Abstract:
An outdoor unit includes: a heat exchanger in which heat transmission fins are fitted to and fixed to heat transmission pipes with predetermined distances so that heat is exchanged between refrigerant passing through the heat transmission pipes and air passing between the heat transmission fins; an electric component that controls equipment; and a cooling member disposed above a channel of air that has passed through the heat exchanger and configured to dissipate heat from the electric component to the air. The distance between the heat transmission fins in a position corresponding to the position of the cooling member and serving as a passage of the air passing through the cooling member is larger than that in the other positions.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an outdoor unit for an air-conditioning apparatus using a fin-and-tube heat exchanger. In particular, the present invention relates to a cooling structure of an electric component installed in an outdoor unit. 
       BACKGROUND ART  
       [0002]    An outdoor unit for an air-conditioning apparatus includes various electric components (electric parts) such as an inverter circuit for variably controlling the rotation speed of, for example, a compressor or a fan. Some electric components generate heat because of a flow of large current, for example. A high temperature may cause damage to the electric components, unstable driving, and other problems, which lead to reduced reliability of the outdoor unit. To prevent this, such electric components are cooled in order to prevent the electric components from reaching high temperatures. 
         [0003]    In some cooling structures in electric components of outdoor units for air-conditioning apparatuses, for example, a cooling member is placed in an air passage of a heat exchanger and removes heat from the electric components so that the electric components are cooled (see, for example, Patent Literature 1). In the cooling structure, to increase the flow rate of air flowing in the cooling member, the heat exchanger is configured such that the distance between heat transmission fins of the heat exchanger in a position where the heat exchanger is located close to the cooling member is larger than other positions therein. 
       CITATION LIST 
     Patent Literature 
       [0004]    Patent Literature 1: Japanese Unexamined Patent Application Publication 
         [0005]    No. 2005-331141 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    In such an outdoor unit for an air-conditioning apparatus as described in Patent Literature 1, a plurality of molds are needed for preparing heat transmission fins in order for the apparatus to have different distances between the heat transmission fins. This disadvantageously increases the manufacturing cost. 
         [0007]    It is therefore an object of the present invention to provide, for example, an outdoor unit that can maintain the cooling effect of electric components with reduced cost. 
       Solution to Problem 
       [0008]    An outdoor unit according to the present invention includes: a heat exchanger including heat transmission fins and heat transmission pipes, the heat transmission fins being spaced from one another with a distance, fitted to and fixed to the heat transmission pipes, so that heat is exchanged between refrigerant passing through the heat transmission pipes and air passing between the heat transmission fins; an electric component including a part of an electric system that controls equipment; and a cooling member disposed in a channel of air passing through the heat exchanger, the cooling member configured to dissipate heat from the electric component to the air, wherein the heat transmission fins are fitted to the heat transmission pipes such that the distance between the heat transmission fins is configured to be larger, in a position corresponding to a position where the cooling member is located and that serves as a passage of the air passing through the cooling member, than in other positions in the heat exchanger. 
       Advantageous Effects of Invention 
       [0009]    According to the present invention, the cooling member is disposed in the channel of air passing through the heat exchanger so as to cool an electric component. Thus, the electric component can be efficiently cooled. In the cooling, the heat transmission fins are fitted to the heat transmission pipes with increased distances therebetween in a position corresponding to the location of the cooling member. This configuration makes it possible to provide, at low cost, an outdoor unit including a heat exchanger in which air resistance caused by the heat transmission fins can be reduced so that a large amount of air is allowed to pass through the cooling member in order to maintain the cooling effect. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is an illustration (a first illustration) of, for example, a configuration of an outdoor unit  10  according to Embodiment 1 of the present invention. 
           [0011]      FIG. 2  is an illustration (a second illustration) of, for example, the configuration of the outdoor unit  10  according to Embodiment 1 of the present invention. 
           [0012]      FIG. 3  is an illustration (a first illustration) of an arrangement of, for example, an electric component chamber  30  according to Embodiment 1 of the present invention. 
           [0013]      FIG. 4  is an illustration (a second illustration) of the arrangement of, for example, the electric component chamber  30  according to Embodiment 1 of the present invention. 
           [0014]      FIG. 5  illustrates a heat exchanger  20  according to Embodiment 1 of the present invention in detail. 
           [0015]      FIG. 6  illustrates a configuration of an air-conditioning apparatus according to Embodiment 2 of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS  
     Embodiment 1 
       [0016]    Embodiment 1 of the present invention will be described hereinafter. 
         [0017]      FIGS. 1 and 2  illustrate a configuration of an outdoor unit  10  according to Embodiment 1 of the present invention, for example.  FIG. 1  is a perspective view of the outdoor unit  10  when viewed from an air outlet.  FIG. 2  is an illustration for describing the internal configuration of the outdoor unit  10  when viewed from above. 
         [0018]    The outdoor unit  10  has a body  11  including a casing having two side surfaces  11   a  and  11   c,  a front surface  11   b,  a rear surface  11   d,  an upper surface  11   e,  and a bottom surface  11   f.  The side surface  11   a  and the rear surface  11   d  have openings through which air is taken in from the outside. The front surface  11   b  has an opening serving as an air outlet through which air blows out to the outside. The air outlet is covered with a fan grille in order to prevent contact between an object or the like and a blower device  40  for safety. 
         [0019]    The body  11  includes at least a heat exchanger  20 , an electric component chamber  30 , a cooling member  32 , and a blower device  40 . The blower device  40  includes, for example, a propeller fan in which a plurality of vanes are disposed around a propeller boss. A fan motor disposed near the rear surface of the propeller fan is driven to rotate and creates an air flow in which air in the outside (outdoor air) passes through the heat exchanger  20 . The inside of the body  1  is partitioned by a partition plate  12  into a blower device chamber  13  in which the blower device  40  is disposed and a machinery chamber  14  in which the compressor and an electric component  31 , for example, are disposed. 
         [0020]      FIGS. 3 and 4  illustrate an arrangement of the electric component chamber  30  and other components in Embodiment 1 of the present invention. As illustrated in  FIG. 3 , the machinery chamber  14  further includes an electric component chamber  30 , and the electric component chamber  30  accommodates the electric component  31 . The electric component  31  is, for example, an electric circuit that performs control for, for example, driving equipment (an actuator) such as the compressor in the outdoor unit  10 . The cooling member  32  is a member such as a comb-shaped heat sink that takes away (receives) heat generated by the electric component  31  in the electric component chamber  30  and rejects heat. As illustrated in  FIG. 4 , the cooling member  32  of Embodiment 1 is disposed at a location in an air passage through which air is caused to pass by driving the blower device  40 . 
         [0021]    The heat exchanger  20  is formed in an L shape by bending and is designed such that air flows in two directions from the side surface  11   a  and the rear surface  11   d,  respectively. When used in an air-conditioning apparatus, for example, the heat exchanger  20  serves as a condenser for condensing refrigerant in a cooling operation and serves as an evaporator for evaporating refrigerant in a heating operation. As will be described later, the heat exchanger  20  of Embodiment 1 includes heat transmission fins  21  and heat transmission pipes  22  and exchanges heat between the refrigerant and air outside the room (outdoor air). Each of the heat transmission fins  21  and the heat transmission pipes  22  is made of aluminum or an aluminum alloy. The use of, for example, aluminum can enhance the heat exchange efficiency and reduce the weight and size of the heat exchanger. The heat transmission fins  21  of Embodiment 1 are flat-plate (rectangular) fins. The heat transmission pipes  22  are flat tubes that are flat-shaped heat transmission pipes partially curved in cross section. 
         [0022]    The heat transmission fins  21  serve as a resistance to air passing through the heat exchanger  20 . Thus, the heat transmission fins  21  are obstacles in supplying air in order to facilitate heat dissipation of the cooling member  32 . In view of this, as illustrated in  FIG. 4 , the heat exchanger  20  of Embodiment 1 is configured such that the distance between the heat transmission fins  21  is increased in a position (a position close to the cooling member  32 ) of the heat exchanger  20  so as to obtain a sufficiently large air passage for the cooling member  32 . Since the distance is partially increased, the efficiency of the cooling member  32  can be increased without a significant decrease in the area of the heat transmission fins  21  in the entire heat exchanger  20 . 
         [0023]      FIG. 5  illustrates the heat exchanger  20  of Embodiment 1 of the present invention in detail. As illustrated in  FIG. 5 , in the heat exchanger  20  of Embodiment 1, the heat transmission pipes  22  are arranged with predetermined distances and fixed in, for example, a dedicated device. The direction in which the heat transmission pipes  22  are arranged side by side is orthogonal to the channel direction of the refrigerant flowing in the pipes. 
         [0024]    As also illustrated in  FIG. 5 , the heat transmission fins  21  include a plurality of insertion cutouts  23  arranged in the longitudinal direction (i.e., the direction in which the heat transmission pipes  22  are arranged side by side). Each of the insertion cutouts has one open end on one of the longitudinal edges of a corresponding of the heat transmission fins  21 , so that the heat transmission pipes  22  can be fitted to the heat transmission fins  21 . That is, the heat transmission fins  21  have comb-like shapes. In conformity with the arrangement of the heat transmission pipes  22 , the number of the insertion cutouts  23  is equal to that of the heat transmission pipes  22 , and the insertion cutouts  23  are arranged with the same distances therebetween as those between the heat transmission pipes  22  (except both ends), for example. In addition, the heat transmission fins  21  are fitted to and fixed to the heat transmission pipes  22  such that the heat transmission fins  21  are parallel to one another in the refrigerant channel direction (i.e., the direction orthogonal to the direction in which the heat transmission pipes  22  are arranged side by side). Slits formed by cutting and raising part of the heat transmission fins  21  may be, but are not limited to being, provided between the insertion cutouts  23 . Fin collars may be formed so as to stand vertically on the heat transmission fins  21  at the rims of the insertion cutouts  23 . 
         [0025]    Portions (brazed portions) in which the heat transmission fins  21  are in contact with the heat transmission pipes  22  are joined by brazing, thereby fabricating the heat exchanger  20 . This fabrication enables the heat transmission fins  21  to be fitted to the heat transmission pipes  22  with desired distances therebetween. Thus, the configuration in which the distance between the heat transmission fins  21  varies in the single heat exchanger  20  can be obtained at a relatively low cost. 
         [0026]    As described above, the outdoor unit  10  of Embodiment 1 includes the cooling member  32  for cooling the electric component  31  in the air passage of air flow formed when driving the blower device  40  in the blower device chamber  13 . Thus, the electric component  31  can be efficiently cooled. As a result, reliability can be enhanced. In addition, the heat exchanger  20  is configured such that the heat transmission fins  21  are fitted to and fixed to the heat transmission pipes  22 . Thus, in fabrication, insertion can be easily performed with wide distances between the heat transmission fins  21  serving as a channel of air that is in contact with the cooling member  32 . Thus, both enhancement of cooling efficiency of the electric component  31  and maintenance of efficiency of the heat exchanger  20  can be achieved at a relatively low cost. 
       Embodiment 2 
       [0027]      FIG. 6  illustrates a configuration of an air-conditioning apparatus according to Embodiment 2 of the present invention. In Embodiment 2, a refrigeration cycle apparatus using the above-described outdoor unit  10  as an outdoor unit  100  will be described. Here, the air-conditioning apparatus will be described as a typical example of a refrigeration cycle apparatus. The air-conditioning apparatus illustrated in  FIG. 6  includes the outdoor unit  100  and an indoor unit  200  that are connected to each other by refrigerant pipes so that refrigerant circulates therein. Among the refrigerant pipes, a pipe in which a gas refrigerant flows will be referred to as a gas pipe  300  and a pipe in which a liquid refrigerant (which may be a two-phase gas-liquid refrigerant) flows will be referred to as a liquid pipe  400 . 
         [0028]    In Embodiment 2, the outdoor unit  100  includes a compressor  101 , a four-way valve  102 , an outdoor-side heat exchanger  103 , an outdoor-side blower device  104 , and an expansion device (an expansion valve)  105 . 
         [0029]    The compressor  101  compresses a sucked refrigerant and discharges the compressed refrigerant. Here, the presence of, for example, an inverter as an electric component  31  can change the operating frequency of the compressor  101  as intended so that the capacity (the amount of the refrigerant that is sent from the compressor  101  in a unit time) of the compressor  101  can be minutely changed. On the basis of an instruction from a control device (not shown), the four-way valve  102  switches a flow of the refrigerant between a cooling operation and a heating operation. 
         [0030]    The outdoor-side heat exchanger  103  constituted by the heat exchanger  20  described above exchanges heat between refrigerant and air (outdoor air). Specifically, in the heating operation, the outdoor-side heat exchanger  103  serves as an evaporator that exchanges heat between a low-pressure refrigerant from the liquid pipe  400  and air, evaporates the refrigerant, and vaporizes the refrigerant. In the cooling operation, the outdoor-side heat exchanger  103  serves as a condenser that exchanges heat between refrigerant that has flowed from the four-way valve  102  and that has been compressed in the compressor  101  and air, condenses the refrigerant, and liquefies the refrigerant. An outdoor-side blower device  104  that is the above-described blower device  40  is provided. The outdoor-side blower device  104  may also be configured such that the inverter as the electric component  31  can change the operating frequency of the fan motor as intended so as to minutely change the rotation speed. The expansion device  105  changes its opening degree so as to adjust the pressure of the refrigerant, for example. 
         [0031]    On the other hand, the indoor unit  200  includes a load-side heat exchanger  201  and a load-side blower device  202 . The load-side heat exchanger  201  exchanges heat between refrigerant and air. Specifically, in the heating operation, the load-side heat exchanger  201  serves as a condenser that exchanges heat between refrigerant from the gas pipe  300  and air, condenses the refrigerant, liquefies the condensed refrigerant (or changes the refrigerant into a two-phase gas-liquid refrigerant), and causes the refrigerant to flow out toward the liquid pipe  400 . On the other hand, in the cooling operation, the load-side heat exchanger  201  serves as an evaporator that exchanges heat between refrigerant that has changed into a low-pressure state by the expansion device  105 , for example, and air, causes the refrigerant to receive heat from the air, evaporates and vaporizes the refrigerant, and causes the resulting refrigerant to flow out toward the gas pipe  300 . The indoor unit  200  also includes a load-side blower device  202  for adjusting the flow of air for use in the heat exchange. The operation speed of the load-side blower device  202  can be set by, for example, a user. 
         [0032]    Here, the above-described refrigeration cycle apparatus can use HCFC (R22), HFC (e.g., R116, R125, R134a, R14, R143a, R152a, R227ea, R23, R236ea, R236fa, R245ca, R245fa, R32, R41, RC318, or a refrigerant mixture of some of these refrigerants, such as R407A, R407B, R407C, R407D, R407E, R410A, R410B, R404A, R507A, R508A, or R508B), HC (e.g., butane, isobutane, ethane, propane, propylene, or a refrigerant mixture of some of these refrigerants), a natural refrigerant (e.g., air, carbon dioxide, ammonia, or a refrigerant mixture of some of these refrigerant substances), a low-GWP refrigerant such as HFO1234yf, or a refrigerant mixture of some of these refrigerants. 
         [0033]    Irrespective of the solubility of a refrigerant and oil, the above-described advantages can be obtained by using any types of refrigerating machine oil such as mineral oil-based refrigerating machine oil, alkylbenzene oil-based refrigerating machine oil, ester oil-based refrigerating machine oil, ether oil-based refrigerating machine oil, or fluorine oil-based refrigerating machine oil. 
         [0034]    Similar advantages can also be obtained in a case where the heat exchanger  20  of Embodiment 1 is used in the load-side heat exchanger  201  of the indoor unit  200 . 
         [0035]    As described above, in the refrigeration cycle apparatus of Embodiment 2, the heat exchanger  20  of Embodiment 1 is used as the outdoor-side heat exchanger  103 . Thus, the electric component  31  can be efficiently cooled, thereby enhancing the reliability of the apparatus. 
       INDUSTRIAL APPLICABILITY  
       [0036]    The present invention is widely applicable to outdoor units constituting refrigeration cycle apparatuses, such as an outdoor unit of an air-conditioning apparatus or a hot water supply, and other apparatuses and equipment. 
       REFERENCE SIGNS LIST   
       [0037]      10  outdoor unit,  11  body,  11   a,    11   c  side surface,  11   b  front surface,  11   d  rear surface,  11   e  upper surface,  11   f  bottom surface,  12  partition plate,  13  blower device chamber,  14  machinery chamber,  20  heat exchanger,  21  heat transmission fin,  22  heat transmission pipe,  23  insertion cutout,  30  electric component chamber,  31  electric component,  32  cooling member,  40  blower device,  100  outdoor unit,  101  compressor,  102  four-way valve,  103  outdoor-side heat exchanger,  104  outdoor-side blower device,  105  expansion device,  200  indoor unit,  201  load-side heat exchanger,  202  load-side blower device,  300  gas pipe,  400  liquid pipe.