Combined heat exchanger, heat exchanging system and the optimization method thereof

A method for optimizing a refrigeration system for an electric transport vehicle, the heat exchange system comprising:

• an enhanced vapor injection compressor, a condenser, an expansion valve and an evaporator, which are located in a main circuit;
• wherein the heat exchange system further comprises a first branch branched from the main circuit to an vapor injection port of the compressor at a branch point P downstream of the condenser, and a first heat exchange unit and a second heat exchange unit are further provided in the main circuit between the branch point P and the expansion valve;
• the method comprising:
• dividing a refrigerant leaving the condenser at the branch point P into a first portion passing through the first heat exchange unit and the second heat exchange unit from the main circuit, and a second portion passing through the first branch to the vapor injection port;
• causing the second portion of the refrigerant to pass through a branch expansion valve and exchange heat in the first heat exchange unit with the first portion of the refrigerant in the main circuit;
• and
• causing the first portion of the refrigerant to exchange heat in the second heat exchange unit with the refrigerant flowing from the evaporator to an inlet of the compressor;
• wherein the first heat exchange unit and the second heat exchange unit are included in an integrated, combined heat exchanger, the combined heat exchanger is a plate heat exchanger;
• wherein the combined heat exchanger comprises:
• a main flow path, which extends between an inlet of the main flow path and an outlet of the main flow path, and which comprises a first portion located in the first heat exchange unit and a second portion located in the second heat exchange unit;
• a first heat-exchange flow path, which extends between an inlet of the first heat-exchange flow path and an outlet of the first heat-exchange flow path, and which exchanges heat in the first heat exchange unit with the first portion of the main flow path;
• and
• a second heat-exchange flow path, which extends between an inlet of the second heat-exchange flow path and an outlet of the second heat-exchange flow path, and which exchanges heat in the second heat exchange unit with the second portion of the main flow path;
• wherein the refrigerants exchange heat in the first heat exchange unit and the second heat exchange unit in sequence.