Corrosion sensor and air conditioner

Abstract

A corrosion sensor according to the present disclosure detects corrosion of refrigerant piping of an air conditioner, and comprises: a container which is formed of a conductive material and in which a gas having a pressure higher than atmospheric pressure is sealed; a pressure change detection unit which detects a change in pressure of the gas in the container; a preferential corrosion part which is disposed in the container and corrodes more preferentially than the container; and a detection unit which detects corrosion of the container on the basis of detection results of the pressure change detection unit.

Description

Corrosion Sensor and Air Conditioner

[0001] The present disclosure relates to a corrosion sensor and an air conditioner.

[0002] In a refrigeration cycle device such as an air conditioner, a corrosion sensor is used to detect corrosion of a refrigerant pipe.

[0003] For example, Patent Document 1 discloses a refrigeration cycle device including a refrigerant pipe, an ACM sensor that detects a corrosion current, and a processing unit that determines corrosion of the refrigerant pipe.

[0004] Japanese Patent Application Laid-Open No. 2022-36621

[0005] In the refrigeration cycle device described in Patent Document 1, there is still room for improvement in terms of reducing manufacturing costs.

[0006] The present disclosure provides a corrosion sensor with a simple and inexpensive configuration and an air conditioner including the corrosion sensor with a simple and inexpensive configuration.

[0007] A corrosion sensor according to one aspect of the present disclosure is a corrosion sensor that detects corrosion of a refrigerant pipe of an air conditioner, and includes a container formed of a conductive material and sealed with a gas having a pressure higher than atmospheric pressure, a pressure change detection unit that detects a change in the pressure of the gas in the container, a corrosion-priority unit disposed in the container and corroding preferentially to the container, and a detection unit that detects corrosion of the container based on a detection result of the pressure change detection unit.

[0008] An air conditioner according to one aspect of the present disclosure includes a heat exchanger having a refrigerant pipe, a control unit, and the above-described corrosion sensor, and the control unit outputs information regarding corrosion of the refrigerant pipe when the corrosion of the container is detected by the corrosion sensor.

[0009] According to the present disclosure, it is possible to provide a corrosion sensor with a simple and inexpensive configuration and an air conditioner including the corrosion sensor with a simple and inexpensive configuration.

[0010] Figure 1 schematically shows a corrosion sensor 1 according to Embodiment 1 of the present disclosure. A schematic diagram showing corrosion progressing and causing corrosion to penetrate the container of the corrosion sensor. Figure 3 schematically shows the indoor unit of an air conditioner equipped with the corrosion sensor of Figure 1. A schematic block diagram showing the indoor unit of an air conditioner. Figure 5 schematically shows a corrosion sensor according to Embodiment 2 of the present disclosure. A schematic diagram showing corrosion progressing and causing corrosion to penetrate the container of the corrosion sensor.

[0011] (Background to this disclosure) In refrigeration cycle devices such as air conditioners, refrigerant piping made of materials such as copper pipes is used. To prevent refrigerant leakage, detecting corrosion of copper pipes has been considered. For example, Patent Document 1 discloses the detection of corrosion current in refrigerant piping using an ACM sensor.

[0012] Patent Document 1 describes a tendency for high costs to be incurred in forming a circuit for detecting corrosion currents on the order of μA or nA. For example, expensive, high-precision operational amplifiers are required. Therefore, there is a need for a corrosion sensor that can be realized with a simpler configuration and at a lower cost.

[0013] Therefore, the inventors investigated a corrosion sensor that could reduce costs with a simpler configuration, and an air conditioner equipped with a corrosion sensor, and arrived at the following invention.

[0014] (Embodiment 1) [Overall Configuration] Figure 1 is a schematic diagram showing a corrosion sensor 1 according to Embodiment 1 of the present disclosure.

[0015] <Corrosion Sensor> The corrosion sensor 1 is a sensor that detects corrosion in refrigerant piping of refrigeration cycle equipment such as air conditioners. The corrosion sensor 1 is not a sensor that directly detects actual corrosion of refrigerant piping, but rather it can indirectly detect corrosion of refrigerant piping by simulating corrosion of refrigerant piping when placed in the same environment as the refrigerant piping. By placing the corrosion sensor 1 in the space where the refrigerant piping is located, the corrosion sensor 1 can indirectly detect corrosion of the refrigerant piping.

[0016] As shown in Figure 1, the corrosion sensor 1 comprises a container 10, a pressure change detection unit 20, a corrosion priority unit 30, and a detection unit 40.

[0017] The container 10 is made of a conductive material such as metal. Examples of materials that can be used for the container 10 include copper, copper-phosphorus alloy, aluminum, aluminum-manganese alloy, or aluminum-zinc alloy. The same material used for the refrigerant piping may also be used for the container 10. By using the same material for the refrigerant piping as for the container 10, corrosion of the refrigerant piping can be detected more accurately as a corrosion sensor.

[0018] The gas is sealed inside the container 10. The fact that the gas is sealed inside the container 10 means that the container 10 is sealed so that the gas does not leak out. The gas is sealed inside the container 10 at a pressure higher than atmospheric pressure. The pressure of the gas sealed in the container 10 is greater than 1 atmosphere, and can be, for example, 4.15 MPa, which is the design pressure of the refrigerant in an air conditioner.

[0019] The gas to be filled inside the container 10 can be, for example, air, nitrogen, helium, or carbon dioxide. The gas sealed inside the container 10 should be selected with safety in mind in case of gas leakage from the container 10.

[0020] In this embodiment, the container 10 is formed in a tubular shape and has a U-shaped portion 10a that is bent in a U-shape. Sealing materials 11 are placed at both ends of the container 10. The sealing material 11 is made of, for example, a metal flare cap or a resin cap containing epoxy resin. In this embodiment, the sealing material 11 is placed at both ends of the container 10, but for example, the container 10 may have an opening at one end and the other end may not be open. In this case, after filling the container 10 with gas, the container 10 can be sealed by sealing the opening at one end with the sealing material 11.

[0021] The pressure change detection unit 20 detects the pressure of the gas inside the container 10. In this embodiment, the pressure change detection unit 20 is composed of a pressure sensor. Any type of pressure sensor can be used for the pressure change detection unit 20, such as a resistive film type, a capacitive type, a piezoelectric element type, an optical type, or a MEMS.

[0022] The container 10 is provided with a corrosion-preferred portion 30. The corrosion-preferred portion 30 is a part where corrosion occurs preferentially over the metal material of the container 10. In other words, the corrosion-preferred portion 30 is more susceptible to corrosion than other parts of the container 10. Therefore, it can be said that the corrosion-preferred portion 30 is a part where corrosion is more likely to occur earlier than other parts of the container 10. In this embodiment, the corrosion-preferred portion 30 is provided with an electrode 30 having a potential higher than the material constituting the container 10. The term "potential" here refers to the corrosion potential of the target material in a typical operating environment for air conditioning equipment, for example, in condensed water.

[0023] As in this embodiment, when the container 10 has a U-shaped portion 10a, the U-shaped portion 10a is more susceptible to corrosion than other parts of the container 10. The U-shaped portion 10a has higher tensile stress than other parts of the container 10 due to residual stress during processing, etc., and is therefore more prone to stress corrosion cracking than other parts of the container 10. By placing the corrosion priority area 30 in the U-shaped portion 10a, it becomes possible to detect corrosion of the container 10 at an earlier stage.

[0024] The electrode 30 is made of a material having a higher potential than the material of the container 10. Specifically, the electrode 30 can be made of a material such as silver or conductive carbon. The material of the electrode 30 is not limited to silver or conductive carbon; various materials having a higher potential than the material of the container 10 can be used.

[0025] The detection unit 40 is a circuit that detects corrosion of the container 10 based on the detection results of the pressure change detection unit 20. In this embodiment, the detection unit 40 can detect corrosion of the container 10 based on the fact that the pressure of the gas inside the container 10 detected by the pressure change detection unit 20 has fallen below atmospheric pressure or has been continuously decreasing. A continuously decreasing pressure of the gas inside the container 10 means, for example, that the pressure inside the container 10 continues to decrease for a predetermined period of time.

[0026] Figure 2 is a schematic diagram showing that corrosion has progressed and caused a corrosion penetration in the container 10 in the corrosion sensor 1 of Figure 1. Corrosion penetration means that a hole has formed in the container 10 due to corrosion. As shown in Figure 2, as corrosion of the container 10 progresses, a corrosion penetration hole 30a occurs in the container 10. As described above, the corrosion-priority area 30 is more susceptible to corrosion than other parts of the container 10, so corrosion penetration holes 30a usually occur in the corrosion-priority area 30. When a corrosion penetration hole 30a occurs, as shown by arrow A1 in Figure 2, the gas sealed in the container 10 leaks out of the container 10 through the corrosion penetration hole 30a. As the gas leaks out of the container 10, the pressure of the gas inside the container 10 gradually decreases. The detection unit 40 detects corrosion of the container 10 based on the decrease in the pressure of the gas inside the container 10 due to corrosion penetration. For example, if the pressure of the gas inside the container 10 detected by the pressure change detection unit 20 is below atmospheric pressure, the detection unit 40 detects that the container 10 has corroded. Alternatively, if the pressure inside the container 10 detected by the pressure change detection unit 20 is continuously decreasing, the detection unit 40 detects that the container 10 has corroded.

[0027] In this embodiment, the corrosion sensor 1 can detect the occurrence of corrosion based on the fact that corrosion penetration has occurred in the container 10 and the pressure of the gas inside the container 10 has decreased. A corrosion sensor can be provided with a simple configuration consisting of a container 10 that seals the gas and is provided with a corrosion priority section 30, a pressure change detection section 20, and a detection section 40, while also reducing manufacturing costs.

[0028] The corrosion sensor 1 can be used to detect corrosion in the refrigerant piping of a heat exchanger such as the air conditioner 100 shown in Figures 3 and 4. In this embodiment, an example will be described in which the corrosion sensor 1 is used to detect corrosion in the refrigerant piping 3 of the indoor heat exchanger 2 located inside the indoor unit 50 of the air conditioner 100.

[0029] <Air Conditioner> Figure 3 is a schematic diagram showing the internal configuration of the indoor unit 50 of the air conditioner 100 equipped with the corrosion sensor 1 shown in Figure 1. Figure 4 is a schematic block diagram showing the indoor unit 50 of the air conditioner 100 shown in Figure 3. The air conditioner 100 equipped with the corrosion sensor 1 will be described with reference to Figures 3 and 4.

[0030] As shown in Figures 3 and 4, the indoor unit 50 of the air conditioner 100 has an indoor heat exchanger 2 and an indoor fan 5 located inside the housing 6. The air conditioner 100 also has a control unit 7 that controls the indoor fan 5.

[0031] The indoor heat exchanger 2 includes refrigerant piping 3 and heat dissipation fins 4. Air is drawn into the housing 6 of the indoor unit 50 by the indoor fan 5, and the heat exchanger 2 returns the air to be discharged into the indoor space where the indoor unit 50 is installed, thereby adjusting the temperature of the indoor space.

[0032] The control unit 7 includes, for example, a memory that stores a program and a processing circuit corresponding to a processor such as a CPU (Central Processing Unit). The functions of the control unit 7 may be configured solely with hardware, or they may be realized by a combination of hardware and software. The control unit 7 realizes predetermined functions by reading data and programs stored in memory and performing various arithmetic operations. In this embodiment, the control unit 7 can, for example, control the rotation speed of the indoor fan 5.

[0033] As shown in Figure 3, the refrigerant piping 3 has a plurality of U-shaped curved bends 3a to house inside the housing 6. Among the refrigerant piping 3, the bends 3a are particularly susceptible to corrosion due to tensile stress. For this reason, it is preferable to place the corrosion sensor 1 near the bends 3a of the refrigerant piping 3. By placing the corrosion sensor 1 near the bends 3a, the corrosion sensor 1 and the bends 3a can be placed under similar environmental conditions. Therefore, when corrosion penetration of the container 10 of the corrosion sensor 1 is detected, it can be estimated that corrosion penetration may also occur in the bends 3a.

[0034] When the corrosion sensor 1 detects corrosion in the container 10, the control unit 7 outputs information regarding corrosion of the refrigerant piping 3. This information regarding corrosion of the refrigerant piping 3 may include, for example, a warning to alert the user to the possibility of refrigerant leakage due to corrosion penetrating the refrigerant piping 3. The control unit 7 can display the warning on, for example, the display unit of the air conditioner 100, such as an LED display or liquid crystal display (not shown), or on a terminal device such as a remote controller or smartphone that can communicate with the air conditioner 100 (not shown). Alternatively, the control unit 7 may notify the user of the information by voice, such as by using the buzzer of the air conditioner 100.

[0035] Since the corrosion sensor 1 is equipped with a corrosion priority section 30, corrosion penetration is more likely to occur in the corrosion sensor 1 earlier than in the refrigerant piping 3. Therefore, by notifying the user when corrosion penetration in the container 10 is detected by the corrosion sensor 1, the user can recognize the possibility of corrosion penetration before refrigerant leakage occurs.

[0036] [Effects] The above-described embodiment provides the following effects.

[0037] The corrosion sensor 1 is a sensor that detects the corrosion of the refrigerant pipe 3 of the air conditioner 100. The corrosion sensor 1 includes a container 10, a pressure change detection unit 20, a corrosion priority unit 30, and a detection unit 40. The container 10 is formed of a conductive material and seals a gas with a pressure higher than the atmospheric pressure. The pressure change detection unit 20 detects a change in the pressure of the gas inside the container 10. The corrosion priority unit 30 is disposed in the container 10 and corrodes preferentially to the container 10. The detection unit 40 detects the corrosion of the container 10 based on the detection result of the pressure change detection unit 20.

[0038] With such a configuration, a corrosion sensor with a simple and inexpensive configuration can be provided.

[0039] The container 10 is formed in a tubular shape with both ends sealed and has a bent portion 10a in a U shape.

[0040] With such a configuration, even when the tensile stress is large and corrosion progresses easily, corrosion penetration can be detected earlier.

[0041] The corrosion priority unit 30 is disposed in the bent portion 10a in a U shape.

[0042] With such a configuration, by further providing the corrosion priority unit 30 in the U-shaped portion 10a, earlier detection of corrosion penetration becomes possible.

[0043] The corrosion priority unit 30 is disposed on the outer surface of the container 10 and is composed of an electrode having a nobler potential than the container 10.

[0044] With such a configuration, the corrosion priority unit 30 can be configured more simply.

[0045] The detection unit 40 detects the corrosion of the container 10 when the pressure change detection unit detects that the pressure of the gas inside the container 10 is below the atmospheric pressure.

[0046] With such a configuration, it can be detected that corrosion penetration has occurred in the container 10 due to the leakage of the gas inside the container 10 to the outside and the pressure inside the container 10 becoming below the atmospheric pressure.

[0047] When the pressure of the gas inside the container 10 continuously decreases by the pressure change detection unit, the detection unit 40 detects the corrosion of the container 10.

[0048] With such a configuration, since the pressure inside the container 10 continuously decreases, it is possible to detect that corrosion penetration has occurred in the container 10.

[0049] The pressure change detection unit 20 is composed of a pressure sensor.

[0050] With such a configuration, the corrosion sensor 1 can be configured with a simpler configuration.

[0051] The air conditioner 100 includes a heat exchanger 2 having a refrigerant pipe 3, a control unit 7, and a corrosion sensor 1. When the corrosion sensor 1 detects the corrosion of the container 10, the control unit 7 outputs information regarding the corrosion of the refrigerant pipe 3.

[0052] With such a configuration, an alert can be issued to the user before the refrigerant leaks from the refrigerant pipe 3.

[0053] In the above-described embodiment, an example in which the container 10 is formed in a tubular shape having a U-shaped portion 10a bent in a U shape has been described, but the present invention is not limited to this. The container 10 may be any container that can seal gas.

[0054] Further, in the above-described embodiment, an example in which the corrosion priority portion 30 is disposed on the outer surface of the container 10 and is composed of an electrode having a nobler potential than the container 10 has been described, but the present invention is not limited to this. The corrosion priority portion 30 may be, for example, a part of the container 10 that is formed to have a thinner wall thickness than other parts of the container 10. By making the wall thickness of the corrosion priority portion 30 thinner than that of other parts of the container 10, the period until corrosion progresses and penetrates can be made shorter than that of other parts of the container 10. Alternatively, the wall thickness of the corrosion priority portion 30 or the overall wall thickness of the container 10 may be made thinner than the wall thickness of the thinnest part of the refrigerant pipe used in the target air conditioner. By making the wall thickness of the container 10 thinner than the wall thickness of the refrigerant pipe of the air conditioner, corrosion penetration can be detected earlier.

[0055] Furthermore, in the above-described embodiment, an example was described in which the detection unit 40 detects that corrosion has occurred in the container 10 when the pressure of the gas inside the container 10 detected by the pressure change detection unit 20 is below atmospheric pressure, but the invention is not limited to this. Instead of below atmospheric pressure, for example, the detection unit 40 may detect corrosion in the container 10 when the pressure of the gas inside the container 10 detected by the pressure change detection unit 20 is below a predetermined threshold. The predetermined threshold may be, for example, a value greater than atmospheric pressure.

[0056] Furthermore, although the above-described embodiment described an example in which the corrosion sensor 1 is placed on the indoor unit 50 of the air conditioner 100, the invention is not limited to this. The corrosion sensor 1 may also be placed on the outdoor unit of the air conditioner 100. Alternatively, the corrosion sensor 1 may be placed near the refrigerant piping of a refrigeration cycle device other than an air conditioner.

[0057] (Embodiment 2) Embodiment 2 will be described with reference to Figures 5 and 6. In Embodiment 2, components that are the same as or equivalent to those in Embodiment 1 will be denoted by the same reference numerals. Also, in Embodiment 2, descriptions that overlap with those in Embodiment 1 will be omitted.

[0058] Figure 5 is a schematic diagram showing a corrosion sensor 1A according to Embodiment 2 of the present disclosure. As shown in Figure 5, Embodiment 2 differs from Embodiment 1 in that the pressure change detection unit is composed of a conductive pin 21 and the pin 21 and the container 10 are electrically connected. Furthermore, Embodiment 2 differs from Embodiment 1 in that the detection unit 41 is composed of an ammeter that detects the current flowing between the pin 21 and the container 10.

[0059] In this embodiment, at least one of the sealing materials 12 arranged at both ends of the container 10 is made of an insulating material. In the example shown in Figure 5, an example is described in which both sealing materials 12 arranged at both ends of the container 10 are made of an insulating material. The sealing material 12 is formed, for example, by a resin cap containing epoxy resin. In this embodiment, the container 10 is formed in a tubular shape with openings at both ends, but for example, the container 10 may have an opening at only one end.

[0060] In this embodiment, a pressure change detection unit 21 is located at the end of the container 10, which is sealed with an insulating material. The pressure change detection unit 21 consists of a pin 21 made of a conductive material and wiring 22 that electrically connects the pin and the container 10.

[0061] The pin 21 is positioned inside the container 10 at the sealed end 10b, and is biased toward the end 10b of the container 10 by the pressure of the gas inside the container 10. Since the pressure of the gas inside the container 10 is higher than atmospheric pressure, the pin 21 remains biased toward the end 10b of the container 10 unless corrosion penetration occurs in the container 10. In addition, a sealing member 21a such as an O-ring may be placed on the pin 21 to seal the space between the pin 21 and the sealing material 12.

[0062] The pin 21 is electrically connected to the container 10 via the wiring 22. In this embodiment, the wiring 22 electrically connects the pin 21 to the surface of the container 10. In the state shown in Figure 5, the pin 21 is in contact with the insulating sealing material 12, but not with the conductive container 10, so no current flows between the pin 21 and the container 10.

[0063] In this embodiment, the detection unit 41 includes an ammeter 41 that detects the current flowing between the pin 21 and the container 10. The detection unit 41 detects corrosion of the container 10 based on the current between the pin 21 and the container 10.

[0064] Figure 6 is a schematic diagram showing that corrosion has progressed and caused a corrosion penetration in the container 10 at the corrosion sensor 1A in Figure 5. As shown in Figure 6, as corrosion progresses in the container 10, a corrosion penetration hole 30a is created in the container 10. When a corrosion penetration hole 30a is created, the gas inside the container 10 leaks out to the outside of the container 10, as shown by arrow A2. Due to the gas leakage, the pressure of the gas inside the container 10 gradually decreases, and the pin 21, which was biased to the end 10b of the container 10, falls into the inside of the container 10. Since the container 10 is made of a conductive material, a current flows between the container 10 and the pin 21 due to contact between the container 10 and the pin 21. The detection unit 41 detects corrosion in the container 10 based on the current flowing between the container 10 and the pin 21. More specifically, the detection unit 41 detects corrosion in the container 10 when the current flowing between the container 10 and the pin 21 is greater than 0.

[0065] [Effects] The above-described embodiment can achieve the following effects.

[0066] At least one end 10b of the container is sealed with an insulating material. The pressure change detection unit consists of a pin 21 and wiring 22. The pin 21 is made of a conductive material and is positioned inside the container 10 at the end 10b sealed with the insulating material, and is biased toward the end 10b by the pressure of the gas. The wiring 22 electrically connects the pin 21 and the container 10. The detection unit 41 consists of an ammeter that detects the current flowing between the pin 21 and the container 10. The detection unit 41 detects corrosion of the container 10 based on the current between the pin 21 and the container 10 detected by the ammeter.

[0067] This configuration makes it possible to provide a simple and inexpensive corrosion sensor.

[0068] In the above-described embodiment, an example was explained in which the pressure change detection unit is composed of a pin 21 and wiring 22, but it is not limited to this. For example, it may be a member such as a lid made of a conductive material that is biased to the end 10b of the container 10.

[0069] (Note) The above description of embodiments discloses the following technology.

[0070] (Technology 1) A corrosion sensor for detecting corrosion of refrigerant piping in an air conditioner, comprising: a container made of a conductive material and sealed with a gas at a pressure higher than atmospheric pressure; a pressure change detection unit for detecting changes in the pressure of the gas inside the container; a corrosion priority unit disposed in the container and where corrosion occurs preferentially over the container; and a detection unit for detecting corrosion of the container based on the detection result of the pressure change detection unit.

[0071] This configuration makes it possible to provide a simple and inexpensive corrosion sensor.

[0072] (Technology 2) The corrosion sensor according to Technology 1, wherein the container is formed in a tubular shape with both ends sealed and has a U-shaped curved portion.

[0073] This configuration allows for earlier detection of corrosion, even when tensile stress is high and corrosion is likely to progress.

[0074] (Technology 3) The corrosion priority area is the corrosion sensor described in Technology 2, which is positioned in a U-shaped curved section.

[0075] This configuration allows for earlier detection of corrosion penetration by providing a corrosion-priority area within the U-shaped section.

[0076] (Technology 4) A corrosion sensor according to any one of Technologies 1 to 3, wherein the corrosion priority portion is arranged on the outer surface of the container and consists of an electrode having a potential greater than that of the container.

[0077] This configuration allows for a simpler construction of the corrosion-prevention zone.

[0078] (Technology 5) The corrosion sensor according to any one of Technologies 1 to 3, wherein the corrosion-preferred portion is part of the container, and the thickness of the corrosion-preferred portion is formed to be thinner than the thickness of the other parts of the container.

[0079] This configuration allows for a simpler construction of the corrosion-prevention zone.

[0080] (Technology 6) The corrosion sensor according to any one of Technologies 1 to 3, wherein the corrosion priority portion is part of the container, and the thickness of the corrosion priority portion is formed to be thinner than the thinnest part of the refrigerant piping of the air conditioner.

[0081] This configuration allows for a simpler construction of the corrosion-prevention zone.

[0082] (Technology 7) A corrosion sensor according to any one of Technologies 1 to 6, wherein the detection unit detects corrosion of a container when the pressure of the gas inside the container detected by the pressure change detection unit is below atmospheric pressure.

[0083] With this configuration, it is possible to detect corrosion penetration in the container when gas leaks from inside the container to the outside, causing the internal pressure to fall below atmospheric pressure.

[0084] (Technology 8) A corrosion sensor according to any one of Technologies 1 to 6, wherein the detection unit detects corrosion of a container when the pressure of the gas inside the container detected by the pressure change detection unit is continuously decreasing.

[0085] This configuration allows for the detection of corrosion penetration in the container because the internal pressure of the container is continuously decreasing.

[0086] (Technology 9) A corrosion sensor according to any one of Technologies 1 to 8, wherein the pressure change detection unit is composed of a pressure sensor.

[0087] This configuration allows for the construction of a corrosion sensor with a simpler design.

[0088] (Technology 10) A corrosion sensor according to any one of Techniques 1 to 4, wherein at least one end of a container is sealed with an insulating material, and the pressure change detection unit comprises a pin made of a conductive material, positioned at the end sealed with the insulating material inside the container and biased toward the end by the pressure of a gas, and wiring electrically connecting the pin to the container, the detection unit includes an ammeter for detecting a current flowing between the pin and the container, and the detection unit detects corrosion of the container based on the current between the pin and the container detected by the ammeter.

[0089] This configuration makes it possible to provide a simple and inexpensive corrosion sensor.

[0090] (Technology 11) An air conditioner comprising a heat exchanger having refrigerant piping, a control unit, and a corrosion sensor as described in any one of Technologies 1 to 10, wherein the control unit outputs information regarding corrosion of the refrigerant piping when the corrosion sensor detects corrosion of the container.

[0091] This configuration allows for alerts to be sent to the user before refrigerant leaks from the refrigerant piping.

[0092] This disclosure is applicable to corrosion sensors for detecting corrosion in refrigerant piping.

[0093] 1, 1A Corrosion sensor 2 Heat exchanger 3 Refrigerant piping 7 Control unit 10 Container 10a U-shaped section 10b End section 11, 12 Sealing material 20, 21 Pressure change detection section 21 Pin 22 Wiring 30 Corrosion priority section 30a Corrosion through hole 40, 41 Detection section 100 Air conditioner

Claims

1. A corrosion sensor for detecting corrosion of refrigerant piping in an air conditioner, comprising: a container made of a conductive material and sealed with a gas at a pressure higher than atmospheric pressure; a pressure change detection unit for detecting changes in the pressure of the gas in the container; a corrosion priority unit disposed in the container and in which corrosion occurs preferentially over that of the container; and a detection unit for detecting corrosion of the container based on the detection result of the pressure change detection unit.

2. The corrosion sensor according to claim 1, wherein the container is formed in a tubular shape with both ends sealed and has a U-shaped curved portion.

3. The corrosion-prioritizing portion is arranged in the U-shaped curved portion, as described in claim 2.

4. The corrosion-priority portion is disposed on the outer surface of the container and comprises an electrode having a potential greater than that of the container, according to any one of claims 1 to 3.

5. The corrosion sensor according to any one of claims 1 to 3, wherein the corrosion-priority portion is a part of the container, and the thickness of the corrosion-priority portion is formed to be thinner than the thickness of the other parts of the container.

6. The corrosion-priority portion is a part of the container, and the thickness of the corrosion-priority portion is formed to be thinner than the thinnest part of the refrigerant piping of the air conditioner, according to any one of claims 1 to 3.

7. The corrosion sensor according to any one of claims 1 to 6, wherein the detection unit detects corrosion of the container when the pressure of the gas inside the container detected by the pressure change detection unit is below atmospheric pressure.

8. The corrosion sensor according to any one of claims 1 to 6, wherein the detection unit detects corrosion of the container when the pressure of the gas inside the container, as detected by the pressure change detection unit, is continuously decreasing.

9. The corrosion sensor according to any one of claims 1 to 8, wherein the pressure change detection unit is composed of a pressure sensor.

10. The corrosion sensor according to any one of claims 1 to 4, wherein at least one end of the container is sealed with an insulating material, the pressure change detection unit is made of a conductive material and comprises a pin located in the container at the end sealed with the insulating material and biased toward the end by the pressure of the gas, and wiring electrically connecting the pin and the container, the detection unit includes an ammeter for detecting a current flowing between the pin and the container, and the detection unit detects corrosion of the container based on the current between the pin and the container detected by the ammeter.

11. An air conditioner comprising: a heat exchanger having refrigerant piping; a control unit; and a corrosion sensor according to any one of claims 1 to 10, wherein the control unit outputs information relating to corrosion of the refrigerant piping when the corrosion sensor detects corrosion of the container.

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