Sound insulation and air return device for ship and design method of sound insulation and air return device

Abstract

The invention discloses a ship sound insulation air return device which comprises a box body and a sound absorption structure arranged in the box body. An air inlet is formed in the lower portion of one side of the box body and provided with an air inlet grille. An air outlet is formed in the other side of the box body, and an air outlet grille is mounted at the air outlet; the sound absorption structure is vertically arranged, and the lower end of the sound absorption structure is fixed to the inner bottom of the box body. An air inlet area is formed between the sound absorption structure and the air inlet grille; an air outlet area is formed between the sound absorption structure and the air outlet grille; a gap is reserved between the upper end of the sound absorption structure and the inner top of the box body to form a communicating area communicating the air outlet area with the air inlet area, and a flow guide plate is arranged at the top of the communicating area; and the air inlet area, the communicating area and the air outlet area form a U-shaped air duct. The invention further discloses a design method of the ship sound insulation air return device. The air duct has the beneficial effects that the U-shaped air duct, the flow guide plate and the sound absorption structure are designed, airflow is guided to flow along a smooth path, the overall circulation efficiency of the air duct is improved, and the problems of insufficient air return amount and poor sound insulation effect in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the design of return air and noise control, specifically to a ship soundproof return air device and its design method. Background Technology

[0002] Shipboard living quarters require both sound insulation and air conditioning return air. The return air volume varies depending on the size of the cabin, necessitating the installation of sound-insulating return air structures on the bulkheads. Currently, ships typically utilize fire escape routes on soundproof doors for return air functionality. However, with increasing comfort standards in living quarters, traditional return air systems cannot simultaneously meet the requirements of large return air volume, low pressure loss, and high sound insulation. Current shipboard living quarters have high air conditioning airflow requirements, and traditional return air grilles on soundproof doors are insufficient for ventilation. Furthermore, the weighted sound insulation of the return air structure needs to be increased to over 15dB. Simultaneously, to prevent excessive pressure differences between the interior and exterior of the cabin due to poor ventilation, which could affect door opening and closing, the pressure loss of the return air grille at rated airflow generally cannot exceed 30Pa.

[0003] In ship design, living quarters must simultaneously meet two core requirements: air conditioning return air and sound insulation. The air conditioning system must achieve air circulation in the cabin through the return air structure set in the bulkhead, and the return air volume must be adapted and adjusted according to the cabin volume. Mechanical noise and fluid noise generated during ship navigation must be blocked through sound insulation measures to avoid affecting the living comfort of the people in the cabin.

[0004] In existing shipboard living quarters, fire escape routes on soundproof doors typically also serve as return air channels. This is achieved by installing return air grilles on the soundproof doors, thus serving the dual purpose of ventilation and basic sound insulation. However, with the continuous improvement of shipboard living comfort standards, this traditional return air structure has the following drawbacks: 1. Insufficient return air volume: The air conditioning demand in current shipboard living quarters is constantly increasing, and the return air grilles on traditional soundproof doors cannot meet the needs of large return air volumes; 2. Insufficient sound insulation performance: The weighted sound insulation of existing return air structures is difficult to achieve above 15dB, resulting in limited noise reduction; 3. Excessive pressure loss: The duct design of traditional return air grilles lacks optimization, easily generating pressure losses exceeding 30Pa under rated return air volume, leading to a large pressure difference between the inside and outside of the cabin, which in turn affects the normal opening and closing of the cabin doors.

[0005] Therefore, there is an urgent need to develop a return air device specifically adapted to shipboard living quarters. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a ship sound insulation return air device and its design method, aiming to solve the problem of insufficient return air volume in existing technologies.

[0007] The technical solution adopted in this invention is: a ship sound insulation return air device, comprising a box and a sound-absorbing structure built into the box; An air inlet is provided on the lower part of one side of the housing, and an air inlet grille is installed on the air inlet; an air outlet is provided on the other side of the housing, and an air outlet grille is installed on the air outlet. The sound-absorbing structure is vertically arranged, with its lower end fixed to the inner bottom of the housing. An air inlet area is formed between the sound-absorbing structure and the air inlet grille. An air outlet area is formed between the sound-absorbing structure and the air outlet grille. A gap is left between the upper end of the sound-absorbing structure and the inner top of the housing, forming a connecting area that connects the air outlet area and the air inlet area. A guide plate is provided at the top of the connecting area. The air inlet area, the connecting area, and the air outlet area form a U-shaped air duct.

[0008] According to the above scheme, the sound-absorbing structure includes a sound-absorbing shell and a sound-absorbing material filled inside the sound-absorbing shell; the sound-absorbing shell is provided with sound-absorbing holes.

[0009] According to the above scheme, the diameter of the sound-absorbing holes in the sound-absorbing shell is 1~3mm, and the opening rate of the sound-absorbing shell is 20%~30%.

[0010] According to the above scheme, the sound-absorbing material is made of ultrafine glass wool.

[0011] According to the above scheme, the guide plate is located at the four corners of the inner top of the box, and the space between the guide plate and the inner top of the box is filled with sound-absorbing material.

[0012] According to the above scheme, the sound-absorbing shell is made of stainless steel plate welded together, and the thickness of the stainless steel plate is 0.4mm~0.6mm.

[0013] According to the above scheme, the air outlet grille is a double-layer grille panel.

[0014] The present invention also discloses a design method for a ship sound insulation return air device as described above, the method comprising the following steps: Step 1: Based on the cabin return air volume requirements, design the external dimensions and U-shaped air duct of the ship's sound insulation return air device; Step 2: Based on the cabin return air volume requirements, box shape constraints, and duct wind speed control requirements, and in combination with the balance target of sound absorption performance and pressure loss, design the sound absorption structure. Step 3: Considering the space constraints of the bulkhead installation, and taking pressure loss as the control target, design the installation opening size of the air outlet and air inlet to meet the weighted sound insulation requirements. Step 4: Using pressure loss and weighted sound insulation as control indicators, design the structural parameters of the air inlet and outlet. Iterate and verify the weighted sound insulation and pressure loss indicators to determine the final design parameters.

[0015] According to the above scheme, the method of step two is as follows: Based on the cabin return air volume requirements, the box shape constraints and the air duct speed control requirements, determine the range of values ​​for the total thickness of the sound-absorbing structure in combination with the initial parameters, so that the actual air velocity in the air duct is ≤10m / s; then fix other initial parameters, and gradually adjust the total thickness of the sound-absorbing structure within the thickness range of 20~30mm, calculate the weighted sound insulation and pressure loss data corresponding to different thicknesses respectively, and under the requirement of ensuring that the air duct speed is ≤10m / s, select the optimal parameter combination that meets the design standard for weighted sound insulation and minimizes pressure loss, and determine the total thickness of the sound-absorbing structure.

[0016] According to the above scheme, step three is as follows: Based on the bulkhead installation space, the total area of ​​the box panel, and the airflow requirements, a preliminary range of values ​​for the outlet installation opening size is set to ensure that the opening size is compatible with the box structure and the reserved installation position on the bulkhead. The middle value of the range is selected as the initial value. The actual pressure loss at the inlet and outlet is calculated and compared with the set pressure loss value. If the actual pressure loss is greater than the set pressure loss value, the requirement is not met. The outlet opening size is then increased to improve airflow efficiency, and the actual pressure loss is recalculated until the requirement is met. If the actual pressure loss is less than the set pressure loss value, the requirement is met. The weighted sound insulation is calculated, and it is verified whether the calculated weighted sound insulation meets the requirement of ≥15dB. If the weighted sound insulation is ≥15dB, the design requirements are met, and the parameter combination at this time is the required design parameters; if the weighted sound insulation is <15dB, the design requirements are not met, the sound insulation loss ΔR of the holes and gaps exceeds the allowable range, the size of the air outlet is gradually reduced, and iterative verification is performed until the weighted sound insulation meets the standard. The final determined parameter combination is the design parameters.

[0017] The beneficial effects of this invention are as follows: 1. The ship sound insulation return air device of the present invention is designed with grilles and sound-absorbing structures at the air inlet and outlet, forming a U-shaped air duct inside the sound insulation device. A guide plate is set at the top of the U-shaped air duct to guide the airflow along a smooth path, eliminate the vortex at the corner of the air duct, and allow the airflow to pass through the air inlet area, the connecting area and the air outlet area without obstruction, thereby improving the overall circulation efficiency of the air duct and ensuring that the return air volume stably reaches the rated value, thus solving the problem of insufficient return air volume in the prior art; at the same time, the sound-absorbing structure designed inside the sound insulation return air device solves the problem of poor sound insulation effect.

[0018] 2. In this invention, the perforated design of the sound-absorbing shell of the sound-absorbing structure provides an efficient penetration channel for sound waves, allowing low-frequency noise inside the cabin to enter the interior of the sound-absorbing material, weakening the noise energy, greatly improving the sound insulation effect, and solving the problem of poor sound insulation effect in existing technologies.

[0019] 3. This invention, through frame structure design and sound absorption structure design, balances the two contradictory and mutually influential indicators of sound insulation and pressure loss under rated return air volume, and designs a soundproof return air device with large return air volume, high sound insulation, and low pressure loss. This ensures smooth ventilation and meets the sound insulation requirements of ship living quarters, and solves the design problem of ship living quarters requiring both large air volume, low pressure loss return air, and high sound insulation. It has strong engineering application value and significant economic benefits. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the internal structure of Embodiment 1.

[0021] Figure 2 This is a schematic diagram of the air inlet side in Example 1.

[0022] Figure 3 This is a schematic diagram of the air outlet side in Example 1.

[0023] The components include: 1. housing; 2. air outlet grille; 3. opening and closing knob; 4. air inlet grille; 5. air guide plate; 6. sound-absorbing material; and 7. sound-absorbing shell. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0027] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. Additionally, the term "a plurality of" indicates two or more.

[0029] Example 1 like Figure 1 The illustrated ship sound insulation return air device includes a housing 1 and a sound-absorbing structure built into the housing 1; An air inlet is provided on the lower side of the housing 1, and an air inlet grille 4 is installed on the air inlet, such as... Figure 2 As shown; an air outlet is provided on the other side of the housing 1, and an air outlet grille 2 is installed on the air outlet, as shown. Figure 3 As shown; The sound-absorbing structure is vertically arranged, and its lower end is fixed to the inner bottom of the housing 1. An air inlet area is formed between the sound-absorbing structure and the air inlet grille 4. An air outlet area is formed between the sound-absorbing structure and the air outlet grille 2. A gap is left between the upper end of the sound-absorbing structure and the inner top of the housing 1 to form a connecting area that connects the air outlet area and the air inlet area. A guide plate 5 is provided on the top of the connecting area. The air inlet area, the connecting area, and the air outlet area form a U-shaped air duct.

[0030] Preferably, the air intake grille 4 has an upward opening.

[0031] In this invention, the upward-facing design of the air inlet grille 4 guides the airflow towards the internal U-shaped duct for directional flow, achieving airflow reversal in conjunction with the U-shaped duct structure. As the airflow flows along the U-shaped path, the path extension and cross-section adaptation allow the airflow to naturally decelerate, effectively controlling pressure loss and preventing additional airflow noise caused by excessive wind speed.

[0032] Preferably, the air outlet grille 2 is a double-layer grille.

[0033] In this invention, a double-layer grille with a movable structure and equipped with an opening / closing knob 3 is used. The overlapping arrangement of the double-layer grille can form a secondary barrier against penetrating noise while airflow is flowing, thus achieving a sound insulation effect. The air outlet grille 2 is designed with double oblong holes, which can maximize the ventilation cross-sectional area within the limited installation space, ensuring a stable passage of the rated return air volume and meeting the cabin air conditioning return air requirements. In this invention, the double-layer grille is an existing structure and will not be described in detail here.

[0034] Preferably, the sound-absorbing structure includes a sound-absorbing shell 7 and a sound-absorbing material 6 filled inside the sound-absorbing shell 7; the sound-absorbing shell 7 has sound-absorbing holes.

[0035] In this invention, the sound-absorbing shell 7 is made of stainless steel plate welded together, and the thickness of the stainless steel plate is 0.4mm~0.6mm; the diameter of the sound-absorbing hole of the sound-absorbing shell 7 is 1~3mm, and the opening ratio of the sound-absorbing shell 7 is 20%~30%, which takes into account both sound transmission and sound absorption and structural strength.

[0036] In this invention, the sound-absorbing holes on the sound-absorbing shell 7 serve as sound wave channels, allowing incident sound waves to penetrate the shell wall and enter the interior of the sound-absorbing material 6. Through the action of air molecule friction and pore resonance, the sound energy is converted into heat energy and dissipated, thereby achieving a noise reduction effect.

[0037] In this invention, the sound-absorbing material 6 can be made of ultrafine glass wool with a high sound absorption coefficient.

[0038] Preferably, the guide plates 5 are located at the four corners of the inner top of the housing 1, and the space between the guide plates 5 and the inner top of the housing 1 is filled with sound-absorbing material 6. Further, the guide plates 5 are upwardly convex arc-shaped plates.

[0039] In this invention, the guide plate 5 can guide the airflow to smoothly transition along the surface of the guide plate 5, eliminate the eddies and airflow stagnation at the four corners of the connecting area, and optimize the airflow velocity distribution; at the same time, the sound-absorbing material filled between the guide plate 5 and the box 1 can absorb the airflow turbulence noise and the vibration noise of the guide plate 5, so as to achieve the synergistic optimization of airflow guidance and noise reduction.

[0040] Example 2 A design method for a ship's sound insulation return air device, the method comprising the following steps: Step 1: Based on the cabin return air volume requirements, design the external dimensions and U-shaped air duct of the ship's sound insulation return air device.

[0041] In this invention, the return air volume of the ship's living quarters is determined according to the number of air distributors in the cabin, wherein the rated return air volume of the air conditioner in a two-person cabin does not exceed 500m³ / h; for cabins with greater return air volume requirements, such as multi-person cabins, multiple soundproof return air devices can be installed in parallel to achieve air volume adaptation.

[0042] In this invention, the conventional bulkhead support structure of the ship's cabin uses double-ball-head flat steel as the frame profile (the center-to-center spacing between adjacent flat steel bars is 500mm, and the flat steel specification is 12mm). Based on the conventional bulkhead support structure of the ship's living quarters and the on-site installation space constraints, the housing 1 of the ship's sound insulation return air device is determined to be rectangular, with the following external dimensions: length 480mm ~ 540mm, width 380mm ~ 420mm, and thickness 110mm ~ 150mm.

[0043] In this embodiment, the initial dimensions of the housing 1 of the ship's sound insulation return air device can be set to 500mm (length) × 390mm (width) × 120mm (height), which is suitable for the installation space of the gap between the bulkhead flat steel and avoids occupying too much space inside the cabin.

[0044] In this invention, the ship sound insulation return air device is designed with an inverted U-shaped air duct structure, and the air inlet and air outlet are both located on the lower part of both sides of the box 1; this design can guide the airflow to form a flow path of downward entry, upward circulation, and downward exit.

[0045] Step 2: Based on the cabin return air volume requirements, the shape constraints of box 1, and the airflow velocity control requirements of the duct, and combining the balance target of sound absorption performance and pressure loss, design the sound absorption structure. The specific method is as follows: Based on the cabin return air volume requirements, the shape constraints of box 1, and the airflow velocity control requirements of the duct, the range of values ​​for the total thickness of the sound-absorbing material 6 and the sound-absorbing structure was determined in conjunction with the initial parameters, ensuring that the actual airflow velocity in the duct is ≤10m / s. Then, other initial parameters were fixed, and the total thickness of the sound-absorbing structure was gradually adjusted within a thickness range of 20~30mm. The weighted sound insulation and pressure loss data corresponding to different thicknesses were calculated, and the performance coupling relationship within this thickness range was analyzed. Increasing the thickness can significantly improve the sound insulation effect, but it will simultaneously compress the cross-sectional area of ​​the airflow duct, resulting in increased airflow resistance and pressure loss. Decreasing the thickness can expand the airflow space and reduce pressure loss, but it may lead to a decrease in sound absorption performance due to insufficient sound absorption path. Under the requirement of ensuring that the airflow velocity in the duct is ≤10m / s, the optimal parameter combination that meets the design standards for weighted sound insulation and minimizes pressure loss was selected, and the total thickness of the sound-absorbing structure was determined.

[0046] In this invention, to achieve higher sound insulation, the internal air duct velocity is calculated based on the cabin's return air volume requirements, as well as the external dimensions and internal sound-absorbing structure parameters. The maximum air duct velocity is required to be no more than 10 m / s to avoid airflow noise caused by excessive velocity. To meet the requirements of sound absorption and controlling the air duct velocity to ≤10 m / s, a sound-absorbing structure is designed, with specific parameters controlled as follows: Total thickness of sound-absorbing structure: ranges from 20 to 30 mm, balancing sound absorption performance and cross-sectional area of ​​air duct; 7 parameters of the sound-absorbing shell: It is made of stainless steel plate with initial thickness of 0.6mm (range 0.4~0.6mm), initial opening diameter of 2mm (range 1~3mm), initial opening ratio of 25% (range 20%~30%), balancing sound transmission, sound absorption effect and structural strength; Sound-absorbing material 6: Made of ultra-fine glass wool; The density of the filling sound-absorbing material is initially 80 kg / m³ (range 64~96 kg / m³), which is suitable for the sound absorption requirements of ship noise frequency bands.

[0047] In this embodiment, the total thickness of the sound-absorbing structure is calculated to be 25mm. When the ship's sound insulation return air device operates at a rated return air volume of 500m³ / h, the actual wind speed in the internal air duct is 8.0m / s (calculated based on the ratio of return air volume to the cross-sectional area of ​​the air duct). This not only meets the airflow noise control requirement of ≤10m / s, but also further optimizes the pressure loss by increasing the cross-sectional area of ​​the air passage.

[0048] In this invention, a weighted sound insulation of 15 dB meets the design standards.

[0049] Step 3: Considering the space constraints of the bulkhead installation and taking pressure loss as the control target, design the installation opening dimensions of the air outlet and air inlet to meet the weighted sound insulation requirements. The specific method is as follows: Based on the bulkhead installation space, the total area of ​​the panel of Box 1, and the airflow requirements, a preliminary range for the outlet installation opening size was set to ensure that the opening size is compatible with the Box 1 structure and the reserved installation position on the bulkhead. The midpoint of the range was selected as the initial value. The actual pressure loss at the inlet and outlet was calculated and compared with the set pressure loss value. If the actual pressure loss was greater than the set pressure loss value, the requirements were not met. The outlet opening size was then increased to improve airflow efficiency, and the actual pressure loss was recalculated until the requirements were met. If the actual pressure loss was less than the set pressure loss value, the requirements were met. The weighted sound insulation was calculated, and it was verified that the calculated weighted sound insulation met the requirement of ≥15dB. If the weighted sound insulation is ≥15dB, the design requirements are met, and the parameter combination at this time is the required design parameters; if the weighted sound insulation is <15dB, the design requirements are not met, the sound insulation loss ΔR of the holes and gaps exceeds the allowable range, the size of the air outlet is gradually reduced, and iterative verification is performed until the weighted sound insulation meets the standard (≥15dB). The final determined parameter combination is the design parameters.

[0050] In this invention, the size of the air inlet installation opening is designed using the same method.

[0051] In this invention, the basic sound insulation of the soundproof return air device R The formula is obtained through the mass law of sound insulation structures and the calculation method of sound insulation through holes and gaps, and is as follows: (1); In formula (1), R The basic sound insulation of the soundproof return air device is expressed in dB. m The combined surface density of the sound-absorbing structure (the density of the sound-absorbing shell 7 and the sound-absorbing material 6 combined), in kg / m³. 2 ; f The incident wave frequency is expressed in Hz.

[0052] At the same time, it is necessary to calculate the ratio of the total area of ​​the openings to the total area of ​​the panel of box 1 (the total area of ​​the openings is the total area of ​​the inlet and outlet and the air outlet, and the total area of ​​the panel of box 1 is the sum of the panel area of ​​the side where the air inlet is located and the panel area of ​​the side where the air outlet is located). The weighted sound insulation of the sound insulation return air device can be obtained by referring to the table of sound insulation loss of holes and gaps (the corresponding relationship can be found in the noise and vibration control engineering manual).

[0053] In this embodiment, according to the sound insulation mass law of the formula and the sound insulation calculation method of the hole and gap, the weighted sound insulation of the sound insulation return air device is 20dB (weighted sound insulation = basic sound insulation - sound insulation loss of hole and gap), which meets the requirement of greater than 15dB. Finally, the installation opening size of the air outlet is determined to be 370×360mm.

[0054] Step 4: Using pressure loss and weighted sound insulation as control indicators, design the structural parameters of the air inlet and outlet of the ship's sound insulation return air device. Iteratively verify the weighted sound insulation and pressure loss indicators to determine the final design parameters.

[0055] In this invention, the design methods for the structural parameters of the air inlet and air outlet are the same. Taking the air inlet as an example, the specific method is as follows: First, set the initial parameters: the air inlet is an upward-opening air inlet grille 4 (370×360mm, opening rate 60%), the air outlet size matches the air inlet, an R80mm inverted U-shaped guide plate 5 is added inside the air duct, and the sound absorption structure thickness is 25mm to maximize the cross-sectional area of ​​the air passage; Then, referring to the GJB 4061 standard, the total pressure loss is calculated by superimposing the frictional resistance loss and the local resistance loss; Determine if the total pressure loss is ≤30Pa: If the total pressure loss exceeds 30Pa, the total pressure loss exceeds the standard. Optimize the structure of the guide vane 5, increase the size of the air inlet, or fine-tune the sound absorption thickness. If the total pressure loss is ≤30Pa, the total pressure loss meets the design requirements. At this time, verify whether the weighted sound insulation under this parameter meets the standard. If it does, the parameter combination is the required design parameter. If the weighted sound insulation does not meet the standard, appropriately reduce the size of the air outlet or increase the sound absorption thickness. Iterate and verify until both indicators are met. The final parameter combination is the design parameter.

[0056] This invention aims to control pressure loss to ≤30Pa at rated airflow, achieving this through structural optimization and resistance calculation. A guide vane 5 is added inside the duct to guide airflow smoothly along an inverted U-shaped path; the air inlet is designed as an air inlet grille 4 with its openings facing upwards, optimizing the airflow direction and reducing local vortex resistance.

[0057] In this invention, the total pressure loss of the ship's sound insulation return air device Loss due to frictional resistance and local resistance loss It consists of two parts, and the calculation formula is: (2); (3); (4); In formulas (2) to (4), λ The coefficient of friction resistance is selected with reference to GJB 4061; This is the local drag coefficient, selected with reference to GJB 4061; ρ Air density, unit: kg / m³ 3 ; v The average air velocity within the duct is expressed in m / s.L This is the total length of the U-shaped air duct, in meters. P The perimeter of the U-shaped air duct is expressed in meters (m). F This is the maximum cross-section of the U-shaped duct, in meters. 2 g is the acceleration due to gravity, with a value of 9.8 m / s².

[0058] In this embodiment, based on the above-mentioned design structural parameters, the pressure loss of the ship's sound insulation return air device is calculated according to equations (2) to (4), at 500 m 3 At the rated return air volume of / h, the pressure loss of the soundproof return air device is 23.7Pa, which meets the design requirement of not more than 30Pa.

[0059] In this invention, the determination of the optimal parameter combination in steps two, three, and four can be accomplished using existing technologies disclosed in the art, without the need for designing new parameter optimization methods.

[0060] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0061] Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A shipboard sound insulation and return air device, characterized in that, Includes the enclosure and the sound-absorbing structure built into the enclosure; An air inlet is provided on the lower part of one side of the housing, and an air inlet grille is installed on the air inlet; an air outlet is provided on the other side of the housing, and an air outlet grille is installed on the air outlet. The sound-absorbing structure is vertically arranged, with its lower end fixed to the inner bottom of the housing. An air inlet area is formed between the sound-absorbing structure and the air inlet grille. An air outlet area is formed between the sound-absorbing structure and the air outlet grille. A gap is left between the upper end of the sound-absorbing structure and the inner top of the housing, forming a connecting area that connects the air outlet area and the air inlet area. A guide plate is provided at the top of the connecting area. The air inlet area, the connecting area, and the air outlet area form a U-shaped air duct.

2. The ship sound insulation return air device as described in claim 1, characterized in that, The sound-absorbing structure includes a sound-absorbing shell and a sound-absorbing material filled inside the sound-absorbing shell; the sound-absorbing shell has sound-absorbing holes.

3. The ship sound insulation return air device as described in claim 2, characterized in that, The sound-absorbing shell has a sound-absorbing hole diameter of 1~3mm and an opening rate of 20%~30%.

4. The shipboard sound insulation and return air device as described in claim 2 or 3, characterized in that, The sound-absorbing material is made of ultrafine glass wool.

5. The ship sound insulation return air device as described in claim 3, characterized in that, The guide plates are located at the four corners of the inner top of the box, and the space between the guide plates and the inner top of the box is filled with sound-absorbing material.

6. The shipboard sound insulation and return air device as described in claim 2, characterized in that, The sound-absorbing shell is made of stainless steel plates welded together, and the thickness of the stainless steel plates is 0.4mm~0.6mm.

7. The shipboard sound insulation and return air device as described in claim 1, characterized in that, The air outlet grille is a double-layer grille panel.

8. A design method for a ship sound insulation return air device as described in claim 1, characterized in that, The method includes the following steps: Step 1: Based on the cabin return air volume requirements, design the external dimensions and U-shaped air duct of the ship's sound insulation return air device; Step 2: Based on the cabin return air volume requirements, box shape constraints, and duct wind speed control requirements, and in combination with the balance target of sound absorption performance and pressure loss, design the sound absorption structure. Step 3: Considering the space constraints of the bulkhead installation, and taking pressure loss as the control target, design the installation opening size of the air outlet and air inlet to meet the weighted sound insulation requirements. Step 4: Using pressure loss and weighted sound insulation as control indicators, design the structural parameters of the air inlet and outlet. Iterate and verify the weighted sound insulation and pressure loss indicators to determine the final design parameters.

9. The design method for a ship sound insulation return air device as described in claim 8, characterized in that, The method for step two is as follows: Based on the cabin return air volume requirements, the box shape constraints and the air duct speed control requirements, combined with the initial parameters, determine the range of values ​​for the total thickness of the sound-absorbing material and sound-absorbing structure, so that the actual air velocity in the air duct is ≤10m / s. Then, with other initial parameters fixed, the total thickness of the sound-absorbing structure is gradually adjusted within the thickness range of 20~30mm. The weighted sound insulation and pressure loss data corresponding to different thicknesses are calculated respectively. Under the requirement of ensuring that the duct wind speed is ≤10m / s, the optimal parameter combination that meets the design standard for weighted sound insulation and minimizes pressure loss is selected, and the total thickness of the sound-absorbing structure is determined.

10. The design method for a ship sound insulation return air device as described in claim 8, characterized in that, Step three involves the following steps: Based on the bulkhead installation space, the total area of ​​the enclosure panels, and airflow requirements, a preliminary range for the outlet opening size is set. This ensures the opening size is compatible with the enclosure structure and the reserved installation location on the bulkhead. The midpoint of the range is selected as the initial value. The actual pressure loss at the inlet and outlet is calculated and compared with the set pressure loss value. If the actual pressure loss exceeds the set value, the requirement is not met. In this case, the outlet opening size is increased to improve airflow efficiency, and the actual pressure loss is recalculated until the requirement is met. If the actual pressure loss is less than the set value, the requirement is met. The weighted sound insulation is then calculated, and it is verified that the calculated weighted sound insulation meets the requirement of ≥15dB. If the weighted sound insulation is ≥15dB, the design requirements are met, and the parameter combination at this time is the required design parameters; if the weighted sound insulation is <15dB, the design requirements are not met, the sound insulation loss ΔR of the holes and gaps exceeds the allowable range, the size of the air outlet is gradually reduced, and iterative verification is performed until the weighted sound insulation meets the standard. The final determined parameter combination is the design parameters.

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