JP4703290B2 - Blower - Google Patents

Description

  The present invention relates to a blower.

  Generally, a fan (blower) is used for cooling a heating element mounted inside a personal computer or for cooling air in a refrigerator. As the flow path configuration of the fan provided inside these products, the distance between the fan (blade) and the fan suction side opposing wall approaches, the distance between the fan and the fan outlet side opposing wall approaches, etc. There is a problem that the performance of the fan is significantly reduced.

  In addition, due to the arrangement of devices around the fan, there is a problem that the flow is biased when the fan is installed at a position asymmetrical or biased with respect to the flow path.

  If there is such a problem in the flow path configuration where the fan is installed, the operating point of the fan moves to the low flow rate range, pre-swirl occurs in the suction flow, or drift occurs in the suction flow path. Phenomena such as uneven flow causing secondary flow occur, and problems such as low static pressure and low air volume, which are a decrease in fan performance, arise. When the operating point of the fan becomes lower than the design point, the reverse flow generated at the fan inlet transports the angular momentum of the fan to the suction side, and the suction flow has a circumferential speed component.

  As described in Non-Patent Document 1 below, this circumferential speed component is called pre-turn. The secondary flow is a flow generated in a cross section perpendicular to the main flow, and has a circumferential velocity component as in the pre-turn.

JP-A-10-205966 Turbo blower and compressor, Corona, P725-733 Turbopump, Turbomachinery Association, P22-23 Turbopump, Turbomachinery Association, P41-43

  Patent Document 1 is a refrigerator that uses a fan that sucks cold air from a cooler and blows cool air into a freezer compartment and a refrigerator compartment, and in order to improve defrosting efficiency and cooling efficiency in the cooler, A rectifying plate is disposed in the suction flow channel in between.

  However, since this rectifying plate is not arranged near the fan-facing wall on the suction side, pre-swirl of the suction flow generated when the operating point of the fan shifts to a low flow rate region, and drift occurs in the suction flow path. There is a problem that the secondary flow caused by the drift cannot be suppressed.

  As described above, when the fan is installed in a flow path where the distance between the fan-facing wall on the suction side and the fan is short and the fan facing wall is imminent to the fan, or the fan is asymmetrical or biased with respect to the suction flow path. When installed in a different position, a rectifying plate is required to achieve a high static pressure and high air volume for the fan.

  The purpose of the present invention is to reduce the pre-swirl of the suction flow that occurs when the operating point shifts to a low flow rate region, and the secondary flow that occurs due to the bias of the suction flow path. An object of the present invention is to provide a blower that achieves air volume.

  The above object is provided in a blower device including a plurality of blades attached to a rotating shaft of a motor and a venturi provided so as to cover the outer periphery of the blades, and having a wall surface located on the suction side and the opposed surface of the blades. This is achieved by providing a plate material asymmetric with respect to the suction flow path of the blades on the wall surface.

  Further, the above object is achieved by arranging a plurality of plate materials radially on the wall surface around a rotation axis attached to the blade.

  Further, the above object is achieved by attaching plate members extending outward and inward with respect to the inner diameter of the venturi so as to include a suction flow having a pre-swirl generated when the blades are operated in a low flow rate region. .

  Moreover, the said objective is achieved because the shape of a baffle plate has a curvature according to the curvature of the shape of a suction flow path.

  The above object is achieved by extending the length of the current plate to the fan rotation shaft inside the venturi inner diameter.

  ADVANTAGE OF THE INVENTION According to this invention, the secondary flow which generate | occur | produces by the pre-rotation of a suction flow and the suction flow path being biased can be reduced, and the air blower which achieves a high static pressure and high air volume of a fan can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a fan provided with an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.
1 and 2, a current plate 2 (plate material) is attached to the front surface of the fan 1. Reference numeral 3 denotes a rotating shaft of the fan 1. Reference numeral 4 denotes a venturi, which supports the column 5. 6 is a fan motor. Reference numeral 7 denotes a fan facing wall on the suction side. The rectifying plate 2 is attached to the fan facing wall 7.

FIG. 3 is a diagram showing a pre-swirl flow that occurs during low-flow-rate operation.
FIG. 4 is a diagram showing a flow of pre-turning suppressed by the current plate.
3 and 4, the fan 1 driven by the fan motor 6 raises the suction flow 8 to a high static pressure and blows out the blowing flow 9. When the fan operates in a low flow rate region, a pre-turn 10 as shown in FIG. 3 occurs on the suction side of the fan 1. As shown in FIGS. 1 and 2, by arranging the rectifying plate 2 on the fan opposing wall 7 on the suction side of the fan 1, as shown in FIG. Can be suppressed.

As described in the description described in Non-Patent Document 1, Equation (1) is an equation representing the theoretical head of the turbomachine. u ₁ and _{Cu 1} are the impeller rotational speed and fluid swirl speed at the impeller inlet, and u ₂ and _{Cu 2} are the impeller rotational speed and fluid swirl speed at the impeller exit, respectively.
H _th∞ = (u ₂ C _u2 −u ₁ C _u1 ) / g (1)
From equation (1), it can be seen that the theoretical head can be increased by reducing the swirling speed of the fluid at the inlet. Therefore, by arranging the rectifying plate 2 shown in FIGS. 1 and 2, it is possible to realize a high static pressure and high air volume of the fan.

  As shown in FIGS. 1 and 2, a suction flow generated during operation in a low flow rate region by arranging a plurality of rectifying plates 2 radially around the fan rotation shaft 3 on the fan facing wall 7 on the suction side of the fan 1. The pre-turn of the fan can be reduced, and a high static pressure and high air volume of the fan can be realized. 1 and 2, the number of the rectifying plates 2 is eight, but the number is not limited and the number of rectifying plates is changed according to the magnitude of the effect.

FIG. 5 is a side view corresponding to FIG. 2 for explaining another embodiment of the present invention.
In FIG. 5, when the fan 1 is operated in a low flow rate region, a reverse flow 11 having a pre-swirl is generated in the suction flow path as shown in FIG. When the distance between the fan 1 and the fan opposing wall 7 is short, the backflow 11 bounces off the fan opposing wall 7 and flows into the fan again, so that a return flow 12 having a pre-turn in the suction flow path is generated.

FIG. 6 is a diagram showing a three-dimensional flow analysis result when the fan 1 is operating in a low flow rate region without a rectifying plate.
In FIG. 6, it turns out that the backflow 11 and the return flow 12 have generate | occur | produced. Both the backflow 11 and the backflow 12 have a pre-turn, which causes a reduction in fan performance. Therefore, in order to efficiently reduce the pre-swirling of the reverse flow 11 and the return flow 12, the length of the rectifying plate 2 is extended outward and inward from the venturi inner diameter 13 in the radial direction so as to include the reverse flow 11 and the return flow 12. Deploy. The distances a and b to be extended are optimum values according to the size of the region of the reverse flow 11 and the return flow 12 of the suction flow path. Thereby, the pre-swirl of the suction flow at the time of low flow area operation can be efficiently suppressed, and high static pressure and high air volume of the fan 1 can be realized.

FIG. 7 is a front view of a current plate provided with this embodiment.
In FIG. 7, when the suction flow passage outer wall 14 of the fan 1 has a curved shape as shown in FIG. 7, according to the aspect of the flow of the suction flow sucked into the fan 1, the first, second, Further, the shape of the rectifying plate is given a curvature with respect to the rectifying plate having the function described in 3. By arranging the rectifying plates 15 and 15 'having a curvature, it is possible to suppress the pre-swirl of the suction flow generated during operation in the low flow rate region, and further, by providing the rectifying plate with a curvature, the suction flow Can be further rectified, and higher static pressure and higher air volume can be realized.

FIG. 8 is a front view of a current plate provided with this embodiment.
9 is a cross-sectional view taken along the line BB ′ of FIG.
8 and 9, the fan is asymmetrical or biased with respect to the suction flow path due to the arrangement of the surrounding equipment, apart from the pre-swirl that occurs in the vicinity of the venturi inner diameter described in the first, second, third, and fourth embodiments. In the case where it is installed at a certain position, drifts 17 and 17 'are generated in the suction flow path as shown in FIG. 10, and the drift causes a secondary flow 18 having a swirling speed. This secondary flow causes a decrease in fan performance by the same mechanism as described in the pre-turn. As shown in FIGS. 8, 9, and 11, a rectifying plate 16 having a length extending to the rotation axis of the fan is arranged on the fan facing wall 7 of the fan 1 inside the venturi inner diameter. FIG. 11 shows that the rectifying plate 16 can suppress the secondary flow. The rectifying plate 16 can simultaneously suppress the pre-swirl and the secondary flow that are generated in the vicinity of the venturi inner diameter, and can achieve higher static pressure and higher air volume of the fan 1.

FIG. 12 is a front view of a current plate provided with the present embodiment.
In FIG. 12, the two types of rectifying plates having different lengths described in the second and third embodiments and the fifth embodiment are simultaneously arranged on the fan-facing wall on the suction side, so that the suction flow generated in the low flow range operation can be predicted. Both the swirl and the secondary flow generated due to the drift of the suction flow path can be suppressed at the same time, and a high static pressure and high air volume of the fan 1 can be realized.

FIG. 13 is a cross-sectional view of a current plate provided with this embodiment.
In FIG. 13, a rectifying plate 19 is a rectifying plate obtained by integrally forming the rectifying plate described in the first, second, third, fourth, fifth and sixth embodiments with a fan facing wall. Thereby, reduction of manufacturing cost is realizable.

FIG. 14 is a cross-sectional view of a current plate provided with this embodiment.
In FIG. 14, in the rectifying plate described in the first, second, third, fourth, fifth, sixth, and seventh embodiments, a rectifying plate 20 having rounded corners as shown in FIG. The noise generated by the arrangement can be reduced.

15 and 16 are views showing a state in which the current plate of the present invention is incorporated in a refrigerator.
15 and 16, rectifying plates 2 and 16 described in Examples 1, 2, 3, 5, and 6 are attached to a part of the freezer compartment. The refrigerator is provided with a flow path in which a fan 1 that sucks cold air from the cooler 21 and blows the cold air into a cold air passage connected to the freezer compartment 22 and the refrigerator compartment 23 is provided. The operating point of the fan 1 used in the refrigerator shifts to a low flow rate region because the distance between the fan 1 and the fan facing wall on the suction side and the blowout side is short. Therefore, a pre-turn as shown in FIG. 3 occurs in the suction flow path. Further, due to the arrangement of the devices around the fan, as shown in FIG. 15, the fan 1 is installed at a position that is asymmetrical or biased with respect to the suction flow path. As a result, a secondary flow due to a drift as shown in FIG. 10 is generated.

  FIG. 6 shows a three-dimensional flow analysis result in the refrigerator when no rectifying plate is installed, and represents a velocity vector distribution in a cross section parallel to the fan rotation axis. It can be seen from FIG. 6 that a reverse flow 11 and a return flow 12 having a pre-turn are generated. In order to suppress the pre-swirl that the reverse flow 11 and the return flow 12 have, the dimension a of the rectifying plate 2 shown in FIG. 5 is set to 10 mm and b is set to 20 mm. However, the value of this dimension employ | adopts an optimal value according to the condition of the flow in each refrigerator.

FIG. 17 is a diagram showing the viewpoint position CC ′ for explaining the analysis result of FIG.
FIG. 18 shows a three-dimensional flow analysis result in the refrigerator including the fan 1 when the fan 1 is operated in a low flow rate region, and shows a velocity vector distribution.
In FIG. 18, FIG. 18A shows a three-dimensional flow analysis result when there is no current plate, and FIG. 18B shows a three-dimensional flow analysis result when there is a current plate. When there is no current plate, the secondary flow 18 appears remarkably, but it can be seen that the secondary flow can be suppressed by attaching this current plate.

FIG. 19 shows the results of an experimental investigation of the static pressure characteristics of the refrigerator fan provided with the current plate shown in FIGS.
In FIG. 19, the quadratic curve is the resistance curve of the flow path. The intersection between the static pressure characteristic curve of the fan and the resistance curve of the flow path becomes the air volume and the static pressure increase when the fan is incorporated into the flow path. From FIG. 19, it can be seen that by installing the current plate, high static pressure and high air flow can be achieved under the same fan speed.

FIG. 20 is a diagram illustrating the static pressure characteristics when the operating air volume of the fan on which the rectifying plate is disposed is made equal to the operating air volume Φ when the rotational speed is lowered to reduce the rotational speed.
In FIG. 20, in this case, the rotational speed can be reduced by 6.7%.

  FIG. 21 shows the initial rotation speed and the sound pressure level when the rotation speed is reduced by 6.7%. When the operating air volume is Φ, the noise level SPL = 60log (N0 / N) described in Non-Patent Document 1 (N0: initial rotation speed, N: rotation speed reduced by 6.7%) is 1.8 [dB]. It can be seen that it can be reduced. Therefore, the noise reduction of the fan in the refrigerator can be realized by the current plate. In FIGS. 15 and 16, the number of rectifying plates arranged radially is six, and the number of rectifying plates whose length is extended to the rotation shaft inward with respect to the inner diameter of the venturi is one. As for the arrangement method, the one having the best fan performance is adopted according to the shape of the flow path in the refrigerator.

  According to the present invention, when the fan is used in a flow path in which the distance between the fan-facing wall on the suction side and the fan is short and the fan facing wall is imminent to the fan, or the fan is In order to suppress the secondary flow caused by the pre-swirl of the suction flow that occurs during low-flow-rate operation and the drift flow that occurs in the suction flow path. A current plate is placed on the opposing wall. As a result, high static pressure and high air flow of the fan can be realized.

  Further, in order to effectively suppress the pre-swirl of the suction flow generated during operation in the low flow rate region, a plurality of rectifying plates are radially arranged on the suction side fan facing wall with the fan rotation axis as the center.

In addition, in order to effectively suppress the pre-swirl of the suction flow that occurs during low-flow-rate operation, the reverse flow with pre-swirl that occurs near the inside diameter of the venturi and the reverse flow bounces back to the fan-facing wall on the suction side, A rectifying plate extending outward and inward with respect to the inner diameter of the venturi is arranged so as to include a return flow having a returning pre-turn.
Further, when the shape of the fan suction flow path has a curvature, the flow straightening plate having the above function is arranged with a curvature in the shape of the flow straightening plate according to the aspect of the suction flow sucked into the fan.

  Further, the pre-swirl of the suction flow at the time of the low flow rate operation is suppressed, and further, the secondary flow caused by the drift generated in the suction channel when the fan is installed at a position that is asymmetric or biased with respect to the suction channel. In order to suppress it, the length of the current plate is extended to the inner fan rotation shaft with respect to the venturi inner diameter. Further, the two kinds of rectifying plates are simultaneously arranged on the fan facing wall.

  In order to reduce the manufacturing cost of the rectifying plate, the rectifying plate having the above function is formed integrally with the suction-side fan counter wall.

  In addition, the corners of the current plate are rounded in order to reduce the noise generated by arranging the current plate.

  Also, in a refrigerator having a flow path in which a fan that sucks cold air from a cooler and blows out cold air in a cold air passage connected to the freezer compartment and the refrigerator compartment is provided, a rectifying plate having the above function on the fan-facing wall on the suction side Place.

  In a refrigerator having a flow path in which a fan that sucks cold air from a cooler and blows out cold air in a cold air passage that leads to a freezer room and a refrigerator room is installed, by arranging a rectifying plate on the fan counter wall on the suction side In addition, it is possible to suppress the secondary flow caused by the pre-swirl of the suction flow during the low flow rate operation and the drift generated in the suction flow path, thereby realizing a high static pressure and a high air volume of the fan. Moreover, since the rotation speed can be lowered thereby, it is possible to provide a reduction in noise of the fan used in the refrigerator.

It is sectional drawing which shows the 1st, 2nd Example of the baffle plate by this invention. It is sectional drawing corresponding to A-A 'of FIG. It is a figure which shows the pre-turn which generate | occur | produces at the time of low flow area operation. It is a figure which shows that a pre-turn can be suppressed by arrange | positioning a baffle plate. It is sectional drawing which shows the 3rd Example of the baffle plate by this invention. It is a figure which shows the result of the velocity vector distribution around the fan by a three-dimensional flow analysis. It is sectional drawing which shows the 4th Example of the baffle plate by this invention. It is sectional drawing which shows the 5th Example of the baffle plate by this invention. FIG. 9 is a cross-sectional view corresponding to BB ′ in FIG. 8. It is a figure which shows a mode that a secondary flow generate | occur | produces by a drift. It is a figure which shows that a secondary flow can be suppressed by arrange | positioning a baffle plate. It is sectional drawing which shows the 6th Example of the baffle plate by this invention. FIG. 10 is a cross-sectional view showing a seventh embodiment of the current plate according to the present invention. FIG. 10 is a cross-sectional view showing an eighth embodiment of the current plate according to the present invention. FIG. 10 is a view showing a ninth embodiment of the current plate according to the present invention. FIG. 10 is a view showing a ninth embodiment of the current plate according to the present invention. It is a figure which shows the position of the cross section which displays a three-dimensional flow analysis result. It is a figure which shows the result of the velocity vector distribution by a three-dimensional flow analysis. It is a figure which shows the experimental result of the refrigerator which applied the baffle plate by this invention. It is a figure which shows the static pressure characteristic when the rotation speed is lowered. It is a figure which shows the sound pressure level in each rotation speed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fan, 2 ... Current plate, 3 ... Fan rotating shaft, 4 ... Venturi, 5 ... Strut, 6 ... Motor, 7 ... Fan opposing wall, 8 ... Suction flow, 9 ... Blowing flow, 10 ... Pre-rotation, 11 ... Reverse flow, 12 ... Return flow, 13 ... Venturi inner diameter, 14 ... Suction flow passage outer wall, 15 ... Curved rectifying plate, 16 ... Long rectifying plate, 17 ... Diffusion, 17 '... Diffusion, 18 ... Secondary flow, 19 ... Countermeasure A rectifying plate shaped integrally with a wall, 20 ... a rectifying plate with rounded corners, 21 ... a cooler, 22 ... a freezer compartment, 23 ... a refrigerator compartment.

Claims (2)

In the air blower having a plurality of blades attached to the rotating shaft of the motor and a venturi provided so as to cover the outer periphery of the blades, and having a wall surface located on the surface facing the suction side of the blades,
An air blower characterized in that a plurality of plate members that stand vertically to the wall surface and that are arranged radially about the rotation axis are provided on the wall surface. The blower device according to claim 1,
An air blower characterized in that plate members extending outward and inward with respect to the venturi inner diameter are included so as to include a suction flow having a pre-swirl generated when the blades are operated in a low flow rate region.

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