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 a plurality of fins;
• the microchannel flat tube comprising a flat tube body and a row of channels;
• the flat tube body comprising a first surface, a second surface, a first side surface and a second side surface, the first surface and the second surface being disposed on opposite sides of the flat tube body along a thickness direction, respectively, the first side surface and the second side surface being disposed on opposite sides of the flat tube body along a width direction, respectively, the first side surface connecting the first surface and the second surface, the second side surface connecting the first surface and the second surface;
• the 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 group of first channels, a second group of second channels and a third group of third channels, the second group of second channels being disposed adjacent to the first group of first channels without any channel disposed between the second group of second channels and the first group of first channels along the width direction, the third group of third channels being disposed adjacent to the second group of second channels;
• the first channels, the second channels and the third channels being disposed in sequence along the width direction;
• wherein the first channels, the second channels and the third channels have the same first height, and the first channels, the second channels and the third channels have first widths which are decreased at a fixed value;
• the first widths of the first channels, the second channels and the third channels decrease sequentially across all the channels and satisfy a relationship:
• y=−mx+n, wherein x represents a sequence number of the first channels, the second channels and the third channels;
• y represents a dimension of the first width of a corresponding x-th channel;
• m represents a first constant;
• and n represents a second constant;
• wherein the microchannel flat tubes are connected between the first collecting pipe and the second collecting pipe, each fin is connected between two adjacent microchannel flat tubes, and the 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 number of the first channels in the first group is equal to the number of the third channels in the third group.

A microchannel heat exchanger, comprising:

• a first collecting pipe comprising a first inner cavity;
• a second collecting pipe comprising a second inner cavity;
• and
• a plurality of microchannel flat tubes connected between the first collecting pipe and the second collecting pipe, each flat tube defining a row of channels fluid communicating the first inner cavity and the second inner cavity;
• each microchannel flat tube comprising a first surface, a second surface, a first side surface and a second side surface, the first surface and the second surface being disposed on opposite sides of the flat tube body along a thickness direction, respectively, the first side surface and the second side surface being disposed on opposite sides of the flat tube body along a width direction, respectively, each channel extending through the flat tube body along a length direction;
• the row of channels comprising a first channel, a second channel and a third channel disposed in sequence along the width direction the row of channels at least comprising a first group of first channels, a second group of second channels and a third group of third channels, the second group of second channels being disposed adjacent to the first group of first channels without any channel disposed between the second group of second channels and the first group of first channels along the width direction, the third group of third channels being disposed adjacent to the second group of second channels without any channel disposed between the third group of third channels and the second group of second channels along the width direction, the first channels, the second channels and the third channels being disposed in sequence along the width direction;
• wherein cross-sectional areas of the first channels, cross-sectional areas of the second channels and cross-sectional areas of the third channels decrease sequentially across all the channels and satisfy a relationship:
• y=−mx+n, wherein x represents a sequence number of the first channel, the second channel and the third channel;
• y represents a cross-sectional area of a corresponding x-th channel;
• m represents a first constant;
• and n represents a second constant;
• distances between two adjacent first channels in the first group are equal, distances between two adjacent second channels in the second group are equal, and distances between two adjacent third channels in the third group are equal;
• a group distance between the second group of the second channels and the third group of the third channels is equal to the distance between two adjacent third channels in the third group;
• and wherein the group distance between the second group of the second channels and the third group of the third channels is smaller than the distance between two adjacent second channels in the second group.