Patent Publication Number: US-2013240187-A1

Title: Heat exchanger and air conditioner equipped with same

Description:
TECHNICAL FIELD 
     The present invention relates to a side-flow type parallel-flow heat exchanger and an air conditioner equipped with the same. 
     BACKGROUND ART 
     A parallel-flow heat exchanger has a configuration in which a plurality of flat tubes are arranged between a plurality of header pipes such that a plurality of refrigerant passages in the flat tubes communicate with interiors of the header pipes, and fins such as corrugated fins are disposed between the flat tubes. Such a parallel-flow heat exchanger is widely used in vehicle air conditioners, outdoor units of air conditioners for buildings, and so on. 
     In the parallel-flow heat exchanger, the corrugated fins may be installed exclusively between the flat tubes or may be mounted therebetween and also to an outward facing surface of each outermost positioned one of the plurality of flat tubes. Examples of the latter case can be seen in Patent Documents 1 to 3. 
     A heat exchanger described in Patent Document 1 is a parallel-flow heat exchanger in which flat tubes are arranged in horizontal rows. In this heat exchanger, corrugated fins are mounted also to an outward facing flat surface of each outermost one of the flat tubes, and a side plate for fin protection is disposed on an outside of each outermost one of the corrugated fins. 
     A heat exchanger described in Patent Document 2 also is a parallel-flow heat exchanger in which flat tubes are arranged in horizontal rows. In this heat exchanger, corrugated fins are mounted also to an outward facing flat surface of each outermost one of the flat tubes, and a side plate for reinforcing a core portion composed of the flat tubes and the corrugated fins, which are alternately layered on each other, is disposed on an outside of each outermost one of the corrugated fins. 
     A heat exchanger described in Patent Document 3 also is a parallel-flow heat exchanger in which flat tubes are arranged in horizontal rows. In this heat exchanger, a side sheet is brazed to an exterior of one of the corrugated fins at each of both ends of the heat exchanger. 
     In a case where a heat exchanger is used as an evaporator, moisture in the atmosphere condenses on a cooled surface of the heat exchanger, and thus condensate water is formed. In a side-flow type parallel-flow heat exchanger, if condensate water is accumulated on surfaces of flat tubes or of corrugated fins, an area of an air flow passage is narrowed by the water, so that heat exchange performance is deteriorated. For this reason, it is required that a side-flow type parallel-flow heat exchanger be configured to allow condensate water to be quickly drained, thereby preventing it from being accumulated therein. 
     When an air temperature is low, condensate water turns into frost on a surface of a heat exchanger. Such frost may even turn into ice. In this specification, the term “condensate water” is intended to encompass so-called defrosted water that is water resulting from melting of such frost or ice. 
     When, as in the configurations described in the above patent documents, a parallel-flow heat exchanger including a side sheet provided on an outside of each outermost fin is used by adopting a so-called side-flow method in which header pipes are arranged in perpendicular rows, and flat tubes are arranged in horizontal rows, there occurs a problem that condensate water is held by a lower-side one of the side sheets. Patent Documents 4 and 5 disclose technical ideas for solving this problem. 
     In a heat exchanger described in Patent Document 4, when seen from below, an outermost corrugated fin positioned at a lower portion is at least partly exposed to have an exposed portion. The exposed portion is made to emerge by reducing a width of a side plate positioned on an outside of this outermost corrugated fin. 
     In a heat exchanger described in Patent Document 5, water drainage holes for draining condensate water are provided through a side plate as a bottom surface plate. Through the lower-side side plate, the water drainage holes are provided in such a number and size as not to deteriorate mechanical strength of the side plate. 
     LIST OF CITATIONS 
     Patent Literature 
     
         
         Patent Document 1: JP-A-H5-79788 
         Patent Document 2: JP-A-2006-64194 
         Patent Document 3: JP-A-2007-139376 
         Patent Document 4: JP-A-2010-249388 
         Patent Document 5: JP-A-S61-223465 
       
    
     SUMMARY OF THE INVENTION 
     Technical Problem 
     It is an object of the present invention to provide, in a side-flow type parallel-flow heat exchanger, a structure capable of draining condensate water from a lower-side outermost fin as quickly as possible. 
     Solution to the Problem 
     A side-flow type parallel-flow heat exchanger according to the present invention includes: a plurality of header pipes that are arranged parallel to each other at an interval therebetween; a plurality of flat tubes that are arranged between the plurality of header pipes and each have therein a refrigerant passage communicating with interiors of the plurality of header pipes; a plurality of fins that are mounted to flat surfaces of the plurality of flat tubes; and a side sheet that is attached to an outside of each outermost positioned one of the plurality of fins. One of the side sheets, which is positioned at a lower portion of said heat exchanger, is provided, at an edge thereof on a condensate water gathering side in said heat exchanger, with a plurality of notches formed at intervals from each other, and each of the notches has a width extending over a length plural times a length of an interval pitch of the fins. 
     In the heat exchanger configured as above, preferably, the notches have a shape having an angle of less than 180° inside from the edge of the one of the side sheets. 
     In the heat exchanger configured as above, preferably, the notches are tapered from the edge of the one of the side sheets. 
     In the heat exchanger configured as above, preferably, the one of the side sheets is provided, at an edge thereof on a side opposite to the condensate water gathering side, with a plurality of notches formed at intervals from each other, and each of the notches has a width extending over a length plural times a length of the interval pitch of the fins. 
     In the heat exchanger configured as above, preferably, the notches formed in the one of the side sheets on the condensate water gathering side or the notches formed in the one of the side sheets on the side opposite to the condensate water gathering side have a depth exceeding half a depth of the one of the side sheets. 
     In the heat exchanger configured as above, preferably, the notches formed on the condensate water gathering side and the notches formed on the side opposite to the condensate water gathering side are arranged so as to be mutually staggered. 
     In the heat exchanger configured as above, preferably, a part of said heat exchanger can be formed into a curved portion by bending, and a part of the one of the side sheets, which is to be subjected to the bending, is provided, at an edge thereof that is to be convex after the bending, with a plurality of slits formed by cutting at intervals from each other. 
     In the heat exchanger configured as above, preferably, the one of the side sheets is provided, at an edge thereof that is to be concave after bending, with a plurality of the notches that have a width extending over a length plural times a length of the interval pitch of the fins and are formed at intervals from each other. 
     In the heat exchanger configured as above, preferably, the one of the side sheets has a plurality of through holes formed at intervals from each other at portions thereof other than portions where the notches are formed. 
     In the heat exchanger configured as above, preferably, each of the through holes is formed to have a width extending over a length plural times a length of the interval pitch of the fins. 
     In the heat exchanger configured as above, preferably, in a depth direction, the one of the side sheets has a width smaller than a width of the fins, and the fins are exposed to an outside of the one of the side sheets on each of the condensate water gathering side and a side opposite to the condensate water gathering side. 
     An air conditioner according to the present invention includes the heat exchanger of any one of the above-described configurations, and the heat exchanger is incorporated in an outdoor unit or an indoor unit of the air conditioner. 
     Advantageous Effects of the Invention 
     According to the present invention, even if condensate water is formed on an outermost fin positioned at a lower portion of a heat exchanger, or condensate water formed at an upper part of the heat exchanger flows down to the lower portion of the heat exchanger, such condensate water quickly drips down, i.e. is quickly drained. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of a heat exchanger according to an embodiment of the present invention. 
         FIG. 2  is a perspective view of the heat exchanger shown in  FIG. 1 . 
         FIG. 3  is a bottom view of the heat exchanger shown in  FIG. 1 . 
         FIG. 4  is a partially enlarged view based on  FIG. 1 . 
         FIG. 5  is a partial perspective view of the heat exchanger shown in  FIG. 1 . 
         FIG. 6  is an explanatory view explaining a relationship between an interval pitch of fins and a width of a notch. 
         FIG. 7  is an explanatory view explaining a relationship between the interval pitch of the fins and a width of a through hole. 
         FIG. 8  is a first diagram explaining a shape of the notch. 
         FIG. 9  is a second diagram explaining a shape of the notch. 
         FIG. 10  is a third diagram explaining a shape of the notch. 
         FIG. 11  is a fourth diagram explaining a shape of the notch. 
         FIG. 12  is a fifth diagram explaining a shape of the notch. 
         FIG. 13  is a sixth diagram explaining a shape of the notch. 
         FIG. 14  is a first diagram explaining a shape of the through hole. 
         FIG. 15  is a second diagram explaining a shape of the through hole. 
         FIG. 16  is a third diagram explaining a shape of the through hole. 
         FIG. 17  is a view explaining a method for forming the notches at a curved portion of the heat exchanger. 
         FIG. 18  is a view explaining a modified form of a side sheet. 
         FIG. 19  is a schematic sectional view of an outdoor unit of an air conditioner equipped with the heat exchanger according to the present invention. 
         FIG. 20  is a schematic configuration view of the air conditioner equipped with the heat exchanger according to the present invention, showing a state at the time of an air-warming operation. 
         FIG. 21  is a schematic configuration view of the air conditioner equipped with the heat exchanger according to the present invention, showing a state at the time of an air-cooling operation. 
         FIG. 22  is a perpendicular sectional view explaining a basic structure of a side-flow type parallel-flow heat exchanger. 
         FIG. 23  is a perpendicular sectional view taken along a line A-A of  FIG. 22 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     With reference to the appended drawings, the following describes embodiments of the present invention. 
       FIGS. 22 and 23  show a basic structure of a side-flow type parallel-flow heat exchanger. In each of  FIGS. 22 and 23 , an upper side of the figure is an upper side of the heat exchanger, and a lower side of the figure is a lower side of the heat exchanger. In a heat exchanger  1 , two perpendicular header pipes  2  and  3  are arranged parallel to each other at an interval therebetween in a horizontal direction, and between the header pipes  2  and  3 , a plurality of horizontal flat tubes  4  are arranged at a predetermined pitch in a perpendicular direction. Each of the flat tubes  4  is an elongated metal member formed by extrusion and has therein a refrigerant passage  5  for a refrigerant to flow therethrough. The flat tubes  4  are arranged with an extrusion direction thereof, which is also a longitudinal direction thereof, set to be horizontal, and thus a direction in which a refrigerant flows through the refrigerant passage  5  also is horizontal. A plurality of the refrigerant passages  5  equal in sectional shape and sectional area are arranged in a depth direction in  FIG. 22 , so that a perpendicular section of each of the flat tubes  4  has a harmonica-like shape as shown in  FIG. 23 . Each of the refrigerant passages  5  communicates with interiors of the header pipes  2  and  3 . Fins  6  are mounted to flat surfaces of the flat tubes  4 , respectively. While, as the fins  6 , corrugated fins are used herein, plate fins also may be used. Needless to say, at a stage of actually being incorporated in equipment, the parallel-flow heat exchanger  1  is installed at various angles as required from a design standpoint, and there are many cases where strict meanings of “perpendicular” and “horizontal” are not applicable. 
     The header pipes  2  and  3 , the flat tubes  4 , and the fins  6  are all made of a metal having good thermal conductivity, such as aluminum. The flat tubes  4  are fixed to the header pipes  2  and  3  by brazing or welding, and the fins  6  are fixed to the flat tubes  4  by brazing or welding. 
     The fins  6  are disposed between the flat tubes  4  such that each of the fins  6  is fixed at both of its upper and lower ends to the flat surfaces of each pair of adjacent upper and lower ones of the flat tubes  4 , respectively. Naturally, a fin disposed on an outward facing flat surface of each outermost (uppermost or lowermost) positioned one of the plurality of flat tubes  4  arranged in vertical rows is fixed only at one of its upper and lower ends to the flat surface of the each tube. Henceforth, such a fin is referred to as an outermost fin. An outermost fin positioned at an upper portion of the heat exchanger  1  is indicated by a reference symbol  6   a U, and an outermost fin positioned at a lower portion of the heat exchanger  1  is indicated by a reference symbol  6   a D. 
     A side sheet  10 U is disposed on an outside of the outermost fin  6   a U, and a side sheet  10 D is disposed on an outside of the outermost fin  6   a D. The side sheets  10 U and  10 D are made of a metal sheet such as of aluminum and fixed to the outermost fins  6   a U and  6   a D, respectively, by brazing or welding. 
     The heat exchanger  1  is of a side-flow type, and only the header pipe  3  is provided with refrigerant gates  7  and  8 . In the header pipe  3 , two partition plates  9   a  and  9   c  are provided at an interval therebetween in a vertical direction, and in the header pipe  2 , a partition plate  9   b  is provided at a height intermediate between heights at which the partition plates  9   a  and  9   c  are provided, respectively. 
     In a case where the heat exchanger  1  is used as an evaporator, a refrigerant flows in through the lower-side refrigerant gate  7  as shown by a solid line arrow in  FIG. 22 . The refrigerant that has entered through the refrigerant gate  7  is blocked by the partition plate  9   a  to be directed to the header pipe  2  via some of the flat tubes  4 . This flow of the refrigerant is represented by a left-pointing block arrow. The refrigerant that has entered the header pipe  2  is blocked by the partition plate  9   b  to be directed to the header pipe  3  via other ones of the flat tubes  4 . This flow of the refrigerant is represented by a right-pointing block arrow. The refrigerant that has entered the header pipe  3  is blocked by the partition plate  9   c  to be directed again to the header pipe  2  via still other ones of the flat tubes  4 . This flow of the refrigerant is represented by another left-pointing block arrow. The refrigerant that has entered the header pipe  2  turns around to be directed again to the header pipe  3  via still other ones of the flat tubes  4 . This flow of the refrigerant is represented by another right-pointing block arrow. The refrigerant that has entered the header pipe  3  flows out through the refrigerant gate  8 . In this manner, the refrigerant flows from bottom to top of the heat exchanger  1 , forming a zigzag path. The herein described case of using three partition plates is merely one example, and the number of partition plates used and a resulting number of times the flow of a refrigerant turns around can be set arbitrarily as required. 
     In a case where the heat exchanger  1  is used as a condenser, a flow direction of a refrigerant is reversed. That is, a refrigerant enters the header pipe  3  through the refrigerant gate  8  as shown by a dotted line arrow in  FIG. 22  and then is blocked by the partition plate  9   c  to be directed to the header pipe  2  via some of the flat tubes  4 . In the header pipe  2 , the refrigerant is blocked by the partition plate  9   b  to be directed to the header pipe  3  via other ones of the flat tubes  4 . In the header pipe  3 , the refrigerant is blocked by the partition plate  9   a  to be directed again to the header pipe  2  via still other ones of the flat tubes  4 . In the header pipe  2 , the refrigerant turns around to be directed again to the header pipe  3  via still other ones of the flat tubes  4 . Then, the refrigerant flows out through the refrigerant gate  7  as shown by another dotted line arrow. In this manner, the refrigerant flows from top to bottom of the heat exchanger  1 , forming a zigzag path. 
     The heat exchanger  1  is not limited in configuration to the above-described one. A configuration is also possible in which both of the header pipes  2  and  3  are provided with a refrigerant gate. Another configuration is also possible in which no partition plates are provided in the header pipes  2  and  3 . 
       FIGS. 1 to 5  show a structure of the heat exchanger  1  as an embodiment of the present invention. In these figures, constituent components common with those in the basic structure shown in  FIGS. 22 and 23  are indicated by the same reference symbols as used in  FIGS. 22 and 23 , and descriptions thereof are omitted. 
     In a case where the heat exchanger  1  is used as an evaporator, moisture in the atmosphere condenses on a cooled surface of the heat exchanger  1 , and thus condensate water is fowled. The intended meaning of “condensate water” is as described earlier. In a parallel-flow heat exchanger such as the heat exchanger  1 , if condensate water is accumulated on surfaces of flat tubes or of fins, a sectional area of an air flow passage is narrowed by the water, so that heat exchange performance is deteriorated. In addition, since the heat exchanger  1  is of the side-flow type, condensate water formed on an upper one of flat tubes  4  or of fins  6  flows therefrom sequentially down to the lower ones of the flat tubes  4  or of the fins  6 , and an outermost fin  6   a D, therefore, is a place where accumulation of condensate water is most likely to occur. 
     Accumulated condensate water narrows an area of an air flow passage of the heat exchanger  1  and thus hinders ventilation, so that heat exchange performance is deteriorated. Furthermore, in a case where the heat exchanger  1  is incorporated in an outdoor unit of an air conditioner, with a drop of an outside air temperature to a freezing point or lower, condensate water may freeze to cause damage to the heat exchanger  1 . For this reason, it is required that condensate water formed in the heat exchanger  1  be drained as quickly as possible. 
     In the present invention, in order to solve the above-described problem, a side sheet  10 D positioned at the lower portion of the heat exchanger  1  is configured as follows. That is, the side sheet  10 D is provided, at an edge thereof on a condensate water gathering side in the heat exchanger  1 , with a plurality of notches  11  formed at intervals from each other. 
     In the case where the heat exchanger  1  is incorporated in an outdoor unit of an air conditioner, condensate water gathers on a windward side of the heat exchanger  1 . This is for the following reason. That is, in an outdoor unit, the heat exchanger  1  is installed in a state of standing substantially upright without being tilted. In a case where the heat exchanger  1  is used as an evaporator (as in, for example, an air-warming operation), heat exchange is performed more actively on a windward side than on a leeward side, and thus condensate water is accumulated on the windward side. Hence, the windward side is a condensate water gathering side. 
     The heat exchanger  1  is designed to be incorporated in an outdoor unit of an air conditioner and, as shown in  FIGS. 2 ,  3 , and  5 , has one curved portion la at some point along its length, thus having a substantially L-shaped planar shape. A convex side of the curved portion la is a windward side in the outdoor unit. Accordingly, in each of  FIGS. 3 and 4 , a lower side of the figure is a condensate water gathering side, and the side sheet  10 D has the notches  11  formed at the edge thereof on this side. 
     Preferably, the individual notches  11  have a shape having an angle of less than 180° inside the side sheet  10 D from the edge of the side sheet  10 D and are tapered from the edge of the side sheet  10 D. In the embodiment, as a shape satisfying these conditions, a V shape is selectively adopted. As shown in  FIG. 6 , each of the notches  11  has, at its widest portion, a width W 1  extending over a length plural times a length of an interval pitch P of the fins  6 . 
     Since the notches  11  are tapered from the edge of the side sheet  10 D, as shown by arrows in  FIG. 8 , condensate water, upon contact with an edge of each of the notches  11 , is guided deep into the each of the notches  11 , and at a deepest point thereof, flows of the water join together to form a water droplet. Such a water droplet grows fast and drips down, i.e. is drained. Since the notches  11  have a width extending over a length plural times a length of the interval pitch P of the fins  6 , it takes only a short time for condensate water to gather to form a large water droplet, thus enabling efficient drainage of condensate water. 
     The notches  11  in the present invention are not limited in shape to a V shape. Any of various shapes exemplarily shown in  FIGS. 9 to 12  or any other shape can be adopted. 
     Notches  11  shown in  FIG. 9  have a semicircular shape or a U shape. While not having an angle at their depths, the notches  11  of this type satisfy the condition that they are tapered from the edge of the side sheet  10 D. 
     Notches  11  shown in  FIG. 10  have a trapezoidal shape. The notches  11  of this type satisfy the condition that they have an angle of less than 180° inside the side sheet  10 D from the edge thereof by having two angles of less than 180° and more than 90°, namely, two obtuse angles  11   a . Furthermore, the notches  11  of this type also satisfy the condition that they are tapered from the edge of the side sheet  10 D. 
     Notches  11  shown in  FIG. 11  have an inverted M shape. The notches  11  of this type satisfy the condition that they have an angle of less than 180° inside the side sheet  10 D from the edge thereof by having two angles of less than 90°, namely, two acute angles  11   b . Furthermore, the notches  11  of this type also satisfy the condition that they are tapered from the edge of the side sheet  10 D. 
     Notches  11  shown in  FIG. 12  have an inverted trapezoidal shape, each having a width that is reduced at its entry provided at the edge of the side sheet  10 D and increases with increasing depth from the entry. The notches  11  of this type satisfy the condition that they have an angle of less than 180° inside the side sheet  10 D from the edge thereof by having two angles of less than 90°, namely, two acute angles  11   b.    
     No matter which shape the notches  11  have among the shapes shown in  FIGS. 8 to 12 , condensate water, upon contact with an edge of each of the notches  11 , is guided deep into the each of the notches  11 , and at a deepest point thereof, flows of the water join together to form a large water droplet, which then drips down. 
     The side sheet  10 D is provided, also at an edge thereof on a side opposite to the condensate water gathering side in the heat exchanger  1 , with a plurality of notches  12  formed at intervals from each other. That is, the side sheet  10 D has notches formed at the edges of both sides thereof. In each of  FIGS. 3 and 4 , an upper side of the figure is the side opposite to the condensate water gathering side. In the case where the heat exchanger  1  is incorporated in an outdoor unit of an air conditioner, the side opposite to the condensate water gathering side is a leeward side of the heat exchanger  1 . Similarly to the notches  11 , the notches  12  have a width extending over a length plural times a length of the interval pitch P of the fins  6  and are tapered from the edge of the side sheet  10 D. 
     In the embodiment shown in  FIGS. 1 to 5 , the notches  11  and the notches  12  are the same in shape (V shape) and size, which, however, is not necessarily required. The notches  12  may have a shape (any of the shapes exemplarily shown in  FIGS. 9 to 12  or any other shape) different from that of the notches  11 , and there may be a difference in width between the notches  11  and the notches  12 . 
     As described above, in the case where the heat exchanger  1  is incorporated in an outdoor unit of an air conditioner, the side sheet  10 D is provided, also at the edge thereof on the side (leeward side) opposite to the condensate water gathering side (windward side) in the heat exchanger  1 , with the notches  12  and, therefore, has notches fainted at the edges of both sides thereof. This further enhances a condensate water drainage capability of the side sheet  10 D, and thus condensate water at the outermost fin  6   a D can be quickly drained. 
     While this embodiment adopts a configuration in which the side sheet  10 D is provided with notches at the edge thereof on the condensate water gathering side and at the edge thereof on the side opposite thereto in the heat exchanger  1 , in other words, a configuration in which the side sheet  10 D has notches formed at the edges of both sides thereof, a configuration also may be adopted in which the side sheet  10 D has notches formed only at the edge thereof on the condensate water gathering side. 
     The notches  11  and  12  may have a size increased to such an extent as to have respective depths exceeding half a depth of the side sheet  10 D. With this configuration, the side sheet  10 D has a shape shown in  FIG. 13  and thus allows condensate water to be quickly drained from the outermost fin  6   a D. 
     While in  FIG. 13 , notches  11  and  12  are arranged such that each of the notches  11  is staggered with respect to each of the notches  12 , there is no limitation thereto. For example, a configuration also may be adopted in which the notches  11  and  12  are arranged such that every two of the notches  11  are staggered with respect to each of the notches  12 . 
     The side sheet  10 D has through holes  13  formed at portions thereof other than portions where the notches  11  and  12  are formed. In the embodiment, at positions between the notches  11  and the notches  12 , a plurality of the through holes  13  are formed at intervals from each other. The through holes  13  have a shape of an elongated circle (racetrack circle) whose longitudinal axis is aligned with a length direction of the flat tubes  4  and, as shown in  FIG. 7 , have a width W 2  extending over a length plural times a length of the interval pitch P of the fins  6 . 
     Since the through holes  13  are present, drainage of condensate water accumulated at the outermost fin  6   a D is even further enhanced. 
     The through holes  13  are not limited in shape to an elongated circular shape. Various shapes such as an elliptical shape shown in  FIG. 14  can be selectively adopted. 
     Preferred as the shape of the through holes  13  is not only a non-angular shape such as an elongated circular shape or an elliptical shape. A shape having an angle of less than 180° also is preferred as the shape of the through holes  13 . 
     For example, in a case of having a rectangular shape shown in  FIG. 15 , each of the through holes  13  has a right angle at each of four corners thereof. In a case of having a rhombus shape shown in  FIG. 16 , each of the through holes  13  has, on one diagonal axis thereof, two angles of less than 180° and more than 90°, namely, two obtuse angles, and on the other diagonal axis thereof orthogonal to the one diagonal axis, two angles of less than 90°, namely, two acute angles. 
     With the through holes  13  shaped to have an angle of less than 180° as in the above-described shapes, condensate water is guided toward the angle where flows of the water join together to form a large water droplet, which then drips down. Thus, condensate water is quickly drained. 
     It is not necessarily required that the though holes  13  have a width extending over a length plural times a length of the interval pitch P of the fins  6 . Setting the through holes  13  to have a width extending over a length plural times a length of the interval pitch P of the fins  6 , however, allows a large amount of condensate water to collect and thus can expedite drainage of the water. 
     A side sheet  10 D shown in  FIG. 18  has through holes  13  but is not provided with notches  11  and  12 . Even the side sheet  10 D having such a configuration has a function of accelerating drainage of condensate water from the outermost fin  6   a D. 
     A comparison between a width of the outermost fin  6   a D in a depth direction thereof, namely, an air-passing direction and a width of the side sheet  10 D in the same direction indicates that the width of the side sheet  10 D is made smaller than the width of the outermost fin  6   a D. Consequently, as shown in  FIGS. 2 to 5 , the outermost fin  6   a D is exposed to an outside of the side sheet  10 D on each of the condensate water gathering side and the side opposite thereto. A portion thus exposed is present, and such an exposed portion acts as a drainage port, so that condensate water is quickly drained from the outermost fin  6   a D. It is not required that the side sheet  10 U be smaller in width than the outermost fin  6   a U. For example, the side sheet  10 U may be the same in width as the outermost fin  6   a U. 
     As described earlier, the heat exchanger  1  has one curved portion  1   a  at some point along its length, thus having a substantially L-shaped planar shape. After the heat exchanger  1  is formed by using the flat tubes  4  of a linear shape, the curved portion  1   a  is formed by bending the heat exchanger  1 , and this process of bending can be utilized also to form the notches  11 . 
     As shown in a rectangular framed area at a lower portion of  FIG. 17 , a part of the side sheet  10 D that is to be subjected to bending is provided, at an edge thereof that is to be convex after the bending, with a plurality of slits  14  formed by cutting at intervals from each other. As a result of bending, the slits  14  are opened into a V shape as shown in an upper drawing in  FIG. 17  and thus constitute the notches  11  having a width extending over a length plural times a length of the interval pitch P of the fins  6 . This can facilitate the formation of the notches  11 . 
     The side sheet  10 D is provided with the notches  12  at an edge thereof on a side that is to be concave after bending. In consideration of the fact that bending causes the notches  12  to be reduced in open angle, in order that, even in such a state, the notches  12  will have an open angle equal to that thereof at a non-bent portion of the side sheet  10 D, i.e. the notches  12  will have a width extending over a length plural times a length of the interval pitch P of the fins  6 , the notches  12  are set to have a V shape having a wide pre-bending angle. 
     The above-described heat exchanger  1  can be incorporated in an outdoor unit or an indoor unit of a separate type air conditioner.  FIG. 19  shows an example in which the heat exchanger  1  is incorporated in the outdoor unit. 
     An outdoor unit  20  shown in  FIG. 19  includes a sheet-metal housing  20   a  having a substantially rectangular planar shape, longer sides of which constitute a front face  20 F and a back face  20 B, and shorter sides of which constitute a left side face  20 L and a right side face  20 R. An exhaust port  21  is formed in the front face  20 F, a back-face air intake port  22  is formed in the back face  20 B, and a side-face air intake port  23  is formed in the left side face  20 L. The exhaust port  21  is an assembly of a plurality of horizontal slit-shaped openings, and the back-face air intake port  22  and the side-face air intake port  23  are lattice-shaped openings. Four sheet-metal members that are the front face  20 F, the back face  20 B, the left side face  20 L, and the right side face  20 R, together with unshown top and bottom panels, form the box-shaped housing  20   a.    
     In the housing  20   a , a heat exchanger  1  having an L-shaped thermal plane is disposed on an immediately inner side relative to the back-face air intake port  22  and the side-face air intake port  23 . A blower  24  is disposed between the heat exchanger  1  and the exhaust port  21  in order to forcibly cause heat exchange between the heat exchanger  1  and outdoor air. The blower  24  is formed by combining an electric motor  24   a  with a propeller fan  24   b . In the housing  20   a , on an inner surface of the front face  20 F, a bell mouth  25  is fitted so as to surround the propeller fan  24   b  for improved blowing efficiency. The housing  20   a  includes a space on an inner side relative to the right side face  20 R, which is isolated by a partition wall  26  from an air flow flowing from the back-face air intake port  22  to the exhaust port  21 , and a compressor  27  is accommodated in this space. 
     Condensate water formed in the heat exchanger  1  of the outdoor unit  20  narrows an area of an air flow passage, so that heat exchange performance is deteriorated. Moreover, in a cold climate environment where an outside air temperature stays below the freezing point, such condensate water may even freeze to cause damage to the heat exchanger  1 . Thus, in the outdoor unit  20 , drainage of condensate water from the heat exchanger  1  is a crucial problem. 
     For the reason described earlier, in the outdoor unit  20 , condensate water gathers on a windward side of the heat exchanger  1 . Condensate water formed on the windward side rarely flows over to a leeward side but directly reaches a lower portion of the heat exchanger  1  on the windward side. When an outside air temperature is low, condensate water freezes to the heat exchanger  1  in the form of frost. An increased amount of frost necessitates a defrosting operation. During the defrosting operation, the blower  24  is stopped from operating, and thus water resulting from melting of the frost flows mainly downward to be accumulated due to gravity without being affected by wind. For this reason, the side sheet  10 D at a lower portion of the heat exchanger  1  is formed to have the configuration of the present invention, so that condensate water is quickly drained, and this can reduce detrimental effects caused by accumulation of condensate water. 
     That is, the side sheet  10 D attached to an outside of the outermost fin  6   a D is provided, at the edge thereof on a condensate water gathering side, with the plurality of notches  11  formed at intervals from each other. Each of the notches  11  has a width extending over a length plural times a length of the interval pitch of the fins. By the configuration described above, assuming that condensate water is formed on the outermost fin  6   a D positioned at the lower portion of the heat exchanger  1 , or that condensate water formed at an upper part of the heat exchanger  1  flows down to the outermost fin  6   a D, the condensate water is drawn deep into each of the notches  11  to collect and thus quickly drips down, i.e. is drained. This can prevent a situation in which condensate water is accumulated at the outermost fin  6   a D positioned at the lower portion of the heat exchanger  1 , so that a ventilation characteristic is impaired to deteriorate heat exchange performance. 
       FIGS. 20 and 21  show an example in which the heat exchanger  1  is incorporated in an indoor unit of a separate type air conditioner. In the separate type air conditioner shown in  FIGS. 20 and 21 , an outdoor unit includes a compressor, a four-way valve, an expansion valve, an outdoor-side heat exchanger, an outdoor-side blower, and so on, and the indoor unit includes an indoor-side heat exchanger, an indoor-side blower, and so on. In an air-warming operation, the outdoor-side heat exchanger functions as an evaporator, and in an air-cooling operation, as a condenser. In an air-warming operation, the indoor-side heat exchanger functions as a condenser, and in an air-cooling operation, as an evaporator. 
       FIG. 20  shows a basic configuration of the separate type air conditioner using a heat pump cycle as a refrigeration cycle. A heat pump cycle  101  is formed by connecting, in a loop, a compressor  102 , a four-way valve  103 , an outdoor-side heat exchanger  104 , a decompression expansion device  105 , and an indoor-side heat exchanger  106 . The compressor  102 , the four-way valve  103 , the heat exchanger  104 , and the decompression expansion device  105  are housed in a housing of an outdoor unit  110 , and the heat exchanger  106  is housed in a housing of an indoor unit  120 . The heat exchanger  104  is combined with an outdoor-side blower  107 , and the heat exchanger  106  is combined with an indoor-side blower  108 . The blower  107  includes a propeller fan  107   a  for forming a blow-off airflow, and the blower  108  includes a cross-flow fan  108   a  for forming a blow-off airflow. The cross-flow fan  108   a  is disposed below the heat exchanger  106 , with its axis line set to be horizontal. 
     The heat exchanger  1  according to the present invention can be used as a constituent component of the heat exchanger  106  of the indoor unit. The heat exchanger  106  is composed of three heat exchangers  106 A,  106 B, and  106 C arranged in the shape of a roof covering the blower  108 , and any one or all of the heat exchangers  106 A,  106 B, and  106 C can be constituted by the heat exchanger  1 . 
       FIG. 20  shows a state at the time of an air-warming operation. At this time, a refrigerant at a high temperature and a high pressure expelled from the compressor  102  enters the indoor-side heat exchanger  106 , where it radiates heat and condenses. Via the decompression expansion device  105 , the refrigerant that has flowed out of the heat exchanger  106  enters the outdoor-side heat exchanger  104 , where it expands and takes in heat from outdoor air, after which it returns to the compressor  102 . An airflow generated by the indoor-side blower  108  accelerates heat radiation from the heat exchanger  106 , and an airflow generated by the outdoor-side blower  107  accelerates heat absorption by the heat exchanger  104 . 
       FIG. 21  shows a state at the time of an air-cooling operation or a defrosting operation. At this time, the four-way valve  103  is switched to reverse a flow direction of a refrigerant from that in an air-warming operation. That is, a refrigerant at a high temperature and a high pressure expelled from the compressor  102  enters the outdoor-side heat exchanger  104 , where it radiates heat and condenses. Via the decompression expansion device  105 , the refrigerant that has flowed out of the heat exchanger  104  enters the indoor-side heat exchanger  106 , where it expands and takes in heat from indoor air, after which it returns to the compressor  102 . An airflow generated by the outdoor-side blower  107  accelerates heat radiation from the heat exchanger  104 , and an airflow generated by the indoor-side blower  108  accelerates heat absorption by the heat exchanger  106 . 
     In a case where the heat exchanger  1  according to the present invention is used as a constituent component of the heat exchanger  106  of the indoor unit, condensate water gathers on a surface of the heat exchanger  1  on a leeward side thereof that may also be a lower surface side thereof depending on a posture of the heat exchanger  1 . Through the use of the heat exchanger  1  according to the present invention, condensate water, even if formed, can be quickly drained, and thus it is possible to reduce a phenomenon in which condensate water drips over the cross-flow fan  108   a  by which it is splashed. 
     The foregoing has described the embodiments of the present invention. The present invention, however, is not limited in scope thereto and can be implemented in variously modified forms within the spirit of the invention. 
     INDUSTRIAL APPLICABILITY 
     The present invention is applicable to a side-flow type parallel-flow heat exchanger and an integrated air conditioner equipped with the same. 
     LIST OF REFERENCE SYMBOLS 
     
         
         
           
               1  heat exchanger 
               2 ,  3  header pipe 
               4  flat tube 
               5  refrigerant passage 
               6  fin 
               6   a U,  6   a D outermost fin 
           
         
           10 U,  10 D side sheet
         11 ,  12  notch     13  through hole     20  outdoor unit     110  outdoor unit     120  indoor unit