KR20240007460A - Leakage and leakage location detection device and method for film-type organic solvent detection sensor - Google Patents

Abstract

The present invention relates to a leak and a leak location detection device (10) using a film-type organic solvent detection sensor (40). More specifically, when organic solvent leakage occurs in the film-type organic solvent detection sensor, a direct current voltage is applied. Liquid leakage is detected by changing the resistance value of the sensing line 421 of the sensing line 42 so that it is disconnected or close to a disconnection (liquid leakage). When liquid leakage is detected, switching is applied to an alternating current voltage to determine the location of the disconnection (liquid leakage). By measuring the capacitance up to and comparing the measured capacitance value with the capacitance value before liquid leakage, distance information to the disconnection (liquid leakage) distance can be calculated. At this time, the length of the detection sensor 40 is formed as a length within a linear area where the capacitance increases with distance in the electrostatic capacitance distribution diagram, so that the distance position by electrostatic capacitance can be accurately detected and information provided to the management system. In particular, when the capacitance is measured on both sides of the detection sensor 40, the length of the detection sensor 40 can be doubled, and the location of leakage and liquid leakage can simplify installation to reduce costs and improve management convenience. It relates to a sensing device (10).

Description

Leakage and leakage location detection device and method for film-type organic solvent detection sensor}

The present invention relates to a device for detecting leakage and location of leakage using a film-type organic solvent detection sensor. More specifically, when organic solvent leakage occurs in the film-type organic solvent detection sensor, it is detected in the sensing line 42 by a direct current voltage applied. Liquid leakage is detected by changing the resistance value of the detection line 421 so that it is disconnected or close to disconnection. When liquid leakage is detected, switching is applied to AC voltage to measure the capacitance up to the disconnection (leakage) position, and the measured capacitance By comparing the value with the capacitance value before leakage, the distance information to the disconnection (liquid leakage) distance can be calculated to detect the leakage location.

At this time, the length of the detection sensor 40 is formed as a length within a linear region in which the capacitance increases with distance in the capacitance distribution diagram (see FIG. 2C), so that the sensor distance by capacitance can be accurately detected. In particular, if capacitance is measured on both sides of the detection sensor 40, the effective length of the detection sensor 40 can be doubled.

Liquid leak detection devices are used in industrial sites such as processes for processing dangerous compound liquids, computer rooms, devices that supply compound liquids and organic solvents through long pipelines, or piping in water treatment plants, and can cause fire and environmental problems in the event of water leakage. It is widely used to prevent contamination, equipment damage, and resource waste.

Conventional liquid leak detection devices use a liquid leak detection cable composed of multiple wires to determine whether liquid is leaking by detecting changes in resistance due to leakage between adjacent wires included in the cable. However, cable-type liquid leak detection devices have lower installation costs. It is expensive, its use is limited because the installation length of the cable is limited, and it is difficult to install and cannot be reused, making maintenance difficult.

In order to compensate for the shortcomings of the cable-type leak detection device, a leak detection device using film-type sensors such as a water leak detection sensor, a chemical leak detection sensor, and an organic solvent and oil detection sensor has been developed. However, leak detection devices using conventional film-type sensors used parallel-connected sensors to extend the installation length, which had the problem of increasing installation costs due to an increase in the number of controllers and installation complexity, and leakage at some point within the detection sensor. Since the location of the leak could not be detected, there was the inconvenience of having to inspect all sections where detection sensors were installed to repair the leak on site.

Therefore, there is a need for a new detection device that can extend the length of use of film-type organic solvent detection sensors, reduce installation costs, and provide information by not only detecting liquid leakage but also accurately identifying the location of leakage within the detection sensor. This came to the fore.

[Patent Document 1] Korean Patent No. 10-1719523 (registered on March 20, 2017): Organic solvent leak detection device [Patent Document 2] Korean Patent Registration No. 10-1932892 (registered on December 19, 2018): Multiple leak and fire detection device

In order to solve the above problem, the purpose is to provide a method and detection device for detecting leakage and location using a film-type organic solvent detection sensor that can detect leakage and accurately calculate the location of leakage.

In the leakage and leakage location detection device (10) using a film-type organic solvent detection sensor (40),

The leakage and leakage location detection device 10 includes a film-type organic solvent detection sensor 40 formed by sequentially stacking a base film and a protective film layer having a plurality of line layers and sensing holes; One or more slave controllers (30) coupled to an end of the detection sensor (40) to apply power to the detection sensor (40); It includes a master controller (20) connected in series or parallel with the one or more slave controllers (30) to perform power supply and communication functions,

The slave controller 20 applies direct current power, and the master controller 20 detects liquid leakage based on the change in resistance value of the detection sensor 40. When liquid leakage is detected, the slave controller 20 Switching is applied to AC power, and the master controller 20 determines the location of leaked liquid based on the capacitance value formed in the detection sensor 40,

The detection sensor 40 includes a detection line 421 formed of conductive carbon and alkyd resin and a circuit line 422 formed of conductive metal, and the slave controller 30 includes a direct current voltage generator 31 and an alternating current voltage generator. It includes a generator (32),

The length of the film-type organic solvent detection sensor 40 is within a range corresponding to the linear region where the capacitance increases among the capacitance distribution according to the distance,

In the master controller 20, slave controllers 30 and film-type organic solvent detection sensors 40, each assigned a unique number, are alternately connected and arranged in series,

The film-type organic solvent detection sensor 40 is a power outage in the detection sensor 40 measured at the power line 41 and the sensing line 42 that supply power from the master controller 20 to each slave controller 30. A leakage and leakage location detection device (10), characterized in that a communication line (43) for transmitting the capacity value to the master controller (20) is further formed.

In the method of detecting the leakage position by a leakage position detection device including a film-type organic solvent detection sensor (40), a slave controller (30), and a master controller (20),

The slave controller 20 applies direct current power, and the master controller 20 detects liquid leakage based on a change in the resistance value of the detection sensor 40; If it is determined that there is a leak in the detection step, the slave controller 20 switches to AC power and applies power; a power switching step; The master controller 20 includes a leakage position detection step of determining the leakage position based on the capacitance value formed in the detection sensor 40, and

The leakage location detection step is a method of detecting the leakage location using a leakage location detection device, characterized in that the leakage location is calculated based on ' Lo = (Co/C _T ) L _T '.

Co: Capacitance value measured when the detection sensor is disconnected (leakage)

C _T : Capacitance value measured by the detection sensor before disconnection (liquid leakage)

Lo: Length from the slave controller (30) to the point of disconnection (liquid leakage)

L _T : Length of detection sensor connected to slave controller

The leakage and leakage location detection device (10) using the film-type organic solvent detection sensor (40) according to the present invention,

1. The detection sensor 40 quickly detects leakage by applying a direct current voltage, and switches to alternating current voltage after detecting the leakage, which has the effect of quickly detecting the location of the leakage through capacitance measurement up to the point of leakage.

2. The effective length of the detection sensor 40 is limited by the linear area in the capacitance distribution diagram, and AC voltage can be applied to each detection sensor 40 from the slave controller 30 mounted on both sides of the detection sensor 40. By providing a structure with a structure, the effective length of the detection sensor 40 is doubled.

3. The sequential simple series connection structure of the detection sensor 40 and the controller makes it easy to install, and provides information on the exact location of the leak rather than the area where the leak occurs, which has the effect of reducing maintenance time and costs.

1A to 1C are plan views showing various connection methods of the master controller 20, the slave controller 30 equipped with a direct current voltage and an alternating current voltage generator, and the detection sensor 40 according to the present invention.
Figure 2a is a schematic diagram showing a representative film-type detection sensor 40 with five lines used in the present invention.
Figure 2b is a graph showing the resistance distribution of the detection line 421 of the detection sensor 40 according to one embodiment over time.
Figure 2c is a capacitance distribution diagram according to the sensor distance after liquid leakage occurs in the detection sensor 40 according to an embodiment.
Figure 3 is a block diagram of leakage detection and distance detection measurement of the detection sensor 40 according to the present invention.
Figure 4 is a configuration diagram of the sensing device 10 showing the circuit connection state when applying DC voltage to the front slave controller 30 according to the present invention.
Figure 5 is a schematic diagram illustrating the measurement of the liquid leakage distance after liquid leakage occurs in the detection sensor 40 according to the present invention.
Figure 6 is a structural diagram of doubling the length of the detection sensor 40 by applying an alternating current voltage to each slave controller 30 installed at both ends of the detection sensor 40.
FIG. 7 is a structural diagram combining a measurement structure diagram and a capacitance distribution diagram when leakage occurs due to deflection from the detection sensor 40 toward the front slave controller 30.
FIG. 8 is a structural diagram combining a measurement structure diagram and a capacitance distribution diagram when leakage occurs due to deflection from the detection sensor 40 toward the rear slave controller 30.
Figure 9 is a capacitance distribution chart measured for the length of the disconnected sensor after liquid leakage or disconnection occurs in the detection sensor 40 according to an embodiment.

One. leakage and Location of leak Sensing device (10)

The leakage and leakage location detection device (10) using the film-type organic solvent detection sensor (40) of the present invention,

It is comprised of a master controller (20), a slave controller (30), and a film-type organic solvent detection sensor (40).

go. Master Controller(20)

The master controller 20 supplies power to the slave controller 30 and performs the function of controlling the slave controller 30. Data received from the slave controller 30 through the communication line 43 (two-way communication) Based on the information, determine whether there is a leak and the location of the leak.

me. Slave controller (30)

The slave controller 30 consists of a direct current (DC) voltage generator 31, an alternating current (AC) voltage generator 32, a signal amplifier 33, and an active filter 34, and a film-type organic solvent detection sensor 40. It is coupled to the end of and plays the role of applying power.

In relation to the application of power, the slave controller 30 is equipped with a direct current voltage generator 31 and an alternating current voltage generator 32 or only an alternating current voltage generator and generates direct current (DC) voltage and alternating current (AC) voltage by the supplied power. It is generated selectively and applied to the sensing line 42 of the detection sensor 40.

In other words, in the past, only direct current voltage was applied to the detection sensor 40 to determine whether a wire was broken (liquid leakage). However, by switching and applying an alternating current voltage, the leakage distance was calculated by measuring capacitance up to the location of the broken wire (liquid leakage) due to leakage. will be.

all. Film-type organic solvent detection sensor (40)

The film-type organic solvent detection sensor 40 is formed in a strip shape by sequentially stacking a base film and a protective film layer with a plurality of line layers and sensing holes. A slave controller is installed at the end of the film-type organic solvent detection sensor 40. (30) is combined.

The base film and protective film layer maintain the line formation without damage while preventing the inner line layer from being exposed to the outside, and contact with the outside is made through the sensing holes at both ends of the detection sensor 40 or the protective film layer. .

Figure 2a is a schematic diagram showing a film-type organic solvent detection sensor 40 with five representative lines used in the present invention.

The detection sensor 40 consists of two power lines 41 for applying power, a detection line 421 for detecting liquid leakage, and a circuit line 422 made of a conductive material (silver or copper, etc.). and a communication line 43 that performs two-way communication between the slave controller 30 and the master controller 20.

The sensing line 421 can be formed using a polymer compound containing conductive carbon and alkyd resin. The conductive carbon conducts the applied power, and alkyd resin is included as a binder. Preferably, the line can be formed by mixing 50 to 90% by weight of conductive carbon, 5 to 30% by weight of alkyd resin, and 5 to 20% by weight of POSS (Polyhedral Oligomeric Silsequioxane) as another polymer compound.

The detection line 421 communicates with the outside through a sensing hole in the protective film layer, and when leakage occurs, the leakage liquid contacts the detection line 421 through the sensing hole. When the detection line 421 is contacted with leakage liquid, the alkyd resin decomposes and expands to swell, resulting in a disconnection phenomenon that increases the resistance value to a disconnection or close to disconnection in a short period of time. Therefore, the present invention detects leakage using the disconnection phenomenon and confirms the location of the disconnection in the sensor through electrostatic capacitance.

The length of the detection sensor 40 can be adjusted in the range of AC voltage 1~5V, frequency 100Hz~1KHz, and sensor resistance value 1~990㏀. If it is outside the above range, the sensing line 421 may be overheated and damaged or the capacitance may not be measured properly, so it is desirable to adjust it to the above range.

When the applied voltage is high, the capacitance of the sensor increases, and when the applied frequency or initial resistance value is high, the linear area in the capacitance distribution over the length of the sensor is reduced, which reduces the installation length of the sensor installed between each slave controller (30). There is. On the other hand, if the frequency is too low, the sensor's response speed is too slow, and if the initial resistance value is too low, the sensor's detection characteristics deteriorate. Therefore, it is desirable to select an appropriate voltage, frequency, and initial DC resistance value that satisfies the user's needs.

2. Connection type between components of leakage and leakage location detection device (10)

1A to 1C are plan views showing the connection method of the master controller 20, the slave controller 30 equipped with an AC voltage generator, and the detection sensor 40 according to the present invention.

Figure 1a shows a configuration in which a plurality of slave controllers 30 are connected in series to one master controller 20, and the slave controllers 30 are connected with a detection sensor 40.

In the above configuration, power is supplied to and communication with the other slave controller 30 through the detection sensor 40, so the detection sensor 40 has two power lines 41, two sensing lines 42, and one communication line. It is preferable to use a form that has all five lines, such as (43). In this configuration, the slave controllers 30 on both sides of the detection sensor 40 are each equipped with an AC voltage generator 32, so that the capacitance value can be measured in each direction by applying an AC voltage through both ends of the detection sensor 40. You can.

Figure 1b shows that the detection sensor 40 is used alone, and a slave controller 30 with an AC voltage generator 32 is installed at both ends of the detection sensor 40, and the slave controller 30 is installed in the master controller 20. ) is a configuration connected in parallel.

The length of the detection sensor 40 can be provided by increasing it to twice the length of the linear region (LR) in the capacitance distribution diagram according to the length. A single sensor device capable of bidirectional capacitance measurement can be connected in parallel to the master controller 20 to detect leakage in multiple, non-continuous directions through one master controller 20.

As shown in Figure 1c , the detection sensor 40 can be used alone, and the detection device 10 can be configured with an AC voltage generator 32 on only the slave controller 30 on one side of the detection sensor 40.

In this configuration, the detection sensor 40 is provided with a length equal to the linear area. Therefore, a single sensor device capable of measuring unidirectional capacitance can be connected in parallel to the master controller 20 to detect leakage in multiple, non-continuous directions through one master controller 20.

Since the detection device 10 of FIG. 1C supplies power and controls from the master controller 20 only to the slave controller 30 on one side of the detection sensor 40, it is connected to the slave controller 30 installed at the end opposite to the detection sensor 40. Since power supply and communication connection are not required, the line in the detection sensor 40 can be used in a form in which only the sensing line 42 is formed.

3. Determination of leakage and location of leakage

Figure 3 is a measurement block diagram that can measure leakage and location of liquid using the organic solvent detection sensor 40 according to an embodiment of the present invention, and Figure 4 shows the front of both ends of the detection sensor 40 of the present invention. This is a block diagram showing an example of installing the slave controller 30 and the rear slave controller 30.

go. Determination of leakage

1) Applying direct current voltage

A direct current voltage is applied to the end of the detection sensor 40 through the direct current voltage generator 31.

2) Determination of leakage through change in resistance value

Leakage of liquid is determined through a change in the resistance value of the sensing line 42 of the detection sensor 40.

Since the detection line 421 of the detection sensor 40 is made of conductive materials such as conductive carbon and alkyd resin, when it comes into contact with spilled oil or organic solvent, phenomena such as expansion and swelling of the alkyd resin occur for a short period of time. As shown in FIG. 2b, the resistance change of the detection sensor 40 rapidly increases from the initial value of tens of KΩ to hundreds of MΩ, and the leakage state of the organic solvent is detected using the characteristics of this disconnection phenomenon.

me. Determination of leak location

3) When detecting leakage, apply AC voltage to the detection sensor (40)

The slave controller 30, which detects the disconnection (liquid leakage) of the detection sensor 40 by measuring the resistance value, switches from the DC voltage generator 31 to the AC voltage generator 32 using the MUX to generate the AC voltage generator 32. ) is applied to the detection sensor 40.

4) Measurement of capacitance value (capacitance) generated between detection line 421 and circuit line 422 and calculation of distance

The capacitance generated between the sensing line 421 and the circuit line 422 of the sensing line 42 is measured, and the signal amplifier 33, active filter 34, ADC (analog-to-digital converter), and DSP (digital converter) are measured. Measure the capacitance value through a signal processor).

That is, after detecting the occurrence of liquid leakage, an alternating current voltage is applied to the end of the detection sensor 40 to measure the capacitance value up to the point where a disconnection phenomenon occurs on the sensing line 42, and the measured capacitance value is the amount of liquid leakage. The distance to the leakage location can be calculated by comparing the capacitance value for the entire detection sensor 40 distance.

For example, as shown in Figure 2c, the capacitance value is divided into a linear region (LR) and a saturation region (SR) depending on the length. The capacitance value in the linear region increases linearly with the sensor length (distance), and the capacitance value in the saturation region does not change depending on the sensor length (distance). Therefore, in the linear region, the distance can be measured by the capacitance value, but in the saturated region, the capacitance values at all distances are almost the same, so the change in capacitance value according to distance cannot be known.

Therefore, if the length of the detection sensor 40 is set within the range of the linear region and then the capacitance value is measured and compared, the length to the disconnection part can be calculated based on the capacitance value, so the location of the leak can be accurately known. Additionally, when AC voltage is applied to both ends of the detection sensor 40, the total length of the detection sensor 40 can be set to within twice the linear area.

all. Comparison with existing organic solvent detection sensors

The installation length of existing organic solvent detection sensors is limited to around 10m per channel of the controller due to malfunction problems caused by water and organic solvents. Therefore, when installing tens to hundreds of meters, 10 m long sensors are connected in parallel and installed using dozens of controllers. This existing method increases installation costs and maintenance/repair costs due to the use of multiple controllers. However, in the case of the detection device 10, which is installed continuously in series as in the present invention and accurately calculates the location of leakage within the detection sensor 40, installation costs can be reduced and scalability can be improved, so there are disadvantages of parallel installation. can complement.

4. How to calculate the distance to the point of leakage according to the electrostatic capacity value

Figure 5 is an explanatory diagram showing a method of measuring the capacitance value of the detection sensor 40 when a disconnection (liquid leakage) occurs in the sensing line 42 after liquid leakage occurs.

The detection sensor 40 is composed of a detection line 421, a resistance 421a of the detection line, a circuit line 422, a resistance 422a of the circuit line, and a capacitor 423 between the detection line and the circuit line. When this occurs, a disconnection phenomenon occurs at the point of leakage, and the leakage distance (Lo) is determined by the formula below.

Lo = (Co/C _T ) L _T

■Co: Capacitance value measured when the detection sensor is disconnected (leakage)

■C _T : Total capacitance value measured by the detection sensor before disconnection (liquid leakage)

■Lo: Length from the slave controller (30) to the point of disconnection (liquid leakage)

■L _T : Length of detection sensor connected to slave controller

5. Example of calculating leakage location by type of leakage location

Figure 6 is a structural diagram of doubling the length of the detection sensor 40 by applying an alternating current voltage to each slave controller 30 installed at both ends of the detection sensor 40.

The detection device 10 is equipped with alternating current voltage generators in the slave controllers 30a and 30b at both ends of the detection sensor 40, and the detection sensor 40 has a 2LR length of the linear region (LR) in the capacitance distribution according to the distance. It has a structure installed by setting it to .

① The sensing device 10 measures the capacitance value after applying AC voltage to one slave controller 30a, and ② sequentially applies AC voltage to the other slave controller 30b and measures the capacitance value. Compare and review the two values to determine the location of the leak.

Using this method, the location of leaked liquid can be detected between 2LR, which is twice the linear area distance of the sensor, so compared to the method of detecting the location of leaked liquid by applying AC voltage only on one side of the detection sensor 40, the detection sensor (40) is twice as large. 40) Length can be provided. In other words, increasing the length of the detection sensor 40 can reduce the usage of the slave controller 30, thereby reducing installation costs.

In the drawing, C1 is the capacitance value measured according to the distance by applying an alternating current (AC) voltage from the front slave controller (30a), and C2 is a capacitance value measured according to the distance by applying an alternating current (AC) voltage from the rear slave controller (30b). This is the electrostatic capacity value. The highest capacitance value C _T is the capacitance value at which LR, the center of the detection sensor 40, is located.

Figure 7 shows C1, which is the capacitance value distribution when leakage occurs due to bias towards the detection sensor 40 in the direction of the front slave controller 30a.

As shown in the figure, leakage occurred at the detection sensor (40) distance LRS1 in the direction of the front slave controller (30a), causing a disconnection, and the highest capacitance value Co of the front slave controller (30a) was measured at that point. do.

On the other hand, no liquid leakage occurs in the detection sensor 40 in the direction of the rear slave controller 30b, so the C2 value has the highest capacitance C _T value. In other words, if the leakage point is biased to an area shorter than LR based on the central point of the sensor length 2LR between the two slave controllers 30 and leakage occurs, the highest value Co of C1 becomes the capacitance value of the leakage point. At this time, Co in the direction (≤LR) of the slave controller 30a where liquid leakage occurred always has a smaller value than the C _T value in the direction of the slave controller 30 where liquid leakage did not occur (C _T ≥ Co).

Figure 8 shows the C1 and C2 values when leakage occurs in the detection sensor 40 in the direction (≥LR) of the rear slave controller 30b and a disconnection occurs.

A leak occurred at the detection sensor (40) distance LRS1 in the direction of the rear slave controller (30b), causing a disconnection. At that point, the maximum capacitance value Co of the rear slave controller (30b) was measured, and on the other hand, the maximum capacitance value Co of the rear slave controller (30b) was measured. The maximum C value at the detection sensor 40 in the direction (30a) has a C _T value.

Therefore, the location distance of the leakage liquid can be calculated as 2LR-(LR+LRS2) based on the rear slave controller 30b.

Figure 9 is a distribution chart of electrostatic capacity (capacitance) measured over the sensor length up to the disconnected position after a disconnection occurs in the detection sensor 40. In other words, it is the capacitance distribution over the sensor length.

※ The voltage used in the above measurement is AC 1V, the frequency is 100Hz, and the initial DC resistance value of the 30m sensor is 1.5MΩ (53 KΩ per 1m).

As a result of the measurement, the capacitance distribution for the length of the single-wire sensor in the linear area is linear, and the linear length is about 30m.

Therefore, when the slave controllers 30 on both sides of the detection sensor 40 are equipped with AC voltage generators and AC voltage is applied, the detection sensor 40, which is twice the length LR of the linear detection sensor 40, is installed at 60 m with a length of 2LR. This allows you to detect the location of the leak.

Here, the length of the linear area of the detection sensor 40 according to the application of alternating current to the detection sensor 40 is determined as a function of the resistance of the detection sensor 40, the applied AC voltage, and the applied frequency.

6. Leakage location measurement experiment according to the present invention

Front and rear slave controllers (30) equipped with a direct current voltage generator and an alternating current voltage generator at both ends of a detection sensor (40) equipped with two power lines, two sensing lines (421), and one communication line according to the present invention. Each was installed and configured in the same way as the measurement experiment in Figure 9.

Before disconnection occurred, the resistance value when supplying direct current voltage was measured within a certain range.

Additionally, the capacitance (C _T ) when supplying AC voltage was measured to be about 1000 pF.

An organic solvent is supplied to a point 20 m behind the front slave controller 30, which is a point deviated 10 m from the center of the detection sensor 40 toward the front slave controller 30, to cause disconnection, and then the resistance value when direct current voltage and alternating current voltage are applied. and capacitance were measured.

Direct current voltage was detected as leakage occurred through a sudden increase in resistance value.

The capacitance value (Co) measured by switching and supplying AC voltage was found to be 780 pF.

As the length at which the capacitance changes to the linear region is 30 m, as shown in FIG. 9, the total sensor length (L _T ) detected by the front slave controller 30 is 30 m.

When calculating the location of the disconnection using the formula, it was confirmed that the length (Lo) to the disconnection was 23.4m according to the formula Lo = (Co/C _T )L _T. Although there is a slight error, it was possible to calculate the distance to a relatively nearby location.

In addition, when calculating the disconnection position by comparing it with the data value in FIG. 9, the capacitance value measured after disconnection was 780 pF, so calculating the sensor length showing a capacitance of 780 pF in FIG. 9 confirmed that it was 20 m. Therefore, it was confirmed that the correct value appeared.

In addition, if the rear slave controller 30 checks the change in resistance value by applying a direct current voltage and measures the capacitance value by applying an alternating current voltage, the change in resistance value can be confirmed, but the capacitance value is within the allowed linear region. Because it is located outside of the location, there is no change from the single-line battle. Therefore, it was confirmed that no liquid leakage occurred in the 30m section above the middle of the total length of the detection sensor 40 of 60m.

7. Example of liquid leak detection and location measurement by organic solvent detection sensor

As shown in Figure 1a, the master controller 20, slave controller 30, and film-type sensor are connected in series. At this time, the organic solvent detection sensor connected between the slave controllers 30 is formed of a 5-wire line, including 2 power lines, 2 detection lines 421, and 1 two-way communication line, and has a length of approximately 5 m to 100 m. . At this time, the sensor is installed between the front slave controller 30 and the rear slave controller 30 at a length twice the length of the sensor linear area.

① Apply a DC voltage of 1 to 5V using the MUX switch to supply the DC voltage and AC voltage of the slave controller 30 alternately.

② Determine whether liquid is leaking by measuring the resistance value of the sensor. (Initial resistance is 50~200KΩ per 1m, resistance value after leakage increases to hundreds of MΩ)

③ If leakage occurs in the direction of the front slave controller (30) based on the center of the sensor length, AC voltage of 1~2V is applied from the AC voltage generator installed in the front slave controller (30) to the sensor connected to the front slave controller (30). Apply it to measure the capacitance of the sensor and obtain a C1 value (Co) of several tens of pF to nF as shown in Figure 7.

④ Apply AC voltage of 1 to 2 V from the AC voltage generator installed in the rear slave controller 30 to the sensor connected to the rear slave controller 30 to measure the capacitance of the sensor and obtain a C2 value of several tens of pF to nF as shown in FIG. 7. At this time, the C2 value is equal to the CT value, and the C1 value is always smaller than the CT value.

⑤ The C1 value is sent to the master controller (20) using a communication line, and the leakage location is determined using this value using the lookup table installed in the master controller (20).

⑥ As shown in Figure 8, if leakage occurs in the direction of the rear slave controller (30) based on the center of the sensor length, measure the C2 value in the same way as when leakage occurs in the direction of the front slave controller (30) and connect the C2 value to the communication line. It is sent to the master controller (20) and this value is used to determine the leakage location using the lookup table installed in the master controller (20).

10: Leakage and leakage location detection device (10)
20: Master controller (20)
30: Slave controller (30)
30a, 30b: front and rear slave controllers (30)
31: Direct current (DC) voltage generator 32: Alternating current (AC) voltage generator
33: signal amplifier 34: active filter
40: Detection sensor (40)
41: power line 42: sensing line (42)
43: communication line
421: Sensing line (421) 422: Circuit line
421a, 422a: Resistor 423: Capacitor

Claims (6)

In the leakage and leakage location detection device (10) using a film-type organic solvent detection sensor (40),
The leakage and leakage location detection device 10 is
A film-type organic solvent detection sensor (40) formed by sequentially stacking a base film and a protective film layer having a plurality of line layers and sensing holes;
One or more slave controllers (30) coupled to an end of the detection sensor (40) to apply power to the detection sensor (40);
It includes a master controller (20) connected in series or parallel with the one or more slave controllers (30) to perform power supply and communication functions,

The slave controller 20 applies direct current power, and the master controller 20 detects liquid leakage based on the change in resistance value of the detection sensor 40.
When the leaked liquid is detected, the slave controller 20 applies switching to AC power, and the master controller 20 determines the location of the leaked liquid based on the capacitance value formed in the detection sensor 40. Leak location detection device (10)
According to claim 1,
The detection sensor 40 includes a detection line 421 formed of conductive carbon and alkyd resin and a circuit line 422 formed of conductive metal.
The slave controller (30) includes a direct current voltage generator (31) and an alternating current voltage generator (32). Leakage and leakage location detection device (10).
According to claim 2,
The length of the film-type organic solvent detection sensor (40) is a leakage and leakage location detection device (10), characterized in that the length is within a range corresponding to the linear region where the capacitance increases among the capacitance distribution according to distance.
According to claim 1,
In the master controller 20, slave controllers 30 and film-type organic solvent detection sensors 40, each assigned a unique number, are alternately connected and arranged in series,
The film-type organic solvent detection sensor 40,
Communication that transmits the electrostatic capacity value in the detection sensor 40 measured by the power line 41 and sensing line 42 that supplies power from the master controller 20 to each slave controller 30 to the master controller 20. Leakage and leakage location detection device (10), characterized in that a line (43) is further formed.
In the method of detecting the leakage position by a leakage position detection device including a film-type organic solvent detection sensor (40), a slave controller (30), and a master controller (20),
The slave controller 20 applies direct current power, and the master controller 20 detects liquid leakage based on a change in the resistance value of the detection sensor 40;
If it is determined that there is a leak in the detection step, the slave controller 20 switches to AC power and applies power; a power switching step;
The master controller 20 includes a leakage position detection step of determining the leakage position based on the capacitance value formed in the detection sensor 40. A leakage position detection method using a leakage position detection device.
According to claim 5,
The leak location detection step is ' Lo = (Co/C _T )L _T; A method of detecting the location of leakage using a leakage location detection device, characterized in that the point of leakage is calculated based on '

Co: Capacitance value measured when the detection sensor is disconnected (leakage)
C _T : Capacitance value measured by the detection sensor before disconnection (liquid leakage)
Lo: Length from the slave controller (30) to the point of disconnection (liquid leakage)
L _T : Length of detection sensor connected to slave controller

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