To improve the unit thermal efficiency and reduce pollutants emissions

two once-through lignite boilers in a power plant have adopted the flue gas waste heat deep cascade utilization and emission reduction system to heat the high pressure feed water and hot condensation water. Experimental study and operational effect analysis on the running and stop running system were performed. The results show that

after the flue gas waste heat deep cascade utilization and emission reduction system was put into service

at 660 MW

the actual measured coal consumption for power generation and power supply declined by 4.97 g/(k W·h) and 5.12 g/(k W·h)

respectively. At high loads

the dust emission concentration

desulfurization process water

draft fan and induced draft fan current decreased greatly. The annual economic benefit of single unit is about 7.50 million yuan

and the payback period of the equipment investment is about 6 years. It is suggested that the bypass diameter be enlarged to increase the flue gas temperature

and the soot blowing frequency be increased to compensate the insufficient soot blowing capability of the compressed air rotary ash removal system.