Patent Publication Number: US-10760837-B2

Title: Evaporator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2 017-0 04 37 51; filed on Apr. 4, 2017 and Korean Patent Application No. 10-2018-0032403, filed on Mar. 21, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The following disclosure relates to a dual evaporator including first and second rows allowing a refrigerant to flow separately, in which a header tank is partitioned by a partition to form a first compartment and a second compartment and the partition includes a communication hole connecting the first compartment and the second compartment. 
     BACKGROUND 
     Air conditioners for vehicles are installed to cool or heat the interior of vehicles during summer or winter or remove frost formed on wind shields when it rains or during the winter, and the like, to secure drivers&#39; front or rear visual fields. Air-conditioners generally include both a heating system and a cooling system to selectively receive internal or external air, heat or cool the received air, and blow air to the inside of vehicles to cool or heat the inside or ventilate it. 
     A typical refrigerating cycle of such an air conditioner includes an evaporator for absorbing heat from the surroundings, a compressor for compressing a refrigerant, a condenser for releasing heat to the surroundings, and an expansion valve for expanding the refrigerant. In a cooling system, a gaseous refrigerant flowing to the compressor from the evaporator is compressed to have a high temperature and high pressure in the compressor, and when the compressed refrigerant in the gaseous state passes through the condenser and is liquefied, heat of liquefaction is released to the surroundings. The liquefied refrigerant passes through the expansion valve again to become low-temperature and low-pressure wet saturated steam, and then flows to the evaporator again and is vaporized to absorb the heat of vaporization from the surroundings to cool ambient air, thus cooling the inside of a vehicle. 
     The condenser, the evaporator, and the like, used in the cooling system are typical heat exchangers, and a lot of continuous research includes studies on effective heat exchange between ambient air of a heat exchanger and a heat exchange medium, i.e., a refrigerant, inside the heat exchanger. The most direct effect of indoor cooling is manifested by efficiency of evaporators, and thus, various structural research and development have been done and made to improve heat exchange efficiency of evaporators. 
     In order to enhance heat exchange efficiency of evaporators, an example having a dual-evaporation structure in which a core including tubes and fins are dually provided to form first and second rows as spaces in which a refrigerant flows therein has been proposed. 
     Conventionally, Japanese Patent Laid-Open Publication No. 2005-308384 (“Ejector Cycle”, Nov. 4, 2005) discloses a configuration similar to a dual-evaporator in which a refrigerant flows in each of a first row and a second row. 
     Here, in the dual-evaporator, a header tank arranged on an upper side or a lower side is divided into two rows by a partition and a communication hole may be provided in the partition, which partitions first and second rows each allowing a refrigerant to flow therein, in order to connect the first and second rows to configure a flow path for flowing of a refrigerant. 
     However, the header tank does not have a drain hole in a portion corresponding to an intermediate position between the first row and the second row, making it difficult for condensate generated in refrigerant tubes and fins configuring the evaporator to be drained through the header tank when heat is exchanged. 
     In order to form a drain hole to drain condensate in the header tank, a portion corresponding to an intermediate position between the first and second rows may be narrowed to form a drain hole, but with this structure, it is difficult to form a communication hole connecting the first row and the second row and structural strength is so weak to degrade durability. 
     RELATED ART DOCUMENT 
     [Patent Document] 
     Japanese Patent Laid-Open Publication No. 2005-308384 A (Nov. 4, 2005) 
     SUMMARY 
     An embodiment is directed to providing an evaporator in which a drain hole to drain condensate is easily formed in a transverse central portion of a header tank formed in two rows, the degree of freedom of a size and position of a communication hole connecting first and second rows of the header tank is high, and durability of a portion in which the communication hole of the header tank is formed is high. 
     In one general aspect, an evaporator may include: a first header tank and a second header tank arranged abreast of each other and spaced apart from each other at a predetermined distance and partitioned by a partition to form a first row and a second row and to be divided into first compartment s and second compartments in a transverse direction; a plurality of tubes connected and fixed to the first header tank and the second header tank at both ends; and fins interposed between the plurality of tubes, wherein the second header tank includes a header in which a depressed portion is formed by concavely depressing downwards a transverse central portion in a longitudinal direction from an upper surface, the portion in which the depressed portion is formed protrudes downwards to form a pair of partitions spaced apart from each other, and a communication hole is formed in a penetrating manner in a transverse direction in each of the pair of partitions; a tank in which a transverse central portion is coupled to a lower end of the partition of the header and both sides in the transverse direction are coupled to the header; and an insert plate inserted into the depressed portion of the header such that both surfaces are tightly coupled to the pair of partitions, and having a through hole provided at a position corresponding to the communication holes provided in the pair of partitions. 
     The second header tank may include a condensate drain hole penetrating through the depressed portion in a vertical direction such that a lower external space of the tank and the depressed portion communicate with each other. 
     The insert plate may include a drainage flow path connecting an upper outer space of the header and the condensate drain hole. 
     The drainage flow path may include a first drainage flow path penetrating through both width-directional surfaces at a position spaced apart downwards from an upper end of the insert plate and a second drainage flow path connected to the first drainage flow path on an upper side and connected to the condensate drain hole on a lower side, and penetrating through both width-directional surfaces thereof. 
     The condensate drain holes may be provided in plurality and spaced apart from each other in the longitudinal direction, and the plurality of drainage flow paths may be provided in the insert plate and spaced apart from each other in the longitudinal direction to correspond to the condensate drain holes, respectively. 
     The first drainage flow path may extend to both sides in the longitudinal direction from an upper end of the second drainage flow path. 
     A fixing tab protrudes from a lower portion of the insert plate and a coupling hole vertically penetrating through the depressed portion is formed in the second header tank, so that the fixing tab may be inserted into the coupling hole and coupled therewith. 
     A vertically penetrating brazing ascertainment hole may be provided at a position corresponding to a portion in which the header is blocked, in a transverse central portion of the tank to which a lower end of the partition is coupled. 
     In another general aspect, an evaporator may include a first header tank and a second header tank arranged abreast of each other and spaced apart from each other at a predetermined distance and partitioned by a partition to form a first row and a second row and to be divided into first compartments and second compartments in a transverse direction; a plurality of tubes connected and fixed to the first header tank and the second header tank at both ends; and fins interposed between the plurality of tubes, wherein the second header tank includes a header in which a depressed portion is formed by concavely depressing downwards a transverse central portion in a longitudinal direction from an upper surface, the portion in which the depressed portion is formed protrudes downwards to form a pair of partitions spaced apart from each other, and a communication hole is formed in a penetrating manner in a transverse direction in each of the pair of partitions; and a tank in which a transverse central portion is coupled to a lower end of the partition of the header and both sides in the transverse direction are coupled to the header, wherein protrusions protruding from a circumferential portion of the communication hole in a transverse direction are formed in surfaces of the pair of partitions which face each other and the communication holes formed in the pair of partitions may be connected to each other. 
     The protrusions may protrude from the pair of partitions so that the protrusions facing each other may be in contact with each other. 
     The second header tank may include a condensate drain hole penetrating through the depressed portion in a vertical direction such that a lower external space of the tank and the depressed portion communicate with each other. 
     A plurality of communication holes may be formed in the pair of partitions and spaced apart from each other in the longitudinal direction, and protrusions are formed in the positions where the communication holes may be formed, the protrusions may be spaced apart from each other in the longitudinal direction, and the condensate drain holes may be formed in positions between the protrusions in the longitudinal direction. 
     A vertically penetrating brazing ascertainment hole may be provided at a position corresponding to a portion in which the header is blocked, in a transverse central portion of the tank to which a lower end of the partition is coupled. 
     In another general aspect, an evaporator may include: a first header tank and a second header tank arranged abreast of each other and spaced apart from each other at a predetermined distance and partitioned by a partition to form a first row and a second row and to be divided into first compartments and second compartments in a transverse direction; a plurality of tubes connected and fixed to the first header tank and the second header tank at both ends; and fins interposed between the plurality of tubes, wherein the second header tank includes a header in which a depressed portion is formed by concavely depressing downwards a transverse central portion in a longitudinal direction from an upper surface, the portion in which the depressed portion is formed protrudes downwards to form a pair of partitions spaced apart from each other, and a communication hole is formed in a penetrating manner in a transverse direction in each of the pair of partitions; a tank in which a transverse central portion is coupled to a lower end of the partition of the header and both sides in the transverse direction are coupled to the header; and a communication tube inserted into the communication holes respectively formed in the pair of partitions of the header and coupled at both ends thereof, wherein the communication holes formed in the pair of partitions may be connected to each other by the communication tube. 
     A flange may protrude outwardly from an outer circumferential surface of the communication tube at one end so that the flange may be caught by the partition adjacent to the first compartment or the second compartment. 
     A plurality of communication holes may be formed and spaced apart from each other in the header in the longitudinal direction, and the plurality of communication tubes may be separately formed and individually inserted and coupled to the communication holes. 
     The header includes a plurality of communication holes spaced apart from each other in the longitudinal direction, and the plurality of communication tubes may be provided and connected to each other by a communication portion. 
     A flange may protrude outwardly from an outer circumferential surface of the communication tube at one end so that the flange may be caught by the partition adjacent to the first compartment or the second compartment. 
     The second header tank may include a condensate drain hole penetrating through the depressed portion in a vertical direction such that a lower external space of the tank and the depressed portion communicate with each other. 
     A vertically penetrating brazing ascertainment hole may be provided at a position corresponding to a portion in which the header is blocked, in a transverse central portion of the tank to which a lower end of the partition is coupled. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  are an assembled perspective view and a partially exploded perspective view of an evaporator according to a first exemplary embodiment, respectively. 
         FIGS. 3 and 4  are a partial cross-sectional perspective view and a cross-sectional view of a header, a tank, and an insert plate of a second header tank according to the first exemplary embodiment, respectively. 
         FIGS. 5 to 7  are partial cross-sectional perspective views illustrating a modification of the header, the tank, and the insert plate of the second header tank according to the first exemplary embodiment. 
         FIGS. 8 and 9  are a partial cross-sectional perspective view and a cross-sectional view illustrating a coupling structure of a header, a tank, and an insert plate of a second header tank according to a second exemplary embodiment, respectively. 
         FIGS. 10 to 12  are an exploded perspective view, an assembled perspective view, and a cross-sectional view illustrating a coupling structure of a header, a tank, and an insert plate of a second header tank according to a third exemplary embodiment, respectively. 
         FIGS. 13 to 17  are exploded perspective views, assembled perspective views, and a cross-sectional view illustrating a modification of the header, the tank, and the insert plate of the second header tank according to the third exemplary embodiment, respectively. 
         FIGS. 18 and 19  are conceptual views illustrating flow of a refrigerant in an evaporator of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The advantages, features and aspects of the present disclosure will become apparent from the following description of the exemplary embodiments with reference to the accompanying drawings, which is set forth hereinafter. The present disclosure may, however, be embodied in different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting of example exemplary embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Hereinafter, an evaporator having the aforementioned configuration according to exemplary embodiments will be described in detail with reference to the accompanying drawings. 
     EXEMPLARY EMBODIMENT 1 
       FIGS. 1 and 2  are an assembled perspective view and a partially exploded perspective view of an evaporator according to a first exemplary embodiment, respectively, and  FIGS. 3 and 4  are a partial cross-sectional perspective view and a cross-sectional view of a header, a tank, and an insert plate of a second header tank according to the first exemplary embodiment, respectively. 
     As illustrated, the evaporator  1000  according to the first exemplary embodiment may include; a first header tank  100  and a second header tank  200  arranged abreast of each other and spaced apart from each other at a predetermined distance and partitioned by a partition to form a first row and a second row and to be divided into first compartments  100   a  and  200   a  and second compartments  100   b  and  200   b  in a transverse direction; a plurality of tubes  300  connected and fixed to the first header tank  100  and the second header tank  200  at both ends; and fins  400  interposed between the plurality of tubes  300 , wherein the second header tank  200  includes a header  210  in which a depressed portion  212  is formed by concavely depressing downwards a transverse central portion in a longitudinal direction from an upper surface, the portion in which the depressed portion  212  is formed protrudes downwards to form a pair of partitions  211  spaced apart from each other, and a communication hole  213  is formed in a penetrating manner in a transverse direction in each of the pair of partitions  211 ; a tank  220  in which a transverse central portion is coupled to a lower end of the partition  211  of the header  210  and both sides in the transverse direction are coupled to the header  210 ; and an insert plate  230  inserted into the depressed portion  212  of the header  210  such that both surfaces are tightly coupled to the pair of partitions  211 , and having a through hole  231  provided at a position corresponding to the communication holes  213  provided in the pair of partitions  211 . 
     The evaporator of the present disclosure may include a first header tank  100 , a second header tank  200 , a tube  300  and a fin  400 . Here, inner spaces of the first header tank  100  and the second header tank  200  may be partitioned by the partitions and refrigerant flow paths in which a refrigerant may flow may be arranged in two rows in a longitudinal direction. Thus, the first compartment  100   a  and the second compartment  100   b  of the first header tank  100  may be formed by coupling the header  110  and the tank  120 , and the first compartment  200   a  and the second compartment  200   b  of the second header tank  200  may be formed by coupling the header  210  and the tank  220 . Also, a plurality of tubes  300  may be coupled and fixed such that both ends thereof are connected to the first compartment  100   a  of the first header tank  100  and the first compartment  200   a  of the second header tank  200  forming a fist row, and a plurality of tubes  300  may be coupled and fixed such that both ends thereof are also connected to the second compartment  100   b  of the first header tank  100  and the second compartment  200   b  of the second header tank  200  forming the second row. The fins  400  are interposed and coupled between the tubes  300  forming the first row, and the fins  400  are interposed and coupled between the tubes  300  forming the second row. Accordingly, the first row and the second row may be stacked and coupled abreast of each other. 
     Here, the second header tank  200  may include the header  210 , the tank  220 , and the insert plate  230 . The header  210  is a part combined with the tank  220  (to be described later) to form a space in which the refrigerant may flow. The header  210  includes a depressed portion  212  formed by concavely depressing a transverse central portion between a portion in which the first compartment  200   a  is formed and a portion in which the second compartment  200   b  is formed, downwards from an upper surface in a longitudinal direction. The portion in which the depressed portion  212  is formed protrudes downwards such that the pair of partitions  211  are spaced apart from each other in the transverse direction, and lower ends of the pair of partitions  211  may be connected to each other in the transverse direction. Here, as illustrated, in the header  210 , the portion in which the depressed portion  212  is formed has a U-shape concavely downwards by bending a single plate member, and the portion in which the first compartment  200   a  and the second compartment  200   b  are formed may be curved upwards to be slightly convex. A tube insertion hole penetrating through upper and lower surfaces may be formed in the curved portion, so that after an end of the tube  300  is inserted into the tube insertion hole, the header  210  and the tubes  300  may be coupled through brazing, and width-directional both sides of the header  210  may be bent downwards. 
     The tank  220  is another part which is combined with the header  210  and forms a space in which the refrigerant may flow. A portion of the tank  220  forming the first compartment  200   a  and the second compartment  200   b  may be curved to be convex downwards, and width-directional both sides may be bent upwards and the bent portions are coupled to the both bent portions of the header  210  and joined through brazing, or the like. The transverse central portion of the tank  220  may be coupled to be in contact with lower ends of the partitions  211  of the header  210  and joined through brazing, or the like. Here, the transverse central portion of the tank  220  may include a seating recess concave in a longitudinal direction such that lower ends of the partitions  211  of the header  210  may be inserted and seated as illustrated. 
     The insert plate  230  may be formed as a plate extending in a height direction and a longitudinal direction so as to be longer than a thickness in a transverse direction. The insert plate  230  may be inserted into the depressed portion  212  of the header  210  such that both surfaces of the insert plate  230  are tightly attached to the pair of partitions  211 . Here, a lower end surface of the insert plate  230  may be in contact with a bottom surface of the depressed portion  212  and supported, and both surfaces of the insert plate  230  may be joined through brazing, or the like, in a state of being tightly attached to the pair of partitions  211 . The insert plate  230  includes a through hole  231  to correspond to the communication holes  213  provided in the pair of partitions  211 , and the communication hole  213  provided in one partition  211 , the through hole  231  of the insert plate  230 , and the communication hole  213  provided in the other partition  211  may communicate in a transverse direction. Here, a plurality of communication holes  213  provided in the partition  211  may be spaced apart from each other in a longitudinal direction, and the insert plate  230  is also formed to extend such that a length thereof is longer in a longitudinal direction than in a height direction such that the through holes  231  are formed in positions corresponding to the communication holes  213 . Accordingly, the insert plate  230  with the through holes  231  serves as a connection passage connecting the communication holes formed in one partition  211  and the communication holes  213  formed in the other partition  211  and serves as a structure firmly combining the two separated partitions  211 . 
     Accordingly, in the evaporator of the present disclosure, it is easy to form a drain hole to drain condensate in the depressed portion, which is a transverse central portion of a header tank in the header tank formed in two rows, the degree of freedom in a formation size and position of the communication hole connecting the first compartment and the second compartment as the first row and the second row of the header tank is high, and durability of the portion in which the communication hole of the header tank is formed is high. 
     The second header tank  200  may include a condensate drain hole  240  penetrating through the depressed portion  212  in a vertical direction such that an external space below the tank  220  and the depressed portion  212  communicate with each other. 
     That is, the condensate drain hole  240  penetrating through a portion in which the central portion of the header  210  and the central portion of the tank  220  are coupled may be formed in the portion in which the depressed portion  212  is formed, and since the depressed portion  212  and an external space below the tank  220  are connected by the condensate drain hole  240 , condensate drained down on a surface of the tubes  300  may gather in the depressed portion  212  and may be drained to a lower side of the second header tank  200  through the condensate drain hole  240 , Here, a plurality of condensate drain holes  240  may be spaced apart from each other in a longitudinal direction in a portion in which the depressed portion  212  is formed. 
       FIGS. 5 to 7  are partial cross-sectional perspective views illustrating a modification of the header, the tank, and the insert plate of the second header tank according to the first exemplary embodiment. 
     As illustrated, the insert plate  230  may include a drainage flow path  232  connecting an upper outer space of the header  210  and the condensate drain hole  240 . 
     That is, in case where the condensate drain hole  240  is provided on a lower side of the insert plate  230 , condensate, which may be collected on an upper side of the insert plate  230  or on an upper side of the header  210 , may flow along the drainage flow path  232  formed in the insert plate  230  and may be discharged through the condensate drain hole  240 . Accordingly, the condensate drain hole  240  may also be provided even at the length-directional section of the second header tank  200  in which the insert plate  230  is present, and condensate which may gather on both width-directional upper sides of the insert plate  230  may easily be drained. 
     The drainage flow path  232  may include a first drainage flow path  232 - 1  penetrating through both width-directional surfaces at a position spaced apart downwards from an upper end of the insert plate  230  and a second drainage flow path  232 - 2  connected to the first drainage flow path  232 - 1  on an upper side and connected to the condensate drain hole  240  on a lower side, and penetrating through both width-directional surfaces thereof. 
     This is an example of the drainage flow path  232  formed in the insert plate  230 . As illustrated, the drainage flow path  232  may be formed to penetrate through both surfaces of the insert plate  230  in the transverse direction. The insert plate  230  may protrude to be exposed to an upper side of the depressed portion  212  and the drainage flow path  232  may be perforated to penetrate through both surfaces thereof in the transverse direction. The drainage flow path  232  may include the first drainage flow path  232 - 1  provided in a longitudinal direction at a position slightly spaced from the upper end of the drainage flow path  232  in the height direction downwards and the second drainage flow path  232 - 2  provided in the height direction, so that the upper side of the second drainage flow path  232 - 2  may be connected to the first drainage flow path  232 - 1  and a lower side of the second drainage flow path  232 - 2  may be connected to the condensate drain hole  240 . Accordingly, the drainage flow path  232  may easily be formed, and condensate may easily gather toward the second drainage flow path  232 - 2  along the first drainage flow path  232 - 1  formed in the longitudinal direction, 
     The condensate drain holes  240  are provided in plurality and the plurality of condensate drain holes  240  are spaced apart from each other in the longitudinal direction. The plurality of drainage flow paths  232  may be provided in the insert plate  230  and spaced apart from each other in the longitudinal direction to correspond to the condensate drain holes  240 , respectively. 
     That is, when the plurality of condensate drain holes  240  are provided, the drainage flow paths  232  may be formed in the insert plate  230  in positions corresponding to the condensate drain holes  240  spaced apart from each other, respectively. Here, the first drainage flow path  232 - 1  may be provided, at a position spaced apart from both ends in the longitudinal direction of the insert plate  230 . When the plurality of drainage flow paths  232  are formed as illustrated, the first drainage flow paths  232 - 1  are spaced apart from each other, rather than being connected to each other, so that the insert plate  230  may be integrally formed without being divided into several separate parts by virtue of the drainage flow paths  232 . 
     In addition, the first drainage flow path  232 - 1  may extend to both sides in the longitudinal direction from an upper end of the second drainage flow path  232 - 2 . 
     That is, as illustrated, in the drainage flow path  232  formed in the insert plate  230 , the first drainage flow path  232 - 1  extends to both sides in the longitudinal direction from the upper end of the second drainage flow path  232 - 2  formed in a height direction to form a T-shaped drainage flow path  232 . 
     A fixing tab  233  protrudes from a lower portion of the insert plate  230  and a coupling hole  241  vertically penetrating through the depressed portion  212  is formed in the second header tank  200 , so that the fixing tab  233  may be inserted into the coupling hole  241  and coupled therewith. 
     That is, the fixing tabs  233  protrude downwards from a lower end of the insert plate  230 , and the vertically penetrating coupling holes  241  are formed in a portion where the depressed portion  212  of the second header tank  200  is formed. As the fixing taps  233  are inserted and coupled to the coupling holes  241 , a length-directional position of the insert plate  230  may be fixed. Here, as for the coupling holes  241  provided in the second header tank  200 , some of the condensate drain holes  240  may be used as the coupling holes  241 . In a state of being inserted and coupled to the coupling holes  241 , the fixing taps  233  of the insert plate  230  may protrude downwards, relative to a lower surface of a central portion of the tank  220  and protruding portions may be caulked through compression, bending, or the like, such that the insert plate  230  may not be released upwards in the height direction opposite to a direction in which the insert plate  230  is inserted. 
     A vertically penetrating brazing ascertainment hole  242  may be provided at a position corresponding to a portion in which the header  210  is blocked, in a transverse central portion of the tank  220  to which a lower end of the partition  211  of the header  210  is coupled. 
     That is, since the transverse central portion of the header  210  and the transverse central portion of the tank  220  may be joined to each other through brazing, the brazing ascertainment hole  242  may be formed at the transverse central portion of the tank  220  in contact with the lower end of the partition  21 , the transverse central portion of the header  210  to ascertain whether the joined portion is completely sealed. Here, the brazing ascertainment hole  242  is formed at a position corresponding to a blocked portion without the condensate drain hole  240  at the central portion of the header  210 , is joined using brazing. Thereafter, it is inspected whether leakage occurs when a gas having specific pressure is injected through the brazing ascertainment hole  242  to confirm whether the joined portion based on brazing is completely sealed. The brazing ascertainment hole  242  may be provided in plurality in a longitudinal direction, which are spaced apart from each other. 
     EXEMPLARY EMBODIMENT 2 
       FIGS. 8 and 9  are a partial cross-sectional perspective view and a cross-sectional view illustrating a coupling structure of a header, a tank, and an insert plate of a second header tank according to a second exemplary embodiment, respectively. 
     As illustrated in the drawings, the evaporator  1000  according to the second exemplary embodiment may include: a first header tank  100  and a second header tank  200  arranged abreast of each other and spaced apart from each other at a predetermined distance and partitioned by a partition  111  to form a first row and a second row and to be divided into first compartments  100   a  and  200   a  and second compartments  100   b  and  200   b  in a transverse direction; a plurality of tubes  300  connected and fixed to the first header tank  100  and the second header-tank  200  at both ends; and fins  400  interposed between the plurality of tubes  300 , wherein the second header tank  200  includes a header  210  in which a depressed portion  212  is formed by concavely depressing downwards a transverse central portion in a longitudinal direction from an upper surface, the portion in which the depressed portion  212  is formed protrudes downwards to form a pair of partitions  211  spaced apart from each other, and a communication hole  213  is formed in a penetrating manner in a transverse direction in each of the pair of partitions  211 ; and a tank  220  in which a transverse central portion is coupled to a lower end of the partition  211  of the header  210  and both sides in the transverse direction are coupled to the header  210 , wherein protrusions  214  protruding from a circumferential portion of the communication hole  213  in a transverse direction are formed in surfaces of the pair of partitions  211  of the header  210  which face each other and the communication holes  213  formed in the pair of partitions  211  may be connected to each other by the protrusion  214 . 
     This is because although a basic structure of the evaporator is similar to that of the first exemplary embodiment, the protrusions  214  protrude from the circumferential portion of the communication hole  213  in the width direction in the pair of facing partitions  211 , instead of inserting a separate insert plate into the depressed portion to couple the same, so that the communication hole  213  formed in one partition  211  and the facing communication hole  213  formed in the other partition are connected by the protrusion  214 . 
     More specifically, the evaporator of the present disclosure may include a first header tank  100 , a second header tank  200 , a tube  300  and a fin  400 . Here, inner spaces of the first header tank  100  and the second header tank  200  may be partitioned by the partitions  111  and  211  and refrigerant flow paths in which a refrigerant may flow may be arranged in two rows in a longitudinal direction. Thus, the first compartment  100   a  and the second compartment  100   b  of the first header tank  100  may be formed by coupling the header  110  and the tank  120 , and the first compartment  200   a  and the second compartment  200   b  of the second header tank  200  may be formed by coupling the header  210  and the tank  220 . Also, a plurality of tubes  300  may be coupled and fixed such that both ends thereof are connected to the first compartment  100   a  of the first header tank  100  and the first, compartment  200   a  of the second header tank  200  forming the first row, and a plurality of tubes  300  may be coupled and fixed such that both ends thereof are also connected to the second compartment  100   b  of the first header tank  100  and the second compartment  200   b  of the second header tank  200  forming the second row. The fins  400  are interposed and coupled between the tubes  300  forming the first row, and the fins  400  are interposed and coupled between the tubes  300  forming the second row. Accordingly, the first row and the second row may be stacked and coupled abreast of each other. 
     Here, the second header tank  200  may include the header  210  and the tank  220 . The header  210  is a part combined with the tank  220  to form a space in which the refrigerant may flow. The header  210  includes a depressed portion  212  formed by concavely depressing a transverse central portion between a portion in which the first compartment  200   a  is formed and a portion in which the second compartment  200   b  is formed, downwards from an upper surface in a longitudinal direction. The portion in which the depressed portion  212  is formed protrudes downwards such that the pair of partitions  211  are spaced apart from each other in the transverse direction, and lower ends of the pair of partitions  211  may be connected to each other in the transverse direction. Here, as illustrated, in the header  210 , the portion in which the depressed portion  212  is formed has a U-shape concavely downwards by bending a single plate member, and the portion in which the first compartment  200   a  and the second compartment  200   b  are formed may be curved upwards to be slightly convex. A tube insertion hole penetrating through upper and lower surfaces may be formed in the curved portion, so that after an end of the tube  300  is inserted into the tube insertion hole, the header  210  and the tubes  300  may be coupled through brazing, and both sides of the header  210  in a transverse direction may be bent downwards. 
     The tank  220  is another part which is combined with the header  210  and forms a space in which the refrigerant may flow. A portion of the tank  220  forming the first compartment  200   a  and the second compartment  200   b  may be curved to be convex downwards, and both sides in a transverse direction may be bent upwards and the bent portions are coupled to the both bent portions of the header  210  and joined through brazing, or the like. The transverse central portion of the tank  220  may be coupled to be in contact lower ends of the partitions  211  of the header  210  and joined through brazing, or the like. Here, the transverse central portion of the tank  220  may include a seating recess concave in a longitudinal direction such that lower ends of the partitions  211  of the header  210  may be inserted and seated as illustrated. 
     Here, the header  210  may include a communication hole  213  perforated to penetrate through both surfaces of the pair of partitions  211  in the transverse direction. The protrusion  214  may protrude from a circumferential portion of the communication hole  213  in the pair of facing partitions  211  in the transverse direction. 
     The protrusion  214  may be integrally formed with the partition  211  of the header  210  using pressing, or the like, and may protrude from the partition  211 . The protrusions  214  protruding from the pair of the partitions  211  may extend toward the center of the communication hole  213  in a longitudinal direction and a height direction from end portions protruding from the partitions in the transverse direction to form a sufficient joining area in the portion where the protrusions  214  are in contact with each other to join together. 
     Accordingly, the protrusions  214  serve as a connection passage for connecting the communication hole  213  formed in one partition  211  and the communication hole  213  formed in the other partition  211  and serve as a structure firmly combining the two separated partitions  211 . 
     Accordingly, in the evaporator of the present disclosure, it is easy to form a drain hole to drain condensate in the depressed portion, which is a transverse central portion of a header tank in the header tank formed in two rows, the degree of freedom in a formation size and position of the communication hole connecting the first compartment and the second compartment as the first row and the second row of the header tank is high, and durability of the portion in which the communication hole of the header tank is formed is high. 
     The protrusions  214  may protrude from the pair of partitions  211  so that the protrusions  214  on both sides facing each other may be in contact with each other. 
     That is, as illustrated, the protrusions  214  protrude in a facing direction in the two partitions  211  and the facing protrusions may be in contact with each other so as to be joined through brazing, or the like. In addition, the protrusion  214  may protrude only from one partition  211 , an end of the protruding protrusion  214  may be in contact with a circumferential portion of the communication hole  213  of the other partition  211 , and surfaces in contact with each other may be joined through brazing, or the like. 
     The second header tank  200  may include a condensate drain hole  240  penetrating through the depressed portion  212  in a vertical direction such that an external space below the tank  220  and the depressed portion  212  communicate with each other. 
     That is, as in the first exemplary embodiment, in the second exemplary embodiment, the condensate drain hole  240  penetrating through a portion where the central portion of the header  210  and the central portion of the tank  220  are coupled may be formed in the portion in which the depressed portion  212  is formed. 
     In addition, a plurality of communication holes  213  may be formed in the pair of partitions  211  and spaced apart from each, other in the longitudinal direction, and protrusions  214  are formed in the positions where the communication holes  213  are formed. The protrusions  214  may be spaced apart from each other in the longitudinal direction, and the condensate drain holes  240  may be formed in positions between the protrusions  214  in the longitudinal direction. 
     That is, as illustrated, when a plurality of communication holes  213  are formed and spaced apart from each other in the longitudinal direction in one partition  211 , the protrusions  214  are formed in the communication holes  213 , respectively and may be spaced apart from each other in the longitudinal direction. The condensate drain hole  240  is formed between the protrusions  214  in the longitudinal direction so that condensate on the upper side of the second header tank  200  may flow between the protrusions  214  spaced apart from each other in the longitudinal direction and may easily be drained through the condensate drain hole  240 . 
     A vertically penetrating brazing ascertainment hole  242  may be provided at a position corresponding to a portion in which the header  210  is blocked, in a transverse central portion of the tank  220  to which a lower end of the partition  211  of the header  210  is coupled. 
     That is, as in the first exemplary embodiment, in the second exemplary embodiment, the brazing ascertainment hole  242  is also formed and joined using brazing, and thereafter, it is inspected whether leakage occurs when a gas having specific pressure is injected through the brazing ascertainment hole  242  to confirm whether the joined portion based on brazing is completely sealed. 
     EXEMPLARY EMBODIMENT 3 
       FIGS. 10 to 12  are an exploded perspective view, an assembled perspective view, and a cross-sectional view illustrating a coupling structure of a header, a tank, and an insert plate of a second header tank according to a third exemplary embodiment, respectively. 
     As illustrated in the drawings, the evaporator  1000  according to the third exemplary embodiment may include: a first header tank  100  and a second header tank  200  arranged abreast of each other and spaced apart from each other at a predetermined distance and partitioned by a partition  111  to form a first row and a second row and to be divided into first compartments  100   a  and  200   a  and second compartments  100   b  and  200   b  in a transverse direction; a plurality of tubes  300  connected and fixed to the first header tank  100  and the second header tank  200  at both ends; and fins  400  interposed between the plurality of tubes  300 , wherein the second header tank  200  includes a header  210  in which a depressed portion  212  is formed by concavely depressing downwards a transverse central portion in a longitudinal direction from an upper surface, the portion in which the depressed portion  212  is formed protrudes downwards to form a pair of partitions  211  spaced apart from each other, and a communication hole  213  is formed in a penetrating manner in a transverse direction in each of the pair of partitions  211 ; a tank  220  in which a transverse central portion is coupled to a lower end of the partition  211  of the header  210  and both sides in the transverse direction are coupled to the header  210 ; and a communication tube  260  inserted into the communication holes  213  respectively formed in the pair of partitions  211  of the header  210  and coupled at both ends thereof, wherein the communication holes  213  formed in the pair of partitions  211  may be connected to each other by the communication tube  260 . 
     This is because although a basic structure of the evaporator is similar to that of the first or second exemplary embodiment, the communication tube  260  is inserted into the communication holes  213  formed respectively in the pair of partitions  211  facing each other such that one end of the communication tube  260  is inserted into the communication hole  213  formed in one partition  211  and coupled to the partition  211  in the transverse direction and the other end of the communication tube  260  is inserted and coupled to the communication hole  213  formed in the other partition  211 , instead of inserting a separate insert plate into the depressed portion. Here, the communication tube  260  may be provided toward the first compartment  200   a  or the second compartment  200   b  of the header  210  before the header  210  and the tank  220  are coupled to each other and subsequently inserted and coupled to the communication hole  213  formed in the partition  211  in the transverse direction and the communication tube  260  may be joined in a portion in contact with the communication hole  213  through brazing, or the like. 
     Accordingly, it is easy to form a drain hole to drain condensate in the depressed portion, which is a transverse central portion of a header tank in the header tank formed in two rows, the degree of freedom in a formation size and position of the communication hole connecting the first compartment and the second compartment as the first row and the second row of the header tank is high. 
     A flange  261  may protrude outwardly from an outer circumferential surface of the communication tube  260  at one end so that the flange  261  may be caught by the partition  211  adjacent to the first compartment  200   a  or the second compartment  200   b.    
     As illustrated, the flange  261  protrudes from one end of the linear tubular communication tube  260  to the outside of the outer circumferential surface, so that when the communication tube  260  is inserted and coupled to the communication hole  213  formed in the partition  211 , the flange  261  may be caught by the partition  211 , limiting a depth of insertion of the communication tube  260 . Thus, the other end of the communication tube  260  at which the flange  261  is not formed may be easily positioned to match the inner surface of the partition  211  forming the second compartment  200   b  and the communication tube  260  may not be released in a state of being inserted into the communication hole  213 . Further, the flange  261  may be tightly attached to the partition  211  and may be joined through brazing, or the like, enhancing a coupling force between the communication tube  260  and the partition  211 . 
     A plurality of communication holes  213  are formed and spaced apart from each other in the header  210  in the longitudinal direction. The plurality of communication tubes  260  may be separately formed and individually inserted and coupled to the communication holes  213 . 
     As illustrated, the plurality of communication holes  213  may be spaced apart from each other in the longitudinal direction of the header  210 , and the communication tubes  260  may be inserted into the communication holes  213 , respectively. Thus, it is easy to form the drain hole through which the condensate may be drained in the position between the communication tubes  260 , the degree of freedom with respect to a formation position of the communication hole  213  is high, and it is easy to assemble the communication tube  260 , regardless of position of the communication holes  213 . 
       FIGS. 13 to 17  are exploded perspective views, assembled perspective views, and a cross-sectional view illustrating a modification of the header, the tank, and the insert plate of the second header tank according to the third exemplary embodiment, respectively. 
     As illustrated, the header  210  includes a plurality of communication holes  213  spaced apart from each other in the longitudinal direction, and the plurality of communication tubes  260  may be provided and connected to each other by a connection portion  262 . 
     As illustrated, the plurality of communication holes  213  may be provided in the longitudinal direction of the header  210  and the integrated communication tubes  260  integrally connected to each other by the connection portion  262  may be inserted into the communication holes  213  at a time so as to be easily assembled thereto. Here, the connection portion  262  may connect one ends of the neighboring communication tubes  260  in the transverse direction. For example, the connection portion  262  may be formed in a linear line shape such that adjacent portions of the neighboring communication tubes  260  are connected to each other. When the integrated communication tubes  260  are inserted, into the communication holes  213  and coupled, the connection portion  262  is caught by the partition  211  to limit a depth of the inserted communication tube  260 . 
     Here, as illustrated, the flange  261  may protrude from one end of the linear tubular communication tubes  260  to the outside of the outer circumferential surface and may also be connected to the connecting portion  262 . Further, the neighboring communication tubes  260  may be connected to each other by the connection portion without a flange. 
     As in the first exemplary embodiment and the second exemplary embodiment, also in the third exemplary embodiment, the condensate drain hole  240  vertically penetrating through a portion where the central portion of the header  210  and the central portion of the tank  220  are coupled may be formed in the portion where the depressed portion  212  is formed, and the brazing ascertainment hole  242  may be formed so that, after the header  210  and the tank  220  are joined using brazing. Thereafter, it is inspected whether leakage occurs when a gas having specific pressure is injected through the brazing ascertainment hole  242  to confirm whether the joined portion based on brazing is completely sealed. 
     In all the evaporators according to the first to third exemplary embodiments of the present disclosure, the depressed portions may be formed in the tank  220  to form the partitions and the communication holes, and the insert plate may be inserted into the depressed portion formed in the tank  220  and coupled thereto, protrusions protruding from the communication holes may be formed, or the communication tubes may be inserted into the communication holes. Also, in the aforementioned exemplary embodiments, it is described that the communication holes are formed only in the second header tank  200  and connected by the insert plate or the communication tubes or by the protrusions, but the aforementioned configuration may also be applied to the first header tank  100  or may be applied to both the first header tank  100  and the second header tank  200 . Also, as illustrated, the communication holes may be formed such that the entire perimeter of the communication holes in the longitudinal direction and transverse direction of the portion perforated in the transverse direction are clogged or the communication holes may be perforated in a penetrating manner, 
       FIGS. 18 and 19  are conceptual views illustrating flow of a refrigerant in an evaporator of the present disclosure. 
     As illustrated, in any one or more of the first header tank  100  and the second header tank  200 , the spaces forming the first compartments  100   a  and  200   a  and the second compartments  100   b  and  200   b  are partitioned to be divided in the longitudinal direction by the baffles  150  and  250  to form various types of path (flow path) in which a refrigerant may flow. For example, when flow of a refrigerant flowing in one of the downward or upward directions along the tubes  300  is referred to as one path, as illustrated in  FIG. 18 , a first path P 1  in which a refrigerant introduced through an inlet tube  160  flows downwards along the tube  300  of the first row may be formed, a second path P 2  in which the refrigerant flows upwards along the tube  300  may be formed, and a third path P 3  in which the refrigerant flows downwards along the tube  300  may subsequently be formed. Thereafter, the refrigerant flows from the first row toward the second row through the communication hole  213  formed in the second header tank  300 , a fourth path P 4  in which the refrigerant flows upwards along the tube  300  in the second row may be formed, a fifth path P 5  in which the refrigerant flows downwards along the tube  300  may be formed, and a sixth path P 6  in which the refrigerant flows upwards along the tube  300  may be formed, and thus, the refrigerant flow path including a total of six paths in which the refrigerant is discharged through an outlet tube  170  may be formed. Alternatively, a refrigerant flow path including a total of four paths as illustrated in  FIG. 19  may also be formed, and here, the communication hole  213  may be formed, in the first header tank  100 . Also, a refrigerant path including a total of two paths in which the entire first row is configured as a first path and the entire second row is configured as a second path may be formed, and in addition, various flow paths may be configured and communication holes may be variously provided accordingly. 
     According to the exemplary embodiments, the evaporator may be advantageous in that the drain hole to drain condensate may be easily formed in the transverse central portion of the header tank formed in two rows, the degree of freedom of the size and position of the communication holes connecting the first and second rows of the header tank may be high, and durability of the portion in which the communication holes of the header tank are formed is high.