AIR CONDITIONING UNIT AND AIR CONDITIONING SYSTEM

Abstract

The present invention relates to signaling a refrigerant leak. An air conditioning unit 1 comprises a variable part (17) whose visual appearance changes upon contact with a flammable refrigerant, an image capture means (12) that captures images of the variable part (17), and a detection means (101) that detects a refrigerant leak in the event of a change in the image of the variable part (17) captured by the image capture means (12). Figure for the abstract: Fig. 3

Description

Title of the invention: AIR CONDITIONING APPARATUS AND AIR CONDITIONING SYSTEM Technical field

[0001] The present invention relates to an air conditioning apparatus and an air conditioning system. Previous techniques

[0002] HFC refrigerants used in air conditioning units have a high global warming potential (GWP) and their phase-out is planned to combat global warming. Propane, a refrigerant with a low GWP and high efficiency, is considered one of the new generation refrigerants. However, it poses a safety problem due to its flammability in the event of a leak inside the room. With regard to refrigerant leakage, JP 2002-195707 A describes a refrigeration cycle device comprising a refrigerant detecting member which changes color upon contact with the refrigerant to visibly detect any refrigerant leakage in the refrigeration cycle device which uses a flammable refrigerant.

[0003] However, since the air conditioning unit is often installed in a location far from the user, even if a refrigerant detecting member is installed on the unit, it is not always visible to the user, hence the problem of difficulty in detecting refrigerant leakage. Statement of the invention

[0004] To solve this problem, the present invention aims to detect a refrigerant leak.

[0005] The present invention provides an air conditioning apparatus comprising a variable part whose visual appearance changes upon contact with a flammable refrigerant, an image capturing means which captures images of said variable part and a detection means which detects a refrigerant leak in the event of a change in the image of said variable part captured by said image capturing means.

[0006] Advantageously, said image capturing means is placed on the front face of an indoor unit and

[0007] said variable part is placed opposite said image capturing means.

[0008] Optionally, said variable part is placed inside an up-down blowing flap provided in said indoor unit.

[0009] Advantageously, said variable part is placed between the front face of said indoor unit and a filter.

[0010] Optionally, the air conditioning unit further comprises an air flow regulator which ensures, in the event of detection of a refrigerant leak by said detection means, ventilation at a flow rate greater than a threshold.

[0011] Advantageously, said image capturing means further captures images of an air-conditioned space and

[0012] said air flow regulator ensures the adjustment of the direction of the air flow according to the situation of said air-conditioned space captured by said image capturing means.

[0013] Optionally, the air conditioning apparatus further comprises an output processor which, in the event of detection of a refrigerant leak by said detection means, requests an output means to output leak detection information.

[0014] According to one embodiment, said image capturing means captures images of the air-conditioned space,

[0015] said output processor requests, in the event of detection of a refrigerant leak by said detection means, a sound broadcasting means to output said leak detection information if a human presence is detected in the image of said air-conditioned space captured by said image capturing means, or transmits said leak detection information to a predetermined recipient if no human presence is detected.

[0016] Advantageously, the air conditioning apparatus further comprises a thermal camera and in which said output processor outputs the alert information in the event of detection by said thermal camera of a temperature equal to or greater than a predetermined threshold in the air-conditioned space.

[0017] The present invention provides an air conditioning system comprising a variable part whose visual appearance changes upon contact with a flammable refrigerant, an image capturing means which captures images of said variable part and a detection means which detects a refrigerant leak in the event of a change in the image of said variable part captured by said image capturing means.

[0018] The present invention makes it possible to detect the refrigerant leak. Brief description of the drawings

[0019] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example and made with reference to the appended drawings in which:

[0020] - [Fig.l] represents an exterior configuration of an air conditioning unit;

[0021] - [Fig.2] represents a circuit of a refrigerant;

[0022] - [Fig.3] represents a structure of an indoor unit;

[0023] - [Fig.4A] is an enlarged view of an image capturing means and a part variable;

[0024] - [Fig.4B] is an enlarged view of the image capturing means and the part variable;

[0025] - [Fig.5A] represents the variable part;

[0026] - [Fig.5B] represents the variable part;

[0027] - [Fig.6] represents a configuration of the indoor unit;

[0028] - [Fig.7] is a diagram illustrating the process of detecting a leak in a re refrigerant;

[0029] - [Fig.8] represents a variant of the arrangement of the variable part; and

[0030] - [Fig.9] represents a variant of the arrangement of the variable part. Detailed description

[0031] [Fig.l] shows an exterior configuration of an air conditioning unit 1 according to one embodiment. The air conditioning unit 1 provides air conditioning by circulating a refrigerant in a refrigeration cycle (heat pump cycle). As shown in [Fig.l], the air conditioning unit 1 comprises an indoor unit 10 installed inside the room (conditioned space), an outdoor unit 20 installed outside (outside the room) and a remote control 30 operated by the user.

[0032] The indoor unit 10 comprises a remote communication means 11. The remote communication means 11 receives a signal transmitted by the remote control 30, in particular by infrared communication. Furthermore, the remote communication means 11 transmits a predetermined signal to the remote control 30. The remote communication means 11 receives from the remote control 30, in particular, the start / stop control signals, temperature change signals, operating mode change signals, and timer setting signals. The indoor unit 10 and the outdoor unit 20 are connected by a refrigerant pipe and a communication cable (not shown in [Fig. 1]). The indoor unit 10 further comprises an image capture means 12. The image capture means 12 captures images of the air-conditioned space, in particular using a CMOS (complementary metal oxide semiconductor) image sensor.The image capturing means 12 is placed, as shown in [Fig.l], at the bottom of a front face 161 of the indoor unit 10 and approximately in the center in the lateral direction.

[0033] [Fig. 2] shows a circuit of a refrigerant Q of the air conditioning unit 1 according to the embodiment. The solid arrows in [Fig. 2] show the refrigerant flow in the heating operation mode and the dotted arrows in [Fig. 2] show the refrigerant flow in the cooling operation mode. A low GWP refrigerant such as propane is used as the refrigerant.

[0034] The indoor unit 10 comprises, in addition to the remote communication means 11 and the image capture means 12, an indoor heat exchanger 14 and an indoor fan 15. In the indoor heat exchanger 14, heat exchange takes place between the refrigerant circulating in the heat transfer tube and the indoor air drawn in by the indoor fan 15. The indoor heat exchanger 14 operates as a condenser or an evaporator by switching a four-way valve 25 described below. The indoor fan 15 is installed near the indoor heat exchanger 14. The indoor fan 15 discharges the indoor air into the indoor heat exchanger 14.

[0035] The outdoor unit 20 comprises a compressor 21, an outdoor heat exchanger 22, an outdoor fan 23, an expansion valve 24 and the four-way valve 25. The compressor 21 compresses a low-temperature, low-pressure gaseous refrigerant and ejects a high-temperature, high-pressure gaseous refrigerant. In the outdoor heat exchanger 22, heat exchange takes place between the refrigerant circulating in the heat transfer tube and the outdoor air drawn in by the outdoor fan 23. The outdoor heat exchanger 22 functions as a condenser or an evaporator by switching the four-way valve 25.

[0036] As shown in [Fig.l], the outdoor fan 23 is installed near the outdoor heat exchanger 22. The outdoor fan 23 discharges the outdoor air into the outdoor heat exchanger 22. The expansion valve 24 has the function of decompressing the refrigerant condensed by the "condenser" (one between the outdoor heat exchanger 22 and the indoor heat exchanger 14). The refrigerant decompressed by the expansion valve 24 is guided to the "evaporator" (the other between the outdoor heat exchanger 22 and the indoor heat exchanger 14). The four-way valve 25 is a valve for switching the circulation path of the refrigerant according to the operating mode of the air conditioning unit 1.

[0037] [Fig. 3] represents a structure of the indoor unit 10. [Fig. 3] is a sectional view perpendicular to the rear face 18 of the indoor unit 10 and parallel to the top-bottom direction of the indoor unit 10. In the remainder of the description, the direction of the x-axis in 3D coordinates as shown in [Fig. 3] (toward the bottom of the page) corresponds to the lateral direction of the indoor unit 10, the direction of the y-axis (longitudinal direction of the page) corresponds to the top-bottom direction of the indoor unit 10 (the top of the page corresponds to the upper side) and the direction of the z-axis (lateral direction of the page) corresponds to the depth direction of the indoor unit 10. In the lateral direction, the right corresponds to the right side seen in the depth direction (toward the front of the page) and the left corresponds to the left side seen in the depth direction (toward the bottom of the page).

[0038] The indoor unit 10 is installed near the ceiling of the room so that its rear face 18 is in contact with a wall B. In [Fig.3], the room, namely the air-conditioned space, extends on the left side of the page and the indoor unit 10 has a structure allowing ventilation to regulate the room temperature.

[0039] The indoor unit 10 comprises the indoor fan 15 inside an enclosure 16 having the front face 161 provided with an air intake port and an upper face 162. The indoor heat exchanger 14 is located in a space delimited by the front face 161, the upper face 162 and the indoor fan 15. In the indoor heat exchanger 14, the heat exchange takes place with an air flow generated by the activation of the indoor fan 15. The indoor unit 10 is further provided with a front filter 141a provided on the front face 161, an upper filter 141b provided on the upper face 162, an up-down blowing flap 142 and a housing 143.

[0040] Air is drawn through the front face 161 and the upper face 162 into the indoor unit 10 and, after removing large dust using the front filter 141a and the upper filter 141b, passes through the indoor heat exchanger 14. Activation of the indoor fan 15 creates an airflow passing through the indoor heat exchanger 14. The indoor fan 15 may be a tangential fan in particular. However, it is sufficient that the indoor fan 15 is able to create an airflow and it is not limited to the tangential fan. The air having passed through the indoor heat exchanger 14 is guided by the indoor fan 15 to the housing 143 and then ejected into the air-conditioned space, the direction of the airflow being adjusted by the up-down blowing flap 142 and a left-right blowing flap (not shown).

[0041] Furthermore, the image capturing means 12 is placed at the bottom of the front face 161. And the variable part 17 is provided between the image capturing means 12 and the front face 161. The variable part 17 is a lamellar element glued to the up-down blowing flap 142 in particular using the double-sided tape. The variable part 17 changes its pattern by reacting with the refrigerant.

[0042] Figures 4A and 4B are enlarged views of the image capturing means 12 and the variable portion 17. The image capturing means 12 can rotate 360 ​​degrees in the lateral direction (on the xz plane). The image capturing means 12 can also rotate in the up-down direction (y-axis direction). In addition, the variable portion 17 can rotate in the lateral direction from the position where it does not overlap the image capturing means 12 as shown in [Fig. 4A], to the position where it overlaps the image capturing means 12 as shown in [Fig. 4B]. In the position where it overlaps with the image capturing means 12, the variable part 17 is placed opposite the image capturing means 12. Thus, the variable part 17 enters the visual field (image capturing field) of the image capturing means 12 and the image of the variable part 17 can be obtained. The image capturing means 12 periodically captures images.The image capturing means 12 captures images with the backup power supply even when the air conditioning is not activated. In addition, the image capturing means 12 captures the image of the . variable part 17. For example, the image capturing means 12 captures, at a first interval, the image of the air-conditioned space and at a second interval, the image of the variable part 17. In this case, the second interval is longer than the first interval. The variable part 17 moves at the second interval to the position where it overlaps the image capturing means 12.

[0043] Figures 5A and 5B show the variable part 17. [Fig. 5A] shows the variable part 17 in the absence of a refrigerant leak. [Fig. 5B] shows the variable part 17 in the presence of a refrigerant leak. As described above, propane is used as the refrigerant and a sheet impregnated with a substance which changes color upon contact with such a flammable refrigerant gas is placed as the variable part 17. Among the substances which change color upon contact with the refrigerant gas, precious metal compounds may be mentioned. In particular, platinum group metal compounds and especially palladium oxide exhibit a pronounced color change. Platinum group metals generally have a high standard electrode potential and their compounds such as chloride, nitrate, sulfate, oxide, etc., are easily transformed into mono-metal by the reduction reaction upon contact with a flammable gas such as hydrogen. In the present embodiment, palladium oxide is used. When the refrigerant leaks and comes into contact with the variable part 17, the area impregnated with a precious metal compound of the variable part 17 changes color and, as shown in [Fig. 5B], the appearance of the variable part 17 changes from, for example, a monochrome appearance to a striped pattern. In the examples of FIGS. 5A and 5B, an area of ​​the variable part 17 is impregnated with a precious metal compound so as to obtain a striped pattern as shown in [Fig. 5B]. .

[0044] In another example, it is possible to form the variable portion 17 by applying to the area to be occupied by the variable portion 17 a mixture of a coating with a precious metal compound. In another example, it is also possible to create the variable portion 17 by mixing a precious metal compound into the plastic material.

[0045] Thus, in the event of a refrigerant leak, the pattern of the variable portion 17 changes. However, the user has difficulty noticing the change of the variable portion 17 because the indoor unit 10 of the air conditioning unit 1 is often installed at the top of the room. Therefore, the image capturing means 12 of the present embodiment captures the image of this variable portion 17 to detect a refrigerant leak based on the captured image.

[0046] [Fig.6] is a block diagram of a configuration of the indoor unit 10 for refrigerant leak detection. The indoor unit 10 comprises a control unit 100, a communication means 110, a recording medium 120, a speaker 130 and the image capture means 12. The control unit 100 comprises a central unit, a RAM, a ROM, etc., not shown, and ensures the execution of the programs contained in the recording medium 120 and in the ROM. The communication means 110 is a device for communicating with an external device via a network. The control unit 100 ensures communication, in particular, with a portable terminal of the user via the communication means 110. The recording medium 120 stores various information and various programs. The speaker 130 broadcasts the sound. The speaker 130 is an example of the sound broadcasting means.

[0047] The control unit 100 functions as a detection means 101, a situation identification means 102, an airflow regulator 103, and an output processor 104, by executing the programs contained in the recording medium 120 and in the read-only memory. In other words, in the following description, the process described as executed by the detection means 101, the situation identification means 102, the airflow regulator 103, and the output processor 104 is a process executed by the control unit 100.

[0048] The detection means 101 detects a refrigerant leak on the basis of the image of the variable part 17 captured by the image capturing means 12 (hereinafter referred to as the "variable part image"). The detection means 101 judges that a refrigerant leak occurs when a captured variable part image is different from that previously captured. The detection means 101 judges, especially when the degree of correspondence obtained by comparison with the previously captured variable part image is less than a threshold, that the two images are different. In another example, the detection means 101 may judge, when the pixels whose value has changed exceed a certain number, that the two images are different. Thus, the concrete process for judging that the variable part image is different from that previously captured is not limited to the embodiment.

[0049] The situation identification means 102 identifies the situation of the air-conditioned space based on the image of the air-conditioned space (hereinafter referred to as the "space image") captured by the image capture means 12. In particular, the situation identification means 102 identifies the size and position of objects such as furniture or humans in the air-conditioned space. The airflow regulator 103 controls the flow rate and direction of the air according to the situation of the air-conditioned space. The output processor 104 controls, in the event of a refrigerant leak, the execution of a process to request an output means to output leak detection information signaling the leak detection. The output means that outputs the leak detection information are the speaker 130 and the communication means 110.

[0050] [Fig. 7] is a diagram illustrating the refrigerant leak detection process executed by the control unit 100 of the indoor unit 10. According to the refrigerant leak detection process, the control unit 100 firstly requests the image capturing means 12 at S100 to start image capturing. Then, the detection means 101 detects at S102 whether there is a refrigerant leak based on the image of the variable part obtained periodically. As described above, the detection means 101 judges that a refrigerant leak occurs when the image of the variable part changes. Then, the situation identifying means 102 identifies at S104 the situation of the conditioned space based on the image of the space captured by the image capturing means 12.

[0051] Then, the airflow regulator 103 ensures at S106 the adjustment of the air flow rate and direction according to the situation of the conditioned space identified at S104. In particular, the airflow regulator 103 sets the air flow direction to a place that is not occupied by objects and people. Furthermore, the airflow regulator 103 sets the air flow rate at a level equal to or higher than the predetermined threshold. For example, when the air flow rate can be set to three levels, namely low, medium and high, the airflow regulator 103 sets the air flow rate at a high level. Thus, the leaking refrigerant flows with a relatively large flow rate to the place not occupied by objects and people. Therefore, the leaking refrigerant will be quickly dispersed and the refrigerant concentration in the conditioned space may be equal to or lower than a level that may cause combustion.In addition, any flow of leaking refrigerant towards humans can be prevented.

[0052] Then, the output processor 104 checks at S108 on the basis of the image of the space captured by the image capturing means 12, the presence or absence of a human(s) in the air-conditioned space. If a human presence is detected (Y at S108), the output processor 104 broadcasts via the loudspeaker 130 the leak detection sound information (S110). The loudspeaker 130 broadcasts for example as leak detection sound information: “The refrigerant is leaking. Ensure ventilation”.

[0053] If no human presence is detected (N to S108), the output processor 104 transmits the leak detection information via the communication means 110 to a predetermined recipient (S112). In this case, the predetermined recipient is in particular a portable terminal of the user of the air conditioning unit 1. Thus, any refrigerant leak can be reported to the user. In addition, the recipient can be changed depending on whether or not the user is present in the air-conditioned space. Thus, any refrigerant leak can be reported to the user with certainty.

[0054] It should be noted that the present invention is not limited to such a specific embodiment and several variations and modifications can be envisaged within the limits of the essential elements of the present invention as set forth in the res indications, for example the application of a variant of one embodiment to another embodiment.

[0055] According to a first variant, the indoor unit 10 may further comprise a thermal camera. The thermal camera is placed on the front face 161 of the indoor unit 10 and captures a thermal image which shows the temperature distribution in the air-conditioned space, by means of the detection of the infrared radiation emitted by each object. Thus, it is conceivable to output the alert information in the event of detection of a temperature equal to or greater than a predetermined threshold, for example for the stove. Thus, the ignition of the leaking refrigerant can be prevented. In this case, the temperature threshold can be determined on the basis of the combustion temperature of the refrigerant.

[0056] According to a second variant, the image capturing means 12 can capture the image comprising both the air-conditioned space and the variable part 17. For example, the variable part 17 can be placed to occupy a part of the image capturing field, in particular the bottom right part. Thus, the image of the variable part 17 can be captured with the air-conditioned space without moving the variable part 17.

[0057] According to a third variant, the position of the variable part 17 is not limited to that of the embodiment. It is sufficient that the variable part 17 is placed at a position opposite the image capturing means 12, in particular in the image capturing field covered by the image capturing means 12. For example, as shown in [Fig. 8], the variable part 17 can be placed inside the up-down blowing flap 142. In another example, as shown in [Fig. 9], the variable part 17 can be placed between the image capturing means 12 and the internal heat exchanger 14, in particular on the front filter 141a. In this case, the image capturing means 12 must be able to pivot to capture the image of the variable part 17 placed on the front filter 141a. Thus, the variable part 17 is preferably placed at the bottom of the indoor unit 10.This position allows it to detect the refrigerant leak flowing from above because it is heavier than air.

[0058] According to a fourth variant, it is sufficient that the airflow regulator 103 can adjust the direction of the air according to the situation of the air-conditioned space and its concrete process is not limited to that of the embodiment. For example, the airflow regulator 103 can adjust the air flow rate so that it increases as the number of objects reported in the air-conditioned space increases.

[0059] According to a fifth variant, the airflow regulator 103 can adjust the air direction downward for a certain time after the detection of the refrigerant leak, regardless of the situation of the conditioned space, and then upward so as to disperse the leaking refrigerant throughout the conditioned space. Because it is heavier than air, the refrigerant may, at first, stagnate just below of indoor unit 10. This variant allows for the rapid dispersion of leaking refrigerant that stagnates just below indoor unit 10.

[0060] According to a sixth variant, the output processor 104 can vary the output information depending on the situation of the air-conditioned space. For example, the output processor 104 can, when a window is detected in the image of the space captured by the image capturing means 12, output via the loudspeaker 130 information that requests an action such as: "Open the window".

[0061] According to a seventh variant, the recipient of the leak detection information may be either the speaker 130 only, or the recipient's portable terminal only. In another example, the leak detection information may be displayed on a display portion provided on the remote control, for example, to replace or supplement the speaker 130 and the recipient's portable terminal.

[0062] According to an eighth variant, the position of each function of the control unit 100 (detection means 101, situation identification means 102, air flow regulator 103 and output processor 104 of the indoor unit 10), the loudspeaker 130, the image capture means 12 and the variable part 17 of the present embodiment shown in [Fig. 6] is not limited to that of the embodiment. For example, if the air conditioning unit 1 is controlled by the central unit (not shown) provided independently of said air conditioning unit, this central unit can be provided with all the functions of the control unit 100. Furthermore, it is sufficient for the loudspeaker 130 to be installed in the air-conditioned space and it is not necessarily integrated into the indoor unit 10. The variable part 17 can be provided independently of the indoor unit 10.It should be noted that the variable part 17 must be placed at a position capable of both being exposed to the flow of the leaking refrigerant and being within the capture field of the image capturing means 12, for example on the wall just below the indoor unit 10. It is sufficient that the image capturing means 12 is placed at a position where it can capture the image of the conditioned space and that of the variable part 17 and it is not necessarily integrated into the indoor unit 10.

[0063] According to another variant, the variable part 17 and the image capturing means 12 can be provided in the outdoor unit 20. In this case, the refrigerant leaking from the side of the outdoor unit 20 can be detected.

[0064] According to a ninth variant, it is sufficient that the variable part is the one which changes its visual appearance upon contact with the flammable refrigerant and, for example, the one which changes its color. List of reference signs

[0065] 1 Air conditioning unit

[0066] 10 Indoor unit

[0067] 11 Means of remote communication

[0068] 12 Image capture means

[0069] 14 Indoor heat exchanger

[0070] 15 Interior fan

[0071] 16 Pregnant

[0072] 17 Variable part

[0073] 18 Back face

[0074] 20 Outdoor unit

[0075] 21 Compressor

[0076] 22 Outdoor heat exchanger

[0077] 23 Outdoor fan

[0078] 24 Regulator

[0079] 25 Four-way valve

[0080] 100 Control Unit

[0081] 101 Detection means

[0082] 102 Means of identifying situations

[0083] 103 Airflow regulator

[0084] 104 Output Processor

[0085] 110 Means of communication

[0086] 120 Recording medium

[0087] 130 Speaker

[0088] 141a Front filter

[0089] 141b Upper Filter

[0090] 142 Up-down blowing flap

[0091] 143 Housing

[0092] 161 Front face

[0093] 162 Upper face

Claims

Claims

1. Air conditioning apparatus (1) characterized in that it comprises: - a variable part (17) whose visual appearance changes upon contact with a flammable refrigerant, - an image capturing means (12) which captures images of said variable part (17) and - a detection means (101) which detects a refrigerant leak in the event of a change in the image of said variable part (17) captured by said image capturing means (12).

2. An air conditioning apparatus (1) according to claim 1, wherein said image capturing means (12) is placed on the front face (161) of an indoor unit (10) and said variable portion (17) is placed opposite said image capturing means (12).

3. An air conditioning apparatus (1) according to claim 2, wherein said variable portion (17) is placed inside an up-down blowing flap (142) provided in said indoor unit (10).

4. An air conditioning apparatus (1) according to claim 2, wherein said variable portion (17) is placed between the front face (161) of said indoor unit (10) and a filter.

5. Air conditioning apparatus (1) according to claim 1, further comprising an air flow regulator (103) which ensures, in the event of detection of a refrigerant leak by said detection means (101), ventilation at a flow rate greater than a threshold.

6. An air conditioning apparatus (1) according to claim 5, wherein said image capturing means (12) further captures images of an air-conditioned space and said airflow regulator (103) adjusts the direction of the airflow according to the situation of said air-conditioned space captured by said image capturing means (12).

7. An air conditioning apparatus (1) according to claim 1, further comprising an output processor (104) which, upon detection of a refrigerant leak by said detection means (101), requests a leak detection information output means.

8. An air conditioning apparatus (1) according to claim 7, wherein said image capturing means (12) captures images of the space air-conditioned space, said output processor (104) requests, in the event of detection of a refrigerant leak by said detection means (101), a sound diffusion means to output said leak detection information if a human presence is detected in the image of said air-conditioned space captured by said image capturing means (12), or transmits said leak detection information to a predetermined recipient if no human presence is detected.

9. An air conditioning apparatus (1) according to claim 7, further comprising a thermal camera and wherein said output processor outputs the alert information upon detection by said thermal camera of a temperature equal to or greater than a predetermined threshold in the air-conditioned space.

Images