JP2008008542A - Heat exchanger and indoor unit of air conditioner comprising heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger, and an indoor unit of an air conditioner comprising the heat exchanger, capable of preventing stagnation of drainage among heat transfer fins. <P>SOLUTION: Heat exchangers 6-6b exchange heat between a refrigerant and air by utilizing a supercritical refrigerant as the refrigerant, and comprise groups of heat transfer fins 71-74, 71a-74a, 71b-74b, and a plurality of heat transfer tubes 12. The groups of heat transfer fins are composed of a plurality of plate-shaped heat transfer fins 11-11b disposed in parallel with the vertical direction at prescribed intervals. The plurality of heat transfer tubes penetrate through the groups of heat transfer fins. Heat transfer tube arrays 61-68, 61a-68a, 61b-68b formed by arranging the heat transfer tubes in the first direction intersecting with the airflow are formed by four or more arrays from the upstream to the downstream of the airflow. Each of the plurality of heat transfer fins has a first side 75 of its lower end inclined to a horizontal face. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchanger that has taken measures against drainage during cooling, and an indoor unit of an air conditioner that includes the heat exchanger.

2. Description of the Related Art Conventionally, there is a heat exchanger provided in an indoor unit of an air conditioner that exchanges heat between refrigerant and air using a cross fin type. This cross fin type heat exchanger arranges a plurality of fins substantially parallel to the air flow direction at predetermined intervals, and a multi-row heat transfer tube group that penetrates each fin in the plate thickness direction. (Refer to Patent Document 1).
By the way, in the heat exchanger, drainage may occur during cooling. The drain is transferred from the upper part to the lower part through the heat transfer fins, but the stagnation between the heat transfer fins and the heat transfer fins may cause clogging. In such a case, it becomes a large air resistance and causes a decrease in cooling capacity.

  An object of the present invention is to provide a heat exchanger that suppresses the stagnation of drain between heat transfer fins and easily passes air, and an indoor unit of an air conditioner including the heat exchanger. .

  A heat exchanger according to a first aspect of the present invention is a heat exchanger that performs heat exchange between a refrigerant and air using a supercritical refrigerant as a refrigerant, and includes a heat transfer fin group and a plurality of heat transfer tubes. The heat transfer fin group is formed by a plurality of plate-like heat transfer fins arranged in parallel to the vertical direction with a predetermined interval. The plurality of heat transfer tubes penetrate through the heat transfer fin group. Four or more heat transfer tube rows formed by arranging heat transfer tubes in the first direction intersecting the air flow are formed from the upstream side to the downstream side of the air flow. The first sides of the lower ends of the plurality of heat transfer fins are inclined with respect to the horizontal plane.

  In the present invention, the lower ends of the plurality of heat transfer fins are inclined to facilitate drainage through the lower ends of the heat transfer fins. Therefore, it is possible to reduce the occurrence of clogging due to the drain, and to facilitate the passage of air. For this reason, the fall of the cooling capability can be suppressed.

  The heat exchanger according to the second aspect of the present invention is the heat exchanger according to the first aspect of the present invention, wherein the first side is inclined in a range of 45 degrees or more with respect to the horizontal plane.

  In this heat exchanger, the drain can be discharged from the inside of the heat exchanger more efficiently by inclining the first side in a range of 45 degrees or more with respect to the horizontal plane.

  A heat exchanger according to a third aspect of the present invention is the heat exchanger according to the first aspect of the present invention or the second aspect of the present invention, wherein the first surface including the upper end of the first side of the two ends of the first side is: It is substantially perpendicular to the first side. In the heat transfer fin group, a portion above the first surface is cut.

  The air flow tends to take the shortest distance as it passes through the heat exchanger. In the case of a heat exchanger in which the heat transfer tube rows are inclined obliquely, the air flow tends to pass in a direction nearly perpendicular to the heat transfer tube rows. Therefore, the air flow is less likely to pass above the first surface. That is, the heat transfer fins and heat transfer tubes above the first surface do not contribute much to heat exchange.

  In the present invention, the heat transfer fins above the first surface are cut. For this reason, the part which is not heat-exchanged so much can be excluded, and the production cost of a heat exchanger can be reduced.

  A heat exchanger according to a fourth aspect of the present invention is the heat exchanger according to the third aspect of the present invention, further comprising a first plate that suppresses the passage of airflow. The first plate is installed at the end of the heat transfer fin group along the first surface.

  As in the third aspect of the invention, simply cutting the heat transfer fins above the first surface may cause the air flow to escape from the cut portion without passing through the entire heat exchanger.

  In this invention, the 1st board is provided in the part which cut the heat-transfer fin, and it is preventing that the airflow which flows in into a heat exchanger escapes from the part by which the heat-transfer fin was cut. Therefore, an air flow can be spread over the entire heat exchanger, and efficient heat exchange can be performed.

  A heat exchanger according to a fifth aspect is the heat exchanger according to any one of the first to fourth aspects, wherein the first side and the second side of the upper end of the heat transfer fin are substantially in the first direction. Parallel.

  By arranging the first side at the lower end and the second side at the upper end of the heat transfer fin in parallel with the direction of the heat transfer tube row, the arrangement of the heat transfer tubes can be matched to the shape of the heat transfer fin. Therefore, the area of the heat transfer fin that does not contribute much to heat exchange can be reduced. For this reason, the production cost of a heat exchanger can be reduced.

  A heat exchanger according to a sixth aspect of the present invention is the heat exchanger according to the fifth aspect of the present invention, wherein the second surface including the lower end of the second side of the two ends of the second side is the second side. And is almost vertical. The plurality of heat transfer tubes are not inserted into the heat transfer fin group below the second surface.

  Since the air flow tends to pass through the heat exchanger through the shortest path, the heat transfer fins and the heat transfer tubes below the second surface do not contribute much to the heat exchange.

  In the present invention, the heat transfer tube below the second surface is not inserted, so that the drain is easy to fall down through the heat transfer fins, and the portion that does not exchange heat much is eliminated. For this reason, the production cost of a heat exchanger can be reduced.

  A heat exchanger according to a seventh aspect of the present invention is the heat exchanger according to the first or second aspect of the present invention, wherein the plurality of heat transfer tubes are arranged so that an air flow easily flows in the vertical direction.

  In this heat exchanger, since the air flow tends to pass through the shortest path of the heat exchanger, a portion of the heat exchanger that does not contribute much to the heat exchange with respect to the air flow appears.

  In the present invention, for example, by arranging the heat transfer tubes so as to form a gap with respect to the vertical direction, the air flow can easily flow in the vertical direction. Therefore, an air flow can be flowed over the whole heat exchanger, and the whole heat exchanger can be contributed to heat exchange. For this reason, efficient heat exchange can be performed.

  A heat exchanger according to an eighth aspect is the heat exchanger according to the seventh aspect, wherein the plurality of heat transfer tubes are arranged with a plurality of gaps as viewed in the vertical direction.

  In this heat exchanger, the heat transfer tubes are arranged with a gap in the vertical direction. Therefore, the air flow can be easily flowed in the vertical direction. For this reason, an air flow can be sent through the whole heat exchanger, and the area which contributes to heat exchange can be increased. Thereby, heat exchange can be performed efficiently.

  A heat exchanger according to a ninth aspect is the heat exchanger according to the seventh aspect or the eighth aspect, wherein the plurality of heat transfer tubes pass the air flow in a second direction substantially perpendicular to the first direction. Arranged to be difficult.

  In the present invention, the heat transfer tubes are arranged so that the air flow is less likely to flow substantially perpendicular to the first direction, so that the air flow is less likely to pass through the shortest path. Therefore, an air flow can be flowed over the whole heat exchanger, and the whole heat exchanger can be contributed to heat exchange.

  A heat exchanger according to a tenth aspect of the present invention is the heat exchanger according to the ninth aspect of the present invention, wherein the plurality of heat transfer tubes are arranged without gaps when viewed in the second direction.

  In this heat exchanger, the heat transfer tubes are arranged without gaps when viewed in the second direction, so that the air flow does not easily pass through the heat exchanger in the shortest distance.

  A heat exchanger according to an eleventh aspect of the present invention is the heat exchanger according to any one of the first to tenth aspects of the present invention, wherein the heat transfer fins are divided between at least one set of adjacent heat transfer tube rows.

  In an air conditioner using a supercritical refrigerant, the indoor heat exchanger is a gas cooler that cools the refrigerant during heating operation. In the gas cooler, the temperature differs between the inlet side and the outlet side of the refrigerant in the entire heat exchanger. For this reason, when adjacent heat transfer tube rows are connected by heat transfer fins, heat exchange may be performed between the heat transfer tubes via the heat transfer fins, which may cause heat loss.

  In the present invention, the heat transfer fins are divided between adjacent heat transfer tube rows so that heat exchange via the heat transfer fins is difficult to be performed. For this reason, the heat loss which arises by this heat exchange can be suppressed.

  A heat exchanger according to a twelfth aspect of the present invention is the heat exchanger according to any of the first to eleventh aspects of the present invention, wherein the heat transfer fins are divided between all adjacent heat transfer tube rows.

  In the indoor unit of this air conditioner, heat transfer fins are divided for each heat transfer tube row. Therefore, it can reduce that more heat exchanger tubes perform heat exchange via a heat-transfer fin.

  A heat exchanger according to a thirteenth aspect of the present invention is the heat exchanger according to any of the first to twelfth aspects of the present invention, wherein the refrigerant belongs to the heat transfer tube array on the downstream side of the air flow during the heating operation. It flows from the heat pipe to the heat transfer pipe belonging to the heat transfer pipe row on the upstream side of the air flow.

  By making the flow direction of the refrigerant and the direction of the air flow face each other during the heating operation, the temperature difference between the refrigerant and the air in the entire heat exchanger can be kept large. For this reason, heating operation can be performed efficiently.

  A heat exchanger according to a fourteenth aspect of the present invention is the heat exchanger according to the first to thirteenth aspects of the present invention, in which the air flow flows from the lower part to the upper part of the heat transfer fin.

  In the lower suction upper blowout type indoor unit, the drain is less likely to drop due to the wind from the lower part of the heat exchanger. Even in such a heat exchanger, drain clogging can be reduced.

  A heat exchanger according to a fifteenth aspect of the present invention is the heat exchanger according to any of the first to fourteenth aspects of the present invention, wherein the heat transfer fin has a hydrophilic surface.

  Since the surface of the heat transfer fin is subjected to hydrophilic treatment, when the drain is generated, the heat transfer fin can be transmitted and the drain can easily flow.

  A heat exchanger according to a sixteenth aspect of the present invention is the heat exchanger according to any one of the eleventh aspect of the present invention to the fourteenth aspect of the present invention, and the heat transfer fin has a water repellent surface.

  Since the surface of the heat transfer fin is water-repellent, when drain is generated, the drain can be repelled and easily removed from the heat exchanger.

  In the heat exchanger according to the first aspect of the invention, the lower ends of the plurality of heat transfer fins are inclined to facilitate drainage along the lower ends of the heat transfer fins. Therefore, it is possible to reduce the occurrence of clogging due to the drain, and to facilitate the passage of air. For this reason, the fall of the cooling capability can be suppressed.

  In the heat exchanger according to the second invention, the drain can be discharged more efficiently from the inside of the heat exchanger by inclining the first side in a range of 45 degrees or more with respect to the horizontal plane.

  In the heat exchanger according to the third aspect of the invention, the heat transfer fins above the first surface are cut. For this reason, the part which is not heat-exchanged so much can be excluded, and the production cost of a heat exchanger can be reduced.

  In the heat exchanger according to the fourth aspect of the invention, by providing the first plate at the portion where the heat transfer fin is cut, the air flow flowing into the heat exchanger escapes from the portion where the heat transfer fin is cut. Is preventing. Therefore, an air flow can be spread over the entire heat exchanger, and efficient heat exchange can be performed.

  In the heat exchanger according to the fifth aspect of the invention, the heat transfer fins are arranged in the shape of the heat transfer fins by making the first side of the lower end of the heat transfer fins and the second side of the upper end parallel to the direction of the heat transfer tube row. Can be matched. Therefore, the area of the heat transfer fin that does not contribute much to heat exchange can be reduced. For this reason, the production cost of a heat exchanger can be reduced.

  In the heat exchanger according to the sixth aspect of the invention, the heat transfer tube below the second surface is not inserted, so that the drain is easy to fall down through the heat transfer fins, and the portion that does not exchange much heat is excluded. Yes. For this reason, the production cost of a heat exchanger can be reduced.

  In the heat exchanger according to the seventh aspect of the invention, the air flow is made easier to flow in the vertical direction. Therefore, an air flow can be flowed over the whole heat exchanger, and the whole heat exchanger can be contributed to heat exchange. For this reason, efficient heat exchange can be performed.

  In the heat exchanger according to the eighth aspect of the invention, the air flow can be easily flowed in the vertical direction. For this reason, an air flow can be sent through the whole heat exchanger, and the area which contributes to heat exchange can be increased. Thereby, heat exchange can be performed efficiently.

  In the heat exchanger according to the ninth aspect of the invention, the heat transfer tubes are arranged so that the air flow is less likely to flow substantially perpendicularly to the first direction, so that the air flow is less likely to pass through the shortest path. Therefore, an air flow can be flowed over the whole heat exchanger, and the whole heat exchanger can be contributed to heat exchange.

  In the heat exchanger according to the tenth aspect of the invention, the heat transfer tubes are arranged without gaps when viewed in the second direction, so that the air flow does not easily pass through the heat exchanger in the shortest distance.

  In the heat exchanger according to the eleventh aspect of the invention, the heat transfer fins are divided between adjacent heat transfer tube rows so that heat exchange via the heat transfer fins is difficult to be performed. For this reason, the heat loss which arises by this heat exchange can be suppressed.

  In the heat exchanger according to the twelfth aspect of the invention, the heat transfer fins are divided for each heat transfer tube row. Therefore, it can reduce that more heat exchanger tubes perform heat exchange via a heat-transfer fin.

  In the heat exchanger according to the thirteenth invention, the temperature difference between the refrigerant and the air in the entire heat exchanger can be kept large by making the flow direction of the refrigerant and the direction of the air flow face each other during the heating operation. . For this reason, heating operation can be performed efficiently.

  In the heat exchanger according to the fourteenth aspect of the invention, in the lower suction upper blowout type indoor unit, the drain is less likely to drop due to the wind from the lower part of the heat exchanger. Even in such a heat exchanger, drain clogging can be reduced.

  In the heat exchanger according to the fifteenth aspect, since the surface of the heat transfer fin is subjected to hydrophilic treatment, when the drain is generated, the heat transfer fin can be made to flow easily.

  In the heat exchanger according to the sixteenth aspect of the invention, since the surface of the heat transfer fin is subjected to water repellent treatment, when drain is generated, the drain can be repelled and easily removed from the heat exchanger.

<Refrigeration circuit of air conditioner>
FIG. 1 is a refrigeration circuit of an air conditioner 1 using a CO2 refrigerant. The air conditioner 1 has a refrigeration circuit in which a compressor 2, a four-way switching valve 3, an outdoor heat exchanger 4, an expansion valve 5, and an indoor heat exchanger 6 are connected by a refrigerant pipe 7. In FIG. 1, solid and broken arrows indicate the flow direction of the refrigerant. The air conditioner 1 can switch between the heating operation and the cooling operation by switching the flow direction of the refrigerant with the four-way switching valve 3.

  During the cooling operation, the outdoor heat exchanger 4 serves as a gas cooler, and the indoor heat exchanger 6 serves as an evaporator. On the other hand, during the heating operation, the outdoor heat exchanger 4 serves as an evaporator and the indoor heat exchanger 6 serves as a gas cooler. The outdoor heat exchanger 4 and the indoor heat exchanger 6 each include a heat transfer fin 11 (see FIG. 3) and a heat transfer tube 12 (see FIG. 3), and the refrigerant in the heat transfer tube 12 transfers heat via an air flow. Heat exchange with the fin 11 is performed.

  In FIG. 1, point A is the suction side of the compressor 2 during the heating operation, and point B is the discharge side of the compressor 2 during the heating operation. Point C is the refrigerant outlet side of the indoor heat exchanger 6 during heating operation, and point D is the refrigerant inlet side of the outdoor heat exchanger 4 during heating operation.

  FIG. 2A is a pressure-enthalpy state diagram of the CO 2 refrigerant, in which the vertical axis represents the pressure P and the horizontal axis represents the enthalpy h. Tk is an isotherm passing through the critical point K, and Tx is an isotherm of the temperature Tx. Tx> Tk, and on the right side of the isotherm Tk, the CO2 refrigerant is neither liquefied nor two-phased. The region above the critical pressure Pk on the right side of the isotherm Tk is called a supercritical state, and the air conditioner 1 using the heat exchanger of the first embodiment is operated in a refrigeration cycle including the supercritical state. A, B, C, and D in FIG. 2A represent refrigerant states corresponding to points A, B, C, and D in FIG.

  FIG. 2B is a temperature-entropy state diagram of the CO2 refrigerant, where the vertical axis represents the temperature T and the horizontal axis represents the entropy s. A, B, C, and D in FIG. 2B represent refrigerant states corresponding to points A, B, C, and D in FIG. The temperature of the refrigerant decreases from the point B that is the discharge side of the compressor 2 to the point C that is the refrigerant outlet of the indoor heat exchanger 6. For this reason, the temperature of the surface of the indoor heat exchanger 6 has a temperature distribution in which the temperature on the upstream side of the refrigerant is high and the temperature on the downstream side is low. Therefore, when the air flow passes from the downstream side of the refrigerant toward the upstream side of the refrigerant, the temperature difference between the air and the indoor heat exchanger 6 is stabilized, and the heat exchange amount between the air and the indoor heat exchanger 6 is increased. Will increase.

<Structure of indoor heat exchanger>
FIG. 3 is a perspective view of the indoor heat exchanger of the air-conditioning apparatus according to the first embodiment of the present invention. The indoor heat exchanger 6 is a cross fin type heat exchanger. The heat transfer fin 11 is a thin flat plate made of aluminum, and a plurality of through holes 14 are formed in one heat transfer fin 11. The heat transfer tube 12 includes a straight tube 12a that is inserted into the through hole 14 of the heat transfer fin 11, and a U-shaped tube 12b that connects ends of adjacent straight tubes 12a. In the heat transfer tube 12 of the first embodiment, the straight tube 12a and the U-shaped tube 12b are integrally formed, and the U-shaped tube (not shown) on the back side of FIG. After being inserted into the through hole 14 of the fin 11, it is connected to the end of the straight pipe 12 a by welding or the like.

  The air flow passes through the indoor heat exchanger 6 and exchanges heat with the refrigerant flowing in the heat transfer tube 12. The heat transfer tube rows 61 to 68 of the heat transfer tubes 12 arranged in a direction intersecting with the air flow are arranged in eight rows from the upstream of the air flow toward the downstream of the air flow. The refrigerant flows from the heat transfer tubes 12 belonging to the heat transfer tube row 68 on the downstream side of the air flow to the heat transfer tubes 12 belonging to the heat transfer tube row 61 on the upstream side of the air flow. This refrigerant distribution path is called a path 91 (see FIG. 4). By this path 91, the air flow and the refrigerant flow are opposed to each other, and the amount of heat exchange is increased as compared with the non-opposed one. However, it has been found from experiments that in a heat exchanger having three or less heat transfer tube rows, there is no significant difference in effect whether the air flow and the refrigerant flow are opposed or not.

  3 is the path 91 (see FIG. 4) through which the refrigerant flows, and the connection pipes 12d (see FIG. 4) are adjacent to the adjacent heat transfer tube rows 61 to 68. The heat transfer tubes 12 positioned at opposite ends are connected to each other.

  The heat transfer fins 11 are divided between the heat transfer tube row 62 and the heat transfer tube row 63. This division is also performed between the heat transfer tube row 64 and the heat transfer tube row 65 and between the heat transfer tube row 66 and the heat transfer tube row 67. The heat transfer fins 11 include a heat transfer fin group 71 into which the heat transfer tube row 61 and the heat transfer tube row 62 are inserted, a heat transfer fin group 72 into which the heat transfer tube row 63 and the heat transfer tube row 64 are inserted, and a heat transfer tube. The heat transfer fin group 73 into which the row 65 and the heat transfer tube row 66 are inserted is divided into the heat transfer fin group 74 into which the heat transfer tube row 67 and the heat transfer tube row 68 are inserted. As a result, the heat on the surface of the heat transfer fins 11 can hardly move beyond the dividing portion 13.

  In the heat transfer fin 11, the first side 75 at the lower end of the heat transfer fin group 71 and the second side 76 at the upper end of the heat transfer fin group 74 are inclined 45 degrees with respect to the horizontal plane. Further, the surface of the heat transfer fin 11 is subjected to a hydrophilic treatment. The indoor heat exchanger 6 becomes an evaporator when the indoor unit performs a cooling operation. For this reason, drainage is generated. In this way, by installing the inclined first side 75 of the lower ends of the heat transfer fin groups 71 to 74 of the indoor heat exchanger 6, the drain is transferred along the first side 75 of the heat transfer fins 11 and dropped. It is easy. Thereby, clogging due to drain is reduced, and air can easily pass through the indoor heat exchanger 6.

<Configuration of air conditioner>
FIG. 4 is a longitudinal sectional view of the indoor unit of the air-conditioning apparatus according to the first embodiment of the present invention. The indoor unit 51 has the indoor heat exchanger 6 mounted inside the casing 52. A fan 53 that generates an air flow is disposed above the indoor heat exchanger 6, and an air outlet 52 a is provided above the fan 53. An air suction port 52b is provided below the indoor heat exchanger 6. Note that the fan 53 used in the first embodiment is a sirocco fan.

  The line connecting the centers of the heat transfer tubes 12 indicates the path 91 through which the refrigerant flows during the heating operation, the solid line indicates the U-shaped tube 12b on the front side of the figure, and the broken line indicates the U-shaped tube on the opposite side ( A not shown) and a connecting pipe (not shown) are shown. During the heating operation, the refrigerant flows in the path 91 of the indoor heat exchanger 6 from the upper side to the lower side, and the airflow flows from the lower side of the indoor heat exchanger 6 to the upper side. For this reason, since an air flow heat-exchanges with a refrigerant | coolant of a higher temperature, and temperature rises as it approaches the air blower outlet 52a, refrigerant | coolant temperature and air are exhausted through the whole heat radiation process when the indoor heat exchanger 6 functions as a gas cooler. The temperature difference from the temperature is properly maintained.

<Features of First Embodiment>
(1)
In the indoor heat exchanger 6 of the present invention, the first side 75 at the lower end of the plurality of heat transfer fins 11 is inclined by 45 degrees with respect to the horizontal plane, so that the drain passes along the first side 75 at the lower end of the heat transfer fin 11. It is easy to discharge. Therefore, it is possible to reduce the occurrence of clogging of the drain and to facilitate the passage of air. For this reason, the fall of the cooling capability can be suppressed. Further, in the lower suction upper blow-out type indoor unit 51 as in the present embodiment, the drain is less likely to drop due to the wind from the lower portion of the indoor heat exchanger 6. Also in such an indoor heat exchanger 6, drain clogging can be reduced.

(2)
By making the first side 75 of the heat transfer fin group 71 and the second side 76 of the heat transfer fin group 74 parallel to the row direction of the heat transfer tube rows 61 to 68, the shape of the heat transfer fin 11 is changed to the heat transfer tube 12. Can be combined. Therefore, the area of the heat transfer fin 11 that does not contribute much to heat exchange can be reduced. For this reason, the production cost of the indoor heat exchanger 6 can be reduced.

(3)
In the indoor heat exchanger 6 of the present invention, the heat transfer fins 11 are divided between adjacent heat transfer tube rows so that heat exchange via the heat transfer fins 11 is not performed. For this reason, the heat loss which arises by this heat exchange can be suppressed.

(4)
By making the flow direction of the refrigerant and the direction of the air flow face each other during the heating operation, the temperature difference between the refrigerant and the air in the entire indoor heat exchanger 6 can be kept large. For this reason, heating operation can be performed efficiently.

(5)
Since the surface of the heat transfer fin 11 is subjected to a hydrophilic treatment, when the drain is generated, the heat transfer fin 11 can be transmitted and the drain can easily flow.

(Second Embodiment)
Regarding the heat exchanger according to the second embodiment, differences from the indoor heat exchanger 6 of the first embodiment will be mainly described below.

<Structure of indoor heat exchanger>
FIG. 5 is a longitudinal sectional view of an air conditioner 1a according to the second embodiment of the present invention. The indoor heat exchanger 6a is a cross-fin type heat exchanger, and mainly includes heat transfer fins 11a and heat transfer tubes 12.

  The heat transfer tubes 12 are arranged in a direction intersecting with the air flow, and eight heat transfer tube rows 61a to 68a are arranged from the upstream of the air flow toward the downstream of the air flow. The refrigerant flows from the heat transfer tubes 12 belonging to the heat transfer tube row 68a on the downstream side of the air flow to the heat transfer tubes 12 belonging to the heat transfer tube row 61a on the upstream side of the air flow. This refrigerant distribution path is called a path 91a (see FIG. 6). By this path 91a, the air flow and the refrigerant flow are opposed to each other, and the amount of heat exchange is increased as compared with those not opposed to each other.

  The heat transfer fins 11a are divided between the heat transfer tube row 62a and the heat transfer tube row 63a. This is also performed between the heat transfer tube row 64a and the heat transfer tube row 65a and between the heat transfer tube row 66a and the heat transfer tube row 67a. As a result, the heat on the surface of the heat transfer fins 11a cannot move beyond the divided portion 13a.

  Further, the heat transfer fin 11a is inclined at 45 degrees with respect to the horizontal plane at the first side 75 at the lower end. That is, the first sides 75 at the lower ends of the heat transfer fin groups 71a to 74a are inclined 45 degrees with respect to the horizontal plane. Compared with the indoor heat exchanger 6 in the first embodiment, the indoor heat exchanger 6a includes an upper first end 77 of two ends of the first side 75 at the lower end of the heat transfer fin group 71a. In addition, the heat transfer fin groups 71a to 74a are cut on the first surface 80 that is perpendicular to the first side 75 at the lower end of the heat transfer fin group 71a. And the air passage prevention board 60 is connected to the edge part of this cut heat-transfer fin group 71a-74a. Further, in this indoor heat exchanger 6a, the transmission on the lower side than the second surface 81 including the lower second end 78 of the two ends of the second side 76 and parallel to the air passage prevention plate is included. The heat transfer tube 12 does not penetrate the heat fin 11a.

  The air flow tends to take the shortest distance as the passage path of the heat exchanger. In the case of the indoor heat exchanger 6 in which the heat transfer tube rows 61 to 68 are inclined obliquely as in the first embodiment, the air flow is in a direction nearly perpendicular to the heat transfer tube rows 61 to 68 (FIG. 4). Pass through the broken line white arrow A1). For this reason, the air flow does not pass through the space above the air passage prevention plate 60 and the space below the second surface 81. Compared with the heat transfer fins 11 in the indoor heat exchanger 6 of the first embodiment, the heat transfer fins 11a in the indoor heat exchanger 6a of the second embodiment have a portion cut away from the first surface 80. . And by providing the air passage prevention plate 60 in the cut portion, the air flow is prevented from escaping from the cut portion, and the air flow is distributed over the entire indoor heat exchanger 6a. And an air flow flows like the broken-line white arrow A2 of FIG. In the indoor heat exchanger 6a of the second embodiment, the production cost is reduced by eliminating a portion that does not allow much air flow and does not contribute to heat exchange. Further, since the heat transfer tubes 12 are not inserted into the heat transfer fins 11a below the second surface 81, the production cost is similarly reduced. That is, in this indoor heat exchanger 6a, the production cost can be reduced without significantly reducing the heat exchange capability by eliminating the portion that does not easily contribute to the heat exchange.

<Features of Second Embodiment>
In the indoor heat exchanger 6a according to the second embodiment, the heat transfer fins 11a above the first surface 80 are cut. And the air passage prevention board 60 is provided in the part from which the heat-transfer fin 11a was cut. Further, the heat transfer tube 12 is not penetrated below the second surface 81 of the heat transfer fin 11a.

  For this reason, the part which is not heat-exchanged so much can be excluded, and the production cost of the indoor heat exchanger 6a can be reduced. In addition, it is possible to prevent the airflow flowing into the indoor heat exchanger 6a from escaping from the cut portion, and the airflow can be distributed throughout the indoor heat exchanger 6a. Thereby, efficient heat exchange can be performed.

(Third embodiment)
Regarding the heat exchanger according to the third embodiment, differences from the indoor heat exchanger 6 of the first embodiment and the indoor heat exchanger 6a of the second embodiment will be mainly described below.

<Structure of indoor heat exchanger>
FIG. 6 is a longitudinal sectional view of an air conditioner 1b according to a third embodiment of the present invention. The indoor heat exchanger 6b is a cross fin type heat exchanger, and mainly includes heat transfer fins 11b and heat transfer tubes 12.

  The heat transfer tubes 12 are arranged in a direction crossing the air flow, and eight heat transfer tube rows 61b to 68b are arranged from the upstream of the air flow toward the downstream of the air flow. The refrigerant flows from the heat transfer tubes 12 belonging to the heat transfer tube row 68b on the downstream side of the air flow to the heat transfer tubes 12 belonging to the heat transfer tube row 61b on the upstream side of the air flow. This refrigerant distribution path is called a path 91b (see FIG. 6). By this path 91b, the air flow and the refrigerant flow are opposed to each other, and the amount of heat exchange is increased as compared with the non-opposed one.

  The heat transfer fins 11b are divided between the heat transfer tube row 62b and the heat transfer tube row 63b. This is also performed between the heat transfer tube row 64b and the heat transfer tube row 65b and between the heat transfer tube row 66b and the heat transfer tube row 67b. As a result, the heat on the surface of the heat transfer fin 11b cannot move beyond the dividing portion 13b. Further, the heat transfer fin 11b has the first side 75 at the lower end inclined at 45 degrees with respect to the horizontal plane. That is, the first sides 75 at the lower ends of the heat transfer fin groups 71b to 74b are inclined 45 degrees with respect to the horizontal plane.

  Further, the heat transfer tube rows 61b to 68b are arranged so that the straight tubes 12a of the heat transfer tubes 12 overlap with each other in a top view of the indoor heat exchanger 6b, and a gap is formed between the straight tubes 12a of the adjacent heat transfer tubes 12. Placed in. That is, the air flow is formed so as to penetrate between the straight pipes 12a of the heat transfer pipe 12 in the vertical direction (see the dashed white arrow A3 in FIG. 6). Further, the straight pipes 12a of the heat transfer tubes 12 are all arranged so as not to have any gaps in a vertical view with respect to the first side 75 at the lower end of the heat transfer fins 11b. That is, the straight pipe 12a of the heat transfer pipe 12 is arranged so that there is no gap penetrating the entire indoor heat exchanger 6b in the vertical view with respect to the first side 75 at the lower end of the heat transfer fin 11b. The air flow tends to take the shortest distance as the passage path of the heat exchanger. In the case of the indoor heat exchanger 6b in which the heat transfer tube rows 61b to 68b are inclined obliquely as in the present invention, the air flow is in a direction nearly perpendicular to the heat transfer tube rows 61b to 68b (the broken line in FIG. 6). Try to pass with white arrow A4). In the indoor heat exchanger 6b according to the third embodiment, when an air flow is about to flow in a direction nearly perpendicular to the heat transfer tube rows 61b to 68b as indicated by a dashed white arrow A4, The path is obstructed by the heat transfer tube 12 (see the x mark at the tip of the dashed white arrow A4 in FIG. 6). In the indoor heat exchanger 6b, the air flow is difficult to pass through the interior of the indoor heat exchanger 6 through the shortest path, and easily passes in the vertical direction. For this reason, an air flow can be flowed over the whole indoor heat exchanger 6b, and the whole indoor heat exchanger 6b can be contributed to heat exchange.

<Features of Third Embodiment>
In the indoor heat exchanger 6b according to the third embodiment, the heat transfer tubes 12 are arranged so as to form a gap with respect to the vertical direction, thereby facilitating the flow of air in the vertical direction. Further, by arranging the heat transfer tubes 12 without gaps when viewed in a direction perpendicular to the heat transfer tube rows 61 to 68, the air flow distribution path does not take the shortest distance inside the indoor heat exchanger 6b. Therefore, an air flow can be flowed over the whole indoor heat exchanger 6b, and the whole indoor heat exchanger 6b can be contributed to heat exchange. For this reason, efficient heat exchange can be performed.

<Modification>
(1)
In the indoor heat exchangers 6 to 6b according to the above-described embodiment, two heat transfer tube rows pass through one heat transfer fin group. You may make it the structure which a heat pipe row penetrates 1 row.

(2)
The indoor heat exchangers 6 to 6b according to the above embodiment are floor-standing air conditioners, but are not limited thereto, and may be a wall-hanging type, a ceiling-embedded type, a wall-embedded type, or the like.

(3)
In the indoor heat exchangers 6 to 6b according to the above-described embodiment, the surface of the heat transfer fin 11 has been subjected to a hydrophilic treatment, but this is not a limitation, and a water repellent treatment may be performed.

  In this indoor heat exchanger, when drain is generated, it is possible to easily remove the drain from the heat exchanger.

  The heat exchanger which concerns on this invention can suppress the fall of a cooling capability, and is useful as a heat exchanger etc. which gave the drain countermeasure at the time of cooling.

A refrigeration circuit for an air conditioner using a CO2 refrigerant. (A) CO2 refrigerant pressure-enthalpy state diagram. (B) Temperature-entropy state diagram of CO2 refrigerant. The perspective view of the indoor heat exchanger of the air conditioning apparatus which concerns on 1st Embodiment. The longitudinal cross-sectional view of an air conditioning apparatus. The longitudinal cross-sectional view of the air conditioning apparatus which concerns on 2nd Embodiment. The longitudinal cross-sectional view of the air conditioning apparatus which concerns on 3rd Embodiment.

Explanation of symbols

6-6b Indoor heat exchanger (heat exchanger)
11-11b Heat transfer fin 12 Heat transfer tube 60 Air passage prevention plate (first plate)
61-68, 61a-68a, 61b-68b Heat transfer tube rows 71-74, 71a-74a, 71b-74b Heat transfer fin group 75 First side 76 Second side 77 First end (first side upper end)
78 second end (second side lower end)
80 First surface 81 Second surface

Claims (17)

A heat exchanger that performs heat exchange between the refrigerant and air using a supercritical refrigerant as the refrigerant,
A heat transfer fin group (71-74, 71a-74a, 71b-74b) formed by a plurality of plate-like heat transfer fins (11-11b) arranged parallel to the vertical direction with a predetermined interval;
A plurality of heat transfer tubes (12) penetrating the heat transfer fin group;
With
Four or more heat transfer tube rows (61-68, 61a-68a, 61b-68b) formed by arranging the heat transfer tubes in the first direction intersecting with the air flow are formed from the upstream to the downstream of the air flow. ,
The plurality of heat transfer fins, the first side (75) at the lower end thereof is inclined with respect to the horizontal plane,
Heat exchanger (6-6b). The first side is inclined in a range of 45 degrees or more with respect to a horizontal plane.
The heat exchanger (6-6b) according to claim 1. Of the two ends of the first side, the first surface (80) including the upper first side upper end (77) is substantially perpendicular to the first side,
In the heat transfer fin group, a portion above the first surface is cut,
The heat exchanger (6a) according to claim 1 or 2. A first plate (60) for suppressing the passage of the airflow;
The first plate is installed at an end of the heat transfer fin group along the first surface.
The heat exchanger (6a) according to claim 3. The first side and the second side (76) at the upper end of the heat transfer fin are substantially parallel to the first direction.
The heat exchanger (6-6b) in any one of Claim 1 to 4. Of the two ends of the second side, the second surface (81) including the lower second side lower end (78) is substantially perpendicular to the second side,
The plurality of heat transfer tubes are not inserted into the heat transfer fin group below the second surface,
The heat exchanger (6a) according to claim 5. The plurality of heat transfer tubes are arranged so that the air flow easily flows in a vertical direction.
The heat exchanger (6b) according to claim 1 or 2. The plurality of heat transfer tubes are arranged with a plurality of gaps in a vertical view,
The heat exchanger (6b) according to claim 7. The plurality of heat transfer tubes are arranged so that the air flow is less likely to pass in a second direction substantially perpendicular to the first direction.
The heat exchanger (6b) according to claim 7 or 8. The plurality of heat transfer tubes are arranged without a gap in the second direction view,
The heat exchanger (6b) according to claim 9. The heat transfer fins are divided between at least one pair of adjacent heat transfer tube rows;
The heat exchanger (6-6b) according to any one of claims 1 to 10. The heat transfer fins are divided between all adjacent heat transfer tube rows,
The heat exchanger (6-6b) according to any one of claims 1 to 11. In the heating operation, the refrigerant flows from the heat transfer tube belonging to the heat transfer tube row on the downstream side of the air flow to the heat transfer tube belonging to the heat transfer tube row on the upstream side of the air flow.
The heat exchanger (6-6b) according to any one of claims 1 to 12. The air flow flows from the bottom to the top of the heat transfer fins,
The heat exchanger (6-6b) according to any one of claims 1 to 13. The heat transfer fin has a hydrophilic surface.
The heat exchanger (6-6b) according to any one of claims 1 to 14. The heat transfer fin has a water repellent surface.
The heat exchanger (6-6b) according to any one of claims 1 to 14. The heat exchanger (6-6b) of claim 1,
A fan (53) for generating the air flow;
The indoor unit (51-51b) of an air conditioning apparatus (1-1b) provided with.

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