JP2003074945A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate uncomfortable feeling of residents while preventing cost increase by reducing a strange sound sufficiently and instantaneously upon occurrence when refrigerant passes through an indoor expansion valve (15) provided in the refrigerant circuit (10) of a vapor compression type refrigeration cycle. SOLUTION: A strange sound occurring when refrigerant passes through the indoor expansion valve (15) is detected by means of an acoustic sensor, e.g. a microphone (21), and a control for cancelling the strange sound is effected upon occurrence of the strange sound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vapor compression refrigeration cycle, and more particularly to a technique for preventing abnormal noise when a refrigerant passes through an indoor expansion mechanism.

[0002]

2. Description of the Related Art Generally, an air conditioner for a vapor compression refrigeration cycle includes a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger. The circuit is configured. A so-called multi-type air conditioner in which a plurality of indoor heat exchangers are connected in parallel is known as an air conditioner. This multi-type air conditioner is generally provided with an indoor expansion valve corresponding to each indoor heat exchanger. The air conditioner includes an outdoor unit that is a heat source side unit and a plurality of indoor units that are use side units, and the outdoor unit includes a compressor, an outdoor heat exchanger, and an outdoor expansion valve for each indoor unit. Is provided with an indoor heat exchanger and an indoor expansion valve.

By the way, in this type of air conditioner, the refrigerant normally passes through the indoor expansion valve in a liquid phase state.
For example, when the temperature difference between the room temperature and the set temperature is large, the operation of reducing the subcooling of the refrigerant as much as possible is performed in order to obtain sufficient performance. Therefore, in some cases, the refrigerant passes through the indoor expansion valve in a gas-liquid two-phase state. Then, at that time, an abnormal noise such as "sur-shuru", "bumpy", or "gurgling" is generated due to the pressure fluctuation. When such an abnormal noise is generated, the occupants may feel uncomfortable, especially when operating the air conditioner in a quiet space.

[0004]

When an unpleasant noise is generated when the refrigerant passes through the indoor expansion valve in this way, conventionally, "putty" or the like is generated in the abnormal noise generating portion around the indoor expansion valve. By attaching a soundproof material (or anti-vibration material), noise is reduced.

However, in such a coping method, since the post-processing is performed after the abnormal noise is generated, the abnormal noise continues to be generated until the putty is processed, and the device is disassembled during the work at the site. Therefore, the number of work steps is large, the cost is high, and a large amount of putty needs to be used to sufficiently reduce the abnormal noise, whereas there is not enough space in the casing of the indoor unit. There is a problem that the noise reduction effect tends to be insufficient.

On the other hand, in order to suppress the generation of refrigerant noise itself, a silencer may be used in which a mechanism for making the bubbles of the refrigerant fine and uniform is incorporated, but it cannot be said that the silencer is effective under all conditions, and the operating conditions Depending on the situation, the abnormal noise may not be reduced.

The present invention was devised in view of the above problems, and an object thereof is to make an abnormal noise instantaneously when an abnormal noise is generated when the refrigerant passes through the indoor expansion valve. By sufficiently reducing it, the discomfort of the occupants can be eliminated, and at the same time, the cost can be prevented from increasing.

[0008]

SUMMARY OF THE INVENTION According to the present invention, when an abnormal noise occurs due to passage of a refrigerant in an indoor expansion mechanism, the opening degree of the expansion mechanism, the amount of air blown to a condenser, or the capacity of a compressor is adjusted. It is the one.

Specifically, the first to fourth means for solving the problems according to the present invention include a refrigerant circuit (10) for a vapor compression refrigeration cycle, and the indoor expansion mechanism (15) is provided in the refrigerant circuit (10). It is based on the provided air conditioner.

The air conditioner according to the first solving means includes the abnormal noise detecting means (21, 22) for detecting the abnormal noise generation when the refrigerant in the indoor expansion mechanism (15) passes, and the abnormal noise detecting means when the abnormal noise occurs. An abnormal sound canceling means (20) for canceling the abnormal sound is provided.

In the first solving means, when the abnormal noise detecting means (21, 22) detects that abnormal noise is generated when the refrigerant passes through the indoor expansion mechanism (15), the abnormal noise eliminating means (2
By 0), the operation for eliminating the generation of the abnormal noise is performed.

The second means for solving the problems of the present invention is as follows.
In the first solving means, the indoor expansion mechanism (15) is configured so that the opening degree can be adjusted, and the abnormal noise canceling means (20) is configured to generate an abnormal noise when the indoor expansion mechanism (15) passes through the refrigerant. It is characterized in that it is configured to control the opening of (15) in the direction of narrowing.

In the second solving means, when the refrigerant flows through the indoor expansion mechanism (15) in a gas-liquid two-phase state and an abnormal noise is generated, the opening degree of the indoor expansion mechanism (15) is narrowed. . Therefore, the low-pressure pressure of the refrigerant circuit (10) decreases, the degree of refrigerant superheat increases, and the refrigerant circulation amount decreases. Also, the refrigerant circuit (10)
The high-pressure pressure of A becomes low, and supercooling occurs, so that the inlet side of the indoor expansion mechanism (15) becomes a single phase of liquid.

The third means for solving the problems of the present invention is as follows.
In the first or second solving means, the fan (13F) for blowing air to the heat exchanger (13) which is a condenser is configured so that the rotation speed can be adjusted, and the abnormal noise eliminating means (20) is an indoor expansion mechanism. (15)
When abnormal noise occurs due to the passage of refrigerant in
It is characterized by being configured to increase the rotation speed of F).

In the third means for solving the problems, when the refrigerant flows through the indoor expansion mechanism (15) in a gas-liquid two-phase flow state and abnormal noise is generated, the fan (13F) for the heat exchanger, which is the condenser, operates. The air volume increases. Therefore, the cooling capacity is increased and supercooling is advanced, and the inlet side of the indoor expansion mechanism (15) becomes a single phase of liquid.

The fourth means for solving the problems of the present invention is as follows.
In the air conditioner according to the first, second or third solving means, the compressor (11) is configured to have a variable capacity, and the abnormal noise eliminating means (20) is provided by the passage of the refrigerant in the indoor expansion mechanism (15). It is characterized in that the capacity of the compressor (11) is reduced when abnormal noise occurs.

In the fourth solution means, when the refrigerant flows through the indoor expansion mechanism (15) in a gas-liquid two-phase flow state and abnormal noise is generated, the capacity of the compressor (11) becomes small. Therefore, the circulation amount of the refrigerant is reduced, so that the refrigerant is surely liquefied in the condenser (13), and the inlet side of the indoor expansion mechanism (15) becomes a single phase of the liquid.

Next, the fifth to tenth means for solving the problems according to the present invention include a refrigerant circuit (30) of a vapor compression refrigeration cycle, and the refrigerant circuit (30) is an outdoor heat exchanger (33). A plurality of indoor heat exchangers (36) are connected in parallel with respect to the so-called multi-type, the air conditioner provided with an indoor expansion mechanism (35) corresponding to each indoor heat exchanger (36) Is assumed.

The air conditioner according to the fifth solution means is the abnormal noise detecting means (51) for detecting the abnormal noise generation in each indoor expansion mechanism (35) during the passage of the refrigerant, and the abnormal noise detecting means (51) for generating the abnormal noise. It is characterized by being provided with an abnormal noise elimination means (50) for eliminating the occurrence of abnormal noise.

In the fifth solving means, when the abnormal noise detecting means (51) detects that abnormal noise is generated when the indoor expansion mechanism (35) passes through the refrigerant, the abnormal noise eliminating means (50) detects the abnormal noise. , The operation for eliminating the generation of the abnormal noise is performed.

The sixth means for solving the problems of the present invention is as follows.
In the fifth solving means, the indoor expansion mechanism (35) is configured so that the opening degree can be adjusted, and the abnormal noise canceling means (50) produces an abnormal noise when the abnormal noise occurs due to the passage of the refrigerant in the indoor expansion mechanism (35). It is characterized in that it is configured to control the degree of opening of the generated indoor expansion mechanism (35) in a direction of narrowing it.

In the sixth solution means, when the refrigerant flows through the indoor expansion mechanism (35) in a gas-liquid two-phase state and abnormal noise occurs, the opening degree of the indoor expansion mechanism (35) is narrowed. . Therefore, the low-pressure pressure of the refrigerant circuit (30) decreases, the degree of refrigerant superheat increases, and the refrigerant circulation amount decreases. Also, the refrigerant circuit (30)
The high-pressure pressure of A becomes low, and supercooling occurs, so that the inlet side of the indoor expansion mechanism (35) becomes a single phase of liquid.

The seventh means for solving the problems of the present invention is as follows.
In the sixth solving means, the abnormal noise eliminating means (50) controls the opening degree of the indoor expansion mechanism (35) in which abnormal noise is generated so as to reduce the opening degree of the indoor expansion mechanism (35). It is characterized in that the opening degree is also controlled so as to be narrowed.

In the seventh solving means, when an abnormal noise is generated in a certain indoor expansion mechanism (35), the opening degree of each indoor expansion mechanism (35) is narrowed. Therefore, as in the sixth solving means, the liquid refrigerant is supercooled and the inlet side of the indoor expansion mechanism (35) becomes a single phase of the liquid.

The eighth means for solving the problems of the present invention is as follows.
In the fifth, sixth or seventh means for solving the above problems, the high pressure liquid refrigerant having passed through the outdoor heat exchanger (33) and the gas refrigerant on the suction side of the compressor (31) are heat-exchanged to generate the high pressure liquid refrigerant. The abnormal noise elimination means (50) is provided with a supercooling passage (41) for supercooling, and when the abnormal noise occurs due to the passage of the refrigerant in the indoor expansion mechanism (35), the high-pressure liquid refrigerant is caused to flow through the supercooling passage (41). It is characterized in that it is configured to increase the degree of supercooling of the refrigerant.

In the eighth solution means, when abnormal noise is generated in the indoor expansion mechanism (35), the high-pressure liquid refrigerant flows through the supercooling passage (41) to increase the degree of supercooling. Therefore, the refrigerant flowing into the indoor expansion mechanism (35) becomes a single-phase liquid.

The ninth means for solving the problems of the present invention is as follows.
In the fifth, sixth, seventh or eighth solving means,
The fan (33F) that blows air to the heat exchanger (33), which is a condenser, is configured so that the number of rotations can be adjusted, and the abnormal noise elimination means (50) is used when abnormal noise occurs due to the passage of refrigerant in the indoor expansion mechanism (35). It is characterized in that it is configured to increase the rotation speed of the fan (33F).

In the ninth means for solving the problems, when the refrigerant flows through the indoor expansion mechanism (35) in a gas-liquid two-phase state and abnormal noise occurs, a fan for the heat exchanger (33), which is a condenser, is generated. The air volume of (33F) increases. Therefore, the cooling capacity is increased and supercooling is advanced, and the inlet side of the indoor expansion mechanism (35) becomes a single phase of liquid.

The tenth means for solving the problems of the present invention is that, in the fifth, sixth, seventh, eighth or ninth means, the compressor (31) has a variable capacity, The sound canceling means (50) is characterized in that it is configured to reduce the capacity of the compressor (31) when abnormal noise occurs due to passage of the refrigerant in the indoor expansion mechanism (35).

In the tenth means for solving the problem, when the refrigerant flows through the indoor expansion mechanism (35) in a gas-liquid two-phase state and an abnormal noise is generated, the capacity of the compressor (31) is reduced. Therefore, the circulation amount of the refrigerant is reduced, so that the refrigerant is surely liquefied in the condenser (33), and the inlet side of the indoor expansion mechanism (35) becomes a single phase of the liquid.

Next, the eleventh to thirteenth solving means taken by the present invention is characterized by abnormal sound detecting means (21, 22, 51).

Specifically, the eleventh solving means is the above first
In any one of the tenth to tenth solving means, the abnormal sound detecting means analyzes the vibration sensor (22) and a measurement signal from the vibration sensor (22) to determine whether or not the abnormal sound is generated.
It is characterized by having (25) and.

A twelfth solving means of the present invention is the solution means according to any one of the first to tenth above, wherein the abnormal noise detecting means comprises an acoustic sensor (21, 51) and an acoustic sensor ( 21, 51) and the abnormal sound judging means (25, 57) for judging the presence or absence of the abnormal sound by analyzing the measured signal.

In the eleventh and twelfth solving means, when a sound is generated in the indoor expansion mechanism (15, 35),
The presence or absence of abnormal noise is determined by analyzing the measurement signal measured by the vibration sensor (22) or the acoustic sensor (21, 51) by the abnormal noise determining means (25, 57). Then, when it is determined that the abnormal noise is generated, the operation for eliminating the abnormal noise is performed in the first to tenth solving means.

Further, a thirteenth solving means devised by the present invention is the acoustic sensor (51) according to the twelfth solving means.
However, the wave receiving unit (51b) for receiving a sound wave, and the frequency resolving unit (51c, 51d) connected to the wave receiving unit (51b) for frequency resolving,
It is characterized in that the vibration decomposed by the frequency decomposition section (51c, 51d) is converted into an electric signal and inputted to the abnormal sound judging means (57).

In the thirteenth solution means, when sound is generated in the indoor expansion mechanism (35), the sound wave is received by the wave receiving portion (51).
It is transmitted to the frequency decomposing unit (51d, 51d) via b), the signal is converted into an electric signal and input to the abnormal noise determining means (57), and it is determined whether or not an abnormal noise is generated.

[0037]

According to the first solving means, when the abnormal noise detecting means (21, 22) detects that abnormal noise is generated when the refrigerant in the indoor expansion mechanism (15) passes, the abnormal noise is eliminated. Means (2
Due to 0), the operation for eliminating the generation of the abnormal noise is performed, so that the abnormal noise is suppressed instantaneously. Therefore, post-processing such as attaching a soundproofing material when an abnormal noise occurs is unnecessary, and the work cost does not occur. In addition, putty etc. indoor expansion mechanism (15)
Unlike the case where the noise is covered to suppress the abnormal noise, the noise is suppressed by the control, so that the insufficient noise reduction effect due to the insufficient space for putty does not occur. Further, unlike the case where the silencer is used, the abnormal noise can be reliably reduced regardless of the operating conditions. Thus, according to the first solving means,
When abnormal noise is generated while the refrigerant passes through the indoor expansion mechanism (15), the abnormal noise is instantly sufficiently reduced regardless of the operating conditions to eliminate the discomfort of the occupants, and at the same time the cost is increased. Can also be prevented.

Further, according to the second solving means, the abnormal noise eliminating means (20) narrows the opening degree of the expansion mechanism (15) when abnormal noise occurs due to passage of the refrigerant in the indoor expansion mechanism (15). Indoor expansion mechanism (15) because it is configured to control
The inlet side of the liquid becomes a single phase of liquid, and the generation of abnormal noise due to the refrigerant flowing through the indoor expansion mechanism (15) in a gas-liquid two-phase flow can be suppressed.

Further, according to the third solving means, the abnormal noise eliminating means (20) causes the fan (13F) for the condenser (13) when the abnormal noise occurs due to the passage of the refrigerant in the indoor expansion mechanism (15). Because it is configured to increase the rotation speed of
The inlet side of (15) becomes a single phase of liquid, and the generation of abnormal noise due to the refrigerant flowing through the indoor expansion mechanism (15) in a gas-liquid two-phase flow can be suppressed.

Further, according to the fourth solving means, the abnormal noise eliminating means (20) reduces the capacity of the compressor (11) when an abnormal noise occurs due to passage of the refrigerant in the indoor expansion mechanism (15). Therefore, the inlet side of the indoor expansion mechanism (15) becomes a single phase of liquid, and the generation of abnormal noise due to the refrigerant flowing through the indoor expansion mechanism (15) in a gas-liquid two-phase flow state can be suppressed.

Further, according to the fifth solving means, in the so-called multi-type refrigerant circuit (30), the indoor expansion mechanism (3
When the abnormal noise detection means (51) detects that abnormal noise is generated during passage of the refrigerant in 5), the abnormal noise elimination means (50),
Since the operation for eliminating the generation of the abnormal noise is performed, the abnormal noise is suppressed instantly. Therefore, there is no need for post-processing such as applying a soundproofing material when abnormal noise occurs, and no work is required, so there is no cost. Also, use an indoor expansion mechanism (3
Unlike the case where 5) is covered to suppress the abnormal noise, the abnormal noise is controlled to be suppressed, so that the effect of reducing the abnormal noise is surely obtained. Further, unlike the case where the silencer is used, the abnormal noise is not reduced depending on the operating condition. Thus, when abnormal noise occurs when the refrigerant passes through the indoor expansion mechanism (35), the occupant's discomfort is eliminated by sufficiently reducing the abnormal noise instantly regardless of operating conditions,
At the same time, it is possible to prevent the cost from increasing.

Further, according to the sixth and seventh solving means, the abnormal noise eliminating means (50) narrows the opening degree of the expansion mechanism (35) when abnormal noise occurs due to passage of the refrigerant in the expansion mechanism (35). Indoor expansion mechanism because it is configured to control
The inlet side of (35) becomes a single phase of liquid, and the generation of abnormal noise due to the refrigerant flowing through the indoor expansion mechanism (35) in a gas-liquid two-phase flow state can be suppressed.

Further, according to the eighth solving means, the abnormal noise eliminating means (50) supplies the high-pressure liquid refrigerant to the supercooling passage (41) when the abnormal noise occurs due to the passage of the refrigerant in the indoor expansion mechanism (35). Since it is configured to increase the degree of supercooling of the refrigerant by flowing, the inlet side of the indoor expansion mechanism (35) is a single phase of liquid, the refrigerant in the indoor expansion mechanism (35) of the gas-liquid two-phase flow. It is possible to suppress the generation of abnormal noise caused by flowing in the state.

According to the ninth solving means, the abnormal noise eliminating means (50) causes the fan (33F) for the condenser (33) when the abnormal noise is generated by the passage of the refrigerant in the indoor expansion mechanism (35). Because it is configured to increase the rotation speed of
The inlet side of (35) becomes a single phase of liquid, and the generation of abnormal noise due to the refrigerant flowing through the indoor expansion mechanism (35) in a gas-liquid two-phase flow state can be suppressed.

Further, according to the tenth solving means, the abnormal noise eliminating means (50) reduces the capacity of the compressor (31) when an abnormal noise occurs due to the passage of the refrigerant in the indoor expansion mechanism (35). Therefore, the inlet side of the indoor expansion mechanism (35) becomes a single phase of liquid, and the generation of abnormal noise due to the refrigerant flowing through the indoor expansion mechanism (35) in a gas-liquid two-phase flow state can be suppressed.

According to the eleventh and twelfth solving means,
The vibration sensor (22) or the acoustic sensor (21, 51) and the abnormal noise determining means (25, 57) can be used to determine whether or not an abnormal noise is occurring. Moreover, since the operation of eliminating the abnormal noise is performed after that, the whole process can be performed in one step.

Further, according to the twelfth solving means, since the sound is frequency-decomposed and inputted to the abnormal sound judging means (57), the abnormal sound frequency pattern is preset by the abnormal sound judging means (57). By doing so, it is possible to easily and surely determine whether or not abnormal noise is generated.

[0048]

Embodiment 1 of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a refrigerant circuit diagram of the air conditioner (1) according to the first embodiment. The refrigerant circuit (10) of the air conditioner (1) includes a compressor (11), a four-way switching valve (12), an outdoor heat exchanger (13) which is a heat source side heat exchanger, and a heat source side expansion. An outdoor expansion valve (14) that is a mechanism, an indoor expansion valve (15) that is a usage-side expansion mechanism, and an indoor heat exchanger (16) that is a usage-side heat exchanger.
And the accumulator (17) are sequentially connected by a refrigerant pipe (18).

The compressor (11) has a variable capacity by controlling the rotation speed by the inverter (19). The discharge side of the compressor (11) is connected to one port of the four-way switching valve (12), and the suction side of the compressor (11) is connected to the accumulator (1
It is connected to another port of the four-way switching valve (12) via 7).

The other two ports of the four-way switching valve (12) are
The outdoor heat exchanger (13) is connected to one side and the indoor heat exchanger (16) is connected to the other side. And from the outdoor heat exchanger (13) to the compressor
The part that goes through the (11) to the indoor heat exchanger (16) is the gas line (1
8G).

The outdoor heat exchanger (13) and the indoor heat exchanger (16) are
Liquid line (18L) between the ends opposite the gas line (18G)
Connected by. The liquid line (18L) has an outdoor expansion valve (14) near the outdoor heat exchanger (13) and an indoor heat exchanger (1
An indoor expansion valve (15) is arranged near 6). The outdoor expansion valve (14) and the indoor expansion valve (15) are electric expansion valves, respectively, and their opening degrees are adjustable.

Outdoor heat exchanger (13) and indoor heat exchanger (16)
Are fin-and-tube heat exchangers of the cross fin type, and an outdoor fan is located near the outdoor heat exchanger (13).
(13F) has an indoor fan (16F) near the indoor heat exchanger (16)
Are arranged. Further, temperature sensors (Thi1, Thi2) are provided at both ends of the indoor heat exchanger (16).

In the vicinity of the indoor expansion valve (15), a microphone (21) (or a vibration sensor (22)) is provided as an acoustic sensor, and the microphone (21) serves as an abnormal sound detecting means (20) ( It is configured to input a signal to the abnormal noise elimination means). In addition, the controller (20) receives the input signal and determines the opening degree of the indoor expansion valve (15), the capacity of the compressor (11), the rotation speed of the outdoor fan (13F) and the indoor fan (16F), etc. Is configured to control.

Specifically, as shown in FIG. 2, a microphone (21) is arranged near the indoor expansion valve (15), or a vibration sensor (22) (acceleration pickup) is shown by a broken line.
Are directly attached to the indoor expansion valve (15). And
If the microphone (21) or vibration sensor (22)
3) It is connected to the CPU (25) which is the abnormal sound judging means through the A / D converter (24).

In this configuration, the signal picked up by the microphone (21) or the like is amplified by the amplifier (23) and converted into a digital signal by the A / D converter (24). Then, the obtained waveform is input to the CPU (25) and compared with a predetermined waveform of abnormal sound data to determine whether the detected sound is abnormal sound.

-Driving Operation- Next, the driving operation of the air conditioner (1) will be described.

During the cooling operation, the four-way switching valve (12) is set to the communication state indicated by the solid line in the figure. Further, the outdoor expansion valve (14) is set to be fully opened, and the indoor expansion valve (15) is opened so that a predetermined degree of superheat can be obtained by the inlet and outlet temperatures (Thi1, Thi2) of the indoor heat exchanger (16). Temperature is controlled (superheat control).

In this state, the gas refrigerant discharged from the compressor (11) flows into the outdoor heat exchanger (13) through the four-way switching valve (12) and the indoor heat exchanger (13) It exchanges heat with air and condenses to become a high-pressure liquid refrigerant. Liquid refrigerant is a fully open outdoor expansion valve (14)
Through the indoor expansion valve (15) to reduce the pressure. This refrigerant is evaporated in the indoor heat exchanger (16) to become a gas refrigerant, which is sucked into the compressor (11) from the four-way switching valve (12) through the accumulator (17).

A microphone is provided near the indoor expansion valve (15).
(21) is arranged, or the vibration sensor (22) is directly attached to the indoor expansion valve (15), the indoor expansion valve (1
When sound is generated in 5), the sound (or vibration) is input to the amplifier (23) and amplified, and then the A / D converter.
Converted to digital data at (24). With this signal,
In the CPU (25), FFT (Fast Fourier Transfor
m) or Wavelet operation is performed, and the abnormal sound data that the CPU (25) has in advance is compared with the waveform pattern to determine whether the sound is abnormal sound.

The indoor expansion valve (1
When the refrigerant flows into 5) as a gas-liquid two-phase flow, a sound is generated due to pressure fluctuation, and this sound is judged as an abnormal sound. When the generation of abnormal noise is detected in this way, the controller (20) operates to throttle the indoor expansion valve (15). Specifically, when abnormal noise is detected by the microphone (21), the indoor expansion valve (15) is controlled to be closed by a predetermined pulse, and when abnormal noise is no longer detected, the indoor expansion valve (15) of that state is closed. Hold the opening.

In this operation, if the indoor expansion valve (15) is throttled, the low-pressure pressure tends to decrease as shown in the Mollier diagram of FIG. Then, the degree of superheat of the refrigerant increases and the amount of refrigerant circulation decreases. In addition, the refrigerant circuit (10)
The high pressure becomes low, and the refrigerant is supercooled, so that the inlet side of the indoor expansion valve (15) becomes a single phase of liquid and abnormal noise is suppressed.

In the above example, when the abnormal noise is detected, the indoor expansion valve (15) is controlled so as to be narrowed.
Instead of this control or in combination with this control, the frequency of the compressor (11) is lowered, or the outdoor fan (1
You may increase the rotation speed of 3F). When the capacity of the compressor (11) is reduced, the circulation amount of the refrigerant is reduced,
As a result, the refrigerant is sufficiently liquefied in the outdoor heat exchanger (13), and the refrigerant at the inlet of the indoor expansion valve (15) becomes a single-phase liquid. Further, even if the rotation speed of the outdoor fan (13F) is increased, the refrigerant is sufficiently liquefied in the outdoor heat exchanger (13), and the refrigerant at the inlet of the indoor expansion valve (15) becomes a single phase of liquid. Therefore, generation of abnormal noise in the indoor expansion valve (15) is suppressed.

-Effects of the first embodiment- According to the first embodiment, the fact that the abnormal noise is generated when the indoor expansion valve (15) passes through the refrigerant is input from the microphone (21) to the controller (20). When detected, whether the controller (20) controls the opening degree of the indoor expansion valve (15) in a direction to reduce it or increases the rotation speed of the outdoor fan (13F),
Alternatively, an operation is performed to eliminate the occurrence of abnormal noise, such as reducing the capacity of the compressor (11). As a result, the inlet side of the indoor expansion valve (15) becomes a single-phase liquid, so that abnormal noise caused by the refrigerant flowing through the indoor expansion valve (15) in a gas-liquid two-phase flow state is instantaneously suppressed. Therefore, there is no need for post-processing such as applying a soundproofing material when abnormal noise occurs, and no work is required, so there is no cost.

Further, unlike the case where the indoor expansion valve (15) is covered with putty or the like to suppress the abnormal noise, the abnormal noise is controlled so as to suppress the abnormal noise. There will be no shortage. Further, unlike the case where the silencer is used, the effect of reliably reducing abnormal noise can be obtained.

As described above, according to the first embodiment, when abnormal noise is generated when the refrigerant passes through the indoor expansion valve (15),
Since the abnormal noise can be sufficiently reduced instantly regardless of the driving condition, the discomfort of the occupants can be eliminated and the cost can be prevented from becoming high at the same time.

[0067]

Embodiment 2 of the present invention relates to a so-called multi-type air conditioner (2) in which a plurality of indoor units (Ui) are connected to one outdoor unit (Uo). is there.

The refrigerant circuit (30) of this air conditioner (2) is
As shown in FIG. 4, the compressor (31), the four-way switching valve (32),
The outdoor heat exchanger (33), the outdoor expansion valve (34), and the outdoor expansion valve (3
The indoor expansion valve (35) in parallel with 4) and the indoor heat exchanger (36) in series with each indoor expansion valve (35) in parallel with the compressor (31) It is configured by pipe connection.
An accumulator (37) is provided on the suction side of the compressor (31).

Also in this embodiment, the compressor (31) is of a variable capacity type controlled by an inverter.
Also, the outdoor fan (33F) for the outdoor heat exchanger (33) and the indoor fans (36F) for the indoor heat exchangers (36) control the air volume by operating the rotation speed of the fan motor. It is configured to be adjustable. Further, the outdoor expansion valve (34) and the indoor expansion valve (35) are electric expansion valves with adjustable opening.

An electromagnetic valve (40) is provided between the outdoor expansion valve (34) and the branch point to each indoor expansion valve (35). Supercooling passages (41) are connected to both ends of the solenoid valve (40). The subcooling passage (41) and the suction side pipe of the compressor (31) are provided with a subcooling heat exchanger (42) to supercool the liquid refrigerant when the solenoid valve (40) is closed. Is configured. Further, the supercooling passage (41) is configured as a one-way passage through which the refrigerant flows only from the outdoor expansion valve (34) to each indoor expansion valve (35), for which a check valve (43) is provided. Has been.

An acoustic sensor (51) is provided in the vicinity of each indoor expansion valve (35). Each acoustic sensor (51)
Is connected to the controller (50) and controls the signal
Enter in (50). Further, the controller (50) is connected to each indoor expansion valve (35), each indoor fan (36F), outdoor fan (33F), compressor (31), and solenoid valve (40) of the supercooling passage (41). And configured to control these devices.

As shown in FIG. 5, the acoustic sensor (51) includes a diaphragm (51b) and a diaphragm (51b) on a semiconductor silicon substrate (51a).
The backbone (51c) and a plurality of cantilevers (51d) are provided and configured. The cantilevers (51d) have different lengths and have different resonance frequencies.
Then, the acoustic signal received by the diaphragm (51b), which is the wave receiving unit, is transmitted to the backbone (51c), and each cantilever.
It is frequency decomposed at the resonance frequency of (51d). That is, the backbone (51c) and each cantilever (51d) form a frequency decomposition section. The vibration of the cantilever (51d) is converted into an electric signal by a piezoresistor (not shown) built in the base of the cantilever (51d) and output.
As shown in FIG. 6, the acoustic sensor (51) includes an amplifier (5
3), multiplexer (54), sample hold circuit (55),
It is connected to the CPU (57) through the A / D converter (56).

-Driving Operation- Next, the driving operation of the air conditioner (2) will be described.

During the cooling operation, the four-way switching valve (32) is set to the state shown by the solid line in the figure, the outdoor expansion valve (34) is fully opened, and the indoor expansion valves (35) are superheated. Further, the solenoid valve (40) provided between the subcooling passages (41) in the liquid line is open.

In this state, the refrigerant discharged from the compressor (31) flows into the outdoor heat exchanger (33) and is heat-exchanged with the outdoor air in the outdoor heat exchanger (33) to be condensed. The condensed liquid refrigerant passes through the outdoor expansion valve (34) and the electromagnetic valve (40) of the liquid line (38L), branches and passes through each indoor expansion valve (35). Indoor expansion valve
In (35), the liquid refrigerant is decompressed, and the indoor heat exchanger
At (36), heat is exchanged with room air to evaporate. The evaporated gas refrigerant is sucked into the compressor (31) from the four-way switching valve (32) through the accumulator (37). During the cooling operation, the above operation is repeated as one cycle and the indoor air is cooled.

In this state, the sound generated from each indoor expansion valve (35) is monitored by the acoustic sensor (51), and the sound is detected by the refrigerant inside the indoor expansion valve (35) as gas-liquid two-phase. It is determined by the controller (50) whether or not it is an abnormal sound generated by flowing in.

Specifically, the sound generated by the indoor expansion valve (35) vibrates the diaphragm (51b) of the acoustic sensor (51),
The vibration propagates through the backbone (51c) and each cantilever
It is transmitted to (51d). Then, the cantilever (51d) decomposes the frequency, and the vibration is converted into an electric signal and output.

This output is amplified by the amplifier (53), and further the multiplexer (54) and the sample & hold circuit (5
The output of each cantilever (51d) is taken in for each frequency band by 5), and further converted into a digital signal by the A / D converter (56). Then, the controller (50) compares this signal with abnormal sound data to determine whether the sound is abnormal sound. In FIG. 6, in the measurement data and the abnormal sound data, the vertical axis represents frequency, the horizontal axis represents time, and the color depth of each segment represents the magnitude of output.

When it is determined that the sound generated in the indoor expansion valve (35) is abnormal noise by comparing the magnitude of the output for each frequency band, the controller (50) turns on the solenoid valve (40). The liquid refrigerant is caused to flow through the supercooling passage (41) by closing it, and the liquid refrigerant is heat-exchanged with the gas refrigerant on the suction side of the compressor (31) to increase the degree of supercooling. By supercooling in this way, the refrigerant flowing into the indoor expansion valve (35) becomes a single-phase liquid. Therefore, the pressure fluctuation caused by the flow of the gas / liquid two-phase refrigerant in which the liquid / gas is mixed into the indoor expansion valve (35) is eliminated, and abnormal noise is prevented.

When abnormal noise is generated in the indoor expansion valve (35), the following operation may be performed instead of using the supercooling passage (41) or together with using the supercooling passage (41).

For example, when an abnormal noise is generated in the indoor expansion valve (35), the opening of the indoor expansion valve (35) in which the abnormal noise is generated may be reduced. In this way, the low-pressure pressure of the refrigerant circuit (30) tends to decrease and the degree of refrigerant superheat increases as described in the first embodiment. Also,
The circulation amount of the refrigerant is reduced, and the high pressure is also reduced. Then, the condensed refrigerant is supercooled, the refrigerant on the inlet side of the expansion valve becomes a single phase of the liquid, and abnormal noise is reduced.

When an abnormal sound is generated in the indoor expansion valve (35), in addition to operating the indoor expansion valve (35) in which the abnormal sound is generated, the opening degree of the indoor expansion valve (35) is reduced. (35) may also be operated in the direction of narrowing the opening. Even in this case, the refrigerant on the inlet side of the expansion valve becomes a single phase of liquid as in the above case, and the effect of reducing abnormal noise can be obtained.

As in the first embodiment, the capacity of the compressor (31) may be reduced by lowering the frequency, or an outdoor fan may be used.
You may increase the air volume of (33F). When the capacity of the compressor (31) is reduced, the circulation amount of the refrigerant is reduced, as a result, the refrigerant is sufficiently liquefied in the outdoor heat exchanger (33), and the refrigerant at the inlet of the indoor expansion valve (35) is It becomes a single phase of liquid. Even if the rotation speed of the outdoor fan (33F) is increased, the refrigerant remains in the outdoor heat exchanger (3
It is sufficiently liquefied in 3), and the refrigerant at the inlet of the indoor expansion valve (35) becomes a single-phase liquid. Therefore, generation of abnormal noise in the indoor expansion valve (35) is suppressed.

On the other hand, during the heating operation, the four-way switching valve (32) is switched to the state shown by the broken line in the figure, and each indoor expansion valve (35) adjusts the refrigerant flow rate of each indoor heat exchanger (36). The opening is set to. The opening degree of the outdoor expansion valve (34) is set so that the refrigerant sucked into the compressor (31) has a predetermined degree of superheat.

In this state, the refrigerant discharged from the compressor (31) flows into the indoor heat exchanger (36), and the indoor heat exchanger (36)
Heats the room air by exchanging heat with the room air to condense.
The condensed liquid refrigerant passes through the indoor expansion valve (35) and
At (34), the pressure is reduced to a predetermined low pressure. Then, the outdoor heat exchanger (33) exchanges heat with the outdoor air to evaporate, and is sucked into the compressor (31) through the accumulator (37).

Even during this heating operation, the sound generated from the indoor expansion valve (35) is monitored in the same manner as during the cooling operation, and it is determined whether or not there is an abnormal noise. The method of this determination is the same as that described in the cooling operation, and thus the description thereof is omitted here.

When it is determined that the sound generated from the indoor expansion valve (35) is an abnormal sound, the operation of reducing the opening degree of the indoor expansion valve (35) is performed. By doing so, the refrigerant flowing into the indoor expansion valve (35) becomes a single phase of the liquid by the same operation as described during the cooling operation, and the generation of abnormal noise is prevented.

Even when the frequency of the compressor (31) is reduced to reduce the capacity, the indoor expansion valve operates in the same manner as in the cooling operation.
It is possible to reduce abnormal noise by making the refrigerant flowing into (35) a liquid single phase.

Further, during the heating operation, the indoor fan (36F) of the indoor heat exchanger (36) corresponding to the indoor expansion valve (35) causing the abnormal noise may be accelerated. In this case, since the cooling capacity of the indoor heat exchanger (36) increases, the flash of the refrigerant is eliminated, and the refrigerant flowing into the indoor expansion valve (35) becomes a liquid single phase, so that the generation of abnormal noise can be prevented. .

-Effect of Second Embodiment- According to the second embodiment, when it is detected by the acoustic sensor (51) that abnormal noise is generated when the refrigerant passes through the indoor expansion valve, the controller (50) causes an excessive noise. Supercool the high-pressure liquid refrigerant in the cooling passage (41), control the opening degree of the indoor expansion valve (35) in a direction of decreasing it, increase the rotation speed of the blower, or increase the capacity of the compressor (31). An operation is performed to reduce the occurrence of abnormal noise, such as reducing noise. Since the inlet side of the expansion valve has a single-phase liquid, abnormal noise caused by the refrigerant flowing through the indoor expansion valve in a gas-liquid two-phase flow state is instantaneously suppressed. Therefore,
As in the first embodiment, post-processing such as attaching a soundproofing material when an abnormal noise occurs is not necessary, and no work is required, so that no cost is required.

Further, unlike the case where the expansion valve is covered with putty or the like to suppress the abnormal noise, the abnormal noise is suppressed by the control, so that the effect of reducing the abnormal noise due to the insufficient space for the putty is not insufficient. Further, unlike the case where the silencer is used, the abnormal noise is not reduced depending on the operating conditions. Therefore, similar to the first embodiment, when an abnormal noise is generated when the refrigerant passes through the expansion valve, the abnormal noise is instantly sufficiently reduced regardless of the operating condition to eliminate the occupant's discomfort and at the same time. It is possible to prevent the cost from increasing.

[0092]

Other Embodiments of the Invention The present invention may have the following configurations in the above embodiments.

For example, in the second embodiment, the supercooling passage
(41) does not necessarily have to be provided. That is, also in the multi-type air conditioner (2), as with the paired machine of the first embodiment, when the abnormal noise of the indoor expansion valve (35) occurs, the opening of the indoor expansion valve (35) is reduced or the outdoor fan is closed. (33F) or indoor fan (36
The operation may be performed only by increasing the air volume of F) or reducing the capacity of the compressor (31).

Further, in the multi-type air conditioner (2), the outdoor unit (Uo) is not limited to one unit, and a plurality of units may be connected in parallel with each other.

The acoustic sensor (51) of the second embodiment may be used in the first embodiment.
In the above, the microphone (21) or the vibration sensor (22) of the first embodiment may be used.

In addition, although the description goes back and forth, in the first embodiment, the subcooling passage (41) and the solenoid valve (4) described in the second embodiment are used.
0), the subcooling heat exchanger (42), the refrigerant circuit provided with the check valve (43) is configured to increase the degree of supercooling of the refrigerant when abnormal noise occurs in the indoor expansion valve (15). The effect of reducing abnormal noise may be obtained.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration for detecting abnormal noise in an indoor expansion valve.

FIG. 3 is a Mollier diagram showing a change in the state of the refrigerant with the operation of the indoor expansion valve.

FIG. 4 is a refrigerant circuit diagram of an air conditioner according to a second embodiment of the present invention.

FIG. 5 is an external view of an acoustic sensor.

FIG. 6 is a block diagram showing a configuration for detecting abnormal noise in the indoor expansion valve.

[Explanation of symbols]

(1,2) Air conditioner (10) Refrigerant circuit (11) Compressor (13) Outdoor heat exchanger (outdoor heat exchanger) (13F) Outdoor fan (14) Outdoor expansion valve (15) Indoor expansion valve (indoor expansion valve) (16) Indoor heat exchanger (indoor heat exchanger) (16F) Indoor fan (20) Controller (abnormal noise elimination means) (21) Microphone (acoustic sensor, abnormal sound detection means) (22) Vibration sensor (abnormal noise detection means) (25) CPU (abnormal noise determination means) (30) Refrigerant circuit (31) Compressor (33) Outdoor heat exchanger (outdoor heat exchanger) (33F) Outdoor fan (35) Indoor expansion valve (indoor expansion valve) (36) Indoor heat exchanger (indoor heat exchanger) (36F) Indoor fan (41) Supercooling passage (50) Controller (abnormal noise elimination means) (51) Acoustic sensor (abnormal noise detection means) (51b) Diaphragm (wave receiver) (51c) Backbone (frequency decomposition section) (51d) Cantilever (frequency decomposition section) (57) CPU (abnormal noise determination means)

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Claims (13)

[Claims] 1. A refrigerant circuit (10) for a vapor compression refrigeration cycle.
An air conditioner including the indoor expansion mechanism (15) in the refrigerant circuit (10), wherein abnormal noise detection means (21) for detecting abnormal noise generated during passage of refrigerant in the indoor expansion mechanism (15). , 22) and an abnormal noise canceling means (20) for canceling the abnormal noise when the abnormal noise is generated. 2. The indoor expansion mechanism (15) is configured so that its opening can be adjusted, and the abnormal noise canceling means (20) is provided when the abnormal noise due to the passage of the refrigerant in the indoor expansion mechanism (15) occurs. The air conditioner according to claim 1, wherein the air conditioner is configured to control the opening degree of the air conditioner in a direction to reduce the opening degree. 3. A fan (13F) for blowing air to a heat exchanger (13), which is a condenser, is configured so that the number of revolutions can be adjusted, and the abnormal noise elimination means (20) is a refrigerant passage in the indoor expansion mechanism (15). The fan (13F) is configured to increase the number of revolutions when an abnormal noise is generated.
Or the air conditioning apparatus according to 2. 4. The compressor (11) is configured to have a variable capacity, and the abnormal noise elimination means (20) reduces the capacity of the compressor (11) when abnormal noise occurs due to passage of a refrigerant in the indoor expansion mechanism (15). The air conditioner according to claim 1, 2 or 3, wherein the air conditioner is configured to: 5. A refrigerant circuit (30) for a vapor compression refrigeration cycle.
The refrigerant circuit (30), the indoor heat exchanger (36) is connected in parallel to the outdoor heat exchanger (33), the indoor expansion corresponding to each indoor heat exchanger (36) An air conditioner provided with a mechanism (35), which is an abnormal noise detecting means (51) for detecting the occurrence of abnormal noise during passage of refrigerant in each indoor expansion mechanism (35), and the abnormal noise when the abnormal noise occurs. An air conditioner comprising: an abnormal noise canceling means (50) for canceling the generation. 6. The indoor expansion mechanism (35) is configured so that its opening can be adjusted, and the abnormal noise elimination means (50) generates an abnormal noise when the abnormal noise occurs due to passage of the refrigerant in the indoor expansion mechanism (35). The air conditioner according to claim 5, wherein the indoor expansion mechanism (35) is configured to control the opening degree of the indoor expansion mechanism (35) in a direction to reduce the opening degree. 7. The abnormal noise elimination means (50) controls the opening degree of the indoor expansion mechanism (35) in which abnormal noise is generated so as to reduce the opening degree of the indoor expansion mechanism (35). The air conditioner according to claim 6, wherein the air conditioner is configured to control in a squeezing direction. 8. A supercooling passage (41) for supercooling the high-pressure liquid refrigerant by exchanging heat between the high-pressure liquid refrigerant having passed through the outdoor heat exchanger (33) and the gas refrigerant on the suction side of the compressor (31). The abnormal noise elimination means (50) increases the degree of supercooling of the refrigerant by causing high-pressure liquid refrigerant to flow in the supercooling passage (41) when abnormal noise occurs due to passage of the refrigerant in the indoor expansion mechanism (35). The air conditioner according to claim 5, 6 or 7, wherein the air conditioner is configured as described above. 9. A fan (33F) for blowing air to a heat exchanger (33), which is a condenser, is configured so that the number of rotations thereof can be adjusted, and the abnormal noise elimination means (50) is a refrigerant passage in the indoor expansion mechanism (35). 9. The air conditioner according to claim 5, 6, 7 or 8, wherein the number of rotations of the fan (33F) is increased when abnormal noise is generated. 10. The compressor (31) is configured to have a variable capacity, and the abnormal noise elimination means (50) reduces the capacity of the compressor (31) when abnormal noise occurs due to passage of a refrigerant in the indoor expansion mechanism (35). It is constituted so that it may be constituted.
The air conditioner according to 7, 8 or 9. 11. The abnormal noise detecting means includes a vibration sensor (22),
An air conditioner according to any one of claims 1 to 10, further comprising: an abnormal sound judging means (25) for analyzing a measurement signal from the vibration sensor (22) and judging whether or not an abnormal sound is generated. apparatus. 12. The abnormal noise detecting means is an acoustic sensor (21, 51).
11. An abnormal sound judging means (25, 57) for analyzing the measurement signal from the acoustic sensor (21, 51) and judging whether or not an abnormal sound is generated, according to any one of claims 1 to 10. The air conditioner according to item 1. 13. The acoustic sensor (51) comprises a wave receiving portion (51b) for receiving a sound wave and a frequency resolving portion (51c, 51d) connected to the wave receiving portion (51b) for frequency resolving. 13. The air conditioner according to claim 12, characterized in that the vibration decomposed into frequencies by the parts (51c, 51d) is converted into an electric signal and input to the abnormal noise judging means (57).