Method for optimizing vibration of single-rotor compressor of air conditioner

Abstract

The invention mainly relates to the technical field of air conditioner control. The invention provides a method for optimizing the vibration of a single-rotor compressor of an air conditioner, and aims to optimize the vibration characteristics of the single-rotor compressor by controlling the torque compensation current of the full frequency band of the operation frequency of the compressor. Assembling a model machine, performing stress and vibration acceleration test on a pipeline of a compressor of the model machine, adding a balance weight, segmenting the compressor frequency of the model machine, and loading different components of a maximum torque compensation current value to the compressor added with the balance weight for each frequency band; and the maximum torque compensation current component value corresponding to the minimum stress value of the corresponding frequency band is obtained and serves as the actual torque compensation current of the corresponding frequency band to be loaded to the compressor, the torque compensation control frequency upper limit is released from about 43 Hz, the maximum running frequency of the compressor is achieved, and the vibration strength of the compressor at different running frequencies is reduced.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of air conditioner control, and particularly relates to a method for optimizing the vibration of a single-rotor compressor of an air conditioner. Background Art

[0002] For common household air conditioners on the market at present, especially air conditioners with a capacity below 2HP, due to fierce price competition in the market, the overall machine cost is restricted. The compressors used are basically low-cost single-rotor compressors. The advantage of this single rotor is simple structure and low cost. However, compared with piston-type or turbo compressors and double-rotor compressors, its main disadvantages are large vibration and noise.

[0003] In view of the defect of large vibration of the single-rotor compressor, the common control measures in the industry mainly include two parts. One is to optimize the design of the four-way valve pipeline connected to it, conduct simulation design on the combined body of the compressor and the pipeline, reduce the pipeline mode, reduce the displacement stress brought by the compressor vibration to the pipeline, and improve the pipeline reliability. This measure has a certain effect. However, under the inherent characteristic of large low-frequency vibration of the compressor, relying on pipeline simulation constraints has limited effect, and constraints are also needed in the compressor drive control. The commonly used technical means in the industry at present is to apply a torque compensation current to the compressor in the low-frequency band of the compressor to restrain and suppress the low-frequency vibration of the compressor.

[0004] In the prior art, from the perspective that torque loading control technology will increase power consumption when applying torque compensation, it mainly focuses on low-frequency torque loading control measures to avoid optimization control technologies such as compressor out-of-step shutdown caused by sudden change or too fast loading. For example, the patent document with the patent number CN202410076187.7 discloses a control method, device and air conditioner for a single-rotor compressor of an air conditioner. Its core idea is: adjust the torque compensation shunt control coefficient according to the change of the outdoor ambient temperature in the low-frequency band of the compressor to improve low-frequency vibration noise; the patent document with the patent number CN202310764317.1 discloses a compressor frequency control method, device, equipment and storage medium. Its core idea is: when compensating the low-frequency torque of the compressor, predict the time difference between the torque compensation applied when the compressor frequency drops and the pressure stability, so that the torque-loaded compressor is not protected; the patent document with the patent number CN202110121455.9 discloses a control method for an air conditioner compressor and an air conditioner. Its core idea is: through the low-frequency torque loading control speed loop of the compressor and adjusting the torque compensation amount, prevent sudden change of the compressor torque. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to provide a method for optimizing the vibration of a single-rotor compressor of an air conditioner, aiming to optimize the vibration characteristics of the single-rotor compressor by controlling the torque compensation current in the full frequency band of the compressor operating frequency.

[0006] The technical solution adopted by the present invention to solve the above technical problems:

[0007] A method for optimizing the vibration of a single-rotor compressor of an air conditioner, comprising:

[0008] Step 1: Simulate the compressor pipeline of the prototype with the minimization of the pipeline stress and vibration acceleration of the compressor as the simulation target;

[0009] Step 2: Assemble the compressor pipeline of the prototype based on the simulation results, and conduct full-frequency stress and vibration acceleration tests on the compressor pipeline of the prototype in the state without loading torque compensation current. Add counterweights according to the difference between the test results and the simulated minimum stress and vibration acceleration;

[0010] Step 3: Segment the compressor frequency of the prototype, and apply different components of the maximum torque compensation current value to the compressor with added counterweights for each frequency band respectively. Obtain the corresponding maximum torque compensation current component value when the pipeline stress and vibration acceleration of the compressor are minimized in the corresponding frequency band as the actual torque compensation current for the corresponding frequency band;

[0011] Step 4: When the prototype is running, apply the corresponding actual torque compensation current to the compressor for different frequency bands respectively.

[0012] Further, the acquisition of the pipeline stress and vibration acceleration of the compressor includes: arranging strain gauges and vibration meters at the compressor suction port, the first bending position of the suction pipe, the compressor discharge port, and the first bending position of the discharge pipe respectively, and detecting the stress and vibration acceleration at the corresponding positions.

[0013] Further, the acquisition of the pipeline stress and vibration acceleration of the compressor also includes: arranging vibration meters at the compressor liquid storage tank and the compressor cylinder block to detect the vibration acceleration at the corresponding positions.

[0014] Further, the method also includes Step 5: When the prototype is running, if the pipeline stress and vibration acceleration in the corresponding frequency band do not meet the set requirements after applying the corresponding actual torque compensation current to the compressor, return to Step 1 to re-simulate the compressor pipeline, and repeat Steps 2 and 3 to re-obtain the actual torque compensation current for the corresponding frequency band.

[0015] Further, the method also includes Step 6: Optimize the size and counterweight of the compressor pipeline based on the actual torque compensation current corresponding to each frequency band.

[0016] Further, when the operating frequency of the compressor is less than 50 Hz, the actual torque compensation current value is 100% of the maximum torque compensation current. When the operating frequency of the compressor is 50 - 60 Hz, the actual torque compensation current is 20% of the maximum torque compensation current value. When the operating frequency of the compressor is 60 - 100 Hz, the actual torque compensation current is 10% of the maximum torque compensation current value.

[0017] Advantages of the present invention:

[0018] A method for optimizing the vibration of a single-rotor compressor in an air conditioner according to the present invention optimizes the torque compensation current for the entire frequency band of the operating frequency of the single-rotor compressor by means of frequency-segmented loading of the torque compensation current, breaks through the existing upper limit of the torque compensation control frequency, releases the current upper limit of the torque compensation control frequency from about 43 Hz, and reaches the maximum operating frequency of the compressor at the highest, reduces the vibration intensity of the compressor at different operating frequencies, makes the compressor operate more smoothly, and also reduces the power consumption of the compressor, thereby improving the quality of the air conditioner product. And based on the actual torque compensation current in different frequency bands, the size and weight of the compressor pipeline are optimized to reduce the production cost of the air conditioner and improve the core competitiveness of the air conditioner product. Description of the drawings

[0019] Figure 1 It is a schematic diagram of the installation positions of the strain gauges and vibration meters;

[0020] A - Compressor liquid storage tank, B - Compressor cylinder block, 110 - Compressor suction port, 111 - First bend of the suction pipe, 112 - Compressor exhaust port, 113 - First bend of the exhaust pipe, 114 - Four-way valve pipeline. Detailed implementation manners

[0021] A method for optimizing the vibration of a single-rotor compressor in an air conditioner according to the present invention includes the following steps:

[0022] Step 1: In the air conditioner product development stage, first design and draw the pipeline of the compressor four-way valve assembly, use a pipeline finite element simulation tool such as ANSYS software to simulate the pipeline, theoretically reduce the modes of the compressor and the pipeline, and minimize the pipeline stress and vibration acceleration obtained by simulation;

[0023] Step 2: Assemble a sample unit based on the simulation results, and then conduct outdoor unit noise and pipeline stress tests; such as Figure 1As shown, it includes, but is not limited to, arranging vibration meters at the compressor liquid storage tank A and the compressor cylinder block B to test the acceleration at the corresponding positions, and arranging strain gauges on the compressor four-way valve pipeline 114 to test the stress and strain of the pipeline. The specific positions are the compressor suction port 110, the first bend of the suction pipe 111 (the bend closest to the compressor on the suction pipe), the compressor discharge port 112, the first bend of the discharge pipe 113 (the bend closest to the compressor on the discharge pipe), and the second bend of the suction pipe and the discharge pipe (the next bend closest to the first bend on the suction pipe or the discharge pipe), etc. Test the vibration acceleration and stress at the corresponding positions of the compressor pipeline in the state of no torque compensation current in the full frequency band, and check whether the stress and vibration acceleration of the pipeline are consistent with the minimum stress and vibration acceleration in the simulation of step 1. Combine the test situation to further determine whether to add counterweight blocks and the number of counterweight blocks.

[0024] Step 3: In this step, the maximum torque compensation current component loading mechanism will be determined. The maximum torque compensation current of a single-rotor compressor with a capacity less than or equal to 2HP is generally 10 - 15A. Divide the compressor frequency of the prototype into segments. Load 100% torque compensation current below (including) the set frequency a, and for the remaining frequency bands, start from 10% of the torque compensation current according to the compressor frequency division result, and load the torque compensation current to the compressor by increasing 10% each time. Observe and record the acceleration and stress values at the corresponding positions through the vibration meter and strain gauge, and synchronously record the core parameters such as the power, current, and phase current of the compressor to evaluate the effect of the maximum torque compensation component loading.

[0025] Step 4: After the above maximum torque compensation current component loading test verification is completed, analyze the pipeline stress data and the compressor vibration acceleration data, and compare them with the stress and acceleration data obtained in step 2 without loading torque compensation current in each frequency band to determine the effect of the torque compensation current. Maybe the effect will be better when loading 20% or 30% of the maximum torque compensation current in a certain frequency band, maybe the effect will be better when loading 10% of the maximum torque compensation current in a certain high-frequency band, or maybe there is no effect or the effect becomes worse after loading the torque compensation current in a certain frequency band. If there are still stress or acceleration exceeding the standard and being unqualified in a certain frequency band or multiple frequency bands after the analysis in step 4 is completed, then enter step 5; if both the stress and vibration acceleration are qualified after the analysis in step 4 is completed, then enter step 6.

[0026] Step 5: Return to step 1 to re-design and optimize the pipeline simulation, and repeat steps 2, 3, and 4 to conduct actual measurements of the pipeline stress and vibration acceleration and verify the maximum torque compensation current component loading to determine the final actual torque compensation current in each medium and high-frequency band, ensuring that when the compressor operates according to the corresponding frequency bands, the stress and vibration acceleration of the compressor pipeline are minimized.

[0027] Step 6: After increasing the number of prototype machines to verify consistency, solidify the torque current compensation component loading mechanism and apply it to product mass production. Further evaluate the effect of the determined full-frequency torque compensation current component, and repeat Steps 1 to 5 to determine whether to reduce the pipeline size or the weight of the counterweight to achieve cost reduction.

[0028] Example: In this example, a 1HP variable-frequency single-rotor compressor product of a certain brand model is selected to illustrate and verify a method for optimizing the vibration of an air-conditioning single-rotor compressor described in the present invention.

[0029] Install strain gauges and vibration meters according to the positions of the strain gauges and vibration meters described in Step 2. From the principle and experimental demonstration, it can be determined that during the actual torque compensation current loading process of the compressor, the actual vibration acceleration of the compressor is consistent with the trend of the pipeline displacement stress. Therefore, only the pipeline stress data are listed in this experimental data.

[0030] In this example, when the compressor operates at five operating frequencies of 50Hz, 60Hz, 70Hz, 80Hz, and 100Hz, the stress at different positions in the compressor pipeline is detected according to no torque compensation current loading, 10% maximum torque compensation current loading, 20% maximum torque compensation current loading, and 30% maximum torque compensation current loading. The results are shown in Table 1. At the same time, the comparison data of the compressor power current under each torque compensation current value are also detected, and the detection results are shown in Table 2.

[0031] Table 1 Comparison data of stress under maximum torque compensation current component loading

[0032]

[0033] Table 2 Comparison data of power current under maximum torque compensation current component loading

[0034]

[0035]

[0036] From the statistical data in Table 1 and Table 2, it can be seen that when the compressor operating frequency is 50 - 60Hz (including 60Hz), when 20% of the maximum torque compensation current is loaded as the actual torque compensation current for the compressor, the stress of the compressor pipeline is the smallest, and the power, current, and phase current are all the lowest; when the compressor operating frequency is 60 - 100Hz, when 10% of the maximum torque compensation current is loaded as the actual torque compensation current for the compressor, the stress of the compressor pipeline is the smallest, and the power, current, and phase current are all the lowest.

Claims

1. A method for optimizing the vibration of a single-rotor compressor of an air conditioner, characterized in that: include: Step 1: Simulate the compressor pipeline of the prototype machine with the minimization of compressor pipeline stress and vibration acceleration as the simulation goal; Step 2: Assemble the prototype compressor pipeline based on the simulation results, perform full-band stress and vibration acceleration tests on the prototype compressor pipeline without loading the torque compensation current, and add counterweights according to the difference between the test results and the simulated minimum stress and vibration acceleration; Step 3: Divide the compressor frequency of the prototype into segments, and load different components of the maximum torque compensation current value to the compressor after adding the counterweight for each frequency band, and obtain the maximum torque compensation current component value corresponding to the corresponding frequency band when the compressor pipeline stress and vibration acceleration are minimum as the actual torque compensation current of the corresponding frequency band; Step 4: When the prototype is running, the corresponding actual torque compensation current is loaded to the compressor for different frequency bands.

2. A method for optimizing vibration of a single-rotor compressor of an air conditioner according to claim 1, characterized in that: The acquisition of compressor pipeline stress and vibration acceleration includes: arranging strain gauges and vibration meters at the compressor suction port, the first bend of the suction pipe, the compressor exhaust port and the first bend of the exhaust pipe, respectively, to detect the stress and vibration acceleration at the corresponding positions.

3. A method for optimizing vibration of a single-rotor compressor of an air conditioner according to claim 2, characterized in that: The acquisition of compressor pipeline stress and vibration acceleration also includes: arranging vibration meters at the compressor liquid storage tank and the compressor cylinder body to detect the vibration acceleration at corresponding positions.

4. A method for optimizing vibration of a single-rotor compressor of an air conditioner according to any one of claims 1 to 3, characterized in that: The method also includes step 5: when the prototype is running, if the corresponding frequency band stress and vibration acceleration do not meet the set requirements after the corresponding actual torque compensation current is loaded into the compressor, return to step 1 to re-simulate the compressor pipeline, and repeat steps 2 and 3 to re-acquire the actual torque compensation current of the corresponding frequency band.

5. A method for optimizing vibration of a single-rotor compressor of an air conditioner according to claim 4, characterized in that: The method further comprises step 6: optimizing the size and counterweight of the compressor pipeline based on the actual torque compensation current corresponding to each frequency band.

6. A method for optimizing vibration of a single-rotor compressor of an air conditioner according to any one of claims 1 to 3, characterized in that: When the compressor operating frequency is less than 50Hz, the actual torque compensation current value is 100% of the maximum torque compensation current; when the compressor operating frequency is 50-60Hz, the actual torque compensation current is 20% of the maximum torque compensation current value; when the compressor operating frequency is 60-100Hz, the actual torque compensation current is 10% of the maximum torque compensation current.

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