JPH09292303A - Leaking-liquid sensor, leaking-liquid detecting method and liquid supplying and discharging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide leaking-liquid sensor, a leaking-liquid detecting method and a liquid supplying and discharging system, which can perform the perfect detection of the leakage of water supplied into a device and equipment and can also detect leaking oil. SOLUTION: This leaking-liquid sensor has a water-supply channel 2, which supplies liquid circulating in a device and equipment 1, a water-draining channel 3 for discharging the circulated liquid, a bypass 4 for communicating the water supply channel and the water-draining channel through switch valves 5 and 6, flow-rate sensors 7 and 8, which are provided at the water supplying channel at the front stage of the directional control valves and the water draining channel, and a microcomputer controller 10, which performs the control of the switch valves, the detection of the detected value of the flow-rate sensor and the correction of the detected value of the flow rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid leakage sensor for detecting liquid leakage, a liquid leakage detection method, and a liquid supply / drainage system, even though a liquid such as water or oil is used in the apparatus.

[0002]

2. Description of the Related Art Examples of the water used in the apparatus include, for example, an evacuation device for cooling a heat generating part with water, an electron microscope using a power source having a water cooling part, a physicochemical machine such as a mass spectrometer, an ion beam. There are semiconductor manufacturing equipment such as an ion implantation equipment having a water cooling part of a line, and an automatic medical analyzer for washing samples with water.

Further, examples of using oils include a hydraulic control device, a cutting machine, a grinding machine and the like.

When water is used in these devices, water leakage accidents occur due to work failure, corrosion, damage to parts due to service life, etc. at the connection parts, piping parts and the like. Basically, it is a device that does not cause work failure and proper replacement of life parts, but it is not possible to completely prevent water leakage.
A method is generally used in which a string-shaped sensor is provided inside the device to detect a change in impedance of the string sensor when water leaks and to treat the sensor.

Further, effective means for detecting oil leakage has not been easily obtained.

[0006]

A drawback of the prior art using a string-shaped sensor is that the detection of water leakage is linear,
This means that perfect detection cannot be performed. It takes a lot of time and labor to actually wire the equipment, such as heights and gaps in the equipment, and at the same time, there are always parts that cannot be wired.
Further, since oil itself has high insulation, it cannot be used as an oil leak sensor with a conventional string sensor.

For this reason, one of the inventors of the present application, in order to make it possible to detect the leakage of water in a portion that cannot be stretched, which is a drawback of the prior art using a strap-shaped sensor, is that the work of stretching the string is unnecessary. We have developed a method to detect water leakage by the direct measurement of water flow rate and comparison method (see: JIII Journal of Technical Disclosure, Official Gazette No. 95-8110).

The present invention improves the method of directly measuring the flow rate of water and the method based on the comparison method so as to be able to detect the complete leakage of water and further to detect the leakage of oil, a leakage detection method and a supply method. The purpose is to provide a drainage system.

[0009]

Means for Solving the Problems The constitution of the present invention to solve the above problems is as follows.

The liquid leakage sensor includes (1) first and second liquid supply passages for supplying liquid to the apparatus and equipment, and a drain passage for discharging liquid from the equipment and equipment. A flow sensor, a subtraction means for subtracting the measured flow rate values by the first and second flow rate sensors, and a comparison means for comparing the subtracted value of the subtraction means with a reference value. It is characterized in that it has a flow path for bypassing the facility and means for opening and closing the bypass flow path, and means for correcting the variation in the measured value of the flow rate by the first and second flow rate sensors.

(2) First and second flow rate sensors, which are provided in a liquid supply passage for liquid supplied to the device and equipment and a drain passage for discharging liquid from the device and equipment, respectively. First
A liquid leakage sensor having subtraction means for subtracting the measured value of the flow rate by the second flow rate sensor, and comparison means for comparing the subtracted value of the depletion means with a reference value.
Correction of the flow rate measured by the flow rate sensor as an input value, and the input value is corrected based on the variation of the flow rate measured values in the first and second flow rate sensors, which has been obtained in advance, as an output value. Means are provided.

(3) In (1) or (2), there is provided a first and second temperature sensor for measuring the temperature when passing through the inside of the device or equipment on the side of the liquid supply passage and the side of the liquid discharge passage. However, it is characterized in that it has means for correcting the comparison output of the comparison means by a flow rate change caused by a temperature difference between the first and second temperature sensors.

The liquid supply / drainage system has (4) the liquid leakage sensor of (1) or (2) or (3), and the comparison output obtained by the means for comparing the subtracted value with the reference value It is characterized by having an opening / closing valve provided on the side of the liquid supply path, or on the side of the liquid supply path and the side of the liquid discharge path, which is adapted to open and close.

(5) In (4), a constant flow valve provided in place of the first flow sensor provided on the liquid supply path side, an output of the second flow sensor and the constant flow rate. It is characterized by comprising means for comparing with a designated value of the valve and opening and closing the opening / closing valve on the side of the liquid supply passage or on the side of the liquid supply passage and the side of the liquid discharge passage by the comparison output.

(6) In (4) or (5), there is provided a means for displaying a liquid leakage state at the time of liquid leakage.

(7) In (4) or (5) or (6), there is provided means for displaying a flow rate value measured by the first and second flow rate sensors.

The liquid leakage detection method includes (8) a liquid supply path for supplying a liquid circulating in the device and the equipment, and a liquid supply path for discharging the liquid circulating in the device and the equipment. A drainage passage, a bypass passage that connects the liquid supply passage and the drainage passage via a switching valve, and a liquid supply passage and a drainage passage in front of the switching valve, respectively. A first and a second flow rate sensor, a flow rate adjuster for correcting the variation provided in the preceding stage of the flow rate sensor in either the liquid supply path or the drainage path, control of the switching valve, the flow rate The detection value of the sensor, and
In a leak sensor having a microcomputer (microcomputer) controller for controlling the flow rate regulator,
A first step of switching the switching valve to the bypass side with the flow rate regulator closed;
With a predetermined flow rate (for example, 20 liters / min) set to, a memory (Y7) for pulse counting of the flow meter on the liquid supply path side and the liquid discharge path side for a large flow rate.
H, Y8H) and a second predetermined flow rate (for example, 2 liters / min) of the flow rate adjuster, and the liquid supply path side and the drainage path side for a small flow rate. Memory for the pulse counting of the flow meter (Y7
L, Y8L) to obtain a third step,

[0018]

[Formula 2] a7 · Y7 + b7 → X7 a8 · Y8 + b8 → X8 The fourth step of establishing the parameter analysis flow rate conversion formula, and the fifth step of switching the switching valve to the device side and fully opening the flow rate regulator. A sixth step of calculating the flow rate (X7, X8) by the parameter analysis flow rate conversion formula determined in the fourth step, and a seventh step of calculating a flow rate difference ΔX of the flow rate (X7, X8). And Σ (ΔX ・ Δt) → ΔL
Eighth step of calculating the leakage amount more, and ΔL ≧ leakage set value? And a ninth step of outputting an alarm according to.

In the present invention, liquid is supplied to the liquid supply system to the apparatus and equipment via the flow rate sensor, and liquid is also discharged to the drainage system via the flow rate sensor. The principle method is that the values of the flow rate sensors are equal. However, in actual use, unless the fluctuations of the flow rate sensor are corrected, it will not function accurately as a leak sensor, and there will be a change in the flow rate due to the liquid that has absorbed heat when the liquid circulates inside the device. However, this is also done by paying attention to the fact that it does not function as an accurate leak sensor without correction. For example, a microcomputer is used to correct variations in the flow sensor and changes in the flow rate due to temperature changes. This makes it possible to achieve the intended purpose.

FIG. 2 schematically shows the characteristics of the flow sensor on the water supply channel side and the drain channel side when water is supplied to the equipment and facilities. The horizontal axis indicates the flow rate and the vertical axis indicates the output from the flow rate sensor. The number of pulses is taken. Axial flow impeller flow meter (FSW) RJ10- which is generally used as a flow sensor
When the 280 is used, the characteristics of the flow rate sensor on the water supply side and the flow rate sensor on the drainage side are as shown in this figure.
Shows characteristic straight lines with different slopes,
Since the variation of a general flow sensor is 10% of soil, it is too large to be used as a water leak sensor. On the other hand, when the water leakage sensor of the present invention is used, the variation can be kept within ± 1%.

[0021]

1 and 3 are explanatory views of an embodiment of a leak sensor according to the present invention. FIG. 1 is a system configuration diagram,
FIG. 3 is a flow diagram. In FIG. 1, 1 is an apparatus, equipment (for example, an electron microscope), 2 is an apparatus, a water supply channel for supplying water circulating in the equipment 1, 3 is an apparatus, equipment 1. A drainage channel for discharging the water circulating in the inside, 4 is a bypass channel connecting the water supply channel 2 and the drainage channel 3 via the switching valves 5 and 6, respectively, and 7 and 8 are in front of the switching valves 5 and 6. Water supply channel 2
And a flow rate sensor provided in the drainage channel 3,
Reference numeral 9 is a flow rate adjuster that is provided in the preceding stage of the water supply channel 2 and is used for correcting variations. 10 is control of the switching valves 5 and 6, detection of detection values of the flow rate sensors 7 and 8, and flow rate adjuster. 9 shows a microcomputer control device for performing the control of FIG.
The flow rate controller may be provided in the upstream of the drainage channel 3 or in the upstream of the water supply channel 2 and the drainage channel 3.

In this liquid leakage sensor, the flow rate sensors 7 and 8 are used.
The microcomputer controller 10 obtains the variation in the flow rate of the water discharged from the water supply channel 2 to the device and the drainage channel 3 supplied to the facility 1, and the leak determination is performed based on the result.

The operation will be described below with reference to FIGS. 1 and 3. In FIG. 1, a thick solid line indicates the flow of water and a thin broken line indicates the control line. FIG. 3 is a schematic flow of a control operation for correcting the variation of the flow rate sensor.

In FIG. 1, water enters the flow rate sensor 7 from the side of the water supply passage 2 through the flow rate adjuster 9, and the number of pulses proportional to the flow rate is sent to the microcomputer controller 10. Then, the water is directly sent to the device / equipment 1, exits the device / equipment 1, and is drained through the flow rate sensor 8 on the drain side.

At this time, the number of pulses proportional to the flow rate is sent to the microcomputer control unit 10, and the microcomputer control unit 10 detects the difference between the detected values of the flow rate sensor 7 on the water supply side and the flow rate sensor 8 on the drainage side. It is possible to detect the measured values of the flow rate sensor 7 and the flow rate sensor 8 in the state where the equipment and the device 1 are bypassed by the valves 5 and 6, and correct the flow rate as follows based on the detected values.

In FIG. 3, parameters are: water supply side 7, drainage side, flow rate (X) / pulse number (Y) = a, offset value = b, leak amount = ΔL.

First, as shown in FIG. 3A, with the flow rate regulator 9 closed, as shown in B, the switching valves 5 and 6 are switched to the bypass side (first step), and C
With the flow rate regulator 9 set to 20 liters / min, as shown in FIG. 4, as shown in D, a memory Y for pulse counting of the flow meter on the water supply side and the drainage side for large flow rate.
7H and Y8H are obtained (second step). Next, as shown in E, with the flow rate regulator 9 set to 2 liters / min, as shown in F, on the water supply side and the drainage side for the small flow rate. Memories Y7L, Y8 for pulse counting of flow meters
To obtain L (third step), and as shown in G,

[0028]

[Formula 3] a7 ・ Y7 + b7 → X7 a8 ・ Y8 + b8 → X8 The parameter analysis flow rate conversion formula is determined (fourth step) Next, as shown by H, switching valves 5, 6 (V1, V2) are switched to As shown in I, the flow rate regulator 9 is fully opened (fifth
Process).

As indicated by J, the flow rates X7 and X8 are calculated by the parameter analysis flow rate conversion formula determined in the fourth step (sixth step). As indicated by K, the flow rate difference ΔX between the flow rates X7 and X8 is calculated. Calculate (seventh step), as shown in L, Σ
Calculate leakage amount from (ΔX · Δt) → ΔL (eighth step)
Then, compare ΔL with the leak setting value, and as shown in M, ΔL
If is greater than or equal to the leakage set value, an alarm is output (ninth step). After that, as indicated by O, it is determined whether or not the alarm cancellation needs to be continued, and if necessary, the alarm is canceled as indicated by P. As an alarm output, a lamp may be blinked or a puzzer may be sounded, and the output can be used to perform various control operations.

As shown in the flow chart of FIG. 3, C, D, E,
Correction is performed at the F and G stages, and real-time measurement and determination are performed at the J, K, L, and M stages.

It was confirmed that an alarm output was generated when a leak amount of 5 cc (about 2%) was actually set between 5 liters and 20 liters in this leak sensor and water was leaked beyond the leak amount of 5 cc.

FIG. 4 is a system configuration diagram of the second embodiment, in which a temperature sensor is further provided in the system configuration of FIG. Reference numerals 11 and 12 denote temperature sensors provided on the water supply channel 2 side and the drain channel 3 side, respectively.
The detection results of 1 and 12 are input to the microcomputer control device 10 to perform temperature correction of the means for correcting the detection values of the flow rate sensors provided in the water supply passage 2 and the drainage passage 3. The difference from the system of FIG. 1 is that the temperature sensor 11
And 12 are provided for temperature correction.

In this example, when the water circulates in the device / equipment 1, the heat generated in the device / equipment 1 causes the temperature of the water to rise and the flow rate to change, resulting in deterioration of the performance of the water leakage sensor. Is improved by correction. The volume expansion rate due to temperature of water is 0.21 × 10- ^3, 50 ℃
The flow rate changes by about 1% due to the rise of the above value and cannot be ignored.

The leak detection method described with reference to FIGS.
The leak sensor has been described in the case where the switching valves 5 and 6 and the flow rate adjuster 9 are provided, but by the method as described above,
With the switching valves 5 and 6 and the flow rate adjuster 9 provided, the variation correction of the flow rate sensor is once determined by the flow rate conversion formula, and is stored in the microcomputer. Since the valves 5 and 6 and the flow rate regulator 9 are not required, the measured values of the flow rate by the first and second flow rate sensors are used as input values, and the input values are obtained in advance for the first and second flow rate sensors. By making the microcomputer operate the correction based on the variation of the measured value of the flow rate at the output value by the microcomputer, the device can be simplified, downsized, and priced.

FIG. 5 is a system configuration diagram of the third embodiment, and shows only the main part. In the system of FIG. 1 or 2, instead of the flow rate regulator 9, the water supply passage 2 and the drainage passage 3 are opened and closed. Valves 13 and 14 are provided. Other elements are the same as those in FIG. 1, and the variation correction and temperature correction portions are omitted. In this example, the opening / closing valve 13 on the water supply side (and the drain side in the case of the circulation type) is controlled by the output of the water leak sensor.

FIG. 6 is a system configuration diagram of the fourth embodiment, in which a constant flow valve 15 is used instead of the flow sensor 7 of FIG. The flow rate set in the constant flow valve 15 is separately provided to the microcomputer control device 10.

In the above embodiment, the case where water is supplied to and discharged from equipment and devices has been described. However, since it is a direct measurement method, it can be similarly used when oil is used. It can also be applied to equipment and devices that use oil, which was not possible with.

As shown in the above embodiments, the present invention is
The shortcomings of the water leak sensor method using the conventional string sensor are (1) the work of stretching the string is not necessary, and (2) the problem that the leak cannot be detected in the part that cannot be stretched does not occur. Since the liquid leakage can be detected completely and the variation of the flow rate sensor can be corrected by the comparison method, a high-performance liquid leakage sensor, a liquid leakage detection method, and a liquid supply / drainage system can be provided at low cost.
It is also possible to display the flow rate, which was not possible with the string sensor.

Further, it is possible to provide a high-performance liquid leakage sensor by compensating the flow rate change due to the temperature inside the equipment and the device, and further, controlling the liquid supply side and the liquid discharge side by the output of the liquid leakage sensor. By doing so, it is possible to stop the liquid supply and the liquid drainage, so that it is possible to prevent damage due to liquid leakage.

[0040]

INDUSTRIAL APPLICABILITY The present invention improves the method of directly measuring the flow rate of water and the method based on the comparison method to enable complete leak detection and further leak detection, and a leak detection method. Also, it is possible to provide a liquid supply / drainage system, which has a great industrial effect.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a liquid supply / drainage system having a liquid leakage sensor of the present invention.

FIG. 2 is a characteristic diagram of a flow rate sensor used in the leak sensor of FIG.

FIG. 3 is a flow diagram of the liquid supply / drainage system of FIG. 1.

FIG. 4 is an explanatory view of another embodiment of the liquid supply / drainage system having the liquid leakage sensor of the present invention.

FIG. 5 is an explanatory view of a main part of still another embodiment of the liquid supply / drainage system having the liquid leakage sensor of the present invention.

FIG. 6 is an explanatory view of a main part of still another embodiment of the liquid supply / drainage system having the liquid leakage sensor of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Device, equipment, 2 ... Water supply channel, 3 ... Drainage channel, 4 ... Bypass channel, 5, 6 ... Switching valve, 7, 8 ... Flow rate sensor, 9 ... Flow rate regulator, 10 ... Microcomputer control apparatus, 11, 12 ... Temperature sensor, 13, 14 ... Open / close valve, 15 ... Constant flow valve.

Claims (8)

[Claims] 1. A first flow rate sensor and a second flow rate sensor, which are respectively provided in a liquid supply path of a liquid supplied to an apparatus and a facility and a drain path discharged from the apparatus and a facility. In a liquid leakage sensor having subtraction means for subtracting the measured values of the flow rates by the first and second flow rate sensors, and means for comparing the subtracted value of the subtraction means with a reference value, a flow path that bypasses the device and equipment. And a means for opening and closing the bypass flow path,
A leak sensor, comprising means for correcting variations in the measured values of flow rate by the first and second flow rate sensors. 2. A first flow rate sensor and a second flow rate sensor, which are respectively provided in a liquid supply path for a liquid supplied to an apparatus and a facility and a drain path for discharging a liquid from the apparatus and a facility. In the liquid leakage sensor having subtraction means for subtracting the measured values of the flow rates by the first and second flow rate sensors, and means for comparing the subtracted value of the subtraction means with a reference value, the first and second flow rates There is provided correction means for taking the measured value of the flow rate by the sensor as an input value, and correcting the input value based on the variation of the measured value of the flow rate in the first and second flow rate sensors which has been obtained in advance to obtain the output value. A leak sensor, which is provided. 3. A first and a second measuring the temperature of the liquid passing through the apparatus and the equipment on the liquid supply passage side and the liquid discharge passage side.
3. The liquid leakage sensor according to claim 1 or 2, further comprising: a temperature sensor according to claim 1, and means for correcting the comparison output of the comparison means according to a flow rate change caused by a temperature difference between the first and second temperature sensors. 4. The liquid leakage sensor according to claim 1, 2 or 3, which is adapted to be opened and closed by a comparison output obtained by a means for comparing the subtracted value with the reference value. A supply / drainage system having an opening / closing valve provided on the liquid passage side or on the liquid supply passage side and the drainage passage side. 5. The first device provided on the liquid supply path side
Constant flow valve provided in place of the flow sensor of the second flow sensor, the output of the second flow sensor and a specified value of the constant flow valve are compared, and the comparison output is used for the liquid supply passage side or the liquid supply. The liquid supply / drainage system according to claim 4, further comprising means for opening and closing a switching valve on a road side and on the drainage path side. 6. The liquid supply / drainage system according to claim 4, further comprising means for displaying a liquid leakage state at the time of liquid leakage. 7. The liquid supply / drainage system according to claim 4, further comprising means for displaying a flow rate value measured by the first and second flow rate sensors. 8. A liquid supply passage for supplying a liquid circulating in the device and the equipment, a drainage passage for discharging the liquid circulating in the device and the equipment, and the liquid supply First and second flow rates respectively provided in a bypass passage that connects the liquid passage and the drain passage via a switching valve, and in the liquid supply passage and the drain passage before the switching valve, respectively. A sensor, a flow rate adjuster for correcting variations provided in the preceding stage of the flow rate sensor in any one of the liquid supply path and the drainage path, control of the switching valve, detection of a detection value of the flow rate sensor, A first step of switching the switching valve to a bypass side in a liquid leakage sensor having a microcomputer controller for controlling the flow rate regulator, with the flow rate regulator being closed; With the flow rate regulator set to the first predetermined flow rate,
Memory (Y7H, Y8H) for pulse counting of the flow meter on the liquid supply path side and the liquid discharge path side for a large flow rate.
And a second step of obtaining the flow rate adjuster at a second predetermined flow rate,
Memory (Y7L, Y8L) for pulse counting of the flow meter on the liquid supply path side and the liquid discharge path side for a small flow rate.
And a fourth step of determining the parameter analysis flow rate conversion formula by a7.Y7 + b7.fwdarw.X7 a8.Y8 + b8.fwdarw.X8, and switching the switching valve to the device side to control the flow rate regulator. And a sixth step of calculating a flow rate (X7, X8) by the parameter analysis flow rate conversion formula determined in the fourth step, and a flow rate difference Δ of the flow rate (X7, X8). Seventh step of calculating X, an eighth step of calculating the leakage amount from Σ (ΔX · Δt) → ΔL, and ΔL ≧ leakage set value? And a ninth step of outputting an alarm according to.