Flat-tube heat exchanger structure and assembling method thereof

The invention discloses a flat-tube heat exchanger structure. The flat-tube heat exchanger structure comprises fins which are provided with pipeline slots and a flat tube which passes through the pipeline slots of the fins, wherein the flat tube comprises a hollow flat tube and a micro-channel flat tube fixedly connected to the hollow flat tube. The invention further discloses an assembling method, which comprises the following steps: 1) stacking and fixing the fins in turn; 2) inserting the flat tube into the pipeline slots of the fins till the flat tube passes through the lowest fin; 3) expanding the hollow flat tube by using a mechanical tube expansion method, thereby tightly connecting the micro-channel flat tube with the fins or fixing rings; and 4) respectively connecting the two ends of the flat tube to an inlet collecting tube and an outlet collecting tube, thereby finishing the assembling. By using the flat-tube heat exchanger structure provided by the invention, the radiating property of a heat exch