JP7227103B2 - air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air conditioner capable of performing a heating operation for blowing warm air into a room.

Conventionally, this type includes a refrigeration cycle in which a compressor with a variable rotation speed, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger are connected in a ring with refrigerant piping, and an instruction to start cooling and heating operation is provided. In some cases, the compressor was driven and the refrigerant circulated in the refrigeration cycle. (For example, Patent Document 1)

JP 2012-184886 A

However, in this conventional system, especially when the internal space volume of the compressor is small, the phase state of the refrigerant in the refrigeration cycle becomes unstable when the compressor is started at the start of operation and the rotational speed is rapidly increased. As a result, the inventors discovered that when the refrigerant in the form of bubble masses flows into the expansion valve, sudden pressure fluctuations occur, and the refrigerant flow noise is conspicuous.
In order to suppress the generation of refrigerant flow noise, it is known to install orifice pipes that reduce the pipe diameter in the refrigerant pipes before and after the expansion valve. An improvement method that does not increase the score has been sought.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an air conditioner capable of suppressing refrigerant flow noise generated at the start of operation without increasing the number of parts.

In order to solve the above problems, in claim 1 of the present invention, a compressor whose value (B/A) obtained by dividing the internal space volume B by the displacement amount A is 50 or less and whose rotation speed is variable,
an indoor heat exchanger installed in the indoor unit;
an expansion valve that decompresses the refrigerant;
an outdoor heat exchanger installed in the outdoor unit;
a refrigeration cycle in which the compressor, the indoor heat exchanger, the expansion valve, and the outdoor heat exchanger are annularly connected by refrigerant pipes;
a control unit that maintains the compressor at a predetermined intermediate rotation speed for a predetermined time from when the compressor starts to start until it reaches the target rotation speed ;
The control unit is characterized in that when the value of B/A is small, the predetermined time for maintaining the compressor at the predetermined intermediate rotation speed is longer than when the value is large.

Further, in claim 2 , it comprises stop time determination means for determining the stop time of the compressor,
The control unit is characterized in that the predetermined time for maintaining the compressor at the predetermined intermediate rotation speed increases as the stop time of the compressor determined by the stop time determining means increases. and

According to the present invention, a value obtained by dividing the internal space volume B by the displacement amount A (B/A) is 50 or less and the compressor uses a variable rotation speed, and the target rotation is Since the compressor is maintained at a predetermined intermediate rotation speed for a predetermined period of time until the number of revolutions is reached, especially when the internal space volume of the compressor is small, the phase state of the refrigerant is stabilized at the start of the heating operation, Since the generation of bubbly refrigerant can be suppressed, the generation of refrigerant flow noise can be suppressed without increasing the cost due to an increase in the number of parts.

1 is a schematic diagram illustrating an embodiment of the invention; FIG. It is a control block diagram of 1st Embodiment of the same invention. It is a figure explaining the structure of the compressor of this invention. It is a figure explaining the rotation speed change of the compressor at the time of heating operation in 1st Embodiment of the same invention. It is a figure explaining the setting method of the presence or absence of rotation speed maintenance time in 1st Embodiment of the same invention. It is a control block diagram of 2nd Embodiment of the same invention. It is a figure explaining the rotation speed maintenance time with respect to the B/A value of 2nd Embodiment of the same invention. It is a figure explaining the rotation speed change of the compressor at the time of heating operation in 2nd Embodiment of the same invention. It is a control block diagram of 3rd Embodiment of the same invention. It is a figure explaining the rotation speed maintenance time with respect to the B/A value of 3rd Embodiment of the same invention. It is a figure explaining the rotation speed change of the compressor at the time of heating operation in 3rd Embodiment of the same invention.

An embodiment of the invention will now be described.
Please refer to FIG. An air conditioner 1 is composed of an indoor unit 10 installed indoors and an outdoor unit 20 installed outdoors.

Please refer to FIG. The indoor unit 10 includes an indoor heat exchanger 11 in which refrigerant flows through a plurality of pipes, a cross-flow fan 12 that supplies indoor air to the indoor heat exchanger 11, and a device for detecting the indoor temperature. A room temperature sensor 13 is provided, and high and low temperature refrigerants are circulated in the indoor heat exchanger 11, and the cross flow fan 12 is driven to supply indoor air to the indoor heat exchanger 11. A room in which the indoor unit 10 is provided is air-conditioned.

Please refer to FIGS. The outdoor unit 20 includes a compressor 21 that compresses the refrigerant to high temperature and high pressure, a four-way valve 22 that changes the flow direction of the refrigerant, and an expansion valve 23 that expands the refrigerant to low temperature and low pressure. An outdoor heat exchanger 24 in which a refrigerant flows in a plurality of pipes, a blower fan 25 as an outdoor fan that supplies outside air toward the outdoor heat exchanger 24, and the temperature of the outdoor heat exchanger 24 is detected. a discharge temperature sensor 27 for detecting the temperature of the refrigerant discharged from the compressor 21; , the direction of the four-way valve 22 can be switched to switch between the cooling operation and the heating operation.

Please refer to FIG. Inside the indoor unit 10 and the outdoor unit 20, refrigerant pipes connecting the compressor 21, the four-way valve 22, the indoor heat exchanger 11, the expansion valve 23, and the outdoor heat exchanger 24 in a ring form. A refrigeration cycle 30 is installed, and by switching the four-way valve 22 according to various operating states such as heating operation and cooling operation, the flow direction of the refrigerant flowing in the refrigerant pipe can be switched.

Please refer to FIG. The compressor 21 is a rotary compressor of a fully sealed high-pressure dome type. The compressor 21 is covered with a cylindrical casing 21a. Inside the casing 21a are a compression mechanism 21b for compressing refrigerant and a motor 21d for driving the compression mechanism 21b via a drive shaft 21c. is stored.
A suction pipe 21e is connected to the lower portion of the casing 21a to suck the low-pressure refrigerant flowing in the refrigerating cycle 30 and sends it to the compression mechanism 21b. A discharge pipe 21f for discharging the refrigerant in the space 21g into the refrigerating cycle 30 is connected.

Please refer to FIG. Refrigerant in the compression mechanism 21b is compressed by driving the motor 21d, and the high-pressure refrigerant is discharged into the high-pressure space 21g from a discharge port (not shown) in the compression mechanism 21b. Accordingly, the refrigerant in the high-pressure space 21g is discharged into the refrigerating cycle 30 from the discharge pipe 21f.

Here, when the motor 21d is driven, the amount of refrigerant discharged into the high-pressure space 21g from the discharge port of the compression mechanism 21b each time the rotor 21d1 constituting the motor 21d and connected to the drive shaft 21c rotates once is the displacement amount. , a unique value (here, 6.4 cm ³ ) is set for each compressor 21 .

In addition, the high-pressure space 21g above the compression mechanism 21b of the casing 21a and excluding the compression mechanism 21b and the motor 21d is the internal space volume of the compressor 21, and is a unique value for each compressor 21 (here, 270 cm ³ ) is set.

Next, a specific operation in one embodiment of the invention will be described.
When the heating operation is selected with an operation switching button provided on a remote controller (not shown), the compressor 21 is driven after the four-way valve 22 is switched so that the refrigerant in the refrigeration cycle 30 flows in the direction indicated by the solid line in FIG. , the high-temperature and high-pressure refrigerant compressed by the compressor 21 flows into the indoor heat exchanger 11 that functions as a condenser, and the indoor air supplied to the indoor heat exchanger 11 is heated by driving the cross-flow fan 12. and warm air is blown into the room.

The refrigerant flowing out of the indoor heat exchanger 11 is expanded by the expansion valve 23 and becomes low temperature and low pressure and flows into the outdoor heat exchanger 24. It evaporates by the outdoor air that is generated, changes into a gaseous state, and flows into the compressor 21 . As the refrigerant flows in the refrigerating cycle 30 in this way, the heating operation becomes possible.

Further, when the cooling operation is selected by an operation switching button provided on a remote controller (not shown), the four-way valve 22 is switched so that the refrigerant in the refrigerating cycle 30 flows in the direction indicated by the dashed line in FIG. Since the driving is started, the refrigerant compressed by the compressor 21 to become high temperature and high pressure flows into the outdoor heat exchanger 24, and the refrigerant flowing into the outdoor heat exchanger 24 by the outdoor air supplied by the blower fan 25 is condense.

The refrigerant flowing into the expansion valve 23 from the outdoor heat exchanger 24 is expanded to become low temperature and low pressure, and the refrigerant flows into the indoor heat exchanger 11 that works as an evaporator and absorbs the heat of the indoor air supplied by the cross flow fan 12. The gaseous refrigerant that has flowed out of the indoor heat exchanger 11 flows into the compressor 21 while blowing cold air into the room. As the refrigerant flows in the refrigerating cycle 30 in this way, the cooling operation becomes possible.

Next, a change in the rotation speed of the compressor 21 at the start of heating operation in the first embodiment of the present invention will be described.
First, when an instruction to start the heating operation is issued, the control unit 28 determines whether the value (B/A) obtained by dividing the previously input internal space volume B of the compressor 21 by the displacement amount A is 50 or less, which is a predetermined value. to confirm. For example, if the displacement of the compressor 21 installed in the outdoor unit 20 is 6.4 cm ³ and the internal space volume is 270 cm ³ , the B/A is 42.2, so it is determined to be below the predetermined value. .

Please refer to FIG. When it is confirmed that the B/A is equal to or less than the predetermined value of 50, the control unit 28 switches the four-way valve 22 so that the refrigerant flows in the direction of the heating operation, drives the compressor 21, and increases the rotation speed. raise.
The rotation speed of the compressor 21 gradually increases over time, and when it reaches a predetermined intermediate rotation speed of 70 rps, the controller 28 stops increasing the rotation speed of the compressor 21 and starts the compressor 21 at 70 rps. maintain.

When the control unit 28 determines that the predetermined time of 120 seconds has elapsed while the compressor 21 is maintained at 70 rps, the controller 28 increases the rotation speed of the compressor 21 again, and controls the rotation speed to reach the target rotation speed of 100 rps. do.

In this manner, the rotation speed of the compressor 21 is maintained at the intermediate rotation speed for a predetermined period of time without abruptly increasing at the start of the heating operation. Refrigerant generation can be suppressed, and refrigerant flow noise at the start of heating operation can be suppressed.

In this embodiment, the control unit 28 confirms the value (B/A) obtained by dividing the internal space volume B of the compressor 21 by the displacement amount A at the start of operation, and maintains the compressor 21 at a predetermined intermediate rotation speed. However, as described below, the compressor 21 is set to a predetermined intermediate value at the start of the heating operation based on the B/A values of the plurality of compressors 21 in advance. The content may be such that whether or not to perform control to maintain the rotation speed can be set.

Please refer to FIG. The controller 28 maintains the compressor 21 at a predetermined intermediate rotation speed at the start of heating operation based on the value of B/A for each of the plurality of compressors 21 (here, A to E) of different types. Presence or absence of rotation speed maintenance time is stored.
Then, switches No. 1 to 5 in the DIP switches arranged on the board of the control unit 28 correspond to the compressors 21 A to E, respectively, so that the compressor 21 installed in the outdoor unit 20 When the No. switch corresponding to the type is switched to the ON state, the presence or absence of the rotation speed maintenance time is automatically set.

Therefore, if the type of the compressor 21 installed in the outdoor unit 20 is A, turning No. 1 to the ON state eliminates the rotation speed maintenance time of the compressor 21 at the start of the heating operation. If the type of the compressor 21 installed in the outdoor unit 20 is C, by turning No. 3 ON, there is a rotation speed maintenance time for the compressor 21 at the start of the heating operation.

In this way, it is possible to set the presence or absence of the rotation speed maintenance time of the compressor 21 at the start of the heating operation with the DIP switch. When the switch is switched, the presence or absence of the rotation speed maintenance time of the compressor 21 at the start of the heating operation is automatically set.

Next, the rotation speed change of the compressor 21 at the start of the heating operation in the second embodiment of the present invention will be described.
First, differences from the first embodiment will be described.

Please refer to FIG. The control unit 28 has a maintenance time determination means 28a for determining the time (rotation speed maintenance time) during which the compressor 21 is maintained at the intermediate rotation speed when the heating operation is started. This maintenance time determination means 28a varies the rotation speed maintenance time according to the value (B/A) obtained by dividing the internal space volume B of the compressor 21 by the displacement amount A. Specifically, When B/A is small, the rotational speed maintenance time is set longer than when B/A is large.
Other configurations are the same as those of the first embodiment.

Please refer to FIG. Assuming that the calculation result of B/A is X, the maintenance time determination means 28a determines the rotation speed maintenance time based on the calculated value of X.
For example, if the calculation result of B/A is 38, the rotation speed maintenance time is set to 140 seconds by the maintenance time determination means 28a.
Further, if the calculation result of B/A is 47, the rotation speed maintenance time is set to 100 seconds by the maintenance time determination means 28a.

When the internal space volume of the compressor 21 is large and the value of B/A is large, the flow noise of the refrigerant at the start of the heating operation becomes small. By setting the rotational speed maintenance time to be short, the time from the start of the heating operation until the compressor 21 reaches the target rotational speed is shortened, so that hot air of a predetermined temperature or higher is quickly supplied from the indoor unit 10. Allows ventilation to improve user comfort.

Please refer to FIG. After confirming the calculation result of B/A, the control unit 28 switches the four-way valve 22 so that the refrigerant flows in the direction of the heating operation, drives the compressor 21, and increases the rotational speed.
The rotation speed of the compressor 21 gradually increases over time, and when it reaches a predetermined intermediate rotation speed of 70 rps, the controller 28 stops increasing the rotation speed of the compressor 21 and starts the compressor 21 at 70 rps. maintain.

After the compressor 21 is maintained at 70 rps, the controller 28 determines the rotation speed maintenance time according to the calculation result of B/A, and starts counting.
For example, when the calculation result of B/A is 38, the rotation speed maintenance time is 140 seconds, so the control unit 28 starts counting after the compressor 21 reaches 70 rps, and 140 seconds after the start of counting. After the time elapses, the rotation speed of the compressor 21 is increased again.
Further, when the calculation result of B/A is 47, the rotation speed maintenance time is 100 seconds, so the control unit 28 starts counting after the compressor 21 reaches 70 rps, and 100 seconds after the start of counting. After the time elapses, the rotation speed of the compressor 21 is increased again.

In this way, the rotation speed maintenance time for maintaining the intermediate rotation speed is changed according to the calculation result of B/A without rapidly increasing the rotation speed of the compressor 21 at the start of the heating operation. When the value of /A is small and the internal space volume of the compressor 21 is small, compared to the case where the value of B/A is large, the rotational speed maintenance time is set longer. It is possible to stabilize the state, suppress the generation of bubbly refrigerant, and suppress the refrigerant flow noise at the start of the heating operation.

In addition, when the B/A value is large, the refrigerant flow noise is smaller than when the B/A value is small. By shortening the time, it is possible to shorten the time required for the compressor 21 to reach the target rotation speed, thereby improving the user's comfort.

Next, the rotation speed change of the compressor 21 at the start of the heating operation in the third embodiment of the present invention will be described.
First, differences from the first and second embodiments will be described.

See FIG. The control unit 28 has stop time determination means 28 b for determining the stop time of the compressor 21 from the difference between the temperature detected by the discharge temperature sensor 27 and the temperature detected by the outdoor heat exchanger sensor 26 . The stop time determining means 28b determines that the longer the difference between the temperature detected by the discharge temperature sensor 27 and the temperature detected by the outdoor heat exchanger 26 is, the shorter the operation stop time of the compressor 21 is.

Then, based on the stop time of the compressor 21 determined by the stop time determination means 28b, the maintenance time determination means 28a sets the time during which the compressor 21 is maintained at the predetermined intermediate rotation speed. Specifically, the longer the stop time of the compressor 21 is, the longer the time during which the intermediate rotation speed is maintained is set.
Other configurations are the same as those of the first and second embodiments.

Please refer to FIG. The controller 28 sets the rotational speed maintenance time according to the difference between the temperature detected by the discharge temperature sensor 27 and the temperature detected by the outdoor heat exchanger sensor 26 .
For example, if the temperature detected by the discharge temperature sensor 27 is 3° C. and the temperature detected by the outdoor heat exchanger sensor 26 is 2° C., the difference between the discharge temperature and the heat exchanger temperature is 1, so the stop time of the compressor 21 is long. is determined by the stop time determining means 28b, and the rotation speed maintaining time is set to 240 seconds by the maintaining time determining means 28a.

Also, if the temperature detected by the discharge temperature sensor 27 is 35° C. and the temperature detected by the outdoor heat exchanger 26 is 2° C., the difference between the discharge temperature and the heat exchanger temperature is 33, so the stop time of the compressor 21 is The stop time determination means 28b determines that it is short, and the rotation speed maintenance time is set to 150 seconds by the maintenance time determination means 28a.

If the difference between the discharge temperature and the heat exchanger temperature is large, it is estimated that the stop time of the compressor 21 is short. is small.
In addition, when the difference between the discharge temperature and the heat exchanger temperature is small, it is estimated that the compressor 21 is stopped for a long time, so that the effect of the refrigerant stagnation in the refrigeration cycle 30 increases, and the refrigerant at the start of the heating operation increases. The flow noise is loud.
Therefore, by setting the rotational speed maintenance time to be shorter as the difference between the discharge temperature and the heat exchanger temperature is larger, it is possible to suppress the flow noise of the refrigerant and improve the user's comfort.

Please refer to FIG. When it is confirmed that the value (B/A) obtained by dividing the internal space volume B of the compressor 21 by the displacement amount A is equal to or less than a predetermined value of 50, the control unit 28 causes the refrigerant to flow in the direction during heating operation. The four-way valve 22 is switched to drive the compressor 21 to increase the rotation speed.
The rotation speed of the compressor 21 gradually increases over time, and when it reaches a predetermined intermediate rotation speed of 70 rps, the controller 28 stops increasing the rotation speed of the compressor 21 and starts the compressor 21 at 70 rps. maintain.

When the compressor 21 is maintained at 70 rps, the controller 28 causes the stop time determination means 28b to determine the stop time of the compressor 21 based on the difference between the temperature detected by the discharge temperature sensor 27 and the temperature detected by the outdoor heat exchanger sensor 26. Counting of the rotational speed maintenance time estimated and set by the maintenance time determination means 28a is started.
For example, if the difference between the discharge temperature and the heat exchanger temperature is 1, the control unit 28 starts counting when the compressor 21 reaches 70 rps, and after counting 240 seconds, increases the rotation speed of the compressor 21 again. Raise it to 100 rps, which is the target rotation speed.

Also, if the difference between the discharge temperature and the heat exchanger temperature is 33, the control unit 28 starts counting when the compressor 21 reaches 70 rps, and after counting 150 seconds, increases the rotation speed of the compressor 21 again. Raise it to 100 rps, which is the target rotation speed.

In this manner, when the rotation speed of the compressor 21 reaches a predetermined intermediate rotation speed after the start of the heating operation, the rotation speed maintenance time is changed according to the difference between the discharge temperature and the heat exchanger temperature. If it is estimated to be long, the refrigerant flow noise can be suppressed by lengthening the rotation speed maintenance time, and if the sleep time is estimated to be short, shortening the rotation speed maintenance time will improve user comfort. can be improved.

Next, effects of the present invention will be described.

In an air conditioner 1 including a compressor 21 whose value (B/A) obtained by dividing the internal space volume B by the displacement amount A is equal to or less than a predetermined value, the rotation speed of the compressor 21 is increased at the start of heating operation, and a predetermined value is obtained. When the intermediate rotation speed is reached, the rotation speed increase of the compressor 21 is stopped, and the intermediate rotation speed is maintained for the rotation speed maintenance time, so that the phase state of the refrigerant can be stabilized. When using the air conditioner 21, it is possible to suppress the refrigerant flow noise at the start of the heating operation without increasing the number of parts such as installing small-diameter pipes before and after the expansion valve 23.

In addition, when the value of B/A is small, the rotational speed maintenance time is lengthened compared to when the value of B/A is large. When using a compressor 21 with a small value, the phase state of the refrigerant can be stabilized by lengthening the rotation speed maintenance time maintained at the intermediate rotation speed, so the refrigerant flow noise at the start of heating operation can be suppressed. In addition, when the compressor 21 with a large value of B/A is used, the rotation speed maintenance time is shortened, and the compressor 21 reaches the target rotation speed early, so that the user's comfort is improved. do.

Further, the smaller the difference between the temperature detected by the discharge temperature sensor 27 and the temperature detected by the heat exchanger temperature sensor 26, the longer the rotational speed maintenance time. If the stop time of the compressor 21 is long and the effect of the refrigerant stagnation is large, the rotation speed maintenance time for maintaining the compressor 21 at a predetermined intermediate rotation speed at the start of heating operation is increased. Since the state is stabilized, it is possible to suppress the flow noise of the refrigerant. By shortening the rotation speed maintenance time maintained at , the compressor 21 reaches the target rotation speed early, so that the user's comfort is improved.

In the present embodiment, the rotation speed control of the compressor 21 at the start of the heating operation has been described. When it is confirmed that the value (B/A) obtained by dividing the internal space volume B of the compressor 21 by the displacement amount A is equal to or less than a predetermined value, the control unit 28 starts the cooling operation and the compressor After increasing the rotational speed of the compressor 21, when it reaches a predetermined intermediate rotational speed, the increase in the rotational speed of the compressor 21 is stopped, and by maintaining the intermediate rotational speed for the rotational speed maintenance time, the refrigerant is reduced in the same manner as in the heating operation. Fluid sound can be suppressed.

Further, in the present embodiment, the value (B/A) obtained by dividing the internal space volume B of the compressor 21 by the displacement amount A was described as 50, but the value can be set without being limited to this value. Any numerical value may be used as long as it can specify the compressor 21 that generates the flow noise of the refrigerant at the start of operation.

In the third embodiment, the stop time of the compressor 21 is estimated from the difference between the temperature detected by the discharge temperature sensor 27 and the temperature detected by the outdoor heat exchanger sensor 26. The stop time of the compressor 21 may be estimated from the difference between the detection result of the outside air temperature sensor that detects the temperature around the compressor 20 and the discharge temperature, or the stop time of the compressor 21 may be directly counted. There may be.

1 air conditioner 10 indoor unit 11 indoor heat exchanger 20 outdoor unit 21 compressor 21g high pressure space (internal space volume)
23 expansion valve 24 outdoor heat exchanger 28 controller 30 refrigerating cycle

Claims (2)

A compressor in which the value obtained by dividing the internal space volume B by the displacement amount A (B/A) is 50 or less and the rotation speed is variable;
an indoor heat exchanger installed in the indoor unit;
an expansion valve that decompresses the refrigerant;
an outdoor heat exchanger installed in the outdoor unit;
a refrigeration cycle in which the compressor, the indoor heat exchanger, the expansion valve, and the outdoor heat exchanger are annularly connected by refrigerant pipes;
a control unit that maintains the compressor at a predetermined intermediate rotation speed for a predetermined time from when the compressor starts to start until it reaches the target rotation speed ;
The control unit sets the predetermined time for maintaining the compressor at the predetermined intermediate rotation speed to be longer when the B/A value is small than when the B/A value is large. Device. A stop time determination means for determining the stop time of the compressor,
The control unit is characterized in that the predetermined time for maintaining the compressor at the predetermined intermediate rotation speed increases as the stop time of the compressor determined by the stop time determining means increases. The air conditioner according to claim 1 , wherein

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