WO2025187031A1 - Indoor unit and air conditioner - Google Patents

Abstract

Provided is an indoor unit of an air conditioner, said indoor unit comprising: a centrifugal fan which rotates about a center axis that extends in the vertical direction; a heat exchanger inside which a coolant flows, which extends in a peripheral direction with respect to the center axis, and which surrounds the centrifugal fan from the radially outer side of the center axis; a coolant sensor unit which has a sensor body that is capable of detecting the coolant and a sensor housing that accommodates the sensor body; a partition plate; and a housing which accommodates the centrifugal fan, the heat exchanger, the coolant sensor unit, and the partition plate. The heat exchanger has a pair of end parts which are positioned at either end thereof in the peripheral direction. The partition plate divides an internal space of the housing into a first space in which the centrifugal fan is disposed and a second space which is positioned to the radially outer side of the first space and in which the pair of end parts are disposed. An attachment hole is provided to the partition plate. The coolant sensor unit is disposed so as to pass through the attachment hole and span from the first space to the second space. The sensor housing has an inflow port which opens to the second space and through which the coolant flows into the sensor housing.

Description

Indoor units and air conditioners

This disclosure relates to indoor units and air conditioners.

Conventionally, air conditioners that use flammable refrigerants are known that have a refrigerant sensor unit attached to the indoor unit. Patent Document 1 discloses an indoor unit that has a drain pan that collects condensed water and a refrigerant sensor installed on the underside of the drain pan.

Japanese Patent Application Laid-Open No. 2021-014963

Generally, vaporized refrigerant (hereafter referred to as refrigerant gas) is heavier than air. If a refrigerant sensor is installed on the underside of the drain pan, the refrigerant sensor will detect refrigerant gas that leaks from the refrigerant circuit, accumulates in the drain pan, and then overflows from the drain pan. As a result, it takes time for the drain pan to fill with refrigerant gas, making it difficult to detect leaking refrigerant gas early on.

In light of the above circumstances, one of the objectives of this disclosure is to provide an indoor unit and an air conditioner that have a refrigerant sensor unit that can quickly detect refrigerant gas leaking from the refrigerant circuit.

One aspect of the indoor unit according to the present disclosure is an indoor unit for an air conditioner, comprising: a centrifugal fan that rotates around a central axis that extends in the vertical direction; a heat exchanger through which a refrigerant flows, extending circumferentially around the central axis and surrounding the centrifugal fan from the radial outside of the central axis; a refrigerant sensor unit having a sensor main body that can detect the refrigerant and a sensor housing that accommodates the sensor main body; a partition plate; and a housing that accommodates the centrifugal fan, the heat exchanger, the refrigerant sensor unit, and the partition plate, wherein the heat exchanger has a pair of ends located at both ends in the circumferential direction, and the partition plate divides the internal space of the housing into a first space in which the centrifugal fan is disposed and a second space that is located radially outside the first space and in which the pair of ends are disposed, the partition plate is provided with a mounting hole, and the refrigerant sensor unit is disposed so as to pass through the mounting hole and straddle the first space and the second space, and the sensor housing has an inlet that opens into the second space and allows the refrigerant to flow into the sensor housing.

One aspect of the air conditioner disclosed herein comprises the indoor unit described above, a refrigerant circuit connected to the heat exchanger and through which the refrigerant circulates, and an outdoor unit.

This disclosure provides an indoor unit and air conditioner equipped with a refrigerant sensor unit that can detect refrigerant gas early.

1 is a schematic diagram showing a general configuration of an air conditioner according to an embodiment. FIG. 2 is an exploded perspective view of the indoor unit according to the embodiment. FIG. 2 is a plan view of the indoor unit according to the embodiment. FIG. 2 is a partial perspective view of the indoor unit according to the embodiment. FIG. 2 is a perspective view of a partition plate and a refrigerant sensor unit according to the embodiment. FIG. 2 is an exploded perspective view of a partition plate, a refrigerant sensor unit, and a cover according to the embodiment. FIG. 2 is an exploded perspective view of a partition plate, a refrigerant sensor unit, and a cover according to the embodiment. FIG. 2 is a perspective view of a refrigerant sensor unit and a cover according to the embodiment. FIG. 2 is an exploded perspective view of the refrigerant sensor unit according to the embodiment.

Embodiments of the present disclosure will be described below with reference to the drawings. The drawings appropriately show a Z axis indicating the up-down direction. The side of the up-down direction toward which the arrow on the Z axis points (+Z side) is the upper side, and the side opposite to the side toward which the arrow on the Z axis points (-Z side) is the lower side. Note that the orientation of the indoor unit 10 relative to the up-down direction described in this embodiment is merely an example, and does not limit the assembly orientation of the indoor unit 10.

<Air conditioner>
Fig. 1 is a schematic diagram showing the general configuration of an air conditioner 100 according to the present embodiment. As shown in Fig. 1, the air conditioner 100 includes an indoor unit 10, an outdoor unit 20, and a refrigerant circuit 30. The indoor unit 10 is located indoors. The outdoor unit 20 is located outdoors. The indoor unit 10 and the outdoor unit 20 are connected to each other by the refrigerant circuit 30, through which a refrigerant 33 circulates. The indoor unit 10 and the outdoor unit 20 are heat exchange units that exchange heat with the air.

The air conditioner 100 is capable of adjusting the temperature of the indoor air by exchanging heat between the refrigerant 33 flowing through the refrigerant circuit 30 and the air in the room where the indoor unit 10 is located. Examples of the refrigerant 33 include fluorine-based refrigerants or hydrocarbon-based refrigerants with low global warming potential (GWP). Examples of the refrigerant 33 include a single refrigerant such as R1234yf, R1234ze, R32, or R290, or a mixture of two or more of these, or a mixture of any of these with another refrigerant. Examples of the refrigerant 33 include a mixed refrigerant containing R1132(E), or a mixed refrigerant containing R1123. Examples of refrigerant 33 include mixed refrigerants of R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

The outdoor unit 20 has a compressor 21, an outdoor heat exchanger 23, a flow control valve 24, a blower 25, and a four-way valve 22. The compressor 21, the outdoor heat exchanger 23, the flow control valve 24, and the four-way valve 22 are connected by a refrigerant circuit 30.

The four-way valve 22 is disposed in a portion of the refrigerant circuit 30 that is connected to the discharge side of the compressor 21. The four-way valve 22 switches a portion of the path of the refrigerant circuit 30, thereby reversing the direction of the refrigerant 33 flowing within the refrigerant circuit 30. When the path connected by the four-way valve 22 is the path shown by the solid line on the four-way valve 22 in Figure 1, the refrigerant 33 flows within the refrigerant circuit 30 in the direction shown by the solid arrow in Figure 1. On the other hand, when the path connected by the four-way valve 22 is the path shown by the dashed line on the four-way valve 22 in Figure 1, the refrigerant 33 flows within the refrigerant circuit 30 in the direction shown by the dashed arrow in Figure 1.

The indoor unit 10 has a centrifugal fan 40 and a heat exchanger 14 arranged around the centrifugal fan 40. The indoor unit 10 is capable of cooling operation, which cools the air in the room in which the indoor unit 10 is located, and heating operation, which warms the air in the room in which the indoor unit 10 is located.

When the indoor unit 10 is operating in cooling mode, the refrigerant 33 flowing through the refrigerant circuit 30 flows in the direction shown by the solid arrow in Figure 1. In other words, when the indoor unit 10 is operating in cooling mode, the refrigerant 33 flowing through the refrigerant circuit 30 circulates through the compressor 21, the outdoor heat exchanger 23 of the outdoor unit 20, the flow control valve 24, and the heat exchanger 14 of the indoor unit 10, in that order, before returning to the compressor 21. During cooling mode, the outdoor heat exchanger 23 in the outdoor unit 20 functions as a condenser, and the heat exchanger 14 in the indoor unit 10 functions as an evaporator.

On the other hand, when the indoor unit 10 is in heating operation, the refrigerant 33 flowing within the refrigerant circuit 30 flows in the direction shown by the dashed line in Figure 1. In other words, when the indoor unit 10 is in heating operation, the refrigerant 33 flowing within the refrigerant circuit 30 circulates through the compressor 21, the heat exchanger 14 of the indoor unit 10, the flow control valve 24, and the outdoor heat exchanger 23 of the outdoor unit 20, in that order, before returning to the compressor 21. During heating operation, the outdoor heat exchanger 23 in the outdoor unit 20 functions as an evaporator, and the heat exchanger 14 in the indoor unit 10 functions as a condenser.

<Indoor unit>
Next, the indoor unit 10 of this embodiment will be described in further detail.
Fig. 2 is an exploded perspective view of the indoor unit 10. Fig. 3 is a plan view of the indoor unit 10 as viewed from below. Note that in Fig. 3, some components of the indoor unit 10 (drain pan 41, bell mouth 42, control unit 43, decorative panel 44, and grill 45) are omitted from the illustration.

As shown in FIG. 2, the indoor unit 10 has a centrifugal fan 40 centered on a central axis R. In this embodiment, the direction in which the central axis R extends is the up-down direction. In the following description, the axial direction of the central axis R, i.e., the direction parallel to the Z-axis, may be simply referred to as the "axial direction," the radial direction centered on the central axis R may be simply referred to as the "radial direction," and the circumferential direction centered on the central axis R may be simply referred to as the "circumferential direction." Furthermore, in the following description, "radially outer" refers to the side in the radial direction that is away from the central axis R, and "radially inner" refers to the side in the radial direction that is opposite the radially outer side and approaches the central axis R.

The indoor unit 10 of this embodiment is a ceiling-mounted indoor unit that is installed by being embedded in the ceiling. In addition to the centrifugal fan 40 and heat exchanger 14 described above, the indoor unit 10 also includes a housing 11, a refrigerant sensor unit 50, a partition plate 90, a cover 80, a drain pan 41, a bell mouth 42, a control unit 43, a decorative panel 44, and a grill 45.

<Case>
The housing 11 covers the centrifugal fan 40, heat exchanger 14, refrigerant sensor unit 50, partition plate 90, and cover 80 from above and from the horizontal sides. The housing 11 is fixed by a hanger to the ceiling space of the building in which the indoor unit 10 is installed. The fan motor of the centrifugal fan 40 and a drain pan 41 are fixed to the housing 11.

As shown in FIG. 3 , a first space A1, a second space A2, and a third space A3 are provided inside the housing 11. The first space A1, the second space A2, and the third space A3 are located above the drain pan 41. The first space A1 is located in the center in the radial direction when viewing the indoor unit 10 from below. The second space A2 and the third space A3 surround the first space A1 from the radial outside. The centrifugal fan 40 is located in the first space A1. The pair of ends 14a, 14b and the connecting pipe 14c of the heat exchanger 14 are located in the second space A2. The main body of the heat exchanger 14 is located in the third space A3. The third space A3 extends circumferentially and surrounds the first space A1 from the radial outside. The second space A2 is formed in the portion where the third space A3 is discontinued in the circumferential direction.

<Drain pan>
As shown in FIG. 2 , the drain pan 41 is located below the heat exchanger 14. The drain pan 41 has a rectangular frame shape when viewed axially (i.e., vertically). The drain pan 41 is located below the heat exchanger 14, the refrigerant sensor unit 50, the partition plate 90, and the cover 80. The drain pan 41 is provided with a central opening 41h and an outlet 41a. The central opening 41h and the outlet 41a penetrate the drain pan 41 in the vertical direction Z. The central opening 41h is substantially circular and centered on the central axis R. The central opening 41h is located below the centrifugal fan 40. The outlet 41a is located radially outward from the heat exchanger 14 when viewed axially. The outlet 41a blows air that has passed through the heat exchanger 14 downward. The drain pan 41 collects condensation water generated during heat exchange by the heat exchanger 14.

<Bellmouth>
The bell mouth 42 is fixed to the drain pan 41. The bell mouth 42 is disposed below the centrifugal fan 40. The bell mouth 42 is provided with an intake port 42a. The intake port 42a is substantially circular and has its center on the central axis R. The intake port 42a overlaps with a central opening 41h of the drain pan 41 when viewed in the axial direction.

<Control unit>
The control unit 43 is fixed to the underside of the bell mouth 42. The control unit 43 has a control board (not shown) that controls each part of the indoor unit 10. The control unit 43 controls the components necessary for the air conditioner 100 to perform heating and cooling operations.

<Decorative panel>
The decorative panel 44 is fixed to the underside of the drain pan 41. The decorative panel 44 is formed in a frame shape so as to expose the suction port 42a of the bell mouth 42. A grill 45 is fixed to the decorative panel 44. The grill 45 is disposed below the suction port 42a and faces the suction port 42a.

<Centrifugal fan>
The centrifugal fan 40 rotates about a central axis R. The centrifugal fan 40 blows air drawn in through an air inlet 42a radially outward from the central axis R. The heat exchanger 14 is disposed radially outward from the centrifugal fan 40. The centrifugal fan 40 has an impeller 40a and a fan motor (not shown) that rotates the impeller 40a.

<Heat exchanger>
As shown in FIG. 3 , the heat exchanger 14 extends in the circumferential direction. The heat exchanger 14 surrounds the centrifugal fan from the radially outer side. The heat exchanger 14 has a pair of end portions 14a, 14b located at both ends in the circumferential direction. The heat exchanger 14 has a heat transfer tube that extends back and forth between the pair of end portions 14a, 14b multiple times and a plurality of fins arranged in a direction perpendicular to the extension direction of the heat transfer tube. A pair of connecting pipes 14c is connected to one end portion 14a of the heat exchanger 14. The pair of connecting pipes 14c are connected to the refrigerant circuit 30. A refrigerant flows inside the heat transfer tubes of the heat exchanger 14. The heat exchanger 14 exchanges heat between the air sent from the centrifugal fan 40 and the refrigerant.

<Divider>
The partition plate 90 is made of a resin material and has a plate shape extending along a plane perpendicular to the radial direction. The partition plate 90 is located radially outward of the centrifugal fan 40. The partition plate 90 is also located radially inward of the pair of ends 14 a, 14 b of the heat exchanger 14.

The internal space of the housing 11 is divided by a partition plate 90 into a first space A1 located radially inside the partition plate 90 and a second space A2 located radially outside the partition plate 90. A centrifugal fan 40 is disposed in the first space A1. A pair of ends 14a, 14b of the heat exchanger 14 are disposed in the second space A2.

Figure 4 is a partial perspective view of the indoor unit 10 near the partition plate 90. Figure 5 is a perspective view of the partition plate 90 and refrigerant sensor unit 50 as viewed from the second space A2 side. Figures 6 and 7 are exploded perspective views of the partition plate 90, refrigerant sensor unit 50, and cover 80. Figure 8 is a perspective view of the refrigerant sensor unit 50 and cover 80. Arrows indicating the radial direction D are shown in each figure as necessary. In each figure, the direction in which the tip of the arrow in the radial direction D points represents the radially outward direction (+D), and the opposite side represents the radially inward direction (-D).

As shown in FIG. 4, the partition plate 90 has a partition plate main body 91, a first fixing portion 92, and a second fixing portion 93. The partition plate main body 91 is plate-shaped. The first fixing portion 92 is provided at one circumferential end of the partition plate main body 91, and the second fixing portion 93 is provided at the other circumferential end of the partition plate main body 91. The first fixing portion 92 is screwed to the other circumferential end 14b of the heat exchanger 14. The second fixing portion 93 is screwed to the one circumferential end 14a of the heat exchanger 14. The screws fastening the first fixing portion 92 and the second fixing portion 93 to the heat exchanger 14 are screwed into the heat exchanger 14 from below. In other words, the partition plate 90 is fixed to the pair of ends 14a, 14b of the heat exchanger 14 at the first fixing portion 92 and the second fixing portion 93.

As shown in Figure 3, the partition plate 90 entirely overlaps the drain pan 41 when viewed from below (-Z). Therefore, the first fixing portion 92 and the second fixing portion 93 overlap the drain pan 41 when viewed from below. Therefore, in order to remove the partition plate 90 from the heat exchanger 14, it is necessary to remove the drain pan 41.

As shown in FIG. 6, the partition plate main body 91 has a convex portion 91d that protrudes radially inward (-D) (i.e., toward the first space A1), and a concave portion 91g that is located below (-Z) the convex portion 91d and is recessed radially outward (+D) relative to the convex portion 91d. The refrigerant sensor unit 50 is disposed in the concave portion 91g. The concave portion 91g is also covered by the cover 80. That is, the refrigerant sensor unit 50 and the cover 80 are attached to the partition plate 90.

The convex portion 91d has a partition plate flow straightening surface 91f and a partition plate side surface 91m. The partition plate flow straightening surface 91f and the partition plate side surface 91m face the first space A1. In this embodiment, the partition plate flow straightening surface 91f and the partition plate side surface 91m are each flat surfaces. The partition plate flow straightening surface 91f and the partition plate side surface 91m may each be curved surfaces. The partition plate flow straightening surface 91f and the partition plate side surface 91m are arranged side by side in the circumferential direction. The boundary between the partition plate flow straightening surface 91f and the partition plate side surface 91m extends linearly in the vertical direction Z. The partition plate flow straightening surface 91f and the partition plate side surface 91m are arranged so that the boundary is convex radially inward (-D).

Here, the direction in which the centrifugal fan 40 shown in Figure 3 rotates around the central axis R is referred to as the forward rotational direction (+θ), and the opposite side is referred to as the backward rotational direction (-θ). Figures 3 and 4 show an arrow representing the rotational direction θ. The forward rotational direction (+θ) is the direction toward which the tip of the arrow indicating the rotational direction θ points, and the other side of the rotational direction (-θ) is the opposite side. In this embodiment, the forward rotational direction (+θ) is the counterclockwise direction when viewing the indoor unit 10 from below.

As shown in Figure 3, in this embodiment, the partition plate flow straightening surface 91f and the partition plate side surface 91m are aligned in this order on the forward side (+θ) in the direction of rotation. In other words, the partition plate side surface 91m is located on the forward side (+θ) in the direction of rotation relative to the partition plate flow straightening surface 91f. The partition plate flow straightening surface 91f extends in the radial direction. On the other hand, the partition plate flow straightening surface 91f extends at an angle toward the forward side (+θ) in the direction of rotation as it extends radially outward (+D).

As shown in FIG. 7, the recessed portion 91g has a first plate portion 91e and a second plate portion 91h. The first plate portion 91e extends along a plane perpendicular to the up-down direction Z. The second plate portion 91h extends downward from the radially outer (+D) end of the first plate portion 91e. The second plate portion 91h extends along a plane perpendicular to the radial direction D.

Furthermore, the recessed portion 91g is provided with a first mounting hole 91a (mounting hole), a second mounting hole 91b, and a third mounting hole 91c. The first mounting hole 91a, the second mounting hole 91b, and the third mounting hole 91c penetrate the partition plate main body 91. The first mounting hole 91a and the second mounting hole 91b are provided in the second plate portion 91h. The first mounting hole 91a and the second mounting hole 91b penetrate the second plate portion 91h in the radial direction D. The second mounting hole 91b is located below the first mounting hole 91a.

The third mounting hole 91c is provided so as to straddle the corner between the first plate portion 91e and the second plate portion 91h. The third mounting hole 91c penetrates the first plate portion 91e in the vertical direction and penetrates the second plate portion 91h in the radial direction D. The third mounting hole 91c is located above the first mounting hole 91a and the second mounting hole 91b.

As shown in Figure 6, one upper claw 91k and two lower claws 91j are provided on the surface of the recessed portion 91g facing radially inward (-D). The one upper claw 91k and two lower claws 91j are located below the first mounting hole 91a. The upper claw 91k is located above the second mounting hole 91b, and the two lower claws 91j are located below the second mounting hole 91b. One of the two lower claws is located on one circumferential side of the upper claw 91k, and the other is located on the other circumferential side of the upper claw 91k.

The upper claw portion 91k has a leaf spring portion 91ka that protrudes radially inward (-D) and a convex portion 91kb that is located at the tip of the leaf spring portion on the radially inward (-D) side and protrudes downward. The two lower claw portions 91j are arranged side by side in the circumferential direction. Each of the two lower claw portions 91j has a convex portion 91jb that protrudes upward.

A metal fastened member 99 is attached to the partition plate 90. The fastened member 99 is a roughly rectangular plate extending along a plane perpendicular to the radial direction D. The fastened member 99 is supported by one upper claw 91k and two lower claws 91j. Therefore, the fastened member 99 is located on the radially inner (-D) side of the partition plate 90. The fastened member 99 covers the second mounting hole 91b from the radially inner (-D) side. The fastened member 99 has a screw hole 99h that penetrates in the radial direction D. A fixing screw 89 that fastens the cover 80 and refrigerant sensor unit 50 to the partition plate 90 is screwed into the screw hole 99h. The tip of the fixing screw 89 is positioned inside the second mounting hole 91b.

The fastened member 99 has an upper edge 99a and a lower edge 99b. The upper edge 99a and the lower edge 99b extend linearly in a direction perpendicular to the vertical direction. A worker assembling the indoor unit 10 first hooks the lower edge 99b of the fastened member 99 onto the convex portions 91jb of the two lower claws 91j. The worker then pushes the plate surface of the fastened member 99 radially outward (+D) to press the upper edge 99a against the convex portions 91kb. This causes the leaf spring portion 91ka of the upper claw portion 91k to elastically deform upward, causing the upper edge 99a to overcome the convex portions 91kb. Finally, the upper edge 99a hooks onto the convex portions 91kb of the upper claw portion 91k, and the fastened member 99 is fixed to the partition plate 90.

<Refrigerant sensor unit>
Figure 9 is an exploded perspective view of the refrigerant sensor unit 50. The refrigerant sensor unit 50 has a sensor main body 59 capable of detecting refrigerant and a sensor housing 55 that houses the sensor main body 59. The sensor housing 55 is provided with an accommodation space B that houses the sensor main body 59 and an inlet 55a that introduces refrigerant gas into the accommodation space B. Although not shown in Figure 9, a wire 58 (see Figure 8) extends from the sensor main body 59. The wire 58 is drawn to the outside of the sensor housing 55 through a first drawing hole 51h formed in the sensor housing 55.

The sensor main body 59 has a substrate 59b, a sensor element 59a, and an element case 59d. The substrate 59b is fixed to the inner surface of the sensor housing 55. Multiple elements, including the sensor element 59a, are mounted on the substrate 59b. The sensor element 59a detects vaporized refrigerant gas. The sensor element 59a is surrounded and protected by the element case 59d. A cylindrical member 59e is attached to the element case 59d. The cylindrical member 59e is a sponge-like member made of a resin material. The cylindrical member 59e has a cylindrical shape that surrounds the outer surface of the element case 59d. The cylindrical member 59e has a rectangular parallelepiped outer shape. The cylindrical member 59e contacts the inner surface of the sensor housing 55. The cylindrical member 59e forms a path in the storage space B for the refrigerant gas to reach the sensor element 59a.

The sensor housing 55 has a housing body 51 and a lid body 52. The housing body 51 and the lid body 52 face each other in the radial direction D. The housing body 51 is box-shaped with an internal storage space B. The housing body 51 is open in one direction. The opening of the housing body is covered by the lid body 52. The housing body 51 has a bottom 51b facing the lid body 52. The inlet 55a is provided in the bottom 51b.

A fixed piece 53 and a guide hook 56 are provided on the outer surface of the housing main body 51. The fixed piece 53 and guide hook 56 protrude downward (-Z) from the outer surface of the housing main body 51. The fixed piece 53 is plate-shaped and extends along a plane perpendicular to the radial direction D. The guide hook 56 is formed in a C-shape that opens radially inward (-D). The guide hook 56 guides the wiring 58 (see Figure 8).

A leaf spring portion 54 is provided on the outer surface of the lid body 52. The leaf spring portion 54 is provided at the upper end of the outer surface of the lid body 52. The leaf spring portion 54 is formed in a U-shape that extends in the radial direction D and then folds back. The leaf spring portion 54 is elastically deformable in the vertical direction Z. A claw portion 54a that protrudes upward is provided at the upper end of the leaf spring portion 54.

As shown in FIG. 5, the refrigerant sensor unit 50 is attached to the partition plate 90 and positioned so that it passes through the first mounting hole 91a of the partition plate 90. In other words, the refrigerant sensor unit 50 is positioned across the first space A1 and the second space A2.

A portion of the sensor housing 55 protrudes into the second space A2. An inlet 55a is provided on the outer surface of the sensor housing 55, in the portion exposed to the second space A2 through the first mounting hole 91a. Therefore, the inlet 55a of the sensor housing 55 opens into the second space A2.

As shown in FIG. 3, the second space A2 is occupied by the pair of ends 14a, 14b of the heat exchanger 14 and the connecting pipe 14c connected to one end 14a. Generally, the pair of ends 14a, 14b, and the connecting pipe 14c of the heat exchanger 14 are more likely to experience refrigerant leakage than other locations. According to this embodiment, by opening the inlet 55a of the refrigerant sensor unit 50 to the second space A2 where the pair of ends 14a, 14b, and the connecting pipe 14c of the heat exchanger 14 are located, refrigerant gas leaking from the heat exchanger 14 can be easily detected immediately by the refrigerant sensor unit 50.

In addition, in this embodiment, the second space A2 is located above the drain pan 41. If refrigerant leaks from the refrigerant circuit 30, which includes the heat exchanger 14, the refrigerant vaporizes and becomes refrigerant gas. Refrigerant gas is heavier than air and therefore accumulates above the drain pan 41. According to this embodiment, by positioning the inlet 55a of the refrigerant sensor unit 50 in the second space A2, refrigerant gas accumulating above the drain pan 41 can be immediately detected.

<Cover>
6, the cover 80 is fixed to the partition plate 90 from the first space A1 side. When attached to the partition plate 90, the cover 80 covers the recessed portion 91g of the partition plate 90. The cover 80 also covers the refrigerant sensor unit 50 from the radially inner side (-D) of the refrigerant sensor unit 50. That is, the cover 80 and the partition plate 90 accommodate the refrigerant sensor unit 50 between the surface of the cover 80 facing radially outward (+D) and the recessed portion 91g.

The cover 80 covers the first mounting hole 91a, the second mounting hole 91b, and the third mounting hole 91c of the partition plate 90. According to this embodiment, the wind generated by the rotation of the centrifugal fan 40 can be prevented from flowing from the first space A1 into the second space A2 via the first mounting hole 91a, the second mounting hole 91b, and the third mounting hole 91c. This allows the wind generated by the centrifugal fan 40 to efficiently pass through the heat exchanger 14. Furthermore, this prevents the wind generated by the centrifugal fan 40 from disrupting the air flow in the second space A2. This makes it less likely that the wind generated by the centrifugal fan 40 will obstruct the flow of refrigerant gas accumulating in the second space A2 from below into the inlet 55a of the refrigerant sensor unit 50.

The cover 80 has a cover body 81, an upper plate portion 83, and a pair of locking hooks 82. In this embodiment, the cover body 81 is plate-shaped. The cover body 81 has a rectifying surface 81f, a cover side surface 81m, and a cover undersurface 81c. The rectifying surface 81f, the cover side surface 81m, and the cover undersurface 81c face the first space A1. In this embodiment, the rectifying surface 81f, the cover side surface 81m, and the cover undersurface 81c are each flat surfaces. The rectifying surface 81f, the cover side surface 81m, and the cover undersurface 81c may each be curved surfaces.

The flow straightening surface 81f and the cover side surface 81m are arranged side by side in the circumferential direction. The boundary between the flow straightening surface 81f and the cover side surface 81m extends linearly in the vertical direction Z. The flow straightening surface 81f and the cover side surface 81m are arranged so that the boundary is convex radially inward (-D).

As shown in Figure 3, in this embodiment, the flow straightening surface 81f and the cover side surface 81m are aligned in this order toward the forward side (+θ) in the direction of rotation. In other words, the cover side surface 81m is located toward the forward side (+θ) in the direction of rotation relative to the flow straightening surface 81f. The flow straightening surface 81f extends in the radial direction. On the other hand, the flow straightening surface 81f extends at an angle toward the forward side (+θ) in the direction of rotation as it moves radially outward (+D).

As shown in Figure 4, when the cover 80 is attached to the partition plate 90, the flow straightening surface 81f is continuous with the partition plate flow straightening surface 91f, and the cover side surface 81m is continuous with the partition plate side surface 91m. In other words, the flow straightening surface 81f and the partition plate flow straightening surface 91f are surfaces that are arranged on the same plane, and the cover side surface 81m and the partition plate side surface 91m are surfaces that are arranged on the same plane.

In this embodiment, the flow straightening surface 81f and the partition plate flow straightening surface 91f both extend in the axial direction (i.e., the up-down direction Z). The flow straightening surface 81f and the partition plate flow straightening surface 91f face backward (-θ) in the direction of rotation of the centrifugal fan 40. As the centrifugal fan 40 rotates, air flows forward (+θ) in the direction of rotation around the centrifugal fan 40. Therefore, the flow straightening surface 81f and the partition plate flow straightening surface 91f face the air being sent in the circumferential direction by the centrifugal fan 40. The air being sent in the circumferential direction by the centrifugal fan 40 hits the flow straightening surface 81f and the partition plate flow straightening surface 91f, changing its flow direction axially and radially outward (+D), and is then guided to the heat exchanger 14 and the air outlet 41a (see Figure 2).

As shown in FIG. 7, the cover body 81 of this embodiment is provided with an insertion hole 81a and a first through hole 81b. The insertion hole 81a and the first through hole 81b are located near the lower end of the cover body 81. The insertion hole 81a and the first through hole 81b are arranged side by side in the vertical direction. The insertion hole 81a is located above the first through hole 81b. The insertion hole 81a penetrates the cover body 81 in the vertical direction. The fixing piece 53 of the refrigerant sensor unit 50 is inserted into the insertion hole 81a. As a result, the fixing piece 53 is positioned radially inward (-D) of the cover 80 and exposed to the first space A1. The first through hole 81b penetrates the cover body 81 in the radial direction D. When the fixing piece 53 is inserted into the insertion hole 81a, the first through hole 81b overlaps with the second through hole 53h provided in the fixing piece 53. Fixing screws 89 (see Figure 6) that are fastened to the fastening member 99 of the partition plate 90 are inserted into the first through-hole 81b and the second through-hole 53h.

As shown in Figure 7, the upper plate portion 83 of the cover 80 extends along a plane perpendicular to the vertical direction Z. When the cover 80 is attached to the partition plate 90, the upper plate portion 83 is located below the first plate portion 91e of the partition plate 90. A locking hole 80h is provided in the upper plate portion 83. The locking hole 80h passes through the upper plate portion 83 in the vertical direction. The locking hole 80h is an elongated hole extending in a direction perpendicular to the radial direction. The claw portion 54a provided on the leaf spring portion 54 of the refrigerant sensor unit 50 is engaged in the locking hole 80h.

The pair of locking hooks 82 of the cover 80 extend upward from the radially outer (+D) end of the upper plate portion 83. The pair of locking hooks 82 are arranged side by side in a direction perpendicular to both the radial direction D and the up-down direction Z. The tip of the locking hook 82 is provided with a locking protrusion 82a that protrudes radially outward (+D). As shown in Figure 5, when the cover 80 is attached to the partition plate 90, the locking hook 82 is inserted into the third mounting hole 91c of the partition plate 90. The locking protrusion 82a is engaged with the edge portion 91ca of the third mounting hole 91c facing radially outward (+D).

<Wiring>
As shown in FIG. 8 , the refrigerant sensor unit 50 has wiring 58. The wiring 58 is drawn from the interior to the exterior of the sensor housing 55 through the first drawing hole 51h. The wiring 58 extends along the lower end of the sensor housing 55 on the radially outer side (+D) of the sensor housing 55. The wiring 58 is hooked onto the guide hook 56 of the sensor housing 55 and drawn to the exterior of the cover 80 through the second drawing hole 80t provided in the cover 80. As shown in FIG. 4 , the wiring 58 drawn from the cover 80 extends downward. The wiring 58 is connected to the control unit 43 shown in FIG. 2 . The control unit 43 determines the presence or absence of a refrigerant leak based on the refrigerant gas detection result of the refrigerant sensor unit 50.

<Installation procedure>
Next, a procedure for attaching the refrigerant sensor unit 50 and the cover 80 to the partition plate 90 will be described. Note that the procedure for removing the refrigerant sensor unit 50 and the cover 80 from the partition plate 90 can be performed in the reverse order of the attachment procedure described below.

As shown in Figure 8, the worker installing the refrigerant sensor unit 50 first attaches the refrigerant sensor unit 50 to the cover 80. As shown in Figure 7, the worker inserts the fixing piece 53 of the refrigerant sensor unit 50 into the insertion hole 81a of the cover 80 from above. The worker then presses the sensor housing 55 of the refrigerant sensor unit 50 against the cover 80. The leaf spring portion 54 of the refrigerant sensor unit 50 elastically deforms, and the claw portion 54a engages with the engagement hole 80h of the cover 80. This secures the refrigerant sensor unit 50 to the cover 80.

Next, the worker attaches the cover 80, with the refrigerant sensor unit 50 attached, to the partition plate 90. A fastening member 99 has already been attached to the partition plate 90. As shown in FIG. 7, the locking hook 82 of the cover 80 protrudes upward. As shown in FIG. 5, the worker inserts the locking hook 82 into the third mounting hole 91c of the partition plate 90 and engages the locking protrusion 82a of the locking hook 82 with the edge portion 91ca of the third mounting hole 91c. Furthermore, as shown in FIG. 6, the worker inserts the fixing screw 89 into the second through hole 53h and the first through hole 81b from the radially inner side (-D) and tightens it into the screw hole 99h. This secures the cover 80 to the partition plate 90. The fixing piece 53 of the refrigerant sensor unit 50 is clamped between the cover 80 and the fastening member 99.

The refrigerant sensor unit 50 of this embodiment can be replaced or maintained by performing the above-mentioned installation procedure and the removal procedure in the reverse order. The installation and removal procedures of this embodiment are preferably performed after the impeller 40a of the centrifugal fan 40 (see Figure 2) has been removed from the housing 11. Furthermore, the installation and removal procedures of this embodiment can be performed without removing the refrigerant sensor unit 50 and components such as the drain pan 41, bell mouth 42, and decorative panel 44 located below the partition plate 90.

<Summary>
As shown in FIG. 2 , the indoor unit 10 of this embodiment includes a centrifugal fan 40, a heat exchanger 14, a refrigerant sensor unit 50, a partition plate 90, and a housing 11. The centrifugal fan 40 rotates about a central axis R extending in the vertical direction Z. Refrigerant flows through the heat exchanger 14. The heat exchanger 14 extends circumferentially about the central axis R. The heat exchanger 14 surrounds the centrifugal fan 40 from the radially outer side of the central axis R. As shown in FIG. 9 , the refrigerant sensor unit 50 includes a sensor main body 59 capable of detecting refrigerant and a sensor housing 55 that houses the sensor main body 59. As shown in FIG. 3 , the housing 11 houses the centrifugal fan 40, the heat exchanger 14, the refrigerant sensor unit 50, and the partition plate 90. The heat exchanger 14 has a pair of end portions 14a, 14b located at both ends in the circumferential direction. The partition plate 90 divides the interior space of the housing 11 into a first space A1 in which the centrifugal fan 40 is disposed and a second space A2 located radially outward of the first space A1 in which the pair of ends 14a, 14b are disposed. As shown in FIG. 5 , a first mounting hole 91a is formed in the partition plate 90. The refrigerant sensor unit 50 is disposed through the first mounting hole 91a and straddles the first space A1 and the second space A2. The sensor housing 55 has an inlet 55a that opens to the second space A2 and allows refrigerant to flow into the sensor housing 55.

With this configuration, by opening the inlet 55a of the refrigerant sensor unit 50 to the second space A2, where the pair of ends 14a, 14b of the heat exchanger 14 and the connecting pipe 14c are located, the refrigerant sensor unit 50 can easily immediately detect refrigerant gas leaking from the refrigerant circuit 30, including the heat exchanger 14. In other words, the indoor unit 10 of this embodiment can quickly detect refrigerant gas leaking from the refrigerant circuit 30, including the heat exchanger 14. Furthermore, with this configuration, the refrigerant sensor unit 50 passes through the first mounting hole 91a and is positioned across the first space A1 and the second space A2. Therefore, while the inlet 55a is positioned in the second space A2, the refrigerant sensor unit 50 can be attached or detached from the first space A1 side, simplifying the attachment and detachment process.

As shown in FIG. 6, the indoor unit 10 of this embodiment includes a cover 80 that covers the first mounting hole 91a and the refrigerant sensor unit 50 from the first space A1 side. This configuration prevents air blown by the centrifugal fan 40 that does not pass through the heat exchanger 14 from escaping through the gap between the refrigerant sensor unit 50 and the inner edge of the first mounting hole 91a of the partition plate 90.

In the indoor unit 10 of this embodiment, the refrigerant sensor unit 50 is fixed to the cover 80. The cover 80 is fixed to the partition plate 90. According to this embodiment, by removing the cover 80 from the partition plate 90, the refrigerant sensor unit 50 can be simultaneously detached from the partition plate 90. This makes it easier to detach the refrigerant sensor unit 50 from the partition plate 90 compared to when the cover 80 and the refrigerant sensor unit 50 are each fixed to the partition plate 90. The indoor unit 10 of this embodiment is mainly installed in the attic space. Therefore, the refrigerant sensor unit 50 is removed at a high altitude using a stepladder or the like. According to this embodiment, removal work performed at a high altitude can be simplified, and work safety can be increased. Similarly, when installing the refrigerant sensor unit 50, work performed at a high altitude can be simplified, and work safety can be increased. In this embodiment, the refrigerant sensor unit 50 is fixed to the cover 80 by inserting the fixing piece 53 of the sensor housing 55 into the insertion hole 81a of the cover 80 from above and engaging the claw portion 54a of the sensor housing 55 with the engaging hole 80h of the cover 80.

In the indoor unit 10 of this embodiment, the cover 80 is fixed to the partition plate 90 with screws from the radially inner side. This configuration makes it possible to attach and remove the refrigerant sensor unit 50 from the radially inner side. As a result, when attaching and removing the refrigerant sensor unit 50, it is not necessary to remove components located below the refrigerant sensor unit 50 (e.g., the drain pan 41, bell mouth 42, and decorative panel 44), making it easier to attach and remove the refrigerant sensor unit 50.

The indoor unit 10 of this embodiment includes a metal fastening member 99 that is fixed to the partition plate 90 and has a screw hole 99h formed therein, and a fixing screw 89 that is screwed into the screw hole 99h. The cover 80 has a first through hole 81b into which the fixing screw 89 is inserted, and is fixed to the fastening member 99 by the fixing screw 89. Generally, when forming screw holes in a resin material, it is difficult to increase the fastening force of the screw to avoid damaging the resin material and crushing the screw hole. According to this embodiment, the metal fastening member 99 is fixed to the partition plate 90, and the cover 80 is fastened to the fastening member 99, so resin can be selected as the material for the partition plate 90. This makes it possible to reduce the weight of the partition plate 90.

In the indoor unit 10 of this embodiment, a fixing piece 53 is provided on the outer surface of the sensor housing 55. An insertion hole 81a is provided in the cover 80, into which the fixing piece 53 is inserted. The fixing piece 53 has a second through hole 53h that overlaps with the first through hole 81b from the first space A1 side when inserted into the insertion hole 81a. A fixing screw 89 is inserted into the second through hole 53h and the first through hole 81b and tightened into the screw hole 99h. With this configuration, tightening the fixing screw 89 firmly secures the refrigerant sensor unit 50 to the cover 80, and secures the cover 80 to the partition plate 90. In other words, the refrigerant sensor unit 50 and cover 80 can be firmly secured to the partition plate 90 without increasing the number of fastening steps, thereby suppressing vibration and noise in the indoor unit 10.

The cover 80 has a straightening surface 81f facing the first space A1. The straightening surface 81f faces the air sent in the circumferential direction by the centrifugal fan 40 and extends in the vertical direction. With this configuration, the air sent in the circumferential direction by the centrifugal fan 40 hits the straightening surface 81f, changing the air flow direction vertically (i.e., axially) and radially outward, and can be guided to the heat exchanger 14. This allows the air sent in the circumferential direction by the centrifugal fan 40 to be sent smoothly to the heat exchanger 14.

Although the embodiments of this disclosure have been described above, this disclosure is not limited to the configurations of the above-described embodiments, and the following configurations and methods may also be employed. Furthermore, the configurations and methods described in this specification may be combined as appropriate within the scope of not being mutually inconsistent.

10...Indoor unit, 11...Housing, 14...Heat exchanger, 14a, 14b...End portion, 20...Outdoor unit, 30...Refrigerant circuit, 33...Refrigerant, 40...Centrifugal fan, 50...Refrigerant sensor unit, 53...Fixing piece, 53h...Second through-hole, 55...Sensor housing, 55a...Inlet, 59...Sensor body, 80...Cover, 81a...Insertion hole, 81b...First through-hole, 81f...Flow straightening surface, 89...Fixing screw, 90...Partition plate, 99...Member to be fastened, 99h...Threaded hole, 100...Air conditioner, A1...First space, A2...Second space, D...Radial direction, R...Central axis, Z...Up-down direction

Claims (8)

An indoor unit of an air conditioner,
a centrifugal fan that rotates around a central axis that extends in the vertical direction;
a heat exchanger through which a refrigerant flows, the heat exchanger extending in a circumferential direction of the central axis and surrounding the centrifugal fan from a radially outer side of the central axis;
a refrigerant sensor unit having a sensor body capable of detecting the refrigerant and a sensor housing that accommodates the sensor body;
A partition board and
a housing that houses the centrifugal fan, the heat exchanger, the refrigerant sensor unit, and the partition plate,
The heat exchanger has a pair of ends located at both ends in the circumferential direction,
the partition plate divides an internal space of the housing into a first space in which the centrifugal fan is disposed and a second space located radially outward of the first space in which the pair of end portions are disposed,
The partition plate is provided with a mounting hole,
the refrigerant sensor unit is disposed across the first space and the second space, passing through the mounting hole;
the sensor housing has an inlet opening that opens to the second space and allows the refrigerant to flow into the sensor housing.
Indoor unit. a cover that covers the mounting hole and the refrigerant sensor unit from the first space side;
The indoor unit according to claim 1. The refrigerant sensor unit is fixed to the cover,
The cover is fixed to the partition plate.
The indoor unit according to claim 2. The cover is fixed to the partition plate from the radially inner side with screws.
The indoor unit according to claim 2 or 3. a metal fastening member fixed to the partition plate and having a screw hole;
a fixing screw that is fastened into the screw hole,
the cover has a first through hole into which the fixing screw is inserted, and is fixed to the fastened member by the fixing screw;
The indoor unit according to claim 4. A fixing piece is provided on the outer surface of the sensor housing,
The cover is provided with an insertion hole into which the fixing piece is inserted,
the fixing piece has a second through hole that overlaps with the first through hole from the first space side when inserted into the insertion hole,
the fixing screw is inserted into the second through hole and the first through hole and screwed into the screw hole;
The indoor unit according to claim 5. the cover has a flow straightening surface facing the first space,
the rectifying surface faces the air blown in the circumferential direction by the centrifugal fan and extends in the vertical direction;
The indoor unit according to any one of claims 2 to 6. An indoor unit according to any one of claims 1 to 7;
a refrigerant circuit connected to the heat exchanger and through which the refrigerant circulates;
An outdoor unit;
Air conditioner.