Application Research on deep recovery and utilization technology of flue gas waste heat of coal water slurry boiler

Coal water slurry boiler has attracted great attention in the field of urban heat system because of its efficient and clean coal combustion. The coal water slurry contains 35% moisture, which makes the waste heat recovery potential of flue gas greater. After the combustion of coal water slurry, the 100°Cunsaturated flue gas becomes 50°C saturated wet flue gas after Wet Desulfurization Process. The Direct Contact Thermal Storage System and Heat Pump technology are used to realize the deep recovery of low-temperature flue gas. The technology has been successfully applied in the 6×70MW coal water slurry boiler of La Shan Heat Source Company. After 120 days of operation, 393000 GJ of flue gas waste heat is recovered, about 23000 tons of coal water slurry is replaced, and 84000 tons of flue gas condensate is recovered. It has good economic and social utility. It is an effective way to recover and utilize waste heat from flue gas of coal-fired boiler, and has a broad application prospect.