JP6642913B2 - Turbo fan and air conditioner using it - Google Patents

Description

  The present invention relates to a turbofan that blows air sucked in the axial direction from a shroud side while changing the direction in a radial direction, and an air conditioner using the same.

  The turbofan includes a hub that is rotationally driven by a motor or the like, a shroud arranged to face the hub, and a plurality of blades arranged between the hub and the shroud. Most of the blades of this turbofan are arranged between the hub and the shroud such that the leading edge, which is the inner peripheral end, is arranged on the rotational direction side than the trailing edge, which is the outer peripheral end, and also have an airfoil shape. However, due to restrictions on molding and the like, the cross-sectional shape is generally a two-dimensional shape that is uniform in the axial direction (for example, see Patent Document 1). However, in recent years, restrictions on the manufacturing method have been eliminated, and many blades having a three-dimensional shape in the axial direction and hollow blades have been proposed (for example, see Patent Documents 2-4). .

  On the other hand, as a technique that emphasizes performance in order to reduce noise and improve efficiency, for example, as shown in Patent Documents 5-7, in order to suppress a horseshoe-shaped eddy current generated at a joint portion between a hub and a blade, In the vicinity of the leading edge on the hub side, a curved structure is formed in the rotating or anti-rotating direction, and a horseshoe-shaped vortex suppression part is formed. The blade is connected to the arc surface of the shroud through the bent portion, or the hub side of the trailing edge of the blade is curved in both the rotation direction and the anti-rotation direction to accelerate the airflow at the trailing edge of the blade What has been made possible has been proposed.

  In other words, in the case of a turbofan, the airflow sucked in the axial direction changes in the radial direction, so that the airflow sucked from the outer edge side of the suction port does not bend due to the inertia force, but is deflected to the hub side inside. The blades do not function effectively near the suction port, causing a decrease in efficiency.In addition, high-speed jets are generated due to uneven airflow on the outlet side, and backflow occurs near the suction port, resulting in noise. It was easy to grow. In addition, when a turbofan is used in an air conditioner, air is sucked in from a rectangular passage passing through a grill or a filter, and the outlet side is operated in a non-axisymmetric pressure field surrounded by a square heat exchanger. It is difficult to realize a uniform flow over the entire span direction (axial direction) of the fan, and as described above, various ideas aiming at low noise and high efficiency have been proposed.

JP-A-2002-235695 JP 2007-170331 A JP 2007-170771 A JP 2010-216486 A JP 2009-127541 A International Publication No. 2009/069606 International Publication No. WO 2010/128618

  However, in the above-described turbo fan and an air conditioner using the turbo fan, when a fan input which is a driving force of the turbo fan is used as an evaluation parameter, there is still room for improvement in the turbo fan. In other words, reducing the fan input is an eternal problem. From such a viewpoint, when the fluid analysis of the turbo fan is performed by the finite volume method, in the current turbo fan, the suction surface on the outer peripheral side (the trailing edge side) of the blade is used. In this case, the air flow along the blade tends to separate from the blade surface, while a high static pressure region is generated on the pressure surface side of the blade, whereby the air flow along the blade is decelerated (driving force loss). Occurred), and it was found that the fan efficiency was reduced.

  The present invention has been made in view of such circumstances, and suppresses the separation of the air flow on the negative pressure surface on the outer peripheral side (the trailing edge side) of the blade and reduces the speed of the air flow on the pressure surface side of the blade. It is an object of the present invention to provide a turbofan capable of improving fan efficiency and reducing a fan input which is a driving force of the fan, and an air conditioner using the turbofan.

MEANS TO SOLVE THE PROBLEM In order to solve said subject, the turbofan of this invention and the air conditioner using the same employ | adopt the following means.
That is, the turbofan according to the present invention includes a hub connected to a motor drive shaft and driven to rotate, an annular shroud arranged to face the hub and forming an air suction port, and a space between the hub and the shroud. A plurality of blades arranged on the rotation direction side with respect to the rear edge of the outer peripheral side, and the plurality of blades are arranged at the rear edge. There is a concave in the counter air flow direction to the coupling portion with respect to the hub and the shroud, the coupling portion relative to the hub of the vane is formed smoothly curved surface in the direction of rotation or counterclockwise rotation direction across the air flow direction It is characterized by being.

According to the present invention, the trailing edges (also referred to as trailing edge lines) of the plurality of blades are concave in the direction opposite to the airflow with respect to the connection portion to the hub and the shroud, so that the trailing edges of the blades are straight. Compared with the blades and those that are convex in the air flow direction, the separation of the air flow on the negative pressure side of the blade is improved, and the turbulence of the air flow can be suppressed. It is possible to improve the fan efficiency and reduce the fan driving force (fan input) by reducing the generated high static pressure region and suppressing the deceleration of air flow (loss of driving force). That is, by making the trailing edge of the blade concave in the anti-airflow direction, the radius of the concave area becomes smaller than the original shape, and when the fan is rotated at the same rotation speed, the airflow passing through the fan is reduced. The pressure rise (static pressure) in the vicinity of the trailing edge of the blade is reduced at a portion of the negative pressure surface where peeling is easy, particularly on the shroud side. On the other hand, on the positive pressure surface, the effect of the airflow passing through the fan being biased toward the hub side is remarkable, and the pressure on the blade surface also shows a distribution that rises sharply toward the hub side. By making the edge concave, the pressure (static pressure) near the blade trailing edge can be reduced, the static pressure on the positive pressure surface can be reduced, the fan efficiency can be improved, and the fan input can be reduced. Therefore, it is possible to further increase efficiency and reduce noise of the turbo fan.

Further, in the turbofan of the present invention, in the above-described turbofan, the trailing edge of the blade may have an air-repellent shape as described above, wherein a center portion of the blade in the span direction is in a range of 25% to 75% of the span direction. It is characterized by being concave in the flow direction.

According to the present invention, since the center portion of the trailing edge of the blade is concave in the anti-airflow direction in the range of 25 to 75% of the span direction of the blade, the function of the connection portion between the hub and the shroud of the blade, The blades can be coupled to the hub and shroud without affecting performance. Therefore, the air flow is not disturbed at the hub-side connection portion and the shroud-side connection portion of the blade, so that low noise and high efficiency can be achieved.

Further, in the turbofan of the present invention, in any one of the above-described turbofans, the concave amount of the trailing edge of the blade in the direction opposite to the airflow (−indicated) is −0.0 to the fan outer diameter D. 014D to -0.0153D.

According to the present invention, since the concave amount (-indicated) of the trailing edge of the blade in the anti-airflow direction is in the range of -0.0142D to -0.0153D with respect to the fan outer diameter D, The fan input, which is the driving force of the turbo fan, can be reduced to a preferable range. Therefore, the efficiency and the noise of the turbo fan can be reduced.

Furthermore, in the turbofan of the present invention, in any one of the above-described turbofans, the leading edge of the blade is concave in an air flow direction or convex in an anti-air flow direction with respect to a coupling portion to the hub and the shroud. It is characterized by that.

According to the present invention, the leading edge of the blade (also referred to as a leading edge line) is concave in the air flow direction or convex in the anti-air flow direction with respect to the connection with the hub and the shroud, so that the leading edge is provided. The air flow may be displaced concavely in the air flow direction, causing slight turbulence in the air flow on the negative pressure surface of the blade.However, the high static pressure area on the positive pressure surface side is reduced to suppress the deceleration of the air flow. On the other hand, by displacing the leading edge in a convex shape in the anti-airflow direction, the high static pressure region on the positive pressure surface side may be slightly larger, and the effect of suppressing the deceleration of the airflow may slightly decrease. Separation can be suppressed by suppressing turbulence of the air flow on the negative pressure surface. In other words, by making the leading edge of the blade concave in the airflow direction, the length of the blade in the airflow direction is shortened, the friction loss between the airflow and the blade surface is reduced, and the fan input can be reduced. However, if the shape is too concave, the blade length in the air flow direction with respect to the distance between adjacent blades becomes too short, and the blade performance deteriorates. Also, by making the leading edge of the blade convex in the anti-airflow direction, frictional loss between the airflow and the blade surface generally increases, while the length of the blade in the airflow direction substantially increases. Therefore, by stably guiding the flow flowing from the upstream side of the blade to the downstream side, the peak value of the static pressure on the blade surface is suppressed, the flow is hardly separated, and the fan input can be reduced. Fan noise can be reduced. Therefore, also in this case, the fan input can be sufficiently reduced, and the efficiency and the noise of the turbo fan can be improved.

Further, in the turbofan according to the present invention, in the above-described turbofan, the concave amount (indicated by +) of the leading edge of the blade in the airflow direction is 0.0091D to 0.0153D with respect to the fan outer diameter D. , And the amount of protrusion (−indicated) in the anti-airflow direction is -0.0438D with respect to the fan outer diameter D.

  According to the present invention, the concave amount (indicated by +) of the leading edge line in the air flow direction is in the range of 0.0091D to 0.0153D with respect to the fan outer diameter D, and the convex in the anti-air flow direction. Since the state quantity (-indicated) is -0.0438D with respect to the fan outer diameter D, the fan input, which is the driving force of the turbofan, can be reduced to a preferable range. Can be improved in efficiency and noise can be reduced.

  Further, in the turbofan of the present invention, in any one of the above-described turbofans, the leading edge line of the blade may be such that a center portion of the blade in a span direction is in a range of 25% to 75% of the span direction. As described above, it is characterized by being concave in the air flow direction or convex in the anti-air flow direction.

  According to the present invention, the center portion of the leading edge line of the blade is concave in the air flow direction or convex in the counter air flow direction in the range of 25% to 75% of the span direction of the blade. The blades can be coupled to the hub and shroud without affecting the function and performance of the coupling to the hub and shroud. Therefore, the airflow is not disturbed at the hub-side connection portion and the shroud-side connection portion of the blade, and noise reduction and high efficiency can be achieved.

  Further, in the turbofan of the present invention, in any one of the above-described turbofans, a connecting portion of the blade to the hub has a smooth curved surface in an anti-rotation direction, and a connecting portion of the blade to the shroud is , Characterized in that the curved surface is smooth in the rotation direction.

  According to the present invention, the connecting portion of the blade to the hub has a smooth curved surface in the anti-rotation direction, and the connecting portion of the blade to the shroud has a smooth curved surface in the rotating direction. By making the connecting portion a curved surface that is smooth in the anti-rotational direction, the connecting portion is left-right asymmetric, and stagnation of air flow at the connecting portion can be suppressed, while the connecting portion of the blade to the shroud is smooth in the rotating direction. With the curved surface, the separation of the flow on the negative pressure surface side by the blade force can be suppressed, and the air flow can be made smooth. Therefore, the blade performance can be improved, the fan input can be further reduced, and the efficiency can be improved, and the turbulence of the air flow can be suppressed, and the noise can be reduced.

  Furthermore, in the turbofan of the present invention, in the above-described turbofan, an angle (+ display) of a curved surface of the connecting portion of the blade to the hub in the anti-rotation direction with respect to one pitch angle θ of the blade is 0.0563θ to 0.0972θ, and the angle of the curved surface in the rotation direction of the connecting portion with respect to the shroud (−indicated) is −0.0154θ to −0 with respect to one pitch angle θ of the blade. 0.0972θ.

  According to the present invention, the angle of the curved surface in the anti-rotation direction of the connecting portion of the blade with respect to the hub (+ display) is in a range of 0.0563θ to 0.0972θ with respect to one pitch angle θ of the blade. Since the angle of the curved surface in the rotation direction of the connecting portion with respect to the shroud (-indicated) is in the range of -0.0154θ to -0.0972θ with respect to one pitch angle θ of the blade, the hub-side connecting portion. Stagnation of the air flow can be suppressed, and separation of the air flow on the negative pressure surface side can be suppressed by the blade force, so that the blade performance can be further improved. Therefore, the fan input, which is the driving force of the turbo fan, can be reduced to a preferable range, and the efficiency and noise of the turbo fan can be reduced.

  Further, in the turbofan of the present invention, in any one of the above-described turbofans, a connecting portion of the blade to the hub has a smoothly curved surface in a rotational direction, and a connecting portion of the blade to the shroud includes: It is characterized by having a smooth curved surface in the anti-rotation direction.

According to the present invention, the connecting portion of the blade to the hub has a smooth curved surface in the rotational direction, and the connecting portion of the blade to the shroud has a smooth curved surface in the anti-rotating direction. by setting the coupling portion direction of rotation into a smooth curved surface, the coupling portion is asymmetrical, it is possible to suppress the stagnation of air flow at the coupling portion. In addition, by forming the connecting portion of the blade to the shroud with a curved surface that is smooth in the anti- rotation direction, the air flow on the negative pressure surface side near the shroud can be made smooth, and separation can be suppressed. Therefore, the blade performance can be improved, the fan input can be further reduced, and the efficiency can be improved, and the turbulence of the air flow can be suppressed, and the noise can be reduced.

  Further, in the turbofan of the present invention, in the above-described turbofan, the angle (-indicated) of the curved surface of the blade in the rotation direction of the connecting portion with respect to the hub is-with respect to one pitch angle θ of the blade. 0.0768θ, and the angle of the curved surface in the anti-rotation direction of the coupling portion with respect to the shroud in the anti-rotation direction (+ display) is 0.0031θ with respect to one pitch angle θ of the blade. .

  According to the present invention, the angle (-indicated) of the curved surface of the connecting portion of the blade with respect to the hub in the rotation direction is -0.0768θ with respect to one pitch angle θ of the blade, and the connection with the shroud is made. The angle (+ display) of the curved surface in the anti-rotation direction of the portion is set to 0.0031θ with respect to one pitch angle θ of the blade, so that the stagnation of the air flow at the hub-side coupling portion is suppressed. In addition, the separation of the air flow on the negative pressure side near the shroud can be suppressed, and the blade performance can be further improved. Therefore, the fan input, which is the driving force of the turbo fan, can be reduced to a preferable range, and the efficiency and noise of the turbo fan can be reduced.

  Further, in the turbofan of the present invention, in any one of the above-described turbofans, a connecting portion of the blade to the hub is a curved surface that is smoothly curved in a rotation direction, and a connecting portion of the blade to the shroud is It is characterized by having a smooth curved surface in the rotation direction.

According to the present invention, the connecting portion of the blade to the hub has a smoothly curved surface in the rotational direction, and the connecting portion of the blade to the shroud has a smooth curved surface in the rotational direction. parts by the a smooth curved surface in the direction of rotation, the coupling portion is asymmetrical, whereas it is possible to suppress the stagnation of air flow at the junction, smooth the coupling portion with respect to the shroud of the blade in the rotational direction With the curved surface, separation of the flow on the negative pressure surface side by the blade force can be suppressed, and the air flow can be made smooth. Therefore, the blade performance can be improved, the fan input can be further reduced, and the efficiency can be improved, and the turbulence of the air flow can be suppressed, and the noise can be reduced.

  Further, in the turbofan of the present invention, in the above-described turbofan, the angle (-indicated) of the curved surface of the blade in the rotation direction of the connecting portion with respect to the hub is-with respect to one pitch angle θ of the blade. 0.0154θ, and the angle of the curved surface in the rotation direction of the coupling portion with respect to the shroud (−indicated) is −0.0461θ with respect to one pitch angle θ of the blade. .

  According to the present invention, the angle (-indicated) of the curved surface in the rotation direction of the coupling portion with respect to the hub of the blade is set to -0.0154θ with respect to one pitch angle θ of the blade, and the rotation of the coupling portion with respect to the shroud. Since the angle of the curved surface in the direction (-display) is -0.0461 [theta] with respect to one pitch angle [theta] of the blade, it is possible to suppress the stagnation of the airflow at the hub-side joint portion. Further, the separation of the air flow on the negative pressure side can be suppressed by the blade force, and the blade performance can be further improved. Therefore, the fan input, which is the driving force of the turbo fan, can be reduced to a preferable range, and the efficiency and noise of the turbo fan can be reduced.

  Furthermore, the air conditioner according to the present invention includes a blower that sucks and blows room air, and a heat exchanger that is arranged on either the suction side or the blow side of the blower and that cools or heats the room air. And the blower is any one of the above-described turbo fans.

  According to the present invention, since the blower that sucks indoor air, cools or heats the heat by the heat exchanger, and blows out the temperature-regulated air into the room is the above-described turbo fan, the driving force of the turbo fan , The fan input can be reduced, and the efficiency and the noise of the turbo fan can be reduced. Therefore, the air conditioner can have higher performance and lower noise.

  ADVANTAGE OF THE INVENTION According to the turbofan of this invention, while improving the separation of the airflow on the negative pressure side of the blade, the turbulence of the airflow can be suppressed, and the high static pressure region generated on the positive pressure side of the blade is reduced. The fan efficiency can be improved by suppressing the deceleration of air flow (loss of driving force), and the driving force of the fan (fan input) can be reduced, so that the efficiency and the noise of the turbo fan are further improved. Can be achieved.

  ADVANTAGE OF THE INVENTION According to the air conditioner of this invention, since the fan input which is the driving force of a turbo fan can be reduced and the efficiency and the noise of the turbo fan can be reduced, the air conditioner can be made more efficient and the noise can be reduced. Can be

It is an exploded perspective view of the air conditioner concerning one embodiment of the present invention. It is a figure which shows the fan shape (A) of the turbofan applied to the said air conditioner, the critical streamline (B) on the blade surface, and the static pressure contour (C) on the blade surface. FIG. 9 is a comparison diagram of turbofan shapes (A) to (E) used when the turbofan is subjected to fluid analysis by the finite volume method. FIG. 5 is a comparison diagram of critical streamlines (A) to (E) on the blade surface of each of the turbofans. FIG. 3 is a comparison diagram of static pressure contours (A) to (E) on the blade surface of each of the turbofans. FIG. 9 is a comparison diagram of displacement shapes (B) and (C) with respect to an original shape (A) of a blade leading edge used as a design variable of each turbofan. FIG. 8 is a comparison diagram of displacement shapes (B) and (C) with respect to an original shape (A) of a blade trailing edge used as a design variable of each turbofan. FIG. 7 is a comparison diagram of displacement shapes (B) and (C) with respect to an original shape (A) of a blade hub side curved shape used as a design variable of each turbofan. FIG. 9 is a comparison diagram of displacement shapes (B) and (C) with respect to an original shape (A) of a blade shroud side curved shape used as a design variable of each turbofan. FIG. 4 is a superposition diagram of two blades obtained by rotating the entire blade used as a design variable of each turbofan around a rotation axis. FIG. 5 is a superposition diagram of two blades showing displacement of a leading edge and a trailing edge of a blade used as a design variable of each turbofan. It is explanatory drawing explaining the displacement state of the front edge and rear edge of the blade | wing used as the design variable of each said turbofan. It is a schematic diagram for demonstrating the blade force of each said turbofan. It is a chart which shows the design variable (A) and objective function (B) used for the analysis of each said turbofan. 4 is a chart showing values of design variables in the analysis result by the finite volume method. It is a bar graph which shows the comparison result of the objective function D '(the ratio of the airflow adjustment input to the original). 9 is a graph showing a correlation between an objective function D ′ and a design variable (1). 9 is a graph showing a correlation between an objective function D ′ and a design variable (2). 9 is a graph showing a correlation between an objective function D ′ and a design variable (3). 9 is a graph showing a correlation between an objective function D ′ and a design variable (4).

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an exploded perspective view of an air conditioner according to one embodiment of the present invention.
Although the air conditioner 1 according to the present embodiment is an in-ceiling air conditioner 1, the present invention is not limited to such an in-ceiling air conditioner 1, and other types of air conditioners Of course, it may be applied to 1.

The ceiling-embedded air conditioner 1 has a substantially square unit body 2 suspended from a ceiling by bolts or the like, an indoor air inlet 4 and a temperature-controlled air outlet provided on a lower surface of the unit body 2. A bell-shaped ceiling panel 3 provided with a bell 5; a bell mouth 6 arranged in the unit body 2 so as to face the indoor air inlet 4 of the ceiling panel 3; A turbo fan (blower) 7 fixedly installed on the top plate, and a square heat exchanger 8 installed in the unit body 2 so as to surround the turbo fan (blower) 7.

  The turbo fan 7 includes a motor 9 fixedly installed on a top plate of the unit main body 2, a hub (main plate) 10 coupled to a rotating shaft 9 </ b> A of the motor 9 and driven to rotate by the motor 9, and a hub (main plate) 10. A casing-less system comprising: an annular shroud (side plate) 11 arranged to face each other; and a plurality of blades 12 each having both ends coupled to the hub (main plate) 10 and the shroud (side plate) 11. It is a fan of the structure. In the plurality of blades 12 of the turbofan 7, the inner peripheral side front edge (sometimes referred to as a leading edge line) 13 is opposed to the outer peripheral side rear edge (sometimes referred to as a trailing edge line) 14. And is disposed so as to be located on the rotation direction N side.

  As shown in FIG. 2 (A), the turbo fan 7 of the present embodiment is obtained by devising the shape of the blade 12 as described later, and thereby, the air flow on the negative pressure surface 15 side of the blade 12 is reduced as shown in FIG. As shown in FIG. 3B, the streamline is a clean streamline (without separation) with little sudden change in interval, and a positive pressure surface 16 of the blade 12 like a critical streamline (a visualization of the flow on the blade surface in a linear shape). As shown in the static pressure contour diagram shown in FIG. 2 (C), the static pressure on the side of the turbo fan 7 is reduced by eliminating the high static pressure region or minimizing the static pressure to reduce the deceleration (loss) of the air flow. This is to reduce the fan input which is the driving force.

  In the present embodiment, in order to evaluate the performance of the turbo fan 7 using a fan input as a driving force of the turbo fan 7 as a parameter, the turbo fan 7 is analyzed by a finite volume method with the turbo fan 7 attached to the air conditioner 1, and based on the analysis, The shape of the blade 12 is set. To perform this fluid analysis, as shown in FIG. 14A, (1) displacement (movement amount) of the leading edge 13 of the blade 12, (2) displacement (movement amount) of the trailing edge 14 of the blade 12, Using the four parameters of 3) the curvature (rotation angle) of the hub-side coupling portion 17 of the blade 12 and (4) the curvature (rotation angle) of the shroud-side coupling portion 18 of the blade 12 as a design variable, a parameter study of 41 cases is performed. An evaluation was performed. Further, the optimum shape (No. 59) was obtained based on the first shape (No. 31) in the parameter study.

  FIGS. 2 (A) and 3 (A) to 3 (E) show that the fan with the optimal shape (No. 59) and the 41 cases evaluated by the parameter study ranked first (No. 31) and second. (No. 32) The shape of the third-rank (No. 06) fan, the original-shaped fan (No. 0) used as the evaluation criterion, and the shape of the lowest-ranked (41st-rank) fan (No. 14) are shown. It is shown. The detailed shape of the fan shown in FIGS. 2A and 3A to 3E will be described later. In the fan of the original shape, as shown in FIG. A straight line in which the leading edge line 13 and the trailing edge line 14 of the blade 12 are parallel to each other, a hub-side coupling portion 17 that connects both ends of the blade 12 to the hub 10 and the shroud 11, and a shroud side The connecting portion 18 is connected to the hub 10 and the shroud 11 at a substantially right angle.

In addition, the case No. with the lowest evaluation of 41st place. As shown in FIG. 3 (E), the fan shape of the blade 14 has a front edge line 13 of the blade 12 with a concave shape 13A in the air flow direction and a trailing edge with respect to the original fan shape shown in FIG. 3 (D). The line 14 has a convex shape 14B in the airflow direction, the hub-side coupling portion 17 has a curved surface 17A curved in the anti-rotation direction, and the shroud-side coupling portion 18 has a curved surface 18A curved in the anti-rotation direction. Have been.
Further, FIGS. 4A to 5E and FIGS. 5A to 5E show critical streamlines of the fans corresponding to the fan shapes shown in FIGS. 3A to 3E. And a diagram comparing the static pressure contours.

Here, the shape of the four design variables described above (1) to (4), the configuration, based on 6 to 9, will be described in detail.
(1) The displacement (movement amount) of the front edge 13 of the blade 12 refers to the original shape shown in FIG. 6A in which the front edge 13 of the blade 12 is linear as shown in FIG. As shown in FIG. 6 (B), the leading edge line 13 is depressed in the air flow direction with respect to the connection portions 17 and 18 to the hub 10 and the shroud 11 (a displacement amount is indicated by +), or FIG. As shown in C), it means that the projection 13B has a convex shape 13B (movement amount is indicated by minus) which swells in the anti-airflow direction.

(2) The displacement (movement amount) of the trailing edge 14 of the blade 12 refers to the original shape shown in FIG. 7A in which the trailing edge 14 of the blade 12 is linear as shown in FIG. 7 (B), the concave 14A with Hekomashi the trailing edge line 14 with respect to the coupling portion 17 and 18 to the hub 10 and the shroud 11 in the counter air flow direction (the amount of movement - display), or 7 As shown in (C), it means that it has a convex shape 14B swelling in the air flow direction (movement amount is indicated by +).

(3) The curve (rotation angle) of the hub-side coupling portion 17 of the blade 12 refers to the case where the hub-side coupling portion 17 of the blade 12 is coupled to the hub 10 at a substantially right angle as shown in FIG. As shown in FIG. 8B, the hub 10 in which the hub-side coupling portion 17 of the blade 12 has a curved surface 17A that is curved in the anti-rotation direction (counterclockwise direction) with respect to the original shape shown in FIG. 8 (C), or the rotation angle with respect to the hub 10 when the curved surface 17B is curved in the rotation direction (clockwise) as shown in FIG. 8 (C) (the rotation angle is displayed as −). ).

  (4) The curve (rotation angle) of the shroud-side connecting portion 18 of the blade 12 refers to the case where the shroud-side connecting portion 18 of the blade 12 is connected to the shroud 11 side at a substantially right angle, as shown in FIG. As shown in FIG. 9B, a shroud in which the shroud-side connecting portion 18 of the blade 12 has a curved surface 18A that is curved in the counter-rotating direction (counterclockwise) with respect to the original shape shown in FIG. The rotation angle with respect to the shroud 11 (when the rotation angle is minus), or the rotation angle with respect to the shroud 11 when the curved surface 18B is curved in the rotation direction (clockwise direction) as shown in FIG. Display).

  As shown in FIG. 10, the connecting portions 17 and 18 of the blade 12 with respect to the hub 10 and the shroud 11 move the entire blade with respect to the center O of the rotating shaft 9A so that the angle between the blade 12 and the airflow does not change. Thus, it is curved in a counter-rotating direction (counterclockwise direction) or a rotating direction (clockwise direction).

  Further, as shown in FIG. 11, the displacement (movement amount) of the leading edge 13 and the trailing edge 14 of the blade 12 is such that the outer diameter direction of the blade 12 is the + direction, and the warp line (camber line) of the blade (wing) 12. And, on the extension line thereof, it is configured to be displaced in a concave or convex shape. That is, as shown in FIG. 12, the displacement of the leading edge 13 and the trailing edge 14 of the blade 12 is substantially the same as the blade height in the span direction (rotation axis direction) on both the leading edge 13 and the trailing edge 14 sides. It is moved by the same amount along the sled line (camber line) in the range of 25% to 75% to be concave or convex. The hub 10 and the shroud 11 are connected to each other with a smooth curve.

FIG. 13 illustrates the blade force BF of the turbofan 7.
The blade force BF of the turbofan 7 corresponds to a pressure gradient acting between a plurality of blades (blades 12), and is a force exerted by the blades on an air flow as a fluid. As shown in FIG. ), The blade force BF acts in a direction perpendicular to the blade surface. The blade force BF acts to suppress the separation on the negative pressure side by pressing the airflow against the wall surface (the wall surface of the shroud 11 in FIG. 13).

Hereinafter, the shape and configuration of the blade 12 set to reduce the fan input of the turbo fan 7 based on the above-described items will be described in detail.
[Optimal shape fan (Case No. 59)]
FIG. It is a perspective view of the turbo fan 7 provided with the blade 12 of 59 optimal shapes.
The blade 12 has a leading edge line 13 having a concave shape 13A in the air flow direction (see FIG. 6B), and a trailing edge line 14 having a concave shape 14A in the opposite air flow direction (see FIG. 7B). It is the structure which was done.

A connecting portion (hub-side connecting portion) 17 of the blade 12 to the hub 10 has a curved surface 17A (see FIG. 8B) that curves in a counter-rotating direction (counterclockwise direction). The coupling portion (shroud-side coupling portion) 18 to the shroud 11 is configured to have a curved surface 18B (see FIG. 9C) that is curved in the rotation direction (clockwise direction). As shown in FIG. 10, the hub-side coupling portion 17 and the shroud-side coupling portion 18 are all curved with respect to the rotation axis center O so that the angle between the blade 12 and the air flow does not change. ing.

  Further, as shown in FIGS. 11 and 12, the leading edge line 13 and the trailing edge line 14 are arranged such that the center portion of the blade 12 in the span direction (rotation axis direction) has a range of 25 to 75% of the dimension in the span direction. By moving the same amount on the sled line (camber line) of the blade (wing) 12 and its extension line, the leading edge line 13 is concave 13A in the air flow direction and the trailing edge line 14 is concave 14A in the anti-air flow direction. It is the structure which was done.

  When the outer diameter of the turbo fan 7 is D [m] (see FIGS. 10 and 12) and one pitch angle of the blades 12 is θ [°] (see FIG. 10) in the blade 12 having the optimum shape, As shown in the table of FIG. 15, the design variables (1) to (4) are as follows: (1) The displacement (movement amount) of the leading edge (pull-LE) 13 of the blade 12 is in the air flow direction (+ display). On the other hand, it is a concave 13A equivalent to 0.0153D, and (2) the displacement (movement amount) of the trailing edge (pull-TE) 14 of the blade 12 is -0. It is a concave 14A equivalent to 0153D.

  Also, (3) the curved surface (rotation angle) of the hub-side coupling portion 17 of the blade 12 is a curved surface 17A of 0.0972θ in the anti-rotation direction (counterclockwise direction, + display), and (4) the blade 12 The curvature (rotation angle) of the shroud-side coupling portion 18 is a curved surface 18B of −0.0972θ in the rotation direction (clockwise direction, −display).

[Case No. 31 (No. 1) fan shape]
FIG. A perspective view of a turbo fan 7 having a 31 (first place) blade shape is shown.
The blade 12 has a leading edge line 13 having a concave shape 13A (see FIG. 6B) in the airflow direction and a trailing edge line 14 having a concave shape 14A (see FIG. 6B) in the anti-airflow direction. FIG. 7B).

A connecting portion (hub-side connecting portion) 17 of the blade 12 to the hub 10 has a curved surface 17A (see FIG. 8B) that curves in a counter-rotating direction (counterclockwise direction). The coupling portion (shroud-side coupling portion) 18 to the shroud 11 is configured to have a curved surface 18B (see FIG. 9C) that is curved in the rotation direction (clockwise direction). As shown in FIG. 10, the hub-side coupling portion 17 and the shroud-side coupling portion 18 are all curved with respect to the rotation axis center O so that the angle between the blade 12 and the airflow does not change. ing.

  Further, as shown in FIGS. 11 and 12, the leading edge line 13 and the trailing edge line 14 are arranged such that the center portion of the blade 12 in the span direction (rotation axis direction) is within a range of 25 to 75% of the span direction dimension. By moving by the same amount on the sled line (camber line) of (wing) 12 and its extension, the leading edge line 13 is concave 13A in the air flow direction and the trailing edge line 14 is concave 14A in the anti-air flow direction. Configuration.

  In this case No. In the 31st (first) blade 12, the design variables (1) to (4) are, as shown in the table of FIG. 15, (1) displacement (movement amount) of the leading edge (pull-LE) 13 of the blade 12 ) Is a concave portion 13A equivalent to 0.0153D with respect to the air flow direction (+ display). (2) The displacement (movement amount) of the trailing edge (pull-TE) 14 of the blade 12 is −), The concave shape 14A is equivalent to −0.0153D.

  (3) The curvature (rotation angle) of the hub-side coupling portion 17 of the blade 12 is a curved surface 17A of 0.0563θ in the anti-rotation direction (counterclockwise direction, + display), and (4) the blade 12 The curvature (rotation angle) of the shroud-side coupling portion 18 is a curved surface 18B of −0.0154θ in the rotation direction (clockwise direction, −display).

[Case No. 32 (2nd) fan shape]
FIG. 3B shows the case No. A perspective view of a turbo fan 7 having a 32 (second position) blade shape is shown.
The blade 12 has a leading edge line 13 having a concave shape 13A (see FIG. 6B) in the airflow direction and a trailing edge line 14 having a concave shape 14A (see FIG. 6B) in the anti-airflow direction. FIG. 7B).

On the other hand, a connecting portion (hub-side connecting portion) 17 of the blade 12 to the hub 10 has a curved surface 17 </ b> B (see FIG. 8C) that is curved in the rotating direction (clockwise direction), and the shroud 11 of the blade 12 is formed. (Shroud-side connecting portion) 18 has a curved surface 18A (see FIG. 9B) that is curved in the counter-rotating direction (counterclockwise direction). As shown in FIG. 10, the hub-side coupling portion 17 and the shroud-side coupling portion 18 are all curved with respect to the rotation axis center O so that the angle between the blade 12 and the airflow does not change. ing.

  Further, as shown in FIGS. 11 and 12, the leading edge line 13 and the trailing edge line 14 are arranged such that the center portion of the blade 12 in the span direction (rotation axis direction) is within a range of 25 to 75% of the span direction dimension. By moving by the same amount on the sled line (camber line) of (wing) 12 and its extension, the leading edge line 13 is concave 13A in the airflow direction and the trailing edge line 14 is concave 14A in the anti-airflow direction. Configuration.

  In this case No. In the thirty-second (second) blade 12, the design variables (1) to (4) are, as shown in the table of FIG. 15, (1) displacement (movement amount) of the leading edge (pull-LE) 13 of the blade 12. ) Is a concave 13A equivalent to 0.0091D with respect to the air flow direction (+ display). (2) The displacement (movement amount) of the trailing edge (pull-TE) 14 of the blade 12 is −Display), the concave shape 14A is equivalent to −0.0142D.

  In addition, the curvature (rotation angle) of the hub-side coupling portion 17 of the blade 12 of (3) is a curved surface 17B of −0.0768θ in the rotation direction (clockwise direction, −display), and the blade of (4). The curvature (rotation angle) of the shroud-side joint portion 12 is a curved surface 18A of 0.0031θ in the anti-rotation direction (counterclockwise direction, + display).

[Case No. 06 (3rd place) fan shape]
FIG. 3C shows the case No. A perspective view of a turbo fan 7 having a blade shape of No. 06 (third position) is shown.
In the blade 12, the leading edge line 13 has a convex shape 13B in the anti-air flow direction (see FIG. 6C), and the trailing edge line 14 has a concave shape 14A in the anti-air flow direction (see FIG. 7B). ).

On the other hand, a connecting portion (hub-side connecting portion) 17 of the blade 12 to the hub 10 has a curved surface 17 </ b> B (see FIG. 8C) that is curved in the rotating direction (clockwise direction), and the shroud 11 of the blade 12 is formed. coupling portion (shroud side coupling portion) 18 for is a curved surface 18B (see FIG. 9 (C)) and has been configured to bend in the direction of rotation (clockwise direction). As shown in FIG. 10, the hub-side coupling portion 17 and the shroud-side coupling portion 18 are all curved with respect to the rotation axis center O so that the angle between the blade 12 and the airflow does not change. ing.

Further, as shown in FIGS. 11 and 12, the leading edge line 13 and the trailing edge line 14 are arranged such that the center portion of the blade 12 in the span direction (rotation axis direction) is within a range of 25 to 75% of the span direction dimension. By moving by the same amount on the sled line (camber line) of (wing) 12 and its extension, the leading edge line 13 is convex 13 B in the anti-airflow direction, and the trailing edge line 14 is concave in the anti-airflow direction. 14A.

  In this case No. In the 06 (third) blade 12, the design variables (1) to (4) are, as shown in the table of FIG. 15, (1) the displacement (movement amount) of the leading edge (pull-LE) 13 of the blade 12 ) Is a convex 13B corresponding to -0.0438D in the anti-airflow direction (-indicated), and (2) displacement (movement amount) of the trailing edge (pull-TE) 14 of the blade 12 is It is a concave 14A corresponding to -0.0153D with respect to the direction (-display).

  In addition, the curvature (rotation angle) of the hub-side coupling portion 17 of the blade 12 in (3) is a curved surface 17B of −0.0154θ in the rotation direction (clockwise direction, −display), and the blade in (4). The curvature (rotation angle) of the shroud-side joint portion 12 of FIG. 12 is a curved surface 18B of −0.0461θ in the rotation direction (clockwise direction, −display).

  By the way, case no. In the original blade shape of 0, as shown in the table of FIG. 15, all the four design variables (1) to (4) are set to 0. In addition, the case No. with the lowest evaluation (the 41st place). The blade shape of the blade 14 is as follows: (1) The displacement (movement amount) of the leading edge (pull-LE) 13 of the blade 12 is set to a concave shape 13A equivalent to 0.0153D in the air flow direction (+ display), and (2) The displacement (movement amount) of the trailing edge (pull-TE) 14 is set to be a convex shape 14B corresponding to 0.0438D with respect to the air flow direction (+ display), and (3) the hub-side coupling portion 17 of the blade 12 The curvature (rotation angle) is a curved surface 17A of 0.0563θ in the anti-rotation direction (+ display), and (4) the curvature (rotation angle) of the shroud-side coupling portion 18 is in the anti-rotation direction (+ display). And a curved surface 18A of 0.0358.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
In the turbo fan 7 and the air conditioner 1, the room air sucked from the room air suction port 4 of the ceiling panel 3 by the rotation of the turbo fan 7 passes through the bell mouth 6 to the opening on the shroud 11 side of the turbo fan 7. Is sucked in the axial direction. The air flow sucked into the turbofan 7 is blown out in a radial direction by a plurality of blades 12 and is cooled in a process of passing through a heat exchanger 8 arranged so as to surround the turbofan 7. Alternatively, by being heated , the air is blown into the room from the four temperature control outlets 5 provided on the four sides of the ceiling panel 3 as temperature controlled air, and is supplied to the room for air conditioning.

  In the case of the turbo fan 7, since the air flow sucked in the axial direction is changed in the radial direction (centrifugal direction), the air flow particularly sucked from the vicinity of the outer edge of the suction port (shroud 11 side) is not bent by inertia force. The flow is biased toward the hub 10 inside the fan, the blades 12 do not function effectively on the side close to the shroud 11, the efficiency is reduced, and a high-speed jet is generated due to the bias of the air flow on the outlet side, or the suction side In such a case, a backflow was generated, and aerodynamic noise was easily increased. Further, when used in the air conditioner 1, the air is often sucked from a square air passage and operated in a non-axisymmetric pressure field surrounded by a square heat exchanger 8, and the fan span direction. It has been difficult to achieve a uniform flow throughout.

  Under these circumstances, the turbofan 7 according to the present embodiment performs the fluid analysis by the finite volume method parametrically using the above four items (1) to (4) shown in FIG. The shape of the blade 12 is set based on the value of a variable. FIG. 14B shows the definition of the objective function D '. Further, the list of FIG. 15 summarizes the values of the design variables in the analysis result by the finite volume method.

  The table of FIG. 59 fans with the optimal shape, and three fans ranked first (Case No. 31), second (Case No. 32) and third (Case No. 06) with high evaluation in the 41 parameter studies, Only the results of the original fan (case No. 0) as the evaluation criterion and the fan of the 41st rank (case No. 14) with the lowest evaluation are shown for a total of 6 cases.

  Further, FIG. 16 shows a bar graph comparing the values of the six cases with respect to the objective function D ′. FIGS. 17 to 20 show the objective function D ′, the design variable (1), and the objective function D ′. And a design variable (2), a graph showing a correlation between the objective function D ′ and the design variable (3), and a graph showing a correlation between the objective function D ′ and the design variable (4).

  As is clear from these analysis results, in the turbofan 7 of the present embodiment, the center part of the trailing edge line 14 of the plurality of blades 12 is shown in FIG. 2 (A) or FIGS. 3 (A) to 3 (C). As shown in the drawing, the air flow on the negative pressure surface 15 side of the blade 12 is shown in FIG. 2 (B) or a clean flow with no rapid change in the interval (no separation), as shown in the critical streamline (a flow visualized linearly on the blade surface) shown in FIGS. 4 (A) to 4 (C). It can be a line.

  That is, case No. Case No. 0 in which the original shape and the evaluation of No. 0 are the lowest. In the case of No. 14, the airflow on the negative pressure surface 15 side of the blade 12 has a turbulent portion X as shown in the critical streamlines shown in FIGS. 4D and 4E, and the airflow is separated. However, the case No. shown in FIG. 2A or FIGS. Case No. 59 in which the optimum shape or evaluation of No. 59 was ranked 1st to 3rd. 31, case no. 32 and case no. In any of the six samples, there is no portion X that is disturbed in the critical streamline of the suction surface 15, and it can be seen that the separation on the suction surface 15 is improved.

  The static pressure (blade surface pressure) is distributed on the positive pressure surface 16 of the blade 12 due to the rotation of the turbofan 7, and the air flow along the blade 12 increases as the static pressure increases or the high static pressure region increases. Means that the fan efficiency is reduced due to the loss. In the turbofan 7 of the present embodiment, this high static pressure region is defined by the static pressure contours shown in FIG. 2C or FIGS. 5A to 5C, as shown in FIGS. The pressure can be reduced or the area can be made smaller than that shown in FIG.

  That is, case No. Case No. 0 in which the original shape and the evaluation of No. 0 are the lowest. 14, the high static pressure region Y generated on the positive pressure surface 16 of the blade 12 occurs in a relatively large region Y as shown in FIGS. 5D and 5E, but FIG. C) or the case No. shown in FIGS. Case No. 59 in which the optimum shape or evaluation of No. 59 was ranked 1st to 3rd. 31, case no. 32 and case no. In the case of No. 6, the high static pressure area Y is not generated or is set to a very small area Y, and it is understood that the air flow does not decelerate and the fan efficiency does not decrease due to the loss due to the deceleration. .

  As described above, by forming the trailing edge line 14 of the blade 12 in a concave shape 14A in the counter airflow direction, the separation of the airflow on the negative pressure surface 15 side of the blade 12 is improved, and the turbulence of the airflow can be suppressed. In addition to the above, the high static pressure region Y distributed on the positive pressure surface 16 side is reduced, the fan efficiency is improved by suppressing the deceleration of the air flow, and the driving force of the turbo fan 7 is increased as shown in FIGS. Certain fan inputs can be reduced.

  This is because when the trailing edge line 14 of the blade 12 is formed in a concave shape 14A in the anti-airflow direction, the radius of the concave region becomes smaller than the original shape, and the turbo fan 7 is rotated at the same rotation speed. Thus, the pressure rise of the airflow passing through the turbofan 7 can be reduced, so that the pressure (static pressure) near the trailing edge 14 of the blade 12 at the suction surface 15, particularly at the portion where the shroud 11 is easily peeled off, can be reduced. This means that the air flow becomes easier and the separation can be suppressed.

  On the other hand, on the positive pressure surface 16, the effect of the airflow passing through the turbofan 7 being biased toward the hub 10 side is remarkable, and the pressure on the surface of the blade 12 also shows a distribution that rises sharply toward the hub 10 side. By making the trailing edge line 14 concave, the pressure (static pressure) near the trailing edge 14 of the blade 12 can be reduced and the static pressure at the positive pressure surface 16 can be reduced, thereby improving the fan efficiency of the turbofan 7. That is, the fan input can be reduced, so that the noise and efficiency of the turbo fan 7 can be further reduced.

  The trailing edge line 14 may be concave 14A in the anti-airflow direction within a range of 25 to 75% of the central portion in the span direction, and the function and performance of the connecting portions 17 and 18 with respect to the hub 10 and the shroud 11 may be reduced. The blade 12 can be coupled to the hub 10 and shroud 11 without affecting. For this reason, the air flow is not disturbed in the hub-side joint portion 17 and the shroud-side joint portion 18, and the noise can be reduced and the efficiency can be improved.

  Further, the concave amount (-indicated) of the trailing edge line 14 of the blade 12 in the direction opposite to the airflow is in the range of -0.0142D to -0.0153D, where D is the outer diameter of the turbofan 7. Accordingly, as shown in FIGS. 16 and 18, the fan input, which is the driving force of the turbo fan 7, can be reduced to a preferable range.

On the other hand, in the turbofan 7 of the present embodiment, the leading edge line 13 of the blade 12 has the center portion in the span direction (rotation axis direction) as shown in FIG. 2 (A) or FIG. 3 (A), (B). In the range of 25% to 75%, the joints 17 and 18 for the hub 10 and the shroud 11 are concave 13A in the air flow direction, or as shown in FIG. It is a convex 13B.

  In this way, by displacing the leading edge line 13 in the concave shape 13A in the air flow direction, as shown in FIG. 4B, the negative pressure surface 15 of the blade 12 is compared with the blade 12 of the optimal shape shown in FIG. In some cases, a small turbulence may occur in the air flow on the side, but the high static pressure region on the positive pressure surface 16 side can be reduced as shown in FIG. 5B to suppress the deceleration of the air flow. On the other hand, by displacing the leading edge line 13 in a convex shape 13B in the anti-airflow direction, as shown in FIG. 5C, the high static pressure area on the positive pressure surface 16 side slightly increases, and Although the deceleration suppressing effect may slightly decrease, as shown in FIG. 4C, the turbulence of the air flow on the negative pressure surface 15 can be suppressed to suppress the separation.

  This is because, by making the leading edge line 13 of the blade 12 concave 13A in the air flow direction, the length of the blade 12 in the air flow direction is shortened, the friction loss between the air flow and the surface of the blade 12 is reduced, and the fan 12 This is because the input can be reduced. However, if the shape is too concave, the blade length in the air flow direction with respect to the distance between the adjacent blades 12 becomes too short, and the performance of the blades 12 may be deteriorated. In addition, by making the leading edge line 13 of the blade 12 convex 13B in the anti-airflow direction, friction loss between the airflow and the surface of the blade 12 generally increases, while the length of the blade 12 in the airflow direction increases. Is substantially longer, and by stably guiding the flow flowing from the upstream side of the blade to the downstream side, the peak value of the static pressure on the surface of the blade 12 is suppressed, and the flow is less likely to be separated. The input can be reduced and the fan noise can be reduced.

  Accordingly, also in this embodiment, as shown in FIGS. 16, 17, and 18, the fan input, which is the driving force of the turbo fan 7, can be reduced to a preferable range, and the efficiency and the efficiency of the turbo fan 7 can be reduced. Noise can be reduced.

Also in this case, the central portion of the leading edge line 13 of the blade 12 is shown in FIG. 2 (A) or FIGS. 3 (A) to 3 (C) in the range of 25 to 75% of the span direction (rotation axis direction). As shown in the figure, the connecting portions 17 and 18 for the hub 10 and the shroud 11 have a concave shape 13A in the air flow direction or the convex portion 13B for the anti-air flow direction. , 18 can be coupled to the hub 10 and shroud 11 without affecting the function or performance of the blade. Therefore, the air flow is not disturbed in the hub-side joint portion 17 and the shroud-side joint portion 18, and the noise can be reduced and the efficiency can be improved.

  Further, in the leading edge line 13 of the blade 12 described above, the concave amount (indicated by +) of the concave portion 13A in the air flow direction is in the range of 0.0091D to 0.0153D with respect to the fan outer diameter D. Since the convex amount (−indicated) of the convex 13B in the direction is −0.0438D with respect to the fan outer diameter D, the fan input which is the driving force of the turbo fan 7 as shown in FIGS. Can be reduced to a preferable range. Thereby, the noise and the efficiency of the turbo fan 7 can be reduced.

  Further, in the turbofan 7 of the present embodiment, as shown in FIGS. 2A and 3A, the connecting portion (hub-side connecting portion) 17 of the blade 12 to the hub 10 is smooth in the anti-rotation direction. A curved surface 17A is provided, and a connecting portion (shroud-side connecting portion) 18 of the blade 12 to the shroud 11 is a curved surface 18B which is smooth in the rotation direction.

  As described above, the connecting portion 17 of the blade 12 to the hub 10 has a smooth curved surface 17A in the anti-rotation direction, so that the connecting portion 17 to the hub 10 is left-right asymmetric, and the stagnation of the airflow at the connecting portion 17 In addition, the separation of the flow can be suppressed by the wing force BF, and the air flow can be made smooth by making the connecting portion of the blade 12 to the shroud 11 a curved surface 18B that is smooth in the rotation direction. . At the same time, as shown in FIGS. 2B and 4A, turbulence of the air flow on the negative pressure surface 15 side of the blade 12 can be suppressed, and FIGS. 2C and 5A. As shown in (1), by reducing the high static pressure region on the pressure side 16 of the blade 12, the deceleration of the airflow (loss of driving force) can be suppressed.

  Therefore, the blade performance of the turbofan 7 can be improved, and as shown in FIGS. 16, 19, and 20, the fan input, which is the driving force of the turbofan 7, can be reduced to increase the efficiency and improve the air efficiency. The turbulence of the flow can be suppressed, and the noise can be reduced.

  Further, in the present embodiment, the angle (+ display) of the curved surface 17A in the anti-rotation direction of the connecting portion (hub-side connecting portion) 17 of the blade 12 to the hub 10 and the pitch angle θ of the blade 12 are 0. .0563θ to 0.0972θ, and the angle (−indicated) of the curved surface 18B in the rotation direction of the joint (shroud-side joint) 18 with respect to the shroud 11 is −0 with respect to one pitch angle θ of the blade. It is configured to be in the range of 0.0154θ to -0.0972θ.

  For this reason, the stagnation of the air flow at the hub-side coupling portion 17 of the blade 12 can be suppressed, and the separation of the air flow at the negative pressure surface 15 side is suppressed by the blade force, so that the performance of the blade 12 is further improved. Also, as shown in FIGS. 16, 19, and 20, the fan input, which is the driving force of the turbo fan 7, is reduced to a preferable range, thereby improving the efficiency of the turbo fan 7 and reducing noise. Can be

  Note that the present invention is not limited to the invention according to the above-described embodiment, and can be appropriately modified without departing from the gist thereof. For example, in the above-described embodiment, an example in which the heat exchanger 8 is arranged on the blowout side of the turbofan 7 and applied to the ceiling-embedded air conditioner 1 has been described. However, the present invention is not limited to this. It is needless to say that the present invention can also be applied to an air conditioner or the like in which the temperature-regulated air that has exchanged heat is sucked through the heat exchanger and then blown into the room from the upper and lower outlets in the centrifugal direction. Further, it goes without saying that the turbo fan 7 itself may be applied to equipment other than the air conditioner.

1 air conditioner 7 turbo fan (blower)
8 heat exchanger 10 hub 11 shroud 12 blade 13 leading edge (leading edge line)
13A concave 13B convex 14 trailing edge (rear edge line)
14A Concave 15 Negative pressure surface 16 Pressure surface 17 Joint (hub-side joint)
17A, 17B curved surface 18 joint (shroud side joint)
18A, 18B curved surface

Claims (11)

A hub connected to the motor drive shaft and driven to rotate,
An annular shroud disposed opposite the hub to form an air inlet;
Both ends are connected between the hub and the shroud, and a plurality of blades are disposed on the rotation direction side with respect to the rear edge on the inner peripheral side with respect to the rear edge on the inner peripheral side,
The plurality of blades are arranged such that, at the trailing edge , a center portion in the span direction of the blade is in a range of 25% to 75% of the span direction in a direction opposite to an airflow direction with respect to a joint with the hub and the shroud. The concave amount of the trailing edge of the blade in the direction opposite to the airflow (-indicated) is in the range of -0.0142D to -0.0153D with respect to the fan outer diameter D.
The turbo fan according to claim 1, wherein a connecting portion of the blade to the hub has a smooth curved surface formed in a rotation direction or a counter rotation direction throughout the air flow direction. It said leading edge of said blade, turbo fan according to claim 1, characterized in that there is a convex concave or anti airflow direction in the airflow direction with respect to the coupling portion with respect to the hub and the shroud. The concave amount of the leading edge of the blade in the air flow direction (+ display) is in the range of 0.0091 D to 0.0153 D with respect to the fan outer diameter D, and the convex amount in the counter air flow direction (+). 3. The turbo fan according to claim 2 , wherein (-display) is -0.0438D with respect to the fan outer diameter D. The leading edge of the blade is concave in the air flow direction or convex in the anti-air flow direction, as described above, at a center portion of the blade in the span direction of 25% to 75% of the span direction. The turbofan according to claim 2 or 3 , wherein: The joint of the blade to the hub has a smooth curved surface in the anti-rotation direction, and the joint of the blade to the shroud has a smooth curved surface in the rotation direction. Item 7. The turbofan according to Item 1 . The angle of the curved surface in the anti-rotation direction of the connecting portion of the blade with respect to the hub (indicated by +) is in the range of 0.0563θ to 0.0972θ with respect to one pitch angle θ of the blade. The angle (-display) of the curved surface in the rotation direction of the connecting portion is in a range of -0.0154θ to -0.0972θ with respect to one pitch angle θ of the blade. 5. The turbofan according to 5 . The connecting portion of the blade to the hub has a smoothly curved surface in the rotation direction, and the connecting portion of the blade to the shroud has a smooth curved surface in the anti-rotation direction. Item 5. A turbofan according to any one of Items 2 to 4 . The angle of the curved surface of the blade relative to the hub in the rotation direction of the coupling portion (-indicated) is -0.0768θ with respect to one pitch angle θ of the blade, and the anti-rotation direction of the coupling portion with respect to the shroud. The turbo fan according to claim 7 , wherein the angle of the curved surface (+ display) is 0.0031θ with respect to one pitch angle θ of the blade. The coupling portion of the blade to the hub has a curved surface that is smooth in the rotational direction, and the coupling portion of the blade to the shroud has a curved surface that is smooth in the rotational direction. The turbofan according to any one of 2 to 4 . The angle (-indicated) of the curved surface of the blade in the rotation direction of the coupling portion with respect to the hub is -0.0154θ with respect to one pitch angle θ of the blade, and is in the rotational direction of the coupling portion with respect to the shroud. 10. The turbo fan according to claim 9 , wherein an angle of the curved surface of the blade (−) is −0.0461θ with respect to one pitch angle θ of the blade. 11. A blower that sucks and blows indoor air,
A heat exchanger that is arranged on either the suction side or the blow side of the blower and cools or heats the room air,
An air conditioner, wherein the blower is the turbofan according to any one of claims 1 to 10 .