JPH11241868A - Rotation controller having auxiliary function of vibration measurement and refrigerating device having vibration measurement function employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit grasping of the vibration of a compressor and a conduit arranged from the compressor, by a method wherein a program for measuring the vibration characteristics of the compressor and the conduit, arranged from the compressor, is run by putting a vibration measurement starting switch ON. SOLUTION: The amplitude of vibration in a conduit 9 is inputted from a vibration sensor 17 into a recorder 19 through a vibrometer 18. Next, a vibration measurement starting switch 14 is put ON to start vibration measurement. In this case, a frequency control signal 21 from a control unit 15 is given to an inverter 16 so as to increase the frequency from the lowest operation frequency to the highest operation frequency at every given times and, thus, a frequency having a big vibration is specified. Then, the specified frequency is set in the inverter 16, or the frequency is programmed in the control unit 15 so as to be skipped to effect operation so as to skip the frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus having a vibration measuring function for realizing energy saving of a refrigerator by controlling the rotation speed of a drive motor of the refrigerator.

[0002]

2. Description of the Related Art In a rotation control device that is attached to an existing refrigerator and controls the rotation of a drive motor of a compressor of the refrigerator to realize energy saving, vibration of a compressor and a conduit provided from the compressor is a problem. It may be. Since the compressor of the existing refrigerator is rotated by a commercial three-phase AC power supply,
When the induction motor of the compressor is rotated at that frequency (50 Hz in Kanto, 60 Hz in Kansai), it is only necessary that vibration of the compressor and a conduit provided from the compressor be suppressed. However, in the case of a device for controlling the rotation of the drive motor, the rotation frequency is in a wide range (for example, the drive frequency is 30 Hz to 6 Hz).
0 Hz), and if no countermeasures are taken, there is a risk of causing a serious failure such as resonance of the conduit depending on the driving frequency during operation. As a countermeasure, it is common to adopt a method of operating while avoiding a drive frequency at which large vibration occurs due to resonance or the like (frequency skipping method).

The method of specifying the frequency to be skipped can be obtained by a method of measuring vibration characteristics by hammering a target refrigerator using a vibrometer or a method of measuring characteristics by changing a rotation frequency. Conceivable. FIG. 5 is a configuration diagram of a measurement system when the rotation frequency is changed. In the figure, reference numeral 1 denotes a refrigerator, which comprises a compressor 3, a condenser 4, an expansion valve 5, and an evaporator 6, and connects an inverter 16 to a three-phase AC power supply 20 received from a power company. The output of the inverter 16 is connected to the input of the drive motor 12. The inverter 16 is a three-phase AC variable frequency inverter. Further, the frequency control signal 21 from the signal generator 31 is input to the inverter 16.
Here, a three-phase induction motor is used as the drive motor 12, and the compressor 3 is driven. A conduit 9 from the discharge section of the compressor 3 is connected to the condenser 4,
The condenser 4 is provided with a cooling device. The conduit 10 from the outlet of the condenser 4 is connected to the inlet of an evaporator 6 via an expansion valve 5, and the evaporator 6 is installed in a refrigeration or freezing chamber. The vibration sensor 17 is attached to the conduit 9 connected to the condenser 4 from the discharge part of the compressor 3. Further, a vibration meter 18 is connected to the vibration sensor 17. Further, the output of the vibrometer 18 is connected to the input of the recorder 19. The frequency characteristic of the vibration amplitude of the conduit 9 is changed by inputting the frequency control signal 21 for changing the frequency from the signal generator 22 to the inverter 16 by assembling the measurement system having the above-described configuration separately from the control device. It will be drawn on the recorder 19. However, in any of these methods, it is general that a measurement system is set up outside the rotation control device and measurement is performed over time.

[0004]

In the measurement of vibration characteristics required when installing a rotation control device, in the above method, the operation of the refrigerator is stopped for the measurement, or
Since it takes time, the temperature of the frozen or refrigerated product rises, and there is a problem that freshness is impaired. Also,
When the measurement is performed in a short time, it is difficult to measure accurate characteristics. Furthermore, it is difficult to perform measurement while activating the protection function of the refrigerator or the control device, so that measurement cannot be performed while safely operating the refrigerator.

According to the present invention, in order to solve the above-mentioned problems and problems, it is easy to grasp the vibration of a compressor and a conduit provided from the compressor, and to operate the refrigerator safely.
An object of the present invention is to provide a refrigeration apparatus having a vibration measuring function for accurately measuring vibration characteristics with respect to a motor driving frequency.

[0006]

In order to achieve the above object, the present invention provides a rotation control device having an auxiliary function for vibration measurement, comprising: a refrigerator for compressing a refrigerant gas; a drive motor for driving the compressor; A refrigerating apparatus comprising a condenser, an expansion valve, and an evaporator sequentially connected to the compressor, wherein the evaporator is connected to a suction portion of the compressor via a conduit. And a pressure sensor is provided between the pressure sensor and the pressure sensor detects the suction pressure of the refrigerant gas detected in real time at a time interval, so as to be transmitted to a control unit provided with a target pressure setter and a vibration measurement start switch. In addition, the control unit applies a negative feedback to the frequency control signal based on a deviation between the target pressure set by the target pressure setter and the suction pressure of the refrigerant gas, and performs step-by-step processing in real time. A rotation control device in which a program for correcting a frequency control signal and a program for performing vibration measurement are incorporated into the compressor, and the frequency control signal is input to an inverter. Alternatively, it has an auxiliary function of vibration measurement in which a program for measuring vibration characteristics of a conduit arranged in the compressor starts running.

[0007] The program for performing the vibration measurement is
When the vibration measurement start switch is turned on, the program provides the frequency control signal so that the motor drive frequency of the inverter changes continuously or stepwise at a constant speed.

[0008] The refrigeration apparatus having the vibration measuring function of the present invention comprises:
A refrigerator for compressing the refrigerant gas, a drive motor for driving the compressor, a condenser and an expansion valve sequentially connected to the compressor,
A refrigerating apparatus comprising: an evaporator; and a rotation control device having an auxiliary function of the vibration measurement, wherein a vibration sensor is attached to the compressor or a conduit provided to the compressor, and the vibration sensor is connected to the vibration sensor. It is characterized by having a vibration measuring function for recording the output with a recorder. Further, the recorder is provided with a marker function in order to improve the accuracy of the measurement, and a marker control signal is sent from the control unit so that the marker is provided on the recording paper for the marker provided in the recorder.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a configuration diagram of a refrigeration apparatus having a vibration measurement function according to a first embodiment of the present invention.
In the figure, reference numeral 1 denotes a refrigerator, and a control function 2 and a compressor 3
, A condenser 4, an expansion valve 5, and an evaporator 6. The rotation control device 2, which is a component of the refrigeration system 1, mainly includes a pressure sensor 11, a target pressure setter 13, and a vibration measurement start. The control unit 15 includes a switch 14 and an inverter 16.

The target pressure setting device 13 has an operation unit for setting a target pressure. Pressure sensor 11
Is provided between the compressor 3 and the evaporator 6 by being connected to a branch 8 from a conduit 7 connected to a suction part of the compressor 3 and an outlet of the evaporator 6. The output of the pressure sensor 11 is led to the control unit 15. Also, the inverter 16 is connected to the three-phase AC power supply 20 received from the power company,
The output of inverter 16 is connected to the input of drive motor 12. The inverter 16 is a three-phase AC variable frequency inverter. Further, a frequency control signal 21 as a cooling capacity control signal from the control unit 15 is input to the inverter 16.

In this embodiment, a three-phase induction motor is used as the drive motor 12, and the compressor 3 is driven. A conduit 9 from the discharge section of the compressor 3 is connected to the condenser 4, and the condenser 4 is provided with a cooling device. The conduit 10 from the outlet of the condenser 4 is connected to the inlet of an evaporator 6 via an expansion valve 5, and the evaporator 6 is installed in a refrigeration or freezing chamber.

The refrigerating apparatus 1 is configured as described above, and the refrigerating apparatus of the present invention has a vibration measuring function in the refrigerating apparatus 1. The vibration measuring function includes a vibration sensor 17, a vibration meter 18, and a recorder 19. The vibration sensor 17 is attached to the conduit 9 connected to the condenser 4 from the discharge part of the compressor 3. Further, the vibration meter 18 is connected to the vibration sensor 17.
Connected to Further, the output of the vibrometer 18 is connected to the input of the recorder 19. In this embodiment, the vibration sensor 17 is attached to the conduit 9. However, in the case of a multi-compressor (not shown), a pipe is provided between the compressor 3 and the conduits 7, 8, and 10 other than the conduit 3. It may be attached to the equalized oil pipe.

In the refrigeration system configured as described above, the resonance frequency is specified as follows. First,
The vibration amplitude in the conduit 9 is input from a vibration sensor 17 via a vibrometer 18 to a recorder 19. Next, the vibration measurement start switch 1 connected to the control unit 15
By entering 4, vibration measurement is started. At this time, the frequency control signal 21 to the inverter 16 is given so as to increase from the lowest operating frequency to the highest operating frequency at regular intervals. As a result, the vibration characteristics of the conduit 9 within the driving frequency range are clarified on the recording paper, and a frequency with a large vibration can be specified. In an actual operation, the specified frequency is set in the inverter 16 or the control unit 15 performs programming so as to skip the frequency, and the operation is performed so as to skip the frequency. Note that the measurement start switch 14 may be not only a mechanical switch but also a so-called semiconductor memory switch. A personal computer may be connected to the rotation control device and the memory switch may be operated to start the measurement. is there.

Further, in order to grasp an accurate vibration characteristic from the recording of the recorder, a marker can be placed at a position of a specific frequency on the recording paper. The configuration diagram in this case is shown in FIG. The recorder 19 is provided with a marker operation control terminal, to which a marker control signal 23 from the control unit 15 is input. Recorder 1
9 does not need to be limited to a recorder for vibration measurement. The output of the control unit 15 is a contact output,
When the contact of the control unit 15 is ON, the recorder 19 writes a marker. In the case of a general recorder, a voltage change is recorded by a marker command by using a 2-pen recorder in a synchronous operation and a pull-up resistor is attached to the pen input of the marker, and the recorded position is represented by the marker frequency. You can see that there is.

In this case, the vibration is measured by the control unit 1
5 is a marker control signal for instructing a frequency from the recorder 1
9 to be input. At this time, the frequency is increased from the lowest operation frequency to the highest operation frequency at regular intervals (in FIG. 3, the frequency is increased by 0.2 Hz per second), and at the same time, the recorder 19 is increased every constant frequency (for example, 5 Hz). To a marker control signal. In this case, as described above, the contact of the control unit 15 may be set to be turned on every time the frequency reaches a certain frequency. In this embodiment, the frequency is changed stepwise, but may be changed continuously.

FIG. 4 shows a measurement example of the pipe vibration measured by the above method. Although the horizontal axis in FIG. 4 is originally a time axis, the motor driving frequency is increased at a constant speed, and a specific frequency can be identified by a marker. Therefore, the horizontal axis can be regarded as a frequency axis. The vertical axis is the vibration amplitude. In this measurement example, the vibration amplitude increases when the frequency is 42 to 44 Hz. Therefore, in the operation in this measurement example, the operation is performed with the frequency set to be skipped.

When a frequency to be skipped is specified by such a method, a high-pressure cut function of the discharge gas pressure of the compressor 3, a low-pressure cut function of the suction gas pressure, a protection function of the rotation control device 2, and the like are provided. Can be performed while working, and measurements can be taken while driving safely. Also,
The command frequency may be increased from a low frequency to a high frequency. When the frequency is lowered from the high frequency to the low frequency, the refrigerating capacity of the refrigerator starts from a large state. Therefore, when the refrigerating load is light, the low pressure cut works and the compressor 3 stops immediately, and the characteristics cannot be obtained. It is. Further, since the refrigerant gas has time to travel around the entire refrigerator including the freezing or refrigeration chamber, the pressure change is delayed for a while with respect to the frequency change. Therefore, this is effective.

[0018]

According to the present invention, the following effects can be obtained from the above configuration. First, the rotation control device having the auxiliary function of vibration measurement according to the present invention has only one additional switch in configuration compared to the rotation control device having no auxiliary function of vibration measurement, so that this auxiliary device can be used without significant cost increase. Function can be obtained. In addition, when attaching a rotation control device to an existing refrigerator, a vibration sensor is attached to the compressor or a conduit provided for the compressor, and the output of a vibration meter to which the vibration sensor is connected is recorded by a recorder. By doing so, there is an effect that the vibration of the compressor and its piping can be quickly grasped without assembling a large-scale vibration measurement system as in the related art.

Next, when the refrigeration system having the vibration measuring function of the present invention is installed, a vibration sensor is attached to the compressor or a conduit arranged in the compressor, and the output of the vibration meter to which the vibration sensor is connected is used. In addition, the recording by the recorder has an effect that the vibration of the compressor and its piping can be quickly grasped without separately assembling a large-scale vibration measuring system as in the related art.

Further, a marker function is provided in the recorder, and a marker control signal is sent from the control unit so that the marker is put on the recording paper for the marker provided in the recorder. Vibration characteristics can be measured, and the refrigerator can be operated while ensuring high safety when saving energy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration apparatus having a vibration measurement function according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a refrigeration apparatus having a vibration measurement function according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a command frequency and a timing of a marker signal with respect to a vibration measurement time.

FIG. 4 is a diagram showing a measurement example in which vibration characteristics with respect to a motor drive frequency are measured.

FIG. 5 is a configuration diagram of a conventional vibration measurement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Rotation control apparatus 3 Compressor 4 Condenser 5 Expansion valve 6 Evaporator 11 Pressure sensor 12 Drive motor 13 Target pressure setter 14 Vibration measurement start switch 15 Control unit 16 Inverter 17 Vibration sensor 18 Vibrometer 19 Recorder 20 Three Phase AC power supply 21 Frequency control signal 22 Signal generator 23 Marker control signal

Claims (5)

[Claims] 1. A refrigerator for compressing refrigerant gas, a drive motor for driving the compressor, a condenser, an expansion valve, and an evaporator sequentially connected to the compressor. In a refrigerator connected to a suction portion of the compressor through a pressure sensor provided between the compressor and the evaporator,
The pressure sensor is configured to transmit the suction pressure of the refrigerant gas detected in real time at a time interval to a control unit provided with a target pressure setter and a vibration measurement start switch, and the control unit includes: A program for correcting the frequency control signal stepwise in real-time processing by adding negative feedback to the frequency control signal based on a deviation between the target pressure set by the target pressure setter and the suction pressure of the refrigerant gas, and vibration measurement A rotation control device in which the frequency control signal is input to an inverter, and when the vibration measurement start switch is turned on, the vibration characteristic of the compressor or a conduit provided to the compressor is changed. A rotation control device having an auxiliary function of vibration measurement in which a program for measurement starts running. 2. A program for performing the vibration measurement, wherein when the vibration measurement start switch is turned on, the frequency control signal is changed so that the motor driving frequency of the inverter changes continuously or stepwise at a constant speed. 2. The rotation control device according to claim 1, wherein the program is a program to be given. 3. A refrigerator for compressing refrigerant gas, a drive motor for driving the compressor, a condenser, an expansion valve, an evaporator, and a rotation control device having an auxiliary function of vibration measurement, which are sequentially connected to the compressor. A vibration sensor is attached to the compressor or a conduit disposed in the compressor,
In a refrigerating apparatus in which the output of a vibrometer to which the vibration sensor is connected is recorded by a recorder, a rotation control device having an auxiliary function of the vibration measurement includes a pressure control between the compressor and the evaporator. A sensor is provided, and the suction pressure of the refrigerant gas detected in real time by the pressure sensor is transmitted to a control unit provided with a target pressure setter and a vibration measurement start switch. The unit includes a program for correcting the frequency control signal stepwise in real time by adding a negative feedback to the frequency control signal based on a deviation between the target pressure set by the target pressure setter and the suction pressure of the refrigerant gas. And a rotation control device incorporating a program for performing vibration measurement and inputting the frequency control signal to an inverter, A refrigeration system having a vibration measurement function in which, when the vibration measurement start switch is turned on, a program for measuring the vibration characteristics of the compressor or a conduit disposed in the compressor starts running. 4. A program for performing the vibration measurement, wherein when the vibration measurement start switch is turned on, the frequency control signal is changed so that the motor driving frequency of the inverter is changed continuously or stepwise at a constant speed. 4. The refrigeration apparatus according to claim 3, wherein the program is a program to give. 5. The vibration according to claim 3, wherein the recorder is provided with a marker function, and a marker control signal is sent from the control unit so that the marker is put on the recording paper for the marker provided in the recorder. A refrigeration system having a measurement function.