JP2010197332A - Grease deterioration detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously detect the deterioration of grease. <P>SOLUTION: This grease deterioration detector 20 has a grease arranging part 2 for arranging grease, an acoustic viscosity sensor 5 and a judging part 12 comparing the viscosity of unused grease with the viscosity of the grease detected by the acoustic viscosity sensor 5 to judge the deterioration degree of the grease. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a grease deterioration detection device.

  Conventionally, grease has been used to keep the drive section lubricated and airtight. When used in rotating equipment, grease deteriorates in characteristics due to high temperature overheating and contamination. Therefore, the rotating equipment is periodically stopped to measure the deterioration of the grease, and the grease is replaced.

In order to judge the deterioration of grease in such rotating equipment, a technique has been proposed in which the grease is irradiated with infrared rays and the degree of deterioration of the grease is evaluated based on a spectrum obtained from transmitted light. For example, a technique for evaluating the degree of deterioration of grease by infrared spectroscopy (hereinafter referred to as “IR”) at a frequency of 3,500 cm ⁻¹ (wavelength 286 nm) has been proposed (Patent Document 1). At a frequency of 1,725 cm ⁻¹ (wavelength 5, 797 nm), the infrared absorption intensity of the synthetic oil and the absorption intensity of the thickening agent appear to overlap, making it difficult to evaluate the deterioration degree of grease by IR. Therefore, in the proposed method, the degradation degree is evaluated using a short wavelength region of a frequency of 3,500 cm ⁻¹ (wavelength 286 nm).

On the other hand, since the power switchgear has a very low operating frequency, the method of using grease is close to that of a stationary device. Therefore, the cause of grease deterioration is different from high temperature overheating and foreign matter contamination. For example, a case where grease is used in a gas insulated switchgear (hereinafter referred to as “GIS”) will be described. When the system-operated GIS is operated after it has been inactive for a long time, the grease deterioration causes a malfunction, and it is impossible to cut off, and the electric circuit such as a coil is burned out.
Therefore, research on deterioration of grease in GIS has been performed (Non-Patent Document 1). The results of this study show that the main deterioration factor of grease is the base oil evaporation.

  In addition, a grease deterioration diagnosis device is proposed that is attached to a body of a gas tank of a gas circuit breaker and includes an observation window and a grease holder (Patent Document 2). This grease deterioration diagnosis device enables external monitoring of grease while the gas circuit breaker is in a live line state by monitoring the grease placed in the grease holder by a person using the observation window.

JP-A 63-263451 JP 2004-129344 A

“GIS disconnector life evaluation research” Technology Development News, No. 127, 2007 No.7

The proposed technique is a technique for periodically collecting grease for inspection or periodically monitoring the grease. For this reason, the proposed technology cannot detect grease degradation that occurs during other than periodic inspections.
Therefore, the present grease deterioration detection device aims to continuously detect grease deterioration.

In order to solve the above problems, a grease deterioration detection device is provided.
The grease deterioration detection apparatus according to the present invention is as described in the following (1) to (7).

(1) a grease placement section for placing grease;
An acoustic viscosity sensor;
A determination unit that determines the degree of deterioration by comparing the viscosity of the unused grease with the viscosity of the grease detected by the acoustic viscosity sensor;
Grease deterioration detecting device having
(2) The determination unit stores data defining the relationship between the viscosity of the grease and the period of use,
The determination of the degree of deterioration by the determination unit refers to the data, obtains a use period corresponding to the detected viscosity of the grease, and determines deterioration of the grease based on the obtained use period. The grease deterioration detection device described.
(3) The grease deterioration detecting device according to (1) or (2), wherein the grease is a colored grease.
(4) The grease deterioration detection device according to any one of (1) to (3), wherein the grease deterioration detection device detects grease deterioration of an operating mechanism mechanism portion of a gas insulated switchgear.
(5) The grease deterioration detection device according to any one of (1) to (3), wherein the grease deterioration detection device detects deterioration of grease in a bus container of the gas insulated switchgear.
(6) The grease deterioration detecting device according to (4), wherein the grease disposition unit, the acoustic viscosity sensor, and the determination unit are disposed inside an operation device container of the gas-insulated switchgear.
(7) The grease disposition unit and the acoustic viscosity sensor are disposed inside the bus bar container of the gas insulated switchgear, and the determination unit is disposed inside the operation device container of the gas insulated switchgear (5 ) Grease deterioration detector.

  This grease deterioration detection device has an effect of continuously detecting grease deterioration.

2 is a schematic diagram of a hardware configuration of a grease deterioration detection device 20. FIG. It is a figure which shows the relationship between the viscosity measured by the grease deterioration detection apparatus 20, and temperature. It is a figure which shows an example of the secular change of the grease viscosity measured by the grease deterioration detection apparatus. 3 is an example of a flowchart of deterioration detection processing by a grease deterioration detection device 20. It is a figure which shows an example which has arrange | positioned the grease deterioration detection apparatus 20 in GIS.

Hereinafter, a grease deterioration detection device according to one embodiment will be described with reference to the drawings.
The grease deterioration detection device determines the deterioration degree of the grease from the viscosity of the grease detected by the acoustic viscosity sensor. In the present specification, a product obtained by uniformly dispersing a thickener such as calcium, sodium, lithium, and aluminum soap in a synthetic oil called a base oil is referred to as “grease”.

  FIG. 1 is a diagram showing an outline of a hardware configuration of the grease deterioration detection device 20. As illustrated in FIG. 1, the grease deterioration detection device 20 includes a grease placement unit 2, an acoustic viscosity sensor 5, a control circuit 6, a determination unit 12, and a communication unit 18.

Hereinafter, each hardware component of the grease deterioration detection device 20 will be described in order.
The grease disposing unit 2 is a case for disposing the grease to be subjected to deterioration detection. As shown in FIG. 1, the grease disposing portion 2 may be integrally formed with the acoustic viscosity sensor 5.

The acoustic viscosity sensor 5 includes wavelength resonators 1 a and 1 b, an input converter 3, and an output converter 4.
The wavelength resonator 1a generates a predetermined standing wave by interacting with an electric signal output from the input converter 3. The frequency of the standing wave has a value determined by the design of the wavelength resonator 1a, and the amplitude is determined by the power level of the electric signal applied to the wavelength resonator 1a.
The grease layer at the boundary between the grease and the wavelength resonator 1a is swung by the standing wave, and generates a surface acoustic wave in the grease layer. The thickness of the layer is determined by the viscosity of the grease. If the viscosity is small, a thin layer is formed and a surface acoustic wave having a small amplitude is generated. If the viscosity is large, a thick layer is formed and a surface acoustic wave having a large amplitude is generated.
The surface acoustic wave propagated to the grease layer propagates from the contact surface between the wavelength resonator 1a and the grease to the contact surface between the wavelength resonator 1b and the grease. The wavelength resonator 1b vibrates the output converter 4 with the propagated surface acoustic wave. The output converter 4 converts vibration caused by surface acoustic waves into an electric signal.

In this way, the acoustic viscosity sensor 5 detects the viscosity of the grease by outputting an electrical signal based on the surface acoustic wave determined by the grease viscosity.
Further, since the acoustic viscosity sensor 5 can measure the physical properties of the viscosity itself, even the colored grease can detect the viscosity in the same manner. Therefore, unlike the optical measurement such as IR that cannot detect the viscosity of the grease discolored due to aging, the acoustic viscosity sensor 5 can detect the viscosity even for the grease discolored due to aging. .

The control circuit 6 is a circuit that converts an analog electric signal output from the acoustic viscosity sensor 5 into a digital signal or a general-purpose analog signal and transmits the digital signal to the determination unit 12.
The control circuit 6 may be integrated with the acoustic viscosity sensor 5 or may be integrated with the determination unit 12.

The determination unit 12 is a functional unit that determines the degree of deterioration of the grease from the viscosity of the grease detected by the acoustic viscosity sensor 5.
The determination unit 12 is, for example, the processing device 14 and the main storage device 16.
The processing device 14 is a device that executes arithmetic processing such as four arithmetic operations and logical operations. The processing device 14 executes the arithmetic processing by reading out and executing instructions in the program stored in the main storage device 16 from the main storage device 16. The program is an object program in which functions performed by the determination unit 12 are described. The processing device 14 implements the function of the determination unit 12 by executing the program.

  The main storage device 16 is, for example, at least one of a main memory, a cache memory, and a flash memory, and stores programs, instructions, and data. The main memory is, for example, an SRAM (Static Random Access Memory) and / or a DRAM (Dynamic Random Access Memory). The flash memory is, for example, an EEPROM (Electric Erasable Programmable ROM). As will be described later, the main storage device 16 stores the viscosity of the unused grease and / or data defining the relationship between the grease viscosity and the usage period.

  The communication unit 18 is hardware used to communicate with an external device such as a computer. The communication unit 18 is a circuit or a contact for performing communication using a specific physical layer and a data link layer according to a predetermined communication standard such as Ethernet (registered trademark) or token ring, for example, for network communication. It is a contact point for connection. By transmitting the degradation degree of grease determined by the determination unit 12 from the communication unit 18 to a remotely located computer or the like, the degradation degree of grease can be continuously monitored by a remotely located computer or the like. .

FIG. 2 is a diagram showing the relationship between the viscosity and temperature measured by the grease deterioration detection device 20.
The unused grease curve 51 shown in FIG. 2 shows the relationship between the viscosity detected from the unused grease and the temperature. An actual use grease curve 52 shown in FIG. 2 shows the relationship between the viscosity and temperature detected from the actually used grease. The acceleration deterioration grease curve 53 shown in FIG. 2 shows the relationship between the viscosity and temperature detected from the accelerated deterioration grease.

The conditions under which the grease was accelerated and deteriorated are as follows.
Temperature Normal temperature (range of -20 ℃ -60 ℃)
Pressure Normal pressure Acceleration condition Fixed amount of regular grease is left on the moisture absorbent material for a certain period of time. The degree of oil absorption due to accelerated deterioration is managed by preparing a plurality of samples having different standing times.

The usage conditions of the grease actually used are as follows.
Temperature Normal temperature (range of -20 ℃ -60 ℃)
Pressure Normal pressure Usage time 2,000 minutes

  As shown in FIG. 2, it can be seen that the viscosity curves of the grease shown in the unused grease curve 51 to the acceleration deterioration grease curve 53 increase with use.

FIG. 3 is a diagram illustrating an example of a change in grease viscosity over time measured by the grease deterioration detection device 20.
The grease viscosity change curve 101 shown in FIG. 3 shows that the viscosity increases as the grease usage time elapses.
As described in Non-Patent Document 1, generally, assuming that the initial base oil amount is 100%, the grease deteriorates when the residual oil content of the grease reaches 50%.
As the amount of base oil in the grease decreases, the viscosity increases. Therefore, when the amount of base oil is changed from 100% to 50%, the viscosity increases 2 to 3 times. Therefore, assuming that the viscosity due to the aging of the grease is twice the initial value, the deterioration threshold is 158AV in FIG. 3, and therefore the viscosity that can be determined as grease deterioration is 316AV.

Therefore, according to the example illustrated in FIG. 3, the determination unit 12 stores the initial viscosity, and transmits an alarm signal via the communication unit 18 when the detected viscosity is twice the initial viscosity. I can do it. The determination unit 12 may continuously measure the viscosity of the grease until the viscosity reaches twice the initial value, and may use the viscosity as the degree of deterioration of the grease. For example, when the viscosity is twice the initial value, the degree of deterioration is 100%, and when the viscosity is the initial value, the degree of deterioration is 0%. The determination unit 12 transmits the viscosity and / or deterioration degree to the remote monitoring system shown in FIG. 1 via the communication unit 18, so that an operator who uses the remote monitoring system can know the deterioration degree of the grease. I can do it.
As described above, the grease deterioration detection device 20 can continuously detect the deterioration of the grease by determining the degree of deterioration of the grease from the unused grease viscosity and the detected grease viscosity.

  Further, as shown in FIG. 3, the viscosity and the use time have a certain relationship. Therefore, the determination unit 12 can determine the use time from the detected viscosity by storing the data in the main storage device 16 and referring to the relationship between the viscosity and the use time as shown in FIG. For example, when it is determined to replace the grease after 10 years of use, the determination unit 12 refers to the above data to obtain a use period corresponding to the detected viscosity, and sets the threshold that this trial period is 10 years. You may determine the presence or absence of deterioration by whether it exceeds.

  FIG. 4 is an example of a flowchart of deterioration detection processing by the grease deterioration detection device 20. The determination unit 12 detects the viscosity of the grease to be detected arranged in the grease arrangement unit 2 by turning on a start switch (not shown) (S201). The determination part 12 memorize | stores the detected viscosity in the main memory 16 as an initial viscosity or the viscosity of unused grease, when the viscosity detection in step S201 is the first viscosity detection (S202 Yes). The determination part 12 progresses to step S204, when the viscosity detection in step S201 is not the first viscosity detection (S202 No).

  The determination unit 12 determines the degree of deterioration by comparing the viscosity of the grease detected in step S201 with the viscosity of the unused grease stored in the main storage device 16 (S204). When the deterioration level is larger than the predetermined threshold (S205 Yes), the grease deterioration detection device 20 outputs an alarm via the communication unit 18 (S206). The predetermined threshold is, for example, a value of 100% when the viscosity is 316AV as described above. When it is less than the threshold (No in S206), the grease deterioration detection device 20 outputs the viscosity and / or the deterioration degree via the communication unit 18 (S207). If there is a stop signal (Yes in S208), the grease deterioration detection device 20 ends the deterioration detection process. If there is no stop signal (No in S208), the grease deterioration detection apparatus 20 returns to Step S201 and continuously performs the deterioration detection process.

  FIG. 5 is a diagram illustrating an example in which the grease deterioration detection device 20a and the grease deterioration detection device 20b are arranged in the GIS 30. The GIS 30 includes busbar containers 31 a and 31 b and an operation device container 32. The busbar containers 31a and 31b house operating devices for opening and closing circuits such as the busbar BUS, the circuit breaker CB, the grounding switch disconnector DS / ES, and the disconnector DS. An operation device for operating the circuit breaker CB, the disconnect switch DS / ES with a ground switch, the disconnect switch DS, and the like has an operation transmission mechanism such as a crank. The operating device is operated by a driving force generated by a driving unit such as a motor disposed in the operation device container 32.

As shown in FIG. 5, the grease deterioration detection device 20 a includes a grease placement unit 2, a grease viscosity detection unit 22 a having an acoustic viscosity sensor 5, a determination circuit 24 a having a control circuit 6, a determination unit 12, and a communication unit 18. It may be installed separately. This is because the determination device 24a is an electronic device, and thus avoids being uncontrollable due to a high voltage environment inside the GIS 30. When the determination device 24a is housed in the operating device container, it is not normally affected by the high voltage due to the shielding effect of the busbar containers 31a and 31b. In addition, the acoustic viscosity sensor 5 is not affected by electromagnetic waves because it detects the viscosity of grease using a physical phenomenon called surface acoustic waves.
In this way, the grease deterioration detecting device 20a can detect the viscosity of the grease even when the voltage is increased.

  The grease deterioration detection device 20a shown in FIG. 5 does not detect the deterioration of the grease actually applied to the operation equipment inside the GIS 30, but is located in the same environment inside the GIS 30 and is separately arranged in the grease arrangement portion 2. Detects grease deterioration. The inside of the bus container of the GIS 30 is an environment filled with an inert gas such as SF6 at a high pressure. The grease is placed in an environment where oxidative deterioration due to high temperature does not occur.

  Grease is applied to the operating device in the GIS 30 and the driving unit in the operation device container 32, and the operating device and the driving unit perform a smooth operation due to the fluidity characteristic of the grease. The grease applied to the operating device and the drive unit is heated by converting kinetic energy into heat energy during operation of these devices. However, the operation of the GIS 30 to open and close the circuit is extremely rare, such as during maintenance once a year to several years, or during an abnormality that detects discharge. Therefore, the grease applied to the operating device and the driving unit is disposed in the operating device and the driving unit that are stationary at room temperature.

  As described above, since the operating equipment inside the GIS 30 is operated in a stationary state, the grease deterioration detection device 20 is arranged in the same environment as the actually used grease. Can be accurately estimated. Further, by disposing the grease deterioration detection device inside the GIS 30, it is possible to accurately detect the deterioration of the grease without checking the opening of the GIS 30.

Further, the grease deterioration detection device 20b shown in FIG. 5 is disposed in the operation device container 32 in order to monitor the state of the grease applied to the drive unit in the operation device container 32.
The grease deterioration detection device 20b does not detect the deterioration of the grease actually applied to the drive unit in the operation device container 32, but is in the same environment in the operation device container 32 and separately disposed in the grease arrangement unit 2. Detect the deterioration of the grease. The operation device container 32 has a rainproof and moistureproof structure, and is an environment in which dust and the like are not mixed. In addition, since the operation device in the GIS 30 does not operate, the drive unit in the operation device container 32 does not operate in the same manner.
As described above, since the operation device inside the operation device container 32 is operated in a stationary state, the grease deterioration detection device 20 can be realized by arranging the grease deterioration detection device 20 in the same environment as the actually used grease. It is possible to accurately detect the deterioration of the grease used.

  As described above, the grease deterioration detection device 20 can continuously and automatically detect the deterioration of grease in a normal temperature environment. Further, by disposing inside the GIS 30, it is possible to detect the deterioration of the grease without checking the opening of the GIS 30. These deterioration detections can be confirmed by a remotely located computer.

DESCRIPTION OF SYMBOLS 1a, 1b Wavelength resonator 2 Grease arrangement | positioning part 3 Input converter 4 Output converter 5 Acoustic-type viscosity sensor 6 Control circuit 12 Judgment part 14 Processing apparatus 16 Main memory 18 Communication part 20, 20a, 20b Grease deterioration detection apparatus 22a Grease Viscosity detector 24a determination device 30 GIS
31a Busbar container 32 Actuator container

Claims (7)

A grease placement section for placing grease;
An acoustic viscosity sensor;
A determination unit that determines the degree of deterioration by comparing the viscosity of the unused grease with the viscosity of the grease detected by the acoustic viscosity sensor;
Grease deterioration detecting device having The determination unit stores data defining a relationship between the viscosity of the grease and a use period,
The determination of the degree of deterioration by the determination unit refers to the data, obtains a use period corresponding to the detected viscosity of the grease, and determines deterioration of the grease based on the obtained use period. The grease deterioration detection device described.   The grease deterioration detection device according to claim 1, wherein the grease is a colored grease.   The grease deterioration detection device according to any one of claims 1 to 3, wherein the grease deterioration detection device detects the deterioration of grease in an operating mechanism mechanism of a gas insulated switchgear.   The grease deterioration detection device according to any one of claims 1 to 3, wherein the grease deterioration detection device detects deterioration of grease in a bus container of a gas insulated switchgear.   The grease deterioration detection device according to claim 4, wherein the grease placement unit, the acoustic viscosity sensor, and the determination unit are placed inside an operation device container of the gas insulated switchgear.   The said grease arrangement | positioning part and the said acoustic viscosity sensor are arrange | positioned inside the bus-bar container of the said gas insulated switchgear, The said determination part is arrange | positioned inside the operating device container of the said gas insulated switchgear. Grease deterioration detector.

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