JPH11141961A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the noise level of a fan in an indoor unit from lowering below the noise level of refrigerant by providing a control section for delaying the rotation decrease starting time of an indoor fan by a predetermined time after the operating state of an air conditioner is commanded to decrease before the refrigerant noise is reduced thereby masking the refrigerant noise with the supply air noise. SOLUTION: A control section 6 conducts operational control of an air conditioner 1 and has a circuit for delaying an operation change command by a preset time. The control section 6 controls a compressor 33, an indoor fan drive section 22a, and the like, such that the noise of circulating refrigerant is masked with the noise of air being supplied from an indoor fan 22, or the like. In case of a fan r.p.m. decrease command, operating condition of the indoor fan 22 is held in 'strong' and a fan delay control for delaying the supply air noise level decrease behind the refrigerant noise level decrease is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoor unit for air conditioning, and more particularly to a technique suitable for controlling refrigerant flow noise.

[0002]

2. Description of the Related Art FIG. 6 is a bar graph showing the contribution of indoor noise of a conventional air conditioner. Most of the indoor noise of the air conditioner is a blowing sound and a refrigerant sound as shown in FIG. Among them, the refrigerant sound has many high frequency components and is auditoryly unpleasant. On the other hand, since the blowing sound has a high frequency component and a large perceptually acceptable level, a method of masking the refrigerant sound with the blowing sound by lowering the noise level of the cooling sound than the blowing sound is usually used. I have.

FIG. 7 shows an example in which an inverter drive motor is mounted.
Blowing sound of indoor unit of air conditioner by mounted compressor
-Represents the relationship between the noise level of refrigerant sound and time
You. In FIG.₁Is the blowing sound level, D_TwoIs cold
Medium sound level, T₀Is changed from "strong cooling" to "weak"
"Cooling", etc., when the reduction command is applied, D_ThreeIs reduced
Later blast sound level, D_FourIndicates the refrigerant sound level after reduction
You. T₀When the command is received at the timing of
From high speed to low speed, and compressor speed to fan speed
It decreases in conjunction with it. At this time, the fan speed changes from high to low
The noise of the blower is
D₁From the blowing sound level D_ThreeIt drops rapidly. Only
And refrigerant sound D_TwoIs the refrigerant circulation amount, that is, inverter compression
It is linked to the rotation speed of the machine and the rotation cannot be changed rapidly
In the case of an inverter compressor, the rotation slows down.
Therefore, the noise at the time of refrigerant circulation is the refrigerant sound level D _TwoFrom refrigerant sound
Level D_FourTo, refrigerant sound level D_FiveGradually low as shown
Down.

Japanese Patent Application Laid-Open No. Hei 6-101948 discloses that the operation of a blower is started a predetermined time before the start of operation of a compressor and the operation of the blower is stopped after a predetermined time of stopping the compressor. And a method for reducing the starting current at the same time.

[0005]

[SUMMARY OF THE INVENTION However, in the above air conditioner, as shown in FIG. 7, a high refrigerant noise level D ₅ from the blowing noise level D ₃ in the region indicated by D _0, not even be expected masking effect Therefore, there was a problem that it became very uncomfortable. Further, in the technique described in Japanese Patent Application Laid-Open No. 6-101948, a technique of masking another sound by a blower sound is used. The purpose is to mask the sound, or to disperse the large current at the time of startup, and to mask the refrigerant sound that continuously changes with rotation when the rotation of the inverter compressor changes. Different concepts.

The present invention has been made in view of the above circumstances, and aims to achieve the following objects. At the time of the reduced operation command, masking of the unpleasantly audible refrigerant sound is performed so that the fan noise level of the indoor unit does not transiently become lower than the refrigerant sound.

[0007]

SUMMARY OF THE INVENTION The present invention comprises an indoor unit having an indoor heat exchanger and an indoor fan, and an outdoor unit having an outdoor heat exchanger and a compressor. In the air conditioner constituting the refrigerant circuit, the refrigerant sound is masked by the blowing sound by delaying the start time of the decrease of the indoor fan rotation for a certain time until the refrigerant sound is reduced from the time of the reduction command for the operation state of the air conditioner. The object has been solved by means having a control unit. Further, in the present invention, an indoor unit having an indoor heat exchanger and an indoor fan, and an outdoor unit having an outdoor heat exchanger and a compressor, the two units are connected by a pipeline to form a refrigerant circuit, In an air conditioner in which an expansion valve is connected to the refrigerant circuit, when the reduction command for the operation state of the air conditioner is issued, the expansion valve opening is controlled to be slightly throttled for a certain period of time until the refrigerant sound is reduced, so that the blowing sound causes Means having a control unit for masking a sound may be employed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of an air conditioner according to the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes an air conditioner, 2 denotes an indoor unit, 3 denotes an outdoor unit, 4 denotes a pipeline, 5 denotes an expansion valve, and 6 denotes a control unit.

As shown in FIG. 1, the air conditioner 1 includes, for example, an indoor unit 2 having an indoor heat exchanger 21, an indoor fan 22, and a control unit 6, an outdoor heat exchanger 31, an outdoor fan 32, and a compressor 33. And an outdoor unit 3 having a four-way valve 34. The two units 2 and 3 are connected in a ring by a pipe 4 to form a refrigerant circuit 40. Indoor fan 22
And the outdoor fan 32,
a, 32a. The four-way valve 34 switches between the cooling operation and the heating operation by switching the circulation direction of the refrigerant by switching the four-way valve 34. An expansion valve 5 is connected to the pipe 4, and the expansion valve 5 is an indoor expansion valve 5 </ b> A disposed in the indoor unit 2 and an outdoor expansion valve 5 </ b> B disposed in the outdoor unit 3. The control unit 6 includes an indoor fan driving unit 22a, an outdoor fan driving unit 32a, and the compressor 3
3, the four-way valve 34, the indoor expansion valve 5A, and the outdoor expansion valve 5B are connected to each other, and the operation of the air conditioner 1 is controlled by controlling these by a command from a remote controller (not shown).
In addition, as described later, a circuit is provided for delaying the operation change instruction according to, for example, a preset delay time.

During the cooling operation of the air conditioner 1, the refrigerant compressed by the compressor 33 flows into the outdoor heat exchanger 34 via the pipeline 4 and the four-way valve 34, and is driven by the outdoor fan drive 32a. The driven outdoor fan 32 exchanges heat with the outside air and condenses to become a high-pressure liquid refrigerant. The liquid refrigerant is supplied to the outdoor expansion valve 5B and the indoor expansion valve 5B.
The air is decompressed by A, evaporates by exchanging heat with the air from the indoor fan 22 driven by the indoor fan drive unit 22a in the indoor heat exchanger 21, and returns to the compressor 33 again via the pipeline 4 and the four-way valve 34. In the heating operation of the air conditioner 1, the flow direction of the refrigerant is opposite to that in the cooling operation.

At this time, the indoor fan 22 is controlled by the control unit 6.
The compressor 33 and the indoor fan drive unit 2 are designed to mask the refrigerant sound due to the circulating refrigerant and the like by the blowing sound from
2a and the like are controlled. FIG. 2A shows an air conditioner noise level (blowing sound level, refrigerant sound level) controlled by the control unit 6.
FIG. 3B is a flowchart showing the control of the control unit 6 to perform the fan rotation speed reduction delay control at this time.

[0012] In FIG. 2 (a), D ₁ is the blowing noise level in the operating state of "strong", D ₂ is refrigerant noise level in the operating state of "strong", T ₀ is the remote controller or the like (not shown) of the "strong" timing took from the operation state of change instruction to the operating state of "weak", D ₃ is the blowing noise level in the operating state of "weak", D ₄ is refrigerant noise level in the operating state of "weak", D ₅ Figure 7 5 shows the refrigerant sound level at the time of the reduced operation command of the air conditioner shown in FIG. D _3A indicates the air blowing sound level at the time of delay control in which the operation state of the indoor fan 22 is maintained at “strong” for a predetermined time T _A after the timing T ₀ and thereafter switched to the “weak” operation state. I have.

[0013] fan speed decreases the delay control by the control unit 6, as shown in FIG. 3 (a), the operating state changing command by the remote controller or the like (not shown) at T ₀ in FIG. 2 (step S
According to 1), it is determined whether or not the command is a command to lower the fan speed of the indoor fan 22 (step S2). If the command is a command to lower the fan speed, the operation of the air conditioner 1 is reduced by controlling the compressor 33 and the like. 2A, the rotation speed of the indoor fan 22 is changed from D ₁ → D _3A → D
_As shown by ₃ , after the timing T _0, the operation state of the indoor fan 22 is maintained at “strong” for a predetermined time T _A , and delay control for delaying a decrease in the blower sound level with respect to a decrease in the refrigerant sound level is performed. A fan delay control is performed (step S3). By the fan delay control, a predetermined time T _A from the timing T ₀
Thereafter, an operation state change command is output to the indoor fan drive unit 22a (step S4). In step S2, if it is not a command to decrease the number of rotations of the fan, an operation state change command is output to the indoor fan drive unit 22a as in step S4.

By performing such control, it is possible to mask the refrigerant sound by the blowing sound so that the refrigerant sound level does not exceed the blowing sound level.

Hereinafter, a second embodiment of the air conditioner of the present invention will be described. In the second embodiment, the first
FIG. 2B and FIG. 3B are different from the embodiment.
As shown in (1), the number of rotations of the indoor fan 22 is controlled in multiple stages. Here, an example of two stages is shown. This embodiment is applied, for example, when the change amount of the air conditioner from a “strong” operating state to a “weak” operating state is large. A predetermined time T _B1 at timing T ₀ shown in FIG.
During this time, the blowing sound level D _3A is maintained as “strong”, and thereafter, during a predetermined time T _B2 , the state of the blowing sound level D _3B is maintained as the rotation speed “medium” at which the refrigerant sound can be masked,
It is a blowing noise level D ₃ as the final rotation speed "weak". FIG. 3B shows the control unit 6 according to the present embodiment.
Is a flowchart of a fan rotation speed reduction delay control flow according to the first embodiment. A difference from the first embodiment is that in step 3 ′, when a decrease in the blower sound level is reduced so as to be delayed with respect to a decrease in the refrigerant sound level. , And FIG. 2B shows D _3A → D _3B
As shown in the figure, the point is that fan delay control for performing delay control stepwise is performed. Here, an example in which the number of revolutions of the indoor fan 22 is stepwise reduced is shown. However, when an inverter is used as the indoor fan drive unit 22a, for example, the number of revolutions of the fan can be continuously reduced by the number of fan revolutions that can mask the refrigerant noise. May be lowered.

[0016] In this embodiment, the rotation of the inverter compressor from the timing T ₀ of the rotary reduction instruction by the remote controller gradually so on are lowered, but decreases gradually even refrigerant noise level D _5, the blowing noise level D _3A, not to always be greater than D _3B, can be masked by blowing sound audibly very unpleasant refrigerant noise, it can be reduced refrigerant noise.

Hereinafter, a third embodiment of the air conditioner of the present invention will be described. In the third embodiment, FIG.
3 is different from the first and second embodiments shown in FIGS. 3 and 3 in that the opening degree of the expansion valve 5 is controlled with respect to the indoor fan 22 as shown in FIGS. FIGS. 4A and 4B show a third embodiment of the present invention, in which FIG. 4A shows the relationship between noise level and time, FIG. 4B shows the relationship between compressor speed and time, and FIG. 4C shows the relationship between expansion valve opening and time. FIG. 5 is a flowchart showing the control of the expansion valve opening degree by the control unit 6 at this time.

[0018] In FIG. 4 (a), D ₁ is the blowing noise level in the operating state of "strong", D ₂ is refrigerant noise level in the operating state of "strong", T ₀ is the remote controller or the like (not shown) of the "strong" timing took from the operation state of change instruction to the operating state of "weak", D ₃ is the blowing noise level in the operating state of "weak", D ₄ is refrigerant noise level in the operating state of "weak", D ₅ Figure 7 refrigerant noise level at the time of reduction operation command of the air conditioner shown in, D _5A, after the timing T _0, indicates a refrigerant noise level at the time of controlling the expansion valve to the aperture slightly in the expansion valve 5. In FIG. 4B, R ₂ indicates the number of rotations of the compressor in the “strong” operating state, R ₄ indicates the number of rotations of the compressor in the “weak” operating state, and R ₅
Indicates the number of revolutions of the compressor when the operating state of “strong” is changed to the operating state of “weak”. In FIG. 4 (c), V ₂ is the expansion valve opening in the operating state of the expansion valve in the operating state of "strong", V ₄ is "weak", V ₅ is the timing T ₀
After, the expansion valve opening degree of the state of association with the decrease in the rotational speed of the compressor, V _5A, after the timing T _0, indicates an expansion valve opening degree at the time of subjected to squeezing slightly control the expansion valve.

[0019] The expansion valve diaphragm Pounds control by the control unit 6, as shown in FIG. 5 (a), a remote controller operation state changing command by not shown in the T ₀ in FIG. 4 (step S11)
It is determined whether or not the command is a command to lower the fan speed of the indoor fan 22 (step S12). If the command is a command to lower the fan speed, the compressor 33 is controlled as shown in FIG. Control to reduce the operation of the expansion machine 1 and the opening degree of the expansion valve of the expansion valve 5 is changed as shown in FIG.
As shown by V ₂ → V _5A → V ₄ , the expansion valve opening degree V ₅ linked to the decrease in the number of rotations of the compressor is controlled to be more narrow than the opening degree V ₅ .
An expansion valve throttle control is performed so that the decrease in the refrigerant sound level does not exceed the decrease in the blower sound level (step S1).
3). By the expansion valve throttle control, the timing T
_At step S14, an opening adjustment change command is output to an opening adjustment means (not shown) of the expansion valve 5 (step S14). Further, in step S12, and if not the fan rotational speed reducing instruction outputs the normal operating state changing command shown in V ₅ in FIG. 2 (c) with respect to the expansion valve 5 as in step S14. At this time, it is desirable that a predetermined ratio be set in advance as the throttle ratio of the expansion valve 5.

By performing such control, the refrigerant sound level changes in a state indicated by D ₂ → D _5A → D ₄ in FIG. 4B so that the refrigerant sound level does not exceed the blowing sound level. Masking of the refrigerant sound by the blowing sound can be performed.

As shown in FIG. 5B, it is possible to perform the expansion valve throttle correction in multiple steps in step S13 '.

[0022]

According to the air conditioner of the present invention, the following effects can be obtained. (1) At the time of the reduced operation command, by delaying the indoor fan rotation reduction control for a certain period of time, masking of the unpleasantly audible refrigerant sound is performed so that the fan noise level of the indoor unit does not transiently become lower than the refrigerant sound. be able to. (2) Masking of an unpleasantly audible refrigerant sound so that the fan noise level of the indoor unit does not transiently become lower than the refrigerant sound by controlling the expansion valve to be slightly throttled at the time of the reduced operation command. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an air conditioner according to the present invention.

FIG. 2 is a graph showing a relationship between a refrigerant sound level, a blowing sound level, and time in fan delay control in the first and second embodiments of the air conditioner according to the present invention.

FIG. 3 is a flowchart showing fan delay control in the first and second embodiments of the air conditioner according to the present invention.

FIG. 4 shows (a) refrigerant sound level, blow sound level and time, (b) compressor speed and time, and (c) expansion in the expansion valve throttle control in the third embodiment of the air conditioner according to the present invention. It is a graph which shows the relationship between valve opening degree and time.

FIG. 5 is a flowchart showing expansion valve throttle control in a third embodiment of the air conditioner according to the present invention.

FIG. 6 is a bar graph showing a blowing sound and a refrigerant sound at a noise level of a conventional air conditioner.

FIG. 7 is a graph showing a relationship between a noise level and time in a conventional air conditioner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Air conditioner 2 ... Indoor unit 3 ... Outdoor unit 4 ... Pipe line 5 ... Expansion valve 6 ... Control part 21 ... Indoor heat exchanger 22 ... Indoor fan 31 ... Outdoor heat exchanger 32 ... Outdoor fan 33 ... Compressor 34 ... Four directions valve 40 ... refrigerant circuit 22a ... indoor fan drive unit (fan drive) 32a ... outdoor fan driving unit (fan drive) 5A ... indoor expansion valve 5B ... outdoor expansion valves D ₁ ... blowing noise level "strong" D ₂ ... refrigerant Sound level “High” T ₀ … Operation state command timing D ₃ … Blowing sound level “Low” D ₄ … Refrigerant sound level “Low” D _3A … Blowing sound level (during fan rotation delay control) D _3B … Blowing sound level ( fan during rotation delay control) D ₅ ... refrigerant noise level (during operation reduced) D _5A ... refrigerant noise level (when the expansion valve aperture Pounds control) R ₂ ... rotational speed of the compressor "strong" rotation number of R ₄ ... compressor “Weak” R ₅ … Number of rotations of the compressor (When operation is reduced) V ₂ … Expansion valve opening “strong” V ₄ … Expansion valve opening “weak” V ₅ … Expansion valve opening (when operation is reduced) V _5A … Expansion valve opening (Expansion valve throttle control) Time)

Claims (2)

[Claims] 1. An air conditioner comprising: an indoor unit having an indoor heat exchanger and an indoor fan; and an outdoor unit having an outdoor heat exchanger and a compressor, wherein the two units are connected by a pipeline to form a refrigerant circuit. An air conditioner, comprising: a control unit that masks a refrigerant sound by blowing air by delaying a start time of a decrease in rotation of an indoor fan from a reduction command for an operation state of the air conditioner. 2. An indoor unit having an indoor heat exchanger and an indoor fan, and an outdoor unit having an outdoor heat exchanger and a compressor. The two units are connected by a pipeline to form a refrigerant circuit. In an air conditioner in which an expansion valve is connected to a refrigerant circuit, the air conditioner has a control unit that masks the refrigerant sound by blowing air by controlling the expansion valve opening to be slightly throttled when reducing the operation state of the air conditioner. An air conditioner characterized by the following.