JP5240738B2 - Leak detection device and air conditioner - Google Patents

Description

  The present invention relates to a leak detection device and an air conditioner, and more particularly to a leak detection device that detects a fluid leak and an air conditioner including the leak detection device.

  The air conditioner cools the space to be cooled by using a refrigerant refrigeration cycle that circulates between the space to be cooled (cooling target space) and the external space. In general, a copper pipe laid between the space to be cooled and the external space is used for circulating the refrigerant. These copper tubes are connected to a compressor and a heat exchanger, for example, by a joint or a flare nut.

  In this type of apparatus, the refrigerant circulating through the copper pipe may leak to the outside due to loose connection points, aging of the copper pipe, and the like. The leakage of the refrigerant not only lowers the cooling efficiency of the apparatus, but may cause an unexpected failure depending on the use of the apparatus. Therefore, various techniques for detecting refrigerant leakage have been proposed (see, for example, Patent Documents 1 and 2).

International Publication No. 2009/054353 JP 2007-85892 A

  The leakage detection method described in Patent Document 1 utilizes the fact that the impedance of the fluid holding body arranged at a location where leakage is expected changes before and after the refrigerant leakage occurs, It detects leakage of refrigerant. However, the impedance of the fluid holding body also changes due to adhesion of dirt or condensation. For this reason, it is conceivable that erroneous detection occurs due to changes in the temperature and humidity of the surrounding environment. Further, as the aging of the fluid holder progresses, the impedance changes. In this case, it becomes difficult to accurately detect the leakage of the refrigerant.

  The apparatus described in Patent Document 2 uses a sensor located in a space formed between an internal space and an external space of a pipe through which the refrigerant circulates to allow the refrigerant that enters the above-described space before leakage starts. By detecting, leakage of the refrigerant is detected in advance. However, if a new space is formed between the internal space and the external space, it is conceivable that the connection portion of the pipe has a double structure, and sufficient connection strength cannot be obtained.

  The present invention has been made under the above-described circumstances, and an object thereof is to accurately detect fluid leakage over a long period of time.

In order to achieve the above object, the leak detection apparatus of the present invention provides:
A covering material that covers the connection portion between the pipes in which fluid exists;
A plurality of detection circuits arranged on one side of the connection part and wound around the pipe via the covering material, and arranged on the other side of the connection part and wound around the pipe via the covering material Detection means for detecting a change in the covering material based on a change in resistance value of the plurality of detection circuits ,
Determination means for determining the presence or absence of leakage of the fluid based on the detection result of the detection means;
Transmission means for transmitting the detection result to the determination means;
Is provided.

  According to the present invention, a change in the covering material caused by fluid leakage is detected. And the leak from piping is detected based on the change degree of a coating | covering material. For this reason, the use of a material that is resistant to dirt and has a slow progress of deterioration as the covering material enables accurate detection of fluid leakage over a long period of time.

It is a figure which shows the leak detection apparatus which concerns on 1st Embodiment. It is a figure which shows the positional relationship of a coating | covering material, a coupling, and a copper pipe. It is a figure for demonstrating operation | movement of a leak detection apparatus. It is a figure which shows the leak detection apparatus which concerns on the modification 1. FIG. It is a figure for demonstrating operation | movement of the leak detection apparatus which concerns on the modification 1. FIG. It is a figure which shows the leak detection apparatus which concerns on the modification 2. It is a figure for demonstrating operation | movement of the leak detection apparatus which concerns on the modification 2. FIG. It is a figure which shows another example of the leak detection apparatus which concerns on the modification 3. It is a figure for demonstrating operation | movement of the leak detection apparatus which concerns on the modification 3. It is a figure which shows the leak detection apparatus which concerns on the modification 4. It is a figure which shows the leak detection apparatus which concerns on the modification 5. FIG. It is a figure for demonstrating operation | movement of the leak detection apparatus which concerns on the modification 5. FIG. It is a block diagram of the air conditioner which concerns on 2nd Embodiment.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a leak detection apparatus 10 according to the present embodiment. The leak detection device 10 is a device that detects a fluid leaking from a connection portion between the joint 51 and the copper pipe 50. As shown in FIG. 1, the leak detection apparatus 10 includes a covering material 12 that covers a connection portion between a joint 51 and a copper pipe 50, two strain gauges 13 ₁ and 13 ₂ provided on the covering material 12, The determination device 11 is connected to the strain gauges 13 ₁ and 13 ₂ via the cable 20.

  The copper pipe 50 and the joint 51 constitute, for example, a refrigerant path that circulates between the outdoor unit and the indoor unit of the air conditioner. As shown in FIG. 2, a flange 50 a is formed at the end of the copper tube 50. The flare nut 53 attached to the end of the copper tube 50 is screwed into the male threaded portion 51 a of the joint 51, so that the flange 50 a is in close contact with the joint 51 via the packing 60. Thereby, the joint 51 and the copper pipe 50 are connected to each other.

  The covering material 12 covers the connecting portion of the copper pipe 50 and the joint 51 together with the flare nut 53. The covering material 12 is made of a material that is deformed or broken by a relatively weak force such as resin, rubber, and silicon.

  The covering portion 12 is covered with the covering member 12 by shrinking the covering member 12 in a state where the connecting portion of the copper pipe 50 and the joint 51 is inserted into the covering member 12 made of resin formed into a cylindrical shape, for example. Do.

The strain gauges 13 ₁ and 13 ₂ are elements that increase in resistance when deformed. These strain gauges 13 _1, 13 ₂ has an insulating sheet, a conductor pattern formed on the surface of the insulating sheet. As shown in FIG. 1, the strain gauge 13 _1, 13 ₂ are each disposed so as to sandwich the flare nut 53, in a state of close contact with the coating material 12.

The determination device 11 is a microcomputer including, for example, a CPU (Central Processing Unit), a main storage unit, and the like. The determination unit 11 measures the strain gauge ₁₃ 1, 13 ₂ of the resistance value through the cable 20. When the resistance value of the strain gauge 13 _1, 13 ₂ is equal to or greater than the threshold value, it determines that the refrigerant is leaking from the connection of the copper pipe 50 and the joint 51, and outputs the determination result to an external device .

  The determination result output by the determination device 11 is, for example, low level when there is no leakage from the connection unit and the determination by the determination device 11 is denied, and leakage from the connection unit occurs. This is done by outputting a detection signal that goes to a high level when affirmative.

Next, the operation of the leak detection apparatus 10 configured as described above will be described. When the refrigerant leaks from the connection portion between the copper pipe 50 and the joint 51, the leaked refrigerant enters the gap between the copper pipe 50 and the covering material 12 and the gap between the joint 51 and the covering material 12. And if the leakage from a connection part continues, as FIG. 3 shows, the coating | covering material 12 will expand | swell and deform | transform. If dressing 12 is deformed, the strain gauges ₁₃ 1 in close contact with the coating material 12, 13 ₂ also deforms similarly, the resistance value of the strain gauge ₁₃ 1, 13 ₂ is increased.

The determination device 11 monitors the resistance values of the strain gauges 13 ₁ and 13 ₂ via the cable 20. When the strain gauge 13 _1, 13 or the resistance value of ₂ is equal to or greater than a threshold value, the value of the detection signal to the high level. Thereby, the occurrence of leakage is notified to the outside.

As described above, in the present embodiment, on the basis of the strain gauge 13 _1, 13 ₂ of the resistance value increased with the change of the dressing 12 due to the occurrence of leakage, the leakage of refrigerant is detected. The covering material 12 expands in proportion to the amount of refrigerant that has flowed out, even if, for example, dirt adheres or condenses. For this reason, leakage can be detected with high accuracy. In addition, by selecting the material of the covering material 12 according to the use of the leak detection device 10 and the usage environment, it is possible to suppress detection failures due to aging degradation of the device over a long period of time.

  In the above embodiment, the material of the covering material 12 is a resin or the like. The covering material 12 may be at least partially deformed by the fluid leaking from the connection portion. Therefore, the material of the covering material 12 is not limited to the above-described resin or the like.

  In the said embodiment, it decided to coat | cover the connection part of the copper pipe 50 and the coupling 51 using the coating | covering material 12 shape | molded by the cylinder shape. For example, a sheet-like material may be used as the covering material 12, and the connection portion may be covered by attaching the sheet-like material to the connection portion.

  A liquid resin may be applied to the connection portion using a brush or sprayed, and then the applied resin may be cured to form the covering material 12 that covers the connection portion. In this case, it is conceivable to use, as the covering material 12, a resin having ultraviolet curability or a resin that cures when it comes into contact with air.

  The covering material 12 is preferably adhered to the copper tube 50 and the joint 51 as much as possible with no gap. For example, if there is a gap between the covering material 12 and the copper pipe 50 or the joint 51, the leaked fluid is discharged to the outside through this gap. In this case, since the pressure inside the covering material 12 does not sufficiently increase, the amount of change in the covering material 12 becomes small. On the other hand, when the covering material 12 is in close contact with the copper tube 50 and the joint 51 without a gap, the fluid that has entered the covering material 12 does not leak to the outside. For this reason, the pressure inside the covering material 12 increases sufficiently, and the covering material 12 changes greatly. This makes it possible to detect fluid leakage with high accuracy. Moreover, the coating | covering material 12 closely_contact | adhered to the copper pipe 50 and the coupling 51 suppresses advancing of a leak. For this reason, the covering material 12 is preferably in close contact with the copper pipe 50 and the joint 51.

  The material used as the covering material 12 does not necessarily need to be integrally molded, and may be composed of a plurality of members. In this case, it is desirable that at least one of the plurality of members is a member that easily deforms or breaks.

  When covering the connecting portion between the copper pipe 50 and the joint 51 using the covering material 12 composed of a plurality of members, it is necessary to connect the members constituting the covering material 12 so that they are in close contact with each other. There is. When the members are in close contact with each other with no gap, the covering material 12 is greatly deformed due to leakage from the connection portion, and therefore, leakage of the fluid can be detected with high accuracy.

In the present embodiment, as shown in FIG. 1, the strain gauge 13 _1, 13 ₂ are arranged inside the covering material 12. Not limited thereto, the strain gauge ₁₃ 1, 13 ₂ may be disposed on the outside of the dressing 12. Further, it may be integrated with the covering material 12. In this case, it is conceivable to form a conductor pattern whose resistance value changes due to deformation on the surface or inside of the covering material 12. By using a strain gauge integrated with the covering material 12, it is possible to prevent the strain gauge 13 _1, 13 ₂ of the mounting miss to dressing 12.

  In the present embodiment, the copper tube 50 and one end of the joint 51 and the flare nut 53 are covered with the covering material 12. It is good also as covering not only this but the copper pipe 50, the coupling 51, and the flare nut 53 using the coating | covering material 12. FIG. In particular, when it is difficult to identify a location where leakage is expected to occur or when expansion of damage due to leakage is expected, most of the piping is preferably covered with the covering material 12.

  Specifically, when the fluid circulating in the pipe is flammable like HFC refrigerant, building fire and explosion are feared due to leakage of the refrigerant. Moreover, when the fluid has a bad influence on the human body, it is considered that the living environment is adversely affected by the leakage of the fluid. In such a case, the expansion of damage caused by leakage can be suppressed by covering most of the piping with the covering material 12.

In the present embodiment, the determination device 11 outputs a detection signal having a value corresponding to the determination result. Is not limited to this, judgment unit 11, the strain gauge 13 _1, 13 chronologically stores _second resistance value to generate a database, is also possible to output data regarding the resistance value as needed to the external device Good. Thereby, by referring to the database, it is possible to grasp the occurrence frequency of the leak, the degree of the leak, the amount of the fluid that has flowed out, the progress of the aging of the equipment, and the like. In addition, it is possible to accurately grasp the cost required for the maintenance plan and repair of equipment to some extent.

In the present embodiment, the strain gauges 13 ₁ and 13 ₂ and the determination device 11 are connected by a cable 20. Not limited to this, when the strain gauges 13 ₁ and 13 ₂ and the installation position of the determination device 11 are far away, the resistance values of the strain gauges 13 ₁ and 13 ₂ are determined using wireless communication. 11 may be notified. In this case, the strain gauge 13 _1, 13 _2, connect the transmitter for transmitting the modulated signals outputted from the strain gauge 13 _1, 13 _2, receives the output signal from the transmitter to the judging device 11 It is conceivable to arrange a receiver to perform.

Further, a strain gauge ₁₃ 1, 13 ₂ and determine device 11 connected through a copper pipe 50, decision device 11 via a copper tube 50, as by measuring the resistance of the strain gauge ₁₃ 1, 13 ₂ Also good. Furthermore, power may be supplied to the determination device 11 through the copper pipe 50.

  In this embodiment, the case where the copper pipe 50 and the joint 51 were connected by the flare nut was demonstrated. Not limited to this, the copper pipe 50 may be connected to the joint 51 by being welded to the joint 51. Also in this case, leakage from the connection portion between the copper pipe 50 and the joint 51 can be detected in the manner described above.

  The configuration of the leak detection apparatus 10 according to the present embodiment is an example, and various modifications can be made. Hereinafter, modified examples of the leak detection apparatus 10 according to the present embodiment will be described. In addition, an equivalent code | symbol is used about the same or equivalent structure as the leak detection apparatus 10 which concerns on this embodiment.

<< Modification 1 >>
FIG. 4 is a diagram illustrating a leak detection apparatus 10A according to the first modification. As shown in FIG. 4, metal wires 14 ₁ and 14 ₂ made of, for example, copper or aluminum are wound around both sides of the covering material 12 constituting the leak detection device 10A. Then, both ends of the metal wires 14 ₁ and 14 ₂ are connected to the determination device 11 via the cable 20.

In the leak detection apparatus 10A, when fluid leaks from the connection portion between the copper tube 50 and the joint 51, the covering material 12 expands and the metal wires 14 ₁ and 14 ₂ are disconnected as shown in FIG. The determination device 11 monitors the resistance value of the metal wires 14 ₁ and 14 ₂ , and when the resistance value exceeds a threshold value due to the disconnection of the metal wire 14 ₁ or the metal wire 14 ₂ , the determination device 11 sets the detection signal to a high level. To. Thereby, the occurrence of leakage is notified to the outside.

<< Modification 2 >>
FIG. 6 is a diagram illustrating a leak detection apparatus 10B according to the second modification. This leak detection device 10B is different from the leak detection device 10A according to the modified example 1 in that it has conductor patterns 15 ₁ and 15 ₂ instead of the metal wire 14.

The conductor pattern 15 can be formed by applying a conductive paste such as a carbon paste to the surface of the covering material 12 and curing it. The conductor patterns 15 ₁ and 15 ₂ may be formed in advance on the covering material 12. In this case, for example, the conductor pattern 15 can be formed by attaching a copper foil to the covering material 12 and etching the copper foil.

In the leak detection device 10B, when the fluid leaks from the connection portion between the copper pipe 50 and the joint 51, the covering material 12 expands as shown in FIG. 7, and the conductor patterns 15 ₁ and 15 ₂ break. The determination device 11 sets the detection signal to a high level when the conductor pattern 15 ₁ , 15 ₂ breaks and its resistance value exceeds a threshold value. Thereby, the occurrence of leakage is notified to the outside.

<< Modification 3 >>
In the first modification and the second modification, the case where the metal wire 14 or the conductor pattern 15 is formed on each side of the covering material 12 is described. For example, a plurality of metal wires 14 or conductor patterns 15 may be arranged on both sides of the covering material 12 as in a leak detection device 10C shown in FIG. In this case, even if the deformation amount of the covering material 12 is small, it is considered that at least one of the plurality of conductor patterns 15 is broken as shown in FIG. For this reason, the slight deformation of the covering material 12 can be accurately detected by individually measuring the resistance value of the conductor pattern 15. Therefore, even a small amount of fluid leakage can be detected with high accuracy.

  Further, the degree of leakage can be predicted to some extent by the number of conductor patterns 15 that have been broken. Usually, the deformation of the covering material 12 proceeds from the center to both ends. For this reason, in the conductor pattern 15, the conductor pattern 15 disposed in the vicinity of the center is broken at the initial stage of leakage, and the conductor pattern 15 positioned on the outer side is sequentially broken as the leakage proceeds. When the leakage is slight, only the conductor pattern 15 located near the center of the covering material 12 is broken. Therefore, it is possible to predict the degree of leakage to some extent by specifying at which position the conductor pattern 15 is broken. Further, by measuring the time from the time when a certain conductor pattern 15 breaks until the next conductor pattern breaks, the scale of leakage and the degree of progress can be predicted to some extent.

<< Modification 4 >>
Similarly, for example, a plurality of strain gauges 13 described in the above embodiment may be arranged as in a leak detection device 10D shown in FIG. As a result, the deformation of the covering material 12 can be detected with high accuracy, and as a result, even a small amount of fluid leakage can be detected with high accuracy.

<< Modification 5 >>
FIG. 11 is a diagram illustrating a leak detection apparatus 10E according to the fifth modification. As shown in FIG. 11, temperature sensors 16 such as a thermistor are disposed on both sides of the covering material 12 constituting the leak detection device 10E. The temperature sensor 16 measures the temperature of the covering material 12 and the fluid that rises due to a chemical reaction between the leaked fluid and the covering material.

  In the leak detection device 10E, when the fluid leaks from the connection portion between the copper pipe 50 and the joint 51, the fluid enters the inside of the covering material 12 and the covering material 12 expands as shown in FIG. Inside the expanded covering material 12, the fluid and the covering material react, and the temperature of the covering material and the fluid near the temperature sensor 16 rises.

  The determination device 11 measures the temperature of the covering material 12 or the fluid via the temperature sensor 16. Then, when the measured temperature exceeds the threshold value, the detection signal is set to a high level. Thereby, the occurrence of leakage is notified to the outside.

  In the leak detection apparatus 10E according to this modification, for example, when the fluid is ammonia, it is conceivable to use a material containing water that reacts with ammonia as the covering material 12. Moreover, in this modification, the case where the leaked fluid and the coating | covering material 12 reacted was demonstrated. However, the present invention is not limited to this, and a reactive agent that reacts with the leaking fluid may be added inside the covering material 12.

  As mentioned above, although the modification of the leak detection apparatus 10 which concerns on 1st Embodiment was demonstrated, these modifications are examples. For example, the determination device 11 observes the waveform of an electric signal converted from sound and vibration when the covering material 12 breaks due to deformation, and when the peak value of the waveform exceeds a threshold value, fluid leakage occurs. It is good also as judging.

  As described above, when judging leakage of the fluid based on the sound or vibration generated when the covering material 12 is broken, it is not necessary to directly install a detecting means such as a strain gauge on the covering material 12. For this reason, for example, it is possible to detect breakage of the plurality of covering materials 12 only by installing one sound collecting microphone as a detecting means. This makes it possible to reduce the manufacturing cost of the device when there are relatively many locations where leakage is detected.

  Further, a pressure sensor that measures the pressure inside the covering material 12 may be used as a detecting means for detecting the deformation of the covering material 12. In this case, the determination device 11 measures the pressure inside the covering material 12 via the pressure sensor. Then, when the measured pressure exceeds the threshold, it is determined that fluid leakage has occurred. In a leak detection device that detects a leak based on pressure, a hard coating material 12 can be used.

  In addition, as a material of the covering material 12, a material that is normally transmissive to visible light and loses its transparency when contacted with a leaked fluid is used, and light that has passed through the covering material 12 is used as a leakage detection means. You may use the optical sensor to detect. As an optical sensor for detecting light transmitted through the covering material 12, for example, an infrared sensor or the like can be used.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described. FIG. 13 is a block diagram of an air conditioner 100 according to the second embodiment. The air conditioner 100 is a vapor compression type air conditioner. As shown in FIG. 13, the air conditioner 100 includes an outdoor unit 110 and two indoor units 120A and 120B.

  The outdoor unit 110 is arranged, for example, on the roof of an office building. The outdoor unit 110 includes a control device 111, a heat exchanger 112, an electric fan 113, a compressor 114, a four-way valve 115, and a closing valve 116.

  The control device 111 includes a CPU (Central Processing Unit) and a communication unit that communicates with the indoor units 120A and 120B. The control device 111 measures the temperatures of the primary and secondary refrigerants of the heat exchanger 112 and the temperature of the air discharged through the heat exchanger 112 via the temperature sensors TH1 to TH3. Further, the pressures on the primary side and the secondary side of the compressor 114 are measured via the pressure sensors HP and LP. And based on the measured result, the output of the compressor 114 and the electric fan 113 is adjusted.

  The heat exchanger 112 is, for example, a cross-fin type fin-and-tube heat exchanger having heat transfer tubes and radiating fins. The heat exchanger 112 functions as a condenser when the air conditioner 100 is performing a cooling operation, and functions as an evaporator when the air conditioner 100 is performing a heating operation.

  The electric fan 113 includes a centrifugal fan or a multiblade fan, and a fan motor that rotates the fan. The electric fan 113 supplies outside air to the heat exchanger 112.

  The compressor 114 is a positive displacement compressor including an inverter motor. The compressor 114 compresses the refrigerant and discharges it to the four-way valve 115.

  The four-way valve 115 is a valve for switching the direction of the refrigerant flowing through the heat exchanger 112. The four-way valve 115 circulates the refrigerant in the direction indicated by the arrow b2 when the air conditioner 100 is performing a cooling operation. Then, when the air conditioner 100 is performing the heating operation, the refrigerant is circulated in the direction indicated by the arrow b1.

  Each of the indoor units 120A and 120B is disposed, for example, on the ceiling or wall surface of a space to be air-conditioned. Then, conditioned air is discharged into the space to be air-conditioned. In the present embodiment, the indoor unit 120A and the indoor unit 120B are connected in parallel to the outdoor unit 110. As shown in FIG. 13, these indoor units 120 </ b> A and 120 </ b> B have a control device 121, a heat exchanger 122, and an electric fan 123, similarly to the expansion valve 124 and the outdoor unit 110.

  The expansion valve 124 is an electric expansion valve for adjusting the flow rate of the refrigerant flowing through the heat exchanger 122.

  As shown in FIG. 13, each unit constituting the outdoor unit 110 and each unit constituting the indoor units 120 </ b> A and 120 </ b> B are connected by a copper tube 50. The refrigerant circulates between the outdoor unit 110 and the indoor units 120A and 120B via the copper pipe 50.

  The leak detection apparatus 10 according to the first embodiment is indicated by connection points between the closing valve 116 and the copper pipe 50 indicated by arrows a1 and a7 in FIG. 13, arrows a2 to a4, and arrows a8 to a10. The connection location between the joint 51 and the copper tube 50, the connection location between the copper tube 50 and the indoor unit 120A indicated by the arrows a5 and a11, and the copper tube 50 and the indoor unit 120B indicated by the arrows a6 and a12. It is provided at the connection location. These places are places where it is considered that there is a high probability of leakage in the refrigerant circuit formed by the respective parts constituting the copper pipe 50, the outdoor unit 110, and the indoor units 120A and 120B.

  In the air conditioner 100 according to the present embodiment, leakage from the refrigerant circuit is constantly monitored via the leakage detection device 10 disposed at the positions indicated by the arrows a1 to a12. And when the leak detection apparatus 10 detects the leak from any location, a detection result will be displayed on the liquid crystal display of the control apparatus 121 which comprises indoor unit 120A, 120B, for example. Thereby, the user of the air conditioner 100 can visually recognize the leakage from the air conditioner 100.

  As described above, the air conditioner 100 according to the present embodiment includes the leakage detection device 10 that detects leakage from the refrigerant circuit. For this reason, leakage from the refrigerant circuit is detected with high accuracy. Accordingly, it is possible to accurately grasp the necessity of repair of the device, the degree of progress of aging deterioration, and the like, and the air conditioner 100 can be operated safely.

  In the above embodiment, the case where the air conditioner 100 includes the leak detection device 10 has been described. Not only this but the air conditioner 100 may be provided with leak detection apparatus 10A-10E.

  The place where the leak detection device 10 is installed is not limited to the positions indicated by arrows a1 to a12 in FIG. For example, the leak detection device may be arranged at a place where the refrigerant flow is disturbed, such as a place where the copper pipe 50 is bent in an L shape.

  The outdoor unit 110 and the indoor units 120A and 120B according to the present embodiment include a fin-and-tube heat exchanger of a cross fin type. In this heat exchanger, since the connection part of the heat transfer tube is U-shaped, a leak detection device may be arranged in this part.

  The main purpose of the leak detection device 10 in the present embodiment is to detect a leak from the refrigerant circuit while the air conditioner 100 is in operation. In addition, by using the leak detection device according to the present invention, for example, after the abnormality of the air conditioner 100 is discovered, the leak detection device according to the present invention is installed at a place where it is thought that the leak has occurred, thereby generating an abnormality. This makes it possible to accurately specify the location or the scale of leakage.

  In the present embodiment, the case where the air conditioner 100 includes the leakage detection device 10 including the determination device 11 has been described. Not only this but the function of the judgment apparatus 11 which comprises the leak detection apparatus 10 may be added to the control apparatus 111 of the outdoor unit 110. FIG. Thereby, the outdoor unit 110 and the leak detection apparatus can be configured as one unit. Therefore, it is possible to reduce the size and cost of the apparatus.

  For the same reason, the function of the determination device 11 may be added to the control device 121 of the indoor units 120A and 120B. In this case, by displaying the leakage detection result on the display of the control device 121, the presence or absence of leakage can be confirmed in the room where the indoor units 120A and 120B are installed. The copper pipe 50 drawn into the indoor units 120A and 120B is often arranged at a place where access is difficult, such as the back of the ceiling. For this reason, the subsequent maintenance of the air conditioner 100 is facilitated by confirming leakage in the room.

  Moreover, in this embodiment, the case where the air conditioner 100 has the two indoor units 120A and 120B was demonstrated. Not only this but the air conditioner 100 may have three or more indoor units.

  As mentioned above, although embodiment of this invention was described, this invention is not limited by the said embodiment. For example, in the leak detection device according to the embodiment and the modification, the detection unit such as a strain gauge and the determination device 11 are connected via the cable 20. Not only this but the detection means and the judgment apparatus 11 may be connected via the copper pipe 50. FIG. In this case, the detection result of the detection means is output to the determination device 11 via the copper pipe 50.

  Moreover, in the said embodiment and modification, the judgment apparatus 11 which comprises the leak detection apparatus 10 performed the judgment of the presence or absence of a leak. Not limited to this, a single determination device 11 arranged at a distance monitors the output from a plurality of detection means via a LAN (Local Area Network), the Internet, a telephone line, or a wireless communication network. It is good also as detecting the leakage of.

  Various embodiments and modifications can be made to the present invention without departing from the broad spirit and scope of the present invention. Further, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiments but by the claims. Various modifications within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

  The leak detection device of the present invention is suitable for detection of fluid leaks. The air conditioner of the present invention is suitable for air conditioning a space to be air conditioned.

10, 10A to 10E Leakage detection device 11 Judgment device 12 Coating material 13 Strain gauge 14 Metal wire 15 Conductor pattern 16 Temperature sensor 20 Cable 50 Copper pipe 50a Flange 51 Joint 51a Male thread portion 53 Flare nut 60 Packing 100 Air conditioner 110 Outdoor unit DESCRIPTION OF SYMBOLS 111 Control apparatus 112 Heat exchanger 113 Electric fan 114 Compressor 115 Four-way valve 116 Closing valve 120A, 120B Indoor unit 121 Control apparatus 122 Heat exchanger 123 Electric fan 124 Expansion valve HP Pressure sensor LP Pressure sensor TH1-TH3 Temperature sensor

Claims (11)

A covering material that covers the connection portion between the pipes in which fluid exists;
A plurality of detection circuits arranged on one side of the connection part and wound around the pipe via the covering material, and arranged on the other side of the connection part and wound around the pipe via the covering material Detection means for detecting a change in the covering material based on a change in resistance value of the plurality of detection circuits,
Determination means for determining the presence or absence of leakage of the fluid based on the detection result of the detection means;
Transmission means for transmitting the detection result to the determination means;
A leak detection device comprising:   The leak detection device according to claim 1, wherein the covering material is deformed by the fluid.   The leak detection device according to claim 1, wherein the covering material is a molded product.   The leak detection device according to claim 1, wherein the covering material is obtained by curing a material applied to the pipe.   The leak detection device according to claim 1, wherein the covering material is a seal that can be attached to the pipe.   The leakage detection apparatus according to claim 1, wherein the transmission unit transmits a detection result of the detection unit using wireless communication. It said transmission means via said pipe, leak detection system according to any one of claims 1 to 5 for transmitting a detection result of said detecting means.   The leak detection device according to any one of claims 1 to 7, wherein power to the determination unit is supplied via the pipe.   The leak detection apparatus according to claim 1, further comprising a storage unit that stores a detection result of the detection unit. An indoor unit that supplies conditioned air to the air-conditioned space;
An outdoor unit that is disposed outside the air-conditioning target space and exchanges heat with outside air;
Piping for circulating a refrigerant between the indoor unit and the outdoor unit;
The leak detection device according to any one of claims 1 to 9 provided in the pipe,
An air conditioner.   The air conditioner according to claim 10, wherein electric power to the leak detection device is supplied via the indoor unit.

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