HK1091258B - Air conditioner - Google Patents

Description

Air conditioner

Technical Field

The present invention relates to an air conditioner, and more particularly, to an air conditioner having a cross flow fan capable of reducing an input of a fan motor required for obtaining a predetermined air volume from an indoor unit.

Background

The conventional air conditioner improves aerodynamic performance of a cross flow fan or heat conduction performance of a heat exchanger by changing only a blade shape of the cross flow fan without changing a configuration of the heat exchanger or by changing only a configuration of the heat exchanger without changing a blade shape of the cross flow fan.

In a conventional air conditioner in which the arrangement of the heat exchanger is changed without changing the shape of the blades of the cross-flow fan, the front-face side heat exchanger and the back-face side heat exchanger are provided above the cross-flow fan in a state of being combined into a λ shape, and the front-face side heat exchanger and the back-face side heat exchanger each exhibit the maximum heat exchange performance, thereby improving the performance of the indoor unit (see patent document 1).

Patent document 1: japanese patent laid-open No. 2000-329364 (paragraphs 0009 to 0015, FIG. 1)

In the conventional air conditioner, when only the blade shape of the cross flow fan is changed without changing the arrangement of the heat exchanger, the flow direction of the wind in the intake region of the cross flow fan is defined by the arrangement of the heat exchanger, and therefore the blades form a blade shape that does not stall in the intake region and a blade shape that does not easily discharge the wind in the discharge region.

On the other hand, when only the arrangement of the heat exchanger is changed without changing the blade shape of the cross flow fan, the inflow direction of the wind in the cross flow fan suction region is changed by the arrangement of the heat exchanger, and the attack angle of the blade is also changed, and therefore, the optimal blade shape is not formed.

As described above, the conventional air conditioner has a problem that the input of the fan motor or the number of rotations required to obtain a predetermined air volume from the indoor unit is large because only the arrangement of the heat exchanger is changed or only the blade shape of the cross flow fan is changed without changing the blade shape of the cross flow fan or the arrangement of the heat exchanger.

Disclosure of Invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide an air conditioner capable of reducing the fan motor input or the number of rotations required to obtain a predetermined air volume from an indoor unit.

The present invention is an air conditioner having: an indoor unit is provided with at least one suction port and one discharge port, a cross flow fan connected to a fan motor, a front heat exchanger and a rear heat exchanger, respectively, wherein an angle alpha of the front heat exchanger located above a rotation center of the cross flow fan is set to 65 DEG to 90 DEG with respect to a horizontal direction, a point of the rear heat exchanger closest to the front heat exchanger is located on the side of the front heat exchanger with respect to the rotation center of the cross flow fan, and an outlet angle beta 2 of a blade of the cross flow fan is set to 22DEG to beta 2 to 28 deg.

In the present invention, the relative horizontal installation angle α of the front heat exchanger located above the rotation center of the cross flow fan is set to 65 ° or more and 90 ° or less, the point of the rear heat exchanger closest to the front heat exchanger is located on the side of the front heat exchanger relative to the rotation center of the cross flow fan, and the outlet angle β 2 of the blades of the cross flow fan is set to 22 ° or more and β 2 or less and 28 °, whereby the fan motor input or the number of rotations required to obtain a predetermined air volume can be reduced.

Drawings

Fig. 1 is a configuration diagram showing an air conditioner according to a first embodiment of the present invention.

Fig. 2 is a diagram showing the inner path of the air conditioner according to the first embodiment of the present invention.

Fig. 3 is a view showing a structure of a blade of a cross flow fan according to a first embodiment of the present invention.

Fig. 4 is a view showing a structure of a blade of a cross flow fan according to a first embodiment of the present invention.

Fig. 5 is a relative velocity distribution diagram showing blades of a cross flow fan configured in the first embodiment of the present invention.

Fig. 6 is a configuration diagram showing an air conditioner according to a configuration of the first embodiment of the present invention.

Fig. 7 is a diagram showing a trajectory of an air conditioner according to a first embodiment of the present invention.

Fig. 8 is a diagram showing the inner path of the heat exchanger according to the first embodiment of the present invention.

Fig. 9 is a flow explanatory diagram showing the downstream side of the heat exchanger configured in the first embodiment of the present invention.

Fig. 10 is a diagram showing a relationship between an air volume and a heat exchanger installation angle in the first embodiment of the present invention.

Fig. 11 is a diagram showing a relationship between the fan motor input and the heat exchanger installation angle in the configuration of the first embodiment of the present invention.

Fig. 12 is a diagram showing a relationship between the fan motor input and the outlet angle in the configuration of the second embodiment of the present invention.

Fig. 13 is a torque distribution diagram of a cross flow fan according to a second embodiment of the present invention.

Fig. 14 is a diagram showing a relationship between the fan motor input and the inlet angle in the configuration of the third embodiment of the present invention.

Fig. 15 is a cutaway view showing a negative pressure surface of a cross flow fan suction region configured in the third embodiment of the present invention.

Fig. 16 is a schematic diagram showing a pressure surface of a cross flow fan discharge area according to a third embodiment of the present invention.

Fig. 17 is a schematic diagram showing a state in which the negative pressure surface near the stabilizer according to the third embodiment of the present invention is peeled off.

Fig. 18 is a fan motor input diagram showing a configuration of the fourth embodiment of the present invention.

Fig. 19 is an air volume diagram showing the configuration of the fourth embodiment of the present invention.

Fig. 20 is a schematic diagram showing a cross flow fan according to a fourth embodiment of the present invention.

Fig. 21 is a sectional view showing an indoor unit configured in a sixth embodiment of the present invention.

Fig. 22 is a fan motor input diagram showing a configuration of a sixth embodiment of the present invention.

Fig. 23 is a velocity vector diagram showing a configuration of the sixth embodiment of the present invention.

Description of the symbols

Cross flow fan 1, front heat exchanger 2, back heat exchanger 3, 4 setting angle, suction inlet 6, discharge outlet 7, indoor unit 8, fan suction area 10, attack angle 12, blade 13, suction surface 14, pressure surface 15, inlet angle 21, angle 38, fan discharge area 40, area near stabilizer 43, 44 auxiliary heat exchanger, 48 distance.

Detailed Description

First embodiment

Fig. 1 is a sectional view showing an air-conditioning indoor unit according to a first embodiment of the present invention, fig. 2 is a flow path of air in the indoor unit according to the first embodiment of the present invention, and fig. 3 and 4 are configuration diagrams showing blades of a cross flow fan configured according to the first embodiment of the present invention.

In fig. 1, an indoor unit 8 includes a cross flow fan 1, a front heat exchanger 2, a rear heat exchanger 3, an air cleaning filter 5, a stabilizer 39, an auxiliary heat exchanger 43, and an auxiliary heat exchanger 44, the cross flow fan 1 is provided corresponding to the discharge ports 7 of the indoor unit 8 and the indoor unit 8, the indoor unit 8 is provided with suction ports 6 at the front and upper surfaces and a discharge port 7 at the lower surface of a front panel 56, the front heat exchanger 2 is provided so as to recede to form an upper edge portion and a lower edge portion respectively and face the suction ports 6 at the front and upper surfaces, the rear heat exchanger 3 is provided at the rear surface side of the front heat exchanger 2 so as to be disposed at a position where the upper edge portion is close to the upper edge portion of the front heat exchanger 2 and face the suction ports 6 at the upper surface and the lower edge portion is inclined in a direction away, the stabilizer 39 causes air generated in the cross-flow fan 1 to flow smoothly, and the auxiliary heat exchanger 43 and the auxiliary heat exchanger 44 are provided in the front heat exchanger 2 and the rear heat exchanger 3, respectively. The rotation center point of the cross flow fan 1 is denoted by O, the point at which the rear heat exchanger 3 is closest to the front heat exchanger 2 is denoted by a, and the installation state of the front heat exchanger 2 is denoted by an installation angle 4 at the upper portion of the front heat exchanger 2.

The operation of the indoor unit 8 will be described below with reference to fig. 1 to 11.

Fig. 2 is a diagram showing a flow path of air in the indoor unit 8, where the suction area 10 is a part of the suction area of the cross flow fan 1, and the discharge area 38 is a part of the discharge area of the cross flow fan 1. And, the region 40 is the region 40 near the stabilizer 39. Then, the air 9 flows into the fan suction area 10 from the direction of the rear heat exchanger 3 as indicated by an arrow 11.

Fig. 3 shows the blade 13 of the cross flow fan, the negative pressure surface 14 of the blade 13, the pressure surface 15, the end point B of the leading edge 18 of the blade 13, and the end point C of the trailing edge 19, and the attack angle 12 is an angle formed by the straight line BC and the relative velocity vector 17 of the air 9 at the point B, and is positive in the direction of the arrow 16.

In fig. 4, when the exit angle is 20, the entrance angle is 21, the blade chord is 22, the blade chord length representing the length of the blade chord 22 is 23, the bend line is 24, and the point where the perpendicular line from the point D on the blade chord 22 intersects the bend line 24 is E, the maximum camber representing the maximum length of the line segment DE is 25, the maximum blade thickness is 41, the circle passing through the point B is 26 centered on the rotation center O of the cross flow fan 1, the circle passing through the point C is 27 centered on the rotation center O of the cross flow fan 1, and the radius of the circle 26 is larger than the radius of the circle 27. Here, the exit angle 20 is an angle formed by the bend line 24 and the circle 26, the entrance angle 21 is an angle formed by the bend line 24 and the circle 27, the blade chord 22 is a line segment BC, and the maximum blade thickness 41 is the maximum diameter of the circle in contact with the suction surface 14 and the pressure surface.

In the above configuration, when the cross-flow fan 1 is rotated by the operation of the fan motor (not shown), the air 9 outside the indoor unit 8 is sucked through the suction port 6, passes through the air cleaning filter 5, the front and rear heat exchangers 2 and 3, and the cross-flow fan 1, and is discharged through the discharge port 7. At this time, the air cleaning filter 5 removes dust contained in the air 9, the front heat exchanger 2 and the rear heat exchanger 3 exchange heat with the air 9, the air 9 is cooled when the air conditioner is operated, and the air 9 is heated when the air heater is operated.

Here, the relative velocity distribution of the blades 13 of the cross flow fan 1 will be described with reference to fig. 5. Fig. 5 shows a state in which the angle of attack is large in the fan suction region 10 and peeling occurs on the negative pressure surface 14. This causes a problem that if the negative pressure surface 14 is peeled off, the fan motor input required to obtain a predetermined air volume increases, and the number of fan revolutions increases.

As shown in fig. 2, there are a method of suppressing the separation on the negative pressure surface 14 by causing the air 9 to flow into the suction region 10 not from the direction of the rear heat exchanger 3 but from the direction of the front heat exchanger 2, and a method of modifying the shape of the blade 13 by reducing the exit angle 20 of the blade 13, and the like. However, in the latter method, since the discharge area is formed in a shape in which the air does not easily flow, there is a problem that the fan motor input required for obtaining a predetermined air volume and the number of fan revolutions increase, and therefore, it is preferable that the air flow is made to flow into the suction area 10 from the direction of the front heat exchanger 2.

Hereinafter, a method of flowing from the front heat exchanger 2 into the suction area 10 will be described with reference to fig. 6 to 9. Fig. 6 is a diagram showing the configuration of an air conditioner according to the first embodiment of the present invention, fig. 7 is a diagram showing the trajectory of the air conditioner, fig. 8 is a diagram showing the relationship between the inflow angle and the outflow angle of wind to the heat exchanger, and fig. 9 is an explanatory diagram showing the flow on the leeward side of the heat exchanger.

Fig. 6 shows an example in which the installation angle 4 of the front heat exchanger 2, in which the front heat exchanger 2 and the rear heat exchanger 3 are disposed above the rotation center O of the cross flow fan 1, is 65 ° or more with respect to the horizontal, and the closest point of the rear heat exchanger 3 to the front heat exchanger 2 is located closer to the front heat exchanger 2 than the rotation center O of the cross flow fan 1. 28 is the angle formed by the straight line OA and the line extending perpendicularly from point O, and in fig. 6, angle 4 is 73.6 ° and angle 28 is 17.6 °.

As shown in fig. 7, the air conditioner of this configuration has a flow path of air that is different from that of fig. 2, and forms a flow that flows into the fan suction area 10 from the direction of the front heat exchanger 2.

The reason why the flow flowing into the fan suction area 10 from the direction of the front heat exchanger 2 is formed in this way will be described.

First, a relationship between an inflow angle and an outflow angle of wind to the heat exchanger will be described with reference to fig. 8. Fig. 8 is a diagram showing the results of a ternary fluid analysis showing the outflow angle 31 of the heat exchanger 29 when the heat exchanger 29 as a model is placed on the air duct and the inflow angle 30 of the wind is changed. As shown in fig. 8, regardless of the inflow angle 30, the outflow angle 31 is small, and the wind flows out substantially perpendicularly to the heat exchanger 29. This is achieved by utilizing the interaction between the refrigerant pipe 32 and the fins (not shown) 33.

The reason why the flow flowing into the fan suction area 10 from the direction of the front heat exchanger 2 is formed will be described below with reference to fig. 9. Fig. 9 is an explanatory diagram for explaining the reason why the flow flowing into the fan suction region 10 from the direction of the front heat exchanger 2 in fig. 7 is formed.

As shown in fig. 8, since the outflow angle 31 is substantially perpendicular to the heat exchanger 29 regardless of the inflow angle 30 of the heat exchanger 29 of the model, a velocity vector 34 perpendicular to the front heat exchanger 2 and a velocity vector 35 perpendicular to the rear heat exchanger 3 are considered. On the combined velocity vector 36 of the velocity vector 34 and the velocity vector 35, the combined velocity vector 36 is in the direction from the front heat exchanger 2 toward the fan suction area 10, and the smaller the angle 37 formed by the combined velocity vector 36 and the vector 42 of the horizontal component of the combined velocity vector 36, the easier it flows on the fan suction area from the direction of the front heat exchanger 2 into the suction area 10. Further, it is preferable to reduce the angle 37 by increasing the installation angle 4 of the front heat exchanger 2 and increasing the angle 28 formed by the straight line OA and the perpendicular line passing through the point O (see fig. 6).

Here, the experimental results of the installation angle 4 of the front heat exchanger 2 will be described with reference to fig. 10 and 11. Fig. 10 is a graph showing experimental values of the relationship between the air volume discharged from the indoor unit 8 and the angle 4 when the rotational speed of the cross flow fan 1 is set to 1500rpm and the angle 4 is changed, and fig. 11 is a graph showing the air volume discharged from the indoor unit 8 as 16m³Graph of experimental values of fan motor input versus angle 4 at/min. In addition, the blade 13 of the crossflow fan 1 used in the experiments shown in fig. 10 and 11 had an outer diameter of Φ 100, an exit angle 20 of 26 °, an entrance angle 21 of 94 °, a blade chord 23 of 12.4mm, and a maximum camber 25 of 2.5 mm.

The experiment was carried out with the number of layers of the front heat exchanger 2 and the rear heat exchanger 3 being 4 layers and 6 layers, the number of rows being 2 rows, the row pitch of the refrigerant piping 32 being 12.7mm, the layer pitch being 20.4mm, the height of the indoor unit 8 being 305mm, the shortest distance between the vane 13 and the front heat exchanger 2 being 15mm, and the angle 4 being 60 to 90 °. In fig. 10, the air volume at an angle of 60 ° and 1500rpm was 100. In fig. 11, the fan input at an angle of 60 ° and 1500rpm is 100.

As shown in FIG. 10, the larger the angle 4, the larger the air volume at 1500rpm, and as shown in FIG. 11, the larger the angle 4, the air volume of 16m³The fan motor input at/min is reduced. When the air-conditioning apparatus is operated, the air 9 is condensed when passing through the front heat exchanger 2 and the auxiliary heat exchanger 43, and is likely to form water droplets, but when the angle 4 is less than 65 °, some of the water droplets flow into the cross-flow fan 1, and are discharged to the outside of the indoor unit 8, or adhere to the wall surface of the outlet 7. If the angle 4 is greater than 90 °, the distance between the front heat exchanger 2 and the auxiliary heat exchanger 43 is shortened near the joint, and a downwind resistance is formed. And also has a problem that the depth of the unit increases.

As described above, when the angle 4 of the front heat exchanger 2 is not between 65 ° and 90 ° and the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is not located closer to the rear heat exchanger 3 than the point O of the rotation center of the cross flow fan 1, there is a problem that the fan motor input required for obtaining the predetermined air volume is large and the number of revolutions is large, but when the angle 4 of the front heat exchanger 2 is between 65 ° and 90 ° and the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the front heat exchanger 2 than the point O of the rotation center of the cross flow fan 1, the fan motor input required for obtaining the predetermined air volume can be reduced.

In the present embodiment, as shown in fig. 6, the description has been given of the case where the point F and the point G of the front heat exchanger 2 are on the same straight line, but the point F and the point G may not be on the same straight line, and in this case, the angle 4 when F and G are curved lines is the maximum value of the angle formed by the tangent line on the curved line FG and the horizontal line.

Second embodiment

The present embodiment experimentally confirms that the range of the outlet angle 20 of the blade 13 of the crossflow fan 1, which can reduce the fan motor input required to obtain a predetermined air volume, can be reduced.

Fig. 12 is a diagram showing a relationship between an input angle and an outlet angle of a fan motor configured in the second embodiment of the present invention, and fig. 13 is a torque distribution diagram showing a cross flow fan configured in the second embodiment of the present invention. The configuration of the air conditioner is the same as that of the first embodiment of fig. 6, and the range of the exit angle 20 of fig. 4 of the first embodiment is determined, and therefore, the description of the configuration is omitted.

The cross flow fan 1 used in the experiment had the blades 13 having the outer diameter of Φ 100, the inlet angle 21 of 94 °, the blade chord 23 of 12.4mm, the maximum bend 25 of 2.5mm, the angle 4 of 73.6 °, the angle 28 of 17.6 ° in fig. 6, the number of layers of the front heat exchanger 2 and the back heat exchanger 3 was 4 and 6, respectively, the number of rows was 2, the pitch of the refrigerant pipes 32 was 12.7mm, the layer pitch was 20.4mm, and the height of the indoor unit 8 was 305 mm.

Furthermore, the outlet angle 20 of the blade 13 of the crossflow fan 1 is changed to 22-30 DEG, and the air volume discharged from the indoor unit 8 is detected to be 16m³Fan motor input required at min.

The results of the experiment are shown in FIG. 12. In fig. 12, the outlet angle 20 is 25 °, and the air volume discharged from the indoor unit 8 is 16m³The fan motor input at/min is 100.

As shown in fig. 12, the fan motor input is minimal when the exit angle 20 is 25 °.

The reason will be described below with reference to fig. 6, 12, and 13. Fig. 13 is a distribution ratio of the torque of the blades 13 of each crossflow fan 1 when the exit angle 20 is 22 °, 25 °, 28 °. The position and value of the curve of fig. 13 mean the ratio of the torque at the position of each blade 13 in fig. 6, which is the torque of the blade 13 at each position divided by the sum of the torques of the entire blade 13. In fig. 13, for example, "+ (22 deg)" and "- (22 deg)" mean that "+" is a region where the fan motor input is increased and "-" is a region where the fan motor input is decreased. In addition, the region of "-" where the fan motor input is reduced is a region where the static pressure of the pressure surface 15 is lower than the static pressure of the negative pressure surface 14 because the attack angle 12 is too small and the pressure surface 15 peels off.

According to fig. 13, the larger the exit angle 20, the smaller the torque ratio of the fan discharge area 38, but the larger the torque ratio of the fan suction area 10. This is because the area between the blades 13 effective for the air volume increases in the fan discharge region 38, the attack angle 12 increases in the fan suction region, and the negative pressure surface 14 is likely to be peeled off.

Conversely, the smaller the exit angle 20, the smaller the torque ratio of the fan intake area 10, but the larger the torque ratio of the fan discharge area 38. This is because the fan suction region 10 is gradually narrowed in the attack angle 12 (see fig. 3), so that the negative pressure surface 14 is less likely to be peeled off, and the fan discharge region 38 is reduced in the area between the blades 13 effective for the air volume.

In fig. 12, the fan motor input is the smallest when the outlet angle 20 is 25 °, but as described above, the fan motor input of 25 ° is most advantageous when the outlet angle 20 is large or small, in view of both advantages and disadvantages.

In the above description, the outlet angle in the case where the angle 4 is 73.6 ° was described, but the outlet angle 20 at which the fan motor input is minimum is increased as the installation angle 4 is larger, and the outlet angle 20 at which the fan motor input is minimum is decreased as the angle 4 is smaller. Although not specifically described, when the angle 4 is 90 °, the exit angle 20 at which the fan motor input is minimum is 28 °, and when the angle 4 is 65 °, the exit angle 20 at which the fan motor input is minimum is 22 °.

As described above, when the angle 4 of the front heat exchanger 2 is not between 65 ° and 90 °, the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the rear heat exchanger 3 than the point O of the rotation center of the cross flow fan 1, and the outlet angle 20 of the blade 13 of the cross flow fan 1 is not between 22 ° and 28 °, there is a problem that the fan motor input required for obtaining the predetermined air volume is large, but by making the angle 4 of the front heat exchanger 2 between 65 ° and 90 °, the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the front heat exchanger 2 than the point O of the rotation center of the cross flow fan 1, and the outlet angle 20 of the blade 13 of the cross flow fan 1 between 22 ° and 28 °, the fan motor input required for obtaining the predetermined air volume can be reduced.

Third embodiment

The present embodiment experimentally determines the range of the inlet angle 21 of the blade 13 of the crossflow fan 1 in which the air volume of the fan motor at a predetermined rotation number can be increased.

Fig. 14 is a diagram showing a relationship between a fan motor input and an inlet angle in the third embodiment of the present invention, fig. 15 is a diagram showing a peeling of a negative pressure surface 14 in a cross flow fan suction area in the third embodiment of the present invention, fig. 16 is a diagram showing a peeling of a pressure surface in a cross flow fan discharge area in the third embodiment of the present invention, and fig. 17 is a diagram showing a peeling of a negative pressure surface 14 in the vicinity of a stabilizer in the third embodiment of the present invention.

The configuration of the air conditioner is the same as that of the first embodiment of fig. 6, and the range of the inlet angle 21 of fig. 4 of the first embodiment is determined, and therefore, the description of the configuration is omitted.

The cross flow fan 1 used in the experiment had the blades 13 with an outer diameter of Φ 100, an exit angle of 20 of 25 °, a blade chord 23 of 12.4mm, and a maximum bend of 2.5mm, and the angles 4 and 28 of 73.6 and 17.6 in fig. 6, and the number of layers of the front heat exchanger 2 and the back heat exchanger 3 was 4 and 6, respectively, the number of rows was 2, the pitch of the refrigerant pipes 32 was 12.7mm, the layer pitch was 20.4mm, and the height of the indoor unit 8 was 305 mm.

The inlet angle 21 of the blade 13 of the cross flow fan 1 is changed to 88-104 DEG, and the air volume discharged from the indoor unit 8 when the number of revolutions of the cross flow fan 1 is 1500rpm is detected.

The results of the experiment are shown in FIG. 14. In fig. 14, the air volume discharged from the indoor unit 8 when the inlet angle 21 is 96 ° and the number of rotations of the cross flow fan 1 is 1500rpm is 100. As shown in fig. 14, when the inlet angle 21 is 96 °, the air volume is maximum.

The reason for this will be described below with reference to fig. 6 and 14 to 17. Fig. 15 is a diagram showing a relative velocity distribution in which peeling occurs on the negative pressure surface 14 in the fan suction region 10, fig. 16 is a diagram showing a relative velocity distribution in which peeling occurs on the pressure surface 15 in the fan discharge region 38, and fig. 17 is a diagram showing a relative velocity distribution in which peeling occurs on the negative pressure surface 14 in the vicinity of the stabilizer 39 shown in fig. 1.

If the inlet angle 21 is small, the negative pressure surface 14 is less likely to peel off in the fan suction region 10, and since the attack angle 12 (see fig. 3) is not too small in the fan discharge region 38, the negative pressure surface 14 is less likely to peel off in the pressure surface 15, and there is a problem that the negative pressure surface 14 is more likely to peel off in the region 40 near the stabilizer 39 as shown in fig. 17. On the other hand, if the inlet angle 21 is large, the negative pressure surface 14 is less likely to peel off in the region 40 near the stabilizer 39, and as shown in fig. 15, the negative pressure surface 14 is likely to peel off in the fan suction region 10, and as shown in fig. 16, the attack angle 12 is too small in the fan discharge region 38, and there is a problem that peeling off is likely to occur in the pressure surface 15.

In fig. 14, the air volume at 1500rpm is the largest when the inlet angle 21 is 96 °, which is a disadvantage in both cases where the inlet angle 21 is large or small as described above, and the air volume is most advantageous when the inlet angle 21 is 96 ° in consideration of both advantages and disadvantages.

The air quantity is maximum when the inlet angle 21 is 96 degrees, the air quantity ratio at the time is 100, and 99.5-100% of the range of 0.5% of the maximum air quantity ratio is set as an allowable range, corresponding to the maximum air quantity ratio. The most preferable range of the inlet angle 21 is 96 ° to 100 °.

As described above, although there is a problem that the air volume at the predetermined revolution is small when the angle 4 of the front heat exchanger 2 is not between 65 ° and 90 °, the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the rear heat exchanger 3 than the point O of the rotation center of the cross flow fan 1, and the inlet angle 21 of the blade 13 of the cross flow fan 1 is not between 91 ° and 100 °, the air volume at the predetermined revolution can be increased by setting the angle 4 of the front heat exchanger 2 between 65 ° and 90 °, the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the front heat exchanger 2 than the point O of the rotation center of the cross flow fan 1, and the inlet angle 21 of the blade 13 of the cross flow fan 1 between 91 ° and 100 °.

Fourth embodiment

In the present embodiment, it has been experimentally confirmed that when the maximum curvature of the blade 13 of the crossflow fan 1 is hc and the outer diameter of the blade 13 is D, the range of hc/D of the blade 13 of the crossflow fan 1 required to obtain the fan motor input required for the predetermined air volume can be reduced.

FIG. 18 shows an air volume discharged from the indoor unit 8 of 16m when the hc/D of the vane 13 of the air conditioner according to the fourth embodiment of the present invention is changed³Fig. 19 is a graph showing experimental values of the relationship between the fan motor input at/min and hc/D, fig. 19 is a graph showing experimental values of the relationship between the air volume at 1500rpm of the air conditioner according to the fourth embodiment of the present invention and hc/D, and fig. 20 is a graph showing the separation of the negative pressure surface in the cross flow fan suction region configured in the fourth embodiment of the present invention.

The configuration of the air conditioner is the same as that of the first embodiment of fig. 6, and the range of hc/D in fig. 4 of the first embodiment is determined, and therefore, the description of the configuration is omitted.

The cross-flow fan 1 used in the experiment had blades 13 with an outer diameter of Φ 100, an outlet angle 20 of 25 °, an inlet angle 21 of 96 °, a blade chord 23 of 12.4mm, a maximum blade thickness 41 of 1.07mm, an angle 4 of 73.6 ° and an angle 28 of 17.6 ° in fig. 6, the front heat exchanger 2 and the rear heat exchanger 3 had 4 and 6 layers, respectively, 2 rows, a pitch of the refrigerant pipes 32 of 10.2mm, and a height of the indoor unit 8 of 305 mm.

And, change hc/D toBecomes 0.024-0.029, and detects the air volume discharged from the indoor unit 8 as 16m³Fan motor input required at/min. hc is the maximum bend 25 of the blade 13 and D is the outer diameter of the blade 13.

The results of the experiment are shown in FIG. 18. In FIG. 18, hc/D is 0.026, and the volume of air discharged from the indoor unit 8 is 16m³The fan motor input at/min is 100. In FIG. 19, hc/D is 0.024, and the air volume at 1500rpm is 100.

As shown in FIG. 18, when hc/D is 0.026, the air volume discharged from the indoor unit 8 is 16m³The fan motor input required for/min is minimal and, as shown in FIG. 19, the greater the hc/D the greater the air volume at 1500 rpm.

The reason will be described below with reference to FIGS. 18 to 20. Fig. 20 is a diagram showing a state where the negative pressure surface 14 is detached from the fan suction area 10.

As shown in fig. 20, if hc/D is large, peeling is easy at the front edge 18 of the negative pressure surface 14 in the fan suction area 10, and if hc/D is small, peeling is not easy at the front edge 18 of the negative pressure surface 14 in the fan suction area 10, and peeling is easy at the rear edge 19 of the negative pressure surface 14. Therefore, as shown in FIG. 18, the fan motor input is minimal at a hc/D of 0.026.

And, the larger the hc/D, the larger the bending, resulting in high lift. Therefore, as shown in fig. 19, the air volume increases at a predetermined rotation speed.

In the above description, the hc/D when the angle 4 is 73.6 ° is described, and when the angle 4 is 90 °, the hc/D when the fan motor input is minimum is 0.025, and when the angle 4 is 65 °, the hc/D when the fan motor input is minimum is 0.028.

Therefore, when hc/D is 0.025 to 0.028, the fan motor input required to obtain a predetermined air volume can be minimized, and the air volume at a predetermined number of revolutions can be maximized.

As described above, when the angle 4 of the front heat exchanger 2 is not between 65 ° and 90 °, the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the rear heat exchanger 3 than the point O of the rotation center of the cross flow fan 1, the outer diameter of the blade 13 of the cross flow fan 1 is D, the maximum blade thickness is hc, and hc/D is not between 0.025 and 0.028, there is a problem that the fan motor input required for obtaining a predetermined air volume is large, however, by setting the angle 4 of the front heat exchanger 2 to 65 ° to 90 °, the point a of the rear heat exchanger 3 closest to the front heat exchanger 2 is located closer to the front heat exchanger 2 than the point O of the rotation center of the cross flow fan 1, the outer diameter of the blade 13 of the cross flow fan 1 is D, the maximum blade thickness is 41 hc, and the hc/D is 0.025 to 0.028, it is possible to reduce the fan motor input required to obtain a predetermined air volume.

Fifth embodiment

In the present embodiment, the magnitude of the pressure loss of the fan motor input, the draft resistance member on the front heat exchanger 2 side, and the draft resistance member on the rear heat exchanger 3 side, which are required to obtain a predetermined air volume, is determined by experiments.

The configuration of the air conditioner is the same as that of the first embodiment of fig. 9, and a description thereof will be omitted.

As shown in fig. 9, experiments were conducted in which the air resistance body on the front heat exchanger 2 side was set as the auxiliary heat exchanger 43 and the air resistance body on the back heat exchanger 3 side was set as the auxiliary heat exchanger 44, and as shown in table 1, example a was a case where the air resistances of the auxiliary heat exchanger 43 and the auxiliary heat exchanger 44 were set to 1, example B was a case where the air resistance of the auxiliary heat exchanger 43 was set to 2 (twice the air resistance of the auxiliary heat exchanger 43 of example a) and the air resistance of the auxiliary heat exchanger 44 was set to 1 (the same as the air resistance of the auxiliary heat exchanger 44 of example a), and example C was a case where the air volume discharged from the indoor unit 8 in a state where the air resistance of the auxiliary heat exchanger 43 was set to 1 and the air resistance of the auxiliary heat exchanger 44 was set to 2³Fan motor input at/min.

[ Table 1]

Ventilation resistance and fan motor input to auxiliary heat exchanger

As shown in table 1, in example a, when the ventilation resistances of the auxiliary heat exchanger 43 and the auxiliary heat exchanger 44 were set to 1, the air volume was set to 16m³The fan motor input at/min is 100.

The fan motor input is minimum in example a, 106.4 maximum in example B, and 104.6 centered in example C. From this result, in order to reduce the fan motor input, it is preferable that the ventilation resistances of the auxiliary heat exchanger 43 and the auxiliary heat exchanger 44 are made equal, and it is preferable that the ventilation resistance of the auxiliary heat exchanger 43 is made smaller than the ventilation resistance of the auxiliary heat exchanger 44.

That is, in order to reduce the fan motor input, it is preferable that the ventilation resistance on the front heat exchanger 2 side is the same as the ventilation resistance on the front heat exchanger 3 side, and the ventilation resistance on the auxiliary heat exchanger 2 side is smaller than the ventilation resistance on the rear heat exchanger 3 side.

The reason will be described below with reference to fig. 9. Considering the vector diagram shown in fig. 9, the larger the magnitude of the velocity vector 36 and the smaller the angle 37, the smaller the attack angle 16 can be in the fan suction region 10, and therefore, the separation on the negative pressure surface 14 can be suppressed. In order to increase the magnitude of the velocity vector 36 and reduce the angle 37, it is preferable to increase the magnitude of the velocity vector 34 to make the vector direction horizontal and decrease the magnitude of the velocity vector 35 to make the vector direction vertical. The results of Table 1 show that the greater the magnitude of the velocity vector 36, the smaller the angle 37, the smaller the fan motor input.

In the present embodiment, the auxiliary heat exchangers 43 and 44 are used as the resistance bodies on the upstream side of the front heat exchanger 2 and the rear heat exchanger 3, but may be a ventilation resistance body such as an electric dust collector. However, the ventilation resistance body does not include the air cleaning filter 5. The pressure loss of the draft resistance member on the front heat exchanger 2 side and the pressure loss of the draft resistance member on the back heat exchanger 3 side are defined as static pressure differences on the windward side and the leeward side of the draft resistance members when the respective resistance members are installed in the wind tunnel and the same volume of air is made to flow in the vertical direction with respect to the front heat exchanger 2 and the back heat exchanger 3. The pressure loss of the air flow resistor on the front heat exchanger 2 side and the pressure loss of the air flow resistor on the back heat exchanger 3 side can be adjusted by the fin pitch of the front heat exchanger 2 and the back heat exchanger 3, the tube pitch of the refrigerant tubes 32, the shape of the slits 46, and the like.

As described above, when the pressure loss of the front heat exchanger side draft resistance body is larger than the pressure loss of the rear heat exchanger 3 side draft resistance body, there is a problem that the fan motor input required for obtaining the predetermined air volume is large, and by making the pressure loss of the front heat exchanger side draft resistance body smaller than the pressure loss of the rear heat exchanger 3 side draft resistance body, the air flow from the front heat exchanger side to the cross flow fan 1 is generated, the attack angle of the blade 13 on the suction region of the cross flow fan 1 can be reduced, and the stall is not easily caused on the negative pressure surface 14, so that the fan motor input required for obtaining the predetermined air volume can be reduced.

Sixth embodiment

Fig. 21 is a cross-sectional view showing an indoor unit of an air conditioner according to a sixth embodiment of the present invention, and fig. 22 is a cross-sectional view showing an amount of air discharged from the indoor unit 8 when changing L/D by setting an outer diameter of blades 13 of the cross flow fan 1 to D and a distance 48 to L³Graph of experimental values of fan motor input versus L/D at/min. Here, the distance 48 is a horizontal distance between a point of the uppermost portion of the suction plate 47, which is far from the front heat exchanger 2, and a point of the front heat exchanger 2, which is closest to the suction plate 47. In fig. 22, the fan motor input when L/D is 0.6 is set to 100.

Fig. 23 is a diagram showing a synthesized velocity vector. The resultant velocity vector 49 in fig. 23 is a resultant vector of the velocity vector 50 and the velocity vector 51, the velocity vector 50 is a velocity vector at the intersection P of the front heat exchanger 2 and a straight line passing through the auxiliary heat exchanger 43 at the point H and the point L of the point I in fig. 21, and the velocity vector 51 is a velocity vector at the intersection Q of the rear heat exchanger 3 and a straight line passing through the auxiliary heat exchanger 44 at the point J and the point M of the point K and the rear heat exchanger 3.

As shown in FIG. 22, the fan motor input required to obtain a predetermined air volume decreases as L/D increases, but if L/D is not less than 0.4, the fan motor input hardly changes.

The reason for this will be explained below. Since the greater the distance 48, the more easily the air flows toward the front heat exchanger 2, the greater the magnitude of the resultant velocity vector 49 shown in fig. 23, the greater the horizontal vector component 52 of the resultant velocity vector 49, and the smaller the angle 53. Therefore, the incidence angle 12 is reduced in the suction region 10 of the cross flow fan 11, and the stall is less likely to occur on the negative pressure surface 14. In addition, the suction plate 47 does not ventilate, and if the distance 48 is small, the ventilation resistance at the minimum lower portion of the rear heat exchanger 3 or the front heat exchanger 2 is small, and therefore, the wind does not easily flow in the upper portion of the front heat exchanger 2.

As described above, since there is a problem that the fan motor input required to obtain a predetermined air volume is large when L/D < 0.4, the attack angle 12 can be reduced in the suction area 10 of the cross flow fan 1 by setting L/D to 0.4 or more, and the fan motor input required to obtain a predetermined air volume can be reduced.

Claims (5)

1. An air conditioner in which at least one suction port and one discharge port are provided in an indoor unit, respectively, the air conditioner comprising: a cross flow fan connected to a fan motor, a front heat exchanger and a rear heat exchanger, wherein an angle α of installation of the front heat exchanger located above a rotation center of the cross flow fan with respect to the horizontal is 65 ° or more and 90 ° or less, a point of the rear heat exchanger closest to the front heat exchanger is located on the side of the front heat exchanger with respect to the rotation center of the cross flow fan, and an outlet angle β 2 of a blade of the cross flow fan is 22 ° or more and β 2 or less and 28 °.

2. An air conditioner in which at least one suction port and one discharge port are provided in an indoor unit, respectively, the air conditioner comprising: a cross flow fan connected to a fan motor, a front heat exchanger and a back heat exchanger, wherein an installation angle alpha of the front heat exchanger located above a rotation center of the cross flow fan relative to the horizontal is set to 65 DEG-90 DEG, a point of the back heat exchanger closest to the front heat exchanger is located on the side of the front heat exchanger than the rotation center of the cross flow fan, and an inlet angle beta 1 of a blade of the cross flow fan is set to 91 DEG-beta 1-100 deg.

3. An air conditioner in which at least one suction port and one discharge port are provided in an indoor unit, respectively, the air conditioner comprising: a cross flow fan connected to a fan motor, a front heat exchanger and a back heat exchanger, wherein an angle α of the front heat exchanger located above a rotation center of the cross flow fan is set to 65 DEG to 90 DEG with respect to a horizontal direction, a point of the back heat exchanger closest to the front heat exchanger is located on the side of the front heat exchanger with respect to the rotation center of the cross flow fan, and when an outer diameter of a blade of the cross flow fan is D and a maximum curvature thereof is hc, hc/D is 0.025 to 0.028.

4. An air conditioner according to any one of claims 1 to 3, wherein at least one type of ventilation resistor is provided on each of the upstream sides of the front heat exchanger and the rear heat exchanger, and the ventilation resistance of the ventilation resistor on the front heat exchanger side is made to be the same as or smaller than the ventilation resistance of the ventilation resistor on the rear heat exchanger side.

5. An air conditioner according to any one of claims 1 to 3, wherein L/D is 0.4 or more when the outer diameter of the cross flow fan blade is D and the maximum distance between the suction plate and the front heat exchanger is L.