heat exchanger

Abstract

To provide a heat exchanger where the angle of the end of a cut-and-raised slit to the direction of distributing heat exchange air is symmetrically larger in proportion as coming from a center line along the center of a heat transfer pipe close to the edge of a fin, for avoiding an event that part of an air flow to the upstream side of the heat transfer pipe is guided into the cut-and-raised slit by the end of the upstream side cut-and-raised slit, to reduce the heat exchange amount in the heat transfer pipe and increase a difference between the flow velocity of the heat exchange air distributed in the cut-and-raised slit and the flow velocity of the heat exchange air downstream of the heat transfer pipe, resulting in the possibility of generating noise in a cross flow fan due to the wind speed distribution worsening of air flowing therein.SOLUTION: A1<A2 is established for an upstream side cut-and-raised slit end angle A1 and a downstream side cut-and-raised slit end angle A2. This reduces a difference between the flow velocity of the het exchange air distributed in the cut-and-raised slit and the flow velocity of a downstream part of the heat transfer pipe to suppress the generation of noise in the cross flow fan, while improving the heat exchange efficiency.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a heat exchanger of an air conditioner.

Background Art

[0002] Patent Document 1 provides a raised piece portion 5a on the heat transfer fins 2 of the heat exchanger 1 on the center line connecting the center points of the collar portion 3 and the heat transfer tube 4 adjacent to each other in a direction orthogonal to the air flow direction of the air flowing through the heat exchanger 1, a raised piece portion 5b in the middle row, and a raised piece portion 5c near the fin edge. The raised piece portions 5a, 5b, and 5c are connected to the flat surface of the heat transfer fin 2 at the end portions 5d, 5e, and 5f, respectively. As the raised piece portion 5a on the center line, the raised piece portion 5b in the middle row, and the raised piece portion 5c near the fin edge, the angles X1 and X2 of the end portions 5e and 5f are set larger.

[0003] In the heat exchanger 1 with the above configuration, the end portion 5f of the raised piece portion 5c near the fin edge makes it easier to guide the heat exchange air to the downstream side of the heat transfer tube 4.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a heat exchanger that can reduce the pressure loss, guide the flowing heat exchange air to the downstream side of the heat transfer tube, reduce the dead water area in the downstream portion of the heat transfer tube to improve the heat exchange efficiency, and substantially uniformize the wind speed distribution to suppress noise.

Means for Solving the Problems

[0006] The heat exchanger in the present disclosure includes fins and heat transfer tubes passing through the fins. The fins have at least two or more raised slits that are substantially perpendicular to the fin edges between the step directions of the heat transfer tubes. Among the raised slits, the upstream raised slit end angle A1 formed by the upstream raised slit end of the most upstream raised slit as viewed from the air flow direction and the orthogonal straight line perpendicular to the fin edge, and the downstream raised slit end angle A2 formed by the downstream raised slit end of the most downstream raised slit as viewed from the air flow direction and the orthogonal straight line, are such that A1 < A2.

Advantages of the Invention

[0007] The heat exchanger in the present disclosure suppresses the collision at the upstream raised slit end of the flowing heat exchange air to reduce the pressure loss, while guiding the flowing heat exchange air to the downstream side of the heat transfer tube by the downstream raised slit end, reducing the dead water area in the downstream part of the heat transfer tube to improve the heat exchange efficiency. At the same time, it suppresses the excessive air induction into the raised slit by the upstream raised slit end, alleviates the flow velocity difference between the flow velocity of the heat exchange air flowing through the raised slit and the flow velocity in the downstream part of the heat transfer tube, and substantially equalizes the wind speed distribution of the air flowing into the cross-flow fan arranged downstream of the heat exchanger to suppress noise.

Brief Description of the Drawings

[0008] [Figure 1] Cross-sectional view showing the indoor unit of the air conditioner according to Embodiment 1 [Figure 2] Configuration diagram showing a part of the heat exchanger according to Embodiment 1 [Figure 3] Wind speed distribution diagram of the heat exchange air flowing through the heat exchangers according to Embodiment 1 and the comparative example [Figure 4] Wind speed distribution diagram of the heat exchange air flowing through the heat exchanger according to Embodiment 1 [Figure 5] Configuration diagram showing the heat exchanger according to Patent Document 1

Modes for Carrying Out the Invention

[0009] (Knowledge and other information that formed the basis of this disclosure) At the time the inventors conceived this disclosure, air conditioners had recently been using fin tube heat exchangers, and efforts were being made to improve heat exchange performance by changing the shape of the slits provided in the fins.

[0010] However, in the conventional technology, as shown in Patent Document 1, the angle of the end 5f of the cut-up section 5c near the upstream fin edge and the end 5f of the cut-up section 5c near the downstream fin edge are provided symmetrically. In this case, the angle of the end 5f of the cut-up section 5c near the upstream fin edge becomes larger, causing the air flowing through the end 5f to collide and increasing the airflow resistance. Furthermore, a portion of the airflow flowing upstream of the heat exchanger 4 is guided by the end 5f to the cut-up sections 5a, 5b, and 5c, resulting in a decrease in the amount of heat exchanged in the heat exchanger 4. In addition, the difference in flow velocity between the heat exchange air flowing through the cut-up sections 5a, 5b, and 5c and the heat exchange air downstream of the heat exchanger 4 widens, which may cause noise due to a deterioration in the air velocity distribution of the incoming air in the cross-flow fan installed downstream of the heat exchanger 1.

[0011] Under these circumstances, the inventors, inspired by the wind speed distribution of the heat-exchanged air flowing through the heat exchanger, arrived at the subject matter of this disclosure.

[0012] This disclosure provides a heat exchanger that suppresses collisions at the upstream cut-up slit end of the heat exchange air, reduces pressure loss by guiding the heat exchange air downstream of the heat transfer tube through the downstream cut-up slit end, guides the circulating heat exchange air downstream of the heat transfer tube, reduces the dead water zone downstream of the heat transfer tube, improves heat exchange efficiency, and suppresses noise by making the air velocity distribution nearly uniform.

[0013] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art.

[0014] Note that the attached drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0015] (Embodiment 1) FIG. 1 is a cross-sectional view showing an indoor unit of an air conditioner 100 according to the present embodiment. Further, FIG. 2 is a configuration diagram showing a part of a heat exchanger 107 according to the present embodiment. Hereinafter, Embodiment 1 will be described with reference to FIGS. 1 and 2.

[0016] [1-1. Configuration] As shown in FIG. 1, the air conditioner 100 includes a main body casing 103 having a suction port (101) and a blowout port (102), a stabilizer (104), a rear guide (105), a cross-flow fan (106), and a heat exchanger (107).

[0017] The heat exchanger 107 includes two rows of a plurality of fins 108 in the air flow direction. The fins 108 are penetrated by heat transfer tubes 109, and have three raised slits 111 substantially orthogonal to the edges of the fins 108 between the steps of the heat transfer tubes 109. Note that at least two or more raised slits 111 may be provided.

[0018] Among the raised slits 111, an upstream raised slit end angle A1 formed by an upstream raised slit end 111d of an upstream-side raised slit 111a, which is the most upstream when viewed from the air flow direction, and an orthogonal line orthogonal to the edge of the fin 108, and a downstream raised slit end angle A2 formed by a downstream raised slit end 111f of a downstream-side raised slit 111c, which is the most downstream when viewed from the air flow direction, and an orthogonal line orthogonal to the fin edge, A2 is 35° or more, and A1 < A2. In the present Embodiment 1, A1 = 30° and A2 = 45°.

[0019] The tube diameter D of the heat transfer tube 109 and the raised slit width L on the downstream side satisfy L / D ≧ 0.2. In the present Embodiment 1, L = 1 mm and D = 5 mm.

[0020] The distance H1 between the center line 110 connecting the centers of the heat transfer tubes 109 and the upstream edge of the upstream side cut-up slit 111a, and the distance H2 between the center line 110 connecting the centers of the heat transfer tubes 109 and the downstream edge of the downstream side cut-up slit 111c satisfy H1 > H2. In the present embodiment, H1 = 4.0 mm and H2 = 2.5 mm. It is preferable that H2 is at least 1 / 4 of the tube diameter D.

[0021] The distances from the heat transfer tube 109 to the upstream side cut-up slit end 111d, the center side cut-up slit end 111e, and the downstream side cut-up slit end 111f are preferably at least 1 / 2 of the tube diameter D.

[0022] In the first embodiment, the heat exchanger 107 includes two rows of fins 108 in the air flow direction, but it is not limited to two rows and may include one row or three or more rows.

[0023] Also, the distance between the heat exchanger 107 and the outer peripheral side end of the blade of the cross-flow fan 106 is 12 mm or less, and in the first embodiment, it is 10 mm.

[0024] [1-2. Operation] Regarding the heat exchanger 107 configured as described above, its operation and action will be described below.

[0025] FIG. 3 shows the wind speed distribution diagram of the heat exchange air flowing through the heat exchanger 107. FIG. 3(a) shows the wind speed distribution diagram of the heat exchange air flowing through the heat exchanger 107 with A1 = 30° and A2 = 45° according to the first embodiment, and FIG. 3(b) shows the wind speed distribution diagram of the heat exchange air flowing through the heat exchanger 207 with A11 = 30° and A21 = 30° as a comparative example.

[0026] As shown in Figures 3(a) and (b), by setting the downstream cut-up slit end angle A2 to 45°, compared to the heat exchanger 207, the heat exchange air is guided downstream of the heat transfer tube 109 by the downstream cut-up slit end 111f, reducing the dead water area downstream of the heat transfer tube 109. This improves the heat exchange efficiency and, at the same time, suppresses excessive air induction into the cut-up slit 111 by the upstream cut-up slit end 111d, thereby mitigating the flow velocity difference between the heat exchange air flowing through the cut-up slit 111 and the flow velocity downstream of the heat transfer tube 109.

[0027] Figure 4 shows the velocity distribution of heat-exchanged air flowing through the heat exchanger 107. Figure 4(a) shows the velocity distribution of heat-exchanged air flowing through the heat exchanger 107 according to Embodiment 1 of the present invention, where A1=30° and A2=45°, and Figure 4(b) shows the velocity distribution of heat-exchanged air flowing through the heat exchanger 307, where A12=45° and A22=45°, as a comparative example.

[0028] As shown in Figures 4(a) and 4(b), the heat exchanger 107 according to Embodiment 1 of the present invention has an upstream cut-up slit end angle A1 of 30°, which suppresses collision of the flowing heat exchange air at the upstream cut-up slit end 111d compared to the heat exchanger 307, ensuring airflow into the upstream side of the heat transfer tube 109. At the same time, by setting the downstream cut-up slit end angle A2 to 45°, the heat exchange air is guided downstream of the heat transfer tube 109 by the downstream cut-up slit end 111f compared to the heat exchanger 307, reducing the dead water zone downstream of the heat transfer tube 109. This improves heat exchange efficiency and, at the same time, suppresses excessive air induction into the cut-up slit 111 by the upstream cut-up slit end 111d, mitigating the flow velocity difference between the heat exchange air flowing through the cut-up slit 111 and the flow velocity downstream of the heat transfer tube 109. In the heat exchanger 107 according to this embodiment 1, by mitigating the velocity difference between the heat exchange air flowing through the cut-out slits 111 and the flow velocity downstream of the heat transfer tubes 109, the velocity distribution of the heat exchange air after passing through the heat exchanger 107 can be made substantially uniform. As a result, the heat exchange air flows into the cross-flow fan 106, which is positioned downstream of the heat exchanger 107 with a distance of 10 mm between the downstream end of the fins 108 and the outer peripheral end of the blades of the cross-flow fan, with substantially the same relative velocity difference in any direction circumferentially around the cross-flow fan 106, thereby suppressing noise generated in the cross-flow fan 106. Furthermore, the distance H1 between the center line 110 connecting the centers of the heat transfer tubes 109 and the upstream edge of the upstream cut-up slit 111a, and the distance H2 between the center line 110 connecting the centers of the heat transfer tubes 109 and the downstream edge of the downstream cut-up slit 111c are H1 = 4.0 mm and H2 = 2.5 mm, respectively, and since H1 > H2, the vortex of the circulating heat exchange air generated when passing through the downstream cut-up slit 111c is resolved by the time it reaches the downstream edge of the fin 108, suppressing turbulence in the airflow after passing through the heat exchanger 107, suppressing turbulence in the airflow flowing into the cross-flow fan 106 located downstream of the heat exchanger 107, and thus suppressing noise generated in the cross-flow fan 106.

[0029] [1-3. Effects, etc.] As described above, in this embodiment, the heat exchanger 107 comprises fins 108 and heat transfer tubes 109 that penetrate the fins 108. The fins 108 have at least two cut-out slits 111 that are substantially perpendicular to the fin edge between the stepped sections of the heat transfer tubes 109. Of the cut-out slits 111, the upstream cut-out slit end angle A1 is formed by the upstream cut-out slit end 111d of the upstream cut-out slit 111a, which is the uppermost cut-out slit as viewed from the airflow direction, and a perpendicular straight line perpendicular to the fin edge. The downstream cut-out slit end angle A2 is formed by the downstream cut-out slit end 111f of the downstream cut-out slit 111c, which is the lowermost cut-out slit as viewed from the airflow direction, and a perpendicular straight line perpendicular to the fin edge. <A2としている。

[0030] This reduces pressure loss by suppressing collisions at the upstream cut-up slit end 111d of the circulating heat exchange air, while guiding the circulating heat exchange air downstream of the heat transfer tube 109 through the downstream cut-up slit end 111f, thereby reducing the dead water zone downstream of the heat transfer tube 109 and improving heat exchange efficiency. At the same time, it suppresses excessive air induction into the cut-up slit 111 by the upstream cut-up slit end 111d, and mitigates the velocity difference between the heat exchange air circulating through the cut-up slit 111 and the circulating air downstream of the heat transfer tube 109.

[0031] In this embodiment, the heat exchanger 107 may have a downstream cut-up slit end angle A2 such that A2 > 35°.

[0032] As a result, when A2 is greater than 35°, the airflow along the downstream cut-up slit end 111f is effectively guided to the downstream side of the heat transfer tube 109, further reducing the dead water area downstream of the heat transfer tube 109, improving heat exchange efficiency, and further mitigating the flow velocity difference between the heat exchange air flowing through the cut-up slit 111 and the flow velocity downstream of the heat transfer tube 109.

[0033] Furthermore, in this embodiment, the heat exchanger 107 may have a pipe diameter D of the heat transfer tube 109 and a slit width L of the downstream cut-up slit 111c such that L / D ≥ 0.2.

[0034] This makes it possible to effectively guide the airflow downstream of the heat transfer tube 109, especially when the width of the downstream cut-up slit 111c is about 1 mm and the heat transfer tube 109 is a small-diameter tube heat exchanger with a diameter of D=5 mm or less, thereby further reducing the dead water area downstream of the heat transfer tube 109, improving heat exchange efficiency, and further improving the uniformity of the airflow distribution after passing through the heat exchanger.

[0035] Furthermore, in this embodiment, the heat exchanger 107 may have a distance H1 between the center line connecting the centers of the heat transfer tubes and the upstream edge of the upstream cut-up slit, and a distance H2 between the center line connecting the centers of the heat transfer tubes and the downstream edge of the downstream cut-up slit, where H1 > H2.

[0036] This allows the flowing heat exchange air to be effectively guided downstream of the heat exchange tube 109 by the downstream cut-up slit end 111f, closer to the heat exchange tube 109, thereby reducing the dead water area downstream of the heat exchange tube 109 and improving heat exchange efficiency. At the same time, by bringing the downstream edge of the downstream cut-up slit 111c closer to the center line connecting the centers of the heat exchange tube 109, and increasing the distance between the downstream edge of the downstream cut-up slit 111c and the downstream edge of the fin 108, the vortex of the flowing heat exchange air generated when passing through the downstream cut-up slit 111c is eliminated before reaching the downstream edge of the fin 108, thereby suppressing turbulence in the airflow after passing through the heat exchanger 107.

[0037] In this embodiment, the air conditioner 100 may also include a heat exchanger 107 in which a cross-flow fan 106 is disposed downstream of the fins 108 when viewed from the airflow direction, and the distance between the downstream end of the fins 108 and the outer peripheral end of the blades of the cross-flow fan 106 is 12 mm or less.

[0038] According to this, the airflow is guided downstream of the heat transfer tube 109 along the downstream cut-up slit end 111f, reducing the dead water area downstream of the heat transfer tube 109, mitigating the velocity difference between the flow velocity passing through the cut-up slit 111 and the flow velocity downstream of the heat transfer tube 109, and when the heat exchanger 107 and the cross-flow fan 106 are arranged close together downstream of the heat exchanger 107, the airflow distribution flowing into the cross-flow fan 106 is made nearly uniform, and the outer edge of the blades and the incoming airflow collide with approximately the same relative velocity difference in any direction in the circumferential direction of the cross-flow fan 106, thereby suppressing the noise generated in the cross-flow fan 106.

[0039] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents. [Industrial applicability]

[0040] The heat exchanger according to the present invention maintains high heat exchange efficiency, uniformizes the airflow distribution after passing through the heat exchanger, suppresses airflow turbulence, and can suppress noise generated by a cross-flow fan installed downstream of the heat exchanger, making it suitable for use in household and commercial air conditioning systems. [Explanation of Symbols]

[0041] 100 Air conditioners 101 Inlet 102 Air outlet 103 Main casing 104 Stabilizer 105 Rear Guide 106 Cross-flow fan 107, 207, 307 heat exchanger 108, 208, 308 fins 109, 209, 309 heat transfer tubes 110 Center line 111, 211, 311 Cut and bend slits 111a, 211a, 311a Upstream cut-up slit 111b, 211b, 311b Central cut and bent slit 111c, 211c, 311c Downstream cut-up slit 111d, 211d, 311d Upstream cut-up slit end 111e, 211e, 311e Central side cut and bent slit end 111f, 211f, 311f Downstream cut-up slit end A1, A11, A12 Upstream cut-up slit end angle A2, A21, A22 Downstream cut-up slit end angle D Pipe diameter L Downstream cut-up slit width H1 Distance between the center line connecting the centers of the heat transfer tubes and the upstream edge of the upstream cut-up slit Distance between the center line connecting the centers of the H2 heat transfer tubes and the downstream edge of the downstream cut-up slit. 1 heat exchanger 2 Heat transfer fins 3. Color section 4 Heat transfer tubes 5a Cut and bent portion on the center line 5b Cut portion of the intermediate row 5c Cut and bent portion near the fin edge 5d Cut and bend end of slit on the center line 5e Cut and lifted slit ends of the intermediate row 5f Cut and bent end near the fin edge X1 Angle of the cut end of the intermediate column Angle of the cut-up end near the edge of the X2 fin

Claims

1. A heat exchanger comprising fins and heat transfer tubes penetrating the fins, wherein the fins have at least two cut-out slits between the stepped sections of the heat transfer tubes that are substantially perpendicular to the edge of the fins, and the upstream cut-out slit end angle A1, formed by the upstream cut-out slit end of the upstream cut-out slit furthest upstream as viewed from the airflow direction and a perpendicular straight line perpendicular to the edge of the fin, and the downstream cut-out slit end angle A2, formed by the downstream cut-out slit end of the downstream cut-out slit furthest downstream as viewed from the airflow direction and the perpendicular straight line, are characterized in that 0 < A1 < A2.

2. The heat exchanger according to claim 1, characterized in that the downstream cut-up slit end angle A2 is A2 > 35°.

3. The heat exchanger according to either claim 1 or 2, characterized in that the diameter D of the heat transfer tube and the slit width L of the downstream cut-up slit are L / D ≥ 0.

2.

4. The heat exchanger according to any one of claims 1 to 3, characterized in that the distance H1 between the center line connecting the centers of the heat transfer tubes and the upstream edge of the upstream cut-up slit and the distance H2 between the center line connecting the centers of the heat transfer tubes and the downstream edge of the downstream cut-up slit are set to H1 > H2.

5. An air conditioner comprising a heat exchanger according to any one of claims 1 to 4, wherein a cross-flow fan is disposed downstream of the fins when viewed from the airflow direction, and the distance between the downstream end of the fins and the outer peripheral end of the blades of the cross-flow fan is 12 mm or less.

Images