Internal heat exchanger and refrigeration cycle apparatus having the internal heat exchanger

An internal heat exchanger comprising:

• an outer pipe forming an outside pipe of a double pipe;
• and
• an inner pipe formed separately from the outer pipe and forming an inside pipe of the double pipe, wherein
• the inner pipe forms, thereinside, an inner flow path through which a refrigerant of a low-pressure side for a refrigeration cycle flows, and wherein
• the inner pipe and the outer pipe form, therebetween, an inner-outer flow path through which the refrigerant of a high-pressure side for the refrigeration cycle flows, and wherein
• the outer pipe has an outer diameter of 30 millimeters or less, and wherein
• a ratio of a difference between an inner diameter of the outer pipe and an outer diameter of the inner pipe to the inner diameter of the outer pipe is 25% or less, and wherein
• the inner pipe and the outer pipe form, therebetween, a concentric structure which increases a flow path cross-sectional area of the inner-outer flow path and arrange the outer pipe and the inner pipe concentrically, and wherein
• the inner pipe has a distal end which extends more outwardly in an axial direction than a distal end of the outer pipe, and further comprising:
• a connector which is interposed between the outer pipe and the inner pipe and a connection target member and defines both a low-pressure communication flow path communicating the inner flow path with a refrigerant passage of the connection target member and a high-pressure communication flow path communicating the inner-outer flow path with a refrigerant flow path of the connection target member, wherein
• the distal end of the outer pipe is separated from an innermost portion of the outer pipe insertion portion of the connector to form a high-pressure communication space communicating the high-pressure communication flow path, and wherein
• an outer pipe side sealing member which is interposed between the outer pipe and the outer pipe insertion portion of the connector to prevent a refrigerant leakage from the high-pressure communication space, and wherein
• an inner pipe side sealing member which is interposed between the inner pipe and the inner pipe insertion portion of the connector to prevent a refrigerant leakage from the high-pressure communication space, and wherein
• the double pipe and the connector are mechanically fixed, and wherein
• a positional relationship between the distal end of the inner pipe, the inner pipe side sealing member, the distal end of the outer pipe, and the outer pipe side sealing member, and the inner pipe insertion portion and the outer pipe insertion portion of the connector define a structure,
• at inserting the inner pipe and the outer pipe into the connector,
• first, the distal end of the inner pipe comes into contact with the inner pipe insertion portion, next, the distal end of the outer pipe comes into contact with the outer pipe insertion portion, after that, the inner pipe side sealing member comes into contact with the inner pipe insertion portion, finally the outer pipe side sealing member comes into contact with the outer pipe insertion portion.

A refrigeration cycle apparatus comprising:

• a compressor;
• a condenser;
• an expansion valve for an indoor air conditioning unit;
• an evaporator for the indoor air-conditioning unit;
• an expansion valve for a rear cooler;
• an evaporator for the rear cooler;
• and an internal heat exchanger, wherein
• the internal heat exchanger includes:
• an outer pipe forming an outside pipe of a double pipe;
• and
• an inner pipe formed separately from the outer pipe and forming an inside pipe of the double pipe, and wherein
• the inner pipe forms, thereinside, an inner flow path through which a refrigerant of a low-pressure side for a refrigeration cycle flows, and wherein
• the inner pipe and the outer pipe form, therebetween, an inner-outer flow path through which the refrigerant of a high-pressure side for the refrigeration cycle flows, and wherein
• the outer pipe has an outer diameter of 30 millimeters or less, and wherein
• a ratio of a difference between an inner diameter of the outer pipe and an outer diameter of the inner pipe to the inner diameter of the outer pipe is 25% or less, and wherein
• the inner pipe and the outer pipe form, therebetween, a concentric structure which increases a flow path cross-sectional area of the inner-outer flow path and arrange the outer pipe and the inner pipe concentrically, further comprising:
• a connector which is located at end portions of the outer pipe and the inner pipe, and forms a high-pressure communication flow path communicating the inner-outer flow path with a refrigerant flow path of a connection target member, and a low-pressure communication flow path communicating the inner flow path with a refrigerant passage of the connection target member;
• an outer pipe side sealing member located at the end portion of the outer pipe to prevent a refrigerant leakage;
• and
• an inner pipe side sealing member located at the end portion of the inner pipe to prevent a refrigerant leakage, wherein
• the double pipe and the connector are mechanically fixed at a place other than places where the outer pipe side sealing member and the inner pipe side sealing member are arranged, and wherein
• the concentric structure is not formed at a position where the outer pipe side sealing member and the inner pipe side sealing member are arranged, but is formed at an end portion of at least one of the outer pipe and the inner pipe in a vicinity of the connector, and wherein
• the end portion among the outer pipe in a vicinity of the connector is pressed and deformed inward in the radial direction of the outer pipe over a predetermined distance, and wherein
• the end portions of the outer pipe and the inner pipe in a vicinity of the connector are joined to each other via the concentric structure, and wherein
• the internal heat exchanger is interposed between the condenser and the compressor, and the expansion valve for the indoor air-conditioning unit and the expansion valve for the rear cooler, and wherein
• the connector connects the high-pressure communication flow path with at least the condenser or one of the expansion valve for the indoor air-conditioning unit and the expansion valve for the rear cooler, and connects the low-pressure communication flow path with at least the expansion valve for the indoor air-conditioning unit and one of the expansion valve for the rear cooler or the compressor.

An internal heat exchanger comprising:

• an outer pipe forming an outside pipe of a double pipe;
• and
• an inner pipe formed separately from the outer pipe and forming an inside pipe of the double pipe, and wherein
• the inner pipe forms, thereinside, an inner flow path through which a refrigerant of a low-pressure side for a refrigeration cycle flows, and wherein
• the inner pipe and the outer pipe form, therebetween, an inner-outer flow path through which the refrigerant of a high-pressure side for the refrigeration cycle flows, and wherein
• the inner pipe and the outer pipe form, therebetween, a concentric structure which arranges the outer pipe and the inner pipe concentrically, and wherein
• the inner pipe has a distal end which extends more outwardly in an axial direction than a distal end of the outer pipe, and further comprising:
• a connector which is interposed between the outer pipe and the inner pipe and a connection target member and defines both a low-pressure communication flow path communicating the inner flow path with a refrigerant passage of the connection target member and a high-pressure communication flow path communicating the inner-outer flow path with a refrigerant flow path of the connection target member;
• an outer pipe side sealing member which is interposed between the outer pipe and the outer pipe insertion portion of the connector to prevent a refrigerant leakage from a high-pressure communication space;
• and
• an inner pipe side sealing member which is interposed between the inner pipe and the inner pipe insertion portion of the connector to prevent a refrigerant leakage from the high-pressure communication space, wherein
• the double pipe and the connector are mechanically fixed at a place other than places where the outer pipe side sealing member and the inner pipe side sealing member are arranged, and wherein
• the high-pressure communication space is formed so that the distal end of the outer pipe is separated from an innermost portion of the outer pipe insertion portion of the connector, and wherein
• the high-pressure communication flow path communicates with the high-pressure communication space, and wherein
• the distal end of the inner pipe and the innermost portion of the inner pipe insertion portion form a gap therebetween, and wherein
• the distal end of the inner pipe and the distal end of the outer pipe are capable of being shifted in an axial deviation.