JP6482503B2 - Water leak detection system - Google Patents

Description

  The present invention relates to a water leakage detection system.

  Conventionally, a water leakage detection system is known as means for detecting leakage of refrigerant liquid in an air conditioning system. The water leakage detection system includes a water leakage detector and a water leakage detection zone. The water leakage detection zone is configured to include at least two conductive wires extending in parallel (for example, in a stranded state) in a non-conductive state. The leak detector supplies current to the leak detection zone. When water leakage occurs around the water leakage detection zone, the conductive wires of the water leakage detection zone are conducted to form a short circuit due to this water leakage. The water leakage detector determines that water leakage has occurred by detecting the switching from the open circuit to the short circuit.

  For example, in patent document 1, the water leak location on the water leak detection zone is specified based on the resistance value (wiring resistance) per unit length of the water leak detection zone. In addition, as in Patent Document 2, water leakage occurred at any place in the water leakage detection zone without specifying the water leakage location, or water leakage occurred at any location (over the entire length) of the water leakage detection zone. In some cases, only the alternative detection of whether or not it is performed is performed.

Japanese Utility Model Publication No. 6-62282 JP-A-8-166313

  By the way, the water leak detection zone which can specify a water leak location is required to have high accuracy in the processing of the conductive wire, for example, uniform resistance values per unit length, and is relatively expensive as a result. If such a water leak detection zone is installed along the refrigerant pipe of a large-scale building, for example, it will cause a cost increase, for example, a water leak detection zone must be laid over a length of about 1 km.

  On the other hand, the water leakage detection zone that does not specify the water leakage location is relatively low cost, but when the occurrence of water leakage is detected, the location is, for example, which portion of the refrigerant pipe has a total length of 1 km. It will be difficult. Then, an object of this invention is to provide the water leak detection system which can pinpoint a water leak location at lower cost than before.

  The present invention provides a leakage detection zone, a leakage detector for supplying a current to the leakage detection zone, and detecting a short circuit caused by leakage in the vicinity of the leakage detection zone, and an interval in the longitudinal direction of the leakage detection zone. The present invention relates to a water leakage detection system including a plurality of interposed circuit breakers. The plurality of circuit breakers are set such that the rated current decreases as the distance from the water leakage detector along the longitudinal direction of the water leakage detection zone increases. When the water leakage detector detects the short circuit, the current supplied to the water leakage detection zone is increased step by step, and the circuit breaker that has performed the circuit break operation when the short circuit is eliminated by the circuit break operation, and the circuit breaker In addition, a leakage point specifying process is performed in which a region between the circuit breakers on the downstream side as viewed from the leakage detector is determined as a leakage occurrence point.

  In the above invention, the water leak detector increases the current supplied to the water leak detection zone step by step when the short circuit is detected as the water leak location specifying process, and the current value is the water leak detection. When the breaking action does not occur in any of the breakers until the rated current value of the breaker closest to the breaker is exceeded, between the leak detector and the breaker closest to the leak detector You may make it determine an area | region as a water leak generation | occurrence | production location.

  Moreover, in the said invention, you may provide the memory | storage part which memorize | stores the said water leak occurrence location after the determination of the said water leak occurrence location.

  Further, another aspect of the present invention is a water leakage detection zone, a water leakage detector for supplying a current to the water leakage detection zone and detecting a short circuit caused by water leakage around the water leakage detection zone, and a longitudinal direction of the water leakage detection zone The present invention relates to a leak detection system including a plurality of circuit breakers interposed at intervals and a control unit that controls the leak detector. The plurality of circuit breakers are set such that the rated current value thereof becomes lower as the separation distance from the water leakage detector along the longitudinal direction of the water leakage detection zone is longer. When the water leakage detector detects the short circuit, the control unit gradually increases the current supplied to the water leakage detection zone, and the circuit breaker that has performed the interruption operation when the short circuit is eliminated by the interruption operation, The water leakage detector is caused to execute a water leakage location specifying process in which a region between the circuit breakers on the downstream side of the water leakage detector with respect to the water leakage detector is determined as a water leakage occurrence location.

  According to the present invention, it is possible to specify the location of water leakage at a lower cost than before.

It is a figure which illustrates the composition of the water leak detection system concerning this embodiment. It is a figure explaining the water leak detection by the water leak detection system which concerns on this embodiment, and a water leak location specific process. It is a flowchart which illustrates the water leak location specific process by the water leak detection system which concerns on this embodiment. It is a figure which illustrates the change process of the electric current supplied to a water leak detection zone in a water leak location specific process.

FIG. 1 illustrates a water leakage detection system 10 according to this embodiment. The water leakage detection system 10 includes a water leakage detector 12, a water leakage detection zone 14 _n (n = 1, 2, 3... K + 1), a circuit breaker 16 _k (k = 1, 2, 3...), A power source 18, A buzzer 20, a lamp 22, and a controller 24 are provided.

  The water leak detector 12, the buzzer 20, the lamp 22, and the controller 24 are connected by an internal bus 26. These devices may be compliant with a communication protocol BACnet (Building Automation and Control Network) in order to be compatible with BA (Building Automation).

  The controller 24 may be a PLC (programmable logic controller), for example, and can control various devices connected to the internal bus 26 including the buzzer 20, the lamp 22, and the water leakage detector 12.

  The controller 24 includes a memory 28, a user interface 30 (UI), a CPU 32, and an external interface 34.

  The memory 28 includes nonvolatile and volatile memories such as ROM, RAM, and hard disk drive (HDD). The memory 28 stores a water leak occurrence location which will be described later. The CPU 32 transmits the water leakage occurrence location stored in the memory 28 to the central monitoring device, outputs a warning sound output command to the buzzer 20, and outputs a lighting command to the lamp 22. The user interface 30 is used when inputting user information and is also used when displaying information. The external interface 34 is used for connection with external devices and data communication.

  The buzzer 20 receives the output command from the controller 24 and outputs a warning sound. As will be described later, when the water leakage detector 12 detects the occurrence of water leakage, a warning signal (water leakage generation signal) is transmitted from the water leakage detector 12 to the controller 24 and is received from the controller 24 and output to the buzzer 20. A command is sent.

  Similarly, the lamp 22 is a so-called warning lamp and lights up in response to a lighting command from the controller 24. As will be described later, when the water leakage detector 12 detects the occurrence of water leakage, a warning signal is transmitted from the water leakage detector 12 to the controller 24, and a lighting command is transmitted from the controller 24 to the lamp 22.

  The water leakage detection zone 14 is configured by extending at least two conductive wires in a non-conductive state. In FIG. 1, for convenience, only two conductive wires are extended in parallel, but this is not a limitation. For example, it may be a twisted wire shape in which three or more conductive wires are twisted together. The plurality of conductive wires are covered with a water-absorbing insulating coating, for example. Each of these conductive wires has one end connected to the water leak detector 12 and the other end opened. When water leakage occurs around the water leakage detection zone 14, the liquid is absorbed by the insulating coating, and the conductive wires are conducted through the absorbed liquid.

In the present embodiment, the water leakage detection zone 14 is divided into a plurality of regions 14 _n (n = 1, 2, 3,... K + 1) by the circuit breaker 16 _k . By providing such a configuration, it is possible to specify a water leak location in units of the divided areas as described later. Here, in FIG. 1, for convenience of explanation, a younger number is assigned as the distance from the leak detector 12 increases in the longitudinal direction of the leak detection zone 14.

The circuit breaker 16 is interposed in the water leakage detection zone 14 with an interval in the longitudinal direction of the water leakage detection zone 14. For example, the circuit breaker 16 _k is interposed between the water leakage detection zones 14 _{k + 1} and 14 _k . For example, when the water leakage detection zone 14 is installed in the refrigerant pipe of the air conditioning system, the circuit breaker 16 is arranged adjacent to the area where the operator can visually check when the ceiling panel on which the refrigerant pipe is laid is opened. It is good also as the arrangement interval of the device 16.

  The circuit breaker 16 includes a bimetal 36, for example. The bimetal 36 may be connected to at least one of the plurality of parallel conductive lines of the water leakage detection zone 14. From the viewpoint of cost reduction, it is preferable to connect the bimetal 36 to only one of the plurality of conductive lines of the water leakage detection zone 14.

  In addition, the circuit breaker 16 illustrated in FIG. 1 is a so-called box type, and is easily installed in the existing water leak detection zone 14. That is, the bundle of conductive wires of the water leakage detection zone 14 is cut at an arbitrary location, and the bimetal 36 is connected to one conductive wire (a set of one conductive wire before cutting). A connecting wiring member such as a jumper wire is connected to the other conductive wires.

Moreover, the circuit breaker 16 is set so that the rated current becomes lower as the distance from the water leakage detector 12 along the longitudinal direction of the water leakage detection zone 14 is longer. That is, in the example of FIG 1, rated current Ir _k of each breaker 16 _k becomes _{Ir 1 <Ir 2 <Ir 3} . By comprising in this way, in the leak location specific process mentioned later, when the electric current value supplied to the leak detection zone 14 is raised, it is far from the leak detector 12 (far along the longitudinal direction of the leak detection zone 14). The circuit breaker 16 is sequentially disconnected.

  The water leak detector 12 is connected to the internal bus 26 and can communicate with the controller 24. The water leak detector 12 includes a memory 38, a user interface 40 (UI), a CPU 42, an external interface 44, and a current sensor 46.

The memory 38 includes nonvolatile and volatile memories such as a ROM, a RAM, and a hard disk drive (HDD). In the memory 38, the value of the current sensor 46 when the water leakage detection zone 14 forms an open circuit, that is, a normal value (for example, 0 A), and the value of the current sensor 46 when a short circuit is formed, that is, the occurrence of water leakage A threshold value I _th (for example, several μA) for determination is stored. Further, the memory 38 stores a program for executing a water leak location specifying process described later.

  In addition to executing the above-described water leakage location specifying process, the CPU 42 compares the measured value of the current sensor 46 with the threshold value stored in the memory 38 to determine whether or not water leakage has occurred. The user interface 40 is used when the user inputs information, and is also used when displaying information. The external interface 44 is used for connection with external devices and data communication.

<Water leakage detection>
With reference to FIG. 2, the water leakage detection (detection of occurrence of water leakage) processing by the water leakage detector 12 will be described. The water leakage detector 12 constantly supplies a current from the power source 18 to at least one conductive line of the water leakage detection zone 14 (monitoring current I ₀ ). When water leakage does not occur, the conductive wires are insulated and non-conductive with each other. Therefore, when the supply current is a direct current, the measured value of the current sensor 46 is theoretically 0A.

As shown in FIG. 2, when water leakage 48 occurs at an arbitrary location in the water leakage detection zone 14, the insulating coating that covers the conductive wires absorbs the liquid, and as a result, the conductive wires are short-circuited. Thereby, the short circuit L as shown with the broken line of FIG. 2 is formed. Due to the formation of the short circuit, the measured value of the current sensor 46 becomes equal to or greater than the threshold value I _th . When the water leakage detector 12 detects that the measured value of the current sensor 46 is switched from the normal value (0 A) to the threshold value I _th or more, it determines (detects) that water leakage has occurred. Based on the determination, the water leakage detector 12 outputs an alarm signal. The alarm signal is transmitted to the controller 24. In response to the alarm signal, the controller 24 transmits an output command to the buzzer 20 and transmits a lighting command to the lamp 22.

<Identification of the location of water leakage>
Following the water leak occurrence determination, the water leak detector 12 identifies the water leak location. FIG. 3 illustrates a flowchart of the water leak location specifying process. When a short circuit, that is, occurrence of water leakage is detected, the water leakage detector 12 gradually increases the current supplied to the water leakage detection zone 14 from the monitoring current I _{0 as} shown in FIG. Specifically, leakage detector 12, the monitoring current I _0, exceeds the rated current Ir ₁ of the circuit breaker 16 _1, and the circuit breaker 16 _{and second} current I ₁ as a rated current Ir ₂ below (Ir ₁ < The supply current is raised to I ₁ ≦ Ir ₂ ) (S10).

At this time, if the circuit breaker 16 ₁ is included in the short circuit L, the circuit breaker 16 ₁ performs an interruption operation with the supply of the current I ₁ , and the short circuit L is opened (the short circuit is eliminated). ). Accordingly, the measured value of the current sensor 46 is less than the threshold value I _th . The water leak detector 12 refers to the measured value of the current sensor 46 and determines whether or not the value is less than the threshold value I _th (S12).

In consideration of the period from when Joule heat is accumulated in the bimetal 36 of the circuit breaker 16 to the circuit breaking operation, a predetermined waiting time is required from step S10 to step S12 for switching the current from I ₀ to I _1. May be set.

In the example shown in FIG. 2, since the short circuit L does not include the circuit breaker 16 ₁ , the short circuit L is not opened even when the current is rounded up from I ₀ to I ₁ . In response to this, the leak detector 12 has the current value I _k closest to the leak detector 12, that is, the maximum current value I _kmax (Ir _kmax <I _kmax ) at which the breaker 16 _kmax having the highest rated current operates. It is determined whether it is set to (S14). If the maximum current value I _kmax has not yet been set, the water leakage detector 12 returns to step S10 and increments the suffix k of the current value. That leak detector 12, as shown in FIG. 4, the current I _1, exceeds the rated current of the circuit breaker 16 _2, and the current I ₂ equal to or less than the rated current of the circuit breaker 16 _3, raising the supply current To do.

By supplying the current I ₂ , the circuit breaker 16 ₂ included in the short circuit L is cut off. Along with this, the short circuit L is opened (short circuit is eliminated), and the measured value of the current sensor 46 becomes less than the current I _th . At this time, the water leakage detector 12 determines whether or not k = 1 for the suffix k of the supply current (S16).

In the example of FIG. 2, since k ≠ 1 (k = 2), the water leakage detector 12 is a region between the circuit breaker 16 ₂ that has performed a circuit break operation and the circuit breaker 16 ₁ on the downstream side, that is, The water leakage detection zone 14 ₂ is determined as a water leakage occurrence location (S18).

  Here, in the example shown in FIG. 2, there is a water leakage point in a region sandwiched between two circuit breakers 16, and one circuit breaker on the downstream side as viewed from the circuit breaker 16 that has performed the circuit breakage and the water leakage detector 12. Although the area between 16 was determined to be a leak occurrence location, when the leak occurrence location is not sandwiched between the two circuit breakers 16, it is determined as follows.

If the measured value of the current sensor 46 at step S12 when the current value I ₁ is below the threshold value I _th, the process proceeds from step S16 to step S20. Water leak detector 12 determines that the leakage occurrence point the terminal region 14 ₁ of the leak detection zone 14 downstream of the circuit breaker 16 ₁ most downstream (S20).

On the other hand, steps S10, S12 and S14 are repeated, and the maximum current value I ₃ (k = kmax = 3, Ir) closest to the water leakage detector 12, that is, the circuit breaker 16 ₃ having the highest rated current Ir _k operates. _The supply current I _k is set so that ₃ <I ₃ ). If the short circuit L is not opened by this, in other words, if no breaking operation occurs in any of the circuit breakers 16 ₁ , 16 ₂ , 16 ₃ , the water leakage detector 12 is connected to the circuit breaker 16 ₃ and the water leakage detector. the region between the 12, i.e. determines water leak detection zone 14 ₄ and leak occurrence point (S22).

  When the leak occurrence location is determined in steps S18, S20, and S22, the leak detector 12 records the leak occurrence location in the memory 38 (storage unit) and notifies the controller 24 (S24). If the scale of water leakage is relatively small, the liquid may evaporate due to the heat generated by the formation of the short circuit L, making it difficult to confirm the location of the water leakage. By recording, confirmation work can be easily performed.

Furthermore, the water leak detector 12 returns the current value supplied to the water leak detection zone 14 to the normal value I ₀ (S26). Thereby, the load of the water leak detection zone 14 by supply of a large current is reduced.

<Another embodiment>
In the above-described embodiment, the water leak detector 12 executes the water leak location specifying process, but the present invention is not limited to this mode. For example, as described above, the water leakage detector 12 detects the presence or absence of water leakage, and as a result, an alarm signal indicating that water leakage has occurred is sent to the controller 24 (control unit). In the controller 24, the water leak detector 12 may be operated so as to execute a water leak location specifying process for the water leak detector 12 in response to the alarm signal.

Specifically, in the flowchart of the water leakage location specifying process of FIG. 3, the controller 24 sends a command for raising the supply current from the monitoring current I ₀ to the current I ₁ to the water leakage detector 12 (S10). The controller 24 refers to the measurement value of the current sensor 46, it determines whether the value is less than the threshold value I _th (S12).

When the measured value of the current sensor 46 is less than the current I _th, the controller 24, the suffix k of the supply current, it is determined whether or not k = 1 (S16), distal region 14 ₁ of water leakage detecting band 14 Is determined as a water leak occurrence location (S20).

When the measured value of the current sensor 46 at step S12 is a current I _th or more, the controller 24 determines whether or not the current value I _k is set to the maximum current value I _kmax (S14), yet the maximum current If the value I _kmax is not set, the process returns to step S10 to increment the suffix k of the current value.

After the current value suffix k is incremented and the current value I _k is increased stepwise, the controller 24 refers to the measured value of the current sensor 46 (S12). When the measured value referred to is less than the threshold value I _th , the controller 24 leaks the region between the circuit breaker 16 _k that has cleared the short circuit and the circuit breaker 16 _k-1 adjacent to the downstream side, that is, the water leakage detection zone 14 _k . The occurrence location is determined (S18).

Further, when the shut-off operation does not occur even when the maximum current I ₃ is supplied, the controller 24 determines that the region between the breaker 16 ₃ and the water leak detector 12, that is, the water leak detection zone 14 ₄ is the location where the water leak has occurred ( S22).

When the leak occurrence location is determined in steps S18, S20, and S22, the controller 24 records the leak occurrence location in the memory 28 and notifies the central monitoring device (S24). Furthermore, the controller 24 returns the current value supplied to the water leakage detection zone 14 to the normal value I ₀ (S26).

  As described above, in the present embodiment, the controller 24 causes the leak detector 12 to execute the leak point specifying process by remote operation without storing the leak point specifying process program in the memory 38 of the leak detector 12. . Thereby, the water leak location specifying process according to the present embodiment can be executed even for the existing water leak detector 12 that has only the water leak detection function.

  Specifically, the existing water leak detection zone 14 is appropriately divided and the circuit breaker 16 is interposed, and the controller 24 accepts a water leak location specifying command from the controller 24 according to a protocol that the CPU 42 of the existing water leak detector 12 can accept. By outputting, the water leak detection system 10 according to the present embodiment can be constructed.

  10 Water Leakage Detection System, 12 Water Leakage Detector, 14 Water Leakage Detection Zone, 16 Circuit Breaker, 18 Power Supply, 20 Buzzer, 22 Lamp, 24 Controller, 36 Bimetal, 46 Current Sensor.

Claims (4)

A leak detection zone,
A water leak detector for supplying a current to the water leak detection zone and detecting a short circuit caused by water leak around the water leak detection zone,
A plurality of circuit breakers interposed at intervals in the longitudinal direction of the water leakage detection zone;
A water leakage detection system comprising:
The plurality of circuit breakers are set so that the rated current value is lower as the separation distance from the water leakage detector along the longitudinal direction of the water leakage detection zone is longer.
When the water leakage detector detects the short circuit, the current supplied to the water leakage detection zone is increased step by step, and the circuit breaker that has performed the circuit break operation when the short circuit is eliminated by the circuit break operation, and the circuit breaker Also determine a region between the circuit breakers on the one downstream side as seen from the water leak detector as a water leak occurrence location, and execute a water leak location specifying process.
A water leakage detection system characterized by that. The water leakage detection system according to claim 1,
The water leakage detector increases the current supplied to the water leakage detection zone step by step when the short circuit is detected as the water leakage location specifying process, and the current value is closest to the water leakage detector. When the breaking operation does not occur in any of the breakers until the rated current value of the breaker is exceeded, a region between the leak detector and the breaker closest to the leak detector is defined as a leak occurrence point. judge,
A water leakage detection system characterized by that. The water leakage detection system according to claim 1 or 2,
A water leak detection system comprising a storage unit for storing the water leak occurrence location after determination of the water leak occurrence location. A leak detection zone,
A water leak detector for supplying a current to the water leak detection zone and detecting a short circuit caused by water leak around the water leak detection zone,
A plurality of circuit breakers interposed at intervals in the longitudinal direction of the water leakage detection zone;
A control unit for controlling the water leakage detector;
A water leakage detection system comprising:
The plurality of circuit breakers are set so that the rated current value is lower as the separation distance from the water leakage detector along the longitudinal direction of the water leakage detection zone is longer.
When the water leakage detector detects the short circuit, the control unit gradually increases the current supplied to the water leakage detection zone, and the circuit breaker that has performed the interruption operation when the short circuit is eliminated by the interruption operation, Determining the region between the circuit breakers on the downstream side as viewed from the water leakage detector relative to the circuit breaker as a water leakage occurrence location, causing the water leakage detector to execute a water leakage location specifying process,
A water leakage detection system characterized by that.

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