JP5835907B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger that is used in an air conditioner or a refrigerator and performs heat exchange between a refrigerant and a fluid such as air.

  As a conventional heat exchanger, a fin tube type heat exchanger including a pipe through which a refrigerant flows and a fin having a fin hole through which the pipe is inserted is known (for example, see Patent Document 1). In this heat exchanger, the fin pitch, which is the distance between the fins, is 1.1 mm to 1.4 mm. In order to enhance heat exchange performance, the fin is formed with a cut and raised protruding to the front surface side and a cut and raised protruding to the back surface side, and these cut and raised are formed between the centers of the fin holes. The angle formed by the connecting straight line is set to 5 ° to 10 °.

JP 2008-202907 A

  However, according to the configuration of Patent Document 1, since the cuts and protrusions that protrude from both surfaces of the fin are formed, the cuts and protrusions that face each other between adjacent fins may be in a positional relationship as the fin pitch becomes narrower. is there. The improvement of the heat exchange performance by forming the cut and raised is due to the so-called “leading edge effect” that promotes heat transfer by updating the cut and raised temperature boundary layer developed upstream in the direction of air flow. However, when the cut-and-raised parts are close to each other, the downstream-side cut-and-raised part is buried in the temperature boundary layer developed by the upstream-side raised part, making it difficult to contribute to heat transfer and heat exchange performance. There was a problem that decreased.

  Then, even if a heat exchanger plate pitch is narrow, this invention makes it a subject to provide the heat exchanger which can improve heat exchange performance.

  The heat exchanger of the present invention is a heat exchanger including a heat transfer tube through which a refrigerant flows and a plurality of heat transfer plates attached to the heat transfer tube in the axial direction of the heat transfer tube. The plurality of heat transfer plates provided on both sides of the heat transfer plate have a distance between the heat transfer plates in the stacking direction of 0.9 mm or more and 1.3 mm or less. The distance between the cut-and-raised parts in the stacking direction is 0.3 mm or more.

  According to this structure, the flow of media, such as air which passes a heat exchanger plate, can be made suitable by making the distance between cuts and raisings into 0.3 mm or more. Thereby, the distance between the cut and raised portions can be increased, and the leading edge effect functions effectively, so that the heat exchange performance can be enhanced.

  In this case, each cut and raised is preferably such that the angle of each heat transfer plate to the plate surface is 5 ° or more and 10 ° or less.

  According to this configuration, even when the cut-and-raised portion is formed to be inclined with respect to the plate surface of the heat transfer plate, the distance between the cut-and-raised portions can be increased, and the leading edge effect functions effectively. Therefore, heat exchange performance can be improved. Further, when the cut and raised are formed to be inclined with respect to the plate surface of the heat transfer plate, the distance of heat exchange with the heat transfer plate is increased by meandering the flow of a medium such as air passing through the heat transfer plate. Therefore, the heat exchange performance can be further enhanced.

  In this case, the heat transfer tubes are arranged in the row direction which is the depth direction in the plate surface of each heat transfer plate, and are arranged in the step direction orthogonal to the depth direction. The relationship between the outer diameter Do of the heat transfer tube and the step pitch Dp that is the distance between the centers of the heat transfer tubes in the step direction is “2.8 ≦ Dp / Do ≦ 3.8”, and the heat transfer tube The relationship between the outer diameter Do and the row pitch Lp, which is the distance between the centers of the heat transfer tubes in the row direction, is preferably “1.2 ≦ Lp / Do ≦ 2.0”.

  According to this configuration, the step pitch and the row pitch of the plurality of heat transfer tubes can be set with respect to the outer diameter of each heat transfer tube so that the heat exchange performance is optimized.

  In this case, the heat transfer tubes are arranged side by side in a step direction orthogonal to the depth direction in the plate surface of each heat transfer plate, and the plurality of cuts and rises are plate surfaces between adjacent heat transfer tubes in the step direction. The cut-and-raised region is formed in the cut-and-raised region, and the cut-and-raised region is formed in the center in the step direction where the cut-and-raised region is not formed, and the cut-and-raised portion provided on both sides in the step direction across the non-formed region. And a formation region.

  According to this configuration, the resistance to the medium such as air passing through the heat transfer plate is smaller in the non-formation region than in the formation region. For this reason, the medium flows more easily in the non-formation region having a lower resistance than in the formation region. Thereby, by providing a non-formation area | region with respect to the dead water area | region formed in the downstream of a heat exchanger tube and in which a medium does not flow easily, it can be set as the flow which flows a medium around to the downstream of a heat exchanger tube. Thereby, since the dead water area | region formed can be made small, heat exchange performance can further be improved.

  According to the heat exchanger of the present invention, even if the heat transfer plate pitch is narrow, the distance between the cut and raised portions can be increased, and the flow of a medium such as air can be made suitable. Performance can be increased.

FIG. 1 is a schematic diagram illustrating a heat exchanger according to the present embodiment. FIG. 2 is a plan view showing a part of the heat transfer plate viewed from the axial direction of the heat transfer tube. FIG. 3 is a graph of heat exchange performance that varies depending on the outer diameter and step pitch of the heat transfer tubes. FIG. 4 is a graph of heat exchange performance that varies depending on the outer diameter of the heat transfer tubes and the row pitch. FIG. 5 is a cross-sectional view of the heat transfer plate cut in the plate thickness direction. FIG. 6 is an explanatory diagram showing a plurality of cuts and raises in a plurality of stacked heat transfer plates. FIG. 7 is a graph of the heat exchange performance that varies depending on the distance between the cut and raised parts.

  Hereinafter, a heat exchanger according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  The heat exchanger according to the present embodiment is provided in an indoor unit of an air conditioner, and exchanges heat between circulating refrigerant and air (medium). Hereinafter, the heat exchanger will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic view showing a heat exchanger according to the present embodiment, and FIG. 2 is a plan view showing a part of a heat transfer plate viewed from the axial direction of the heat transfer tube. As shown in FIG. 1, the heat exchanger 1 includes a heat transfer tube 5 through which a refrigerant flows, and a plurality of heat transfer plates 6 attached to the heat transfer tube 5. The air flowing into the heat exchanger 1 has a wind speed of 0.5 to 2.0 m / s.

  The heat transfer tube 5 is made of a copper tube, and its outer diameter Do is “4 mm ≦ Do ≦ 6 mm”. The heat transfer tube 5 includes a plurality of straight tube portions 5a and a curved tube portion 5b that connects the straight tube portions 5a, and is configured in a pleat shape. At this time, as shown in FIG. 2, the plurality of straight pipe portions 5 a are arranged side by side in the row direction that is the depth direction, and are arranged in a row direction orthogonal to the depth direction. In other words, the plurality of straight pipe portions 5a are located on the upstream side in the row direction and are arranged on the upstream side composed of the plurality of straight pipe portions 5a arranged in the step direction, and on the downstream side in the row direction and in the step direction. And a downstream stage composed of a plurality of straight pipe portions 5a arranged side by side. The plurality of straight pipe portions 5a in the upstream stage and the plurality of straight pipe portions 5a in the downstream stage are provided to be shifted in the step direction and are arranged in a staggered manner. That is, each straight pipe part 5a in the downstream stage is provided so as to be positioned between the straight pipe parts 5a adjacent to each other in the upstream stage direction. Note that air flows in the row direction.

  FIG. 3 is a graph of heat exchange performance that varies depending on the outer diameter and step pitch of the heat transfer tube, and FIG. 4 is a graph of heat exchange performance that varies depending on the outer diameter and row pitch of the heat transfer tube. Here, the heat transfer tubes 5 have a step pitch Dp that is a distance between the axial centers of the straight tube portions 5a in the step direction and a row pitch Lp that is a distance between the axes of the straight tube portions 5a in the row direction. Is set so as to be within a predetermined range described below, thereby improving the heat exchange performance. That is, as shown in FIG. 3, the heat transfer tube 5 and the step pitch are set so that the relationship between the outer diameter Do and the step pitch Dp of the heat transfer tube 5 is in the range of “2.8 ≦ Dp / Do ≦ 3.8”. By configuring Dp, the heat exchange performance is enhanced. Further, as shown in FIG. 4, the heat transfer tube 5 and the row pitch Lp are set so that the relationship between the outer diameter Do and the row pitch Lp of the heat transfer tube is in the range of “1.2 ≦ Lp / Do ≦ 2.0”. By configuring, heat exchange performance is enhanced. Note that Dp / Do and Lp / Do are within the range where the heat exchange performance is reduced by 3% with respect to the maximum heat exchange performance, that is, within the range where the heat exchange performance is 97% to 100%. It has become.

  Next, the plurality of heat transfer plates 6 will be described with reference to FIGS. 2, 5, and 6. FIG. 5 is a cross-sectional view of the heat transfer plate cut in the plate thickness direction, and FIG. 6 is an explanatory view showing a plurality of cut-ups in a plurality of stacked heat transfer plates. The plurality of heat transfer plates 6 are attached by being stacked in the axial direction of the heat transfer tube 5, and the stacking direction of the heat transfer plates 6 and the axial direction of the heat transfer tube 5 are the same direction. The plurality of heat transfer plates 6 have a heat transfer plate pitch Fp, which is a distance between the heat transfer plates 6 in the stacking direction, of 0.9 mm to 1.3 mm.

  Each heat transfer plate 6 is made of aluminum or an aluminum alloy and has a thickness of 0.05 mm to 0.15 mm. Further, as shown in FIG. 2, each heat transfer plate 6 is provided with a plurality of insertion holes 7 through which the straight tube portion 5 a of the heat transfer tube 5 is inserted, and has a complementary arrangement with the plurality of straight tube portions 5 a. They are arranged in a staggered pattern. That is, the plurality of insertion holes 7 are divided into an upstream stage and a downstream stage, similarly to the plurality of straight pipe portions 5a, and the plurality of insertion holes 7 in the upstream stage and the plurality of insertion holes 7 in the downstream stage are: The position is shifted in the step direction. That is, each insertion hole 7 in the downstream stage is provided so as to be positioned between the insertion holes 7 adjacent in the upstream stage direction. Further, as shown in FIG. 5, each insertion hole 7 is formed so that the peripheral edge protrudes from one plate surface of the heat transfer plate 6.

  Each heat transfer plate 6 is formed with a plurality of cut-and-raised portions 8 on both sides thereof. The plurality of cut-and-raised portions 8 are formed in the cut-and-raised region E, and the cut-and-raised region E is provided on the plate surface between the adjacent insertion holes 7 in the step direction. The cut-and-raised region E has a non-forming region Ea provided in the center in the step direction and a pair of forming regions Eb provided on both sides in the step direction with the non-forming region Ea interposed therebetween. The non-formed region Ea is a region where the cut and raised 8 is not formed, and each formed region Eb is a region where the cut and raised 8 is formed. For this reason, air is less likely to flow in the formation region Eb than in the non-formation region Ea. In other words, air is more likely to flow in the non-formation region Ea than in the formation region Eb.

  The plurality of cut and raised portions 8 formed in the cut-and-raised region E forming region Eb are, for example, formed in four and are formed in parallel to the step direction. Further, the four cut-and-raised parts 8 are formed so as to protrude from both surfaces of the heat transfer plate 6, and the two cut-and-raised parts 8 on the outer side in the row direction protrude in the same direction as the insertion holes 7. Two cut-and-raised portions 8 on the inner side in the direction protrude in the direction opposite to the insertion hole 7.

  Each cut and raised 8 has a length L in the row direction of approximately 1.0 mm. Each cut and raised 8 has an angle θ with respect to the plate surface of the heat transfer plate 6 in the row direction of 5 ° or more and 10 ° or less. At this time, the plurality of cut-and-raised portions 8 are arranged in a V shape centered at the center in the column direction. Further, the distance S1 between the cut-and-raised portions 8 in the stacking direction is 0.3 mm or more at any location. In addition, although the distance S1 attaches | subjects the same code | symbol, it is not necessarily the same distance. As shown in FIG. 6, when the heat transfer plates 6 are overlapped in the stacking direction, the plurality of cuts 8 formed on the adjacent heat transfer plates 6 are cut and raised 8 in the stacking direction. The distance S2 between them is 0.3 mm or more. The distance S2 is also given the same symbol as the distance S1, but is not necessarily the same distance.

  FIG. 7 is a graph of the heat exchange performance that varies depending on the distance between the cut and raised parts. In the graph shown in FIG. 7, the horizontal axis represents the distances S <b> 1 and S <b> 2 between the cuts and the vertical axis, and the vertical axis represents the heat exchange performance. As shown in FIG. 7, the distances S1 and S2 between the cut and raised portions are 0.3 mm or more, thereby improving the heat exchange performance.

  According to the configuration of the present embodiment, the distances S1 and S2 between the cuts and raises are set to 0.3 mm or more, so that the cuts and raises on the downstream side in the flow direction (row direction) of the air passing through the heat transfer plate 6 are performed. Since the leading edge effect functions effectively without being embedded in the temperature boundary layer developed by the cut and raised 8 on the upstream side, the heat exchange performance can be enhanced.

  Further, when the step pitch Dp is increased, the cut-and-raised region E is widened, and the formation region Eb of the cut-and-raised 8 can be widened, so that heat exchange is promoted. On the other hand, when the step pitch Dp increases, the fin efficiency of the heat transfer plate 6 decreases. Therefore, as in the configuration of the present embodiment, the heat transfer tube 5 and the heat transfer tube 5 are set so that the relationship between the outer diameter Do and the step pitch Dp of the heat transfer tube 5 is in the range of “2.8 ≦ Dp / Do ≦ 3.8”. By configuring the step pitch Dp, the heat exchange performance can be further enhanced.

  Further, when the row pitch Lp is increased, the heat transfer area of the heat exchanger 1 is increased while the fin efficiency is decreased. Therefore, as in the configuration of the present embodiment, the heat transfer tube 5 and the heat transfer tube 5 are set so that the relationship between the outer diameter Do and the row pitch Lp of the heat transfer tube 5 is in the range of “1.2 ≦ Lp / Do ≦ 2.0”. By configuring the row pitch Lp, the heat exchange performance can be further enhanced.

  Further, according to the configuration of this example, in the cut-and-raised region E, the non-forming region Ea is provided in the center in the step direction, and the forming regions Eb are provided on both sides in the step direction with the non-forming region Ea interposed therebetween. For this reason, air becomes easy to flow into non-formation field Ea. By the way, the dead water area | region M shown in FIG. 2 is formed in the plate | board surface of the heat exchanger plate 6 by the some straight pipe part 5a, and the dead water area | region M is formed in the downstream of each straight pipe part 5a of an upstream. . At this time, the non-forming region Ea is located on the downstream side of the dead water region M, and since air easily flows into the non-forming region Ea, the formation of the dead water region M can be suppressed. The formed dead water region M can be reduced, and thereby the heat exchange performance can be further enhanced.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 5 Heat transfer tube 5a Straight pipe part 5b Curved tube part 6 Heat transfer plate 7 Insertion hole 8 Cut and raised Do Outer diameter Dp Step pitch Lp Row pitch Fp Heat transfer plate pitch S1, S2 Distance between cut and raised L Length in row direction of cut and raised θ Angle of cut and raised to heat transfer plate E Cut and raised region Ea Non-formed region Eb formed region M Dead water region

Claims (3)

In a heat exchanger comprising a heat transfer tube through which a refrigerant circulates and a plurality of heat transfer plates attached to the heat transfer tube by being stacked in the axial direction of the heat transfer tube,
Each of the heat transfer plates has a plurality of cut and raised portions provided on both sides thereof,
The plurality of heat transfer plates have a heat transfer plate pitch of 0.9 mm or more and 1.3 mm or less, which is a distance between the heat transfer plates in the stacking direction,
The distance between the cut and raised parts including the distance between the cut and raised parts in the stacking direction of the heat transfer plates and the distance between the cut and raised parts in the stacking direction of the adjacent heat transfer plates. Is 0.3 mm or more ,
Each of the cut and raised portions has an angle with respect to the plate surface of each of the heat transfer plates of 5 ° or more and 10 ° or less . The heat transfer tubes are arranged in a row direction that is a depth direction in the plate surface of each heat transfer plate, and are arranged in a step direction orthogonal to the depth direction,
In the heat transfer tube, the relationship between the outer diameter Do of the heat transfer tube and the step pitch Dp that is the distance between the centers of the heat transfer tubes in the step direction is “2.8 ≦ Dp / Do ≦ 3.8. The relationship between the outer diameter Do of the heat transfer tubes and the row pitch Lp that is the distance between the centers of the heat transfer tubes in the row direction is “1.2 ≦ Lp / Do ≦ 2. The heat exchanger according to claim 1, wherein the heat exchanger is “0”. The heat transfer tubes are arranged side by side in a step direction orthogonal to the depth direction in the plate surface of each heat transfer plate,
The plurality of cut and raised portions are formed in a cut and raised region that is a plate surface between the heat transfer tubes adjacent in the step direction,
The cut-and-raised region is formed at the center in the step direction where the cut-and-raised region is not formed, and the cut-and-raised region is formed on both sides of the step direction with the non-formed region interposed therebetween. the heat exchanger according to claim 1 or 2, characterized in that it has a, and region.

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