Efficient low NOx chain grate furnace coupled with swirling pulverized coal combustion and enhanced flue gas recirculation

The invention discloses a high-efficiency low-NOx chain grate furnace coupled with swirling pulverized coal combustion and enhanced flue gas recycling, By reducing the fraction of combustion in gratezone, A low NOx swirl pulverize coal burner and a burned-out air are arrange on that left and right side walls, and an enhanced flue gas recirculation is constructed (i. E., flue gas recirculation isintroduce from a primary air chamber at the lower part of the grate, a front and rear arch secondary air burner and a swirl burner respectively), Deep-air staged low-nitrogen combustion conditions including horizontal staging and suspension staging and enhanced flue gas recirculation low-nitrogen combustion conditions are formed to significantly inhibit NOx formation. A low NOx swirl pulverize coal burner is added to increase that combustion fraction of the suspension combustion zone, Flue gas temperature level and hot air utilization ratio can reduce exhaust gas loss and increase fly ash burnout. In addition, reasonable distribution of flue gas in grate combustion zone and reduction of combustion share can help to improve slag burnout rate, thus achieving the effect of significantly improving boiler thermal efficiency.