Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
  • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
  • F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
  • F28D1/053—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/02—Header boxes; End plates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/22—Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/26—Arrangements for connecting different sections of heat-exchange elements, e.g. of radiators

Definitions

• the technology disclosed herein relates to heat exchangers, outdoor units, and refrigeration cycle devices.
• it relates to heat exchangers having a header that serves as a refrigerant distributor.
• a heat exchanger configured with refrigerant inlet and outlet pipes connected vertically to a header
• the refrigerant flows at a slower rate through the heat transfer pipes.
• the refrigerant is affected by gravity, and differences in flow rate reduce the heat exchange performance of the heat exchanger.
• the heat exchange performance may be reduced depending on the connection configuration of the pipes connecting the main heat exchange section and the subcooling section.
• the objective is to provide a heat exchanger, outdoor unit, and refrigeration cycle device that can solve the above-mentioned problems and improve heat exchange performance.
• the heat exchanger comprises a pair of headers arranged at a distance from each other in the height direction, through which a refrigerant passes in cylindrical tubes; a plurality of heat transfer tubes connected in rows at intervals along the length of the pair of headers, each having a flow path therein through which the refrigerant flows; a plurality of heat exchange sections connected to the lower header of the pair of headers, which is the lower one of the pair of headers, and which have refrigerant inlet and outlet pipes through which the refrigerant flows in and out of the external refrigerant piping; a heat exchange section which serves as the main heat exchange section for exchanging heat between the air and the refrigerant and condensing the refrigerant; and a heat exchange section which functions as the main heat exchange section for exchanging heat between the air and the refrigerant and condensing the refrigerant.
• the lower header includes a connecting pipe that connects the refrigerant that has passed through the main heat exchanger to a heat exchanger that serves as a subcooling heat exchanger that exchanges heat between the refrigerant that has passed through the main heat exchanger and air, and subcools the refrigerant that has passed through the main heat exchanger.
• the subcooling heat exchanger has an unconnected area on one end of the top surface of the lower header where no heat transfer pipes are connected, and the refrigerant inlet and outlet pipes are connected in the unconnected area.
• the connecting pipe connects the refrigerant inlet and outlet pipes on the refrigerant outlet side of the main heat exchanger to the refrigerant inlet and outlet pipes on the refrigerant inlet and outlet side of the subcooling heat exchanger.
• the outdoor unit according to this disclosure has the heat exchanger according to this disclosure as its outdoor heat exchanger.
• the refrigeration cycle device has the outdoor unit according to this disclosure.
• the lower header has refrigerant inlet and outlet pipes connected from the top surface, and the refrigerant inlet and outlet pipes on the refrigerant outflow side of the main heat exchange section are connected to the refrigerant inlet and outlet pipes on the refrigerant inflow side of the subcooling heat exchange section by connecting pipes.
• FIG. 1 is a diagram showing the configuration of an air conditioning apparatus according to a first embodiment.
• 1A and 1B are diagrams illustrating a heat exchanger 1000 according to a first embodiment.
• FIG. 10 is a diagram showing the relationship between the stage ratio R and heat exchange performance according to the first embodiment.
• 10 is a diagram showing a part of a cross section of a heat exchanger 1000 according to a second embodiment when viewed along the Y direction.
• FIG. 10 is a diagram showing a part of a cross section of a heat exchanger 1000 according to a second embodiment when viewed along the X direction.
• FIG. 10A and 10B are diagrams illustrating corrugated fins 1500 in a heat exchange section 1010 according to embodiment 3.
• 10 is a diagram illustrating the arrangement of an outdoor heat exchanger 230 in an outdoor unit 200 according to a fourth embodiment.
• FIG. 10 is a diagram illustrating the arrangement of an outdoor heat exchanger 230 in an outdoor unit 200 according to a fifth embodiment.
• FIG. 1 is a diagram showing the configuration of an air conditioner according to Embodiment 1.
• the air conditioner will be described as an example of a refrigeration cycle apparatus having a heat exchanger according to Embodiment 1.
• the air conditioning apparatus of embodiment 1 has an outdoor unit 200, an indoor unit 100, and two refrigerant pipes 300.
• the outdoor unit 200 is a unit that includes a compressor 210, a four-way valve 220, and an outdoor heat exchanger 230 as its equipment.
• the indoor unit 100 is a unit that includes an indoor heat exchanger 110 and an expansion valve 120 as its equipment.
• the equipment inside the outdoor unit 200 and the equipment inside the indoor unit 100 are connected by refrigerant pipes 300, forming a refrigerant circuit in which refrigerant, a fluid that transports heat, circulates.
• the air conditioning apparatus of embodiment 1 has one outdoor unit 200 and one indoor unit 100 that are connected by pipes. However, the number of connected units is not limited to this.
• the indoor unit 100 also has an indoor fan 130.
• the indoor heat exchanger 110 and expansion valve 120 are connected by piping within the indoor unit 100.
• the expansion valve 120 such as a throttling device, reduces the pressure of the refrigerant to expand it. If the expansion valve 120 is configured as an electronic expansion valve, for example, it adjusts its opening based on instructions from a control device (not shown).
• the indoor heat exchanger 110 exchanges heat between the refrigerant and the indoor air that is the space to be air-conditioned. For example, during heating operation, the indoor heat exchanger 110 functions as a condenser, condensing and liquefying the refrigerant.
• the indoor heat exchanger 110 functions as an evaporator, evaporating and vaporizing the refrigerant.
• the indoor fan 130 passes indoor air through the indoor heat exchanger 110 and supplies the air that has passed through the indoor heat exchanger 110 into the room.
• outdoor unit 200 has a compressor 210, a four-way valve 220, an outdoor heat exchanger 230, and an accumulator 240 as components that make up the refrigerant circuit. These components are connected by piping within outdoor unit 200. Outdoor unit 200 also has an outdoor fan 250. Compressor 210 compresses and discharges the refrigerant it draws in. Compressor 210 is, for example, a scroll compressor, a reciprocating compressor, or a vane compressor. Furthermore, although not particularly limited, the capacity of compressor 210 can be changed by arbitrarily changing the drive frequency using, for example, an inverter circuit or the like.
• the four-way valve 220 which serves as a flow path switching device, is a valve that switches the flow of refrigerant between cooling operation and heating operation, for example.
• the four-way valve 220 connects the discharge side of the compressor 210 to the indoor heat exchanger 110, and connects the suction side of the compressor 210 to the outdoor heat exchanger 230.
• the four-way valve 220 connects the discharge side of the compressor 210 to the outdoor heat exchanger 230, and connects the suction side of the compressor 210 to the indoor heat exchanger 110. While the use of a four-way valve 220 is illustrated here as an example, the flow path switching device is not limited to this.
• the flow path switching device may also be a device that combines multiple two-way valves, for example.
• the accumulator 240 is installed on the suction side of the compressor 210.
• the accumulator 240 allows gaseous refrigerant (hereinafter referred to as gas refrigerant) to pass through and stores liquid refrigerant (hereinafter referred to as liquid refrigerant).
• the outdoor heat exchanger 230 exchanges heat between the refrigerant and outdoor air.
• the refrigerant is a fluid that serves as a heat exchange medium.
• the outdoor heat exchanger 230 of embodiment 1 functions as an evaporator during heating operation, evaporating and vaporizing the refrigerant.
• the outdoor heat exchanger 230 functions as a condenser and subcooler during cooling operation, condensing and liquefying the refrigerant, thereby subcooling it.
• the outdoor heat exchanger 230 of embodiment 1 has one or more heat exchangers 1000, including a heat exchange section 1010 that serves as the main heat exchange section 1011 and a heat exchange section 1010 that serves as the subcooling heat exchange section 1012, as described below.
• the outdoor fan 250 when driven, sends air from outside the outdoor unit 200 to the outdoor unit 200, passing it through the outdoor heat exchanger 230 and forming a flow of air that flows out of the outdoor unit 200.
• the refrigerant is decompressed as it passes through the expansion valve 120.
• the refrigerant passes through the subcooling heat exchanger 1012 and then the main heat exchanger 1011 in that order.
• the refrigerant evaporates by exchanging heat with the outdoor air sent from the outdoor fan 250, and the gaseous refrigerant passes through the four-way valve 220 and the accumulator 240, and is again drawn into the compressor 210. In this way, the refrigerant in the air conditioner circulates to perform air conditioning related to heating.
• the dotted arrows in Figure 1 indicate the flow of refrigerant during cooling operation.
• the high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 210 passes through the four-way valve 220 and flows into the outdoor heat exchanger 230.
• the refrigerant passes through the main heat exchange section 1011 of the heat exchanger 1000 (described later) and condenses and liquefies by exchanging heat with outdoor air supplied by the outdoor fan 250.
• the liquefied refrigerant then passes through the subcooling heat exchange section 1012 of the heat exchanger 1000 (described later) and is subcooled by exchanging heat with outdoor air supplied by the outdoor fan 250.
• the subcooled refrigerant passes through the expansion valve 120.
• the refrigerant is decompressed as it passes through the expansion valve 120, becoming a two-phase gas-liquid state.
• the refrigerant, decompressed and in a two-phase gas-liquid state by the expansion valve 120 passes through the indoor heat exchanger 110.
• the refrigerant evaporates, for example, by exchanging heat with the air in the space to be air-conditioned, and becomes gaseous refrigerant.
• This passes through the four-way valve 220 and is again drawn into the compressor 210. In this way, the refrigerant in the air conditioner circulates, performing air conditioning related to cooling.
• ⁇ Configuration of heat exchanger 1000> 2 is a diagram illustrating the heat exchanger 1000 according to the first embodiment.
• the up-down direction of the heat exchanger 1000 is referred to as the Z direction (height direction or gravity direction).
• the direction perpendicular to the Z direction is referred to as the horizontal direction.
• a certain direction in the horizontal direction is referred to as the X direction (vertical-horizontal direction), and the direction perpendicular to the X direction is referred to as the Y direction (horizontal-vertical direction).
• the outdoor heat exchanger 230 has one or more heat exchangers 1000.
• the heat exchanger 1000 shown in FIG. 2 connects the heat exchanger 1010 serving as the main heat exchanger 1011 and the heat exchanger 1010 serving as the subcooling heat exchanger 1012 via a connecting pipe 1020.
• the heat exchanger 1010 (main heat exchanger 1011 and subcooling heat exchanger 1012) exchanges heat between the refrigerant and the air.
• the connecting pipe 1020 according to the first embodiment is a pipe that connects the multiple heat exchanger sections 1010 together. The connection relationship between the multiple heat exchanger sections 1010 via the connecting pipe 1020 according to the first embodiment will be described later.
• Each heat exchange unit 1010 has a fin-tube heat exchanger with parallel piping.
• the heat exchange unit 1010 has a lower header 1100, a refrigerant inlet/outlet pipe 1200, a row header 1300, multiple heat transfer tubes 1400, and multiple corrugated fins 1500.
• the lower header 1100 and the refrigerant inlet/outlet pipe 1200 have lower headers 1100A and 1100B, and refrigerant inlet/outlet pipes 1200A and 1200B, respectively.
• a pair of headers each consisting of two lower headers 1100 and a row-transfer header 1300, is arranged above and below in the Z direction.
• a plurality of heat transfer tubes 1400 are arranged in multiple rows along the Y direction between the two lower headers 1100 and the row-transfer header 1300.
• the heat transfer tubes 1400 in embodiment 1 have a flattened cross section.
• a group of a plurality of heat transfer tubes 1400 is arranged in rows, with their flat surfaces facing each other and perpendicular to the lower headers 1100 and the row-transfer header 1300 and parallel to each other.
• the group of heat transfer tubes 1400 in one row is connected to one lower header 1100. While an example in which the heat transfer tubes 1400 are arranged in two rows is described here, the same can also be applied to a heat exchange unit 1010 with three or more rows.
• Each lower header 1100 is connected to other devices that make up the refrigeration cycle system and has cylindrical pipes through which refrigerant, a fluid that serves as a heat exchange medium, flows in and out and through which the refrigerant branches or merges.
• the heat exchanger 1000 in embodiment 1 functions as a condenser
• the lower header 1100A serves as a gas header through which gas refrigerant (including two-phase gas-liquid refrigerant) passes and branches the refrigerant.
• the lower header 1100B serves as a liquid header through which liquid refrigerant (including two-phase gas-liquid refrigerant) passes and merges the refrigerant.
• Each lower header 1100 is connected to refrigerant inlet/outlet pipes 1200 (refrigerant inlet/outlet pipes 1200A and refrigerant inlet/outlet pipes 1200B).
• the top surface of the lower header 1100, located above it, has an unconnected area 1101 at one end in the Y direction, where a heat transfer tube 1400 (described later) is not inserted and connected.
• the refrigerant inlet/outlet pipe 1200 is a pipe whose one end connects to the lower header 1100 in the unconnected region 1101 and whose pipe axis extends in the Z direction.
• the other end of the refrigerant inlet/outlet pipe 1200 is connected to a connection pipe with an external device, through which the refrigerant flows in and out.
• the refrigerant inlet/outlet pipe 1200 is arranged in a corner of the housing to match the arrangement of the piping.
• the refrigerant inlet/outlet pipe 1200 By configuring the refrigerant inlet/outlet pipe 1200 to connect to the lower header 1100 at the top end surface of the lower header 1100, it is not necessary to ensure a large bending radius when bending piping such as the connecting pipe 1020 at the corner of the housing.
• This allows, for example, the heat exchange unit 1010 to be installed within the housing to be wider, thereby increasing the area occupied by the heat exchange unit 1010 on the side of the housing.
• the piping connecting to the lower header 1100B which is upstream of the air flow located outside within the housing, would be long because it is located outside within the housing. However, this can be reduced, and the space can be expanded by the shorter piping length.
• the row-to-row header 1300 also functions as a bridge, joining the refrigerant flowing in from the group of heat transfer tubes 1400 in one row and allowing it to branch out and flow out to the group of heat transfer tubes 1400 in the other row.
• the heat transfer tube 1400 is a flattened heat transfer tube having a flat cross section, with the outer surface on the long side of the flat shape along the depth direction, which is the air flow direction, being flat, and the outer surface on the short side perpendicular to the long side being curved.
• the heat transfer tube 1400 of embodiment 1 is a multi-hole heat transfer tube having multiple holes inside the tube that serve as refrigerant flow paths.
• the holes of the heat transfer tube 1400 are formed facing the height direction to serve as flow paths between the lower header 1100 and the row-to-row header 1300.
• the heat transfer tubes 1400 are arranged horizontally at equal intervals with their outer surfaces facing each other on their long sides.
• each heat transfer tube 1400 is inserted into insertion holes (not shown) in the lower header 1100 and the row-to-row header 1300, and then brazed and joined.
• the brazing filler metal used is, for example, a brazing filler metal containing aluminum. This allows communication between the lower header 1100, the row header 1300, and the interior of each heat transfer tube 1400.
• the number of stages of heat transfer tubes 1400 differs between the main heat exchange section 1011 and the subcooling heat exchange section 1012.
• the number of stages of heat transfer tubes 1400 in the subcooling heat exchange section 1012 is fewer than the number of stages of heat transfer tubes 1400 in the main heat exchange section 1011. Therefore, the volume (flow path area) in the subcooling heat exchange section 1012 of the heat exchanger 1000 is smaller than the volume in the main heat exchange section 1011 of the heat exchanger 1000.
• the number of heat transfer tube stages in the main heat exchange section 1011 is set to n1
• the number of heat transfer tube stages in the subcooling heat exchange section 1012 is set to n2.
• the stage ratio R is configured so that 0.1 ⁇ R ⁇ 0.5.
• FIG 3 shows the relationship between the stage ratio R and heat exchange performance in embodiment 1.
• Heat exchange performance is represented, for example, by the amount of energy, such as heat, supplied relative to the temperature change of the refrigerant. If the number of stages of heat transfer tubes 1400 in the subcooling heat exchange section 1012 is fewer than the number of stages of heat transfer tubes 1400 in the main heat exchange section 1011, the flow rate of liquid refrigerant flowing through the subcooling heat exchange section 1012 will be faster. This makes it possible to maintain a balance between condensation from the gas refrigerant in the main heat exchange section 1011 and subcooling in the subcooling heat exchange section 1012.
• corrugated fins 1500 are arranged between the opposing flat surfaces of the arranged heat transfer tubes 1400.
• the corrugated fins 1500 are arranged to increase the heat transfer area between the refrigerant and the outside air.
• the corrugated fins 1500 are formed by corrugating a plate material and folding it into a zigzag shape with repeated mountain and valley folds, forming a wavy bellows.
• the heat exchange unit 1010 of the heat exchanger 1000 in embodiment 1 when the heat exchange unit 1010 is used as a condenser and a subcooler, high-temperature and high-pressure refrigerant flows through the refrigerant flow path within the heat transfer tube 1400. Furthermore, when the heat exchange unit 1010 is used as an evaporator, low-temperature and low-pressure refrigerant flows through the refrigerant flow path within the heat transfer tube 1400.
• the dotted arrows in FIG. 2 indicate the flow of refrigerant when the heat exchanger 1000 of embodiment 1 is used as a condenser and a subcooler.
• the heat exchange unit 1010 functions as a condenser or a subcooler, as in the heat exchanger 1000 of embodiment 1, the refrigerant flows countercurrently to the air.
• countercurrent flow refers to the refrigerant flowing from the heat transfer tube 1400 in the row downstream in the air flow toward the heat transfer tube 1400 in the row upstream.
• the connecting tube 1020 connects the refrigerant inlet/outlet tube 1200B, which is the refrigerant outlet side of the main heat exchange unit 1011, which functions as a condenser, to the refrigerant inlet/outlet tube 1200A, which is the refrigerant inlet side of the subcooling heat exchange unit 1012, which functions as a subcooler.
• the refrigerant sent from the compressor 210 flows via refrigerant inlet/outlet pipe 1200A into the lower header 1100A of the main heat exchange unit 1011, which is connected to the heat transfer tube 1400 in the row furthest downstream in the air flow.
• the heat exchange unit 1010 of the heat exchanger 1000 in embodiment 1 has a two-row configuration, the most downstream will be described below as "downstream.”
• the refrigerant that flows into the lower header 1100A of the main heat exchange unit 1011 is distributed and passes through the heat transfer tube 1400 in the row downstream in the air flow.
• the heat transfer tube 1400 exchanges heat between the refrigerant passing through the tube and the outside air passing outside the tube. At this time, the refrigerant releases heat to the outside air while passing through the heat transfer tube 1400.
• the refrigerant then turns back at the row-to-row header 1300, passes through the heat transfer tubes 1400 in the row that is upstream in the air flow, and exchanges heat.
• the refrigerant then flows into the lower header 1100B of the main heat exchange section 1011 and merges. If there are three or more rows of heat transfer tubes 1400 lined up along the air flow, the refrigerant passes through the upstream heat transfer tubes 1400 and repeats heat exchange.
• the liquid refrigerant that merges in the lower header 1100B, which is furthest upstream in the air flow passes through the refrigerant inlet/outlet pipe 1200B connected to the lower header 1100B, and then passes through the connecting pipe 1020.
• the refrigerant that passes through the connecting pipe 1020 flows via the refrigerant inlet/outlet pipe 1200A into the lower header 1100A of the subcooling heat exchange unit 1012, which is connected to a group of heat transfer tubes 1400 in the row that is downstream in the air flow.
• the refrigerant that flows into the lower header 1100A of the subcooling heat exchange unit 1012 is distributed and passes through the heat transfer tubes 1400 in the row that is downstream in the air flow, where it is subcooled.
• the refrigerant that passes through the heat transfer tubes 1400 in the row that is downstream in the air flow is further turned back at the row transfer header 1300.
• the turned back refrigerant passes through the heat transfer tubes 1400 in the row that is upstream in the air flow, where it is subcooled, and flows into the lower header 1100B of the subcooling heat exchange unit 1012, where it joins.
• the merged liquid refrigerant flows out of the heat exchanger 1000 through the refrigerant inlet/outlet pipe 1200B connected to the lower header 1100B, passes through the refrigerant piping 300, and is sent to the expansion valve 120 of the indoor unit 100.
• heat transfer tubes 1400 in the row downstream in the air flow heat is exchanged between refrigerant that has not undergone heat exchange and air that has undergone heat exchange in the heat transfer tubes 1400 in the row upstream in the air flow.
• heat transfer tubes 1400 in the row upstream in the air flow heat is exchanged between refrigerant that has undergone heat exchange in the heat transfer tubes 1400 in the row downstream in the air flow and air that has not undergone heat exchange. Therefore, a temperature difference sufficient to effectively exchange heat between refrigerant and air can be maintained in both the heat transfer tubes 1400 in the row upstream in the air flow and the heat transfer tubes 1400 in the row downstream in the air flow.
• flowing the refrigerant and air in countercurrents improves heat transfer performance.
• the heat exchanger 1000 in embodiment 1 is configured such that the refrigerant inlet/outlet pipe 1200B in the main heat exchange section 1011 and the refrigerant inlet/outlet pipe 1200A in the subcooling heat exchange section 1012 are connected by the connecting pipe 1020. Therefore, when the heat exchanger 1000 functions as a condenser and a subcooler, the refrigerant flow in the heat exchange section 1010 can be made to counterflow with the air passing through the heat exchange section 1010. Therefore, heat exchange can be performed throughout the entire refrigerant flow path of the heat exchanger 1000, maintaining a temperature difference that allows effective heat exchange between the refrigerant and the air, thereby improving the heat transfer performance of the heat exchanger 1000.
• the refrigerant inlet/outlet pipe 1200 is connected to the lower header 1100 at the unconnected region 1101 on the top surface of the lower header 1100. Therefore, especially when the piping on the windward side (which is the upstream side in the air flow) is bent and housed in the housing, the longer piping does not obstruct the air flow path. Furthermore, the flow path area related to heat exchange can be increased, improving heat exchange performance.
• the main heat exchange section 1011 and the subcooling heat exchange section 1012 are configured so that the stage ratio R of the number of heat transfer tube stages n2 in the subcooling heat exchange section 1012 in the entire heat exchanger 1000 satisfies the relationship 0.1 ⁇ R ⁇ 0.5.
• the flow rate of the refrigerant which is reduced by condensing into a liquid state in the main heat exchange section 1011, increases as the flow path area narrows in the subcooling heat exchange section 1012, allowing the refrigerant to move smoothly within the heat exchanger 1000.
• Fig. 4 is a diagram showing a part of a cross section of the heat exchanger 1000 according to the second embodiment when viewed along the Y direction.
• Fig. 5 is a diagram showing a part of a cross section of the heat exchanger 1000 according to the second embodiment when viewed along the X direction.
• Figs. 4 and 5 show the configuration of the lower header 1100A that serves as the gas header of the subcooling heat exchange section 1012.
• the present invention is not limited to this. The configuration can also be applied to other lower headers 1100.
• the lower header 1100 in the heat exchanger 1000 of embodiment 2 is a double-structure refrigerant distributor having an outer pipe 1110 and an inner pipe 1120.
• the lower header 1100A also has a partition plate 1130.
• the outer tube 1110 is a tube formed by combining a first member 1111 and a second member 1112.
• the first member 1111 is an inverted U-shaped semi-open member that forms the top surface and flattened sides of the long, cylindrical outer tube 1110 extending in the Y direction.
• the second member 1112 is the member that forms the bottom surface of the cylindrical outer tube 1110.
• the partition plate 1130 also serves as a wall that divides the space within the outer pipe 1110 between the inner pipe 1120 and the outer pipe 1110 into a second space 1150 that communicates with the heat transfer pipe 1400 and a third space 1160 that communicates with the refrigerant inlet/outlet pipe 1200.
• the inner pipe 1120 is a long pipe that is installed inside the outer pipe 1110 along the outer pipe 1110.
• the inner pipe 1120 serves as a wall that divides the space inside the outer pipe 1110 into a first space 1140 and a second space 1150.
• the dimensional center of the inner pipe 1120 is located lower than the dimensional center of the outer pipe 1110 in the Z direction.
• the inner pipe 1120 has an orifice 1121 which serves as a refrigerant inlet/outlet hole.
• the orifice 1121 is not located directly below the inner pipe 1120, but rather diagonally below the inner pipe 1120, and is oriented so as to spray gas-liquid two-phase refrigerant downwind (downstream in the air flow) of the air passing through the heat exchanger 1000.
• refrigerant that flows from the refrigerant inlet/outlet pipe 1200 into the outer pipe 1110 passes through the third space 1160 and flows into the first space 1140 inside the inner pipe 1120.
• the refrigerant that flows out from the orifice 1121 is sprayed into the second space 1150 inside the outer pipe 1110 and flows into the heat transfer pipe 1400.
• refrigerant that flows from the heat transfer pipe 1400 into the outer pipe 1110 of the lower header 1100 passes through the second space 1150, flows from the orifice 1121 into the first space 1140 inside the inner pipe 1120, passes through the third space 1160 and flows out of the refrigerant inlet/outlet pipe 1200.
• the gas-liquid two-phase refrigerant flows into the third space 1160 inside the outer pipe 1110 and then passes through the first space 1140.
• the gas refrigerant and liquid refrigerant of the gas-liquid two-phase refrigerant are mixed in the third space 1160 and pass through the first space 1140.
• the gas-liquid two-phase refrigerant is also agitated as it passes through the first space 1140 and flows out of the orifice 1121 into the second space 1150 between the inner pipe 1120 and the outer pipe 1110.
• the liquid refrigerant and gas refrigerant become nearly homogeneous.
• the heat transfer tube 1400 has multiple flow paths along the X direction, which is the direction in which air passes.
• gas-rich refrigerant which has a higher proportion of gas refrigerant components in the gas-liquid two-phase refrigerant
• liquid-rich refrigerant which has a higher proportion of liquid refrigerant components in the gas-liquid two-phase refrigerant, is supplied to the flow path on the upwind side (upstream in the air flow) of the heat transfer tube 1400. Therefore, more liquid refrigerant can be distributed to the upwind side, where the temperature difference between the refrigerant and the air is greater, improving heat transfer performance.
• FIG. 6 is a diagram illustrating a corrugated fin 1500 in a heat exchanger unit 1010 according to the third embodiment.
• the surfaces of the flanks between the peaks of the corrugated fin 1500 are referred to as fins 1510.
• FIG. 6 shows the fins 1510 at a certain position in the corrugated fin 1500.
• the heat exchanger unit 1010 is configured with heat transfer tubes 1400, which serve as refrigerant flow paths, arranged in multiple rows in the air flow direction.
• heat transfer tube 1400A the heat transfer tube 1400 on the windward side, which is upstream in the air flow
• heat transfer tube 1400B the heat transfer tube 1400 on the leeward side, which is downstream in the air flow
• the corrugated fins 1500 of the heat exchange section 1010 in the heat exchanger 1000 according to embodiment 3 are arranged across the heat transfer tubes 1400A and 1400B and are brazed and joined to the heat transfer tubes 1400A and 1400B.
• the corrugated fins 1500 are arranged integrally in multiple rows without being separated, allowing the fins 1510 to transfer heat between the rows, and since heat transfer is not interrupted, a large temperature difference is maintained between the air and the refrigerant.
• Each fin 1510 of the corrugated fin 1500 has a louver 1511 and drainage slits 1512. Multiple louvers 1511 are arranged side by side in the air flow direction on each fin 1510. Therefore, the louvers 1511 are lined up along the airflow.
• the louvers 1511 have slits that allow air to pass through and plate portions that guide the air that passes through the slits, thereby increasing the surface area of the fin 1510.
• the drainage slits 1512 also drain water generated on the fins 1510.
• the drainage slits 1512 are formed in a rectangular shape extending horizontally.
• the drainage slits 1512 are arranged in each fin 1510 at a position corresponding to the center of the respective heat transfer tube 1400 in the air flow direction.
• this is not limited to this.
• adjusting the spacing between the drainage slits 1512 and the slit length can improve drainage on the upwind side of the fin 1510, where heat transfer performance is higher than on the downwind side. Heat transfer performance can also be improved on the downwind side, where heat transfer performance is lower than on the upwind side.
• improving the heat transfer performance on the downwind side can reduce the difference in heat transfer performance on the fin 1510. This allows the thickness of frost that forms on the surface of the fin 1510 to be more uniform under low-temperature air conditions, thereby improving heat exchange performance under low-temperature air conditions.
• FIG. 7 is a diagram illustrating the arrangement of the outdoor heat exchanger 230 in the outdoor unit 200 according to the fourth embodiment.
• FIG. 7 illustrates the arrangement within the housing 201 when the outdoor unit 200 is viewed from above along the height direction.
• the row transfer header 1300 is not illustrated in FIG. 7.
• white arrows indicate the flow of air
• black arrows indicate the flow of refrigerant when the heat exchanger 1000 serving as the outdoor heat exchanger 230 functions as a condenser.
• the outdoor unit 200 according to the fourth embodiment is a side-flow type unit having an outlet (not shown) for the outdoor fan 250 on a side surface of the housing 201.
• the rotation axis of the outdoor fan 250 is arranged horizontally, and air flows into the housing 201 from one side surface in the longitudinal direction of the housing 201 and is blown out toward the opposite side surface.
• two heat exchange units 1010 are arranged in an L-shape. As shown in Figure 7, in a side-flow type unit, the main heat exchange unit 1011 is arranged along the longitudinal direction of the housing 201, and the subcooling heat exchange unit 1012 is arranged along the lateral direction of the housing 201.
• the outdoor unit 200 in embodiment 4 is a side-flow type unit in which the main heat exchange section 1011, which has a large number of heat transfer tube stages, is arranged along the longitudinal direction of the housing 201. Furthermore, the subcooling heat exchange section 1012, which has a small number of heat transfer tube stages, is arranged along the lateral direction of the housing 201. Therefore, the heat exchanger 1000 can be efficiently arranged within the housing 201 as the outdoor heat exchanger 230.
• FIG. 8 is a diagram illustrating the arrangement of the outdoor heat exchanger 230 in the outdoor unit 200 according to the fifth embodiment.
• FIG. 8 illustrates the arrangement of the outdoor heat exchanger 230 in the housing 201 when the outdoor unit 200 is viewed from above along the Z direction.
• the row transfer header 1300 is not illustrated in FIG. 8 .
• white arrows indicate the air flow
• black arrows indicate the refrigerant flow when the heat exchanger 1000 serving as the outdoor heat exchanger 230 functions as a condenser and a subcooler.
• the outdoor unit 200 according to the fifth embodiment is a top-flow type unit having an outlet (not shown) for the outdoor fan 250 at the center of the top of the housing 201. In the outdoor unit 200, the rotation axis of the outdoor fan 250 is vertically arranged, and air flows into the housing 201 from the side and is blown out toward the top.
• the heat exchanger 1000 that serves as the outdoor heat exchanger 230 has three heat exchange units 1010 arranged in a U-shape so that the heat exchange units 1010 surround the outdoor fan 250 at an upper position on the side of the housing 201 of the outdoor unit 200.
• the gas refrigerant discharged from the compressor 210 flows into two main heat exchange units 1011.
• the liquid refrigerant that condenses in the two main heat exchange units 1011 and flows out of the two main heat exchange units 1011 joins in the connecting pipe 1020, flows into the subcooling heat exchange unit 1012, and is subcooled before flowing out.
• the outdoor unit 200 in embodiment 5 is a top-flow type unit, and can combine and arrange multiple heat exchange units 1010, such as arranging one subcooling heat exchange unit 1012 in multiple main heat exchange units 1011. This allows the heat exchanger 1000 to be efficiently arranged within the housing 201 as the outdoor heat exchanger 230.
• the heat exchanger 1000 is used in the outdoor heat exchanger 230 of the outdoor unit 200, but this is not limited to this. It may also be used in the indoor heat exchanger 110 of the indoor unit 100, or in both the outdoor heat exchanger 230 and the indoor heat exchanger 110.
• the first embodiment described above is directed to an air conditioning system, it can also be applied to other refrigeration cycle devices, such as refrigerators, freezers, and hot water heaters.
• both the main heat exchange section 1011 and the subcooling heat exchange section 1012 are described as fin tube types using corrugated fins 1500, but either one may also be a fin tube type.

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• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

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• 2024
  • 2024-01-23 JP JP2025571744A patent/JPWO2025158523A1/ja active Pending
  • 2024-01-23 WO PCT/JP2024/001824 patent/WO2025158523A1/ja active Pending

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