JP2009103364A - Refrigerant leak detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect refrigerant leakage while specifying from which place of a refrigerant circuit of the refrigerator the refrigerant leakage occurs. <P>SOLUTION: In the refrigerant leakage detection method of detecting refrigerant leakage from the refrigerant circuit, a fluid holding element 88 for holding a refrigerant or fluid resulting from the refrigerant leakage is arranged in a part of the refrigerant circuit for detecting the refrigerant leakage or in the proximity of the part, the impedance of a part including the fluid holding element 88 is measured by an impedance measuring device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigerant leak detection method, and more particularly to a refrigerant leak detection method for detecting refrigerant leak from a refrigerant circuit of a refrigeration apparatus.

As a method for detecting refrigerant leakage from the refrigerant circuit of the refrigeration apparatus, there is a method of calculating the refrigerant amount enclosed in the refrigerant circuit from various operation state quantities and detecting refrigerant leakage from the calculated refrigerant amount (patent) Reference 1).
JP 2007-163099 A

  However, with the above-described method, it is difficult to specify the place where the refrigerant leakage occurs.

  In addition, when refrigerant leakage is detected, there is also a demand to specify from where in the refrigerant circuit the refrigerant leakage occurs in order to take appropriate measures against the refrigerant leakage.

  An object of the present invention is to enable detection of refrigerant leakage including identification of where in the refrigerant circuit of the refrigeration apparatus the refrigerant leakage occurs.

  A refrigerant leakage detection method according to a first aspect of the present invention is a refrigerant leakage detection method for detecting refrigerant leakage from a refrigerant circuit of a refrigeration apparatus, wherein a refrigerant or A fluid holding body for holding fluid due to refrigerant leakage is arranged, and the impedance of the portion including the fluid holding body is measured by an impedance measuring device.

  In this refrigerant leak detection method, a fluid holding body is disposed in or near the portion of the refrigerant circuit that detects refrigerant leakage, and when the impedance of the portion including the fluid holding body is measured by an impedance measuring device, the fluid holding body is Due to the influence of the retained refrigerant or the fluid resulting from the refrigerant leakage, the impedance changes between when the refrigerant leaks from the refrigerant circuit and when no refrigerant leakage occurs. In this refrigerant leakage detection method, based on such a change in impedance, refrigerant leakage has occurred from the portion where the fluid holding body is provided, that is, where the refrigerant leakage has occurred from any location in the refrigerant circuit of the refrigeration apparatus. It is possible to detect refrigerant leakage including the identification of whether or not. Moreover, even if the amount of leakage is very small, the refrigerant or the fluid resulting from the refrigerant leakage can be held and accumulated in the fluid holding body, so that the refrigerant leakage can be easily detected and the detection accuracy of the refrigerant leakage is improved. be able to. Moreover, even if it is an existing refrigeration apparatus that does not have a function of detecting refrigerant leakage, it is possible to detect refrigerant leakage by measuring impedance with an impedance measuring device if a fluid holding body is attached later. It becomes like this. Here, the “fluid resulting from refrigerant leakage” means refrigerating machine oil leaking together with the refrigerant, dew condensation water generated by the refrigerant leakage, or the like.

  A refrigerant leakage detection method according to a second invention is the refrigerant leakage detection method according to the first invention, wherein the fluid holding body is paper.

  In this refrigerant leakage detection method, refrigeration oil that is difficult to evaporate and diffuse even after leakage can be retained and stored by soaking it in paper, which is a fluid holding body, and thus easily evaporates and diffuses after leakage. Compared to the case where the refrigerant is held by the fluid holding body, the trace of the refrigerant leakage can be surely captured, and thereby the detection accuracy of the refrigerant leakage can be improved.

  A refrigerant leak detection method according to a third invention is the refrigerant leak detection method according to the first or second invention, wherein the fluid holding body is attached to a pipe or a pipe joint constituting the refrigerant circuit, and When performing detection, the impedance measuring device is connected via a holder-side electrode that can be attached to and detached from the fluid holder, and a tube-side electrode that can be attached to and detached from a pipe or pipe joint that contacts the fluid holder.

  In this refrigerant leak detection method, when the refrigerant leak is detected, it can be connected to the impedance measuring device via two electrodes that can be attached to and detached from the fluid holder, so that the work of measuring the impedance of the fluid holder is performed. It can be done easily.

  The refrigerant leakage detection method according to a fourth aspect of the present invention is the refrigerant leakage detection method according to the third aspect of the present invention, wherein the fluid holder is attached so as to surround a pipe or a pipe joint constituting the refrigerant circuit, and the holder side electrode The tube side electrode has a structure capable of gripping a tube or a pipe joint constituting the refrigerant circuit.

  In this refrigerant leak detection method, since the fluid holding body is attached so as to surround the pipe or the pipe joint constituting the refrigerant circuit, the refrigerant or the fluid resulting from the refrigerant leak can be effectively held, and Since the holding body side electrode and the tube side electrode have a structure capable of gripping the tube or the pipe joint constituting the refrigerant circuit, the attachment state of the electrode can be stabilized. Thereby, the variation in the measurement of impedance can be reduced, and the detection accuracy of refrigerant leakage can be increased.

  As described above, according to the present invention, the following effects can be obtained.

  In the first aspect of the invention, it is possible to detect refrigerant leakage including identification of where the refrigerant leakage occurs from the refrigerant circuit of the refrigeration apparatus. Moreover, even if the amount of leakage is very small, the refrigerant or the fluid resulting from the refrigerant leakage can be held and accumulated in the fluid holding body, so that the refrigerant leakage can be easily detected and the detection accuracy of the refrigerant leakage is improved. be able to. Moreover, even if it is an existing refrigeration apparatus that does not have a function of detecting refrigerant leakage, it is possible to detect refrigerant leakage by measuring impedance with an impedance measuring device if a fluid holding body is attached later. It becomes like this.

  In the second invention, it is possible to reliably capture the trace of refrigerant leakage, and thereby improve the detection accuracy of refrigerant leakage.

  In the third invention, the work of measuring the impedance of the fluid holding body can be easily performed.

  In the fourth aspect of the invention, variation in impedance measurement can be reduced, and the detection accuracy of refrigerant leakage can be increased.

  Hereinafter, embodiments of a fluid sensor according to the present invention, a refrigeration apparatus including the fluid sensor, and a refrigerant leakage detection method will be described with reference to the drawings.

(1) Overall Configuration of Air Conditioner FIG. 1 is a schematic configuration diagram of an air conditioner 1 as an embodiment of a refrigeration apparatus according to the present invention. The air conditioner 1 is a so-called separate type air conditioner, and mainly includes a heat source unit 2, a use unit 4, and refrigerant communication tubes 5 and 6 that connect the heat source unit 2 and the use unit 4. The vapor compression refrigerant circuit 10 is configured. The refrigerant circuit 10 includes a CFC refrigerant such as R12, an HCFC refrigerant such as R22, an HFC refrigerant such as R410A, an FC refrigerant, an HC refrigerant such as propane, and various refrigerants such as carbon dioxide and ammonia. Is enclosed.

<Usage unit>
The usage unit 4 is installed on, for example, a ceiling, a ceiling surface, a wall surface, or the like of an air conditioning room, and includes a usage-side refrigerant circuit 10 a that constitutes a part of the refrigerant circuit 10. The use side refrigerant circuit 10 a mainly has a use side heat exchanger 41.

  The use-side heat exchanger 41 is a heat exchanger that functions as a refrigerant heater during cooling operation to cool indoor air and functions as a refrigerant cooler during heating operation to heat indoor air. One end of the use side heat exchanger 41 is connected to the first refrigerant communication pipe 5, and the other end of the use side heat exchanger 41 is connected to the second refrigerant communication pipe 6. As the use-side heat exchanger 41, for example, a fin-and-tube heat exchanger composed of a heat transfer tube through which a refrigerant flows and a large number of fins is used.

  In the present embodiment, the usage unit 4 has a usage-side fan 42 for sucking indoor air into the unit, exchanging heat, and supplying the indoor air to the indoor space. It is possible to exchange heat with the flowing refrigerant. The use side fan 42 is driven by a use side fan motor 43.

  In addition, the usage unit 4 includes a usage-side control unit 44 that controls the operation of each unit constituting the usage unit 4. The usage-side control unit 44 includes a microcomputer, a memory, and the like provided for controlling the usage unit 4, and a remote controller (not shown) for operating the usage unit 4 individually. Control signals and the like can be exchanged between them, and control signals and the like can be exchanged with the heat source unit 2.

<Heat source unit>
The heat source unit 2 is installed outside the air conditioning room, for example, and includes a heat source side refrigerant circuit 10 b that constitutes a part of the refrigerant circuit 10. The heat source side refrigerant circuit 10b mainly includes a compressor 21, a four-way switching valve 23, a heat source side heat exchanger 24, an expansion mechanism 25, and first and second closing valves 26 and 27. Yes.

  The compressor 21 is a compressor having a function of sucking a low-pressure gas refrigerant, compressing it into a high-pressure gas refrigerant, and discharging it. In the present embodiment, the compressor 21 is a hermetic compressor in which a compressor motor 22 is built in a housing. Further, refrigeration oil is also enclosed in the refrigerant circuit 10 for lubrication in the compressor 21.

  The four-way switching valve 23 is a valve that functions as a switching mechanism that switches the direction of the refrigerant flow. During the cooling operation, the heat source side heat exchanger 24 is used as a cooler for the refrigerant compressed in the compressor 21 and used. In order for the side heat exchanger 41 to function as a heater for the refrigerant cooled in the heat source side heat exchanger 24, the discharge side of the compressor 21 and one end of the heat source side heat exchanger 24 are connected and the compressor 21 The suction side and the second refrigerant communication pipe 6 side (that is, the second closing valve 27) are connected (see the solid line of the four-way switching valve 23 in FIG. 1), and the use side heat exchanger 41 is compressed during the heating operation. In order to function as a cooler for the refrigerant compressed in the machine 21 and as a heater for the refrigerant cooled in the use-side heat exchanger 41, the heat source side heat exchanger 24 is connected to the discharge side of the compressor 21 and the second side. Refrigerant communication pipe 6 side (sunawa And the second closing valve 27) and the suction side of the compressor 21 and one end of the heat source side heat exchanger 24 can be connected (see the broken line of the four-way switching valve 23 in FIG. 1). .

  The heat source side heat exchanger 24 is a heat exchanger that functions as a refrigerant cooler using outdoor air as a heat source during cooling operation, and functions as a refrigerant heater using outdoor air as a heat source during heating operation. One end of the heat source side heat exchanger 24 is connected to the four-way switching valve 23, and the other end of the heat source side heat exchanger 24 is connected to the expansion mechanism 25. As the heat source side heat exchanger 24, for example, a fin-and-tube heat exchanger configured by a heat transfer tube through which a refrigerant flows and a large number of fins is used.

  The expansion mechanism 25 is a mechanism that depressurizes the high-pressure refrigerant. In the present embodiment, the expansion mechanism 25 is an electric expansion valve that depressurizes the high-pressure refrigerant during the cooling operation and the heating operation.

  The first and second closing valves 26 and 27 are valves provided at connection ports with external devices and pipes (specifically, the first and second refrigerant communication pipes 5 and 6). The first closing valve 26 is connected to the expansion mechanism 25. The second closing valve 27 is connected to the four-way switching valve 23.

  In the present embodiment, the heat source unit 2 has a heat source side fan 28 for sucking outdoor air into the unit, exchanging heat, and then discharging the air to the outside, and the outdoor air and the heat source side heat exchanger 24 are connected to each other. It is possible to exchange heat with the flowing refrigerant. The heat source side fan 28 is driven by a heat source side fan motor 29.

  In addition, the heat source unit 2 includes a heat source side control unit 30 that controls the operation of each unit constituting the heat source unit 2. The heat source side control unit 30 includes a microcomputer and a memory provided for controlling the heat source unit 2, and exchanges control signals and the like with the use side control unit 44 of the use unit 4. Can be done. Thus, the control part 7 which controls operation | movement of each part of the air conditioning apparatus 1 is comprised by both the heat-source side control part 30 and the utilization side control part 44. FIG.

(2) Configuration for Detecting Refrigerant Leakage of Fluid Holding Body, and Refrigerant Leakage Detection Method In the above-described refrigerant circuit 10, various devices, pipes, or pipe joints constituting the refrigerant circuit 10 are connected to the outside of the refrigerant circuit 10. There is a risk of refrigerant leaking. And when refrigerant | coolant leakage arises, it is desirable to specify from which place of the refrigerant | coolant circuit 10 the refrigerant | coolant leakage has arisen, when taking an appropriate measure with respect to refrigerant | coolant leakage.

  Therefore, in the air conditioning apparatus 1 of the present embodiment, the fluid holding body 88 for holding the refrigerant or the fluid resulting from the refrigerant leakage is disposed in or near the portion where the refrigerant leakage is likely to occur in the refrigerant circuit 10. The fluid holder 88 can be used to detect refrigerant leakage from the refrigerant circuit 10 of the air conditioner 1, including specifying where in the refrigerant circuit 10 the refrigerant leakage occurs. Here, the “fluid resulting from refrigerant leakage” means refrigerating machine oil leaking together with the refrigerant, dew condensation water generated by the refrigerant leakage, or the like. Hereinafter, a configuration for detecting refrigerant leakage of the fluid holding body 88 and the like in the present embodiment will be described with reference to FIGS. Here, FIG. 2 is a diagram illustrating a state in which the fluid holding body 88 according to the present embodiment is provided in a portion of the refrigerant circuit 10 that detects refrigerant leakage or in the vicinity thereof. 3 is a cross-sectional view taken along the line II of FIG. FIG. 4 is a diagram showing the holder-side electrode 81, the tube-side electrode 82, and the impedance measuring device 9 used in the present embodiment. FIG. 5 is a diagram showing a state where the holder-side electrode 81 and the tube-side electrode 82 are attached to a portion where refrigerant leakage is detected or in the vicinity thereof. 6 and 7 are schematic configuration diagrams of the impedance measurement circuit.

  In the air conditioner 1 of the present embodiment, pipe joints such as brazed portions and flare nut connecting portions that are present at various locations in the refrigerant circuit 10 are conceivable as portions of the refrigerant circuit 10 that are likely to cause refrigerant leakage. Therefore, as shown in FIG. 1, the pipe joint connecting the first closing valve 26 and the first refrigerant communication pipe 5 or the vicinity thereof, and the second closing valve 27 and the second refrigerant communication pipe 6 are connected. A pipe joint or the vicinity thereof, a pipe joint connecting the use unit 4 and the first refrigerant communication pipe 5 or the vicinity thereof, and a pipe joint connecting the use unit 4 and the second refrigerant communication pipe 6 or the vicinity thereof, respectively. A fluid holding body 88 is disposed. In the present embodiment, the fluid holding bodies 88 are arranged at the four locations described above, but the present invention is not limited to this, and the fluid holding bodies 88 are arranged at other portions of the refrigerant circuit 10. May be. Moreover, the pipe | tube and pipe joint which comprise the refrigerant circuit 10 are metal members, such as copper.

  Next, a specific configuration of the fluid holding body 88 in the present embodiment will be described. In addition, since the fluid holding bodies 88 arranged at the four locations described above have the same configuration, they are handled as common to all the fluid holding bodies 88 unless otherwise specified.

  In the present embodiment, the fluid holding body 88 is attached so as to surround a pipe or a pipe joint constituting the refrigerant circuit 10, and leaked from a part of the refrigerant circuit 10 that detects refrigerant leakage as described above. It is a member for holding and accumulating refrigerant or fluid resulting from refrigerant leakage. The fluid holding body 88 is a measurement target at the time of refrigerant leakage detection using the holding body side electrode 81, the tube side electrode 82, and the impedance measuring device 9 described later.

  For example, when refrigeration oil is used as a fluid resulting from refrigerant leakage, paper is used as the fluid holding body 88, and the refrigeration oil leaked together with the refrigerant is retained and accumulated by soaking it in the fluid holding body 88. Can do. Here, when paper is used as the fluid holding body 88, the refrigerating machine oil can be effectively held because of its high lipophilicity, and it is difficult to swell even if the refrigerating machine oil permeates. In addition, it is possible to prevent a decrease in the electric capacity at the time of use, and further, by using a water repellent material, it is possible to prevent the condensation water from penetrating into the paper due to the leakage of the refrigerant and to suppress the influence of the condensation water. Can do. In addition, unlike the case of refrigeration oil, when the condensed water generated by cooling the surrounding air due to refrigerant leakage is used as the fluid resulting from the refrigerant leakage, the fluid is highly hydrophilic and the condensed water does not ooze out. However, by using the fluid holder 88 made of paper that does not easily swell, it is possible to prevent the effective retention of condensed water and the reduction of the electric capacity due to the penetration of the refrigerating machine oil. By using this, it is possible to prevent the refrigerating machine oil from penetrating into the paper due to the leakage of the refrigerant, and to suppress the influence of the refrigerating machine oil. Further, when the refrigerant is to be held by the fluid holding body 88, for example, an adsorbent that adsorbs the refrigerant (for example, zeolite) is used as the fluid holding body 88, or the adsorbent that adsorbs the refrigerant is paper. What is carried on the can be used as the fluid holding member 88. In addition, when using the adsorbent adsorbing the refrigerant or the paper carrying the adsorbent as the fluid holding body 88, it is desirable to use an adsorbent having high selectivity for the refrigerant used in the air conditioner 1. . In addition to paper, a porous body such as cloth, resin, ceramics, a crystal body, a film body, or the like can be used as the fluid holding body 88. In the case of detecting refrigerant leakage mainly due to the influence of refrigerating machine oil. For this, it is preferable to use paper in consideration of the cost and workability of the material.

  And in the air conditioning apparatus 1 provided with such a fluid holding body 88, the impedance measurement device 9 is connected to the fluid holding body 88, and the impedance of the portion including the fluid holding body 88 is measured. The refrigerant leakage from the refrigerant circuit 10 of the apparatus 1 is detected.

  Here, first, the principle of refrigerant leakage detection by impedance measurement will be described. As described above, when the fluid holding body 88 is provided in the refrigerant circuit 10 at or near the portion where the refrigerant leakage is detected and the impedance of the portion including the fluid holding body 88 is measured, the fluid holding body 88 is held. Due to the influence of the refrigerant or the fluid resulting from the refrigerant leakage, the impedance changes between the case where the refrigerant leakage from the refrigerant circuit 10 occurs and the case where the refrigerant leakage does not occur. And based on such a change in impedance, refrigerant leakage has occurred from the portion where the fluid holding body 88 is provided, that is, from where in the refrigerant circuit 10 of the air conditioner 1 refrigerant leakage has occurred. It is possible to detect refrigerant leakage including the identification of the above. In addition, in order to make the influence of the refrigerant | coolant hold | maintained at the fluid holding body 88 or the fluid resulting from a refrigerant | coolant leakage appear clearly, as shown in FIG. 2, the part which detects a refrigerant | coolant leak, and the fluid holding body 88 Is preferably covered with a film 87 or the like so that the fluid or the fluid resulting from the refrigerant leakage is easily held by the fluid holding body 88.

  As described above, in order to measure the impedance of the portion including the fluid holding body 88, it is necessary to connect the fluid holding body 88 to be measured and the impedance measuring device 9, but in this embodiment, The fluid holding body 88 includes a holding body side electrode 81 that can be attached to and detached from the fluid holding body 88 and a pipe side electrode 82 that can be attached to and detached from a pipe or pipe joint that contacts the fluid holding body 88 when detecting refrigerant leakage. Via the impedance measuring device 9.

  In the present embodiment, the holding body side electrode 81 and the tube side electrode 82 have a structure capable of gripping a tube or a pipe joint constituting the refrigerant circuit 10. More specifically, the holding body side electrode 81 and the tube side electrode 82 have a metal clamp portion connected to the electric wire 83, and the clamp portion can grasp a tube or a pipe joint constituting the refrigerant circuit 10. It has a possible structure. Then, the holder-side electrode 81 is mounted so as to grasp the outer periphery of the fluid holder 88, and the tube-side electrode 82 is a part of the tube or pipe joint that is slightly separated from the holder-side electrode 81 (at least directly touching the fluid holder 88). A part including the fluid holding body 88 (here, a part of a pipe or a pipe joint constituting the refrigerant circuit 10 is also included by attaching the electric wire 83 to the impedance measuring device 9. The impedance of the part) can be measured.

  Next, the impedance measuring device 9 that measures the impedance of the portion including the fluid holding body 88 (that is, between the two electrodes 81 and 82) will be described. The impedance measuring device 9 includes a measuring system that obtains the impedance of the measuring object based on the voltage applied to the measuring object and the flowing current, and the impedance of the measuring object (here, the impedance of the measuring object). The impedance measurement circuit shown in FIG. 6 is called an LCR meter corresponding to the former measurement method, and is shown in FIG. The impedance measurement circuit is called a bridge circuit corresponding to the latter measurement method.

  First, an impedance measurement circuit using an LCR meter will be described. This impedance measurement circuit mainly includes a power source 91, a feedback resistor RS, an operational amplifier 92, and a detector 93, and an impedance ZX (here, a fluid) By connecting the portion including the holding body 88, a circuit called an automatic balancing bridge is configured. In this impedance measurement circuit, when a voltage is applied from the power supply 91, the negative side of the operational amplifier 92 is connected to the point P between the impedance ZX and the feedback resistor RS. The voltage becomes zero, and all the current that flows through the impedance ZX from the power supply 91 flows into the feedback resistor RS. Then, the voltage applied to the impedance ZX becomes the same as the voltage of the power supply 91, and the output voltage of the operational amplifier 92 is obtained as the product of the current flowing through the impedance ZX and the feedback resistor RS. And the impedance ZX can be obtained by taking the product of the feedback resistor RS in the ratio of the two voltages.

  Next, an impedance measurement circuit using a bridge circuit will be described. This impedance measurement circuit mainly includes impedances Z1, Z2, and Z3, a detector 94, and a power source 95, and impedance ZX (here, fluid The bridge circuit is configured by connecting the portion including the holding body 88). In this impedance measuring circuit, the impedance ZX of the portion including the fluid holding body 88 is adjusted by applying the voltage from the power source 95 and adjusting the impedances Z1, Z2, and Z3 so that the output at the detector 94 becomes zero. Can be obtained.

  Then, using such an impedance measuring device 9, the holder-side electrode 81, and the tube-side electrode 82, refrigerant leakage can be detected as follows. First, refrigerant leakage from the refrigerant circuit 10 occurs. In a state where the fluid holding body 88 is not connected (for example, immediately after the air conditioning apparatus 1 is installed or immediately after the fluid holding body 88 is installed), the portion including the fluid holding body 88 is connected to the impedance measuring device 9 via the holding body side electrode 81 and the tube side electrode 82. Then, the impedance ZX is measured in a state in which no refrigerant leakage occurs from the portion of the refrigerant circuit 10 that detects refrigerant leakage. Then, after a predetermined period, the portion including the fluid holding body 88 is connected to the impedance measuring device 9 via the holding body side electrode 81 and the tube side electrode 82 again to measure the impedance ZX. Compared to the impedance ZX measured in a state where no refrigerant leakage from the part where leakage detection is performed, if there is a change exceeding the threshold, refrigerant leakage from the refrigerant circuit 10 has occurred, In addition, it is determined that the place where the refrigerant leakage occurs is the portion where the fluid holding body 88 to be measured is disposed or in the vicinity thereof, and there is no change exceeding the threshold value in all the fluid holding bodies 88. In the case, it is determined that the refrigerant circuit 10 has not leaked the refrigerant. As the impedance measuring device 9, either an LCR meter or a bridge circuit can be used, but the LCR meter is small and easy to carry as compared with a bridge circuit that has high measurement accuracy but requires a little labor for management and adjustment. Is more advantageous. In particular, as in the present embodiment, only the fluid holding body 88 is provided in the air conditioner 1, and the impedance measuring device is provided via the holding body side electrode 81 and the tube side electrode 82 only when the refrigerant leakage is detected. When connecting 9, an LCR meter that is small and easy to carry is advantageous.

  Thereby, in the refrigerant leakage detection method using the fluid holding body 88, the impedance measuring device 9, the holding body side electrode 81, and the tube side electrode 82 of the present embodiment, based on the change in impedance of the portion including the fluid holding body 88, Refrigerant leakage can be detected, including the fact that the refrigerant leakage has occurred from the portion where the fluid holding body 88 is provided, that is, the location where the refrigerant leakage has occurred from the refrigerant circuit 10 of the air conditioner 1. It becomes like this. In particular, in the air conditioning apparatus 1 of the present embodiment, the fluid holding body 88 is provided in the refrigerant circuit 10 at or near the portion that detects the refrigerant leakage, so when the refrigerant leakage is detected, the holding body side By connecting the impedance measuring device 9 to the fluid holding body 88 via the electrode 81 and the tube side electrode 82, refrigerant leakage has occurred from the portion where the fluid holding body 88 is provided, that is, the air conditioner 1 Refrigerant leakage can be detected, including identifying where in the refrigerant circuit 10 the refrigerant is leaking.

  Moreover, even if the leakage amount is very small, the refrigerant or the fluid resulting from the refrigerant leakage can be held and accumulated in the fluid holding body 88, so that the refrigerant leakage can be easily detected, and the detection accuracy of the refrigerant leakage is improved. Can be increased. In addition, when using paper as the fluid holding body 88, it is possible to hold and accumulate refrigeration oil that does not easily evaporate and diffuse even after leakage by soaking it into the paper that is the fluid holding body 88. Compared with the case where the fluid holding body 88 holds the refrigerant that easily evaporates and diffuses after the leakage, it is possible to reliably capture the trace of the refrigerant leakage, thereby improving the detection accuracy of the refrigerant leakage.

  Moreover, in this embodiment, since the electrodes 81 and 82 are not provided in the part which detects the refrigerant | coolant leakage of the air conditioning apparatus 1, or the vicinity thereof, the part including the part which detects the refrigerant leakage and the fluid holding body 88 is included. It becomes possible to completely seal with the film 87 or the like, and it is possible to obtain the maximum effect of holding the refrigerant or the fluid resulting from the refrigerant leakage in the fluid holding body 88. If the electrodes 81 and 82 are provided together with the fluid holding body 88 in the vicinity of the part that detects the refrigerant leakage of the air conditioner 1 or in the vicinity thereof, the fluid or the fluid resulting from the refrigerant leakage is held by the fluid holding body 88. In order to facilitate, it is necessary to cover not only the part that detects the refrigerant leakage and the part that includes the fluid holding body 88 but also the film 87 and the like including the electrodes 81 and 82. When measuring the impedance, in order to connect the impedance measuring device 9 and the electrodes 81 and 82 by the electric wire 83, it is necessary to remove the film 87 and the like. In this embodiment, the electrodes 81 and 82 are used. Therefore, when connecting the impedance measuring device 9 and the electrodes 81 and 82 by the electric wire 83, it is not necessary to remove the film 87 or the like. It is.

  In addition, in the present embodiment, the electrodes 81 and 82 are not provided in the vicinity of the portion that detects the refrigerant leakage of the air conditioner 1 or in the vicinity thereof, so that the electrodes 81 and 82 are not deteriorated due to rust or dirt, Further, in the case where the change in impedance is measured by holding the refrigerant or refrigerating machine oil in the fluid holding body 88, the electrode 81, 82 together with the fluid holding body 88 or a portion in the vicinity of detecting the refrigerant leakage of the air conditioner 1. However, in this embodiment, there is no possibility of causing such a short circuit due to condensation on the electrode when measuring the impedance.

  Further, even if the air conditioner 1 is an existing device that does not have a function of detecting refrigerant leakage, an impedance measuring device can be provided via the holding body side electrode 81 and the tube side electrode 82 if the fluid holding body 88 is retrofitted. By connecting to 9, it becomes possible to detect refrigerant leakage.

  Further, in the refrigerant leak detection method of the present embodiment, when the refrigerant leak is detected, it can be connected to the impedance measuring device 9 via the two electrodes 81 and 82 that can be attached to and detached from the fluid holding body 88. The operation of measuring the impedance of the fluid holding body 88 can be easily performed. In addition, in the refrigerant leak detection method of the present embodiment, the fluid holding body 88 is attached so as to surround the pipe or the pipe joint constituting the refrigerant circuit 10, so that the refrigerant or the fluid resulting from the refrigerant leak is effectively removed. In addition, since the holding body side electrode 81 and the tube side electrode 82 have a structure capable of gripping a tube or a pipe joint constituting the refrigerant circuit 10, the mounting state of the electrodes 81 and 82 is stabilized. be able to. Thereby, the variation in the measurement of impedance can be reduced, and the detection accuracy of refrigerant leakage can be increased.

(3) Other Embodiments Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments and can be changed without departing from the scope of the invention. It is.

  (A) In the above-described embodiment, the present invention has been described by taking a so-called pair-type air conditioner 1 in which one use unit 4 is connected to one heat source unit 2 as an example. The present invention may be applied to a so-called multi-type air conditioner 1 in which a plurality of utilization units are connected to a single heat source unit. In this case, since the branch part according to the number of utilization units is formed in a refrigerant | coolant communication pipe | tube, you may make it provide the fluid sensor 8 in the pipe joint etc. in these branch parts.

  (B) In the above-described embodiment, the present invention has been described by taking the air conditioner 1 that can be operated by switching between cooling and heating as an example. The present invention may be applied to various air conditioners such as a heat storage type air conditioner. The present invention is not limited to an air conditioner, but can be applied to any refrigeration apparatus that has a refrigerant circuit and has a risk of refrigerant leakage, such as a heat pump type hot water heater.

(C)
In the above-described embodiment, the holder-side electrode 81 and the tube-side electrode 82 are configured such that the clamp portion constitutes an electrode. However, the present invention is not limited to this, and the clamp portion and the electrode portion are separate members. The specific shape of the clamp portion is not limited to that of the above-described embodiment.

(D)
In the above-described embodiment, the fluid holding body 88 is attached so as to surround the pipe or the pipe joint constituting the refrigerant circuit 10, and the electrodes 81 and 82 grip the pipe or the pipe joint constituting the refrigerant circuit 10. However, the present invention is not limited to this. For example, as shown in FIGS. 8 to 11, the fluid holding body 88 is outside the pipe or the pipe joint constituting the refrigerant circuit 10. The two electrodes 81 and 82 may be mounted so as to sandwich this portion, and the impedance may be measured.

  More specifically, the fluid holding body 88 includes an annular part 88a attached so as to surround a pipe or pipe joint constituting the refrigerant circuit 10, and a pipe or pipe joint constituting the refrigerant circuit 10 from the tip of the annular part 88a. Projecting portion 88b projecting outward (in this case, in the radial direction of the pipe or the pipe joint). Here, the protruding portion 88b is integrally formed of the same material as the annular portion 88a and has a flat plate shape. The electrodes 81 and 82 have a shape (here, a flat plate shape) that matches the shape of the protrusion 88b. Then, both surfaces of the protruding portion 88b are sandwiched between the electrode 81 and the electrode 82 (the electrode 82 is not shown in FIG. 11), and the electrodes 81 and 82 are connected to the impedance measuring device 9 through the electric wire 83, The refrigerant leakage is detected by measuring.

  Even in such a configuration, similarly to the above-described embodiment, based on the change in impedance of the portion including the fluid holding body 88, refrigerant leakage has occurred from the portion where the fluid holding body 88 is provided, that is, Refrigerant leakage can be detected, including the identification of where the refrigerant leakage occurs in the refrigerant circuit 10 of the air conditioner 1.

  By using the present invention, it is possible to detect refrigerant leakage including identification of where in the refrigerant circuit of the refrigeration apparatus the refrigerant leakage occurs.

It is a schematic block diagram of the air conditioning apparatus as one Embodiment of the freezing apparatus concerning this invention. It is a figure which shows the state which provided the fluid holding body in the part which detects a refrigerant | coolant leakage in a refrigerant circuit. It is II sectional drawing of FIG. It is a figure which shows a holding body side electrode, a tube side electrode, and an impedance measuring device. It is a figure which shows the state by which the holding body side electrode and the tube | pipe side electrode were mounted | worn by the part which detects a refrigerant | coolant leak, or its vicinity. It is a schematic block diagram of an impedance measurement circuit. It is a schematic block diagram of an impedance measurement circuit. It is a figure which shows the state which provided the fluid holding body in other embodiment in the part which detects a refrigerant | coolant leakage in a refrigerant circuit. It is II sectional drawing of FIG. It is a figure which shows the electrode and impedance measurement apparatus in other embodiment. It is a figure which shows the state by which the electrode was mounted | worn in the part which detects the refrigerant | coolant leakage in other embodiment, or its vicinity.

Explanation of symbols

1 Air conditioning equipment (refrigeration equipment)
DESCRIPTION OF SYMBOLS 9 Impedance measuring apparatus 10 Refrigerant circuit 81 Holding body side electrode 82 Pipe side electrode 88 Fluid holding body

Claims (4)

A refrigerant leakage detection method for detecting refrigerant leakage from the refrigerant circuit (10) of the refrigeration apparatus (1),
A fluid holding body (88) for holding a refrigerant or a fluid resulting from the refrigerant leakage is disposed in or near the portion where the refrigerant leakage is detected in the refrigerant circuit,
The impedance of the part including the fluid holding body is measured by an impedance measuring device (9).
Refrigerant leak detection method.   The refrigerant leakage detection method according to claim 1, wherein the fluid holding body (88) is paper.   The fluid holder (88) is attached to a pipe or a pipe joint constituting the refrigerant circuit (10), and a holder-side electrode (81) that can be attached to and detached from the fluid holder when refrigerant leakage is detected. ) And a refrigerant according to claim 1 or 2 connected to the impedance measuring device (9) via a tube-side electrode (82) that can be attached to and detached from a tube or tube joint that contacts the fluid holding body. Leak detection method. The fluid holding body (88) is attached so as to surround a pipe or a pipe joint constituting the refrigerant circuit (10),
The holding body side electrode (81) and the tube side electrode (82) have a structure capable of gripping a tube or a pipe joint constituting the refrigerant circuit (10).
The refrigerant leakage detection method according to claim 3.

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