JP2017015324A - Indoor machine of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor machine of an air conditioner capable of surely detecting refrigerant leakage with a minimum numbers of refrigerant sensors.SOLUTION: An indoor machine 1 of an air conditioner blows air, passing through a heat exchanger 9 using finely-combustible or combustible refrigerant with a specific gravity larger than air, from a blowout port 5 by an indoor fan 8; and includes a refrigerant sensor thereinside. The indoor machine further includes a control unit P configured to control opening/closing of the blowout port 5 and operation of the indoor fan 8. The control unit P performs leakage detection operation in which in a state of closing the blowout port 5, air is circulated through the indoor machine by driving the indoor fan 8 at a rotational frequency equal to or less than a minimum rotational frequency in normal operation.SELECTED DRAWING: Figure 2

Description

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

  In recent years, the adoption of R32 refrigerant having a low global warming potential is progressing in air conditioners that cool and heat indoors using a vapor compression refrigeration cycle. However, the R32 refrigerant has a slight flammability (slight flammability), and if a refrigerant having a specific gravity greater than that of air leaks, it may stay near the floor and reach a flammable concentration. For this reason, a refrigerant sensor is arranged in the indoor unit in order to determine the presence or absence of leakage from the refrigerant circuit, and when this refrigerant sensor detects refrigerant leakage, the on-off valve provided in the refrigerant circuit is opened to It has been proposed to collect the leaked refrigerant in a container connected to the on-off valve (see Patent Document 1), or drive the indoor fan provided in the indoor unit to diffuse the leaked refrigerant (Patent Document 2). Yes.

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

  However, when the refrigerant leak location is separated from the location where the refrigerant sensor is installed, or when the refrigerant leak location is close to the refrigerant leak location, the flow path (for example, an air inlet or the like) allows the refrigerant to leak outside the machine. ) May not be able to be detected. If the amount of leaked refrigerant is small, even if it continues to leak, there is almost no possibility of reaching a flammable concentration. For example, a refrigerant circuit like an air conditioner in which a plurality of indoor units are connected to one outdoor unit When a large amount of refrigerant is sealed inside, if a refrigerant leaks in one indoor unit, a large amount of refrigerant will continue to leak, and there is a possibility of reaching a flammable concentration.

  On the other hand, it is conceivable to arrange a large number of refrigerant sensors at different locations in the machine, but this increases the cost significantly and is not a realistic solution.

  This invention is made | formed in view of such a situation, and it aims at providing the indoor unit of an air conditioning apparatus which can detect a refrigerant | coolant leak reliably with the minimum refrigerant | coolant sensor.

(1) The indoor unit of the air conditioner of the present invention (hereinafter, also simply referred to as “indoor unit”) allows air passing through a heat exchanger using a slightly flammable or flammable refrigerant having a specific gravity greater than that of air to the room. It is an indoor unit of an air conditioner that is blown out from a blowout port by a fan, and a refrigerant sensor is arranged in the machine,
A control unit for controlling the opening and closing of the air outlet and the operation of the indoor fan;
The control unit performs a leak detection operation in which the indoor fan is driven at a rotation speed equal to or lower than the minimum rotation speed during normal operation in a state where the air outlet is closed to circulate air in the apparatus.

  In the indoor unit of the present invention, the control unit circulates air in the machine by driving the indoor fan at a rotation speed equal to or lower than the lowest rotation speed during normal operation in a state where the outlet of the indoor unit is closed ( Leak detection operation). As a result, even if the location where the refrigerant leaks and the location where the refrigerant sensor is disposed are separated, the leaked refrigerant can be guided to the air flow by being put on the air flow, and the refrigerant leakage can be detected. . As a result, even if the number of refrigerant sensors is the minimum number, usually one, refrigerant leakage can be detected. If the rotation speed of the indoor fan becomes larger than the minimum rotation speed, the refrigerant may diffuse and cannot be detected by the refrigerant sensor.

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

(3) In the indoor unit of (1), the control unit may perform the leakage detection operation when starting the operation of the indoor unit. In this case, leakage detection for detecting leakage of the refrigerant at the time of start-up operation with a small number of revolutions immediately after the start of operation can be performed together. At that time, it is necessary to close the air outlet during the leak detection operation.

(4) In the indoor unit of (1), the control unit may perform the leakage detection operation every predetermined time after the operation of the indoor unit is started. In this case, it can be periodically checked whether or not the refrigerant is leaking.

(5) In the indoor units of (1) to (4) above, it is preferable that the control unit repeats a cycle including the operation and stop of the indoor fan at the rotation speed a plurality of times in the leakage detection operation. In this case, the air can be circulated to every corner of the machine by temporarily stopping the operation, rather than continuously operating the indoor fan.

(6) In the indoor units of the above (1) to (5), the refrigerant sensor can be disposed below a connection portion where a refrigerant pipe from outside the apparatus is connected to the heat exchanger. In this case, the refrigerant leakage can be detected more reliably by disposing the refrigerant sensor below the portion where the possibility of refrigerant leakage is high.

(7) In the indoor units of (1) to (6), the refrigerant sensor can be disposed in the vicinity of a drain discharge portion in a drain pan disposed below the heat exchanger. In this case, the refrigerant leaking from the heat exchanger moves in the drain pan disposed below the heat exchanger toward the drain discharge portion, so that the refrigerant leakage can be detected more reliably. .
(8) The indoor unit of the above (1) to (5) may include a box body that surrounds a pipe connection portion outside the casing of the indoor unit, and a flow path that guides a leakage refrigerant in the box body into the casing. it can. In this case, since the box body surrounding the pipe connection part outside the casing is provided and the flow path for guiding the leaked refrigerant in the box body into the casing is provided, the leakage point of the refrigerant can be obtained by performing the leakage detection operation described above. Even if the location where the refrigerant sensor is disposed is separated, the leakage refrigerant introduced into the casing can be guided to the refrigerant sensor by being put on the air flow, and leakage of the refrigerant can be detected.

  According to the indoor unit of the present invention, refrigerant leakage can be reliably detected with the minimum refrigerant sensor.

It is a perspective view of one embodiment of the indoor unit of the present invention. It is a section explanatory view of the indoor unit shown in FIG. It is a plane explanatory view of the indoor unit shown in FIG. It is a figure explaining the motion of a flap. It is a plane explanatory view of other embodiments of the indoor unit of the present invention. FIG. 6 is a partially enlarged plan explanatory view of the indoor unit shown in FIG. 5. FIG. 6 is a cross-sectional explanatory diagram of the indoor unit shown in FIG. 5.

  Hereinafter, embodiments of an indoor unit of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of an indoor unit 1 according to an embodiment of the present invention, FIG. 2 is a cross-sectional explanatory view of the indoor unit 1 shown in FIG. 1, and FIG. 3 is a view of the room shown in FIG. It is a plane explanatory view of the machine 1.

  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 formed of a box-like body having an open lower end surface, and is disposed in an opening formed in the ceiling C as shown in FIG. The decorative panel 3 is formed of a quadrangular plate, and a suction port 4 for sucking air in the air-conditioned room is formed at the center. In addition, an elongated rectangular air outlet 5 that blows out conditioned air into the air-conditioned room is formed around the inlet 4 so as to extend along each side of the decorative panel 3.

  Each air outlet 5 is provided with a flap 5a that adjusts the direction of the conditioned air blown from the air outlet 5 into the air-conditioned room. The flap 5a can be rotated around an axis along the longitudinal direction of the outlet 5. The flap 5a can be rotated by a motor (not shown). The flap 5a has a size and shape that can substantially close the air outlet 5 as shown in the flap 5a on the left side of FIG.

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

  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 is performed on the air, the indoor fan 8 that blows conditioned air into the air-conditioned room from the outlet 5 of the decorative panel 3. And the heat exchanger 9 arrange | positioned so that the said indoor fan 8 may be enclosed. The indoor fan 8 has a motor 10 and an impeller 11. Further, a control unit P for controlling the opening / closing of the air outlet 5 by the rotation of the flap 5 a and the operation of the indoor fan 8 is disposed in the casing 2.

  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 has one end 9 a (see FIG. 3) from an outdoor unit (not shown). Refrigerant piping is connected. Below the heat exchanger 9, a drain pan 12 is provided for receiving drainage generated by condensation of moisture in the air heat exchanged by the heat exchanger 9.

  A groove 13 is formed in the drain pan 12, and the lower end of the heat exchanger 9 is disposed in the groove 13. The bottom surface of the groove portion 13 is inclined so that one portion becomes the lowest portion, and the groove portion having the lowest bottom surface 13a falls from the heat exchanger 9 and flows through the inclined bottom surface. A drain pump 14 is provided for discharging the drain. In the drain pan 12, a suction hole 15 corresponding to the suction port 4 of the decorative panel 3 and a blowout hole 16 corresponding to the blowout port 5 of the decorative panel 3 are formed. A bell mouth 17 for guiding air sucked from the suction port 4 of the decorative panel 3 to the impeller 11 of the indoor fan 8 is attached to the inner edge of the suction hole 15.

  The indoor unit 1 in the present embodiment uses R32 refrigerant, which is a slightly flammable or flammable refrigerant, as the refrigerant. Since this R32 refrigerant has a higher specific gravity than air, it may reach a flammable concentration if it leaks and stays on the floor or the like. For this reason, in this embodiment, there is a high possibility of refrigerant leakage, and in the vicinity of the end portion 9a of the heat exchanger 9 provided with a connection portion where the heat exchanger 9 and the refrigerant pipe from the outside are connected. A refrigerant sensor 18 is provided. More specifically, a refrigerant sensor 18 is disposed on the bottom surface 13b of the groove 13 of the drain pan 12 in the vicinity of the end 9a.

  In the present embodiment, in addition to the normal operation of the indoor unit 1, the control unit P performs a leakage detection operation in order to detect the refrigerant that has leaked from the heat exchanger 9 and the like. In this leak detection operation, the air is circulated in the machine by driving the indoor fan 8 at a rotation speed equal to or lower than the minimum rotation speed during normal operation in a state where the flap 5a is driven to close the outlet 5. As a result, even if the leakage location of the refrigerant and the vicinity of the end 9a of the heat exchanger 9 where the refrigerant sensor 18 is disposed are separated from each other, the leakage refrigerant is put on the air flow and the refrigerant sensor. 18 can be detected, and refrigerant leakage can be detected.

  The “number of revolutions equal to or less than the minimum number of revolutions” is not particularly limited in the present invention as long as a wind speed or air volume capable of circulating air in the machine is obtained. The minimum rotational speed of the indoor fan 8 varies depending on the model and the like, but is, for example, 300 rpm.

  Further, in this specification, “closing” of the air outlet means not only when the air flow from the air outlet to the air-conditioned room is substantially blocked (see the air outlet on the left side of FIG. 2), but also the air flow. This is a concept including a state in which is suppressed. For example, as shown in FIG. 4 (a), the flap 25a provided at the outlet 25 is not only in a normal closed state in which the convex curved surface of the flap 25a faces the outside of the machine, ), Since the flow of air into the air-conditioned room is suppressed even when the flap 25a is inverted and the convex curved surface faces the inside of the machine, the state where the flap is inverted is also the outlet in the present specification. It shall be included in “Closed” of In addition, in FIG. 4, the code | symbol C has shown the ceiling and the code | symbol "3" has shown the decorative panel of the indoor unit.

  There are various possible timings for performing the leak detection operation. For example, when the difference between the temperature of the air sucked into the machine and the operation set temperature of the indoor unit 1 becomes a predetermined value or less, that is, the thermo-off is entered. When conditions are met, leakage detection operation can be performed. 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-conditioned room is temporarily stopped, There is no loss of comfort in space.

  Moreover, the leakage detection operation can be performed when the operation of the indoor unit 1 is started. In this case, it is possible to perform leakage detection for detecting refrigerant leakage at the time of start-up operation with a small rotation speed (rotation speed equal to or lower than the minimum rotation speed) immediately after the start of operation. During the leak detection operation, the air outlet 5 needs to be closed by the flap 5a.

  Further, after the operation of the indoor unit 1 is started, the leak detection operation can be performed every predetermined time, for example, every hour. In this case, it can be periodically checked whether or not the refrigerant is leaking.

  Further, in the leak detection operation, the indoor fan 8 may be continuously operated at the rotation speed, but it is preferable to repeat a cycle including operation and stop at the predetermined rotation speed a plurality of times. Rather than continuously operating the indoor fan, it is possible to circulate air to every corner of the machine by temporarily stopping the operation.

[Other variations]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.
For example, in the above-described embodiment, the refrigerant sensor is disposed in the vicinity of the end 9a of the heat exchanger 9, but the drain in the drain pan 12 disposed at other locations, for example, below the heat exchanger 9, is provided. It can arrange | position in the vicinity of the discharge part (location where the drain pump is arrange | positioned). In this case, since the refrigerant leaking from the heat exchanger 9 moves toward the drain discharge portion in the drain pan 12 disposed below the heat exchanger 9, it is possible to reliably detect the refrigerant leak. Can do.

  In the above-described embodiment, the ceiling-embedded indoor unit is illustrated. However, as long as the air outlet is configured to be closed, other types of indoor units such as a ceiling-suspended indoor unit and a wall-mounted indoor unit are illustrated. The present invention can also be applied to a machine or the like.

  In the above-described embodiment, the number of refrigerant sensors is “1”. However, the number may be “2” depending on the size of the indoor unit. In this case, the effect of cost reduction is reduced, but the leakage of the refrigerant can be detected more reliably. In the present specification, “minimum” means that the number of refrigerant sensors is not necessarily limited to “1”.

  In the above-described embodiment, the control unit is disposed in the casing of the indoor unit. However, such a control unit can be incorporated in a remote controller outside the indoor unit, for example.

  In the above-described embodiment, the refrigerant leaked inside the casing of the indoor unit is detected, but the refrigerant leaked outside the casing can also be detected. For example, as shown in FIGS. 5 to 7, when the refrigerant pipe from the outdoor unit and the refrigerant pipe from the inside of the casing 2 are connected to the outside of the casing 2, the refrigerant leakage from the pipe connection portion 30 is detected as the refrigerant in the casing 2. It can also be detected by the sensor 18. In the indoor units shown in FIGS. 5 to 7, the same or equivalent components as those in the indoor units shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted for simplicity.

Specifically, the pipe connection portion 30 existing outside the casing 2 is hermetically surrounded by the box body 31, and a flow path 32 from the inside of the box body 31 to the groove portion 13 of the drain pan 12 is provided. 5 to 7, the flow path 32 is a flow path that leads to the refrigerant sensor 18 disposed in the deepest portion D (see FIG. 5) of the renpan (see arrow A in FIG. 6). As shown by a two-dot chain line in FIG. 6, a flow path 32 a that leads to the refrigerant sensor 18 a disposed in the vicinity of the air outlet 16 may be used.
By adopting the above configuration, the refrigerant leaked from the pipe connection portion 30 fills the inside of the box body 30 and then flows through the flow path 32 to the deepest portion D of the drain pan. Then, by performing the above-described leakage detection operation, even if the outlet of the flow path 32 and the location where the refrigerant sensor 18 is disposed are separated, the leaked refrigerant can be guided to the refrigerant sensor 18 by being put on the air flow. The refrigerant leakage can be detected.

DESCRIPTION OF SYMBOLS 1: Indoor unit 2: Casing 3: Cosmetic panel 4: Suction port 5: Air outlet 5a: Flap 6: Suction grill 7: Filter 8: Indoor fan 9: Heat exchanger 9a: End part 10: Motor 11: Impeller 12 : Drain pan 13: Groove portion 13a: Bottom surface 13b: Bottom surface 14: Drain pump 15: Suction hole 16: Blowout hole 17: Bell mouth 18: Refrigerant sensor 18a: Refrigerant sensor 25: Outlet 25a: Flap 30: Piping connection part 31: Box Body 32: Channel C: Ceiling D: Deepest part P: Control part

Claims (8)

Air passing through a heat exchanger (9) using a slightly flammable or flammable refrigerant having a specific gravity greater than that of air is blown out from an outlet (5) by an indoor fan (8), and a refrigerant sensor (18) is put into the machine. Is an indoor unit (1) for an air conditioner,
A control unit (P) for controlling the opening and closing of the air outlet (5) and the operation of the indoor fan (8);
The controller (P) detects leakage in which the indoor fan (8) is driven at a rotational speed equal to or lower than the lowest rotational speed during normal operation with the air outlet (5) closed, thereby circulating air in the machine. An indoor unit (1) of an air conditioner that operates.   The control unit (P) according to claim 1, wherein the control unit (P) performs the leakage detection operation when a difference between a temperature of the intake air into the apparatus and an operation set temperature of the indoor unit (1) becomes a predetermined value or less. Indoor unit (1).   The indoor unit (1) according to claim 1, wherein the control unit (P) performs the leakage detection operation when starting the operation of the indoor unit (1).   The indoor unit (1) according to claim 1, wherein the control unit (P) performs the leakage detection operation every predetermined time after the operation of the indoor unit (1) is started.   The said control part (P) repeats the cycle which consists of a driving | operation and a stop of the indoor fan (8) in the said rotation speed in the said leak detection driving | operation several times. Indoor unit (1).   The said refrigerant | coolant sensor (18) is arrange | positioned under the connection part to which the refrigerant | coolant piping from the outside of the apparatus is connected to the said heat exchanger (9). The indoor unit (1) described.   The said refrigerant | coolant sensor (18) is arrange | positioned in the vicinity of the drain discharge part in the drain pan (12) arrange | positioned under the said heat exchanger (9). The indoor unit (1) described in the paragraph. A box (31) surrounding the pipe connection (30) outside the casing (2) of the indoor unit (1), and a flow path (32) for guiding the leaked refrigerant in the box (31) into the casing (2). The indoor unit (1) according to any one of claims 1 to 5, further comprising:

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