Microchannel flat tube and microchannel heat exchanger

A microchannel heat exchanger comprising a plurality of microchannel flat tubes, a first collecting pipe, a second collecting pipe and fins;

• the microchannel flat tube comprising a flat tube body and a row of channels;
• the flat tube body comprising a first plane, a second plane, a first side surface and a second side surface, the first plane and the second plane being disposed on opposite sides of the flat tube body along a thickness direction, the first side surface and the second side surface being disposed on opposite sides of the flat tube body along a width direction, the first side surface connecting the first plane and the second plane, the second side surface connecting the first plane and the second plane;
• a row of channels being disposed in the flat tube body along the width direction, the row of channels extending through the flat tube body along a length direction, each channel comprising a first width in the width direction and a first height in the thickness direction, the row of channels at least comprising a first channel, a second channel and a third channel disposed in the width direction;
• wherein the first channel, the second channel and the third channel have the same first height, and the first widths of the first channel, the second channel and the third channel are decreased at a fixed rate;
• wherein
• the microchannel flat tubes are connected between the first collecting pipe and the second collecting pipe, each fin is sandwiched between two adjacent microchannel flat tubes, and a row of channels of each microchannel flat tube communicates with an inner cavity of the first collecting pipe and an inner cavity of the second collecting pipe;
• wherein the row of channels comprises a group of first channels and a group of second channels, the group of first channels comprise a plurality of the first channels, the group of second channels comprise a plurality of the second channels, and the number of the first channels in the group is equal to the number of the second channels in the group.