CN106151111A - A kind of train low noise cooling blower - Google Patents

Abstract

The invention relates to a low-noise cooling fan for trains. A combined micro-perforated plate is provided in the gap inside the side plate. The combined micro-perforated plate is a plate with microholes of two different sizes. The combined micro-perforated plate and the side plate are provided with There is a support plate for connection; the back of the air inlet and the inner surface of the air outlet are provided with a thin plastic box-type sound-absorbing body, and the thin-plastic box-type sound-absorbing body is a board with convex double-cavity box-type sound-absorbing blocks evenly distributed on the surface; The leaves are perforated. The beneficial effects of the present invention are: the combination of micro-perforated plates is installed to form a resonant sound-absorbing body, and the air molecules in the perforations and the cavity generate vibration friction and consume sound energy; the walls of the thin plastic box-type sound-absorbing body will vibrate, and the During the process, part of the sound energy is converted into heat energy; blade perforation treatment reduces and suppresses the generation of vortex shedding, the separation area of the outlet section of the working wheel will be reduced, the strength and size of the vortex in the wind area will be reduced, and the eddy current noise radiated by the cascade will be reduced accordingly.

Description

A low-noise cooling fan for trains

technical field

The invention relates to a low-noise cooling fan for trains.

Background technique

The train cooling unit is a key component of the train traction system. It is installed in the equipment compartment under the frame of the EMU. During the operation, the cooling fan of the cooling unit will inevitably generate noise. The noise reaches a certain intensity, which will affect the interior of the vehicle and The surrounding people cause damage, which directly affects the comfort of passengers. With the progress of society and the improvement of people's living standards, the requirements for noise are becoming more and more stringent. It has become an urgent problem to use appropriate means to reduce noise.

Application number CN201410432115.8 relates to a noise-reducing box-type volute for a centrifugal fan used in the cooling unit of an electric multiple unit. In order to reduce noise, a sound-absorbing layer made of a porous material is provided inside the shell. Ester fiber sound-absorbing cotton. The inner support plate of the volute adopts a microporous support plate structure, and there is an anti-sound space behind the porous sound-absorbing material, which can also reduce noise. However, this solution has a complex structure and a large thickness direction, which is not suitable for the requirement of compact structure, and the sound-absorbing cotton is easily affected by environmental factors such as humidity and temperature, which reduces the noise reduction effect.

Contents of the invention

The technical problem to be solved by the present invention is: based on the above problems, the present invention provides a low-noise cooling fan for trains.

A technical solution adopted by the present invention to solve the technical problem is: a low-noise cooling fan for trains, including a volute, an air inlet, an air outlet and an impeller, the volute includes a side plate and a worm plate, and the side plate includes a front side plate and the rear side plate, the impeller includes a front disc, a rear disc, a wheel hub and blades, and a combined micro-perforated plate is provided in the gap inside the side plate. There are supporting plates for connection between the side plates; the back of the air inlet and the inner surface of the air outlet are equipped with thin plastic box-type sound-absorbing bodies, and the thin-plastic box-type sound-absorbing body is a double-cavity box-type sound-absorbing body with convex surfaces evenly distributed. The body of the block; the blades are perforated.

Further, the gap between the combined micro-perforated plate and the side plate is 30-50mm, the diameters of the large and small holes of the combined micro-perforated plate are 0.6mm and 0.4mm respectively, the first horizontal row is 0.6mm holes, the second and third horizontal rows It is a 0.4mm hole, and so on, the hole distance is 3.5mm, and the opening rate is 1-3%.

Furthermore, the sound-absorbing block is a trapezoidal boss with a narrow outside and a wide inside, and the partition parallel to the surface in the cavity of the sound-absorbing block separates it into double cavities.

Further, the size of the upper surface of the sound-absorbing block is 40mm×50mm, the size of the bottom surface is 50mm×60mm, the height is 30-50mm, and the distance between adjacent sound-absorbing blocks is 3-8mm.

Further, the blade is pierced with 5-7 rows of holes parallel to the direction of rotation of the blade, the perforation angle α=30-45°, the perforation coefficient K=0.08, and the perforation diameter is 2-4mm. The first hole of each row is located at the separation point in front.

Further, the material of the thin plastic box-type sound absorbing body is modified PVC, and the material of the composite micro-perforated plate is aluminum.

The beneficial effects of the present invention are: a combination of micro-perforated plates are installed on the inner side of the front and rear side plates to form a resonant sound absorbing body. Sound energy, when the frequency of the sound in the perforation is consistent with the frequency of the sound in the cavity, severe resonance will occur, and a large amount of sound energy will be converted into heat energy and consumed, so as to achieve the purpose of sound absorption, thereby effectively reducing the noise pollution of the cooling unit; thin The plastic box-type sound-absorbing body is evenly arranged along the air inlet and the air outlet. When the sound wave is incident on the surface of the sound-absorbing body, the walls of the plastic box will vibrate. Due to the large damping coefficient of the plastic, there is a part of the sound energy during the vibration process. It is converted into heat energy, so as to achieve the purpose of sound absorption, and effectively reduce the noise pollution of the cooling unit; the blade perforation treatment reduces and suppresses the generation of vortex separation, the separation area of the outlet section of the working wheel will be reduced, and the vortex intensity and size in the wind area will be reduced. The eddy current noise radiated by the cascade is correspondingly reduced, thereby effectively reducing the noise pollution of the cooling unit.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is the structural representation of blower fan;

Fig. 2 is the structural representation of combined micro-perforated plate;

Figure 3 is a schematic diagram of the structure of a thin plastic box-type sound absorbing body;

Fig. 4 is the structural schematic diagram II of the thin plastic box-type sound absorbing body;

Fig. 5 is a structural schematic diagram of an air inlet with a thin plastic box-type sound absorbing body;

Fig. 6 is the structural representation of blade;

Among them: 1. Air inlet, 2. Air outlet, 3. Worm plate, 4. Front side plate, 5. Back side plate, 6. Blade, 7. Combined micro-perforated plate, 8. Support plate, 9. Thin plastic box sound absorbing body.

detailed description

The present invention will now be further described in conjunction with specific examples, and the following examples are intended to illustrate the present invention rather than further limit the present invention.

A low-noise cooling fan for trains as shown in Figures 1 to 6, includes a volute, an air inlet 1, an air outlet 2 and an impeller, the volute includes a side plate and a worm plate 3, and the side plate includes a front side plate 4 and a rear The side plate 5 and the impeller include a front disc, a rear disc, a hub and blades 6 .

There is a combined micro-perforated plate 7 in the inner gap of the side plate. The combined micro-perforated plate 7 is a plate with micro-holes of two different sizes, which form a resonant sound-absorbing body with the cavity respectively. The body 7 has a larger sound-absorbing bandwidth than a sound-absorbing body with an aperture, and has a better noise reduction effect. A supporting plate 8 for connection is provided between the combined micro-perforated plate 7 and the side plate.

The gap between the combined micro-perforated plate 7 and the side plate is 30-50mm, the diameters of the large and small holes of the combined micro-perforated plate 7 are 0.6mm and 0.4mm respectively, the first horizontal row is 0.6mm holes, and the second and third horizontal rows are 0.4mm hole, and so on, the hole distance is 3.5mm, and the opening rate is 1-3%. The sound absorption coefficient of the composite micro-perforated plate 7 is 0.6-0.7.

The back of the air inlet 1 and the inner surface of the air outlet 2 are provided with a thin plastic box-type sound-absorbing body 9, and the thin-plastic box-type sound-absorbing body 9 is a board body with convex double-cavity box-type sound-absorbing blocks evenly distributed on the surface. The sound-absorbing block and the board body are modified PVC integrated structures that are vacuum-absorbed and high-frequency welded.

The sound-absorbing block is a trapezoidal boss with a narrow outside and a wide inside, and the partition parallel to the surface in the cavity of the sound-absorbing block separates it into a double cavity. The size of the upper surface of the sound-absorbing block is 40mm×50mm, the size of the bottom surface is 50mm×60mm, the height is 30-50mm, and the distance between adjacent sound-absorbing blocks is 3-8mm. When the sound wave is incident on the surface of the sound absorbing body, the walls of the plastic box will vibrate. Due to the large damping coefficient of the plastic, part of the sound energy is converted into heat energy during the vibration process, thereby achieving the purpose of sound absorption. The sound absorption coefficient of the double cavity of the sound-absorbing block is 0.60-0.97 in the frequency range of 250-3150 Hz.

The blade 6 is perforated, which can reduce the vortex separation area and reduce the drag coefficient, which can not only achieve the purpose of noise reduction, but also improve the economy of the fan. The blade 6 is pierced with 5-7 rows of holes parallel to the direction of rotation of the blade, the perforation angle α=30-45°, the perforation coefficient K=0.08, the perforation aperture is 2-4mm, and the first hole of each row is located at the separation point. In the front, the generation of eddy current detachment is effectively suppressed. The coordinates of the separation point are determined by experiments, and no perforation is arranged in the middle part of the blade, because it provides most of the lift force, which can ensure that the lift coefficient drops to a minimum. Noise reduction through perforated fan blades For train cooling fans, a noise reduction of 3-5dB(A) has been achieved.

Through the combination of resonance noise reduction and impeller perforation treatment, the cooling fan achieves a noise reduction of more than 8dB.

Inspired by the above-mentioned ideal embodiment according to the present invention, through the above-mentioned description content, relevant workers can make various changes and modifications within the scope of not departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, but must be determined according to the scope of the claims.

Claims (6)

1. a train low noise cooling blower, including spiral case, air inlet (1), air outlet (2) and impeller, spiral case includes side Plate and snail plate (3), side plate includes front side board (4) and back side panel (5), and impeller includes shroud, hub disk, wheel hub and blade (6), and it is special Levying and be: described side plate interior sides gap is provided with combination microperforated panel (7), combination microperforated panel (7) varies in size two for being equipped with Plant the plate of aperture micropore, be provided with between combination microperforated panel (7) and side plate and be connected with gripper shoe (8)；Air inlet (1) back side and going out Air port (2) inner surface is provided with thin boxlike sound absorber (9) of moulding, and thin boxlike sound absorber (9) of moulding is the two-chamber that surface is evenly equipped with evagination The plate body of boxlike sound absorption block；Blade (6) carries out perforation process.

A kind of train low noise cooling blower the most according to claim 1, is characterized in that: described combination microperforated panel (7) gap and between side plate is 30～50mm, and the aperture of the big aperture of combination microperforated panel (7) is respectively 0.6mm and 0.4mm, First is horizontally-arranged for 0.6mm hole, and second and third is horizontally-arranged for 0.4mm hole, by that analogy, pitch-row 3.5mm, percent opening 1～3%.

A kind of train low noise cooling blower the most according to claim 1, is characterized in that: described sound absorption block is outer narrow The trapezoid boss of inner width, the dividing plate parallel with surface of sound absorption block intracavity by it every in two-chamber.

A kind of train low noise cooling blower the most according to claim 3, is characterized in that: the upper table of described sound absorption block Face a size of 40mm × 50mm, basal surface a size of 50mm × 60mm, height is 30～50mm, the spacing between adjacent sound absorption block It is 3～8mm.

A kind of train low noise cooling blower the most according to claim 1, is characterized in that: wear on described blade (6) Having the hole that 5～7 rows are parallel with blade rotation direction, perforation angle [alpha]=30～45 °, COEFFICIENT K=0.08 of boring a hole, piercing aperture is 2 ～4mm, first hole often arranged is positioned at before burble point.

A kind of train low noise cooling blower the most according to claim 1, is characterized in that: described thin boxlike of moulding absorbs sound The material of body (9) is modified PVC, and combination microperforated panel (7) material is aluminum.