A vibration control method and device for an air conditioner compressor pipeline system

Abstract

The present application relates to the technical field of air conditioner control, in particular to a kind of air conditioner compressor pipeline system vibration control method and device.Through the strain gauge of multiple monitoring points of pipeline arrangement, the pipeline vibration stress value under different suction and exhaust pressure difference and frequency combination is collected, to train the AI agent prediction model with pressure difference and frequency as input, vibration state grade as output.Again through real-time acquisition current pressure difference and frequency, input model prediction current vibration grade, and according to grade execute hierarchical control: to slight or greater vibration preferentially apply reverse compensation current to carry out active vibration reduction, and re-verify vibration state after compensation, if not up to standard, then increase compensation or execute frequency hopping;For severe vibration, directly frequency hopping.Thereby with pipeline stress as direct control target, compared with traditional method with environmental temperature as variable more accurate and reliable;Through active compensation priority, hierarchical intervention strategy, maximum limit retains compressor available frequency.

Description

Technical Field

[0001] This invention relates to the field of air conditioning control technology, specifically to a vibration control method and device for an air conditioning compressor piping system. Background Technology

[0002] The air conditioning compressor and its piping system are the core of the refrigeration cycle, operating under harsh conditions of high pressure and cyclical loads for extended periods. Current piping systems are prone to vibration due to refrigerant pulsation, compressor excitation, and external stress. Excessive or abnormal vibration is a major cause of pipe weld cracking, refrigerant leakage, abnormal noise, and even system failure. Therefore, effectively identifying and suppressing piping vibration while ensuring refrigeration performance and user comfort has been a long-standing technical challenge for the air conditioning industry.

[0003] In existing technologies, traditional vibration monitoring methods for air conditioners mainly rely on pipeline stress-strain testing in a laboratory environment. This involves using the ambient temperature of the outdoor unit as a variable, testing the stress values ​​at various measuring points within the compressor's frequency sweep range, and directly performing frequency hopping on frequencies exceeding the vibration limit. However, this method indirectly characterizes the compressor load using ambient temperature, failing to comprehensively cover actual user scenarios (different regions and seasons). Furthermore, the physical correlation between temperature and pipeline vibration is weak, leading to insufficient vibration identification accuracy. Frequency hopping also renders some compressor operating frequencies unusable, easily causing frequent frequency fluctuations in the actual operation of inverter air conditioners, resulting in room temperature overshoot and impacting user experience. The few solutions using torque compensation are mostly fixed, "one-size-fits-all" compensations, lacking refined, graded control based on the actual stress state of the pipeline, leading to increased energy consumption or poor vibration reduction. Therefore, a control method that can accurately identify pipeline vibration states and adaptively suppress vibration is urgently needed. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a vibration control method and device for air conditioning compressor piping system to solve the technical problem that the existing technology is not accurate in identifying piping vibration but is difficult to adaptively suppress vibration.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A vibration control method for an air conditioning compressor piping system includes:

[0007] Data acquisition and modeling steps: Strain gauges are placed at multiple preset monitoring points in the air conditioning compressor piping system, and the pipeline vibration stress values ​​at each monitoring point are collected under different operating conditions; the compressor suction and discharge pressure difference ΔP and operating frequency f under the operating conditions are used as input features, and the vibration state level determined based on the pipeline vibration stress values ​​is used as the output label to train a vibration prediction model.

[0008] Online prediction steps: When the air conditioner is actually running, the current intake and exhaust pressure difference ΔP_current and the current operating frequency f_current are collected in real time and input into the vibration prediction model to obtain the current vibration state level;

[0009] The graded control steps are as follows: Vibration suppression operation is performed according to the current vibration state level, and the vibration suppression operation includes active compensation control and / or frequency avoidance control;

[0010] The active compensation control includes: applying a reverse compensation current of a predetermined amplitude to the compressor motor; and after applying the reverse compensation current, re-executing the online prediction step or directly acquiring the pipeline vibration stress value; if the vibration state level obtained again is not reduced to the preset target level compared with before the application, then increasing the amplitude of the reverse compensation current and / or executing frequency avoidance control.

[0011] The frequency avoidance control includes: prohibiting operation at the current frequency point, or switching the current operating frequency to a preset safe frequency.

[0012] Furthermore, in the hierarchical control step, when the compressor frequency is locked due to the execution of active compensation control, an unlocking condition is also set; when the unlocking condition is met, the frequency lock is released, allowing the compressor frequency to change with load demand.

[0013] Furthermore, the unlocking conditions include at least one of the following:

[0014] The predetermined time has elapsed since the locking time;

[0015] The re-predicted vibration state level remains below the preset threshold for a predetermined time.

[0016] The user-set temperature has changed.

[0017] Furthermore, the amplitude of the reverse compensation current is defined as a percentage of the rated current of the compressor motor, or as a ratio relative to a preset maximum allowable compensation current.

[0018] Furthermore, the vibration state level is determined by comparing the maximum pipeline vibration stress value at multiple monitoring points with one or more preset stress thresholds.

[0019] Furthermore, the vibration prediction model is trained using one of the following algorithms: support vector machine, neural network, or linear regression.

[0020] Furthermore, the multiple preset monitoring points include multiple or all of the following points: compressor exhaust port, compressor exhaust pipe bend, compressor suction port, compressor suction pipe bend, condenser connection pipe bend, and shut-off valve connection pipe bend.

[0021] Furthermore, the exhaust pipe bends include a first bend and a second bend in the exhaust pipe; the intake pipe bends include a first bend and a second bend in the intake pipe; the condenser connection pipe bends include a first bend and a second bend in the condenser connection pipe; and the shut-off valve connection pipe bends include a first bend in the shut-off valve connection pipe. The strain gauges are attached at a distance of 3mm from the pipe opening at the compressor intake and exhaust ports, with the attachment direction perpendicular to the line connecting the intake and exhaust ports. At the pipe bends, the strain gauges are attached on the inside of the bend.

[0022] A vibration control device for an air conditioning compressor piping system, comprising:

[0023] The strain gauge array is arranged at multiple preset monitoring points in the compressor piping system to collect the pipeline vibration stress value;

[0024] Pressure sensors are installed at the compressor's intake and exhaust ports to collect intake and exhaust pressures.

[0025] The controller is configured to perform the method as described in any one of claims 1 to 8.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention first places strain gauges at multiple monitoring points along the pipeline to collect pipeline vibration stress values ​​under different combinations of intake and exhaust pressure differences and frequencies. This data is then used to train an AI-assisted prediction model that takes pressure difference and frequency as input and vibration level as output. During actual air conditioning operation, the current pressure difference and frequency are acquired in real time and input into the model to predict the current vibration level. Based on the level, graded control is implemented: for minor or significant vibrations, a reverse compensation current is applied for active vibration reduction, and the vibration state is re-verified after compensation. If the standard is not met, the compensation is increased or frequency hopping is executed; for severe vibrations, frequency hopping is performed directly. Simultaneously, an unlocking mechanism is set after frequency locking to prevent room temperature runaway. Therefore, this solution uses pipeline stress as the direct control target, which is more accurate and reliable than traditional methods that use ambient temperature as a variable. Through the strategy of prioritizing active compensation and graded intervention, the usable compressor frequency is preserved to the maximum extent, reducing room temperature fluctuations caused by frequency hopping and improving user comfort. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the steps of a vibration control method for an air conditioning compressor piping system according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the monitoring points of the pipeline system in Embodiment 2 of the vibration control device for the air conditioning compressor pipeline system of the present invention.

[0030] The reference numerals in the accompanying drawings include:

[0031] 1. Compressor discharge port; 2. First bend of compressor discharge pipe; 3. Second bend of compressor discharge pipe; 4. Compressor suction port; 5. First bend of compressor suction pipe; 6. Second bend of compressor suction pipe; 7. First bend of condenser connection pipe; 8. Second bend of condenser connection pipe; 9. First bend of shut-off valve connection pipe. Detailed Implementation

[0032] The present invention will be further described in detail below through specific embodiments:

[0033] The specific implementation process is as follows:

[0034] Example 1

[0035] Example 1 is attached. Figure 1 As shown, a vibration control method for an air conditioning compressor piping system includes:

[0036] Data acquisition and modeling steps: Strain gauges are placed at multiple preset monitoring points in the air conditioning compressor piping system, and the pipeline vibration stress values ​​at each monitoring point are collected under different operating conditions; the compressor suction and discharge pressure difference ΔP and operating frequency f under the operating conditions are used as input features, and the vibration state level determined based on the pipeline vibration stress values ​​is used as the output label to train a vibration prediction model.

[0037] Online prediction steps: When the air conditioner is actually running, the current intake and exhaust pressure difference ΔP_current and the current operating frequency f_current are collected in real time and input into the vibration prediction model to obtain the current vibration state level;

[0038] The graded control steps are as follows: Vibration suppression operation is performed according to the current vibration state level, and the vibration suppression operation includes active compensation control and / or frequency avoidance control;

[0039] The active compensation control includes: applying a reverse compensation current of a predetermined amplitude to the compressor motor; and after applying the reverse compensation current, re-executing the online prediction step or directly acquiring the pipeline vibration stress value; if the vibration state level obtained again is not reduced to the preset target level compared with before the application, then increasing the amplitude of the reverse compensation current and / or executing frequency avoidance control.

[0040] The frequency avoidance control includes: prohibiting operation at the current frequency point, or switching the current operating frequency to a preset safe frequency.

[0041] Specifically, this invention first arranges strain gauges at multiple preset monitoring points in the air conditioning compressor piping system. In this embodiment, the multiple preset monitoring points include nine points: compressor discharge port 1, compressor discharge pipe first bend 2, compressor discharge pipe second bend 3, compressor suction port 4, compressor suction pipe first bend 5, compressor suction pipe second bend 6, condenser connecting pipe first bend 7, condenser connecting pipe second bend 8, and shut-off valve connecting pipe 9. The strain gauges are attached as follows: at the suction and discharge ports, the strain gauges are attached 3mm from the pipe opening, perpendicular to the direction of the line connecting the suction and discharge ports; at each bend, the strain gauges are attached to the inside of the bend.

[0042] Then, the pipeline vibration stress values ​​at each monitoring point were collected under different operating conditions. In this embodiment, the compressor suction and discharge pressure difference ΔP and the compressor operating frequency f were used as operating condition variables. The range of the pressure difference ΔP covers the actual operating pressure range of the compressor. For example, for a 98-displacement rotary compressor used in a 1.5 HP air conditioner, the suction pressure range is 0.5MPa~1.2MPa, the discharge pressure range is 1.5MPa~3.8MPa, and the corresponding pressure difference ΔP range is 0.5MPa~3.3MPa. Multiple ΔP values ​​were collected at 0.2MPa intervals. Under each ΔP value, the compressor was controlled to sweep from the starting frequency f_start=10Hz to the ending frequency f_end=110Hz, with a frequency interval of 1Hz. The pipeline vibration stress value at each of the nine measuring points was recorded under each combination of ΔP and f.

[0043] The vibration state is divided into four levels based on preset stress thresholds: normal level (stress values ​​at all measuring points ≤ 13 MPa); slight vibration level (stress values ​​at at least one measuring point > 13 MPa and ≤ 18 MPa); relatively large vibration level (stress values ​​at least one measuring point > 18 MPa and ≤ 25 MPa); and fracture risk level (stress values ​​at least one measuring point > 25 MPa). In this embodiment, the vibration state level is the level corresponding to the maximum stress value among the nine measuring points.

[0044] Using ΔP and f as input features and the corresponding vibration state level (normal / slight / significant / fracture) as output labels, a vibration prediction model is trained using the Support Vector Machine (SVM) algorithm. After training, three identical prototypes are randomly selected, and the stress values ​​at various measuring points within the range of ΔP from 0.5 MPa to 3.3 MPa and frequency from 10 Hz to 110 Hz are tested using the data acquisition method described above. The results are then compared with the model's predictions, with an accuracy requirement greater than 95%. If this is not met, the training sample size is increased until the accuracy requirement is satisfied.

[0045] Then, online prediction is performed. After the air conditioner is actually installed and running in the user's environment, the suction pressure and discharge pressure are obtained in real time through pressure sensors set at the compressor suction port 4 and the compressor discharge port 1, and the current suction and discharge pressure difference ΔP_current is calculated; at the same time, the current operating frequency f_current is read from the compressor controller. ΔP_current and f_current are input into the aforementioned trained vibration prediction model, and the model outputs the current vibration state level.

[0046] Then, based on the current vibration state level output by the model, the corresponding vibration suppression operation is performed.

[0047] In the first scenario, the model output level is normal. At this time, the controller does not perform any vibration suppression operations, the compressor operates according to the conventional inverter strategy, and there is no compensation current injection.

[0048] In the second scenario, the model output level is either slight vibration or significant vibration. In this case, the controller performs active compensation control, applying a reverse compensation current to the compressor motor. The amplitude of the compensation current is defined as a percentage of the compressor motor's rated current. In this embodiment, the rated current is I_rated. For slight vibration, a compensation current with an amplitude of 50% × I_rated is applied; for significant vibration, a compensation current with an amplitude of 100% × I_rated is applied. The phase of the compensation current is opposite to the phase of the compressor's excitation force. It is superimposed on the original drive current through a vector control algorithm, generating a reverse electromagnetic torque to counteract the pipeline vibration energy.

[0049] After applying the compensation current, this embodiment executes a closed-loop verification process: a 0.5-second delay (waiting for the electromechanical system to stabilize), followed by re-execution of the online prediction step, i.e., re-collecting the current ΔP_current and f_current, inputting them into the model to obtain a new vibration state level. If the new level decreases to the preset target level compared to before application (e.g., from slight to normal, or from large to slight or normal), the current compensation current is maintained, allowing for dynamic adjustment based on level changes. If the new level does not decrease (e.g., still slight or large), the following incremental strategy is executed: for slight vibration levels, the compensation current amplitude is increased to 75% × I_rated; for large vibration levels, if it remains large after 100% compensation, frequency avoidance control is further implemented. Simultaneously, if the level decreases to slight but not normal after 100% compensation, compensation can be maintained and timing monitoring can be initiated.

[0050] Regarding frequency locking and unlocking: When performing active compensation control, the controller temporarily locks the current operating frequency to prevent frequency changes from causing compensation detuning. However, this lock is not permanent, and this embodiment sets unlocking conditions. Unlocking is triggered when any of the following conditions are met: a predetermined time has elapsed since the locking time, for example, 5 minutes; three consecutive re-predicted vibration state levels are all normal; the user changes the set temperature via remote control, causing a significant change in load demand. After unlocking, the compressor frequency resumes normal PID regulation, and the new frequency is used to re-predict the level and determine whether to continue compensation.

[0051] In the third scenario, the model output level is fracture risk. In this case, the controller directly executes frequency avoidance control, i.e., frequency hopping, prohibiting operation at the current frequency and switching the compressor frequency to a preset safe frequency (e.g., 30Hz). An alarm signal may also be issued.

[0052] Furthermore, to ensure the feasibility of defining amplitudes such as 50% and 100%, this embodiment performs calibration tests before shipment: Under laboratory conditions, the compressor is operated under typical vibration conditions (e.g., ΔP = 2.5 MPa, f = 70 Hz, measured pipeline stress of 22 MPa, which is considered a relatively high vibration level), and the reverse compensation current is gradually increased, recording the changes in pipeline stress values. When the compensation current reaches 100% of the rated current, the stress value drops below 15 MPa (normal level). Therefore, 100% compensation current is determined to be the maximum effective value, and 50% is the half-rated value. This calibration data is stored in the air conditioning controller.

[0053] Example 2

[0054] Example 2 is attached. Figure 2 As shown, a vibration control device for an air conditioning compressor piping system is disclosed. The device includes a strain gauge assembly, a pressure sensor, and a controller.

[0055] Specifically, the strain gauge assembly consists of multiple strain gauges, which are respectively attached to multiple preset monitoring points on the compressor piping system. Specifically, nine strain gauges are attached to the compressor discharge port, the first bend 2 of the compressor discharge pipe, the second bend 3 of the compressor discharge pipe, the compressor suction port, the first bend 5 of the compressor suction pipe, the second bend 6 of the compressor suction pipe, the first bend 7 of the condenser connection pipe, the second bend 8 of the condenser connection pipe, and the first bend 9 of the shut-off valve connection pipe. At the suction and discharge ports, the strain gauges are attached 3mm from the pipe opening, perpendicular to the direction of the line connecting the suction and discharge ports; at each bend, the strain gauges are attached to the inside of the bend.

[0056] Two pressure sensors are used: one installed on the compressor suction port 4 pipe and the other on the compressor discharge port 1 pipe, for real-time acquisition of suction and discharge pressures. The sensor types are silicon piezoresistive or ceramic capacitive, with an accuracy of ±0.5%FS.

[0057] The controller employs a microcontroller (MCU) or a digital signal processor (DSP), and its built-in memory stores a computer program that executes the method described in Embodiment 1 when run. The controller also includes a motor drive module capable of generating a reverse compensation current and superimposing it onto the drive signal; and a communication module for exchanging frequency commands and temperature setpoints with the air conditioning main control board.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A vibration control method for an air conditioning compressor piping system, characterized in that, include: Data acquisition and modeling steps: Strain gauges are placed at multiple preset monitoring points in the air conditioning compressor piping system, and the pipeline vibration stress values ​​at each monitoring point are collected under different operating conditions. Using the compressor intake and exhaust pressure difference ΔP and operating frequency f in the aforementioned operating conditions as input features, and the vibration state level determined based on the pipeline vibration stress value as the output label, a vibration prediction model is trained. Online prediction steps: When the air conditioner is actually running, the current intake and exhaust pressure difference ΔP_current and the current operating frequency f_current are collected in real time and input into the vibration prediction model to obtain the current vibration state level; The graded control steps are as follows: Vibration suppression operation is performed according to the current vibration state level, and the vibration suppression operation includes active compensation control and / or frequency avoidance control; The active compensation control includes: applying a reverse compensation current of a predetermined amplitude to the compressor motor; and after applying the reverse compensation current, re-executing the online prediction step or directly acquiring the pipeline vibration stress value; if the vibration state level obtained again is not reduced to the preset target level compared with before the application, then increasing the amplitude of the reverse compensation current and / or executing frequency avoidance control. The frequency avoidance control includes: prohibiting operation at the current frequency point, or switching the current operating frequency to a preset safe frequency.

2. The vibration control method for an air conditioning compressor piping system according to claim 1, characterized in that: In the hierarchical control steps, when the compressor frequency is locked due to the execution of active compensation control, an unlocking condition is also set; when the unlocking condition is met, the frequency lock is released, allowing the compressor frequency to change with load demand.

3. The vibration control method for an air conditioning compressor piping system according to claim 2, characterized in that: The unlocking conditions include at least one of the following: The predetermined time has elapsed since the locking time; The re-predicted vibration state level remains below the preset threshold for a predetermined time. The user-set temperature has changed.

4. The vibration control method for an air conditioning compressor piping system according to claim 1, characterized in that: The magnitude of the reverse compensation current is defined as a percentage of the compressor motor's rated current, or as a ratio relative to a preset maximum allowable compensation current.

5. The vibration control method for an air conditioning compressor piping system according to claim 1, characterized in that: The vibration state level is determined by comparing the maximum pipeline vibration stress value at multiple monitoring points with one or more preset stress thresholds.

6. The vibration control method for an air conditioning compressor piping system according to claim 1, characterized in that: The vibration prediction model is trained using one of the following algorithms: support vector machine, neural network, or linear regression.

7. The vibration control method for an air conditioning compressor piping system according to claim 1, characterized in that: The multiple preset monitoring points include multiple or all of the following points: compressor exhaust port, compressor exhaust pipe bend, compressor suction port, compressor suction pipe bend, condenser connection pipe bend, and shut-off valve connection pipe bend.

8. The vibration control method for an air conditioning compressor piping system according to claim 7, characterized in that: The exhaust pipe bends include a first bend and a second bend; the intake pipe bends include a first bend and a second bend; the condenser connection pipe bends include a first bend and a second bend; and the shut-off valve connection pipe bends include a first bend. Furthermore, the strain gauges are attached at a distance of 3mm from the pipe opening at both the compressor intake and exhaust ports, with the attachment direction perpendicular to the line connecting the intake and exhaust ports. At the pipe bends, the strain gauges are attached on the inside of the bend.

9. A vibration control device for an air conditioning compressor piping system, characterized in that, include: The strain gauge array is arranged at multiple preset monitoring points in the compressor piping system to collect the pipeline vibration stress value; Pressure sensors are installed at the compressor's intake and exhaust ports to collect intake and exhaust pressures. The controller is configured to perform the method as described in any one of claims 1 to 8.

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