BACKGROUND
1. Technical Field
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The present disclosure relates to an indoor unit of an air conditioner, and more particularly to an indoor unit of an air conditioner that uses a flammable (including lower flammability) refrigerant.
Description of the Related Art
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In recent years, in view of minimizing the influence on the environment to be as small as possible, refrigerants used for air conditioners have small ozone depletion potential (ODP) and small global warming potential (GWP) as possible. A typical example is difluoromethane (R32). Difluoromethane has an ODP of 0 and a relatively low GWP, and has a good refrigerant performance.
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However, difluoromethane has flammability. According to ISO 817:2014, the flammability of difluoromethane is classified as lower flammability (Class 2L), not as no flame propagation (Class 1).
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A known air conditioner using a flammable refrigerant such as difluoromethane is, in particular, an air conditioner having a refrigerant leakage sensor provided in an indoor unit.
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For example, PTL 1 discloses a configuration in which a refrigerant leakage sensor is attached to an outer surface of a housing of an indoor unit and a communication hole is formed at a sensor attachment to provided communication between the inside and the outside of the housing. PTL 2 discloses a configuration in which a gas detection sensor that detects presence or absence of refrigerant gas is disposed lower than an electrical part (electrical component) in a use-side heat exchanger unit that can be used as an indoor unit.
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The indoor unit described in PTL 1 and the use-side heat exchanger unit described in PTL 2 are both floor-mounted type, and use difluoromethane as a flammable refrigerant.
Citation List
Patent Literature
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- PTL 1: Unexamined Japanese Patent Publication No. 2019-027662
- PTL 2: Unexamined Japanese Patent Publication No. 2020-051734
SUMMARY
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Recently, in view of further reducing influences on the environment, a natural refrigerant having a smaller GWP has attracted attention. Typical examples of the natural refrigerant include hydrocarbons such as propane (R290), isobutane (R600a), and ethane (R170). These hydrocarbons have higher flammability than difluoromethane, and are often classified as higher flammability (Class 3). Therefore, a leakage of the flammable refrigerant, when occurred, has to be detected as quickly as possible.
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As described above, the configuration disclosed in PTL 1 or PTL 2 is directed to a leakage of difluoropropane, which has lower flammability, and to detection of a leakage of a flammable (lower flammability) refrigerant along the height direction of an indoor unit, as description is made for a floor-mounted indoor unit as a specific example.
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For example, PTL 1 discloses an example in which a refrigerant leakage sensor is disposed lower than a dew pan disposed lower than a heat exchanger. PTL 2 describes an example in which a gas detection sensor is disposed lower than the electrical part (electrical component) as described above. Therefore, the configurations disclosed in these patent literatures may not be able to quickly detect a leakage of a flammable refrigerant along the depth direction (front-rear direction) of the indoor unit.
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An object of the present disclosure is to more quickly detect a leakage of a flammable refrigerant in an indoor unit of an air conditioner using a flammable refrigerant, particularly a leakage along the front-rear direction of the indoor unit.
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An indoor unit of an air conditioner according to one aspect of the present disclosure is an indoor unit of an air conditioner using a flammable refrigerant, the indoor unit including a housing, a power line drawn into the housing from the back side of the housing, a power line guide that is provided in the housing and guides the power line, and a refrigerant leakage sensor that detects a leakage of the flammable refrigerant, where the refrigerant leakage sensor is located on the front side of the housing as viewed from the power line guide, and the power line guide includes a communication hole that provides communication between a region where the refrigerant leakage sensor is located and a region on the back side as viewed from the power line guide.
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According to this configuration, by providing the communication hole in the power line guide, the region on the back side of the indoor unit defined by the power line guide and the region on the front side of the indoor unit where the refrigerant leakage sensor is located communicate with each other to allow gas to flow. As a result, also when the flammable refrigerant leaks in the back side of the indoor unit, the flammable refrigerant can pass through the communication hole and quickly arrive at the refrigerant leakage sensor, so that the refrigerant leakage sensor can more quickly detect the leakage of the flammable refrigerant. As a result, in the air conditioner using the flammable refrigerant, the flammable refrigerant can be more quickly detected particularly along the front-rear direction (depth direction) of the indoor unit, and the reliability of the indoor unit can be improved.
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According to the configuration of the present disclosure described above, an effect of more quickly detecting a leakage of a flammable refrigerant in an indoor unit of an air conditioner using the flammable refrigerant, particularly a leakage along the front-rear direction of the indoor unit, can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
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- Fig. 1A is a perspective view illustrating an example external configuration of the front side of an indoor unit of an air conditioner according to a representative exemplary embodiment of the present disclosure;
- Fig. 1B is a perspective view illustrating an example external configuration of the back side of the indoor unit illustrated in Fig. 1A;
- Fig. 2 is a longitudinal sectional view of the indoor unit illustrated in Figs. 1A and 1B, illustrating an example configuration across the front side to the back side around a central portion of the indoor unit;
- Fig. 3A is a sectional view in the vertical direction illustrating an example configuration of the indoor unit illustrated in Figs. 1A and 1B around an end portion where a power line is located;
- Fig. 3B is an enlarged sectional view in which a portion surrounded by a thick dotted line in Fig. 3A is enlarged;
- Fig. 4A is a partial perspective view of the indoor unit, illustrating an example configuration of a communication hole included in the indoor unit illustrated in Fig. 3A;
- Fig. 4B is a partial perspective view of the indoor unit, illustrating another example configuration of the communication hole included in the indoor unit illustrated in Fig. 3A;
- Fig. 5A is a partial back view of the indoor unit, illustrating a still another example configuration of the communication hole included in the indoor unit illustrated in Fig. 3A;
- Fig. 5B is a partial back view of the indoor unit, illustrating a still another example configuration of the communication hole included in the indoor unit illustrated in Fig. 3A;
- Fig. 6A is a sectional view of a power line guide included in the indoor unit illustrated in Fig. 3A;
- Fig. 6B is a partial sectional view illustrating an example configuration of a communication hole provided in the power line guide illustrated in Fig. 6A;
- Fig. 6C is a partial perspective view illustrating another example configuration of the power line guide included in the indoor unit illustrated in Fig. 3A;
- Fig. 6D is a sectional view illustrating a configuration of a communication hole provided in the power line guide illustrated in Fig. 6C;
- Fig. 6E is a partial perspective view illustrating a still another example configuration of the power line guide included in the indoor unit illustrated in Fig. 3A; and
- Fig. 6F is a sectional view illustrating a configuration of a communication hole provided in the power line guide illustrated in Fig. 6E.
DETAILED DESCRIPTIONS
[Knowledge and the like underlying the present disclosure]
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When a flammable refrigerant is used as a refrigerant of an air conditioner, quickly detecting a leakage of the flammable refrigerant in an indoor unit when occurred is important. It is known that a portion where a leakage of the refrigerant is likely to occur in the indoor unit of the air conditioner is a pipe connection where a heat exchanger unit of the indoor unit and a heat exchanger unit of an outdoor unit are connected. Since the pipe connection is constructed at a portion where the indoor unit is installed, a leakage of the refrigerant may be caused by a human error of a worker. The pipe connection is usually provided on the back side of the indoor unit.
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Meanwhile, in consideration of maintenance or the like after construction of the indoor unit, a refrigerant leakage sensor included in the indoor unit of the air conditioner is usually installed at such a place that allows access from the front face (front side) of the indoor unit for ease of maintenance, for example, on the front-lower side. In this case, when a leakage of the flammable refrigerant occurs in the back side of the indoor unit, the refrigerant leakage sensor located on the front side of the indoor unit may fail to quickly detect the leakage of the refrigerant, particularly the leakage along the front-rear direction (depth direction).
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In view of this, the present inventors have intensively studied to find out by themselves that providing a communication hole in a power line guide included in an indoor unit allows the refrigerant leakage sensor to quickly detect a leakage along the front-rear direction (depth direction) of the refrigerant, and have eventually completed the present disclosure.
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That is, an indoor unit of an air conditioner according to the present disclosure is an indoor unit of an air conditioner using a flammable refrigerant, the indoor unit including a housing, a power line drawn into the housing from the back side of the housing, a power line guide that guides the power line to be disposed in the housing, and a refrigerant leakage sensor that detects a leakage of the flammable refrigerant, where the refrigerant leakage sensor is located on the front side of the housing as viewed from the power line guide, and the power line guide includes a communication hole that provides communication between a region where the refrigerant leakage sensor is located and a region on the back side as viewed from the power line guide.
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Usually, an electrical component section (terminal) of an indoor unit is provided on a front side of the indoor unit, and a power line for supplying power to the electrical component section is introduced into the inside of the indoor unit from the back side of the indoor unit to be connected to the electrical component section. In this configuration, a power line guide is used to guide the power line to a suitable position inside the indoor unit. The power line guide is a member installed across the back side of the indoor unit to the front side of the indoor unit.
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By providing a communication hole in the power line guide, gas can flow between a back region (space) of the indoor unit where a pipe connection exists and a front region (space) where a refrigerant leakage sensor exists. As a result, when the flammable refrigerant leaks from the pipe connection in the back side of the indoor unit, for example, the flammable refrigerant can pass through the communication hole and quickly arrive at the region (space) where the refrigerant leakage sensor is located. Therefore, the refrigerant leakage sensor can more quickly detect a leakage of the flammable refrigerant. As a result, in the air conditioner using the flammable refrigerant, the flammable refrigerant can be more quickly detected particularly along the front-rear direction (depth direction) of the indoor unit, and the reliability of the indoor unit can be improved.
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In addition, since the power line guide has a shape like a flow channel to guide the power line in the indoor unit, the leaked flammable refrigerant is easily guided to the communication hole. Therefore, what can be expected is that not only the flammable refrigerant is readily guided to arrive at the refrigerant leakage sensor but also the possibility of diffusion of the flammable refrigerant inside the indoor unit is avoided. Thus, with expectation of a refrigerant leakage being detected further more quickly, the reliability of the air conditioner using the flammable refrigerant can be further improved.
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Hereinafter, representative exemplary embodiments of the present disclosure will be described with reference to the drawings. In the following, the same or corresponding elements will be appended with the same reference numeral in all the drawings and duplicate description will be omitted.
[Example Configuration of Air Conditioner and Indoor Unit]
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An air conditioner according to the present disclosure includes an indoor unit and an outdoor unit that are connected by a refrigerant pipe. The indoor unit of the air conditioner according to the present disclosure, in the exemplary embodiment, is of a wall-mounted type that is attached to a wall in a room. However, it is needless to say that the present disclosure is not limited to such a configuration. In the present exemplary embodiment, an example of a specific configuration of a wall-mounted type indoor unit will be described by way of example.
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As schematically illustrated in Fig. 1A, indoor unit 10 according to the present exemplary embodiment has a rectangular parallelepiped shape whose left-right direction is longer than its up-down direction and front-rear direction. There is upper opening 18b on the upper side of indoor unit 10. Indoor unit 10 includes front panel 11 on the front side and air outlet 12 in a front lower portion. As illustrated in Fig. 1B, indoor unit 10 includes pipe connection 13 on the back side. Refrigerant pipe 14 is connected to pipe connection 13. Refrigerant pipe 14 is a pipe that allows the refrigerant to flow between a heat exchanger unit included in indoor unit 10 and a heat exchanger unit included in the outdoor unit. In the present exemplary embodiment, for convenience of description, the left-right direction is also referred to as "lateral direction" and the up-down direction is also referred to as "vertical direction".
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As illustrated in a longitudinal sectional view in Fig. 2, indoor unit 10 includes, in addition to front panel 11, heat exchanger unit 15, indoor fan 16, base frame 17, housing (casing) 18, vertical airflow deflector 19, and auxiliary airflow deflector 20. Note that the longitudinal sectional view in Fig. 2 schematically illustrates the configuration of main parts inside indoor unit 10, and various known members, mechanisms, and the like are provided in blank portions according to a specific configuration of indoor unit 10.
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On the left side in Fig. 2 is the front side of indoor unit 10, on the right side in Fig. 2 is the back side (or rear side) of indoor unit 10, on the upper side in Fig. 2 is the upper side of indoor unit 10, and on the lower side in Fig. 2 is the lower side of indoor unit 10. A member, a mechanism, or the like illustrated in Fig. 2 is also a representative example, and the present disclosure is not limited to the illustration.
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Housing 18 forms an outer shape of the main body of indoor unit 10. Heat exchanger unit 15 is housed in housing 18. Indoor unit 10 according to the present exemplary embodiment includes, as heat exchanger unit 15, front heat exchanger 15a disposed at a front portion inside indoor unit 10 and back heat exchanger 15b disposed in a rear portion inside indoor unit 10. Indoor fan 16 is disposed below and between front heat exchanger 15a and back heat exchanger 15b.
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As described above, the upper portion of indoor unit 10 forms upper opening 18b. Front panel 11 is provided on the front side of indoor unit 10. Front panel 11 that is movably provided to open and close front opening 18a closes front opening 18a. Thus, housing 18 has front opening 18a in a front portion thereof and upper opening 18b in an upper portion thereof. With respect to heat exchanger unit 15, front opening 18a is disposed in front of heat exchanger unit 15, and upper opening 18b is disposed above heat exchanger unit 15.
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Heat exchanger unit 15 (front heat exchanger 15a and back heat exchanger 15b) is supported by base frame 17 inside housing 18. Indoor fan 16 causes front heat exchanger 15a and back heat exchanger 15b to exchange heat with indoor air taken in through front opening 18a and upper opening 18b, and blows the air into the room through air outlet 12 at the lower front portion of indoor unit 10.
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As described above, front panel 11 is movably provided to open and close front opening 18a. Front panel 11 closes front opening 18a when the air conditioner is stopped, and moves in a direction away from housing 18 to open front opening 18a when the air conditioner is operating. Fig. 2 schematically illustrates a state in which front panel 11 closes front opening 18a. The back surface of housing 18, that is, the back surface of indoor unit 10 is a surface to be attached to a wall in the room.
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On the lower side of housing 18, air outlet 12 is provided below indoor fan 16. In the example illustrated in Fig. 2, air outlet 12 is provided with an airflow deflector such as vertical airflow deflector 19 and auxiliary airflow deflector 20. Vertical airflow deflector 19 and auxiliary airflow deflector 20 open and close air outlet 12 and can change the vertical direction of the airflow from air outlet 12. Air outlet 12 may be provided with a lateral airflow deflector. The lateral airflow deflector can change the left-right direction of airflow from air outlet 12.
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As illustrated in a longitudinal sectional view in Fig. 3A, indoor unit 10 further includes electrical component section 21, power line 22, power line guide 23, and refrigerant leakage sensor 24. The longitudinal sectional view in Fig. 2 corresponds to a cross section of a central portion in the lateral direction of indoor unit 10 illustrated in Fig. 1A. Meanwhile, the longitudinal sectional view in Fig. 3A corresponds to a cross section of a portion where power line 22 is disposed. In the present exemplary embodiment, for example, as illustrated in Fig. 1B, power line 22 is disposed at the left end of the back side of indoor unit 10. Therefore, in indoor unit 10 viewed from the front side illustrated in Fig. 1A, power line 22 is disposed at the right end. Therefore, in the present exemplary embodiment, the longitudinal sectional view in Fig. 3A corresponds to a cross section near the right end, in the lateral direction, of indoor unit 10 illustrated in Fig. 1A. Figs. 3A and 3B schematically illustrate fan motor 16a of indoor fan 16.
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At the end where power line 22 is disposed in indoor unit 10 as illustrated in Fig. 3A, similarly to the central portion, front panel 11 is provided at front opening 18a, upper opening 18b is provided on the upper side, air outlet 12 is provided in the front lower portion, and airflow deflectors such as vertical airflow deflector 19 and auxiliary airflow deflector 20 are provided at air outlet 12. In addition, in a portion represented by the longitudinal sectional view illustrated in Fig. 3A (portion near the right end in the lateral direction), fan motor 16a of indoor fan 16 is located above air outlet 12, and pipe connection 13 is located below and rearward as viewed from fan motor 16a.
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In the example illustrated in Fig. 3A, power line 22 extends from a back-lower portion of indoor unit 10 to run below fan motor 16a to front opening 18a. Note that power line 22 may run above fan motor 16a or may run other places. In Figs. 3A and 3B, power line 22 is schematically illustrated by a thick broken line for convenience. Electrical component section 21 is provided on the front side of indoor unit 10. Electrical component section 21 includes, for example, a control board for controlling electric components such as a drain pump and a float switch, and electrical components such as a terminal block for connecting power line 22 and internal electric wiring, and these electrical components are usually housed in a dedicated housing.
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Since the electrical components include ones that generate heat, the electrical components are usually disposed on the front side of indoor unit 10 where there is much airflow. In the example illustrated in Fig. 3A, electrical component section 21 is disposed on the upper front side as viewed from fan motor 16a, but the present disclosure is not limited to this configuration. In the example illustrated in Fig. 3A, power line 22 extends from below fan motor 16a to the front side and further upward to be connected to electrical component section 21.
[Example Configuration of Power Line Guide and Communication Hole]
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As described above, in the example illustrated in Fig. 3A, power line guide 23 is provided to dispose power line 22 to extend from the back-lower portion of indoor unit 10 to run below fan motor 16a to the upper front side. In the example illustrated in Fig. 3A, power line guide 23 is disposed below fan motor 16a, and has a shape generally inclined upward from the back side toward the front side. Power ling guide 23 may have a horizontal part between a back portion and a front portion. In the present exemplary embodiment, the back portion of power line guide 23 is back side guide portion 23a extending along the up-down direction.
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As illustrated in Fig. 3A, refrigerant leakage sensor 24 is located below fan motor 16a and below power line guide 23. As illustrated in Fig. 3A, in the present exemplary embodiment, back side guide portion 23a extends along the up-down direction to partition the inside of indoor unit 10 (inside of housing 18) into a back side region and a front-lower side region. Refrigerant leakage sensor 24 is located in front of back side guide portion 23a. Power line 22 is guided by back side guide portion 23a from near the back lowermost portion to extend upward and is generally guided further forward by power line guide 23.
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Fig. 3B is an enlarged view of a portion surrounded by a thick dotted line in the longitudinal sectional view in Fig. 3A, that is, a lower portion of indoor unit 10. In the present exemplary embodiment, as schematically illustrated in Fig. 3B, communication hole 25 is formed in back side guide portion 23a of power line guide 23. As described above, back side guide portion 23a partitions the inside of indoor unit 10 into the back side region and the front-lower side region. Pipe connection 13 is located in the back side region. That is, pipe connection 13 is positioned on the back side of housing 18 (indoor unit 10) as viewed from power line guide 23. Pipe connection 13 is where a leakage of the flammable refrigerant is likely to occur. Meanwhile, refrigerant leakage sensor 24 is located in the front-lower side region.
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Back side guide portion 23a is disposed between the back side region where pipe connection 13 is located on the upper side and refrigerant leakage sensor 24 located in the front-lower side region so as to isolate the back side region and refrigerant leakage sensor 24 from each other. By providing communication hole 25 in back side guide portion 23a, the back side region and the front-lower side region communicate with each other to allow gas to flow. As a result, also when the flammable refrigerant leaks in the back side of indoor unit 10, the flammable refrigerant can pass through communication hole 25 and quickly arrive at refrigerant leakage sensor 24, so that refrigerant leakage sensor 24 can more quickly detect the leakage of the flammable refrigerant.
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A specific example configuration of refrigerant leakage sensor 24 is not particularly limited. Typical examples of refrigerant leakage sensor 24 include a semiconductor sensor, a hot-wire semiconductor sensor, and a non-dispersive infrared sensor. The semiconductor sensor detects, as a gas concentration, a change in resistance caused by a metal oxide semiconductor coming into contact with the flammable refrigerant. The hot-wire semiconductor sensor detects, as a gas concentration, a change in resistance caused by a metal oxide semiconductor coming into contact with the flammable refrigerant. The non-dispersive infrared sensor irradiates a measurement cell with an infrared ray and detects a change amount of the infrared ray due to absorption by the flammable refrigerant. In general, a semiconductor sensor or a hot-wire semiconductor sensor, which is easy to be downsized, is used.
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In the present disclosure, the flammable refrigerant used in the air conditioner is not particularly limited. In the present disclosure, "flammable" also includes "lower flammability". Typically, included among flammability categories in ISO 817:2014 are not only flammable (Class 2) and higher flammability (Class 3) but also lower flammability (Class 2L). In other words, the flammable refrigerant of the present disclosure exhibits any one of these flammability categories except no flame propagation (Class 1). Note that the definition of "flammability" in the present disclosure is not limited to the flammability categories in ISO 817:2014, and reference may be made to other definitions of flammability or combustibility known for refrigerants or in fields related to refrigerants.
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Typical examples of the flammable refrigerant of the present disclosure include propane (R290), isobutane (R600a), and ethane (R170). Another example is a lower flammability refrigerant such as difluoromethane (R32). These flammable refrigerants may be used singly or in combination of two or more types. Furthermore, in the present disclosure, a flammable refrigerant other than propane, isobutane, ethane, and difluoromethane may be used in combination, or a non-flammable refrigerant may be used in combination.
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In other words, in the present disclosure, required of the refrigerant used in the air conditioner is that the refrigerant is a mixed refrigerant containing a flammable refrigerant and that the mixed refrigerant as a whole has lower or more flammability. Therefore, a mixed refrigerant containing a non-flammable refrigerant used in the air conditioner is also the flammable refrigerant of the present disclosure as long as the mixed refrigerant is flammable. As described above, in the present disclosure, the flammable refrigerant used in the air conditioner may be any refrigerant that contains at least one selected from the group consisting of propane (R290), isobutane (R600a), ethane (R170), and difluoromethane (R32).
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In indoor unit 10 of the air conditioner according to the present disclosure, specific configurations of components other than refrigerant leakage sensor 24 and the flammable refrigerant are not particularly limited, and those known in the field of air conditioners can be suitably used. For example, as housing 18, base frame 17, power line guide 23, airflow deflectors, and the like, those made of known resin can be suitably used. As power line 22, electrical component section 21, and the like, electric and electronic components known in the field of air conditioners can be suitably used.
[Exemplary Modifications]
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Required of indoor unit 10 of the air conditioner according to the present disclosure is that refrigerant leakage sensor 24 is located on the front side of housing 18 as viewed from power line guide 23, and power line guide 23 is provided with communication hole 25 that provides communication between the region where refrigerant leakage sensor 24 is located and the region on the back side as viewed from power line guide 23. Therefore, for example, power line guide 23 may not have back side guide portion 23a. Communication hole 25 may be provided in any portion of power line guide 23 as long as a portion with communication hole 25 allows gas to flow between the region where refrigerant leakage sensor 24 is located and the region on the back side of housing 18 (indoor unit 10).
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As described above, power line guide 23 has back side guide portion 23a, and by providing communication hole 25 in back side guide portion 23a, refrigerant leakage sensor 24 can be disposed in front of back side guide portion 23a and close to communication hole 25 as illustrated in Fig. 3B. Therefore, when a leakage of the flammable refrigerant has occurred, refrigerant leakage sensor 24 can further more quickly detect the leakage.
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In the present exemplary embodiment, pipe connection 13 is exemplified as a portion where a leakage of the flammable refrigerant is likely to occur, and thus communication hole 25 is provided in power line guide 23 between pipe connection 13 and refrigerant leakage sensor 24. However, in the present disclosure, the portion where a leakage of the flammable refrigerant is assumed to occur is not limited to pipe connection 13. According to a more specific configuration of indoor unit 10, when there is a portion where a leakage of the flammable refrigerant is likely to occur, communication hole 25 may be provided in power line guide 23 so as to allow air to flow between the portion and refrigerant leakage sensor 24.
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Furthermore, in the present disclosure, a more specific configuration of communication hole 25 is not particularly limited. Communication hole 25 may have any shape that allows gas to flow between the region where refrigerant leakage sensor 24 is located and the region on the back side of housing 18 (indoor unit 10). For example, as illustrated in Fig. 4A, communication holes 25 may be provided as slits extending along the lateral direction in power line guide 23. Alternatively, as illustrated in Fig. 4B, communication holes 25 may be provided as slits inclined with respect to a side surface in power line guide 23. The direction of inclination of communication hole 25 as a slit is not particularly limited.
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Alternatively, as illustrated in Fig. 5A, communication holes 25 may be provided as slits extending along the vertical direction in power line guide 23. Alternatively, as illustrated in Fig. 5B, communication holes 25 may be provided as circular holes in power line guide 23. Furthermore, communication holes 25 may be provided in power line guide 23 as polygonal holes, or as a combination of slits, circular holes, and polygonal holes. Also, the number of communication holes 25 provided in power line guide 23 is not particularly limited. Communication holes 25 may be provided by any number that allows gas to flow between the region where refrigerant leakage sensor 24 is located and the region on the back side of housing 18 (indoor unit 10).
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Alternatively, in the present disclosure, communication hole 25 may not be a through-hole penetrating power line guide 23 but may be a gap. For example, as illustrated in Figs. 6A to 6F, communication hole 25 may be a gap in power line guide 23 that is divided into a plurality of parts.
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In the example illustrated in Figs. 6A and 6B, a sleeve-shaped power line guide 23 is divided substantially equally into two parts as illustrated in Fig. 6A, and the divided parts have abutting portions each of which thickness is reduced to overlap the opposing one. As illustrated in Fig. 6B, communication hole 25 is formed as a gap at overlapping portions of the divided parts. As illustrated in Fig. 6B, communication hole 25 is not straight but has a labyrinth structure having two corners.
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In the example illustrated in Figs. 6C and 6D, channel-shaped power line guide 23 is substantially equally divided at the bottom center into two parts as illustrated in Fig. 6C, and communication hole 25 is formed between abutting portions of the two parts. As illustrated in Fig. 6D, the abutting portion of the first divided part has a large thickness and has a recess in the abutting surface, and the abutting portion of the second divided part has a small thickness to be insertable into the recess in the abutting portion of the first divided part. Thus, communication hole 25 has a labyrinth structure having four corners.
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Note that, communication hole 25 as a gap in power line guide 23 that is divided into a plurality of parts may not necessarily have a labyrinth structure. In the example illustrated in Figs. 6E and 6F, channel-shaped power line guide 23 is substantially equally divided at the bottom center into two parts as illustrated in Fig. 6E, and communication hole 25 is formed between abutting portions of the two parts. This is similar to the example illustrated in Figs. 6C and 6D, but communication hole 25 is a straight slit gap as illustrated in Fig. 6F. Note that communication hole 25 may be a gap between power line guide 23 and a component adjacent to power line guide 23 or a labyrinth structure in which a portion of power line guide 23 overlaps a portion of the component adjacent to power line guide 23.
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As described above, an indoor unit of an air conditioner according to the present disclosure uses a flammable refrigerant, and includes a housing, a power line drawn into the housing from the back side of the housing, a power line guide that guides the power line to be disposed in the housing, and a refrigerant leakage sensor that detects a leakage of the flammable refrigerant, and what is required of the indoor unit is that the refrigerant leakage sensor is located on the front side of the housing as viewed from the power line guide, and the power line guide includes a communication hole that provides communication between the region where the refrigerant leakage sensor is located and the region on the back side as viewed from the power line guide.
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With this configuration, by providing the communication hole in the power line guide, the region on the back side of the indoor unit defined by the power line guide and the region on the front side of the indoor unit where the refrigerant leakage sensor is located communicate with each other to allow gas to flow. As a result, also when a leakage of the flammable refrigerant occurs in the back side of the indoor unit, the flammable refrigerant can pass through the communication hole and suitably arrive at the refrigerant leakage sensor, so that the refrigerant leakage sensor can more quickly detect the leakage of the flammable refrigerant. As a result, in the air conditioner using the flammable refrigerant, the flammable refrigerant can be more quickly detected particularly along the front-rear direction (depth direction) of the indoor unit, and the reliability of the indoor unit can be improved.
(Supplement)
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The above description of the exemplary embodiments discloses in the specification the following technologies.
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(Technology 1) An indoor unit of an air conditioner using a flammable refrigerant, the indoor unit including a housing, a power line drawn into the housing from the back side of the housing, a power line guide that is provided in the housing and guides the power line, and a refrigerant leakage sensor that detects a leakage of the flammable refrigerant, where the refrigerant leakage sensor is located on the front side of the housing as viewed from the power line guide, and the power line guide includes a communication hole that provides communication between a region where the refrigerant leakage sensor is located and a region on a back side as viewed from the power line guide.
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According to this configuration, by providing the communication hole in the power line guide, the region on the back side of the indoor unit defined by the power line guide and the region on the front side of the indoor unit where the refrigerant leakage sensor is located communicate with each other to allow gas to flow. As a result, also when the flammable refrigerant leaks in the back side of the indoor unit, the flammable refrigerant can pass through the communication hole and quickly arrive at the refrigerant leakage sensor, so that the refrigerant leakage sensor can more quickly detect the leakage of the flammable refrigerant. As a result, in the air conditioner using the flammable refrigerant, the flammable refrigerant can be more quickly detected particularly along the front-rear direction (depth direction) of the indoor unit, and the reliability of the indoor unit can be improved.
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(Technology 2) The indoor unit of an air conditioner according to Technology 1, further including a heat exchanger unit housed in the housing, and a pipe connection that connects the heat exchanger unit to a refrigerant pipe, where the pipe connection is located on the back side of the housing as viewed from the power line guide, and the communication hole is provided in the power line guide at a position between the pipe connection and the refrigerant leakage sensor.
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According to this configuration, the pipe connection which is a place where a leakage of the refrigerant is relatively likely to occur is usually located on the back side of the housing. Therefore, the communication hole is provided in a portion of the power line guide between the pipe connection and the refrigerant leakage sensor. As a result, when a leakage of the flammable refrigerant occurs, the flammable refrigerant can pass through the communication hole to suitably arrive at the refrigerant leakage sensor, and the refrigerant leakage sensor can more quickly detect the leakage of the flammable refrigerant.
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(Technology 3) The indoor unit of an air conditioner according to Technology 2, where the housing includes a back side region and a front-lower side region, the power line guide includes a back side guide portion extending along the up-down direction of the housing between the back side region and the front-lower side region, the refrigerant leakage sensor is located on a front side of the housing as viewed from the back side guide portion, and the communication hole is provided in the back side guide portion.
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According to this configuration, the power line guide has the back side guide portion extending along the up-down direction inside the housing, and by providing the communication hole in the back side guide portion, the refrigerant leakage sensor can be disposed in front of and close to the back side guide portion. Therefore, when a leakage of the flammable refrigerant occurs, the refrigerant leakage sensor can further more quickly detect the leakage.
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(Technology 4) The indoor unit of an air conditioner according to any one of Technologies 1 to 3, where the communication hole is at least one of a slit or a circular hole in the power line guide, a gap between the power line guide and a component adjacent to the power line guide, a gap in the power line guide divided into a plurality of parts, and a labyrinth structure between a portion of the power line guide and a portion of a component adjacent to the portion of the power line guide, the portion of the power line guide and the portion of the component overlapping each other.
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According to this configuration, the communication hole having any one of the configurations described above allows the leaked flammable refrigerant to further more suitably arrive at the refrigerant leakage sensor.
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(Technology 5) The indoor unit of an air conditioner according to any one of Technologies 1 to 4, where the flammable refrigerant contains at least one selected from the group consisting of propane (R290), isobutane (R600a), ethane (R170), and difluoromethane (R32).
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According to this configuration, when the air conditioner is configured to use a flammable refrigerant containing at least any refrigerant selected from the group described above and when a leakage of such a flammable refrigerant occurs, the communication hole provided in the power line guide allows the refrigerant leakage sensor to further more quickly detect the leakage.
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The present disclosure is not limited to the above description of the exemplary embodiments, and various modifications can be made within the scope defined by claims, and exemplary embodiments that are obtained by appropriately combining technical measures disclosed in different exemplary embodiments and modified examples are also encompassed in the technical scope of the present disclosure.
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The present disclosure can be widely and suitably used in the field of air conditioners using a flammable (including lower flammability) refrigerant.