Air conditioner compression pipe vibration detection method and system

Abstract

The application discloses a kind of air conditioner compression pipe vibration detection method and system, the method includes: obtaining the problem frequency of air conditioner compression pipeline;Air conditioner compression pipe is carried out acoustic cavity modal analysis, and the acoustic cavity modal frequency of pipeline is obtained;Whether the problem frequency and acoustic cavity modal frequency are coupled is judged;If yes, when the length of air conditioner compression pipe cannot grow, and wall thickness cannot thicken, the anti-node position corresponding to acoustic cavity modal frequency in air conditioner compression pipeline is determined;Expansion chamber muffler is added in anti-node position, and the 3D solid grid model of improved air conditioner compression pipe is constructed;Transmission loss analysis is carried out to muffler based on the 3D solid grid model of improved air conditioner compression pipe, and according to the analysis result, the expansion ratio and expansion chamber length of expansion chamber muffler are adjusted, to optimize the frequency and sound reduction amount of the expansion chamber muffler, the application provides a kind of complete solution to the vibration problem of automobile air conditioner compression pipe, saves development cost and time.

Description

Technical Field

[0001] This invention relates to the automotive field, and in particular to a method and system for detecting vibration of an air conditioning compressor pipe. Background Technology

[0002] The development of new energy vehicles involves multiple tests, among which vibration testing of the air conditioning compressor pipe is a necessary test item. The traditional method for vibration testing of the air conditioning compressor pipe of new energy vehicles is generally to add a muffler to solve the problem if vibration problems are found in the air conditioning compressor pipe during the initial prototype vehicle driving evaluation.

[0003] However, currently, there are no clear guidelines regarding the location and noise reduction capacity of silencers when adding them. The only way to verify their effectiveness is to continuously create different silencer prototypes for testing or to test the same silencer in different pipe layouts. If the optimization is found to be unsatisfactory, the silencer structure is modified, and a new prototype is made for retesting. This iterative process is too costly, requiring constant structural adjustments, prototype fabrication, and repeated testing, with the risk of test failures still present. Repeated iterations are both time-consuming and costly.

[0004] How can we develop a complete method for vibration testing of air conditioning compressor pipes in new energy vehicles after problems occur, which can reduce the time required to manufacture mufflers and air conditioning compressor pipe prototypes, and also reduce development costs associated with testing and verification? Summary of the Invention

[0005] In view of the above situation, it is necessary to provide a method and system for detecting vibration of air conditioning compressor pipes to address the problems in the existing technology.

[0006] This invention provides a method for detecting vibration of an air conditioning compressor pipe, comprising:

[0007] Obtain the frequency of problems in the air conditioning compressor piping;

[0008] The acoustic cavity modal analysis of the air conditioning compressor pipe was performed to obtain the acoustic cavity modal frequencies of the pipe.

[0009] Determine whether the problem frequency is coupled with the acoustic cavity modal frequency;

[0010] If so, obtain the pipe parameters of the air conditioning compressor pipe, which are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased;

[0011] When it is determined from the pipeline parameters that the length of the air conditioning compressor pipe cannot be increased and the wall thickness cannot be increased, the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compressor pipe is determined.

[0012] An expansion cavity silencer is added at the anti-node position to improve the air conditioning compressor pipe, and a 3D volumetric mesh model of the improved air conditioning compressor pipe is constructed.

[0013] Based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, the transmission loss of the expansion cavity muffler is analyzed, and the expansion ratio and expansion cavity length of the expansion cavity muffler are adjusted according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler.

[0014] Furthermore, in the above-mentioned air conditioning compressor pipe vibration detection method, after the step of determining whether the problem frequency is coupled with the acoustic cavity modal frequency, the method further includes:

[0015] When the problem frequency is not coupled with the acoustic cavity modal frequency, a corrugated pipe is added in the middle of the air conditioning compressor pipe, and the output result is judged after vibration decoupling.

[0016] When the vibration decoupling result meets the standard, a sound-absorbing sleeve is added to the bellows.

[0017] When the vibration decoupling result is not up to standard, the length of the bellows is increased, and a sound-absorbing sleeve is added to the bellows.

[0018] Furthermore, in the above-mentioned method for detecting vibration of the air conditioning compressor pipe, the step of performing acoustic modal analysis on the air conditioning compressor pipe to obtain the acoustic modal frequencies of the pipe includes:

[0019] A 3D volumetric mesh model of the acoustic cavity of the air conditioning duct was constructed.

[0020] Define the material parameters for air density and sound velocity, and define the air properties onto the acoustic cavity mesh;

[0021] Set all nodes as fluid-structure interaction nodes;

[0022] The operating conditions and output displacement are set, and the cavity modal frequencies are calculated using the Nastran model.

[0023] Furthermore, in the above-mentioned air conditioning compressor pipe vibration detection method, the step of performing transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjusting the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler includes:

[0024] The improved 3D volumetric mesh model of the air conditioning compressor pipe was imported into the acoustic finite element module of the simulation software in acoustic mesh mode.

[0025] Define air acoustic materials and their properties;

[0026] Define the incident acoustic power at the inlet as 1W;

[0027] Define the non-reflective boundary conditions at the exit;

[0028] Perform transmission loss analysis, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results until the transmission loss center frequency of the muffler meets the problem frequency and the noise reduction reaches the threshold.

[0029] Furthermore, in the above-mentioned air conditioning compressor pipe vibration detection method, the simulation software includes Virtual Lab software.

[0030] Furthermore, in the above-mentioned method for detecting vibration of the air conditioning compressor pipe, the step of determining the inverse node in the air conditioning compressor pipe corresponding to the acoustic cavity modal frequency includes:

[0031] Based on the results of the acoustic cavity modal analysis, find the displacement pattern diagram that matches the frequency of the problem and the frequency of the acoustic cavity modal.

[0032] The point where the displacement of the displacement array is at its maximum is determined to be the inverse node corresponding to the modal frequency of the acoustic cavity.

[0033] This invention also discloses an air conditioning compressor pipe vibration detection system, comprising:

[0034] The first acquisition module is used to acquire the problem frequency of the air conditioning compressor pipeline;

[0035] The membrane analysis module is used to perform acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequencies of the pipe.

[0036] The judgment module is used to determine whether the problem frequency is coupled with the acoustic cavity modal frequency;

[0037] The second acquisition module is used to acquire the pipe parameters of the air conditioning compressor pipe when the problem frequency is coupled with the acoustic cavity modal frequency. The pipe parameters are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased.

[0038] The determination module is used to determine the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compression pipe when it is determined from the pipe parameters that the length of the air conditioning compression pipe cannot be increased and the wall thickness cannot be increased.

[0039] The model building module is used to add an expansion cavity muffler at the anti-node position to improve the air conditioning compressor pipe, and to build a 3D volumetric mesh model of the improved air conditioning compressor pipe.

[0040] The optimization module is used to perform transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results, so as to optimize the frequency and noise reduction of the expansion cavity muffler.

[0041] Furthermore, the aforementioned air conditioning compressor pipe vibration detection system also includes:

[0042] When the problem frequency is not coupled with the acoustic cavity modal frequency, a corrugated pipe is added in the middle of the air conditioning compressor pipe, and the output result is judged after vibration decoupling.

[0043] When the vibration decoupling result meets the standard, a sound-absorbing sleeve is added to the bellows.

[0044] When the vibration decoupling result is not up to standard, the length of the bellows is increased, and a sound-absorbing sleeve is added to the bellows.

[0045] Furthermore, in the aforementioned air conditioning compressor pipe vibration detection system, the step of performing acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequencies of the pipe includes:

[0046] A 3D volumetric mesh model of the acoustic cavity of the air conditioning duct was constructed.

[0047] Define the material parameters for air density and sound velocity, and define the air properties onto the acoustic cavity mesh;

[0048] Set all nodes as fluid-structure interaction nodes;

[0049] The operating conditions and output displacement are set, and the cavity modal frequencies are calculated using the Nastran model.

[0050] Furthermore, in the aforementioned air conditioning compressor pipe vibration detection system, the step of performing transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjusting the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler includes:

[0051] The improved 3D volumetric mesh model of the air conditioning compressor pipe was imported into the acoustic finite element module of the simulation software in acoustic mesh mode.

[0052] Define air acoustic materials and their properties;

[0053] Define the incident acoustic power at the inlet as 1W;

[0054] Define the non-reflective boundary conditions at the exit;

[0055] Perform transmission loss analysis, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results until the transmission loss center frequency of the muffler meets the problem frequency and the noise reduction reaches the threshold.

[0056] This invention first determines whether the vibration problem of the air conditioning compressor pipe is caused by the acoustic modes of the air conditioning compressor pipe by judging whether the problem frequency is coupled with the acoustic mode frequency of the cavity. If so, it first identifies the location of the inverse node in the air conditioning compressor pipe corresponding to the acoustic mode frequency, and adds an expansion cavity muffler at this location. Then, it performs transmission loss analysis on the muffler and adjusts the expansion ratio and expansion cavity length of the muffler based on the analysis results to optimize the frequency and noise reduction of the muffler. This solution provides a complete method for solving the vibration problem of automotive air conditioning compressor pipes, saving development costs and time. Attached Figure Description

[0057] Figure 1 A flowchart of the air conditioning compressor pipe vibration detection method provided in the first embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram of the expansion cavity.

[0059] Figure 3 A schematic diagram illustrating the effect of the expansion ratio of the expansion cavity muffler on transmission loss;

[0060] Figure 4 A schematic diagram illustrating the effect of the length of the expansion cavity silencer on transmission loss;

[0061] Figure 5 A flowchart of the air conditioning compressor pipe vibration detection method provided in the second embodiment of the present invention;

[0062] Figure 6 This is a structural block diagram of an air conditioning compressor pipe vibration detection system provided in the second embodiment of the present invention. Detailed Implementation

[0063] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0064] These and other aspects of the embodiments of the invention will become clear from the following description and accompanying drawings. In these descriptions and drawings, some specific embodiments of the invention are specifically disclosed to illustrate some ways of implementing the principles of the embodiments of the invention; however, it should be understood that the scope of the embodiments of the invention is not limited thereto. Rather, the embodiments of the invention include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0065] Please see Figure 1 The method for detecting vibration of an air conditioning compressor pipe in the first embodiment of the present invention includes steps S11 to S17.

[0066] Step S11: Obtain the problem frequency of the air conditioning compressor pipeline.

[0067] In practice, the frequency of the problem can be determined by testing the vibration of the air conditioning compressor pipe and the response inside the vehicle.

[0068] Step S12: Perform acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequency of the pipe.

[0069] Specifically, the step of performing cavity modal analysis on the air conditioning compressor pipe to obtain the cavity modal frequencies of the pipe includes:

[0070] A 3D volumetric mesh model of the acoustic cavity of the air conditioning duct was constructed.

[0071] Define the material parameters for air density and sound velocity, and define the air properties onto the acoustic cavity mesh;

[0072] Set all nodes as fluid-structure interaction nodes;

[0073] By setting the operating conditions and output displacement, the acoustic cavity modal frequencies are calculated using the Nastran model.

[0074] Step S13: Determine whether the problem frequency is coupled with the acoustic cavity modal frequency.

[0075] Step S14: If yes, obtain the pipe parameters of the air conditioning compressor pipe. The pipe parameters are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased.

[0076] Step S15: When it is determined from the pipeline parameters that the length of the air conditioning compressor pipe cannot be increased and the wall thickness cannot be increased, the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compressor pipe is determined.

[0077] If the problem frequency coincides with the cavity modal frequency, it can be considered that the problem frequency is coupled with the cavity diaphragm frequency, thus identifying the problem as an acoustic issue caused by the cavity modality. The pipe parameters of the air conditioning compressor pipe are then obtained to determine if the pipe can be extended. These parameters are primarily related to the vehicle layout; if space allows, it can be extended; otherwise, it cannot. If extension is possible, increasing the length of the air conditioning compressor pipe solves the problem. If not, the pipe wall thickness is assessed based on the pipe parameters. Whether the pipe wall thickness can be increased depends on factors such as cost and manufacturing feasibility. If it is possible, increasing the wall thickness of the air conditioning compressor pipe solves the problem; if not, the inverse node in the air conditioning compressor pipe corresponding to the cavity modal frequency is identified.

[0078] In practice, the displacement pattern diagram that matches the problem frequency and the acoustic cavity modal frequency can be found through the acoustic cavity modal analysis results in step S12. The place with the largest displacement is the inverse node position corresponding to the acoustic cavity modal frequency.

[0079] Step S16: Add an expansion cavity silencer at the reverse node position to improve the air conditioning compressor pipe, and construct a 3D volumetric mesh model of the improved air conditioning compressor pipe.

[0080] Step S17: Based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, the transmission loss of the expansion cavity muffler is analyzed, and the expansion ratio and expansion cavity length of the expansion cavity muffler are adjusted according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler.

[0081] An expansion cavity muffler was added to the inverse node of the acoustic cavity mode of the air conditioning compressor pipe, and a 3D volumetric mesh model of the acoustic cavity was built to obtain an improved 3D volumetric mesh model of the air conditioning compressor pipe. Based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, transmission loss analysis was performed on the muffler, and the expansion ratio and expansion cavity length of the muffler were adjusted according to the analysis results to optimize the frequency and noise reduction of the muffler. Specifically, the improved 3D volumetric mesh model of the air conditioning compressor pipe was imported into the acoustic finite element module of the simulation software in acoustic mesh mode; airborne acoustic materials and properties were defined; the incident sound power of 1W at the inlet was defined; the no-reflection boundary condition at the outlet was defined; transmission loss analysis was performed, and the expansion ratio and expansion cavity length of the expansion cavity muffler were adjusted according to the analysis results until the center frequency of the muffler's transmission loss met the problem frequency and the noise reduction reached the threshold. The simulation software used included Virtual Lab software.

[0082] The structure of the expansion cavity is as follows Figure 2 As shown, the transmission loss formula for the expansion cavity muffler is:

[0083]

[0084] In the formula, m = S2 / S1, which is called the expansion ratio. For a circular pipe, m = D 2 / d 2 D and d are the diameters of the expansion cavity and the pipe, respectively.

[0085] The transmission loss of an expansion muffler depends on the expansion ratio and the length of the expansion chamber, and is also a function of wavelength (or frequency). If the length L of the expansion chamber muffler is fixed, the transmission loss increases as the expansion ratio m increases, such as... Figure 3 As shown, if the calculated center frequency of the muffler matches the problem frequency and the noise reduction reaches the threshold (e.g., 20 dBA), the muffler design is complete. If the noise reduction does not reach 20 dBA, the expansion ratio m needs to be optimized until the noise reduction reaches the target requirement of 20 dBA. If the noise reduction of the expanded cavity muffler reaches the target of 20 dBA, but the center frequency does not match the problem frequency, the expansion cavity L needs to be optimized to adjust the center frequency until an expanded muffler with transmission loss center frequency matching the problem frequency and noise reduction reaching the target of 20 dBA is obtained. The effect of the expansion cavity L on the center frequency is as follows. Figure 4 As shown.

[0086] Having thus completed the vibration testing method for the air conditioning compressor pipe of new energy vehicles, we then moved on to the prototype manufacturing stage.

[0087] To address the acoustic problems caused by the acoustic modes of the air conditioning compressor pipe during the design phase, this paper first identifies the inverse node in the air conditioning compressor pipe corresponding to the acoustic mode frequency. An expansion cavity muffler is then added to this inverse node. Transmission loss analysis is performed on the muffler, and the expansion ratio and expansion cavity length are adjusted based on the analysis results to optimize the muffler's frequency and noise reduction. This solution provides a complete method for solving the vibration problem of automotive air conditioning compressor pipes, saving development costs and time.

[0088] Please see Figure 5 The second embodiment of the present invention is a method for detecting vibration of an air conditioning compressor pipe, which includes steps S21 to S30.

[0089] Step S21: Obtain the problem frequency of the air conditioning compressor pipeline.

[0090] Step S22: Perform acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequency of the pipe.

[0091] Step S23: Determine whether the problem frequency is coupled with the acoustic cavity modal frequency. If yes, proceed to step S24; otherwise, proceed to step S28.

[0092] Step S24: Obtain the pipe parameters of the air conditioning compressor pipe. The pipe parameters are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased.

[0093] Step S25: When it is determined from the pipeline parameters that the length of the air conditioning compressor pipe cannot be increased and the wall thickness cannot be increased, the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compressor pipe is determined.

[0094] Step S26: Add an expansion cavity muffler at the reverse node position to improve the air conditioning compressor pipe, and construct a 3D volumetric mesh model of the improved air conditioning compressor pipe.

[0095] Step S27: Based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, the transmission loss of the expansion cavity muffler is analyzed, and the expansion ratio and expansion cavity length of the expansion cavity muffler are adjusted according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler.

[0096] In practice, the problem frequency is determined by testing the vibration of the pipeline and the response inside the vehicle. A cavity modal analysis is performed on the air conditioning compressor pipe. If the problem frequency is coupled with the cavity modal frequency, the problem can be identified as an acoustic issue caused by the cavity modality. It is then necessary to determine if the length of the air conditioning compressor pipe can be increased. If so, the length of the air conditioning compressor pipe is increased to resolve the problem. If the length of the air conditioning pipe cannot be increased, it is necessary to determine if the inner wall of the air conditioning compressor pipe can be thickened. If so, the inner wall of the air conditioning compressor pipe is thickened to resolve the problem. When the length of the air conditioning compressor pipe cannot be increased, and the wall thickness cannot be increased, the inverse node in the air conditioning compressor pipe corresponding to the cavity modal frequency is identified. An expansion cavity muffler is added to the cavity modal inverse node of the air conditioning compressor pipe. Transmission loss analysis is performed on the muffler, and the frequency and noise reduction of the muffler are optimized by increasing the expansion ratio and the length of the expansion cavity to resolve the problem.

[0097] Step S28 involves adding a corrugated pipe in the middle of the air conditioning compressor pipe and performing vibration decoupling before outputting the result for judgment.

[0098] Step S29: When the vibration decoupling result meets the standard, add a sound-absorbing sleeve to the bellows.

[0099] Step S30: When the vibration decoupling result is not up to standard, increase the length of the bellows and add a sound-absorbing sleeve to the bellows.

[0100] When it is determined that the problem frequency is not coupled with the acoustic cavity modal frequency, the problem in the air conditioning compressor pipe can be identified as forced vibration caused by airflow pulses. When forced vibration caused by airflow pulses occurs, a corrugated pipe can be added in the middle of the air conditioning compressor pipe for vibration decoupling, with more than five corrugations added. If the vibration decoupling is satisfactory, a sound-absorbing sleeve is added outside the corrugated pipe; if the vibration decoupling is not satisfactory, the length of the corrugated pipe is increased, and an attraction sleeve is added outside the corrugated pipe. This completes the vibration detection method for the air conditioning compressor pipe of new energy vehicles, and the process then moves to the prototype fabrication stage.

[0101] This invention effectively distinguishes between acoustic problems caused by cavity modes and forced vibration problems caused by airflow pulses in air conditioning compressor pipes. Different solutions are employed for the acoustic characteristics caused by cavity modes and the forced vibration problems caused by airflow pulses in air conditioning compressor pipes, saving development costs and time and improving efficiency.

[0102] Please see Figure 6 The air conditioning compressor pipe vibration detection system in the third embodiment of the present invention includes:

[0103] The first acquisition module 31 is used to acquire the problem frequency of the air conditioning compressor pipeline;

[0104] The membrane analysis module 32 is used to perform acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequency of the pipe;

[0105] The judgment module 33 is used to determine whether the problem frequency is coupled with the acoustic cavity modal frequency;

[0106] The second acquisition module 34 is used to acquire the pipe parameters of the air conditioning compressor pipe when the problem frequency is coupled with the acoustic cavity modal frequency. The pipe parameters are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased.

[0107] The determination module 35 is used to determine the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compression pipe when it is determined from the pipe parameters that the length of the air conditioning compression pipe cannot be increased and the wall thickness cannot be increased.

[0108] Model building module 36 is used to add an expansion cavity muffler at the anti-node position to improve the air conditioning compressor pipe and build a 3D volume mesh model of the improved air conditioning compressor pipe.

[0109] The optimization module 37 is used to perform transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results, so as to optimize the frequency and noise reduction of the expansion cavity muffler.

[0110] Furthermore, the aforementioned air conditioning compressor pipe vibration detection system also includes:

[0111] When the problem frequency is not coupled with the acoustic cavity modal frequency, a corrugated pipe is added in the middle of the air conditioning compressor pipe, and the output result is judged after vibration decoupling.

[0112] When the vibration decoupling result meets the standard, a sound-absorbing sleeve is added to the bellows.

[0113] When the vibration decoupling result is not up to standard, the length of the bellows is increased, and a sound-absorbing sleeve is added to the bellows.

[0114] Furthermore, in the aforementioned air conditioning compressor pipe vibration detection system, the step of performing acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequencies of the pipe includes:

[0115] A 3D volumetric mesh model of the acoustic cavity of the air conditioning duct was constructed.

[0116] Define the material parameters for air density and sound velocity, and define the air properties onto the acoustic cavity mesh;

[0117] Set all nodes as fluid-structure interaction nodes;

[0118] The operating conditions and output displacement are set, and the cavity modal frequencies are calculated using the Nastran model.

[0119] Furthermore, in the aforementioned air conditioning compressor pipe vibration detection system, the step of performing transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjusting the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler includes:

[0120] The improved 3D volumetric mesh model of the air conditioning compressor pipe was imported into the acoustic finite element module of the simulation software in acoustic mesh mode.

[0121] Define air acoustic materials and their properties;

[0122] Define the incident acoustic power at the inlet as 1W;

[0123] Define the non-reflective boundary conditions at the exit;

[0124] Perform transmission loss analysis, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results until the transmission loss center frequency of the muffler meets the problem frequency and the noise reduction reaches the threshold.

[0125] The air conditioning compressor pipe vibration detection system provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0126] Those skilled in the art will understand that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system or apparatus (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from or in conjunction with such an instruction execution system or apparatus). For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit programs for use by or in conjunction with an instruction execution system or apparatus.

[0127] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0128] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0129] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. 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.

[0130] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for detecting vibration of an air conditioning compressor pipe, characterized in that, include: Obtain the frequency of problems in the air conditioning compressor piping; The acoustic cavity modal analysis of the air conditioning compressor pipe was performed to obtain the acoustic cavity modal frequencies of the pipe. Determine whether the problem frequency is coupled with the acoustic cavity modal frequency; If so, obtain the pipe parameters of the air conditioning compressor pipe, which are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased; When it is determined from the pipeline parameters that the length of the air conditioning compressor pipe cannot be increased and the wall thickness cannot be increased, the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compressor pipe is determined. An expansion cavity silencer is added at the anti-node position to improve the air conditioning compressor pipe, and a 3D volumetric mesh model of the improved air conditioning compressor pipe is constructed. Based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, the transmission loss of the expansion cavity muffler is analyzed, and the expansion ratio and expansion cavity length of the expansion cavity muffler are adjusted according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler.

2. The method for detecting vibration of an air conditioning compressor pipe as described in claim 1, characterized in that, The step of determining whether the problem frequency is coupled with the acoustic cavity modal frequency further includes: When the problem frequency is not coupled with the acoustic cavity modal frequency, a corrugated pipe is added in the middle of the air conditioning compressor pipe, and the output result is judged after vibration decoupling. When the vibration decoupling result meets the standard, a sound-absorbing sleeve is added to the bellows. When the vibration decoupling result is not up to standard, the length of the bellows is increased, and a sound-absorbing sleeve is added to the bellows.

3. The method for detecting vibration of an air conditioning compressor pipe as described in claim 1, characterized in that, The step of performing cavity modal analysis on the air conditioning compressor pipe to obtain the cavity modal frequencies of the pipe includes: A 3D volumetric mesh model of the acoustic cavity of the air conditioning compressor pipe was constructed. Define the material parameters for air density and sound velocity, and define the air properties onto the acoustic cavity mesh; Set all nodes as fluid-structure interaction nodes; The operating conditions and output displacement are set, and the cavity modal frequencies are calculated using the Nastran model.

4. The method for detecting vibration of an air conditioning compressor pipe as described in claim 1, characterized in that, The steps of performing transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjusting the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler include: The improved 3D volumetric mesh model of the air conditioning compressor pipe was imported into the acoustic finite element module of the simulation software in acoustic mesh mode. Define air acoustic materials and their properties; Define the incident acoustic power at the inlet as 1W; Define the non-reflective boundary conditions at the exit; Perform transmission loss analysis, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results until the transmission loss center frequency of the muffler meets the problem frequency and the noise reduction reaches the threshold.

5. The method for detecting vibration of an air conditioning compressor pipe as described in claim 4, characterized in that, The simulation software includes Virtual Lab software.

6. The method for detecting vibration of an air conditioning compressor pipe as described in claim 1, characterized in that, The step of determining the inverse node in the air conditioning compression pipeline corresponding to the acoustic cavity modal frequency includes: Based on the results of the acoustic cavity modal analysis, find the displacement pattern diagram that matches the frequency of the problem and the frequency of the acoustic cavity modal. The point where the displacement of the displacement array is at its maximum is determined to be the inverse node corresponding to the modal frequency of the acoustic cavity.

7. A vibration detection system for an air conditioning compressor pipe, characterized in that, include: The first acquisition module is used to acquire the problem frequency of the air conditioning compressor pipeline; The membrane analysis module is used to perform acoustic cavity modal analysis on the air conditioning compressor pipe to obtain the acoustic cavity modal frequencies of the pipe. The judgment module is used to determine whether the problem frequency is coupled with the acoustic cavity modal frequency; The second acquisition module is used to acquire the pipe parameters of the air conditioning compressor pipe when the problem frequency is coupled with the acoustic cavity modal frequency. The pipe parameters are used to indicate whether the length of the air conditioning compressor pipe can be increased and whether the wall thickness can be increased. The determination module is used to determine the position of the inverse node corresponding to the acoustic cavity modal frequency in the air conditioning compression pipe when it is determined from the pipe parameters that the length of the air conditioning compression pipe cannot be increased and the wall thickness cannot be increased. The model building module is used to add an expansion cavity muffler at the anti-node position to improve the air conditioning compressor pipe, and to build a 3D volumetric mesh model of the improved air conditioning compressor pipe. The optimization module is used to perform transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results, so as to optimize the frequency and noise reduction of the expansion cavity muffler.

8. The air conditioning compressor pipe vibration detection system as described in claim 7, characterized in that, Also includes: When the problem frequency is not coupled with the acoustic cavity modal frequency, a corrugated pipe is added in the middle of the air conditioning compressor pipe, and the output result is judged after vibration decoupling. When the vibration decoupling result meets the standard, a sound-absorbing sleeve is added to the bellows. When the vibration decoupling result is not up to standard, the length of the bellows is increased, and a sound-absorbing sleeve is added to the bellows.

9. The air conditioning compressor pipe vibration detection system as described in claim 7, characterized in that, The step of performing cavity modal analysis on the air conditioning compressor pipe to obtain the cavity modal frequencies of the pipe includes: A 3D volumetric mesh model of the acoustic cavity of the air conditioning compressor pipe was constructed. Define the material parameters for air density and sound velocity, and define the air properties onto the acoustic cavity mesh; Set all nodes as fluid-structure interaction nodes; The operating conditions and output displacement are set, and the cavity modal frequencies are calculated using the Nastran model.

10. The air conditioning compressor pipe vibration detection system as described in claim 7, characterized in that, The steps of performing transmission loss analysis on the expansion cavity muffler based on the improved 3D volumetric mesh model of the air conditioning compressor pipe, and adjusting the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results to optimize the frequency and noise reduction of the expansion cavity muffler include: The improved 3D volumetric mesh model of the air conditioning compressor pipe was imported into the acoustic finite element module of the simulation software in acoustic mesh mode. Define air acoustic materials and their properties; Define the incident acoustic power at the inlet as 1W; Define the non-reflective boundary conditions at the exit; Perform transmission loss analysis, and adjust the expansion ratio and expansion cavity length of the expansion cavity muffler according to the analysis results until the transmission loss center frequency of the muffler meets the problem frequency and the noise reduction reaches the threshold.

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