air conditioner

Abstract

To provide an air conditioner reducing input in a cross flow fan by expanding an area where air flow passing through a heat exchanger flows into the cross flow fan, and thereby suppressing noise.SOLUTION: An air conditioner in the present disclosure includes a cross flow fan, a rear guider, a heat exchanger and an auxiliary heat exchanger. The rear guider is provided with an upper end projection part, and the relation of a distance RX between an intersection point X and an upper end point R and a distance QX between the intersection point X and a lower end point QX satisfies QX / (RX+QX)≥0.5 when a straight line is perpendicular to the front surface of a back surface heat exchanger and circumscribed on the upper end projection part is made to be a straight line A; an intersection point between the straight line A and the back surface of the back surface heat exchanger is made to be the intersection point X; the upper end of the surface facing the back surface heat exchanger in the auxiliary heat exchanger is made to be the upper end point R; and the lower end of the surface facing the back surface heat exchanger in the auxiliary heat exchanger is made to be the lower end point Q on a cross section orthogonal to the rotary shaft of the cross flow fan.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates primarily to air conditioners for home use. [Background technology]

[0002] Generally, an air conditioner includes a housing containing a crossflow fan with multiple blades, a stabilizer, a rear guider, and a heat exchanger consisting of a front heat exchanger on the front side of the crossflow fan and a rear heat exchanger on the rear side. The air conditioner draws air in from the top side of the housing, exchanges heat between the drawn air and a refrigerant flowing inside the heat exchanger, and then blows the air out from the bottom side of the housing to condition the room. The rear guider has a proximity portion that faces and is close to the crossflow fan and is separated from the crossflow fan by a predetermined distance, and an upper-end protrusion that extends upward from the proximity portion.

[0003] Patent Document 1 discloses an air conditioner that prevents a decline in heat exchange performance and an increase in noise. In this air conditioner, the air passage of the housing is formed continuously with the rear side wall portion located behind the rear heat exchanger and the air outlet, and includes a front nose portion and a back nose portion located between the crossflow fan and the heat exchanger. The heat exchanger is configured in a roughly inverted V shape with the front heat exchanger and the rear heat exchanger, and is arranged to cover the crossflow fan, including the front nose portion and the back nose portion. The rear heat exchanger has a rear main heat exchanger and a rear auxiliary heat exchanger, each of which has a fixed number of heat transfer tubes arranged in the air flow direction. The auxiliary heat exchanger is positioned on the upwind side of the rear main heat exchanger and is spaced apart from the rear wall surface portion, and when the distance from the lower edge of the rear auxiliary heat exchanger to the rear wall surface portion along a direction perpendicular to the arrangement direction of the heat transfer tubes is defined as L1, the shortest distance between the auxiliary heat exchanger and the rear wall surface portion is defined as L2, and the distance between the rear main heat exchanger and the tip of the back nose portion is defined as L3, the relationships 0.4<(L2 / L1)<0.6 and 0.55<(L3 / L1) are satisfied. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2014-20718 Summary of the Invention [Problem to be solved by the invention]

[0005] The air conditioner disclosed in Patent Document 1 achieves uniform velocity distribution of air passing through the rear heat exchanger and auxiliary heat exchanger, and uniform velocity distribution of air passing through only the rear heat exchanger. However, the air conditioner disclosed in Patent Document 1 has a problem in that large backflow vortices occur between the upper end protrusion and the crossflow fan, resulting in reduced air blowing performance.

[0006] The present disclosure provides an air conditioner that enables improved air blowing performance. [Means for solving the problem]

[0007] An air conditioner according to the present disclosure includes a crossflow fan, a front heat exchanger arranged on the front side of the crossflow fan, a rear heat exchanger arranged on the rear side of the crossflow fan, an auxiliary heat exchanger arranged on the rear side of the rear heat exchanger, and a rear guider arranged between the crossflow fan and the rear heat exchanger, the rear guider has a proximity portion that is close to the cross flow fan and an upper end protrusion that extends upward from the proximity portion, In a cross section orthogonal to the rotation axis of the crossflow fan, if a straight line perpendicular to the front surface of the rear heat exchanger and circumscribing the upper-end protrusion is defined as line A, the intersection of line A with the rear surface of the rear heat exchanger is defined as intersection X, the upper end of the surface of the auxiliary heat exchanger facing the rear heat exchanger is defined as upper end point R, and the lower end of the surface of the auxiliary heat exchanger facing the rear heat exchanger is defined as lower end point Q, then the distance RX between intersection point X and upper end point R and the distance QX between intersection point X and lower end point Q satisfy the relationship QX / (RX+QX)≧0.5. [Effects of the Invention]

[0008] The air conditioner of the present disclosure suppresses an increase in the heat exchanger ventilation resistance above the upper end of the upper protrusion of the rear guider and improves airflow turbulence near the upper end of the upper protrusion, thereby improving air blowing performance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of an air conditioner according to a first embodiment. [Figure 2] FIG. 1 is a vertical cross-sectional view of the vicinity of a rear heat exchanger of an air conditioner according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing an air flow near a rear heat exchanger of an air conditioner according to a first embodiment. [Figure 4] FIG. 1 is a diagram showing airflow distribution near a rear heat exchanger of an air conditioner according to a first embodiment. [Figure 5] FIG. 10 is a diagram showing changes in blown air volume with respect to QX / (RX+QX) of the air conditioner according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing changes in input power to a crossflow fan relative to QX / (RX+QX) in the air conditioner according to the first embodiment. [Figure 7] Vertical cross-sectional view of an air conditioner according to Patent Document 1 [Figure 8] A longitudinal cross-sectional view of the rear heat exchanger and its vicinity in the air conditioner according to Patent Document 1 DETAILED DESCRIPTION OF THE INVENTION

[0010] (Findings that formed the basis of this disclosure) At the time the inventors arrived at this disclosure, there was a problem in that a backflow occurred in the gap between the crossflow fan and the rear guider in the direction opposite to the rotational direction of the crossflow fan. When this backflow passed through the area adjacent to the crossflow fan and the rear guider, it drew in surrounding airflow and formed a backflow vortex upstream of the area adjacent to the crossflow fan and the rear guider. When the blades passed through the backflow vortex, interference noise was generated. To address this problem, there was a technology that used an upper-end protrusion provided from the area adjacent to the crossflow fan, which separates the upstream and downstream sections behind the crossflow fan, toward the top of the crossflow fan. This caused the backflow vortex to attach to the surface of the upper-end protrusion facing the crossflow fan, positioning the vortex center upstream of the area adjacent to the crossflow fan, thereby reducing interference with the blades and suppressing noise. In an air conditioner using this technology, a rear-end heat exchanger located behind the crossflow fan and behind the rear guider is configured so that the lower end of the rear-end heat exchanger is inserted below the upper end of the upper-end protrusion, and an air passage is formed between the downstream side of the rear-end heat exchanger and the surface of the upper-end protrusion facing the rear-end heat exchanger. With this configuration, the intake airflow passing through the rear heat exchanger located below the upper end of the upper end protrusion flows upward along the surface of the upper end protrusion facing the rear heat exchanger, swirls toward the crossflow fan near the upper end of the upper end protrusion, and flows into the crossflow fan.

[0011] Here, Patent Document 1 will be described as an example of a conventional air conditioner with reference to FIGS.

[0012] The structure of the air conditioner 1 disclosed in Patent Document 1 will be described using FIG. 7. The air conditioner 1 includes a housing 4 having an air inlet 2 and an air outlet 3. The housing 4 includes a cross-flow fan 5, a heat exchanger 6 between the air inlet 2 and the cross-flow fan 5, a front casing 7, and a back casing 8. The cross-flow fan 5 includes multiple fan blades 5A. The heat exchanger 6 includes a front heat exchanger 6A, a rear heat exchanger 6B, and an auxiliary heat exchanger 6C. The heat exchanger 6 includes fins 6D and heat transfer tubes 6E that pass through the fins 6D. The front heat exchanger 6A and the rear heat exchanger 6B are arranged in a roughly inverted V shape to cover the cross-flow fan 5 from above. The auxiliary heat exchanger 6C of the heat exchanger 6 functions as a so-called subcooler and is arranged upwind of the rear heat exchanger 6B (upstream of the air flow).

[0013] The front casing 7 is located in front of the cross-flow fan 5, and a stabilizer 7A that is bent into a substantially rectangular shape is formed integrally with the tip of the front casing 7.

[0014] Back casing 8 is located on the rear side of cross-flow fan 5, and has an upper end protrusion 8C that protrudes from an upper end (tip) 8B of curved surface 8A between cross-flow fan 5 and heat exchanger 6, and has flow path wall surface 8D that extends vertically upward behind upper end protrusion 8C. A recess 8E into which part of back heat exchanger 6B is inserted is formed between upper end 8B of curved surface 8A of back casing 8 and the lower end of flow path wall surface 8D.

[0015] The back-surface heat exchanger 6B has a generally rectangular cross section, with its longitudinal direction inclined downward from above the cross-flow fan 5 toward the flow path wall surface 8D, and its lower end is in contact with the flow path wall surface 8D. The lower end of the back-surface heat exchanger 6B is inserted into the recess 8E.

[0016] The auxiliary heat exchanger 6C is formed shorter than the rear heat exchanger 6B in the longitudinal direction and overlaps a portion of the upstream surface of the rear heat exchanger 6B. The auxiliary heat exchanger 6C is spaced apart from the flow path wall surface 8D. The corner of the end of the auxiliary heat exchanger 6C closer to the flow path wall surface 8D is cut out so that it is parallel to the flow path wall surface 8D. Because the auxiliary heat exchanger 6C is not in contact with the flow path wall surface 8D, the air passing through the rear heat exchanger 6B and the auxiliary heat exchanger 6C can either pass through both the rear heat exchanger 6B and the auxiliary heat exchanger 6C or pass only through the rear heat exchanger 6B.

[0017] The structure near the rear heat exchanger 6B of the air conditioner 1 disclosed in Patent Document 1 will be described using Figure 8. The lower end of the rear heat exchanger 6B is inserted into the recess 8E, and a narrow section S1 is formed between the downstream surface of the rear heat exchanger 6B and the surface of the upper end protrusion 8C facing the rear heat exchanger 6B. On the upstream side of the rear heat exchanger 6B in a portion where the auxiliary heat exchanger 6C is not present, a narrow section S2 is formed between the flow path wall surface 8D and the auxiliary heat exchanger 6C.

[0018] When the distance from the lower edge of the auxiliary heat exchanger 6C to the flow path wall surface 8D along a direction perpendicular to the arrangement direction of the heat transfer tubes 6E (the direction of arrows A and B) is defined as L1, the dimension of the narrow section S2 upstream of the rear heat exchanger 6B, i.e., the shortest distance between the auxiliary heat exchanger 6C and the flow path wall surface 8D, is defined as L2, and the dimension of the narrow section S1 downstream of the rear heat exchanger 6B, i.e., the distance between the rear heat exchanger 6B and the tip of the upper end protrusion portion 8C, is defined as L3, the relationships are set to satisfy 0.4<(L2 / L1)<0.6 and 0.55<(L3 / L1).

[0019] In this way, by setting the relationship between the distances L1, L2, and L3, the total ventilation resistance of these two narrow sections S1 and S2 is matched to the ventilation resistance of the auxiliary heat exchanger 6C, thereby reducing the bias between the wind speed distribution of the air passing through the rear heat exchanger 6B and the auxiliary heat exchanger 6C (arrow A) and the wind speed distribution of the air passing only through the rear heat exchanger 6B (arrow B), thereby preventing a decrease in heat exchange performance and an increase in noise, and providing an air conditioner 1 with little variation in performance.

[0020] However, since the air passing only through the rear heat exchanger 6B flows from bottom to top through the narrow section S1 between the surface of the upper end protrusion 8C facing the rear heat exchanger 6B and the rear heat exchanger 6B, even if the wind speed distribution of the air passing through the rear heat exchanger 6B and the auxiliary heat exchanger 6C (arrow A) and the wind speed distribution of the air passing only through the rear heat exchanger 6B (arrow B) are made uniform, a difference will occur between the speed of the airflow that has passed through the rear heat exchanger 6B and the auxiliary heat exchanger 6C and the speed of the airflow that passes only through the rear heat exchanger 6B, flows from below through the narrow section S1, and then deflects toward the cross-flow fan 5 at the tip of the upper end protrusion 8C. Depending on the speed at which the air deflects toward cross-flow fan 5 at the tip of upper-end protrusion 8C after passing only rear-face heat exchanger 6B and flowing from below through narrow section S1, the swirl radius near the tip of upper-end protrusion 8C may become large, causing the position at which the intake airflow passing through heat exchanger 6 flows into cross-flow fan 5 to be farther forward from the tip of upper-end protrusion 8C, expanding the backflow vortex generated between cross-flow fan 5 and the surface of upper-end protrusion 8C facing cross-flow fan 5 and narrowing the area where the airflow passing through heat exchanger 6 flows into cross-flow fan 5. In this case, the inventors discovered problems such as a decrease in the fan's output airflow volume, an increase in fan input, and inability to suppress noise, and have come to constitute the subject matter of the present disclosure in order to solve these problems.

[0021] Therefore, the present disclosure provides an air conditioner that improves air blowing performance by reducing the swirl radius of the airflow near the tip of the upper protrusion, moving the position where the intake airflow that has passed through the heat exchanger flows into the crossflow fan closer to the tip of the upper protrusion, reducing the backflow vortex that occurs between the crossflow fan and the surface of the upper protrusion facing the crossflow fan, and expanding the area where the airflow that has passed through the heat exchanger flows into the crossflow fan.

[0022] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0023] The accompanying 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.

[0024] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0025] [1-1.Configuration] In FIG. 1, the air conditioner 100 includes a main body casing 103 having an inlet 101 and an outlet 102 , a stabilizer 104 , a rear guider 105 , a cross-flow fan 106 , and a heat exchanger 107 .

[0026] The rear guider 105 has a proximity portion 105A that faces and is close to the cross flow fan 106 and is separated from the cross flow fan 106 by a predetermined distance, and an upper end protrusion portion 105B that extends upward from the proximity portion 105A. The rear guider 105 is disposed between the cross flow fan 106 and a rear heat exchanger 107B, which will be described later.

[0027] The cross-flow fan 106 has a plurality of blades 106A arranged in a cylindrical shape.

[0028] The heat exchanger 107 is composed of a front heat exchanger 107A, a rear heat exchanger 107B, and an auxiliary heat exchanger 108. The front heat exchanger 107A is disposed on the front side of the crossflow fan 106. The rear heat exchanger 107B is disposed on the rear side of the crossflow fan 106. The auxiliary heat exchanger 108 is disposed on the rear side of the rear heat exchanger 107B, that is, on the side opposite to the side where the crossflow fan 106 and rear heat exchanger 107B face each other. In other words, the auxiliary heat exchanger 108 is disposed on the surface of the rear heat exchanger 107B that is upstream of the air that flows in from the air inlet 101 when the crossflow fan is rotating. Hereinafter, for convenience, the surface on the windward side of the heat exchanger with respect to the air that flows in from the air inlet 101 will be referred to as the upstream surface, and the surface on the leeward side of the heat exchanger will be referred to as the downstream surface.

[0029] The front heat exchanger 107A and the rear heat exchanger 107B are provided with fins 107C and heat transfer tubes 107D that penetrate the fins 107C, and the heat transfer tubes 107D have an outer diameter D1 of 5 mm.

[0030] The auxiliary heat exchanger 108 includes fins 108A and heat transfer tubes 108B that penetrate the fins 108A, and the heat transfer tubes 108B have an outer diameter D2 of 6 mm.

[0031] Next, the detailed shape of the vicinity of the rear heat exchanger 107B will be described with reference to Fig. 2. The rear guider 105 has a proximity portion 105A that faces and is close to the cross flow fan 106 and is separated from the cross flow fan 106 by a predetermined distance, and has an upper end protrusion 105B that extends upward from the proximity portion 105A.

[0032] Let line A be the line perpendicular to the substantially planar front surface (downstream surface) of rear heat exchanger 107B and circumscribing upper end protrusion 105B, the intersection of line A with the rear surface (upstream surface) of rear heat exchanger 107B be intersection X, the upper end of the surface (downstream surface) of the auxiliary heat exchanger facing the rear heat exchanger be upper end point R, and the lower end of the surface (downstream surface) of the auxiliary heat exchanger facing the rear heat exchanger be lower end point Q. Then, the length of the distance RX between intersection point X and upper end point R and the distance QX between intersection point X and lower end point Q are QX / (RX+QX)≧0.5.

[0033] The intersection point of line A and the rear surface (upstream surface) of rear heat exchanger 107B is intersection point X, the lower end point of the rear surface (upstream surface) of rear heat exchanger 107B is bottom end point Y, the distance between intersection point X and bottom end point Y is distance XY, and the length in the row direction of auxiliary heat exchanger 108 is length H. Distance XY and length H satisfy the relationship XY / H≧1.0. Here, row direction length H of auxiliary heat exchanger 108 is defined as the distance between the upper end and the lower end of the surface of auxiliary heat exchanger 108 closest to rear heat exchanger 107B, i.e., the surface (downstream surface) of the auxiliary heat exchanger facing the rear heat exchanger.

[0034] [1-2. Operation] The operation of the air conditioner 100 configured as described above will be described below with reference to Figure 3. In the air conditioner 100, as the crossflow fan 106 rotates, indoor air is drawn into the main body casing 103 through the air inlet 101. The indoor air drawn into the main body casing 103 passes through the front heat exchanger 107A, the rear heat exchanger 107B, and the auxiliary heat exchanger 108, flows into the crossflow fan 106, and is then blown out from the air outlet 102 into the indoor space.

[0035] At this time, there are four intake airflows: intake airflows 200A and 200B that pass only through the rear heat exchanger 107B, and intake airflows 200C and 200D that pass through both the rear heat exchanger 107B and the auxiliary heat exchanger 108.

[0036] The intake airflow 200A passes through a portion of the rear heat exchanger 107B that is located below the upper end of the upper end protrusion 105B.

[0037] The intake airflow 200B passes through a portion of the rear heat exchanger 107B that is located above the upper end of the upper end protrusion 105B.

[0038] The intake airflow 200C passes through both the auxiliary heat exchanger 108 and a portion of the rear heat exchanger 107B that is located below the upper end of the upper end protrusion 105B.

[0039] The intake airflow 200D passes through both the auxiliary heat exchanger 108 and a portion of the rear heat exchanger 107B that is located above the upper end of the upper end protrusion 105B.

[0040] The intake airflow 200A and the intake airflow 200C pass through the portion of the rear heat exchanger 107B located below the upper end of the upper end protrusion 105B, flow upward along the surface of the upper end protrusion 105B facing the rear heat exchanger 107B, swirl toward the crossflow fan 106 near the upper end of the upper end protrusion 105B, and flow into the crossflow fan 106.

[0041] In addition, intake airflow 200B and intake airflow 200D, which pass through a portion of rear heat exchanger 107B located above the upper end of upper end protrusion 105B, merge with intake airflow 200A and intake airflow 200C, which pass through a portion of rear heat exchanger 107B located below the upper end of upper end protrusion 105B, near the upper end of upper end protrusion 105B, and flow into crossflow fan 106.

[0042] The intake airflow 200A and the intake airflow 200C passing through the portion of the rear heat exchanger 107B located below the upper end of the upper end protrusion 105B flow upward along the surface of the upper end protrusion 105B facing the rear heat exchanger 107B, and when they merge with the intake airflow 200B and the intake airflow 200D passing through the portion of the rear heat exchanger 107B located above the upper end of the upper end protrusion 105B near the upper end of the upper end protrusion 105B, they are forced downward from above and swirl toward the crossflow fan 106, and flow into the crossflow fan 106.

[0043] The ventilation resistance of the rear heat exchanger 107B and the auxiliary heat exchanger 108 is higher than the ventilation resistance of the rear heat exchanger 107B alone, and due to the difference in ventilation resistance, the wind speed of the intake airflow 200C and the intake airflow 200D passing through the rear heat exchanger 107B and the auxiliary heat exchanger 108 is lower than the wind speed of the intake airflows 200A and 200B passing through only the rear heat exchanger 107B.

[0044] Auxiliary heat exchanger 108 is located at a position where QX / (RX+QX)≧0.5, that is, more than half of auxiliary heat exchanger 108 in the row direction is below straight line A that is perpendicular to the downstream surface of backside heat exchanger 107B and circumscribes upper-end protrusion 105B. With this arrangement, near the tip of upper-end protrusion 105B, the converging wind speed of inlet airflow 200A and inlet airflow 200C flowing from below upper-end protrusion 105B toward the tip of upper-end protrusion 105B is relatively lower than the converging wind speed of inlet airflow 200B and inlet airflow 200D flowing from above upper-end protrusion 105B toward the vicinity of the tip of upper-end protrusion 105B. Due to this difference in wind speed, the intake airflow 200A and the intake airflow 200C passing through the rear heat exchanger 107B located below the upper end of the upper end protrusion 105B are strongly suppressed near the upper end of the upper end protrusion 105B by the intake airflow 200C and the intake airflow 200D passing through the rear heat exchanger 107B located above the upper end of the upper end protrusion 105B.

[0045] In the space between cross flow fan 106 and the surface of upper end protrusion 105B facing cross flow fan 106, a backflow vortex 201 is generated in the direction opposite to the rotation direction of cross flow fan 106. Backflow vortex 201 attaches to the surface of upper end protrusion 105B facing cross flow fan 106, and the vortex center is located upstream of proximity portion 105A.

[0046] 4, 5, and 6, the improvement in air blowing performance depending on the position of the auxiliary heat exchanger will be described in detail for the case where the line A intersects with the auxiliary heat exchanger 108, that is, the intersection point X is in contact with the auxiliary heat exchanger 108.

[0047] The airflow distribution in the vicinity of the rear heat exchanger 107B of the air conditioner 100 in this embodiment, particularly in the vicinity of the upper end of the upper end protrusion 105B, will be described in detail below with reference to FIG.

[0048] Figure 4 compares the intake airflow near the tip of the upper-end protrusion 105B and the inflow airflow into the cross-flow fan 106 depending on the position of the auxiliary heat exchanger 108.The figures show a comparison of the wind speed distribution of the intake airflow near the tip of the upper-end protrusion 105B and a comparison of the streamline distribution of the inflow airflow into the cross-flow fan 106 by numerical analysis for the case where the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.34 and the case where the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.67.

[0049] The position of the auxiliary heat exchanger is shown in the upper part of Fig. 4. In the region enclosed by a square in the figure, the wind speed distribution in the vicinity of upper end protrusion 105B is shown in the middle part of Fig. 4, and the streamline distribution of the airflow flowing into cross flow fan 106 is shown in the lower part.

[0050] The wind speed distribution near upper end protrusion 105B will be described using the middle part of Fig. 4. In the middle part of Fig. 4, the dashed line indicates the boundary line for a wind speed of 3M / S, and the area inside the dashed line indicates wind speeds of 3M / S or higher.

[0051] 4 shows the wind speed distribution when the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.34, and the middle right shows the wind speed distribution when the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.67. The dotted line on the middle right of Fig. 4 indicates a wind speed of 3M / S when the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.34.

[0052] Comparing the cases where the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.34 and QX / (RX+QX)=0.67, it is clear that the region near the upper protrusion 105B has an air velocity of 3 m / s or more. However, when the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.67, the dashed line is narrower toward the upper end of the upper protrusion 105B. In other words, when the auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.67, the air velocity of the intake airflow passing through the back surface heat exchanger 107B, which is located below the upper end of the upper protrusion 105B, is lower.

[0053] The streamline distribution of the inflow airflow into crossflow fan 106 will be explained using the lower part of Figure 4. The solid lines in the streamline diagram indicate the inflow airflow swirling toward crossflow fan 106 near the upper end of upper-end protrusion 105B. Of the streamlines flowing into crossflow fan 106, the solid line with an arrow indicates the rearmost streamline from the tip of upper-end protrusion 105B. In other words, the solid line with an arrow indicates the boundary between the inflow airflow that actually flows into crossflow fan 106 and the backflow vortex.

[0054] The lower left side of Figure 4 shows the flow line distribution when the auxiliary heat exchanger 108 is positioned so that QX / (RX+QX)=0.34, and the lower right side shows the flow line distribution when the auxiliary heat exchanger 108 is positioned so that QX / (RX+QX)=0.67. The lower right side of Figure 4 shows the rearmost flow line with a dotted line when the auxiliary heat exchanger 108 is positioned so that QX / (RX+QX)=0.34.

[0055] When auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.67, the boundary between the intake airflow that actually flows into crossflow fan 106 and the backflow vortex shifts to the right in the figure, and the backflow vortex area shrinks, compared to when auxiliary heat exchanger 108 is positioned such that QX / (RX+QX)=0.34. This indicates that the area where the airflow that has passed through heat exchanger 107 flows into crossflow fan 106 has expanded.

[0056] FIG. 5 illustrates the change in airflow rate relative to QX / (RX+QX). FIG. 5 shows the change in airflow rate from the air conditioner 100 when QX / (RX+QX) is a parameter determined by numerical analysis. The horizontal axis represents QX / (RX+QX), and the vertical axis represents the airflow ratio (100% airflow rate when QX / (RX+QX)=0.5) when the rotation speed of the crossflow fan 106 of the air conditioner 100 is constant. The coordinates of the five points plotted on the XY coordinate system are (0, 97.8), (0.34, 99.4), (0.5, 100), (0.67, 100.3), and (1.0, 99.8). As shown in FIG. 5, the airflow rate ratio drops sharply when QX / (RX+QX) falls below 0.5. On the other hand, the airflow rate ratio remains nearly constant when QX / (RX+QX) is 0.5 or greater. In other words, when the value of QX / (RX+QX) is increased from 0 to 1, the airflow ratio increases rapidly between 0 and 0.5, and reaches its upper limit when it reaches 0.5. In other words, when QX / (RX+QX) is 0.5 or greater, the airflow ratio increases and the airflow performance improves.

[0057] FIG. 6 illustrates input changes relative to QX / (RX+QX). FIG. 6 is a diagram showing input changes to the air conditioner 100 when QX / (RX+QX) obtained through numerical analysis is used as a parameter. The horizontal axis represents QX / (RX+QX), and the vertical axis represents the input ratio of the crossflow fan when the air discharge volume of the air conditioner 100 is the same (the input ratio is 100% when QX / (RX+QX) is 0.0). The coordinates of the five points plotted on the XY coordinate system are (0, 100), (0.34, 100.1), (0.5, 99.9), (0.67, 99.9), and (1.0, 99.8). As shown in FIG. 6, the input ratio increases when QX / (RX+QX) is between 0.0 and 0.34, but drops sharply between 0.34 and 0.5, and then remains low until the input ratio reaches 1.0. In other words, there is a point where QX / (RX+QX) improves sharply between 0.34 and 0.5, and it can be said that the input ratio can be reduced if QX / (RX+QX) is at least 0.5 or more. Furthermore, if QX / (RX+QX) is 0.5 or more, the input ratio can be reduced by 0.1%, and a sufficient improvement in air flow performance can be expected.

[0058] The above has explained the improvement in air blowing performance when line A intersects with auxiliary heat exchanger 108, that is, when intersection point X comes into contact with auxiliary heat exchanger 108. However, even when intersection point X does not come into contact with auxiliary heat exchanger 108, that is, when all auxiliary heat exchangers 108 are located below line A, the relationship QX / (RX+QX)≧0.5 is satisfied and a similar effect is achieved, improving the air blowing performance of the air conditioner.

[0059] [1-3. Effects, etc.] As described above, in this embodiment, air conditioner 100 includes main body casing 103 having air inlet 101 and air outlet 102, stabilizer 104, rear guider 105, cross flow fan 106, front heat exchanger 107A, rear heat exchanger 107B, and auxiliary heat exchanger 108. Rear guider 105 has proximity portion 105A that faces cross flow fan 106 and is close to it and spaced a predetermined distance from cross flow fan 106, and has upper end protrusion 105B that extends upward from proximity portion 105A, and has upper end protrusion 105B that extends upward from proximity portion 105A. The intersection point X of a straight line A that is perpendicular to the front surface (downstream surface) of the rear heat exchanger 107B and circumscribes the upper end protrusion 105B and the rear surface (upstream surface) of the rear heat exchanger 107B, the upper end point R of the surface (downstream surface) of the auxiliary heat exchanger that faces the rear heat exchanger, and the lower end point Q of the surface (downstream surface) of the auxiliary heat exchanger that faces the rear heat exchanger, the distance RX between the intersection point X and the lower end point R, and the distance QX between the intersection point X and the lower end point Q are such that QX / (RX+QX)≧0.5. The auxiliary heat exchanger 108 is located at a position where QX / (RX+QX)≧0.5, and more than half of the auxiliary heat exchanger 108 in the row direction is below the line A that is perpendicular to the downstream surface of the rear-surface heat exchanger 107B and circumscribes the upper-end protrusion 105B. Therefore, near the tip of the upper-end protrusion 105B, the wind speed of the intake airflow flowing from below the upper-end protrusion 105B toward the tip of the upper-end protrusion 105B is relatively slower than the wind speed of the intake airflow flowing from above the upper-end protrusion 105B toward the vicinity of the tip of the upper-end protrusion 105B. Due to this wind speed difference, the intake airflow passing through the portion of the rear-surface heat exchanger 107B located below the upper end of the upper-end protrusion 105B is strongly suppressed by the intake airflow passing through the portion of the rear-surface heat exchanger 107B located above the upper end of the upper-end protrusion 105B near the upper end of the upper-end protrusion 105B. This allows the air conditioner 100 to reduce the swirl radius of the air current swirling toward the cross flow fan 106 near the upper end of the upper end protrusion 105B.Therefore, by reducing the backflow vortex that occurs between the crossflow fan 106 and the surface of the upper end protrusion 105B facing the crossflow fan 106 and expanding the area through which the airflow that has passed through the heat exchanger 107 flows into the crossflow fan 106, the amount of air blown out from the crossflow fan 106 can be increased, the input power to the crossflow fan 106 can be reduced, noise can be suppressed, and the air-blowing performance of the air conditioner can be improved.

[0060] As in this embodiment, the distance XY between the intersection X of the straight line A and the upstream surface of the rear heat exchanger 107B and the lower end point Y of the upstream surface of the rear heat exchanger 107B, and the length H in the row direction of the auxiliary heat exchanger 108 may satisfy XY / H≧1.0.

[0061] Since the length H of the auxiliary heat exchanger 108 satisfies XY / H≧1.0, the entire auxiliary heat exchanger 108 can be positioned below a straight line A that is perpendicular to the front surface (downstream surface) of the rear-end heat exchanger 107B and circumscribes the upper-end protrusion 105B. By positioning the entire auxiliary heat exchanger 108 below the straight line A, it is possible to further increase the relative wind speed difference between the wind speed of the intake airflow flowing from below the upper-end protrusion 105B toward the tip of the upper-end protrusion 105B and passing through the rear-end heat exchanger 107B and the auxiliary heat exchanger 108, and the wind speed of the intake airflow flowing from above the upper-end protrusion 105B toward the vicinity of the tip of the upper-end protrusion 105B and passing only through the rear-end heat exchanger 107B. Due to this difference in wind speed, the intake airflow passing through a portion of rear-surface heat exchanger 107B located below the upper end of upper-end protrusion 105B is strongly suppressed near the upper end of upper-end protrusion 105B by the intake airflow passing through a portion of rear-surface heat exchanger 107B located above the upper end of upper-end protrusion 105B. This allows the air conditioner 100 to further reduce the swirl radius of the airflow swirling toward crossflow fan 106 near the upper end of upper-end protrusion 105B. This more effectively reduces the backflow vortex that occurs between crossflow fan 106 and the surface of upper-end protrusion 105B facing crossflow fan 106, and expands the area where the airflow that has passed through heat exchanger 107 flows into crossflow fan 106 depending on various conditions, thereby increasing the blown air volume of crossflow fan 106, reducing input power, and suppressing noise.

[0062] As in this embodiment, the heat exchanger 107 includes fins 107C and a heat transfer tube 107D passing through the fins 107C, and the auxiliary heat exchanger 108 includes fins 108A and a heat transfer tube 108B passing through the fins 108A. The outer diameter D1 of the heat transfer tube 107D and the outer diameter D2 of the heat transfer tube 108B may satisfy D1 < D2. However, the outer diameter D1 = 5MM of the heat transfer tube 107D and the outer diameter D2 = 6MM of the heat transfer tube 108B shown in this embodiment are merely examples. The heat exchanger 107 may be a heat transfer tube 107D that satisfies D1 ≤ 5MM. Thereby, in the air conditioner 100, the outer diameter D1 of the heat transfer tube 107D and the outer diameter D2 of the heat transfer tube 108B satisfy D1 < D2, and the ventilation resistance of the auxiliary heat exchanger 108 with respect to the rear heat exchanger 107B increases. Then, the relative wind speed difference between the wind speed of the suction air flow that flows through the rear heat exchanger 107B and the auxiliary heat exchanger 108 from below the upper end protrusion 105B toward the tip of the upper end protrusion 105B and the wind speed of the suction air flow that flows through only the rear heat exchanger 107B from above the upper end protrusion 105B toward the vicinity of the tip of the upper end protrusion 105B can be further enlarged.

[0063] Further, it includes a rear heat exchanger 107B designed to reduce the pressure loss when the outer diameter D1 of the heat transfer tube 107D is D1 = 5MM. When a large-volume suction air flow passes through the rear heat exchanger 107B, the wind speed of the suction air flow that flows through only the rear heat exchanger 107B from above the upper end protrusion 105B toward the vicinity of the tip of the upper end protrusion 105B can be actively increased. Therefore, the reverse flow vortex generated between the cross-flow fan 106 and the surface of the upper end protrusion 105B facing the cross-flow fan 106 can be more effectively reduced, and the air volume blown out by the cross-flow fan 106 can be increased by expanding the region where the air flow passing through the heat exchanger 107 flows into the cross-flow fan 106, thereby reducing the input and suppressing the noise.

[0064] In addition, in the above-described embodiment, when the upper end point of the upstream surface of the rear heat exchanger 107B is defined as the upper end point Z, the distance XZ between the intersection point X of the straight line A and the upstream surface of the rear heat exchanger 107B and the upper end point Z, and the distance XY between the intersection point X of the straight line A and the upstream surface of the rear heat exchanger 107B and the lower end point Y of the upstream surface of the rear heat exchanger 107B are such that XZ < XY. In such a case, the more the region located below the upper end of the upper protrusion 105B in the rear heat exchanger 107B, the more preferable it is.

[0065] In addition, since the above-described embodiment is for exemplifying the technology in the present disclosure, various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or the equivalent scope thereof.

Industrial Applicability

[0066] The present disclosure can improve the blowing performance by reducing the turning radius of the airflow that turns toward the cross-flow fan near the upper end of the upper protrusion, reducing the reverse flow vortex formed upstream of the proximity portion of the rear spoiler, and expanding the region where the airflow that has passed through the heat exchanger flows into the cross-flow fan. Therefore, it is suitable for use in household air conditioners and commercial air conditioners.

Explanation of Reference Numerals

[0067] 100 Air conditioner 101 Suction port 102 Outlet 103 Main body casing 104 Stabilizer 105 Rear spoiler 105A Proximity portion 105B Upper protrusion 106 Cross-flow fan 107 Heat exchanger 107A Front heat exchanger 107B Rear heat exchanger 107C Fin 107D Heat transfer tube 108 Auxiliary heat exchanger 108A Fin 108B Heat transfer tube

Claims

1. a cross-flow fan, a front heat exchanger arranged on the front side of the cross-flow fan, a rear heat exchanger arranged on the rear side of the cross-flow fan, an auxiliary heat exchanger arranged on the rear side of the rear heat exchanger, and a rear guider arranged between the cross-flow fan and the rear heat exchanger, the rear guider has a proximity portion that is close to the cross flow fan and an upper end protrusion that extends upward from the proximity portion, In a cross section orthogonal to the rotation axis of the cross flow fan, when a straight line perpendicular to the front surface of the rear heat exchanger and circumscribing the upper-end protrusion is defined as line A, an intersection of line A with the rear surface of the rear heat exchanger is defined as intersection X, an upper end of a surface of the auxiliary heat exchanger facing the rear heat exchanger is defined as upper end point R, and a lower end of a surface of the auxiliary heat exchanger facing the rear heat exchanger is defined as lower end point Q, a distance RX between the intersection point X and upper end point R and a distance QX between the intersection point X and lower end point Q satisfy QX / (RX+QX)≧0.5, When the intersection point X is the lower end point Y of the rear surface of the rear heat exchanger, the distance XY between the intersection point X and the lower end point Y is X, and the length of the auxiliary heat exchanger in the stage direction is H, XY / H≧1.0, and the auxiliary heat exchangers are all located below the line A that is perpendicular to the front surface of the rear heat exchanger and circumscribes the upper end protrusion.

2. 2. The air conditioner of claim 1, wherein the rear heat exchanger comprises rear heat exchanger fins and rear heat exchanger heat transfer tubes that penetrate the rear heat exchanger fins, the auxiliary heat exchanger comprises auxiliary heat exchanger fins and auxiliary heat exchanger heat transfer tubes that penetrate the auxiliary heat exchanger fins, and an outer diameter D1 of the rear heat exchanger heat transfer tubes and an outer diameter D2 of the auxiliary heat exchanger heat transfer tubes satisfy the relationship D1 < D2.

3. The air conditioner according to claim 2, wherein the outer diameter D1 of the rear heat exchanger heat transfer tube satisfies D1≦5 mm.

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