Apparatus for detecting and diagnosing abnormality of inverter booster pump

Abstract

The present invention relates to an apparatus for detecting and diagnosing an abnormality of an inverter booster pump, which can accurately and directly detect and diagnose cavitation, freezing damage, and low water level by attaching an acoustic emission sensor to the inverter booster pump and analyzing an acoustic emission signal generated from the inverter booster pump. The apparatus for detecting and diagnosing an abnormality of an inverter booster pump comprises: an acoustic emission sensor (10) attached to the inverter booster pump in a film form so as to receive an acoustic emission signal in the form of elastic waves generated from the inverter booster pump; an amplifier unit (20) for amplifying the acoustic emission signal transmitted from the acoustic emission sensor (10); a noise filter (30) for filtering noise from the signal amplified by the amplifier unit (20); a digital signal processing unit (40) for converting the analog acoustic emission signal transmitted through the noise filter (30) into a digital signal; and a control PC (50) for analyzing the digital signal transmitted from the digital signal processing unit (40) to determine cavitation, freezing damage, and low water level.

Description

Abnormal detection and diagnosis device for inverter booster pumps

[0001] The present invention relates to a device capable of detecting and diagnosing abnormal conditions such as cavitation, low water level, and freezing that may occur in a booster pump, and more specifically, to an abnormality detection and diagnosis device for an inverter booster pump capable of directly and accurately detecting and diagnosing the occurrence of cavitation, freezing, and low water level by attaching an acoustic emission sensor to the inverter booster pump and analyzing an acoustic emission signal generated from the inverter booster pump.

[0002]

[0003] Korean Patent No. 10-0908385 (registered on July 10, 2009) introduces “Inverter booster pump system and cavitation detection method using the same.”

[0004] The above-mentioned cavitation detection method of the inverter booster pump system comprises: a step S1 of determining whether the pump is operating at a set operating speed (ωe_TCV_set) or higher of a TCV (ωe ≥ωe_TCV_set), and if the pump is operating at a set operating speed (ωe_TCV_set) or higher, proceeding to step S2; and performing step S8 if the pump is operating at a speed lower than the set operating speed; a step S2 of calculating the output power (Pout) of the inverter using an equation; a step S3 of determining whether the output power (Pout) of the inverter calculated at step S2 is smaller than the set power (PTCV_set) of the TCV; a step S4 of increasing the TCV holding time (TTCV) of the pump; a step S5 of determining whether the TCV holding time (TTCV) of the pump has reached a set time (Tset); It includes step S6 in which the TCV holding time (TTCV) of the pump system is determined to have occurred a cavitation state because it has reached a set time (Tset), and at this time, the TCV holding time (TTCV) is reset to 0; and step S7 in which the operation of the pump is stopped and an alarm is sounded because the cavitation state (TCV) of the pump has occurred (ωe = 0).

[0005] However, the above-mentioned cavitation detection method of the inverter booster pump system determines whether inverter booster cavitation has occurred through calculation, and thus cannot directly detect the occurrence of cavitation in the inverter booster pump.

[0006]

[0007] Accordingly, the purpose of the present invention is to provide an abnormality detection and diagnosis device for an inverter booster pump, which can accurately and directly detect and diagnose cavitation, freezing, and low water level by attaching an acoustic emission sensor to the inverter booster pump and analyzing the acoustic emission signal generated from the inverter booster pump.

[0008]

[0009] An example of an abnormality detection and diagnosis device of an inverter booster pump according to the present invention for achieving the above purpose is as follows:

[0010] It is characterized by comprising an acoustic emission sensor attached to an inverter booster pump in the form of a film so as to receive an acoustic emission signal in the form of an elastic wave generated from the inverter booster pump, an amplifier unit that amplifies the acoustic emission signal transmitted from the acoustic emission sensor, a noise filter for filtering noise from the signal amplified by the amplifier unit, a digital signal processing unit that converts the analog acoustic emission signal transmitted through the noise filter into a digital signal, and a control PC that analyzes the digital signal transmitted from the digital signal processing unit to determine cavitation, freezing, and low water level.

[0011] The above acoustic emission sensor has a wideband frequency characteristic, a piezoelectric material that receives an acoustic emission signal is formed in a film shape, the piezoelectric material is coated with an epoxy resin containing carbon powder, and is characterized in that it detects an acoustic emission signal generated when cavitation, low water level, and freezing occur in an inverter booster pump.

[0012] The above acoustic emission sensor is characterized in that it is attached to the upper surface of the lever of the opening / closing valve placed on the discharge side of the inverter booster pump.

[0013] Alternatively, the acoustic emission sensor is characterized in that it is attached to the upper or lower surface of the stop plate of the opening / closing valve arranged on the discharge side of the inverter booster pump.

[0014] As another alternative, the acoustic emission sensor is characterized in that it is attached to the circumference of a bolt provided on a stop plate of an on-off valve disposed on the discharge side of the inverter booster pump.

[0015] As another alternative, the acoustic emission sensor is characterized in that it is attached to a disc of an on-off valve arranged on the discharge side of the inverter booster pump.

[0016] As another alternative, the acoustic emission sensor is characterized in that it is attached to the casing of a check valve arranged on the discharge side of the inverter booster pump.

[0017] The above control PC is characterized in that it determines that cavitation has occurred if the number of vibrations higher than the threshold voltage during the event maintenance time in the input frequency band of 5 to 15 kHz exceeds the set number of times, and if the measured temperature is 0℃ or lower and the inverter booster pump is stopped and the number of vibrations higher than the threshold voltage during the event maintenance time in the input frequency band of 10 to 1000 Hz exceeds the set number of times, it determines that freezing has occurred, and if the time for which the average effective voltage of the input continuous acoustic emission signal exceeds the threshold voltage exceeds the set time, it determines that the event energy has increased due to low water level.

[0018] The above control PC is characterized in that it standardizes data on cavitation, freezing, and low water level of an inverter booster pump through repetitive experiments, extracts characteristic variables according to cavitation, characteristic variables according to freezing, and characteristic variables according to low water level from the standardized data, selects the characteristic variables that are easiest to distinguish from the extracted characteristic variables, selects the main characteristic variables of cavitation, the main characteristic variables according to freezing, and the main characteristic variables according to low water level, and compares the set values ​​of the main characteristic variables with the measured values ​​of the main characteristic variables of the measured signal to identify the characteristics of the measured signal and determine the risk index.

[0019]

[0020] By this, the abnormality detection and diagnosis device of the inverter booster pump according to the present invention has the effect of being able to accurately and directly detect and diagnose the occurrence of cavitation, freezing, and low water level in the inverter booster pump.

[0021]

[0022] Fig. 1 is a block diagram illustrating an abnormality detection and diagnosis device of an inverter booster pump according to the present invention.

[0023] Figures 2 to 6 illustrate examples in which an acoustic emission sensor is mounted on an on-off valve and a check valve of an inverter booster pump.

[0024]

[0025] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

[0026] Referring to FIG. 1, an abnormality detection and diagnosis device for an inverter booster pump according to the present invention is composed of an acoustic emission sensor (10) attached to an inverter booster pump in the form of a film so as to receive an acoustic emission signal in the form of an elastic wave generated from the inverter booster pump, an amplifier unit (20) for amplifying the acoustic emission signal transmitted from the acoustic emission sensor (10), a noise filter (30) for filtering noise from the signal amplified by the amplifier unit (20), a digital signal processing unit (40) for converting an analog acoustic emission signal transmitted through the noise filter (30) into a digital signal, and a control PC (50) for analyzing the digital signal transmitted from the digital signal processing unit (40) to determine cavitation, freezing, and low water level.

[0027] The above acoustic emission sensor (10) has a wideband frequency characteristic, a piezoelectric material that receives an acoustic emission signal is formed in a film shape, an epoxy resin (15) containing carbon powder is coated on the piezoelectric material, and detects an acoustic emission signal generated when cavitation, low water level, and freezing occur in an inverter booster pump.

[0028] The above epoxy resin (15) attenuates the energy of the acoustic emission signal passing through the piezoelectric material by scattering and absorbing it, thereby preventing it from returning to the piezoelectric material.

[0029] Referring to FIG. 2, the acoustic emission sensor (10) can be attached to the upper surface of the lever (3a) of the opening / closing valve (3; so-called butterfly valve) placed on the discharge side of the inverter booster pump (1).

[0030] Referring to FIG. 3, as another alternative, the acoustic emission sensor (10) may be attached to the upper or lower surface of the stop plate (3b) of the opening / closing valve (3) disposed on the discharge side of the inverter booster pump (1).

[0031] Referring to FIG. 4, as another alternative, the acoustic emission sensor (10) may be attached to the circumference of a bolt (3c) provided on a stop plate of an on-off valve (3) disposed on the discharge side of an inverter booster pump (1).

[0032] Referring to FIG. 5, as another alternative, the acoustic emission sensor (10) may be attached to the disk (3d) of the opening / closing valve (3) arranged on the discharge side of the inverter booster pump (1).

[0033] Referring to FIG. 6, as another alternative, the acoustic emission sensor (10) may be attached to the casing (5a) of the check valve (5) arranged on the discharge side of the inverter booster pump (1).

[0034] In this way, the acoustic emission sensor (10) is placed on the opening / closing valve (3) or check valve (5) located on the discharge side of the inverter booster pump (1) because the acoustic emission signal is best transmitted to the acoustic emission sensor (10) located on the opening / closing valve (3) or check valve (5) by the flow of water.

[0035] The sound waves generated by the above cavitation refer to the sound or vibration generated when the water pressure partially drops to a certain level within the inverter booster pump, causing steam bubbles to form and these bubbles to collapse when the pressure increases.

[0036] The sound waves generated by the above freezing waves refer to the sound or vibrations that occur when water freezes - due to changes in stress and pressure in the ice as its volume expands or contracts.

[0037] The sound waves generated by the above low water level refer to the sound or vibration generated when the inside of the inverter booster pump is filled with air or gas to form a vapor cavity, and the vapor cavity is compressed.

[0038] The above control PC (50) determines that cavitation has occurred if the number of vibrations higher than the threshold voltage during the event maintenance time in the input frequency band of 5 to 15 kHz exceeds the set number of times, and if the measured temperature is 0°C or lower and the inverter booster pump is stopped and the number of vibrations higher than the threshold voltage during the event maintenance time in the input frequency band of 10 to 1000 Hz exceeds the set number of times, it determines that freezing has occurred, and if the time for which the average root mean square (rms) voltage of the input continuous acoustic emission signal exceeds the threshold voltage exceeds the set time, it determines that the event energy has increased due to low water level.

[0039] The above control PC (50) standardizes data on cavitation, freezing, and low water level of the inverter booster pump through repeated experiments, extracts characteristic variables according to cavitation, characteristic variables according to freezing, and characteristic variables according to low water level from the standardized data, selects the characteristic variables that are easiest to distinguish from the extracted characteristic variables, selects the main characteristic variables of cavitation, the main characteristic variables according to freezing, and the main characteristic variables according to low water level, and compares the set values ​​of the main characteristic variables with the measured values ​​of the main characteristic variables of the measured signal to identify the characteristics of the measured signal and determine the risk index.

[0040]

[0041] As described above, the device for detecting and diagnosing abnormalities in an inverter booster pump according to the present invention can easily determine cavitation, freezing, and low water level of an inverter booster pump using an acoustic emission sensor, and has the advantage of accurately detecting and diagnosing the occurrence of cavitation, freezing, and low water level through pattern analysis and spectrum analysis of acoustic emission signals according to the occurrence of cavitation, freezing, and low water level.

Claims

1. An abnormality detection and diagnosis device for an inverter booster pump, characterized in that it comprises an acoustic emission sensor (10) attached to an inverter booster pump in the form of a film so as to receive an acoustic emission signal in the form of an elastic wave generated from the inverter booster pump, an amplifier unit (20) for amplifying the acoustic emission signal transmitted from the acoustic emission sensor (10), a noise filter (30) for filtering noise from a signal amplified by the amplifier unit (20), a digital signal processing unit (40) for converting an analog acoustic emission signal transmitted through the noise filter (30) into a digital signal, and a control PC (50) for analyzing the digital signal transmitted from the digital signal processing unit (40) to determine cavitation, freezing, and low water level.

2. In paragraph 1, The above acoustic emission sensor (10) has a wideband frequency characteristic, a piezoelectric material that receives an acoustic emission signal is formed in a film shape, the piezoelectric material is coated with an epoxy resin (15) containing carbon powder, and an abnormality detection and diagnosis device for an inverter booster pump is characterized in that it detects an acoustic emission signal generated when cavitation, low water level, and freezing occur in the inverter booster pump.

3. In paragraph 1, An abnormality detection and diagnosis device for an inverter booster pump, characterized in that the above acoustic emission sensor (10) is attached to the upper surface of the lever (3a) of the opening / closing valve (3) arranged on the discharge side of the inverter booster pump (1).

4. In paragraph 1, An abnormality detection and diagnosis device for an inverter booster pump, characterized in that the above acoustic emission sensor (10) is attached to the upper or lower surface of the stop plate (3b) of the opening / closing valve (3) arranged on the discharge side of the inverter booster pump (1).

5. In paragraph 1, An abnormality detection and diagnosis device for an inverter booster pump, characterized in that the above acoustic emission sensor (10) is attached to the circumference of a bolt (3c) provided on a stop plate of an opening / closing valve (3) placed on the discharge side of an inverter booster pump (1).

6. In paragraph 1, An abnormality detection and diagnosis device for an inverter booster pump, characterized in that the above acoustic emission sensor (10) is attached to a disk (3d) of an opening / closing valve (3) arranged on the discharge side of the inverter booster pump (1).

7. In paragraph 1, An abnormality detection and diagnosis device for an inverter booster pump, characterized in that the above acoustic emission sensor (10) is attached to the casing (5a) of a check valve (5) arranged on the discharge side of the inverter booster pump (1).

8. In paragraph 1, The above control PC (50) determines that cavitation has occurred when the number of vibrations higher than the threshold voltage during the event maintenance time in the input frequency band of 5 to 15 kHz exceeds the set number of times, determines that freezing has occurred when the measured temperature is 0°C or lower and the inverter booster pump is stopped and the number of vibrations higher than the threshold voltage during the event maintenance time in the input frequency band of 10 to 1000 Hz exceeds the set number of times, and determines that event energy has increased due to low water level when the time for which the average effective voltage in the input continuous acoustic emission signal exceeds the threshold voltage exceeds the set time.

9. In paragraph 1, The above control PC (50) is an abnormality detection and diagnosis device for an inverter booster pump, characterized in that it standardizes data on cavitation, freezing, and low water level of an inverter booster pump through repeated experiments, extracts characteristic variables according to cavitation, characteristic variables according to freezing, and characteristic variables according to low water level from the standardized data, selects the most distinguishable characteristic variables from the extracted characteristic variables, selects the main characteristic variables of cavitation, the main characteristic variables according to freezing, and the main characteristic variables according to low water level, and compares the set values ​​of the main characteristic variables with the measured values ​​of the main characteristic variables of the measured signal to identify the characteristics of the measured signal and determine the risk index.

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