable high-temperature field, central coarse-particle pulverized coal is promoted to be completely burnt out, the burning stability of inferior coal and wide-particle-size pulverized coal is remarkably improved, and the loss of unburnt carbon and the generation amount of NOx are effectively reduced.