JP2010230181A - Refrigerant leakage detection sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerant leakage detection sensor eliminated in the possibility of detection errors of refrigerant leakage caused by water and steam. <P>SOLUTION: When a leaked refrigerant is adhered to a coating material 15 of the refrigerant leakage detection sensor 10, the coating material 15 is dissolved by refrigerating machine oil included in the refrigerant. Then, when the refrigerating machine oil comes into contact with an oil adsorbent 13, the refrigerating machine oil is guided to a space between electrodes 12a, 12b. Since the refrigerating machine oil includes a high relative dielectric constant generally, at this time, an electrostatic capacity between the electrodes 12a, 12b is changed. When the change in the electrostatic capacity is detected, an electronic circuit 14 informs external control equipment via a signal cable 18 that refrigerant leakage is detected. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigerant leak detection sensor.

  Currently, there has been proposed a technique for electrically detecting the state of the refrigerant in the refrigerant cycle by measuring a change in dielectric constant between electrodes installed in the refrigerant flow path.

  For example, in the refrigerant state detection device disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-125393), a capacitor is provided inside a liquid separator (accumulator) in a refrigerant cycle of an air conditioner. This capacitor continuously detects the state of the refrigerant as a change in the electrical signal by utilizing the fact that the capacitance between the electrodes changes according to the change in the dielectric constant of the refrigerant existing between the electrodes. Thereby, this refrigerant | coolant state detection apparatus can measure the ratio of the quantity of refrigerant liquid and the quantity of refrigerant gas which exists in the inside of a liquid separator, and the ratio of the quantity of refrigerant | coolant and the quantity of refrigerating machine oil.

  Further, in the ammonia absorption heat pump system disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 8-68569), the leakage of ammonia is electrically measured by measuring the dielectric constant of the gas in the atmosphere in the outdoor unit with a capacitor. Can be detected.

  However, in the refrigerant leak detection sensor that detects the presence of refrigerating machine oil contained in the refrigerant by measuring the change in the dielectric constant between the electrodes with a capacitor, water and water vapor present between the electrodes are the cause of false detection of the refrigerant leak. There is a case. This is because the dielectric constant of water is several tens of times higher than the dielectric constant of oil, so the measured value of the dielectric constant between the electrodes of the refrigerant leak detection sensor is affected by the water and water vapor existing between the electrodes. It is very easy to receive.

  Therefore, an object of the present invention is to provide a refrigerant leakage detection sensor that eliminates the possibility of erroneous detection of refrigerant leakage due to water and water vapor.

  A refrigerant leakage detection sensor according to a first invention includes a housing, a pair of electrodes, an oil adsorbent, an electronic circuit, and a coating material. The housing has an opening. The housing has an opening that is closed by an oil adsorbent described later. The pair of electrodes is disposed inside the housing. The oil adsorbent fills the space between the pair of electrodes inside the housing, closes the opening of the housing, and partially protrudes outside the housing. The oil adsorbent adsorbs refrigeration oil. The electronic circuit is disposed inside the housing and connected to the pair of electrodes. The electronic circuit detects a capacitance between the pair of electrodes. The coating material is coated on the surface of the oil adsorbent protruding outside the housing. The coating material has airtightness, water repellency and oil solubility.

  According to the present invention, when the leaked refrigerant comes into contact with the coating material covering the oil adsorbent protruding outside the housing, the refrigerating machine oil contained in the refrigerant dissolves the coating material. Next, after the refrigeration oil comes into contact with the oil adsorbent, the refrigeration oil is adsorbed on the oil adsorbent. After the refrigerating machine oil is adsorbed by the oil adsorbent, it transmits the oil adsorbent and penetrates between the pair of electrodes. As a result, the dielectric constant of the oil adsorbent between the pair of electrodes changes depending on the permeated refrigerator oil. Here, the pair of electrodes and the oil adsorbent between the pair of electrodes function as a capacitor. Accordingly, the capacitance held between the pair of electrodes shows different values before and after the oil adsorbent between the pair of electrodes adsorbs the refrigerating machine oil. The electronic circuit detects the refrigerant leakage by measuring the change in capacitance and detecting the refrigerant leakage. And since a coating material has airtightness and water repellency, the water and water vapor | steam of the exterior of a housing | casing permeate | penetrate a coating material, and are not adsorb | sucked by an oil adsorbent. Thereby, the refrigerant | coolant leak detection sensor which excluded the possibility of the misdetection of the refrigerant | coolant leak by water and water vapor | steam is realizable.

  The refrigerant leakage detection sensor according to the second invention is the refrigerant leakage detection sensor according to the first invention, and the coating material is a coating film applied to the oil adsorbent.

  According to the present invention, in order to coat the oil adsorbent protruding outside the housing with the coating material, the coating material is directly applied to the surface of the oil adsorbent using a spray, a brush or the like. Thereby, coating | cover of the coating material to the oil adsorbent with which a refrigerant | coolant leak detection sensor is equipped can be performed simply.

  A refrigerant leakage detection sensor according to a third invention is the refrigerant leakage detection sensor according to the first invention, and the coating material is a cap covered with an oil adsorbent.

  According to the present invention, the cap is attached to the oil adsorbent in order to cover the oil adsorbent protruding outside the housing with the coating material. The cap is molded with a coating material. The cap completely covers the oil adsorbent protruding outside the housing. Thereby, coating | cover of the coating material to the oil adsorbent with which a refrigerant | coolant leak detection sensor is equipped can be performed simply. Further, in the refrigerant leak detection sensor according to the second aspect of the present invention, compared to the case where the coating material is applied to the surface of the oil adsorbent, this coating method in which the cap is attached to the oil adsorbent is more effective in adsorbing the coating material to the oil adsorbent. It has characteristics that are difficult to do. Thereby, the fall of the adsorption power of an oil adsorbent can be prevented.

  A refrigerant leakage detection sensor according to a fourth aspect of the present invention includes a housing, a window material, a pair of electrodes, an oil adsorbent, and an electronic circuit. The housing has a window portion. The housing has a pair of electrodes, an oil adsorbent, and an electronic circuit, which will be described later. The window material closes the window portion of the housing. The window material has airtightness, water repellency and oil solubility. The pair of electrodes is disposed inside the housing. The oil adsorbent fills the space between the pair of electrodes inside the housing, and is disposed adjacent to the window material inside the housing. The oil adsorbent adsorbs refrigeration oil. The electronic circuit is disposed inside the housing and connected to the pair of electrodes. The electronic circuit detects a capacitance between the pair of electrodes.

  According to the present invention, when the leaked refrigerant comes into contact with the window material closing the window portion of the housing, the refrigerating machine oil contained in the refrigerant dissolves the window material. Next, after the refrigeration oil comes into contact with the oil adsorbent, the refrigeration oil is adsorbed on the oil adsorbent. After the refrigerating machine oil is adsorbed by the oil adsorbent, it transmits the oil adsorbent and penetrates between the pair of electrodes. As a result, the dielectric constant of the oil adsorbent between the pair of electrodes changes depending on the permeated refrigerator oil. Here, the pair of electrodes and the oil adsorbent between the pair of electrodes function as a capacitor. Accordingly, the capacitance held by the pair of electrodes shows different values before and after the oil adsorbent between the pair of electrodes adsorbs the refrigerating machine oil. The electronic circuit can detect the leakage of the refrigerant by detecting the change in the capacitance. Since the window material has airtightness and water repellency, water and water vapor outside the housing do not penetrate the window material and are adsorbed by the oil adsorbent. And compared with the case where the coating material is applied to the surface of the oil adsorbent protruding outside the casing in the refrigerant leak detection sensor according to the first to third inventions, the oil adsorbent is used in the refrigerant leak detection sensor according to the present invention. Can be further shortened. Thereby, refrigeration oil can be efficiently adsorbed to the oil adsorbent. Furthermore, in the refrigerant leak detection sensor according to the present invention, since the oil adsorbent coated with the coating material does not protrude outside the casing, the refrigerant leak detection sensor can be made robust.

  The refrigerant leakage detection sensor according to the fifth aspect of the present invention further includes a filler. The filler fills a space (hereinafter referred to as a filling space) other than the space occupied by the pair of electrodes, the oil adsorbent, and the electronic circuit inside the housing. The filler has airtightness, water repellency and oil repellency.

  According to the present invention, since the filler has airtightness and water repellency, water and water vapor enter the filling space from the outside of the casing and are not adsorbed by the oil adsorbent. Thereby, the possibility of erroneous detection of refrigerant leakage due to water and water vapor can be more reliably eliminated. Furthermore, since the filler has oil repellency, the refrigerating machine oil adsorbed by the oil adsorbent does not penetrate into the filling space. Thereby, refrigeration oil can be efficiently adsorbed by the oil adsorbent.

  The refrigerant leakage detection sensor according to the first invention can eliminate the possibility of erroneous detection of refrigerant leakage due to water and water vapor.

  In the refrigerant leakage detection sensor according to the second aspect of the present invention, the coating material can be easily applied to the oil adsorbent provided in the refrigerant leakage detection sensor.

  In the refrigerant leakage detection sensor according to the third aspect of the present invention, the coating material can be easily applied to the oil adsorbent provided in the refrigerant leakage detection sensor, and a decrease in the adsorption force of the oil adsorbent can be prevented.

  In the refrigerant leak detection sensor according to the fourth aspect of the invention, the refrigeration oil can be efficiently adsorbed to the oil adsorbent, and the refrigerant leak detection sensor can be made robust.

  In the refrigerant leakage detection sensor according to the fifth aspect of the invention, the possibility of erroneous detection of refrigerant leakage due to water and water vapor can be more reliably eliminated, and the refrigerating machine oil can be efficiently adsorbed by the oil adsorbent.

It is side surface sectional drawing of the refrigerant | coolant leak detection sensor which concerns on 1st Embodiment of this invention. It is a refrigerant | coolant leak detection sensor which concerns on 1st Embodiment of this invention, Comprising: It is side surface sectional drawing of a refrigerant | coolant leak detection sensor after oil was adsorb | sucked to the oil adsorbent. It is side surface sectional drawing of the refrigerant | coolant leak detection sensor which concerns on 2nd Embodiment of this invention. It is a refrigerant | coolant leak detection sensor which concerns on 2nd Embodiment of this invention, Comprising: It is side surface sectional drawing of the refrigerant | coolant leak detection sensor after oil was adsorbed | sucked to an oil adsorption material. (A) It is side surface sectional drawing of the refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention. (B) It is an external view of the bottom face part of the refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention. (C) It is an external view of the front part of the refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention. (A) It is a refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention, Comprising: It is side surface sectional drawing of the refrigerant | coolant leak detection sensor after oil was adsorb | sucked to an oil adsorption material. (B) It is a refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention, Comprising: It is an external view of the bottom face part of the refrigerant | coolant leak detection sensor after oil is adsorb | sucked to an oil adsorbent. (C) It is a refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention, Comprising: It is an external view of the front part of the refrigerant | coolant leak detection sensor after oil is adsorb | sucked to an oil adsorption material. (A) It is a refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention, Comprising: It is side surface sectional drawing of the refrigerant | coolant leak detection sensor which changed the shape and arrangement | positioning of the oil adsorption material and the window. (B) It is a refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention, Comprising: It is an external view of the bottom face part of the refrigerant | coolant leak detection sensor which changed the shape and arrangement | positioning of the oil adsorption material and the window. (C) It is a refrigerant | coolant leak detection sensor which concerns on 3rd Embodiment of this invention, Comprising: It is an external view of the front-surface part of the refrigerant | coolant leak detection sensor which changed the shape and arrangement | positioning of the oil adsorption material and the window.

= First embodiment =
<Configuration>
The conceptual diagram of the refrigerant | coolant leak detection sensor 10 which concerns on 1st Embodiment of this invention is shown in FIG. In FIG. 1, the refrigerant leak detection sensor 10 includes a casing 11, electrodes 12 a and 12 b, an oil adsorbent 13, an electronic circuit 14, a coating material 15, a filler 16, lead wires 17 a and 17 b, A signal cable 18 and a power cable 19 are provided. Hereinafter, each element constituting the refrigerant leakage detection sensor 10 will be described.

(1) Housing The housing 11 includes electrodes 12a and 12b, a part of the oil adsorbent 13, an electronic circuit 14, a filler 16, lead wires 17a and 17b, a part of the signal cable 18, A part of the power cable 19 is accommodated. The housing 11 has an opening through which the oil adsorbent 13, the signal cable 18 and the power cable 19 pass. As a material for forming the housing 11, a resin that does not dissolve in oil is used.

(2) Electrodes The electrodes 12a and 12b are disposed to face each other with a part of the oil adsorbent 13 interposed therebetween. The electrodes 12a and 12b are connected to the electronic circuit 14 via lead wires 17a and 17b, respectively.

(3) Oil adsorbent The oil adsorbent 13 fills the space between the electrodes 12 a and 12 b and partially penetrates the casing 11 and protrudes outside the casing 11. Silicon paper is used as the oil adsorbent 13.

(4) Electronic circuit The electronic circuit 14 has a function of measuring the capacitance held between the pair of electrodes 12a and 12b, and the presence of refrigerating machine oil adsorbed on the oil adsorbent 13 from the change in the measured capacitance. And a function of notifying leakage of refrigerant to an external control device (not shown) via the signal cable 18. The electronic circuit 14 operates by receiving power supplied from an external power supply device (not shown) via the power cable 19. The electronic circuit 14 is connected to the electrodes 12a and 12b via lead wires 17a and 17b, respectively.

(5) Coating Material The coating material 15 is applied to the surface of the oil adsorbent 13 protruding outside the housing 11 using a spray. A varnish is used as the coating material 15.

(6) Filler Filler 16 is a space inside housing 11, and includes electrodes 12 a and 12 b, part of oil adsorbent 13, electronic circuit 14, lead wires 17 a and 17 b, and signal cable 18. And a space other than a space filled by a part of the power cable 19 is filled. As the filler 16, a resin that does not dissolve in oil is used.

(7) Lead wire As the lead wires 17a and 17b, general conductive wires are used.

(8) Signal Cable As the signal cable 18, a general signal cable is used.

(9) Power cable A general power cable is used as the power cable 19.

<Operation>
A process in which the refrigerant leakage detection sensor 10 according to the first exemplary embodiment of the present invention detects refrigerant leakage will be described.

  The refrigerant leakage detection sensor 10 is installed at a location where refrigerant leakage is desired to be detected, such as outside the refrigerant pipe. When the leaked refrigerant adheres to the coating material 15 of the refrigerant leak detection sensor 10, the coating material 15 is dissolved by the refrigerating machine oil contained in the refrigerant. As the coating material 15 is dissolved, the refrigerating machine oil comes into contact with the oil adsorbent 13 covered with the coating material 15. As shown in FIG. 2, the oil adsorbent 13 adsorbs the refrigerating machine oil 91 and guides the refrigerating machine oil to between the electrodes 12a and 12b. Here, the refrigerating machine oil 91 is PAG (polyalkylene glycol).

  Here, the oil adsorbent 13 between the electrodes 12a and 12b and the electrodes 12a and 12b can be regarded as a capacitor. The electronic circuit 14 measures the capacitance between the electrodes 12a and 12b via the lead wires 17a and 17b. Since the refrigerating machine oil has a high relative dielectric constant, the electrostatic capacity held by the capacitor is changed by inducing the refrigerating machine oil between the electrodes 12a and 12b. When the electronic circuit 14 detects the change in the capacitance, the electronic circuit 14 notifies the external control device that the refrigerant leakage has been detected via the signal cable 18.

<Features>
(1) The electrodes 12a and 12b, the oil adsorbent 13, the electronic circuit 14, the lead wires 17a and 17b, the signal cable 18 and the power cable 19 are surrounded by the coating material 15 and the filling material 16. Therefore, it is not affected by the substance in the atmosphere of the place where the refrigerant leak detection sensor 10 is installed.

  (2) Since the coating material 15 dissolves only when the refrigeration oil contained in the leaked refrigerant comes into contact with the coating material 15, the oil in which the coating material 15 is coated with water or water vapor in the atmosphere where the refrigerant leakage detection sensor 10 is installed It is not adsorbed by the adsorbent 13. Therefore, the refrigerant leakage detection sensor 10 can eliminate the possibility of erroneous detection of refrigerant leakage due to water and water vapor.

<Modification>
(1) In the refrigerant leak detection sensor 10 according to the previous embodiment, a resin that does not dissolve in oil is used as a material for forming the housing 11, but the material that does not react with the coating material 15, the refrigerant, and the refrigerating machine oil. As long as the material is stable with respect to the environment such as temperature and humidity at the place where the refrigerant leak detection sensor 10 is installed, other materials may be used.

  (2) In the refrigerant leakage detection sensor 10 according to the previous embodiment, silicon paper is used as the oil adsorbent 13, but other substances are used as long as they are substances that adsorb refrigeration oil contained in the refrigerant. It may be. For example, a porous cloth-like substance can be mentioned.

  (3) In the refrigerant leak detection sensor 10 according to the previous embodiment, varnish is used as the coating material 15, but it is a substance that does not pass gas, has water repellency, and dissolves in refrigerating machine oil contained in the refrigerant. For example, lacquer or the like may be used.

  (4) In the refrigerant leak detection sensor 10 according to the previous embodiment, the coating material 15 is applied to the surface of the oil adsorbent 13 using a spray, but may be applied with a brush or the like.

  (5) In the refrigerant leak detection sensor 10 according to the previous embodiment, the coating material 15 is applied to the surface of the oil adsorbent 13 using a spray, but adsorbs a thin film molded with the coating material 15 of several tens of μm. It may be affixed to the agent 13.

  (6) In the refrigerant leak detection sensor 10 according to the previous embodiment, the filler 16 is made of a resin that does not dissolve in oil. However, the filler 16 is a substance that does not contain gas such as air and does not dissolve in water and oil. Other substances may be used as long as they are present.

  (7) In the refrigerant leak detection sensor 10 according to the previous embodiment, PAG (polyalkylene glycol) is used as the refrigerating machine oil 91, but PVE (polyvinyl ether), POE (polyol ester), or the like is used. Also good.

= Second Embodiment =
<Configuration>
The conceptual diagram of the refrigerant | coolant leak detection sensor 20 which concerns on 2nd Embodiment of this invention is shown in FIG. In FIG. 3, the refrigerant leakage detection sensor 20 is a refrigerant leakage detection sensor in which the coating material 15 provided in the refrigerant leakage detection sensor 10 according to the first embodiment of the present invention is replaced with a cap 25. In the present embodiment, the components other than the cap 25 are the same as those of the refrigerant leakage detection sensor 10 according to the first embodiment shown in FIG.

  The cap 25 is molded so that the surface of the oil adsorbent 13 protruding from the housing 11 can be completely covered. The cap 25 can cover the oil adsorbent 13. As the cap 25, polystyrene foam is used.

<Operation>
The refrigerant leakage detection sensor 20 according to the second embodiment of the present invention detects the refrigerant leakage, except that the coating material 15 is replaced with the cap 25, and the refrigerant leakage according to the first embodiment of the present invention. This is the same as the process in which the detection sensor 10 detects refrigerant leakage. FIG. 4 shows the refrigerant leakage detection sensor 20 in a state where the refrigerating machine oil 91 is dissolved in the cap 25 and adsorbed by the oil adsorbent 13. Here, the refrigerating machine oil 91 is PAG (polyalkylene glycol).

<Features>
(1) Since the coating material 15 is directly applied to the surface of the oil adsorbent 13, if the coating material 15 penetrates into the oil adsorbent 13, the oil adsorbing power decreases, but the cap 25 directly covers the oil adsorbent 13. Therefore, the adsorption of oil to the oil adsorbent 13 is not hindered.

  (2) Since the cap 25 dissolves only when the refrigerating machine oil contained in the leaked refrigerant comes into contact, the oil adsorbent in which the cap 25 is coated with water or water vapor in the atmosphere in which the refrigerant leak detection sensor 20 is installed 13 is not adsorbed. Therefore, the refrigerant leakage detection sensor 20 can eliminate the possibility of erroneous detection of refrigerant leakage due to water and water vapor.

<Modification>
(1) In the refrigerant leak detection sensor 20 according to the previous embodiment, foamed polystyrene is used as the cap 25, but it is a substance that does not pass gas, has water repellency, and dissolves in refrigerating machine oil contained in the refrigerant. Chicle, acrylic rubber, ethylene propylene rubber, butyl rubber, or the like may be used.

  (2) In the refrigerant leakage detection sensor 20 according to the previous embodiment, PAG (polyalkylene glycol) is used as the refrigerating machine oil 91, but PVE (polyvinyl ether), POE (polyol ester), or the like is used. Also good.

= Third embodiment =
<Configuration>
The conceptual diagram of the refrigerant | coolant leak detection sensor 30 which concerns on 3rd Embodiment of this invention is shown in FIG. In FIG. 5, the refrigerant leak detection sensor 30 replaces the coating material 15 included in the refrigerant leak detection sensor 10 according to the first embodiment of the present invention with window materials 35 a and 35 b that close the windows opened in the housing 31. This is a refrigerant leakage detection sensor. In the present embodiment, the components other than the window members 35a and 35b are the same as those of the refrigerant leakage detection sensor 10 according to the first embodiment shown in FIG.

  The window members 35a and 35b are molded in accordance with the shape of the window opened in a part of the front surface and the bottom surface of the casing 31, and are installed so as to completely close the windows. The oil adsorbent 13 does not protrude to the outside of the casing 31, and is disposed adjacent to the window members 35 a and 35 b inside the casing 31. Styrofoam is used as the window members 35a and 35b.

<Operation>
The process of detecting the leakage of the refrigerant by the refrigerant leak detection sensor 30 according to the third embodiment of the present invention is the same as that of the first embodiment of the present invention except that the coating material 15 is replaced with the window materials 35a and 35b. The refrigerant leak detection sensor 10 is the same as the process of detecting the refrigerant leak. FIG. 6 shows the refrigerant leak detection sensor 30 in a state where the refrigerator oil 91 is dissolved in the window materials 35a and 35b and is adsorbed by the oil adsorbent 13. Here, the refrigerating machine oil 91 is PAG (polyalkylene glycol).

<Features>
(1) The refrigerant leak detection sensor 10 according to the first embodiment and the refrigerant leak detection sensor 20 according to the second embodiment are different from the oil adsorbent 13 because the oil adsorbent 13 protrudes outside the housing 11. When an impact is applied, the part is easily damaged. On the other hand, the refrigerant leak detection sensor 30 according to the present embodiment does not include a member protruding outside the housing 31, and thus has a robust structure as a whole.

  (2) In the refrigerant leak detection sensor 30 according to the present embodiment, the length of the oil adsorbent 13 is compared with the refrigerant leak detection sensor 10 according to the first embodiment and the refrigerant leak detection sensor 20 according to the second embodiment. It can be made shorter. As a result, the adsorbed refrigerating machine oil efficiently penetrates between the electrodes, so that the detection accuracy of the refrigerant leak detection sensor 30 is improved.

  (3) In the refrigerant leak detection sensor 30 according to the present embodiment, in consideration of the installation location of the refrigerant leak detection sensor 30, the position of the window is set at a place where the refrigerating machine oil contained in the leaked refrigerant is likely to contact. Can be changed. As a result, the adsorbed refrigerating machine oil efficiently penetrates between the electrodes, so that the detection accuracy of the refrigerant leak detection sensor 30 is improved.

<Modification>
(1) In the refrigerant leak detection sensor 30 according to the previous embodiment, windows are arranged on a part of the front surface and the bottom surface of the casing 31, and the oil adsorbing material is molded so as to match the position of the window. As shown in FIG. 7, the shapes and positions of the window members 35 ′ a and 35 ′ b included in the casing 31 ′ of the refrigerant leak detection sensor 30 ′ may be changed.

  (2) In the refrigerant leak detection sensor 30 according to the previous embodiment, foamed polystyrene is used as the window members 35a and 35b. However, the substance does not pass gas, has water repellency, and dissolves in refrigerating machine oil contained in the refrigerant. If so, a chicle, acrylic rubber, ethylene propylene rubber, butyl rubber or the like may be used.

  (3) In the refrigerant leak detection sensor 30 according to the previous embodiment, PAG (polyalkylene glycol) is used as the refrigerating machine oil 91, but PVE (polyvinyl ether), POE (polyol ester), or the like is used. Also good.

  The refrigerant leakage detection sensor according to the present invention eliminates the possibility of erroneous detection of refrigerant leakage due to water and water vapor. Therefore, by installing the refrigerant leakage detection sensor according to the present invention in the air conditioner, refrigerant leakage can be detected accurately, and more efficient maintenance of the air conditioner is possible.

10, 20, 30, 30 'Refrigerant leakage detection sensor 11, 31, 31' Housing 12a, 12b Electrode 13 Oil adsorbent 14 Electronic circuit 15 Coating material 16 Filling material 17a, 17b Lead wire 18 Signal cable 19 Power cable 25 Cap 35a, 35b, 35'a, 35'b Window material 91 Refrigerating machine oil

JP 2004-125393 A Japanese Patent Laid-Open No. 8-685669

Claims (5)

A housing (3) having an opening (2);
A pair of electrodes (4) disposed inside the housing;
An oil adsorbent (5) that fills the space between the pair of electrodes inside the casing, closes the opening, and partially protrudes outside the casing to adsorb refrigeration oil. When,
An electronic circuit (6) disposed inside the housing and connected to the pair of electrodes to detect a capacitance between the pair of electrodes;
A coating material (7) coated on the surface of the oil adsorbent protruding outside the housing and having airtightness, water repellency and oil solubility;
A refrigerant leakage detection sensor (1).   The refrigerant leakage detection sensor according to claim 1, wherein the coating material is a coating film (17) applied to the oil adsorbent.   The refrigerant leakage detection sensor according to claim 1, wherein the coating material is a cap (27) covered with the oil adsorbent. A housing (13) having a window (12);
An airtight, water-repellent and oil-soluble window material (37) that closes the window of the housing;
A pair of electrodes (4) disposed inside the housing;
An oil adsorbent (15) that fills the space between the pair of electrodes inside the housing and is disposed adjacent to the window material inside the housing and adsorbs refrigerating machine oil;
An electronic circuit (6) disposed inside the housing and connected to the pair of electrodes to detect a capacitance between the pair of electrodes;
A refrigerant leakage detection sensor (11).   Filling a space other than the space occupied by the pair of electrodes, the oil adsorbent, and the electronic circuit inside the casing, and a filler (8) having airtightness, water repellency, and oil repellency. The refrigerant leakage detection sensor according to claim 1, further comprising:

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