Wide-temperature-range noise reduction control device and method for variable-frequency rotary compressor

Abstract

The invention discloses a wide-temperature-range noise reduction control device and method for a variable-frequency rotary compressor, and relates to the technical field of compressors. According to the method, under the wide-temperature-range working condition, the environment temperature is collected through a temperature sensor, and the environment temperature is divided into a low-temperature range, a medium-temperature range and a high-temperature range; calculating load coefficients by combining operation parameters such as exhaust pressure and motor current, and dividing the load coefficients into high, medium and low load grades; and differential noise reduction strategies are executed according to different temperature domain-load combination scenes, specifically, the oil supply pressure is dynamically adjusted during high load in a low-temperature domain, the preset resonant frequency is avoided during conventional load in a medium-temperature domain, and the carrier frequency and the modulation mode of variable frequency driving are optimized during low load in the high-temperature domain. Wide-temperature-range all-working-condition accurate noise reduction is achieved, the operation stability of the compressor under the extreme temperature and the complex load is improved, the noise reduction problem that the compressor is difficult to adapt to the all-temperature-range working condition in the prior art is solved, and the use comfort of a user is improved.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more specifically to a wide-temperature-range noise reduction control device and method for a variable frequency rotary compressor. Background Technology

[0002] Variable frequency rotary compressors are widely used in air conditioning, heat pumps and other refrigeration and heating equipment due to their advantages such as high efficiency, energy saving and stable operation. However, the actual operating environment temperature of the compressor is wide (e.g. -30℃ to 70℃), and the noise generation mechanism is significantly different under different temperature ranges: In low temperature environments, the viscosity of the lubricating oil increases, leading to poor lubrication. Under high load, the rotor vibration intensifies, generating strong mechanical noise. Under normal medium temperature conditions, the compressor is prone to structural resonance noise due to the operating frequency falling into the resonance range. In high temperature environments, the electromagnetic interference of the variable frequency drive system increases when operating at low load, and electromagnetic noise becomes the main noise source.

[0003] In existing technologies, compressor noise reduction solutions are mostly designed for a single temperature range or a specific noise type, without considering the impact of temperature range changes on the noise generation mechanism. They are difficult to adapt to complex operating conditions over a wide temperature range. When the compressor is running under extreme temperature and complex load combinations, the noise reduction effect of existing solutions drops significantly, and may even lead to reduced compressor operating stability due to improper control strategies, affecting equipment lifespan and user experience.

[0004] Therefore, it is necessary to propose a wide-temperature-range noise reduction control device and method for variable frequency rotary compressors to solve the above problems. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The purpose of this invention is to solve the problem of noise reduction in existing technologies that are difficult to adapt to all temperature range operating conditions, and to achieve accurate noise reduction under different temperature range and load combination scenarios. This invention provides a wide temperature range noise reduction control device and method for variable frequency rotary compressors.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0009] A wide-temperature-range noise reduction control device and method for a variable frequency rotary compressor, the method comprising: during the operation of the compressor, real-time acquisition of ambient temperature data, determining the current temperature range according to a preset temperature range division rule, wherein the temperature range includes a low temperature range, a medium temperature range and a high temperature range, wherein the low temperature range is ≤-10℃, the medium temperature range is -10℃<T<45℃, and the high temperature range is ≥45℃;

[0010] The compressor's operating parameters are collected, including discharge pressure, suction pressure, motor current, and operating frequency. Based on these operating parameters, a load factor is calculated, and a load level is determined according to the load factor. The load levels include high load, normal load, and low load, where high load is defined as a load factor ≥ 70%, normal load as 30% < load factor < 70%, and low load as a load factor ≤ 30%.

[0011] Based on the combination of the current temperature range and load level, the corresponding noise reduction control strategy is executed; if it is a low temperature range high load scenario, the oil supply pressure of the compressor is dynamically adjusted, and the oil supply pressure adjustment value is positively correlated with the load coefficient.

[0012] For a medium-temperature range normal load scenario, obtain the compressor's current operating frequency, query the preset resonant frequency library, and if the current operating frequency falls within the resonant frequency range, adjust the operating frequency to the preset safe frequency range and maintain it for the set duration.

[0013] For high-temperature, low-load scenarios, optimize the carrier frequency and modulation method of the frequency converter drive module. The carrier frequency increases in a stepwise manner as the ambient temperature rises, and the modulation method is switched to space vector pulse width modulation.

[0014] Furthermore, the load factor K is calculated using the following formula:

[0015]

[0016] in, This is the actual exhaust pressure. This is the actual inhalation pressure. Rated exhaust pressure, The rated intake pressure, This represents the actual motor current. This is the rated motor current.

[0017] Furthermore, under low-temperature, high-load conditions, the oil supply pressure adjustment value ΔP is calculated using the following formula:

[0018] in, For load factor, The rated reference temperature for the low-temperature range. This represents the actual ambient temperature.

[0019] Furthermore, the preset resonant frequency library is obtained through experimental calibration, including the inherent resonant frequency points and continuous resonant frequency segments of the compressor in different temperature ranges. The interval between the safe frequency range and the resonant frequency range is not less than 5Hz. The setting time is dynamically adjusted according to the load factor. The larger the load factor, the shorter the setting time, with a minimum of not less than 10s.

[0020] Furthermore, in the high-temperature low-load scenario, the carrier frequency optimization rule is as follows: when 45℃≤T<55℃, the carrier frequency is set to 10kHz; when 55℃≤T<65℃, the carrier frequency is set to 15kHz; when T≥65℃, the carrier frequency is set to 20kHz; before switching the modulation mode, the motor winding temperature needs to be detected. If the winding temperature exceeds 85℃, the carrier frequency is reduced by 5kHz before switching the modulation mode.

[0021] Furthermore, the method also includes: real-time detection of the compressor's vibration acceleration and noise decibel value; if the vibration acceleration exceeds a preset threshold or the noise decibel value exceeds a preset standard, an emergency noise reduction mode is activated, the operating frequency is adjusted to the lowest safe frequency, and the oil supply pressure is increased to the maximum value, maintaining the emergency state until the vibration and noise return to the normal range.

[0022] Furthermore, the ambient temperature data is collected by dual temperature sensors located at the compressor intake and the outer casing, and the average value of the two is taken as the actual ambient temperature, with a collection period of 1 second; the collection period for the operating parameters is 0.5 seconds, and the judgment period for the load level is 5 seconds.

[0023] A wide-temperature-range noise reduction control device for a variable-frequency rotary compressor, and a method for implementing the device, characterized in that the device comprises:

[0024] The temperature range identification module includes dual temperature sensors and a temperature range division unit, which is used to collect ambient temperature data and determine the current temperature range.

[0025] The load detection module, including a pressure sensor, a current sensor, and a load calculation unit, is used to collect compressor operating parameters and calculate the load factor to determine the load level.

[0026] The multi-dimensional control module includes a scene matching unit, a parameter calculation unit, and a strategy generation unit, which are used to generate corresponding noise reduction control commands based on the combination of temperature range and load level.

[0027] The execution unit, including the oil supply regulating valve and the frequency converter drive module, is used to receive control commands and perform corresponding adjustment operations.

[0028] (III) Beneficial Effects

[0029] The beneficial effects of this invention are as follows:

[0030] 1. This invention, through the collaborative identification of temperature range and load, designs differentiated noise reduction strategies for different combination scenarios, covering the entire temperature range from low to high temperature and the full range of high, medium and low loads, thus solving the problem of poor adaptability of existing solutions.

[0031] 2. This invention addresses two core noise sources: structural resonance and electromagnetic interference. By adjusting multiple parameters such as oil supply pressure, operating frequency, and carrier frequency, it achieves precise noise reduction with significant results.

[0032] 3. This invention, while reducing noise, also takes into account the lubrication effect, motor characteristics and structural strength under different temperature conditions, avoiding operational failures caused by noise reduction alone and extending the service life of the compressor. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please refer to Figure 1. A wide-temperature-range noise reduction control method for a variable frequency rotary compressor includes the following core steps:

[0036] Temperature range and load collaborative identification: The ambient temperature is collected by dual temperature sensors (the average temperature of the intake port and the outer casing is taken to improve detection accuracy), and the temperature range is divided into three zones: low temperature range (≤-10℃), medium temperature range (-10℃<T<45℃), and high temperature range (≥45℃). The operating parameters such as exhaust pressure, intake pressure, and motor current are collected, and the load coefficient is calculated based on the multi-parameter fusion formula to divide the load into three levels: high, medium, and low, so as to achieve accurate positioning of the working condition.

[0037] Differentiated noise reduction strategy implementation:

[0038] Low temperature range and high load: At low temperatures, the lubricating oil has high viscosity and poor fluidity. By dynamically adjusting the oil supply pressure, the lubrication effect and vibration noise can be improved.

[0039] Medium-temperature range conventional load: Resonance noise is most prominent in this scenario. Based on the experimentally calibrated resonance frequency library, the operating frequency is monitored in real time. Once it falls into the resonance range, it is immediately adjusted to a safe frequency range and maintained for the set duration to avoid resonance.

[0040] High temperature and low load: Under high temperature and low load conditions, the motor hysteresis loss increases and electromagnetic noise becomes significant. By stepping up the carrier frequency and switching to space vector pulse width modulation, electromagnetic interference and electromagnetic noise can be reduced.

[0041] Emergency noise reduction protection: Real-time monitoring of vibration acceleration and noise decibel levels. When the preset threshold is exceeded, the emergency mode is activated to quickly adjust the operating parameters to a safe state and ensure stable operation of the compressor.

[0042] The corresponding wide-temperature-range noise reduction control device includes a temperature range identification module, a load detection module, a multi-dimensional control module, and an execution unit:

[0043] Temperature range identification module: It consists of dual temperature sensors and a temperature range division unit. The dual sensors collect the temperature of the air intake and the outer casing respectively, and take the average value to improve the detection accuracy. The temperature range division unit outputs the current temperature range signal according to preset rules.

[0044] Load detection module: includes a pressure sensor, a current sensor and a load calculation unit. The pressure sensor detects the exhaust and intake pressure, the current sensor collects the motor current, and the load calculation unit calculates the load factor and determines the load level based on a preset formula.

[0045] Multi-dimensional control module: The core control unit includes a scene matching unit, a parameter calculation unit, and a strategy generation unit. The scene matching unit combines and matches temperature ranges with load levels. The parameter calculation unit calculates specific adjustment parameters based on the matching results. The strategy generation unit outputs corresponding control commands.

[0046] The multi-dimensional control module adopts an embedded architecture design. The hardware is based on a high-performance MCU, coupled with signal processing circuits, storage units, and communication interfaces. The software layer includes three major functional sub-units, each with a clear division of labor and working collaboratively.

[0047] Scene matching unit: The core data fusion and judgment module is responsible for receiving real-time data from the temperature range identification module and the load detection module, and accurately classifying the working conditions and scenarios.

[0048] Parameter calculation unit: Based on preset algorithms, formulas and calibration rules, it calculates the noise reduction control parameters for the corresponding scenario to ensure the accuracy of the adjustment.

[0049] Strategy generation unit: Based on the scenario type and calculated control parameters, it generates standardized control commands and receives feedback data from the execution unit to achieve closed-loop calibration.

[0050] The execution unit includes an oil supply regulating valve and a variable frequency drive module, which respectively perform operations such as adjusting the oil supply pressure and optimizing the carrier frequency and modulation method. Existing variable frequency rotary compressors generally have built-in gear pumps or screw oil pumps, and the oil circuit system has reserved adjustment interfaces. The oil supply regulating valve in this solution is a solenoid valve that can be directly connected in series between the oil pump outlet and the key lubrication parts. There is no need to modify the compressor body design structure; only a small solenoid valve and pressure feedback element need to be added.

[0051] Example 1: Noise Reduction Control in High-Load Scenarios in Low-Temperature Ranges (≤-10℃)

[0052] This embodiment is designed for high-load scenarios in the low-temperature range where T≤-10℃ and load factor K≥70%. In this scenario, the core noise source is mechanical vibration noise, which is caused by poor lubrication and uneven rotor force due to increased lubricating oil viscosity.

[0053] Initialization settings: preset low temperature threshold, high load threshold; low temperature rated reference temperature T_rated_low = -10℃; oil supply pressure adjustment formula parameters; emergency thresholds are vibration acceleration ≥3m / s² and noise ≥60dB.

[0054] Data Acquisition: The temperature range identification module collects temperature data once per second through dual temperature sensors set at the intake port and the outer casing, and takes the average value as the actual ambient temperature T_loop; the load detection module collects the exhaust pressure P_exhaust, intake pressure P_intake, and motor current I_actual every 0.5 seconds, and at the same time obtains the current operating frequency of the compressor, and calculates the K value based on the load coefficient formula.

[0055] Operating condition identification: T ring = -25℃ was detected, K = 85% was calculated, and the scene matching unit determined it to be a "low temperature domain high load" scene.

[0056] Noise reduction strategy execution:

[0057] Oil supply pressure adjustment: According to the formula ΔP=K×0.05×(T_rated_low-T_ring), substituting the data, we get ΔP=85%×0.05×(-10-(-25))=0.6375MPa. The multi-dimensional control module sends a command to the oil supply regulating valve to increase the oil supply pressure by 0.6375MPa, thereby improving the fluidity of the lubricating oil at low temperatures and reducing mechanical friction.

[0058] Emergency response and effectiveness verification: Real-time monitoring of vibration acceleration and noise. In the initial state, the vibration acceleration was 4.5 m / s² and the noise was 72 dB. Within 10 seconds after the strategy was implemented, the vibration acceleration dropped to 2.8 m / s² and the noise dropped to 58 dB, meeting the normal operation standards.

[0059] Example 2: Noise Reduction Control in Conventional Load Scenarios in the Mid-Temperature Range

[0060] This embodiment is for a conventional load scenario in the medium temperature range of -10℃ < T < 45℃ and 30% < K < 70%. In this scenario, the core noise source is structural resonance noise, which is caused by the operating frequency falling into the inherent resonance range.

[0061] Initialization settings: preset mid-temperature range threshold and normal load threshold; preset resonant frequency library calibrated through experiments, exclusive to mid-temperature range: resonant frequency points 25Hz and 38Hz, continuous resonant frequency range 55-60Hz; safe frequency range is 20-23Hz, 40-53Hz, and 62-65Hz; set duration adjustment, the larger the regular load coefficient, the shorter the duration, with a minimum of 10s.

[0062] Data acquisition: The temperature identification module uses dual sensors to collect temperature and take the average value; the load detection module collects pressure and current parameters and calculates the load factor K; at the same time, the current operating frequency f of the compressor is collected in real time.

[0063] Operating condition identification: T ring = 30℃ was detected, K = 55% was calculated, and it was determined to be a "medium temperature range normal load" scenario.

[0064] Noise reduction strategy execution:

[0065] Frequency monitoring and determination: Real-time monitoring of the current operating frequency f=58Hz, querying the resonant frequency database, it was found that 58Hz falls within the continuous resonant frequency range of 55-60Hz.

[0066] Frequency adjustment and duration setting: Based on the safe frequency range, adjust the operating frequency to 63Hz; combined with the load factor K=55%, set the maintenance duration to 30s to avoid the compressor staying in the resonance range.

[0067] Effect verification: The noise level was 65dB before adjustment, and dropped to 55dB within 3 seconds after adjustment. No resonance phenomenon was observed during the 30-second period.

[0068] Example 3: Noise Reduction Control in High-Temperature Low-Load Scenarios

[0069] This embodiment is for a high-temperature, low-load scenario where T≥45℃ and K≤30%. In this scenario, the core noise source is electromagnetic noise, which is caused by the increased hysteresis loss of the motor and the enhanced electromagnetic interference under high temperature and low load.

[0070] Initialization settings: preset high temperature threshold, low load threshold; carrier frequency step rule: 45℃≤T<55℃ corresponds to 10kHz, 55℃≤T<65℃ corresponds to 15kHz, T≥65℃ corresponds to 20kHz; modulation mode switching conditions; motor winding temperature monitoring threshold.

[0071] Data acquisition: The temperature range identification module collects the ambient temperature and takes the average value T_ring; the load detection module collects pressure and current parameters and calculates the K value; at the same time, it monitors the motor winding temperature.

[0072] Operating condition identification: T ring temperature was detected at 65℃, K was calculated to be 20%, and the scenario was determined to be "high temperature domain low load"; the motor winding temperature was detected at 78℃, which met the conditions for modulation mode switching.

[0073] Noise reduction strategy execution:

[0074] Carrier frequency optimization: According to the step rule, T-ring=65℃ corresponds to a carrier frequency of 20kHz. The multi-dimensional control module sends a command to the frequency conversion drive module to increase the carrier frequency from the default 5kHz to 20kHz, thereby reducing the intensity of electromagnetic interference.

[0075] Modulation mode switching: Since the winding temperature does not exceed 85℃, the modulation mode is directly switched from sinusoidal pulse width modulation to space vector pulse width modulation to optimize the motor magnetic field distribution and reduce electromagnetic noise caused by hysteresis loss.

[0076] Special case handling: If the T-ring temperature is detected to be 60℃ and the winding temperature is 88℃, the carrier frequency is first reduced by 5kHz. After the winding temperature drops below 85℃, the modulation mode is switched and the carrier frequency is increased to 15kHz.

[0077] Effect verification: Before the strategy was implemented, the electromagnetic noise was 60dB. After implementation, the noise dropped to 52dB within 5 seconds. If the ambient temperature dropped to 50℃, the carrier frequency was automatically adjusted to 10kHz to maintain the noise at around 53dB, ensuring stable noise reduction effect across the entire range of high temperature and low load.

[0078] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for wide-temperature-range noise reduction of a variable frequency rotary compressor, characterized in that: The method includes: during the operation of the compressor, real-time acquisition of ambient temperature data, and determination of the current temperature range according to a preset temperature range division rule. The temperature range includes a low temperature range, a medium temperature range, and a high temperature range, wherein the low temperature range is ≤-10℃, the medium temperature range is -10℃<T<45℃, and the high temperature range is ≥45℃. The compressor's operating parameters are collected, including discharge pressure, suction pressure, motor current, and operating frequency. Based on these operating parameters, a load factor is calculated, and a load level is determined according to the load factor. The load levels include high load, normal load, and low load, where high load is defined as a load factor ≥ 70%, normal load as 30% < load factor < 70%, and low load as a load factor ≤ 30%. Based on the combination of the current temperature range and load level, the corresponding noise reduction control strategy is executed; if it is a low temperature range high load scenario, the oil supply pressure of the compressor is dynamically adjusted, and the oil pressure adjustment value is positively correlated with the load coefficient. For a medium-temperature range normal load scenario, obtain the compressor's current operating frequency, query the preset resonant frequency library, and if the current operating frequency falls within the resonant frequency range, adjust the operating frequency to the preset safe frequency range and maintain it for the set duration. For high-temperature, low-load scenarios, optimize the carrier frequency and modulation method of the frequency converter drive module. The carrier frequency increases in a stepwise manner as the ambient temperature rises, and the modulation method is switched to space vector pulse width modulation.

2. The wide-temperature-range noise reduction method for a variable frequency rotary compressor according to claim 1, characterized in that: The load factor K is calculated using the following formula: in, This is the actual exhaust pressure. This is the actual inhalation pressure. Rated exhaust pressure, The rated intake pressure, This represents the actual motor current. This is the rated motor current.

3. The wide-temperature-range noise reduction method for a variable frequency rotary compressor according to claim 1, characterized in that: In low-temperature, high-load scenarios, the oil supply pressure adjustment value ΔP is calculated using the following formula: in, For load factor, The rated reference temperature for the low-temperature range. This represents the actual ambient temperature.

4. The wide-temperature-range noise reduction method for a variable frequency rotary compressor according to claim 1, characterized in that: The preset resonant frequency library is obtained through experimental calibration and includes the inherent resonant frequency points and continuous resonant frequency segments of the compressor in different temperature ranges. The interval between the safe frequency range and the resonant frequency range is not less than 5Hz. The setting time is dynamically adjusted according to the load factor. The larger the load factor, the shorter the setting time, with a minimum of not less than 10s.

5. A wide-temperature-range noise reduction method for a variable frequency rotary compressor according to claim 1, characterized in that: In the high-temperature, low-load scenario, the carrier frequency optimization rule is as follows: when 45℃≤T<55℃, the carrier frequency is set to 10kHz; when 55℃≤T<65℃, the carrier frequency is set to 15kHz; when T≥65℃, the carrier frequency is set to 20kHz. Before switching the modulation mode, the motor winding temperature needs to be detected. If the winding temperature exceeds 85℃, the carrier frequency is reduced by 5kHz before switching the modulation mode.

6. The wide-temperature-range noise reduction method for a variable frequency rotary compressor according to claim 1, characterized in that: The method also includes: real-time detection of the compressor's vibration acceleration and noise decibel value. If the vibration acceleration exceeds the preset threshold or the noise decibel value exceeds the preset standard, an emergency noise reduction mode is activated, the operating frequency is adjusted to the lowest safe frequency, and the oil supply pressure is increased to the maximum value to maintain the emergency state until the vibration and noise return to the normal range.

7. A wide-temperature-range noise reduction method for a variable-frequency rotary compressor according to claim 1, characterized in that: The ambient temperature data is collected by dual temperature sensors located at the compressor intake and the outer casing, and the average value of the two is taken as the actual ambient temperature. The collection period is 1 second. The collection period for the operating parameters is 0.5 seconds, and the judgment period for the load level is 5 seconds.

8. A wide-temperature-range noise reduction control device for a variable-frequency rotary compressor according to claim 1, used to implement the method of any one of claims 1 to 7, characterized in that, The device includes: The temperature range identification module includes dual temperature sensors and a temperature range division unit, which is used to collect ambient temperature data and determine the current temperature range. The load detection module, including a pressure sensor, a current sensor, and a load calculation unit, is used to collect compressor operating parameters and calculate the load factor to determine the load level. The multi-dimensional control module includes a scene matching unit, a parameter calculation unit, and a strategy generation unit, which are used to generate corresponding noise reduction control commands based on the combination of temperature range and load level. The execution unit, including the oil supply regulating valve and the frequency converter drive module, is used to receive control commands and perform corresponding adjustment operations.

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