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
  • F28D1/05316—Assemblies of conduits connected to common headers, e.g. core type radiators
  • F28D1/05333—Assemblies of conduits connected to common headers, e.g. core type radiators with multiple rows of conduits or with multi-channel conduits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
  • F28F1/24—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
  • F28F1/32—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F2215/00—Fins
  • F28F2215/08—Fins with openings, e.g. louvers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F2215/00—Fins
  • F28F2215/12—Fins with U-shaped slots for laterally inserting conduits

Definitions

• Embodiments of the present invention relate to a heat exchanger.
• fin-tube heat exchanger provided with a plurality of fins arranged at intervals and a plurality of heat transfer tubes. These tubes extend in a direction in which the fins are aligned, penetrate each fin in its thickness direction, and are spaced apart from each other in a direction perpendicular to the fin alignment.
• the heat transfer tubes have a flattened cross-sectional shape.
• Patent Document 1 Japanese Patent No. 6710205
• Heat transfer tubes having a flattened cross-sectional shape offer superior heat transfer performance compared to circular heat transfer tubes (hereinafter sometimes referred to as “circular tubes”).
• the cross-sectional shape of the flattened tubes tends to hinder smooth drainage, as compared to tubes with a circular cross-section.
• a related phenomenon has been observed in which water accumulated in the region between vertically aligned heat transfer tubes (hereinafter sometimes referred to as the "water retention region") is obstructed from flowing out by the lower heat transfer tube, and water that has passed over the front edge portion of the upper heat transfer tube enters the water retention region, thereby hindering prompt drainage.
• Patent Document 1 discloses a technique in which slit-like or louver-like raised portions are formed in the fins between vertically aligned heat transfer tubes. Capillary action occurring in the gaps between these raised portions and adjacent fins promotes the movement of water from the vicinity of the lower surface of the upper tube to the vicinity of the upper surface of the lower tube within the water retention region.
• This technique facilitates the discharge of water formed near the lower surface of the upper tube by guiding it along the raised portion and then to the lower tube, effectively repeating inflow and outflow of water into the water retention region.
• it does not aim to suppress the ingress of water into the water retention region. In other words, it differs from techniques that seek to accelerate drainage by forming a water flow path outside the water retention region.
• a heat exchanger in one aspect of the present invention includes a plurality of fins spaced apart from each other in a thickness direction, a plurality of heat transfer tubes having a flat cross-sectional shape, which extend through the respective fins in the thickness direction and are arranged with spacing in a direction perpendicular to the thickness direction.
• the heat exchanger is configured such that the plurality of heat transfer tubes are arranged in a vertical direction, and airflow passes between the vertically aligned heat transfer tubes in a transverse direction corresponding to the minor axis of the tubes.
• Each of the plurality of fins includes an opening between the vertically aligned heat transfer tubes, which extends in the vertical direction and penetrates the fin in the thickness direction.
• the opening is formed in a portion of a water retention region of the fin located between the vertically aligned heat transfer tubes, where a first virtual plane, a second virtual plane, and a third virtual plane overlap with each other.
• the first virtual plane has upper and lower boundaries defined by a lower surface of a first heat transfer tube as an upper tube of the vertically aligned tubes, and a first virtual line extending in the transverse direction of the heat transfer tubes at a position intermediate between an upper surface of a second heat transfer tube as a lower tube of the vertically aligned tubes and the lower surface of the first heat transfer tube.
• the second virtual plane extends in a direction from front edge portions of the first and second heat transfer tubes toward their opposite rear edge portions, with a boundary defined by a second virtual line connecting the respective front edge portions of the first and second heat transfer tubes.
• the third virtual plane extends in a direction toward the front edge portions, with a boundary defined by a third virtual line connecting intermediate portions in the transverse direction of the first and second heat transfer tubes.
• the opening may be formed in the fin by punching in the thickness direction and include a through-hole penetrating the fin.
• the opening may be formed by lancing the fin in the thickness direction, and include a protruding portion that protrudes from a surface of the fin and covers the through-hole on one side of the fin in the thickness direction.
• the distance between the opening and the second virtual line may be between 1 mm and 4 mm.
• the distance between the opening and the lower surface of the first heat transfer tube may be between 0.5 mm and 2 mm.
• the heat exchanger may be further provided with a ridge or groove extending in the vertical direction in a portion of the water retention region other than the overlapping portion.
• a heat exchanger in another aspect of the present invention, includes a plurality of fins spaced apart from each other in a thickness direction, and a plurality of heat transfer tubes having a flat cross-sectional shape, which extend through the respective fins in the thickness direction and are arranged with spacing in a direction perpendicular to the thickness direction.
• the heat exchanger is configured such that the plurality of heat transfer tubes are arranged in a vertical direction, and airflow passes between the vertically aligned heat transfer tubes in a transverse direction corresponding to the minor axis of the tubes.
• Each of the plurality of fins includes an opening in a water retention region defined between the vertically aligned heat transfer tubes, which penetrates the fin in the thickness direction and extends in the vertical direction along a virtual line connecting the front edge portions of the heat transfer tubes.
• the heat exchanger is configured such that water flowing down from above a first heat transfer tube as an upper tube of the vertically aligned tubes and passing over the front edge portion of the first heat transfer tube flows downward along the edge of the opening located near the front edge portion, merges with water discharged from the water retention region, and flows downward below a second heat transfer tube as a lower tube of the vertically aligned tubes.
• water generated by condensation adheres to the surfaces of the fins and heat transfer tubes, and flows along the surface of the fins while repeatedly coalescing and migrating toward the upper surfaces of the heat transfer tubes.
• This condensate water then travels along the upper surface of the heat transfer tube, flows over the front edge portion of the heat transfer tube, and wraps around to the underside of the heat transfer tube.
• the condensate water merges with water discharged from the water retention region, and as the influence of gravity becomes relatively dominant, the flow is accelerated by its own weight and is promptly discharged from the heat exchanger.
• the opening suppresses the ingress of water descending over the front edge portion of the upper heat transfer tube into the water retention region, thereby promoting the flow of water along the exterior of the water retention region.
• the distance between the opening and the second virtual plane By setting the distance between the opening and the second virtual plane to be between 1 mm and 4 mm, a favorable water flow along the opening can be formed, thereby improving drainage performance.
• the distance between the opening and the lower surface of the first heat transfer tube is between 0.5 mm and 2 mm, ingress of water into the opening can be effectively suppressed.
• a downward flow of water present in the water retention region can be actively formed, thereby facilitating smooth water discharge from the water retention region.
• the opening that extends along a virtual line connecting the front edge portions of the respective heat transfer tubes and penetrates the fin in the thickness direction, and configuring the structure such that condensate water descending over the front edge portion of the first heat transfer tube as an upper tube of the vertically aligned heat transfer tubes from above the first heat transfer tube flows downward along the edge of the opening near the front edge portions, merges with water discharged from the water retention region, and flows downward to the second heat transfer tube as a lower tube of the vertically aligned heat transfer tubes, it becomes possible to provide a heat exchanger that achieves high heat exchange efficiency through the use of flattened heat transfer tubes, while also ensuring enhanced drainage performance.
• FIG. 1 is a schematic diagram illustrating the configuration of a refrigeration cycle apparatus C including a heat exchanger 1 according to one embodiment of the present invention.
• the heat exchanger 1 is configured as an outdoor heat exchanger and is disposed outdoors.
• the refrigeration cycle apparatus C is configured as an air conditioning system and includes, in addition to the heat exchanger 1, a compressor 2, a four-way valve 3, an expansion valve 4, and an indoor heat exchanger 5. These refrigeration cycle components are connected via refrigerant piping 6 (including segments 6a to 6f).
• the heat exchanger 1 is provided with an outdoor fan 1', which introduces outdoor air, or ambient air, into the heat exchanger 1.
• the indoor heat exchanger 5 is provided with an indoor fan 5', which introduces indoor air into the indoor heat exchanger 5.
• the compressor 2 includes a compressor body 2a and an accumulator 2b.
• the accumulator 2b separates the refrigerant into gas and liquid phases and supplies the separated gas refrigerant to the compressor body 2a.
• the compressor body 2a compresses the supplied gas refrigerant and discharges it as a high-temperature, high-pressure gas refrigerant.
• the operation of the refrigeration cycle apparatus C can be switched between cooling and heating modes by changing the flow path in the four-way valve 3.
• FIG. 1 shows the flow of refrigerant during cooling operation by solid arrows A1.
• the refrigerant flows through the refrigerant piping 6 in the following order: from the compressor 2, through the four-way valve 3, the heat exchanger 1, the expansion valve 4, and then to the indoor heat exchanger 5.
• the high-pressure gas refrigerant compressed by the compressor 2 is cooled and condensed through heat exchange with outdoor air as passing through the heat exchanger 1.
• the resulting gas-liquid mixed refrigerant passes through the expansion valve 4, where its pressure is reduced, and is supplied as low-pressure liquid refrigerant to the indoor heat exchanger 5.
• the indoor heat exchanger 5 the liquid refrigerant is heated and evaporated through heat exchange with indoor air.
• the evaporated gas-liquid mixed refrigerant then returns to the compressor 2 via the four-way valve 3.
• FIG. 1 shows the flow of refrigerant during heating operation by dashed arrows A2.
• the refrigerant flows through the refrigerant piping 6 in the following order: from the compressor 2, through the four-way valve 3, the indoor heat exchanger 5, the expansion valve 4, and then to the heat exchanger 1.
• the high-pressure gas refrigerant compressed by the compressor 2 is cooled as it passes through the indoor heat exchanger 5 by exchanging heat with indoor air, that is, by releasing heat to the indoor air and thereby condensing.
• the resulting gas-liquid mixed refrigerant passes through the expansion valve 4, where its pressure is reduced, resulting in a low-pressure liquid refrigerant that is supplies to the heat exchanger 1.
• the liquid refrigerant As the liquid refrigerant enters the heat exchanger 1, it is heated by exchanging heat with outdoor air, that is, by absorbing heat from the outdoor air and thereby evaporating.
• the evaporated gas-liquid mixed refrigerant then returns to the compressor 2 via the four-way valve 3.
• the four-way valve 3 is set to the same state as in cooling operation, and the refrigerant flows in the same sequence as in cooling mode. However, both the outdoor fan 1' and the indoor fan 5' are stopped. The heat exchange components of the heat exchanger 1 are heated by the high-temperature, high-pressure gas refrigerant discharged from the compressor 2, thereby melting the frost. The resulting water is drained from the heat exchanger 1.
• FIG. 2 is a front view illustrating the configuration of the heat exchanger 1.
• the heat exchanger 1 is a so-called fin-tube type heat exchanger and includes a heat exchanger core composed of a fin-tube assembly in which plate-like fins 11 are assembled with heat transfer tubes 12.
• FIG. 2 shows the configuration of the heat exchanger core with the housing 1a being removed from the heat exchanger 1.
• the two-dot chain line schematically indicates the outer contour of the housing 1a.
• the refrigerant flows in the lateral direction relative to the plane of the drawing.
• the direction indicated by arrow X is defined as the X-direction.
• the X-direction corresponds to both the stacking direction of the plate-like fins 11 and the extending direction of the heat transfer tubes 12.
• outdoor air passing through the heat exchanger 1 flows in a direction perpendicular to the drawing plane, from front to back.
• the direction indicated by arrow Z which is a flow direction of outdoor air, is defined as the Z-direction. That is, the outdoor air flows in the direction of arrow Z and passes through the heat exchanger 1.
• the downstream side corresponds to the tip direction of arrow Z
• the upstream side corresponds to the base direction.
• Arrow Y represents the vertical downward direction, i.e., the direction of gravity, and coincides with the arrangement direction of the heat transfer tubes 12.
• the heat exchanger 1 includes a plurality of plate-like fins 11, a plurality of heat transfer tubes 12, headers 13, 14, a gas-side fitting 15, and a liquid-side fitting 16.
• the plate-like fins 11 are generally rectangular in shape.
• the headers 13, 14 are cylindrical and have their upper and lower ends in the Y-direction sealed with sealing members.
• the gas-side fitting 15 is connected to the refrigerant piping 6, 6b leading to the four-way valve 3, and the liquid-side fitting 16 is connected to the refrigerant piping 6, 6c leading to the expansion valve 4.
• the refrigerant flowing into the heat exchanger 1 from the refrigerant piping 6 enters one of the headers 13 or 14 via the gas-side fitting 15 or the liquid-side fitting 16, and is distributed to each of the heat transfer tubes 12. While flowing through the heat transfer tubes 12, the refrigerant exchanges heat with outdoor air flowing between the plate-like fins 11, and condenses or evaporates depending on the operating mode of the heat exchanger 1.
• the condensed or evaporated refrigerant is collected in the other header 14 or 13 and discharged to the refrigerant piping 6 via the liquid-side fitting 16 or the gas-side fitting 15.
• FIG. 3 is a schematic enlarged view illustrating the configuration of the fin-tube assembly provided in the heat exchanger 1.
• FIG. 3(a) is a side view of the fin-tube assembly shown in FIG. 2 , as viewed along the stacking direction of the plate-like fins 11, i.e., the X-direction in which the plurality of plate-like fins 11 are aligned.
• FIG. 3(b) is a rear view of the fin-tube assembly shown in FIG. 2 , as seen from the downstream side with respect to the flow direction of outdoor air, i.e., in the direction opposite to the Z-direction (reverse Z-direction).
• FIG. 3(c) is a cross-sectional view of the fin-tube assembly shown in FIG. 2 taken along line A-A in FIG. 3(a) .
• the fin-tube assembly includes a plurality of plate-like fins 11 spaced apart in the thickness direction of the fins 11, and a plurality of heat transfer tubes 12 arranged to extend in a direction perpendicular to the surface of the plate-like fins 11, i.e., in the stacking direction of the fins 11, and penetrate each plate-like fin 11 in the thickness direction of the fins 11.
• the plurality of heat transfer tubes 12 are arranged with spacing between them in a direction perpendicular to their extending direction, i.e., to the thickness direction of the plate-like fins 11.
• the heat exchanger 1 is installed such that the Y-direction, in which the heat transfer tubes 12 are arranged, aligns with the vertical direction, as shown in FIG. 2 .
• the heat exchanger 1 is installed with the plate-like fins 11 being arranged horizontally and the heat transfer tubes 12 being arranged vertically.
• Each heat transfer tube 12 has a flattened cross-sectional shape, such as an approximately elliptical or oval shape, and includes a plurality of internal passages 121 formed in parallel for refrigerant flow.
• the internal passages 121 extend inside the heat transfer tube 12 in the X-direction which is the extending direction of the heat transfer tube 12 and are arranged in the Z-direction, i.e., the flow direction of outdoor air.
• Each end of the heat transfer tube 12 in the X-direction is connected to the headers 13, 14, and each internal passage 121 communicates with one of the headers 13 at one end and with the other header 14 at the other end.
• the heat transfer tubes 12 are inserted into tube insertion portions n formed in each plate-like fin 11, and are fixed to the plate-like fins 11 by brazing or similar means, thereby being assembled into the fins 11.
• FIG. 3(a) shows a state in which some of the heat transfer tubes 12 are removed to clearly illustrate the tube insertion portions n.
• the tube insertion portions n are formed along the cross-sectional shape or outer contour of the heat transfer tubes 12, and have a shape elongated in the Z-direction.
• each tube insertion portion n is formed as a notch in the plate-like fin 11, opening at one edge 11a of the fin 11 in the Z-direction which is the flow direction of outdoor air, and closed at the opposite edge 11b.
• the tube insertion portion n terminates between the two edges 11a, 11b, and in this embodiment is in a state where it is open on the downstream side and closed on the upstream side.
• each heat transfer tube 12 has a width dimension defined in the Z-direction, i.e., the transverse direction, that is smaller than the width dimension of the plate-like fins 11 defined in the same Z-direction.
• the plate-like fins 11 are formed such that their length dimension, defined in the Y-direction in which the heat transfer tubes 12 are arranged, is greater than their width dimension.
• the thickness dimension the dimension of the plate-like fins 11 defined in the X-direction, which corresponds to the extending direction of the heat transfer tubes 12, is referred to as the thickness dimension, the thickness of each plate-like fin 11 is smaller than both its width and length dimensions.
• the tube insertion portion n can be formed, for example, by punching the plate-like fin 11 in the X-direction at a location where the tube insertion portion n is to be provided, prior to assembly. Upon formation of the tube insertion portion n, a collar 111 is formed around its peripheral edge, protruding in the punching direction.
• the collar 111 serves to guide the insertion of the heat transfer tube 12 into the tube insertion portion n, and also supports the heat transfer tube 12 after insertion.
• each plate-like fin 11 includes an opening 112 that penetrates through the fin 11 in the thickness direction, and is located between vertically aligned heat transfer tubes 12.
• the opening 112 has a rectangular shape that is elongated in the Y-direction, in which the heat transfer tubes 12 are arranged, and shorter in the Z-direction, which corresponds to the transverse direction of the heat transfer tubes 12.
• the opening 112 is formed in a portion of the water retention region R of the plate-like fin 11, which is located between the vertically aligned heat transfer tubes 12.
• the water retention region R is vertically bounded between a horizontal plane including the lower surface 12b of a first heat transfer tube 12, 12u, which is the upper one of a pair of the vertically aligned heat transfer tubes 12, and a horizontal plane including the upper surface 12t of a second heat transfer tube 12, 12l, which is the lower one of the pair.
• the front and rear boundaries corresponding respectively to the windward and leeward sides, are defined by a vertical plane connecting the front edge portions 12f of the pair of heat transfer tubes 12, 12u, 12l on the windward side, and a vertical plane connecting the rear edge portions 12r on the leeward side.
• the first virtual line VL1 is defined as a straight line extending in the horizontal direction, or in the Z-direction, at an intermediate position in the Y-direction between the upper surface 12t of the second heat transfer tube 12l and the lower surface 12b of the first heat transfer tube 12u.
• the second virtual line VL2 is defined as a straight line extending in the vertical direction, or in the Y-direction, and connecting the front edge portions 12f of the first and second heat transfer tubes 12u and 12l.
• the third virtual line VL3 is defined as a straight line extending in the vertical direction, or in the Y-direction, and connecting the intermediate portions in the Z-direction of the first and second heat transfer tubes 12u and 12l.
• the opening 112 is formed in a portion of the water retention region R where the following three virtual planes overlap with each other: a first virtual plane, whose upper and lower boundaries are defined by the lower surface 12b of the first heat transfer tube 12u and the first virtual line VL1; a second virtual plane extending from the second virtual line VL2, which serves as the windward-side boundary, in a direction away from the front edge portions 12f, i.e., toward the rear edge portions 12r; and a third virtual plane extending from the third virtual line VL3, which serves as the leeward-side boundary, in a direction approaching the front edge portions 12f.
• the opening 112 is located within a region extending from the front edge portion 12f of the first heat transfer tube 12u in the flow direction of outdoor air up to a distance of Dwf/2, and extending vertically downward from the lower surface 12b of the first heat transfer tube 12u up to a distance of Ddf/2.
• the distance Dga between the opening 112 and the second virtual line VL2, specifically the distance between the windward-side edge of the opening 112 and the second virtual line VL2, is preferably between 1 mm and 4 mm.
• the distance Dgb between the opening 112 and the first heat transfer tube 12u, specifically the distance between the upper edge of the opening 112 and the lower surface 12b of the first heat transfer tube 12u, is preferably between 0.5 mm and 2 mm.
• FIG. 4 is a schematic diagram showing specific examples of the opening 112 applicable to the plate-like fin 11 of the heat exchanger 1 according to this embodiment.
• FIG. 4(a) illustrates an example in which a through-hole 112a is formed by punching the plate-like fin 11 in the thickness direction, thereby forming the opening 112 with the through-hole 112a itself.
• the through-hole 112a is shown with hatching in FIGS. 4(a)-(c) .
• the opening 112 does not include a corresponding configuration to the protrusion portion 112b described below.
• the projection of the periphery of the opening 112 onto a plane perpendicular to the flow direction of outdoor air (Z-direction) has a dimension, in the thickness direction (X-direction) of the plate-like fin 11, that is equal to the thickness of the plate-like fin 11.
• the opening 112 may also be formed by lancing, in other words partially shearing and forming, the plate-like fin 11 in the thickness direction (X-direction).
• the opening 112 includes a through-hole 112a that penetrates the plate-like fin 11 in the thickness direction, and a protruding portion 112b that protrudes from the surface of the plate-like fin 11 and covers the through-hole 112a on one side of the fin 11 in the thickness direction.
• FIGS. 4(b) and 4(c) show specific examples of openings 112 with protruding portions 112b.
• FIG. 4(b) illustrates a slit-type opening 112
• FIG. 4(c) illustrates a louver-type opening 112.
• the slit-type opening 112 is configured to open the through-hole 112a toward both the front and rear edge portions 12f, 12r of the heat transfer tube 12, i.e., in this embodiment, both in the upstream and downstream directions of airflow.
• louver-type opening 112 is configured to open the through-hole 112a only toward the front edge portion 12f of the heat transfer tube 12, i.e., in the upstream direction of airflow, while the through-hole 112a is closed toward the rear edge portion 12r of the heat transfer tube 12, i.e., in the downstream direction, by means of the protruding portion 112b.
• FIG. 5 is a schematic diagram showing examples of the arrangement of the opening 112 in the plate-like fin 11.
• FIG. 5(a) illustrates an example in which a single opening 112 is arranged vertically, i.e., with its longitudinal axis aligned with the vertical or gravitational direction, perpendicular to the flow direction of outdoor air.
• FIG. 5(b) illustrates an example in which the opening 112 is arranged obliquely with respect to the airflow direction.
• the number of openings 112 is not limited to one and may be plural.
• FIG. 5(c) illustrates an example in which multiple openings 112 are arranged.
• the openings 112 are aligned in the airflow direction and may be arranged either parallel to each other or at an angle.
• the heat exchanger 1 according to this embodiment has the configuration described above. The effects obtained by this embodiment will be explained below.
• FIG. 6 is a schematic diagram illustrating the drainage behavior of water from the water retention region R of the heat exchanger 1.
• FIG. 6(a) shows a case in which the opening 112 formed in a louvered shape is provided
• FIG. 6(b) shows a comparative example in which no opening 112 is provided, i.e., the surface of the water retention region R is formed as a continuous single plane.
• the heat transfer tubes 12 having a flattened cross-sectional shape is advantageous for achieving superior heat transfer performance and high heat exchange efficiency.
• FIGS. 6(a) and 6(b) schematically show the water accumulated near the upper surfaces of the heat transfer tubes 12 using frames W1 and W2 of two-dot chain lines.
• the water W1 and W2 flows along the upper surfaces of the heat transfer tubes 12 toward the front edge portions 12f and rear edge portions 12r, i.e., toward the windward and leeward sides. Water flowing toward the leeward side reaches the rear edge portion 12r and separates from the heat transfer tube 12, being dispersed by the external airflow.
• the water flowing toward the windward side as indicated by arrow a2 passes over the front edge portion 12f of the first heat transfer tube 12u, and then flows along the lower surface of the first heat transfer tube 12u. Subsequently, the water wraps around to the underside of the first heat transfer tube 12u and infiltrates into the water retention region R located directly beneath it as indicated by arrows a31 and a32.
• the infiltrated water merges with water W2 present in the water retention region R, forming a larger water mass, which then flows out from the water retention region R as indicated by arrow a4.
• the opening 112 is formed along the front edge portion of the water retention region R, i.e., along the second virtual line VL2 connecting the front edge portions 12f of the vertically aligned heat transfer tubes 12.
• the water then merges with the water flowing out from the water retention region R as indicated by arrow a4 below the opening 112 or near the lower end portion of the opening 112, forming a larger water mass that is significantly affected by gravity and flows outside the water retention region R.
• the infiltration of water into the water retention region R which arrives after passing over the front edge portion 12f of the upper heat transfer tube (i.e., the first heat transfer tube 12u), is suppressed by the opening 112.
• the flow of water is promoted outside the water retention region R, namely along the outer side of the second virtual line VL2 relative to the water retention region R.
• the heat exchanger 1 can achieve both high heat exchange efficiency through the use of flattened heat transfer tubes 12 and excellent drainage performance.
• This effect is not limited to defrosting operation of the refrigeration cycle apparatus C, but can also be obtained during normal heating operation when the outdoor fan 1' is operating.
• the formation of the opening 112 facilitates the discharge of water adhering to the surfaces of the plate-like fins 11 or heat transfer tubes 12 during heating operation.
• the opening 112 is formed within a portion where the following three virtual planes overlap.
• a first virtual plane is defined vertically between the lower surface of the upper heat transfer tube 12 (first heat transfer tube 12u) and the first virtual line VL1 extending in the horizontal direction (Z-direction) at a position intermediate between a pair of vertically aligned heat transfer tubes 12.
• a second virtual plane is bounded by the second virtual line VL2 defined vertically (in the Y-direction) so as to connect the front edge portions 12f of the pair of heat transfer tubes 12, and extends in a direction from the front edge portions 12f toward the rear edge portions 12r on the opposite side.
• a third virtual plane is bounded by a third virtual line VL3 defined vertically so as to connect intermediate portions in the transverse direction (Z-direction) of the pair of heat transfer tubes 12, and extends toward the front edge portions 12f.
• the opening 112 is formed, it is possible to suppress degradation in the heat transfer characteristics of the plate-like fin 11, which may otherwise be adversely affected due to interference with heat conduction caused by the opening 112.
• the opening 112 formed in a louvered shape as shown in FIG. 4(c) is used.
• the opening 112 is not limited to this configuration and may be a simple through-hole 112a as shown in FIG. 4(a) , or a through-hole 112a covered by a protrusion 112b having a slit or other shape as shown in FIG. 4(b) .
• This allows for improved heat transfer characteristics of the plate-like fin 11 while maintaining drainage performance.
• airflow resistance can be suppressed, promoting smooth flow of outdoor air.
• the opening 112 may be formed with its longitudinal direction aligned with the vertical or gravitational direction, as shown in FIG. 5(a) , or may be formed diagonally, as shown in FIG. 5(b) . This enables the water flowing along the opening 112 to acquire a flow velocity component directed away from the water retention region R, thereby actively promoting drainage from the water retention region R.
• the opening 112 is formed with an appropriate distance Dga from the second virtual line VL2. This allows for optimization of the surface tension acting on water at the periphery of the opening 112, particularly at the long-side portion near the front edge portion 12f.
• the distance Dga is preferably between 1 mm and 4 mm.
• the opening 112 is preferably formed with an appropriate distance Dgb from the lower surface 12b of the upper heat transfer tube 12u. This suppresses the entry of water generated near the lower surface 12b into the opening 112 and promotes the movement of water along the periphery of the opening 112, particularly along the long-side portion near the front edge portion 12f.
• the distance Dgb is preferably between 0.5 mm and 2 mm.
• FIG. 7 illustrates a schematic view illustrating the configuration of the fin-tube assembly according to another embodiment of the present invention, in which a recessed-and-protruded portion 113 is formed on the plate-like fin 11 in addition to the opening 112.
• the recessed-and-protruded portion 113 is provided such that a plurality of ridges 113a and 113b are formed in a raw in the flow direction of outdoor air, or the transverse direction of the heat transfer tubes 12, and to extend in a direction perpendicular to the airflow.
• the ridges formed by the recessed-and-protruded portion 113 include a first ridge 113a which is relatively short in the vertical direction, and a second ridge 113b which is longer in the vertical direction than the first ridge 113a.
• the first ridge 113a is formed below the opening 112, i.e., between the upper surface 12t of the lower heat transfer tube 12 and the first virtual line VL1.
• the second ridge 113b is formed on the opposite side of the second virtual line VL2 with respect to the opening 112, or in this embodiment, on the leeward side of the opening 112 and between the second virtual line VL2 and the third virtual line VL3.
• the recessed-and-protruded portion 113 also includes grooves extending in the vertical direction, which are formed between adjacent first ridges 113a, 113a and between the first ridge 113a and the second ridge 113b, respectively.
• the recessed-and-protruded portion 113 can promote the downward movement of water present in the water retention region R due to its own weight, i.e., flow toward the upper surface 12t of the lower heat transfer tube 12, thereby facilitating drainage from the water retention region R.
• headers 13 and 14 are illustrated as cylindrical headers. However, the headers 13 and 14 are not limited to this configuration and may alternatively be laminated-type headers formed by stacking plate-like members.
• the plate-like fin 11 is not limited to a flat shape except for the opening 112 and the recessed-and-protruded portion 113.
• the fin 11 may include a stepped portion extending in the Y-direction, in which the heat transfer tubes 12 are aligned.
• direction of airflow between the plate-like fins 11 is not limited to the Z-direction and may alternatively be in the reverse Z-direction.
• the outdoor air passes through the water retention region R from the rear edge portion 12r toward the front edge portion 12f of the heat transfer tubes 12.
• the downstream edge of the second virtual plane is defined by the second virtual line VL2
• the upstream edge of the third virtual plane is defined by the third virtual line VL3.
• the direction in which the through-hole 112a opens is not limited to the direction toward the front edge portion 12f of the heat transfer tubes 12, and may alternatively be toward the rear edge portion 12r.
• the louver-shaped opening 112 may be configured such that the through-hole 112a opens toward the rear edge portion 12r of the heat transfer tube 12 while being closed in the direction toward the front edge portion 12f.
• C refrigeration cycle apparatus
• 1 heat exchanger (outdoor heat exchanger)
• 1a housing
• 1' outdoor fan
• 2 compressor
• 2a compressor body
• 2b accumulator
• 3 four-way valve
• 4 expansion valve
• 5' indoor fan
• 6a-6f refrigerant piping
• 11 plate-like fin
• 111 collar
• 12 heat transfer tube
• 121 internal passage
• 13 header
• 15 gas-side fitting
• 16 liquid-side fitting
• X thickness direction of plate-like fin, extending direction of heat transfer tube
• Y direction in which heat transfer tubes are aligned
• Z flow direction of outdoor air
• R water retention region
• VL1 first virtual line
• VL2 second virtual line
• VL3 third virtual line.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Geometry (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=92903546

Family Applications (1)

Country Status (4)

Citations (1)

Family Cites Families (4)

• 2023
  • 2023-03-28 JP JP2025509317A patent/JPWO2024201694A1/ja active Pending
  • 2023-03-28 EP EP23930334.0A patent/EP4692711A1/en active Pending
  • 2023-03-28 CN CN202380095419.7A patent/CN120826580A/zh active Pending
  • 2023-03-28 WO PCT/JP2023/012423 patent/WO2024201694A1/ja not_active Ceased

Patent Citations (1)

Also Published As

Similar Documents

Legal Events