Flue gas waste heat utilization device

The utility model discloses a flue gas waste heat utilization device. The boiler is connected with a pipeline, the other end of the pipeline is connected with a filter, the left end of the heat exchange pipe is connected with the filter, the right end of the heat exchange pipe is connected with a chimney pipe, the heat exchange pipe comprises an inner pipe and an outer pipe, the inner pipe is arranged in the outer pipe, a flow channel is formed between the inner pipe and the outer pipe, and a smoke vent is formed in the inner pipe. A liquid level control mechanism is arranged in the middle ofthe water tank and comprises a floating block, a connecting rod and a connecting plate, the floating block is arranged in the water tank and connected with the lower end of the connecting rod, and theupper end of the connecting rod is arranged above the water tank and fixedly connected with the connecting plate. The heat exchange pipe is divided into the inner pipe and the outer pipe, water usedfor heat exchange circulate