Patent Publication Number: US-9891007-B2

Title: Bent heat exchanger and method for manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a national phase entry under 35 USC § 371 of International Patent Application No. PCT/CN2014/070686 filed Jan. 15, 2014, which claims priority to and all the benefits of Chinese Patent Application No. 201310093380.3 filed Mar. 21, 2013, and Chinese Patent Application No. 201320132908.9 filed Mar. 21, 2013, the entire disclosures of which are hereby expressly incorporated herein by reference in their entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates to a bent heat exchanger and a method for manufacturing the same. 
     2. Description of the Related Art 
     A heat exchanger, e.g., a parallel flow heat exchanger, is widely used in a refrigerating system. In some cases of applications, there is a need to bend the heat exchanger. Traditionally, in the bent heat exchanger, no-fin segments of a flat tube are twisted toward a same direction, and then bent. Because the accumulation of the bending deformation is over large, the bending method may affect the final assembly and the appearance of the heat exchanger, which affects the application. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present disclosure seek to solve at least one of the problems existing in the related art to at least some extent or provide a useful commercial choice. Accordingly, an object of the present disclosure is to provide a bent heat exchanger with advantages of a neat, aesthetic appearance, a better assembly effect, a wide application and a high reliability. 
     Another object of the present disclosure is to provide a method for manufacturing the bent heat exchanger. 
     To achieve the object described above, a bent heat exchanger is provided according to embodiments of a first aspect of the present disclosure. The bent heat exchanger includes: first and second headers spaced apart from each other; a plurality of flat tubes disposed between the first and second headers and divided into a plurality of groups, each flat tube defining two ends connected with the first and second headers respectively, each flat tube having straight segments and a bent segment which is between the straight segments and twisted by a predetermined angle relative to the straight segment around a longitudinal direction of the flat tube, the bent segments of the plurality of the flat tubes forming a bent segment row extended in a thickness direction of the flat tube, twisting directions of the bent segments of the flat tubes in a same group being identical, and the twisting direction of the bent segment of the flat tube in one group being opposite to that of the bent segment of the flat tube in another group adjacent to the one group; and a plurality of fins each disposed between the straight segments of adjacent flat tubes. 
     With the bent heat exchanger according to embodiments of the present disclosure, since the twisting directions of the bent segments of the flat tubes in the same group are identical and the twisting direction of the bent segment of the flat tube in one group is opposite to that of the bent segment of the flat tube in another group adjacent to the one group, it is possible to avoid an over large accumulation of the bending deformation of the bent segments after the flat tubes are bent. Thus, the appearance of the bent heat exchanger is neater and more aesthetic, and the bent heat exchanger has a better assembly effect (easy to assemble with an application hardware). Moreover, the length of an arrangement of the flat tubes in the length direction of the first header and the second header is greater than 500 mm (i.e., the length of the first header and the second header is greater than 500 mm), and thus the application range of the bent heat exchanger is widened. Therefore, the bent heat exchanger according to embodiments of the present disclosure has advantages of a neat, aesthetic appearance, a better assembly effect, a wide application and a high reliability. 
     Furthermore, the bent heat exchanger according to embodiments of the present disclosure may also have the additional technical features as follows. 
     In some embodiments, each of the flat tubes has one bent segment and the bent segments of the plurality of the flat tubes form one bent segment row. In this way, the bent heat exchanger has an advantage of a simple structure. 
     In some embodiments, each of the flat tubes has a plurality of the bent segments spaced apart from each other in the longitudinal direction of the flat tube, the bent segments of the plurality of the flat tubes form a plurality of bent segment rows. Thus, the flat tubes can be bent into a plurality of shapes, i.e., the bent heat exchanger may have a plurality of shapes, so that the application range of the bent heat exchanger may be widened. 
     In some embodiments, an interrupted flat tube is disposed between adjacent groups of the flat tubes and defines first and second segments, a first end of the first segment is connected with the first header, a second end of the first segment is closed, a first end of the second segment is connected with the second header, a second end of the second segment is closed and spaced apart from the second end of the first segment by a predetermined distance equal to or greater than a length of the bent segment. By providing the interrupted flat tube between adjacent groups of the flat tubes, it would be avoided that protrusions produced after the bending of the flat tubes of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger may be further improved and the appearance of the bent heat exchanger is neater and more aesthetic. 
     In some embodiments, a distance between two adjacent flat tubes belonging to different groups is greater than that between two adjacent flat tubes belonging to a same group. Thus, it would be avoided that protrusions produced after the bending of the flat tubes of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger may be further improved and the appearance of the bent heat exchanger is neater and more aesthetic. 
     In some embodiments, a separation flat tube is disposed between adjacent groups of the flat tubes and has straight segments and a bent segment located between the straight segments and corresponding to the bent segment of the flat tube, a width of the separation flat tube is smaller than that of the flat tube. Thus, it would be avoided that protrusions produced after the bending of the flat tubes of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger may be further improved and the appearance of the bent heat exchanger is neater and more aesthetic. 
     In some embodiments, a distance between the separation flat tube and the flat tube adjacent to the separation flat tube is greater than that between adjacent flat tubes. Thus, it would be avoided that protrusions produced after the bending of the flat tubes of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger may be further improved and the appearance of the bent heat exchanger is neater and more aesthetic. 
     In some embodiments, a separation flat tube is disposed between adjacent groups of the flat tubes and has straight segments and a bent segment located between the straight segments and corresponding to the bent segment of the flat tube, a length of the bent segment of the separation flat tube is greater than that of the bent segment of the flat tube. Thus, it would be avoided that protrusions produced after the bending of the flat tubes of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger may be further improved and the appearance of the bent heat exchanger is neater and more aesthetic. 
     According to embodiments of a second aspect of the present disclosure, a method for manufacturing the bent heat exchanger according to embodiments of the first aspect of the present disclosure is provided. The method includes steps of: a) twisting a portion of a flat tube by a predetermined angle relative to a remaining portion of the flat tube around a longitudinal direction of the flat tube so as to form a bent segment, forming a bent segment row extended in a thickness direction of the flat tube by the bent segments of a plurality of the flat tubes, dividing the plurality of the flat tubes into a plurality of groups, twisting directions of the bent segments of the flat tubes in a same group being identical, and the twisting direction of the bent segment of the flat tube in one group being opposite to that of the bent segment of the flat tube in another group adjacent to the one group; b) connecting the flat tube between first and the second headers; c) disposing a plurality of fins between the remaining portions of adjacent flat tubes; and d) bending the flat tubes at the bent segments. 
     With the method for manufacturing the bent heat exchanger according to embodiments of the present disclosure, since a plurality of the flat tubes are divided into a plurality of groups and the twisting directions of the bent segments of the flat tubes in the same group are identical and the twisting direction of the bent segment of the flat tube in one group is opposite to that of the bent segment of the flat tube in another group adjacent to the one group, it is possible to avoid an over large accumulation of the bending deformation of the bent segments after the flat tubes are bent. Thus, the appearance of the bent heat exchanger is neater and more aesthetic, and the bent heat exchanger has a better assembly effect (easy to assemble with an application hardware). Moreover, the length of an arrangement of the flat tubes in the length direction of the first header and the second header is greater than 500 mm (i.e., the length of the first header and the second header is greater than 500 mm), and thus the application range of the bent heat exchanger is widened. Therefore, the bent heat exchanger having advantages of a neat, aesthetic appearance, a better assembly effect, a wide application and a high reliability may be manufactured by the method for manufacturing the bent heat exchanger according to embodiments of the present disclosure. 
     In some embodiments, the steps a)-d) can be performed in any order and the step a) is performed prior to the step d). Thus, the method for manufacturing the bent heat exchanger can be more suitable for the actual situation of a manufacturing process, so that the manufacture of the bent heat exchanger is more convenient and easier. 
     In some embodiments, each of the flat tubes has a plurality of the bent segments spaced apart from each other in the longitudinal direction of the flat tube, the bent segments of the plurality of the flat tubes form a plurality of bent segment rows. Thus, the flat tubes can be bent into a plurality of shapes, i.e., the bent heat exchanger may have a plurality of shapes, so that the application range of the bent heat exchanger may be widened. 
     Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects and advantages of embodiments of the present disclosure will become apparent and more readily appreciated from the following descriptions made with reference to the drawings, in which: 
         FIG. 1  is a schematic view of a bent heat exchanger before being bent according to an embodiment of the present disclosure; 
         FIG. 2  is a schematic view of a bent heat exchanger before being bent according to another embodiment of the present disclosure; 
         FIG. 3  is a schematic view of a bent heat exchanger before being bent according to a further embodiment of the present disclosure; 
         FIG. 4  is a schematic side view of a bent heat exchanger after being bent according to an embodiment of the present disclosure; 
         FIG. 5  is a schematic side view of a bent heat exchanger after being bent according to another embodiment of the present disclosure; 
         FIG. 6  is a flow chat of a method for manufacturing a bent heat exchanger according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will be made in detail to embodiments of the present disclosure. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure. 
     In the specification, unless specified or limited otherwise, relative terms such as “central”, “longitudinal”, “lateral”, “front”, “rear”, “right”, “left”, “inner”, “outer”, “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “anticlockwise” as well as derivative thereof (e.g., “horizontally”, “downwardly”, “upwardly”, etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the present disclosure be constructed or operated in a particular orientation, thus, it should not be construed to limit the present disclosure. 
     In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance. Thus, features limited by “first” and “second” are intended to indicate or imply including one or more than one these features. In the description of the present disclosure, “a plurality of” relates to two or more than two, unless specified or limited otherwise. 
     In the description of the present disclosure, unless specified or limited otherwise, it should be noted that, terms “mounted,” “connected” “coupled” and “fastened” may be understood broadly, such as permanent connection or detachable connection, electronic connection or mechanical connection, direct connection or indirect connection via intermediary, inner communication or inter reaction between two elements. These having ordinary skills in the art should understand the specific meanings in the present disclosure according to specific situations. 
     In the description of the present disclosure, a structure in which a first feature is “on” a second feature may include an embodiment in which the first feature directly contacts the second feature, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature so that the first feature does not directly contact the second feature, unless otherwise specified. Furthermore, a first feature “on,” “above,” or “on top of” a second feature may include an embodiment in which the first feature is right “on,” “above,” or “on top of” the second feature, and may also include an embodiment in which the first feature is not right “on,” “above,” or “on top of” the second feature, or just means that the first feature has a sea level elevation larger than the sea level elevation of the second feature. While first feature “beneath,” “below,” or “on bottom of” a second feature may include an embodiment in which the first feature is right “beneath,” “below,” or “on bottom of” the second feature, and may also include an embodiment in which the first feature is not right “beneath,” “below,” or “on bottom of” the second feature, or just means that the first feature has a sea level elevation smaller than the sea level elevation of the second feature. 
     With reference to  FIG. 1  to  FIG. 5 , a bent heat exchanger  1  will be described according to embodiments of the present disclosure. As shown in  FIGS. 1-5 , the bent heat exchanger  1  includes a first header  10 , a second header  20 , a plurality of flat tubes  30  and a plurality of fins  40 . 
     The first header  10  and the second header  20  are spaced apart from each other. A plurality of flat tubes  30  are disposed between the first header  10  and the second header  20 . Each of the flat tubes  30  defines two ends connected with the first header  10  and the second header  20  respectively and has straight segments  31  and a bent segment  32  located between the straight segments  31 . The bent segment  32  is twisted by a predetermined angle relative to the straight segment  31  around a longitudinal direction of the flat tube  30 , the longitudinal direction of the flat tube  30  is parallel to a length direction of the flat tube  30  before being bent, the length direction of the flat tube  30  before being bent is shown by an arrow E in  FIG. 1  to  FIG. 3 . The bent segments  32  of a plurality of the flat tubes  30  form a bent segment row extending in a thickness direction of the flat tube  30 , the thickness direction of the flat tube  30  is shown by an arrow F in  FIG. 1  to  FIG. 5 . The plurality of the flat tubes are divided into a plurality of groups. Twisting directions of the bent segments  32  of the flat tubes  30  in the same group are identical, and the twisting direction of the bent segment  32  of the flat tube  30  in one group is opposite to that of the bent segment  32  of the flat tube  30  in another group adjacent to the one group. Each fin  40  is disposed between the straight segments  31  of adjacent flat tubes  30 , i.e., no fin  40  is disposed between the bent segments  32 . 
     Specifically, if the bent segment  32  of each flat tube  30  of a first group are clockwise twisted by a predetermined angle relative to the straight segment  3  around the longitudinal direction of the flat tube  30 , the bent segment  32  of each flat tube  30  of a second group adjacent to the first group are anticlockwise twisted by a predetermined angle relative to the straight segment  31  around the longitudinal direction of the flat tube  30 . If the bent segment  32  of each flat tube  30  of a first group are anticlockwise twisted by a predetermined angle relative to the straight segment  3  around the longitudinal direction of the flat tube  30 , the bent segment  32  of each flat tube  30  of a second group adjacent to the first group are clockwise twisted by a predetermined angle relative to the straight segment  31  around the longitudinal direction of the flat tube  30 . 
     With reference to  FIG. 6 , a method for manufacturing the bent heat exchanger  1  will be described according to embodiments of the present disclosure. As shown in  FIG. 6 , the method for manufacturing the bent heat exchanger  1  according to embodiments of the present disclosure includes the following steps a)-d).
         a) A portion of a flat tube  30  is twisted by a predetermined angle relative to a remaining portion of the flat tube  30  around a longitudinal direction of the flat tube  30  so as to form a bent segment  32 , a bent segment row extended in a thickness direction of the flat tube  30  is formed by the bent segments  32  of a plurality of the flat tubes  30 , the plurality of the flat tubes  30  are divided into a plurality of groups, in which twisting directions of the bent segments  32  of the flat tubes  30  in a same group are identical, and the twisting direction of the bent segment  32  of the flat tube  30  in one group being opposite to that of the bent segment  32  of the flat tube  30  in another group adjacent to the one group.       

     In other words, the bent segment  32  of each flat tube  30  refers to a portion of the flat tube  30  twisted around the longitudinal direction of the flat tube  30 , and the straight segments  31  of each flat tube  30  refer to the remaining portion of the flat tube  30 , i.e., a portion of the flat tube  30  being not twisted.
         b) The flat tube  30  is connected between first and the second headers  10 ,  20 .   c) A plurality of fins  40  are disposed between the remaining portions of adjacent flat tubes  30 .   d) The flat tubes  30  are bent at the bent segments  32 .       

     With the bent heat exchanger  1  according to embodiments of the present disclosure, since the twisting directions of the bent segments  32  of the flat tubes  30  in the same group are identical and the twisting direction of the bent segment  32  of the flat tube  30  in one group being opposite to that of the bent segment  32  of the flat tube  30  in another group adjacent to the one group, it is possible to avoid an over large accumulation of the bending deformation of the bent segments  32  after the flat tubes  30  are bent. Thus, the appearance of the bent heat exchanger  1  is neater and more aesthetic, and the bent heat exchanger  1  has a better assembly effect (easy to assemble with an application hardware). Moreover, the length of an arrangement of the flat tubes  30  in the length direction of the first header  10  and the second header  20  is greater than 500 mm (i.e., the length of the first header  10  and the second header  20  is greater than 500 mm), and thus the application range of the bent heat exchanger  1  is widened. Therefore, the bent heat exchanger  1  according to embodiments of the present disclosure has advantages of a neat, aesthetic appearance, a better assembly effect, a wide application and a high reliability. 
     With the method for manufacturing the bent heat exchanger  1  according to embodiments of the present disclosure, since a plurality of the flat tubes  30  are divided into a plurality of groups and the twisting directions of the bent segments  32  of the flat tubes  30  in the same group are identical and the twisting direction of the bent segment  32  of the flat tube  30  in one group being opposite to that of the bent segment  32  of the flat tube  30  in another group adjacent to the one group, it is possible to avoid an over large accumulation of the bending deformation of the bent segments  32  after the flat tubes  30  are bent. Thus, the appearance of the bent heat exchanger  1  is neater and more aesthetic, and the bent heat exchanger  1  has a better assembly effect (easy to assemble with an application hardware). Moreover, the length of an arrangement of the flat tubes  30  in the length direction of the first header  10  and the second header  20  is greater than 500 mm (i.e., the length of the first header  10  and the second header  20  is greater than 500 mm), and thus the application range of the bent heat exchanger  1  is widened. Therefore, the bent heat exchanger  1  having advantages of a neat, aesthetic appearance, a better assembly effect, a wide application and a high reliability may be manufactured by the method for manufacturing the bent heat exchanger  1  according to embodiments of the present disclosure. 
       FIG. 1  is a schematic view showing a bent heat exchanger  1  before being bent according to an embodiment of the present disclosure. A plurality of the flat tubes  30  are divided into two groups, an arrow G shows the twisting direction of the bent segment  32  of each flat tube  30  of a first group, an arrow G′ shows the twisting direction of the bent segment  32  of each flat tube  30  of a second group. Specifically, the bent segment  32  of each flat tube  30  of the first group is twisted in a direction away from the flat tube  30  of the second group and the bent segment  32  of each flat tube  30  of the second group is twisted in a direction away from the flat tube  30  of the first group. 
     Specifically,  FIG. 4  and  FIG. 5  are schematic views showing a bent heat exchanger  1  after being bent according to some embodiments of the present disclosure. The bent heat exchanger  1  shown in  FIG. 1  may have a shape of J-J′ segment in  FIG. 4  and  FIG. 5  after being bent. 
     In some embodiments of the present disclosure, the steps a)-d) may be performed in any order and the step a) is performed prior to the step d). Thus, the method for manufacturing the bent heat exchanger  1  can be more suitable for the actual situation of a manufacturing process, so that the manufacture of the bent heat exchanger  1  is more convenient and easier. 
       FIG. 2  is a schematic view showing a bent heat exchanger  1  before being bent according to another embodiment of the present disclosure. An interrupted flat tube  50  may be disposed between adjacent groups of the flat tubes  30  and may define a first segment  51  and a second segment  52 , a first end  511  of the first segment  51  may be connected with the first header  10 , a second end  512  of the first segment  51  may be closed, a first end  521  of the second segment  52  may be connected with the second header  20 , a second end  522  of the second segment  52  may be closed and spaced apart from the second end  512  of the first segment  51  by a predetermined distance, the predetermined distance may be equal to or greater than a length of the bent segment  32 . 
     When the bent segment  32  of each flat tube  30  of the first group of two adjacent groups is twisted toward the direction of the second group of the two adjacent groups and the bent segment  32  of each flat tube  30  of the second group of the two adjacent groups is twisted toward the direction of the first group (i.e., the flat tubes  30  of two groups are twisted toward each other), after the flat tubes  30  are bent at the bent segment  32 , the protrusions produced after the bending of the flat tubes  30  of the two groups collide and interfere with each other (that is, meet). By providing the interrupted flat tube  50  between two adjacent groups of the flat tubes  30 , it would be avoided that protrusions produced after the bending of the flat tubes  30  of two groups twisted toward each other collide and interfere with each other and the protrusions are. Thus, the assembly effect of the bent heat exchanger  1  may be further improved and the appearance of the bent heat exchanger  1  is neater and more aesthetic. 
     Specifically, as shown in  FIG. 2 , a plurality of the flat tubes  30  are divided into two groups, an arrow H shows the twisting direction of the bent segment  32  of each flat tube  30  of a first group, an arrow H′ shows the twisting direction of the bent segment  32  of each flat tube  30  of a second group. Because the predetermined distance between the second end  522  of the second segment  52  and the second end  512  of the first segment  51  may be greater than or equal to the length of the bent segment  32 , a containing space is formed between two groups of the flat tubes  30 , which may be used for containing the protrusions produced after the bending of the flat tubes  30  of the two groups. The bent heat exchanger  1  shown in  FIG. 2  may have a shape of K-K′ segment in  FIG. 4  and  FIG. 5  after being bent. 
     Advantageously, there may be a plurality of the interrupted flat tubes  50 , which may be provided between two adjacent groups of the flat tubes  30 . Thus, it would be further avoided that protrusions produced after the bending of the flat tubes  30  of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger  1  may be further improved and the appearance of the bent heat exchanger  1  is neater and more aesthetic. 
     In some embodiments of the present disclosure, the distance between the two adjacent flat tubes  30  belonging to different groups may be greater than that between the two adjacent flat tubes  30  belonging to the same group. In other words, the distance between the flat tubes  30  of two adjacent groups may be greater than that between the flat tubes  30  of the same group. Thus, it would be avoided that protrusions produced after the bending of the flat tubes  30  of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger  1  may be further improved and the appearance of the bent heat exchanger  1  is neater and more aesthetic. 
       FIG. 3  is a schematic view showing a bent heat exchanger  1  before being bent according to a further embodiment of the present disclosure. A separation flat tube  60  may be disposed between adjacent groups of the flat tubes  30  and may have straight segments  61  and a bent segment  62  located between the straight segments  61 , the bent segment  62  of the separation flat tube  60  may correspond to the bent segment  32  of the flat tube  30 , a width of the separation flat tube  60  is smaller than that of the flat tube  30 . In other words, the bent segment  62  of the separation flat tube  60  may correspond to the bent segment  32  of the flat tube  30  in the thickness direction of the flat tube  30 . Advantageously, a projection of the bent segment  62  of the separation flat tube  60  in the thickness direction of the flat tube  30  may coincide with a projection of the bent segment  32  of the flat tube  30  in the thickness direction of the flat tube  30 . 
     Because the width of the separation flat tube  60  is smaller than that of the flat tube  30 , the distance between the separation flat tube  60  and the flat tube  30  may be increased. Thus, it would be avoided that protrusions produced after the bending of the flat tubes  30  of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger  1  may be further improved and the appearance of the bent heat exchanger  1  is neater and more aesthetic. 
     Advantageously, as shown in  FIG. 3 , the separation flat tube  60  may be disposed between adjacent groups of the flat tubes  30  and may have straight segments  61  and a bent segment  62  located between the straight segments  61 , the bent segment  62  of the separation flat tube  60  may correspond to the bent segment  32  of the flat tube  30 , the distance between the separation flat tube  60  and the flat tube  30  adjacent to the separation flat tube  60  may be greater than that between adjacent flat tubes  30 . Thus, it would be avoided that protrusions produced after the bending of the flat tubes  30  of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger  1  may be further improved and the appearance of the bent heat exchanger  1  is neater and more aesthetic. 
     Specifically, as shown in  FIG. 3 , a plurality of the flat tubes  30  are divided into two groups, an arrow I shows the twisting direction of the bent segment  32  of each flat tube  30  of a first group, an arrow I′ shows the twisting direction of the bent segment  32  of each flat tube  30  of a second group. Because the distance between the separation flat tube  60  and the flat tube  30  adjacent to the separation flat tube  60  may be greater than that between adjacent flat tubes  30 , a containing space is formed between the separation flat tube  60  and the flat tube  30  adjacent to the separation flat tube  60 , which may be used for containing the protrusions produced after the bending of the flat tubes  30  of the two groups. The bent heat exchanger  1  shown in  FIG. 3  may have a shape of L-L′ segment in  FIG. 5  after being bent. 
     In another specific embodiment of the present disclosure, a separation flat tube  60  may be disposed between adjacent groups of the flat tubes  30  and may have straight segments  61  and a bent segment  62  located between the straight segments  61 , the bent segment  62  of the separation flat tube  60  may correspond to the bent segment  32  of the flat tube  30 , the length of the bent segment  62  of the separation flat tube  60  may be greater than that of the bent segment  32  of the flat tube  30 . Thus, it would be avoided that protrusions produced after the bending of the flat tubes  30  of two groups twisted toward each other collide and interfere with each other. Thus, the assembly effect of the bent heat exchanger  1  may be further improved and the appearance of the bent heat exchanger  1  is neater and more aesthetic. 
     As shown in  FIG. 1  to  FIG. 3 , in one embodiment of the present disclosure, each flat tube  30  may have one bent segment  32 , and the bent segments  32  of a plurality of the flat tubes  30  may form one bent segment row. In this way, the bent heat exchanger  1  has an advantage of simple structure. 
     In another embodiment of the present disclosure, each of the flat tubes  30  has a plurality of bent segments  32  spaced apart from each other in the length direction of the flat tube  30  and the bent segments  32  of a plurality of the flat tubes  30  may form a plurality of bent segment rows. Thus, the flat tubes  30  can be bent into a plurality of shapes, i.e., the bent heat exchanger  1  may have a plurality of shapes, so that the application range of the bent heat exchanger  1  may be widened. 
     The bent heat exchanger  1  according to embodiments of the present disclosure has advantages of a neat, aesthetic appearance and a better assembly effect. 
     Reference throughout this specification to “an embodiment,” “some embodiments,” “an example,” “a specific example,” or “some examples,” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as “in some embodiments,” “in one embodiment”, “in an embodiment”, “in another example,” “in an example,” “in a specific example,” or “in some examples,” in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. 
     The invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.