Patent Publication Number: US-2023132926-A1

Title: Heat exchanger and air-conditioning system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 16/710,079, filed Dec. 11, 2019, which claims foreign priority benefits under 35 U.S.C. § 119 to Chinese Patent Application No. 201811538892.5 filed on Dec. 14, 2018, the contents of each of which are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relate to a heat exchanger and an air-conditioning system. 
     BACKGROUND 
     Heat exchangers for two circuits are separate from each other in a conventional air-conditioning system. 
     SUMMARY 
     An object of embodiments of the present invention is to provide a heat exchanger and an air-conditioning system, thereby, for example, improving a heat exchange capacity of the heat exchanger in a part load condition. 
     Embodiments of the present invention provide a heat exchanger including: heat exchange tubes, wherein the heat exchange tubes include first heat exchange tubes configured to form a first circuit, and second heat exchange tubes configured to form a second circuit. 
     According to embodiments of the present invention, the heat exchanger further includes: first fins, at least a portion of each of which extends in a first direction, which are arranged in a row in a second direction perpendicular to the first direction, and which are arranged alternately with the heat exchange tubes. 
     According to embodiments of the present invention, the heat exchanger is bent in an L shape, a U shape, or a C shape when viewed in the second direction. 
     According to embodiments of the present invention, the heat exchange tube includes a first end on one side of the heat exchanger in the first direction, a second end on the other side of the heat exchanger in the first direction, and an intermediate part between the first end and the second end, the first end of the first heat exchange tube is bent towards a side of the heat exchanger in a third direction perpendicular to both the first direction and the second direction, and the intermediate part and the second end of the first heat exchange tube extend in the first direction, and the second end of the second heat exchange tube is bent towards the side of the heat exchanger in the third direction perpendicular to both the first direction and the second direction, and the intermediate part and the first end of the second heat exchange tube extend in the first direction. 
     According to embodiments of the present invention, the heat exchanger further includes: two first manifolds which are connected with and are in fluid communication with the first ends and the second ends of the first heat exchange tubes, respectively; and two second manifolds which are connected with and are in fluid communication with the first ends and the second ends of the second heat exchange tubes, respectively. 
     According to embodiments of the present invention, the heat exchange tube includes a first end and a second end, the heat exchanger further includes: two first manifolds which are connected with and are in fluid communication with the first ends and the second ends of the first heat exchange tubes, respectively; and two second manifolds which are connected with and are in fluid communication with the first ends and the second ends of the second heat exchange tubes, respectively, and one of the first manifold and the second manifold on one side, in the first direction, of the heat exchanger is closer to a center, in the first direction, of the heat exchanger than the other in the first direction, such that at least a portion of the one of the first manifold and the second manifold is located in a region between the other of the first manifold and the second manifold and the first fins in the first direction, to hinder at least a portion of an air stream bypassed through a gap between the other of the first manifold and the second manifold and the first fins. 
     According to embodiments of the present invention, first heat exchange tube sets each composed of at least one first heat exchange tube, and second heat exchange tube sets each composed of at least one second heat exchange tube are arranged alternately in the second direction. 
     According to embodiments of the present invention, the first heat exchange tubes, the second heat exchange tubes, and the first fins are aligned, on at least one side in a third direction perpendicular to both the first direction and the second direction, with one another in the second direction. 
     According to embodiments of the present invention, the first heat exchange tube includes: a first heat exchange tube part and a second heat exchange tube part arranged in a third direction perpendicular to both the first direction and the second direction; and a connection part connecting and fluidly communicating the first heat exchange tube part and the second heat exchange tube part with each other, and the first heat exchange tube part and the second heat exchange tube part are in contact with a same first fin located on one side of the first heat exchange tube part and the second heat exchange tube part in the second direction and are in contact with a same first fin located on the other side of the first heat exchange tube part and the second heat exchange tube part in the second direction. 
     According to embodiments of the present invention, the heat exchanger further includes: first fins, at least a portion of each of which extends in a first direction, and which are arranged in a row in a second direction perpendicular to the first direction; and second fins, at least a portion of each of which extends in the first direction, and which are arranged in a row in the second direction perpendicular to the first direction, wherein the first heat exchange tube includes: a first heat exchange tube part and a second heat exchange tube part arranged in a third direction perpendicular to both the first direction and the second direction; and a connection part connecting and fluidly communicating the first heat exchange tube part and the second heat exchange tube part with each other, wherein the first fins and a first set of heat exchange tubes composed of both the first heat exchange tube parts of the first heat exchange tubes and the second heat exchange tubes are arranged alternately in a row in the second direction perpendicular to the first direction, and wherein the second fins and a second set of heat exchange tubes composed of the second heat exchange tube parts of the first heat exchange tubes are arranged alternately in a row in the second direction perpendicular to the first direction. 
     According to embodiments of the present invention, the first heat exchange tube part, the second heat exchange tube part, and the connection part of the first heat exchange tube are formed by bending a single heat exchange tube. 
     According to embodiments of the present invention, the heat exchange tubes further include third heat exchange tubes configured to form a third circuit, and first heat exchange tube sets each composed of at least one of the first heat exchange tubes, second heat exchange tube sets each composed of at least one of the second heat exchange tubes, and third heat exchange tube sets each composed of at least one of the third heat exchange tubes are arranged alternately in the second direction. 
     According to embodiments of the present invention, the heat exchanger further includes: first fins, at least a portion of each of which extends in a first direction, and which are arranged in a row in a second direction perpendicular to the first direction; second fins, at least a portion of each of which extends in the first direction, and which are arranged in a row in the second direction perpendicular to the first direction; and third fins, at least a portion of each of which extends in the first direction, and which are arranged in a row in the second direction perpendicular to the first direction, wherein the heat exchange tubes further include third heat exchange tubes configured to form a third circuit, wherein each of the first heat exchange tube and the second heat exchange tube includes: a first heat exchange tube part and a second heat exchange tube part arranged in a third direction perpendicular to both the first direction and the second direction; and a connection part connecting and fluidly communicating the first heat exchange tube part and the second heat exchange tube part with each other, wherein the first heat exchange tube parts of the first heat exchange tubes, the first heat exchange tube parts of the second heat exchange tubes, and the third heat exchange tubes are arranged in a row, the second heat exchange tube parts of the first heat exchange tubes are arranged in a row, the second heat exchange tube parts of the second heat exchange tubes are arranged in a row, and the second heat exchange tube parts of the first heat exchange tubes and the second heat exchange tube parts of the second heat exchange tubes are located on two sides of the third heat exchange tubes in the third direction, respectively, wherein the first fins and a first set of heat exchange tubes composed of the second heat exchange tube parts of the first heat exchange tubes are arranged alternately in a row in the second direction, wherein the second fins and a second set of heat exchange tubes composed of the first heat exchange tube parts of the first heat exchange tubes, the first heat exchange tube parts of the second heat exchange tubes, and the third heat exchange tubes are arranged alternately in a row in the second direction, and wherein the third fins and a third set of heat exchange tubes composed of the second heat exchange tube parts of the second heat exchange tubes are arranged alternately in a row in the second direction. 
     According to embodiments of the present invention, the heat exchanger further includes: first fins, at least a portion of each of which extends in a first direction, and which are arranged in a row in a second direction perpendicular to the first direction; and second fins, at least a portion of each of which extends in the first direction, and which are arranged in a row in the second direction perpendicular to the first direction, wherein the heat exchange tubes further include third heat exchange tubes configured to form a third circuit, wherein each of the first heat exchange tube and the second heat exchange tube includes: a first heat exchange tube part and a second heat exchange tube part arranged in a third direction perpendicular to both the first direction and the second direction; and a connection part connecting and fluidly communicating the first heat exchange tube part and the second heat exchange tube part with each other, wherein the first heat exchange tube parts of the first heat exchange tubes, the first heat exchange tube parts of the second heat exchange tubes, and the third heat exchange tubes are arranged in a row, and the second heat exchange tube parts of the first heat exchange tubes and the second heat exchange tube parts of the second heat exchange tubes are arranged in a row and are located on a side of the third heat exchange tubes in the third direction, wherein the first fins and a first set of heat exchange tubes composed of the second heat exchange tube parts of the first heat exchange tubes and the second heat exchange tube parts of the second heat exchange tubes are arranged alternately in a row in the second direction, and wherein the second fins and a second set of heat exchange tubes composed of the first heat exchange tube parts of the first heat exchange tubes, the first heat exchange tube parts of the second heat exchange tubes, and the third heat exchange tubes are arranged alternately in a row in the second direction. 
     According to embodiments of the present invention, in a third direction perpendicular to both the first direction and the second direction, a size of the first fin is the same as a bigger one of a size of a portion of the first heat exchange tube in contact with the first fin and a size of a portion of the second heat exchange tube in contact with the first fin. 
     According to embodiments of the present invention, the heat exchange tube includes a first end and a second end, the heat exchanger further includes: two first manifolds which are connected with and are in fluid communication with the first ends and the second ends of the first heat exchange tubes, respectively; two second manifolds which are connected with and are in fluid communication with the first ends and the second ends of the second heat exchange tubes, respectively, and two third manifolds which are connected with and are in fluid communication with the first ends and the second ends of the third heat exchange tubes, respectively. 
     Embodiments of the present invention provide an air-conditioning system including the above heat exchanger. 
     With the heat exchanger according to the embodiments of the present invention, for example, the heat exchange capacity of the heat exchanger in the part load condition is improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic perspective view of a heat exchanger according to a first embodiment of the present invention; 
         FIG.  2    is a schematic top view of the heat exchanger according to the first embodiment of the present invention; 
         FIG.  3    is a schematic top view of a heat exchanger according to a second embodiment of the present invention; 
         FIG.  4    is a schematic partially enlarged view of a heat exchanger according to a third embodiment of the present invention; 
         FIG.  5    is a schematic top view of a heat exchanger according to a fourth embodiment of the present invention, in which flow directions of a refrigerant are indicated by arrows along heat exchange tubes; 
         FIG.  6    is a schematic perspective view of a heat exchanger according to a fifth embodiment of the present invention; 
         FIG.  7    is a schematic top view of the heat exchanger according to the fifth embodiment of the present invention; 
         FIG.  8    is a schematic top view of a heat exchanger according to a sixth embodiment of the present invention, in which flow directions of a refrigerant are indicated by arrows along heat exchange tubes; 
         FIG.  9    is a schematic perspective view of a heat exchanger according to a seventh embodiment of the present invention; 
         FIG.  10    is a schematic top view of the heat exchanger according to the seventh embodiment of the present invention; 
         FIG.  11    is a schematic perspective view of a heat exchanger according to an eighth embodiment of the present invention; 
         FIG.  12    is a schematic top view of the heat exchanger according to the eighth embodiment of the present invention; 
         FIG.  13    is a schematic perspective view of a heat exchanger according to a ninth embodiment of the present invention; and 
         FIG.  14    is a schematic top view of the heat exchanger according to the ninth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     An air-conditioning system according to embodiments of the present invention includes a heat exchanger. Specifically, the air-conditioning system according to the embodiments of the present invention includes a compressor, a heat exchanger as an evaporator, a heat exchanger as a condenser, an expansion valve, and the like. The air-conditioning system may include two or more circuits. Each circuit is constituted by a portion of a heat exchanger configured to form this circuit. A plurality of portions of the heat exchanger respectively configured to form the circuits are connected in parallel and are independent of one another. 
     Referring to  FIGS.  1  to  14   , a heat exchanger  100  according to embodiments of the present invention includes heat exchange tubes  1 . The heat exchange tubes  1  include first heat exchange tubes  1 A configured to form a first circuit, and second heat exchange tubes  1 B configured to form a second circuit. 
     Referring to  FIGS.  1  to  3  and  9  to  14   , the heat exchanger  100  according to the embodiments of the present invention further includes first fins  2 , at least a portion of each of which extends in a first direction D 1 , which are arranged in a row in a second direction D 2  perpendicular to the first direction D 1 , and which are arranged alternately with the heat exchange tubes  1 . Thereby, for example, if one of two circuits of a two-circuit air-conditioning system is turned off, at least some of fins for the one circuit may be used for the other circuit to improve a heat exchange efficiency of the heat exchanger. 
     Referring to  FIGS.  1  to  3  and  9  to  14   , the first heat exchange tubes  1 A and the second heat exchange tubes  1 B are arranged alternately in the second direction D 2 . In other embodiments of the present invention, first heat exchange tube sets each composed of at least one (one, two, three or more) of the first heat exchange tubes  1 A, and second heat exchange tube sets each composed of at least one (one, two, three or more) of the second heat exchange tubes  1 B are arranged alternately in the second direction D 2 . In other words, a plurality of first heat exchange tube sets and a plurality of second heat exchange tube sets are arranged alternately. The heat exchange tube  1  may be a flat tube. According to examples of the present invention, the first heat exchange tubes  1 A, the second heat exchange tubes  1 B, and the first fins  2  are aligned, on at least one side in a third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 , with one another in the second direction D 2 . In some examples of the present invention, the first heat exchange tubes  1 A include a plurality of first heat exchange tube sets, the second heat exchange tubes  1 B include a plurality of second heat exchange tube sets, and the plurality of first heat exchange tube sets and the plurality of second heat exchange tube sets are arranged alternately in the second direction D 2 . The plurality of first heat exchange tube sets may have the same number or different numbers of first heat exchange tubes  1 A. The plurality of second heat exchange tube sets may have the same number or different numbers of second heat exchange tubes  1 B. 
     Referring to  FIGS.  1  to  3  and  9  to  14   , in some embodiments of the present invention, the first fin  2  has a same size in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2  as a bigger one of a portion of the first heat exchange tube  1 A in contact with the first fin  2  and a portion of the second heat exchange tube  1 B in contact with the first fin  2 . Thereby, both the first heat exchange tube  1 A and the second heat exchange tube  1 B are in contact with the first fin  2  over their entire sizes (for example their entire widths) in the third direction D 3 . 
     According to embodiments of the present invention, referring to  FIGS.  3  and  9  to  14   , the heat exchanger  100  is bent in an L shape ( FIGS.  9  and  10   ), a U shape ( FIGS.  3 ,  13  and  14   ), or a C shape ( FIGS.  11  and  12   ) when viewed in the second direction D 2  (i.e. when viewed in a top view). In addition, the heat exchanger  100  may be bent in any other shape such as a V shape. A heat exchange area may be increased by bending the heat exchanger. The bent heat exchanger is obviously superior in heat exchange capability to a single-row heat exchanger. The number of circuits of the heat exchanger may be greater than or equal to 2. 
     According to embodiments of the present invention, referring to  FIGS.  1  to  3   , the heat exchange tube  1  includes a first end  11  on one side of the heat exchanger  100  in the first direction D 1 , a second end  12  on the other side of the heat exchanger  100  in the first direction D 1 , and an intermediate part  13  between the first end  11  and the second end  12 . The first end  11  of the first heat exchange tube  1 A is bent towards a side of the heat exchanger  100  in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 , and the intermediate part  13  and the second end  12  of the first heat exchange tube  1 A extend in the first direction D 1 . In addition, the second end  12  of the second heat exchange tube  1 B is bent towards the side of the heat exchanger  100  in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 , and the intermediate part  13  and the first end  11  of the second heat exchange tube  1 B extend in the first direction D 1 . The heat exchange tube  1  is bent at only one end and not bent in the other end. All the heat exchange tubes  1  may have the same shape and size, so that the number of types of the heat exchange tubes  1  is reduced, thereby remarkably increasing a manufacturing efficiency of the heat exchanger. 
     According to embodiments of the present invention, referring to  FIGS.  1  to  4  and  9  to  14   , the heat exchanger  100  further includes: two first manifolds  3 A which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the first heat exchange tubes  1 A, respectively; and two second manifolds  3 B which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the second heat exchange tubes  1 B, respectively. 
     According to embodiments of the present invention, referring to  FIGS.  1    to  4  and  9  to  14 , the heat exchange tube  1  includes a first end  11  and a second end  12 . The heat exchanger  100  further includes: two first manifolds  3 A which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the first heat exchange tubes  1 A, respectively; and two second manifolds  3 B which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the second heat exchange tubes  1 B, respectively. One of the first manifold  3 A and the second manifold  3 B on one side, in the first direction D 1 , of the heat exchanger  100  is closer to a center, in the first direction D 1 , of the heat exchanger  100  than the other in the first direction D 1 , such that at least a portion of the one of the first manifold  3 A and the second manifold  3 B is located in a region between the other of the first manifold  3 A and the second manifold  3 B and the first fins  2  in the first direction D 1 , to hinder at least a portion of an air stream A bypassed through a gap between the other of the first manifold  3 A and the second manifold  3 B and the first fins  2  as shown in  FIG.  4   . Referring to  FIG.  4   , a height difference between a center line of the first manifold  3 A and a center line of the second manifold  3 B is H. 
     Referring to  FIG.  5   , in some embodiments of the present invention, the first heat exchange tube  1 A includes: a first heat exchange tube part  1 A 1  and a second heat exchange tube part  1 A 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 A 3  connecting and fluidly communicating the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  with each other. The first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  are in contact with a same first fin  2  located on one side of the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  in the second direction D 2  and are in contact with a same first fin  2  located on the other side of the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  in the second direction D 2 . For example, the first heat exchange tube part  1 A 1 , the second heat exchange tube part  1 A 2 , and the connection part  1 A 3  of the first heat exchange tube  1 A are formed by bending a single heat exchange tube  1 . 
     According to the embodiments of the present invention, at least some of the plurality of first fins  2  are shared by the first heat exchange tubes  1 A and the second heat exchange tubes  1 B. Therefore, if one of two circuits of a two-circuit air-conditioning system is turned off, at least some of the first fins for the one circuit may be used for the other circuit to improve a heat exchange efficiency of the heat exchanger. 
     Referring to  FIG.  5   , in some embodiments of the present invention, the heat exchanger  100  further includes: first fins  2 , at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 ; and second fins, at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 . The first heat exchange tube  1 A includes: a first heat exchange tube part  1 A 1  and a second heat exchange tube part  1 A 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 A 3  connecting and fluidly communicating the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  with each other. The first fins  2  and a first set of heat exchange tubes  1  composed of both the first heat exchange tube parts  1 A 1  of the first heat exchange tubes  1 A and the second heat exchange tubes  1 B are arranged alternately in a row in the second direction D 2  perpendicular to the first direction D 1 , and the second fins and a second set of heat exchange tubes  1  composed of the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A are arranged alternately in a row in the second direction D 2  perpendicular to the first direction D 1 . A height of the second fin in the second direction D 2  is substantially equal to a distance between two adjacent second heat exchange tube parts  1 A 2 , and is greater than a height of the first fin  2  in the second direction D 2 . In other words, in the present embodiment, the first heat exchange tube  1 A has a greater length than the second heat exchange tube  1 B, thereby achieving different heat exchange capabilities of different circulation circuits. In addition to the achievement of the different heat exchange capabilities of the different circulation circuits, an installation space for the heat exchanger is sufficiently utilized. The heat exchanger is obviously superior in heat exchange capability to a single-row heat exchanger. The first heat exchange tube parts  1 A 1  and the second heat exchange tube parts  1 A 2  may be substantially parallel to one another, and may be substantially parallel to the second heat exchange tubes  1 B. 
     Referring to  FIG.  8    and referring also to  FIGS.  6  and  7   , in some embodiments of the present invention, the heat exchange tubes  1  further include third heat exchange tubes  1 C configured to form a third circuit. As shown in  FIG.  8   , the first heat exchange tube  1 A includes: a first heat exchange tube part  1 A 1  and a second heat exchange tube part  1 A 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 A 3  connecting and fluidly communicating the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  with each other. As shown in  FIG.  8   , the second heat exchange tube  1 B includes: a first heat exchange tube part  1 B 1  and a second heat exchange tube part  1 B 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 B 3  connecting and fluidly communicating the first heat exchange tube part  1 B 1  and the second heat exchange tube part  1 B 2  with each other. The first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  of the first heat exchange tube  1 A are in contact with a same first fin  2  located on one side of the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  of the first heat exchange tube  1 A in the second direction D 2  and are in contact with a same first fin  2  located on the other side of the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  of the first heat exchange tube  1 A in the second direction D 2 . The first heat exchange tube part  1 B 1  and the second heat exchange tube part  1 B 2  of the second heat exchange tube  1 B are in contact with a same first fin  2  located on one side of the first heat exchange tube part  1 B 1  and the second heat exchange tube part  1 B 2  of the second heat exchange tube  1 B in the second direction D 2  and are in contact with a same first fin  2  located on the other side of the first heat exchange tube part  1 B 1  and the second heat exchange tube part  1 B 2  of the second heat exchange tube  1 B in the second direction D 2 . According to examples of the present invention, the first heat exchange tube parts  1 A 1  of the first heat exchange tubes  1 A, the first heat exchange tube parts  1 B 1  of the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C are arranged in a row, the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A are arranged in a row, the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are arranged in a row, and the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A and the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are located on two sides of the third heat exchange tubes  1 C in the third direction D 3 , respectively. 
     Referring to  FIG.  8    and referring also to  FIGS.  6  and  7   , in some embodiments of the present invention, the heat exchanger  100  further includes: first fins  2 , at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 ; second fins, at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 ; and third fins, at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 . The heat exchange tubes  1  further include third heat exchange tubes  1 C configured to form a third circuit. The first heat exchange tube  1 A includes: a first heat exchange tube part  1 A 1  and a second heat exchange tube part  1 A 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 A 3  connecting and fluidly communicating the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  with each other. The second heat exchange tube  1 B includes: a first heat exchange tube part  1 B 1  and a second heat exchange tube part  1 B 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 B 3  connecting and fluidly communicating the first heat exchange tube part  1 B 1  and the second heat exchange tube part  1 B 2  with each other. The first heat exchange tube parts  1 A 1  of the first heat exchange tubes  1 A, the first heat exchange tube parts  1 B 1  of the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C are arranged in a row, the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A are arranged in a row, the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are arranged in a row, and the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A and the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are located on two sides of the third heat exchange tubes  1 C in the third direction D 3 , respectively. The first fins  2  and a first set of heat exchange tubes  1  composed of the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A are arranged alternately in a row in the second direction D 2 . The second fins and a second set of heat exchange tubes  1  composed of the first heat exchange tube parts  1 A 1  of the first heat exchange tubes  1 A, the first heat exchange tube parts  1 B 1  of the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C are arranged alternately in a row in the second direction D 2 . In addition, the third fins and a third set of heat exchange tubes  1  composed of the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are arranged alternately in a row in the second direction D 2 . 
     Referring to  FIG.  8    and referring also to  FIGS.  6  and  7   , in some embodiments of the present invention, the heat exchanger  100  further includes: first fins  2 , at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 ; and second fins, at least a portion of each of which extends in the first direction D 1 , and which are arranged in a row in the second direction D 2  perpendicular to the first direction D 1 . The heat exchange tubes  1  further include third heat exchange tubes  1 C configured to form a third circuit. The first heat exchange tube  1 A includes: a first heat exchange tube part  1 A 1  and a second heat exchange tube part  1 A 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 A 3  connecting and fluidly communicating the first heat exchange tube part  1 A 1  and the second heat exchange tube part  1 A 2  with each other. The second heat exchange tube  1 B includes: a first heat exchange tube part  1 B 1  and a second heat exchange tube part  1 B 2  arranged in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 ; and a connection part  1 B 3  connecting and fluidly communicating the first heat exchange tube part  1 B 1  and the second heat exchange tube part  1 B 2  with each other. The first heat exchange tube parts  1 A 1  of the first heat exchange tubes  1 A, the first heat exchange tube parts  1 B 1  of the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C are arranged in a row, and the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A and the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are arranged in a row and are located on a side of the third heat exchange tubes  1 C in the third direction D 3 . The first fins  2  and a first set of heat exchange tubes  1  composed of the second heat exchange tube parts  1 A 2  of the first heat exchange tubes  1 A and the second heat exchange tube parts  1 B 2  of the second heat exchange tubes  1 B are arranged alternately in a row in the second direction D 2 . In addition, The second fins and a second set of heat exchange tubes  1  composed of the first heat exchange tube parts  1 A 1  of the first heat exchange tubes  1 A, the first heat exchange tube parts  1 B 1  of the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C are arranged alternately in a row in the second direction D 2 . 
     Referring to  FIGS.  6  to  8   , in some embodiments of the present invention, the heat exchange tube  1  includes a first end  11  and a second end  12 . the heat exchanger  100  further includes: two first manifolds  3 A which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the first heat exchange tubes  1 A, respectively; two second manifolds  3 B which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the second heat exchange tubes  1 B, respectively; and two third manifolds  3 C which are connected with and are in fluid communication with the first ends  11  and the second ends  12  of the third heat exchange tubes  1 C, respectively. According to embodiments of the present invention, the manifolds for one circuit may not be used or may be closed so that the heat exchanger  100  may be applied to a two-circuit system. In addition, an arrangement sequence, in the third direction, of three manifolds of the heat exchanger  100  on a side of the heat exchanger  100  in the first direction may be changed according to requirements. 
     Referring to  FIGS.  6  to  7   , in some embodiments of the present invention, the first heat exchange tubes  1 A, the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C are arranged alternately in the second direction D 2 . In other embodiments of the present invention, first heat exchange tube sets each composed of at least one (one, two, three or more) of the first heat exchange tubes  1 A, second heat exchange tube sets each composed of at least one (one, two, three or more) of the second heat exchange tubes  1 B, and third heat exchange tube sets each composed of at least one (one, two, three or more) of the third heat exchange tubes  1 C are arranged alternately in the second direction D 2 . In other words, a plurality of first heat exchange tube sets, a plurality of second heat exchange tube sets, and a plurality of third heat exchange tube sets are arranged alternately. The heat exchange tube  1  may be a flat tube. According to examples of the present invention, the first heat exchange tubes  1 A, the second heat exchange tubes  1 B, the third heat exchange tubes  1 C, and the first fins  2  are aligned, on at least one side in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2 , with one another in the second direction D 2 . According to examples of the present invention, the first heat exchange tubes  1 A, the second heat exchange tubes  1 B, the third heat exchange tubes  1 C, and the first fins  2  are arranged alternately in a row in the second direction D 2 , or are arranged in a row in any other way. In some examples of the present invention, the first heat exchange tubes  1 A include a plurality of first heat exchange tube sets, the second heat exchange tubes  1 B include a plurality of second heat exchange tube sets, the third heat exchange tubes  1 C include a plurality of third heat exchange tube sets, and the plurality of first heat exchange tube sets, the plurality of second heat exchange tube sets, and the plurality of third heat exchange tube sets are arranged alternately in the second direction D 2 . The plurality of first heat exchange tube sets may have the same number or different numbers of first heat exchange tubes  1 A. The plurality of second heat exchange tube sets may have the same number or different numbers of second heat exchange tubes  1 B. The plurality of third heat exchange tube sets may have the same number or different numbers of third heat exchange tubes  1 C. 
     Referring to  FIGS.  6  to  7   , in some embodiments of the present invention, the first fin  2  has a same size in the third direction D 3  perpendicular to both the first direction D 1  and the second direction D 2  as a biggest one of a portion of the first heat exchange tube  1 A in contact with the first fin  2 , a portion of the second heat exchange tube  1 B in contact with the first fin  2 , and a portion of the third heat exchange tube  1 C in contact with the first fin  2 . Thereby, all the first heat exchange tube  1 A, the second heat exchange tube  1 B, and the third heat exchange tube  1 C are in contact with the first fin  2  over their entire sizes (for example their entire widths) in the third direction D 3 . 
     Referring to  FIG.  8    and referring also to  FIGS.  6  and  7   , in some embodiments of the present invention, different heat exchange capabilities of different circulation circuits may be achieved by changing lengths of the heat exchange tubes  1 , while a length of a different heat exchange tube  1  for a different circuit may be achieved by bending a heat exchange tube  1 . In addition to the achievement of the different heat exchange capabilities of the different circulation circuits, an installation space for the heat exchanger is sufficiently utilized. The heat exchanger is obviously superior in heat exchange capability to a single-row heat exchanger. The number of the circulation circuits may be greater than or equal to 2. A length of a heat exchange tube  1  for at least one circuit is greater than a length of a heat exchange tube  1  for the other circuit(s), and heat exchange tube parts formed by bending the heat exchange tubes  1  for the at least one circuit are substantially parallel to the other heat exchange tubes  1 . 
     Referring to  FIG.  8    and referring also to  FIGS.  6  and  7   , in some embodiments of the present invention, the first heat exchange tube part, the second heat exchange tube part, and the connection part of the heat exchange tube  1  are formed by bending a single heat exchange tube  1 . 
     According to the embodiments of the present invention, referring to  FIGS.  6  to  8   , at least some of the plurality of first fins  2  are shared by the first heat exchange tubes  1 A, the second heat exchange tubes  1 B, and the third heat exchange tubes  1 C. Therefore, if one of three circuits of a three-circuit air-conditioning system is turned off, at least some of the first fins for the one circuit may be used for the other two circuits to improve a heat exchange efficiency of the heat exchanger. 
     According to the embodiments of the present invention, the heat exchange capacity of the heat exchanger in the part load condition is improved, the heat exchanger can maintain an enough flow rate of a refrigerant for returning an oil in the part load condition, and in the case where one circuit fails, the air-conditioning system can continue to operate through another circuit. 
     According to the embodiments of the present invention, the heat exchanger has more than two circuits, and can be applied to a system having a plurality of completely separate circuits. Each circuit has a separate compressor, and in each circuit, a refrigerant flows independently. The three-circuit heat exchanger can be applied to not only a three-circuit system, and but also a two-circuit system. 
     In addition, the above embodiments of the present invention may be combined into new embodiments. 
     While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.