Heat exchangers and refrigeration cycle systems

Abstract

It accurately detects when defrosting has been completed across the entire surface of the heat exchanger. [Solution] The first heat source heat exchanger 13 includes a flow divider 90, a plurality of capillary tubes 80, and a main body 85. The plurality of capillary tubes 80 extend from the flow divider 90. The main body 85 has a plurality of paths 93a. Each of the plurality of paths 93a is connected to a plurality of capillary tubes 80. The capillary tube 80 connected to the defrost completion detection path 931 among the plurality of paths 93a is designated as the first capillary tube 81, and the highest vertical portion of the first capillary tube 81 is designated as the first portion 811. When the vertical distance from the upper end of the main body 85 to the end of the first capillary tube 81 on the flow divider 90 side is designated as the first distance D1, the first portion 811 is positioned above the flow divider 90 and at a position higher than 50% of the first distance D1 above the end of the first capillary tube 81 on the flow divider 90 side.

Description

Technical Field

[0001] It relates to a heat exchanger and a refrigeration cycle device.

Background Art

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-256304) describes a heat source heat exchanger of a refrigeration cycle device capable of performing a defrosting operation during a heating operation.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In the defrosting operation, the determination of the completion of defrosting greatly affects the operation efficiency. Therefore, it is required to accurately detect that the entire surface of the heat exchanger has completed defrosting.

Means for Solving the Problems

[0004] The heat exchanger of the first aspect has a diverter, a plurality of capillary tubes, and a main body. The plurality of capillary tubes extend from the diverter. The main body has a heat transfer part. The heat transfer part is connected to each of the plurality of capillary tubes. Among the plurality of heat transfer parts, the capillary tube connected to the heat transfer part for detecting the completion of defrosting is defined as the first capillary tube. The highest part in the vertical direction of the first capillary tube is defined as the first part. When the vertical distance from the upper end of the main body to the end of the first capillary tube on the diverter side is defined as the first distance, the first part is above the diverter and is arranged at a position higher than 50% of the first distance upward from the end of the first capillary tube on the diverter side.

[0005] According to this heat exchanger, it is possible to accurately detect that the entire surface of the heat exchanger has completed defrosting.

[0006] The heat exchanger of the second aspect is the heat exchanger of the first aspect, and the first part is above the diverter and is arranged at a position higher than 80% of the first distance upward from the end of the first capillary tube on the diverter side.

[0007] The heat exchanger in the third view is a heat exchanger in the first view or the second view, wherein the first part is positioned at a height below the upper end of the main body.

[0008] The heat exchanger of the fourth perspective is a heat exchanger of any of the first to third perspectives, in which, when the second part is defined as the highest vertical portion of the multiple capillary tubes other than the first capillary tube, the first part is positioned higher than the second part.

[0009] The heat exchanger of the fifth aspect is a heat exchanger of any of the first to fourth aspects, wherein the first capillary tube has a portion that is wound multiple times.

[0010] The heat exchanger in the sixth aspect is a heat exchanger of any of the first to fifth aspects, and the first capillary tube is the longest of the multiple capillary tubes.

[0011] The heat exchanger in the seventh aspect is the heat exchanger in the sixth aspect, where the length of the first capillary tube is 1.5 times or more the length of the second capillary tube. The second capillary tube is the second longest of the multiple capillary tubes.

[0012] The heat exchanger of the eighth aspect is a heat exchanger of any of the first to seventh aspects, and the inner diameter of the first capillary tube is the smallest among the multiple capillary tubes.

[0013] The refrigeration cycle device of the ninth aspect comprises a heat exchanger of any of the first to eighth aspects, a compressor, an expansion valve, and a heat exchanger on the utilization side. The refrigeration cycle device is capable of both cooling and heating operation. The heat transfer unit for detecting the completion of defrosting functions as a condensing unit during cooling operation and as an evaporation unit during heating operation. [Brief explanation of the drawing]

[0014] [Figure 1] This is a simplified refrigerant circuit diagram showing the configuration of the air conditioning system 100. [Figure 2] This is a schematic diagram of the first heat source heat exchanger 13. [Figure 3] This is a schematic perspective view of the first heat source heat exchanger 13. [Figure 4] This is a schematic cross-sectional view of the main body 85 of the first heat source heat exchanger 13. [Figure 5] This is a magnified view of the area around the capillary tube 80. [Figure 6] This is a schematic diagram showing the flow of refrigerant in the first heat source heat exchanger 13 during heating operation. [Modes for carrying out the invention]

[0015] Embodiments of this disclosure will be described below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, the embodiments, modifications, and other examples described below can be combined or partially replaced to the extent that the present invention is implementable.

[0016] In the following description, expressions indicating directions such as "up" and "down" are used as appropriate, but these represent the directions when the air conditioning unit 100 is installed and in normal use. In this embodiment, the up and down direction is the vertical direction.

[0017] (1) Overall structure An outdoor unit 10 according to one embodiment of this disclosure is used in an air conditioning system 100, which is an example of a refrigeration cycle system.

[0018] A refrigeration cycle system can be configured in the form of an air conditioning system 100, a refrigerator, a freezer, a water heater, a floor heating system, etc. The refrigeration cycle system provides the user with cold or heat obtained from a heat source by circulating a refrigerant. The air conditioning system 100 provides cold to the user in cold energy utilization operation. The air conditioning system 100 provides heat to the user in heat energy utilization operation. When the refrigeration cycle system is an air conditioning system, cold energy utilization operation and heat energy utilization operation correspond to cooling operation and heating operation, respectively.

[0019] As shown in Figure 1, the air conditioning system 100 comprises an outdoor unit 10, a plurality of indoor units 20, and refrigerant piping 30. In this embodiment, an air conditioning system in which three indoor units 20 are connected in parallel to one outdoor unit 10 will be described as an example. However, in Figure 1, the connection between the outdoor unit 10 and the indoor units 20 is omitted. Although the air conditioning system 100 comprises a plurality of indoor units 20, only one indoor unit 20 is shown in Figure 1.

[0020] The outdoor unit 10 houses the outdoor circuit. Each indoor unit 20 houses the indoor circuit. The indoor units 20 and the outdoor unit 10 are connected by refrigerant piping 30, forming a refrigerant circuit through which the refrigerant circulates. In the refrigerant circuit, three indoor circuits are connected in parallel to the outdoor circuit. The type of refrigerant filled into the refrigerant circuit is not particularly limited, but for example, it is filled with R407C, a non-azeotropic mixed refrigerant.

[0021] The air conditioning system 100 selectively performs either cooling or heating in each indoor unit 20 (cooling / heating free system). Depending on the open / closed state of various valves provided in the outdoor unit 10, etc., this air conditioning system 100 can perform various operations such as heating operation (all indoor units 20 are in heating operation), heating-dominant operation (when the total capacity required by the indoor units 20 performing heating operation exceeds the total capacity required by the indoor units 20 performing cooling operation), cooling operation (all indoor units 20 are in cooling operation), and cooling-dominant operation (when the total capacity required by the indoor units 20 performing cooling operation exceeds the total capacity required by the indoor units 20 performing heating operation).

[0022] (2) Detailed Configuration (2-1) Outdoor Unit 10 The outdoor unit 10 obtains cold or warm heat from the air as the heat source. The outdoor unit 10 includes a first heat source heat exchanger 13, a second heat source heat exchanger 13B, a refrigerant pipe 30, a compressor 11, a first four-way switching valve 12A, a second four-way switching valve 12B, a first heat source expansion valve 15A connected to the first heat source heat exchanger 13, a second heat source expansion valve 15B connected to the second heat source heat exchanger 13B, a liquid shut-off valve 17, a gas shut-off valve 18, and a heat source control unit 19. Each member is connected by the refrigerant pipe 30.

[0023] (2-1-1) First Heat Source Heat Exchanger 13 As shown in FIG. 2, the first heat source heat exchanger 13 obtains cold or warm heat in the refrigerant by performing heat exchange between the air as the heat source and the refrigerant. When performing cold heat utilization operation, the first heat source heat exchanger 13 functions as a condenser or radiator of the refrigerant to obtain cold heat in the refrigerant. When performing warm heat utilization operation, the first heat source heat exchanger 13 functions as an evaporator or heat absorber of the refrigerant to obtain warm heat in the refrigerant.

[0024] As shown in FIGS. 2 and 3, the first heat source heat exchanger 13 includes a main body 85, a diverter 90, and a capillary tube 80.

[0025] The main body 85 is a so-called microchannel type heat exchanger. The main body 85 includes a heat exchange part 95, a first header 91, and a second header 92. The heat exchange part 95 includes a plurality of flat tubes 93 and a plurality of insertion fins 94.

[0026] The flattened tube 93 carries the refrigerant through it. Figure 4 is a magnified view of the heat exchange section 95 when the flattened tube 93 and the insertion fins 94 are cut vertically. The flattened tube 93 functions as a heat transfer tube, transferring the heat moving between the insertion fins 94 and the outside air to the refrigerant flowing inside. The flattened tube 93 has multiple through-holes formed in a predetermined direction through which the refrigerant, which is heat-exchanged with the outside air in the first heat source heat exchanger 13, passes. The through-holes of the flattened tube 93 penetrate along the direction in which the first heat source heat exchanger 13 extends. As a result, the flattened tube 93 constitutes multiple paths 93a.

[0027] Of the multiple paths 93a, the path 93a located at the bottom of the first heat source heat exchanger 13 is the defrosting completion detection path 931. A refrigerant temperature sensor 52 is attached to the defrosting completion detection path 931. The refrigerant temperature sensor 52 measures the temperature of the refrigerant passing through this section. The defrosting completion detection path 931 functions as a condensing section during cooling operation and as an evaporation section during heating operation.

[0028] The insert fins 94 consist of multiple fins and are flat plate-shaped members. The insert fins 94 are connected to the flattened pipes 93. Multiple horizontally elongated notches are formed in the insert fins 94 so that they can be inserted into multiple stages of flattened pipes 93 arranged between the first header 91 and the second header 92. The shape of these notches on the insert fins 94 is approximately consistent with the outer cross-sectional shape of the flattened pipes 93.

[0029] Multiple insert fins 94 are stacked in the first direction in which the flattened tube 93 extends. In addition, multiple insert fins 94 extend vertically so as to intersect (in this case perpendicular to) the flattened tube 93.

[0030] The insert fins 94 increase the heat transfer surface area between the flattened tube 93 and the outside air, thereby promoting heat exchange between the refrigerant and the outside air.

[0031] The first header 91 and the second header 92 are positioned one at each end of the main body 85. Multiple flattened tubes 93 are connected to the first header 91 and the second header 92. The refrigerant passing through the inside of the multiple flattened tubes 93 is collected in the first header 91 and the second header 92. Partition plates may be formed inside the first header 91 and the second header 92 to divide the internal space. Capillary tubes 80 are connected to the first header 91 and the second header 92.

[0032] The flow divider 90 is located on the side of the main body 85, near the bottom of the first header 91. The flow divider 90 is formed in the shape of a hollow inverted frustocone. As shown in Figure 2, the flow divider 90 has multiple branch-side connection ports 90a and one manifold-side connection port 90b opening on the upper surface of the inverted frustocone. Therefore, the flow divider 90 is installed with the branch-side connection ports 90a facing directly upwards. These manifold-side connection ports 90b and branch-side connection ports 90a communicate with the internal space of the flow divider 90.

[0033] Each branch side connection port 90a of the flow divider 90 is connected to a single capillary tube 80. Each capillary tube 80 is connected to a corresponding flat pipe 93 via a first header 91. Meanwhile, a liquid-side refrigerant pipe 31 is connected to the manifold side connection port 90b of the flow divider 90.

[0034] Multiple capillary tubes 80 extend from the shunt 90. The capillary tubes 80 are connected to multiple paths 93a via a first header 91.

[0035] The capillary tube 80 includes a first capillary tube 81, a second capillary tube 82, and other capillary tubes. The first capillary tube 81 is connected to the defrosting completion detection path 931, one of several paths 93a.

[0036] The first capillary tube 81 includes a first portion 811, which is the highest vertical portion of the first capillary tube 81.

[0037] The first part 811 is positioned above the flow divider 90. When the vertical distance from the upper end of the main body 85 to the flow divider 90 side end of the first capillary tube 81 is defined as the first distance D1, the first part 811 is positioned at a height of more than 50% of the first distance D1 above the flow divider 90 side end of the first capillary tube 81. More preferably, the first part 811 is positioned at a height of more than 80% of the first distance D1 above the flow divider 90 side end of the first capillary tube 81. The flow divider 90 side end of the first capillary tube 81 is the boundary position between the branch side connection port 90a of the flow divider 90 and the capillary tube 80 that branches off from the branch side connection port 90a. Here, "upper end of the main body 85" refers to the upper end of the insertion fin 94 of the heat exchanger of the first heat source heat exchanger 13.

[0038] The first part 811 is positioned at a height below the upper end of the main body 85.

[0039] When the highest vertical portion of the multiple capillary tubes 80 other than the first capillary tube 81 is designated as the second portion 822, the first portion 811 is positioned higher than the second portion 822.

[0040] The first capillary tube 81 is the longest of the multiple capillary tubes 80. The second capillary tube 82 is the second longest of the multiple capillary tubes 80. The length of the first capillary tube 81 is more than 1.5 times the length of the second capillary tube 82, which is the second longest of the multiple capillary tubes 80.

[0041] The first capillary tube 81 is shaped to rise from the shunt 90. More specifically, as shown in Figures 3 and 5, the first capillary tube 81 is shaped to rise upward from the branch side connection port 90a of the shunt 90. The method of raising the first capillary tube 81 upward is not particularly limited, but for example, the first capillary tube 81 is fastened to the other capillary tubes 80 with fasteners. The fasteners are, for example, cable ties.

[0042] The first capillary tube 81 rising from the flow divider 90 has a portion 812 that is wound multiple times on its way to the first portion 811. The method of securing the portion 812 that is wound multiple times is not particularly limited, but for example, the wound first capillary tube 81 is fastened to the other capillary tubes 80 with a fastener. The fastener is, for example, a cable tie.

[0043] The first capillary tube 81 rises further after the multiple-wound section 812 and reaches the first section 811. After reaching the first section 811, the first capillary tube 81 descends and connects to the defrosting completion detection path 931.

[0044] The inner diameter of the first capillary tube 81 is the smallest among the multiple capillary tubes 80.

[0045] (2-1-2)Second heat source heat exchanger 13B As shown in Figure 1, the second heat source heat exchanger 13B allows the refrigerant to acquire cooling or heating energy by exchanging heat between the air, which is the heat source, and the refrigerant. The second heat source heat exchanger 13B functions as a condenser during cooling operation. The second heat source heat exchanger 13B does not operate during heating operation. During heating operation, no refrigerant flows through the second heat source heat exchanger 13B.

[0046] (2-1-3) Refrigerant piping 30 As shown in Figure 1, the refrigerant piping 30 includes a liquid-side refrigerant piping 31 and a gas-side refrigerant piping 32. The liquid-side refrigerant piping 31 mainly passes refrigerant in a liquid state or a gas-liquid two-phase state. The liquid-side refrigerant piping 31 connects the liquid shut-off valve 17 to the first heat source heat exchanger 13. The gas-side refrigerant piping 32 mainly passes refrigerant in a high-pressure gas state or a low-pressure gas state. The gas-side refrigerant piping 32 connects the gas shut-off valve 18 to the first heat source heat exchanger 13.

[0047] (2-1-4) Compressor 11 The compressor 11 has an intake pipe and a discharge pipe. The compressor 11 draws in refrigerant in a low-pressure gas state from the intake pipe, compresses the refrigerant, and discharges the refrigerant in a high-pressure gas state from the discharge pipe.

[0048] (2-1-5) First four-way switching valve 12A, second four-way switching valve 12B The first four-way switching valve 12A and the second four-way switching valve 12B switch between cooling operation and heating operation by switching the direction of refrigerant flow. When performing cooling operation, the first four-way switching valve 12A and the second four-way switching valve 12B form the connection shown by the solid line in Figure 1, and the refrigerant flows in the direction indicated by the arrow CO. When performing heating operation, the first four-way switching valve 12A and the second four-way switching valve 12B form the connection shown by the dashed line in Figure 1, and the refrigerant flows in the direction indicated by the arrow HO.

[0049] (2-1-6) First heat source expansion valve 15A and second heat source expansion valve 15B The first heat source expansion valve 15A is connected to the first heat source heat exchanger 13. The second heat source expansion valve 15B is connected to the second heat source heat exchanger 13B.

[0050] The first heat source expansion valve 15A and the second heat source expansion valve 15B reduce the pressure of the refrigerant. The first heat source expansion valve 15A and the second heat source expansion valve 15B are composed of electrically operated valves that can adjust the degree of opening. When the opening of the first heat source expansion valve 15A and the second heat source expansion valve 15B is set to a small value, the amount of refrigerant that can pass through the first heat source expansion valve 15A and the second heat source expansion valve 15B decreases, and the pressure of the refrigerant after passing through the first heat source expansion valve 15A and the second heat source expansion valve 15B decreases.

[0051] During heating operation, the second heat source expansion valve 15B is in a fully closed state.

[0052] (2-1-7) Liquid shut-off valve 17 and gas shut-off valve 18 Liquid shut-off valve 17 and gas shut-off valve 18 are connected to liquid-side refrigerant piping 31 and gas-side refrigerant piping 32, respectively.

[0053] The liquid shut-off valve 17 and the gas shut-off valve 18 are for shutting off the movement of refrigerant during installation work of the air conditioning system 100. The liquid shut-off valve 17 and the gas shut-off valve 18 are opened and closed manually by the air conditioning system 100 installer.

[0054] (2-1-8) Heat source control unit 19 The heat source control unit 19 is a computer that performs various calculations. The heat source control unit 19 acquires signals from various sensors, including the refrigerant temperature sensor 52. Furthermore, the heat source control unit 19 controls actuators mounted on the compressor 11, the first four-way switching valve 12A, the first heat source expansion valve 15A, and other components.

[0055] The heat source control unit 19 is implemented by a computer. The heat source control unit 19 comprises a control calculation unit and a memory device. A processor such as a CPU or GPU can be used for the control calculation unit. The control calculation unit reads a program stored in the memory device and performs predetermined calculation processing according to this program. Furthermore, the control calculation unit can write the calculation results to the memory device or read information stored in the memory device according to the program.

[0056] The heat source control unit 19 determines whether defrosting is complete based on the refrigerant gas temperature result detected by the refrigerant temperature sensor 52.

[0057] (2-2) Indoor unit 20 The indoor unit 20 provides the user with the cooling or heating obtained by the outdoor unit 10 from the heat source. The indoor unit 20 has a heat exchanger 23.

[0058] Refrigerant piping 30 extends from the indoor unit 20 towards the outdoor unit 10.

[0059] The utilization heat exchanger 23 provides cooling or heating to the user by exchanging heat between the air in the user's environment or a refrigerant such as water used by the user. When operating for cooling, the utilization heat exchanger 23 functions as an evaporator or absorber for the refrigerant, providing cooling to the user. When operating for heating, the utilization heat exchanger 23 functions as an evaporator or absorber for the refrigerant, providing heating to the user.

[0060] (3) Overall operation This section describes the basic operation of the air conditioning system 100. This air conditioning system 100 allows switching between heating operation, where the first heat source heat exchanger 13 operates as an evaporator, and cooling operation, where the first heat source heat exchanger 13 operates as a condenser. Furthermore, during heating operation, the air conditioning system 100 allows switching between normal operation and defrosting operation. The cooling operation will not be described. Also, since the second heat source heat exchanger 13B does not operate during heating operation, the operation of the second heat source heat exchanger 13B will also not be described.

[0061] (3-1) Heating operation The operation of the air conditioning system 100 during heating operation will be explained with reference to Figure 1. Here, we will describe the normal operation in which the first heat source heat exchanger 13 acts as an evaporator.

[0062] During normal heating operation, the compressor 11, the outdoor fan of the outdoor unit 10, and the indoor fans of each indoor unit 20 are operated. Also during this normal operation, the first four-way switching valve 12A and the second four-way switching valve 12B are set to the state shown in Figure 1, and the opening degree of the first heat source expansion valve 15A and each utilization expansion valve is adjusted as appropriate.

[0063] During heating operation, the first four-way switching valve 12A and the second four-way switching valve 12B of the outdoor unit 10 are switched as shown in Figure 1, thereby causing the first heat source heat exchanger 13 to function as an evaporator.

[0064] The dashed arrows along the refrigerant circuit 30 in Figure 1 indicate the flow of refrigerant during heating operation. The refrigerant discharged from the compressor 11 flows into the gas-side refrigerant piping 32 and is then distributed to each indoor circuit. The refrigerant that flows into the indoor circuits flows into the utilization heat exchanger 23, where it releases heat into the indoor air and condenses. The indoor air heated in the utilization heat exchanger 23 is sent back into the room. The refrigerant condensed in the utilization heat exchanger 23 passes through the utilization expansion valve and then flows into the liquid-side refrigerant piping 31.

[0065] The refrigerant flowing into the liquid-side refrigerant piping 31 is depressurized as it passes through the first heat source expansion valve 15A before flowing into the first heat source heat exchanger 13. The refrigerant flowing into the first heat source heat exchanger 13 absorbs heat from the outside air and evaporates, and is then drawn into the compressor 11. The refrigerant drawn into the compressor 11 is compressed and then discharged from the compressor 11.

[0066] The flow of refrigerant in the first heat source heat exchanger 13 during normal operation will be explained with reference to Figure 6.

[0067] In the first heat source heat exchanger 13, the refrigerant, which is depressurized and becomes a gas-liquid two-phase state as it passes through the first heat source expansion valve 15A, flows into the flow divider 90 through the liquid-side refrigerant piping 31. The refrigerant that flows into the flow divider 90 is distributed to each capillary tube 80 and flows into the liquid-side end of each pass 93a via the first header 91 of the main body 85. The refrigerant that flows into the main body 85 absorbs heat from the air and evaporates as it flows through each pass 93a. The refrigerant that has passed through each pass 93a flows into the second header 92 from the gas-side end of each pass 93a, and after merging, flows into the gas-side refrigerant piping 32.

[0068] (3-2) Defrosting operation As described above, during normal heating operation, the first heat source heat exchanger 13 acts as an evaporator. In operating conditions where the outside temperature is low and the evaporation temperature of the refrigerant in the first heat source heat exchanger 13 falls below 0°C, frost will accumulate on the first heat source heat exchanger 13. Therefore, if the operating conditions are such that frost may accumulate on the first heat source heat exchanger 13, a defrosting operation is performed to melt the frost on the first heat source heat exchanger 13, for example, each time the duration of normal operation reaches a predetermined standard value.

[0069] During the defrosting operation, the outdoor fan and indoor fan are stopped. During the defrosting operation, high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 is supplied to the first heat source heat exchanger 13, and the frost adhering to the first heat source heat exchanger 13 is warmed by the refrigerant and melted.

[0070] The flow of refrigerant in the first heat source heat exchanger 13 during defrosting will be explained with reference to Figure 2.

[0071] In the first heat source heat exchanger 13, the refrigerant discharged from the compressor 11 flows into the second header 92 through the gas-side refrigerant piping 32, and is then distributed to each pass 93a of the main body 85. In each pass 93a of the main body 85, the refrigerant introduced from the second header 92 to its gas-side end condenses as it flows through the pass 93a and releases heat. In the main body 85, frost adhering to the surface of the fins is heated and melted by the refrigerant flowing through each pass 93a.

[0072] The refrigerant that has passed through each path 93a of the main unit 85 flows from the liquid-side end of each path 93a through the first header 91 into the corresponding capillary tube 80. At the same time, the refrigerant that has passed through each path 93a flows through the corresponding capillary tube 80 into the flow divider 90, and after merging, flows into the liquid-side refrigerant piping 31. The refrigerant passing through the first capillary tube 81 is the last to complete its flow into the flow divider 90 compared to the refrigerant passing through the other capillary tubes 80.

[0073] (4) Features (4-1) The first heat source heat exchanger 13 includes a flow divider 90, a plurality of capillary tubes 80, and a main body 85. The plurality of capillary tubes 80 extend from the flow divider 90. The main body 85 has a plurality of paths 93a. Each of the plurality of paths 93a is connected to a plurality of capillary tubes 80. The capillary tube 80 connected to the defrost completion detection path 931 among the plurality of paths 93a is designated as the first capillary tube 81, and the highest vertical portion of the first capillary tube 81 is designated as the first part 811. When the vertical distance from the upper end of the main body 85 to the end of the first capillary tube 81 on the flow divider 90 side is designated as the first distance D1, the first part 811 is positioned above the flow divider 90 and at a position higher than 50% of the first distance D1 above the end of the first capillary tube 81 on the flow divider 90 side.

[0074] In this first heat source heat exchanger 13, the first portion 811 of the first capillary tube 81 connected to the defrosting completion detection path 931 is positioned higher than 50% of the first distance D1. This makes it difficult for the liquid refrigerant flowing through the defrosting completion detection path 931 to flow towards the flow divider 90 due to gravity when switching from heating operation to defrosting operation. As a result, the defrosting time of the defrosting completion detection path 931 can be delayed, and it is possible to ensure that defrosting is completed last in the defrosting completion detection path 931. As a result, it is possible to accurately detect that the entire surface of the heat exchanger has been defrosted.

[0075] Furthermore, with this first heat source heat exchanger 13, it is only necessary to extend the first capillary tube 81 relative to the flow divider 90. Therefore, there is no need to extend the length of the first capillary tube 81 or reduce its inner diameter. As a result, the defrosting time of the defrosting completion detection path 931 can be delayed without complicating the structure of the first heat source heat exchanger 13 or worrying about wax clogging.

[0076] Furthermore, the heat transfer unit used for detecting the completion of defrosting is often located at the bottom of the multiple heat transfer units.

[0077] (4-2) The first portion 811 is positioned above the shunt 90 and at a position higher than 80% of the first distance D1 above the shunt 90-side end of the first capillary tube 81.

[0078] In this configuration, the system can be more susceptible to the effects of gravity. Therefore, the defrosting time of the defrosting completion detection path 931 can be delayed.

[0079] (4-3) The first part 811 is positioned at a height below the upper end of the main body 85.

[0080] In this configuration, it is possible to prevent the first heat source heat exchanger 13 from becoming larger.

[0081] (4-4) When the highest vertical portion of the multiple capillary tubes 80 other than the first capillary tube 81 is designated as the second portion 822, the first portion 811 is positioned higher than the second portion 822.

[0082] In this configuration, the gravitational effect on the first capillary tube 81 can be made greater than the gravitational effect on the other capillary tubes 80.

[0083] (4-5) The first capillary tube 81 has a portion 812 that is wound multiple times.

[0084] In this configuration, the length of the first capillary tube 81 can be extended. Therefore, the defrosting time of the defrosting completion detection path 931 can be delayed.

[0085] (4-6) The first capillary tube 81 is the longest of the multiple capillary tubes 80.

[0086] In this configuration, the defrosting completion time of the defrosting completion detection path 931 can be delayed compared to the defrosting completion times of the other capillary tubes 80.

[0087] (4-7) The length of the first capillary tube 81 is more than 1.5 times the length of the second capillary tube 82. The second capillary tube 82 is the second longest of the multiple capillary tubes 80.

[0088] In this configuration, the defrosting completion time of the defrosting completion detection path 931 can be delayed compared to the defrosting completion times of the other capillary tubes 80.

[0089] (4-8) The inner diameter of the first capillary tube 81 is the smallest among the multiple capillary tubes 80.

[0090] In this configuration, the defrosting completion time of the defrosting completion detection path 931 can be delayed compared to the defrosting completion times of the other capillary tubes 80.

[0091] (4-9) The air conditioning system 100 includes a first heat source heat exchanger 13, a compressor 11, a first heat source expansion valve 15A, and a utilization heat exchanger 23. The air conditioning system 100 is capable of both cooling and heating operation. The defrosting completion detection path 931 functions as a condensing section during cooling operation and as an evaporation section during heating operation.

[0092] In this configuration, when switching from heating operation to defrosting operation, the liquid refrigerant flowing through the defrosting completion detection path 931 is less likely to flow towards the flow divider 90 due to gravity. As a result, the defrosting time in the defrosting completion detection path 931 can be delayed, and the complete defrosting of the heat exchanger can be detected with high accuracy.

[0093] (5) Variant (5-1) Variation A In the above embodiment, the shunt 90 is installed with the branch side connection port 90a facing directly upwards, but it is not limited to this. The shunt 90 may be installed, for example, with the branch side connection port 90a facing directly downwards.

[0094] (5-2) Variation B In the above embodiment, the multiple capillary tubes 80 are connected to the multiple paths 93a via the first header 91, but are not limited thereto. The multiple capillary tubes 80 may also be connected to the first header 91.

[0095] (5-3) Modification C In the above embodiment, the first heat source heat exchanger 13 is a so-called microchannel type heat exchanger, but is not limited to this. The first heat source heat exchanger 13 may be, for example, a so-called cross-fin type fin-and-tube type heat exchanger.

[0096] (5-4) In the above embodiment, the liquid-side refrigerant piping 31 is located on the upper surface of the flow divider 90, but is not limited to this. The liquid-side refrigerant piping 31 may be located, for example, on the lower surface of the flow divider 90.

[0097] While embodiments of this disclosure have been described above, it will be understood that various modifications to the form and details are possible without departing from the spirit and scope of this disclosure as described in the claims. Furthermore, these embodiments and modifications may be combined or substituted as appropriate, as long as they do not impair the function of the subject matter of this disclosure. The terms “First,” “Second,” etc., described above are used to distinguish the phrases to which these terms are attached, and do not limit the number or order of such phrases. [Industrial applicability]

[0098] As described above, this disclosure is useful for heat exchangers and refrigeration cycle systems. [Explanation of Symbols]

[0099] 10:Outdoor unit 11: Compressor 12A: First four-way switching valve 13: First heat source heat exchanger (an example of a heat exchanger) 15A: First heat source expansion valve (an example of an expansion valve) 17: Liquid shut-off valve 18: Gas shut-off valve 19: Heat source control unit 20: Indoor unit 30: Refrigerant piping 31: Liquid side refrigerant piping 32: Gas-side refrigerant piping 52: Refrigerant temperature sensor 80: Capillary tube 81: First capillary tube 82: Second capillary tube 85: Main unit 90: Flow divider 91: First Header 92: Second Header 93 :Flat tube 93a: Pass (an example of a heat transfer section) 94: Insert fins 95:Heat exchange part 100: Air conditioning system (an example of a refrigeration cycle system) 811 :1st part 812 :part 822 :Second part 931: Defrosting completion detection path D1: First distance [Prior art documents] [Patent Documents]

[0100] [Patent Document 1] Japanese Patent Publication No. 2008-256304

Claims

1. A shunt (90) and Multiple capillary tubes (80) extending from the aforementioned diverter, A main body (85) having multiple heat transfer sections (93a) to which multiple capillary tubes are each connected, Equipped with, Among the plurality of heat transfer units, the capillary tube connected to the heat transfer unit for detecting the completion of defrosting is defined as the first capillary tube (81), the highest vertical portion of the first capillary tube is defined as the first portion (811), and the vertical distance from the upper end of the main body to the end of the first capillary tube on the flow divider side is defined as the first distance (D1), wherein the first portion is positioned above the flow divider and at a position higher than 50% of the first distance above the end of the first capillary tube on the flow divider side. heat exchanger.

2. The first portion is positioned above the flow divider and at a position higher than 80% of the first distance above the flow divider-side end of the first capillary tube. The heat exchanger according to claim 1.

3. The first part is positioned at a height below the upper end of the main body, The heat exchanger according to claim 1.

4. When the highest vertical portion of the plurality of capillary tubes other than the first capillary tube is defined as the second portion, the first portion is positioned higher than the second portion. The heat exchanger according to claim 1.

5. The first capillary tube has a portion that is wound multiple times, The heat exchanger according to claim 1.

6. The first capillary tube is the longest of the plurality of capillary tubes. The heat exchanger according to claim 1.

7. The length of the first capillary tube is 1.5 times or more the length of the second capillary tube (82), which is the second longest of the multiple capillary tubes. The heat exchanger according to claim 6.

8. The inner diameter of the first capillary tube is the smallest of the plurality of capillary tubes. The heat exchanger according to claim 1.

9. A heat exchanger according to any one of claims 1 to 8, Compressor (11) and Expansion valve (15A), The heat exchanger (23) used, A refrigeration cycle device (100) comprising, The aforementioned refrigeration cycle device is capable of both cooling and heating operations. The heat transfer unit for detecting the completion of defrosting functions as a condensing unit during cooling operation and as an evaporation unit during heating operation. Refrigeration cycle device.

Images