Heat exchanger and air conditioning device

Abstract

This heat exchanger is provided with: a plurality of heat transfer pipes arranged vertically at an interval; a first distributor that is formed so as to extend vertically and distributes a refrigerant to the plurality of heat transfer pipes. The first distributor has: an insertion surface part through which the plurality of heat transfer pipes are inserted; an opposite surface part that is opposite to the insertion surface part in a direction in which the plurality of heat transfer pipes extend; a lateral surface part that is a wall extending between the insertion surface part and the opposite surface part in an axially-perpendicular cross-section, being a perpendicular cross-section relative to the longitudinal direction of the first distributor, and that is joined to the opposite surface part. The opposite surface part has: a flat-plate portion connected to the lateral surface part; and a swelling-expansion portion that is formed such that a portion of an inner wall forming the internal space of the first distributor swellingly expands from the flat-plate portion toward the insertion surface part, in the axially-perpendicular cross-section. The first distributor is configured such that, in the axially-perpendicular cross-section, when the minimum distance from the the leading ends of the plurality of the heat transfer pipes to the swelling-expansion portion is defined as a first distance M1 and the distance from the leading ends of the plurality of heat transfer pipes in the extension direction of the plurality of heat transfer pipes to the position of the flat-plate portion is defined as a second distance M2, the relationship of second distance M2 ≥ 1.5×first distance M1 is satisfied.

Description

Heat exchanger and air conditioning device

[0001] The present disclosure relates to a heat exchanger and an air conditioner having heat transfer tubes, and more particularly to a distributor that branches a refrigerant and supplies it to the heat transfer tubes.

[0002] Vapor compression refrigeration cycle devices, which are commonly used in heat pump systems such as air conditioners, are composed of four components: a compressor, a heat exchanger functioning as a condenser, an expansion valve, and a heat exchanger functioning as an evaporator. In this refrigeration cycle device, a refrigerant, which is a first working fluid, flows through these four components while undergoing state changes. Conventionally, evaporators included in vapor compression refrigeration cycle devices include multiple heat transfer tubes to reduce flow losses and a distributor (header) that distributes the refrigerant to the multiple heat transfer tubes. To ensure efficient operation of the evaporator, it is necessary to distribute the refrigerant to each of the multiple heat transfer tubes according to the heat value between the refrigerant and a second working fluid, such as air, with which the refrigerant exchanges heat.

[0003] On the other hand, the refrigerant flowing out of the expansion valve is in a gas-liquid two-phase refrigerant state, consisting of a mixture of low-temperature, low-pressure gas refrigerant and liquid refrigerant, which can easily lead to uneven distribution of the refrigerant to the evaporator. In particular, when the distributor is oriented vertically, the low-density gas refrigerant and the high-density liquid refrigerant tend to separate due to the influence of gravity as the refrigerant moves vertically. Furthermore, as the refrigerant moves vertically, the high-density liquid refrigerant may become biased in the direction of movement due to the influence of inertia when flowing into the distributor.

[0004] To improve refrigerant distribution, a heat exchanger has been proposed that includes a distributor with a wall member inside a cylindrical tube having multiple outlet pipe connection ports in the longitudinal direction (see, for example, Patent Document 1). The heat exchanger in Patent Document 1 has a first space located below the distributor where refrigerant flowing from the flow passage holes of the multiple heat transfer tubes collects in an internal space, and a second space located above the distributor where the gas-liquid two-phase refrigerant collected in the first space is distributed to the flow passage holes of the multiple heat transfer tubes. The heat exchanger in Patent Document 1 includes a partition plate with holes called a wall member between the first and second spaces. This partition plate is said to guide the liquid refrigerant, which tends to be biased toward the opposing wall surface due to inertia when the gas-liquid two-phase refrigerant flows into the first space, to the holes, thereby improving the bias in distribution in the second space.

[0005] JP 2013-61114 A

[0006] However, in the distributor described in Patent Document 1, the liquid refrigerant separates from the gas refrigerant and falls in the downstream part of the distributor where the flow velocity decreases and the liquid refrigerant and gas refrigerant are likely to separate, resulting in an insufficient supply of liquid refrigerant to the upper part of the distributor, and there is a risk of deterioration in heat exchanger performance.

[0007] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a heat exchanger and an air conditioner that suppress a shortage of liquid refrigerant supply to the upper part of a distributor.

[0008] A heat exchanger according to the present disclosure includes a plurality of heat transfer tubes arranged at intervals in the vertical direction, and a first distributor formed to extend in the vertical direction and distributing a refrigerant to the plurality of heat transfer tubes, wherein the first distributor has an insertion surface portion into which the plurality of heat transfer tubes are inserted, an opposing surface portion that faces the insertion surface portion in the extension direction of the plurality of heat transfer tubes, and a side surface portion that is a wall extending between the insertion surface portion and the opposing surface portion in an axis-perpendicular cross section that is a cross section perpendicular to the longitudinal direction of the first distributor and is joined to the opposing surface portion, and the opposing surface portion has: The first distributor has a flat plate portion connected to the side portion, and a bulging portion in which, in a cross section perpendicular to the axis, a part of the inner wall forming the internal space of the first distributor bulges from the flat plate portion toward the insertion surface portion, and the first distributor satisfies the relationship of second distance M2 ≧ 1.5 × first distance M1, where the shortest distance from the tip of each of the plurality of heat transfer tubes to the bulging portion in the cross section perpendicular to the axis is defined as a first distance M1, and the distance from the tip of each of the plurality of heat transfer tubes in the direction in which the plurality of heat transfer tubes extend to the position of the flat plate portion.

[0009] An air conditioning apparatus according to the present disclosure includes a heat exchanger according to the present disclosure and a blower that supplies air to the heat exchanger.

[0010] The heat exchanger according to the present disclosure includes a first distributor that satisfies the relationship: second distance M2 ≥ 1.5 × first distance M1. By setting the second distance M2 to be 1.5 times or greater than the first distance M1, the cross-sectional area of ​​the internal space of the first distributor can be minimized and the wetted perimeter length can be increased. This allows the first distributor to have a small hydraulic equivalent diameter and, as a result, a large flooding constant. As a result, the first distributor can maintain a flow velocity that prevents separation of liquid refrigerant and gas refrigerant in the gas-liquid two-phase refrigerant within the first distributor and prevents the liquid refrigerant from falling, thereby preventing a shortage of liquid refrigerant supply to the upper part of the first distributor.

[0011] The air conditioning apparatus according to the present disclosure is equipped with a heat exchanger having the above-described configuration, and therefore the liquid refrigerant and gas refrigerant are separated from the gas-liquid two-phase refrigerant in the first distributor, maintaining a flow velocity that prevents the liquid refrigerant from falling, thereby preventing a shortage of liquid refrigerant supplied to the upper part of the first distributor.

[0012] 1 is a configuration diagram of an air conditioning apparatus according to Embodiment 1. FIG. 2 is a schematic diagram of a heat exchanger according to Embodiment 1. FIG. 3 is a schematic diagram of a first distributor according to Embodiment 1. FIG. 4 is a perspective view of a first distributor according to Embodiment 1. FIG. 5 is a cross-sectional view perpendicular to the extension direction of the main body section taken along line A-A in FIG. 3. FIG. 6 is a cross-sectional view perpendicular to the extension direction of the main body section taken along line B-B in FIG. 3. FIG. 7 is a cross-sectional view perpendicular to the extension direction of the main body section taken along line C-C in FIG. 3. FIG. 8 is an explanatory diagram for explaining the function of a bulge section. FIG. 9 is a diagram showing the relationship between the height inside the distributor and the flooding constant. FIG. 10 is a schematic diagram showing the flow of refrigerant in a first distributor in a heat exchanger according to Embodiment 1. FIG. 11 is a conceptual cross-sectional view of a bulge section according to Embodiment 2. FIG. 12 is a conceptual cross-sectional view of a first alternative embodiment of a bulge section according to Embodiment 2. FIG. 13 is a conceptual cross-sectional view of a second alternative embodiment of a bulge section according to Embodiment 2. FIG. 14 is a conceptual cross-sectional view of a third alternative embodiment of a bulge section according to Embodiment 2. FIG. 15 is a conceptual cross-sectional view of a fourth alternative embodiment of a bulge section according to Embodiment 2. FIG. 16 is a conceptual cross-sectional view of a fifth alternative embodiment of a bulge section according to Embodiment 2. 1 is a perspective view of a main body of a first distributor according to embodiment 2. FIG. 2 is a conceptual cross-sectional view of a first alternative embodiment of an orifice plate used in a first distributor according to embodiment 3. FIG. 3 is a conceptual cross-sectional view of a second alternative embodiment of an orifice plate used in a first distributor according to embodiment 3. FIG. 4 is a conceptual cross-sectional view of a third alternative embodiment of an orifice plate used in a first distributor according to embodiment 3. FIG. 5 is a conceptual diagram illustrating the relationship between orifice holes and heat transfer tubes in a first distributor according to embodiment 4. FIG. 6 is a schematic diagram of a heat exchanger according to embodiment 5. FIG. 7 is an explanatory diagram of a refrigerant flow path of a heat exchanger according to embodiment 5. FIG. 8 is a schematic diagram of a modified example of a heat exchanger according to embodiment 5. FIG. 9 is a first schematic diagram illustrating the relationship between a heat exchanger and an outdoor fan according to embodiments 1 to 5. FIG. 10 is a second schematic diagram illustrating the relationship between a heat exchanger and an indoor fan according to embodiments 1 to 5. 1 is a third schematic diagram showing the relationship between the heat exchanger and the indoor fan according to Embodiments 1 to 5. FIG. 2 is a fourth schematic diagram showing the relationship between the heat exchanger and the indoor fan according to Embodiments 1 to 5.

[0013] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the drawings. Hereinafter, in the following drawings, including FIG. 1, components with the same reference numerals are the same or equivalent, and are common throughout the entire embodiment described below. Furthermore, the forms of components shown throughout the specification are merely examples, and are not limited to the forms described in the specification.

[0014] Embodiment 1. Figure 1 is a configuration diagram of an air conditioning apparatus 10 according to embodiment 1. In Figure 1, dotted arrows indicate the direction of refrigerant flow when the air conditioning apparatus 10 is in cooling operation, and solid arrows indicate the direction of refrigerant flow when the air conditioning apparatus 10 is in heating operation. Using Figure 1, the configuration and operation of an air conditioning apparatus 10 having one outdoor heat exchanger 5 and one indoor heat exchanger 3, such as a room air conditioner for home use or a packaged air conditioner for use in a store or office, will be described.

[0015] [Configuration of Air Conditioning Apparatus 10] The air conditioning apparatus 10 has a compressor 1, a flow path switching device 2, an indoor heat exchanger 3, a pressure reducing device 4, and an outdoor heat exchanger 5, which are connected by piping to form a refrigerant circuit in which a refrigerant, which is a first working fluid, circulates. The air conditioning apparatus 10 further has an indoor fan 7 that sends air to the indoor heat exchanger 3, and an outdoor fan 6 that sends air to the outdoor heat exchanger 5.

[0016] The compressor 1 is a fluid machine that compresses and discharges the drawn refrigerant. The flow path switching device 2 is, for example, a four-way valve, and is a device that switches the flow path of the refrigerant between cooling operation and heating operation of the air conditioner 10 under the control of a control device (not shown). The indoor heat exchanger 3 is a heat exchanger that exchanges heat between the refrigerant circulating therein and the indoor air supplied by the indoor blower 7. The indoor heat exchanger 3 functions as a condenser during heating operation and as an evaporator during cooling operation.

[0017] The pressure reducing device 4 is, for example, an expansion valve, and is a device that reduces the pressure of the refrigerant. The pressure reducing device 4 can be an electronic expansion valve whose opening is adjusted under the control of a control device (not shown). The outdoor heat exchanger 5 is a heat exchanger that exchanges heat between the refrigerant flowing therethrough and air, which is a second working fluid, supplied by the outdoor blower 6. The outdoor heat exchanger 5 functions as an evaporator during heating operation and as a condenser during cooling operation.

[0018] [Operation of the air conditioner 10] Next, the operating state of the air conditioner 10 during heating operation will be described along with the flow of refrigerant using Figure 1. High-temperature, high-pressure gas refrigerant compressed by the compressor 1 passes through the flow path switching device 2 and reaches point A. After passing point A, the gas refrigerant causes the indoor heat exchanger 3 to function as a condenser as it passes through the indoor heat exchanger 3, and is cooled by air flowing by the indoor blower 7 and reaches point B in a liquefied state.

[0019] The liquefied liquid refrigerant passes through the pressure reducing device 4, becoming a two-phase refrigerant state in which low-temperature, low-pressure gas refrigerant and liquid refrigerant are mixed, and reaches point C. The two-phase refrigerant that has passed point C then flows through the outdoor heat exchanger 5, causing the outdoor heat exchanger 5 to act as an evaporator, and is heated by air flowing by the outdoor blower 6, and reaches point D in a gasified state. The gas refrigerant that has passed point D passes through the flow path switching device 2 and returns to the compressor 1. The air conditioning apparatus 10 performs heating operation to heat indoor air using this refrigerant cycle.

[0020] Next, the operating state of the air conditioning apparatus 10 during cooling operation will be described in terms of the flow of refrigerant using Figure 1. During cooling operation of the air conditioning apparatus 10, the flow direction of the refrigerant is switched using the flow path switching device 2 so that the refrigerant flows in the opposite direction. High-temperature, high-pressure gas refrigerant compressed by the compressor 1 passes through the flow path switching device 2 and reaches point D. After passing point D, the gas refrigerant causes the outdoor heat exchanger 5 to function as a condenser as it passes through the outdoor heat exchanger 5, and is cooled by the air flowing by the outdoor blower 6 and reaches point C in a liquefied state.

[0021] The liquefied liquid refrigerant passes through the pressure reducing device 4, becoming a two-phase refrigerant state in which low-temperature, low-pressure gas refrigerant and liquid refrigerant are mixed, and reaches point B. The two-phase refrigerant that has passed point B then flows through the indoor heat exchanger 3, causing the indoor heat exchanger 3 to act as an evaporator, and is heated by air flowing by the indoor blower 7, and reaches point A in a gasified state. The gas refrigerant that has passed point A passes through the flow switching device 2 and returns to the compressor 1. The air conditioning apparatus 10 performs cooling operation to cool indoor air using this refrigerant cycle.

[0022] [Heat Exchanger 50] FIG. 2 is a schematic diagram of the heat exchanger 50 according to the first embodiment. The arrows in FIG. 2 indicate the direction of refrigerant flow. In the diagram on the left side of FIG. 2, the horizontal axis indicates the wind speed of air passing through the heat exchanger 50, and the vertical axis indicates the height of the heat exchanger 50. The solid line in FIG. 2 indicates the heat quantity of the air. Next, the heat exchanger 50 according to the first embodiment will be described with reference to FIG. 2. In the following description, the heat exchanger 50 will be described as being used as the outdoor heat exchanger 5 that functions as an evaporator when the air conditioning apparatus 10 performs heating operation. Note that the heat exchanger 50 is not limited to being used as the outdoor heat exchanger 5 in the air conditioning apparatus 10, and can also be used as the indoor heat exchanger 3.

[0023] 2, the heat exchanger 50 includes a heat exchange section 50a, a first distributor 20, a second distributor 30, and a header 80. The first distributor 20 and the second distributor 30 may also be referred to as headers.

[0024] (Heat exchange unit 50a) The heat exchange unit 50a exchanges heat between the air present around the heat exchange unit 50a and the refrigerant flowing inside the heat exchange unit 50a. The heat exchange unit 50a is disposed between the first distributor 20 and the second distributor 30 in the flow of refrigerant flowing through the heat exchanger 50. The heat exchange unit 50a is also disposed between the second distributor 30 and the header 80 in the flow of refrigerant flowing through the heat exchanger 50. The heat exchange unit 50a has a plurality of heat transfer tubes 12 and a heat transfer promotion member 13 that connects adjacent heat transfer tubes 12.

[0025] Each of the heat transfer tubes 12 is formed in a tubular shape and allows a refrigerant to flow therethrough. Each of the heat transfer tubes 12 is formed to extend in a first direction (X-axis direction). The heat transfer tubes 12 are arranged at intervals from one another and are parallel to the axial direction (Z-axis direction), which is the extension direction of the first distributor 20 and the second distributor 30.

[0026] The axial direction (Z-axis direction) in which the first distributor 20 and the second distributor 30 extend is the second direction, which intersects with the first direction. The heat transfer tubes 12 are arranged at intervals in the vertical direction in the second direction. Adjacent heat transfer tubes 12 among the plurality of heat transfer tubes 12 are arranged to face each other. A gap that serves as an air flow path is formed between two adjacent heat transfer tubes 12 among the plurality of heat transfer tubes 12.

[0027] In the heat exchanger 50, the extension direction of the plurality of heat transfer tubes 12, which is the first direction, is horizontal. However, the extension direction of the plurality of heat transfer tubes 12, which is the first direction, is not limited to the horizontal direction and may be a direction inclined relative to the horizontal direction. Furthermore, in the heat exchanger 50, the arrangement direction of the plurality of heat transfer tubes 12, which is the second direction, is vertical. However, the arrangement direction of the plurality of heat transfer tubes 12 is not limited to the vertical direction and may be a direction inclined relative to the vertical direction.

[0028] The heat transfer tube 12 is, for example, a circular tube having a circular cross section or an elliptical tube having an elliptical cross section. Note that the heat transfer tube 12 is not limited to a circular tube or an elliptical tube, and may be a flat tube having a plurality of flow paths formed therein.

[0029] Adjacent heat transfer tubes 12 among the plurality of heat transfer tubes 12 are connected to each other by heat transfer promotion members 13. The heat transfer promotion members 13 are, for example, plate fins or corrugated fins. The heat transfer promotion members 13 improve the heat exchange efficiency between the air and the refrigerant. The plurality of heat transfer promotion members 13 are arranged at intervals from each other in the heat exchange section 50a and are parallel to each other in the extension direction (X-axis direction) of the heat transfer tubes 12. When the heat transfer promotion members 13 are plate fins, each of the plurality of heat transfer tubes 12 penetrates the plurality of heat transfer promotion members 13.

[0030] The heat exchange unit 50a is not limited to having the heat transfer tube 12 and the heat transfer promotion member 13. For example, the heat exchange unit 50a may have a plurality of heat transfer tubes 12 without the heat transfer promotion member 13 connecting adjacent heat transfer tubes 12.

[0031] As shown in FIG. 2, the heat exchange section 50a has an auxiliary heat exchange section 5a located upstream of the flowing refrigerant, and a main heat exchange section 5b located downstream of the flowing refrigerant.

[0032] The auxiliary heat exchange section 5a includes the remaining heat transfer tubes 12 that do not constitute the main heat exchange section 5b among the plurality of heat transfer tubes 12. One end of the auxiliary heat exchange section 5a in the extension direction (X-axis direction) of the heat transfer tubes 12 is connected to the first distributor 20, and the other end is connected to the second distributor 30. The auxiliary heat exchange section 5a and the second distributor 30 are connected by piping 300. That is, each of the plurality of heat transfer tubes 12 that constitute the auxiliary heat exchange section 5a has one end connected to the first distributor 20 and the other end connected to the second distributor 30 via the piping 300 in the first direction (X-axis direction).

[0033] The main heat exchange unit 5b has more than half of the plurality of heat transfer tubes 12. One end of the main heat exchange unit 5b in the extension direction (X-axis direction) of the heat transfer tubes 12 is connected to the second distributor 30, and the other end is connected to the header 80. More specifically, each of the plurality of heat transfer tubes 12 constituting the main heat exchange unit 5b has one end connected to the second distributor 30 and the other end connected to the header 80 in the first direction (X-axis direction).

[0034] The main heat exchange section 5b includes an upper main heat exchange section 5b1, an upper-middle main heat exchange section 5b2, a lower-middle main heat exchange section 5b3, and a lower main heat exchange section 5b4. The main heat exchange section 5b is also a collective term for the upper main heat exchange section 5b1, the upper-middle main heat exchange section 5b2, the lower-middle main heat exchange section 5b3, and the lower main heat exchange section 5b4.

[0035] The upper main heat exchange section 5b1 is a section located at the top in the up-down direction (Z-axis direction) of the main heat exchange section 5b, and is a section located higher than the upper-middle main heat exchange section 5b2 and the lower-middle main heat exchange section 5b3, which are located in the center in the direction of gravity. The upper main heat exchange section 5b1 is a section of the main heat exchange section 5b where the heat transfer tubes 12 that make up the upper main heat exchange section 5b1 are connected to the upper second distributor 31, which will be described later. The up-down direction (Z-axis direction) of the main heat exchange section 5b is also the direction of gravity.

[0036] The upper-middle main heat exchange section 5b2 is a section located in the center of the main heat exchange section 5b in the up-down direction (Z-axis direction), and is located lower than the upper main heat exchange section 5b1 in the direction of gravity and higher than the lower-middle main heat exchange section 5b3 in the direction of gravity. The upper-middle main heat exchange section 5b2 is a section of the main heat exchange section 5b where the heat transfer tubes 12 constituting the upper-middle main heat exchange section 5b2 are connected to the upper-middle second distributor 32 described later.

[0037] The lower-middle main heat exchange section 5b3 is a section located in the center of the main heat exchange section 5b in the up-down direction (Z-axis direction), and is located lower than the upper-middle main heat exchange section 5b2 in the direction of gravity and higher than the lower-middle main heat exchange section 5b4 in the direction of gravity. The lower-middle main heat exchange section 5b3 is a section of the main heat exchange section 5b where the heat transfer tubes 12 constituting the lower-middle main heat exchange section 5b3 are connected to the lower-middle second distributor 33 described later.

[0038] The upper-middle main heat exchange section 5b2 and the lower-middle main heat exchange section 5b3 are also referred to as central main heat exchange sections. The central main heat exchange section is disposed between the upper main heat exchange section 5b1 and the lower main heat exchange section 5b4 in the vertical direction (Z-axis direction) of the main heat exchange section 5b. The central main heat exchange section is located toward the center of the main heat exchange section 5b in the vertical direction (Z-axis direction) and in the direction of gravity (Z-axis direction).

[0039] The lower main heat exchange section 5b4 is a portion located at the bottom in the up-down direction (Z-axis direction) of the main heat exchange section 5b, and is a portion located lower than the upper-middle main heat exchange section 5b2 and the lower-middle main heat exchange section 5b3 in the direction of gravity. The lower main heat exchange section 5b4 is a portion of the main heat exchange section 5b where the heat transfer tubes 12 constituting the lower main heat exchange section 5b4 are connected to the lower second distributor 34 described later. The main heat exchange section 5b and the auxiliary heat exchange section 5a are thermally separated by a space.

[0040] (First distributor 20) When the heat exchanger 50 functions as an evaporator, the first distributor 20 is provided on the refrigerant inlet side of the auxiliary heat exchange section 5a. The first distributor 20 is connected to one end of the plurality of heat transfer tubes 12 constituting the auxiliary heat exchange section 5a in the extension direction (X-axis direction). The first distributor 20 is connected to the heat transfer tubes 12 of the auxiliary heat exchange section 5a so that the interior of the first distributor 20 communicates with the inside of the heat transfer tubes 12. The first distributor 20 is arranged on the opposite side of the refrigerant flow from the second distributor 30, across the plurality of heat transfer tubes 12 constituting the auxiliary heat exchange section 5a.

[0041] The first distributor 20 is formed to be long and extends along the arrangement direction (Z-axis direction) of the plurality of heat transfer tubes 12. The first distributor 20 is formed to extend in the vertical direction (Z-axis direction) and distributes the refrigerant to the plurality of heat transfer tubes 12. The first distributor 20 functions as a distribution mechanism in the heat exchanger 50 that distributes the refrigerant flowing into the auxiliary heat exchange section 5a of the heat exchange section 50a to the plurality of heat transfer tubes 12.

[0042] The first distributor 20 is provided with an inlet pipe 201. The inlet pipe 201 is a pipe for allowing the refrigerant distributed to the plurality of heat transfer tubes 12 to flow into the heat exchanger 50. The inlet pipe 201 is a pipe that forms a refrigerant flow path between the heat exchanger 50 and the pressure reducing device 4. The detailed structure of the first distributor 20 will be described later.

[0043] (Second distributor 30) The second distributor 30 is provided on the refrigerant inflow side of the main heat exchange unit 5b when the heat exchanger 50 functions as an evaporator. The second distributor 30 is provided on the refrigerant outflow side of the auxiliary heat exchange unit 5a when the heat exchanger 50 functions as an evaporator. The second distributor 30 is connected to the main heat exchange unit 5b and distributes the refrigerant flowing out of the auxiliary heat exchange unit 5a to the multiple heat transfer tubes 12 that make up the main heat exchange unit 5b.

[0044] The second distributor 30 is connected to one end of the heat transfer tubes 12 constituting the main heat exchange section 5b in the extension direction (X-axis direction). The second distributor 30 is connected to the heat transfer tubes 12 of the main heat exchange section 5b so that the interior of the second distributor 30 communicates with the inside of the heat transfer tubes 12. The second distributor 30 is disposed on the opposite side of the header 80 in the refrigerant flow, across the heat transfer tubes 12 constituting the main heat exchange section 5b. The second distributor 30 is also connected to the heat transfer tubes 12 constituting the auxiliary heat exchange section 5a via piping 300.

[0045] The second distributor 30 is formed to be elongated so as to extend along the arrangement direction (Z-axis direction) of the plurality of heat transfer tubes 12. The second distributor 30 is formed to extend in the vertical direction (Z-axis direction) and distributes the refrigerant to the plurality of heat transfer tubes 12. The second distributor 30 functions as a distribution mechanism in the heat exchanger 50 that distributes the refrigerant flowing into the main heat exchange section 5b of the heat exchange section 50a to the plurality of heat transfer tubes 12.

[0046] The second distributors 30 include an upper second distributor 31, an upper-middle second distributor 32, a lower-middle second distributor 33, and a lower second distributor 34. The second distributor 30 is also a collective term for the upper second distributor 31, the upper-middle second distributor 32, the lower-middle second distributor 33, and the lower second distributor 34. Note that while FIG. 2 shows the configuration of four second distributors 30, the upper second distributor 31 to the lower second distributor 34, the number of second distributors 30 is not limited to four as long as there is more than one.

[0047] The upper second distributor 31 is located at the top in the vertical direction (Z-axis direction) of the second distributor 30, and is located higher than the upper-middle second distributor 32 and the lower-middle second distributor 33, which are located in the center in the direction of gravity. The upper second distributor 31 is connected to the heat transfer tubes 12 that constitute the upper main heat exchange section 5b1.

[0048] The upper-middle second distributor 32 is located in the center of the second distributor 30 in the up-down direction (Z-axis direction), and is located lower in the direction of gravity than the upper-middle second distributor 31 and higher in the direction of gravity than the lower-middle second distributor 33. The upper-middle second distributor 32 is connected to the heat transfer tubes 12 that constitute the upper-middle main heat exchange section 5b2.

[0049] The lower-middle second distributor 33 is located in the center of the second distributor 30 in the up-down direction (Z-axis direction), is located lower than the upper-middle second distributor 32 in the direction of gravity, and is located higher than the lower-middle second distributor 34 in the direction of gravity. The lower-middle second distributor 33 is connected to the heat transfer tubes 12 that constitute the lower-middle main heat exchange section 5b3.

[0050] The lower second distributor 34 is located at the bottom in the up-down direction (Z-axis direction) of the second distributor 30, and is located lower than the upper-middle second distributor 32 and the lower-middle second distributor 33, which are located in the center in the direction of gravity. The lower second distributor 34 is connected to the heat transfer tubes 12 that constitute the lower main heat exchange section 5b4.

[0051] As described above, the auxiliary heat exchange section 5a and the second distributor 30 are connected by the piping 300. The piping 300 includes the upper piping 301, the middle upper piping 302, the middle lower piping 303, and the lower piping 304. The piping 300 is also a collective term for the upper piping 301, the middle upper piping 302, the middle lower piping 303, and the lower piping 304.

[0052] The upper piping 301 is a piping that connects the auxiliary heat exchange section 5a and the upper second distributor 31. The upper piping 301 communicates the lower space 21a of the first distributor 20 with the interior of the upper second distributor 31 via the heat transfer tubes 12. The upper-middle piping 302 is a piping that connects the auxiliary heat exchange section 5a and the upper-middle second distributor 32. The upper-middle piping 302 communicates the upper space 21b of the first distributor 20 with the interior of the upper-middle second distributor 32 via the heat transfer tubes 12.

[0053] The lower-middle piping 303 is a piping that connects the auxiliary heat exchange section 5a and the lower-middle second distributor 33. The lower-middle piping 303 communicates the upper space 21b of the first distributor 20 with the interior of the lower-middle second distributor 33 via the heat transfer tubes 12. The lower piping 304 is a piping that connects the auxiliary heat exchange section 5a and the lower second distributor 34. The lower piping 304 communicates the lower space 21a of the first distributor 20 with the interior of the lower second distributor 34 via the heat transfer tubes 12. The number of piping 300 is not limited to four, and may be any number that is the same as the number of second distributors 30.

[0054] (Header 80) The header 80 is connected to the other end in the extension direction (X-axis direction) of the plurality of heat transfer tubes 12 that constitute the main heat exchange section 5b. The header 80 is connected to the heat transfer tubes 12 of the main heat exchange section 5b so that the interior of the header 80 communicates with the inside of the heat transfer tubes 12. The header 80 is formed long so as to extend along the arrangement direction of the plurality of heat transfer tubes 12 (Z-axis direction).

[0055] The header 80 functions as a confluence mechanism when the refrigerants flowing out from the heat transfer tubes 12 of the main heat exchange section 5b join together in the heat exchanger 50. The header 80 functions as a confluence mechanism when the refrigerants flowing out from the heat exchange section 50a join together in the heat exchanger 50.

[0056] The header 80 is provided with an outflow pipe 801. The outflow pipe 801 is a pipe for discharging the refrigerant that has flowed out from the plurality of heat transfer tubes 12 and joined together from the heat exchanger 50.

[0057] [Example of Operation of Heat Exchanger 50] The operation of the heat exchanger 50 according to the first embodiment will be described using as an example the operation when the heat exchanger 50 functions as an evaporator of the air conditioning apparatus 10. A gas-liquid two-phase refrigerant decompressed by the pressure reducing device 4 flows into the heat exchanger 50 functioning as an evaporator. At this time, the refrigerant flows into the first distributor 20 of the heat exchanger 50, and flows through the passages in the plurality of heat transfer tubes 12 to absorb heat and evaporate. The refrigerant then flows out of the header 80, passes through the flow path switching device 2, and is drawn into the compressor 1.

[0058] An example of the operation of the heat exchanger 50 will be described in more detail using Figure 2. In the heat exchanger 50, the refrigerant flows through the first distributor 20, the auxiliary heat exchange section 5a, the second distributor 30, the main heat exchange section 5b, and the header 80 in this order. When the quality fraction x is used to indicate the mass velocity ratio of gas to the total mass velocity of the gas-liquid two-phase refrigerant, the refrigerant flowing through the heat exchanger 50 constituting the outdoor heat exchanger 5 flows into the first distributor 20 from the inlet pipe 201 in the figure in a gas-liquid two-phase state with a quality fraction x in the range of approximately x = 0.05 to 0.30.

[0059] The gas-liquid two-phase refrigerant that has passed through the inlet pipe 201 flows into the first distributor 20, which is composed of an insertion surface 25 into which the heat transfer tube 12 is inserted, an opposing surface 27a (see FIG. 4 ) that faces the end face of the heat transfer tube 12, the lid 41, the lid 42, and the orifice plate 91. The detailed configuration of the first distributor 20 will be described later. Inside the first distributor 20, the orifice plate 91 adjusts the refrigerant flow so that a gas-rich gas-liquid two-phase refrigerant is present in the lower space 21a located below the orifice plate 91. Inside the first distributor 20, the orifice plate 91 adjusts the refrigerant flow so that a liquid-rich gas-liquid two-phase refrigerant is present in the upper space 21b located above the orifice plate 91. The gas-liquid two-phase refrigerant is distributed to the heat transfer tubes 12 communicating with the lower space 21a and the heat transfer tubes 12 communicating with the upper space 21b, and flows inside the auxiliary heat exchange section 5a, which is part of the outdoor heat exchanger 5.

[0060] At this time, heat exchange occurs between the gas-liquid two-phase refrigerant flowing through the heat transfer tubes 12 of the auxiliary heat exchange section 5a and the air flowing by the outdoor blower 6 (see FIG. 1). As a result of heat exchange between the gas-liquid two-phase refrigerant and the air, the liquid refrigerant in the gas-liquid two-phase refrigerant evaporates, and the proportion of the gas mass velocity in the total mass velocity of the refrigerant changes as the refrigerant passes through the auxiliary heat exchange section 5a.

[0061] The gas-liquid two-phase refrigerant that has passed through the auxiliary heat exchange section 5a flows to the second distributor 30 via the pipe 300. More specifically, a portion of the refrigerant that has passed through the lower space 21a of the first distributor 20 passes through the heat transfer tubes 12 and upper pipe 301 that constitute the auxiliary heat exchange section 5a, and flows into the upper second distributor 31. A portion of the refrigerant that has passed through the lower space 21a of the first distributor 20 passes through the heat transfer tubes 12 and lower pipe 304 that constitute the auxiliary heat exchange section 5a, and flows into the lower second distributor 34. A portion of the refrigerant that has passed through the upper space 21b of the first distributor 20 passes through the heat transfer tubes 12 and upper-middle pipe 302 that constitute the auxiliary heat exchange section 5a, and flows into the upper-middle second distributor 32. In addition, a portion of the refrigerant that has passed through the upper space 21b of the first distributor 20 passes through the heat transfer tubes 12 that constitute the auxiliary heat exchange section 5a and the lower-middle piping 303, and flows into the inside of the lower-middle second distributor 33.

[0062] In this case, the quality fraction x of the gas-liquid two-phase refrigerant flowing through the upper pipe 301, the upper middle pipe 302, the lower middle pipe 303, and the lower pipe 304 can be in the range of about x = 0.05 to 0.60. The quality fraction x value varies depending on the ratio of the auxiliary heat exchange section 5a to the entire heat exchange section 50a, the air volume passing through the auxiliary heat exchange section 5a, the pressure loss from the inlet pipe 201 to the pipe 300, and the like.

[0063] The gas-liquid two-phase refrigerant that flows into the upper second distributor 31 to the lower second distributor 34 is divided into four branches each, resulting in a total of 16 branches in the main heat exchange unit 5b as a whole, which flow into each heat transfer tube 12. The gas-liquid two-phase refrigerant divided into the 16 branches flows through the main heat exchange unit 5b, and exchanges heat with the air flowing by the outdoor blower 6 (see FIG. 1).

[0064] The gas-liquid two-phase refrigerant distributed into four branches by the upper second distributor 31 flows through the upper main heat exchange section 5b1, where it exchanges heat with air flowing by the outdoor fan 6 (see FIG. 1). The gas-liquid two-phase refrigerant distributed into four branches by the upper-middle second distributor 32 flows through the upper-middle main heat exchange section 5b2, where it exchanges heat with air flowing by the outdoor fan 6 (see FIG. 1). The gas-liquid two-phase refrigerant distributed into four branches by the lower-middle second distributor 33 flows through the lower-middle main heat exchange section 5b3, where it exchanges heat with air flowing by the outdoor fan 6 (see FIG. 1). The gas-liquid two-phase refrigerant distributed into four branches by the lower second distributor 34 flows through the lower main heat exchange section 5b4, where it exchanges heat with air flowing by the outdoor fan 6 (see FIG. 1).

[0065] Here, the heat quantity of the air passing through the upper to lower main heat exchange units 5b1 to 5b4 differs depending on the magnitude of the wind speed distributed in the height direction, as shown on the left side of Fig. 2. The upper-middle main heat exchange unit 5b2 and the lower-middle main heat exchange unit 5b3, in which the heat quantity of the air is larger than that of the other units, are able to evaporate more liquid refrigerant than the upper-middle main heat exchange unit 5b1 and the lower-middle main heat exchange unit 5b4, in which the heat quantity of the air is smaller than that of the upper-middle main heat exchange unit 5b2 and the lower-middle main heat exchange unit 5b3.

[0066] Therefore, in the heat exchanger 50, the upper-middle main heat exchange section 5b2 is connected to the upper-middle second distributor 32, and the upper-middle second distributor 32 is connected to the upper space 21b of the first distributor 20 that adjusts the refrigerant to a liquid-rich two-phase gas-liquid refrigerant. That is, the heat exchanger 50 connects the upper-middle main heat exchange section 5b2 that evaporates a large amount of liquid refrigerant via the upper-middle second distributor 32 to the upper space 21b of the first distributor 20 that contains the liquid-rich two-phase gas-liquid refrigerant.

[0067] Furthermore, the heat exchanger 50 has its lower-middle main heat exchange section 5b3 connected to the lower-middle second distributor 33, which is connected to the upper space 21b of the first distributor 20 that adjusts the refrigerant to a liquid-rich two-phase gas-liquid refrigerant. That is, the heat exchanger 50 connects the lower-middle main heat exchange section 5b3, which evaporates a large amount of liquid refrigerant via the lower-middle second distributor 33, to the upper space 21b of the first distributor 20 that contains the liquid-rich two-phase gas-liquid refrigerant.

[0068] The refrigerant passing through the main heat exchange unit 5b exchanges heat with the air, and becomes a gas refrigerant in which all of the liquid refrigerant has evaporated, or becomes a gas-liquid two-phase refrigerant in which most of the liquid refrigerant has evaporated, with a quality factor of x = 0.85 or more, and flows out into the header 80. The 16 branched refrigerants in the main heat exchange unit 5b join together in the header 80 and flow out of the heat exchanger 50 through the outflow pipe 801.

[0069] For example, the heat exchanger 50 is configured such that the refrigerant branches into four at the first distributor 20, flows through a portion of the evaporator (auxiliary heat exchange section 5a), then branches into 16 branches via the upper second distributor 31 to the lower second distributor 34, and then flows through a portion of the evaporator (main heat exchange section 5b). However, the heat exchanger 50 is not limited to this configuration. The number of branches in the auxiliary heat exchange section 5a and the main heat exchange section 5b of the heat exchanger 50 may be different from the above configuration.

[0070] (Detailed configuration of first distributor 20) Fig. 3 is a schematic diagram of the first distributor 20 according to the first embodiment. Fig. 4 is a perspective view of the first distributor 20 according to the first embodiment. Fig. 5 is a cross-sectional view taken along line A-A in Fig. 3, perpendicular to the direction in which the main body 20a extends. Fig. 6 is a cross-sectional view taken along line B-B in Fig. 3, perpendicular to the direction in which the main body 20a extends. Fig. 7 is a cross-sectional view taken along line CC in Fig. 3, perpendicular to the direction in which the main body 20a extends.

[0071] In order to explain the internal structure of the first distributor 20, the lid 41 is not shown in Figure 4. The X-axis direction shown in Figure 4 is the direction in which the heat transfer tubes 12 extend, and the Z-axis direction is the direction in which the main body 20a of the first distributor 20 extends. The Z-axis direction is also the arrangement direction of the heat transfer tubes 12. The Y-axis direction shown in Figure 4 is the direction perpendicular to the X-axis direction and the Z-axis direction. The first distributor 20 will be explained using Figures 3 to 7. As shown in Figure 3, the first distributor 20 has a main body 20a and an inlet pipe 201 attached to the main body 20a.

[0072] (Main body 20a) The main body 20a is a long, cylindrical member with both ends closed, and has an internal space. The main body 20a of the first distributor 20 is installed with the central axis of the first distributor 20 in the longitudinal direction (Z-axis direction) oriented vertically, or with the central axis of the first distributor 20 in the longitudinal direction tilted within a range that has a vector component oriented vertically. The main body 20a has an inlet 44 and an internal space 21 formed therein.

[0073] The inlet 44 is connected to the inlet pipe 201 and is an inlet through which the refrigerant flows from the inlet pipe 201. The internal space 21 is in communication with the space inside the heat transfer tube 12 and with the space inside the inlet pipe 201, and is a space through which the refrigerant that flows in from the inlet 44 via the inlet pipe 201 flows upward.

[0074] The main body 20a has a first part 23, a second part 24, a lid 41, a lid 42, and an orifice plate 91. The first part 23 and the second part 24 are arranged to face each other in the extension direction (X-axis direction) of the heat transfer tube 12. The main body 20a of the first distributor 20 includes the first part 23 having an insertion surface part 25 and a side surface part 26 (described later), and the second part 24 serving as an opposing surface part, and is formed into a cylindrical shape by combining the first part 23 and the second part 24.

[0075] As shown in Fig. 4, the main body 20a is formed into a cylindrical shape by combining a first part 23 and a second part 24, and as shown in Fig. 3, both ends in the longitudinal direction (Z-axis direction) of the cylindrically formed first part 23 and second part 24 are closed by lids 41 and 42. The main body 20a is formed into a columnar shape by combining the first part 23, the second part 24, and the lids 41 and 42.

[0076] The first component 23 is an elongated member, and its cross section perpendicular to the longitudinal direction (Z-axis direction) is U-shaped. The cross section perpendicular to the longitudinal direction (Z-axis direction) of the first distributor 20 including the first component 23 may be referred to as an axis-perpendicular cross section. As shown in FIGS. 4 and 5 , the first component 23 has an insertion surface 25 that forms a U-shaped curved portion and a side surface 26 that forms a flat plate-like portion. The side surface 26 is not limited to a flat plate-like portion, and may be, for example, a plate-like portion that is arc-shaped and curves more gently than the insertion surface 25 in the axis-perpendicular cross section. The insertion surface 25 and the two side surface portions 26 are integrally formed.

[0077] In a cross section perpendicular to the longitudinal direction (Z-axis direction) of the first component 23, the insertion surface 25 is formed in an arc shape, and the side surface 26 is formed in a substantially linear shape. In a cross section perpendicular to the axis, the insertion surface 25 is at least partially curved so as to be convex toward the side on which the multiple heat transfer tubes 12 are arranged. The first component 23 is formed so as to be at least partially curved so as to be convex toward the side opposite the second component 24, which is the opposing surface.

[0078] The first component 23 is formed so that two side surface portions 26 face each other in the Y-axis direction, and a side surface portion 26 is provided at each end of an insertion surface portion 25 that is formed in an arc shape in a cross section perpendicular to the longitudinal direction (Z-axis direction) of the first component 23. The side surface portion 26 is connected to a flat plate portion 28 (described later) of the second component 24. The side surface portion 26 is a wall in the main body 20a that extends between the insertion surface portion 25 and the flat plate portion 28 of the opposing surface portion, which is the second component 24, and is a portion that connects the insertion surface portion 25 and the flat plate portion 28. The side surface portion 26 is formed integrally with the insertion surface portion 25 and is joined to the flat plate portion 28 of the opposing surface portion, which is the second component 24.

[0079] A plurality of heat transfer tubes 12 are inserted into the insertion surface 25 of the first component 23. As shown in FIGS. 3 and 4 , connection ports 43 into which the heat transfer tubes 12 are inserted are formed in the insertion surface 25 of the first component 23. The connection ports 43 are through holes, and a plurality of connection ports 43 are formed along the longitudinal direction (Z-axis direction) of the first component 23. A plurality of connection ports 43 into which the plurality of heat transfer tubes 12 are inserted are formed in the main body 20a at intervals in the vertical direction. The heat transfer tubes 12 are inserted into the connection ports 43 and penetrate the wall of the first component 23. The heat transfer tubes 12 inserted into the connection ports 43 are held by the first component 23.

[0080] As shown in FIGS. 3 and 6 , the second component 24 is an opposing surface portion that faces the insertion surface portion 25 in the extension direction of the heat transfer tubes 12. The second component 24 is an elongated member, and its cross section perpendicular to the longitudinal direction (Z-axis direction) is formed to be approximately Ω-shaped. The second component 24, which serves as the opposing surface portion, has a flat plate portion 28 that connects to the side surface portion 26 and a bulge portion 27, where a portion of the inner wall that forms the internal space 21 of the first distributor 20 bulges from the flat plate portion 28 toward the insertion surface portion 25 in a cross section perpendicular to the axis of the first distributor 20. In other words, the second component 24, which serves as the opposing surface portion, has the bulge portion 27 that forms a curved portion and the flat plate portion 28 that forms a flat portion. The bulge portion 27 and the two flat plate portions 28 located on both sides of the bulge portion 27 in a cross section perpendicular to the longitudinal direction (Z-axis direction) of the second component 24 are integrally formed.

[0081] In a cross section perpendicular to the longitudinal direction (Z-axis direction) of the second component 24, the bulge portion 27 is formed in an arc shape, and the flat plate portion 28 is formed in a straight line. In the second component 24, the flat plate surfaces of the two flat plate portions 28 form the same plane F, and a flat plate portion 28 is provided at each end of the bulge portion 27 in a cross section perpendicular to the longitudinal direction (Z-axis direction) of the second component 24. As shown in FIG. 4 , the same plane F is a plane formed by the Z-axis direction and the Y-axis direction. Note that the flat plate portions 28 are not limited to being provided at both ends of the bulge portion 27, and may be formed, for example, as a single flat plate-like member integrally formed with the flat plate portions 28 located at both ends of the bulge portion 27.

[0082] The bulging portion 27 is a portion where at least a part of the second component 24, which is the opposing surface, bulges toward the insertion surface 25 in a cross section perpendicular to the axis of the first distributor 20. The bulging portion 27 is provided between two flat plate components 28, and bulges so as to protrude from the flat plate components 28 toward the side where the insertion surface 25 is formed, i.e., the side where the heat transfer tubes 12 are arranged. The bulging portion 27 may be configured as a portion where at least a part of one flat plate component 28 bulges toward the insertion surface 25. The bulging portion 27 is formed along the longitudinal direction of the main body 20a, i.e., the longitudinal direction of the second component 24.

[0083] The bulge portion 27 has an opposing surface 27a that faces the inner wall of the insertion surface portion 25. Note that, although the bulge portion 27 is formed in a U-shape in Fig. 4, the shape of the bulge portion 27 is not limited to this shape. The bulge portion 27 may be formed so as to protrude from the flat plate portion 28 toward the side where the insertion surface portion 25 is formed, i.e., the side where the heat transfer tube 12 is arranged, and may be formed in, for example, a solid semicircular shape.

[0084] At least one inlet is formed in the bulging portion 27 of the second component 24, which is the opposing surface portion, through which the refrigerant flows into the internal space 21. The inlet 44 is a through-hole into which an inlet pipe 201 is inserted. The inlet pipe 201 is inserted into the inlet 44 and penetrates the wall of the second component 24. The inlet pipe 201 inserted into the inlet 44 is held by the second component 24.

[0085] The inlet 44 is formed in the internal space 21 of the main body 20a at a position facing the lowest heat transfer tube 12 among the plurality of heat transfer tubes 12. Alternatively, as shown in Fig. 3, the inlet 44 is formed in the internal space 21 of the main body 20a so as to be located lower than the lowest heat transfer tube 12 among the plurality of heat transfer tubes 12.

[0086] The main body 20a is formed so that the bulge 27 is located between two opposing side surfaces 26. In the main body 20a, an internal space 21 is formed by the insertion surface 25, the two side surfaces 26, the bulge 27, the two flat plate portions 28, the lid 41, and the inner wall surfaces of the lid 42. In a cross section perpendicular to the longitudinal direction (Z-axis direction) of the main body 20a, the internal space 21 is formed in a substantially U-shape, as shown in FIG.

[0087] A typical manufacturing method for the main body 20a is as follows: The first part 23 is formed with the connection port 43, which serves as an insertion port for the heat transfer tube 12, and then formed so that the cross section perpendicular to the longitudinal direction is arc-shaped. Therefore, the first part 23 is molded by press working to form the connection port 43 and bending to form the curved surface, and is molded as a semicircular pressed plate part.

[0088] The second part 24 has an inlet 44 formed therein, which serves as a connection port for the inlet pipe 201, and a bulge 27 formed therein, the bulge 27 having an arc-shaped cross section perpendicular to the longitudinal direction. Therefore, the second part 24 is molded by press working to form the inlet 44 and bending to form the curved surface, and is molded as a pressed plate part having the bulge 27.

[0089] The manufacturing method of the main body 20a is not limited to the molding method described above. For example, the main body 20a may be manufactured by extrusion molding the main body 20a, in which the first component 23 and the second component 24 are integrated, and then drilling holes in the main body 20a to form the connection port 43 and the inlet 44. Alternatively, the main body 20a may be manufactured by combining the first component 23 and the second component 24, which are molded by press working and extrusion, respectively, or by using another method such as electric resistance welding pipe processing.

[0090] The first distributor 20 has lids 41 and 42 that close both ends of the first distributor 20 in the longitudinal direction (Z-axis direction) and form the internal space 21 together with the insertion surface 25, the second part 24 which is the opposing surface, and the side surface 26. The lids 41 and 42 are members that close both ends of the cylindrically formed first part 23 and second part 24. The lids 41 and 42 are formed in a plate shape. The lids 41 and 42 close both ends of the longitudinal direction (Z-axis direction) of the main body 20a so as to form the internal space 21 in the main body 20a.

[0091] As shown in Figures 3 and 7, at least one or more orifice plates 91 are provided inside the main body 20a, dividing the internal space 21 of the main body 20a into upper and lower spaces. Inside the main body 20a, the orifice plate 91 defines a lower space 21a located below the orifice plate 91 and an upper space 21b located above the orifice plate 91. The main body 20a is provided with the orifice plate 91 inside, and the internal space 21 is divided into the lower space 21a and the upper space 21b by the orifice plate 91. In the internal space 21 of the main body 20a, the lower space 21a is a space formed below the orifice plate 91, and the upper space 21b is a space formed above the orifice plate 91.

[0092] As shown in Figures 3 and 7, the orifice plate 91 has orifice holes 92 formed therein. The orifice holes 92 are through-holes formed in the orifice plate 91, and connect the upper and lower spaces of the orifice plate 91. In the internal space 21 of the main body 20a, the lower space 21a and the upper space 21b are connected by the orifice holes 92 in the orifice plate 91. In the main body 20a, the refrigerant flows through the orifice holes 92 in the orifice plate 91, and moves from the lower lower space 21a to the upper upper space 21b via the orifice holes 92. By using an orifice plate 91 having such a configuration, the first distributor 20 can suppress uneven distribution of gas refrigerant at low flow rates.

[0093] The upper space 21b of the first distributor 20 communicates with the heat transfer tubes 12 constituting the central main heat exchange sections, such as the upper-middle main heat exchange section 5b2 and the lower-middle main heat exchange section 5b3, via the auxiliary heat exchange section 5a and one or more of the second distributors 30. The lower space 21a of the first distributor 20 communicates with the heat transfer tubes 12 constituting the upper main heat exchange section 5b1 and the lower main heat exchange section 5b4, via the auxiliary heat exchange section 5a and one or more of the other second distributors 30 that are not in communication with the central main heat exchange sections.

[0094] 7, the orifice plate 91 has one circular orifice hole 92 formed near the center of the orifice plate 91. However, the position of the orifice hole 92 is not limited to near the center of the orifice plate 91. Furthermore, the number of orifice holes 92 is not limited to one, and two or more orifice holes 92 may be formed in the orifice plate 91. Furthermore, the shape of the orifice hole 92 is not limited to a circular shape, and it may be formed in, for example, a rectangular shape or an elliptical shape.

[0095] As shown in Fig. 3, the portion of the main body 20a that forms the lower space 21a is the lower main body 20a1, and the portion that forms the upper space 21b is the upper main body 20a2. The lower main body 20a1 and the upper main body 20a2 each have a connection port 43. As shown in Fig. 2, the upper main body 20a2 and the lower main body 20a1 each have two connection ports 43, so that the main body 20a as a whole has four connection ports 43.

[0096] A plurality of heat transfer tubes 12 are attached to the lower main body portion 20a1, and a plurality of other heat transfer tubes 12 are attached to the upper main body portion 20a2. A plurality of heat transfer tubes 12 pass through the connection ports 43 of the lower main body portion 20a1, and a plurality of other heat transfer tubes 12 pass through the connection ports 43 of the upper main body portion 20a2. The number of connection ports 43 formed in the main body portion 20a is not limited to four. The number of connection ports 43 formed is determined by the number of heat transfer tubes 12 included in the heat exchange portion 50a.

[0097] (Inlet Pipe 201) The main body portion 20a is attached with the inlet pipe 201. The inlet pipe 201 is attached to the lower main body portion 20a1. The inlet pipe 201 communicates with the internal space 21 of the main body portion 20a. The inlet pipe 201 communicates with the lower space 21a. When the heat exchanger 50 functions as an evaporator, the gas-liquid two-phase refrigerant flowing through the internal space 21 of the main body portion 20a flows into the inlet pipe 201.

[0098] Next, the installation position of the inlet pipe 201 will be described with reference to Fig. 3. The inlet pipe 201 is preferably installed in a position facing the heat transfer pipe 12 located at the lowest level in the lower space 21a, or in a position where the gas-liquid two-phase refrigerant flows into the space below the heat transfer pipe 12 located at the lowest level, along the extension direction of the heat transfer pipe 12 (X-axis direction).

[0099] If the inlet pipe 201 is installed at the midpoint between the heat transfer tubes 12 in the lower space 21a, both upward and downward refrigerant flows will occur, reducing the upward flow rate of the gas-liquid two-phase refrigerant. If the upward flow rate of the gas-liquid two-phase refrigerant decreases, separation of the gas refrigerant and the liquid refrigerant will become more likely. Therefore, it is desirable to install the inlet pipe 201 at the above-described position.

[0100] Next, the characteristics of the working fluid when the first distributor 20 of this embodiment is used will be described. When the gas-liquid two-phase refrigerant flowing in from the inlet pipe 201 flows vertically upward in the lower space 21a of the first distributor 20, it is sequentially discharged into the plurality of heat transfer tubes 12 connected to the first component 23, and therefore the upward flow velocity decreases stepwise.

[0101] Here, the cross-sectional area of ​​the internal space 21 of the first distributor 20 in the cross-sectional view of line A-A shown in FIG. １ [m ２ 6. The cross-sectional area of ​​the internal space 21 of the first distributor 20 in the cross-sectional view of line B-B in FIG. ２ [m ２ ] is defined as

[0102] Also, the cross-sectional area A １ The perimeter of the cross section of the first distributor 20 that forms the wet edge length L １[m]. Also, the cross-sectional area A ２ The perimeter of the cross section of the first distributor 20 that forms the wet edge length L ２ [m]. Also, the cross-sectional area A １ The hydraulic equivalent diameter of the cross section of the first distributor 20 forming the １ [m]. Also, the cross-sectional area A ２ The hydraulic equivalent diameter of the cross section of the first distributor 20 forming the ２ The circulation rate of the gas-liquid two-phase refrigerant flowing through the internal space 21 is defined as the circulation rate Gr [kg / s], the quality fraction is defined as the quality fraction x [-], and the density is defined as the density ρ [kg / m ３ ] and the apparent velocity is defined as velocity u [m / s]. When each value is defined as above, the dimensionless flooding velocity j is calculated by the following relational expression: ＊ [-] and the flooding constant C Ｎ In the formula below, the subscript [_N] indicates N=1, 2, or 3, the subscript [_G] indicates gas, and the subscript [_L] indicates liquid.

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109] Here, the cross-sectional area A ２ Flooding constant C in ２ If [-] is less than 0.4, separation of the gas refrigerant and the liquid refrigerant is likely to occur. ２ It is preferable to configure the internal space 21 so that the flow rate of [-] is 0.4 or more.

[0110] As shown in Figures 5 and 6, corners 21c and 21d are formed on the main body 20a of the first distributor 20. The first distributor 20 may have only one of the corners 21c and 21d, or both. The corners 21c and 21d are spaces surrounded by the flat plate portion 28, the bulging portion 27, and the side surface portion 26, and are part of the internal space 21. The corners 21c and 21d are spaces near the flat plate portion 28 in the internal space 21. Surface tension acts between the corners 21c and 21d and the liquid refrigerant due to the surrounding wall surfaces formed by the flat plate portion 28, the bulging portion 27, and the side surface portion 26. Therefore, the first distributor 20 can prevent the liquid refrigerant from falling due to the surface tension acting on the corners 21c and 21d.

[0111] Furthermore, by providing the corners 21c and 21d, the first distributor 20 can increase the distance between the joint 28a between the side surface portion 26 and the flat plate portion 28 and the heat transfer tube 12. Therefore, even if an excess amount of brazing material is supplied to the joint 28a when the side surface portion 26 and the flat plate portion 28 are connected by brazing, the distance between the joint 28a and the heat transfer tube 12 is increased, so the refrigerant flow path in the heat transfer tube 12 is not blocked by the brazing material. Note that, to improve the bonding strength between the side surface portion 26 and the flat plate portion 28, a brazing material fillet may be formed at the joint 28a between the side surface portion 26 and the flat plate portion 28. A brazing material fillet is a thick, solidified brazing material that adheres to the corner of the connection between the components and then spreads out like a skirt.

[0112] 8 is an explanatory diagram illustrating the function of the bulge portion 27. In a cross section perpendicular to the longitudinal direction (Z-axis direction) of the main body 20a, a tangent to a portion of the heat transfer tube 12 that is closest to the second component 24, which is the opposing surface, is defined as a first tangent line P. When viewed in a direction parallel to the longitudinal direction (Z-axis direction) of the first distributor 20 and the main body 20a, the first tangent line P is perpendicular to the extension direction (X-axis direction) of the plurality of heat transfer tubes 12.

[0113] In a cross section perpendicular to the longitudinal direction (Z-axis direction) of the main body 20a, a tangent line that contacts the apex 27b of the bulging portion 27 is defined as a second tangent line Q. When viewed in a direction parallel to the longitudinal direction (Z-axis direction) of the first distributor 20 and the main body 20a, the second tangent line Q is a tangent line to a portion of the bulging portion 27 that is closest to the heat transfer tube 12. When viewed in a direction parallel to the longitudinal direction (Z-axis direction) of the first distributor 20 and the main body 20a, the second tangent line Q is perpendicular to the extension direction (X-axis direction) of the multiple heat transfer tubes 12. When viewed in a direction parallel to the longitudinal direction (Z-axis direction) of the first distributor 20 and the main body 20a, the first tangent line P and the second tangent line Q are parallel to each other.

[0114] The apex portion 27b is the portion closest to the heat transfer tube 12 in the direction in which the heat transfer tube 12 extends (the X-axis direction), and is the portion that protrudes the most from the flat plate portion 28. In other words, the apex portion 27b is the portion of the second part 24 that is closest to the connection port 43 in the direction in which the heat transfer tube 12 extends (the X-axis direction).

[0115] In a cross section perpendicular to the longitudinal direction (Z-axis direction) of the main body 20a, a tangent to a portion of the second component 24 that is farthest from the insertion surface 25 and forms the internal space 21 is defined as a third tangent R. When viewed in a direction parallel to the longitudinal direction (Z-axis direction) of the first distributor 20 and the main body 20a, the third tangent R is a line that is tangent to a portion of the flat plate 28 that forms the inner wall of the internal space 21, and is a line parallel to the first tangent P and the second tangent Q.

[0116] In the direction in which the heat transfer tube 12 extends (X-axis direction), if the distance between the first tangent P and the second tangent Q is defined as a first distance M1 and the distance between the first tangent P and the third tangent R is defined as a second distance M2, the second distance M2 is 1.5 times or more the first distance M1. The first distributor 20 is formed so as to satisfy the relationship of second distance M2 ≥ 1.5 × first distance M1 in a cross section perpendicular to the longitudinal direction (Z-axis direction) of the main body 20a.

[0117] In other words, in the first distributor 20, the shortest distance from the tip 12b of each of the heat transfer tubes 12 to the bulging portion 27 in the cross section perpendicular to the axis is defined as the first distance M1. Also, in the first distributor 20, the distance from the tip 12b of each of the heat transfer tubes 12 to the position of the flat plate portion 28 in the extension direction of the heat transfer tubes 12 is defined as the second distance M2. In this case, the first distributor 20 is formed so as to satisfy the relationship of second distance M2 ≥ 1.5 × first distance M1.

[0118] In the first distributor 20, the second distance M2 is 1.5 times or more the first distance M1, so that the cross-sectional area A ２ The wet edge length L ２ Therefore, the first distributor 20 has a hydraulic equivalent diameter D ２ can be reduced, resulting in a smaller flooding constant C ２ can also be made larger.

[0119] FIG. 9 shows the flooding constant C versus the height inside the distributor. Ｎ 9 shows the relationship between the first and second distributors 20 and 21. In FIG. 9, "Conventional" indicates a distributor that does not have the first distributor 20 of the present disclosure, and "Embodiment" indicates the first distributor 20 of this embodiment. Note that the "conventional" distributor is a distributor in which the main body has a cross section that is perfectly circular in a cross section perpendicular to the longitudinal direction (Z-axis direction) of the main body. As shown in FIG. 9, as the height position in the first distributor 20 goes higher, the gas-liquid two-phase refrigerant is sequentially discharged into the heat transfer tubes 12, so the flooding constant C Ｎ is decreasing.

[0120] In the conventional distributor, the hydraulic equivalent diameter D of the internal space 21 ２ becomes large, so the flooding constant C ２ becomes smaller and the flooding constant C ２ When the ratio falls below 0.4, separation of the gas refrigerant and the liquid refrigerant occurs. Therefore, in conventional distributors, only gas refrigerant is supplied to the top of the distributor, which results in uneven distribution of the gas-liquid two-phase refrigerant and is likely to reduce heat exchanger performance.

[0121] On the other hand, in the first distributor 20 of the present disclosure, the second distance M2 is 1.5 times or more the first distance M1, so that the flooding constant C ２ can be increased, and the flooding constant C ２ The gas-liquid two-phase refrigerant can be distributed with a ratio of 0.4 or higher. Therefore, the first distributor 20 can prevent separation of the gas refrigerant and the liquid refrigerant, and can suppress a shortage of liquid refrigerant supplied to the upper part of the first distributor. Furthermore, the first distributor 20 can prevent separation of the gas refrigerant and the liquid refrigerant, and can supply liquid refrigerant to the upper part of the heat exchange section 50a located downstream of the first distributor 20. By including the first distributor 20, the heat exchanger 50 can also supply liquid refrigerant to the upper part of the heat exchange section 50a, and can suppress a decrease in the heat exchange performance of the heat exchanger 50.

[0122] Fig. 10 is a schematic diagram showing the flow of refrigerant in the first distributor 20 in the heat exchanger 50 of Embodiment 1. The role of the orifice plate 91 in the first distributor 20 will be described using Fig. 10. The gas-liquid two-phase refrigerant 35 supplied from the inlet pipe 201 changes into a liquid refrigerant that rises while adhering to the inner wall surface of the lower main body portion 20a1 in the lower space 21a, a gas refrigerant that rises without adhering to the inner wall surface, and scattered liquid refrigerant particles.

[0123] As explained in FIG. 9, the flooding constant C ２ When R is 0.4 or greater, the liquid refrigerant adhering to the wall surface and rising can move upward without falling, and reaches the orifice plate 91. The liquid refrigerant and gas refrigerant that reach the orifice plate 91 are separated into a flow that passes through the orifice hole 92 and a flow that does not pass through the orifice hole 92 due to the influence of pressure loss when passing through the orifice hole 92.

[0124] When passing through a nozzle space such as the orifice hole 92, gas refrigerant, which has a larger volume than liquid refrigerant at the same mass, experiences a large pressure loss. Therefore, the refrigerant passing through the orifice hole 92 is allocated a larger mass flow rate of liquid refrigerant, which has a smaller pressure loss. The gas-liquid two-phase refrigerant in the upper space 21b tends to be a liquid-rich refrigerant, with approximately 50.1% to 58.0% of the mass flow rate being liquid refrigerant. Therefore, in the first distributor 20, the main body 20a is configured such that the refrigerant flow is branched into four branches by four heat transfer tubes 12 as shown in FIG. 8. The gas-liquid two-phase refrigerant flowing into the third and fourth heat transfer tubes 12 from the bottom tends to be a liquid-rich refrigerant with a high liquid refrigerant content. The third and fourth heat transfer tubes 12 from the bottom are connected to the upper space 21b.

[0125] In the main body 20a, the liquid refrigerant and gas refrigerant that do not pass through the orifice hole 92 flow into the first and second heat transfer tubes 12 from the bottom in a configuration in which the refrigerant flow is branched into four by four heat transfer tubes 12 as shown in FIG. 8. In the main body 20a, the gas refrigerant that does not pass through the orifice hole 92 due to the pressure loss caused by passing through the orifice hole 92 tends to flow into the first and second heat transfer tubes 12 from the bottom in a configuration in which the refrigerant flow is branched into four by four heat transfer tubes 12 as shown in FIG. 8. Therefore, in the first distributor 20, the gas-liquid two-phase refrigerant that flows into the first and second heat transfer tubes 12 from the bottom tends to be a gas-rich refrigerant with a high gas refrigerant content. The first and second heat transfer tubes 12 from the bottom are connected to the lower space 21a.

[0126] The orifice holes 92 formed in the orifice plate 91 are holes having a size corresponding to a Cv value of approximately 0.05 to 2.0, which is generally used as a capacity coefficient for valves and the like. In determining the size of the orifice holes 92, for example, a case will be considered in which, in the first distributor 20, R32 refrigerant flows from the inlet pipe 201 into the internal space 21 as a gas-liquid two-phase refrigerant with a mass flow rate of 140 kg / h and a quality fraction of 0.10. Furthermore, a case will be considered in which the first distributor 20 has a configuration in which the refrigerant flow is branched into four branches by four heat transfer tubes 12, and the orifice plate 91 is provided between the second and third heat transfer tubes 12 from the bottom. When the above-mentioned R32 refrigerant is used and an orifice plate 91 is provided between the second and third heat transfer tubes 12 from the bottom out of the four branches, the orifice hole 92 is preferably a hole with a diameter of approximately Φ2.2 [mm] to Φ6.0 [mm].

[0127] [Effects of the Heat Exchanger 50] The heat exchanger 50 according to the present disclosure includes a first distributor 20 that satisfies the relationship of second distance M2 ≥ 1.5 × first distance M1. In the first distributor 20, the second distance M2 is 1.5 times or more the first distance M1, so that the cross-sectional area A ２ The wet edge length L ２ Therefore, the first distributor 20 has a hydraulic equivalent diameter D ２ can be reduced, resulting in a smaller flooding constant C ２ As a result, the first distributor 20 can maintain a flow velocity at which the liquid refrigerant and the gas refrigerant in the gas-liquid two-phase refrigerant inside the first distributor 20 are separated and the liquid refrigerant does not fall, and a shortage of the supply of liquid refrigerant to the upper part of the first distributor 20 can be suppressed.

[0128] Furthermore, in a cross section perpendicular to the axis, at least a portion of the insertion surface 25 is curved so as to be convex toward the side where the plurality of heat transfer tubes 12 are arranged. Since the closer the main body 20a of the first distributor 20 is to a circular shape, the stronger the pressure resistance inside the first distributor 20. Therefore, in the heat exchanger 50, by forming the insertion surface 25 with the above structure, the pressure resistance of the first distributor 20 can be improved.

[0129] The first distributor 20 also has lids 41 and 42 that close both ends of the first distributor 20 in the longitudinal direction (Z-axis direction) and form the internal space 21 together with the insertion surface 25, the second component 24 which is the opposing surface, and the side surface 26. Without the lids 41 and 42 on the top and bottom of the first distributor 20, the refrigerant would leak to the outside and a closed space would not be created, so the first distributor 20 has the lids 41 and 42. The closed space can be easily formed in the first distributor 20 by closing the top and bottom ends with the lids 41 and 42, rather than by bending the top and bottom ends of the first distributor 20 at right angles and crushing the ends to form a closed space.

[0130] The first distributor 20 also has at least one orifice plate 91 that separates the internal space 21 into an upper space 21b located above and a lower space 21a located below in the longitudinal direction (Z-axis direction) of the first distributor 20. The orifice plate 91 has orifice holes 92 formed therein, which are through-holes that connect the upper space 21b and the lower space 21a. When passing through a nozzle space such as the orifice holes 92, gas refrigerant, which has a larger volume than liquid refrigerant at the same mass, experiences a large pressure loss. Therefore, the refrigerant passing through the orifice holes 92 is allocated a larger mass flow rate of liquid refrigerant, which has a smaller pressure loss, and the gas-liquid two-phase refrigerant occupying the upper space 21b tends to be liquid-rich. As a result, the first distributor 20 can prevent a shortage of liquid refrigerant from being supplied to the upper portion of the first distributor 20.

[0131] The inlet 44 is formed in the internal space 21 of the main body 20a at a position opposite the lowest heat transfer tube 12 among the plurality of heat transfer tubes 12. Alternatively, as shown in FIG. 3 , the inlet 44 is formed in the internal space 21 of the main body 20a so as to be located lower than the lowest heat transfer tube 12 among the plurality of heat transfer tubes 12. If the inlet pipe 201 connected to the inlet 44 is attached at a midpoint between the heat transfer tubes 12 in the internal space 21, both upward and downward refrigerant flows will occur, reducing the upward flow velocity of the gas-liquid two-phase refrigerant. Furthermore, a reduction in the upward flow velocity of the gas-liquid two-phase refrigerant will likely cause separation of the gas refrigerant and the liquid refrigerant. Therefore, it is desirable to form the inlet 44 connected to the inlet pipe 201 in the above-described position, which can prevent the refrigerant flow from splitting into an upward flow and a downward flow.

[0132] The first distributor 20 includes a first part 23 having an insertion surface 25 and a side surface 26, and a second part 24 serving as an opposing surface, and is formed into a cylindrical shape by combining the first part 23 and the second part 24. The first distributor 20 can be made by extrusion molding a cylinder in which the insertion surface 25, side surface 26, and opposing surface are all integrated, but this increases manufacturing costs because the connection port 43 and the inlet port 44 must be cut after extrusion molding. Because the first distributor 20 is made up of two parts, the first part 23 and the second part 24, which are split in half, each of the first part 23 and the second part 24 can be manufactured by press working, thereby keeping manufacturing costs low.

[0133] Furthermore, the main body 20a of the first distributor 20 is installed with the central axis of the longitudinal direction (Z-axis direction) of the first distributor 20 oriented vertically, or with the central axis of the longitudinal direction of the first distributor 20 tilted within a range having a vertical vector component. The first distributor 20 is a distributor that extends in the up-down direction (Z-axis direction), and by having the above-mentioned configuration, it is possible to prevent a shortage of liquid refrigerant supply to the upper part of the first distributor 20.

[0134] Furthermore, the upper space 21b of the first distributor 20 communicates with the plurality of heat transfer tubes 12 constituting the central main heat exchange sections, such as the upper-middle main heat exchange section 5b2 and the lower-middle main heat exchange section 5b3, via the auxiliary heat exchange section 5a and one or more of the second distributors 30. The lower space 21a of the first distributor 20 communicates with the plurality of heat transfer tubes 12 constituting the upper main heat exchange section 5b1 and the lower main heat exchange section 5b4, via the auxiliary heat exchange section 5a and one or more of the other second distributors 30 that are not in communication with the central main heat exchange sections.

[0135] In a heat exchanger located downstream of a distributor, heat exchange between a first working fluid and a second working fluid may occur inefficiently, resulting in reduced efficiency. For example, in the heat exchanger disclosed in Patent Document 1, the first working fluid (refrigerant) may not be appropriately distributed as a liquid refrigerant relative to the heat quantity of the second working fluid (air) in the heat exchanger located downstream of the distributor. Therefore, in the heat exchanger disclosed in Patent Document 1, the liquid refrigerant may be supplied evenly to heat transfer tubes with an excess of liquid refrigerant relative to the heat exchange amount, potentially reducing heat exchanger performance.

[0136] The first distributor 20 takes advantage of the characteristics of the liquid-rich gas-liquid two-phase refrigerant passing through the orifice holes 92 of the orifice plate 91 to increase the amount of liquid refrigerant supplied to the heat exchange sections 50a, such as the upper-middle main heat exchange section 5b2 and the lower-middle main heat exchange section 5b3, which have a large heat quantity as shown in FIG. 2 . Therefore, the heat exchanger 50 having the first distributor 20 can improve heat exchanger performance by distributing the liquid refrigerant appropriately for the heat quantity of the second working fluid. The heat exchanger 50 can distribute the liquid refrigerant appropriately for the heat quantity of the second working fluid in the main heat exchange section 5b located downstream of the first distributor 20, while maintaining a flow velocity that prevents separation of the liquid refrigerant and the gas refrigerant in the gas-liquid two-phase refrigerant in the first distributor 20 and prevents the liquid refrigerant from dropping.

[0137] As described above, the first distributor 20 can supply gas-liquid two-phase refrigerant to the heat exchanger 50 in an appropriate liquid refrigerant distribution according to the heat quantity in the heat exchanger 50 using only simple components, even at the top of the distributor, thereby contributing to improved heat exchanger performance while reducing material costs.

[0138] Embodiment 2. Figure 11 is a conceptual cross-sectional view of the bulge portion 27 according to embodiment 2. Note that components having the same functions and actions as those of the first distributor 20 according to embodiment 1, etc., are denoted by the same reference numerals, and their description will be omitted. Figure 11 is a vertical cross-section of the bulge portion 27 with respect to the longitudinal direction (Z-axis direction) of the main body 20a, and is a cross-sectional view conceptually showing the bulge portion 27 shown in embodiment 1. As shown in Figure 11, the bulge portion 27 may be formed in a semicircular shape.

[0139] Fig. 12 is a conceptual cross-sectional view of a first alternative form of the bulging portion 27 according to embodiment 2. Fig. 13 is a conceptual cross-sectional view of a second alternative form of the bulging portion 27 according to embodiment 2. The shape of the vertical cross section of the bulging portion 27 with respect to the longitudinal direction (Z-axis direction) of the main body 20a is not limited to a semicircular shape. The shape of the vertical cross section of the bulging portion 27 with respect to the longitudinal direction (Z-axis direction) of the main body 20a may be formed into a rectangular shape as shown in Fig. 12 or a triangular shape as shown in Fig. 13.

[0140] FIG. 14 is a conceptual cross-sectional view of a third modified example of the bulging portion 27 according to the second embodiment. FIG. 15 is a conceptual cross-sectional view of a fourth modified example of the bulging portion 27 according to the second embodiment. FIG. 16 is a conceptual cross-sectional view of a fifth modified example of the bulging portion 27 according to the second embodiment. The shape of the vertical cross section of the bulging portion 27 with respect to the longitudinal direction (Z-axis direction) of the main body 20a may be formed so that a plurality of small semicircular circular protrusions 27c are continuous, as shown in FIG. 14 . Alternatively, the shape of the vertical cross section of the bulging portion 27 may be formed so that a plurality of small rectangular protrusions 27d are continuous, as shown in FIG. 15 . Alternatively, the shape of the vertical cross section of the bulging portion 27 may be formed so that a plurality of small triangular mountain-shaped protrusions 27e are continuous, as shown in FIG. 16 .

[0141] The bulging portion 27 is formed in a cross section perpendicular to the axis in any one of the following cross-sectional shapes: a semicircular shape, a rectangular shape, a triangular shape, a shape of multiple consecutive semicircles, a shape of multiple consecutive quadrangles, or a shape of multiple consecutive triangles. The bulging portion 27 forms a groove having a cross-sectional shape of a semicircular shape, a rectangular shape, a triangular shape, a shape of multiple consecutive semicircles, a shape of multiple consecutive quadrangles, or a shape of multiple consecutive triangles. The cross-sectional shape of the bulging portion 27 is not limited to these shapes, and may be formed in a combination of the above-mentioned shapes, for example.

[0142] Figure 17 is a perspective view of the main body 20a of the first distributor 20 according to the second embodiment. As an example of the first distributor 20, a first distributor 20 having a bulging portion 27 of the fourth alternative form shown in Figure 15 will be described using Figure 17. Unlike the semicircular bulging portion 27 described in the first embodiment, the first distributor 20 shown in Figure 17 has a bulging portion 27 formed by a plurality of small, rectangular protrusions 27d in succession. Therefore, the first distributor 20 shown in Figure 17 has a plurality of protruding surfaces formed by the plurality of rectangular protrusions 27d protruding into the internal space 21.

[0143] [Effects of the heat exchanger 50] Generally, when gas-liquid two-phase refrigerant flows upward through the internal space of the distributor, liquid refrigerant tends to concentrate on the wall surfaces of the distributor, and gas refrigerant tends to concentrate in the center of the cavity within the distributor. The first distributor 20 of Figure 17 has multiple protruding surfaces formed by the multiple rectangular convex portions 27d that make up the bulging portion 27, thereby increasing the contact area between the wall surfaces of the bulging portion 27 and the gas-liquid two-phase refrigerant. Therefore, compared to the configuration of a single semicircular bulging portion 27 as in the first embodiment, the first distributor 20 having multiple protruding surfaces has a larger area where the surface tension of the gas-liquid two-phase refrigerant acts, further suppressing the liquid refrigerant from falling.

[0144] In addition, in the first distributor 20 of FIG. 17, a plurality of protruding surfaces are formed by a plurality of rectangular convex portions 27d that constitute the bulging portion 27, and thus the wet edge length L is shorter than that of the configuration of a single semicircular bulging portion 27 as in the first embodiment. ２Therefore, the first distributor 20 in which the bulging portion 27 has a plurality of protruding surfaces has a larger flooding constant C than the first embodiment in which the bulging portion 27 has a single semicircular shape. ２ This increases the pressure, and separation of the gas refrigerant and the liquid refrigerant can be suppressed.

[0145] 17 , the first distributor 20 in which the bulging portion 27 has a plurality of protruding surfaces can suppress the liquid refrigerant from falling and can also suppress separation of the gas refrigerant and the liquid refrigerant, and therefore is more likely to supply liquid refrigerant to the upper part of the first distributor 20 than the first distributor 20 of Embodiment 1. Therefore, even if the first distributor 20 has a plurality of heat transfer tubes 12 and the number of refrigerant branches increases, and the mass flow rate of the gas-liquid two-phase refrigerant decreases from the bottom to the top of the first distributor 20, liquid refrigerant can be more easily supplied from the upper part of the first distributor 20.

[0146] Furthermore, when the second part 24 is manufactured by extrusion molding, the first distributor 20 according to the second embodiment can be manufactured inexpensively in the same manner as in the first embodiment, even if the shape of the bulge 27 is formed by a plurality of protrusions as shown in Figures 14 to 16.

[0147] Furthermore, the bulging portion 27 is formed in a cross section perpendicular to the axis in one of the following cross-sectional shapes: one semicircular shape, one square shape, one triangular shape, a shape of a plurality of continuous semicircles, a shape of a plurality of continuous squares, or a shape of a plurality of continuous triangles. By having the bulging portion 27 of this configuration, the first distributor 20 can reduce the flooding constant C ２ As a result, the first distributor 20 can maintain a flow velocity at which the liquid refrigerant and the gas refrigerant in the gas-liquid two-phase refrigerant inside the first distributor 20 are separated and the liquid refrigerant does not fall, thereby preventing a shortage of liquid refrigerant supply to the upper part of the first distributor 20.

[0148] From the above, the first distributor 20 according to the second embodiment can increase the amount of liquid refrigerant supplied to the upper part of the first distributor 20 by increasing the circumferential length of the bulge 27 of the second component 24. Therefore, the first distributor 20 according to the second embodiment can supply liquid refrigerant to the upper part of the first distributor 20 even when the refrigerant distribution path has more branches than the first distributor 20 according to the first embodiment.

[0149] Embodiment 3. Figure 18 is a conceptual cross-sectional view of a first alternative embodiment of the orifice plate 91 used in the first distributor 20 according to embodiment 3. Figure 19 is a conceptual cross-sectional view of a second alternative embodiment of the orifice plate 91 used in the first distributor 20 according to embodiment 3. Figure 20 is a conceptual cross-sectional view of a third alternative embodiment of the orifice plate 91 used in the first distributor 20 according to embodiment 3. The cross-sectional views of Figures 18 to 20 are cross-sectional views of the first distributor 20 taken along line CC in Figure 3. An orifice plate 91 of an alternative embodiment to that of embodiment 1 will be described using Figures 18 to 20. Components having the same functions and actions as those of the first distributor 20 according to embodiments 1 and 2 will be denoted by the same reference numerals, and their description will be omitted.

[0150] The orifice plate 91 may have two orifice holes 92, such as the orifice hole 92a and the orifice hole 92b shown in Figures 18 and 19. Although the orifice plate 91 has two orifice holes 92, such as the orifice hole 92a and the orifice hole 92b, in Figures 18 and 19, it is sufficient that at least one orifice hole 92 is formed in the orifice plate 91. For example, the orifice plate 91 may have only one orifice hole 92, either the orifice hole 92a or the orifice hole 92b shown in Figures 18 and 19.

[0151] When viewed in a direction parallel to the longitudinal direction of the main body 20a, the orifice hole 92 may have a circular shape as shown in Fig. 18, or a rectangular shape as shown in Fig. 20. Furthermore, the orifice hole 92 may have an elliptical shape (not shown) when viewed in a direction parallel to the longitudinal direction of the main body 20a.

[0152] The orifice holes 92 may be formed in the central portion of the orifice plate 91 as shown in Figures 7 and 20, or may be formed in the end portion of the orifice plate 91 as shown in Figures 18 and 19. As shown in Figure 19, the orifice plate 91 may be formed so that each of the two orifice holes 92, orifice hole 92a and orifice hole 92b, is a space surrounded by the side surface portion 26, the flat plate portion 28, the bulging portion 27, and the orifice plate 91. In other words, the orifice holes 92 may be formed in the corners 21c and 21d described above.

[0153] 18 to 20 , the orifice holes 92 are formed in the orifice plate 91 at positions that do not overlap with the heat transfer tubes 12 when viewed in a direction parallel to the longitudinal direction of the main body 20a. That is, the first distributor 20 is disposed at positions that do not overlap with the heat transfer tubes 12 and the orifice holes 92 when the first distributor 20 is projected in the axial direction of the first distributor 20. The heat transfer tubes 12 and the orifice holes 92 are disposed at positions that do not overlap with each other in the traveling direction (Z-axis direction) of the gas-liquid two-phase refrigerant that flows upward in the internal space 21 of the first distributor 20.

[0154] The gas-liquid two-phase refrigerant flowing upward in the internal space 21 of the first distributor 20 is considered to pass through the XY cross section where the flow path cross section does not overlap with the heat transfer tubes 12. In this case, if the orifice hole 92 is positioned to overlap with the heat transfer tubes 12, the flow path of the gas-liquid two-phase refrigerant will detour from the direction of travel due to the presence of the heat transfer tubes 12 and proceed to the orifice hole 92.

[0155] If the distributor causes the gas-liquid two-phase refrigerant to flow bypassing the heat transfer tubes 12 in this way, excessive pressure loss is likely to occur when the refrigerant passes through the orifice hole 92, which reduces not only the supply of gas refrigerant but also the supply of liquid refrigerant. For this reason, as shown in Figures 18 to 20, the first distributor 20 is disposed in a position where the plurality of heat transfer tubes 12 and the orifice hole 92 do not overlap when projected in the axial direction of the first distributor 20.

[0156] [Effects of the Heat Exchanger 50] The first distributor 20 is formed at a position where the orifice hole 92 and the heat transfer tube 12 do not overlap, which makes it difficult for the gas-liquid two-phase refrigerant to bypass the heat transfer tube 12, and the gas-liquid two-phase refrigerant flowing upward in the internal space 21 of the first distributor 20 can easily pass through the orifice hole 92. Therefore, the first distributor 20 is formed at a position where the orifice hole 92 and the heat transfer tube 12 do not overlap, which makes it possible to ensure a sufficient supply of liquid-rich gas-liquid two-phase refrigerant flowing into the upper space 21b, and to suppress a decrease in the heat exchanger performance of the heat exchanger 50.

[0157] Embodiment 4. Figure 21 is a conceptual diagram illustrating the relationship between the orifice holes 92 and the heat transfer tubes 12 in a first distributor 20 according to embodiment 4. Figure 21(a) is a schematic cross-sectional view perpendicular to the extension direction of the main body 20a taken along line CC shown in Figure 3. Figure 21(b) is a schematic cross-sectional view of the main body 20a taken along line EE in Figure 21(a). Figure 21(c) is a diagram illustrating the "air temperature distribution" with respect to the "air flow direction" in the air flow direction indicated by the white arrow in Figure 21(b). Note that components having the same functions and actions as those of the first distributor 20 according to embodiments 1 to 3 are designated by the same reference numerals, and their description will be omitted.

[0158] The relationship between the position of the orifice hole 92 and the heat transfer tube 12 will be described using FIG. 21 . The heat transfer tube 12 shown in FIG. 21 is formed flat with respect to the air flow direction. The heat transfer tube 12 is formed flat with its major axis in the Y-axis direction, which is perpendicular to the Z-axis, which is the axial direction of the main body 20a, and the X-axis direction, which is the extension direction of the heat transfer tube 12. The air flow is created, for example, by the outdoor fan 6 or the indoor fan 7 shown in FIG. 1 . The outdoor fan 6 or the indoor fan 7 supplies air to the heat exchanger 50.

[0159] Each of the heat transfer tubes 12 is a flat tube. A plurality of refrigerant flow path holes 12a are formed inside each of the heat transfer tubes 12, and the refrigerant flow path holes 12a are arranged in a line in the Y-axis direction, which is the air flow direction. The orifice holes 92 in the orifice plate 91 are formed in a position that is biased upwind from the center position of the first distributor 20. In other words, the first distributor 20 is formed so that the orifice holes 92 are located relatively upwind of the heat transfer tubes 12 in which the refrigerant flow path holes 12a are arranged in a line in the air flow direction.

[0160] As shown in Figure 21(c), the air gradually exchanges heat in the flow direction, resulting in a temperature drop. As a result, the heat transfer tube 12 is prone to have an insufficient amount of heat for heat exchange in the refrigerant flow path holes 12a located downstream of the air. Liquid refrigerant that has passed through the orifice hole 92 is most likely to concentrate in the refrigerant flow path hole 12a that is closest to the orifice hole 92. In the first distributor 20, the orifice hole 92 is positioned offset relative to the heat transfer tube 12 so that the refrigerant flow path hole 12a that is closest to the orifice hole 92, where the liquid refrigerant that has passed through the orifice hole 92 is most likely to concentrate, is located on the upwind side of the air.

[0161] [Effects of the Heat Exchanger 50] Each of the plurality of heat transfer tubes 12 has a plurality of refrigerant flow path holes 12a formed therein, and the plurality of refrigerant flow path holes 12a are aligned in the direction of air flow generated by a blower such as the outdoor blower 6 or the indoor blower 7. The first distributor 20 has the orifice holes 92 formed in the orifice plate 91 at a position that is biased upwind from the center of the first distributor 20. Therefore, the first distributor 20 can distribute the liquid refrigerant according to the heat quantity of the heat transfer tubes 12 having the plurality of refrigerant flow path holes 12a, thereby improving the heat exchange performance of the heat exchanger 50.

[0162] Furthermore, the first distributor 20 biases the position of the orifice hole 92 relative to the heat transfer tube 12 so that the refrigerant flow path hole 12a that is closest to the orifice hole 92 is on the upwind side of the air. Therefore, the first distributor 20 can distribute the liquid refrigerant according to the heat quantity of the heat transfer tube 12 that has the multiple refrigerant flow path holes 12a, thereby improving the heat exchanger performance of the heat exchanger 50.

[0163] Fifth Embodiment. Figure 22 is a schematic diagram of a heat exchanger 50 according to a fifth embodiment. Components having the same functions and actions as those of the heat exchangers 50 according to the first to fourth embodiments are denoted by the same reference numerals, and their description will be omitted. The solid arrows shown in Figure 22 indicate the direction of refrigerant flow. The hollow arrows shown in Figure 22 indicate the direction of air flow. In the following description, the heat exchanger 50 will be described as being used as an outdoor heat exchanger 5 that functions as an evaporator when the air conditioning apparatus 10 is used in heating operation.

[0164] 22 , the heat exchanger 50 includes a heat exchange section 50a, a first distributor 20, a second distributor 30, and a header 80. The first distributor 20 and the second distributor 30 may also be referred to as headers.

[0165] (Heat exchange unit 50a) The heat exchange unit 50a exchanges heat between the air present around the heat exchange unit 50a and the refrigerant flowing inside the heat exchange unit 50a. The heat exchange unit 50a is disposed between the first distributor 20 and the second distributor 30 in the flow of refrigerant flowing through the heat exchanger 50. The heat exchange unit 50a is also disposed between the second distributor 30 and the header 80 in the flow of refrigerant flowing through the heat exchanger 50. The heat exchange unit 50a has a plurality of heat transfer tubes 12 and a heat transfer promotion member 13 that connects adjacent heat transfer tubes 12.

[0166] The heat exchange unit 50a of the fifth embodiment has two or more rows of heat exchange units 50a. As shown in Fig. 22, the heat exchange unit 50a has a first heat exchange unit 51 located upstream in the air flow direction and a second heat exchange unit 52 located downstream. The first heat exchange unit 51 and the second heat exchange unit 52 are each formed to form an XZ plane. The first heat exchange unit 51 and the second heat exchange unit 52 are arranged to face each other in the Y-axis direction, which is the air flow direction.

[0167] When the heat exchanger 50 is the outdoor heat exchanger 5 (see FIG. 1 ), the air conditioning apparatus 10 has an outdoor blower 6 that generates an air flow passing through the heat exchanger 50. In this case, the heat exchange unit 50a has a first heat exchange unit 51 located upstream and a second heat exchange unit 52 located downstream in the direction of the air flow generated by the outdoor blower 6. That is, the first heat exchange unit 51 is disposed on the upwind side of the second heat exchange unit 52, and the second heat exchange unit 52 is disposed on the downwind side of the first heat exchange unit 51.

[0168] For example, in the direction of air flow formed by the outdoor blower 6, if the outdoor blower 6 is located on the upwind side of the heat exchanger 50, the first heat exchange unit 51 is arranged closer to the outdoor blower 6 than the second heat exchange unit 52. Alternatively, in the direction of air flow formed by the outdoor blower 6, if the outdoor blower 6 is located on the downwind side of the heat exchanger 50, the first heat exchange unit 51 is arranged farther from the outdoor blower 6 than the second heat exchange unit 52.

[0169] When the heat exchanger 50 is the indoor heat exchanger 3 (see FIG. 1 ), the air conditioning apparatus 10 has an indoor blower 7 that forms an air flow passing through the heat exchanger 50. In this case, the heat exchange unit 50a has a first heat exchange unit 51 located upstream and a second heat exchange unit 52 located downstream in the direction of the air flow formed by the indoor blower 7.

[0170] For example, in the direction of air flow formed by the indoor blower 7, if the indoor blower 7 is located on the upwind side of the heat exchanger 50, the first heat exchange unit 51 is arranged closer to the indoor blower 7 than the second heat exchange unit 52. Alternatively, in the direction of air flow formed by the indoor blower 7, if the indoor blower 7 is located on the downwind side of the heat exchanger 50, the first heat exchange unit 51 is arranged farther from the indoor blower 7 than the second heat exchange unit 52.

[0171] As shown in Fig. 22, the first heat exchange unit 51 has a first auxiliary heat exchange unit 51a located upstream of the flowing refrigerant and a first main heat exchange unit 51b located downstream of the flowing refrigerant. Similarly, as shown in Fig. 22, the second heat exchange unit 52 has a second auxiliary heat exchange unit 52a located upstream of the flowing refrigerant and a second main heat exchange unit 52b located downstream of the flowing refrigerant. In the heat exchange unit 50a, the refrigerant flows through the first auxiliary heat exchange unit 51a, the second auxiliary heat exchange unit 52a, the first main heat exchange unit 51b, and the second main heat exchange unit 52b in this order.

[0172] The first auxiliary heat exchanger section 51a has one end in the extension direction (X-axis direction) of the heat transfer tubes 12 connected to the first distributor 20, and the same end connected to the second auxiliary heat exchanger section 52a via a joint 401. In the first auxiliary heat exchanger section 51a, some of the multiple heat transfer tubes 12 are connected to the first distributor 20, and the other end is connected to the joint 401. The first auxiliary heat exchanger section 51a has a hairpin section 202 formed in a U-shape at the other end in the extension direction (X-axis direction) of the heat transfer tubes 12.

[0173] The first auxiliary heat exchange section 51a changes the flow direction of the refrigerant that flows out of the first distributor 20 and through the heat transfer tubes 12 at the hairpin section 202. The first auxiliary heat exchange section 51a is formed so that the refrigerant flows from the first distributor 20 toward the hairpin section 202, passes through a different heat transfer tube 12, and flows from the hairpin section 202 toward the arrangement side of the first distributor 20. The refrigerant flowing from the hairpin section 202 toward the arrangement side of the first distributor 20 flows into the second auxiliary heat exchange section 52a via the joint 401.

[0174] The second auxiliary heat exchange section 52a has one end in the extension direction (X-axis direction) of the heat transfer tubes 12 connected to the first auxiliary heat exchange section 51a via a joint 401, and also has the same end connected to the second distributor 30 via a pipe 300. In the second auxiliary heat exchange section 52a, some of the multiple heat transfer tubes 12 are connected to the pipe 300, and the other are connected to the joint 401. The second auxiliary heat exchange section 52a has a hairpin section 202 (not shown) formed in a U-shape at the other end in the extension direction (X-axis direction) of the heat transfer tubes 12.

[0175] The second auxiliary heat exchange section 52a is formed so that the refrigerant flowing out of the joint 401 and flowing through the heat transfer tubes 12 changes its flow direction at the hairpin section 202, passes through other heat transfer tubes 12 different from the heat transfer tubes 12 flowing toward the hairpin section 202, and flows toward the piping 300. The second auxiliary heat exchange section 52a and the second distributor 30 are connected by the piping 300.

[0176] The first main heat exchange section 51b includes an upper main heat exchange section 5b1, an upper-middle main heat exchange section 5b2, a lower-middle main heat exchange section 5b3, and a lower main heat exchange section 5b4. The upper main heat exchange section 5b1 is a portion of the first main heat exchange section 51b where the heat transfer tubes 12 constituting the upper main heat exchange section 5b1 are connected to the upper second distributor 31. The upper-middle main heat exchange section 5b2 is a portion of the first main heat exchange section 51b where the heat transfer tubes 12 constituting the upper-middle main heat exchange section 5b2 are connected to the upper-middle second distributor 32 (see FIG. 2 ).

[0177] The middle-lower main heat exchange section 5b3 is a portion of the first main heat exchange section 51b where the heat transfer tubes 12 constituting the middle-lower main heat exchange section 5b3 are connected to the middle-lower second distributor 33 (see FIG. 2 ). The lower main heat exchange section 5b4 is a portion of the first main heat exchange section 51b where the heat transfer tubes 12 constituting the lower main heat exchange section 5b4 are connected to the lower second distributor 34. The first main heat exchange section 51b is also a collective term for the upper main heat exchange section 5b1, the middle-upper main heat exchange section 5b2, the middle-lower main heat exchange section 5b3, and the lower main heat exchange section 5b4.

[0178] One end of the first main heat exchanger unit 51b in the extension direction (X-axis direction) of the heat transfer tubes 12 is connected to the second distributor 30, and the same end is connected to the second main heat exchanger unit 52b via a joint 401. In the first main heat exchanger unit 51b, some of the multiple heat transfer tubes 12 are connected to the second distributor 30, and the other parts are connected to the joint 401. The first main heat exchanger unit 51b has a hairpin portion 202 formed in a U-shape at the other end of the heat transfer tubes 12 in the extension direction (X-axis direction).

[0179] In the first main heat exchange unit 51b, the refrigerant that flows out of the second distributor 30 and through the heat transfer tubes 12 changes its flow direction at the hairpin portion 202. The first main heat exchange unit 51b is formed so that the refrigerant flows from the second distributor 30 toward the hairpin portion 202, passes through a different heat transfer tube 12, and flows from the hairpin portion 202 toward the side where the second distributor 30 is located. The refrigerant flowing from the hairpin portion 202 toward the side where the second distributor 30 is located flows into the second main heat exchange unit 52b via the joint 401.

[0180] The second main heat exchanger section 52b has one end in the extension direction (X-axis direction) of the heat transfer tubes 12 connected to the first main heat exchanger section 51b via a joint 401, and also has the same end connected to the header 80. In the second main heat exchanger section 52b, some of the multiple heat transfer tubes 12 are connected to the header 80, and the other are connected to the joint 401. The second main heat exchanger section 52b has a hairpin section 202 (not shown) formed in a U-shape at the other end in the extension direction (X-axis direction) of the heat transfer tubes 12.

[0181] The second main heat exchange section 52b is formed so that the refrigerant that flows out of the joint 401 and through the heat transfer tube 12 changes its flow direction at the hairpin section 202, passes through other heat transfer tubes 12 different from the heat transfer tube 12 heading toward the hairpin section 202, and heads toward the header 80.

[0182] (First distributor 20) When the heat exchanger 50 functions as an evaporator, the first distributor 20 is provided on the refrigerant inlet side of the first auxiliary heat exchange section 51a. The first distributor 20 is connected to one end of the heat transfer tubes 12 constituting the first auxiliary heat exchange section 51a in the extension direction (X-axis direction). The first distributor 20 is connected to the heat transfer tubes 12 of the first auxiliary heat exchange section 51a so that the interior of the first distributor 20 communicates with the inside of the heat transfer tubes 12.

[0183] The first distributor 20 is formed to extend along the arrangement direction (Z-axis direction) of the plurality of heat transfer tubes 12. The first distributor 20 distributes the refrigerant to the plurality of heat transfer tubes 12. In the heat exchanger 50, the first distributor 20 functions as a distribution mechanism that distributes the refrigerant flowing into the first auxiliary heat exchange section 51a of the heat exchange section 50a to the plurality of heat transfer tubes 12.

[0184] (Second distributor 30) When the heat exchanger 50 functions as an evaporator, the second distributor 30 is provided on the refrigerant inlet side of the first main heat exchange section 51 b. When the heat exchanger 50 functions as an evaporator, the second distributor 30 is provided on the refrigerant outlet side of the second auxiliary heat exchange section 52 a.

[0185] The second distributor 30 is connected to one end of the heat transfer tubes 12 constituting the first main heat exchange section 51b in the extension direction (X-axis direction) of the heat transfer tubes 12. The second distributor 30 is connected to the heat transfer tubes 12 of the first main heat exchange section 51b so that the interior of the second distributor 30 communicates with the inside of the heat transfer tubes 12. The second distributor 30 is connected to the heat transfer tubes 12 constituting the second auxiliary heat exchange section 52a via piping 300.

[0186] The second distributor 30 is formed to extend along the arrangement direction (Z-axis direction) of the plurality of heat transfer tubes 12. The second distributor 30 distributes the refrigerant to the plurality of heat transfer tubes 12. In the heat exchanger 50, the second distributor 30 functions as a distribution mechanism that distributes the refrigerant flowing into the first main heat exchange section 51b of the heat exchange section 50a to the plurality of heat transfer tubes 12.

[0187] As described above, the second auxiliary heat exchange unit 52a and the second distributor 30 are connected by the piping 300. More specifically, the second auxiliary heat exchange unit 52a is connected to the upper piping 301, the middle upper piping 302, the middle lower piping 303, and the lower piping 304.

[0188] The upper piping 301 is a piping that connects the second auxiliary heat exchange section 52a and the upper second distributor 31. The upper piping 301 communicates, via the heat transfer tubes 12, the lower space 21a (see FIG. 2 ) of the first distributor 20 with the interior of the upper second distributor 31. The upper-middle piping 302 is a piping that connects the second auxiliary heat exchange section 52a and the upper-middle second distributor 32. The upper-middle piping 302 communicates, via the heat transfer tubes 12, the upper space 21b (see FIG. 2 ) of the first distributor 20 with the interior of the upper-middle second distributor 32.

[0189] The lower-middle piping 303 is a piping that connects the second auxiliary heat exchange section 52a and the lower-middle second distributor 33. The lower-middle piping 303 communicates, via the heat transfer tubes 12, the upper space 21b (see FIG. 2 ) of the first distributor 20 with the interior of the lower-middle second distributor 33. The lower piping 304 is a piping that connects the second auxiliary heat exchange section 52a and the lower second distributor 34. The lower piping 304 communicates, via the heat transfer tubes 12, the lower space 21a (see FIG. 2 ) of the first distributor 20 with the interior of the lower second distributor 34.

[0190] (Header 80) The header 80 is connected to one end in the extension direction (X-axis direction) of the plurality of heat transfer tubes 12 that constitute the second main heat exchange section 52b. The header 80 is connected to the heat transfer tubes 12 of the second main heat exchange section 52b so that the interior of the header 80 communicates with the inside of the heat transfer tubes 12. The header 80 functions as a confluence mechanism in the heat exchanger 50 when the refrigerants flowing out from the plurality of heat transfer tubes 12 of the second main heat exchange section 52b are confluenced. The header 80 may also be referred to as a gas header.

[0191] In the heat exchanger 50 shown in the fifth embodiment, the second distributor 30 is disposed on the upstream side in the air flow direction and the header 80 is disposed on the downstream side, as shown in Fig. 22. In the heat exchanger 50 shown in the fifth embodiment, the first distributor 20 is disposed on the upstream side in the air flow direction and the header 80 is disposed on the downstream side, as shown in Fig. 22.

[0192] 22 , in the heat exchanger 50 shown in the fifth embodiment, the second distributor 30 is disposed above the first distributor 20, and the first distributor 20 is disposed below the second distributor 30. In the heat exchanger 50 shown in the fifth embodiment, the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31 are arranged in a vertical line. In the heat exchanger 50 shown in the fifth embodiment, the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31 are arranged in this order from bottom to top.

[0193] FIG. 23 is an explanatory diagram of the refrigerant flow path of the heat exchanger 50 according to the fifth embodiment. In FIG. 23 , the "distributor side" represents the end of the heat exchanger 50 on the side where the first distributor 20 is disposed, and the "hairpin side" represents the end of the heat exchanger 50 on the side where the hairpin section 202 is disposed. The dotted and solid arrows in FIG. 23 indicate the flow of refrigerant. The flow of refrigerant through the first heat exchange section 51 and the second heat exchange section 52 will be described using FIG. 23 . Note that the inlet A1, opening A2, opening A3, outlet A4, inlet B1, opening B2, opening B3, and outlet B4 conceptually represent openings at the ends of the heat transfer tubes 12.

[0194] The inlet A1, the opening A2, the opening A3, the outlet A4, the inlet B1, the opening B2, the opening B3, and the outlet B4 are connected to the lower main body 20a1 of the first distributor 20 and communicate with the lower space 21a (see FIG. 3). The inlet A1, the opening A2, the opening A3, the outlet A4, the inlet B1, the opening B2, the opening B3, and the outlet B4 are connected to the upper main body 20a2 of the first distributor 20 and communicate with the upper space 21b (see FIG. 3).

[0195] For example, the flow of refrigerant will be described when the first heat exchange section 51 shown in Fig. 23 is a first auxiliary heat exchange section 51a and the second heat exchange section 52 is a second auxiliary heat exchange section 52a. When the refrigerant RA distributed by the first distributor 20 flows into the first heat exchange section 51 from the inlet A1 of the first heat exchange section 51, the refrigerant RA flows from the inlet A1 to the hairpin section 202 (see Fig. 22).

[0196] In the first heat exchange section 51, the refrigerant RA that reaches the hairpin section 202 makes a U-turn at the hairpin section 202, flows through the heat transfer tube 12 one stage above the heat transfer tube 12 that flowed from the inlet A1 to the hairpin section 202, and heads from the hairpin section 202 toward the opening A2, which is located one stage above the inlet A1.

[0197] The opening A2 of the first heat exchange section 51 and the opening A3 of the second heat exchange section 52 are connected by a U-shaped pipe, a U-bent 402. More specifically, the openings A2 and A3 are provided with joints 401 (see FIG. 22 ), and the U-bent 402 is provided to connect the joint 401 of the opening A2 and the joint 401 of the opening A3.

[0198] The refrigerant RA moves through the column from the first heat exchange section 51 to the second heat exchange section 52 via the U-vent 402. The refrigerant RA that flows out from the opening A2 of the first heat exchange section 51 passes through the U-vent 402 and flows into the opening A3 of the second heat exchange section 52. The refrigerant RA that flows into the second heat exchange section 52 from the opening A3 flows from the opening A3 to the hairpin section 202 (see FIG. 22 ).

[0199] In the second heat exchange section 52, the refrigerant RA that reaches the hairpin section 202 makes a U-turn at the hairpin section 202, flows through the heat transfer tube 12 one stage below the heat transfer tube 12 that flowed from the opening A3 to the hairpin section 202, and then flows from the hairpin section 202 to the outlet A4. The outlet A4 is located one stage below the opening A3. The refrigerant RA that flows out of the second heat exchange section 52 from the outlet A4 passes through the pipe 300 (see FIG. 22 ) and flows into the second distributor 30.

[0200] Furthermore, when the refrigerant RB distributed by the first distributor 20 flows into the first heat exchange section 51 from the inlet B1 of the first heat exchange section 51, the refrigerant RB flows from the inlet B1 to the hairpin section 202 (see FIG. 22 ). The inlet B1 is located one step lower than the inlet A1.

[0201] In the first heat exchange section 51, the refrigerant RB that reaches the hairpin section 202 makes a U-turn at the hairpin section 202, flows through the heat transfer tube 12 that is one stage below the heat transfer tube 12 that flowed from the inlet B1 to the hairpin section 202, and heads from the hairpin section 202 toward the opening B2. The opening B2 is located one stage below the inlet B1.

[0202] The opening B2 of the first heat exchange section 51 and the opening B3 of the second heat exchange section 52 are connected by a U-shaped pipe, a U-bent 402. More specifically, the openings B2 and B3 are provided with joints 401 (see FIG. 22 ), and the U-bent 402 is provided to connect the joint 401 of the opening B2 with the joint 401 of the opening B3.

[0203] The refrigerant RB moves through the column from the first heat exchange section 51 to the second heat exchange section 52 via the U-vent 402. The refrigerant RB that flows out from the opening B2 of the first heat exchange section 51 passes through the U-vent 402 and flows into the opening B3 of the second heat exchange section 52. The refrigerant RB that flows into the second heat exchange section 52 from the opening B3 flows from the opening B3 to the hairpin section 202 (see FIG. 22 ).

[0204] In the second heat exchange section 52, the refrigerant RB that reaches the hairpin section 202 makes a U-turn at the hairpin section 202, flows through the heat transfer tube 12 one stage above the heat transfer tube 12 that flowed from the opening B3 to the hairpin section 202, and then flows from the hairpin section 202 toward the outlet B4. The outlet B4 is located one stage above the opening B3. The refrigerant RB that flows out of the second heat exchange section 52 from the outlet B4 passes through the pipe 300 (see FIG. 22 ) and flows into the second distributor 30. The outlet B4 is located one stage below the outlet A4.

[0205] The above description of the flows of refrigerant RA and refrigerant RB applies to the case where the first heat exchange section 51 is the first auxiliary heat exchange section 51 a and the second heat exchange section 52 is the second auxiliary heat exchange section 52 a. When the first heat exchange section 51 is the first main heat exchange section 51 b and the second heat exchange section 52 is the second main heat exchange section 52 b, refrigerant RA flows from the second distributor 30 into the inlet A1, and refrigerant RB flows from the second distributor 30 into the inlet B1.

[0206] Furthermore, when the first heat exchange section 51 is the first main heat exchange section 51b and the second heat exchange section 52 is the second main heat exchange section 52b, the refrigerant RA flows into the header 80 from the outlet A4 of the second heat exchange section 52, and the refrigerant RB flows into the header 80 from the outlet B4 of the second heat exchange section 52. The flow of the refrigerant RA from the inlet A1 to the outlet A4 and the flow of the refrigerant RB from the inlet B1 to the outlet B4 are the same as those in the case where the first heat exchange section 51 is the first auxiliary heat exchange section 51a and the second heat exchange section 52 is the second auxiliary heat exchange section 52a.

[0207] 24 is a schematic diagram of a modified example of the heat exchanger 50 according to the fifth embodiment. The modified example of the heat exchanger 50 according to the fifth embodiment has a distributor 120. The distributor 120 is formed by integrally forming the first distributor 20 and the second distributor 30. More specifically, the distributor 120 is formed by integrally forming the first distributor 20, the upper second distributor 31, the upper-middle second distributor 32, the lower-middle second distributor 33, and the lower second distributor 34. In the modified example of the heat exchanger 50 according to the fifth embodiment, the second distributor 30 is formed in the same shape as the first distributor 20. That is, the second distributor 30 is formed by the first part 23 and the second part 24 together with the first distributor 20.

[0208] In the distributor 120, the components constituting the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31 are arranged side by side in the vertical direction (Z-axis direction). In the distributor 120, the components constituting the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31 are arranged side by side from bottom to top in this order, and these components are formed integrally.

[0209] The first distributor 20 and the second distributor 30 are integrally formed to extend in the vertical direction (Z-axis direction), and have a partition plate 94 that separates the internal space of the first distributor 20 from the internal space of the second distributor 30.

[0210] The first distributor 20 and the second distributor 30, i.e., the first distributor 20 and the lower second distributor 34, are separated by a partition plate 94. The space of the first distributor 20 and the space of the lower second distributor 34 are separated by a partition plate 94. Similarly, the lower second distributor 34 and the lower-middle second distributor 33, the lower-middle second distributor 33 and the upper-middle second distributor 32, and the upper-middle second distributor 32 and the upper second distributor 31 are also separated by partition plates 94.

[0211] The space of the lower second distributor 34 and the space of the lower-middle second distributor 33 are separated by a partition plate 94. In addition, the space of the lower-middle second distributor 33 and the space of the upper-middle second distributor 32 are separated by a partition plate 94. In addition, the space of the upper-middle second distributor 32 and the space of the upper-middle second distributor 31 are separated by a partition plate 94.

[0212] [Action and effect of heat exchanger 50] In a modified example of the heat exchanger 50 according to the fifth embodiment, the first distributor 20 and the second distributor 30 are integrally formed to extend in the vertical direction (Z-axis direction), and a partition plate 94 is provided to separate the internal space of the first distributor 20 from the internal space of the second distributor 30. In the modified example of the heat exchanger 50 according to the fifth embodiment, if the parts constituting the first component 23 (see FIG. 4 ) and the parts constituting the second component 24 are made long, the first distributor 20 and the second distributor 30 can be constituted by using small parts such as the partition plate 94.

[0213] Furthermore, the distributor 120 is divided into sections that make up the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31 by partition plates 94. If the parts that make up the first component 23 and the parts that make up the second component 24 are made as long parts, the distributor 120 can be divided into the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31 by using small parts such as the partition plate 94.

[0214] A modified example of the heat exchanger 50 according to the fifth embodiment has a distributor 120, and by using a partition plate 94, the first distributor 20, the lower second distributor 34, the middle-lower second distributor 33, the middle-upper second distributor 32, and the upper second distributor 31 can be configured within the distributor 120. The heat exchanger 50 can configure the first distributor 20, the lower second distributor 34, the middle-lower second distributor 33, the middle-upper second distributor 32, and the upper second distributor 31 using simple components, which can reduce material costs and manufacturing costs compared to when these parts are made separately.

[0215] Furthermore, the heat exchanger 50 can be configured with simple components, including the first distributor 20, the lower second distributor 34, the middle-lower second distributor 33, the middle-upper second distributor 32, and the upper second distributor 31, making it possible to make the heat exchanger 50 more compact than if these parts were made separately.

[0216] Furthermore, the heat exchanger 50 can be configured with simple components, including the first distributor 20, the lower second distributor 34, the lower-middle second distributor 33, the upper-middle second distributor 32, and the upper second distributor 31. Therefore, the heat exchanger 50 can contribute to improved assembly by reducing the number of parts compared to when these parts are made separately.

[0217] [Example of Use of Heat Exchanger 50] Fig. 25 is a first schematic diagram showing the relationship between the heat exchanger 50 according to Embodiments 1 to 5 and the outdoor blower 6. The arrows in Fig. 25 indicate the flow of air. The outdoor blower 6 shown in Fig. 25 is a blower that supplies air to the multiple heat transfer tubes 12 of the heat exchanger 50 that constitutes the outdoor heat exchanger 5.

[0218] As shown in Figure 25, the outdoor unit 111 has an outdoor heat exchanger 5 and an outdoor blower 6. The outdoor unit 111 is used in the air conditioning apparatus 10. The outdoor unit 111 is, for example, an outdoor unit for home or commercial use, and has a side-flow type outdoor blower 6. The outdoor heat exchanger 5 used in the outdoor unit 111 uses the heat exchanger 50 described above. Note that the outdoor unit 111 may also be an indoor unit, in which case the outdoor heat exchanger 5 is the indoor heat exchanger 3 (see Figure 1), and the outdoor blower 6 is the indoor blower 7.

[0219] Fig. 26 is a second schematic diagram showing the relationship between the heat exchanger 50 and the outdoor blower 6 according to Embodiments 1 to 5. The arrows in Fig. 26 indicate the flow of air. The outdoor blower 6 shown in Fig. 26 is a blower that supplies air to the multiple heat transfer tubes 12 of the heat exchanger 50 that constitutes the outdoor heat exchanger 5.

[0220] As shown in Figure 26, the outdoor unit 112 has an outdoor heat exchanger 5 and an outdoor blower 6. The outdoor unit 112 is used in the air conditioning apparatus 10. The outdoor unit 112 is, for example, an outdoor unit for a building, and is equipped with a top-flow type outdoor blower 6. The outdoor heat exchanger 5 used in the outdoor unit 112 uses the heat exchanger 50 described above. Note that the outdoor unit 112 may also be an indoor unit, in which case the outdoor heat exchanger 5 is the indoor heat exchanger 3 (see Figure 1), and the outdoor blower 6 is the indoor blower 7.

[0221] Fig. 27 is a first schematic diagram showing the relationship between the heat exchanger 50 and the indoor blower 7 according to Embodiments 1 to 5. The arrows in Fig. 27 indicate the flow of air. The indoor blower 7 shown in Fig. 27 is a blower that supplies air to the multiple heat transfer tubes 12 of the heat exchanger 50 that constitutes the indoor heat exchanger 3.

[0222] As shown in Figure 27, the indoor unit 113 has an indoor heat exchanger 3 and an indoor blower 7. The indoor unit 113 is used in the air conditioning apparatus 10. The indoor unit 113 is, for example, a cassette-type indoor unit for commercial use, and is equipped with a turbofan as the indoor blower 7. The indoor heat exchanger 3 used in the indoor unit 113 uses the heat exchanger 50 described above. Note that the indoor unit 113 may also be an outdoor unit, in which case the indoor heat exchanger 3 would be the outdoor heat exchanger 5 (see Figure 1), and the indoor blower 7 would be the outdoor blower 6.

[0223] Fig. 28 is a second schematic diagram showing the relationship between the heat exchanger 50 and the indoor blower 7 according to Embodiments 1 to 5. The arrows in Fig. 28 indicate the flow of air. The indoor blower 7 shown in Fig. 28 is a blower that supplies air to the multiple heat transfer tubes 12 of the heat exchanger 50 that constitutes the indoor heat exchanger 3.

[0224] As shown in Figure 28, the indoor unit 114 has an indoor heat exchanger 3 and an indoor blower 7. The indoor unit 114 is used in the air conditioning apparatus 10. The indoor unit 114 is, for example, a home indoor unit, and is equipped with a crossflow fan as the indoor blower 7. The indoor heat exchanger 3 used in the indoor unit 114 uses the heat exchanger 50 described above. Note that the indoor unit 114 may also be an outdoor unit, in which case the indoor heat exchanger 3 would be the outdoor heat exchanger 5 (see Figure 1), and the indoor blower 7 would be the outdoor blower 6.

[0225] FIG. 29 is a third schematic diagram showing the relationship between the heat exchanger 50 and the indoor blower 7 according to Embodiments 1 to 5. FIG. 30 is a fourth schematic diagram showing the relationship between the heat exchanger 50 and the indoor blower 7 according to Embodiments 1 to 5. Arrows shown in FIGS. 29 and 30 indicate the flow of air. The indoor blower 7 shown in FIGS. 29 and 30 is a blower that supplies air to the multiple heat transfer tubes 12 of the heat exchanger 50 that constitutes the indoor heat exchanger 3. As shown in FIGS. 29 and 30 , the indoor unit 115 and the indoor unit 116 have the indoor heat exchanger 3 and the indoor blower 7.

[0226] In the indoor unit 115, in the direction of air flow formed by the indoor blower 7, the indoor blower 7 is arranged upstream of the indoor heat exchanger 3, and the indoor heat exchanger 3 is arranged downstream of the indoor blower 7. In the indoor unit 116, in the direction of air flow formed by the indoor blower 7, the indoor blower 7 is arranged downstream of the indoor heat exchanger 3, and the indoor heat exchanger 3 is arranged upstream of the indoor blower 7.

[0227] The indoor units 115 and 116 are used in the air conditioning apparatus 10. The indoor units 115 and 116 are, for example, ceiling-mounted indoor units, and are equipped with a sirocco fan as the indoor blower 7. The indoor heat exchanger 3 used in the indoor units 115 and 116 uses the heat exchanger 50 described above. Note that the indoor units 115 and 116 may also be outdoor units, in which case the indoor heat exchanger 3 is the outdoor heat exchanger 5 (see FIG. 1 ), and the indoor blower 7 is the outdoor blower 6.

[0228] 29 and 30, the problem of liquid refrigerant falling due to separation of the liquid refrigerant and gas refrigerant is less likely to occur. However, a heat exchanger 50 having a distributor according to any of the first to fifth embodiments may be used to prevent a shortage of liquid refrigerant above the distributor when the refrigerant flow rate is low.

[0229] [Operation and effect of air conditioning apparatus 10] The air conditioning apparatus 10 is equipped with the heat exchanger 50 according to any one of the above-described embodiments 1 to 5. Therefore, the air conditioning apparatus 10 can obtain the same effects as any one of the heat exchangers 50 according to embodiments 1 to 5.

[0230] The above-described first to fifth embodiments can be implemented in combination with one another. The configurations described in the above embodiments are merely examples of the content of the present disclosure and can be combined with other known technologies. Parts of the configuration can also be omitted or modified without departing from the spirit of the present disclosure. The heat exchanger 50 according to the present disclosure can be applied to, for example, a heat pump device, a hot water supply device, or a refrigeration device in addition to the air conditioning device 10 described above. The heat exchanger 50 may also be used as an upstream distributor that does not require an auxiliary heat exchange section 5a. The second distributor 30 may also have an orifice plate 91.

[0231] REFERENCE SIGNS LIST 1 Compressor, 2 Flow switching device, 3 Indoor heat exchanger, 4 Pressure reducing device, 5 Outdoor heat exchanger, 5a Auxiliary heat exchange section, 5b Main heat exchange section, 5b1 Upper main heat exchange section, 5b2 Middle upper main heat exchange section, 5b3 Middle lower main heat exchange section, 5b4 Lower main heat exchange section, 6 Outdoor blower, 7 Indoor blower, 10 Air conditioning device, 12 Heat transfer tube, 12a Refrigerant flow path hole, 12b Tip portion, 13 Heat transfer promotion member, 20 First distributor, 20a Main body portion, 20a1 Lower main body portion, 20a2 Upper main body portion, 21 Internal space, 21a Lower space, 21b Upper space, 21c Corner portion, 21d Corner portion, 23 First part, 24 Second part, 25 Insertion surface portion, 26 Side portion, 27 Bulging portion, 27a opposing surface, 27b highest portion, 27c circular convex portion, 27d square convex portion, 27e mountain-shaped convex portion, 28 flat plate portion, 28a joint portion, 30 second distributor, 31 upper second distributor, 32 middle upper second distributor, 33 middle lower second distributor, 34 lower second distributor, 35 gas-liquid two-phase refrigerant, 41 lid, 42 lid, 43 connection port, 44 inlet, 50 heat exchanger, 50a heat exchange section, 51 first heat exchange section, 51a first auxiliary heat exchange section, 51b first main heat exchange section, 52 second heat exchange section, 52a second auxiliary heat exchange section, 52b second main heat exchange section, 80 header, 91 orifice plate, 92 orifice hole, 92a orifice hole, 92b Orifice hole, 94 partition plate, 111 outdoor unit, 112 outdoor unit, 113 indoor unit, 114 indoor unit, 115 indoor unit, 116 indoor unit, 120 distributor, 201 inlet pipe, 202 hairpin portion, 300 piping, 301 upper piping, 302 upper middle piping, 303 lower middle piping, 304 lower piping, 401 joint, 402 U-bent, 801 outlet pipe, A1 inlet, A2 opening, A3 opening, A4 outlet, B1 inlet, B2 opening, B3 opening, B4 outlet.

Claims

1. A refrigerant distribution device comprising: a plurality of heat transfer tubes arranged at intervals in the vertical direction; and a first distributor formed to extend in the vertical direction and distributing a refrigerant to the plurality of heat transfer tubes, wherein the first distributor has an insertion surface portion into which the plurality of heat transfer tubes are inserted; an opposing surface portion that faces the insertion surface portion in the direction in which the plurality of heat transfer tubes extend; and a side surface portion that is a wall extending between the insertion surface portion and the opposing surface portion and that is joined to the opposing surface portion in an axis-perpendicular cross section that is a cross section perpendicular to the longitudinal direction of the first distributor, wherein the opposing surface portion has a flat plate portion that connects to the side surface portion, and a bulge portion in the axis-perpendicular cross section where a part of an inner wall that forms the internal space of the first distributor bulges from the flat plate portion towards the insertion surface portion, and the first distributor is A heat exchanger in which, in a cross section perpendicular to the axis, the shortest distance from the tip of each of the heat transfer tubes to the bulge portion is defined as a first distance M1, and the distance from the tip of each of the heat transfer tubes in the direction in which the heat transfer tubes extend to the position of the flat portion is defined as a second distance M2, and the relationship second distance M2 ≧ 1.5 × first distance M1 is satisfied.

2. A heat exchanger according to claim 1, wherein the insertion surface portion is at least partially curved so as to be convex toward the side on which the plurality of heat transfer tubes are arranged in the cross section perpendicular to the axis.

3. A heat exchanger as described in claim 1 or 2, wherein the first distributor has a lid that closes both longitudinal ends of the first distributor and forms the internal space together with the insertion surface portion, the opposing surface portion, and the side surface portion.

4. A heat exchanger as claimed in any one of claims 1 to 3, wherein the first distributor has at least one orifice plate that separates the internal space into an upper space located above and a lower space located below in the longitudinal direction of the first distributor, and the orifice plate has a through hole formed therein that connects the upper space and the lower space.

5. A heat exchanger as described in claim 4, wherein the first distributor is arranged in a position where the plurality of heat transfer tubes and the orifice holes do not overlap when projected in the axial direction of the first distributor.

6. A heat exchanger as claimed in any one of claims 1 to 5, wherein the opposing surface portion is formed with at least one inlet through which a refrigerant flows into the internal space, and the inlet is formed in a position in the internal space opposite the heat transfer tube located at the lowest position among the plurality of heat transfer tubes, or is formed so as to be located lower than the heat transfer tube located at the lowest position among the plurality of heat transfer tubes.

7. A heat exchanger according to any one of claims 1 to 6, wherein the first distributor comprises a first part having the insertion surface portion and the side surface portion, and a second part which is the opposing surface portion, and is formed into a cylindrical shape by combining the first part and the second part.

8. A heat exchanger according to any one of claims 1 to 7, wherein the bulging portion is formed in a cross section perpendicular to the axis in one of the following cross-sectional shapes: a semicircular shape, a rectangular shape, a triangular shape, a shape of multiple continuous semicircles, a shape of multiple continuous rectangular shapes, or a shape of multiple continuous triangles.

9. A heat exchanger according to any one of claims 1 to 8, comprising: a main heat exchange section having more than half of the plurality of heat transfer tubes; an auxiliary heat exchange section having the remaining heat transfer tubes of the plurality of heat transfer tubes that do not constitute the main heat exchange section; the first distributor connected to the auxiliary heat exchange section; and a second distributor connected to the main heat exchange section and distributing refrigerant flowing out of the auxiliary heat exchange section to the plurality of heat transfer tubes that constitute the main heat exchange section, wherein the first distributor and the second distributor are formed integrally so as to extend in the vertical direction, and have a partition plate that separates the internal space of the first distributor from the internal space of the second distributor.

10. A refrigerant cooling system comprising: a main heat exchange section having at least half of the plurality of heat transfer tubes; an auxiliary heat exchange section having the remaining heat transfer tubes of the plurality of heat transfer tubes that do not constitute the main heat exchange section; the first distributor connected to the auxiliary heat exchange section; and a plurality of second distributors connected to the main heat exchange section and distributing the refrigerant flowing out of the auxiliary heat exchange section to the plurality of heat transfer tubes that constitute the main heat exchange section, wherein the main heat exchange section has: an upper main heat exchange section located at the top in the vertical direction of the main heat exchange section; a lower main heat exchange section located at the bottom in the vertical direction of the main heat exchange section; and a central main heat exchange section disposed between the upper main heat exchange section and the lower main heat exchange section in the vertical direction of the main heat exchange section, wherein the first distributor is formed with the upper space that forms a space above the orifice plate and the lower space that forms a space below the orifice plate, and the upper space is 6. The heat exchanger according to claim 4 or 5, wherein the lower space is in communication with the plurality of heat transfer tubes constituting the central main heat exchange section via the auxiliary heat exchange section and one or more of the plurality of second distributors, and the lower space is in communication with the plurality of heat transfer tubes constituting the upper main heat exchange section and the lower main heat exchange section via the auxiliary heat exchange section and one or more of the other plurality of second distributors that are not in communication with the central main heat exchange section.

11. A heat exchanger according to any one of claims 1 to 10, wherein the first distributor is installed with its longitudinal central axis oriented vertically or with its longitudinal central axis tilted within a range that has a vertical vector component.

12. An air conditioning system comprising: a heat exchanger according to claim 4 or 5; and a blower that supplies air to the heat exchanger, wherein each of the plurality of heat transfer tubes has a plurality of refrigerant flow path holes formed therein, the plurality of refrigerant flow path holes are arranged in a line in the direction of the air flow formed by the blower, and the orifice holes in the orifice plate are formed at a position biased upwind from the center position of the first distributor.

13. An air conditioning device comprising: a heat exchanger according to any one of claims 1 to 11; and a blower that supplies air to the heat exchanger.

Images