Gas-fired boiler water vapor heat-carrying circulating type flue gas waste heat recovery unit set

The utility model discloses a water vapor heat-carrying circulating type flue gas waste heat recovery unit set of a gas-fired boiler, and belongs to the technical field of boiler clean combustion and waste heat heat supply. A water vapor heat-carrying circulating type flue gas waste heat recovery technical route is adopted, main components are integrated into a vertical heat exchange tower integral structure, the vertical heat exchange tower integral structure is composed of a skid-mounted hydraulic module on the lower portion, a flue gas spraying heat exchanger on the upper middle portion and a total heat air pre-heater on the upper portion, and flue gas enters a high-temperature heat exchange area from the middle of the tower and directly exchanges heat with return water of a heat supply network in a countercurrent mode. The flue gas rises to the low-temperature heat exchange area, exchanges heat with low-temperature waste heat water from a water tank at the bottom of the tower of the total heat air pre-hea