JP2017032249A - Indoor unit including discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor unit capable of preventing contact of leaked refrigerant of combustible concentration with a high voltage portion of a discharge device, in the indoor unit in which the discharge device is disposed at a lower portion with respect to a part constituting a refrigeration cycle.SOLUTION: An indoor unit 1 includes a refrigeration cycle constitution portion including a heat exchanger 15 and a refrigerant pipe, an indoor fan 14, a discharge device 8 disposed at a lower portion of the refrigeration cycle constitution portion, and a control portion P for controlling operations of the indoor fan 14 and the discharge device 8, and uses a slightly combustible or combustible refrigerant having a specific gravity higher than that of air. The control portion P starts or stops the operation of the discharge device 8, after lapse of a first prescribed time from the start of the operation of the indoor fan 14, during the operation of the indoor fan 14, or before lapse of a second prescribed time from a command of the operation stop of the indoor fan 14.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an indoor unit including a discharge device. More specifically, the present invention relates to an indoor unit that includes a discharge device and uses a slightly flammable or combustible refrigerant having a specific gravity greater than that of air.

  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, since the R32 refrigerant has slight flammability (slight flammability), it is necessary to be careful in handling it when using it.

  On the other hand, in addition to the conventional cooling and heating functions, an indoor unit has been proposed in which various functions such as dust collection, sterilization, and deodorization using a discharge phenomenon by a discharge device are added. When a flammable refrigerant is used in an indoor unit equipped with such a discharge device, the flammable refrigerant leaks from a part constituting the refrigeration cycle such as a heat exchanger or a refrigerant pipe, and the leaked refrigerant is discharged to a high voltage portion of the discharge device. Contact may cause ignition by discharge energy.

  Therefore, in order to avoid the risk of such ignition, as shown in FIG. 5, the discharge device 50 is disposed above the portion constituting the refrigeration cycle such as the heat exchanger 51 and the refrigerant pipe, and the air An air conditioner 52 that prevents the leaked refrigerant from reaching the high voltage portion of the discharge device 50 even if a refrigerant having a higher specific gravity than the refrigerant leaks from the heat exchanger 51, the refrigerant pipe, or the like has been proposed (patent). Reference 1). In FIG. 5, reference numeral 53 denotes an air filter disposed on the suction side of the indoor fan 54, and reference numeral 55 denotes a gas sensor that detects leakage of the refrigerant.

JP2013-64524A

  However, the technique described in Patent Document 1 can be applied only to an indoor unit in which the air suction port is disposed on the side or upper side of the casing, and its application range is limited. In a ceiling-embedded or ceiling-suspended indoor unit, an air suction port is generally formed on the lower surface of the casing. In this case, a discharge device such as an electric dust collector is disposed on the suction side of the indoor fan. Therefore, when the refrigerant leaks from a heat exchanger or the like located above the discharge device and the leaked refrigerant having a flammable concentration comes into contact with the high voltage portion of the discharge device, the leaked refrigerant may be ignited.

  The present invention has been made in view of such circumstances, and is an indoor unit in which a discharge device is disposed below a portion constituting a refrigeration cycle, in which a leaked refrigerant having a flammable concentration is a high voltage part of the discharge device. An object of the present invention is to provide an indoor unit that can prevent contact with the indoor unit.

(1) An indoor unit including the discharge device of the present invention (hereinafter also simply referred to as “indoor unit”) includes a refrigeration cycle component including a heat exchanger and a refrigerant pipe, an indoor fan, and the refrigeration cycle component An indoor unit that includes a discharge device disposed below and a control unit that controls the operation of the indoor fan and the discharge device, and uses a slightly flammable or flammable refrigerant having a specific gravity greater than that of air,
The control unit starts or stops the operation of the discharge device, after the first predetermined time has elapsed since the start of the operation of the indoor fan, or during the operation of the indoor fan or the operation stop of the indoor fan, respectively. This is performed before the second predetermined time elapses from the instruction.

  In the indoor unit of the present invention, the control unit performs the second predetermined time after the first predetermined time has elapsed since the start of the operation of the indoor fan, or during the operation of the indoor fan or from the instruction to stop the operation of the indoor fan. Before the elapse of time, the operation of the discharge device is started or stopped. In other words, when the discharge device is in operation, the indoor fan is in a state of constant operation, so in the unlikely event that the indoor unit is stopped, a refrigeration cycle configuration including a heat exchanger and refrigerant piping Even if the refrigerant leaks from the section, the leaked refrigerant is diffused by the air flow generated by the drive of the indoor fan, so that it stays in the vicinity of the high voltage section of the discharge apparatus when the discharge apparatus starts operation. Not done. Therefore, it is possible to avoid a risk that the leaked refrigerant ignites when the leaked refrigerant having a combustible concentration comes into contact with the high voltage portion of the operating discharge device. Even if the refrigerant leaks from the refrigeration cycle component during the operation of the indoor unit, the leaked refrigerant is diffused by the air flow generated by driving the indoor fan. Almost does not reach the high voltage part of the arranged discharge device. As a result, it is possible to avoid the risk that the leaked refrigerant ignites when the leaked refrigerant having a flammable concentration comes into contact with the high voltage portion of the operating discharge device. The “state of constant operation” means that the indoor fan is in normal operation, and the rotational speed is lower than that in normal operation, but the leaked refrigerant can be diffused. It is an operating state capable of generating an air flow.

(2) In the indoor unit of (1), the first predetermined time is a time for the rotation speed of the indoor fan to reach a predetermined rotation speed,
The second predetermined time may be a time during which the rotation speed of the indoor fan decreases from the rotation speed during operation to the predetermined rotation speed. In this case, since the control unit starts or stops the operation of the discharge device when the rotational speed of the indoor fan exceeds a predetermined rotational speed, even if the refrigerant leaks from the refrigeration cycle component, It can be diffused, and the leakage refrigerant of combustible concentration can be prevented from coming into contact with the high voltage part of the discharge device arranged below the refrigeration cycle constituent part.

(3) In the indoor unit of (2), the predetermined rotation speed can be set to the minimum rotation speed of the indoor fan. In this case, if the indoor fan is operated at the minimum rotational speed or more, even if the refrigerant leaks from the refrigeration cycle component, the leaked refrigerant can be diffused, and the leaked refrigerant having a flammable concentration is below the refrigeration cycle component. Can be prevented from coming into contact with the high voltage portion of the discharge device disposed in the.

  According to the indoor unit of the present invention, in the indoor unit in which the discharge device is disposed below the portion constituting the refrigeration cycle, it is possible to prevent the leaked refrigerant having a flammable concentration from contacting the high voltage portion of the discharge device. .

It is a perspective explanatory 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 time flow which shows the relationship between ON / OFF operation of an indoor unit, indoor fan rotation speed, and ON / OFF of a discharge device. It is sectional explanatory drawing of other embodiment of the indoor unit of this invention. It is sectional explanatory drawing of the conventional indoor unit.

  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 explanatory view of an indoor unit 1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional explanatory 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 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 suction port 4 of the decorative panel 3 includes a suction grill 6, a pre-filter 7 for removing relatively large dust in the indoor air sucked from the suction port 4, a discharge device 8, and a primary filter from the indoor side. 9 and the secondary filter 10 are arranged in this order.

As shown in FIG. 2, the discharge device 8 includes a counter electrode 11, an ionization line 12, and a streamer discharge electrode 13. The counter electrode 11 is made of a metal plate having a square-wave cross section. The ionization line 12 is made of a tungsten wire having a small diameter and is used as a discharge electrode. The streamer discharge electrode 13 is composed of an electrode bar 13a and a needle electrode 13b.
The counter electrode 11 and the ionization line 12 have a role of charging relatively small dust contained in the air that has passed through the prefilter 7. On the other hand, the counter electrode 11 and the streamer discharge electrode 13 have a role of generating so-called active species. Specifically, when a DC, AC, or pulse discharge voltage is applied between the counter electrode 11 and the streamer discharge electrode 13, a streamer discharge is generated between the electrodes, and low-temperature plasma is generated in the discharge field. This low-temperature plasma generates active species such as tadical species such as ions, ozone, and hydroxy radicals, and cold forging molecules such as excited oxygen molecules and excited nitrogen molecules. These active species have a high energy level and have the ability to decompose and deodorize organic molecules such as ammonia and aldehydes contained in the air.

  The primary filter 9 has an electrostatic filter, and a part of positively charged fine particles, odor molecules, and the like in the discharge device 8 is electrostatically adsorbed. Titanium dioxide is supported on the secondary filter 10, and viruses, fungi, and the like that have not been adsorbed by the primary filter 9 are adsorbed.

  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 14 that blows conditioned air into the air-conditioned room from the outlet 5 of the decorative panel 3. And the heat exchanger 15 arrange | positioned so that the said indoor fan 14 may be enclosed. The indoor fan 14 includes a motor 16 and an impeller 17.

The heat exchanger 15 is a cross fin tube type heat exchanger formed by being bent so as to surround the indoor fan 14. Below the heat exchanger 15, a drain pan 118 is disposed for receiving drainage generated by condensation of moisture in the air heat exchanged by the heat exchanger 15.
A control unit P that controls the operation of the indoor fan 14 and the discharge device 8 is disposed in the casing 2.

  The indoor unit 1 in the present embodiment uses R32 refrigerant, which is a slightly flammable or flammable refrigerant, as the refrigerant. Moreover, the discharge device 8 is arrange | positioned below the refrigerating-cycle structure part containing the heat exchanger 15 and refrigerant | coolant piping. Since the R32 refrigerant has a higher specific gravity than air, if the refrigerant leaks from the refrigeration cycle component, the leaked refrigerant may come into contact with a high voltage part such as the ionization line 12 in the discharge device 8. And when the leaking refrigerant of combustible concentration contacts the operating high voltage part, the leaking refrigerant may be ignited.

  Therefore, in the indoor unit 1 according to the present embodiment, the control unit P has a predetermined time (first predetermined time) from the start of the operation of the indoor fan 14 regarding the operation of the discharge device 8 and the indoor fan 14. After a lapse of time, the operation of the discharge device 8 is started in a state where the rotational speed of the indoor fan 14 exceeds a predetermined rotational speed. Also, during the operation of the indoor fan 14, or before a predetermined time (second predetermined time) has elapsed from an instruction to stop the operation of the indoor fan 14 (for example, an instruction to stop the operation of the indoor unit 1 by remote control operation). The operation of the discharge device 8 is stopped in a state where the rotational speed of the indoor fan 14 exceeds a predetermined rotational speed. In this way, the rotational speed of the indoor fan 14 exceeds the predetermined rotational speed during the operation of the discharge device 8, so that the heat exchanger 15 and the refrigerant pipe should be connected while the indoor unit 1 is stopped. Even if the refrigerant leaks from the refrigeration cycle components including and stays in the vicinity of the high voltage portion of the discharge device 8, the leaked refrigerant is diffused by the air flow generated by driving the indoor fan 14. When the discharge device 8 starts operation when the rotational speed of the indoor fan 14 exceeds the predetermined rotational speed, the indoor fan 14 is no longer staying near the high voltage portion of the discharge device 8. Therefore, it is possible to avoid the risk that the leaked refrigerant ignites when the leaked refrigerant having a combustible concentration comes into contact with the high voltage portion of the discharging device 8 in operation.

  Further, even if the refrigerant leaks from the refrigeration cycle constituent unit during the operation of the indoor unit 1, the leaked refrigerant is diffused by the air flow generated by the indoor fan 14 being driven. Hardly reaches the high-voltage part of the discharge device 8 arranged below. As a result, it is possible to avoid a risk that the leaked refrigerant ignites when the leaked refrigerant having a combustible concentration comes into contact with the high voltage portion of the operating discharge device 8.

  The “predetermined number of rotations” can be the minimum number of rotations of the indoor fan, for example. If the indoor fan 14 is operated at the minimum number of revolutions or more, even if the refrigerant leaks from the refrigeration cycle component, the leaked refrigerant can be sufficiently diffused, and the flammable refrigerant leaks in the refrigeration cycle component. It can prevent contacting the high voltage part of the discharge device arrange | positioned below. The minimum rotational speed of the indoor fan 14 varies depending on the model and the like, but is, for example, 300 rpm.

  For example, the control unit P of the indoor unit 1 monitors the rotational speed of the indoor fan 14 after the start of driving, and the predetermined time (first predetermined time) has passed. When the rotational speed exceeds the predetermined rotational speed, the operation of the discharge device 8 can be started. Moreover, as a timing which stops the driving | operation of the discharge device 8, the driving | operation of the indoor fan 14 can be stopped after stopping the driving | operation of the discharging device 8 first, for example. Further, for example, the rotational speed of the indoor fan 14 exceeds the predetermined rotational speed before a predetermined time (second predetermined time) has elapsed from an instruction to stop the operation of the indoor unit 1, that is, the indoor fan 14 by remote control. Sometimes the operation of the discharge device 8 can be stopped. In this case, since the indoor fan 14 is in a constant operating state during the operation of the discharge device 8, even if the refrigerant leaks from the refrigeration cycle component, the leaked refrigerant can be diffused by the air flow generated by the indoor fan 14. It is possible to prevent the leaked refrigerant having a flammable concentration from coming into contact with the high voltage part of the discharge device 8 disposed below the refrigeration cycle constituent part. In other words, even if the operation of the indoor fan 14 is stopped and the rotational speed of the indoor fan 14 becomes equal to or lower than the predetermined rotational speed, the discharge device 8 stops operating at that time, so that the leaked refrigerant diffuses. Even if it comes into contact with the high voltage portion of the discharge device 8 without being leaked, the leaked refrigerant does not ignite.

FIG. 3 shows the relationship between the on / off operation of the indoor unit 1, the rotational speed of the indoor fan 14, and the on / off of the discharge device 8 when the “predetermined rotational speed” is the minimum rotational speed of the indoor fan 14. Time flow. The horizontal axis indicates time. Rotational speed of the indoor fan 14 in the first time of a predetermined time t1 has elapsed the start of the operation of the indoor fan 14 by turning on the operation of the indoor unit 1 reaches the minimum rotational speed f ₀ of the indoor fan 14 by remote control. Discharge device 8, the operation is started after the indoor fan 14 reaches the minimum rotational speed f _0.
On the other hand, lowering the rotation speed of the indoor fan 14 issues a shutdown instruction of the indoor fan 14 to turn off the indoor unit 1 to the second time the predetermined time t2 has elapsed by remotely controlled to the lowest rotational speed f ₀ of the indoor fan 14 To do. Discharge device 8 stops the operation before the indoor fan 14 is reduced to minimum frequency f _0.

[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 ceiling-embedded indoor unit is illustrated, but as long as the discharge device is disposed below the refrigeration cycle component, other types of indoor units, for example, ceiling-suspended indoor units The present invention can be applied to a machine, a wall-mounted indoor unit, and the like.

  FIG. 4 is a cross-sectional explanatory view of a ceiling-suspended indoor unit 21 according to another embodiment of the present invention. In this indoor unit 21, an air suction port 23 is formed in a part of the lower surface of the casing 22, and the air is sucked into the device from the suction port 23 by the indoor fan 24 and passes through the heat exchanger 25 to exchange heat. The conditioned air is blown out into the living room space from an outlet 26 formed on one side of the casing 22. A discharge device 27 is disposed in the suction port 23. The discharge device 27 includes a frame 28, an electrostatic filter 29, a discharge unit 30, a support frame 31 that supports the discharge unit 30, and a prefilter 32. It causes discharge to decompose harmful substances in the air. A control unit P that controls the operation of the indoor fan 24 and the discharge device 27 is disposed in the casing 22.

  Also in the indoor unit 21 shown in FIG. 4, as in the indoor unit 1, the discharge device 27 is disposed below the refrigeration cycle constituent part including the heat exchanger 25 and the refrigerant pipe, and the R32 refrigerant is from air. Since the specific gravity is large, if the refrigerant leaks from the refrigeration cycle component, the leaked refrigerant may come into contact with the discharge unit 30 in the discharge device 27. Even in this case, the controller P starts or stops the operation of the discharge device 27 in a state where the rotational speed of the indoor fan 24 exceeds the predetermined rotational speed, so that the refrigerant leaks from the refrigeration cycle constituent part. Even if it does, the risk that the leakage refrigerant of the combustible density | concentration will ignite by contacting the high voltage part of the discharge device 27 in operation can be avoided.

  In the embodiment described above, the discharge device is exemplified as one that performs streamer discharge that generates active species, but the discharge device in the present invention is not limited to this, and has a general electric dust collection function. The present invention can also be applied to an indoor unit provided with a discharging device.

  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 start or stop of the operation of the discharge device is controlled based on the rotational speed of the indoor fan, but the air flow that can diffuse the leaked refrigerant after the operation of the indoor fan is started. When the time (first predetermined time) until the amount of air that can be generated is known in advance, the time (first predetermined time) has elapsed since the start of the operation of the indoor fan It can be set as control which starts the operation of the discharge device later. The first predetermined time, that is, the time from the start of the operation of the indoor fan to the start of the operation of the discharge device can be set to, for example, 15 to 25 seconds.
In addition, when the time (second predetermined time) during which the air flow rate capable of generating the air flow capable of diffusing the leaked refrigerant is kept in advance after the operation of the indoor fan is stopped, It can be set as the control which stops the driving | operation of a discharge device before the said time (2nd predetermined time) passes after stopping a fan driving | operation.

DESCRIPTION OF SYMBOLS 1: Indoor unit 2: Casing 3: Cosmetic panel 4: Suction port 5: Air outlet 5a: Flap 6: Suction grill 7: Pre filter 8: Discharge device 9: Primary filter 10: Secondary filter 11: Counter electrode 12: Ionization Line 13: Streamer discharge electrode 13a: Electrode bar 13b: Needle electrode 14: Indoor fan 15: Heat exchanger 16: Motor 17: Impeller 18: Drain pan 21: Indoor unit 22: Casing 23: Suction port 24: Indoor fan 25: Heat exchanger 26: Suction port 27: Discharge device 28: Frame 29: Electrostatic filter 30: Discharge unit 31: Support frame 32: Prefilter 50: Discharge device 51: Heat exchanger 52: Air conditioner 53: Air filter 54: Indoor fan 55: Gas sensor C: Ceiling P: Control unit

Claims (3)

A refrigeration cycle component including a heat exchanger (15) and refrigerant piping, an indoor fan (14), a discharge device (8) disposed below the refrigeration cycle component, the indoor fan (14), and discharge An indoor unit (1) that includes a control unit (P) that controls the operation of the device (8) and uses a slightly flammable or flammable refrigerant having a specific gravity greater than that of air,
The control unit (P) starts or stops the operation of the discharge device (8) after the first predetermined time has elapsed since the start of the operation of the indoor fan (14), or the indoor fan ( The indoor unit (1), which is performed during the operation of 14) or before the second predetermined time has elapsed from the operation stop instruction of the indoor fan (14). The first predetermined time is a time when the rotational speed of the indoor fan (14) reaches a predetermined rotational speed,
The indoor unit (1) according to claim 1, wherein the second predetermined time is a time during which the rotational speed of the indoor fan (14) decreases from the rotational speed during operation to the predetermined rotational speed. The indoor unit (1) according to claim 2, wherein the predetermined rotational speed is a minimum rotational speed of the indoor fan (14).

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