JP6519373B2 - Indoor unit of air conditioner - Google Patents

Description

  The present invention relates to an indoor unit of an air conditioner.

  BACKGROUND ART In recent years, adoption of R32 refrigerant with a low global warming potential has progressed in air conditioners that perform indoor air conditioning by a vapor compression refrigeration cycle. However, R32 refrigerant has slight flammability (slight flammability), and if the refrigerant whose specific gravity is larger than air leaks, it may stay near the floor surface and reach the flammable concentration. For this reason, in order to determine the presence or absence of the leak from a refrigerant circuit, a refrigerant sensor is arranged in an indoor unit, and when this refrigerant sensor detects the leak of a refrigerant, the on-off valve arranged in the refrigerant circuit is opened and the said It has been proposed that the leaked refrigerant be collected in a container connected to the on-off valve (see Patent Document 1), or the indoor fan provided in the indoor unit be driven to diffuse the leaked refrigerant (Patent Document 2). There is.

JP 2000-171130 A Japanese Patent Application Laid-Open No. 11-37619

  However, if the refrigerant leak location is separated from the location where the refrigerant sensor is located, or a flow path (for example, an air inlet, etc.) that allows the refrigerant to leak outside the machine near the coolant leakage location. There is a possibility that the leaked refrigerant can not be detected when the If the amount of leaked refrigerant is small, there is almost no possibility of reaching the flammable concentration even if leakage continues, but for example, a refrigerant circuit like an air conditioner in which a plurality of indoor units are connected to one outdoor unit In the case where a large amount of refrigerant is sealed therein, if a refrigerant leak occurs in one indoor unit, a large amount of the refrigerant continues to leak as it is, which may reach a flammable concentration.

  On the other hand, although it is conceivable to place a large number of refrigerant sensors at different locations in the aircraft, this is a significant cost increase and is not a practical solution.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide an indoor unit of an air conditioner capable of reliably detecting a refrigerant leak with a minimum refrigerant sensor.

(1) A heat exchanger using an indoor unit of the air conditioner according to the first aspect of the present invention (hereinafter simply referred to as "indoor unit") using a slightly flammable or flammable refrigerant having a specific gravity larger than that of air. An indoor unit of an air conditioner, wherein air passing through the air is blown out from a plurality of outlets by an indoor fan and a refrigerant sensor is provided,
And a control unit for controlling the opening and closing of the flaps disposed at each outlet and the operation of the indoor fan,
The refrigerant sensor is provided at or near a flap disposed at one outlet.
The control unit causes the indoor fan to be driven at a rotation speed equal to or lower than the minimum rotation speed in the normal operation in a state where the flaps of the one outlet are opened and the flaps of the outlets other than the one outlet are closed. The leakage detection operation is performed by blowing air from the one air outlet.

  In the indoor unit according to the first aspect of the present invention, the control unit opens the flap of the outlet provided with the refrigerant sensor among the plurality of outlets, and the outlet other than the outlet provided with the refrigerant sensor With the flaps closed, the indoor fan is driven at a rotational speed lower than the minimum rotational speed in normal operation to perform a leakage detection operation in which air is blown out from the one air outlet. In this way, the indoor fan is operated at a low speed, and the air is blown out from one outlet provided with the refrigerant sensor, so that even if the leakage point of the refrigerant and the installation point of the refrigerant sensor are separated, the leakage refrigerant The refrigerant can be introduced to the air flow and guided to the refrigerant sensor, and the leakage of the refrigerant can be detected. As a result, even if the number of refrigerant sensors is one, refrigerant leakage can be detected. When the number of rotations of the indoor fan becomes larger than the minimum number of rotations, the refrigerant may be diffused and may not be detected by the refrigerant sensor. In addition, in this specification, "the vicinity" of a flap is a location or a place within 15 cm from the outer periphery of the said flap.

(2) The indoor unit according to the second aspect of the present invention blows out air passing through a heat exchanger using a slightly flammable or flammable refrigerant having a specific gravity larger than that of air from the blowout port by the indoor fan, and An indoor unit of an air conditioner in which a refrigerant sensor is disposed,
A plurality of flaps are disposed at the outlet,
It further comprises a control unit for controlling the opening and closing of each flap disposed at the outlet and the operation of the indoor fan,
The refrigerant sensor is provided at or near one of a plurality of flaps,
The control unit drives the indoor fan at a rotation speed equal to or lower than the minimum rotation speed in normal operation in a state where the one flap is opened and the flaps other than the one flap are closed to pass through the one flap Perform a leak detection operation to blow out the air.

  In the indoor unit according to the second aspect of the present invention, among the plurality of flaps disposed at the outlet, the flap provided with the refrigerant sensor is opened, and the flap other than the flap provided with the refrigerant sensor is closed. Then, the indoor fan is driven at a rotation speed equal to or lower than the minimum rotation speed at the time of normal operation to perform a leakage detection operation of blowing out air via the one flap. In this way, the indoor fan is operated at a low speed, and air is blown out via one flap provided with the refrigerant sensor, so that even if the leakage point of the refrigerant and the installation point of the refrigerant sensor are separated, leakage occurs. The refrigerant can be introduced into the air flow and guided to the refrigerant sensor, and the leakage of the refrigerant can be detected. As a result, even if the number of refrigerant sensors is one, refrigerant leakage can be detected. When the number of rotations of the indoor fan becomes larger than the minimum number of rotations, the refrigerant may be diffused and may not be detected by the refrigerant sensor.

(3) In the indoor unit of the above (1) or (2), the control unit detects the leak when the difference between the temperature of the intake air into the cabin and the operation set temperature of the indoor unit becomes equal to or less than a predetermined value. It can be driving. In this case, since the indoor temperature is close to the set temperature, the comfort of the living space is not impaired even if the operation of the indoor fan is switched from the normal operation to the leakage detection operation.

(4) In the indoor unit of the above (1) or (2), the control unit may perform the leakage detection operation when starting the operation of the indoor unit. In this case, it is possible to additionally perform the leakage detection for detecting the leakage of the refrigerant during the start-up operation with a small number of rotations immediately after the start of the operation.

(5) In the indoor unit of the above (1) or (2), the control unit may perform the leak detection operation every predetermined time after the start of operation of the indoor unit. In this case, it can be regularly checked whether the refrigerant is leaking.

(6) In the indoor unit of the above (1) to (4), preferably, the control unit repeats a cycle consisting of the operation and stop of the indoor fan at the rotational speed a plurality of times in the leakage detection operation. In this case, air can be circulated to every corner of the machine by stopping the operation once, rather than operating the indoor fan continuously.

  According to the indoor unit of the present invention, it is possible to reliably detect a refrigerant leak with a minimum refrigerant sensor.

It is a perspective view of one embodiment of the indoor unit of the present invention. It is cross-sectional explanatory drawing of the indoor unit shown by FIG. It is a figure explaining movement of a flap. It is a perspective view of other embodiment of the indoor unit of this invention. It is cross-sectional explanatory drawing of the indoor unit shown by FIG.

Hereinafter, embodiments of the indoor unit of the present invention will be described in detail with reference to the attached drawings. The present invention is not limited to these exemplifications, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.
FIG. 1 is a perspective view of an indoor unit 1 according to an embodiment of the present invention, and FIG. 2 is an explanatory sectional view of the indoor unit 1 shown in FIG.

  The indoor unit 1 is a ceiling-embedded indoor unit, and includes a casing 2 that houses various elements such as an indoor fan and a heat exchanger described later, and a decorative panel 3. The casing 2 is a box-like body whose lower end face is opened, and is disposed in an opening formed in the ceiling C as shown in FIG. The decorative panel 3 is formed of a rectangular plate, and a suction port 4 for sucking air in the air-conditioned room is formed at the center. Further, an elongated rectangular air outlet 5 for blowing conditioned air into the air-conditioned room is formed around the inlet 4 along each side of the decorative panel 3.

  Each air outlet 5 is provided with a flap 5 a for adjusting the wind direction of the conditioned air blown out from the air outlet 5 into the air-conditioned room. The flap 5 a is pivotable about an axis along the longitudinal direction of the outlet 5. The rotation of the flap 5a can be performed by a motor (not shown). The flap 5a has a size and a shape that can substantially close the outlet 5, as shown in the flap 5a on the left side of FIG.

  From the indoor side, a suction grill 6 and a filter 7 for removing dust in indoor air sucked from the suction port 4 are disposed in this order from the indoor side to the suction port 4 of the decorative panel 3.

  Inside the casing 2, the air in the air-conditioned room is sucked from the suction port 4 of the decorative panel 3, and after heat exchange, the indoor fan 8 blows out the conditioned air from the blow-out port 5 of the decorative panel 3 into the air-conditioned room And a heat exchanger 9 disposed so as to surround the indoor fan 8. The indoor fan 8 has a motor 10 and an impeller 11. Further, in the casing 2, there is disposed a control unit P which controls the opening and closing of the air outlet 5 and the operation of the indoor fan 8 by the rotation of the flap 5a.

  The heat exchanger 9 is a cross fin tube type heat exchanger formed by being bent so as to surround the indoor fan 8, and in the air to be heat-exchanged by the heat exchanger 9 below the heat exchanger 9. A drain pan 12 is provided for receiving a drain resulting from condensation of water.

  In the drain pan 12, a suction hole 13 corresponding to the suction port 4 of the decorative panel 3 and a blowout hole 14 corresponding to the blowout port 5 of the decorative panel 3 are formed. A bell mouth 15 is attached to the inner edge of the suction hole 13 for guiding the air sucked from the suction port 4 of the decorative panel 3 to the impeller 11 of the indoor fan 8.

  The indoor unit 1 in the present embodiment uses, as a refrigerant, R32 refrigerant which is a slightly flammable or flammable refrigerant. Since this R32 refrigerant has a specific gravity larger than that of air, if it leaks and stays on a floor surface or the like, there is a possibility of reaching the flammable concentration. For this reason, in the present embodiment, the refrigerant sensor 16 is disposed on one of the four flaps 5a (the flap 5a shown on the right in FIG. 2) in order to detect the leaked refrigerant.

In the present embodiment, in addition to the normal operation of the indoor unit 1, the control unit P performs a leakage detection operation to detect the refrigerant that has leaked from the heat exchanger 9 or the like. In this leak detection operation, the control unit P opens the flap 5a provided with the refrigerant sensor 16 and closes the remaining three flaps 5a, and in this state, the minimum number of rotations of the indoor fan 8 during normal operation is Drive at the following speed. Then, the air is blown out from the blowout port 5 provided with the flap 5a in which the refrigerant sensor 16 is disposed. In this way, by operating the indoor fan 8 at a low speed and blowing out the air from one outlet 5 provided with the refrigerant sensor 16, even if the leakage point of the refrigerant and the installation place of the refrigerant sensor 16 are separated The leaked refrigerant can be carried on the air flow and guided to the refrigerant sensor 16, and the leakage of the refrigerant can be detected. As a result, even if the number of refrigerant sensors is one, leakage of the refrigerant can be detected. When the rotation speed of the indoor fan 8 becomes larger than the minimum rotation speed, the refrigerant may be diffused, and the refrigerant sensor 16 may not be able to detect it.
In addition, although the position of the flap 5a in the blower outlet 5 from which air is blown out is not specifically limited in this invention, It is preferable that it is a horizontal direction. While being able to prevent the draft which blows off to the resident of a living room, it is because a saucer-like role of the flap 5a concerned at the time of arranging refrigerant sensor 16 in flap 5a can be heightened.

  The “rotation speed lower than the minimum rotation speed” is not particularly limited in the present invention as long as a wind speed or an air volume capable of circulating air in the machine can be obtained. The minimum number of revolutions of the indoor fan 8 varies depending on the model etc., but is, for example, 300 rpm.

  Further, in the present specification, “close” of the outlet is not limited to the case where the flow of air from the outlet to the air-conditioning room is substantially blocked (see the outlet on the left side of FIG. 2). Is a concept that also includes states that are suppressed. For example, as shown in (a) of FIG. 3, the flap 25 a provided at the outlet 25 is not only in the normal closed state where the convex curved surface of the flap 25 a faces the outer side, but also in FIG. Since the flow of air into the air-conditioned room is suppressed even when the flap 25a is inverted so that the convex curved surface is directed to the inside as shown in FIG. Shall be included in the closing of the In addition, in FIG. 3, the code | symbol C has shown the ceiling and the code | symbol "3" has shown the decorative panel of the indoor unit.

  Various modes can be considered as the timing at which the leak detection operation is carried out. For example, when the difference between the temperature of intake air into the machine and the operation set temperature of the indoor unit 1 becomes equal to or less than a predetermined value, The leak detection operation can be performed when the condition is reached. In this case, since the indoor temperature is close to the set temperature, even if the operation of the indoor fan 8 is switched from the normal operation to the leakage detection operation and the air blowing to the air conditioning chamber is temporarily stopped, the residence There is no loss of space comfort.

  Also, the leak detection operation can be performed when the operation of the indoor unit 1 is started. In this case, it is possible to additionally perform the leak detection for detecting the leakage of the refrigerant during the start-up operation where the number of rotations is small (the number of rotations less than the minimum rotation speed) immediately after the start of operation. During the leak detection operation, it is necessary to open the flap 5a on which the refrigerant sensor 16 is disposed and close the remaining flap 5a.

  In addition, after the start of the operation of the indoor unit 1, it is also possible to perform the leak detection operation every predetermined time, for example, every hour. In this case, it can be regularly checked whether the refrigerant is leaking.

  In the leakage detection operation, the indoor fan 8 may be operated continuously at the rotation speed, but it is preferable to repeat a cycle consisting of operation and stop at the predetermined rotation speed a plurality of times. Air can be circulated to every corner of the machine by stopping the operation once, rather than operating the indoor fan continuously.

[Other Modifications]
The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims.
For example, although the embodiment described above is directed to an indoor unit having a plurality of outlets, the number of the outlets is at least one, and the indoor unit has a plurality of flaps disposed in the outlets. The present invention can also be applied.

FIG. 4 is a perspective view of an indoor unit 31 according to another embodiment of the present invention, and FIG. 5 is a sectional view of the indoor unit 31 shown in FIG.
In the indoor unit 31, although the number of the air outlet 35 is one, the air outlet 35 is provided with two flaps 35a and 35b in parallel. The flaps can be opened and closed independently of each other by a motor (not shown). By driving the indoor fan 38, the air sucked into the machine from the upper surface 32a of the casing 32 is subjected to heat exchange by the heat exchanger 39 and then blown out from the air outlet 35 into the air-conditioned room. A refrigerant sensor 46 is disposed on one of the two flaps 35a and 35b. Driving of both the flaps 35a and 35b and the indoor fan 38 is performed by a control unit P disposed inside the machine.

  The leak detection operation can also be performed in the embodiments shown in FIGS. That is, of the two flaps 35a and 35b disposed at the outlet 35, one of the two flaps 35a provided with the refrigerant sensor 46 is opened and the other flap 35b is closed. The indoor fan 38 is driven at a rotational speed of 1 to perform a leakage detection operation of blowing out air via the one flap 35a. In this way, the indoor fan 38 is operated at a low speed, and air is blown out through one flap 35a provided with the refrigerant sensor 46, so that the leakage point of the refrigerant and the installation place of the refrigerant sensor 46 are temporarily separated. Also, the leaked refrigerant can be put on the air flow and guided to the refrigerant sensor 46, and the leakage of the refrigerant can be detected. As a result, even if the number of refrigerant sensors is one, leakage of the refrigerant can be detected. When the number of rotations of the indoor fan 38 becomes larger than the minimum number of rotations, the refrigerant may be diffused and may not be detected by the refrigerant sensor.

Further, although the refrigerant sensor is disposed on the flap in the embodiment described above, it may be disposed at another place. For example, in the embodiment shown in FIGS. 1 and 2, the refrigerant sensor may be disposed on the wall of the drain pan 12 in the vicinity of the flap 5a, for example, at a place indicated by a or b in FIG. In consideration of the easiness of transmission and reception of signals between the refrigerant sensor and the control unit P, it is more preferable to dispose on the wall of the drain pan 12 inside the machine than to dispose on the flap. Also, in consideration of the flow of air generated by the indoor fan, in other words, the detectability of the leaked refrigerant, the outer wall indicated by a is more desirable than the inner wall indicated by b.
Also, in the embodiments shown in FIGS. 4-5, the refrigerant sensor can also be disposed "in the vicinity" of the flap, i.e., within 15 cm of the outer periphery of the flap. For example, the refrigerant sensor 46a may be disposed on the inner wall of the casing 32 several centimeters away from the edge 35c (see FIG. 5) of the outlet 35. Furthermore, it can also be disposed at the longitudinal end of the flap 35b on the closing side, which is the end closer to the flap 35a on the opening side.

  Moreover, in the embodiment mentioned above, although the indoor unit of a ceiling-embedded type (FIGS. 1-2) or a wall hanging type (FIGS. 4-5) is illustrated, as long as it is the structure which one part of a blower outlet can close. The present invention can also be applied to other types of indoor units, such as a suspended ceiling type indoor unit. Here, a part of the blower outlet refers to a blower outlet other than one blower outlet among a plurality of blower outlets, or when one flap is provided with a plurality of flaps other than one flap It refers to the outlet part where the flap is disposed.

Moreover, in the embodiment described above, the control unit is disposed in the casing of the indoor unit, but such a control unit can be incorporated in, for example, a remote controller outside the indoor unit.
The leak detection driving can be performed by an operation from a remote control or a central management device, or can be performed based on a predetermined schedule. It is also possible to perform leakage detection driving when a person is absent by detecting the absence of a person in the living room with a person detection sensor.

1: indoor unit 2: casing 3: cosmetic panel 4: suction port 5: outlet 5 a: flap 6: suction grille 7: filter 8: indoor fan 9: heat exchanger 10: motor 11: impeller 12: drain 12: drain pan 13: Suction hole 14: blowout hole 15: bell mouth 16: refrigerant sensor 25: outlet 25a: flap 31: indoor unit 32: casing 32a: upper surface 35: outlet 35a: flap 35b: flap 38: indoor fan 39: heat exchanger 46: Refrigerant sensor C: Ceiling P: Controller

Claims (6)

Air passing through a heat exchanger (9) using a slightly flammable or flammable refrigerant having a specific gravity larger than air is blown out from a plurality of outlets (5) by an indoor fan (8), and a refrigerant sensor (16) Is an indoor unit (1) of an air conditioner in which
There is further provided a control unit (P) for controlling the opening and closing of the flaps (5a) disposed in each air outlet (5) and the operation of the indoor fan (8),
The refrigerant sensor (16) is provided in the vicinity of a flap (5a) disposed at one outlet (5) or the flap (5a),
The control unit (P) opens the flap (5a) of the one air outlet (5) and closes the flap (5a) of the air outlet (5) other than the one air outlet (5). An indoor unit (1) of an air conditioner performing a leakage detection operation in which the indoor fan (8) is driven at a rotation speed equal to or lower than a minimum rotation speed in normal operation to blow out air from the one air outlet (5). Air passing through the heat exchanger (39) using a slightly flammable or flammable refrigerant having a specific gravity larger than air is blown out from the blowout port (35) by the indoor fan (38), and the refrigerant sensor (46) It is an indoor unit (31) of an air conditioner, provided
A plurality of flaps are disposed at the outlet (35),
It further comprises a control unit (P) for controlling the opening and closing of each flap (35a) disposed in the air outlet (35) and the operation of the indoor fan (38),
The refrigerant sensor (46) is provided in the vicinity of one of the plurality of flaps (35a) (35a) or the flap (35a),
The control unit (P) opens the one flap (35a) and closes the flaps (35b) other than the one flap (35a), the minimum rotation of the indoor fan (38) in normal operation An indoor unit (31) of an air conditioner, which performs a leakage detection operation in which air is blown out via the one flap (35a) by driving at a rotational speed equal to or less than a number.   The control unit (P) performs the leak detection operation when the difference between the temperature of intake air into the machine and the operation set temperature of the indoor unit (1, 31) becomes equal to or less than a predetermined value. The indoor unit (1, 31) according to claim 2.   The indoor unit (1, 31) according to claim 1 or 2, wherein the control unit (P) performs the leak detection operation when starting the operation of the indoor unit (1, 31).   The indoor unit (1, 31) according to claim 1 or 2, wherein the control unit (P) performs the leak detection operation every predetermined time after the start of the operation of the indoor unit (1, 31).   The control unit (P) repeats a cycle consisting of operation and stop of the indoor fan (8, 38) at the number of rotations in the leakage detection operation, a plurality of times. The indoor unit as described in (1, 31).

Images