Abstract:
An air conditioner performs heating operation by driving a compressor ( 21 ), the heating operation being performed while an indoor heat exchanger ( 13 ) serves as the high-temperature portion of refrigeration cycle and an outdoor heat exchanger ( 23 ) serves as the low-temperature portion of the refrigeration cycle. The air conditioner also performs defrosting operation for defrosting the outdoor heat exchanger ( 23 ) by flowing refrigerant in opposite direction of flow of the refrigerant in the heating operation. In the outdoor heat exchanger ( 23 ), a large number of fins ( 30 ) are affixed to refrigerant pipes ( 2 ) so as to close to each other. Air flow passes through between the fins ( 30 ) to perform heat exchange. A water introduction section ( 31, 32 ) for closing each of the gaps between the fins ( 30 ) at one end thereof in the air flow passage direction is provided at the lower end of the outdoor heat exchanger ( 23 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an air conditioner that performs a warming operation and a defrosting operation. 
       BACKGROUND ART 
       [0002]    A conventional air conditioner is disclosed in a patent document 1. This air conditioner includes an indoor apparatus disposed indoors and an outdoor apparatus disposed outdoors. The outdoor apparatus is provided with a compressor, an outdoor heat exchanger, and an outdoor fan, while the indoor apparatus is provided with an indoor heat exchanger and an indoor fan. The compressor flows a refrigerant to operate a refrigeration cycle. In the indoor heat exchanger and outdoor heat exchanger, a refrigerant pipe is mounted with many fins close to one another and performs heat exchange with air passing through between the fins. 
         [0003]    A refrigerant outlet portion of the compressor is connected to one end of the indoor heat exchanger and one end of the outdoor heat exchanger respectively via a four-way valve by means of the refrigerant pipe. The other ends of the indoor heat exchanger and the outdoor heat exchanger are connected via an expansion valve by means of the refrigerant pipe. The outdoor fan is disposed to oppose the outdoor heat exchanger and promotes the heat exchange between the outdoor heat exchanger and outdoor air. The indoor fan introduces indoor air into the indoor apparatus and sends the air after performing the heat exchange with the indoor heat exchanger, into a room. 
         [0004]    During a warming operation time, the refrigerant output from the compressor by switching of the four-way valve flows through the indoor heat exchanger, the expansion valve, the outdoor heat exchanger and returns to the compressor. According to this, the indoor heat exchanger forms a high temperature portion of the refrigeration cycle, while the outdoor heat exchanger forms a low temperature portion of the refrigeration cycle. The indoor air rises in temperature by the heat exchange with the indoor heat exchanger and is sent into the room, whereby indoor warming is performed. 
         [0005]    During a cooling operation time, the refrigerant output from the compressor by the switching of the four-way valve flows in a direction opposite to the direction during the warming operation time. In other words, the refrigerant flows through the outdoor heat exchanger, the expansion valve, the indoor heat exchanger and returns to the compressor. According to this, the outdoor heat exchanger forms the high temperature portion of the refrigeration cycle, while the indoor heat exchanger forms the low temperature portion of the refrigeration cycle. The indoor air falls in temperature because of the heat exchange with the indoor heat exchanger and is sent into the room, whereby the indoor cooling is performed. 
         [0006]    Besides, the outdoor heat exchanger has frost during the warming operation time, accordingly, a defrosting operation is performed at predetermined intervals. During the defrosting operation time, the indoor fan and the outdoor fan are stopped, and the refrigerant flows in the same direction as the direction during the cooling operation time because of the switching of the four-way valve. According to this, the outdoor heat exchanger forms the high temperature portion of the refrigeration cycle, and the frost on the outdoor heat exchanger melts. The defrosted water due to the melting of the frost flows down the fin and falls below the outdoor heat exchanger, whereby it is possible to defrost the outdoor heat exchanger. 
       CITATION LIST 
     Patent Literature 
       [0007]    PLT1: JP-A-2010-181036 (pages 4 to 6, FIG. 1) 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0008]    However, according to the conventional air conditioner, the defrosted water, which flows down the fin of the outdoor heat exchanger during the defrosting operation time, is held between the adjacent fins by surface tension. Because of this, in a case when the outdoors where the outdoor apparatus is installed is a low temperature in a cold area, if the defrosting operation is stopped, the defrosted water held by the fins freeze again. If the warming operation is performed in this state, a frost grows on the ice that freezes again between the fins, accordingly, the frost amount increases and it is necessary to shorten the interval of the defrosting operation. Accordingly, there is a problem that the indoor warming is not sufficiently performed and comfortableness declines. 
         [0009]    It is an object of the present invention to provide an air conditioner that is able to improve the comfortableness. 
       Solution to Problem 
       [0010]    To achieve the above object, according to the present invention, an air conditioner comprising: a compressor that operates a refrigeration cycle; an indoor heat exchanger that performs heat exchange with indoor air; and an outdoor heat exchanger that performs the heat exchange with outdoor air, the compressor is driven to perform a warming operation in which the indoor heat exchanger is used as a high temperature portion of the refrigeration cycle and the outdoor heat exchanger is used as a low temperature portion, and to perform a defrosting operation for defrosting the outdoor heat exchanger in which the outdoor heat exchanger serving as the high temperature portion of the refrigeration cycle is defrosted by flowing a refrigerant in a direction opposite to a direction during a time of the warming operation, wherein in the outdoor heat exchanger, many fins are fixed to a refrigerant pipe to be close to one another, an airflow passes through between the fins to perform the heat exchange, and a water guide portion for closing a space between the fins at one end in an airflow passing direction is disposed at a lower end of the outdoor heat exchanger. 
         [0011]    According to this structure, during the warming operation time, by driving the compressor, the refrigerant flows and the refrigeration cycle is operated. The outdoor heat exchanger forms the low temperature portion of the refrigeration cycle, and the air which performs a heat exchange with the indoor heat exchanger that forms the high temperature portion of the refrigeration cycle, is sent into a room, whereby the indoor warming is performed. At this time, the outdoor heat exchanger performs the heat exchange with outdoor air that passes through between the fins. If the outdoor heat exchanger has frost, a defrosting operation is performed. During a defrosting operation time, the refrigerant flows in a direction opposite to the direction during the warming operation time, and the outdoor heat exchanger forms the high temperature portion of the refrigeration cycle. According to this, the frost on the outdoor heat exchanger melts and the defrosted water flows down the fins. At this time, the defrosted water flowing down one end portion of the fins (e.g., an airflow outlet portion) is guided by the water guide portion, which closes a lower end space between the fins, to the other end portion (e.g., an airflow inlet portion). The defrosted water guided by the water guide portion joins the defrosted water flowing down the other end portion and falls below the outdoor heat exchanger. 
         [0012]    Besides, the present invention is characterized in that in the air conditioner having the above structure, the defrosted water, which flows down the one end portion of the fins in the airflow passing direction during the warming operation time, is received by the water guide portion and guided to the other end portion. 
         [0013]    Besides, the present invention is characterized in that in the air conditioner having the above structure, the water guide portion is composed of a plate-shaped member having an L shape in section that contacts the lower end of the fins and extends in a direction in which the fins are disposed to be parallel with one another. According to this structure, the defrosted water flowing down the one end portion of the fins is guided to the other end portion by the water guide portion that has the L shape in section. 
         [0014]    Besides, the present invention is characterized in that in the air conditioner having the above structure, the water guide portion is formed by bending a corner portion that includes a lower surface of the fins. According to this structure, the defrosted water flowing down the one end portion of the fins is guided to the other end portion by the water guide portion that is obtained by bending the corner portion of the lower end of the fin. 
         [0015]    Besides, the present invention is characterized in that in the air conditioner having the above structure, a plurality of lines of the refrigerant pipes are disposed in a zigzag pattern in the airflow passing direction, and a lower end of the refrigerant pipe disposed in the one end portion in the airflow passing direction is disposed at a position higher than a lower end of the refrigerant pipe disposed in the other end portion. According to this structure, the refrigerant pipes are disposed to be parallel with one another in the airflow passing direction of the fins, and the water guide portion is disposed on the fin where a distance from the lower end of the fin to the refrigerant pipe is longer. 
         [0016]    Besides, the present invention is characterized in that in the air conditioner having the above structure, in the outdoor heat exchanger, the water guide portion is disposed on a downstream side in the airflow passing direction during the warming operation time. According to this structure, during the warming operation time, outdoor air performs the heat exchange with the refrigerant pipe and fins of the outdoor heat exchanger. At this time, the air passing through between the fins in a lower portion collides with the water guide portion disposed in the downstream portion and flows upward. 
         [0017]    Besides, the present invention is characterized in that in the air conditioner having the above structure, the refrigerant pipe, which is disposed in the high temperature portion of the refrigeration cycle during the warming operation time, is disposed under the outdoor heat exchanger. According to this structure, the refrigerant pipe disposed under the outdoor heat exchanger forms the high temperature portion of the refrigeration cycle during the warming operation time and frost on a lower portion of the outdoor heat exchanger and on a bottom wall of the outdoor apparatus is alleviated. 
       Advantageous Effects of Invention 
       [0018]    According to the present invention, the water guide portion closing the space between the fins at the one end in the airflow passing direction is disposed at the lower end of the outdoor heat exchanger. According to this, it is possible to receive the defrosted water, which flows down the one end portion of the fin during the warming operation time, by means of the water guide portion and to easily guide the defrosted water to the other end portion. As a result of this, the defrosted water flowing down the one end portion of the fin joins the defrosted water flowing down the other end portion and falls downward. Because of this, the flow amount per unit area of the defrosted water guided to the lower end of the fin increases and falls fast from the lower end of the fin. According to this, it is possible to reduce the defrosted water that is held by the lower end of the fin because of the surface tension and reduce the frost amount on the outdoor heat exchanger. Accordingly, it is possible to prolong the interval of the defrosting operation and to improve the comfortableness. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0019]      FIG. 1  is a circuit diagram showing a refrigeration cycle of an air conditioner according to a first embodiment of the present embodiment. 
           [0020]      FIG. 2  is a perspective view showing an inside of an outdoor apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0021]      FIG. 3  is an exploded perspective view showing the outdoor apparatus of the air conditioner according to the first embodiment of the present invention. 
           [0022]      FIG. 4  is a vertical sectional view showing an outdoor heat exchanger of the air conditioner according to the first embodiment of the present invention. 
           [0023]      FIG. 5  is a vertical sectional view showing an outdoor heat exchanger of an air conditioner according to a second embodiment of the present invention. 
           [0024]      FIG. 6  is a view seen in an arrow D direction of  FIG. 5 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    Hereinafter, embodiments of the present invention are described with reference to the drawings.  FIG. 1  is a circuit diagram showing a refrigeration cycle of an air conditioner according to a first embodiment. An air conditioner  1  has an indoor apparatus  10  disposed indoors and an outdoor apparatus  20  disposed outdoors. In the air conditioner  1 , a compressor  21 , which flows a refrigerant in a refrigerant pipe  2  and operates a refrigeration cycle, is disposed in the outdoor apparatus  20 . 
         [0026]    The outdoor apparatus  20  is provided therein with: a four-way valve  22  connected to the compressor  21 ; an outdoor heat exchanger  23 ; an expansion valve  24 ; and an outdoor fan  25 . The indoor apparatus  10  is provided therein with: an indoor heat exchanger  13 ; and an indoor fan  15 . In the indoor heat exchanger  13  and outdoor heat exchanger  23 , many fins  30  (see  FIG. 4 ) are fixed to the refrigerant pipe  2  to be close to one another, and perform heat exchange with air that passes through between the fins  30 . 
         [0027]    The compressor  21  is connected to one end of the outdoor heat exchanger  23  and one end of the indoor heat exchanger  13  via the four-way valve  22  by means of the refrigerant pipe  2 . The other ends of the outdoor heat exchanger  23  and indoor heat exchanger  13  are connected via the expansion valve  24  by means of the refrigerant pipe  2 . Besides, a heat pipe  26  disposed in a lower portion of the outdoor heat exchanger  23  is formed by the refrigerant pipe  2  between the expansion valve  24  and the indoor heat exchanger  13 . 
         [0028]    The outdoor fan  25  is disposed to oppose the outdoor heat exchanger  23 . By driving the outdoor fan  25 , outdoor air is supplied to the outdoor heat exchanger  23  and the heat exchange between the outdoor heat exchanger  23  and the outdoor air is promoted. The air performing the heat exchange with the outdoor heat exchanger  23  is exhausted to outside via an air outlet (not shown) that faces the outdoor fan  25  and opens from the outdoor apparatus  20 . 
         [0029]    The indoor fan  15  and the indoor heat exchanger  13  are disposed in an air path (not shown) formed in the indoor apparatus  10 . By driving the indoor fan  15 , indoor air flows into the air path to be supplied to the indoor heat exchanger  13 , and the heat exchange is performed between the air flowing in the air path and the indoor heat exchanger  13 . The air performing the heat exchange with the indoor heat exchanger  13  is sent into a room via an air outlet (not shown) that opens from the indoor apparatus  10 . 
         [0030]      FIG. 2  is a perspective view showing an inside of the outdoor apparatus  20  of the air conditioner  1 . Besides,  FIG. 3  is an exploded perspective view of a main portion of the outdoor apparatus  20 . In the outdoor apparatus  20 , the compressor  21  is disposed on one end of a bottom plate  29  that has a substantially rectangular shape when viewed from top, and that is short in a front-rear direction and long in a left-right direction. The outdoor heat exchanger  23  is formed into a substantially L shape when viewed from top and disposed upright on a side portion opposite to the compressor  21  and a rear portion of the outdoor apparatus  20 . Besides, the heat pipe  26  is disposed in the lower portion of the outdoor heat exchanger  23 . A water drainage hole  29   a  is disposed through one or more positions of the bottom plate  29  under the outdoor heat exchanger  23 . 
         [0031]    The outdoor fan  25  includes a shaft disposed in the front-rear direction and is disposed to oppose the outdoor heat exchanger  23 . By driving the outdoor fan  25 , outdoor air flows mainly from a rear side of the outdoor apparatus  20  to a front side as shown by an arrow B, to perform the heat exchange with the outdoor heat exchanger  23 . Meanwhile, part of the air flows into the outdoor apparatus  20  from a side to perform a heat exchange via a side portion of outdoor heat exchanger  23  and is guide frontward. 
         [0032]      FIG. 4  shows a vertical sectional view of the outdoor heat exchanger  23 . The outdoor heat exchanger  23  is provided with, in the front-rear direction, two lines of the refrigerant pipes  2  that snake at a predetermined pitch P in a vertical direction. The refrigerant pipes  2  in the front-rear direction are disposed at positions deviated in the vertical direction in a zigzag pattern. According to this, it is possible to make the air flowing as shown by the arrow B contact the refrigerant pipes  2  in the front-rear direction, and to improve the heat exchange efficiency. 
         [0033]    The refrigerant pipes  2  in the front-rear direction are each mounted with a fixed rectangular fin  30  that extends in the vertical direction, and the outdoor heat exchanger  23  is composed to be a fin and tube type. The fins  30  are disposed at a predetermined pitch (e.g., 1.3 mm) to be close to each other in a direction in which the refrigerant pipe  2  extends, and an airflow passes through between the fins  30  as shown by the arrow B. A fin  30   a  is disposed on the refrigerant pipe  2  on an upstream side where the airflow passes, while a fin  30   b  is disposed on the refrigerant pipe  2  on a downstream side. 
         [0034]    A water guide portion  31  is disposed on and contacts a lower end of the fin  30   b  on the downstream side. The water guide portion  31  is formed of a metal plate shaped member that extends in the left-right direction and has an L shape in section, and closes a space between the adjacent fins  30   b.  The water guide portion  31  guides defrosted water which flows down the fin  30   b  on the downstream side, to the fin  30   a  on the upstream side during a defrosting operation time. 
         [0035]    In the air conditioner having the above structure, during a warming operation time, the indoor fan  15  and the outdoor fan  25  are driven and the four-way valve  22  is switched as shown by a solid line in the figure. According to this, by driving the compressor  21 , the refrigerant flows in a direction indicated by an arrow A, and the refrigerant, which is compressed by the compressor  21  to be high temperature and high pressure, radiates heat in the indoor heat exchanger  13  and condenses. 
         [0036]    The high temperature refrigerant passes through the heat pipe  26 , thereafter, is expanded by the expansion valve  24  to be low temperature and low pressure, and sent to the outdoor heat exchanger  23 . Frost on the bottom plate  29  and a lower end of the outdoor heat exchanger  23  is reduced by the heat pipe  26 . Especially, the amount of frost on the outdoor apparatus  20  oriented to a cold area increases, accordingly, the heat pipe  26  is often disposed under the outdoor heat exchanger  23 . 
         [0037]    The refrigerant flowing into the outdoor heat exchanger  23  absorbs heat and evaporates to become a low temperature gas refrigerant and is sent to the compressor  21 . According to this, the refrigerant circulates and the refrigeration cycle is operated. The air, which performs the heat exchange with the indoor heat exchanger  13  forming a high temperature portion of the refrigeration cycle, is sent in to the room by the indoor fan  15 , whereby indoor warming is performed. Besides, the air, which performs the heat exchange with the outdoor heat exchanger  23  forming a low temperature portion of the refrigeration cycle, is exhausted to outside by the outdoor fan  25 . 
         [0038]    During a cooling operation time, the indoor fan  15  and the outdoor fan  25  are driven and the four-way valve  22  is switched as shown by a broken line in the figure. According to this, by driving the compressor  21 , the refrigerant flows in a direction opposite to the arrow A direction, whereby the indoor heat exchanger  13  forms the low temperature portion of the refrigeration cycle, while the outdoor heat exchanger  23  forms the high temperature portion of the refrigeration cycle. The air, which performs the heat exchange with the indoor heat exchanger  13 , is sent into the room by the indoor fan  15 , whereby the indoor cooling is performed. Besides, the air, which performs the heat exchange with the outdoor heat exchanger  23  which forms the high temperature portion of the refrigeration cycle, is exhausted to the outside by the outdoor fan  25 . 
         [0039]    Besides, the outdoor heat exchanger  23  forming the low temperature portion of the refrigeration cycle during a warming operation has frost, accordingly, the defrosting operation is performed at a predetermined interval. During the defrosting operation, the indoor fan  15  and the outdoor fan  25  are stopped and the four-way valve  22  is switched as shown by a broken line in the figure. According to this, by driving the compressor  21 , the refrigerant flows in the direction opposite to the arrow A direction, whereby the indoor heat exchanger  13  forms the low temperature portion of the refrigeration cycle, while the outdoor heat exchanger  23  forms the high temperature portion of the refrigeration cycle. 
         [0040]    Because of the stopping of the outdoor fan  25 , the heat exchange between the outdoor heat exchanger  23  and outdoor air is alleviated, and it is possible to efficiently raise the outdoor heat exchanger  23  in temperature. Besides, by the stopping of the indoor fan  15 , it is possible to prevent low temperature air from being sent into the room. 
         [0041]    Because of the temperature rise of the outdoor heat exchanger  23 , the frost on the outdoor heat exchanger  23  melts and flows down the fins  30 . The defrosted water, which flows down the fin  30   b  in one end portion (downstream side) in an airflow passing direction, is received by the water guide portion  31  closing the lower end and guided to the other end portion (upstream side). The defrosted water, which flows down the fin  30   a  on the upstream side in the airflow passing direction, joins the defrosted water on the downstream side guided by the water guide portion  31  and falls from a lower end of the fin  30   a.  The defrosted water falling from the outdoor heat exchanger  23  is drained via the water drainage hole  29   a.    
         [0042]    At this time, the flow amount per unit area of the defrosted water, which is drained from the lower end of the fin  30  on part of which the water guide portion  31  is disposed, increases compared with a case where the water guide portion  31  is not disposed, and falls fast from the lower end of the fin  30 . According to this, it is possible to reduce the defrosted water that is held by the lower end of the fin  30  because of surface tension. 
         [0043]    Meanwhile, if the water drainage hole  29   a  is disposed under the fin  30   a  on which the water guide portion  31  is not disposed, the drainage improves. In other words, by disposing the water drainage hole  29   a  at a position on which the defrosted water, which flows down the fin  30  and joins because of the water guide portion  31 , falls, it is possible to easily drain the defrosted water via the water drainage hole  29   a.    
         [0044]    According to the present embodiment, the water guide portion  31  closing the space between the fins  30   b  at one end in the airflow passing direction is disposed at the lower end of the outdoor heat exchanger  23 . According to this, during the defrosting operation time, by using the water guide portion  31 , it is possible to receive the defrosted water flowing down one (fin  30   b ) of the fin  30  and to easily guide the defrosted water to the other one (fin  30   a ). As a result of this, the defrosted water flowing down the fin  30   b  on one side joins the defrosted water flowing down the fin  30   a  on the other side and falls downward. 
         [0045]    Because of this, the flow amount per unit area of the defrosted water drained from the lower end of the fin  30  increases and falls fast from the lower end of the fin  30 . According to this, it is possible to reduce the defrosted water held by the lower end of the fin  30  because of the surface tension and to reduce the frost amount on the outdoor heat exchanger  23 . Accordingly, it is possible to prolong the interval of the defrosting operation and to improve comfortableness. 
         [0046]    Besides, by using the plate-shaped member having the L shape in section that extends in the parallel disposition direction of the fin  30  and contacts the lower end of the fin  30 , it is possible to easily provide the water guide portion  31  that guides the defrosted water. 
         [0047]    Besides, the heat pipe  26  (refrigerant pipe  2 ), which is disposed at the high temperature portion of the refrigeration cycle during the warming operation time, is disposed under the outdoor heat exchanger  23 , accordingly, it is possible to reduce the frost on a bottom plate of the outdoor apparatus  20  and a lower portion of the outdoor heat exchanger  23 . Instead of the heat pipe  26 , a heater such as a glass pipe heater or the like may be disposed. 
         [0048]    Meanwhile, the water guide portion  31  may be disposed on the fin  30  on the upstream side in the airflow passing direction during the warming operation time. However, if the water guide portion  31  is disposed on the upstream side, the airflow flows in a direction opposite to the arrow B direction, and the airflow guided to the lower portion of the outdoor heat exchanger  23  collides with the water guide portion  31  to be scattered upward and downward. Because of this, the airflow does not contact the refrigerant pipe  2  in a lower portion that opposes the water guide portion  31  and the fins  30  at the lower portion, accordingly, the heat exchange efficiency declines. 
         [0049]    If the water guide portion  31  is disposed on the fin  30   b  on the downstream side in the airflow passing direction during the warming operation time, the airflow in the lower portion of the outdoor heat exchanger  23  performs the heat exchange with the refrigerant pipe  2  and the fin  30 , thereafter, collides with the water guide portion  31  and flows upward. According to this, compared with the case where the water guide portion  31  is disposed on the upstream side in the airflow passing direction, heat exchange area increases and it is possible to improve the heat exchange efficiency. 
         [0050]    Next,  FIG. 5  shows a vertical sectional view of the outdoor heat exchanger  23  of the air conditioner  1  according to a second embodiment. Besides,  FIG. 6  shows a view when seen in an arrow D direction of  FIG. 5 . For the sake of description, the same portions as the above first embodiment shown in  FIG. 1  to  FIG. 4  are indicated by the same reference numbers. In the present embodiment, instead of the water guide portion  31  (see  FIG. 4 ) in the first embodiment, a water guide portion  32  is disposed. The other portions are the same as the first embodiment. 
         [0051]    The water guide portion  32  is formed by bending a corner portion that includes a lower surface of the fin  30   b  of the outdoor heat exchanger  23 . Besides, the refrigerant pipes  2  are disposed in a zigzag pattern, and the lower end of the refrigerant pipe  2  disposed on the downstream side in the airflow passing direction is disposed at a position higher than the lower portion of the refrigerant pipe  2  disposed on the upstream side. Because of this, a distance H  2  between the lower end of the fin  30   b  on the downstream side forming the water guide portion  32  and the refrigerant pipe  2  at the lowest portion is larger than a distance H 1  between the lower end of the fin  30   a  on the upstream side and the refrigerant pipe  2  at the lowest portion. According to this, it is possible to easily form the water guide portion  32  by bending the fin  30   b.    
         [0052]    At this time, the fins  30   b  are disposed in parallel with one another in the direction in which the refrigerant pipe  2  extends, and the distance between the adjacent fins  30   b  is narrow. Because of this, the water guide portions  32  obtained by bending the adjacent fins  30   b  overlap one another and close the space between the adjacent fins  30   b.    
         [0053]    The defrosted water, which flows down the fin  30   b  in the one end portion (downstream side) in an airflow passing direction during the defrosting operation time, is received by the water guide portion  32  closing the lower end and guided to the other end portion (upstream side). The defrosted water, which flows down the fin  30   a  on the upstream side in the airflow passing direction, joins the defrosted water on the downstream side guided by the water guide portion  32  and falls. The defrosted water falling from the outdoor heat exchanger  23  is drained via the water drainage hole  29   a.    
         [0054]    At this time, compared with a case where the water guide portion  32  is not disposed, the flow amount per unit area of the defrosted water, which is drained from the lower end of the fin  30  on part of which the water guide portion  32  is disposed, increases and falls fast from the lower end of the fin  30 . According to this, it is possible to reduce the defrosted water that is held by the lower end of the fin  30  because of the surface tension. 
         [0055]    According to the present embodiment, the water guide portion  32 , which closes the space between the fins  30  at the one end in the airflow passing direction, is disposed at the lower end of the outdoor heat exchanger  23 . According to this, like the first embodiment, during the defrosting operation time, by using the water guide portion  32 , it is possible to receive the defrosted water flowing down the one (fin  30   b ) of the fin  30  and to easily guide the defrosted water to the other one (fin  30   a ). As a result of this, the defrosted water flowing down the fin  30   b  on the one side joins the defrosted water flowing down the fin  30   a  on the other side and falls downward. 
         [0056]    Because of this, the flow amount per unit area of the defrosted water drained from the lower end of the fin  30  increases and falls fast from the lower end of the fin  30 . According to this, it is possible to reduce the defrosted water held by the lower end of the fin  30  because of the surface tension and to reduce the frost amount on the outdoor heat exchanger  23 . Accordingly, it is possible to prolong the interval of the defrosting operation and to improve the comfortableness. 
         [0057]    Besides, it is possible to easily form the water guide portion  32  for guiding the defrosted water by bending the corner portion that includes the lower surface of the fin  30 . 
         [0058]    Besides, the plurality of lines of refrigerant pipes  2  are disposed in the zigzag pattern in the airflow passing direction, and the lower end of the refrigerant pipe  2  on the downstream side is disposed at the position higher than the lower portion of the refrigerant pipe  2  on the upstream side, accordingly, it is possible to easily form the water guide portion  32  by bending the fin  30 . 
         [0059]    Meanwhile, like the above description, the water guide portion  32  may be disposed on the fin  30  on the upstream side in the airflow passing direction during the warming operation time. However, if the water guide portion  32  is disposed on the fin  30  on the downstream side in the airflow passing direction during the warming operation time, compared with the case where the water guide portion  32  is disposed on the upstream side in the airflow passing direction, the heat exchange area increases and it is possible to improve the heat exchange efficiency. 
         [0060]    In the present embodiment, structure may be employed, in which for example, soldering is applied to the portion where the water guide portions  32  of the adjacent fins  30   b  overlap to fill up a gap of the overlapping portion. According to this structure, the gap occurring at the overlapping portion of the water guide portions  32  is closed, accordingly, it becomes easy to guide the defrosted water on the downstream side to the upstream side. 
         [0061]    In the first and second embodiments, the refrigerant pipes  2  disposed in parallel with each other in the front and rear portions of the outdoor heat exchanger  23  are mounted with the fixed separate fins  30   a  and  30   b,  however, fin common to the refrigerant pipes  2  in the front and rear portions may be disposed. In other words, each of the fins disposed in parallel with each other in the direction in which the refrigerant pipes  2  extend may be fixed bridging the refrigerant pipes  2  in the front and rear portions. 
         [0062]    Hereinbefore, the embodiments of the present invention are described, however, the scope of the present invention is not limited to these embodiments, and it is possible to make various modifications without departing from the spirit of the present invention and put them into practical use. 
       INDUSTRIAL APPLICABILITY 
       [0063]    The present invention is usable for an air conditioner that performs a warming operation and a defrosting operation. 
       REFERENCE SIGNS LIST 
       [0064]      1  air conditioner 
         [0065]      2  refrigerant pipe 
         [0066]      10  indoor apparatus 
         [0067]      13  indoor heat exchanger 
         [0068]      15  indoor fan 
         [0069]      20  outdoor apparatus 
         [0070]      21  compressor 
         [0071]      22  four-way valve 
         [0072]      23  outdoor heat exchanger 
         [0073]      24  expansion valve 
         [0074]      25  outdoor fan 
         [0075]      26  heat pipe 
         [0076]      29  bottom plate 
         [0077]      30  fin 
         [0078]      31 ,  32  water guide portions