The substantial growth of new energy power generation puts forward higher requirements for deep peak regulation of coal-fired power plants. However

at present

coal-fired power plants are difficult to maintain stable combustion at load lower than 20%. To solve this problem

a new type of strongly stable combustion

low temperature and low nitrogen dual-vortex pre-pyrolysis burner is developed. Pulverized coal is preheated firstly at high temperature and then mixed with the entrained high temperature flue gas to ignite to achieve the purpose of strong and stable combustion. A 25 t/h test bench is built

and the test results showed that

the flame temperature of the entire furnace with a single burner was uniform

below 1 000 ℃

presenting a low temperature and low nitrogen environment

and the flame was very stable when the design power of the burner was below 30%～35%. The boiler efficiency of the pilot test bench reached 92.75%

and the NO_x emission was 218 mg/m3(6% O_2 volume fraction).Spraying urea solution in the furnace could reduce the NO_x emission to lower than 80 mg/m~3. Based on this

for large-scale coal-fired boilers

regardless of the swirling combustion system or the direct-flow combustion system

installing new burners on the front and rear walls on middle or upper layer can both realize stable combustion at 10%～20% low load with no need for modification of pulverizing system. This new burner has a good prospect for promotion and application