Refrigeration cycle equipment

Abstract

To provide a refrigeration cycle device capable of suppressing deterioration of refrigerant leakage detection accuracy during operation of a fan.SOLUTION: A refrigeration cycle device includes: an indoor heat exchanger 14 provided in an air course formed in a casing 10 and having a refrigerant flowing therein; and an infrared ray sensor 100 for detecting occurrence of leakage of the refrigerant in the casing 10. The infrared ray sensor 100 includes: a light emitting section 120 that emits infrared rays; a light receiving section 130 that receives the infrared rays emitted from the light emitting section 120; and a case member 110 in which the light emitting section 120 and the light receiving section 130 are accommodated and a gas intake port 111 is formed thereon. The refrigeration cycle device further includes a refrigerant leakage detection section 41 that detects occurrence of leakage of the refrigerant on the basis of an infrared ray receiving state of the light receiving section 130. An opening surface of the gas intake port 111 faces an upstream side of an air current in the air course and is disposed vertically to the air current.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a refrigeration cycle device.

Background Art

[0002] In a refrigeration cycle device, there are an outdoor unit that sends out refrigerant, an indoor unit connected to the outdoor unit via a refrigerant pipe, a control unit that controls the refrigeration cycle formed by the outdoor unit and the indoor unit, and a refrigerant sensor installed in at least one of the housings of the outdoor unit and the indoor unit. The refrigerant sensor has a light emitting part that emits infrared rays and a light receiving part that receives the infrared rays emitted by the light emitting part. The control unit is known to determine that the refrigerant has leaked when the output from the light receiving part decreases (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the refrigeration cycle device as shown in Patent Document 1, since the light emitting part and the light receiving part are directly arranged in the air duct inside the housing, condensation occurs inside the housing, and water droplets may exist on the optical path between the light emitting part and the light receiving part or adhere to the light receiving part, which may change the amount of light received by the light receiving part, and ultimately may lead to a decrease in the refrigerant leakage detection accuracy. Also, when refrigerant leakage occurs during the operation of the fan of the indoor unit, the leaked refrigerant is carried by the air flow in the air duct. Therefore, since the sensor for detecting refrigerant leakage allows the leaked refrigerant to pass through at a relatively high speed, there is a risk that the refrigerant leakage detection accuracy will decrease.

[0005] This disclosure was made to solve these problems. Its purpose is to provide a refrigeration cycle device that can suppress the decrease in the accuracy of refrigerant leak detection during fan operation by a sensor having a light-emitting unit and a light-receiving unit. [Means for solving the problem]

[0006] The refrigeration cycle device according to this disclosure comprises a heat exchanger provided in an air passage formed within a housing through which a refrigerant flows, and a sensor unit for detecting the occurrence of refrigerant leakage within the housing, wherein the sensor unit comprises a light-emitting unit that emits infrared rays, a light-receiving unit that receives infrared rays emitted from the light-emitting unit, and a case member in which the light-emitting unit and the light-receiving unit are housed and a gas intake port is formed, and further comprises a detection unit that detects the occurrence of refrigerant leakage based on the state of infrared ray reception by the light-receiving unit, wherein the opening surface of the gas intake port faces the upstream side of the airflow in the air passage and is arranged perpendicular to the airflow. In a projection plane parallel to the opening surface of the gas intake port, a part of the case member positioned upstream of the airflow from the light-emitting portion overlaps with the light-emitting portion, while the gas intake port and the light-emitting portion do not overlap. Alternatively, the refrigeration cycle device according to the present disclosure comprises a heat exchanger provided in an air passage formed within a housing through which a refrigerant flows, and a sensor unit for detecting the occurrence of refrigerant leakage within the housing, wherein the sensor unit comprises a light-emitting unit that emits infrared rays, a light-receiving unit that receives infrared rays emitted from the light-emitting unit, and a case member in which the light-emitting unit and the light-receiving unit are housed and a gas intake port is formed, and further comprises a detection unit that detects the occurrence of refrigerant leakage based on the state of infrared ray reception by the light-receiving unit, wherein the opening surface of the gas intake port faces the upstream side of the airflow in the air passage and is arranged perpendicular to the airflow, and in a projection plane parallel to the opening surface of the gas intake port, a part of the case member located upstream of the airflow from the light-receiving unit and the light-receiving unit overlap, and the gas intake port and the light-receiving unit do not overlap. Alternatively, the refrigeration cycle device according to the present disclosure comprises a heat exchanger provided in an air passage formed within a housing through which a refrigerant flows, and a sensor unit for detecting the occurrence of refrigerant leakage within the housing, wherein the sensor unit comprises a light-emitting unit that emits infrared rays, a light-receiving unit that receives infrared rays emitted from the light-emitting unit, and a case member in which the light-emitting unit and the light-receiving unit are housed and a gas intake port is formed, and further comprises a detection unit that detects the occurrence of refrigerant leakage based on the state of infrared ray reception by the light-receiving unit, wherein the opening surface of the gas intake port faces the upstream side of the airflow in the air passage and is arranged perpendicular to the airflow, the optical axis of the infrared rays emitted from the light-emitting unit is arranged parallel to the airflow, and the case member has a narrowed portion between the light-emitting unit and the light-receiving unit in a direction perpendicular to the optical axis. [Effects of the Invention]

[0007] According to the refrigeration cycle device described herein, it is possible to suppress the decrease in the accuracy of refrigerant leak detection during fan operation by a sensor having a light-emitting unit and a light-receiving unit. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram shows a schematic configuration of the refrigerant circuit in an air conditioner, which is a refrigeration cycle device according to Embodiment 1. [Figure 2] This diagram schematically shows the configuration of the indoor unit of an air conditioner, which is a refrigeration cycle device according to Embodiment 1. [Figure 3] This is a schematic cross-sectional view showing the configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 4] This is a block diagram showing the configuration of the control system of the refrigeration cycle device according to Embodiment 1. [Figure 5] This is a schematic cross-sectional view showing a modified configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 6] This is a schematic perspective view showing a modified configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 7] This is a schematic cross-sectional view showing a modified configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 8] This is a schematic cross-sectional view showing a modified configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 9] This is a schematic perspective view showing a modified configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 10] This is a schematic cross-sectional view showing a modified configuration of the infrared sensor provided in the refrigeration cycle device according to Embodiment 1. [Figure 11] This diagram schematically shows the configuration of another example of an indoor unit of an air conditioner, which is a refrigeration cycle device according to Embodiment 1. [Figure 12] This diagram schematically shows the configuration of the indoor unit of an air conditioner, which is a refrigeration cycle device according to Embodiment 2. [Modes for carrying out the invention]

[0009] The embodiments for implementing the refrigeration cycle device relating to this disclosure will be described with reference to the attached drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are simplified or omitted as appropriate. For convenience, the positional relationships of each structure may be expressed based on the illustrated state in the following description. This disclosure is not limited to the following embodiments, and any combination of embodiments, any modification of any component of each embodiment, or any omission of any component of each embodiment is possible without departing from the spirit of this disclosure.

[0010] Embodiment 1. Referring to FIGS. 1 to 11, Embodiment 1 of the present disclosure will be described. FIG. 1 is a diagram showing a schematic configuration of a refrigerant circuit included in an air conditioner which is a refrigeration cycle device. FIG. 2 is a diagram schematically showing a configuration of an indoor unit of an air conditioner which is a refrigeration cycle device. FIG. 3 is a cross-sectional view schematically showing a configuration of an infrared sensor included in the refrigeration cycle device. FIG. 4 is a block diagram showing a configuration of a control system of the refrigeration cycle device. FIG. 5 is a cross-sectional view schematically showing a configuration of a modified example of the infrared sensor included in the refrigeration cycle device. FIGS. 6 and 9 are perspective views schematically showing a configuration of a modified example of the infrared sensor included in the refrigeration cycle device. FIGS. 7, 8 and 10 are cross-sectional views schematically showing a configuration of a modified example of the infrared sensor included in the refrigeration cycle device. FIG. 11 is a diagram schematically showing a configuration of another example of an indoor unit of an air conditioner which is a refrigeration cycle device.

[0011] As an example of the refrigeration cycle device according to this disclosure, the configuration of an air conditioner is shown in FIG. 1. Note that examples of the refrigeration cycle device to which the refrigerant leakage detection device according to this invention is applied include, in addition to an air conditioner, for example, a water heater, a showcase, or a refrigerator.

[0012] As shown in FIG. 1, the air conditioner which is the refrigeration cycle device according to this embodiment includes an indoor unit 1 and an outdoor unit 2. The indoor unit 1 is installed inside a room that is the object of air conditioning, that is, indoors. The outdoor unit 2 is installed outside the room, that is, outdoors. The indoor unit 1 includes an indoor heat exchanger 14 and an indoor fan 5. The outdoor unit 2 includes an outdoor heat exchanger 4, an outdoor fan 6, a compressor 7, an expansion valve 8, and a four-way valve 9.

[0013] The indoor unit 1 and the outdoor unit 2 are connected by a refrigerant pipe 3. The refrigerant pipe 3 is provided circularly between the indoor heat exchanger 14 of the indoor unit 1 and the outdoor heat exchanger 4 of the outdoor unit 2. Refrigerant is enclosed in the refrigerant pipe 3. It is desirable to use a refrigerant with a small global warming potential (GWP) for the refrigerant enclosed in the refrigerant pipe 3. For example, a refrigerant having a larger average molecular weight than air is used. The refrigerant in this case has a higher density than air and is heavier than air under atmospheric pressure. Therefore, the refrigerant in this case has the property of sinking downward in the direction of gravity (vertical direction) in the air.

[0014] As such a refrigerant, specifically, for example, a (mixed) refrigerant composed of one or more refrigerants selected from tetrafluoropropene (CF3CF=CH2:HFO-1234yf), difluoromethane (CH2F2:R32), propane (R290), propylene (R1270), ethane (R170), butane (R600), isobutane (R600a), 1,1,1,2-tetrafluoroethane (C2H2F4:R134a), pentafluoroethane (C2HF5:R125), 1,3,3,3-tetrafluoro-1-propene (CF3-CH=CHF:HFO-1234ze), carbon dioxide (CO2:R744), etc. can be used.

[0015] The refrigerant pipe 3 connects the indoor heat exchanger 14, the four-way valve 9, the compressor 7, the outdoor heat exchanger 4, and the expansion valve 8 circularly. Therefore, a refrigerant circuit in which refrigerant circulates between the indoor heat exchanger 14 and the outdoor heat exchanger 4 is formed.

[0016] The compressor 7 is a device that compresses the supplied refrigerant to increase the pressure and temperature of the refrigerant. For the compressor 7, for example, a rotary compressor, a scroll compressor, a reciprocating compressor, etc. can be used. The expansion valve 8 expands the refrigerant condensed in the outdoor heat exchanger 4 and reduces the pressure of the refrigerant. In the configuration example described here, the expansion valve 8 is a linear electric expansion valve (LEV). Therefore, by closing the expansion valve 8, the flow of the refrigerant can be blocked.

[0017] The indoor heat exchanger 14 exchanges heat between the refrigerant flowing into the indoor heat exchanger 14 and the air surrounding the indoor heat exchanger 14. The indoor fan 5 blows air so that indoor air passes around the indoor heat exchanger 14, promoting heat exchange between the refrigerant and air in the indoor heat exchanger 14, and also sends the air that has been heated or cooled by the heat exchange back into the room. The outdoor heat exchanger 4 exchanges heat between the refrigerant flowing into the outdoor heat exchanger 4 and the air surrounding the outdoor heat exchanger 4. The outdoor fan 6 blows air so that outdoor air passes around the outdoor heat exchanger 4, promoting heat exchange between the refrigerant and air in the outdoor heat exchanger 4.

[0018] The refrigerant circuit configured in this way acts as a heat pump that transfers heat between the indoor unit 1 and the outdoor unit 2 by performing heat exchange between the refrigerant and air in the indoor heat exchanger 14 and the outdoor heat exchanger 4, respectively. At this time, by switching the four-way valve 9, the direction of circulation of the refrigerant in the refrigerant circuit can be reversed, allowing the air conditioner to switch between cooling and heating operation.

[0019] Figure 2 shows an example of an indoor unit 1 according to this embodiment. The indoor unit 1 shown in the figure is a ceiling-mounted type (ceiling cassette type). That is, the indoor unit 1 is embedded in the ceiling of the room. The indoor unit 1 comprises a housing 10 and a panel 11. The housing 10 has a box shape with an open bottom. The panel 11 is attached to the bottom surface of the housing 10. The housing 10 is embedded in the ceiling of the room. The panel 11 is exposed into the room on the ceiling. The bottom surface of the housing 10 is the surface facing the space to be air-conditioned.

[0020] Panel 11 has an air intake port 12 and an air outlet port 13. The air intake port 12 is an opening for drawing air from the outside into the inside of the housing 10. The air outlet port 13 is an opening for discharging air from the inside of the housing 10 to the outside. Panel 11 has a rectangular shape, for example. The air intake port 12 is located in the center of panel 11. Four air outlet port 13 are located along each side of the rectangular shape of panel 11.

[0021] The enclosure 10 houses an indoor heat exchanger 14 and an indoor fan 5. The indoor fan 5 is a centrifugal fan. The indoor fan 5 is installed inside the enclosure 10 with its intake side facing downwards. The indoor fan 5 is driven to rotate by a fan motor (not shown). The fan motor is mounted on the top side of the enclosure 10. Below the indoor fan 5 and above the intake port 12, a bell mouth (not shown) is provided. The bell mouth is for introducing air to the indoor fan.

[0022] An indoor heat exchanger 14 is provided on the outer periphery of the indoor fan 5 inside the housing 10. The indoor heat exchanger 14 is arranged to surround the indoor fan 5 in a ring shape. As mentioned above, refrigerant piping 3 is connected to the indoor heat exchanger 14. Therefore, a portion of the refrigerant piping 3 is housed inside the housing 10. The indoor heat exchanger 14 is equipped with heat transfer tubes and fins (not shown). The heat transfer tubes of the indoor heat exchanger 14 are connected to the refrigerant piping 3 at pipe connection parts 16. Refrigerant flows through the heat transfer tubes via the refrigerant piping 3. In other words, refrigerant flows inside the indoor heat exchanger 14.

[0023] In the indoor heat exchanger 14, heat exchange takes place between the refrigerant and the air from the room drawn in through the intake port 12 by the indoor fan 5, generating cold or warm air. A drain pan 15 is provided below the indoor heat exchanger 14 inside the housing 10. The drain pan 15 is for collecting condensation water that is generated when moisture in the air condenses as the air is cooled during the heat exchange process in the indoor heat exchanger 14. An air outlet passage leading to the air outlet 13 is formed between the outer periphery of the indoor heat exchanger 14 and the drain pan 15 inside the housing 10 and the wall surface of the housing 10.

[0024] In this way, an air passage is formed within the housing 10 of the indoor unit 1, passing from the intake port 12 through the indoor fan 5, the indoor heat exchanger 14, and the discharge air passage to the outlet port 13. Therefore, the indoor heat exchanger 14 is positioned within the air passage formed inside the housing 10.

[0025] In the indoor unit 1 of the air conditioner configured as described above, when the indoor fan 5 is rotated by the fan motor, an airflow is generated in the air passage inside the housing 10, moving from the intake port 12 to the outlet port 13. Air is drawn in from the intake port 12 and blown out from the outlet port 13. The air drawn in from the intake port 12 passes through the bell mouth and flows into the intake side of the indoor fan 5. The air that flows into the indoor fan 5 is blown out to the outer periphery of the indoor fan 5. The air blown out from the indoor fan 5 passes through the indoor heat exchanger 14 from the inner periphery to the outer periphery. As the air passes through the indoor heat exchanger 14, it is heated or cooled. Whether the air is heated or cooled depends on whether the air conditioner is operating in cooling or heating mode. The air that has passed through the indoor heat exchanger 14 hits the wall surface of the housing 10 and changes its direction of flow downward. Then, it passes through the discharge air passage between the indoor heat exchanger 14 and the drain pan 15 and the wall surface of the housing 10 and is blown out from the outlet port 13.

[0026] The indoor unit 1 according to this embodiment is equipped with an infrared sensor 100. The infrared sensor 100 is a sensor unit for detecting the occurrence of refrigerant leakage. In this embodiment, the infrared sensor 100 is placed in the aforementioned air passage inside the housing 10. Note that the number of infrared sensors 100 to be installed is not limited to one, and multiple infrared sensors 100 may be installed. In addition, the infrared sensor 100 may be installed inside the housing of the outdoor unit 2.

[0027] As shown in Figure 3, the infrared sensor 100 comprises a light-emitting unit 120, a light-receiving unit 130, and a case member 110. The light-emitting unit 120 is a light-emitting means that emits infrared rays. The light-emitting unit 120 is equipped with, for example, an infrared lamp with a filament or a light-emitting diode (LED) as a light source. The light-receiving unit 130 is a light-receiving means that receives the infrared rays emitted from the light-emitting unit 120. The light-emitting unit 120 emits infrared rays when power is supplied. The light-receiving unit 130 outputs a signal corresponding to the intensity of the received infrared rays.

[0028] In the configuration example shown in Figure 3, the case member 110 has a hollow rectangular parallelepiped shape. The light-emitting unit 120 and the light-receiving unit 130 are housed inside the case member 110. Inside the case member 110, the light-emitting unit 120 and the light-receiving unit 130 are arranged facing each other. The light-receiving surface of the light-receiving unit 130 is positioned perpendicular to the optical axis of the light (infrared) emitted from the light-emitting unit 120.

[0029] Infrared light emitted from the light-emitting unit 120 passes through the optical path 140 and reaches the light-receiving unit 130. The optical path 140 is the region through which the infrared light emitted from the light-emitting unit 120 passes before reaching the light-receiving unit 130. The optical path 140 is formed along the optical axis of the infrared light emitted from the light-emitting unit 120.

[0030] The case member 110 surrounds the light-emitting unit 120, the light-receiving unit 130, and the optical path 140 from all directions: front, back, top, bottom, left, and right. The shape of the case member 110 is not limited to the illustrated example, i.e., a rectangular parallelepiped, as long as it surrounds the light-emitting unit 120, the light-receiving unit 130, and the optical path 140. It may also be cylindrical, prismatic, cocoon-shaped, or the like. A gas intake port 111 is formed in the case member 110. This gas intake port 111 connects the outside and inside of the case member 110. In the configuration example shown in Figure 3, the gas intake port 111 is formed on the upper surface of the case member 110.

[0031] In the configuration example shown in Figure 3, the infrared sensor 100 further includes a substrate 150. The substrate 150 is a flat printed circuit board. The light-emitting unit 120 and the light-receiving unit 130 are connected to the substrate 150 by lead wires 151. The case member 110 is fixed to the substrate 150. In the illustrated example, the substrate 150 is fixed to the side of the case member 110 opposite to the side with the gas intake port 111. The substrate 150 may be provided integrally with the control board of the control device 40 of the air conditioner, which will be described later.

[0032] The refrigerant sealed in the refrigerant piping 3 has the property of absorbing infrared radiation of a specific wavelength. The infrared radiation emitted by the light-emitting unit 120 includes this specific wavelength that the refrigerant absorbs. The infrared sensor 100 may be equipped with a filter that allows the infrared radiation emitted by the light-emitting unit 120 to pass through the aforementioned specific wavelength. When there is no refrigerant between the light-emitting unit 120 and the light-receiving unit 130, the infrared radiation emitted from the light-emitting unit 120 reaches the light-receiving unit 130. When there is refrigerant between the light-emitting unit 120 and the light-receiving unit 130, the infrared radiation emitted from the light-emitting unit 120 of the aforementioned specific wavelength is absorbed by this refrigerant. The infrared radiation emitted from the light-emitting unit 120 of the aforementioned specific wavelength is attenuated by the refrigerant. Whether or not there is refrigerant between the light-emitting unit 120 and the light-receiving unit 130, or more precisely, depending on the concentration of refrigerant between the light-emitting unit 120 and the light-receiving unit 130, the intensity of the infrared radiation received by the light-receiving unit 130 changes.

[0033] Figure 4 shows the configuration of the control system for the air conditioner, which is a refrigeration cycle device according to this embodiment. As shown in the figure, the air conditioner according to this embodiment is equipped with a control device 40. The control device 40 processes signals related to the operation control of the air conditioner and controls the overall operation of the air conditioner. Specifically, the control device 40 controls the operation of the compressor 7, the indoor fan 5, and the outdoor fan 6.

[0034] The control device 40 consists of hardware such as a computer equipped with a processor and memory. The processor is also called a CPU (Central Processing Unit), central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory includes, for example, non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, and EEPROM, or magnetic disks, flexible disks, optical disks, compact disks, minidiscs, and DVDs.

[0035] The control device 40 stores a program as software in its memory. The control device 40 then performs pre-configured processing by having the processor execute the program stored in memory, and as a result of the cooperation between hardware and software, it realizes the functions described later.

[0036] Furthermore, the circuit of the control device 40 may be formed as dedicated hardware, for example. A part of the circuit of the control device 40 may be formed as dedicated hardware, and that circuit may be equipped with a processor and memory. Examples of circuits in which a part is formed as dedicated hardware include single circuits, composite circuits, programmed processors, parallel programmed processors, ASICs, FPGAs, or combinations thereof.

[0037] The air conditioner, which is a refrigeration cycle device according to this embodiment, detects refrigerant leakage from the indoor heat exchanger 14 by utilizing the detection results of the infrared sensor 100. As mentioned above, the infrared sensor 100 can detect the concentration of refrigerant. The infrared sensor 100 then outputs a detection signal corresponding to the detected refrigerant concentration. The detection signal output from the infrared sensor 100 is input to the control device 40.

[0038] The control device 40 includes a refrigerant leak detection unit 41, a storage unit 42, a notification unit 43, and an operation control unit 44. The refrigerant leak detection unit 41 detects the occurrence of a refrigerant leak based on the detection result of the infrared sensor 100. That is, the refrigerant leak detection unit 41 detects the occurrence of a refrigerant leak based on the infrared light reception state by the light receiving unit 130. The light receiving unit 130 outputs a signal corresponding to the received intensity of infrared light of the aforementioned specific wavelength. The signal output from the light receiving unit 130 of the infrared sensor 100 is input to the refrigerant leak detection unit 41 of the control device 40. The signal output from the light receiving unit 130 corresponds to the intensity of infrared light that reached the light receiving unit 130. As mentioned above, this intensity changes depending on the refrigerant concentration between the light emitting unit 120 and the light receiving unit 130.

[0039] The refrigerant leak detection unit 41 detects the occurrence of a refrigerant leak based on the signal output from the light receiving unit 130. Specifically, the refrigerant leak detection unit 41 detects that the refrigerant concentration in the infrared sensor 100 is above a certain level, i.e., that a refrigerant leak has occurred, when the light reception intensity of the light receiving unit 130 is below the leak detection threshold intensity. The leak detection threshold intensity in this case is set in advance according to the refrigerant concentration at which a refrigerant leak should be detected. The leak detection threshold intensity thus set is stored in advance in the storage unit 42.

[0040] The method by which the refrigerant leak detection unit 41 detects the occurrence of refrigerant leakage based on the signal output from the light receiving unit 130 is not limited to the method described above. For example, the following method may also be used. That is, the refrigerant leak detection unit 41 first calculates the refrigerant concentration using the infrared light intensity received by the light receiving unit 130. Then, the refrigerant leak detection unit 41 detects the occurrence of refrigerant leakage based on the time-integrated value of the calculated refrigerant concentration.

[0041] In this case, for example, the refrigerant leak detection unit 41 detects that a refrigerant leak has occurred when the time-integrated value of the calculated refrigerant concentration exceeds the leak judgment criterion integrated value. The leak judgment criterion integrated value is pre-set, for example, to the amount of refrigerant at which the concentration of leaked refrigerant released into the room exceeds a certain level, according to the volume of the room in which the indoor unit 1 is installed. In this way, it is possible to more reliably prevent the concentration of leaked refrigerant released into the room from exceeding a certain level. Furthermore, by linking the system with a ventilation device or the like when a refrigerant leak is detected, it is possible to more reliably prevent the concentration of leaked refrigerant released into the room from exceeding a certain level.

[0042] The notification unit 43 notifies users, workers, etc., when the refrigerant leak detection unit 41 detects the occurrence of a refrigerant leak. This notification unit 43 is equipped with a speaker for sound notification and an LED for light notification when a refrigerant leak has been detected.

[0043] The operation control unit 44 controls the operation of the air conditioner, which is a refrigeration cycle device, by controlling the operation of the compressor 7, indoor fan 5, outdoor fan 6, expansion valve 8, etc. If the refrigerant leak detection unit 41 detects that a refrigerant leak has occurred, the operation control unit 44 stops the operation of the air conditioner, which is a refrigeration cycle device.

[0044] In the refrigeration cycle system configured as described above, refrigerant leakage is detected using the detection results of the infrared sensor 100. The infrared sensor 100 includes a case member 110 that surrounds a light-emitting unit 120, a light-receiving unit 130, and an optical path 140. Leaked refrigerant is introduced into the case member 110 through a gas intake port 111 formed in the case member 110. By surrounding the light-emitting unit 120, the light-receiving unit 130, and the optical path 140 with the case member 110 in which the gas intake port 111 is formed, it is possible to suppress the adhesion of foreign matter such as dust and dirt to the light-emitting unit 120 and the light-receiving unit 130, and to detect refrigerant leakage by introducing the leaked refrigerant into the optical path 140 inside the case member 110.

[0045] As mentioned above, the infrared sensor 100 is installed in the air passage within the housing 10 of the indoor unit 1. In this embodiment, the case member 110 of the infrared sensor 100 is positioned and oriented such that the opening surface of the gas intake port 111 faces upstream of the airflow in the air passage and is perpendicular to the airflow.

[0046] Referring to Figure 2, an example of the arrangement of the case member 110 of the infrared sensor 100 in this embodiment will be described. The position and orientation shown at A in the figure is when the infrared sensor 100 is placed upstream of the outlet 13 in the air passage inside the housing 10. At position A, the airflow in the air passage is downward. Therefore, at A in the figure, the opening surface of the gas intake port 111 is positioned facing upward.

[0047] The position and orientation shown in Figure B represent the case where the infrared sensor 100 is placed downstream of the intake port 12 in the air passage within the housing 10. At position B, the airflow in the air passage is upward. Therefore, in Figure B, the opening surface of the gas intake port 111 is positioned facing downward.

[0048] The position and orientation shown in C of the figure represent the case where the infrared sensor 100 is placed at a bend in the air passage inside the housing 10. As mentioned above, the air that has passed through the indoor heat exchanger 14 from the inner circumference to the outer circumference hits the wall surface of the housing 10 and changes its direction of flow downward. Therefore, the area between the outer circumference of the indoor heat exchanger 14 and the wall surface of the housing 10 is a bend where the direction of the airflow changes from outward to downward. In C of the figure, the infrared sensor 100 is placed at this bend in the air passage. The opening surface of the gas intake port 111 is positioned facing inward so as to face the indoor heat exchanger 14.

[0049] With such a refrigeration cycle device (air conditioner), the case member 110 of the infrared sensor 100 covers the light-emitting part 120, the light-receiving part 130, and the optical path 140, thereby suppressing a decrease in refrigerant leak detection accuracy due to condensation occurring inside the housing 10. Furthermore, in all of the above A, B, and C, the opening surface of the gas intake port 111 of the infrared sensor 100 is positioned facing upstream of the airflow in the air passage and perpendicular to the airflow. Therefore, when a refrigerant leak occurs while the indoor fan 5 is operating, the leaked refrigerant carried by the airflow is easily taken into the case member 110 from the gas intake port 111, and by accumulating the gas containing the leaked refrigerant inside the case member 110, the detection accuracy of refrigerant leaks that occur while the indoor fan 5 is operating can be improved.

[0050] Furthermore, the position shown at C in Figure 2 is also below the pipe connection 16. When the refrigerant is heavier than air, if a refrigerant leak occurs at the pipe connection 16, the leaked refrigerant will mainly flow vertically downward from the pipe connection 16. Therefore, by placing the infrared sensor 100 at the position shown at C in Figure 2, it becomes easier to detect refrigerant leaks occurring at the pipe connection 16.

[0051] Note that the position and orientation shown at D in Figure 2 is above the drain pan 15. If a refrigerant leak occurs in the indoor heat exchanger 14, the refrigerant, which is heavier than air, tends to accumulate on the drain pan 15 located below the indoor heat exchanger 14. By placing the infrared sensor 100 at the position shown at D in Figure 2, it becomes easier to detect refrigerant leaks occurring in the indoor heat exchanger 14. In addition, by facing the opening surface of the gas intake port 111 downwards, it is possible to suppress the entry of foreign matter such as condensation water and dust into the case member 110 from the gas intake port 111.

[0052] Furthermore, in the configuration example of the infrared sensor 100 shown in Figure 3, the optical axis of the infrared light emitted from the light-emitting unit 120 is parallel to the opening surface of the gas intake port 111. Therefore, if the opening surface of the gas intake port 111 is perpendicular to the airflow in the air passage, then the optical axis of the infrared light emitted from the light-emitting unit 120 is positioned perpendicular to the airflow in the air passage. By positioning the optical axis and optical path 140 of the infrared light emitted from the light-emitting unit 120 perpendicular to the airflow in the air passage, leaked refrigerant taken into the case member 110 from the gas intake port 111 can easily cross the optical path 140, thereby further improving the accuracy of refrigerant leak detection.

[0053] Next, a modified example of the infrared sensor 100 according to this embodiment will be described with reference to Figures 5 to 10. Figures 5 and 6 show a modified example in which an exhaust port 112, which is another opening separate from the gas intake port 111, is formed in the case member 110 of the infrared sensor 100. In the modified example shown in Figure 5, the gas intake port 111 is formed on the upper surface of the case member 110, and the exhaust port 112 is formed on the lower surface of the case member 110. That is, the exhaust port 112 is formed on the surface of the case member 110 opposite to the surface on which the gas intake port 111 is formed. In the modified example shown in the same figure, the orientation of the opening surface of the exhaust port 112 is opposite to the orientation of the opening surface of the gas intake port 111. Furthermore, the gas intake port 111 and the exhaust port 112 are arranged so as not to overlap in a projection plane parallel to the opening surface of the gas intake port 111. This modification prevents the pressure inside the case member 110 from rising, which would make it difficult to draw gas into the gas intake port 111, and allows airflow to pass more easily through the optical path 140. Furthermore, by arranging the gas intake port 111 and exhaust port 112 as shown in Figure 5, leaked refrigerant drawn into the case member 110 can be more easily retained. Therefore, it is possible to further improve the accuracy of refrigerant leak detection.

[0054] In the modified example shown in Figure 6, a gas intake port 111 is formed on the upper surface of the case member 110, and an exhaust port 112 is formed on one side of the case member 110. That is, the exhaust port 112 is formed on a surface of the case member 110 that does not face the surface on which the gas intake port 111 is formed. In the modified example shown in the same figure, the orientation of the opening surface of the exhaust port 112 is 90° different from the orientation of the opening surface of the gas intake port 111. Even with this modified example, leaked refrigerant taken into the case member 110 can be more easily retained. Therefore, it is possible to further improve the accuracy of refrigerant leak detection.

[0055] Figures 7 and 8 show a modified example in which a narrowed section 114 is provided in the case member 110 in the intermediate portion between the light-emitting section 120 and the light-receiving section 130. In this modified example, a gas intake port 111 is formed on one side of the case member 110, for example, on the side where the light-emitting section 120 is located. An exhaust port 112 is formed on the other side of the case member 110, for example, on the side where the light-receiving section 130 is located. The exhaust port 112 is formed on the side of the case member 110 opposite to the side where the gas intake port 111 is formed. A partition member 113 is provided inside the case member 110. The partition member 113 is provided in the intermediate portion between the light-emitting section 120 and the light-receiving section 130. The partition member 113 protrudes from the inner wall surface of the case member 110. Figure 7 shows an example configuration in which the partition member 113 is a flat plate-shaped member. Figure 8 also shows an example configuration in which the partition member 113 is a member having a V-shaped inclined surface.

[0056] With such a partition member 113 provided, the case member 110 has a constricted portion 114. The constricted portion 114 is a section between the light-emitting portion 120 and the light-receiving portion 130 where the width in the direction perpendicular to the optical axis is narrowed. In this modified example, the gas intake port 111 is formed on the side of the case member 110 where the light-emitting portion 120 or the light-receiving portion 130 is located. The opening surface of the gas intake port 111 is positioned perpendicular to the airflow in the air passage, so that the optical axis of the infrared rays emitted from the light-emitting portion 120 is positioned parallel to the airflow in the air passage.

[0057] According to the modified configuration shown in Figures 7 and 8, the optical axis and optical path 140 of the infrared sensor 100 are arranged parallel to the airflow in the air passage. This reduces the cross-sectional area of ​​the case member 110 within the air passage, thereby reducing pressure loss. Furthermore, by providing a constricted section 114 within the case member 110, the refrigerant taken into the case member 110 can easily pass through the optical path 140, thereby improving the accuracy of refrigerant leak detection.

[0058] Figure 9 shows a modified configuration in which the substrate 150 is arranged parallel to the airflow in the air duct. In the configuration example shown in Figure 3, the substrate 150 was fixed to the side of the case member 110 opposite to the side with the gas intake port 111. In contrast, in the modified configuration shown in Figure 9, the substrate 150 is fixed to the side of the case member 110 adjacent to the side with the gas intake port 111. That is, the substrate 150 is positioned perpendicular to the opening surface of the gas intake port 111. As a result, the substrate 150 is positioned parallel to the airflow in the air duct. This reduces the pressure loss in the airflow in the air duct caused by the substrate 150 of the infrared sensor 100.

[0059] In this case, it is preferable to position the substrate 150 vertically above the gas inlet 111. By doing so, the substrate 150 can cover the area above the gas inlet 111 like an overhang, preventing condensation water dripping from the indoor heat exchanger 14, etc., from entering the case member 110 through the gas inlet 111. Furthermore, by positioning the component mounting surface of the substrate 150 downwards, it is possible to prevent dripping condensation water from adhering to electronic components mounted on the substrate 150.

[0060] Figure 10 shows a modified example in which the case member 110 of the infrared sensor 100 is equipped with an introduction section 116. The introduction section 116 is for guiding the gas that has passed through the gas intake port 111 into the optical path 140. In the illustrated example, the case member 110 comprises a rectangular parallelepiped case body 115 and an introduction section 116. An inlet 117 is formed on one surface of the case body 115. One end of the introduction section 116 is connected to the inlet 117. A gas intake port 111 is formed at the other end of the introduction section 116. In the illustrated example, the introduction section 116 has an L-shape with a bend in the middle. The opening surface of the gas intake port 111 of the introduction section 116 is positioned facing upstream of the airflow in the air passage and perpendicular to the airflow. The gas that has passed through the gas intake port 111 passes through the introduction section 116, enters the case body 115 from the inlet 117, and is guided to the optical path 140. By providing such an introduction section 116, the degree of freedom in the placement of the case body 115 can be improved, and more gas containing leaked refrigerant can be taken into the optical path 140 of the infrared sensor 100, enabling rapid detection of refrigerant leakage.

[0061] Next, with reference to Figure 11, another example of the indoor unit 1 according to this embodiment will be described. The indoor unit 1 shown in the figure is a ceiling-suspended type. That is, the indoor unit 1 is installed suspended from the ceiling of the room. The indoor unit 1 comprises a housing 10. The housing 10 has an intake port 12 and an outlet port 13. The intake port 12 is an opening for drawing air from the outside into the housing 10. The outlet port 13 is an opening for discharging air from the inside of the housing 10 to the outside. In the illustrated example, the intake port 12 is located on one side of the bottom surface of the housing 10. The outlet port 13 is located on one side of the housing 10.

[0062] The enclosure 10 houses an indoor heat exchanger 14 and an indoor fan 5. The indoor fan 5 is a radiation fan (e.g., a turbo fan, a centrifugal fan, etc.), an axial fan (e.g., a propeller fan), a mixed-flow fan, a through-flow fan, etc. The indoor fan 5 is located above the intake port 12 inside the enclosure 10. The indoor fan 5 is driven to rotate by a fan motor (not shown).

[0063] An indoor heat exchanger 14 is provided between the indoor fan 5 and the air outlet 13 within the housing 10. As mentioned above, refrigerant piping 3 is connected to the indoor heat exchanger 14. Therefore, a portion of the refrigerant piping 3 is housed inside the housing 10. The indoor heat exchanger 14 is equipped with heat transfer tubes and fins (not shown). The heat transfer tubes of the indoor heat exchanger 14 are connected to the refrigerant piping 3 at pipe connection points 16. Refrigerant flows through the heat transfer tubes via the refrigerant piping 3. In other words, refrigerant flows inside the indoor heat exchanger 14.

[0064] In the indoor heat exchanger 14, heat exchange takes place between the refrigerant and the air from the room drawn in through the intake port 12 by the indoor fan 5, generating cold or warm air. A drain pan 15 is provided below the indoor heat exchanger 14 within the housing 10. The drain pan 15 is for collecting condensation water that is generated when moisture in the air condenses as the air is cooled during the heat exchange process in the indoor heat exchanger 14.

[0065] A drain pump 17 is provided in the drain pan 15. The drain pump 17 is for pumping up condensed water from the drain pan 15 and discharging it to the outside. The condensed water in the drain pan 15 is pumped up by the drain pump 17 and discharged to the outside through a drain pipe (not shown). The drain pan 15 is installed with a slope such that one side where the drain pump 17 is installed is lower than the other side. The condensed water in the drain pan 15 flows to the aforementioned side where the drain pump 17 is installed and is collected. The drain pump 17 should be installed at the lowest point of this slope.

[0066] Within the housing 10 of the indoor unit 1, an air passage is formed that runs from the intake port 12, through the indoor fan 5 and the indoor heat exchanger 14, to the outlet port 13. Therefore, the indoor heat exchanger 14 is located within the air passage formed inside the housing 10.

[0067] In the indoor unit 1 of the air conditioner configured as described above, when the indoor fan 5 is rotated by the fan motor, an airflow is generated in the air passage inside the housing 10, moving from the intake port 12 to the outlet port 13. Air is drawn in from the intake port 12 and blown out from the outlet port 13. The air drawn in from the intake port 12 passes through the indoor fan 5. The air blown out from the indoor fan 5 passes through the indoor heat exchanger 14. As the air passes through the indoor heat exchanger 14, it is heated or cooled. Whether the air is heated or cooled depends on whether the air conditioner is operating in cooling or heating mode. The air that has passed through the indoor heat exchanger 14 is blown out from the outlet port 13.

[0068] Next, an example of the arrangement of the case member 110 of the infrared sensor 100 in another example of the indoor unit 1 will be described. The position and orientation shown in Figure E is when the infrared sensor 100 is placed upstream of the air outlet 13 in the air passage inside the housing 10 and downstream of the indoor heat exchanger 14. The position and orientation shown in Figure F is when the infrared sensor 100 is placed downstream of the indoor heat exchanger 14 in the air passage inside the housing 10 and above the drain pan.

[0069] In both E and F described above, the opening surface of the gas intake port 111 of the infrared sensor 100 is positioned so as to face the upstream side of the airflow in the air passage and perpendicular to the airflow. With such a refrigeration cycle device (air conditioner), if a refrigerant leak occurs while the indoor fan 5 is operating, the leaked refrigerant carried by the airflow is more easily drawn into the case member 110 from the gas intake port 111. By allowing the gas containing the leaked refrigerant to accumulate inside the case member 110, the detection accuracy of refrigerant leaks that occur while the indoor fan 5 is operating can be improved.

[0070] Embodiment 2. Embodiment 2 of the present disclosure will be described with reference to Figure 12. Figure 12 is a schematic diagram showing the configuration of the indoor unit of an air conditioner, which is a refrigeration cycle device.

[0071] The following description will focus on the differences between the refrigeration cycle device according to this second embodiment and the first embodiment. Configurations that are not described are basically the same as those in the first embodiment. In the following description, configurations that are the same as or corresponding to those in the first embodiment will, in principle, be denoted by the same reference numerals used in the description of the first embodiment.

[0072] The indoor unit 1 of the air conditioner, which is a refrigeration cycle device according to this embodiment, is a ceiling-mounted type (ceiling cassette type), as shown in Figure 12. The basic configuration of the indoor unit 1 according to this embodiment is the same as that of the indoor unit 1 according to Embodiment 1 shown in Figure 2. Therefore, a redundant explanation will be omitted here.

[0073] The indoor unit 1 according to this embodiment is equipped with an infrared sensor 100. The configuration of the infrared sensor 100 is the same as that of the infrared sensor 100 according to Embodiment 1 shown in Figure 3. Therefore, a redundant explanation is omitted here.

[0074] In the indoor unit 1 according to this embodiment, the gas intake port 111 formed in the case member 110 of the infrared sensor 100 is positioned on the wall surface that defines the boundary of the airflow path at the bend in the airflow path within the housing 10. As described in Embodiment 1, the air that has passed through the indoor heat exchanger 14 from the inner circumference to the outer circumference hits the wall surface of the housing 10 and changes its direction of flow downward. Therefore, the area between the outer circumference of the indoor heat exchanger 14 and the wall surface of the housing 10 is a bend where the direction of the airflow changes from outward to downward. In this embodiment, the surface of the case member 110 on which the gas intake port 111 is formed is positioned on the wall surface of the housing 10 at the bend in the airflow path. Furthermore, the case member 110 is positioned and oriented such that the opening surface of the gas intake port 111 faces upstream of the airflow in the airflow path and is perpendicular to the airflow.

[0075] In the refrigeration cycle device configured as described above, the opening surface of the gas intake port 111 of the infrared sensor 100 faces upstream of the airflow in the air passage and is positioned perpendicular to the airflow. Therefore, similar to Embodiment 1, if a refrigerant leak occurs while the indoor fan 5 is operating, the leaked refrigerant carried by the airflow can be easily taken into the case member 110 from the gas intake port 111. By allowing the gas containing the leaked refrigerant to accumulate inside the case member 110, the detection accuracy of refrigerant leaks that occur while the indoor fan 5 is operating can be improved.

[0076] Furthermore, although the side of the infrared sensor 100's case member 110 with the gas intake port 111 is exposed to the airflow path, the case member 110 as a whole is positioned outside the airflow path. Therefore, compared to the case where the infrared sensor 100's case member 110 is positioned inside the airflow path, the pressure loss of the airflow in the airflow path can be reduced. [Explanation of Symbols]

[0077] 1 Indoor unit 2 Outdoor unit 3 Refrigerant piping 4 Outdoor heat exchanger 5. Indoor fan 6. Outdoor fan 7 Compressor 8. Expansion valve 9. Four-way valve 10 cabinets 11 panels 12 Inlet 13 Air outlet 14 Indoor heat exchanger 15 Drain pan 16. Pipe connection section 17 Drain pump 40 Control device 41 Refrigerant leak detection unit 42 Storage section 43 Hochi Department 44 Operation Control Unit 100 Infrared Sensors 110 Case components 111 Gas intake 112 Exhaust port 113 Partition Member 114 Stenosis 115 Case body 116 Introduction 117 Inlet 120 Light-emitting part 130 Light receiving section 140 light path 150 circuit boards 151 Lead wire

Claims

1. A heat exchanger is provided in an air passage formed inside the enclosure, through which a refrigerant flows, The enclosure includes a sensor unit for detecting the occurrence of leakage of the refrigerant within the enclosure, The aforementioned sensor unit is A light-emitting part that emits infrared rays, A light receiving unit that receives infrared light emitted from the light-emitting unit, The light-emitting unit and the light-receiving unit are housed inside a case member, and a gas intake port is formed therein. The system further includes a detection unit that detects the occurrence of refrigerant leakage based on the infrared light reception state by the light receiving unit, The opening surface of the gas intake port faces the upstream side of the airflow in the air passage and is positioned perpendicular to the airflow. A refrigeration cycle device in which, in a projection plane parallel to the opening surface of the gas intake port, a part of the case member positioned upstream of the airflow from the light-emitting portion overlaps with the light-emitting portion, and the gas intake port and the light-emitting portion do not overlap.

2. A heat exchanger provided in an air passage formed inside the housing, through which a refrigerant flows, The enclosure includes a sensor unit for detecting the occurrence of leakage of the refrigerant within the enclosure, The aforementioned sensor unit is A light-emitting part that emits infrared rays, A light receiving unit that receives infrared light emitted from the light-emitting unit, The light-emitting unit and the light-receiving unit are housed inside a case member, and a gas intake port is formed therein. The system further includes a detection unit that detects the occurrence of refrigerant leakage based on the infrared light reception state by the light receiving unit, The opening surface of the gas intake port faces the upstream side of the airflow in the air passage and is positioned perpendicular to the airflow. A refrigeration cycle device in which, in a projection plane parallel to the opening surface of the gas intake port, a part of the case member positioned upstream of the airflow from the light-receiving portion and the light-receiving portion overlap, and the gas intake port and the light-receiving portion do not overlap.

3. A heat exchanger provided in an air passage formed inside the housing, through which a refrigerant flows, The enclosure includes a sensor unit for detecting the occurrence of leakage of the refrigerant within the enclosure, The aforementioned sensor unit is A light-emitting part that emits infrared rays, A light receiving unit that receives infrared light emitted from the light-emitting unit, The light-emitting unit and the light-receiving unit are housed inside a case member, and a gas intake port is formed therein. The system further includes a detection unit that detects the occurrence of refrigerant leakage based on the infrared light reception state by the light receiving unit, The opening surface of the gas intake port faces the upstream side of the airflow in the air passage and is positioned perpendicular to the airflow. The optical axis of the infrared light emitted from the light-emitting unit is arranged parallel to the airflow. The case member is a refrigeration cycle device having a constricted portion between the light-emitting portion and the light-receiving portion, in which the width is narrowed in a direction perpendicular to the optical axis.

4. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the case member is disposed in the air passage.

5. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the case member is disposed outside the air passage.

6. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the gas intake port is arranged on the wall surface that defines the boundary of the air passage at the bend of the air passage.

7. The refrigeration cycle apparatus according to any one of claims 1, 2, and 4 to 6, wherein the optical axis of the infrared radiation emitted from the light-emitting unit is arranged perpendicular to the airflow.

8. The case member has an exhaust port formed therein. The refrigeration cycle apparatus according to any one of claims 1 to 7, wherein the orientation of the opening surface of the exhaust port is different from the orientation of the opening surface of the gas intake port.

9. The case member has an exhaust port formed therein. The orientation of the opening surface of the exhaust port is opposite to the orientation of the opening surface of the gas intake port. The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the gas intake port and the exhaust port do not overlap in a projection plane parallel to the opening surface of the gas intake port.

10. The case member further comprises a flat substrate fixed to it, The refrigeration cycle apparatus according to any one of claims 1 to 9, wherein the substrate is arranged parallel to the airflow.

11. The refrigeration cycle apparatus according to any one of claims 1 to 10, wherein the case member is provided with an introduction section that guides the gas that has passed through the gas intake port into an optical path through which the infrared rays emitted from the light-emitting section pass until they reach the light-receiving section.

12. The detection unit, The concentration of the refrigerant is calculated using the infrared light intensity received by the light receiving unit. A refrigeration cycle apparatus according to any one of claims 1 to 11, which detects the occurrence of a refrigerant leak based on the time-integrated value of the calculated concentration of the refrigerant.

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