A muffling module suitable for low temperature working conditions

Abstract

The present application belongs to the technical field of wind tunnel test, and discloses a sound attenuation module suitable for low-temperature working conditions. The sound attenuation module comprises an outer frame, standard sound attenuation sheet units and screws; a plurality of standard sound attenuation sheet units are sequentially inserted into the inner recesses of the outer frame from top to bottom, the top and bottom standard sound attenuation sheet units are connected with the outer frame through the screws to form an integral structure; the standard sound attenuation sheet units adopt an integral panel in the length direction, along the airflow direction, without backflow steps, protrusions, pits or grooves, and the flow steps are not greater than 0.2 mm. The sound attenuation module adopts a modular, standardized and detachable design, can adapt to the change of the nitrogen exhaust temperature of a large low-temperature device in the range of 110K-323K, can attenuate the exhaust noise of a low-temperature wind tunnel, control the noise pollution intensity of the wind tunnel to the environment, and make the exhaust noise meet the environmental protection requirements; the structure is simple, the material is economical, and the sound attenuation module is convenient to maintain and check, repair, and has engineering application value.

Description

Technical Field

[0001] This invention belongs to the field of wind tunnel testing technology, specifically relating to a noise reduction module suitable for low-temperature operating conditions. Background Technology

[0002] Large-scale cryogenic equipment continuously discharges nitrogen gas during testing. The exhaust noise must meet three standards: the Hygienic Standard for Industrial Enterprise Design (GBZ1-2002), the Emission Standard for Environmental Noise at the Boundary of Industrial Enterprises (GB12348-2008), and the Environmental Quality Standard for Noise (GB3096-2008). Therefore, a silencing module needs to be installed in the exhaust silencer to reduce exhaust noise, control the intensity of environmental noise pollution, and meet environmental protection requirements.

[0003] The nitrogen exhaust temperature of large-scale cryogenic equipment ranges from 110K to 323K. During cryogenic operation, the temperature of the exhaust nitrogen gas stream is extremely low. Conventional sound-absorbing materials will frost or even freeze in low-temperature environments, reducing the sound absorption performance of the silencer. In addition, because minimal exhaust pressure loss is required during normal pressure operation, sintered metal wire mesh cannot be used as a noise reduction measure.

[0004] Therefore, there are currently no suitable noise reduction products on the market that can achieve noise reduction under wide temperature alternation and low pressure loss conditions. There is an urgent need to develop a noise reduction module suitable for low temperature conditions. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a noise reduction module suitable for low-temperature operating conditions.

[0006] The noise reduction module of the present invention, applicable to low-temperature working conditions, includes an outer frame, standard noise reduction plate units, and screws; several standard noise reduction plate units are sequentially inserted into the inner groove of the outer frame from top to bottom, and the standard noise reduction plate units at the top and bottom are connected to the outer frame by screws to form an integral structure.

[0007] The standard silencer unit adopts an integral panel in the length direction. Along the airflow direction, there are no backflow steps, protrusions, pits or grooves between the standard silencer unit and the outer frame, and the flow-in step is no more than 0.2mm.

[0008] The standard silencer unit retracts freely in the inner groove of the outer frame to accommodate the variation of nitrogen exhaust temperature in large cryogenic equipment within the range of 110K~323K.

[0009] Furthermore, the outer frame, standard sound-absorbing plate unit, and screws are all made of 304L austenitic stainless steel.

[0010] Furthermore, the outer frame includes sharp-corner transition pieces and rounded transition pieces located on the front and rear sides, with the sharp-corner transition pieces facing the incoming flow; it also includes a top plate and a bottom plate located on the upper and lower sides, with the front and rear ends of the top plate and bottom plate respectively fixedly connected to the sharp-corner transition pieces and rounded transition pieces using screws.

[0011] The arc transition component includes a semi-circular cross-section tube and arc stiffeners evenly distributed along the height direction of the semi-circular cross-section tube; the front end face of the arc transition component is provided with a groove that matches the standard sound-absorbing plate unit.

[0012] The sharp corner transition piece includes a triangular cross-section tube and sharp corner stiffeners evenly distributed along the height direction of the triangular cross-section tube. The rear end face of the sharp corner transition piece is provided with a groove that matches the standard sound-absorbing plate unit.

[0013] The thickness of the sheet metal for both the rounded and pointed corner stiffeners is 1.5mm.

[0014] Furthermore, the base plate is a flat plate; the front end of the base plate is a triangular plate that matches the sharp corner transition piece, and the triangular plate is provided with a number of screw holes that match the sharp corner transition piece; the rear end of the base plate is a semi-circular plate that matches the arc transition piece, and the semi-circular plate is provided with a number of screw holes that match the arc transition piece; the middle section of the base plate is provided with a groove that matches the standard sound-absorbing plate unit.

[0015] The top and bottom plates have identical structures and are installed symmetrically.

[0016] Furthermore, the standard sound-absorbing sheet unit includes a skeleton, honeycomb blocks, and a surface layer;

[0017] The skeleton includes a micro-perforated plate II parallel to the airflow direction, and several partitions perpendicular to the micro-perforated plate II and arranged sequentially along the airflow direction; the skeleton is filled with honeycomb blocks.

[0018] The surface layer includes a micro-perforated plate I facing the incoming flow and covering the right side of the skeleton, a micro-perforated plate III covering the left side of the skeleton, a baffle covering the top surface of the skeleton, and boss components covering the front and rear sides of the skeleton and matching the grooves of the sharp corner transition piece and the rounded arc transition piece, respectively.

[0019] Furthermore, the micro-perforated plate II divides the standard sound-absorbing sheet unit into left and right parts, facing the incoming flow, with the left side having a thickness of 120mm and the right side having a thickness of 80mm.

[0020] Furthermore, the thickness of the micro-perforated plate I, micro-perforated plate II, and micro-perforated plate III is 0.8 mm, and the surface is provided with uniformly distributed through holes; the opening rate of micro-perforated plate I is 2%, and the opening rates of micro-perforated plate II and micro-perforated plate III are 1%.

[0021] Furthermore, the honeycomb block has a side-to-side distance of 15mm and a wall thickness of 0.1mm; the honeycomb block and the adjacent micro-perforated plate, as well as the honeycomb block and the boss component, are all fixedly connected by vacuum brazing.

[0022] Furthermore, the thickness of the plates used for the partition, boss components, and baffles is 1.5 mm.

[0023] The silencing module of this invention, suitable for low-temperature operating conditions, adopts a modular, standardized, and detachable design, possessing excellent low-temperature adaptability. It enables noise reduction for large-scale low-temperature equipment under wide temperature alternation and low pressure loss conditions, effectively reducing exhaust noise from low-temperature wind tunnels, controlling the noise pollution intensity of wind tunnels to the environment, and ensuring that exhaust noise meets environmental protection requirements. With its simple structure, economical materials, and ease of maintenance and repair, it reduces subsequent maintenance and repair costs, demonstrating good economic efficiency and maintainability, and possessing engineering application value. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the noise reduction module of the present invention, which is suitable for low-temperature operating conditions;

[0025] Figure 2 This is a schematic diagram of the outer frame structure in the noise reduction module suitable for low-temperature operating conditions of the present invention;

[0026] Figure 3 This is a partial enlarged view of the arc transition component structure in the noise reduction module suitable for low-temperature operating conditions of the present invention.

[0027] Figure 4 This is a partial enlarged view of the sharp-corner transition component structure in the noise reduction module suitable for low-temperature operating conditions of the present invention.

[0028] Figure 5 This is a schematic diagram of the installation of the arc-shaped stiffening plate of the arc-shaped transition component in the noise reduction module suitable for low-temperature working conditions of the present invention.

[0029] Figure 6 This is a schematic diagram of the installation of the sharp corner stiffener plate in the sharp corner transition component of the noise reduction module suitable for low-temperature working conditions according to the present invention.

[0030] Figure 7 This is a schematic diagram of the base plate structure in the noise reduction module suitable for low-temperature operating conditions of the present invention;

[0031] Figure 8 This is a schematic diagram of the standard silencing plate unit structure in the silencing module suitable for low-temperature operating conditions of the present invention.

[0032] In the diagram: 1. Rounded transition piece; 2. Sharp corner transition piece; 3. Base plate; 4. Top plate; 5. Screw; 6. Standard sound-absorbing sheet unit;

[0033] 101. Circular arc stiffening plate;

[0034] 201. Sharp corner stiffener;

[0035] 601. Micro-perforated plate I; 602. Micro-perforated plate II; 603. Micro-perforated plate III; 604. Honeycomb block; 605. Partition; 606. Boss component; 607. Baffle. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] Example: Figure 1 As shown, the noise reduction module suitable for low-temperature working conditions in this embodiment includes an outer frame, standard noise reduction plate units 6 and screws 5; several standard noise reduction plate units 6 are inserted into the inner groove of the outer frame from top to bottom, and the standard noise reduction plate units 6 at the top and bottom are connected to the outer frame by screws 5 to form an integral structure.

[0038] The standard sound-absorbing plate unit 6 adopts an integral panel in the length direction. Along the airflow direction, there are no backflow steps, protrusions, pits or grooves between the standard sound-absorbing plate unit 6 and the outer frame, and the flow-in step is no more than 0.2mm.

[0039] The standard silencer unit 6 can freely retract in the inner groove of the outer frame to adapt to the variation of nitrogen exhaust temperature in the range of 110K~323K in large cryogenic equipment.

[0040] Furthermore, the outer frame, standard sound-absorbing plate unit 6, and screw 5 are all made of 304L austenitic stainless steel.

[0041] Furthermore, such as Figures 2-6 As shown, the outer frame includes a sharp corner transition piece 2 and a rounded transition piece 1 located on the front and rear sides, with the sharp corner transition piece 2 facing the incoming flow; it also includes a top plate 4 and a bottom plate 3 located on the upper and lower sides, with the front and rear ends of the top plate 4 and the bottom plate 3 respectively fixedly connected to the sharp corner transition piece 2 and the rounded transition piece 1 by screws 5.

[0042] The arc transition component 1 includes a semi-circular cross-section tube and arc stiffeners 101 evenly distributed along the height direction of the semi-circular cross-section tube; the front end face of the arc transition component 1 is provided with a groove that matches the standard sound-absorbing plate unit 6.

[0043] The sharp corner transition piece 2 includes a triangular cross-section tube and sharp corner stiffeners 201 evenly distributed along the height direction of the triangular cross-section tube. The rear end face of the sharp corner transition piece 2 is provided with a groove that matches the standard sound-absorbing sheet unit 6.

[0044] The thickness of the sheet material for both the rounded rib plate 101 and the pointed rib plate 201 is 1.5mm.

[0045] Furthermore, such as Figure 7 As shown, the base plate 3 is a flat plate; the front end of the base plate 3 is a triangular plate that matches the sharp corner transition piece 2, and the triangular plate is provided with a number of screw holes that match the sharp corner transition piece 2; the rear end of the base plate 3 is a semi-circular plate that matches the arc transition piece 1, and the semi-circular plate is provided with a number of screw holes that match the arc transition piece 1; the middle section of the base plate 3 is provided with a groove that matches the standard sound-absorbing plate unit 6.

[0046] The top plate 4 and the bottom plate 3 have the same structure and are installed symmetrically.

[0047] Furthermore, such as Figure 8 As shown, the standard sound-absorbing sheet unit 6 includes a skeleton, a honeycomb block 604, and a surface layer;

[0048] The skeleton includes a micro-perforated plate II 602 parallel to the airflow direction, and several partitions 605 perpendicular to the micro-perforated plate II 602 and arranged sequentially along the airflow direction; the skeleton is filled with honeycomb blocks 604.

[0049] The surface layer includes a micro-perforated plate I 601 facing the incoming flow and covering the right side of the skeleton, a micro-perforated plate III 603 covering the left side of the skeleton, a baffle 607 covering the top surface of the skeleton, and boss members 606 covering the front and rear sides of the skeleton and matching the grooves of the sharp corner transition member 2 and the rounded transition member 1, respectively.

[0050] Furthermore, the micro-perforated plate II 602 divides the standard sound-absorbing sheet unit 6 into two parts, facing the incoming flow, with the left side having a thickness of 120mm and the right side having a thickness of 80mm.

[0051] Furthermore, the thickness of the micro-perforated plate I 601, micro-perforated plate II 602 and micro-perforated plate III 603 is 0.8 mm, and the surface is provided with uniformly distributed through holes; the opening rate of micro-perforated plate I 601 is 2%, and the opening rate of micro-perforated plate II 602 and micro-perforated plate III 603 is 1%.

[0052] Furthermore, the honeycomb block 604 has a side-to-side distance of 15mm and a wall thickness of 0.1mm; the honeycomb block 604 is fixedly connected to the adjacent micro-perforated plate and to the boss member 606 by vacuum brazing process.

[0053] Furthermore, the thickness of the plates of the partition 605, the boss component 606, and the baffle 607 is 1.5mm.

[0054] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. For those skilled in the art, all features disclosed in the present invention, or all steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A noise reduction module suitable for low-temperature operating conditions, characterized in that, The silencing module includes an outer frame, standard silencing plate units (6) and screws (5); several standard silencing plate units (6) are inserted into the inner groove of the outer frame from top to bottom, and the standard silencing plate units (6) at the top and bottom are connected to the outer frame by screws (5) to form an integral structure. The standard sound-absorbing plate unit (6) adopts an integral panel in the length direction. Along the airflow direction, there are no reverse flow steps, protrusions, pits or grooves between the standard sound-absorbing plate unit (6) and the outer frame. The flow-in step is no more than 0.2mm. The standard silencer unit (6) can freely retract in the inner groove of the outer frame to adapt to the variation of nitrogen exhaust temperature in the range of 110K~323K in large cryogenic equipment; The standard sound-absorbing unit (6) is made of 304L austenitic stainless steel; The standard anechoic panel unit (6) includes a frame, honeycomb blocks (604), and a surface layer; The skeleton includes a micro-perforated plate II (602) parallel to the airflow direction, and several partitions (605) perpendicular to the micro-perforated plate II (602) and arranged sequentially along the airflow direction; the skeleton is filled with honeycomb blocks (604). The surface layer includes a micro-perforated plate I (601) facing the incoming flow and covering the right side of the skeleton, a micro-perforated plate III (603) covering the left side of the skeleton, a baffle (607) covering the top surface of the skeleton, and a boss member (606) covering the front and rear sides of the skeleton and matching the grooves of the sharp corner transition member (2) and the arc transition member (1), respectively.

2. The noise reduction module suitable for low-temperature operating conditions according to claim 1, characterized in that, The outer frame and screws (5) are both made of 304L austenitic stainless steel.

3. The noise reduction module suitable for low-temperature operating conditions according to claim 1, characterized in that, The outer frame includes a sharp corner transition piece (2) and a rounded transition piece (1) located on the front and rear sides, with the sharp corner transition piece (2) facing the incoming flow; it also includes a top plate (4) and a bottom plate (3) located on the upper and lower sides, with the front and rear ends of the top plate (4) and the bottom plate (3) respectively fixedly connected to the sharp corner transition piece (2) and the rounded transition piece (1) by screws (5); The arc transition piece (1) includes a semi-circular cross-section tube and arc stiffeners (101) evenly distributed along the height direction of the semi-circular cross-section tube; the front end face of the arc transition piece (1) is provided with a groove that matches the standard sound-absorbing sheet unit (6). The sharp corner transition piece (2) includes a triangular cross-section tube and sharp corner stiffeners (201) evenly distributed along the height direction of the triangular cross-section tube. The rear end face of the sharp corner transition piece (2) is provided with a groove that matches the standard sound-absorbing sheet unit (6). The thickness of the sheet metal for both the round arc stiffener (101) and the sharp corner stiffener (201) is 1.5 mm.

4. The noise reduction module suitable for low-temperature operating conditions according to claim 3, characterized in that, The base plate (3) is a flat plate; the front end of the base plate (3) is a triangular plate that matches the sharp corner transition piece (2), and the triangular plate is provided with a number of screw holes that match the sharp corner transition piece (2); the rear end of the base plate (3) is a semi-circular plate that matches the arc transition piece (1), and the semi-circular plate is provided with a number of screw holes that match the arc transition piece (1); the middle section of the base plate (3) is provided with a groove that matches the standard sound-absorbing plate unit (6); The top plate (4) and the bottom plate (3) have the same structure and are installed symmetrically.

5. The noise reduction module suitable for low-temperature operating conditions according to claim 4, characterized in that, The micro-perforated plate II (602) divides the standard sound-absorbing plate unit (6) into two parts, facing the incoming flow. The thickness of the left side is 120mm and the thickness of the right side is 80mm.

6. The noise reduction module suitable for low-temperature operating conditions according to claim 5, characterized in that, The thickness of the micro-perforated plate I (601), micro-perforated plate II (602) and micro-perforated plate III (603) is 0.8 mm, and the surface is provided with uniformly distributed through holes; the opening rate of micro-perforated plate I (601) is 2%, and the opening rates of micro-perforated plate II (602) and micro-perforated plate III (603) are 1%.

7. The noise reduction module suitable for low-temperature operating conditions according to claim 5, characterized in that, The honeycomb block (604) has a side-to-side distance of 15mm and a wall thickness of 0.1mm. The honeycomb block (604) is fixedly connected to the adjacent micro-perforated plate and to the boss component (606) by vacuum brazing.

8. The noise reduction module suitable for low-temperature operating conditions according to claim 5, characterized in that, The thickness of the plate material of the partition (605), the boss component (606) and the baffle (607) is 1.5mm.

Images