CN109185982B

CN109185982B - Air conditioner

Info

Publication number: CN109185982B
Application number: CN201810895807.4A
Authority: CN
Inventors: 铃木康巨; 驹井隆雄; 前田晃; 川岛充; 久保和也
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2014-07-08
Filing date: 2015-05-27
Publication date: 2020-08-18
Anticipated expiration: 2035-05-27
Also published as: JP5918399B2; CN105299751A; CN109185982A; DE112015003180T5; JP2016027291A; WO2016006267A1; CN105299751B

Abstract

The invention provides an air conditioner which can restrain the local increase of the indoor refrigerant concentration and the manufacturing cost even if the refrigerant leakage happens. In an air conditioning device having a refrigeration cycle (40), an outdoor unit (2), and an indoor unit (1), wherein a refrigerant has a density higher than the density of air under atmospheric pressure, the indoor unit (1) is provided with: an upper space (115b) in which the indoor heat exchanger (7) is disposed; a lower space (115a) provided below the upper space (115 b); a partition (20) that separates the upper space (115b) from the lower space (115 a); an indoor air supply fan (7f) disposed in the lower space (115 a); the fan housing (108) is formed with a blowout opening (108a) and a suction opening (108b), the partition (20) is formed with an air passage opening (20a) which becomes an air passage between the upper space (115b) and the lower space (115a), and the blowout opening (108a) is connected to the air passage opening (20 a).

Description

Air conditioner

The present patent application is a divisional application filed on the application entitled "air conditioner" with an application date of 2015, 5-month 27 and an application number of 201510278090.5.

Technical Field

The present invention relates to an air conditioner.

Background

Conventionally, as a refrigerant used in an air conditioner, an HFC refrigerant such as R410A, which is nonflammable, has been used. Unlike conventional HCFC refrigerants such as R22, R410A has zero ozone depletion potential (hereinafter referred to as "ODP"), and therefore does not destroy the ozone layer. But R410A has such a property that global warming potential (hereinafter referred to as "GWP") is high. Therefore, as a part of global warming prevention, studies have been carried out to change from an HFC refrigerant having a high GWP such as R410A to a refrigerant having a low GWP.

As a candidate for such a low GWP refrigerant, R290 (C) as a natural refrigerant is available₃H₈: propane), R1270 (C)₃H₆: propylene) and the like. However, unlike R410A, which is incombustible, R290 and R1270 have combustibility of a strong combustion level (strong combustibility). Therefore, when R290 and R1270 are used as the refrigerant, attention needs to be paid to leakage of the refrigerant.

Further, as a candidate of the low GWP refrigerant, there is an HFC refrigerant having no carbon double bond in the composition, for example, R32 (CH) having a GWP lower than that of R410A₂F₂(ii) a Difluoromethane).

Further, as a similar candidate refrigerant, there is a halogenated hydrocarbon which is one of HFC refrigerants as with R32 and has a carbon double bond in the composition. Examples of the halogenated hydrocarbon include HFO-1234yf (CF)₃CF＝CH₂(ii) a Tetrafluoropropene), HFO-1234ze (CF)₃-CH ═ CHF). In order to distinguish from an HFC refrigerant having no carbon double bond in its composition, such as R32, an HFC refrigerant having a carbon double bond in its composition often uses "O" of an olefin (an unsaturated hydrocarbon having a carbon double bond is referred to as an olefin), and is expressed as "HFO".

Such a low GWP HFC refrigerant (including HFO refrigerant) has a flammability of a micro-ignition level (micro-ignition property) unlike R410A, which is incombustible, although it does not have a strong ignition property like an HC refrigerant such as R290, which is a natural refrigerant. Therefore, attention needs to be paid to leakage of the refrigerant as in R290. Hereinafter, a flammable refrigerant having a micro-ignition level or higher (for example, 2L or higher in the classification of ASHRAE 34) is referred to as a "flammable refrigerant".

When a flammable refrigerant leaks into the indoor space, the refrigerant concentration in the room may increase, and a flammable concentration region may be formed.

Patent document 1 describes an air conditioning apparatus including: in an air conditioner using a combustible refrigerant, a gas sensor is provided on an outer surface of an indoor unit for detecting a combustible refrigerant gas, the indoor unit is of a bottom type, and the gas sensor is provided at a lower portion of the indoor unit. When the sensor detection voltage of the gas sensor is equal to or higher than the reference value, the control unit of the air conditioner determines that the combustible refrigerant is leaked, and immediately issues an alarm by the alarm. This allows the user to know that the flammable refrigerant has leaked, and to take measures such as ventilation of the room and calling of maintenance personnel for repair. If it is determined that the combustible refrigerant has leaked, the control unit immediately performs control to stop the operation of the refrigerant circuit. This makes it possible to immediately shut off the refrigerant circuit by a valve present in the refrigerant circuit even when the air conditioner is in operation, and thus to suppress leakage of a large amount of flammable refrigerant.

Patent document 1: japanese patent No. 4639451

However, the air conditioner described in patent document 1 requires a gas sensor for detecting a flammable refrigerant gas, and therefore has a first problem of increasing the manufacturing cost. Further, although a user who is notified of leakage of the flammable refrigerant by an alarm can take measures such as ventilation of the room and calling of a maintenance person for repair, there is a second problem: in general, a flammable refrigerant leaking from a room as a closed space may form a flammable concentration region until the above-described disposal is performed. Further, since the control unit that determines that the leakage of the flammable refrigerant occurs immediately performs the control of stopping the operation of the refrigerant circuit, it is possible to suppress the leakage of a large amount of the flammable refrigerant, but it is impossible to avoid the leakage of a certain amount of the flammable refrigerant. Therefore, there is a third problem: in a room as a closed space, there is a possibility that a flammable refrigerant leaking from the room may form a flammable concentration region.

During operation of the air conditioner, air is blown out into the room by operation of a fan of the indoor unit. Therefore, even if the flammable refrigerant leaks into the room, the leaked flammable refrigerant can be diffused into the room by the blown air, and therefore, a flammable concentration region is not formed in the room. However, the second or third problem is likely to occur because the fan of the indoor unit is also stopped while the air conditioner is stopped.

Disclosure of Invention

The present invention has been made to solve at least one of the above problems, and an object of the present invention is to provide an air conditioner that can suppress local increase in the refrigerant concentration in a room and can suppress manufacturing cost, even if refrigerant leaks.

The air conditioner of the invention comprises: a refrigeration cycle that circulates a refrigerant through a refrigerant pipe; an outdoor unit that accommodates at least a compressor and an outdoor heat exchanger of the refrigeration cycle; and an indoor unit that houses at least an indoor heat exchanger of the refrigeration cycle and is connected to the outdoor unit via an extension pipe that is a part of the refrigerant pipe, the refrigerant having a density higher than a density of air under atmospheric pressure, the indoor unit including: a frame body; an upper space in which the indoor heat exchanger is disposed inside the housing; a lower space provided in the housing below the upper space; a partition that partitions the upper space and the lower space; a fan disposed in the lower space; and a fan case disposed in the lower space, having a blow-out opening and a suction opening for covering the fan, wherein an air passage opening is formed in the partition portion, the air passage opening forms an air passage between the upper space and the lower space, and one of the blow-out opening and the suction opening is connected to the air passage opening.

Preferably, the indoor heat exchanger and the extension pipe are connected to each other via a joint portion, and the joint portion is disposed in the upper space.

Preferably, the indoor heat exchanger and the extension pipe are connected to each other via a joint portion, and the joint portion is disposed above the fan.

Preferably, the frame has a front surface opening formed in a front surface thereof, and the frame includes at least: a first front panel detachably attached to a lower portion of the front opening; and a second front surface panel detachably attached to a portion of the front surface opening portion above the lower portion, wherein the joint portion is provided below an upper end of the first front surface panel.

Preferably, the indoor heat exchanger includes a joint portion between the tubes, and the joint portion between the tubes forms a part of the flow path of the refrigerant.

Preferably, the frame body is provided with: a lower opening section which is one of the suction port and the discharge port; and an upper opening portion that is disposed above the lower opening portion and serves as the other of the suction port and the discharge port, wherein a diffusion mechanism that diffuses gas flowing out from the inside to the outside of the housing is provided in the lower opening portion.

Preferably, the diffusion mechanism includes a grill having a shape radially expanding from the inside toward the outside of the frame.

Preferably, the diffusion means comprises a filter consisting of a non-woven fabric or a mesh.

Preferably, the fan is an axial fan or a diagonal flow fan.

Preferably, the fan is rotatably stopped while the indoor unit is stopped.

Preferably, an opening hole through which the extension pipe passes is formed in at least one of the partition portion and the frame, and a gap filler is filled between an outer periphery of the extension pipe and an inner periphery of the opening hole.

Preferably, the gap filler is formed using a foaming material of independent bubbles.

Preferably, the housing is formed with an opening hole through which the extension pipe passes, and the opening hole is provided in an upper portion or a top surface of the housing.

Preferably, the upper space is located on a downstream side of the lower space in the air flow generated by the fan.

Preferably, the upper space is located upstream of the lower space in the air flow generated by the fan.

Preferably, the indoor unit is a bottom-mounted type indoor unit installed on an indoor floor.

Preferably, the refrigerant is a flammable refrigerant.

According to the present invention, even if refrigerant leaks in the indoor unit, the leaked refrigerant can be diffused and flow out into the room, and therefore, a local increase in the refrigerant concentration in the room can be suppressed. Further, according to the present invention, since a sensor for detecting refrigerant leakage is not required, the manufacturing cost of the air conditioner can be suppressed.

Drawings

Fig. 1 is a refrigerant circuit diagram showing a schematic configuration of an air conditioner according to embodiment 1 of the present invention.

Fig. 2 is a front view showing an external configuration of an indoor unit 1 of an air conditioning apparatus according to embodiment 1 of the present invention.

Fig. 3 is a front view schematically showing the internal structure of an indoor unit 1 of an air conditioning apparatus according to embodiment 1 of the present invention.

Fig. 4 is a side view schematically showing the internal structure of an indoor unit 1 of an air conditioning apparatus according to embodiment 1 of the present invention.

Fig. 5 is a front view schematically showing the configuration of the indoor heat exchanger 7 and its peripheral components of the air conditioning apparatus according to embodiment 1 of the present invention.

Fig. 6 is a front view schematically showing the structure of the suction port 112 of the indoor unit 1 according to a modification of embodiment 1 of the present invention.

Fig. 7 is a sectional view showing a section VII-VII of fig. 6.

Fig. 8 is a front view schematically showing the internal structure of an indoor unit 1 of an air conditioning apparatus according to embodiment 2 of the present invention.

Fig. 9 is a side view schematically showing the internal structure of an indoor unit 1 of an air conditioning apparatus according to embodiment 2 of the present invention.

Fig. 10 is a front view schematically showing the internal structure of an indoor unit 1 according to a first modification of embodiment 2 of the present invention.

Fig. 11 is a side view schematically showing the internal structure of an indoor unit 1 according to a first modification of embodiment 2 of the present invention.

Fig. 12 is a front view schematically showing an internal structure of an indoor unit 1 according to a second modification of embodiment 2 of the present invention.

Fig. 13 is a side view schematically showing the internal structure of an indoor unit 1 according to a second modification of embodiment 2 of the present invention.

Fig. 14 is a front view schematically showing the internal structure of an indoor unit 1 according to a third modification of embodiment 2 of the present invention.

Fig. 15 is a side view schematically showing the internal structure of an indoor unit 1 according to a third modification of embodiment 2 of the present invention.

Fig. 16 is a diagram showing a structure of an opening hole of an air conditioner according to embodiment 3 of the present invention.

Fig. 17 is a diagram showing a first modification of the structure of an opening hole of an air conditioner according to embodiment 3 of the present invention.

Fig. 18 is a diagram showing a second modification of the structure of an opening hole of an air conditioner according to embodiment 3 of the present invention.

Fig. 19 is a front view schematically showing the internal structure of an indoor unit 1 of an air conditioning apparatus according to embodiment 4 of the present invention.

Fig. 20 is a side view schematically showing the internal structure of an indoor unit 1 of an air conditioning apparatus according to embodiment 4 of the present invention.

Description of reference numerals: an indoor unit; an outdoor unit; a compressor; a refrigerant flow path switching device; an outdoor heat exchanger; an outdoor air supply fan; a pressure relief device; an indoor heat exchanger; 7f. indoor air supply fan; indoor piping; 10a, 10b. A suction tubing; discharge piping; an extension pipe connection valve; maintaining the mouth 14a, 14b, 14 c; 15a, 15b.. the joint portion; 18a, 18b.. insulation; 19. 19a, 19b.. gap filler; a partition; an air duct opening; an electrical box; an operating portion; 30. 30a, 30b, 31.. open hole; a refrigeration cycle; 61.. header main; a header branch; 63.. indoor refrigerant manifold; a fin; 71.. heat conducting pipes; 71a, 71b.. end; a hairpin bend; 73.. U-bend; an air duct space; an intake air temperature sensor; 92.. a heat exchanger inlet temperature sensor; 93.. a heat exchanger temperature sensor; an impeller; a fan housing; blow out openings; a suction opening portion; a frame; a suction inlet; an air outlet; a first front surface panel; 114b.. a second front surface panel; a third front surface panel; a lower space; 115a.. headspace; 120.. a suction grill; a filter; a recess; a main body portion; a mouth; 131. a cover; a bulging portion; a main body portion; a mouth portion; a brazed portion.

Detailed Description

Embodiment mode 1

An air conditioner according to embodiment 1 of the present invention will be described. Fig. 1 is a refrigerant circuit diagram showing a schematic configuration of an air conditioner according to the present embodiment. In the following drawings including fig. 1, the dimensional relationship, shape, and the like of each component may be different from those of the actual drawings.

As shown in fig. 1, the air conditioner includes a refrigeration cycle 40 for circulating a refrigerant. The refrigeration cycle 40 has the following structure: the compressor 3, the refrigerant flow switching device 4, the outdoor heat exchanger 5 (heat source side heat exchanger), the pressure reducing device 6, and the indoor heat exchanger 7 (load side heat exchanger) are sequentially connected in an annular shape via refrigerant pipes. Further, the air conditioner includes: for example, an indoor unit 1 installed indoors, and an outdoor unit 2 installed outdoors. The indoor unit 1 and the outdoor unit 2 are connected to each other through

extension pipes

10a and 10b as a part of refrigerant pipes.

The refrigerant circulating through the refrigeration cycle 40 is, for example, a slightly flammable refrigerant such as R32, HFO-1234yf, HFO-1234ze or a highly flammable refrigerant such as R290, R1270. The refrigerant may be used as a single refrigerant or as a mixed refrigerant in which two or more kinds of refrigerants are mixed.

The compressor 3 is a fluid device that compresses a low-pressure refrigerant drawn in and discharges the refrigerant as a high-pressure refrigerant. The refrigerant flow switching device 4 is a device that switches the direction of flow of the refrigerant in the refrigeration cycle 40 between the cooling operation and the heating operation. As the refrigerant flow switching device 4, for example, a four-way valve is used. The outdoor heat exchanger 5 functions as a condenser during the cooling operation and functions as an evaporator during the heating operation. The outdoor heat exchanger 5 performs heat exchange between the refrigerant flowing inside and air (outside air) blown by an outdoor air blowing fan 5f described later. The decompression device 6 is a device that decompresses the high-pressure refrigerant to convert the refrigerant into a low-pressure refrigerant. As the pressure reducing device 6, for example, an electronic expansion valve or the like capable of adjusting the opening degree is used. The indoor heat exchanger 7 is a heat exchanger that functions as an evaporator during the cooling operation and functions as a condenser during the heating operation. The indoor heat exchanger 7 performs heat exchange between the refrigerant flowing through the inside and air blown by an indoor blowing fan 7f described later. The cooling operation is an operation of supplying a low-temperature and low-pressure refrigerant to the indoor heat exchanger 7, and the heating operation is an operation of supplying a high-temperature and high-pressure refrigerant to the indoor heat exchanger 7.

The outdoor unit 2 accommodates: a compressor 3, a refrigerant flow switching device 4, an outdoor heat exchanger 5, and a pressure reducing device 6. Further, an outdoor blower fan 5f for supplying outside air to the outdoor heat exchanger 5 is housed in the outdoor unit 2. The outdoor air-sending fan 5f is provided to face the outdoor heat exchanger 5. By rotating the outdoor air-sending fan 5f, an air flow passing through the outdoor heat exchanger 5 is generated. As the outdoor air-sending fan 5f, for example, a propeller fan is used. The outdoor air-sending fan 5f is disposed, for example, on the downstream side of the outdoor heat exchanger 5 in the air flow generated by the outdoor air-sending fan 5f.

In the outdoor unit 2, as refrigerant pipes, are disposed: a refrigerant pipe connecting the extension pipe connection valve 13a on the gas side (during cooling operation) to the refrigerant flow switching device 4, a suction pipe 11 connected to the suction side of the compressor 3, a discharge pipe 12 connected to the discharge side of the compressor 3, a refrigerant pipe connecting the refrigerant flow switching device 4 to the outdoor heat exchanger 5, a refrigerant pipe connecting the outdoor heat exchanger 5 to the pressure reducing device 6, and a refrigerant pipe connecting the pressure reducing device 6 to the extension pipe connection valve 13b on the liquid side (during cooling operation). The extension pipe connection valve 13a is a two-way valve that can be opened and closed, and a flare joint is attached to one end thereof. The extension pipe connection valve 13b is formed of a three-way valve that can be opened and closed, and has a maintenance port 14a attached to one end thereof for use in evacuation (during operation before the refrigeration cycle 40 is filled with refrigerant), and a flare fitting attached to the other end thereof.

In either the cooling operation or the heating operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 3 flows through the discharge pipe 12. In either the cooling operation or the heating operation, a low-temperature low-pressure refrigerant (a gas refrigerant or a two-phase refrigerant) subjected to an evaporation action flows through the suction pipe 11. A low-pressure-side maintenance port with a flare joint 14b is connected to the suction pipe 11, and a high-pressure-side maintenance port with a flare joint 14c is connected to the discharge pipe 12. The maintenance ports 14b and 14c are used for connecting pressure gauges and measuring operating pressure during test operation during installation and repair of the air conditioner.

The indoor unit 1 houses an indoor heat exchanger 7. The indoor unit 1 is provided with an indoor blower fan 7f that supplies air to the indoor heat exchanger 7. By rotating the indoor air-sending fan 7f, an air flow passing through the indoor heat exchanger 7 is generated. As the indoor blower fan 7f, a centrifugal fan (e.g., a sirocco fan, a turbo fan, etc.), a cross-flow fan, a diagonal-flow fan, an axial-flow fan (e.g., a propeller fan), etc., are used depending on the form of the indoor unit 1. The indoor air-sending fan 7f of this example is disposed on the upstream side of the indoor heat exchanger 7 with respect to the air flow generated by the indoor air-sending fan 7f, but may be disposed on the downstream side of the indoor heat exchanger 7.

In addition, the indoor unit 1 is provided with the following sensors and the like: an intake air temperature sensor 91 that detects the temperature of the indoor air taken in from the room; a heat exchanger inlet temperature sensor 92 that detects the refrigerant temperature at the inlet (outlet during heating operation) during cooling operation of the indoor heat exchanger 7; and a heat exchanger temperature sensor 93 that detects the refrigerant temperature (evaporation temperature or condensation temperature) of the two-phase portion of the indoor heat exchanger 7. The sensors can output detection signals to a control unit (not shown) that controls the indoor unit 1 or the entire air conditioner.

A joint portion 15a (e.g., a flare joint) for connecting the extension pipe 10a is provided at a connection portion to the gas-side extension pipe 10a in the refrigerant pipe of the indoor unit 1 near the gas-side indoor pipe 9 a. In addition, in the refrigerant pipe of the indoor unit 1, the liquid-side indoor pipe 9b is provided with a joint portion 15b (for example, a flare joint) for connecting the extension pipe 10b at a connection portion to the liquid-side extension pipe 10b.

Next, the operation of the refrigeration cycle 40 of the air conditioner will be described. First, the operation during the cooling operation will be described. In fig. 1, solid arrows indicate the flow direction of the refrigerant during the cooling operation. In the cooling operation, the refrigerant circuit is configured to: the refrigerant flow path is switched as indicated by the solid line by the refrigerant flow path switching device 4, and a low-temperature and low-pressure refrigerant flows through the indoor heat exchanger 7.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 3 first flows into the outdoor heat exchanger 5 via the refrigerant flow switching device 4. In the cooling operation, the outdoor heat exchanger 5 functions as a condenser. That is, in the outdoor heat exchanger 5, heat exchange is performed between the refrigerant flowing inside and the air (outside air) blown by the outdoor air-blowing fan 5f, and the heat of condensation of the refrigerant is dissipated to the blown air. The refrigerant flowing into the outdoor heat exchanger 5 is thereby condensed into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows into the pressure reducing device 6, and is reduced in pressure to become a low-pressure two-phase refrigerant. The low-pressure two-phase refrigerant flows into the indoor heat exchanger 7 of the indoor unit 1 through the extension pipe 10b. In the cooling operation, the indoor heat exchanger 7 functions as an evaporator. That is, the indoor heat exchanger 7 exchanges heat between the refrigerant flowing through the inside thereof and air (indoor air) blown by the indoor blowing fan 7f, and absorbs heat of evaporation of the refrigerant from the blown air. Thereby, the refrigerant flowing into the indoor heat exchanger 7 is evaporated to become a low-pressure gas refrigerant or a two-phase refrigerant. The air blown by the indoor air blowing fan 7f is cooled by the heat absorption action of the refrigerant. The low-pressure gas refrigerant or two-phase refrigerant evaporated in the indoor heat exchanger 7 is sucked into the compressor 3 through the extension pipe 10a and the refrigerant flow switching device 4. The refrigerant sucked into the compressor 3 is compressed to become a high-temperature and high-pressure gas refrigerant. The above cycle is repeated in the cooling operation.

Next, an operation in the heating operation will be described. In fig. 1, the dashed arrows indicate the flow direction of the refrigerant during the heating operation. In the heating operation, the refrigerant circuit is configured to: the refrigerant flow path is switched by the refrigerant flow path switching device 4 as indicated by the broken line, and the high-temperature and high-pressure refrigerant flows through the indoor heat exchanger 7. During the heating operation, the refrigerant flows in the direction opposite to that during the cooling operation, and the indoor heat exchanger 7 functions as a condenser. That is, the indoor heat exchanger 7 performs heat exchange between the refrigerant flowing through the inside and the air blown by the indoor air blowing fan 7f, and the heat of condensation of the refrigerant is radiated to the air. Thus, the air blown by the indoor blower fan 7f is heated by the heat radiation action of the refrigerant.

Fig. 2 is a front view showing an external configuration of the indoor unit 1 of the air conditioning apparatus according to the present embodiment. Fig. 3 is a front view schematically showing the internal structure of the indoor unit 1 (in a state where the front panel is removed). Fig. 4 is a side view schematically showing the internal structure of the indoor unit 1. The left side of fig. 4 shows the front surface side (indoor side) of the indoor unit 1. In the present embodiment, a bottom-mounted indoor unit 1 installed on the floor in a room as a space to be air-conditioned is exemplified as the indoor unit 1. In the following description, the positional relationship (for example, the vertical relationship) between the respective components is, in principle, a relationship in which the indoor unit 1 is placed in a usable state.

As shown in fig. 2 to 4, the indoor unit 1 includes a casing 111, and the casing 111 has a vertically long rectangular parallelepiped shape. A suction port 112 (an example of a lower opening portion) for sucking air in the room is formed in a lower portion of the front surface of the housing 111. In this example, the suction port 112 is provided below the center portion in the vertical direction of the housing 111 and near the floor surface. An outlet 113 (an example of an upper opening) is formed in an upper portion of the front surface of the housing 111, that is, at a position higher than the height of the inlet 112, and the outlet 113 blows out the air sucked from the inlet 112 into the room. The air outlet 113 of this example is provided above the center portion of the housing 111 in the vertical direction. Operation unit 26 is provided on the front surface of casing 111 above suction port 112 and below discharge port 113. The operation unit 26 performs an operation start operation, an operation end operation, switching of operation modes, setting of a set temperature and a set air volume, and the like of the indoor unit 1 (air conditioner) by a user's operation.

The frame 111 is a hollow box, and a front surface opening is formed in the front surface of the frame 111. The frame 111 includes: a first front panel 114a, a second front panel 114b, and a third front panel 114c detachably attached to the front opening. The first front surface panel 114a, the second front surface panel 114b, and the third front surface panel 114c each have a substantially rectangular flat plate-like outer shape. The first front panel 114a is detachably attached to a lower portion of the front opening of the frame 111. The suction port 112 is formed in the first front surface panel 114a. The second front surface panel 114b is disposed adjacent to the upper side of the first front surface panel 114a, and is detachably attached to the center portion in the vertical direction of the front surface opening of the housing 111. The second front surface panel 114b is provided with the operation unit 26. The third front panel 114c is disposed adjacent to the upper side of the second front panel 114b, and is detachably attached to the upper portion of the front opening of the housing 111. The air outlet 113 is formed in the third front surface panel 114c.

The internal space of the housing 111 is roughly divided into: a lower space 115a serving as a blowing unit, and an upper space 115b located above the lower space 115a and serving as a heat exchanging unit. The lower space 115a and the upper space 115b are partitioned by a partition 20. The partition portion 20 has a flat plate shape, for example, and is disposed substantially horizontally. At least an air passage opening 20a serving as an air passage between the lower space 115a and the upper space 115b is formed in the partition 20. When the first front panel 114a is removed from the frame 111, the lower space 115a is exposed on the front side, and when the second front panel 114b and the third front panel 114c are removed from the frame 111, the upper space 115b is exposed on the front side. That is, the height at which the partition 20 is provided substantially coincides with the height of the upper end of the first front surface panel 114a (or the lower end of the second front surface panel 114 b). The partition 20 may be formed integrally with the fan housing 108 described later, may be formed integrally with the drain pan described later, or may be formed separately from the fan housing 108 and the drain pan.

An indoor air-sending fan 7f is disposed in the lower space 115a, and this indoor air-sending fan 7f generates an air flow from the air inlet 112 toward the air outlet 113. The indoor blower fan 7f of this example is a sirocco fan, and includes: a motor, not shown, and an impeller 107 connected to an output shaft of the motor and having a plurality of blades arranged at equal intervals in a circumferential direction. The rotation shaft of the impeller 107 (output shaft of the motor) is disposed substantially parallel to the depth direction of the housing 111. The impeller 107 is covered with a swirl-like fan casing 108. The suction opening 108b provided near the center of the vortex of the fan casing 108 is disposed so as to face the suction port 112. The outlet opening 108a of the fan case 108 is disposed so as to face upward, and is directly connected to the air passage opening 20a of the partition 20, for example. At least the inside of the fan casing 108 in the lower space 115a constitutes a part of the air passage space 81. The air passage space 81 is an internal space of the housing 111, and is a space that serves as an air passage from the suction port 112 to the discharge port 113 or a space that communicates with the space.

In the lower space 115a, an electrical box 25 is provided, and the electrical box 25 accommodates, for example, a microcomputer, various electrical components, a substrate, and the like constituting a control unit and the like of the indoor unit 1.

The upper space 115b is located on the downstream side of the lower space 115a in the air flow generated by the indoor air-sending fan 7f. The indoor heat exchanger 7 is disposed in the air passage space 81 in the upper space 115b. A water receiving tray (not shown) is provided below the indoor heat exchanger 7 to receive the condensed water condensed on the surface of the indoor heat exchanger 7. The drain pan may be formed as a part of the partition 20, or may be formed separately from the partition 20 and disposed on the partition 20.

Fig. 5 is a front view schematically showing the structure of the indoor heat exchanger 7 and its peripheral components. As shown in fig. 5, the indoor heat exchanger 7 of the present example is a plate-fin tube type heat exchanger, and includes: a plurality of fins 70 arranged in parallel at predetermined intervals, and a plurality of heat transfer pipes 71 penetrating the plurality of fins 70 and allowing the refrigerant to flow therethrough. The heat transfer pipe 71 includes: a plurality of hairpin curved tubes 72 each having a long straight tube portion penetrating the plurality of fins 70; a plurality of U-bends 73 that communicate the plurality of hairpin bends 72 with one another. The hairpin bend 72 and the U-bend 73 are joined by a brazed portion W (an example of a joint portion). In fig. 5, the brazed part W is indicated by a black dot. The number of the heat transfer pipes 71 may be one or a plurality of. The number of hairpin bends 72 constituting one heat transfer pipe 71 may be one or more.

A cylindrical header main pipe 61 is connected to the gas-side indoor pipe 9 a. A plurality of manifold branch pipes 62 are branched from the manifold main pipe 61. One end 71a of the heat transfer pipe 71 is connected to each of the plurality of header pipes 62. A plurality of indoor refrigerant branch pipes 63 are branched and connected to the liquid-side indoor pipe 9b. The other end 71b of the heat transfer pipe 71 is connected to each of the plurality of indoor refrigerant branch pipes 63. The indoor pipes 9a and the header main pipe 61, the header main pipe 61 and the header branch pipes 62, the header branch pipes 62 and the heat transfer pipes 71, the indoor pipes 9b and the indoor refrigerant branch pipes 63, and the indoor refrigerant branch pipes 63 and the heat transfer pipes 71 are joined by the brazing portions W.

Returning to fig. 3 and 4, in the present embodiment, the brazed portion W of the indoor heat exchanger 7 (here, the brazed portion W of peripheral components including the indoor pipes 9a, the header main pipes 61, the header branch pipes 62, the indoor refrigerant branch pipes 63, the indoor pipes 9b, and the like) is disposed in the air passage space 81 in the upper space 115b. The joint 15a connecting the indoor pipe 9a and the extension pipe 10a and the joint 15b connecting the indoor pipe 9b and the extension pipe 10b are also disposed in the air passage space 81 in the upper space 115b in the same manner.

As described above, in the present embodiment, as the refrigerant circulating through the refrigeration cycle 40, for example, a flammable refrigerant such as R32, HFO-1234yf, HFO-1234ze, R290, R1270, or the like is used. Therefore, if the indoor unit 1 leaks refrigerant, the refrigerant concentration in the room increases, and a flammable concentration region may be formed. In particular, when the air conditioner is stopped, since the indoor blower fan 7f is also stopped, it is difficult to diffuse the leaking refrigerant by the blower air.

The flammable refrigerant has a density higher than that of air at atmospheric pressure (e.g., at room temperature (25 ℃). Therefore, in the case where the refrigerant leakage occurs at a high position from the floor surface in the room, the leaked refrigerant is diffused in the descending direction, and the refrigerant concentration becomes uniform in the indoor space, so that the refrigerant concentration is difficult to increase. On the other hand, if refrigerant leakage occurs at a low height from the floor surface in the room, the leaked refrigerant accumulates at a low position near the floor surface, and therefore the refrigerant concentration tends to locally increase. Thereby resulting in a relatively high probability of forming a flammable concentration region.

In the indoor unit 1, there is a possibility that the refrigerant leaks: the brazed portion W of the indoor heat exchanger 7 (here, the brazed portion W of the peripheral component is included), and the

joint portions

15a, 15b. In the present embodiment, at least the brazing portion W is disposed in the air passage space 81 in the upper space 115b, that is, the air passage space 81 above the impeller 107 (blade) of the indoor air-blowing fan 7f, and the indoor air-blowing fan 7f is disposed in the lower space 115a. In the present embodiment, in addition to the brazing portion W, the

joints

15a and 15b are also disposed in the air passage space 81 in the upper space 115b. The outlet opening 108a of the fan case 108 is connected to the air passage opening 20a of the partition 20. Therefore, if the refrigerant leaks from the brazed portion W or the

joints

15a and 15b during the stop of the air conditioner (i.e., during the stop of the indoor blower fan 7f), almost all of the refrigerant leaking into the upper space 115b will drop into the fan case 108 through the air passage opening 20a and the outlet opening 108a without going around to another path inside the housing 111. Since the impeller 107 having the plurality of blades is provided in the fan casing 108, the refrigerant flowing into the fan casing 108 collides with the surfaces of the plurality of blades and drops downward while being branched into the plurality of flow paths defined by the plurality of blades. The refrigerant is thus diffused in the air inside the fan housing 108. The refrigerant diffused in the fan casing 108 flows out into the room through the suction opening 108b and the suction port 112 of the fan casing 108. Since the refrigerant diffuses at the time of flowing out into the room, the refrigerant concentration can be prevented from locally increasing. This can prevent the formation of a flammable concentration region in the room, even if a flammable refrigerant leaks in the indoor unit 1. In particular, in the case of the bottom-mounted indoor unit 1, the position where refrigerant leaks into the room is likely to be a low position near the floor surface, and therefore, the leaked refrigerant is likely to accumulate at the low position near the floor surface, which is particularly effective.

In addition, in the present embodiment, since a sensor for detecting refrigerant leakage is not required, the manufacturing cost of the indoor unit 1 and the air conditioning apparatus including the same can be suppressed.

Fig. 6 is a front view schematically showing the configuration of the suction port 112 of the indoor unit 1 according to a modification of the present embodiment. Fig. 7 is a sectional view showing a section VII-VII of fig. 6. As shown in fig. 6 and 7, suction grill 120 (an example of a diffusing mechanism) is provided in suction port 112 (lower opening portion) of the present modification. The suction grill 120 has a shape that radially expands from the inside of the housing 111 toward the outside. A filter 121 (an example of a diffusion mechanism) is provided inside the suction grill 120 (inside the housing 111). The filter 121 is made of a nonwoven fabric or a mesh.

According to the present modification, by providing suction grill 120 at suction port 112, the refrigerant leaking from suction port 112 into the room can be spread over a wider range. The formation of the flammable concentration region within the chamber can be more reliably suppressed. Further, by providing filter 121 at suction port 112, the flow of the leaking refrigerant flowing out into the room from suction port 112 can be disturbed, and as a result, the leaking refrigerant can be further diffused and flow out into the room. The formation of the flammable concentration region within the chamber can be more reliably suppressed.

In addition, instead of the suction grill 120, a suction grill having a shape expanding in the left-right direction from the inside of the housing 111 to the outside may be used, a suction grill having a shape expanding in the up-down direction from the inside of the housing 111 to the outside may be used, or both of the suction grills may be used while being overlapped in the flow direction of the air or the leaking refrigerant.

Embodiment mode 2

An air conditioner according to embodiment 2 of the present invention will be described. Fig. 8 is a front view schematically showing the internal structure of the indoor unit 1 of the air conditioning apparatus according to the present embodiment. Fig. 9 is a side view schematically showing the internal structure of the indoor unit 1. The same reference numerals are given to constituent elements having the same functions and actions as those of embodiment 1, and the description thereof is omitted.

As shown in fig. 8 and 9, in the partition 20, a container-shaped recess 130 is formed in a portion near the

indoor pipes

9a and 9b and the

extension pipes

10a and 10b, the upper space 115b side being recessed and the lower space 115a side being protruded. The space in the recess 130 is a part of the upper space 115b, but is lower than the height of the upper end of the first front surface panel 114a (the lower end of the second front surface panel 114 b). An opening is formed in the front surface side of the recess 130, and a cover 131 that can be attached and detached using a screw or the like is provided in the opening. When the cover 131 is removed, the space in the recess 130 is exposed on the front surface side through the opening. On the other hand, when the cover 131 is attached, the front surface side of the recess 130 is closed.

The

joint portions

15a and 15b are disposed in the space in the recess 130. That is, the

joint portions

15a and 15b are disposed below the upper end of the first front surface panel 114a. By removing the first front panel 114a and further removing the cover 131, the

joint portions

15a and 15b can be exposed on the front surface side.

In a typical bottom-mounted indoor unit, the

joints

15a and 15b are disposed in the lower space 115a together with the electrical box 25 and the like. Therefore, in the case of a general bottom-mounted indoor unit, by simply removing the first front panel 114a from the casing 111, the electrical box 25 and the

joint portions

15a and 15b can be exposed on the front surface side, and operations such as installation, repair, and removal of the indoor unit (for example, connection and removal of electrical wiring and refrigerant piping) can be performed.

In contrast, in the configuration of the indoor unit 1 according to embodiment 1 shown in fig. 2 to 4, the

joint portions

15a and 15b are disposed in the upper space 115b. Therefore, when only the first front panel 114a is removed, the refrigerant pipes (the

indoor pipes

9a and 9b and the

extension pipes

10a and 10b) cannot be connected to and removed from each other. Therefore, when the electrical wiring and the refrigerant pipe are connected and removed, it is necessary to remove not only the first front surface panel 114a but also the second front surface panel 114b.

In the present embodiment, the

joint portions

15a and 15b are disposed in the upper space 115b, but below the upper end of the first front surface panel 114a, and therefore, by removing the first front surface panel 114a and the cover 131, the joint portions can be exposed on the front surface side. Therefore, in the present embodiment, the electrical wiring and the refrigerant piping can be connected and removed without removing the second front panel 114b, and therefore, the operations such as installation, repair, and removal of the indoor unit 1 are facilitated. In a normal use state in which the cover 131 is attached to the recess 130, the front surface side of the recess 130 is closed. Therefore, when the refrigerant leaks from the

joints

15a and 15b, almost the entire amount of the leaked refrigerant can flow into the fan case 108 through the air passage opening 20a and the outlet opening 108a without going around to another path inside the housing 111. Therefore, the same effects as those of embodiment 1 can be obtained also in this embodiment.

Fig. 10 is a front view schematically showing the internal structure of an indoor unit 1 according to a first modification of the present embodiment. Fig. 11 is a side view schematically showing the internal structure of the indoor unit 1. As shown in fig. 10 and 11, in the present modification, the partition portion 20 has a flat plate shape as in embodiment 1. In the present modification, a bulging portion 132 is formed in a part of a side wall of the outlet opening 108a of the fan casing 108, and the bulging portion 132 bulges so as to partially enclose the refrigerant pipes (the

indoor pipes

9a and 9b and the

extension pipes

10a and 10 b). An opening is formed in the front surface side of the bulging portion 132, and a cover 133 that can be attached and detached using a screw or the like is provided in the opening. When the cover 133 is removed, the space in the bulging portion 132 is exposed on the front surface side through the opening. On the other hand, when the cover 133 is attached, the front surface side of the bulging portion 132 is closed. The bulge 132 is located in the lower space 115a, similarly to the other parts of the fan casing 108.

The

joint portions

15a and 15b are disposed in the space inside the bulging portion 132. That is, the

joint portions

15a and 15b are disposed below the upper end of the first front surface panel 114a. By removing the first front panel 114a and further removing the cover 133, the

joint portions

15a and 15b can be exposed on the front surface side. The

joint portions

15a and 15b are disposed above the impeller 107 (blade). Therefore, according to the present modification, the same effects as those of the configurations shown in fig. 8 and 9 can be obtained.

The configuration of the indoor unit 1 according to the present embodiment is not limited to the configuration shown in fig. 8 to 11. For example, in the configuration of embodiment 1 shown in fig. 2 to 4, etc., the height (length in the vertical direction) of the first front surface panel 114a may be increased and the height (length in the vertical direction) of the second front surface panel 114b may be decreased so that the upper end of the first front surface panel 114a (the lower end of the second front surface panel 114 b) is disposed above the

joint portions

15a and 15b in the upper space 115b. With this configuration, similarly to the configurations shown in fig. 8 to 11, the electrical wiring and the refrigerant pipe can be connected and removed without removing the second front surface panel 114b.

The shape of the recess 130 as a part of the partition 20 is not limited to the container shape (bottomed cylindrical shape) shown in fig. 8 and 9. Fig. 12 is a front view schematically showing the internal structure of an indoor unit 1 according to a second modification of the present embodiment. Fig. 13 is a side view schematically showing the internal structure of the indoor unit 1. The recess 130 shown in fig. 12 and 13 has a pot shape, and includes: a body 130a, and a mouth 130b formed to be thinner than the body 130a. The space in the main body 130a communicates with the upper space 115b (the space where the indoor heat exchanger 7 is provided) through the port 130b. That is, the space in the body 130a is a part of the upper space 115b. The body 130a accommodates the

tabs

15a and 15b in a space. According to the present modification, since the space for housing the

joint portions

15a and 15b is a part of the upper space 115b, the same effects as those of the structures shown in fig. 8 and 9 can be obtained. As described above, the concave portion 130 can have various shapes as long as the space for accommodating the

joint portions

15a and 15b communicates with the upper space 115b (the space in which the indoor heat exchanger 7 is provided).

The shape of the bulge portion 132 is not limited to the shape shown in fig. 10 and 11. Fig. 14 is a front view schematically showing the internal structure of an indoor unit 1 according to a third modification of the present embodiment. Fig. 15 is a side view schematically showing the internal structure of the indoor unit 1. The bulging portion 132 shown in fig. 14 and 15 has a lateral pot shape, and includes: a body 132a, and a mouth 132b formed to be thinner than the body 132a. The space in the body 132a communicates with the outlet opening 108a via the opening 132b. The body 132a accommodates the

tabs

joints

15a and 15b communicates with the outlet opening 108a and the

joints

15a and 15b are disposed above the indoor air-sending fan 7f, the same effects as those of the configuration shown in fig. 10 and 11 can be obtained. As described above, the bulging portion 132 can have various shapes as long as the space for accommodating the

joint portions

15a and 15b communicates with the outlet opening 108a.

Embodiment 3

An air conditioner according to embodiment 3 of the present invention will be described. In

embodiment

1 or 2, the frame 111, the partition 20 (including the recess 130), the bulge portion 132, and the like are provided with open holes through which the

extension pipes

10a and 10b pass. For example, in the configuration shown in fig. 3, the

extension pipes

10a and 10b are inserted through the opening holes provided in the partition unit 20 and the opening hole provided in the housing 111, and are taken out from the inside of the housing 111 to the outside of the housing 111, and are connected to the outdoor unit 2.

Fig. 16 is a diagram showing a structure of an opening hole of the air conditioner according to the present embodiment. The

open holes

30a and 30b shown in fig. 16 are of a double-hole type, and the

extension pipes

10a and 10b can be independently passed through. As shown in fig. 16,

heat insulators

18a and 18b made of a foamed urethane material or the like are wound around the outer peripheries of the

extension pipes

10a and 10b, respectively. The inner diameter of the

open hole

30a, 30b is almost the same as or slightly larger than the outer diameter of the

heat insulator

18a, 18b. Therefore, the machining size of the field layout (including bending and length matching) of the

extension pipes

10a and 10b is sufficient at the same general allowable level as in the past. Namely, the field workability is improved.

Gap fillers

19a and 19b are filled between the outer peripheries of the

heat insulators

18a and 18b and the inner peripheries of the

open holes

30a and 30b, respectively. The

gap fillers

19a and 19b are formed using a foam material of independent bubbles. By filling the

gap fillers

19a and 19b, the space between the outer peripheries of the

heat insulators

18a and 18b and the

open holes

30a and 30b is hermetically closed in the pipe axial direction of the

extension pipes

10a and 10b. Therefore, the flow of the gas fluid (for example, the leaking refrigerant) through the gaps between the outer peripheries of the

heat insulators

18a and 18b and the inner peripheries of the opening holes 30a and 30b is minimized.

Fig. 17 is a diagram showing a first modification of the structure of an opening hole. The open hole 30 shown in fig. 17 is a single hole type for collectively penetrating the

extension pipes

10a and 10b. As shown in fig. 17, a gap filler 19 is filled between the outer peripheries of the

heat insulators

18a and 18b and the inner periphery of the opening hole 30. The gap filler 19 is formed using a foaming material of independent bubbles. By filling the gap filler 19, the gap between the outer peripheries of the

heat insulators

18a and 18b and the inner periphery of the opening hole 30 is hermetically closed in the pipe axial direction of the

extension pipes

10a and 10b. Therefore, the flow of the gas fluid through the gaps between the outer peripheries of the

heat insulators

18a and 18b and the inner periphery of the opening hole 30 is minimized.

FIG. 18 is a diagram showing a second modification of the structure of an opening hole. The opening hole 31 shown in fig. 18 is a notch type cut from the end of the plate-like member. As shown in fig. 18, the gap filler 19 is filled between the outer peripheries of the

heat insulators

18a and 18b and the inner periphery of the opening hole 31. By filling the gap filler 19, the gap between the outer peripheries of the

heat insulators

extension pipes

heat insulators

18a and 18b and the inner periphery of the opening hole 30 is minimized.

For example, in the configuration shown in fig. 3, by configuring the opening hole formed in the partition portion 20 as shown in fig. 16 to 18, when refrigerant leakage occurs at the brazing portion W or the

joints

15a and 15b in the upper space 115b, the leaked refrigerant can be prevented from leaking into the lower space 115a (outside the fan casing 108) through the gap of the opening hole. Therefore, the entire amount of the refrigerant leaking through the brazed portion W or the

joints

15a and 15b can flow into the fan case 108 through the air passage opening 20a and the outlet opening 108a without going around to another path inside the housing 111. Therefore, the entire amount of the leaked refrigerant can be diffused in the fan case 108 and then flowed out into the room, and therefore, the formation of a flammable concentration region in the room can be suppressed.

Embodiment 4

An air conditioner according to embodiment 4 of the present invention will be described. Fig. 19 is a front view schematically showing the internal structure of the indoor unit 1 of the air conditioning apparatus according to the present embodiment. Fig. 20 is a side view schematically showing the internal structure of the indoor unit 1. The same reference numerals are given to constituent elements having the same functions and actions as those of embodiment 1, and the description thereof is omitted.

In the indoor unit 1 shown in fig. 19 and 20, the opening holes 30a and 30b through which the

extension pipes

10a and 10b pass are provided at an upper portion or a top surface (top surface in this example) of the casing 111. The

extension pipes

10a and 10b are taken out from the upper space 115b in the housing 111 to the outside through the opening holes 30a and 30b, respectively. The upper portion of the housing 111 refers to a position above the partition 20 in the housing 111. The opening holes 30a and 30b are preferably provided at positions as high as possible (for example, positions above the indoor heat exchanger 7 and the

joints

15a and 15 b).

The

open holes

30a and 30b have the same structure as in embodiment 3, for example. That is, the gap filler 19 is filled between the outer peripheries of the

heat insulators

18a and 18b wound around the

extension pipes

10a and 10b and the inner peripheries of the

open holes

30a and 30b. By filling the gap filler 19, the gaps between the outer peripheries of the

heat insulators

18a and 18b and the inner peripheries of the

open holes

30a and 30b are hermetically closed in the pipe axial direction of the

extension pipes

10a and 10b. Therefore, the refrigerant leaking into the upper space 115b can be suppressed from leaking to the outside of the housing 111 through the gaps between the outer peripheries of the

heat insulators

18a and 18b and the inner peripheries of the

openings

30a and 30b.

However, when the accuracy of the installation work of the indoor unit 1 is low, the gap filler 19 may be displaced, and a slight gap may be formed between the outer peripheries of the

heat insulators

18a and 18b and the inner peripheries of the

open holes

30a and 30b. When the refrigerant leaks in the upper space 115b, the refrigerant leaking from the upper space 115b to the outside of the housing 111 through the gap of the gap filler 19 flows out to the inside of the room without passing through the fan casing 108. Therefore, if the accuracy of the installation work of the indoor unit 1 is low, if refrigerant leakage occurs in the upper space 115b, part of the leaked refrigerant that is not sufficiently diffused in the fan casing 108 may directly leak into the room.

However, in the present embodiment, a refrigerant having a density higher than that of air under atmospheric pressure is used, and the opening holes 30a and 30b are provided in the upper portion or the top surface of the housing 111. Therefore, even when a gap is formed in the gap filler 19, the leaking refrigerant is less likely to flow out of the housing 111 through the gap of the gap filler 19. Even if the refrigerant leaked from the upper space 115b flows out to the outside through the gap of the gap filler 19 into the housing 111, the refrigerant leaked into the room spreads during the descending process and the refrigerant concentration is made uniform because the opening holes 30a and 30b are provided at a high height from the floor surface. Therefore, according to the present embodiment, it is possible to more reliably prevent the formation of a flammable concentration region in the room due to a local increase in the refrigerant concentration in the room.

As described above, the air conditioner of the above embodiment includes: a refrigeration cycle 40 that circulates a refrigerant through a refrigerant pipe; an outdoor unit 2 that accommodates at least the compressor 3 and the outdoor heat exchanger 5 of the refrigeration cycle 40; an indoor unit 1 that houses at least an indoor heat exchanger 7 of a refrigeration cycle 40 and is connected to an outdoor unit 2 via extension pipes 10a and 10b that are part of refrigerant pipes, the refrigerant having a density higher than the density of air under atmospheric pressure, the indoor unit 1 including: a frame body 111; an upper space 115b in which the indoor heat exchanger 7 is disposed inside the housing 111; a lower space 115a provided below the upper space 115b inside the housing 111; a partition 20 that partitions the upper space 115b from the lower space 115 a; an indoor air-sending fan 7f disposed in the lower space 115 a; the fan case 108 is disposed in the lower space 115a, and has a blowout opening 108a and a suction opening 108b formed to cover the indoor air-sending fan 7f, and the partition 20 has an air passage opening 20a formed therein, the air passage opening 20a serving as an air passage between the upper space 115b and the lower space 115a, and one of the blowout opening 108a and the suction opening 108b (the blowout opening 108a in this example) is connected to the air passage opening 20a.

In the air conditioning apparatus according to the above-described embodiment, the indoor heat exchanger 7 and the

extension pipes

10a and 10b may be connected via the

joints

15a and 15b, and the

joints

15a and 15b may be disposed in the upper space 115b.

extension pipes

10a and 10b may be connected via the

joints

15a and 15b, and the

joints

15a and 15b may be disposed above the indoor blower fan 7f (e.g., the impeller 107 (blade)).

In the air conditioning apparatus according to the above embodiment, a front surface opening may be formed in the front surface of the housing 111, and the housing 111 may include at least: a first front surface panel 114a detachably attached to a lower portion of the front surface opening; and a second front surface panel 114b detachably attached to a portion of the front surface opening portion above the lower portion, wherein the

joint portions

15a and 15b are provided below an upper end of the first front surface panel 114a.

In the air conditioning apparatus according to the above-described embodiment, the indoor heat exchanger 7 may have a joint portion (e.g., a brazed portion W) between the tubes that form part of the flow path of the refrigerant.

In the air conditioning apparatus according to the above embodiment, the housing 111 may be provided with: a lower opening portion (in this example, the suction port 112) serving as one of the suction port and the discharge port, and an upper opening portion (in this example, the discharge port 113) disposed above the lower opening portion and serving as the other of the suction port and the discharge port, and a diffusion mechanism for diffusing the gas flowing out to the outside from the inside of the casing 111 is provided in the lower opening portion.

In the air conditioner according to the above-described embodiment, the diffusing means may include a grill (in this example, the suction grill 120) having a shape that radially expands from the inside of the housing 111 toward the outside.

In the air conditioner of the above embodiment, the diffusing means may include a filter 121 made of a nonwoven fabric or a mesh.

In the air conditioning apparatus according to the above embodiment, the indoor air-sending fan 7f may be an axial-flow fan or a diagonal-flow fan.

In the air conditioning apparatus according to the above-described embodiment, the indoor blower fan 7f is rotatably stopped during the stop of the indoor unit 1.

In the air conditioner of the above embodiment, the opening holes 30, 30a, 30b, and 31 through which the

extension pipes

10a and 10b pass may be formed in at least one of the partition portion 20 (including the concave portion 130), the bulging portion 132, and the housing 111, and the

gap fillers

19, 19a, and 19b made of a foam material using independent bubbles may be filled between the outer peripheries of the

extension pipes

10a and 10b and the inner peripheries of the opening holes 30, 30a, 30b, and 31.

In the air conditioning apparatus according to the above embodiment, the housing 111 may be formed with the opening holes 30, 30a, 30b, and 31 through which the

extension pipes

10a and 10b pass, and the opening holes 30, 30a, 30b, and 31 may be provided at an upper portion or a top surface of the housing 111.

In the air conditioning apparatus according to the above-described embodiment, the upper space 115b may be located downstream of the lower space 115a in the air flow generated by the indoor blower fan 7f.

In the air conditioning apparatus according to the above-described embodiment, the indoor unit 1 may be a bottom-mounted type indoor unit installed on an indoor floor.

In the air conditioner of the above embodiment, the refrigerant may be a flammable refrigerant.

Other embodiments

The present invention is not limited to the above-described embodiments, and various modifications are possible.

For example, although the sirocco fan is exemplified as the indoor air blowing fan 7f in the above-described embodiment, a turbo fan, a cross flow fan, an axial flow fan (for example, a propeller fan), or a diagonal flow fan may be used as the indoor air blowing fan 7f. For example, when an axial fan is used as the indoor air blowing fan 7f, a cylindrical fan casing is used. The axial end of the fan casing may be formed in a bell mouth shape. For example, when an axial flow fan or a diagonal flow fan is used as the indoor air sending fan 7f, the indoor air sending fan 7f is preferably configured to be stopped so as to be rotatable (in an unlocked state) while the indoor unit 1 is stopped. When an axial flow fan or a diagonal flow fan is used as the indoor air sending fan 7f, the stopped indoor air sending fan 7f can be rotated in a direction opposite to the rotational direction during operation, by utilizing the density difference between the air and the leaked refrigerant dropping from the upper space 115b to the lower space 115a. By rotating the indoor blower fan 7f in the opposite direction, a flow of the mixed gas of the refrigerant and the air can be generated in a direction from the suction port 112 toward the room. Therefore, the leaked refrigerant flowing out into the room can be further diffused in the air, and therefore, the formation of the flammable concentration region in the room can be more reliably suppressed.

In the above embodiment, the suction port 112 is formed in the lower portion of the housing 111 and the discharge port 113 is formed in a position above the lower portion, but the vertical relationship between the suction port 112 and the discharge port 113 may be reversed. That is, the following configuration may be adopted: an outlet 113 (an example of a lower opening) is formed in a lower portion of the housing 111, and an inlet 112 (an example of an upper opening) is formed above the outlet. In this case, the upper space 115b is located upstream of the lower space 115a in the air flow generated by the indoor air-sending fan 7f.

In the above embodiment, it is preferable that no recess (recess with an upper opening) serving as a retention portion of the leaked refrigerant is present in the air passage space 81. In addition, when such a recess is present, the volume of the recess is preferably small.

In the above embodiment, the flammable refrigerant is exemplified as the refrigerant, but if the refrigerant has a density higher than that of air under atmospheric pressure, the leaked refrigerant can be diffused and flowed out into the room as in the above embodiment regardless of the combustibility of the refrigerant. Therefore, even when a refrigerant other than the flammable refrigerant is used, the local increase in the refrigerant concentration in the room can be suppressed. Further, since a sensor for detecting leakage of the refrigerant is not required, the manufacturing cost of the indoor unit 1 and the air conditioner including the same can be reduced.

The above embodiments and modifications can be combined with each other.

Claims

1. An air conditioning apparatus, comprising:

a refrigeration cycle in which a refrigerant is circulated through a refrigerant pipe;

an outdoor unit that accommodates at least a compressor and an outdoor heat exchanger of the refrigeration cycle; and

an indoor unit that houses at least an indoor heat exchanger of the refrigeration cycle and is connected to the outdoor unit via an extension pipe that is a part of the refrigerant pipe,

the refrigerant has a density at atmospheric pressure greater than that of air,

the indoor unit is provided with:

a frame body;

an upper space in which the indoor heat exchanger is disposed inside the housing;

a lower space provided in the housing below the upper space;

a partition that partitions the upper space and the lower space;

a fan disposed in the lower space; and

a fan case disposed in the lower space, covering the fan, and having a blow-out opening and a suction opening formed therein,

an air passage opening is formed in the partition portion, and the air passage opening forms an air passage between the upper space and the lower space,

one of the blowout opening and the suction opening is connected to the air passage opening,

the indoor heat exchanger and the extension pipe are connected to each other via a joint,

a front surface opening is formed on the front surface of the frame body,

the frame body is provided with at least: a first front panel detachably attached to a lower portion of the front opening; a second front surface panel detachably attached to a portion of the front surface opening portion above the lower portion,

the partition has a container-shaped recess that is recessed toward the upper space and is protruded toward the lower space at a portion near the indoor pipe and the extension pipe,

the joint portion is disposed in a space in the recess portion as the upper space, and is provided below an upper end of the first front surface panel.

2. The air conditioner according to claim 1,

the recess has a pot-like shape, and is provided with: the mouth portion is formed to be thin relative to the main body portion.

3. Air conditioning unit according to claim 1 or 2,

the indoor heat exchanger includes a joint portion between the tubes, and the joint portion between the tubes forms a part of the flow path of the refrigerant.

4. Air conditioning unit according to claim 1 or 2,

the frame body is provided with: a lower opening section which is one of the suction port and the discharge port; an upper opening portion that is disposed above the lower opening portion and that serves as the other of the suction port and the discharge port,

a diffusion mechanism that diffuses the gas flowing out from the inside to the outside of the housing is provided at the lower opening portion.

5. The air conditioner according to claim 1,

the fan is an axial fan or a diagonal fan.

6. Air conditioning unit according to claim 1 or 2,

an opening hole through which the extension pipe passes is formed in at least one of the partition portion and the frame,

a gap filler is filled between the outer periphery of the extension pipe and the inner periphery of the opening hole.

7. Air conditioning unit according to claim 6,

the gap filler is formed using a foam material of independent bubbles.

8. Air conditioning unit according to claim 1 or 2,

an opening hole for penetrating the extension pipe is formed in the frame body,

the opening hole is arranged on the upper part or the top surface of the frame body.

9. Air conditioning unit according to claim 1 or 2,

the upper space is located on a downstream side of the lower space in the air flow generated by the fan.

10. Air conditioning unit according to claim 1 or 2,

the upper space is located upstream of the lower space in the air flow generated by the fan.

11. Air conditioning unit according to claim 1 or 2,

the indoor unit is a bottom-mounted indoor unit arranged on the indoor ground.

12. Air conditioning unit according to claim 1 or 2,

the refrigerant is a flammable refrigerant.