WO2020026371A1 - Outdoor unit for air conditioner - Google Patents

Abstract

This outdoor unit for an air conditioner has therein a machine compartment in which a compressor and an expansion valve are mounted. The outdoor unit is provided with: a microphone which is installed in the machine compartment and which measures a sound in the machine compartment; and a control device which, when detecting, by analyzing a signal measured by the microphone, that an abnormal sound has been generated by the compressor and/or the expansion valve, controls one or both of the compressor and the expansion valve which are generating the abnormal sound, thereby reducing the abnormal sound.

Description

Outdoor unit of air conditioner

The present invention relates to an outdoor unit of an air conditioner having a machine room in which refrigerant circuit components such as a compressor and an expansion valve are installed.

In the air conditioner, abnormal noise may be generated from the compressor and the expansion valve. For example, when the compressor is a vane-type compressor, the vane vibrates violently due to the effect of the vortex of the liquid refrigerant generated immediately after startup, which may generate an abnormal sound. In addition, the expansion valve may generate a high frequency abnormal sound due to the following factors. When the refrigerant passes through the expansion valve, a vortex is generated depending on the flow velocity of the refrigerant and the state of the phase of the refrigerant, and a high-frequency abnormal sound is generated by exciting vibration caused by pressure fluctuation due to the vortex.

Conventionally, there is a technology that detects an abnormal sound generated by the air conditioner and controls a device that is a source of the abnormal sound to reduce the abnormal sound (for example, see Patent Document 1). In Patent Literature 1, a microphone is installed near an expansion valve arranged in an indoor unit, and when an abnormal sound is detected, the opening of the expansion valve is adjusted.

JP-A-2003-077445

圧 縮 A compressor and an expansion valve are installed in the machine room of the outdoor unit, and abnormal noise may be generated from both of them as described above. However, Patent Document 1 targets abnormal noise generated from the expansion valve, and cannot deal with abnormal noise generated from the compressor. For this reason, Patent Literature 1 cannot be said to be a sufficient technique for reducing noise generated from the outdoor unit.

The present invention has been made in view of such a point, and an object of the present invention is to provide an outdoor unit of an air conditioner capable of reducing noise generated from the outdoor unit.

An outdoor unit of an air conditioner according to the present invention is an outdoor unit of an air conditioner having a machine room in which a compressor and an expansion valve are mounted, and is installed in the machine room and measures a sound in the machine room. When the abnormal signal is detected from at least one of the compressor and the expansion valve by analyzing the measurement signal of the microphone, one or both of the compressor and the expansion valve where the abnormal sound is generated is detected. And a control device for controlling so as to reduce the pressure.

According to the present invention, when the occurrence of abnormal sound is detected by analyzing the measurement signal of the microphone, one or both of the compressor and the expansion valve are controlled so as to reduce the abnormal sound. Therefore, noise generated from the outdoor unit can be reduced.

FIG. 2 is a schematic perspective view illustrating a configuration of an outdoor unit of the air conditioner according to Embodiment 1 of the present invention. It is the schematic which shows the inside of the machine room of the outdoor unit of FIG. It is a schematic sectional drawing of the compression mechanism of the compressor of FIG. It is a schematic sectional drawing of the expansion valve of FIG. FIG. 9 is a diagram illustrating an example of a result of spectrum analysis of a measurement signal of a microphone. 5 is a flowchart of a noise reduction process in the outdoor unit of the air conditioner according to Embodiment 1 of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG.
FIG. 1 is a schematic perspective view showing the configuration of the outdoor unit of the air conditioner according to Embodiment 1 of the present invention.
The housing 1a of the outdoor unit 1 of the air conditioner is divided into left and right spaces by a separator 5, the left space is a blower room 2, the lower right space is a mechanical room 3, and the upper right space is an electric space. It is an article room 4. The blower chamber 2 has a heat exchanger 6 and a fan 7 mounted thereon. The machine room 3 has a compressor 8 and an expansion valve 9 mounted thereon. The electrical component room 4 is equipped with a control device 11 for controlling the entire air conditioner. The compressor 8, the heat exchanger 6, and the expansion valve 9 mounted in the outdoor unit 1 constitute a refrigerant circuit together with a heat exchanger mounted in an indoor unit (not shown). Cooling or heating of the room is performed by circulating the refrigerant in the room.

マ イ ク ロ A microphone 10 is further mounted in the machine room 3. The microphone 10 is installed at a position at a certain distance from a panel constituting the housing 1 a and at an intermediate position between the compressor 8 and the expansion valve 9. By arranging the microphone 10 at such a position, the microphone 10 can measure the sound generated from each of the compressor 8 and the expansion valve 9. When there are a plurality of expansion valves 9, the microphone 10 is installed at a position where the distance between the compressor 8 and each expansion valve 9 is the same. The microphone 10 is connected to the control device 11 by wiring, and a measurement signal of the microphone 10 is taken into the control device 11.

The control device 11 performs room temperature control such as adjusting the frequency of the compressor 8 and the opening degree of the expansion valve 9 so that the room temperature maintains the set temperature. In addition, the control device 11 performs a noise reduction control for analyzing the measurement signal taken from the microphone 10 and reducing the noise generated from the machine room 3. Details of the noise reduction control will be described later. The control device 11 is configured by, for example, a microcomputer having a CPU (not shown) and a memory 11a. The memory 11a stores data and programs necessary for room temperature control and noise reduction control. Note that a ROM, an EEPROM, a flash memory, or the like is used as the memory 11a, for example.

FIG. 2 is a schematic diagram showing the inside of the machine room of the outdoor unit of FIG.
The sound absorbing material 12 is spread all over the inner wall of the machine room 3 without gaps. The inner wall of the machine room 3 is specifically composed of a separator 5 and other panels, and the sound absorbing material 12 is spread over each of these inner walls, so that the sound outside the outdoor unit 1 is measured by the microphone 10. Not to be.

圧 縮 The compressor 8 and the expansion valve 9 are mounted in the machine room 3 as described above, and an abnormal sound may be generated from these. Hereinafter, the cause of the abnormal sound generated from each of the compressor 8 and the expansion valve 9 will be sequentially described together with the outline of the structures of the compression mechanism 20 and the expansion valve 9 of the compressor 8.

FIG. 3 is a schematic sectional view of a compression mechanism of the compressor of FIG.
The compression mechanism 20 of the compressor 8 includes a cylindrical cylinder 21, a rotor 22 that rotates in the cylinder 21, a vane 24 that slides in a vane groove 23 formed in the cylinder 21, and a vane spring 25. . The vane spring 25 urges the vane 24 so that the tip 24 a of the vane 24 contacts the outer peripheral surface of the rotor 22.

In the compression mechanism 20 configured as described above, the space in the cylinder 21 is partitioned by the vane 24 to form a compression chamber 26, and the volume of the compression chamber 26 is reduced by the rotation of the rotor 22 so that the compression chamber is reduced. The refrigerant in 26 is compressed.

異常 In such a compression mechanism 20, an abnormal sound is generated when the vane 24 vibrates as shown by the arrow in FIG. That is, when the internal pressure of the compression chamber 26 becomes larger than the spring force of the vane spring 25, the vane 24 vibrates. An abnormal sound is generated when the tip portion 24a of the vane 24 separates from or comes into contact with the rotor 22 due to this vibration. In order to prevent the abnormal sound from being generated by such vane vibration, the frequency of the compressor 8 may be increased to stabilize the circulation state of the refrigerant in the refrigerant circuit.

FIG. 4 is a schematic sectional view of the expansion valve of FIG.
The expansion valve 9 is fully closed when the needle 30 is seated on the valve seat 31. In such an expansion valve 9, when the refrigerant that has passed through the gap between the needle 30 and the valve seat 31 generates a vortex 32, a pressure difference occurs around the needle 30, causing the needle 30 to vibrate in an exciting manner, resulting in high vibration. Generates abnormal frequency sound. In order to prevent the abnormal sound from being generated by the excitation vibration, the opening degree of the expansion valve 9 may be increased to reduce the flow velocity of the refrigerant passing through the expansion valve 9.

The first embodiment is characterized by noise reduction control for reducing abnormal noise for both the compressor 8 and the expansion valve 9 mounted in the machine room 3. In the noise reduction control, the measurement signal of the microphone is analyzed to determine whether the source of the abnormal sound is the compressor 8 or the expansion valve 9 or both, and the abnormal sound from the specified source is determined. Control the source to reduce. Hereinafter, a specification principle for specifying a source of abnormal sound from an analysis result of a measurement signal of the microphone 10 will be described.

FIG. 5 is a diagram illustrating an example of a result of spectrum analysis of a measurement signal of the microphone. In FIG. 5, the horizontal axis represents frequency [Hz] and the vertical axis represents sound pressure [dB].
FIG. 5A shows an abnormal sound due to the vane vibration of the compressor 8. (B) shows an abnormal sound caused by valve vibration of the expansion valve 9. As shown in FIG. 5, the frequency of the abnormal sound from the compressor 8 is different from the frequency of the abnormal sound from the expansion valve 9, and the frequency of the abnormal sound from the compressor 8 is higher than the frequency of the abnormal sound from the expansion valve 9. Is also known to be low. The frequency of the abnormal sound from the compressor 8 is about 200 [Hz] in this example, and the frequency of the abnormal sound from the expansion valve 9 is about 2000 [Hz] in this example. The difference between the frequencies of such abnormal sounds is determined, for example, by the analysis result using the outdoor unit 1 in which the abnormal sound is generated only from the compressor 8 and the outdoor unit in which the abnormal sound is generated only from the expansion valve 9. It can be known from the analysis results used.

Therefore, the spectrum of the sound measured by the microphone 10 is analyzed, and within a frequency band including the frequency of the abnormal sound from the compressor 8 (hereinafter, referred to as a first frequency band), the sound pressure is equal to or higher than a preset first threshold sound pressure. When a sound is detected, it can be specified that the source of the abnormal sound is the compressor 8. Similarly, in a frequency band including the frequency of the abnormal sound from the expansion valve 9 (hereinafter, referred to as a second frequency band), when a sound equal to or higher than a preset second threshold sound pressure is detected, the abnormal sound is detected. It can be specified that the generation source is the expansion valve 9. The first frequency band is, for example, 200 ± 10 [Hz]. The second frequency band is, for example, 2000 ± 20 [Hz]. The number of values to be ± may be set in consideration of the variation between units.

Note that the first threshold sound pressure is determined by using an outdoor unit in which an abnormal sound is generated from the compressor 8 in advance to determine what sound pressure of the abnormal sound from the compressor 8 exceeds the sound pressure. What is necessary is just to specify by actual measurement or simulation. Similarly, for the second threshold sound pressure, it is determined in advance how much the sound pressure of the abnormal sound from the expansion valve 9 exceeds the sound pressure, which may impair hearing, by using an outdoor unit in which the abnormal sound from the expansion valve 9 is generated in advance. It may be specified by actual measurement or simulation. In this example, the first threshold sound pressure and the second threshold sound pressure are the same, and both are set to 1100 [dB].

As described above, the first frequency band and the first threshold sound pressure and the second frequency band and the second threshold sound pressure are stored in the memory 11a as the identification information for identifying the source of the abnormal sound. The source of the abnormal sound can be specified using the result and the identification information.

FIG. 6 is a flowchart of a noise reduction process in the outdoor unit of the air conditioner according to Embodiment 1 of the present invention. In the air conditioner, as described above, room temperature control such as adjusting the frequency of the compressor 8 and the opening of the expansion valve 9 is performed to maintain the room temperature at the set temperature. Is performed in parallel with the room temperature control.

音 During operation of the air conditioner, sound in the machine room 3 is measured by the microphone 10, and the measurement signal is taken into the control device 11. Then, the control device 11 analyzes the spectrum of the measurement signal acquired from the microphone 10 (step S1). Based on the result of the spectrum analysis, the control device 11 determines whether or not an abnormal sound exceeding the first threshold sound pressure occurs in the first frequency band (step S2). When the control device 11 determines that an abnormal sound exceeding the first threshold sound pressure is generated in the first frequency band, the control device 11 specifies that the source of the abnormal sound is the compressor 8 and determines the frequency of the compressor 8. Increase by 1 Hz (step S3), and return to step S1. As described above, the control for increasing the frequency of the compressor 8 by 1 Hz is performed until no sound exceeding the first threshold sound pressure is generated in the first frequency band. As a result, the abnormal sound from the compressor 8 is eliminated.

If the control device 11 determines in step S2 that no sound exceeding the first threshold sound pressure has been generated in the first frequency band, then a sound exceeding the second threshold sound pressure will be generated in the second frequency band. Is determined (step S4). If the control device 11 determines that an abnormal sound exceeding the second threshold sound pressure is generated in the second frequency band, the control device 11 specifies that the source of the abnormal sound is the expansion valve 9 and determines the opening of the expansion valve 9. Is opened by one pulse (step S5), and the process returns to step S1. As described above, the control for opening the opening of the expansion valve 9 one pulse at a time is performed until no sound exceeding the second threshold sound pressure is generated in the second frequency band. As a result, the abnormal sound from the expansion valve 9 is eliminated.

Although not shown in the flowchart of FIG. 6, when an abnormal sound exceeding the first threshold sound pressure occurs in the first frequency band, the current frequency of the compressor 8 is the upper limit frequency on the device. In this case, the following control is performed. That is, the frequency is reduced by 1 Hz until the compressor 8 does not generate an abnormal sound. This control is the reverse of the control in step S3, but is intended to eliminate abnormal sounds by changing the current frequency.

When the frequency of the compressor 8 is operating at the upper limit frequency, it can be said that the air conditioning load is high. For this reason, if the frequency is excessively lowered, the air conditioning capacity may be reduced, and indoor comfort may be impaired. Therefore, when the frequency has reached the upper limit frequency, the frequency is lowered with the lower limit frequency being, for example, 80% of the upper limit frequency. In other words, the frequency is reduced by 1 Hz at a time until the compressor 8 does not generate abnormal noise within the range up to the lower limit frequency. Thus, even if the frequency is lowered to the lower limit frequency, it is not impossible that the abnormal sound is not eliminated, but in this case, the comfort in the room is prioritized, and the lower frequency is not lowered. Note that “80%” is an example and is not limited to this value.

The same applies to the opening of the expansion valve 9. When a sound exceeding the second threshold sound pressure is generated in the second frequency band, the opening of the expansion valve 9 is the upper limit opening on the device. The following control is performed. That is, the opening degree of the expansion source is set to a state where no abnormal noise is generated from the expansion valve 9 within the range up to the lower limit opening, with the opening of, for example, 80% of the upper limit opening being the lower limit opening. Lower by one pulse until

According to the above control, no abnormal noise is generated when abnormal noise is generated from one of the compressor 8 and the expansion valve 9 or when abnormal noise is generated from both the compressor 8 and the expansion valve 9. The refrigerant circuit can be settled down. Here, the description has been made assuming that the control of the flowchart in FIG. 6 is always performed during the operation of the air conditioner. However, the abnormal sound is caused when the frequency of the compressor 8 or the opening of the expansion valve 9 is changed. Often occurs at the timing. Therefore, the processing of steps S1 to S5 in FIG. 6 may be performed at a timing when the frequency of the compressor 8 or the opening of the expansion valve 9 is changed by the room temperature control.

As described above, according to the first embodiment, when the measurement signal of the microphone 10 is analyzed and it is detected that at least one of the compressor 8 and the expansion valve 9 generates an abnormal sound, the abnormal sound is generated. One or both of the compressor 8 and the expansion valve 9 are controlled to reduce abnormal noise. For this reason, even if an abnormal noise is generated from either the compressor 8 or the expansion valve 9, the abnormal noise can be reduced, and the noise in the outdoor unit 1 can be reduced.

{Circle around (1)} The control device 11 includes a memory 11a, and in the memory 11a, identification information for specifying the source of the abnormal sound is stored in accordance with the analysis result. The identification information includes first frequency band information indicating a frequency band in which an abnormal sound from the compressor 8 is detected, a first threshold sound pressure, and a second frequency band indicating a frequency band in which an abnormal sound from the expansion valve 9 is detected. The frequency band information and the second threshold sound pressure are included. The control device 11 can specify whether the source of the abnormal sound in the outdoor unit 1 is the compressor 8 or the expansion valve 9 based on the analysis result and the identification information in the memory 11a. Then, the control device 11 controls the generation source so that the specified generation source does not generate an abnormal sound. For this reason, it is possible to reduce noise in the outdoor unit 1.

(4) When the source of the abnormal sound is the compressor 8, the abnormal sound can be eliminated by increasing the frequency of the compressor 8. When the source of the abnormal sound is the expansion valve 9, the abnormal sound can be eliminated by opening the opening of the expansion valve 9.

(4) The identification information in the memory 11a can be updated. That is, it is possible to add and correct a frequency band that specifies the source of the abnormal sound. Therefore, it is possible to promptly respond to a complaint generated in the market. In addition, it is possible to promptly respond to specification changes on the manufacturer side. This will be described below.

In a case where an abnormal sound is generated from a component other than the compressor 8 and the expansion valve 9 in the machine room 3 of the outdoor unit 1 which is shipped and used in the market, the user gives a noise to the manufacturer. A claim enters. Therefore, the manufacturer incorporates control for reducing the new abnormal sound into the control device 11. In this case, the manufacturer investigates the outdoor unit 1 in which the new abnormal sound has occurred, specifies the sound factor, the sound generation frequency band, and the threshold sound pressure that impairs hearing, and avoids the new abnormal sound. Identify controls. Then, the specified content is newly incorporated in the control device 11. Specifically, the memory 11a of the control device 11 additionally stores frequency band information and a threshold sound pressure relating to a frequency band in which a new abnormal sound occurs. This makes it possible to configure the outdoor unit 1 that can avoid new abnormal sounds and can cope with various abnormal sounds and reduce noise. Therefore, from the viewpoint of the manufacturer, it is possible to reduce noise complaints from users.

Also, when the manufacturer changes the expansion valve 9 to a low-cost expansion valve, for example, the structure of the expansion valve 9 changes and the excitation vibration generation region shifts, and the current noise reduction control causes abnormal noise. May not be reduced. In this case, by correcting the second frequency band information set in the memory 11a to frequency band information corresponding to the expansion valve after the specification change, an outdoor sound that can cope with the abnormal sound generated from the expansion valve 9 after the specification change can be dealt with. Unit 1 can be configured. In addition, there may be a case where the frequency of the abnormal sound deviates from the frequency band set in the memory 11a due to a special installation environment or the like. In such a case, such a situation can be dealt with by correcting the frequency band information in the memory 11a so as to widen the frequency band. Incidentally, such correction of the data in the memory 11a may be performed by, for example, the manufacturer.

In addition, in the first embodiment, since the microphone 10 is arranged at a position intermediate between the compressor 8 and the expansion valve 9, it is possible to detect an abnormal sound generated from both the compressor 8 and the expansion valve 9.

誤 Further, by attaching the sound absorbing material 12 to the inner wall of the machine room 3, it is possible to prevent erroneous detection due to external sound.

It should be noted that specific numerical values such as the frequency and the sound pressure in the first embodiment are merely examples, and they are numerical values calculated based on abnormal sounds confirmed during actual use of the outdoor unit on the user side. It may be used.

1 outdoor unit, 1a housing, 2 blower room, 3 mechanical room, 4 electrical equipment room, 5 separator, 6 heat exchanger, 7 fan, 8 compressor, 9 expansion valve, 10 microphone, 11 control device, 11a memory, 12 sound absorbing material, 20 compression mechanism, 21 cylinder, 22 rotor, 23 vane groove, 24 vane, 24a tip, 25 vane spring, 26 compression chamber, 30 needle, 31 valve seat, 32 vortex.

Claims (10)

An outdoor unit of an air conditioner having a machine room equipped with a compressor and an expansion valve therein,
A microphone that is installed in the machine room and measures sound in the machine room,
When detecting that an abnormal sound has occurred from at least one of the compressor and the expansion valve by analyzing the measurement signal of the microphone, one or both of the compressor and the expansion valve in which the abnormal sound is occurring And a control device for controlling the abnormal sound to reduce the abnormal sound. The control device includes a memory that stores identification information that specifies a source of the abnormal sound in accordance with the analysis result of the measurement signal, and when the occurrence of the abnormal sound is detected, the analysis result and the memory The outdoor of an air conditioner according to claim 1, wherein a source of the abnormal sound is specified to be the compressor or the expansion valve based on the identification information in the inside, and the specified source is controlled. unit. The identification information includes first frequency band information and a first threshold sound pressure indicating a frequency band of an abnormal sound generated from the compressor, and second frequency band information indicating a frequency band of an abnormal sound generated from the expansion valve. And a second threshold sound pressure,
The control device, when detecting a sound exceeding the first threshold sound pressure in a first frequency band indicated by the first frequency band information, specifies that the source is the compressor, and determines the second frequency The outdoor unit of an air conditioner according to claim 2, wherein when a sound exceeding the second threshold sound pressure is detected within a second frequency band indicated by the band information, the generation source is identified as the expansion valve. The outdoor unit of an air conditioner according to any one of claims 1 to 3, wherein the control device increases a frequency of the compressor when a source of the abnormal sound is the compressor. The outdoor unit of an air conditioner according to claim 4, wherein the control device increases the frequency of the compressor until an abnormal sound is not generated from the compressor. The outdoor unit of an air conditioner according to any one of claims 1 to 5, wherein the control device increases the degree of opening of the expansion valve when the source of the abnormal sound is the expansion valve. 7. The outdoor unit of an air conditioner according to claim 6, wherein the control device increases the degree of opening of the expansion valve until an abnormal sound is not generated from the expansion valve. The outdoor unit of an air conditioner according to any one of claims 3 to 7, wherein the identification information in the memory is updatable. The outdoor unit of an air conditioner according to any one of claims 1 to 8, wherein the microphone is installed at a position between the compressor and the expansion valve. The outdoor unit of the air conditioner according to any one of claims 1 to 9, wherein a sound absorbing material is attached to an inner wall of the machine room.

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