JP2008275217A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of suppressing a bias of a heat exchanging amount even if deviation in wind speed distribution is enlarged by the stay of condensed water, and reducing the drift of a refrigerant. <P>SOLUTION: This heat exchanger 20 is composed of a plurality of blocks 20a, 20b and 20c, and comprises a heat transfer fin 4 and a plurality of heat transfer tubes 51. The heat transfer fin is disposed in an air current. The plurality of heat transfer tubes are inserted to the heat transfer fin, and disposed in the direction roughly orthogonal to the flowing direction of the air current. The heat transfer fin has bent parts 61, 62. The plurality of blocks are divided at the bent parts as boundaries. The plurality of heat transfer tubes form a plurality of paths 71, 72 and 73 through which the refrigerant can pass. At least one of the plurality of paths is formed while passing through the first block and the second block. The air current passes through the first block at a first wind speed, and the air current passes through the second block at a second wind speed lower than the first wind speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger composed of a plurality of blocks and having a plurality of refrigerant flow paths.

Conventionally, in an air conditioner or the like, a heat transfer fin arranged in an air flow and a plurality of heat transfer tubes inserted in the heat transfer fin and arranged in a direction substantially orthogonal to the flow direction of the air flow are provided. A cross fin and tube heat exchanger is often used. For example, in a technique such as Patent Document 1, a heat transfer fin is provided with a plurality of bent portions, and the heat exchanger is divided into a plurality of bent portions (see Patent Document 1).
Japanese Patent Laid-Open No. 11-23179

  However, in the technique such as Patent Document 1, the wind speed distribution is often greatly different in each of the heat exchangers divided into a plurality. For example, when this heat exchanger functions as an evaporator, the condensed water becomes a ventilation resistance in the heat exchanger arranged at the lower part of the divided heat exchanger due to the influence of condensed water. Tends to be small. Also, when this heat exchanger functions as a condenser, the wind speed may be different in the divided heat exchanger. In this way, when the difference in wind speed in the divided heat exchangers becomes large, the refrigerant flowing in the heat transfer tubes has a high heat exchange efficiency in the portion where the wind speed is large, and the state of the refrigerant is easily evaporated (or condensed) easily. Also, at the portion where the wind speed is low, the heat exchange rate is not so good, and the state of the refrigerant tends to not completely evaporate (or condense). For this reason, the evaporation state (or condensation state) of the entire heat exchanger is biased, and the heat exchange efficiency is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a heat exchanger that can suppress the deviation of the heat exchange amount and reduce the refrigerant drift even if the deviation of the wind speed distribution increases due to stay of condensed water or the like.

  A heat exchanger according to a first aspect of the present invention is a heat exchanger composed of a plurality of blocks whose longitudinal directions are different from a horizontal plane, and includes heat transfer fins and a plurality of heat transfer tubes. The heat transfer fin is disposed in the airflow. The plurality of heat transfer tubes are inserted into the heat transfer fins, and are arranged in a direction substantially orthogonal to the airflow direction. The heat transfer fin has a bent portion that is narrowed and bent. The plurality of blocks are divided with the bent portion as a boundary. The plurality of heat transfer tubes form a plurality of paths through which the refrigerant can pass. At least one of the plurality of paths is formed so as to pass through the first block and the second block among the plurality of blocks. The first block passes the airflow at the first wind speed. The second block passes at a second wind speed where the airflow is slower than the first wind speed.

  In this invention, it is a heat exchanger divided | segmented into a some block, Comprising: An airflow passes by the 2nd wind speed slower than the 1st block and 1st wind speed which pass a 1st wind speed with a fast wind speed among several blocks At least one of the plurality of paths is formed so as to pass through the second block.

  Therefore, by taking a path so as to pass through both the first block having a high wind speed and the second block having a low wind speed, the first block in which the refrigerant easily exchanges heat and the second block in which the refrigerant hardly exchanges heat In the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path. For this reason, the fall of heat exchange efficiency can be prevented and heat exchange efficiency can be improved.

  The heat exchanger according to the second invention is the heat exchanger according to the first invention, and the first wind speed is twice or more faster than the second wind speed when the refrigerant condenses inside the heat transfer tube.

  In the present invention, when the heat exchanger of the present invention functions as a condenser, the first wind speed of the airflow passing through the first block is twice or more faster than the second wind speed of the airflow passing through the second block. ing.

  Therefore, even when the first wind speed is twice or more than the second wind speed, a decrease in heat exchange efficiency can be prevented by connecting the first block and the second block through the same path.

  The heat exchanger according to the third invention is the heat exchanger according to the first invention or the second invention, wherein the first wind speed is four times higher than the second wind speed when the refrigerant evaporates inside the heat transfer tube. Faster than that.

  When the heat exchanger of the present invention functions as an evaporator, the first wind speed of the airflow passing through the first block is four times or more faster than the second wind speed of the airflow passing through the second block.

  Therefore, even when the first wind speed is four times or more than the second wind speed, it is possible to prevent a decrease in heat exchange efficiency by connecting the first block and the second block through the same path.

  A heat exchanger according to a fourth aspect of the present invention is the heat exchanger according to any one of the first to third aspects, wherein there are three or more blocks.

  The heat exchanger of the present invention is divided into three or more blocks. As described above, even in the heat exchanger divided into three or more blocks, the refrigerant is heated by passing through both the first block having a high wind speed and the second block having a low wind speed. The first block that is easily exchanged and the second block that is difficult for the refrigerant to exchange heat are connected by the same path, and in the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  The heat exchanger which concerns on 5th invention is a heat exchanger which concerns on 4th invention, Comprising: A 1st block exists in the uppermost part among several blocks. The second block is at the bottom of the plurality of blocks.

  In the present invention, a path is formed by the heat transfer tube so as to connect the uppermost block and the lowermost block. When the heat exchanger according to the present invention functions as an evaporator, condensed water is generated. Therefore, in the block at the lowermost part, ventilation resistance is likely to occur due to the condensed water falling from the upper part. The wind speed is lower in the lowermost block than in the uppermost block.

  Therefore, since the path connects the uppermost block and the lowermost block where a difference in wind speed is likely to occur, it is possible to suppress a difference in the amount of heat exchange and to prevent a decrease in heat exchange efficiency.

  The heat exchanger according to the sixth aspect of the present invention is the heat exchanger according to the fourth or fifth aspect of the present invention, wherein the airflow flows fastest in the first block, and the airflow flows latest in the second block.

  In the present invention, a path is formed by the heat transfer tube so as to connect the first block in which the airflow flows most rapidly and the second block in which the airflow flows most slowly.

  Therefore, since the path connects the first block and the second block where the difference in the heat exchange amount is the largest, it is possible to suppress the difference in the heat exchange amount and to prevent the heat exchange efficiency from being lowered. .

  A heat exchanger according to a seventh aspect of the present invention is the heat exchanger according to any one of the fourth to sixth aspects, wherein the angle formed by the longitudinal direction of the second block with respect to the horizontal plane is 15 ° or less.

  In the present invention, the longitudinal direction of the second block passing through the second wind speed, which is slower than the first wind speed, is inclined at an angle smaller than 15 ° with respect to the horizontal plane. For this reason, the airflow is more difficult to pass through the second block. Even in such a heat exchanger, the first block and the refrigerant in which the refrigerant easily exchanges heat by passing through both the first block having a high wind speed and the second block having a low wind speed. Is connected to the second block, which is difficult to exchange heat, by the same path, and in a heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  A heat exchanger according to an eighth aspect of the present invention is the heat exchanger according to any of the fourth to seventh aspects of the present invention, wherein the second block is condensed at the lower end when the refrigerant evaporates inside the heat transfer tube. Contact water.

  In this invention, when the heat exchanger which concerns on this invention functions as an evaporator, the lower end of a 2nd block contacts condensed water. For this reason, the airflow is more difficult to pass through the second block. Even in such a heat exchanger, the first block and the refrigerant in which the refrigerant easily exchanges heat by passing through both the first block having a high wind speed and the second block having a low wind speed. Is connected to the second block, which is difficult to exchange heat, by the same path, and in a heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  A heat exchanger according to a ninth aspect of the present invention is the heat exchanger according to any one of the first to eighth aspects of the present invention, wherein the plurality of passes has three or more passes.

  In the present invention, there are three or more paths as refrigerant paths. For this reason, if the wind speed of the airflow corresponding to each pass is different, the evaporation state or the condensation state of the refrigerant may be different depending on each pass. Even in such a heat exchanger, the first block and the refrigerant in which the refrigerant easily exchanges heat by passing through both the first block having a high wind speed and the second block having a low wind speed. Is connected to the second block, which is difficult to exchange heat, by the same path, and in a heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  A heat exchanger according to a tenth aspect of the present invention is the heat exchanger according to any of the first to ninth aspects of the present invention, wherein the flow direction of the airflow is a substantially horizontal direction.

  In the present invention, the airflow flows in a substantially horizontal direction. When the heat exchanger according to the present invention functions as an evaporator, the generated condensed water tends to fall and concentrate in the lower part, so that a difference is likely to occur between the wind speed at the upper part of the heat exchanger and the wind speed at the lower part. Even in such a heat exchanger, the first block and the refrigerant in which the refrigerant easily exchanges heat by passing through both the first block having a high wind speed and the second block having a low wind speed. Is connected to the second block, which is difficult to exchange heat, by the same path, and in a heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  In the heat exchanger according to the first aspect of the invention, by taking a pass so as to pass through both the first block having a high wind speed and the second block having a low wind speed, the first block and the refrigerant in which the refrigerant easily exchanges heat can be obtained. The second block that is difficult to exchange heat is connected by the same path, and in the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path. For this reason, the fall of heat exchange efficiency can be prevented and heat exchange efficiency can be improved.

  In the heat exchanger according to the second aspect of the invention, even when the first wind speed is twice or more than the second wind speed, the first block and the second block are connected by the same path, thereby preventing the heat exchange efficiency from being lowered. be able to.

  In the heat exchanger according to the third aspect of the invention, even when the first wind speed is four times or more than the second wind speed, the first block and the second block are connected by the same path, thereby preventing a decrease in heat exchange efficiency. be able to.

  In the heat exchanger according to the fourth aspect of the invention, even in the heat exchanger divided into three or more blocks, a path is taken so as to pass through both the first block having a high wind speed and the second block having a low wind speed. Thus, the first block in which the refrigerant easily exchanges heat and the second block in which the refrigerant hardly exchanges heat are connected by the same path, and in the heat exchanger having a plurality of paths, the amount of heat exchange in each path is biased. Can be reduced.

  In the heat exchanger according to the fifth aspect of the present invention, since the uppermost block and the lowermost block that easily cause a difference in wind speed are connected, it is possible to suppress a difference in the amount of heat exchange, resulting in a decrease in heat exchange efficiency. Can be prevented.

  In the heat exchanger according to the sixth aspect of the invention, since the first block and the second block that have the largest difference in heat exchange amount are connected, the difference in heat exchange amount can be suppressed, and the heat exchange efficiency can be reduced. Decline can be prevented.

  In the heat exchanger according to the seventh aspect of the invention, by taking a pass so as to pass through both the first block having a high wind speed and the second block having a low wind speed, the first block and the refrigerant in which the refrigerant easily exchanges heat can be obtained. The second block that is difficult to exchange heat is connected by the same path, and in the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  In the heat exchanger according to the eighth aspect of the invention, by taking a pass so as to pass through both the first block having a high wind speed and the second block having a low wind speed, the first block and the refrigerant in which the refrigerant easily exchanges heat can be obtained. The second block that is difficult to exchange heat is connected by the same path, and in the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  In the heat exchanger according to the ninth aspect of the invention, by taking a pass so as to pass through both the first block having a high wind speed and the second block having a low wind speed, the first block and the refrigerant in which the refrigerant easily exchanges heat can be obtained. The second block that is difficult to exchange heat is connected by the same path, and in the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  In the heat exchanger according to the tenth aspect of the invention, by taking a pass so as to pass through both the first block having a high wind speed and the second block having a low wind speed, the first block and the refrigerant in which the refrigerant easily exchanges heat can be obtained. The second block that is difficult to exchange heat is connected by the same path, and in the heat exchanger having a plurality of paths, it is possible to reduce the unevenness of the heat exchange amount in each path.

  Hereinafter, an embodiment of an air-conditioning apparatus according to the present invention will be described based on the drawings.

<Schematic configuration of air conditioner>
An air conditioner 1 in which an embodiment of the present invention is adopted is an indoor unit 2 installed by being embedded or suspended in a ceiling of a room such as a building (in this embodiment, it is suspended and stored behind the ceiling). ) And an outdoor unit 3 installed outside the room. A heat exchanger is accommodated in each of the indoor unit 2 and the outdoor unit 3, and a refrigerant circuit is configured by connecting each heat exchanger through a refrigerant pipe. The structure of the refrigerant circuit of the air conditioning apparatus 1 is shown in FIG.

  This refrigerant circuit mainly includes an indoor heat exchanger 20, a compressor 32, a four-way switching valve 33, an outdoor heat exchanger 30, and an expansion valve 34.

  The indoor heat exchanger 20 provided in the indoor unit 2 exchanges heat between the introduced indoor air and the refrigerant. The indoor heat exchanger 20 is connected to a liquid pipe 23 through which liquid refrigerant flows and a gas pipe 24 through which gas refrigerant flows. Further, the indoor unit 2 is provided with a cross flow fan 21 for sucking indoor air and exchanging the air after exchanging heat with the indoor heat exchanger 20 into the room. The cross flow fan 21 is configured in a cylindrical shape, and is provided with blades in the direction of the rotation axis on the peripheral surface, and generates an air flow in a direction intersecting with the rotation axis. The cross flow fan 21 is rotationally driven by a fan motor 21 a provided in the indoor unit 2. The indoor unit 2 will be described later.

  The outdoor unit 3 is connected to a compressor 32, a four-way switching valve 33 connected to the discharge side of the compressor 32, an accumulator 31 connected to the suction side of the compressor 32, and a four-way switching valve 33. An outdoor heat exchanger 30 and an expansion valve 34 connected to the outdoor heat exchanger 30 are provided. The expansion valve 34 is connected to a pipe via a liquid closing valve 36 and is connected to one end of the indoor heat exchanger 20 via this pipe. The four-way switching valve 33 is connected to a pipe via a gas closing valve 37, and is connected to the other end of the indoor heat exchanger 20 via this pipe. Further, the outdoor unit 3 is provided with a propeller fan 38 for discharging the air after heat exchange in the outdoor heat exchanger 30 to the outside. The propeller fan 38 is rotationally driven by an outdoor fan motor 38a.

(1) Indoor unit (Configuration of indoor unit)
In FIG. 2, the cross-sectional block diagram of the indoor unit 2 is shown. The indoor unit 2 includes an indoor unit casing 22, and the indoor heat exchanger 20 and the cross flow fan 21 described above are accommodated in the indoor unit casing 22 of the indoor unit 2. Moreover, the indoor heat exchanger 20 is divided | segmented into three heat exchange parts (The 1st heat exchange part 20a, the 2nd heat exchange part 20b, and the 3rd heat exchange part 20c) so that it may demonstrate later. The indoor unit casing 22 is provided with a suction port 22a for taking in indoor air and a blow-out port 22b for sending out the air sent out by the cross flow fan 21. The suction port 22a is provided on the side surface of the indoor unit casing 22, and the air outlet 22b is provided on the side surface of the indoor unit casing 22 on the side opposite to the suction port 22a. The suction port 22a and the air outlet 22b are connected to a ceiling air inlet (not shown) and a ceiling air outlet (not shown) provided on the ceiling of the room by ducts. And the indoor heat exchanger 20 and the crossflow fan 21 are arrange | positioned in the indoor unit casing 22 in the side in which the indoor heat exchanger 20 is near the inlet 22a, and the crossflow fan 21 in the side near the blower outlet 22b. The That is, the indoor heat exchanger 20 is disposed on the upstream side in the airflow direction with respect to the cross flow fan 21. Here, the indoor heat exchanger 20 is arranged in a multistage manner so as to surround the cross flow fan 21 with the suction port 22a in the indoor unit casing 22.

(Arrangement of indoor heat exchanger)
In the present embodiment, the indoor heat exchanger 20 is a three-stage bending heat exchanger, and includes three heat exchange portions 20a, 20b, and 20c. The upper end of the first heat exchange unit 20a is inclined toward the air outlet 22b side of the indoor unit 2, and covers the cross flow fan 21 from above the suction port 22a side upper side of the cross flow fan 21. Are arranged as follows. The second heat exchange unit 20b is disposed below the first heat exchange unit 20a such that the upper end of the second heat exchange unit 20b is inclined toward the suction port 22a side of the indoor unit 2. The first heat exchange part 20a and the second heat exchange part 20b are heat transfer fins 4 (see below) by the first bent part 61 which is the lower end of the first heat exchange part 20a, that is, the upper end of the second heat exchange part 20b. Is formed by being bent. The third heat exchange unit 20c is disposed further below the second heat exchange unit 20b. The second heat exchanging part 20b and the third heat exchanging part 20c are formed by bending the heat transfer fin 4 by the second bent part 62 which is the lower end of the second heat exchanging part 20b, that is, the upper end of the third heat exchanging part 20c. Is formed. In addition, each bending part 61 and 62 is formed by bend | folding in the fin surface direction of the heat-transfer fin 4 so that the notch parts 91 and 92 formed by notching the heat-transfer fin 4 may become an outer side. The third heat exchange unit 20 c is disposed below the cross flow fan 21. The third heat exchanging part 20c is arranged so that the angle α1 made with the horizontal plane is smaller than 15 °.

(Seal member)
As described above, in the indoor heat exchanger 20, the direction in which the airflow passes through the heat transfer fins 4 described later (that is, the surface direction of the heat transfer fins 4) in which the heat exchange units 20a, 20b, and 20c are integrated. However, there is a gap along the longitudinal direction between the divided surfaces of the first heat exchange part 20a and the second heat exchange part 20b. In particular, the gap formed by the first heat exchange part 20a and the second heat exchange part 20b is located just inside the suction port 22a and between the suction port 22a and the cross flow fan 21. The air is easy to pass. And the air which passes this clearance gap causes the fall of a heat exchange rate. For this reason, the seal member 8 that closes the gap is attached to the indoor heat exchanger 20.

(2) Structure of indoor heat exchanger Hereinafter, a detailed configuration of the indoor heat exchanger 20 of the indoor unit 2 will be described. FIG. 3 shows a front view of the second heat exchange unit 20b (viewed from the direction of the arrow D1 in FIG. 2). Here, only the second heat exchanging part 20b will be described, but the first heat exchanging part 20a and the third heat exchanging part 20c have the same configuration, and the shape (mainly in the longitudinal direction) of the heat transfer fins 4 (see later). ), The number of heat transfer tubes 51 (see later), the way of taking the refrigerant path, and the like are different, and the detailed configurations of the first heat exchange unit 20a and the third heat exchange unit 20c are described. Omitted.

  The second heat exchange unit 20b is a finned tube heat exchanger having a rectangular flat plate-like appearance. The second heat exchanging unit 20 b is composed of a plurality of heat transfer tubes 51, a plurality of heat transfer fins 4, a front tube plate 41, and a rear tube plate 42. The plurality of heat transfer tubes 51 are arranged in parallel with a hairpin shape. And from the hairpin part 51a of the heat exchanger tube 51, the rear tube plate 42, the some heat-transfer fin 4, and the front tube plate 41 are arrange | positioned in order. The plurality of heat transfer fins 4 have holes 4a (see FIG. 4) through which the heat transfer tubes 51 penetrate in the plate thickness direction, and are arranged at predetermined intervals in the plate thickness direction. And each pipe | tube end part 51b on the opposite side to the hairpin part 51a of the some heat exchanger tube 51 is connected with the U-shaped pipe | tube 52, respectively. The U-shaped tube 52 has a tube inner diameter that is substantially the same as the tube inner diameter of the heat transfer tube 51, and is disposed so as to protrude further outward from the front tube plate 41. The second heat exchange unit 20b is a so-called two-row heat exchanger in which the heat transfer tubes 51 are arranged in two rows.

(Take a pass)
In the indoor heat exchanger 20 of the present embodiment, there are three refrigerant paths (hereinafter referred to as paths 71, 72, 73) through which the refrigerant flows. Here, the three paths 71, 72, 73 will be described with reference to FIG. FIG. 4 is a diagram showing three paths 71, 72, 73 in the indoor heat exchanger 20. In FIG. 4, what is represented by a bold solid line is a U-shaped tube portion (that is, the U-shaped tube 52) on the front side of the sheet of the heat transfer tube 51 (right side in the front view of the indoor heat exchanger 20). What is represented by a thick broken line is a U-shaped tube portion (that is, a hairpin portion 51a) on the back side of the paper surface of the heat transfer tube 51 (left side in the front view of the indoor heat exchanger 20). In the indoor heat exchanger 20, the plurality of heat transfer tubes 51 form two heat transfer tube rows G <b> 1 and G <b> 2 in a direction intersecting the airflow direction. Here, the heat transfer tube row on the upstream side in the airflow direction is referred to as a first heat transfer tube row G1, and the heat transfer tube row on the downstream side in the airflow direction is referred to as a second heat transfer tube row G2. The first heat transfer tube row G1 and the second heat transfer tube row G2 are formed in the heat exchange portions 20a, 20b, and 20c, respectively.

  Here, the first path 71 is formed by connecting the upper two-stage heat transfer tubes 51 of the first heat exchange section 20a and the lower four stages of the third heat exchange section 20c. The second path 72 is formed by connecting the lower two-stage heat transfer tubes 51 of the first heat exchange unit 20a and the upper four-stage heat transfer tubes 51 of the second heat exchange unit 20b. The third path 73 is formed by connecting the lower two-stage heat transfer tubes 51 of the second heat exchange section 20b and the upper two-stage heat transfer tubes of the third heat exchange section 20c.

  Further, each path 71, 72, 73 is connected to the liquid pipe 23 and is connected to the gas pipe 24, and liquid refrigerant inflow / outflow pipes 71a, 72a, 73a through which the liquid state refrigerant flows in and out flows in and out. Gas refrigerant inflow / outflow pipes 71b, 72b, 73b are provided. When the indoor heat exchanger 20 functions as an evaporator, the refrigerant flows into the liquid refrigerant inflow / outflow pipes 71a, 72a, 73a and passes through the heat transfer pipes 51 belonging to the paths 71, 72, 73 to be gas refrigerant. When the indoor heat exchanger 20 functions as a condenser and flows out from the inflow / outflow pipes 71b, 72b, 73b, it flows into the gas refrigerant inflow / outflow pipes 71b, 72b, 73b and belongs to the paths 71, 72, 73. 51 flows out from the liquid refrigerant inflow / outflow pipes 71a, 72a, 73a. The liquid refrigerant inflow / outflow tubes 71 a, 72 a, 73 a and the gas refrigerant inflow / outflow tubes 71 b, 72 b, 73 b belong to the first heat transfer tube row G 1 that is the heat transfer tube row far from the cross flow fan 21.

  In this way, when the indoor heat exchanger 20 functions as a condenser by disposing the liquid refrigerant inflow / outflow tubes 71a, 72a, 73a and the gas refrigerant inflow / outflow tubes 71b, 72b, 73b in the first heat transfer tube row G1. Since the refrigerant and the airflow can be made to flow in the vicinity of the liquid refrigerant inflow / outflow pipes 71a, 72a, 73a, the liquid refrigerant flowing out of the liquid refrigerant inflow / outflow pipes 71a, 72a, 73a and the air that is not heat-exchanged Subcooling can be applied by heat exchange. Further, when the indoor heat exchanger 20 functions as an evaporator, the refrigerant and the air flow can be made to flow in the vicinity of the gas refrigerant inflow / outflow pipes 71b, 72b, 73b, so that the gas refrigerant inflow / outflow pipes 71b, 72b, The gas refrigerant flowing out from 73b and the air that has not been heat-exchanged can be subjected to heat exchange to further overheat. Thereby, condenser performance and evaporator performance can be improved.

  And each liquid refrigerant inflow / outflow pipe 71a, 72a, 73a which belongs to each path 71, 72, 73 and each gas refrigerant inflow / outflow pipe 71b, 72b, 73b are arranged so that they may not belong to the same heat exchange part. Specifically, in the first pass 71, the liquid refrigerant inflow / outflow pipe 71a is disposed in the first heat exchange section 20a, and the gas refrigerant inflow / outflow pipe 71b is disposed in the third heat exchange section 20c. In the second path 72, the liquid refrigerant inflow / outflow pipe 72a is disposed in the first heat exchange section 20a, and the gas refrigerant inflow / outflow pipe 72b is disposed in the second heat exchange section 20b. In the third path 73, the liquid refrigerant inflow / outflow tube 73a is disposed in the second heat exchange section 20b, and the gas refrigerant inflow / outflow pipe 73b is disposed in the third heat exchange section 20c.

  In this way, the liquid refrigerant inflow / outflow pipe and the gas refrigerant inflow / outflow pipe belonging to the same path are arranged in separate heat exchange sections. Therefore, by arranging the liquid refrigerant inflow / outflow pipes 71a, 72a, 73a and the gas refrigerant inflow / outflow pipes 71b, 72b, 73b in separate heat exchange sections 20a, 20b, 20c, the liquid refrigerant inflow / outflow pipe 71a, It is possible to prevent heat exchange by heat conduction between the heat transfer fins 4 between the 72a, 73a and the gas refrigerant inflow / outflow pipes 71b, 72b, 73b. Thus, since heat exchange between the refrigerants can be prevented and heat exchange with the air can be performed, a decrease in heat exchange efficiency can be prevented.

(Wind speed ratio by each part of indoor heat exchanger)
Here, FIG. 5 shows the plurality of heat transfer tubes 51 forming the indoor heat exchanger 20 of the present embodiment with step numbers. Here, the “stage number” means the end of the heat transfer tube 51 in each row of the two-row heat exchanger (in this embodiment, the heat transfer tube 51 at the lowermost portion of the third heat exchange portion 20c) to the heat transfer tube. Numbers (A1 to A16) assigned in order in the 51 column direction. In addition, the heat transfer tubes 51 assigned the same step number are combined into a step, and the step assigned the X-th step number AX is referred to as an X-th heat transfer tube group AX. Here, for example, the stage assigned the stage number A1 of the first stage is designated as the first stage heat transfer tube group A1, and each stage is called by putting any of the numbers 1 to 16 in X. FIG. 6 shows the wind speed ratio in each stage A1 to A16 of FIG. 5 divided into a case where the indoor heat exchanger 20 functions as an evaporator and a case where the indoor heat exchanger 20 functions as a condenser.

  According to FIGS. 5 and 6, when the indoor heat exchanger 20 functions as an evaporator, the wind speed is the highest in the 16th stage heat transfer tube group A16 regardless of the function as a condenser, and the first stage heat transfer tube group. It can be seen that the wind speed is the smallest at A1. Furthermore, when the indoor heat exchanger 20 functions as an evaporator, the wind speed of the airflow passing through the 16th stage heat transfer tube group A16 is four times or more larger than the wind speed of the airflow passing through the first stage heat transfer tube group A1. Further, when the indoor heat exchanger 20 functions as a condenser, the wind speed of the airflow passing through the 16th stage heat transfer tube group A16 is twice or more than the wind speed of the airflow passing through the first stage heat transfer tube group A1. large. Note that the vicinity of the twelfth stage heat transfer tube group A12 also has a smaller wind speed ratio than the surrounding parts, but this is blocked by the seal member 81 on the upstream side in the airflow direction of the twelfth stage heat transfer tube group A12. It is because it is. Further, the wind speed ratio of the 12th stage heat transfer tube group A12 is not as small as that of the 1st stage heat transfer tube group A1. From these facts, the heat exchange section with the largest wind speed ratio is the first heat exchange section 20a (from the 13th stage heat transfer pipe group A13 to the 16th stage heat transfer pipe group A16), and then the wind speed ratio is The second heat exchange section 20b (from the seventh stage heat transfer tube group A7 to the twelfth stage heat transfer pipe group A12) is larger, and the heat exchange section having the smallest wind speed ratio is the third heat exchange section 20c (the second heat exchange section 20c). It can be said that the first-stage heat transfer tube group A1 to the sixth-stage heat transfer tube group A6). Furthermore, when the indoor heat exchanger 20 functions only as an evaporator, the tendency becomes more prominent. That is, the wind speed in the 16th stage heat transfer tube group A16 when the indoor heat exchanger 20 functions as an evaporator is higher than the wind speed in the 16th stage heat transfer tube group A16 when the indoor heat exchanger 20 functions as a condenser. The wind speed in the first stage heat transfer tube group A1 when the indoor heat exchanger 20 functions as an evaporator is larger in the first stage heat transfer tube group A1 when the indoor heat exchanger 20 functions as a condenser. It is smaller than the wind speed. In other words, in the case of the evaporator than in the case of the condenser, the difference in the wind speed ratio passing through the first heat exchange unit 20a, the second heat exchange unit 20b, and the third heat exchange unit 20c is further widened.

  This is because when the indoor heat exchanger 20 functions as an evaporator, condensed water is likely to be generated. In such a case, the generated condensed water is guided by gravity and moves downward through the heat transfer fins 4, and the third heat exchange unit located at the lower portion of the indoor heat exchanger 20. Condensed water tends to accumulate in 20c. Therefore, when this condensed water accumulates, the condensed water becomes ventilation resistance, and the wind speed of the portion from the first-stage heat transfer tube group A1 to the sixth-stage heat transfer tube group A6 constituting the third heat exchange section 20c. The ratio is getting smaller. Therefore, when the indoor heat exchanger 20 is configured by taking three paths, for example, if the refrigerant path is formed in order from the top of the indoor heat exchanger 20, the upper part of the indoor heat exchanger 20 Since the wind speed ratio is large and the wind speed ratio is small in the lower part, the refrigerant exchanges heat unevenly in each path. In this case, assuming that the indoor heat exchanger 20 functions as an evaporator, the refrigerant circulating in the upper path evaporates quickly because the wind speed ratio in the upper path is large and the heat exchange efficiency is good. The refrigerant flowing through the lower path is discharged from the indoor heat exchanger 20 in the gas-liquid two-phase state because the wind speed ratio in the lower path is small and the heat exchange efficiency is poor. Also, assuming that the indoor heat exchanger 20 functions as a condenser, the refrigerant circulating in the upper path is completely condensed quickly because the wind speed ratio in the upper path is large and the heat exchange efficiency is good. Since the refrigerant flowing through this path has a low wind speed ratio in the lower path and poor heat exchange efficiency, it is discharged from the indoor heat exchanger 20 in the gas-liquid two-phase state. For this reason, a difference occurs at least between the refrigerant state in the upper path and the refrigerant state in the lower path, and the refrigerant contributing to heat exchange is reduced as a whole in the indoor heat exchanger 20. The heat exchange efficiency of the indoor heat exchanger 20 as a whole is deteriorated.

  In the present embodiment, the first path 71 is connected to the upper part of the indoor heat exchanger 20 (the 15th stage heat transfer tube group A15 and the 16th stage heat transfer pipe group A16 of the first heat exchange unit 20a) and the lower part of the indoor heat exchanger 20. By connecting and forming (from the first stage heat transfer tube group A1 to the fourth stage heat transfer tube group A4 of the third heat exchange part 20c), the best heat exchange efficiency part and the worst heat exchange efficiency part And the heat exchange efficiencies in the paths 71, 72, 73 can be made equal. Further, the second path 72 including the 12th stage heat transfer tube group A12 having the second lowest wind speed ratio is formed in 6 stages from the 9th stage heat transfer tube group A9 to the 14th stage heat transfer tube group A14. The wind speed ratio between the second path 72 and the third path 73 is made longer than the third path 73 formed in four stages from the fifth stage heat transfer pipe group A5 to the eighth stage heat transfer pipe group A8 having a large wind speed ratio. To eliminate the difference.

  Thus, in this invention, the heat exchange efficiency of the refrigerant | coolant in each path | pass 71,72,73 is made equivalent, and the heat exchange efficiency of the whole indoor heat exchanger 20 is improved.

<Features>
(1)
The heat exchanger according to the present embodiment is a heat exchanger that is divided into three parts: a first heat exchange unit 20a, a second heat exchange unit 20b, and a third heat exchange unit 20c. And among each heat exchange part 20a, 20b, 20c, it passes through the 1st heat exchange part 20a with the fastest wind speed of the passing air current, and the 3rd heat exchange part 20c with the slowest wind speed of the passing air current. The first path 71 is formed.

  Therefore, the first heat exchange part 20a in which the refrigerant easily exchanges heat and the third heat exchange part 20c in which the refrigerant hardly exchanges heat are connected by the same path, and the first path 71, the second path 72, and the third path In the indoor heat exchanger 20 of the present embodiment having the path 73 and the three paths, it is possible to reduce the unevenness of the heat exchange amount in each of the paths 71, 72, 73. For this reason, as much refrigerant as possible can be contributed to heat exchange, and a reduction in heat exchange efficiency can be prevented. Thereby, the heat exchange efficiency of the indoor heat exchanger 20 can be improved.

(2)
When the heat exchanger according to the present embodiment functions as an evaporator, the wind speed of the airflow passing through the 16th stage heat transfer tube group A16 belonging to the first heat exchange unit 20a belongs to the third heat exchange unit 20c. It is four times faster than the wind speed of the airflow passing through the first stage heat transfer tube group A1. Moreover, when the heat exchanger of this embodiment functions as a condenser, the wind speed of the airflow passing through the 16th stage heat transfer tube group A16 belonging to the first heat exchange unit 20a belongs to the third heat exchange unit 20c. It is twice as fast as the wind speed of the airflow passing through the first stage heat transfer tube group A1.

  Therefore, in the case where the wind speed difference between the sixteenth stage heat transfer tube group A16 and the first stage heat transfer tube group A1 is 4 times or more (when functioning as an evaporator) or 2 times or more (when functioning as a condenser). However, the first heat exchange section 20a (especially the 16th stage heat transfer tube group A16) and the third heat exchange section 20c (particularly the first stage heat transfer tube group A1) are connected by the same path, thereby reducing the heat exchange efficiency. Can be prevented.

(3)
In the heat exchanger according to the present embodiment, the first path 71 is formed so as to connect the first heat exchange part 20a at the uppermost part and the third heat exchange part 20c at the lowermost part. When the heat exchanger according to the present invention functions as an evaporator, condensed water is generated. Therefore, in the third heat exchanging part 20c at the lowermost part, ventilation resistance is likely to occur due to the influence of the condensed water falling from the upper part. In the third heat exchange unit 20c, the wind speed is lower than that in the first heat exchange unit 20a.

  Therefore, since the first heat exchanging portion 20a at the uppermost portion where the difference in wind speed is likely to be connected to the third heat exchanging portion 20c at the lowermost portion, it is possible to suppress the difference in the amount of heat exchange, and the heat exchange efficiency Can be prevented.

(4)
In the heat exchanger according to the present embodiment, the airflow flows in a substantially horizontal direction, and the longitudinal direction of the heat transfer fins 4 of the third heat exchange unit 20c having the slowest wind speed of the passing airflow is from 15 ° with respect to the horizontal plane. Is also inclined at a small angle α1. Furthermore, when the indoor heat exchanger 20 functions as an evaporator, the lower end of the third heat exchange unit 20c comes into contact with the condensed water. For this reason, the airflow is more difficult to pass through the third heat exchange unit 20c.

  Even in such an indoor heat exchanger 20, by forming the first path 71 so as to pass through both the first heat exchange unit 20a having a high wind speed and the third heat exchange unit 20c having a low wind speed, The indoor heat exchanger 20 having three paths 71, 72, and 73 is formed by connecting the first heat exchanging part 20a in which the refrigerant easily exchanges heat and the third heat exchanging part 20c in which the refrigerant hardly exchanges heat through the same path. , The bias of the heat exchange amount in each of the paths 71, 72, 73 can be reduced.

<Modification>
As mentioned above, although embodiment of this invention was described based on drawing, a specific structure is not restricted to these embodiment, It can change in the range which does not deviate from the summary of invention.

(1)
In the heat exchanger according to the above embodiment, the heat exchanger is divided into three heat exchange parts 20a, 20b, and 20c. However, the number of heat exchange parts is not limited to three, and if there are three or more, four heat exchange parts or five heat exchange parts. It may be divided into parts.

(2)
In the heat exchanger according to the above-described embodiment, the refrigerant path is divided into three paths 71, 72, and 73, but the number is not limited to three, and may be two or four or more.

  The heat exchanger according to the present invention can increase the heat exchange efficiency by preventing a decrease in the heat exchange efficiency, and is useful as a heat exchanger or the like including a plurality of blocks and a plurality of refrigerant channels.

The block diagram of the refrigerant circuit of the air conditioning apparatus which concerns on one Embodiment of this invention. The cross-sectional block diagram of an indoor unit. The front view of a 2nd heat exchange part. The figure showing the pass removal in an indoor heat exchanger. The related figure of the heat exchanger tube which forms an indoor heat exchanger, and a stage number. The figure showing the wind speed ratio in each step | level in an indoor heat exchanger.

Explanation of symbols

4 Heat transfer fins 20 Indoor heat exchanger (heat exchanger)
20a 1st heat exchange part (block, 1st block)
20b 2nd heat exchange part (block)
20c 3rd heat exchange part (block, 2nd block)
51 Heat Transfer Tube 61 First Bent Part (Bent Part)
62 2nd bending part (bending part)
71 First pass
72 Second pass
73 3rd pass

Claims (10)

A heat exchanger comprising a plurality of blocks (20a, 20b, 20c) having different longitudinal angles with respect to a horizontal plane,
A heat transfer fin (4) disposed in the air stream;
A plurality of heat transfer tubes (51) inserted in the heat transfer fins and arranged in a direction substantially orthogonal to the flow direction of the airflow;
With
The heat transfer fin has a bent portion (61, 62) whose width is narrowed and bent,
The plurality of blocks are divided with the bent portion as a boundary,
The plurality of heat transfer tubes form a plurality of paths (71, 72, 73) through which the refrigerant can pass,
At least one of the plurality of paths includes a first block (20a) through which the airflow passes at a first wind speed and a second wind speed through which the airflow passes at a second wind speed slower than the first wind speed. Formed to pass through two blocks (20c),
Heat exchanger (20). The first wind speed is at least twice as fast as the second wind speed when the refrigerant condenses inside the heat transfer tube,
The heat exchanger (20) according to claim 1. The first wind speed is at least four times faster than the second wind speed when the refrigerant evaporates inside the heat transfer tube.
The heat exchanger (20) according to claim 1 or 2. There are three or more of the plurality of blocks.
The heat exchanger (20) according to any one of claims 1 to 3. The first block (20a) is at the top of the plurality of blocks,
The second block (20c) is at the bottom of the plurality of blocks.
The heat exchanger (20) according to claim 4. In the first block, the airflow flows the fastest, and in the second block, the airflow flows the slowest,
The heat exchanger (20) according to claim 4 or 5. The angle formed by the longitudinal direction of the second block with respect to the horizontal plane is 15 ° or less.
A heat exchanger (20) according to any of claims 4 to 6. When the refrigerant evaporates inside the heat transfer tube, the lower end of the second block comes into contact with condensed water.
A heat exchanger (20) according to any of claims 4 to 7. The plurality of paths has three or more paths.
A heat exchanger (20) according to any of the preceding claims. The flow direction of the airflow is a substantially horizontal direction.
A heat exchanger (20) according to any of the preceding claims.

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