Patent Publication Number: US-9903667-B2

Title: Heat exchanger

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 10-2013-42779, filed on Apr. 18, 2013 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     One or more embodiments relate to a heat exchanger, more particularly, a heat exchanger having an improved refrigerant-distributing structure. 
     2. Description of the Related Art 
     In general, a heat exchanger is equipped with a tube in which refrigerant is circulated to exchange heat with outside air, a heat-exchanging fin in contact with the tube to increase a heat-radiating surface, and a header communicating with both ends of the tube. The heat exchanger can be utilized as an evaporator or a condenser, and can perform a cooling cycle when equipped with a compressor for compressing the refrigerant and an expansion valve for expanding the refrigerant. 
     The heat exchanger has an inlet pipe and an outlet pipe, the refrigerant flowing into the heat exchanger through the inlet pipe can be distributed to a plurality of tubes through the header. In order to increase the efficiency of heat exchange, it is required to uniformly distribute the refrigerant to a plurality of tubes, and thus two or more inlet pipes may be provided according to a refrigerant flow rate. 
     However, since increasing the number of the inlet pipes impedes reduction of manufacturing cost and securing of design space, a structure which has one inlet pipe and can improve distribution of the refrigerant is required. 
     Moreover, in a heat exchanger equipped with a large number of approximately 36 or more tubes, it is not easy to uniformly distribute the refrigerant in practice. 
     SUMMARY 
     The foregoing described problems may be overcome and/or other aspects may be achieved by one or more embodiments of a heat exchanger having one inlet pipe and one outlet pipe and improving a refrigerant distribution. 
     One or more embodiments relate to a heat exchanger which may mix and stabilize refrigerant flowing into a header through one inlet pipe and then may distribute the refrigerant to tubes. 
     One or more embodiments relate to a heat exchanger that may have an improved assembly structure of a distribution pipe. 
     One or more embodiments relate to a heat exchanger which may improve distribution of refrigerant flowing into a header through an inlet pipe when a cooling cycle is operated. 
     One or more embodiments relate to a heat exchanger which may improve distribution of refrigerant flowing into a header through an outlet pipe when a heating cycle is operated. 
     One or more embodiments relate to a large-sized heat exchanger that may include a plurality of tubes mounted thereto and possibly improving distribution of refrigerant. 
     Additional aspects and/or advantages of one or more embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of one or more embodiments of disclosure. One or more embodiments are inclusive of such additional aspects. 
     According to one or more embodiments, a heat exchanger may include tubes in which refrigerant may be circulated to possibly exchange heat with outside air, the tubes possibly being arranged in a plurality of rows including a first row and a second row; a first header that may have a first chamber communicating with one end portion of each of the tubes of the first row and a second chamber communicating with one end portion of each of the tubes of the second row; a second header that may have a third chamber communicating with the other end portion of each of the tubes of the first row and a fourth chamber communicating with the other end portion of each of the tubes of the second row and the third chamber; an inlet pipe that may communicate with the first chamber; an outlet pipe that may communicate with the second chamber; and a distributer that may be provided in the first chamber to distribute the refrigerant flowing into the first chamber through the inlet pipe to the tubes of the first row. The distributer may include a first separating baffle that may divide the first chamber into a mixing chamber in which the refrigerant may be mixed and a supplying chamber for supplying the refrigerant to the tubes of the first row; a distribution pipe that may penetrate the first separating baffle to communicate the mixing chamber with the supplying chamber, the distribution pipe possibly having a plurality of distribution holes for supplying the refrigerant in the mixing chamber to the supplying chamber; and a second separating baffle that may divide the supplying chamber into a first sub chamber and a second sub chamber. 
     Here, the number of the tubes of the first row and the number of the tubes of the second row may be 36 or more, respectively. 
     In addition, the second separating baffle may be provided at a longitudinal central portion of the supplying chamber. 
     Furthermore, the heat exchanger may further include guide baffles that may be provided at each of the third chamber and the fourth chamber to correspond to a location of the second separating baffle to compartmentalize the third chamber and the fourth chamber. 
     Also, the plurality of distribution holes may include at least one first distribution hole positioned at the first sub chamber and at least one second distribution hole positioned at the second sub chamber. 
     Here, the first sub chamber may be positioned such that a distance between the first sub chamber and the mixing chamber may be smaller than that between the first sub chamber and the second sub chamber, and a size of the first distribution hole may be greater than that of the second distribution hole. 
     Here, two first distribution holes may be provided at the first sub chamber and one second distribution hole may be provided at the second sub chamber. 
     In addition, the first header may include a body having a bottom part and a central partition, and a cover coupled to the body and having an upper wall and a side wall, and the second separating baffle may penetrate the body and be in contact with and supported on an inner surface of the cover. 
     Also, the second separating baffle may include a fixing part that may form a portion of a distribution pipe-receiving hole configured to receive the distribution pipe, an operating part rotatably coupled to the fixing part and forming the remainder of the distribution pipe-receiving hole, and a hinge part connecting the fixing part to the operating part. 
     Here, the fixing part, the operating part and the hinge part that may be included in the second separating baffle may be formed integrally with each other. 
     According to one or more embodiments, a heat exchanger may include tubes in which refrigerant may be circulated to possibly exchange heat with outside air, the tubes possibly being arranged in a plurality of rows that may include a first row and a second row; a first header that may have a first chamber communicating with one end portion of each of the tubes of the first row and a second chamber communicating with one end portion of each of the tubes of the second row; a second header that may have a third chamber communicating with the other end portion of each of the tubes of the first row and a fourth chamber communicating with the other end portion of each of the tubes of the second row and the third chamber; an inlet pipe that may communicate with the first chamber to possibly allow the refrigerant to flow into the first chamber when a cooling cycle is operated and to possibly allow the refrigerant to be discharged from the first chamber when a heating cycle is operated; an outlet pipe that may communicate with the second chamber to allow the refrigerant to flow into the second chamber in the heating cycle operation and to allow the refrigerant to be discharged from the second chamber in the cooling cycle operation; a cooling distributer that may be provided in the first chamber for distributing the refrigerant circulated into the first chamber through the inlet pipe in the cooling cycle operation to the tubes of the first row; and a heating distributer that may be provided in the second chamber for distributing the refrigerant circulated into the second chamber through the outlet pipe in the heating cycle operation to the tubes of the second row. Here, the cooling distributer may include a first separating baffle that may divide the first chamber into a mixing chamber in which the refrigerant may be mixed and a supplying chamber for supplying the refrigerant to the tubes of the first row; a cooling distribution pipe that may penetrate the first separating baffle to communicate the mixing chamber with the supplying chamber and possibly having at least one distribution hole for supplying the refrigerant in the mixing chamber to the supplying chamber; and a second separating baffle that may divide the supplying chamber into a first sub chamber and a second sub chamber. 
     Here, the number of the tubes of the first row and the number of the tubes of the second row may be 36 or more, respectively. 
     In addition, the second separating baffle may be provided at a longitudinal central portion of the supplying chamber. 
     Also, the heating distributer may include a distributing baffle that may divide the second chamber into a first distributing chamber and a second distributing chamber, and a heating distribution pipe possibly penetrating the distributing baffle to communicate the first distributing chamber with the second distributing chamber and that may have at least one distribution hole for supplying the refrigerant in the first distributing chamber to the second distributing chamber. 
     Here, the at least one distribution hole of the heating distribution pipe may be positioned in a zone far away from the outlet pipe with respect to the second separating baffle. 
     According to one or more embodiments, a heat exchanger may include tubes in which refrigerant may be circulated to possibly exchange heat with outside air, the tubes possibly being arranged in a plurality of rows including a first row and a second row; a first header that may have a first chamber communicating with one end portion of each of the tubes of the first row and a second chamber communicating with one end portion of each of the tubes of the second row; a second header that may have a third chamber communicating with the other end portion of each of the tubes of the first row and a fourth chamber communicating with the other end portion of each of the tubes of the second row and the third chamber; an inlet pipe that may communicate with the first chamber; an outlet pipe that may communicate with the second chamber; and a distributer that may be provided in the first chamber to distribute the refrigerant flowing into the first chamber through the inlet pipe to the tubes of the first row. Here, the distributer may include a first separating baffle that may divide the first chamber into a mixing chamber in which the refrigerant is mixed and a supplying chamber for supplying the refrigerant to the tubes of the first row; a distribution pipe that may penetrate the first separating baffle to communicate the mixing chamber with the supplying chamber, the distribution pipe possibly having a plurality of distribution holes for supplying the refrigerant in the mixing chamber to the supplying chamber; and at least one second separating baffle that may divide the supplying chamber into a plurality of sub chambers. 
     Here, the heat exchanger may further include at least one guide baffle provided at each of the third chamber and the fourth chamber to correspond to a location of the at least one second separating baffle to compartmentalize the third chamber and the fourth chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view showing an appearance of a heat exchanger according to one or more embodiments; 
         FIG. 2  is a perspective view showing an appearance of a first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 3  is an exploded perspective view showing a structure of a first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 4  is a view showing a distribution pipe for cooling of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 5  is a view showing a distribution pipe for heating of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 6  is a side sectional view of a first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 7  is a plan sectional view of a first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 8  is a view showing flow of refrigerant in a first chamber of a first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 9  is a view showing flow of refrigerant in a second chamber of a first header when a heating cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated; 
         FIG. 10  is an enlarged sectional view showing flow of refrigerant around a distributing baffle when a heating cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated; 
         FIG. 11  to  FIG. 13  are views showing a process of coupling a second compartment baffle and a distribution pipe for cooling of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 14  is a view illustrating a coupling structure of a second compartment baffle and a first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 15  is a perspective view showing an appearance of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 16  is an exploded perspective view showing a structure of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 17  is a side sectional view of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 18  is a plan sectional view of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ; 
         FIG. 19  is a view showing overall flow of refrigerant when a cooling cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated; and 
         FIG. 20  is a view showing overall flow of refrigerant when a heating cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to one or more embodiments, illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, embodiments of the present invention may be embodied in many different forms and should not be construed as being limited to embodiments set forth herein, as various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be understood to be included in the invention by those of ordinary skill in the art after embodiments discussed herein are understood. Accordingly, embodiments are merely described below, by referring to the figures, to explain aspects of the present invention. 
       FIG. 1  is a perspective view showing an appearance of a heat exchanger according to one or more embodiments. 
     Referring to  FIG. 1 , a heat exchanger  1  according to one or more embodiments may include a plurality of tubes  10  in which refrigerant may be circulated to possibly exchange heat with outside air; a heat-exchanging fin  20  in contact with each of the tubes  10  to possibly increase a heat-transfer area with respect to outside air; a first header  100  and a second header  200  communicating with the plurality of tubes  10 ; an inlet pipe  300  and an outlet pipe  400 ; and a flange  500  configured for coupling the inlet pipe  300  and the outlet pipe  400  to the first header  100 . 
     The heat exchanger  1  may be utilized as an evaporator when a cooling cycle is operated and as a condenser when a heating cycle is operated. 
     The inlet pipe  300  may be formed by coupling a first inlet pipe  301  and a second inlet pipe  302  with each other, and the outlet pipe  400  may be formed by coupling a first outlet pipe  401  and a second outlet pipe  402  with each other. 
     The first inlet pipe  301  and the first outlet pipe  401  may be formed, for example, of copper material, and the second inlet pipe  302  and the second outlet pipe  402  may be formed, for example, of aluminum material, but are not limited thereto. If the flange  500  is formed of aluminum material, then when the inlet pipe and the outlet pipe are coupled with the flange  500 , corrosion may caused by a junction of different materials. By forming the inlet pipe and outlet pipe as above, such corrosion may be prevented. 
     A diameter of the inlet pipe  300  may be smaller than that of the outlet pipe  400 . In addition, one inlet pipe  300  and one outlet pipe  400  may be provided on a longitudinal end portion of the heat exchanger  1 . Thus, a manufacturing cost of the heat exchanger may be saved and a volume may be reduced, compared to a heat exchanger equipped with two or more inlet pipes  300  or outlet pipes  400 . 
     When a cooling cycle is operated, a low-temperature/low-pressure liquefied refrigerant or gaseous refrigerant passing an expansion valve (not shown) may flow into the inlet pipe  300 . The refrigerant flowing into the inlet pipe  300  may pass through the tubes  10  to possibly absorb external heat and may evaporate. The refrigerant may be then discharged to an outside via the outlet pipe  400 . Accordingly, in this cooling cycle the heat exchanger  1  may act as an evaporator. 
     Meanwhile, a high-temperature/high-pressure gaseous refrigerant passing a compressor (not shown) may be circulated through the outlet pipe  400 , may pass through the tubes  10  to release heat to an outside and may condense. The condensed refrigerant may be discharged to an outside via the inlet pipe  300 . Accordingly, in this heating cycle the heat exchanger  1  may act as a condenser. 
     The tubes  10  may have a plurality of micro channels formed therein to possibly enable the refrigerant to flow. The tubes  10  may, for example, have a flat shape, but are not limited thereto. The tubes  10  may, for example, be arranged in two rows of front row tubes  11  and rear row tubes  12 . The tubes  10  may be formed, for example, by extrusion molding aluminum material, but are not limited thereto. 
     The heat-exchanging fin  20  may be disposed between the tubes  10  and may be in contact with outer walls of the tubes  10 . The heat-exchanging fin  20  may have various known shapes and may have a louver for enhancing heat transfer performance and drainage performance. The heat-exchanging fin  20  may be formed, for example, of aluminum material, but is not limited thereto. The heat-exchanging fin may be coupled by brazing with the tubes  10 . 
     On the other hand, the heat-exchanging fin  20  may have a plurality of tubes  10  so as to possibly enable a large quantity of air to exchange heat at the same time. In a large-sized heat exchanger, for example, 36 or more front row tubes  11  may be provided and 36 or more rear row tubes  12  may be provided. 
     Compared to a small-sized heat exchanger, it may not be easy to distribute the refrigerant in a large-sized heat exchanger, such as the heat exchanger  1 . Therefore, one or more embodiments relate to an improvement of distribution of the refrigerant. However, the spirit of the embodiments is not limited thereto, the embodiments may be applied to a small-sized heat exchanger. 
     The first header  100  and the second header  200  may be horizontally disposed. The first header  100  and the second header  200  may be spaced apart from each other, and the tubes  10  may be vertically disposed between the first header  100  and the second header  200 . End portions of the front row tubes  11  and the rear row tubes  12  may communicate with the first header  100 , and the other end portions of the front row tubes  11  and the rear row tubes  12  may communicate with the second header  200 . Alternatively, the first header  100  and the second header  200  may be vertically disposed, and the tubes  10  may be horizontally disposed between the first header  100  and the second header  200 . 
       FIG. 2  is a perspective view showing an appearance of a heat exchanger according to one or more embodiments, such as the first header of the heat exchanger shown in  FIG. 1 , and  FIG. 3  is an exploded perspective view showing a structure of the first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 .  FIG. 4  is a view showing a distribution pipe for cooling of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , and  FIG. 5  is a view showing a distribution pipe for heating of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 .  FIG. 6  is a side sectional view of the first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , and  FIG. 7  is a plan sectional view of the first header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 .  FIG. 8  is a view showing flow of refrigerant in a first chamber of a heat exchanger according to one or more embodiments, such as the first header of the heat exchanger shown in  FIG. 1 , and  FIG. 9  is a view showing flow of refrigerant in a second chamber of the first header when a heating cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated.  FIG. 10  is an enlarged sectional view showing flow of refrigerant around a distributing baffle when a heating cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated; 
     Referring to  FIG. 2  to  FIG. 10 , the first header  100  of the heat exchanger according to the embodiment of the present invention may include a body  110 , a cover  120  coupled to the body  110  and chambers  140  and  150  provided in the body  110  and the cover  120  to possibly allow the refrigerant to flow therein. 
     As shown in  FIG. 6 , the body  110  may include a bottom part  112  and a central partition  111  protruding from a center of the bottom part  112 , and the cover  120  may include an upper wall  121  and side walls  122  extending from both sides of the upper wall  121 . 
     A coupling groove  113  may be formed on the bottom part  112 , and an end portion of the side wall  122  of the cover  120  may be inserted into the coupling groove  113 , so that the body  110  and the cover  120  may be securely coupled to each other. The body  110  and the cover  120  may be formed, for example, of aluminum material, but are not limited thereto, and may be coupled to each other by brazing. 
     The chambers  140 ,  150  may be divided into a first chamber  140  and a second chamber  150  by the central partition  111 . The front row tubes  11  may be connected to the first chamber  140  and the rear row tubes  12  may be connected to the second chamber  150 . 
     In the cooling cycle operation, the refrigerant may flow into the first chamber  140  through the inlet pipe  300  and the refrigerant in the second chamber  150  may be discharged to the outside via the outlet pipe  400 . 
     On the other hand, in the heating cycle operation, the refrigerant may flow into the second chamber  150  through the outlet pipe  400  and the refrigerant in the first chamber  140  may be discharged to the outside via the inlet pipe  300 . 
     A through hole  123  may be formed at a center of the upper wall  121  and a penetrating protrusion  111   a  that may penetrate the through hole  123  may be formed at an upper end of the central partition  111 , so that the first chamber  140  and the second chamber  150  may be separated from each other by inserting the penetrating protrusion  111   a  into the through hole  123 . 
     As best shown in  FIG. 3 , tube holes  124  into which the tubes  10  may be inserted, an inlet hole  125  that may communicate with the inlet pipe  300  and an outlet hole  126  that may communicate with the outlet pipe  400  may be formed in the cover  120 . 
     On the other hand, cover baffles  130 ,  131 ,  132  and  133  may be provided at both longitudinal ends of the first header  100 . The cover baffles  130 ,  131 ,  132  and  133  may restrict longitudinal areas of the first chamber  140  and the second chamber  150 . 
     The cover baffles  130 ,  131 ,  132  and  133  may be inserted into cover baffle holes  114  and  127  that may be formed in the body  110  and the cover  120 , respectively. The cover baffles  130 ,  131 ,  132  and  133  may be formed, for example, of aluminum material, but are not limited thereto, and may be coupled by brazing to the body  110  and the cover  120 . 
     In the cover baffles  130 ,  131 ,  132  and  133 , a cooling distribution pipe  600  and a heating distribution pipe  700  may be inserted into and secured to the cover baffles  131  and  133  disposed away from the inlet pipe  300  and the outlet pipe  400 . 
     Meanwhile, the first chamber  140  may be divided into a mixing chamber  141  and a supplying chamber  142  by a first separating baffle  143 . The mixing chamber  141  may communicate with the inlet pipe  300  and the supplying chamber  142  may communicate with the front row tubes  11 . 
     The first separating baffle  143  may be inserted into first separating baffle holes  115  and  128  formed on the body  110  and  120 , respectively. The first separating baffle  143  may be coupled by brazing to the first header  100 . 
     In addition, the supplying chamber  142  may be divided into a first sub chamber  142   a  and a second sub chamber  142   b  by a second separating baffle  144 . In one or more embodiments, one second separating baffle  144  may be provided. Alternatively, a plurality of second separating baffles  144  may be provided to separate the supplying chamber  142  into three or more sub chambers. 
     The second separating baffle  144  may be provided at an approximately longitudinal central portion of the supplying chamber  142 . In other words, the first sub chamber  142   a  and the second sub chamber  142   b  may have the same size. However, the spirit of the embodiments is not limited to such a location of the second separating baffle  144  and such sizes of the sub chambers  142   a  and  142   b.    
     In the sub chambers  142   a  and  142   b , hereinafter, the sub chamber which is close to the mixing chamber  141  will be referred to as the first sub chamber  142   a  and the other sub chamber will be referred to as the second sub chamber  142   b.    
     In addition, in  FIG. 8  and  FIG. 9 , an upper zone of the first sub chamber  142   a  will be referred to as an X zone and an upper zone of the second sub chamber  142   b  will be referred to as a Y zone. Furthermore, the tubes  11  and  12  disposed in the X zone will be referred to as X zone tubes, and the tubes  11  and  12  disposed in the Y zone will be referred to as Y zone tubes. 
     Since the first sub chamber  142   a  is separated from the second sub chamber  142   b  by the second separating baffle  144 , it may be known that, in the cooling cycle operation, all the refrigerant in the first sub chamber  142   a  may circulate into only the front row tubes  11  in the X zone and all the refrigerant in the second sub chamber  142   b  may flow into only the rear row tubes  12  in the Y zone. 
     On the other hand, it may be known that, in the heating cycle operation, the refrigerant in the front row tubes  11  in the X zone may circulate into only the first sub chamber  142   a  and may flow into only the rear row tubes  12  in the Y zone. 
     The second separating baffle  144  may be inserted into a second separating baffle hole  116  formed on the body  110 . Unlike the first separating baffle  143 , however, the second separating baffle  144  may not be inserted into the cover  120 . 
     In other words, as best shown in  FIG. 14 , the second separating baffle  144  may not penetrate the cover  120 , but may be in contact with and supported by an inner surface  120   a  of the cover  120 . This structure may be provided for the convenience of assembling the second separating baffle  144 , however, the spirit of the embodiments is not limited to the above coupling structure. That is, like the first separating baffle  143 , the second separating baffle  144  may penetrate the body  110  and the cover  120  and may be coupled to them. 
     Consequently, due to the above structure, the mixing chamber  141  may be defined by the body  110 , the cover  120 , the cover baffle  130  and the first separating baffle  143 , the first sub chamber may be defined by the body  110 , the cover  120 , the first separating baffle  143  and the second separating baffle  144 , and the second sub chamber may be defined by the body  110 , the cover  120 , the second separating baffle  144  and the cover baffle  131 . 
     In the cooling cycle operation, the refrigerant may flow into the mixing chamber  141  via the inlet pipe  300 . The refrigerant flowing into the mixing chamber  141  may be primarily mixed in the mixing chamber  141 . Since the refrigerant flowing into the inlet pipe  300  in the cooling cycle operation may have the liquefied refrigerant and the gaseous refrigerant, the liquefied refrigerant and the gaseous refrigerant may be properly mixed in the mixing chamber  141  as described above to possibly enhance distribution efficiency and the heat exchange efficiency. The mixed refrigerant may flow into the supplying chamber  142  through a cooling distribution pipe  600 . 
     The cooling distribution pipe  600  may supply the refrigerant in the mixing chamber  141  to the supplying chamber  142 . The cooling distribution pipe  600  may penetrate and may be coupled with the first separating baffle  143  to communicate the mixing chamber  141  with the supplying chamber  142 . The cooling distribution pipe  600  may have a plurality of distribution holes  680 . 
     The cooling distribution pipe  600  may have an opened pipe shape having an inlet port and an outlet port. It may be preferable that a sectional area of the cooling distribution pipe  600  is, for example, 15 to 30% of a sectional area of the first chamber  140 . 
     A cap  690  may be coupled to the outlet port of the cooling distribution pipe  600  to possibly prevent the refrigerant from leaking. The cooling distribution pipe  600  and the cap  690  may be formed, for example, of aluminum, but are not limited thereto, and the cooling distribution pipe  600  and the cap  690  may be coupled with each other by brazing. 
     At least one distribution hole  680  of the cooling distribution pipe  600  may be provided at positions corresponding to the first sub chamber  142   a  and the second sub chamber  142   b , respectively. In one or more embodiments, two distribution holes  680   a  may be provided at the first sub chamber  142   a  and one distribution hole  680   b  may be provided at the second sub chamber  142   b . However, the embodiments are not limited thereto. 
     Furthermore, in consideration of a pressure of the refrigerant in the cooling distribution pipe  600 , a dimension of the distribution hole  680   a  provided at the first sub chamber  142   a  may differ from that of the distribution hole  680   b  provided at the second sub chamber  142   b.    
     However, since more refrigerant may be advanced by high pressure in the cooling distribution pipe  600 , it may be preferable that a size of the distribution hole  680   a  provided at the first sub chamber  142   a  may be larger than that of the distribution hole  680   b  provided at the second sub chamber  142   b.    
     It may be preferable that these distribution holes  680  may be directed toward the central partition  111 . 
     Due to the above structure, even if only one inlet pipe  300  is provided at a longitudinal end portion of the first header  100 , the refrigerant flowing into the first chamber  140  via the inlet pipe  300  may be uniformly dispersed and distributed to the front row tubes  11 . 
     In particular, by separating the first sub chamber  142   a  from the second sub chamber  142   b  by means of the second separating baffle  144 , it may be possible to prevent the refrigerant in the first sub chamber  142   a  and the refrigerant in the second sub chamber  142   b  from mixing with each other. 
     This means that a pressure and a flow of the first sub chamber  142   a  and a pressure and a flow of the second sub chamber  142   b  may not influence each other. On this basis, the location, the number and the size of the distribution holes  680  of the cooling distribution pipe  600  for a uniform distribution of the refrigerant can be designed. 
     As best shown in  FIG. 4  and  FIG. 6 , meanwhile, the cooling distribution pipe  600  may include an outer wall  610 , an internal space  620  provided inside the outer wall  610  and a plurality of ribs  640 ,  650 ,  660  and  670  protruding from the outer wall  610 . 
     The plurality of ribs  640 ,  650 ,  660  and  670  may include supporting ribs  640 ,  650  and  660  protruding from the outer wall  610  so as to possibly allow the outer wall  610  to be spaced apart from an inner surface of the first header  100  and supported on an inner surface of the first header  100 , and a stopper rib  670  which may restrict an insertion depth of the tubes  10 . 
     According to a protrusion direction, the supporting ribs  640 ,  650  and  660  may be grouped into low supporting ribs  640  protruding toward a low side of the outer wall  610 , left supporting ribs  650  protruding toward a left side of the outer wall  610  and right supporting ribs  660  protruding toward a right side of the outer wall  610 . 
     It may be suitable for the flow of refrigerant to space the outer wall  610  of the cooling distribution pipe  600 , for example, approximately 1 mm or more apart from an inner surface of the first header  100 . 
     The low supporting ribs  640  may be spaced apart from each other so that a flow space through which the refrigerant may flow may be formed between the low supporting ribs  640 . Like the low supporting ribs, the left ribs  650 /the right ribs  660  may be spaced apart from each other so that a flow space through which the refrigerant may flow may be formed between the left ribs/the right ribs. 
     Due to the above structure, the refrigerant flowing into the supplying chamber  142  through the distribution holes  680  of the cooling distribution pipe  600  may flow in a space between the outer wall  610  of the cooling distribution pipe  600  and an inner surface of the supplying chamber  142  and may be distributed to the front row tubes  11 . 
     The stopper rib  670  may protrude from an upper side of the outer wall  610  and may prevent the tubes  10  from being inserted too far into the first chamber  140 . 
     Consequently, the first separating baffle  143 , the second separating baffle  144  and the cooling distribution pipe  600  may constitute a cooling distributer  143 ,  144  and  600  that may uniformly distribute the refrigerant circulated into the first chamber  140  via the inlet pipe  300  in the cooling cycle operation to the front row tubes  11 . 
     Meanwhile, the heat exchanger according to one or more embodiments may further include a heating distributer  153  and  700  that may be provided in the second chamber  150  of the first header  100  for distributing the high-temperature/high-pressure gaseous refrigerant circulated into the second chamber  150  of the first header  100  via the outlet pipe  400  in the heating cycle operation to the rear row tubes  12 . 
     The heating distributer  153  and  700  may include a distributing baffle  153  and a heating distribution pipe  700 . 
     As best shown in  FIG. 10 , the distributing baffle  153  may divide the second chamber  150  into a first distributing chamber  151  and a second distributing chamber  152 . Like other baffles, the distributing baffle  153  may penetrate the body  110  and may be coupled to the body. 
     The distributing baffle  153  may be provided below the outlet hole  126  of the cover  120 . Therefore, the first distributing chamber  151  may communicate with the outlet pipes  400 ,  401  and  402  and not with the tubes  10 . The second distributing chamber  152  may communicate with the outlet pipes  400 ,  401  and  402  as well as the rear row tubes  12 . 
     As a result, the refrigerant flowing through the outlet pipe  400  may be divided by the distributing baffle  153  so that some of the refrigerant is circulated to the first distributing chamber  151  (direction A) and the remainder can flow to the second distributing chamber  152  (direction B). 
     At this time, the refrigerant flowing to the first distributing chamber  151  may flow to the second distributing chamber  152  through the heating distribution pipe  700 . 
     The heating distribution pipe  700  may communicate the first distributing chamber  151  and the second distributing chamber  152  with each other, and the heating distribution pipe may penetrate and may be coupled to the distributing baffle  153 . 
     The heating distribution pipe  700  may have a pipe shape having an inlet port, an outlet port and an inner space. One end of the heating distribution pipe may penetrate and be coupled to the distributing baffle  153  and the other end may penetrate and be coupled to the cover baffle  133 . A cap  790  may be coupled to the outlet port of the heating distribution pipe  700  to possibly prevent the refrigerant from leaking. 
     To allow the refrigerant in the first distributing chamber  151  to flow to the second distributing chamber  152 , the heating distribution pipe  700  may have at least one distribution hole  780  formed at a location spaced a certain interval apart from the distributing baffle  153  toward the second distributing chamber  152 . For example, three distribution holes  780  may be provided, but the embodiments are not limited thereto. 
     On the other hand, as best shown in  FIG. 9 , it may be preferable that the distribution holes  780  of the heating distribution pipe  700  correspond to the Y zone. 
     Due to the above structure, most of the refrigerant flowing into the first distributing chamber  151  may be distributed to the tubes in the Y zone through the heating distribution pipe  700 , and most of the refrigerant flowing into the second distributing chamber  152  may be distributed to the tubes in the X zone. 
     Similar to the aforementioned cooling distribution pipe  600 , the heating distribution pipe  700  may include an outer wall  710  forming an internal space  720  and a plurality of ribs  740 ,  750 ,  760  and  770  protruding from the outer wall  710 . 
     The plurality of ribs  740 ,  750 ,  760  and  770  may include supporting ribs  740 ,  750  and  760  that may protrude from the outer wall  710  so as to possibly allow the outer wall  710  to be spaced apart from an inner surface of the first header  100  and supported on an inner surface of the first header  100 , and a stopper rib  770  which may restrict an insertion depth of the tubes  10 . 
     According to a protrusion direction, the supporting ribs  740 ,  750  and  760  may be grouped into low supporting ribs  740  protruding toward a low side of the outer wall  710 , left supporting ribs  750  protruding toward a left side of the outer wall  710  and right supporting ribs  760  protruding toward a right side of the outer wall  710 . 
     The stopper rib  770  may protrude from an upper side of the outer wall  710  and may prevent the tubes  10  from being inserted too far into the second chamber  150 . 
     As illustrated above, except that the heating distribution pipe  700  may be somewhat longer than the cooling distribution pipe  600  and locations of the distribution holes  780  may differ from those of distribution holes  680 , the heating distribution pipe  700  may have a structure which is substantially the same as that of the cooling distribution pipe  600 . 
     Meanwhile, the structure of the heating distributer may reduce resistance to the flow of refrigerant in the cooling cycle operation. 
     In other words, in the cooling cycle operation, some of the refrigerant flowing into the second chamber  150  of the first header  100  via the rear row tubes  12  may be discharged to the outlet pipe  400  through the heating distribution pipe  700  and the first distributing chamber  151 , and the remainder can be discharged to the outlet pipe  400  through the second distributing chamber  152  without passing through the heating distribution pipe  700 . 
       FIG. 11  to  FIG. 13  are views illustrating a process for coupling the second separating baffle and the cooling distribution pipe of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 . 
     Referring to  FIG. 11  to  FIG. 13 , the second separating baffle  144  of a plurality of the baffles employed in the heat exchanger of one or more embodiments, which may be coupled to an approximately central portion of the cooling distribution pipe  600 , may have an open structure. 
     In other words, the second separating baffle  144  may have a distribution pipe-receiving hole  148  configured to receive the cooling distribution pipe  600  and the distribution pipe-receiving hole  148  may be open. The distribution pipe-receiving hole  148  may be provided for coupling the second separating baffle  144  to the cooling distribution pipe  600 . 
     The second separating baffle  144  may include a fixing part  145  that may form a portion of the distribution pipe-receiving hole  148 , an operating part  146  that may be rotatably provided at the fixing part  145  and that may form the remainder of the distribution pipe-receiving hole  148 , and a hinge part  147  that may connect the fixing part  145  to the operating part  146 . The distribution pipe-receiving hole  148  may include a rib-receiving hole  149  that may be configured to receive a rib of the cooling distribution pipe  600 . 
     The elastically deformable hinge part  147  may enable the fixing part  145  and the operating part  146  to be moved. The above parts that may be included in the second separating baffle  144  may be formed integrally with each other. 
     Therefore, it may be possible to couple the second separating baffle  144  such that after the fixing part  145  and the operating part  146  are spread to open the distribution pipe-receiving hole  148  as shown in  FIG. 11 , the cooling distribution pipe  600  may be inserted into the distribution pipe-receiving hole  148  as shown in  FIG. 12 , and the fixing part  145  and the operating part  146  may then be closed as shown in  FIG. 13 . 
       FIG. 15  is a perspective view showing an appearance of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ,  FIG. 16  is an exploded perspective view showing a structure of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 ,  FIG. 17  is a side sectional view of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , and  FIG. 18  is a plan sectional view of a second header of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 . 
     Referring to  FIG. 15  to  FIG. 18 , the second header  200  of the heat exchanger according to one or more embodiments may include a body  210 , a cover  220  coupled to the body  210  and a chamber  240 ,  250  formed in the body  210  and the cover  220  to allow the refrigerant to flow therein. 
     The body  210  may include a bottom part  212  and a central partition  211  protruding from a center of the bottom part  212 , and the cover  220  may include a lower wall  221  and side walls  222  extending from both sides of the lower wall  221 . 
     A coupling groove may be formed on the bottom part  212 , and an end portion of the side wall  222  may be inserted into the coupling groove, so that the body  210  and the cover  220  may be securely coupled to each other. The body  210  and the cover  220  may be formed, for example, of aluminum material, but are not limited thereto, and may be coupled to each other by brazing. Tube holes  225  into which the tubes  10  may be inserted may be formed on the cover  220 . 
     The chamber  240 ,  250  may be divided into a third chamber  240  and a fourth chamber  250  by the central partition  211 . The front row tubes  11  may be connected to the third chamber  240  and the rear row tubes  12  may be connected to the fourth chamber  250 . 
     At least one through hole  214  may be formed on the central partition  211  to allow the refrigerant in the third chamber  240  to flow into the fourth chamber  250 . 
     A through hole  223  may be formed on a center of the lower wall  221  and a penetrating protrusion  211   a  penetrating the through hole  223  may be formed at a lower end of the central partition  211 , so that the penetrating protrusion  211   a  may penetrate the through hole  223 . 
     Cover baffles  230  may be provided on both longitudinal ends of the second header  200 . The cover baffles  230  may restrict longitudinal areas of the third chamber  240  and the fourth chamber  250 . The cover baffles  230  may be inserted into cover baffle holes  216 ,  224  formed on the body  110  and the cover  120 , respectively, so that the cover baffles may be coupled to the second header  200 . The cover baffles  230  may be formed, for example, of aluminum material, but are not limited thereto, and may be coupled by brazing to the body  210  and the cover  220 . 
     On the other hand, the third chamber  240  may be divided into a plurality of chambers  241 ,  242  by a guide baffle  260 . Like the third chamber, the fourth chamber  250  may be divided into a plurality of chambers  251  and  252  by the guide baffle  260 . The guide baffle  260  may be inserted into a guide baffle hole  217  formed on the body  210  and the cover  220 . 
     The guide baffle  260  may be formed at a location corresponding to the second separating baffle  144  of the first header  100 . Therefore, the chamber  241  of the second header  200  may correspond to the first sub chamber  142   a  of the first header  100 , and the chamber  242  of the second header  200  may correspond to the second sub chamber  142   b  of the first header  100 . 
     In addition, the chamber  241  of the second header  200  may communicate with the front row tubes  11  in the X zone, and the chamber  242  of the second header  200  may communicate with the front row tubes  11  in the Y zone. The chamber  251  of the second header  200  may communicate with the rear row tubes  12  in the X zone, and the chamber  252  of the second header  200  may communicate with the rear row tubes  12  in the Y zone. 
     Due to the above structure, the tubes  10 ,  11 ,  12  of the heat exchanger  1  exchanger according to one or more embodiments may have two (2) independent refrigerant paths. 
       FIG. 19  is a view showing overall flow of refrigerant when a cooling cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated; and  FIG. 20  is a view showing overall flow of refrigerant when a heating cycle of a heat exchanger according to one or more embodiments, such as the heat exchanger shown in  FIG. 1 , is operated. 
     With reference to  FIG. 1  to  FIG. 20 , the flow of the refrigerant in the cooling cycle operation and the heating cycle of the heat exchanger according to one or more embodiments is illustrated. 
     As shown in  FIG. 19 , in the cooling cycle operation, the refrigerant may be circulated into the first chamber  140  of the first header  100  through the inlet pipe  300 . The refrigerant may undergo heat exchange with outside air while passing through the front row tubes  11 , may be circulated in the third chamber  240  and the fourth chamber  250  of the second header  200  and then may undergo heat exchange with outside air while passing through the rear row tubes  12 . Then, the refrigerant may be discharged to the outside through the second chamber  150  of the first header  100  and the outlet pipe  400 . 
     The refrigerant flowing into the first chamber  140  of the first header  100  through the inlet pipe  300  may be the low-temperature and low-pressure liquefied refrigerant and gaseous refrigerant, the liquefied refrigerant and the gaseous refrigerant may be mixed and distributed through the cooling distributer  143 ,  144 ,  600 . 
     As shown in  FIG. 20 , in the heating cycle operation, the refrigerant may be circulated into the second chamber  150  of the first header  100  through the outlet pipe  400 . The refrigerant may undergo heat exchange with outside air while passing through the rear row tubes  12 , may be circulated in the fourth chamber  250  and the third chamber  240  of the second header  200  and then may undergo heat exchange with outside air while passing through the front row tubes  11 . Then, the refrigerant may be discharged to the outside through the first chamber  140  of the first header  100  and the inlet pipe  300 . 
     The refrigerant flowing into the second chamber  150  of the first header  100  through the outlet pipe  400  may be the high-temperature and high-pressure gaseous refrigerant, the gaseous refrigerant may be distributed to the plurality of rear row tubes  12  through the heating distributer  153  and  170 . 
     According to the spirit of the embodiments, since the first header of the heat exchanger may have the mixing chamber into which the refrigerant may be circulated, the supplying chamber communicating with the tubes and the distribution pipe for distributing the refrigerant in the mixing chamber to the supplying chamber, the refrigerant flowing into the first header may be mixed and stabilized and then distributed to the tubes. 
     In addition, since the distribution pipe may penetrate and may be coupled to the cover baffle and the separating baffle may be coupled to the first header, a process of assembling the distribution pipe may be simplified and a coupling force may be secured. 
     Furthermore, in the heating cycle operation, distribution of the refrigerant may be improved through the heating distribution pipe. 
     Here, since the heating distribution pipe may have a structure which may reduce resistance to flow of the refrigerant in the cooling cycle operation, even though the heating distribution pipe may be added, heat exchange efficiency may not be lowered in the cooling cycle operation. 
     In addition, in a case where 36 or more tubes are provided in each row, the refrigerant may be smoothly distributed so that heat exchange efficiency may be increased. 
     While aspects of the present invention have been particularly shown and described with reference to differing embodiments thereof, it should be understood that these embodiments should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in the remaining embodiments. Suitable results may equally be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. 
     Thus, although a few embodiments have been shown and described, with additional embodiments being equally available, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.