Range hood noise reduction system and noise reduction method for realizing impedance control through corona discharge

Abstract

The invention relates to the technical field of kitchen purification equipment, and provides a range hood noise reduction system and noise reduction method for realizing impedance control through corona discharge, and the range hood noise reduction system comprises a high-voltage power supply device, a corona impedance matching sound absorption module, and a signal processing and control module. The corona impedance matching sound absorption module comprises a corona discharge device and a sound pressure monitoring device. A sound absorption cavity is formed in the corona discharge device, and the sound pressure monitoring device is arranged on the side close to the turbofan and used for detecting sound pressure signals of the corona discharge device after noise reduction. The sound pressure monitoring device and the high-voltage power supply device are in electric signal connection with the signal processing and control module, and the corona discharge device is connected with the high-voltage power supply device. The signal processing and control module carries out data processing on the sound pressure signal to obtain a voltage parameter signal, and the high-voltage power supply device outputs a corresponding voltage according to the voltage parameter signal to carry out corona discharge and controls charged particles in the electric field to move to generate sound pressure. The defect that the passive sound absorption low-frequency effect is poor is overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of kitchen purification equipment, and in particular to a range hood noise reduction system that achieves impedance control through corona discharge. The present invention also relates to a noise reduction method for a range hood noise reduction system that achieves impedance control through corona discharge. Background Art

[0002] Range hoods have become an essential appliance in most homes. While they effectively remove cooking fumes and ensure clean kitchen air, they inevitably generate noise during operation. This not only hinders communication but also poses health risks to those exposed to the noise over a long period of time. When range hood noise exceeds 70dB, users tend to lower the setting or shut it off prematurely, reducing suction power and increasing the diffusion of fumes, compromising the need for clean indoor air.

[0003] In the prior art, in order to reduce or suppress the operating noise of the range hood, porous plates, sound-absorbing cotton or a combination of the two are used to absorb and reduce noise. This passive noise reduction method is less effective at low frequencies and the overall noise reduction level is relatively low.

[0004] Active noise reduction is also used to reduce range hood noise. This type of noise reduction system typically uses one or more speakers to generate sound waves with the same amplitude and opposite phase as the range hood noise signal, leveraging the principle of destructive interference to achieve noise reduction. Active noise reduction, based on the principle of destructive interference, can only achieve localized noise reduction, and may even increase noise in some areas, resulting in poor overall noise reduction. Summary of the Invention

[0005] In view of this, the present invention aims to propose a range hood noise reduction system that realizes impedance control through corona discharge, realizes noise reduction in the entire space through impedance matching, and avoids the defect of poor low-frequency effect of passive sound absorption.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A range hood noise reduction system that achieves impedance control through corona discharge, comprising a high-voltage power supply device, a corona impedance matching sound absorption module, and a signal processing and control module;

[0008] The corona impedance matching sound absorption module includes a corona discharge device and a sound pressure monitoring device;

[0009] A sound absorbing cavity is formed in the corona discharge device, and the sound pressure monitoring device is arranged on a side close to the turbine blower to detect the sound pressure signal after the noise of the corona discharge device is reduced;

[0010] The sound pressure monitoring device and the high-voltage power supply device are both electrically connected to the signal processing and control module, and the corona discharge device is connected to the high-voltage power supply device;

[0011] The signal processing and control module processes the sound pressure signal to obtain a voltage parameter signal;

[0012] The high-voltage power supply device outputs a corresponding voltage according to the voltage parameter signal to perform corona discharge and control the movement of charged particles in the electric field to generate sound pressure.

[0013] Furthermore, the corona impedance matching sound absorption module is arranged on the inner wall surface of the range hood housing on both sides of the turbine fan;

[0014] The two corona impedance matching sound absorption modules are respectively arranged at the air inlets on both sides of the turbine fan.

[0015] Furthermore, the corona discharge device includes an insulating frame connected to the inner wall surface, a first grounding electrode provided in the insulating frame, and a high-voltage electrode connected to the insulating frame;

[0016] The sound pressure monitoring device is arranged at one end of the insulating frame.

[0017] Furthermore, the high-voltage electrode includes a plurality of spaced and parallel metal wires, the insulating frame is formed with a groove with an open end, and the first grounding electrode includes a metal plate fixed to the open end of the groove, and the metal plate is formed with a plurality of through holes;

[0018] The through hole is connected to the groove, the diameter of the through hole is 3 mm, and the porosity is 40%.

[0019] Furthermore, the distance between the high-voltage electrode and the first grounding electrode is 6 mm, and the high-voltage electrode is made of nickel-chromium alloy wire.

[0020] Furthermore, the groove and the metal plate form the sound absorption cavity, and the size of the sound absorption cavity is 20cmx25cmx2.2cm;

[0021] The sound pressure monitoring module is arranged between the air inlet of the turbine blower and the sound absorbing cavity.

[0022] Furthermore, the signal processing and control module includes a signal acquisition unit and a signal conversion unit, and the signal conversion unit includes an A / D conversion circuit, a processor and a D / A conversion circuit.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] The range hood noise reduction system of the present invention realizes impedance control through corona discharge. By setting a sound pressure monitoring device of the corona impedance matching sound absorption module, the sound pressure when the range hood turbine fan and the sound absorption module are synchronously turned on is measured and a sound pressure signal is obtained. The sound pressure signal is transmitted to the signal processing and control module for data processing. The data is transmitted to the high-voltage power supply device through calculation via a voltage parameter signal. The high-voltage power supply device controls the output of high-voltage direct current and high-voltage alternating current according to the above-mentioned voltage parameters. The high-voltage power supply device controls the corona discharge device to discharge, ionizes the movement of charged particles generated by the air, so that the acoustic impedance of the surface of the sound absorption module is close to or matches the acoustic impedance of the surrounding air. The noise generated by the turbine fan will not be reflected or penetrated after entering the sound absorption module, and the sound energy will be consumed in the sound absorption cavity in the form of heat energy, mechanical vibration, etc.

[0025] Another object of the present invention is to provide a range hood noise reduction method that achieves impedance control through corona discharge. Using the range hood noise reduction system described above, the noise reduction steps are as follows:

[0026] Step S1: The range hood is turned on, and the noise generated by the turbine fan propagates to both sides. The sound pressure monitoring device measures the sound pressure signal after the noise is reduced by the corona impedance matching sound absorption module, and transmits the sound pressure signal to the signal processing and control module.

[0027] Step S2, the signal processing and control module performs data processing according to the sound pressure signal, and outputs the obtained data to the high-voltage power supply device;

[0028] Step S3: applying the high voltage output by the high voltage power supply device to the high voltage electrode of the corona discharge module; the high voltage power supply device includes a second grounding electrode, and the second grounding electrode is electrically connected to the first grounding electrode.

[0029] Furthermore, step S2 includes the following steps:

[0030] S21, converting the sound pressure signal into a digital signal through an A / D conversion circuit;

[0031] S22, data processing through ZYNQ or DSP processor;

[0032] S23, calculating the required voltage parameters using the transfer function θ(k) and the sound pressure signal;

[0033]

[0034] Among them, C in the expressions of F0 and h0 is the characteristic parameter of the corona discharge module, U0 is the corona onset voltage, and these two parameters can be obtained by measuring its volt-ampere curve and fitting it; S is the area of ​​the corona discharge module, μi is the ion mobility, d is the distance between the positive and negative electrodes of the corona discharge, and UDC is the DC voltage applied to the high-voltage electrode;

[0035] x0 is the distance from the sound pressure monitoring microphone to the center of the high and low voltage poles of the corona discharge module, l is the distance from the inner wall of the sound absorption cavity to the center of the high and low voltage poles of the corona discharge module, T0 is the ambient temperature, Cp is the specific heat of air at constant pressure, c is the speed of sound, R is the reflection coefficient of the sound absorption cavity when the corona discharge is not turned on, ρ is the air density, Ztg is the target impedance, and Zac is the impedance generated by the corona impedance matching sound absorption module at x0;

[0036] S33, converting the voltage parameter calculated in step S23 into an analog signal through a D / A conversion circuit, and outputting the analog signal to the high-voltage power supply device.

[0037] Furthermore, in step S3, the high-voltage power supply device controls the output of high-voltage direct current and high-voltage alternating current according to the analog signal obtained in step S2, and the high-voltage alternating current with a high-voltage direct current bias is connected to the high-voltage electrode. The voltage of the high-voltage direct current is maintained between 8kV and 9kV, the voltage of the high-voltage alternating current is between 100 and 1000Vpp, and the frequency is in the range of 50 to 2000Hz.

[0038] Compared with the existing active noise reduction technology based on acoustic interference cancellation, the range hood noise reduction method of the present invention, which realizes impedance control through corona discharge, can achieve noise reduction in a large space, overcome the defect of local area noise reduction in the existing technology, and at the same time does not produce the defect of poor low-frequency noise reduction effect of passive sound-absorbing materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 This is a schematic diagram of a range hood noise reduction system that implements impedance control through corona discharge according to an embodiment of the present invention installed on a range hood;

[0041] Figure 2 is a three-dimensional schematic diagram of a corona discharge device according to an embodiment of the present invention;

[0042] Figure 3 This is a three-dimensional schematic diagram of the corona discharge device according to the embodiment of the present invention without the first grounding electrode.

[0043] Description of reference numerals:

[0044] 1. High-voltage power supply device; 2. Corona impedance matching sound absorption module; 3. Signal processing and control module; 4. Upper housing; 5. Turbine fan;

[0045] 201. Corona discharge device; 202. Sound pressure monitoring device;

[0046] 2011, sound absorption cavity; 2012, insulation frame; 2013, first grounding electrode; 2014, high-voltage electrode;

[0047] 20131, through hole. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0049] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," and "back" and other terms indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] Furthermore, in the description of the present invention, unless otherwise expressly defined, the terms "mounted," "connected," "connect," and "connector" should be interpreted broadly. For example, these terms may refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will appreciate the specific meanings of these terms in the present invention based on the specific circumstances.

[0051] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0052] This embodiment relates to a range hood noise reduction system that realizes impedance control through corona discharge. As a whole, Figure 1As shown, the noise reduction system includes a high-voltage power supply device 1, a corona impedance matching sound absorption module 2, and a signal processing and control module 3. The corona impedance matching sound absorption module 2 includes a corona discharge device 201 and a sound pressure monitoring device 202. A sound absorption cavity 2011 is formed in the corona discharge device 201, and the sound pressure monitoring device 202 is arranged on a side close to the turbine blower 5 for detecting the sound pressure signal of the corona discharge device 201. The sound pressure monitoring device 202 and the high-voltage power supply device 1 are both electrically connected to the signal processing and control module 3, and the corona discharge device 201 is electrically connected to the high-voltage power supply device 1. The signal processing and control module 3 processes the sound pressure signal to obtain a voltage parameter signal. The high-voltage power supply device 1 outputs a corresponding voltage according to the voltage parameter signal to perform corona discharge and control the movement of charged particles in the electric field to generate sound pressure.

[0053] Therefore, in this embodiment, a sound pressure monitoring device 202 is provided in the corona impedance matching sound absorption module 2 to measure the sound pressure when the range hood turbine fan and the sound absorption module are synchronously turned on and obtain a sound pressure signal. The sound pressure signal is transmitted to the signal processing and control module 3 for data processing. The data is transmitted to the high-voltage power supply device 1 through calculation via a voltage parameter signal. The high-voltage power supply device 1 controls the output of high-voltage direct current and high-voltage alternating current according to the above-mentioned voltage parameters. The high-voltage power supply device 1 controls the corona discharge device 201 to discharge, ionizes the movement of charged particles generated by the air, and makes the acoustic impedance of the surface of the sound absorption module close to or matches the acoustic impedance of the surrounding air. The noise generated by the turbine fan will not be reflected or penetrated after entering the sound absorption module, and the sound energy will be consumed in the sound absorption cavity 2011 in the form of heat energy, mechanical vibration, etc.

[0054] Based on the above overall introduction, if Figure 1 As shown, the turbo fan 5 is disposed within the inner cavity of the range hood upper housing. In this embodiment, the turbo fan 5 employs a dual-sided air inlet configuration. Therefore, two corona impedance matching sound absorption modules 2 are disposed opposite each other at the air inlets on either side of the turbo fan 5. The corona impedance matching sound absorption modules 2 are disposed on the inner wall of the range hood housing on either side of the turbo fan 5. The noise reduction system is disposed within the inner cavity of the range hood upper housing 4, with the turbo fan 5 positioned in the middle of the inner cavity.

[0055] As Figure 1 As shown, the dotted lines represent electrical connections. The two sound pressure monitoring devices 202 are electrically connected to the signal processing and control module 3 via electrical connections. The sound pressure monitoring devices 202 are fixed in front of the corona discharge device 201 by a small insulating member, enabling them to monitor sound pressure fluctuations. The high-voltage power supply unit 1 is electrically connected to the two high-voltage electrodes 2014 via electrical connections.

[0056] In addition, if Figure 1As shown, the high-voltage power supply device 1 and the signal processing and control module 3 are adjacently connected, and the signal processing and control module 3 is fixed on the upper shell of the range hood, reducing the installation distance between the corona impedance matching sound absorption module 2 and the high-voltage power supply device 1 and the signal processing and control module 3, thereby accelerating signal transmission and data transmission speed.

[0057] As a preferred embodiment, Figures 1 to 3 As shown, the corona discharge device 201 includes an insulating frame 2012 connected to the inner wall surface, a first grounding electrode 2013 disposed within the insulating frame 2012, and a high-voltage electrode 2014 connected to the insulating frame 2012. The sound pressure monitoring device 202 is disposed at one end of the insulating frame 2012. The insulating frame 2012 is rectangular and made of insulating material. The insulating frame 2012 is used to secure the high-voltage electrode 2014 and the first grounding electrode 2013. Furthermore, to prevent the sound pressure monitoring device 202 from being affected and interfered with by the high voltage, the sound pressure monitoring device 202 is disposed on one side of the first grounding electrode 2013 of the corona discharge device 201. The first grounding electrode 2013 provides a barrier that provides better interference resistance.

[0058] Furthermore, the high-voltage electrode 2014 includes a plurality of spaced and parallel metal wires. The insulating frame 2012 is formed with a groove with an open end. The first ground electrode 2013 includes a metal plate fixed to the open end of the groove. The metal plate is formed with a plurality of through holes 20131, which communicate with the grooves. The through holes 20131 have a diameter of 3 mm and a porosity of 40%. Preferably, the spacing between the metal wires is 10 mm.

[0059] Preferably, the distance between the high-voltage electrode 2014 and the first grounding electrode 2013 is 6 mm, and the high-voltage electrode 2014 is made of nickel-chromium alloy wire.

[0060] like Figures 1 to 3 As shown, a sound absorbing cavity 2011 is formed between the groove and the metal plate. The size of the sound absorbing cavity 2011 is 20 cm x 25 cm x 2.2 cm. The sound pressure monitoring module is arranged between the air inlet of the turbine fan 5 and the sound absorbing cavity 2011 .

[0061] In addition, the signal processing and control module 3 includes a signal acquisition unit and a signal conversion unit, and the signal conversion unit includes an A / D conversion circuit, a processor, and a D / A conversion circuit. The processor of this embodiment adopts a ZYNQ or DSP processor.

[0062] The basic operating principle of this embodiment is as follows: When the range hood starts operating, the high-voltage power supply 1 also starts operating and drives the corona discharge module. At this time, the sound pressure monitoring device 202 in the corona impedance matching sound absorption module 2 detects a sound pressure signal. This sound pressure signal represents the sound pressure after the range hood and the corona impedance matching sound absorption module 2 work together to reduce noise. This sound pressure signal is then transmitted to the signal processing and control module 3. The sound pressure signal is converted into a digital signal through an A / D conversion circuit. After data processing by a ZYNQ or DSP processor, it is converted into an analog signal through a D / A conversion circuit. The analog signal is then output to the high-voltage power supply 1. The high voltage output of the high-voltage power supply is applied to the filaments, ionizing the surrounding air and generating a large number of charged particles such as free electrons, positive and negative ions. The positive and negative polarity of the alternating current periodically switches, driving the charged particles generated by the ionization to oscillate back and forth in the electric field.

[0063] By setting a distance of 6 mm between the high-voltage electrode 2014 and the first ground electrode 2013 in the sound-absorbing cavity 2011, and processing the measured sound pressure signal through data processing and calculation using the following transfer function formula, the original input sound pressure signal is processed and a specific voltage parameter signal is output to accurately control the working state of the corona discharge module. The acoustic impedance characteristics of the corona impedance matching sound absorption module 2 can be accurately matched and adjusted according to the voltage parameter signal to achieve dynamic regulation of the discharge process, so that the acoustic impedance characteristics are close to or match the acoustic impedance of the surrounding air.

[0064] When the noise waves—or air pressure fluctuations—generated by the range hood's turbine fan 5 propagate to the module's acoustic impedance-matched boundaries, the similar impedances prevent significant reflection at the boundaries. Furthermore, once the sound wave energy enters the module, it is efficiently converted into heat and mechanical vibration energy through complex interactions with oscillating charged particles, such as collisions and friction, and dissipated, significantly reducing noise emanating from the range hood over a large area.

[0065] This embodiment also relates to a range hood noise reduction method that achieves impedance control through corona discharge. The range hood noise reduction method uses the range hood noise reduction system described above, and the noise reduction steps are as follows:

[0066] Step S1: The range hood is turned on, and the noise generated by the turbo fan 5 propagates to both sides. The sound pressure monitoring device 202 measures the sound pressure signal after the noise is reduced by the corona impedance matching sound absorption module 2, and transmits the sound pressure signal to the signal processing and control module 3;

[0067] Step S2: the signal processing and control module 3 processes the sound pressure signal and outputs the obtained data to the high-voltage power supply device 1;

[0068] In step S3 , the high voltage outputted by the high voltage power supply device 1 is applied to the high voltage electrode 2014 of the corona discharge module; the high voltage power supply device 1 includes a second grounding electrode, which is electrically connected to the first grounding electrode 2013 .

[0069] Preferably, step S2 includes the following steps:

[0070] S21, converts the sound pressure signal into a digital signal through an A / D conversion circuit;

[0071] S22, data processing through ZYNQ or DSP processor;

[0072] S23, calculating the required voltage parameters using the transfer function θ(k) and the sound pressure signal;

[0073]

[0074] Among them, C in the expressions of f0 and h0 is the characteristic parameter of the corona discharge module, U0 is the corona onset voltage, and these two parameters can be obtained by measuring its volt-ampere curve and fitting it; S is the area of ​​the corona discharge module, μi is the ion mobility, d is the distance between the positive and negative electrodes of the corona discharge, and U DC is the DC voltage applied to the high voltage electrode;

[0075] x0 is the distance from the sound pressure monitoring microphone to the center of the high and low pressure poles of the corona discharge module, l is the distance from the inner wall of the sound absorption cavity 2011 to the center of the high and low pressure poles of the corona discharge module, T0 is the ambient temperature, Cp is the specific heat capacity of air at constant pressure, c is the speed of sound, R is the reflection coefficient of the sound absorption cavity 2011 when the corona discharge is not turned on, ρ is the air density, Ztg is the target impedance, and Zac is the impedance generated by the plasma at x0;

[0076] S33 , converting the voltage parameter calculated in step S23 into an analog signal through a D / A conversion circuit, and outputting the analog signal to the high-voltage power supply device 1 .

[0077] Furthermore, in step S3, high-voltage power supply device 1 controls the output of high-voltage direct current (HVDC) and high-voltage alternating current (HVAC) based on the analog signal obtained in step S2. The HVAC with a HVDC bias is connected to high-voltage electrode 2014. The HVDC voltage is maintained between 8 kV and 9 kV, while the HVAC voltage is between 100 and 1000 Vpp and the frequency is between 50 and 2000 Hz. The HVAC is primarily used to ionize air to generate charged particles, and the HVAC is used to control the direction of movement of the charged particles.

[0078] Through the above introduction, the noise reduction steps can be summarized as follows: after the range hood is turned on, the noise generated by the turbine fan 5 propagates to both sides. After the sound pressure monitoring device 202 measures the sound pressure in front of the corona impedance matching sound absorption module 2, it is transmitted to the signal processing and control module 3 for data processing, and is converted into a voltage parameter signal for controlling the corona discharge module through a transfer function. The voltage parameter signal is output to the high-voltage power supply device 1 through the signal processing and control module 3.

[0079] The high-voltage power supply device 1 controls the output of high-voltage direct current and high-voltage alternating current according to the input signal, and the high-voltage alternating current with high-voltage direct current bias is connected to the high-voltage electrode 2014 of the corona discharge device 201, and the second grounding electrode of the high-voltage power supply device 1 is connected to the first grounding electrode 2013 of the corona discharge device 201.

[0080] The insulating frame 2012 and the corona discharge device 201 in the working state together constitute an impedance matching absorption module. The impedance of the entire corona impedance matching sound absorption module 2 is close to the acoustic impedance of air, thereby absorbing the range hood noise. The noise transmitted from the turbine fan 5 of the range hood will not be reflected or penetrated after reaching the corona impedance matching sound absorption module 2. The sound energy is dissipated in the corona impedance matching sound absorption module 2 in the form of heat energy, mechanical vibration, etc.

[0081] Compared with the existing active noise reduction technology based on acoustic interference cancellation, the range hood noise reduction method of this embodiment, which uses corona discharge to achieve impedance control, can achieve noise reduction in a large space, overcome the defects of local area noise reduction in the existing technology, and at the same time will not produce the defect of poor low-frequency noise reduction effect of passive sound-absorbing materials.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A range hood noise reduction system that achieves impedance control through corona discharge, characterized by: It comprises a high-voltage power supply device (1), a corona impedance matching sound absorption module (2), and a signal processing and control module (3); The corona impedance matching sound absorption module (2) comprises a corona discharge device (201) and a sound pressure monitoring device (202); A sound absorbing cavity (2011) is formed in the corona discharge device (201), and the sound pressure monitoring device (202) is arranged on a side close to the turbine blower (5) and is used to detect the sound pressure signal of the corona discharge device (201) after noise reduction; The sound pressure monitoring device (202) and the high-voltage power supply device (1) are both electrically connected to the signal processing and control module (3), and the corona discharge device (201) is connected to the high-voltage power supply device (1); The signal processing and control module (3) performs data processing on the sound pressure signal to obtain a voltage parameter signal; The high-voltage power supply device (1) outputs a corresponding voltage according to the voltage parameter signal to perform corona discharge, and controls the movement of charged particles in the electric field to generate sound pressure.

2. The range hood noise reduction system for achieving impedance control through corona discharge according to claim 1, characterized in that: The corona impedance matching sound absorption module (2) is arranged on the inner wall surface of the range hood housing on both sides of the turbine fan (5); The two corona impedance matching sound absorption modules (2) are respectively arranged at the air inlets on both sides of the turbine fan (5) in an opposite manner.

3. The range hood noise reduction system for achieving impedance control through corona discharge according to claim 2, characterized in that: The corona discharge device (201) comprises an insulating frame (2012) connected to the inner wall surface, a first grounding electrode (2013) disposed in the insulating frame (2012), and a high-voltage electrode (2014) connected to the insulating frame (2012); The sound pressure monitoring device (202) is arranged at one end of the insulating frame (2012).

4. The range hood noise reduction system for achieving impedance control through corona discharge according to claim 3, characterized in that: The high-voltage electrode (2014) comprises a plurality of spaced and parallel metal wires, the insulating frame (2012) is formed with a groove with an open end, and the first grounding electrode (2013) comprises a metal plate fixed to the open end of the groove, and the metal plate is formed with a plurality of through holes (20131); The through hole (20131) is connected to the groove, the diameter of the through hole (20131) is 3 mm, and the porosity is 40%.

5. The range hood noise reduction system for achieving impedance control through corona discharge according to claim 4, characterized in that: The distance between the high-voltage electrode (2014) and the first grounding electrode (2013) is 6 mm, and the high-voltage electrode (2014) is made of nickel-chromium alloy wire.

6. The range hood noise reduction system using corona discharge to achieve impedance control according to claim 5, characterized in that: The groove and the metal plate form the sound absorbing cavity (2011), and the size of the sound absorbing cavity (2011) is 20cmx25cmx2.2cm; The sound pressure monitoring module is arranged between the air inlet of the turbine fan (5) and the sound absorption cavity (2011).

7. The range hood noise reduction system for achieving impedance control through corona discharge according to claim 6, characterized in that: The signal processing and control module (3) comprises a signal acquisition unit and a signal conversion unit, and the signal conversion unit comprises an A / D conversion circuit, a processor and a D / A conversion circuit.

8. A range hood noise reduction method using corona discharge to achieve impedance control, characterized in that: The range hood noise reduction system according to claim 7 is used, and the noise reduction steps are as follows: Step S1, the range hood is turned on, the noise generated by the turbine fan (5) propagates to both sides, the sound pressure monitoring device (202) measures the sound pressure signal after the noise is reduced by the corona impedance matching sound absorption module (2), and transmits the sound pressure signal to the signal processing and control module (3); Step S2, the signal processing and control module (3) performs data processing according to the sound pressure signal, and outputs the obtained data to the high-voltage power supply device (1); Step S3, the high voltage electricity output by the high voltage power supply device (1) is applied to the high voltage electrode (2014) of the corona discharge module; the high voltage power supply device (1) includes a second grounding electrode, and the second grounding electrode is electrically connected to the first grounding electrode (2013).

9. The range hood noise reduction method of realizing impedance control through corona discharge according to claim 8, characterized in that: Step S2 includes the following steps: S21, converting the sound pressure signal into a digital signal through an A / D conversion circuit; S22, data processing through ZYNQ or DSP processor; S23, calculating the required voltage parameters using the transfer function θ(k) and the sound pressure signal; Among them, C in the expressions of f0 and h0 is the characteristic parameter of the corona discharge module, U0 is the corona onset voltage, and these two parameters can be obtained by measuring its volt-ampere curve and fitting it; S is the area of ​​the corona discharge module, μi is the ion mobility, d is the distance between the positive and negative electrodes of the corona discharge, and U DC is the DC voltage applied to the high voltage electrode; x0 is the distance from the sound pressure monitoring microphone to the center of the high and low pressure poles of the corona discharge module, l is the distance from the inner wall of the sound absorption cavity (2011) to the center of the high and low pressure poles of the corona discharge module, T0 is the ambient temperature, Cp is the specific heat capacity of air at constant pressure, c is the speed of sound, R is the reflection coefficient of the sound absorption cavity (2011) when the corona discharge is not turned on, ρ is the air density, Ztg is the target impedance, and Zac is the impedance generated by the corona impedance matching sound absorption module (2) at x0; S33, converting the voltage parameter calculated in step S23 into an analog signal through a D / A conversion circuit, and outputting the analog signal to the high-voltage power supply device (1).

10. The range hood noise reduction method of realizing impedance control through corona discharge according to claim 9, characterized in that: In step S3, the high-voltage power supply device (1) controls the output of high-voltage direct current and high-voltage alternating current according to the analog signal obtained in step S2, and the high-voltage alternating current with a high-voltage direct current bias is connected to the high-voltage electrode (2014). The voltage of the high-voltage direct current is maintained between 8kV and 9kV, and the voltage of the high-voltage alternating current is between 100 and 1000Vpp, and the frequency is within the range of 50 to 2000Hz.

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