US20200049364A1

US20200049364A1 - Degradation diagnosis device and air-conditioning device

Info

Publication number: US20200049364A1
Application number: US16/488,462
Authority: US
Inventors: Takaharu Nakamura; Nobuaki Tanaka
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2017-04-26
Filing date: 2017-04-26
Publication date: 2020-02-13
Also published as: CN110573737A; WO2018198221A1; JPWO2018198221A1

Abstract

A degradation diagnosis device that diagnoses whether or not a compressor is abnormal includes a current detector configured to detect electric current and output electric-current information being information of a power current supplied to the compressor; a vibration detector configured to detect vibration of the compressor and output vibration information being information of the vibration of the compressor every set measurement period; an arithmetic unit connected with the current detector and the vibration detector and configured to diagnose whether or not the compressor is abnormal using the electric-current information inputted by the current detector and the vibration information inputted by the vibration detector; and a notification unit configured to give notification about a result of diagnosis as to whether or not the compressor is abnormal.

Description

TECHNICAL FIELD

The present invention relates to a degradation diagnosis device for a compressor as well as to an air-conditioning device.

BACKGROUND ART

Conventionally, various methods for detecting abnormality of compressors mounted on air-conditioning devices and other devices have been proposed. For example, a method for detecting abnormality of a compressor based on a vibration value of the compressor is described in Patent Literature 1. This method involves presetting allowable limit values of compressor vibration for compressor rotation speeds in respective operating modes such as cooling operation and heating operation and detecting vibration of the compressor with a refrigeration cycle stabilized. Then, a detected value of vibration is compared with the set allowable limit value, and based on a result of the comparison, it is determined whether the compressor is abnormal.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Patent Laid-Open No. 10-288379

SUMMARY OF INVENTION

Technical Problem

However, the method described in Patent Literature 1 cannot determine whether the compressor is abnormal when the compressor is not operating at constant rotation speed and the vibration value varies greatly, such as during start-up or acceleration/deceleration of the compressor. Damage and other happenings leading to a failure of a compressor often occur during start-up, acceleration/deceleration, or other events, and thus it is difficult to quickly find abnormality by the method described in Patent Literature 1.
The present invention has been made in view of the above problem with the conventional technique and has an object to provide a degradation diagnosis device and an air-conditioning device that can diagnose whether or not a compressor is abnormal regardless of changes in rotation speed.

Solution to Problem

According to an embodiment of the present invention, there is provided a degradation diagnosis device that diagnoses whether or not a compressor is abnormal, the degradation diagnosis device comprising: a current detector configured to detect electric current and output electric-current information being information of a power current supplied to the compressor; a vibration detector configured to detect vibration of the compressor and output vibration information being information of the vibration of the compressor every set measurement period; an arithmetic unit connected with the current detector and the vibration detector and configured to diagnose whether or not the compressor is abnormal using the electric-current information inputted by the current detector and the vibration information inputted by the vibration detector; and a notification unit configured to give notification about a result of diagnosis as to whether or not the compressor is abnormal.

Advantageous Effects of Invention

As described above, by acquiring a feature value of the compressor based on the electric-current information and vibration information of the compressor, the present invention can diagnose whether or not the compressor is abnormal, regardless of changes in rotation speed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram showing a configuration example of an air-conditioning device equipped with a compressor to be diagnosed by a degradation diagnosis device according to Embodiment 1.

FIG. 2 is a block diagram showing a configuration example of the degradation diagnosis device according to Embodiment 1.

FIGS. 3(a) and 3(b) are schematic diagrams describing how compressor vibration information is collected by changing vibration measuring frequency when rotation speed of a compressor changes.

DESCRIPTION OF EMBODIMENTS

Embodiment

1

A degradation diagnosis device according to Embodiment 1 of the present invention will be described below. The degradation diagnosis device according to Embodiment 1 diagnoses whether or not a compressor mounted on an air-conditioning device is abnormal.

[Configuration Example of Air-Conditioning Device]

First, an air-conditioning device equipped with a compressor to be diagnosed by the degradation diagnosis device according to Embodiment 1 will be described. FIG. 1 is a schematic diagram showing a configuration example of an air-conditioning device 100 equipped with a compressor 11 to be diagnosed by a degradation diagnosis device 3 according to Embodiment 1. As shown in FIG. 1, the air-conditioning device 100 includes an outdoor unit 1, indoor units 2A to 2D, and the degradation diagnosis device 3. In the example shown in FIG. 1, four indoor units are connected to one outdoor unit. Note that the number of outdoor units and indoor units are not limited to this example. For example, the air-conditioning device may be connected with plural outdoor units. Also, for example, the air-conditioning device may be connected with one to three or five or more indoor units.

(Outdoor Unit)

The outdoor unit 1 includes the compressor 11, a refrigerant flow switching device 12 such as a four-way valve, a heat source side heat exchanger 13, an internal heat exchanger 14, an expansion valve 15, an accumulator 16, a heat source side fan 17, and a controller 18.
The compressor 11 suctions low-temperature, low-pressure refrigerant and compresses the refrigerant into a high-temperature, high-pressure state and discharges it. Examples of compressors available for use as the compressor 11 include an inverter compressor capable of controlling capacity, which is a refrigerant delivery rate per unit time, by varying driving frequency under the control of the controller 18 described later.
The refrigerant flow switching device 12 is, for example, a four-way valve, and switches between cooling operation and heating operation by switching a flow direction of the refrigerant. The flow switching of the refrigerant flow switching device 12 is controlled by the controller 18 described later.
The heat source side heat exchanger 13 exchanges heat between air (hereinafter referred to as “outdoor air,” as appropriate) supplied by the heat source side fan 17 comprising a fan or other devices, and the refrigerant. Specifically, during cooling operation, the heat source side heat exchanger 13 functions as a condenser configured to condense the refrigerant by transferring heat from the refrigerant to the outdoor air. During heating operation, the heat source side heat exchanger 13 functions as an evaporator configured to evaporate the refrigerant and cool the outdoor air using resulting heat of evaporation.
The internal heat exchanger 14 branches off from the main circuit and exchanges heat between refrigerant flowing through a main circuit and refrigerant flowing through an injection circuit connected to the accumulator 16. The expansion valve 15 decompresses the refrigerant flowing through the injection circuit branching off from the main circuit.
The accumulator 16 is provided on a low-pressure side, which is a suction side of the compressor 11. The accumulator 16 accumulates surplus refrigerant resulting from differences in operating state between cooling operation and heating operation, surplus refrigerant resulting from transient changes in operation, and other surplus refrigerant.
The controller 18 is made up of software executed, for example, on an arithmetic unit such as a microcomputer or CPU (Central Processing Unit), hardware such as circuit devices that implement various functions, or other software/hardware. The controller 18 controls operation of the entire air-conditioning device 100 based, for example, on settings made by operation by a user by a non-illustrated remote controller and various information received from non-illustrated sensors and other devices provided in various parts of the air-conditioning device 100. For example, based on detection results produced by non-illustrated temperature sensors, pressure sensors, and other devices provided in various parts of the air-conditioning device 100, the controller 18 controls rotation speed of the compressor 11.
Note that although the controller 18 is provided on the outdoor unit 1 in this example, this is not restrictive. For example, the controller 18 may be provided on any of the indoor units 2A to 2D described later or outside the outdoor unit 1 and indoor units 2A to 2D.

(Indoor Unit)

The indoor units 2A to 2D, for example, cool or heat air in air-conditioned space. The indoor units 2A to 2D include respective use side heat exchangers 21A to 21D, decompressors 22A to 22D, and use side fans 23A to 23D. Note that in the following description, the indoor units 2A to 2D will be simply referred to as the “indoor units 2,” as appropriate when there is no particular need to distinguish among them. Similarly, the use side heat exchangers 21A to 21D and decompressors 22A to 22D will be simply referred to as the “use side heat exchangers 21” and “decompressors 22,” as appropriate, respectively.
The use side heat exchangers 21 exchange heat between air and refrigerant, where the air is supplied by the use side fans 23A to 23D or other fans. Consequently, heating air or cooling air to be supplied to indoor space is generated. When the refrigerant is carrying cooling energy during cooling operation, each of the use side heat exchangers 21 functions as an evaporator, and performs cooling to cool the air in the air-conditioned space. On the other hand, when the refrigerant is carrying heating energy during heating operation, each of the use side heat exchangers 21 functions as a condenser and performs heating to heat the air in the air-conditioned space.
Each of the decompressors 22 decompresses and expands the refrigerant. The decompressor 22 is made, for example, of an electronic expansion valve or another similar valve capable of controlling an opening degree. The decompressor 22 is controlled by the controller 18, for example, such that refrigerant outlet temperature of the use side heat exchanger 21 will be optimized.
(Degradation diagnosis device) FIG. 2 is a block diagram showing a configuration example of the degradation diagnosis device 3 according to Embodiment 1. As shown in FIG. 2, the degradation diagnosis device 3 includes a current detector 31, a vibration detector 32, A/ D converters 33 and 34, an arithmetic unit 35, and a notification unit 36.
The current detector 31 detects a power current every preset period, the power current being supplied to an electric current line of the compressor 11, and outputs detection results as compressor current information, including frequency of the power current, in the form of an analog signal. Examples of detectors available for use as the current detector 31 include a current sensor such as an ACCT (AC Current Transformer) configured to detect AC (Alternating Current). However, this is not restrictive, and, for example, a shunt resistor may be used as the current detector 31.
The vibration detector 32 is, for example, a vibration sensor, and is mounted on a body of the compressor 11. The vibration detector 32 detects vibration of the compressor 11 every preset measurement period and outputs compressor vibration information in the form of an analog signal. The compressor vibration information includes, for example, information about displacement of the compressor 11 as well as information about vibration such as vibration velocity and vibration acceleration.
The A/ D converters 33 and 34 convert inputted analog signals into digital signals. The A/D converter 33 converts the compressor current information, which is an analog signal about an electric current of the compressor 11 detected by the current detector 31, into a digital signal and outputs the digital signal. The A/D converter 34 converts the compressor vibration information, which is an analog signal about a vibration of the compressor 11 detected by the vibration detector 32, into a digital signal and outputs the digital signal.
The arithmetic unit 35 determines whether or not the compressor 11 is abnormal based on the compressor current information about the compressor 11 detected by the current detector 31 and converted into a digital signal and the compressor vibration information about the compressor 11 detected by the vibration detector 32 and converted into a digital signal. The arithmetic unit 35 includes a rotation speed detection unit 41, a vibration measuring frequency setting unit 42, a feature value computing unit 43, an abnormality determination unit 44, and a storage unit 45.
The rotation speed detection unit 41 is supplied with the compressor current information from the A/D converter 33. Based on the power current frequency of the compressor 11 contained in the supplied compressor current information, the rotation speed detection unit 41 detects the rotation speed of the compressor 11.
The vibration measuring frequency setting unit 42 is supplied with the rotation speed of the compressor 11 from the rotation speed detection unit 41. Based on the supplied rotation speed of the compressor 11, the vibration measuring frequency setting unit 42 sets vibration measuring frequency used to determine the measurement period to detect vibration of the compressor 11 by the vibration detector 32. Note that details of the method for setting the vibration measuring frequency will be described later.
The feature value computing unit 43 is supplied with the compressor vibration information from the A/D converter 34. Based on a preset number of pieces of compressor vibration information, i.e., the number of samples taken by the vibration detector 32, the feature value computing unit 43 calculates a feature value of vibration of the compressor 11. In this case, as the feature value, at least one piece of information that represents a vibrational state can be used, where examples of the information include vibration displacement, an average value, standard deviation, skewness, kurtosis, tolerance frequency, and other statistics of, vibration velocity and vibration acceleration.
The abnormality determination unit 44 is supplied with the feature value calculated by the feature value computing unit 43. Based on the supplied feature value, the abnormality determination unit 44 determines whether or not the compressor 11 is abnormal. For example, the abnormality determination unit 44 determines whether a value representing the supplied feature value falls within a range set in advance for the feature value, i.e., within a setting range, and determines that the compressor 11 is abnormal if the value representing the feature value falls outside the setting range.
The storage unit 45 stores, in advance, parameters and other data used by various parts of the arithmetic unit 35 in performing various processes. For example, the storage unit 45 stores calculation formulae or a frequency setting table used by the vibration measuring frequency setting unit 42 in setting vibration measuring frequency. Also, the storage unit 45 stores the setting range used by the abnormality determination unit 44 in determining whether or not the compressor 11 is abnormal.
Based on a determination result produced by the abnormality determination unit 44 of the arithmetic unit 35, the notification unit 36 gives notification about a result of diagnosis as to whether or not the compressor 11 is abnormal. Examples of the notification unit 36 available for use include a display, LED (Light Emitting Diode), and speaker. For example, when the notification unit 36 is a display, the result of diagnosis is displayed in characters, graphics, or other similar form. When the notification unit 36 is an LED, the result of diagnosis is indicated by lighting, blinking, lights-out, or other similar means. When the notification unit 36 is a speaker, the result of diagnosis is announced by voice.

[Setting of Vibration Measuring Frequency]

Next, the vibration measuring frequency setting method carried out by the vibration measuring frequency setting unit 42 will be described with reference to FIG. 3.
FIGS. 3(a) and 3(b) are schematic diagrams describing how compressor vibration information is collected by changing vibration measuring frequency when rotation speed of the compressor 11 changes. FIG. 3(a) shows various data obtained with the vibration measuring frequency fixed and FIG. 3(b) shows various data obtained with the vibration measuring frequency varied.
In FIG. 3, “COMPRESSOR ROTATION SPEED” is the rotation speed of the compressor 11. In this example, the compressor rotation speed changes among 30, 60, and 100 [rps]. “VIBRATION MEASURING FREQUENCY” indicates the frequency used to determine the measurement period for detecting vibration of the compressor 11 by the vibration detector 32. In the example of FIG. 3(a), the vibration measuring frequency is set to a fixed value of 48000 [Hz]. In FIG. 3(b), the vibration measuring frequency is set to a variable value. Note that the measurement period is given as the inverse of the vibration measuring frequency.
“SAMPLE SIZE” is the number of pieces of compressor vibration information needed by the feature value computing unit 43 in calculating the feature value. The sample size means the number needed to obtain sufficient accuracy in calculating the feature value and is set in advance, for example, by means of experiments or tests. In this example, the sample size is set to 8192 points.
“FRAME LENGTH” is the time needed for the vibration detector 32 to acquire compressor vibration information corresponding in quantity to the sample size and is calculated by multiplying the measurement period by the sample size. “ROTATION SPEED×FRAME LENGTH” is the number of revolutions per frame and is calculated by multiplying the compressor rotation speed by frame length. “ROTATION ANGLE/SAMPLE” is the conversion of the number of revolutions per sample into a rotation angle.
First, as described above, the vibration detector 32 detects vibration of the compressor 11 every preset measurement period. Also, the vibration measuring frequency setting unit 42 collects compressor vibration information corresponding in quantity to the preset sample size and calculates the feature value based on the compressor vibration information.
Now, a case is considered in which the rotation speed of the compressor 11 changes and compressor vibration information is collected with the vibration measuring frequency fixed. In this case, as shown in FIG. 3(a), regardless of whatever the rotation speed of the compressor 11 may be, the frame length needed to calculate the feature value remains constant: 0.171 [sec]. Therefore, the number of revolutions per frame changes with the rotation speed of the compressor 11. Thus, the rotation angle per sample changes with the rotation speed of the compressor 11.
In the example shown in FIG. 3(a), when the compressor rotation speed is 30 [Hz], the number of revolutions per frame is 5.1 [rev] and the rotation angle per sample is 0.23 [deg/sample]. When the compressor rotation speed is 60 [Hz], the number of revolutions per frame is 10.2 [rev] and the rotation angle per sample is 0.45 [deg/sample]. When the compressor rotation speed is 100 [Hz], the number of revolutions per frame is 17.1 [rev] and the rotation angle per sample is 0.75 [deg/sample].
In this way, when the rotation angle per sample changes with the rotation speed of the compressor 11, the feature values obtained at different compressor rotation speeds are no longer those obtained under same conditions. This impairs reliability of data. Thus, according to Embodiment 1, as shown in FIG. 3(b), the vibration measuring frequency is varied such that the rotation angle per sample remains constant even when the rotation speed of the compressor 11 changes.
For example, according to Embodiment 1, as shown in FIG. 3(b), the sample size is set in a manner similar to FIG. 3(a). Also, in this example, regardless of whatever the value of compressor rotation speed may be, the frame length is determined such that the rotation angle per sample will be kept at a constant value of 0.75 [deg/sample].
In the example shown in FIG. 3(b), when the compressor rotation speed is 30 [Hz], the frame length is 0.570 [sec], and when the compressor rotation speed is 60 [Hz], the frame length is 0.285 [sec]. Also, when the compressor rotation speed is 100 [Hz], the frame length is 0.171 [sec].
Then, the vibration measuring frequency is set based on the frame length determined as described above and on the sample size. Consequently, when the compressor rotation speed is 30 [Hz], the vibration measuring frequency is 14371 [Hz] and when the compressor rotation speed is 60 [Hz], the vibration measuring frequency is 28744 [Hz]. Also, when the compressor rotation speed is 100 [Hz], the vibration measuring frequency is 48000 [sec].
In this way, according to Embodiment 1, the vibration measuring frequency, and thus the measurement period used for detecting vibration of the compressor 11 by the vibration detector 32 is varied according to the rotation speed of the compressor 11.
Note that because the vibration measuring frequency is usually obtained by dividing or multiplying a clock frequency serving as a reference, it is likely that available frequencies are limited. Therefore, in such a case, by taking versatility of measuring instruments into consideration, preferably, for example, of the frequencies obtained by dividing or multiplying the clock frequency, the vibration measuring frequency is set close to such a frequency that is obtained by making the rotation angle per sample constant.

[Operation of Degradation Diagnosis Device]

Next, operation of the degradation diagnosis device 3 according to Embodiment 1 will be described. As described above, based on information about the compressor 11 detected by the current detector 31 and the vibration detector 32, the degradation diagnosis device 3 diagnoses whether or not the compressor 11 is abnormal. Description will be given below of operation performed by the degradation diagnosis device 3 to diagnose whether or not the compressor 11 is abnormal.
First, the vibration detector 32 detects vibration of the compressor 11 every preset measurement period. Compressor vibration information, which is information about detected vibration, is converted from an analog signal into a digital signal by the A/D converter 34, and then supplied to the feature value computing unit 43 of the arithmetic unit 35.
On the other hand, the current detector 31 detects the power current of the compressor 11 every preset period. The compressor current information containing the frequency of the detected power current is converted from an analog signal into a digital signal by the A/D converter 33, and then supplied to the rotation speed detection unit 41 of the arithmetic unit 35.
The rotation speed detection unit 41 detects the rotation speed of the compressor 11 based on the power current frequency of the compressor 11 contained in the supplied compressor current information. Information about the detected rotation speed of the compressor 11 is supplied to the vibration measuring frequency setting unit 42.
Based on the supplied information about the rotation speed of the compressor 11 and with reference to the calculation formulae or frequency setting table stored in the storage unit 45, the vibration measuring frequency setting unit 42 sets the vibration measuring frequency, i.e., the measurement period of the vibration detector 32 according to the current rotation speed of the compressor 11. Then, the vibration detector 32 detects vibration of the compressor 11 every set measurement period and supplies compressor vibration information according to detection results to the feature value computing unit 43 via the A/D converter 34.
The feature value computing unit 43 calculates a feature value such as vibration acceleration contained in the supplied compressor vibration information. Note that the feature value obtained as a result of the calculation at this time may be a single feature value such as an average value of vibration accelerations or a state quantity obtained by combining plural feature values. The calculated feature value is supplied to the abnormality determination unit 44.
The abnormality determination unit 44 reads the setting range out of the storage unit 45 and determines whether a value of the supplied feature value falls within the setting range read out. Then, when the value of the feature value falls within the setting range, the abnormality determination unit 44 determines that the compressor 11 is normal. On the other hand, when the value of the feature value falls outside the setting range, the abnormality determination unit 44 determines that the compressor 11 is abnormal. Then, the abnormality determination unit 44 supplies determination information indicating a determination result to the notification unit 36.
Based on the determination information supplied from the abnormality determination unit 44, the notification unit 36 gives notification corresponding to the determination result. For example, if the compressor 11 is abnormal, the notification unit 36 notifies the user about the abnormality of the compressor 11 using character display, lighting of an LED, voice output, or another method.
In this way, according to Embodiment 1, by varying the vibration measuring frequency of the vibration detector 32 with changes in the rotation speed of the compressor 11, it is determined whether or not the compressor 11 is abnormal, with the rotation angle per sample kept constant regardless of the rotation speed of the compressor 11. Consequently, the feature values at different compressor rotation speeds can be calculated under the same conditions. This makes it possible to improve the reliability of data and more accurately determine whether or not the compressor 11 is abnormal.
As described above, the degradation diagnosis device 3 according to Embodiment 1 is designed to diagnose whether or not the compressor 11 is abnormal, the degradation diagnosis device 3 comprising: the current detector 31 configured to detect electric current and output electric-current information being information of a power current supplied to the compressor 11; the vibration detector 32 configured to detect vibration of the compressor and output vibration information being information of the vibration of the compressor 11 every set measurement period; the arithmetic unit 35 connected with the current detector 31 and the vibration detector 32 and configured to diagnose whether or not the compressor 11 is abnormal using the electric-current information inputted by the current detector 31 and the vibration information inputted by the vibration detector 32; and the notification unit 36 configured to give notification about a result of diagnosis as to whether or not the compressor 11 is abnormal.
Also, the arithmetic unit 35 sets vibration measuring frequency according to the rotation speed of the compressor 11 detected based on the electric current of the compressor 11, the vibration measuring frequency being correlated with the measurement period for detecting vibration and outputting the vibration information by the vibration detector 32, calculates a feature value that represents a vibrational state from the vibration information of the vibration detected at every measurement period based on the set vibration measuring frequency, and diagnoses whether or not the compressor 11 is abnormal based on the calculated feature value. Consequently, Embodiment 1 makes it possible to diagnose whether or not the compressor is abnormal, regardless of the rotation speed of the compressor 11.
Whereas Embodiment 1 of the present invention has been described above, the present invention is not limited to Embodiment 1 of the present invention described above, and various alterations and applications are possible without departing from the spirit of the present invention. For example, although in Embodiment 1 it is determined whether or not the compressor 11 is abnormal, by varying the vibration measuring frequency of the compressor 11 by the vibration detector 32, with the rotation angle per sample kept constant regardless of the rotation speed of the compressor 11, the present invention is not limited to this example.
For example, to make the rotation angle per sample constant, the sample size may be made variable with the vibration measuring frequency fixed. This will make it possible to determine whether or not the compressor 11 is abnormal regardless of the rotation speed of the compressor 11 as with Embodiment 1.
Also, for example, when it is determined that the compressor 11 is abnormal, the degradation diagnosis device 3 may transmit a control signal to the controller 18 of the air-conditioning device 100, instructing the controller 18 to reduce the rotation speed to protect the compressor 11. Upon receiving the control signal, the controller 18 reduces the rotation speed of the compressor 11. Furthermore, for example, a non-illustrated communication unit may be provided on the arithmetic unit 35 to notify a remote or other external site about occurrence of any abnormality of the compressor 11.

REFERENCE SIGNS LIST

1 Outdoor unit 2, 2A, 2B, 2C, 2D Indoor unit 3 Degradation diagnosis device 11 Compressor 12 Refrigerant flow switching device 13 Heat source side heat exchanger 14 Internal heat exchanger 15 Expansion valve
16 Accumulator 17 Heat source side fan 18 Controller 21, 21A, 21B, 21C, 21D Use side heat exchanger 22, 22A, 22B, 22C, 22D Decompressor
23, 23A, 23B, 23C, 23D Use side fan 31 Current detector 32 Vibration detector 33, 34 A/D Converter 35 Arithmetic unit 36 Notification unit
41 Rotation speed detection unit 42 Vibration measuring frequency setting unit 43 Feature value computing unit 44 Abnormality determination unit 45 Storage unit 100 Air-conditioning device

Claims

1. A degradation diagnosis device that diagnoses whether or not a compressor is abnormal, the degradation diagnosis device comprising:

a current detector configured to detect electric current and output electric-current information being information of a power current supplied to the compressor;

a vibration detector configured to detect vibration of the compressor and output vibration information being information of the vibration of the compressor every set measurement period;

an arithmetic unit connected with the current detector and the vibration detector and configured to diagnose whether or not the compressor is abnormal using the electric-current information inputted by the current detector and the vibration information inputted by the vibration detector; and

a notification unit configured to give notification about a result of diagnosis as to whether or not the compressor is abnormal,

wherein the arithmetic unit

sets vibration measuring frequency according to rotation speed of the compressor, the rotation speed of the compressor being detected based on electric current of the compressor, the vibration measuring frequency being correlated with a measurement period for detecting vibration by the vibration detector to output the vibration information, and obtained by dividing or multiplying a clock frequency serving as a reference.

2. The degradation diagnosis device of claim 1, wherein the arithmetic unit

calculates a feature value that represents a vibrational state from the vibration information of the vibration detected at every measurement period based on the set vibration measuring frequency, and

diagnoses whether or not the compressor is abnormal based on the calculated feature value.

3. The degradation diagnosis device of claim 2, wherein the arithmetic unit includes

a rotation speed detection unit configured to detect rotation speed of the compressor based on the electric-current information,

a vibration measuring frequency setting unit configured to set the vibration measuring frequency based on the detected rotation speed of the compressor,

a feature value computing unit configured to calculate the feature value based on the vibration information output by the vibration detector based on the vibration measuring frequency, and

an abnormality determination unit configured to determine whether the compressor is abnormal, based on the calculated feature value.

4. The degradation diagnosis device of claim 3, wherein the abnormality determination unit

compares the calculated feature value with a setting range, which is a preset range of the feature value, and

determines that the compressor is abnormal when the feature value falls outside the setting range.

5. The degradation diagnosis device of claim 1, wherein the arithmetic unit

sets a sample size according to rotation speed of the compressor, where the sample size is the number of pieces of the vibration information needed to diagnose whether the compressor is abnormal, the rotation speed of the compressor being detected based on electric current of the compressor,

calculates a feature value that represents a vibrational state from the vibration information acquired corresponding in quantities to the set sample size, and

6. The degradation diagnosis device of claim 2, wherein

the vibration information is displacement, vibration velocity, or vibration acceleration of the compressor, and

the feature value includes at least one of an average value, standard deviation, skewness, and tolerance frequency of the vibration information.

7. (canceled)

8. The degradation diagnosis device of claim 1, wherein when it is determined that the compressor is abnormal, a signal indicating the abnormality is transmitted outside.

9. The degradation diagnosis device of claim 1, wherein when it is determined that the compressor is abnormal, a control signal for controlling rotation speed of the compressor is transmitted outside.

10. An air-conditioning device in which a compressor, a heat source side heat exchanger, a decompressor, and a use side heat exchanger are connected with one another via pipes and refrigerant circulates through the pipes, the air-conditioning device comprising the degradation diagnosis device of claim 1.