ES2386733T3 - Heat exchanger for outdoor unit - Google Patents

Abstract

A heat exchanger (26) for an outdoor unit comprising: several refrigerant flow paths (26a to 26f) that are independent of each other and are arranged in multiple stages in a vertical direction; capillary tubes (64a to 64f) that are respectively connected to a terminal side of the various coolant flow paths; and a refrigerant flow distributor (65) with which the various capillary tubes are joined, in which the heat exchanger functions as a refrigerant condenser to condense the gaseous refrigerant flowing in from the other side of the various flow paths of the refrigerant and then discharge the liquid refrigerant through the capillary tubes and the refrigerant flow distributor from a terminal side of the various refrigerant flow paths, characterized in that a height (h1) from the lower end of the flow path of the refrigerant from the stage below the paths of the various refrigerant flow paths to the upper end of the refrigerant flow distributor is equal to or less than ¼ times a height (H) from the lower end of the refrigerant flow path of the step below the various coolant flow paths to the top end of the refrig flow path erante of the upper stage of the various coolant flow paths.

Description

Heat exchanger for outdoor unit

Technical field

The present invention relates to a heat exchanger for an outdoor unit and, in particular, to a heat exchanger for an outdoor unit having a structure in which a plurality of coolant flow paths are arranged, independent of each other, in multiple stages in the vertical direction and in which a terminal side of these various coolant flow paths is connected to a coolant flow distributor by means of capillary tubes.

Background Technique

The existence of an air conditioner in which an indoor unit and an outdoor unit are interconnected by means of communication tubes has been known for a long time. As the outdoor unit of said air conditioner, for example, there is an outdoor unit that has a structure (called a trunk-like structure) in which the interior space of a substantially rectangular parallelepiped-shaped housing is divided into a blower chamber and a machinery chamber by means of a dividing plate that extends in the vertical direction. A heat exchanger for an outdoor unit and an outdoor fan are mainly installed in the blower chamber (for example, see JPA-9-236284).

Likewise, JP-A-10-267469 discloses a heat exchanger having the distinctive characteristics defined in the preamble of claim 1.

Likewise, JP-A-9-145198 describes a refrigerant flow path having a horizontal U-shaped portion and a vertical U-shaped portion to standardize the refrigerant flow. The use of a helical portion for the purpose indicated is known from JP-A-9-292135.

Disclosure of the invention

Likewise, as a heat exchanger for an outdoor unit that is installed inside the blower chamber of the outdoor unit, there is a heat exchanger that has a structure in which several independent coolant flow paths are arranged in multiple stages in the vertical direction, with one terminal side of these various refrigerant flow paths connected to a refrigerant flow distributor by means of capillary tubes and the other terminal side being connected to a main distributor by means of communication tubes of the main distributor

When this heat exchanger of an outdoor unit is arranged to function as a refrigerant condenser, it presents the problem that a large amount of the liquid refrigerant ends up accumulating in the refrigerant flow path of the stage below and the degree Undercooling ends up becoming excessively charged.

On the other hand, in relation to the distribution of the refrigerant to each of the refrigerant flow paths in this heat exchanger for the outdoor unit, when the heat exchanger is arranged to function as a refrigerant evaporator, it is difficult for the refrigerant flows into the refrigerant flow path of the upper stage because of a level of the liquid from the refrigerant flow distributor to each of the refrigerant flow paths, so that it is necessary to control, by means of an adjustment, such as by lengthening the length of the capillary tube of the flow path of the refrigerant of the lower stage, the maldistribution of the refrigerant between the flow path of the refrigerant of the upper stage and the flow path of the refrigerant of the lower stage .

However, when such adjustment of the capillary tube is carried out, the problem that it is easier for the liquid refrigerant to accumulate in the refrigerant flow path of the lower stage and so that the degree of its cooling results excessively wide, it is further exacerbated when the heat exchanger of an outdoor unit is arranged to function as a refrigerant condenser.

It is an objective of the present invention to prevent, in a heat exchanger for an outdoor unit having the aforementioned structure, a situation in which the liquid refrigerant accumulates in the refrigerant flow path of the stage below and The degree of subcooling ends up becoming excessively pronounced when the heat exchanger is arranged to function as a refrigerant condenser.

This objective is solved by means of a heat exchanger according to what is defined in claim 1. Embodiments of the invention are specified in the dependent claims.

If the height of the lower end of the refrigerant flow path from the stage below the various refrigerant flow paths to the upper end of the refrigerant flow distributor is equal to or less than ¼ times the

height from the inner end of the refrigerant flow path of the stage below the various refrigerant flow paths to the upper end of the refrigerant flow path of the upper stage of the various refrigerant flow paths, the distance in height from the lower end of the refrigerant flow path from the lower stage to the upper end of the refrigerant flow distributor can be made smaller. In this way, it is easier for the refrigerant existing inside the refrigerant flow path of the lower stage to flow when the heat exchanger is arranged to function as a refrigerant condenser, so that it can be a situation in which the liquid refrigerant accumulates in the refrigerant flow path of the lower stage is avoided and the degree of subcooling ends up being excessively pronounced.

If the height from the lower end of the refrigerant flow path from the lower stage to the upper end of the lower stage the capillary tube is arranged to be equal to or less than ½ times the height from the lower end of the refrigerant flow path from the stage below the various refrigerant flow paths to the upper end of the refrigerant flow path of the upper stage. The refrigerant located inside the refrigerant flow path of the lower stage can even be arranged to flow more easily when the heat exchanger is arranged to function as a refrigerant condenser.

Preferably, a length of the capillary tube of the stage below is equal to or greater than 2/5 times a length of the capillary tube longer than the other capillary tubes excluding the capillary tube from the stage below.

If the length of the capillary tube below is set to be equal to or greater than 2/5 times the length of the longest capillary tube and when the heat exchanger is arranged to function as a refrigerant evaporator, the pressure loss of the refrigerant flowing from the distributor of the refrigerant flow into the refrigerant flow path of the lower stage through the capillary tube of the lower stage can be fixed as much as possible and the damn distribution of the refrigerant of the refrigerant flow path of the lower stage and of the other refrigerant flow paths.

If the capillary tube of the lower stage includes a horizontal U-shaped portion and a vertical U-shaped portion, the height distance from the lower end of the refrigerant flow path of the lower stage to the upper end of the refrigerant flow distributor can be made to be smaller. In this way, it is easier for the refrigerant located inside the refrigerant flow path of the lower stage to flow when the heat exchanger is arranged to function as a refrigerant condenser, so that it can be prevented a situation in which the liquid refrigerant accumulates within the flow path of the refrigerant of the stage below and the degree of subcooling ends up being excessively pronounced.

If the capillary tube of the lower stage includes a coil portion, the height distance from the lower end of the refrigerant flow path of the lower stage to the upper end of the refrigerant flow distributor may be arranged to Make it smaller. In this way, it is easier for the refrigerant located inside the refrigerant flow path of the lower stage to flow when the heat exchanger is arranged to function as a refrigerant condenser, so that it can be avoided a situation in which the liquid refrigerant accumulates in the refrigerant flow path of the lower stage and the degree of subcooling ends up being excessively pronounced.

Brief description of the drawings

FIG 1 is a general diagram of a refrigerant circuit of an air conditioner that includes an outdoor unit in which a heat exchanger is used for an outdoor unit belonging to an embodiment of the present invention.

FIG. 2 is a plan diagram of the outdoor unit (shown by suppressing the components of an upper plate and the refrigerant circuit).

FIG. 3 is a front diagram of the outdoor unit (shown with the suppression of the components of the left and right front plates and the refrigerant circuit.

FIG. 4 is a diagram showing an outdoor heat exchanger as seen from the front side of the outdoor unit.

FIG. 5 is a diagram that schematically shows the structure of the external heat exchanger.

FIG. 6 is a diagram showing an outdoor heat exchanger belonging to a modification 1 as seen from the front side of the outdoor unit.

FIG. 7 is a diagram showing an outdoor heat exchanger belonging to a modification 2 as seen from the front side of the outdoor unit.

Description of the reference symbols

26

External heat exchanger (Heat exchanger for the outdoor unit)

26a to 26f

Coolant flow paths

64a to 64f

Capillary tubes

65

Refrigerant flow distributor

Best way to carry out the invention

Next, a heat exchanger for an outdoor unit belonging to the present invention will be described on the basis of the drawings.

(1) Setting up a refrigerant circuit of an air conditioner

FIG. 1 is a general diagram of a refrigerant circuit of an air conditioner 1 that includes an outdoor unit 2 in which a heat exchanger is used for an outdoor unit belonging to an embodiment of the present invention. The air conditioner 1 is an air conditioner of the type called separate and is primarily arranged with the outdoor unit 2, an indoor unit 4, and a communication tube 5 of the liquid refrigerant and a communication tube 6 of the gas refrigerant that interconnect the outdoor unit 2 and indoor unit 4 and configures a circuit 10 of the vapor compression type refrigerant.

<Coolant circuit configuration of the indoor unit>

The indoor unit 4 is installed inside doors and is arranged with an inner circuit 10a of the refrigerant that configures part of the circuit 10 of the refrigerant. The internal refrigerant circuit 10a basically includes an internal heat exchanger 41.

The internal heat exchanger 41 comprises a heat exchanger of the type of tubes and transverse fins configured by heat transfer tubes and numerous fins, for example, and is a heat exchanger that functions as an evaporator of the refrigerant to cool the air indoor during the cooling operation and functions as a refrigerant condenser to heat the indoor air during the heating operation. A liquid side of the internal heat exchanger 41 is connected to the communication tube 5 of the liquid refrigerant and a gas side of the internal heat exchanger 41 is connected to the communication tube 6 of the gaseous refrigerant.

<Coolant circuit configuration of outdoor unit>

The outdoor unit 2 is installed from doors to the outside and is arranged with an outdoor circuit 10b of the refrigerant that configures part of the circuit 10 of the refrigerant. The external circuit 10b of the refrigerant basically includes a compressor 22, a four-way switching valve 24, an external heat exchanger 26, an expansion valve 28, a liquid shut-off valve 29, and a gas shut-off valve 31 . A suction orifice of the compressor 22 and the four-way switching valve 24 are interconnected by a suction tube 21. A discharge port of the compressor 22 and the four-way switching valve 24 are interconnected by a discharge tube 23. The four-way switching valve 24 and a gas side of the external heat exchanger 26 are interconnected by a first tube 25 of the gas refrigerant. The external heat exchanger 26 and the liquid shut-off valve 29 are interconnected by means of a tube 27 of the liquid refrigerant. Also, the expansion valve 28 is disposed within the tube 27 of the liquid refrigerant. Likewise, the liquid shut-off valve 29 is connected to the communication tube 5 of the liquid refrigerant. The four-way switching valve 24 and the gas shut-off valve 31 are interconnected by a second tube 30 of the gas refrigerant. Likewise, the gas shut-off valve 31 is connected to the gaseous refrigerant communication tube 6.

The compressor 22 is a positive displacement compressor that includes the function of suctioning the low pressure gaseous refrigerant from the suction tube 21, compressing the low pressure gaseous refrigerant by converting it into a high pressure gaseous refrigerant and then discharging the high pressure gaseous refrigerant inside the discharge tube 23.

The four-way switching valve 24 is a valve for switching the direction of refrigerant flow when switching between the cooling operation and the heating operation, such that during the cooling operation, the four-way switching valve 24 it is capable of interconnecting the discharge tube 23 and the first tube 25 of the gaseous refrigerant and, likewise, of interconnecting the tube 21 of

suction and the second tube 30 of the gas refrigerant, and in such a way that, during the heating operation, the four-way switching valve 24 is able to interconnect the discharge tube 23 and the second tube 30 of the gas refrigerant and, thus same, of interconnecting the suction tube 21 and the first tube 25 of the gaseous refrigerant.

The outdoor heat exchanger 26 is an exchanger that functions as a condenser of the refrigerant using the outside air as a source of heat during the cooling operation and functions as an evaporator of the refrigerant using the outside air as a source of heat during the heating operation .

The expansion valve 28 is an electrically energized expansion valve that is capable of depressurizing the high pressure liquid refrigerant that has been condensed inside the external heat exchanger 26 during the cooling operation before sending it to the internal heat exchanger 41 and depressurizing the high pressure liquid refrigerant that has been condensed inside the indoor heat exchanger 41 during the heating operation before sending it to the external heat exchanger 26.

The liquid shut-off valve 29 and the gas shut-off valve 31 and the three-way shut-off valves arranged with a service port that are capable of being communicated with the outside of the refrigerant circuit 10.

(2) Structure of the outdoor unit

Next, the structure of the outdoor unit 2 arranged with the outer circuit 10b of the refrigerant will be described with reference to FIG. 2 and FIG. 3. In this structure, FIG. 2 is a plan diagram of the outdoor unit 2 (shown by suppressing the components of the top plate 53 and the refrigerant circuit). FIG. 3 is a front diagram of the outdoor unit 2 (shown by suppressing the components of the left and right front plates 54 and 56 and the refrigerant circuit)

The outdoor unit 2 has a structure (called a trunk-like structure) in which the inside of a housing 51 of the substantially rectangular parallelepiped box shaped unit is divided into a chamber S1 of the blower and a chamber S2 of the machinery by a dividing plate 58 extending vertically, and the outdoor unit 2 is basically arranged with the housing 51 of the substantially rectangular box-shaped unit, the external heat exchanger 26, the external fans 32, the compressor 22, the components of the refrigerant circuit (see FIG. 1; these are not shown in FIG. 2 and in FIG. 3) which configure the external circuit 10b of the refrigerant together with the external heat exchanger 26 and the compressor 22, and a set of electrical components (not shown) carried out by the control of the operation of the outdoor unit 2.

<Unit housing>

The housing 51 of the unit is basically arranged with a bottom plate 52, a top plate 53, a left front plate 54, a right front plate 56, a right side plate 57, and the partition plate 58.

The bottom plate 52 is a plate-shaped member that is made of metal, has a substantially rectangular shape elongated horizontally, and configures the portion of the bottom surface of the housing 51 of the unit. The peripheral edge portion of the bottom plate 52 is bent upwards. Two fixed feet 59, fixed to an in situ installation surface, are arranged on the outer surface of the bottom plate 52. The fixed feet 59 are plate-shaped members that are made of U-shaped metal, when the Unit housing 51 is visible from the front, and extends from the front side to the rear side of the unit housing 51. The top plate 53 is a plate-shaped member that is made of metal, has a substantially rectangular shape elongated horizontally, and configures the upper surface portion of the outdoor unit 2. The left front plate 54 is a shape member of plate that is made of metal and basically configures the left front surface portion and the left side surface portion of the unit housing 51, and the lower portion of the left front plate 54 is fixed to the lower plate 52 by means of screws or similar elements. A suction opening 55a through which the air is sucked into the housing 51 of the unit by the external fans 32 is constituted in the left front plate 54. Also, an evacuation opening 54a to evacuate, towards outside the air that has been introduced inside from the side of the rear surface and from the side of the left side surface of the housing 51 of the unit by the external fans 32 is arranged in the left front plate

54. A fan grill 60 is disposed within the evacuation opening 54a.

The right front plate 56 is a plate-shaped member that is made of metal and basically configures the portion of the right front surface and the front portion of the right rear surface of the unit housing 51, and the lower portion of the Right front plate 56 is fixed to the bottom plate 52 by means of screws or similar elements. Likewise, the left terminal potion of the right front plate 56 is fixed to the right terminal portion of the left front plate 54 by means of screws or similar elements.

The right side plate 57 is a plate-shaped member that is made of metal and basically configures the rear portion of the right side surface and the portion of the right side surface of the housing 51 of the units, and the lower portion of the Right side plate 57 is fixed to the bottom plate 52 by means of screws or similar elements. Likewise, a suction opening 55b through which air is sucked into the

Inside the housing 51 of the unit by means of the outer fans 32, it is constituted between the rear terminal portion of the left front plate 54 and the terminal portion of the rear surface side of the right side plate 57 in the left-right direction.

The dividing plate 58 is a plate-shaped member that is made of metal, extends vertically, and is arranged on the bottom plate 52, and the dividing plate 58 is arranged to divide the space inside the housing 51 of the unit in two left and right spaces (that is, spaces S1 and S2). The lower potion of the dividing plate 58 is fixed to the bottom plate 52 by means of screws or similar elements. Likewise, the right terminal portion of the left front plate 54 is fixed to the front terminal portion of the partition plate 58 by means of screws or similar elements. Likewise, the terminal portion of the rear surface side of the right side plate 57 is fixed to a tubular plate 63 of the external heat exchanger 26, by means of screws or similar elements.

In this way, the interior space of the housing 51 of the unit is divided into the chamber S1 of the blower and the chamber S2 of the machinery by means of the partition plate 58. More specifically, the chamber S1 of the blower is a space closed by the bottom plate 52, the top plate 53, the left front plate 54 and the partition plate 58 and the external fans 32 and the external heat exchanger 26 are arranged inside the blower chamber S1. The chamber S2 of the machinery is a space closed by the bottom plate 52, the top plate 53, the right front plate 56, the right side plate 57 and the partition plate 58, and the compressor 22, the refrigerant circuit components and the whole of the electrical components are arranged inside the chamber S2 of the machinery. The housing 51 of the unit is configured in such a way that the interior of the chamber S2 of the machinery can be appreciated by removing the right front plate 56.

<Compressor>

The compressor 22 is a hermetic compressor that houses a motor 22a of the compressor (see FIG. 1) inside a housing and is disposed within the chamber S2 of the machinery. As the compressor motor 22a, a so-called reversal control type motor capable of frequency control is used. The compressor 22 has a vertical circular cylindrical shape with a height of approximately 1/3 to ½ the entire height of the unit housing 51, and the lower portion of the compressor 22 is fixed to the bottom plate 52. Likewise, when the housing 51 of the unit is seen in a plan view, the compressor 22 is arranged in the immediate vicinity of the center of the housing 51 of the unit in the front-rear direction.

<Outdoor fans>

The external fans 32 are propeller fans that include several vanes and are arranged on the front side of the external heat exchanger 26 within the blower chamber S1. In this embodiment there are two external fans 32 arranged vertically inside the blower chamber S1. Each of the outdoor fans 32 is configured to be driven to rotate by a motor 32a of the outdoor fans. When the external fans 32 are operated, the air is introduced through the suction openings 55a and 55b located on the rear surface and on the left side surface in the housing 51 of the unit and passes through the external heat exchanger 26 and the air is then evacuated out of the housing 51 of the unit from the evacuation opening 54a located on the front surface of the housing 51 of the unit.

<Coolant circuit components>

The components of the refrigerant circuit are basically parts that make up the external circuit 10b of the refrigerant (excluding the compressor 22 and the external heat exchanger 26) that include the suction tube 21, the discharge tube 23, the switching valve 24 four directions, the first tube 25 of the gas refrigerant, the tube 27 of the liquid refrigerant, the expansion valve 28, the valve 29 for closing the liquid, the second tube 30 for the gas refrigerant and the valve 31 for closing the gas). The components of the refrigerant circuit are basically arranged on the front side, the top side, the right transverse side and the rear side of the compressor 22 inside the chamber S2 of the machinery.

<Set of electrical components>

The assembly of the electrical components is arranged with various electrical components, such as an inverter panel and a control panel P which includes a microcomputer and similar elements for carrying out the operation control, and the assembly of the electrical components is arranged on the upper side of the compressor 22 and next to the dividing plate 58 located inside the chamber S2 of the machinery.

<External heat exchanger>

The main portion of the external heat exchanger 26 is disposed within the chamber S1 of the blower, and the external heat exchanger 26 performs the heat exchange with the air that has been introduced into the housing 51 of the unit by the fans exterior 32. The exterior heat exchanger 26 is substantially L-shaped when the housing 51 of the unit is seen in a plan view and is disposed of

shape that follows the left side surface to the rear surface of the unit housing 51. Likewise, the upper end of the external heat exchanger 26 extends to even the vicinity of the upper plate 53, and the lower end of the external heat exchanger 26 extends to even the bottom plate

52. Also, the tubular plate 63 is disposed on the right terminal portion of the external heat exchanger 26.

The detailed structure of the external heat exchanger 26 will now be described with reference to FIG. 4 and FIG. 5. In this embodiment, FIG. 4 is a diagram showing the outdoor heat exchanger 26 as seen from the front side of the outdoor unit 2. FIG. 5 is a diagram that schematically shows the structure of the external heat exchanger 26.

In the present embodiment, the external heat exchanger 26 comprises a tube and fin heat exchanger of the type of transverse fins and basically includes numerous fins 61 that are arranged at predetermined intervals to follow the left side surface to the rear surface of the housing 51 of the unit, numerous heat transfer tubes 62 that are fixed in a state in which these fins 61 penetrate in a thickness direction of the plate, and the tubular plate 63 that is fixed to the end portion on the side of the rear surface of the divider plate 58. In this exterior heat exchanger 26, the heat transfer tubes 62 are separated into six systems in the vertical direction, and these are a first coolant flow path 26a to a sixth 26f refrigerant flow path that are independent of each other. Likewise, a terminal side of each of the coolant flow paths 26a to 26f (here, the terminal portions become a coolant outlet flow side when the external heat exchanger 26 functions as a refrigerant condenser) respectively, it is connected to a refrigerant flow distributor 65 by means of a capillary tube 64a to a sixth capillary tube 64f, and the other terminal side of each of the refrigerant flow paths 26a to 26f (herein embodiment, the terminal portions that become one side of the refrigerant inlet flow when the external heat exchanger 26 functions as a refrigerant condenser) is respectively connected to a main manifold 67 by means of a first communication tube 66a from the main manifold to a sixth tube 66f of the manifold communication. That is, the first refrigerant flow path 26a to the sixth refrigerant flow path 26f are connected in parallel with each other by means of the refrigerant flow distributor 65 and by means of the main manifold 67; When the external heat exchanger 26 functions as a refrigerant condenser, all refrigerant flow paths function as refrigerant condensers, and when the external heat exchanger 26 functions as a refrigerant evaporator, all refrigerant flow paths work as refrigerant evaporators. It should be noted that these tube members 64a to 64f, 65, 66a to 66f and 67 are disposed within a space located on the side of the right side plate 57 of the tubular plate 63 - that is, in a space located within the chamber S2 of the machinery surrounded by a tubular plate 63 and the right side plate 57.

The main manifold 67 is a tubular member extending from the first refrigerant flow path 26a to the sixth refrigerant flow path 62f of the external heat exchanger 26, and the terminal portion of the main manifold 67 is connected to the first tube 25 of the gaseous refrigerant. Each of the communication tubes 66a to 66f of the main manifold is a tubular member that extends to the main manifold 67 from the other end side of each of the tracks 26a to 26f of the refrigerant flow.

The refrigerant flow distributor 65 is a tubular member that causes the first to the sixth capillary tubes 64a to 64f that are connected to one of the end sides of each of the tracks 26a to 26f of the refrigerant flow so that they join, and the refrigerant flow distributor 65 basically includes a flow distributor body 65a and a nozzle portion 65b. The body 65a of the flow distributor is a substantially cylindrical portion being the first to sixth capillary tubes 64a to 64f connected to its upper end and the nozzle portion 65b constituted at its lower end being constituted. The nozzle portion 65b is a U-shaped tubular member through which the refrigerant flows after the refrigerant has joined with the body 65a of the flow distributor, and the terminal portion of the nozzle portion 65b is connected to the tube 27 of the liquid refrigerant.

The first capillary tube 64a extends downwardly from a terminal side of the first coolant flow path 26a, then reversed and extended upwards, then again reversed and extended downward and connected to the upper end of the body 65a of the flow distributor. The second capillary tube 64b of the capillary tube extends upwardly from a terminal side of the second coolant flow path 26b, then inverted and extended downwardly and is connected to the upper end of the body 65a of the flow distributor. The third capillary tube 64c extends upwardly from a terminal side of the third flow path 26c of the refrigerant, then reverses and extends downward, and is connected to the upper end of the body 65a of the flow distributor. The fourth capillary tube 64d extends upwardly from a terminal side of the fourth flow path 26d of the refrigerant, then reverses and extends downward, and is connected to the upper end of the body 65a of the flow distributor. The fifth capillary tube 64e extends upwardly from a terminal side of the fifth coolant flow path 26e, then reverses and extends downward, and is connected to the upper end of the body 65a of the flow distributor. Within the sixth capillary tube 64f, serving as a capillary tube of the lower stage, a horizontal U-shaped portion 68 is formed that has a shape extending upwardly from a terminal side of the sixth flow path 26f of the refrigerant, then extends in a horizontal direction and then reverses, and a vertical portion 69

U-shaped, which has a shape that extends in the vertical direction and then reverses, is shaped after the horizontal U-shaped portion 68. In the present embodiment, the U-shaped horizontal portion 68 extends in the direction of the right side surface of the unit housing 51. Thus, because the horizontal U-shaped portion 68 and the U-shaped vertical portion 69 are formed within the sixth capillary tube 64f, the height distance from the lower end of the sixth coolant flow path 62f , which serves as the refrigerant flow path from the stage below to the upper end of the refrigerant flow distributor 65, can be arranged to be smaller. In the present embodiment, a height h1 from the lower end of the sixth refrigerant flow path 26f that serves as the refrigerant flow path from the lower stage to the upper end of the distributor 65 of the refrigerant flow, It is equal to or less than ¼ times a height H from the lower end of the sixth refrigerant flow path 26f to the upper end of the first refrigerant flow path 26a, which serves as the refrigerant flow path of the upper stage. Likewise, a height h2 from the lower end of the sixth refrigerant flow path 26f to the end above the sixth capillary tube 64f is equal to or less than ½ times the height H. Also, a length L6 of the sixth tube capillary 64f is equal to or greater than 2/5 times a length Lx of the longer capillary tube of the other capillary tubes 64a to 64e excluding the sixth capillary tube 64f.

(3) Operation of the outdoor unit

Next, the operation of the outdoor unit 2 which includes the outdoor heat exchanger 26 will be described.

First, the operation of the outdoor unit 2 during the cooling operation and during the heating operation will be described.

During the cooling operation, the four-way switching valve 24 of the refrigerant circuit 10 is in the state indicated by the solid lines provided in FIG. 1, that is, the state in which the discharge tube 23 is connected to the first tube 25 of the gaseous refrigerant and in which the suction tube 21 is connected to the second tube 30 of the gaseous refrigerant. Also, the liquid shut-off valve 29 and the gas shut-off valve 31 are open, and the opening of the expansion valve 28 is adjusted to depressurize the refrigerant.

The operation of the external fans 32 and the compressor 22 is carried out in this state of the refrigerant circuit 10. Next, due to the operation of the outer fans 32, an outside air flow is constituted so that the outside air is introduced into the housing 51 of the unit from the suction openings 55a and 55b arranged on the left side surface and in The rear surface of the unit housing 51 is used as a heat source as a result of passage through the external heat exchanger 26, and is evacuated from the evacuation opening 54a located on the front surface of the housing 51 of the unity. Likewise, due to the operation of the compressor 22, the low-pressure gaseous refrigerant is sucked into the compressor 22 through the suction tube 21, it is compressed to constitute the high-pressure gaseous refrigerant and is then discharged into of the discharge tube 23.

The high pressure gas refrigerant that has been discharged into the discharge tube 23 is sent to the external heat exchanger 26 through the four-way switching valve 24 and the first tube 25 of the gas refrigerant is cooled and condensed by the exchange of heat with the outside air, becoming high-pressure liquid refrigerant and is sent to tube 27 of the liquid refrigerant. More specifically, the high-pressure gaseous refrigerant flowing through the interior of the main manifold 67 from the first tube 25 of the gaseous refrigerant is distributed to each of the tracks 26a to 26f of the flow of the refrigerant of the external heat exchanger 26 through of the 66a to 66f communication pipes of the main manifold. Next, this high-pressure gaseous refrigerant is cooled and condensed by the heat exchange with the outside air existing within each of the flow paths 26a to 26f of the refrigerant, it becomes a high-pressure liquid refrigerant, it joins with the distributor 65 of refrigerant flow through the capillary tubes 64a to 64f, and is sent to the tube 27 of the liquid refrigerant.

In the present embodiment, in accordance with the aforementioned, the horizontal U-shaped portion 68 and the U-shaped vertical portion 69 are formed within the sixth capillary tube 64f, such that the height h1 from the end lower of the sixth refrigerant flow path 26f, which serves as the refrigerant flow path from the lower stage to the upper end of the distributor 65 of the refrigerant flow, is smaller (specifically, equal to or less than ¼ times the height H), so that it is easier for the refrigerant to flow into the refrigerant flow path of the lower stage. For this reason, a situation can be prevented in which the liquid refrigerant accumulates in the sixth path 26a of the refrigerant flow and the degree of subcooling becomes excessively pronounced. Likewise, the height h2 from the lower end of the sixth refrigerant flow path 26f to the upper end of the sixth capillary tube 64f is equal to or less than ½ times the height H, so that it is even easier for the refrigerant to flow located within the refrigerant flow path of the stage below.

Next, the high pressure liquid refrigerant that has been sent to the tube 27 of the liquid refrigerant is depressurized inside the expansion valve 28, it becomes the refrigerant in a two-phase state

gas - low pressure liquid, and is sent to the internal heat exchanger 41 through the liquid refrigerant tube 27, the liquid shutoff valve 29 and the liquid refrigerant communication tube 5. The refrigerant, in the two-phase state - gas - low pressure liquid that has been sent to the indoor heat exchanger 41 is heated and evaporated by the heat exchange with the indoor air, it becomes a low pressure gas refrigerant, it is returned to the suction tube 21 through the gas refrigerant communication tube 6, the gas shut-off valve 31, the second gas refrigerant tube 30 and the four-way switching valve 24, and is again suctioned to the inside of the compressor 22.

Then, during the heating operation, the four-way switching valve 24 of the refrigerant circuit 10 is in the state indicated by the dotted lines in FIG. 1, that is, a state in which the discharge tube 23 is connected to the second tube 30 of the gaseous refrigerant and in which the suction tube 21 is connected to the first tube 25 of the gaseous refrigerant. Also, the liquid shut-off valve 29 and the gas shut-off valve 31 are open, and the opening of the expansion valve 28 is adjusted to depressurize the refrigerant.

The operation of the external fans 32 and the compressor 22 is carried out in this state of the refrigerant circuit 10. Then, due to the operation of the external fans 32, an outside air flow is formed when the outside air is introduced into the housing 51 of the unit from the existing suction openings 55a and 55b on the left side surface and on the surface rear of the unit housing 51, is used as a heat source as a result of its passage through the external heat exchanger 26, and is evacuated from the evacuation opening 54a on the front surface of the unit housing 51 . Likewise, due to the operation of the compressor 22, the low pressure gaseous refrigerant is sucked into the compressor 22 through the suction tube 21, it is compressed until it becomes the high pressure gaseous refrigerant and is then discharged. inside the discharge tube 23. The high pressure gaseous refrigerant that has been discharged into the discharge tube 23 is sent to the indoor heat exchanger 41 through the four-way switching valve 24, of the second tube 30 of the gaseous refrigerant, of the shut-off valve 31 of the gas and the communication tube 6 of the gaseous refrigerant, it is cooled and condensed by exchanging heat with the indoor air, it becomes the high pressure liquid refrigerant and is sent to the expansion valve 28 through the tube 5 of communication of the liquid refrigerant, of the liquid shut-off valve 29 and of the tube 27 of the liquid refrigerant. The high pressure liquid refrigerant that has been sent to the expansion valve 28 is depressurized in the expansion valve 28, the refrigerant becoming a two-phase gaseous-liquid low-pressure state, and is sent to the heat exchanger 26 outside through the tube 27 of the liquid refrigerant. The refrigerant in the two-phase gaseous-liquid low-pressure state that has been sent to the external heat exchanger 26 is heated and evaporated by the heat exchange with the outside air, it becomes the low-pressure gaseous refrigerant, and is sent to the first tube 25 of the gaseous refrigerant. More specifically, the refrigerant in the two-phase gas-liquid low-pressure state, which flows into the distributor 65 of the flow of the refrigerant from the tube 27 of the liquid refrigerant is distributed to each of the channels 26a to 26f of coolant flow of the external heat exchanger 26 through the capillary tubes 64a to 64f. Next, the refrigerant in the two-phase gaseous-liquid low-pressure state is heated and evaporated by the heat exchange with the external air existing within each of the coolant flow paths 26a to 26f, becomes the Low pressure gaseous refrigerant, is attached within the main manifold 67 through the communication pipes 66a to 66f of the main manifold, and is sent to the first tube 25 of the gaseous refrigerant.

In the present specification, in accordance with the aforementioned, the length L6 of the sixth capillary tube 64f is equal to or greater than 2/5 times the length Lx of the longer capillary tube of the other capillary tubes 64a to 64e, so that the loss of pressure of the refrigerant flowing from the refrigerant flow distributor 65 to the interior of the sixth refrigerant flow path 26f through the sixth capillary tube 64f can be ensured to the greatest extent possible and the damn distribution can be controlled of the refrigerant between the sixth refrigerant flow path 26f and the other refrigerant flow routes 26a to 26e. That is, a structure is implemented in which, in consideration of the moment in which the heat exchanger 26 is arranged to function as an evaporator of the refrigerant, the length of the sixth capillary tube 64f is secured and, in consideration of the At which time the external heat exchanger 26 is arranged to function as a refrigerant condenser, the height h1 of the refrigerant flow distributor 65 is arranged to be smaller.

Next, the low pressure gaseous refrigerant that has been sent to the first tube 25 of the gaseous refrigerant is returned to the suction tube 21 through the four-way switching valve 24 and is again suctioned into the compressor 22.

(4) Characteristics of the external heat exchanger

The external heat exchanger 26 of the present embodiment has the following characteristics:

(A) In the external heat exchanger 26 of the present embodiment, the sixth capillary tube 64f serving as the capillary tube of the lower stage includes the horizontal U-shaped portion 68 and the vertical shaped portion 69 of U, so that it can be made smaller

distance in height from the lower end of the sixth track 26f of the refrigerant flow which serves as the refrigerant flow path from the stage below to the upper end of the refrigerant flow distributor 65. In this way, it is easier for the refrigerant to flow into the sixth refrigerant flow path 26f, when the external heat exchanger 26 is arranged to function as a refrigerant condenser, so that a situation in which that the liquid refrigerant accumulates within the sixth refrigerant flow path 26f and that the degree of subcooling ends up becoming excessively pronounced.

(B)

Likewise, the height h2 from the lower end of the sixth refrigerant flow path 26f to the upper end of the sixth capillary tube 64f is arranged to be equal to or less than ½ times the height H from the lower end of the sixth path 26f of refrigerant flow to the upper end of the first refrigerant flow path 26a, so that it can be achieved that the refrigerant within the sixth refrigerant flow path 26f can flow even easier when the exchanger 26 of Outside heat is arranged to function as a refrigerant condenser.

(C)

Likewise, the length L6 of the sixth capillary tube 64f is arranged to be equal to or greater than 2/5 times the length Lx of the longer capillary tube, so that when the external heat exchanger 26 is arranged to function as a refrigerant evaporator, can ensure as much as possible the loss of refrigerant pressure flowing from the refrigerant flow distributor 65 into the sixth refrigerant flow path 26f through the sixth capillary tube 64f and can be Controlled the refrigerant distribution between the sixth refrigerant flow path 26f and the other refrigerant flow channels 26a to 26e.

(5) Modification 1

In the preceding embodiment (see FIG. 4 and FIG. 5), the height distance from the lower end of the sixth refrigerant flow path 26f serving as the refrigerant flow path of the stage of further down to the upper end of the coolant flow distributor 65 was arranged to be smaller by forming the horizontal U-shaped portion 68 and the U-shaped vertical portion 69 within the sixth capillary tube 64f, but such and as shown in FIG. 6, instead of the horizontal U-shaped portion 68 and the U-shaped vertical portion 69, a coil portion 70 having a configuration formed by winding part of the sixth capillary tube 64f, can be constituted to achieve thereby, the height h1 from the lower end of the sixth refrigerant flow path 26f to the upper end of the refrigerant flow distributor 65 is equal to or less than ¼ times the height H from the lower end of the sixth path 26f of coolant flow to the upper end of the first coolant flow path 26a which serves as the coolant flow path of the stage above.

In this case, likewise, basically the same effects are obtained as those obtained in the preceding embodiment. Also, in the present modification, the length L6 of the sixth capillary tube 64f can be modified by adjusting the number of windings of the coil portion 70, so that it is easy to achieve that the length L6 is equal to or greater than 2 / 5 times the length Lx of the longer capillary tube, and, likewise, it is possible, for example, to achieve that the length L6 is the same length as the length Lx of the longer capillary tube. Thus, when the external heat exchanger 26 is arranged to function as a refrigerant evaporator, the effect of ensuring, to the greatest extent possible, the loss of pressure of the flowing refrigerant can be further improved. from the refrigerant flow distributor 65 to the interior of the sixth refrigerant flow path 26f through the sixth capillary tube 64f and control the refrigerant distribution between the sixth refrigerant flow path 26f and the other routes 26a to 26e of coolant flow

(6) Modification 2

In the preceding embodiment and in modification 1 (see FIG. 4 to FIG. 6), the height distance from the lower end of the sixth refrigerant flow path 26f which serves as the refrigerant flow path from the lower stage to the upper end of the refrigerant flow distributor 65, it was arranged to be smaller by forming the U-shaped horizontal portion 68 and the U-shaped vertical portion 69 or by forming the portion 70 of coil inside upper capillary tube 64f, but, as shown in FIG. 7, the height h1 from the lower end of the sixth refrigerant flow path 26f to the upper end of the refrigerant flow distributor 65 can also be made equal to or less than ¼ times the height H from the lower end from the sixth refrigerant flow path 26f to the upper end of the first refrigerant flow path 26a which serves as the refrigerant flow path of the upper stage without arranging the U-shaped horizontal portion 68.

In this case, the height h2 from the lower end of the sixth refrigerant flow path 26f to the upper end of the sixth capillary tube 64f is greater than the height h2 of the preceding embodiment and the preceding modification 1, so that the effect of making it easier for the existing coolant to flow into the sixth coolant flow path 26f is somewhat smaller, but basically effects are obtained that are the same as those obtained with respect to the preceding embodiment and Modification 1. Likewise, insofar as a situation in which the height h2 of the present modification can be allowed up to a certain point greater than the height h2 of the preceding embodiment is permitted, it is also possible to make the length L6 of the sixth capillary tube 64f is equal to or greater than 2/5 times the length Lx of the longest capillary tube; in this way, similar to the preceding embodiment and modification 1, when the

5 external heat exchanger 26 is arranged to function as a refrigerant evaporator, the effects of ensuring, to the greatest extent possible, the loss of refrigerant pressure flowing from the refrigerant flow distributor 65 can be obtained as much as possible. , to the interior of the sixth refrigerant flow path 26f through the sixth capillary tube 64f and the control of the refrigerant maldistribution between the sixth path 26f of the refrigerant flow and the other routes 26a to 26e of refrigerant flow.

10 (7) Other embodiments

The embodiments of the present invention have been described in the previous lines on the basis of the drawings, but the basic configuration is not limited to these embodiments and can be altered within a limit that does not deviate from the essentials of the invention.

For example, in the preceding embodiment in which horizontal portion 68 with U-shape and vertical portion

U-shaped 69 were formed within the sixth capillary tube 64f, were shaped as a single horizontal U-shaped portion 68 and a single U-shaped vertical portion 69, but the invention is not limited thereto, and the portion U-shaped horizontal 68 and U-shaped vertical portion 69 may also be formed into a plurality of portions.

Likewise, the invention may also have a configuration in which the embodiment and the

20 modification 1 above are combined - that is, in which the U-shaped horizontal portion 68, the U-shaped vertical portion 69 and the coil-shaped portion 70 are disposed within the sixth capillary tube 64f.

Industrial applicability

By using the present invention, it can be avoided, in a heat exchanger for an outdoor unit that has a structure in which various coolant flow paths independent of each other are

25 arranged in multiple stages in the vertical direction and in which one end of each of these various coolant flow paths is connected to a coolant flow distributor through a capillary tube, a situation in which the liquid refrigerant is accumulate within the refrigerant flow path of the stage below and in which the degree of subcooling ends up being excessively pronounced when the heat exchanger is arranged to function as a refrigerant condenser.

Claims (5)

1. A heat exchanger (26) for an outdoor unit comprising: several coolant flow paths (26a to 26f) that are independent of each other and are arranged in multiple stages in a vertical direction; capillary tubes (64a to 64f) that are respectively connected to a terminal side of the various coolant flow paths; Y a refrigerant flow distributor (65) with which the various capillary tubes are joined, in which The heat exchanger functions as a refrigerant condenser to condense the gaseous refrigerant flowing in from the other side of the various coolant flow paths and then discharge the liquid refrigerant through the capillary tubes and the distributor of coolant flow from a terminal side of the various coolant flow paths, characterized in that a height (h1) from the lower end of the refrigerant flow path of the stage below the paths of the various refrigerant flow paths to the upper end of the refrigerant flow distributor is equal to or less than 1/4 times a height (H) from the lower end of the refrigerant flow path of the stage below the various refrigerant flow paths to the upper end of the refrigerant flow path of the upper stage of the various paths of the coolant flow 2. The heat exchanger (26) for an outdoor unit of claim 1, wherein a height (h2) from the lower end of the refrigerant flow path of the stage below the various tracks (26a at 26f) coolant flow to the upper end of the capillary tube (64f) of the lower stage is equal to or less than ½ times a height (h) from the lower end of the coolant flow path of the stage of below the various coolant flow paths to the upper end of the coolant flow path of the upper stage. 3. The heat exchanger (26) for an outdoor unit of claims 1 or 2, wherein a length (L6) of the capillary tube (64f) of the lower stage is equal to or greater than 2/5 times a length (lx) of the longer capillary tube of the other capillary tubes (64a to 64e) excluding the capillary tube from the stage below. 4. The heat exchanger (26) for an outdoor unit according to any one of claims 1 to 3, wherein: The capillary tube (64f) of the lower stage which is the capillary tube connected to the refrigerant flow path of the stage below the various refrigerant paths includes a horizontal portion (68) U-shaped having a shape that extends in a horizontal direction and then reverses and a U-shaped vertical portion (69) that has a shape that extends in the vertical direction and, to Then it is reversed. 5. The heat exchanger (26) for an outdoor unit according to any one of claims 1 to 3, wherein: The capillary tube (64f) of the lower stage which is the capillary tube connected to the refrigerant flow path of the stage below the various refrigerant flow paths includes a portion (70) of coil which has a rolled form.