JP4073850B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger including an auxiliary heat exchanger and a main heat exchanger.

  In recent years, with the progress of energy saving in air conditioners, there has been a demand for higher efficiency of heat exchangers used in air conditioners. As a configuration for realizing high efficiency of the heat exchanger, there is a heat exchanger provided with an auxiliary heat exchanger for supercooling and a main heat exchanger. A heat exchanger provided with a conventional auxiliary heat exchanger and a main heat exchanger is disclosed in, for example, Japanese Patent Publication No. 62-13574 (Patent Document 1). The heat exchanger disclosed in Patent Document 1 has the following configuration, for example.

  FIG. 11 is a side view showing one configuration of a conventional heat exchanger. FIG. 12 is a perspective view showing one configuration of a conventional heat exchanger.

  Referring to FIGS. 11 and 12, the heat exchanger 110 includes an auxiliary heat exchanger 110a and a main heat exchanger 110b. Then, air is fed into the heat exchanger 110 from the air flow direction 106 indicated by the arrow. With respect to the air flow direction 106, the auxiliary heat exchanger 110a is arranged in parallel with each other on the upstream side (left side in FIG. 11) and the main heat exchanger 110b is arranged on the downstream side (right side in FIG. 11). The auxiliary heat exchanger 110a includes a heat transfer tube 102a and a plurality of fins 101a for heat dissipation. The heat transfer tube 102 a is formed to extend in a meandering manner including the straight portion 109. The plurality of fins 101a are arranged in contact with the straight portion 109 of the heat transfer tube 102a so as to be substantially perpendicular. The main heat exchanger 110b has heat transfer tubes 102b and 102c and a plurality of fins 101b for heat dissipation, and has substantially the same configuration as the auxiliary heat exchanger 110a. Here, the diameter of the heat transfer tube 102a is smaller than the diameter of the heat transfer tubes 102b and 102c.

  When air is sent into such a heat exchanger 110, heat exchange is performed between the air and the refrigerant flowing through the heat transfer tubes 102a to 102c. For example, consider a case where a refrigerant that is a high-temperature gas is liquefied by cooling (when used as a condenser). In this case, in a state where air having a temperature lower than that of the refrigerant is sent in the flow direction 106, the refrigerant that is a high-temperature gas flows in through the inlet / outlet 107. The refrigerant that has flowed in is branched into two directions, the heat transfer tube 102b and the heat transfer tube 102c, at the branch portion 104, and is gradually liquefied by exchanging heat with air. When the refrigerant flowing through each of the heat transfer tubes 102b and 102c is liquefied and is in a gas-liquid two-phase state (a state where gas and liquid are mixed), the temperature and pressure of the refrigerant are kept constant. The gas-liquid two-phase refrigerant merges at the branch portion 103 and is supercooled under a constant pressure while flowing through the heat transfer tube 102a of the auxiliary heat exchanger 110a. As a result, a low-temperature liquid refrigerant flows out from the doorway 105.

  In the conventional heat exchanger 110 shown in FIGS. 11 and 12, the auxiliary heat exchanger 110a and the main heat exchanger 110b are separated. For this reason, when the heat exchanger 110 is used as a condenser, the auxiliary heat exchanger 110a filled with the low-temperature liquid refrigerant is separated from the main heat exchanger 110b, so the main heat exchanger 110b is kept at a high temperature. be able to. As a result, the temperature difference between the air and the heat exchanger increases, so that the heat exchange efficiency (condensation efficiency and evaporation efficiency) of the auxiliary heat exchanger 110a is improved. Further, the heat transfer tube 102a of the auxiliary heat exchanger 110a is constituted by a thin tube (a heat transfer tube having a small diameter). As a result, the flow rate of the liquid refrigerant flowing through the heat transfer tube 102a increases, and the liquid refrigerant flows in a state of being attached to the entire inner wall of the heat transfer tube 102a. As a result, the condensation efficiency of the auxiliary heat exchanger 110a is improved. Thus, the heat exchanger with which the heat exchanger tube was comprised by the thin tube is also disclosed by Unexamined-Japanese-Patent No. 2002-257383 (patent document 2), for example. The heat exchanger disclosed in Patent Document 2 has the following configuration, for example.

  FIG. 13 is a side view showing another configuration of the conventional heat exchanger.

  With reference to FIG. 13, the heat exchanger 120 includes an auxiliary heat exchanger 110a and a main heat exchanger 110b. The main heat exchanger 110b has heat transfer tubes 102d and 102e. Each of the heat transfer tubes 102d and 102e is configured by a thin tube, similar to the heat transfer tubes 102b and 102c of the auxiliary heat exchanger 110a.

  In addition, since the structure of those other than this is as substantially the same as the structure of one of the conventional heat exchangers shown in FIG. 11 and FIG. 12, the same code | symbol is attached | subjected about the same component and the description is abbreviate | omitted.

In the conventional heat exchanger 120 shown in FIG. 13, the heat transfer tubes 102d and 102e of the main heat exchanger 110b are also constituted by thin tubes. As a result, the flow rate of the gas-liquid two-phase refrigerant flowing through the heat transfer tubes 102d and 102e increases, and the liquid refrigerant flows while being stirred. As a result, the heat exchange efficiency of the main heat exchanger 110b is further improved.
Japanese Examined Patent Publication No. 62-13574 JP 2002-257383 A

  However, the heat exchanger 110 disclosed in Patent Document 1 and the heat exchanger 120 disclosed in Patent Document 2 have a problem that the pressure loss generated in the refrigerant flowing through the heat transfer tube 102a is large. Here, the pressure loss is a phenomenon in which the pressure on the downstream side decreases as compared with the upstream side when the fluid flows in the pipe. The pressure loss is inversely proportional to the size of the diameter of the tube through which the fluid flows, and is proportional to the distance through which the fluid flows, that is, the length of the tube through which the fluid flows. In the heat exchanger 110 and the heat exchanger 120, the heat transfer tube 102a of the auxiliary heat exchanger 110a is configured by a single heat transfer tube, and does not have a branch portion (the flow path is reduced). Therefore, the length of the heat transfer tube through which the refrigerant flows is long. Further, since the heat transfer tube 102a of the auxiliary heat exchanger 110a is a thin tube, the diameter of the tube is small. Therefore, the pressure loss generated in the refrigerant flowing through the heat transfer tube 102a is large.

  When the pressure loss generated in the refrigerant flowing through the heat transfer tube 102a is large, a problem arises particularly when the heat exchanger 110 and the heat exchanger 120 are used as an evaporator. That is, when the pressure loss generated in the refrigerant flowing through the heat transfer tube 102a is large, the upstream pressure in the refrigerant flow increases. As a result, the average temperature of the heat exchanger 110 is increased, and the temperature difference between the air and the heat exchanger 110 is reduced, so that the evaporation efficiency (heat exchange efficiency) of the heat exchanger 110 is reduced.

  Accordingly, an object of the present invention is to provide a heat exchanger with high heat exchange efficiency.

A heat exchanger according to one aspect of the present invention is a heat exchanger having a heat transfer tube for flowing a refrigerant, and when the heat exchanger is used as a condenser, the heat exchanger is located in a subcooling region on the downstream side. The diameter of the first heat transfer tube in the region where the liquid refrigerant flows is larger than the diameter of the second heat transfer tube, which is another heat transfer tube in the heat exchanger. Each of the first heat transfer tube and the second heat transfer tube is formed to extend in a meandering manner including a straight portion. The intervals between the straight portions in the first heat transfer tube are larger than the intervals between the straight portions in the second heat transfer tube.

According to the heat exchanger according to one aspect of the present invention, since the diameter of the heat transfer tube in the region where the mainly liquid refrigerant flows in the supercooling region is large, the region where the mainly liquid refrigerant flows in the supercooling region. Pressure loss of the refrigerant flowing through the heat transfer tube is suppressed. As a result, the pressure of the refrigerant flowing through the heat transfer tubes in the supercooling region where the liquid refrigerant mainly flows and the other heat transfer tubes in the heat exchanger can be kept constant. The temperature of the portion where the refrigerant in the gas-liquid two-layer state in the heat transfer tube flows can be kept constant. Therefore, a large temperature difference between the outside air and the heat transfer tube through which the gas-liquid two-layer refrigerant flows can be maintained, and the evaporation efficiency when the heat exchanger is used as an evaporator is increased. On the other hand, since the diameter of the other heat transfer tubes in the heat exchanger is small, when the heat exchanger is used as an evaporator and a condenser, a refrigerant in a gas-liquid two-phase state that flows through the other heat transfer tubes in the heat exchanger And the liquid refrigerant flows while being stirred. As a result, the evaporation efficiency and the condensation efficiency of the other heat transfer tubes in the heat exchanger are increased. For the above reasons, the heat exchange efficiency of the heat exchanger is increased. In addition, since the interval between the first heat transfer tubes is increased, the air flow from the flow direction of the outside air easily hits the second heat transfer tube through the gap between the meandering first heat transfer tubes. That is, the ventilation resistance on the first heat exchanger side decreases. Therefore, the heat exchange efficiency on the second heat exchanger side can be further improved.

A heat exchanger according to another aspect of the present invention is a heat exchanger having a heat transfer tube for flowing a refrigerant, and is located downstream of the auxiliary heat exchanger and the auxiliary heat exchanger with respect to the air flow direction. And a main heat exchanger to be arranged. The auxiliary heat exchanger has a first heat transfer tube for flowing the refrigerant, and the main heat exchanger has a second heat transfer tube connected to the first heat transfer tube. The diameter of the first heat transfer tube is larger than the diameter of the second heat transfer tube. Each of the first heat transfer tube and the second heat transfer tube is formed to extend in a meandering manner including a straight portion. The intervals between the straight portions in the first heat transfer tube are larger than the intervals between the straight portions in the second heat transfer tube.

According to the heat exchanger according to another aspect of the present invention, since the diameter of the first heat transfer tube is large, pressure loss of the refrigerant flowing through the first heat transfer tube is suppressed. As a result, since the pressure of the refrigerant flowing through the first heat transfer tube and the second heat transfer tube can be kept constant, the temperature of the main heat exchanger can be kept constant. Therefore, the temperature difference between the outside air and the main heat exchanger can be kept large, and the evaporation efficiency when the heat exchanger is used as an evaporator is increased. On the other hand, since the diameter of the second heat transfer tube is small, when the heat exchanger is used as an evaporator and a condenser, the flow rate of the gas-liquid two-phase refrigerant flowing through the second heat transfer tube increases, The refrigerant flows while being stirred. As a result, the evaporation efficiency and the condensation efficiency of the main heat exchanger are increased. For the above reasons, the heat exchange efficiency of the heat exchanger is increased. In addition, since the interval between the first heat transfer tubes is increased, the air flow from the flow direction of the outside air easily hits the second heat transfer tube through the gap between the meandering first heat transfer tubes. That is, the ventilation resistance of the auxiliary heat exchanger is reduced. Therefore, the heat exchange efficiency of the main heat exchanger can be further improved.

  In the present specification, the term “auxiliary heat exchanger” means a heat exchanger in a portion where a liquid refrigerant in the supercooling region flows when the heat exchanger is used as a condenser. The “main heat exchanger” means a heat exchanger in a portion where a gas-liquid two-phase refrigerant and a gas refrigerant flow when the heat exchanger is used as a condenser.

  Preferably, in the heat exchanger according to the present invention, the auxiliary heat exchanger further includes a plurality of first fins that contact the first heat transfer tube, and the main heat exchanger includes a plurality of contacts that contact the second heat transfer tube. It further has a second fin. The distance between the first fins is greater than the distance between the second fins.

  Thereby, the heat transfer area of each of the first heat transfer tube and the second heat transfer tube can be increased by each of the plurality of first fins and the plurality of second fins. Therefore, the heat exchange efficiency of the heat exchanger can be further improved. Moreover, since the space | interval of the some 1st fin of an auxiliary heat exchanger becomes wide, the airflow from the flow direction of external air passes through the clearance gap between the some 1st fin of an auxiliary heat exchanger, and the plurality of main heat exchangers. It becomes easy to hit the second fin. That is, the ventilation resistance of the auxiliary heat exchanger is reduced. Therefore, the heat exchange efficiency of the main heat exchanger can be further improved.

  Preferably, in the heat exchanger according to the present invention, the auxiliary heat exchanger further includes a plurality of first fins that contact the first heat transfer tube, and the main heat exchanger includes a plurality of contacts that contact the second heat transfer tube. It further has a second fin. The thickness of each of the first fins is thinner than the thickness of each of the second fins.

  Thereby, the heat transfer area of each of the first heat transfer tube and the second heat transfer tube can be increased by each of the plurality of first fins and the plurality of second fins. Therefore, the heat exchange efficiency of the heat exchanger can be further improved. Moreover, since it becomes easy to widen the space | interval of the some 1st fin of an auxiliary heat exchanger, the airflow from the flow direction of external air passes through the clearance gap between the some 1st fin of an auxiliary heat exchanger, and the main heat exchanger It becomes easy to hit the plurality of second fins. That is, the ventilation resistance of the auxiliary heat exchanger is reduced. Therefore, the heat exchange efficiency of the main heat exchanger can be further improved.

  Preferably, in the heat exchanger according to the present invention, the auxiliary heat exchanger further includes a plurality of first fins that contact the first heat transfer tube, and the main heat exchanger includes a plurality of contacts that contact the second heat transfer tube. It further has a second fin. The width of each of the first fins is larger than the width of each of the second fins.

  Thereby, the heat transfer area of each of the first heat transfer tube and the second heat transfer tube can be increased by each of the plurality of first fins and the plurality of second fins. Therefore, the heat exchange efficiency of the heat exchanger can be further improved. Moreover, since the heat transfer area of the 1st fin in an auxiliary heat exchanger becomes large, it can heat-exchange with more external air. As a result, the heat exchange efficiency of the auxiliary heat exchanger can be improved. In particular, when the heat exchanger is used as a condenser, a liquid refrigerant flows through the first heat transfer tube of the auxiliary heat exchanger. For this reason, the auxiliary heat exchanger has a lower heat exchange efficiency than the main heat exchanger in which the gas-liquid two-phase refrigerant flows. Therefore, particularly when the heat exchanger is used as a condenser, the heat exchange efficiency of the auxiliary heat exchanger can be greatly improved.

In the heat exchanger of the present invention, preferably, a plurality of grooves are formed in the tube of the first heat transfer tube.

Thereby, the refrigerant | coolant which flows through a 1st heat exchanger tube is stirred, and the convection of a refrigerant | coolant is accelerated | stimulated. Therefore, the heat exchange efficiency on the first heat exchanger side is further improved. Here, in the heat exchanger of the present invention , since the diameter of the first heat transfer tube is larger than the diameter of the second heat transfer tube, the diameter of the first heat transfer tube is reduced to increase the flow rate of the refrigerant. Thus, it is difficult to stir the refrigerant flowing through the first heat transfer tube. Therefore, instead of the method of increasing the flow rate of the refrigerant, the first heat transfer tube is configured so that the refrigerant flowing through the first heat transfer tube is turbulent, so that the heat exchange efficiency on the first heat exchanger side is increased. It is particularly effective in that it can be increased.

  Preferably, in the heat exchanger of the present invention, the auxiliary heat exchanger further includes a plurality of first fins that are in contact with the first heat transfer tube, and the main heat exchanger is in contact with the second heat transfer tube. It further has a plurality of second fins. Each of the first fins and each of the second fins are provided with undulations, and the number of undulations per unit area in each of the first fins is per unit area in each of the second fins. More than the number of undulations.

  Accordingly, since the number of undulations in the first fin increases, the airflow of the outside air passing through the surface of each of the first fins is disturbed by the undulations, and the surface of each of the first fins The outside air flows while entraining the outside air that exists in the part away from. As a result, the temperature difference between the outside air passing through the surface of each of the first fins and each of the first fins can be kept larger. Moreover, the heat-transfer area of a 1st fin increases because the number of undulation parts increases. Therefore, the heat exchange efficiency of the auxiliary heat exchanger can be further improved.

  Preferably, in the heat exchanger of the present invention, the number of paths through which the refrigerant flows in the first heat transfer tube is smaller than the number of paths through which the refrigerant flows in the second heat transfer tube.

  Thereby, since the branch part of the 1st heat exchanger tube decreases, it is suppressed that the flow rate of the refrigerant | coolant for every branched heat exchanger tube becomes uneven (it produces a drift). If the first heat transfer tube has fewer branches, the length of the first heat transfer tube becomes longer. However, since the diameter of the first heat transfer tube is large, the pressure loss of the refrigerant flowing through the first heat transfer tube Will not grow. For the above reasons, the refrigerant flow rate for each branched heat transfer tube is suppressed from becoming non-uniform while suppressing the pressure loss of the refrigerant in the first heat transfer tube.

  According to the heat exchanger of the present invention, since the diameter of the heat transfer tube in the region where mainly the liquid refrigerant flows in the supercooling region is large, it flows through the heat transfer tube in the region where mainly the liquid refrigerant flows in the supercooling region. The pressure loss of the refrigerant is suppressed. As a result, the pressure of the refrigerant flowing through the heat transfer tubes in the supercooling region where the liquid refrigerant mainly flows and the other heat transfer tubes in the heat exchanger can be kept constant. The temperature of the portion where the refrigerant in the gas-liquid two-layer state in the heat transfer tube flows can be kept constant. Therefore, a large temperature difference between the outside air and the heat transfer tube through which the gas-liquid two-layer refrigerant flows can be maintained, and the evaporation efficiency when the heat exchanger is used as an evaporator is increased. On the other hand, since the diameter of the other heat transfer tubes in the heat exchanger is small, when the heat exchanger is used as an evaporator and a condenser, a refrigerant in a gas-liquid two-phase state that flows through the other heat transfer tubes in the heat exchanger And the liquid refrigerant flows while being stirred. As a result, the evaporation efficiency and the condensation efficiency of the other heat transfer tubes in the heat exchanger are increased. For the above reasons, the heat exchange efficiency of the heat exchanger is increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a front view showing the configuration of the heat exchanger according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing the configuration of the heat exchanger according to Embodiment 1 of the present invention.

  With reference to FIG. 1 and FIG. 2, the heat exchanger 10 in this Embodiment is provided with the auxiliary | assistant heat exchanger 10a and the main heat exchanger 10b. Then, air is fed into the heat exchanger 10 from the air flow direction 6 indicated by the arrow. With respect to the air flow direction 6, the auxiliary heat exchanger 10a is arranged in parallel with each other on the upstream side (left side in FIG. 1) and the main heat exchanger 10b is arranged on the downstream side (right side in FIG. 1).

  The auxiliary heat exchanger 10a includes heat transfer tubes 2a and 2b (first heat transfer tubes) and a plurality of fins 1a (first fins). Each of the heat transfer tubes 2a, 2b is formed to extend in a meandering manner including the straight portions 13a, 13b, and the plurality of fins 1a are arranged at equal intervals. The respective straight portions of the heat transfer tubes 2a and 2b penetrate the plurality of fins 1a at substantially right angles, so that the heat transfer tubes 2a and 2b and the plurality of fins 1a are in contact with each other. The heat transfer tubes 2 a and 2 b are connected to the entrance / exit 5 by being joined at the branch portion 3 a.

  The main heat exchanger 10b has heat transfer tubes 2c to 2f (second heat transfer tubes) and a plurality of fins 1b (second fins). Each of the heat transfer tubes 2c to 2f is formed to extend in a meandering manner including a straight portion, and the plurality of fins 1b are arranged at equal intervals. Each of the straight portions of the heat transfer tubes 2c to 2f penetrates the plurality of fins 1b substantially at right angles, so that the heat transfer tubes 2c to 2f and the plurality of fins 1b are in contact with each other. The heat transfer tubes 2c and 2d are connected at the branch portion 3b and connected to the heat transfer tube 2a. Further, the heat transfer tubes 2c and 2d are joined at the branch portion 4a and connected to the connection tube 9a. The heat transfer tubes 2e and 2f are connected at the branch portion 3c and connected to the heat transfer tube 2b. Further, the heat transfer tubes 2e and 2f are coupled to each other at the branch portion 4b and connected to the connection tube 9b. The connecting pipes 9a and 9b are connected to the entrance / exit 7 by being joined at the branch portion 4c.

In the heat exchanger 10 of the present embodiment, the heat transfer tube 2a of the auxiliary heat exchanger 10a, each of the diameter D ₁ of the 2b, rather than each diameter D ₂ of the heat transfer tube 2c~2f of the main heat exchanger 10b large. Specifically, the heat transfer tube 2a, each of the diameter D ₁ of the 2b is 7mm for example, the diameter D ₂ of each of the heat transfer tube 2c~2f is 5mm example.

  Subsequently, the flow of the refrigerant in the heat exchanger 10 of the present embodiment will be described.

When the heat exchanger 10 is used as an evaporator of an air conditioner, first, a low-temperature liquid refrigerant flows in from the inlet / outlet 5 and splits in two directions of the heat transfer tube 2a and the heat transfer tube 2b at the branch portion 3a. To do. The liquid refrigerant exchanges heat with the air fed from the air flow direction 6 while flowing through each of the heat transfer tubes 2a and 2b. As a result, the temperature of the refrigerant rises and the refrigerant starts to evaporate. Here, the heat transfer tube 2a of the present embodiment, since each of the diameter D ₁ of the 2b is large, the pressure loss generated in the refrigerant flowing through the heat transfer tubes 2a, 2b is suppressed. Next, the gas-liquid two-phase refrigerant flows into each of the branch portions 3b and 3c of the main heat exchanger 10b through each of the heat transfer tubes 2a and 2b. The refrigerant flowing through the heat transfer tube 2a is further divided into two directions at the branch portion 3b, and flows through each of the heat transfer tubes 2c and 2d of the main heat exchanger 10b. Further, the refrigerant flowing through the heat transfer tube 2b is further divided into two directions at the branch portion 3c, and flows through each of the heat transfer tubes 2e and 2f of the main heat exchanger 10b. While flowing through each of the heat transfer tubes 2c to 2f, the refrigerant exchanges heat with the air fed from the air flow direction 6 to increase the gas ratio (advance the dryness). Here, when the refrigerant flowing through each of the heat transfer tubes 2c to 2f is in a gas-liquid two-phase state, the temperature and pressure of the refrigerant are kept constant. Thereafter, the refrigerant flowing through the heat transfer tubes 2c and 2d joins at the branch portion 4a of the main heat exchanger 10b and flows through the connection tube 9a. Moreover, the refrigerant | coolant which flows through the heat exchanger tubes 2e and 2f merges in the branch part 4b of the main heat exchanger 10b, and flows through the inside of the connection pipe 9b. And the refrigerant | coolant which flows through each of the connecting pipes 9a and 9b merges in the branch part 4c, and flows out from the entrance / exit 7 as high temperature gas.

On the other hand, when the heat exchanger 10 is used as a condenser of an air conditioner, first, a high-temperature gaseous refrigerant flows in from the inlet / outlet 7, and in two directions of the connecting pipe 9a and the connecting pipe 9b at the branching portion 4c. Divide into And a refrigerant | coolant flows in each of the branch parts 4a and 4b of the main heat exchanger 10b through each of the connection pipes 9a and 9b. The refrigerant flowing through the connection pipe 9a is further divided into two directions at the branch portion 4a, and flows through each of the heat transfer pipes 2c and 2d of the main heat exchanger 10b. The refrigerant flowing through the connection pipe 9b is further divided into two directions at the branch portion 4b and flows through the heat transfer pipes 2e and 2f of the main heat exchanger 10b. The refrigerant exchanges heat with air fed from the air flow direction 6 while flowing through each of the heat transfer tubes 2c to 2f. As a result, the temperature of the refrigerant decreases and the refrigerant gradually liquefies. Here, the temperature and the pressure of the refrigerant are kept constant during the gas-liquid two-phase state from when the refrigerant starts to liquefy until it completely liquefies. Further, since the diameter D ₂ of the heat transfer tube 2C～2f is small (consisting of tubules), increases the flow velocity of the refrigerant flowing through each of the heat transfer tube 2C～2f, refrigerant liquid to flow while being stirred . As a result, the heat exchange efficiency of the main heat exchanger 110b is high. Thereafter, the refrigerant flowing through each of the heat transfer tubes 2c and 2d merges at the branch portion 3b and flows into the heat transfer tube 2a of the auxiliary heat exchanger 10a. Moreover, the refrigerant | coolant which flows through each of the heat exchanger tubes 2e and 2f merges in the branch part 3c, and flows into the heat exchanger tube 2b of the auxiliary heat exchanger 10a. At this time, the refrigerant is almost liquid. The refrigerant flowing through each of the heat transfer tubes 2a and 2b of the auxiliary heat exchanger 10a is supercooled by exchanging heat with air fed from the air flow direction 6. The refrigerant flowing through each of the heat transfer tubes 2 a and 2 b merges at the branch portion 3 a, and a low-temperature liquid refrigerant flows out from the entrance / exit 5.

According to the heat exchanger 10 of the present embodiment, since the heat transfer tube 2a, a large diameter D ₁ of the 2b, the pressure loss of the refrigerant flowing through the heat transfer tubes 2a, 2b is suppressed. Thereby, since the pressure of the refrigerant flowing through the heat transfer tubes 2a and 2b and the heat transfer tubes 2c to 2f can be kept constant, the temperature of the main heat exchanger 10b can be kept constant. Accordingly, the temperature difference between the air and the main heat exchanger 10b can be kept large, and the evaporation efficiency when the heat exchanger 10 is used as an evaporator is increased. On the other hand, the diameter D ₂ of the heat transfer tube 2c~2f small, when using a heat exchanger 10 as an evaporator and condenser, the flow rate of refrigerant in the gas-liquid two-phase flow flowing in the heat transfer tube 2c~2f increased The liquid refrigerant flows while being stirred. As a result, the evaporation efficiency and the condensation efficiency of the main heat exchanger 10b are increased. For the above reasons, the heat exchange efficiency of the heat exchanger is increased.

  In the present embodiment, the case where the configuration of the heat exchanger is the configuration shown in FIG. 1 is shown, but the present invention is not limited to such a case, and the first of the auxiliary heat exchangers The diameter of the heat transfer tube should be larger than the diameter of the second heat exchanger of the main heat exchanger. Furthermore, when the heat exchanger is used as a condenser, the diameter of the heat transfer tube in the region where the liquid refrigerant mainly flows in the supercooling region on the downstream side should be larger than the diameter of the other heat transfer tubes in the heat exchanger. That's fine. In other words, any configuration may be used for the number and position of the branch portions, the shape of the pipes and fins of the heat transfer tubes, and the like.

(Embodiment 2)
FIG. 3 is a front view showing the configuration of the heat exchanger according to Embodiment 2 of the present invention. FIG. 4 (a) is a side view showing the configuration of the auxiliary heat exchanger according to Embodiment 2 of the present invention, and FIG. 4 (b) shows the configuration of the main heat exchanger according to Embodiment 2 of the present invention. FIG.

3 and 4 (a) and 4 (b), in heat exchanger 10 in the present embodiment, each of straight portions 13a of heat transfer tubes 2a and 2b extending in a meandering manner has a distance L ₁ . Arranged at intervals. Also, each of the straight portions 13b of the heat transfer tube 2c~2f extending in meandering shape, are arranged at intervals of a distance L _2. Here, the distance (distance L ₁ and distance L ₂ ) between the straight portions 13 a and 13 b is defined by a distance in a direction perpendicular to the air flow direction 6. That is, in FIGS. 4A and 4B, since the air flow direction 6 is a direction perpendicular to the paper surface, the distance between the straight portions 13a (distance L ₁ ) and the distance between the straight portions 13b. (Distance L ₂ ) is defined by the interval on the paper surface in each of the straight line portion 13a and the straight line portion 13b. Each interval (distance L ₁ ) of the straight line portions 13a is larger than each interval (distance L ₂ ) of the straight line portions 13b. That is, the distance L ₁ is 19 mm, for example, and the distance L ₂ is 17 mm, for example.

  Since the other configuration is substantially the same as the configuration of the first embodiment shown in FIGS. 1 and 2, the same components are denoted by the same reference numerals and the description thereof is omitted.

In heat exchanger 10 of the present embodiment, each of heat transfer tubes 2a and 2b and heat transfer tubes 2c to 2f is formed to extend in a meandering manner including straight portions 13a and 13b, and in heat transfer tubes 2a and 2b, Each interval (distance L ₁ ) of the linear portions 13a is larger than each interval (distance L ₂ ) of the linear portions 13b in the heat transfer tubes 2c to 2f.

  Thereby, since the space | interval of the heat exchanger tubes 2a and 2b of the auxiliary heat exchanger 10a becomes wide, the airflow from the air flow direction 6 passes through the clearance between the heat exchanger tubes 2a and 2b of the auxiliary heat exchanger 10a, and the main heat exchanger It becomes easy to hit the heat transfer tubes 2c to 2f of 10b. That is, the ventilation resistance of the auxiliary heat exchanger 10a is reduced. Therefore, the heat exchange efficiency of the main heat exchanger 10b can be further improved.

In addition, in this Embodiment, it showed about the case where the linear part 13a of the heat exchanger tubes 2a and 2b and the linear part 13b of the heat exchanger tubes 2c-2f are all arrange | positioned at equal intervals. However, the present invention is not limited to such a case, and the intervals between the straight portion 13a and the straight portion 13b may be partially different. In this case, it is only necessary that the distance L _{1 of the} portion with the narrowest interval among the straight portions 13a is larger than the distance L _{2 of the} portion with the widest intervals among the straight portions 13b.

(Embodiment 3)
FIG. 5 is a top plan view showing a partial configuration of the heat exchanger according to Embodiment 3 of the present invention. 6A is an enlarged view of a portion A in FIG. 5, and FIG. 6B is an enlarged view of a portion B in FIG.

Referring to FIG. 5, each of the plurality of fins 1 a in the auxiliary heat exchanger 10 a is arranged at equal intervals with a distance E ₁ . Each of the plurality of fins 1b in the main heat exchanger 10b is arranged at equal intervals of a distance E _2. The intervals (distance E ₁ ) between the plurality of fins 1a are larger than the intervals (distance E ₂ ) between the plurality of fins 1b. That is, the distance E ₁ is 1.49mm for example, the distance E ₂ is 1.15mm, for example.

Further, each of the plurality of fins 1a in the auxiliary heat exchanger 10a has a width P _1. Each of the plurality of fins 1b in the main heat exchanger 10b has a width P _2. Here, in the present specification, the width (length P ₁ ) of the plurality of fins _{1 a} and the width (length P ₂ ) of the plurality of fins ₁ b are the widths of the fins per one heat transfer tube (vertical in the figure). Length of direction). That is, each of the plurality of fins 1b are originally has a width P _3. In the plurality of fins 1b, two heat transfer tubes are arranged in the width direction. From the above, a plurality of fins 1b, each of the heat transfer tube 2c~2f is defined to have one-half the width of the width P _3, that is, the width P _2. The width P ₁ of each of the plurality of fins 1a is longer than the width P ₂ of each of the plurality of fins 1b. That is, the width P ₁ is, for example, 11 mm, and the width P ₂ is, for example, 10 mm.

Referring to FIGS. 6A and 6B, the thickness (thickness F ₁ ) of each of the plurality of fins 1a is smaller than the thickness (thickness F ₂ ) of each of the plurality of fins 1b. That is, the thickness F ₁ is 0.1 mm, for example, and the thickness F ₂ is 0.11 mm, for example.

  Since the other configuration is substantially the same as the configuration of the first embodiment shown in FIGS. 1 and 2, the same components are denoted by the same reference numerals and the description thereof is omitted.

In the heat exchanger 10 of the present embodiment, the auxiliary heat exchanger 10a further includes a plurality of fins 1a, and the main heat exchanger 10b further includes a plurality of fins 1b. The interval (distance E ₁ ) between each of the plurality of fins 1a is larger than the interval (distance E ₂ ) between each fin 1b.

  Thereby, the heat transfer area of each of the heat transfer tubes 2a and 2b and the heat transfer tubes 2c to 2f can be increased by each of the plurality of fins 1a and the plurality of fins 1b. Therefore, the heat exchange efficiency of the heat exchanger 10 can be further improved. Moreover, since the space | interval of the several fin 1a of the auxiliary heat exchanger 10a becomes wide, the airflow from the air flow direction 6 passes through the clearance gap between the several fin 1a of the auxiliary heat exchanger 10a, and the plurality of main heat exchangers 10b. It will be easier to hit the fins. That is, the ventilation resistance of the auxiliary heat exchanger 10a is reduced. Therefore, the heat exchange efficiency of the main heat exchanger 10b can be further improved.

In the heat exchanger 10 of the present embodiment, the thickness F ₁ of each of the plurality of fins 1a is thinner than the thickness F ₂ of each of the fins 1b.

  Thereby, since it becomes easy to widen the space | interval of the several fin 1a of the auxiliary heat exchanger 10a, the airflow from the air flow direction 6 passes through the clearance gap between the several fin 1a of the auxiliary heat exchanger 10a, and the main heat exchanger It becomes easy to hit the plurality of fins 10b. That is, the ventilation resistance of the auxiliary heat exchanger 10a is reduced. Therefore, the heat exchange efficiency of the main heat exchanger 10b can be further improved.

In the heat exchanger 10 of the present embodiment, the width P ₁ of each of the plurality of fins 1a is longer than the width P ₂ of each of the fins 1b.

  Thereby, since the heat transfer area of the fin 1a in the auxiliary heat exchanger 10a is increased, heat can be exchanged with more air. As a result, the heat exchange efficiency of the auxiliary heat exchanger 10a can be improved. In particular, when the heat exchanger 10 is used as a condenser, a liquid refrigerant flows through the heat transfer tubes 2a and 2b of the auxiliary heat exchanger 10a. For this reason, the heat exchange efficiency of the auxiliary heat exchanger 10a is lower than that of the main heat exchanger 10b in which the gas-liquid two-phase refrigerant flows. Therefore, particularly when the heat exchanger 10 is used as a condenser, the heat exchange efficiency of the auxiliary heat exchanger 10a can be greatly improved.

(Embodiment 4)
Fig.7 (a) is sectional drawing of the heat exchanger tube of the auxiliary heat exchanger in Embodiment 4 of this invention. FIG.7 (b) is sectional drawing of the heat exchanger tube of the main heat exchanger in Embodiment 4 of this invention.

7 (a) and 7 (b), in heat exchanger 10 of the present embodiment, a plurality of grooves 8a are formed in each of heat transfer tubes 2a and 2b. Groove 8a has a depth H _1. A plurality of grooves 8b are formed in each of the heat transfer tubes 2c to 2f. Groove 8b has a depth H _2. The depth H ₁ is 0.25 mm, for example, and the depth H ₂ is 0.15 mm, for example. Further, for example, 18 grooves 8a are formed in the circumferential direction, and 9 grooves 8a are formed in the circumferential direction, for example. As described above, when the grooves 8a and 8b having an appropriate depth, number, and shape are provided in each of the heat transfer tubes 2a to 2f, the flow of the refrigerant is disturbed by each of the grooves 8a and 8b, and the heat transfer tube 2a. 2b and the refrigerant flowing through each of the heat transfer tubes 2c to 2f are turbulent.

  Since the other configuration is substantially the same as the configuration of the first embodiment shown in FIGS. 1 and 2, the same components are denoted by the same reference numerals and the description thereof is omitted.

  In the heat exchanger of the present invention, preferably, the first heat transfer tube is configured so that the refrigerant flowing through the first heat transfer tube is turbulent.

Thereby, the refrigerant | coolant which flows through the heat exchanger tubes 2a and 2c is stirred, and the convection of a refrigerant | coolant is accelerated | stimulated. Therefore, the heat exchange efficiency of the auxiliary heat exchanger 10a is further improved. Here, in the heat exchanger of the present embodiment, the diameter D ₁ of the heat transfer tube 2a, 2b so larger than the diameter D ₂ of the heat transfer tube 2C～2f, reduced heat transfer tube 2a, the diameter D ₁ of the 2b It is difficult to stir the refrigerant flowing through the heat transfer tubes 2a and 2b by increasing the flow rate of the refrigerant. Therefore, instead of the method of increasing the flow rate of the refrigerant, the heat transfer tubes 2a and 2b are configured so that the refrigerant flowing through the heat transfer tubes 2a and 2b is turbulent, thereby improving the heat exchange efficiency of the auxiliary heat exchanger 10a. This is particularly effective in that it can be increased.

In the heat exchanger 10 of the present embodiment, an example of the depth H ₁ , number, and shape of the groove 8a is shown, but the present invention is limited to the depth, number, and shape of such a groove. The heat transfer tubes 2a and 2b may be configured so that the refrigerant flowing through the heat transfer tubes 2a and 2b is turbulent. Therefore, the groove 8a may have a cross-sectional shape such as a triangle or a semicircle. Moreover, the refrigerant | coolant which flows through the heat exchanger tubes 2c-2f does not need to be turbulent.

(Embodiment 5)
FIG. 8 is an enlarged front view schematically showing the configuration of the fin in the fifth embodiment of the present invention. FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. FIG. 9 shows only one fin among the plurality of fins.

  Referring to FIGS. 8 and 9, each of the plurality of fins 1 a of the auxiliary heat exchanger 10 a is formed with a convex portion 11 and a concave portion 12 (an undulating portion) having a planar shape close to a rectangle. The four convex portions 11 and the concave portions 12 are formed side by side in the width direction of the fin 1a (lateral direction in FIG. 8) so as to surround each of the heat transfer tubes 2a and 2b. Moreover, the convex part 11 and the recessed part 12 are formed also in each of the several fin 1b of the main heat exchanger 10b. The four protrusions 11 and the recesses 12 are formed side by side in the width direction of the fin 1b (lateral direction in FIG. 8) so as to surround each of the heat transfer tubes 2c to 2f. The number of protrusions 11 and recesses 12 per unit area in each fin 1a is larger than the number of protrusions 11 and recesses 12 per unit area in each fin 1b.

  Since the other configuration is substantially the same as the configuration of the first embodiment shown in FIGS. 1 and 2, the same components are denoted by the same reference numerals and the description thereof is omitted.

  In the heat exchanger 10 according to the present embodiment, each of the fins 1a and each of the fins 1b is provided with a convex part 11 and a concave part 12, and the convex part 11 and the concave part 12 per unit area in each of the fins 1a. Is greater than the number of convex portions 11 and concave portions 12 per unit area in each of the fins 1b.

  Thereby, since the number of the convex part 11 and the recessed part 12 in each of the fin 1a increases, the airflow of the external air which passes each surface of the fin 1a comes to be disturbed by the convex part 11 and the recessed part 12, and fin 1a The outside air flows while entraining the outside air existing in the part away from the surface of each. As a result, the temperature difference between the outside air passing through each surface of the fin 1a and each of the fins 1a can be kept larger. Moreover, the heat-transfer area of the fin 1a increases because the number of the convex parts 11 and the recessed parts 12 increases. Therefore, the heat exchange efficiency of the auxiliary heat exchanger 10a can be further improved.

  In the present embodiment, the case where the undulating portion has a shape such as the convex portion 11 and the concave portion 12 shown in FIGS. 8 and 9 is shown, but the present invention is not limited to such a case. The undulations provided on the first fin and the second fin may be used.

(Embodiment 6)
FIG. 10 is a side view showing the configuration of the heat exchanger according to Embodiment 6 of the present invention.

  Referring to FIG. 10, heat exchanger 30 in the present embodiment includes auxiliary heat exchanger 30a and main heat exchanger 10b. In the present embodiment, the configuration of the auxiliary heat exchanger 30a is different from the configuration of the auxiliary heat exchanger 10a of the first embodiment. That is, the auxiliary heat exchanger 30a includes a heat transfer tube 32 (first heat transfer tube) and a plurality of fins 1a. The heat transfer tube 32 is formed to extend in a meandering manner including a straight portion. The heat transfer tube 32 and the plurality of fins 1a are in contact with each other when the straight portion of the heat transfer tube 32 penetrates the plurality of fins 1a at a substantially right angle. The heat transfer tube 32 does not have a branch portion, one end of the heat transfer tube 32 is connected to the entrance / exit 5, and the other end of the heat transfer tube 32 is connected to the branch portion 33. The auxiliary heat exchanger 30a and the main heat exchanger 10b are connected by connecting pipes 9c and 9d. The connecting pipe 9c is connected to the branch portion 33 and the branch portion 3b of the main heat exchanger 10b. The connecting pipe 9d is connected to the branch portion 33 and the branch portion 3c of the main heat exchanger 10b.

  Since the other configuration is substantially the same as the configuration of the first embodiment shown in FIGS. 1 and 2, the same components are denoted by the same reference numerals and the description thereof is omitted.

  Subsequently, the flow of the refrigerant in the heat exchanger 30 of the present embodiment will be described.

  When the heat exchanger 30 is used as an evaporator of an air conditioner, first, a low-temperature liquid or a gas-liquid two-layer refrigerant flows from the inlet / outlet 5 and flows through the heat transfer tube 32. Since the heat transfer tube 32 does not have a branch portion, the refrigerant flows through one path without being divided. While the refrigerant flows through the heat transfer tube 32, the refrigerant exchanges heat with the air fed from the air flow direction 6. As a result, the temperature of the refrigerant rises and the refrigerant starts to evaporate. Then, the gas-liquid two-phase refrigerant flows into the branch portion 33 through the heat transfer tube 32. The refrigerant further splits in two directions at the branch portion 3b and flows into the branch portions 3b and 3c in the main heat exchanger 10b through the connection pipes 9c and 9d. Thereafter, the refrigerant flows through four paths of the heat transfer tubes 2c to 2f in the main heat exchanger 10b. Then, a low-temperature gas or a gas-liquid two-layer refrigerant flows out from the doorway 7.

  On the other hand, when the heat exchanger 10 is used as a condenser of an air conditioner, first, a high-temperature gaseous refrigerant flows from the inlet / outlet 7. The refrigerant that has flowed in joins at each of the branch portions 3b and 3c via the four paths of the heat transfer tubes 2c to 2f in the main heat exchanger 10b. At this time, the refrigerant is almost liquid. The refrigerant joined at the branch portion 3b flows through the connecting pipe 9c, and the refrigerant joined at the branch portion 3c flows through the connecting pipe 9d. And the refrigerant | coolant which flows through each of the connection pipes 9c and 9d merges in the branch part 33, and flows through the heat exchanger tube 32 of the auxiliary heat exchanger 10a. The refrigerant flowing through the heat transfer tubes 32 is supercooled by exchanging heat with the air fed from the air flow direction 6. Thereafter, the supercooled refrigerant flows out from the entrance 5.

In the present embodiment, there is only one path through which the refrigerant flows in the heat transfer tube 32 of the auxiliary heat exchanger 30a. On the other hand, the heat transfer tubes 2a and 2b of the auxiliary heat exchanger 10a of Embodiment 1 are branched into the heat transfer tube 2a and the heat transfer tube 2b at the branch portion 3a, so that there are two paths through which the refrigerant flows. Thus, if the number of paths through which the refrigerant flows decreases, the length of the heat transfer tube through which the refrigerant flows (distance through which the refrigerant flows) increases. However, in the heat exchanger 30 of this embodiment, the diameter D ₁ of the heat transfer tube 32 is greater than the diameter D ₂ of the heat transfer tube 2C～2f, pressure loss is not increased. On the other hand, a decrease in the number of paths through which the refrigerant flows means that the branching portion is reduced. If the branching portion is reduced, it is possible to prevent the flow rate of the branched refrigerant from becoming uneven when the refrigerant is diverted at the branching portion. Here, in order to make the flow rate of the branched refrigerant uniform, a method using a flow divider is also conceivable. However, the use of a shunt causes a problem that the device configuration is complicated. There is also a problem that pressure loss occurs in the refrigerant when the refrigerant flows through the shunt.

  In the heat exchanger 30 of the present embodiment, the number of paths through which the refrigerant flows in the heat transfer tubes 32 is smaller than the number of paths through which the refrigerant flows in the heat transfer tubes 2c to 2f.

Thereby, since the branched portion of the heat transfer tube 32 is eliminated, it is prevented that the flow rate of the refrigerant for each branched heat transfer tube becomes non-uniform (the occurrence of drift). If the branch portion of the heat transfer tube 32 is eliminated, the length of the heat transfer tube 32 is increased, but the diameter D ₁ of the heat transfer tube 32 is large, so that the pressure loss of the refrigerant flowing through the heat transfer tube 32 does not increase. For the above reasons, the refrigerant flow rate in the heat transfer tube 32 is prevented from becoming uneven while suppressing the pressure loss of the refrigerant in the heat transfer tube 32.

  In the present embodiment, there is one path through which refrigerant flows in the heat transfer tubes 32 of the auxiliary heat exchanger 30a, and there are four paths through which refrigerant flows in the heat transfer tubes 2c to 2f of the main heat exchanger 10b. Although the case has been shown, the present embodiment is not limited to such a case, and the number of paths through which the refrigerant flows in the first heat transfer tube of the auxiliary heat exchanger is the second heat transfer of the main heat exchanger. The number should be smaller than the number of paths through which the refrigerant flows in the heat pipe.

  Moreover, in this Embodiment, it branches to the connection pipes 9c and 9d by the branch part 33 from the one heat transfer pipe 32, and also the four heat transfer pipes 2c-2f by the branch parts 3b and 3c from the connection pipes 9c and 9d. The case of branching is shown. However, in this embodiment, in addition to such a case, for example, one heat transfer tube 32 may be branched into four heat transfer tubes 2c to 2f by one branch portion.

  The embodiment disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the scope of claims, and is intended to include all modifications and variations within the scope and meaning equivalent to the scope of claims.

It is a front view which shows the structure of the heat exchanger in Embodiment 1 of this invention. It is a perspective view which shows the structure of the heat exchanger in Embodiment 1 of this invention. It is a front view which shows the structure of the heat exchanger in Embodiment 2 of this invention. (A) It is a side view which shows the structure of the auxiliary heat exchanger in Embodiment 2 of this invention. (B) It is a side view which shows the structure of the main heat exchanger in Embodiment 2 of this invention. It is an upper top view which shows the structure of a part of heat exchanger in Embodiment 3 of this invention. (A) It is an enlarged view of the A section in FIG. (B) It is an enlarged view of the B section in FIG. (A) It is sectional drawing of the heat exchanger tube of the auxiliary heat exchanger in Embodiment 4 of this invention. (B) It is sectional drawing of the heat exchanger tube of the main heat exchanger in Embodiment 4 of this invention. It is a front enlarged view which shows typically the structure of the fin in Embodiment 5 of this invention. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. It is a side view which shows the structure of the heat exchanger in Embodiment 6 of this invention. It is a side view which shows one structure of the conventional heat exchanger. It is a perspective view which shows one structure of the conventional heat exchanger. It is a side view which shows the other structure of the conventional heat exchanger.

Explanation of symbols

  1a, 1b, 101a, 101b Fin, 2a-2f, 32, 102a-102e Heat transfer tube, 3a-3c, 4a-4c, 33, 103, 104 Branch part, 5, 7, 105, 107 Entrance / exit, 6,106 flow Direction, 8a, 8b groove, 9a, 9b, 9c, 9d connecting pipe, 10, 30, 110, 120 heat exchanger, 10a, 30a, 110a auxiliary heat exchanger, 10b, 110b main heat exchanger, 11 convex part, 12 Recess, 13a, 13b, 109 Straight line part.

Claims (8)

A heat exchanger having a heat transfer tube for flowing refrigerant,
When the heat exchanger is used as a condenser, the diameter of the first heat transfer tube in the region where the mainly liquid refrigerant flows in the subcooling region on the downstream side is the other heat transfer tube in the heat exchanger. larger than the diameter of the second heat transfer pipe is a heat pipe rather,
Each of the first heat transfer tube and the second heat transfer tube is formed to extend in a meandering manner including a straight portion,
The heat exchanger according to claim 1, wherein an interval between the linear portions in the first heat transfer tube is larger than an interval between the linear portions in the second heat transfer tube . A heat exchanger having a heat transfer tube for flowing refrigerant,
An auxiliary heat exchanger, and a main heat exchanger disposed downstream of the auxiliary heat exchanger with respect to the air flow direction,
The auxiliary heat exchanger has a first heat transfer tube for flowing the refrigerant,
The main heat exchanger has a second heat transfer tube connected to the first heat transfer tube,
The diameter of the first heat transfer tube is larger than the diameter of the second heat transfer tube,
Each of the first heat transfer tube and the second heat transfer tube is formed to extend in a meandering manner including a straight portion,
The heat exchanger according to claim 1, wherein an interval between the linear portions in the first heat transfer tube is larger than an interval between the linear portions in the second heat transfer tube. The auxiliary heat exchanger further includes a plurality of first fins in contact with the first heat transfer tube, and the main heat exchanger further includes a plurality of second fins in contact with the second heat transfer tube. Have
Wherein each of the distance between the first fin may be greater than the spacing of each of said second fin, the heat exchanger according to claim 2. The auxiliary heat exchanger further includes a plurality of first fins in contact with the first heat transfer tube, and the main heat exchanger further includes a plurality of second fins in contact with the second heat transfer tube. Have
The thickness of each of the first fin is characterized thinner than the thickness of each of said second fin, the heat exchanger according to claim 2 or 3. The auxiliary heat exchanger further includes a plurality of first fins in contact with the first heat transfer tube, and the main heat exchanger further includes a plurality of second fins in contact with the second heat transfer tube. Have
Wherein each of the width of the first fin, and greater than the width of each of said second fin, the heat exchanger according to any one of claims 2-4. The heat exchanger according to any one of claims 1 to 5 , wherein a plurality of grooves are formed in the tube of the first heat transfer tube . The auxiliary heat exchanger further includes a plurality of first fins in contact with the first heat transfer tube, and the main heat exchanger further includes a plurality of second fins in contact with the second heat transfer tube. Have
Each of the first fins and each of the second fins are provided with undulations, and the number of the undulations per unit area in each of the first fins is the number of the undulations of the second fins. The heat exchanger according to any one of claims 2 to 6 , wherein the number of the undulations per unit area in each is larger. The number of the refrigerant flow path in the first heat transfer tube is characterized by less than the number of the refrigerant flow path in the second heat transfer tube, according to claim 1 Heat exchanger.

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