JP7713638B2 - Air Conditioning Equipment - Google Patents

Description

This disclosure relates to air conditioning devices.

Patent Document 1 discloses an air conditioner that can suppress deterioration over time of a semiconductor refrigerant detection sensor.
This air conditioner is equipped with a semiconductor-type first refrigerant detection sensor that detects refrigerant leakage when heated by a built-in heater, a second refrigerant detection sensor that detects refrigerant leakage when not heated, and a control unit that controls the operation of the first refrigerant detection sensor and the second refrigerant detection sensor, and the control unit heats and operates the first refrigerant detection sensor while the air conditioner is operating and for a certain period of time immediately after operation is stopped, and operates the second refrigerant detection sensor while the air conditioner is stopped, while also controlling the first refrigerant detection sensor not to be heated.

JP 2017-180927 A

This disclosure provides an air conditioning device that can ensure safety while suppressing deterioration of the refrigerant detection sensor.

The air conditioning apparatus of the present disclosure comprises a refrigerant shut-off valve that closes when a refrigerant detection sensor detects refrigerant, a control unit that controls the refrigerant shut-off valve, and an indoor heat exchanger, and when the refrigerant shut-off valve is closed due to a factor other than refrigerant detection by the refrigerant detection sensor, the control unit stops the flow of electricity to the refrigerant detection sensor or alternately repeats energizing and de-energizing the refrigerant detection sensor, and when the control unit is in an operating state where refrigerant is not circulating through the indoor heat exchanger, it closes the refrigerant shut-off valve and stops the flow of electricity to the refrigerant detection sensor or alternates repeating energizing and de-energizing the refrigerant detection sensor.

The air conditioning device disclosed herein can reduce the time that the refrigerant detection sensor is energized by stopping the energization of the refrigerant detection sensor or by alternately energizing and de-energizing the refrigerant detection sensor when the refrigerant shutoff valve is closed to shut off the refrigerant flowing into the indoor unit. This makes it possible to ensure safety while suppressing deterioration of the refrigerant detection sensor.

FIG. 1 is a side cross-sectional view showing an indoor unit according to a first embodiment. FIG. 1 is a plan view showing an indoor unit according to a first embodiment. Refrigerant circuit diagram showing an air conditioning apparatus according to embodiment 1 A block diagram showing a control configuration of an air conditioning apparatus according to a first embodiment. A flowchart showing control when the refrigerant shutoff valve of the air conditioner according to the first embodiment is closed. A flowchart showing control when the air conditioning apparatus according to the first embodiment starts operation.

(The knowledge and other information that formed the basis of this disclosure)
At the time when the inventors came up with the present disclosure, the technical field of air conditioners was in a situation where a switch from refrigerants using fluorocarbons was progressing in response to environmental issues, and it was necessary to use slightly flammable or flammable refrigerants. Therefore, in the industry, it was common to design products that suppress the inflow of refrigerant into the room by providing a refrigerant detection sensor and a shutoff valve that closes when the refrigerant detection sensor detects a refrigerant leak, in order to prevent the refrigerant from leaking into the room. In addition, the refrigerant detection sensor used here is generally in a constant energized state, and there was a problem that the refrigerant detection sensor deteriorates as the total energized time increases. Under such circumstances, the inventors came up with the idea of suppressing the deterioration of the refrigerant detection sensor by creating a time when the refrigerant detection sensor is not energized. Then, the inventors discovered that in order to realize the idea, there was a problem that it was necessary to ensure safety when the refrigerant detection sensor is not energized, and in order to solve the problem, they came to constitute the subject of the present disclosure.

Therefore, this disclosure provides an air conditioning device that can ensure safety while suppressing deterioration of the refrigerant detection sensor.

Hereinafter, the embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming more redundant than necessary and to facilitate understanding by those skilled in the art.
It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIG. 1 to FIG.
Fig. 1 is a side cross-sectional view showing an indoor unit according to embodiment 1. Fig. 2 is a plan view showing the indoor unit according to embodiment 1.

[1-1. Configuration]
1 and 2 , an air conditioner 1 in this embodiment includes an indoor unit 5. The indoor unit 5 includes a box-shaped housing 10. The housing 10 includes a top plate 11 and a bottom plate 12.
The left side of the housing 10 in Fig. 1 is an air blowing chamber 13, and the right side of the housing 10 in Fig. 1 is a heat exchanger chamber 14 that houses an indoor heat exchanger 20. The air blowing chamber 13 and the heat exchanger chamber 14 are separated by a partition wall 15.

A suction port 16 for taking in indoor air is provided at the rear of the blower chamber 13, and multiple scroll casings 31 (three in this embodiment) each housing a sirocco fan 30 are provided inside the blower chamber 13. An air outlet 17 is provided in the heat exchanger chamber 14 forward of the indoor heat exchanger 20.

The scroll casing 31 is provided with a fan opening 32 formed at both ends of the scroll casing 31, which draws in air flowing in from the suction port 16 by the rotation of the sirocco fan 30, and an air passage 33 which discharges the air drawn in from the fan opening 32 toward the heat exchanger chamber 14.
An electric motor 34 is provided between the scroll casings 31. The electric motor 34 is connected to a rotating shaft 35 of the sirocco fan 30, and drives the sirocco fan 30 to rotate.

The sirocco fan 30 is a centrifugal fan, and when the sirocco fan 30 is operating, air is drawn in through the suction port 16, and flowed into the inside of the scroll casing 31 from the fan opening 32 in the direction of the rotation shaft 35. The air is then blown out through the air passage 33 to the indoor heat exchanger 20, and the conditioned air that has been heat exchanged in the indoor heat exchanger 20 is discharged into the room through the air outlet 17.
A drain pan 21 is disposed below the indoor heat exchanger 20 housed in the heat exchanger chamber 14 in FIG.

2, in this embodiment, the heat exchanger chamber 14 is provided with a first partition plate 23 that separates the heat exchange region 22 of the indoor heat exchanger 20 from a pipe connection region on one end side of the indoor heat exchanger 20 to which a liquid refrigerant pipe 47 and a gas refrigerant pipe 48 extending from the outdoor unit 40 (see FIG. 3) are connected. The pipe connection region is referred to as a first region 24.
Further, a second partition plate 25 is provided in the heat exchanger chamber 14 to separate the heat exchange area 22 from a bend area on the other end side of the indoor heat exchanger 20 where the refrigerant piping of the indoor heat exchanger 20 is folded back. The bend area is defined as a second area 26.

In the present embodiment, a refrigerant detection sensor 50 that detects refrigerant leakage is disposed in the first region 24. The refrigerant detection sensor 50 is a semiconductor-type refrigerant detection sensor that detects when refrigerant leaks from the refrigerant circuit of the air conditioning device 1 into the room.
The refrigerant detection sensor 50 is capable of detecting leaking refrigerant when powered, and when it detects leaking refrigerant, it transmits a refrigerant detection signal to the control unit 60 (see FIG. 4).

[1-2. Configuration of air conditioner]
Next, the configuration of the air conditioner will be described.
FIG. 3 is a refrigeration cycle diagram showing the configuration of the air conditioner.
As shown in Fig. 3, the air conditioning apparatus 1 includes an outdoor unit 40 and an indoor unit 5. The outdoor unit 40 houses a compressor 41, a four-way valve 42 that switches the refrigerant flow path, an outdoor heat exchanger 43, an outdoor fan 44, and an outdoor throttling device 45, which are connected in sequence by refrigerant piping 46.

The indoor unit 5 accommodates an indoor heat exchanger 20, an indoor expansion device 27, and a sirocco fan 30, and the indoor heat exchanger 20 and the indoor expansion device 27 are connected via a refrigerant piping 28.
The compressor 41 of the outdoor unit 40 and the indoor heat exchanger 20 of the indoor unit 5 are connected by a liquid refrigerant pipe 47 and a gas refrigerant pipe 48 .
A refrigerant shutoff valve 49 is provided in the vicinity of the indoor unit 5 on each of the liquid refrigerant pipe 47 and the gas refrigerant pipe 48 .
Refrigerant shutoff valve 49 is a shutoff valve whose open and closed states are controlled by controller 60, and is disposed in piping near the outside of housing 10. When refrigerant shutoff valve 49 is in a closed state, refrigerant cannot pass through refrigerant shutoff valve 49, and when refrigerant shutoff valve 49 is in an open state, refrigerant can pass through refrigerant shutoff valve 49.

[1-3. Control configuration]
Next, the control configuration of this embodiment will be described.
FIG. 4 is a block diagram showing a control configuration of this embodiment.
As shown in FIG. 4 , the air conditioning apparatus 1 includes a control unit 60 .
The control unit 60 is equipped with a processor such as a CPU or MPU that executes programs, and memory such as a ROM or RAM, and performs various processes through cooperation between hardware and software, such as the processor reading out the control program stored in the memory and executing the processes.

The control unit 60 controls the compressor 41 of the outdoor unit 40, the outdoor expansion device 45, the outdoor fan 44, the sirocco fan 30 of the indoor unit 5, and the indoor expansion device 27 based on a control program.
The control unit 60 controls the opening and closing of the refrigerant shutoff valve 49 and the indoor expansion device 27 based on the detection signal of the refrigerant detection sensor 50 of each indoor unit 5 .

In this embodiment, the control unit 60 determines whether the room temperature measured by the room temperature sensor 51 has reached the set temperature, and if so, executes thermo-off operation, stopping the compressor 41 and driving the sirocco fan 30.

[1-4. Effect]
Next, the operation of this embodiment will be described.
When the air conditioner 1 is in cooling or heating operation, the control unit 60 drives the electric motor 34 to rotate the sirocco fan 30. As a result, air is drawn in from the suction port 16, and this air flows into the scroll casing 31 from the fan opening 32 in the direction of the rotation shaft 35, and is blown out from the air passage 33 to the indoor heat exchanger 20. The conditioned air that has been heat exchanged in the indoor heat exchanger 20 is discharged from the air outlet 17.

When the air conditioner 1 is in cooling or heating operation, the refrigerant is circulating in and around the indoor heat exchanger 20, which is a location where refrigerant leakage into the room is likely to occur. Therefore, at this time, the control unit 60 controls the refrigerant detection sensor 50 to be in an energized state, so that the refrigerant detection sensor 50 can detect refrigerant leakage.

FIG. 5 is a flowchart relating to control when the refrigerant shutoff valve 49 of the air conditioner 1 is closed.
As shown in FIG. 5, when the air conditioning apparatus 1 is in cooling or heating operation, if the refrigerant detection sensor 50 detects a refrigerant leak, the refrigerant detection sensor 50 sends a refrigerant detection signal to the control unit 60 (SA1: Yes).

When the control unit 60 receives the refrigerant detection signal, the control unit 60 closes the refrigerant shutoff valve 49 (SA3), thereby blocking the refrigerant flowing into the indoor heat exchanger 20 and reducing the amount of refrigerant leakage.
At this time, the control unit 60 may be configured to stop the compressor 41 as necessary.
Thereafter, the control unit 60 terminates the operation while continuing to energize the refrigerant detection sensor 50 (SA5).

In this embodiment, even when the refrigerant detection sensor 50 does not detect a refrigerant leak (SA1: No), in an operating state in which the refrigerant is not circulated through the indoor heat exchanger 20, the control unit 60 may close the refrigerant shutoff valve 49. Specifically, when the air conditioning device 1 receives an operation stop signal, in the case of fan operation, or in the case of thermo-off operation (SA2: Yes), the control unit 60 closes the refrigerant shutoff valve 49 (SA4). This blocks the refrigerant flowing into the indoor heat exchanger 20, so that even if a refrigerant leak occurs inside the room after that, the amount of refrigerant leaking into the room can be suppressed.
Therefore, since it is easier to ensure safety in the room without continuing to monitor for refrigerant leakage using the refrigerant detection sensor 50, the control unit 60 closes the refrigerant shut-off valve 49 (SA4), then stops the flow of electricity to the refrigerant detection sensor 50 (SA6), and terminates operation.
That is, when the refrigerant shutoff valve 49 is closed due to a factor other than the detection of refrigerant by the refrigerant detection sensor 50 , the control unit 60 stops the passage of electricity to the refrigerant detection sensor 50 .
Here, instead of stopping the energization of the refrigerant detection sensor 50, the refrigerant detection sensor 50 may be controlled so as to alternately energize and deenergize.

FIG. 6 is a flowchart showing the control when the air conditioning apparatus 1 starts operation.
In this embodiment, when the air conditioning apparatus 1 is not operating, as described above, the refrigerant shutoff valve 49 is closed, and the refrigerant detection sensor 50 is not energized.

In this state, if the control unit 60 receives a signal to start a cooling or heating operation (SB1: Yes), the control unit 60 starts energizing the refrigerant detection sensor 50 (SB2).
The refrigerant detection sensor 50 requires a certain time to be able to detect a refrigerant leak after the start of energization. In particular, the semiconductor sensor used in this embodiment requires a time of several tens of seconds to several minutes after the start of energization before it can detect the refrigerant.
Therefore, in this embodiment, after starting to energize the refrigerant detection sensor 50 (SB2), the system waits until the refrigerant detection sensor 50 is able to detect a refrigerant leak (SB3), and then the refrigerant shut-off valve 49 is opened (SB4), and the operation startup process is terminated.
This prevents refrigerant from flowing into the indoor heat exchanger 20 when the refrigerant detection sensor 50 cannot detect refrigerant leakage.

[1-5. Effects, etc.]
As described above, in this embodiment, the air conditioning apparatus 1 is equipped with a refrigerant shut-off valve 49 that closes when the refrigerant detection sensor 50 detects refrigerant, and a control unit 60 that controls the refrigerant shut-off valve 49, and the control unit 60 stops the flow of electricity to the refrigerant detection sensor 50 when the refrigerant shut-off valve 49 is closed due to a factor other than refrigerant detection by the refrigerant detection sensor 50.
As a result, the refrigerant shutoff valve 49 shuts off the inflow of refrigerant into the indoor heat exchanger 20, and the power supply to the refrigerant detection sensor 50 can be stopped only when there is little possibility of a large amount of refrigerant leaking into the room. Therefore, the power supply time of the refrigerant detection sensor 50 can be reduced and deterioration of the refrigerant detection sensor 50 can be suppressed while suppressing the risk of refrigerant leakage.

As in this embodiment, when the refrigerant shutoff valve 49 is closed due to a factor other than refrigerant detection by the refrigerant detection sensor 50, the control unit 60 may be configured to close the refrigerant shutoff valve 49 and then stop the flow of electricity to the refrigerant detection sensor 50.
As a result, after the refrigerant shutoff valve 49 shuts off the refrigerant flowing into the indoor heat exchanger 20, the refrigerant detection sensor 50 is de-energized, and the refrigerant detection sensor 50 can constantly monitor for refrigerant leakage while refrigerant is flowing into the indoor heat exchanger 20. Therefore, deterioration of the refrigerant detection sensor 50 can be suppressed while further improving safety.

As in the present embodiment, when changing the refrigerant shutoff valve 49 from a closed state to an open state, the control unit 60 may be configured to open the refrigerant shutoff valve 49 after starting to energize the refrigerant detection sensor 50.
As a result, the refrigerant shutoff valve 49 will not be opened when the refrigerant detection sensor 50 is not energized, so the air conditioning apparatus 1 can be operated safely.

As in this embodiment, when changing the refrigerant shutoff valve 49 from a closed state to an open state, the control unit 60 may be configured to open the refrigerant shutoff valve 49 after starting to energize the refrigerant detection sensor 50 and after a time has elapsed during which the refrigerant detection sensor 50 can detect the refrigerant.
As a result, the refrigerant shutoff valve 49 will not be opened when the refrigerant detection sensor 50 is unable to detect refrigerant, so the air conditioning apparatus 1 can be operated more safely.

As in the present embodiment, the control unit 60 may be configured to continue energizing the refrigerant detection sensor 50 when the refrigerant shutoff valve 49 is closed when the refrigerant detection sensor 50 detects a refrigerant leak.
As a result, when the refrigerant detection sensor 50 detects a refrigerant that is more dangerous than usual, the refrigerant shutoff valve 49 is closed to shut off the refrigerant flowing into the indoor heat exchanger 20, and the refrigerant detection sensor 50 continues to be energized, thereby further improving safety.

As in this embodiment, the control unit 60 may be configured to close the refrigerant shutoff valve 49 in at least one of the following cases: when the air conditioning operation is stopped, when the fan operation is in progress, and when the thermostat is off.
According to this configuration, when the unit is stopped, in thermo-off operation, or in fan operation, the refrigerant shutoff valve 49 shuts off the flow of refrigerant into the indoor heat exchanger 20, reducing the possibility of a large amount of refrigerant leaking into the room, and stopping the flow of electricity to the refrigerant detection sensor 50. Therefore, deterioration of the refrigerant detection sensor 50 can be further suppressed while ensuring safety.

Other Embodiments
As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the elements described in the first embodiment to create new embodiments.
Therefore, other embodiments will be exemplified below.

In the first embodiment, it has been described that the air conditioning device 1 is provided with a refrigerant detection sensor 50 inside the housing 10. The refrigerant detection sensor 50 may be disposed in any position that allows it to detect leaked refrigerant. Therefore, the refrigerant detection sensor 50 is not limited to being disposed inside the housing 10. For example, the refrigerant detection sensor 50 may be provided separately from the air conditioning device 1 in the room to be air-conditioned.

In the first embodiment, a semiconductor sensor has been described as an example of the refrigerant detection sensor 50. The refrigerant detection sensor 50 may be any sensor capable of detecting refrigerant leaking while power is applied. Therefore, the refrigerant detection sensor 50 is not limited to a semiconductor sensor. For example, an infrared sensor may be used as the refrigerant detection sensor 50.

In the first embodiment, the refrigerant shutoff valve 49 is described as being disposed in a pipe near the outside of the housing 10. The refrigerant shutoff valve 49 only needs to be disposed so as to be able to shut off the refrigerant flowing into the indoor heat exchanger 20 when the refrigerant shutoff valve 49 is closed. Therefore, the refrigerant shutoff valve 49 is not limited to being disposed in a pipe near the outside of the housing 10. For example, the refrigerant shutoff valve 49 may be provided inside the housing 10. The refrigerant shutoff valve 49 may also be provided on a connecting pipe that connects the indoor heat exchanger 20 to an external pipe.

In the first embodiment, the air conditioner 1 is described as having an air outlet 17 at the front. However, the air conditioner 1 to which the technology of the present disclosure can be applied is not limited to one having an air outlet 17 at the front. For example, the technology can be applied to any air conditioner in which a refrigerant flows into an air conditioner that is placed indoors or near an indoor location, such as a ceiling cassette type including a four-way ceiling cassette type, a wall-mounted type, or a floor-standing type.

In the first embodiment, when the air conditioning device 1 starts operation from a stopped state, the control unit 60 energizes the refrigerant detection sensor 50, and the refrigerant shutoff valve 49 is opened after the time has elapsed until the refrigerant detection sensor 50 can detect the refrigerant. This operation can be applied to operations including the operation of opening the refrigerant shutoff valve 49, and is not limited to being performed when the air conditioning device 1 starts operation from a stopped state. For example, even when the indoor heat exchanger 20 transitions from thermo-off operation or fan operation to cooling or heating operation, the control unit 60 may energize the refrigerant detection sensor 50, and the refrigerant shutoff valve 49 may be opened after the time has elapsed until the refrigerant detection sensor 50 can detect the refrigerant.

In the first embodiment, the air conditioner is described as having one indoor unit, but the present invention can also be applied to a configuration having multiple indoor units. In this case, when refrigerant is circulating in one of the multiple indoor units and refrigerant is not circulating in the other indoor units, it is preferable to close the refrigerant shutoff valve for the indoor unit in which the refrigerant is not circulating and stop the refrigerant detection sensor from being energized, and open the refrigerant shutoff valve corresponding to the indoor unit in which the refrigerant is circulating and continue energizing the refrigerant detection sensor. This allows the refrigerant detection sensor to continue operating during air conditioning operation to ensure safety, and prevents deterioration of the refrigerant detection sensor for indoor units with a low possibility of refrigerant leakage.
In the first embodiment, a configuration has been described in which, when the refrigerant shutoff valve 49 is closed due to a factor other than the detection of a refrigerant leakage by the refrigerant detection sensor 50, the supply of electricity to the refrigerant detection sensor 50 is stopped. In order to suppress deterioration of the refrigerant detection sensor 50, any configuration may be used that can suppress the supply of electricity to the refrigerant detection sensor compared to a case in which electricity is continuously supplied to the refrigerant detection sensor 50. Control may be used that intermittently repeats the supply of electricity and the non-supply of electricity to the refrigerant detection sensor 50. In this case, compared to a case in which electricity is continuously stopped to the refrigerant detection sensor 50, deterioration of the refrigerant detection sensor 50 can be suppressed while further increasing safety against refrigerant leakage.

The above-described embodiments are intended to illustrate the technology disclosed herein, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

As described above, the air conditioner according to the present invention can be used as an air conditioner equipped with measures to prevent refrigerant leakage.

REFERENCE SIGNS LIST 1 air conditioner 5 indoor unit 10 housing 11 top plate 12 bottom plate 13 blower chamber 14 heat exchanger chamber 15 partition wall 16 suction port 17 outlet port 20 indoor heat exchanger 21 drain pan 22 heat exchange area 23 first partition plate 24 first area 25 second partition plate 26 second area 27 indoor throttle device 28 refrigerant piping 30 sirocco fan 31 scroll casing 32 fan opening 33 air passage 34 electric motor 35 rotating shaft 40 outdoor unit 41 compressor 42 four-way valve 43 outdoor heat exchanger 44 outdoor fan 45 outdoor throttle device 46 refrigerant piping 47 liquid refrigerant piping 48 gas refrigerant piping 49 refrigerant shut-off valve 50 refrigerant detection sensor 51 room temperature sensor 60 control unit

Claims (6)

The refrigerant shutoff valve is closed when the refrigerant detection sensor detects a refrigerant, a control unit controls the refrigerant shutoff valve, and an indoor heat exchanger .
When the refrigerant shutoff valve is closed due to a factor other than the detection of refrigerant by the refrigerant detection sensor, the control unit stops energizing the refrigerant detection sensor or alternately repeats energization and de-energization to the refrigerant detection sensor,
When the operating state is such that the refrigerant is not circulated through the indoor heat exchanger, the control unit closes the refrigerant shutoff valve and stops energizing the refrigerant detection sensor, or alternately repeats energization and de-energization of the refrigerant detection sensor.
An air conditioning apparatus characterized by the above. The air conditioning apparatus according to claim 1, characterized in that, when the refrigerant shutoff valve is closed due to a factor other than refrigerant detection by the refrigerant detection sensor, the control unit closes the refrigerant shutoff valve and then stops energizing the refrigerant detection sensor, or alternately repeats energizing and de-energizing the refrigerant detection sensor. The air-conditioning apparatus according to claim 1 or 2, wherein when the control unit changes the refrigerant shutoff valve from a closed state to an open state, the control unit opens the refrigerant shutoff valve after starting energization of the refrigerant detection sensor. The air conditioning apparatus according to claim 3, wherein when the control unit changes the refrigerant shutoff valve from a closed state to an open state, the control unit opens the refrigerant shutoff valve after a time has elapsed during which the refrigerant detection sensor can detect refrigerant after starting to energize the refrigerant detection sensor. The air-conditioning apparatus according to claim 1 , wherein the control unit continues to energize the refrigerant detection sensor when the refrigerant detection sensor detects a refrigerant leakage by closing a refrigerant shutoff valve. The air-conditioning apparatus according to claim 1 or 2 , wherein the control unit closes the refrigerant shutoff valve in at least one of a case where an air-conditioning operation is stopped, a case where an air-blowing operation is performed, and a case where a thermostat is turned off.