Indoor unit of air conditioner
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- MITSUBISHI ELECTRIC CORP
- Filing Date
- 2025-01-27
- Publication Date
- 2026-07-30
Smart Images
Figure JP2025002408_30072026_PF_FP_ABST
Abstract
Description
Indoor unit of an air conditioner
[0001] The present disclosure relates to an indoor unit of an air conditioner.
[0002] As a conventional air conditioner, there is known one in which a refrigerant leakage detection sensor for detecting a refrigerant is attached to an indoor unit. For example, Patent Document 1 describes that a refrigerant leakage detection sensor is disposed on the side of a drain pan provided below a heat exchanger.
[0003] Japanese Patent Application Laid-Open No. 2002-98346
[0004] However, in the technique described in Patent Document 1, since the refrigerant leakage detection sensor is provided on the side of the drain pan, it may take time to detect the refrigerant leaked from the heat exchanger.
[0005] The present disclosure has been made to solve the above-described problems, and an object thereof is to provide an indoor unit of an air conditioner that can efficiently detect refrigerant leakage.
[0006] The indoor unit of an air conditioner according to the present disclosure is an indoor unit of an air conditioner having a refrigerant circuit in which a refrigerant circulates, and includes a housing having a suction port formed at an upper portion and a blowout port formed at a lower portion, a blower fan provided in the housing for generating an air flow from the suction port toward the blowout port, a heat exchanger provided in the housing and having at least a part disposed above the blower fan and having a pipe through which the refrigerant flows, and a first refrigerant leakage detection sensor provided inside the housing between an end portion of the heat exchanger and a side surface of the housing in a left-right direction and at a height at which the blower fan is located in a vertical direction.
[0007] According to the indoor unit of an air conditioner according to the present disclosure, by providing the first refrigerant leakage detection sensor at the height position of the blower fan on the side of the heat exchanger, refrigerant leakage can be efficiently detected.
[0008] This is a schematic diagram showing the general configuration of the air conditioner 100 in the embodiment. This is a perspective view of the indoor unit 10 according to the embodiment. This is a front view of the indoor unit 10 with the front panel removed. This is a cross-sectional view along the line L1-L1 in Figure 3. This is a cross-sectional view along the line L2-L2 in Figure 3. This is a cross-sectional view along the line L3-L3 in Figure 3. This is an enlarged front view of the area A1 in Figure 3. This is a perspective view of the indoor unit with the front panel, first side panel, second side panel, and top panel removed. This is an exploded perspective view of the first refrigerant leak detection sensor. This is a partial enlarged view of Figure 7. This is a graph illustrating the length of the heat exchanger 3 in the left-right direction and the probability of detecting refrigerant leaks. This is an enlarged front view of the area A2 in Figure 3.
[0009] The embodiments for carrying out the subject matter of 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. The subject matter of this disclosure is not limited to the embodiments described below, and it is possible to combine the embodiments or modify or omit any components as long as it does not depart from the spirit of this disclosure.
[0010] Furthermore, the drawings show the X-axis, Y-axis, and Z-axis as appropriate. The X-axis and Y-axis each represent one of the horizontal directions. The Z-axis represents the vertical direction. In the following description, the horizontal direction along the X-axis will be called the "front-back direction X," the horizontal direction along the Y-axis will be called the "left-right direction Y," and the vertical direction along the Z-axis will be called the "up-down direction Z." The up-down direction is the vertical direction when the indoor unit 10 of this disclosure is installed on a wall. The front-back direction X, the left-right direction Y, and the up-down direction Z are mutually orthogonal directions. In the following description, the side of the front-back direction X in which the X-axis arrow points (+X) will be considered the front, and the side of the front-back direction X opposite to the side in which the X-axis arrow points (-X) will be considered the rear. Also, the side of the left-right direction in which the Y-axis arrow points (+Y) will be considered the right side, and the side of the left-right direction Y opposite to the side in which the Y-axis arrow points (-Y) will be considered the left side. Furthermore, the side of the Z-axis arrow pointing (+Z side) in the vertical Z direction is defined as the upper side, and the side opposite to the direction the Z-axis arrow points (-Z) in the vertical Z direction is defined as the lower side. Note that the left-right Y direction, front-back X direction, and vertical Z direction are merely names used to describe the relative positional relationships of each part, and the actual arrangement relationships may differ from those indicated by these names.
[0011] Embodiment 1. <Air Conditioner 100> Figure 1 is a schematic diagram showing the general configuration of the air conditioner 100 in this embodiment. As shown in Figure 1, the air conditioner 100 comprises an indoor unit 10, an outdoor unit 60, and a refrigerant circuit 70. The indoor unit 10 is located indoors. The outdoor unit 60 is located outdoors. The indoor unit 10 and the outdoor unit 60 are connected to each other by a refrigerant circuit 70 through which the refrigerant circulates. The indoor unit 10 and the outdoor unit 60 are heat exchange units that exchange heat with the air.
[0012] The air conditioner 100 can adjust the temperature of the indoor air by performing heat exchange between the refrigerant flowing through the refrigerant circuit 70 and the air in the room where the indoor unit 10 is located. Examples of refrigerants include fluorine-based refrigerants or hydrocarbon-based refrigerants with a low Global Warming Potential (GWP). Examples of refrigerants include a single refrigerant such as R1234yf, R1234ze, R32, or R290, a mixture of two or more of these, or a mixture of one of these with another refrigerant. Examples of refrigerants include a mixture containing R1132(E) or a mixture containing R1123. Furthermore, examples of refrigerants include mixed refrigerants such as R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.
[0013] The outdoor unit 60 includes a compressor 61, an outdoor heat exchanger 63, an expansion device 64, an outdoor blower fan 65, and a four-way valve 62. The compressor 61, the outdoor heat exchanger 63, the expansion device 64, and the four-way valve 62 are connected by a refrigerant circuit 70.
[0014] The four-way valve 62 is located in the part of the refrigerant circuit 70 that is connected to the discharge side of the compressor 61. The four-way valve 62 can reverse the direction of the refrigerant flowing through the refrigerant circuit 70 by switching a part of the path in the refrigerant circuit 70. When the air conditioner 100 is performing cooling or dehumidifying operation, the path connected by the four-way valve 62 is the path shown by the solid line on the four-way valve 62 in Figure 1, and the refrigerant flows through the refrigerant circuit 70 in the direction shown by the solid arrow in Figure 1. On the other hand, when the air conditioner 100 is performing heating operation, the path connected by the four-way valve 62 is the path shown by the dashed line on the four-way valve 62 in Figure 1, and the refrigerant flows through the refrigerant circuit 70 in the direction shown by the dashed arrow in Figure 1.
[0015] The indoor unit 10 includes a blower fan 2 and a heat exchanger 3. The indoor unit 10 is capable of cooling or dehumidifying the air in the room in which the indoor unit 10 is located, and heating the air in the room in which the indoor unit 10 is located.
[0016] When the indoor unit 10 is operating in cooling or dehumidifying mode, the refrigerant flowing through the refrigerant circuit 70 flows in the direction indicated by the solid arrow in Figure 1. In other words, when the indoor unit 10 is operating in cooling or dehumidifying mode, the refrigerant flowing through the refrigerant circuit 70 circulates by passing through the compressor 61, the outdoor heat exchanger 63 of the outdoor unit 60, the expansion device 64, and the heat exchanger 3 of the indoor unit 10 in that order, before returning to the compressor 61. During cooling or dehumidifying operation, the outdoor heat exchanger 63 in the outdoor unit 60 functions as a condenser, and the heat exchanger 3 in the indoor unit 10 functions as an evaporator.
[0017] On the other hand, when the indoor unit 10 is operating in heating mode, the refrigerant flowing through the refrigerant circuit 70 flows in the direction shown by the dashed line in Figure 1. In other words, when the indoor unit 10 is operating in heating mode, the refrigerant flowing through the refrigerant circuit 70 circulates by passing through the compressor 61, the heat exchanger 3 of the indoor unit 10, the expansion device 64, and the outdoor heat exchanger 63 of the outdoor unit 60 in that order, before returning to the compressor 61. In heating mode, the outdoor heat exchanger 63 in the outdoor unit 60 functions as an evaporator, and the heat exchanger 3 in the indoor unit 10 functions as a condenser.
[0018] <Indoor Unit 10> Next, the indoor unit 10 of this embodiment will be described in more detail. Figure 2 is a perspective view of the indoor unit 10 according to this embodiment. As shown in Figure 2, the indoor unit 10 of this embodiment is a wall-mounted indoor unit fixed to the upper area of the wall surface of a room. The indoor unit 10 is a roughly rectangular box shape that is long in the left-right direction Y. The housing 1 of the indoor unit 10 has a front panel 1a, a top panel 1b, a rear panel 1c, a bottom panel 1d, a first side panel 1e, and a second side panel 1f. The front panel 1a covers the internal space of the housing 1 from the front (+X). The top panel 1b covers the internal space of the housing 1 from above (+Z). An intake port 12 is formed in the top panel 1b. The bottom panel 1d covers the internal space of the housing 1 from below (-Z). The first side panel 1e covers the internal space of the housing 1 from the left side (-Y). An outlet port 13 is formed in the bottom panel 1d. The second side panel 1f covers the internal space of the enclosure 1 from the right side (+Y). The rear panel 1c covers the internal space of the enclosure 1 from the rear side (-X).
[0019] Figure 3 is a front view of the indoor unit 10 with the front panel 1a removed. Figure 4 is a cross-sectional view taken along line L1-L1 in Figure 3. Figure 5 is a cross-sectional view taken along line L2-L2 in Figure 3. Figure 6 is a cross-sectional view taken along line L3-L3 in Figure 3. As shown in Figures 3, 4, 5, and 6, the indoor unit 10 of this embodiment includes a heat exchanger 3, a blower fan 2, a drain pan 5, a rear drain pan 6, a control unit 7, a first refrigerant leak detection sensor 41, and a second refrigerant leak detection sensor 42 inside the housing 1.
[0020] An intake port 12 is formed on the top panel 1b of the housing 1, which is the entrance for the airflow generated by the blower fan 2 into the interior of the housing 1. The intake port 12 opens on the upper side of the housing 1 and is formed in a substantially rectangular shape that is long in the left-right direction Y. A filter 12a is placed in the intake port 12 to remove dust from the air being drawn in. An outlet port 13 is formed at the front end of the bottom panel 1d and the lower end of the front panel 1a of the housing 1. The outlet port 13 opens on the front side (+X) and the bottom side (-Z) and is formed in a substantially rectangular shape that is long in the left-right direction Y. Wind direction vanes 13a are provided on the bottom panel 1d and the front panel 1a to adjust the direction of the air blown out from the outlet port 13. When the indoor unit 10 is stopped, the outlet port 13 is covered by the wind direction vanes 13a.
[0021] <Blower Fan 2> The blower fan 2 according to this embodiment is a cross-flow fan. The blower fan 2 has an impeller 2a extending in the left-right direction Y, and a drive motor 2b positioned to the right (+Y) of the impeller 2a. The impeller 2a is substantially cylindrical and has a plurality of blades (not shown) arranged in the circumferential direction of the rotation axis 2c of the blower fan 2. The impeller 2a rotates around the rotation axis 2c extending in the left-right direction Y when driven by the drive motor 2b.
[0022] <Heat Exchanger 3> The heat exchanger 3 has a heat exchanger body 3a, a pipe connection section 3b, and a pipe connection section 3h. The heat exchanger body 3a is composed of a front heat exchanger 3d and a rear heat exchanger 3f, which will be described later. The heat exchanger body 3a is of the fin and tube type. The heat exchanger body 3a is arranged along a plane perpendicular to the left-right direction Y, and has a plurality of fin members aligned in the left-right direction Y, and a plurality of pipes 3c that penetrate these plurality of fin members and through which the refrigerant flows. The pipe connection section 3b is a plurality of hairpin-shaped pipes that connect adjacent pipes 3c at the end of the heat exchanger body 3a. The pipe connection section 3h is a pipe that connects the pipes 3c of the heat exchanger body 3a to external pipes. The pipe connection section 3h is located on the right side of the heat exchanger 3 and is connected to the external pipes that are drawn into the housing 1 by welding or brazing. The piping 3c of the heat exchanger 3 forms part of the refrigerant circuit 70 (see Figure 1), through which the refrigerant flows. The heat exchanger body 3a performs heat exchange between the air inside the housing 1 and the refrigerant. As a result, the heat exchanger 3 cools or heats the air drawn in by the blower fan 2.
[0023] As shown in Figure 4, the heat exchanger body 3a is composed of a front heat exchanger 3d and a rear heat exchanger 3f. In addition, each heat exchanger constituting the heat exchanger body 3a may be equipped with an auxiliary heat exchanger 3g to improve heat exchange performance. The front heat exchanger 3d is formed in a plate shape that is long in the left-right direction Y and is located in front of the blower fan 2 (+X). Also, as shown in Figure 4, the front heat exchanger 3d is bent at a bent portion 3e when viewed from the side, i.e., in the left-right direction Y. The portion of the front heat exchanger 3d above the bent portion 3e extends diagonally rearward (-X) from the bent portion 3e when viewed from the left-right direction Y. The portion of the front heat exchanger 3d below the bent portion 3e extends downward (-Z) from the bent portion 3e when viewed from the left-right direction Y. With this shape, the front heat exchanger 3d can be positioned to cover the front and above the blower fan 2. The rear heat exchanger 3f is located behind (-X) the front heat exchanger 3d. When viewed from the left-right direction Y, the rear heat exchanger 3f extends downward (-Z) and diagonally backward (-X) from the upper end of the front heat exchanger 3d. As shown in Figure 4, the heat exchanger body 3a is positioned to cover the top of the blower fan 2. As a result, the airflow drawn in from the intake port 12 generated by the blower fan 2 passes through the heat exchanger body 3a and is blown out from the outlet port 13, allowing the heat exchanger 3 to perform heat exchange efficiently. In Figure 4, the front heat exchanger 3d of the heat exchanger body 3a extends to the bottom of the blower fan 2, but even if a part of the heat exchanger body 3a is located below the blower fan 2, the effect of efficient heat exchange can be obtained by the airflow from the blower fan 2, as long as at least a part of the heat exchanger body 3a is positioned above the blower fan 2.
[0024] The heat exchanger 3 is supported at its left-right Y-direction ends by a left-side heat exchanger support member 31 and a right-side heat exchanger support member 32, respectively. Furthermore, the heat exchanger 3 is installed inside the housing 1 by fixing the left-side heat exchanger support member 31 and the right-side heat exchanger support member 32 to the inside of the housing 1 by screws or the like. The right-side heat exchanger support member 32, which supports the right side of the heat exchanger 3 where the pipe connection portion 3h is located, is provided with a hole for inserting the pipe connection portion 3h. The right-side heat exchanger support member 32 is made of heat-resistant sheet metal so that the connection between the pipe connection portion 3h and the external piping is made by welding or brazing. In addition, the right-side heat exchanger support member 32 isolates the pipe connection portion 3h and the control unit 7, which will be located on the right side of the housing 1 (described later), from the air passage through which the airflow generated by the blower fan 2 passes. Hereafter, when referring to the left-side heat exchanger support member 31 and the right-side heat exchanger support member 32 without distinction, they will be referred to as the heat exchanger support member.
[0025] <Drain Pan 5> As shown in Figures 3 and 4, the drain pan 5 is located in the internal space of the housing 1, below the heat exchanger 3, and receives condensation water dripping from the heat exchanger 3. The drain pan 5 has a drain pan body 5a and two drain pan side ends 5b. The drain pan side ends 5b are formed at both ends of the drain pan body 5a in the left-right direction Y. As shown in Figure 4, the drain pan body 5a is located directly below the front heat exchanger 3d of the heat exchanger body 3a. As shown in Figures 5 and 6, the drain pan side ends 5b are located directly below the pipe connection part 3b. The upper part of the drain pan body 5a forms a storage part 5c for storing condensation water. Also, the upper part of the drain pan side ends 5b forms a storage part 5d for storing condensation water. The drain pan body 5a extends in a trough shape in the left-right direction Y. The drain pan body 5a receives the condensed water that condenses and drips from the surface of the heat exchanger body 3a in the storage section 5c.
[0026] The drain pan end 5b receives condensation water that condenses and drips from the surface of the pipe connection 3b in its storage section 5d. In particular, the drain pan end 5b on the side where the first refrigerant leak detection sensor 41 is located, i.e., the left side in Figure 3, extends to the space formed between the left heat exchanger support member 31 and the first side panel 1e, which is the side of the housing 1. That is, when viewed from the front, the drain pan end 5b extends to the left of the left heat exchanger support member 31. The storage section 5d of the drain pan end 5b is connected to the storage section 5c of the drain pan body 5a. Therefore, not only condensation water dripping from the pipe connection 3b but also condensation water received by the drain pan body 5a flows into the storage section 5d of the drain pan end 5b. A drain hose 5e is connected to the right drain pan end 5b. The condensed water collected by the drain pan 5 is discharged outdoors via the drain hose 5e.
[0027] Furthermore, the surface of the drain pan body 5a facing the storage section 5c, that is, the drain pan bottom surface 5f of the drain pan body 5a, forms the upper surface of the outlet 13. The drain pan bottom surface 5f functions as a nozzle that guides the airflow generated by the blower fan 2 to the outlet 13.
[0028] <Rear Drain Pan 6> As shown in Figure 4, the rear drain pan 6 is located in the internal space of the housing 1, below the rear heat exchanger 3f, and receives condensation water dripping from the rear heat exchanger 3f. The rear drain pan 6 is connected to the drain pan side end 5b of the drain pan 5 at its right end. The condensation water that drips onto the rear drain pan 6 flows to the drain pan side end 5b and is discharged to the outside via the drain hose 5e.
[0029] <Control Unit 7> As shown in Figure 3, the control unit 7 is located to the right (+Y) of the heat exchanger 3 and the blower fan 2. The control unit 7 controls the components necessary for the heating and cooling operation of the air conditioner 100. Based on the measurement results of the first refrigerant leak detection sensor 41, the second refrigerant leak detection sensor 42, and various sensors provided on the heat exchanger 3, the control unit 7 controls the blower fan 2 and the heat exchanger 3, etc.
[0030] <First Refrigerant Leak Detection Sensor 41> Figure 7 is an enlarged front view of the area A1 in Figure 3. Figure 7 is also a cross-sectional view along the line L4-L4 in Figure 5. Figure 8 is a perspective view of the indoor unit 10 with the front panel 1a, first side panel 1e, second side panel 1f, and top panel 1b removed. Figure 9 is an exploded perspective view of the first refrigerant leak detection sensor 41. Figure 10 is a partially enlarged view of Figure 7. Furthermore, Figure 10 shows a cross-section of the left heat exchanger support member 31 and the first refrigerant leak detection sensor 41. The first refrigerant leak detection sensor 41 will be explained with reference to Figures 7 to 10.
[0031] As shown in Figure 9, the first refrigerant leak detection sensor 41 is attached to a recess 31a formed in the left heat exchanger support member 31.
[0032] The first refrigerant leak detection sensor 41 consists of a sensor unit 41a, a substrate 41b, a substrate fixing unit 41c, and a folder 41d. The folder 41d has a roughly box-shaped case unit 41h that houses the sensor unit 41a, and the opening surface of the case unit 41h is covered by a folder cover 41e. The sensor unit 41a detects vaporized refrigerant. The sensor unit 41a is mounted on the substrate 41b. The top of the substrate 41b is fixed by the substrate fixing unit 41c. With the top fixed by the substrate fixing unit 41c, the substrate 41b is housed in the case unit 41h of the folder 41d. The folder cover 41e is attached to the case unit 41h in which the substrate 41b is housed, so that the opening surface of the case unit 41h is covered and the substrate 41b is protected.
[0033] The folder 41d comprises a case portion 41h, a folder cover 41e that covers the opening surface of the case portion 41h, a plate portion 41i extending forward from the case portion 41h, and a foot portion 41g extending from the plate portion 41i in the direction (+Y) for attachment to the left heat exchanger support member 31. As shown in Figure 8, with the case portion 41h housed in the recess 31a of the left heat exchanger support member 31, the foot portion 41g is positioned in front of the front surface 31b of the left heat exchanger support member 31. In other words, when the case portion 41h of the folder 41d is fitted into the recess 31a of the left heat exchanger support member 31, the left heat exchanger support member 31 is sandwiched between the foot portion 41g from the front of the front surface 31b of the left heat exchanger support member 31. The foot portion 41g and the front surface 31b each have a locking portion and a locking member, and the folder 41d is attached to the left heat exchanger support member 31 by the engagement of the locking portion and the locking member. When the folder 41d is attached to the left heat exchanger support member 31, as shown in Figure 7, the foot portion 41g is formed to a length that creates a gap c1 between the case portion 41h of the folder 41d and the recess 31a of the left heat exchanger support member 31. By positioning the folder 41d between the left heat exchanger support member 31 and the housing 1 with a gap c1 between the first refrigerant leak detection sensor 41 and the left heat exchanger support member 31, the transfer of cold heat from the heat exchanger 3 to the first refrigerant leak detection sensor 41 can be suppressed, and condensation inside the folder 41d can be prevented.
[0034] The folder cover 41e has a grid-like opening 41f formed therein. The folder cover 41e is attached to the side of the folder 41d that faces the first side panel 1e, which is the side of the housing 1. Therefore, when the folder cover 41e is attached, the folder 41d has a grid-like opening 41f formed on the side facing the side of the housing 1. Refrigerant flows into the first refrigerant leak detection sensor 41 through the grid-like opening 41f, and the sensor unit 41a can detect the refrigerant.
[0035] The flow of refrigerant leaking from the heat exchanger 3 will be explained with reference to Figure 10. The dashed arrows in Figure 10 indicate the flow of the leaked refrigerant. Refrigerant is denser than air and flows downwards. The refrigerant passes through the gap between the left heat exchanger support member 31 and the first side panel 1e, hits the upper surface 41j of the folder 41d and branches to the left and right. The refrigerant that flows to the left then flows into the first refrigerant leak detection sensor 41 through the grid-like opening 41f, allowing the sensor unit 41a to detect the refrigerant. Note that no opening is formed on the surface of the folder 41d facing the left heat exchanger support member 31. Therefore, the refrigerant that hits the upper surface 41j of the folder 41d and flows to the right does not enter the interior of the folder 41d, but passes through the gap c1 between the folder 41d and the left heat exchanger support member 31 and accumulates in the storage section 5d at the drain pan side end 5b.
[0036] The installation location of the first refrigerant leak detection sensor 41 will now be described in detail. The first refrigerant leak detection sensor 41 is attached to a recess 31a formed in the left heat exchanger support member 31, which supports the end of the heat exchanger 3 opposite to the end where the piping connection portion 3h is located. That is, the first refrigerant leak detection sensor 41 is positioned inside the housing 1, between the left end of the heat exchanger 3 and the side surface of the housing 1. This allows the first refrigerant leak detection sensor 41 to efficiently detect refrigerant leaking from the piping connection portion 3b located at the end of the heat exchanger 3.
[0037] As shown in Figure 7, the recess 31a of the left heat exchanger support member 31, where the first refrigerant leak detection sensor 41 is installed, is formed in the vertical direction at the height of the range H1 where the blower fan 2 is located. Therefore, the first refrigerant leak detection sensor 41 is installed at the height of the range H1 where the blower fan 2 is located. Since at least a part of the heat exchanger 3 is positioned above the blower fan 2, the installation of the first refrigerant leak detection sensor 41 at the height of range H1 allows refrigerant leaking from the heat exchanger 3 to enter the inside of the folder 41d through the grid-like opening 41f before it accumulates in the drain pan 5. Therefore, refrigerant leaks can be detected earlier than if the first refrigerant leak detection sensor 41 were installed below range H1. Also, if the first refrigerant leak detection sensor 41 were installed above the blower fan 2, the refrigerant would flow to the bottom of the housing 1 without entering the inside of the folder 41d through the grid-like opening 41f. Therefore, by installing the first refrigerant leak detection sensor 41 at a height H1 within the range where the blower fan 2 is located, refrigerant leaks can be detected efficiently.
[0038] Furthermore, in order to detect refrigerant leaking from the piping connection 3b of the heat exchanger 3 before it flows to the drain pan side end 5b, it is desirable that the lower end of the first refrigerant leak detection sensor 41 be positioned above the lower end of range H1. However, if a part of the first refrigerant leak detection sensor 41 is positioned above the lower end of range H1, the effect of the first refrigerant leak detection sensor 41 detecting the leaked refrigerant before it flows to the drain pan side end 5b can be obtained.
[0039] Furthermore, in order to prevent the leaked refrigerant from entering the first refrigerant leak detection sensor 41 and flowing downwards, it is desirable that the upper end of the first refrigerant leak detection sensor 41 be positioned below the upper end of range H1. However, if a part of the first refrigerant leak detection sensor 41 is positioned below the upper end of range H1, the effect of the first refrigerant leak detection sensor 41 detecting the leaked refrigerant before it flows to the bottom of the housing 1 without entering the inside of the folder 41d can be obtained.
[0040] In this embodiment, the case in which the first refrigerant leak detection sensor 41 is attached to a recess 31a formed in the left heat exchanger support member 31 has been described. When the piping connection portion 3h of the heat exchanger 3 is located on the left side, the first refrigerant leak detection sensor 41 is located inside the housing 1, between the right end of the heat exchanger 3 and the right side of the housing 1. That is, the first refrigerant leak detection sensor 41 is attached to the heat exchanger support member that supports the end of the heat exchanger 3 opposite to the end where the piping connection portion 3h is located. The space between the heat exchanger support member that supports the end of the heat exchanger 3 where the piping connection portion 3h is not located and the side of the housing 1 becomes an airflow path for the airflow generated by the blower fan 2. Therefore, by installing the first refrigerant leak detection sensor 41 in the vertical direction at the height of the range H1 where the blower fan 2 is located, it is positioned in the middle of the airflow path, and refrigerant leaking from the heat exchanger 3 can be efficiently detected.
[0041] Furthermore, the first refrigerant leak detection sensor 41 is installed above the drain pan side end 5b in the vertical direction, that is, above the height H2 in Figure 7. The drain pan side end 5b extends to the space formed between the left heat exchanger support member 31 and the first side panel 1e, which is the side of the housing 1. Therefore, refrigerant leaking from the piping connection part 3b of the heat exchanger 3 is detected by the first refrigerant leak detection sensor 41, flows downward, and accumulates in the storage part 5d of the drain pan side end 5b. As a result, the leaked refrigerant enters the first refrigerant leak detection sensor 41 before it flows into the drain pan 5 and is blown into the room, so refrigerant leaks can be detected efficiently.
[0042] Furthermore, it is desirable that the first refrigerant leak detection sensor 41 be positioned below the lower end of the rear heat exchanger 3f in the vertical direction. If refrigerant leaks from the rear heat exchanger 3f, the leaked refrigerant temporarily accumulates in the rear drain pan 6, flows down into the drain pan 5, is then sucked into the blower fan 2, and blows out from the outlet 13. By positioning the first refrigerant leak detection sensor 41 below the rear heat exchanger 3f, the refrigerant leaking from the rear heat exchanger 3f can be detected by the first refrigerant leak detection sensor 41 before it is sucked into the blower fan 2.
[0043] Further, as shown in FIG. 5, it is desirable that the first refrigerant leakage detection sensor 41 be installed below the bent portion 3e of the front heat exchanger 3d in the vertical direction. In the front heat exchanger 3d, at the bent portion 3e, the fin members provided in the upper part and the lower part of the front heat exchanger 3d above the bent portion 3e are arranged to overlap each other. Therefore, at the bent portion 3e, the condensed water adhering to the fins may not drip onto the drain pan 5 and may stay at the bent portion 3e. The staying condensed water may corrode the pipe 3c and cause refrigerant leakage. Therefore, by installing the first refrigerant leakage detection sensor 41 below the bent portion 3e, the refrigerant leaked at the bent portion 3e can be surely detected.
[0044] As shown in FIG. 10, the upper surface 41j of the folder 41d is lower from the side of the first side panel 1e toward the left heat exchanger support member 31. Above the first refrigerant leakage detection sensor 41, there is a pipe connection portion 3b of the heat exchanger 3 protruding from the left heat exchanger support member 31. The solid line arrow in FIG. 10 indicates the flow of the condensed water dripping from the pipe connection portion 3b. When condensed water drips from the pipe connection portion 3b or the heat exchanger body 3a and hits the folder 41d, due to the inclination of the upper surface 41j, the condensed water does not flow to the left side and flows down into the gap c1 between the folder 41d and the left heat exchanger support member 31. No opening is formed on the surface of the folder 41d facing the left heat exchanger support member 31. Since the upper surface 41j is inclined toward the gap c1, it is possible to suppress the condensed water from flowing to the folder cover 41e in which the lattice-shaped opening 41f is formed. Therefore, it is possible to prevent the condensed water from entering the inside of the folder 41d through the lattice-shaped opening 41f, causing false detection by the sensor portion 41a or failure of the sensor portion 41a and the substrate 41b, and reliability can be ensured.
[0045] <Second Refrigerant Leak Detection Sensor 42> As shown in Figure 3, the second refrigerant leak detection sensor 42 is installed inside the housing 1 on the side of the heat exchanger 3 opposite to the side where the first refrigerant leak detection sensor 41 is installed. The side opposite to the side where the first refrigerant leak detection sensor 41 is installed is the area between the end of the heat exchanger 3 where the pipe connection part 3h connecting the piping 3c of the heat exchanger 3 to the piping connected to the outside of the housing 1 is provided, and the side of the housing 1, in the left-right direction. The indoor unit 10 has a long rectangular parallelepiped shape. This allows the air outlet 13 to be widely provided in the left-right direction, enabling air to be blown over a wide area in the room and air conditioning to be performed efficiently. Also, when fixing the indoor unit 10 to the upper area of the wall surface of the room, the size of the housing 1 in the vertical direction can be reduced because the indoor unit 10 has a rectangular parallelepiped shape, and the space in the room can be used effectively. Since the indoor unit 10 is long in the left-right direction, the blower fan 2 and heat exchanger 3 that make up the indoor unit 10 are also formed to be long in the left-right direction. On the other hand, because the heat exchanger 3 has a long shape from left to right, if a refrigerant leak occurs at a location far from the end of the heat exchanger 3 where the first refrigerant leak detection sensor 41 is installed, the detection of the refrigerant leak may be delayed if only the first refrigerant leak detection sensor 41 is installed. Therefore, by placing the second refrigerant leak detection sensor 42 on the side of the heat exchanger 3 opposite to the side where the first refrigerant leak detection sensor 41 is installed, refrigerant leaks can be detected efficiently.
[0046] Figure 11 is a graph illustrating the relationship between the length of the heat exchanger 3 in the longitudinal direction, i.e., the left-right direction, and the probability of detecting refrigerant leakage. In Figure 11, the solid line shows the detection probability when only the first refrigerant leakage detection sensor 41 is installed on one side of the heat exchanger 3. In Figure 11, the dotted line shows the detection probability when the first refrigerant leakage detection sensor 41 is installed on one side of the heat exchanger 3 and the second refrigerant leakage detection sensor 42 is installed on the opposite side. As shown by the solid line in Figure 11, when the length of the heat exchanger 3 in the left-right direction is less than 70 cm, it can be seen that refrigerant leakage can be detected almost entirely by the first refrigerant leakage detection sensor 41 alone. However, when the length of the heat exchanger 3 in the left-right direction exceeds 70 cm, the probability of detecting refrigerant leakage gradually decreases. Therefore, if the length of the heat exchanger 3 in the left-right direction exceeds 70 cm, the probability of detecting refrigerant leakage can be improved and safety ensured by installing the second refrigerant leakage detection sensor 42 on the side of the heat exchanger 3 opposite to the side where the first refrigerant leakage detection sensor 41 is installed. In particular, if the refrigerant used in the air conditioner 100 is a flammable refrigerant, it is necessary to ensure safety by reliably detecting refrigerant leakage. For this reason, it is desirable to install refrigerant leakage sensors on both sides of the heat exchanger 3 whose length in the longitudinal direction exceeds 70 cm.
[0047] As shown by the dotted line in Figure 11, if the length of the heat exchanger 3 in the left-right direction exceeds 100 cm, simply installing refrigerant leak detection sensors on both sides of the heat exchanger 3 will reduce the probability of detecting refrigerant leaks. This is because, if refrigerant leaks near the center of the heat exchanger 3, when the blower fan 2 is operating, the leaked refrigerant will be drawn into the airflow generated by the blower fan 2 and flow out of the housing 1 through the outlet 13 before it can travel through the drain pan 5 and reach the refrigerant leak detection sensors on the sides. Therefore, if the length of the heat exchanger 3 in the left-right direction exceeds 100 cm, it is desirable to install an additional refrigerant leak detection sensor near the center of the heat exchanger 3 in the left-right direction.
[0048] Figure 12 is an enlarged front view of the range of A2 in FIG. 3. In FIG. 12, the range H1 represents the height at which the blower fan 2 is located, similar to FIG. 7. As shown in FIG. 12, the second refrigerant leakage detection sensor 42 is disposed below the range H1 of the height at which the blower fan 2 is located in the vertical direction. While the first refrigerant leakage detection sensor 41 is disposed at the height of the range H1 where the blower fan 2 is located in the vertical direction, the second refrigerant leakage detection sensor 42 is disposed below the range H1. Thus, by providing the second refrigerant leakage detection sensor 42 at a different height position from the first refrigerant leakage detection sensor 41, refrigerant leakage can be detected at different heights inside the housing 1, and the refrigerant can be efficiently detected. Specifically, the refrigerant leaked from the heat exchanger 3 flows to the height position of the first refrigerant leakage detection sensor 41, and the refrigerant is sucked into the blower fan 2 and temporarily stays in the drain pan main body portion 5a. Further, a part of the refrigerant staying in the drain pan main body portion 5a reaches the right drain pan side end portion 5b connected to the drain hose 5e from the drain pan main body portion 5a and is detected by the second refrigerant leakage detection sensor 42. By disposing the second refrigerant leakage detection sensor 42 below the range H1 of the height at which the blower fan 2 is located, the refrigerant that has reached the right drain pan side end portion 5b along the drain pan 5 can be detected. Even when the first refrigerant leakage detection sensor 41 fails to detect the refrigerant, the second refrigerant leakage detection sensor 42 can detect the refrigerant that has reached the drain pan side end portion 5b, improving safety.
[0049] Furthermore, it is desirable that the second refrigerant leak detection sensor 42, located on the side where the pipe connection section 3h connecting the piping 3c of the heat exchanger body 3a to the external piping is located, be installed below the drain pan 5, in a vertical direction. Also, it is desirable that the first refrigerant leak detection sensor 41, located on the side where the pipe connection section 3h is not located, be installed above the drain pan 5, in a vertical direction. By positioning the first refrigerant leak detection sensor 41 above the drain pan 5, the leaked refrigerant enters the first refrigerant leak detection sensor 41 before it flows into the drain pan 5 and is blown into the room, thus enabling efficient detection of refrigerant leaks. Furthermore, the detected refrigerant flows downward and accumulates in the storage section 5d at the drain pan side end 5b, preventing it from being blown out all at once from the outlet 13 by the airflow of the blower fan 2. On the other hand, the right side of the heat exchanger 3 where the second refrigerant leak detection sensor 42 is installed is isolated from the airflow generated by the blower fan 2 by the right heat exchanger support member 32, because the pipe connection section 3h is located there. Therefore, refrigerant that leaks at the pipe connection section 3h and flows downwards, accumulating in the storage section 5d at the drain pan side end 5b, is not blown out of the outlet 13 by the airflow from the blower fan 2. For this reason, by installing the second refrigerant leak detection sensor 42 at the lowest point inside the housing 1, below the drain pan 5, downward-flowing refrigerant can be reliably detected.
[0050] As described above, the indoor unit 10 of this embodiment is an indoor unit 10 of an air conditioner 100 having a refrigerant circuit 70 through which a refrigerant circulates, and comprises a housing 1 having an intake port 12 formed at the top and an outlet port 13 formed at the bottom, a blower fan 2 provided inside the housing 1 that generates an airflow from the intake port 12 to the outlet port 13, a heat exchanger 3 provided inside the housing 1, at least a portion of which is positioned above the blower fan 2 and has piping 3c through which the refrigerant flows, and a first refrigerant leak detection sensor 41 provided inside the housing 1, between the end of the heat exchanger 3 and the side of the housing 1 in the left-right direction, and at the height where the blower fan 2 is located in the vertical direction.
[0051] As a result, refrigerant leaking from the heat exchanger 3 enters the interior of the folder 41d through the grid-like opening 41f before it can accumulate in the drain pan 5. Therefore, refrigerant leakage can be detected earlier than if the first refrigerant leak detection sensor 41 were installed below the range H1. In addition, by installing the first refrigerant leak detection sensor 41 at the height of the range H1 where the blower fan 2 is located, it prevents leaked refrigerant from flowing to the bottom of the housing 1 without entering the interior of the folder 41d through the grid-like opening 41f. Therefore, refrigerant leakage can be detected more efficiently than if the first refrigerant leak detection sensor 41 were installed above or below the height of the range H1 where the blower fan 2 is located.
[0052] Furthermore, the indoor unit 10 further includes a heat exchanger support member that supports the end of the heat exchanger 3 on the side where the first refrigerant leak detection sensor 41 is installed, and a drain pan 5 provided below the heat exchanger 3. The drain pan 5 extends into the space formed between the heat exchanger support member and the side surface of the housing 1. The first refrigerant leak detection sensor 41 is provided above the drain pan in the space formed between the heat exchanger support member and the side surface of the housing 1. As a result, leaked refrigerant enters the first refrigerant leak detection sensor 41 before it flows into the drain pan 5 and is blown into the room, thus enabling efficient detection of refrigerant leaks. In addition, since the refrigerant detected by the first refrigerant leak detection sensor 41 remains in the drain pan 5, it is possible to prevent it from being blown out all at once from the outlet 13 by the airflow of the blower fan 2.
[0053] Furthermore, the heat exchanger body 3a constituting the heat exchanger 3 includes a rear heat exchanger 3f located behind the blower fan 2, and the first refrigerant leak detection sensor 41 is positioned vertically below the lower end of the rear heat exchanger 3f. This allows the first refrigerant leak detection sensor 41 to detect refrigerant leakage from the rear heat exchanger 3f before it is drawn into the blower fan 2.
[0054] Furthermore, the heat exchanger 3 is located in front of the blower fan 2 and includes a front heat exchanger 3d that is bent at a bent portion 3e when viewed from the side. The first refrigerant leak detection sensor 41 is provided vertically below the bent portion 3e of the front heat exchanger 3d. This ensures that refrigerant leaking at the bent portion 3e can be reliably detected by the first refrigerant leak detection sensor 41.
[0055] Furthermore, the indoor unit 10 is further equipped with a second refrigerant leak detection sensor 42 located inside the housing 1, between the end of the heat exchanger 3 opposite to the side where the first refrigerant leak detection sensor 41 is located and the side of the housing 1. As a result, refrigerant leak detection sensors are installed on both sides of the heat exchanger 3, which is long in the left-right direction, making it possible to efficiently detect refrigerant leaks from the heat exchanger 3.
[0056] Furthermore, the longitudinal length of the heat exchanger 3 is 70 cm or more and 100 cm or less. This ensures that in an indoor unit 10 where a first refrigerant leak detection sensor 41 and a second refrigerant leak detection sensor 42 are installed on both sides of the heat exchanger 3, refrigerant leaks can be reliably detected anywhere in the heat exchanger 3.
[0057] Furthermore, if the refrigerant used in the air conditioner 100 is a flammable refrigerant, the safety of the indoor unit 10 is enhanced by installing a first refrigerant leak detection sensor 41 and a second refrigerant leak detection sensor 42 on both sides of the heat exchanger 3, which has a longitudinal length of 70 cm or more and 100 cm or less. If a flammable refrigerant leaks, safety must be ensured by reliably detecting the refrigerant leak inside the indoor unit 10 before it is blown into the room.
[0058] Furthermore, the second refrigerant leak detection sensor 42 is positioned below the height of the blower fan 2 in the vertical direction. By positioning the second refrigerant leak detection sensor 42 at a different height from the first refrigerant leak detection sensor 41 in this way, refrigerant leaks can be detected at different heights inside the housing 1, enabling efficient detection of refrigerant.
[0059] Furthermore, the indoor unit 10 is further equipped with a drain pan 5 located below the heat exchanger 3. The first refrigerant leak detection sensor 41 is located above the drain pan 5 in the vertical direction, and the second refrigerant leak detection sensor 42 is located between the end of the heat exchanger 3 on the side where the pipe connection portion 3h connecting the piping 3c of the heat exchanger 3 to the piping connected to the outside of the housing 1 is provided, and the side of the housing 1, and is located below the drain pan in the vertical direction. The area between the end of the heat exchanger 3 on the side where the pipe connection portion 3h is provided and the side of the housing 1 is isolated from the airflow generated by the blower fan 2 by the heat exchanger support member. Therefore, by installing the second refrigerant leak detection sensor 42 at the lowest point inside the housing 1, below the drain pan 5, it is possible to reliably detect refrigerant that flows downward without being sucked in by the airflow.
[0060] According to this disclosure, by installing the first refrigerant leak detection sensor at the height of the blower fan on the side of the heat exchanger, it is possible to provide an indoor unit of an air conditioner that can efficiently detect refrigerant leaks.
[0061] 1. Enclosure, 1a. Front panel, 1b. Top panel, 1c. Rear panel, 1d. Bottom panel, 1e. First side panel, 1f. Second side panel, 2. Blower fan, 2a. Impeller, 2b. Drive motor, 2c. Rotating shaft, 3. Heat exchanger, 3a. Heat exchanger body, 3b. Pipe connection section, 3c. Piping, 3d. Front heat exchanger, 3e. Bend section, 3f. Rear heat exchanger, 3g. Auxiliary heat exchanger, 3h. Pipe connection section, 5. Drain pan, 5a. Drain pan body, 5b. Drain pan side end, 5c. Storage section, 5d. Storage section, 5e. Drain hose, 5f. Underside of drain pan, 6. Rear drain pan, 7. Control unit, 10. Indoor unit, 12. Intake port, 13. Outlet port, 13a. Air direction vane, 31. Left side heat exchanger support member, 31a. Recessed part, 31b Front view, 32 Right side heat exchanger support member, 41 First refrigerant leak detection sensor, 41a Sensor part, 41b Circuit board, 41c Circuit board fixing part, 41d Folder, 41e Folder cover, 41f Lattice-shaped opening, 41g Foot part, 41h Case part, 41i Plate part, 41j Top view, 42 Second refrigerant leak detection sensor, 60 Outdoor unit, 61 Compressor, 62 Four-way valve, 63 Outdoor heat exchanger, 64 Expansion device, 65 Outdoor blower fan, 70 Refrigerant circuit, 100 Air conditioner.
Claims
1. An indoor unit of an air conditioner having a refrigerant circuit through which a refrigerant circulates, comprising: a housing having an intake port formed at the top and an outlet port formed at the bottom; a blower fan provided inside the housing that generates an airflow from the intake port to the outlet port; a heat exchanger provided inside the housing, at least a portion of which is positioned above the blower fan and having piping through which the refrigerant flows; and a first refrigerant leak detection sensor provided inside the housing, between the end of the heat exchanger and the side of the housing in the left-right direction, and at the height where the blower fan is located in the vertical direction.
2. An indoor unit of an air conditioner according to claim 1, further comprising: a heat exchanger support member that supports the end of the heat exchanger on the side where the first refrigerant leak detection sensor is provided; and a drain pan provided below the heat exchanger, wherein the drain pan extends to a space formed between the heat exchanger support member and the side surface of the housing, and the first refrigerant leak detection sensor is provided above the drain pan in the space.
3. The indoor unit of an air conditioner according to claim 1 or 2, wherein the heat exchanger comprises a rear heat exchanger located behind the blower fan, and the first refrigerant leak detection sensor is provided vertically below the lower end of the rear heat exchanger.
4. The indoor unit of an air conditioner according to any one of claims 1 to 3, wherein the heat exchanger is located in front of the blower fan and comprises a front heat exchanger that is bent at a bent portion when viewed from the side, and the first refrigerant leak detection sensor is provided vertically below the bent portion of the front heat exchanger.
5. The indoor unit of an air conditioner according to any one of claims 1 to 4, further comprising a second refrigerant leak detection sensor provided inside the housing, between the end of the heat exchanger opposite to the side on which the first refrigerant leak detection sensor is provided in the left-right direction and the side of the housing.
6. The indoor unit of the air conditioner according to claim 5, wherein the longitudinal length of the heat exchanger is 70 cm or more and 100 cm or less.
7. The indoor unit of an air conditioner according to claim 5 or 6, wherein the refrigerant is a flammable refrigerant.
8. The indoor unit of an air conditioner according to any one of claims 5 to 7, wherein the second refrigerant leak detection sensor is provided below the height at which the blower fan is located in the vertical direction.
9. The indoor unit of an air conditioner according to claim 2, further comprising a second refrigerant leak detection sensor provided inside the housing, between the end of the heat exchanger opposite to the side on which the first refrigerant leak detection sensor is provided in the left-right direction and the side surface of the housing, wherein the second refrigerant leak detection sensor is provided between the end on which a pipe connection portion connecting the piping of the heat exchanger to piping connected to the outside of the housing is provided and the side surface of the housing, and is located below the drain pan in the vertical direction.