Flue gas reheating and condensing dual-purpose heat exchange system

The utility model provides a flue gas reheating and condensing dual-purpose heat exchange system, and relates to the technical field of boiler flue gas reutilization. The system comprises a gas-fired boiler, a connecting flue, a smoke exhaust channel, an induced draft fan, a dual-purpose heat exchanger, an air pre-air channel, a reheating water supply pipe and a reheating water return pipe, the gas-fired boiler is connected with the connecting flue, the connecting flue is communicated with the smoke exhaust channel, the dual-purpose heat exchanger is arranged on the upper portion of the smoke exhaust channel, and the induced draft fan is arranged on the side face of the smoke exhaust channel; and a sewage draining valve is arranged at the bottom of the smoke discharging channel. The dual-purpose heat exchanger is connected with the induced draft fan and the air pre-heating air duct, and the reheating water supply pipe and the reheating water return pipe are also connected with the dual-purpose heat exchanger.