JPS621637Y2 - - Google Patents

Description

[Detailed description of the invention] This invention allows the number of poles of the compressor motor to be smoothly switched from 4 to 2 when switching from operating one indoor unit to operating two indoor units. Related to air conditioners.

In a plural system air conditioner where multiple indoor units are connected to one outdoor unit, when switching from one indoor unit to multiple indoor units, the compressor motor Switch the number of poles. Figure 1 shows the possible range of switching from 4 poles to 2 poles of a compressor motor for pole number switching, and
This shows the impossible range, with the horizontal axis representing the discharge pressure and the vertical axis representing the suction pressure. In FIG. 1, the shaded area is the range in which the number of poles cannot be changed, and the area not shaded is the range in which the number of poles can be changed.

Also, Figure 2 shows the four-phase compressor motor with single-phase power supply.
It shows the torque-rotation speed curve of a pole (indicated by 4P) and a two-pole (indicated by 2P), and shows the rotation speed on the horizontal axis and the torque on the vertical axis. be. In this Figure 2, a, b,
c shows a load curve applied to the compressor motor, and this load is expressed by the discharge pressure and suction pressure at the positions shown in FIG.

Switching a compressor motor from 4 poles to 2 poles may or may not be possible depending on the load.
If the required torque of the load is as shown in load curve c, switching from 4 poles to 2 poles will be performed without any problem, but if the required torque of the load is as shown in b, the compressor motor will Torque is insufficient and the vehicle stalls. In other words, the operating point during operation with 4 poles is the intersection of the 4 pole torque curve and the load curve b, but from 4 poles to 2
By switching the number of poles to pole, the operating point moves to the 2-pole torque curve (same rotation speed), and at that point, the compressor motor torque at 2-pole is smaller than the load curve b required by the load. Therefore, by switching to two-pole operation, the vehicle cannot accelerate and stalls.

Further, in the load curve b where the load is large, switching from 4 poles to 2 poles is impossible, and in the load curve c where the load is small, switching from 4 poles to 2 poles is possible. The load curve a is shown to be in the middle.

Conventionally, the range in which the number of poles of a compressor motor can be switched was determined by the load, and there was a problem in which switching to two poles was not possible at high loads, making it impossible to operate. In the past, the problem was that this range was narrow.

This idea was developed in consideration of the above points, and includes a single outdoor unit that can perform cooling and heating operations by switching the four-way electromagnetic valve, and has a compressor motor that can switch the number of poles. a plurality of indoor units connected to the outdoor unit; means for generating a predetermined delay time when switching the number of poles of the compressor motor due to load fluctuations of the indoor unit; By providing a means for switching the number of poles of the compressor motor after the compressor is operated to increase the condensing capacity, it is impossible to switch from conventional four-pole operation to two-pole operation. To provide an air conditioner which can be switched to two-pole operation even in normal operation, and which eliminates the problem of being difficult for a user to use because the usable temperature and humidity conditions are determined.

Hereinafter, embodiments of the air conditioner of this invention will be described based on the drawings. First, an outline of the features of this invention will be described, and then a specific explanation of the embodiments will be given. As is well known, plural system air conditioners have two to three indoor units.
One outdoor unit is supported, but in this invention, a certain delay time is provided from when the switching signal to 2-pole operation is issued during 4-pole operation of the compressor motor, which cannot be switched, and the 4-pole It increases the capacitor capacity during operation and switches to two-pole operation when switching becomes possible.In the following explanation, four-pole operation under heating cycle overload conditions will be changed to two-pole operation. Let us now discuss the case of switching.

Figures 3 to 5 are principle explanatory diagrams showing the operating status of the air conditioner of this invention.
One outdoor unit 1 and two indoor units 2 and 3
are connected, one indoor unit 2 is performing heating operation, and the other indoor unit 3 is not operating. In addition, the compressor 1A of the outdoor unit 1 is shown to be driven by a 4-pole compressor motor that performs 4-pole operation.
The load point applied to the compressor motor at this time is the 7th point.
It is as shown in the figure. This figure 7 shows the rotation speed on the horizontal axis and the torque on the vertical axis.
Figure 2 shows a polar torque-speed curve. In this Fig. 7, 4P indicates a quadrupole region, and 2P
indicates a bipolar region.

In addition, in FIG. 4, both indoor units 2 and 3 are in heating operation, and the compressor 1A of outdoor unit 1 is
The case is shown in which the compressor motor is driven in polar operation. The load point applied to the compressor motor at this time is indicated by the point ``X'' in FIG.

FIG. 5 shows a case where the indoor units 2 and 3 are in a heating operation, and the compressor 1A of the outdoor unit 1 is driven by a compressor motor that is in a two-pole operation. The load point applied to the compressor motor at this time is indicated by point C in FIG.

Figure 6 shows the 4-pole to 2-pole switching compressor motor.
This is a diagram showing the range in which switching to the pole is possible and impossible, and the shaded area in the diagram is the impossible range.
The area without diagonal lines indicates the range in which the number of poles can be switched.

Next, from the 4-pole operation of the compressor motor mentioned above, 2
The principle operation for switching to polar operation will be explained. As shown in FIG. 3, when only one indoor unit 2 is in heating operation, the load torque applied to the compression motor is indicated by load point A in FIG. At this point, if indoor units 2 and 3 are heated and the compressor motor is immediately switched to two-pole operation, the torque of the two-pole compression motor is shown by the two points in Figure 7. However, since the motor torque is smaller than the load torque of the compressor motor, the compressor motor stalls and becomes locked.

Therefore, in this invention, the compressor motor is not immediately switched from four-pole operation to two-pole operation at this point, but after a certain delay time is set as shown in FIG. 4, four-pole operation is performed. In other words, in the state shown in Fig. 3, the indoor unit 3 that is out of operation
As shown in FIG. 4, indoor unit 2 and indoor unit 3 are also put into heating operation to increase the capacitor capacity. After that, the load is lowered and the balance point of the compressor motor is shifted to point B.
That is, since two indoor units are in heating operation, the load point shown in FIGS. 6 and 7 shifts to point B.

When the compressor motor is switched to two-pole operation from this load point B, the compressor motor torque in two-pole operation exceeds the load torque, and the difference between the two drives the crankshaft (not shown) of compressor 1A. Since it is used for acceleration, the compressor motor is switched to two-pole operation without any problem, resulting in the operation indicated by load point C.

As is clear from the above, the four compressor motors
Even if switching from pole operation to two-pole operation is not possible, in this invention, when the switching signal to two-pole operation is issued, a certain delay time is set, the capacitor capacity is increased, and the compressor The four-pole operation of the compressor motor is continued, the load point is moved to a range where switching from four-pole operation to two-pole operation is possible, and then the compressor motor is switched to two-pole operation.

Therefore, as in the past, the usable temperature,
Humidity conditions are determined, eliminating the problem of difficulty for the user. In other words, in the conventional air conditioner of the pole number switching type, the load torque that allows pole number switching without any trouble is determined from the motor torque of the compressor motor (see FIG. 2).

In other words, the temperature and humidity conditions are determined so that one indoor unit and two indoor units can be operated without any problems, and when these conditions are exceeded, the compressor The compressor motor could not switch from 4-pole operation to 2-pole operation, and the compressor motor stalled.
It becomes locked.

However, in this invention, the indoor unit 3 is operated to increase the capacitor capacity during a predetermined delay time, and then the load point of the compressor motor is switched to point B in Fig. 7. As for the time, it can be as short as 30 seconds to 1 minute.
There are almost no problems on the user side.

Furthermore, in order to improve the capacitor capacity described above, it is possible to operate a plurality of indoor units during heating operation as described above, and to increase the speed of the outdoor fan during cooling operation.

Next, a specific example of the air conditioner of this invention will be described. FIG. 8 is a diagram showing a refrigeration cycle of one embodiment. In this Figure 8, 3
0 is a compressor, 58 is an electromagnetic four-way valve, 32 is an outdoor heat exchanger, 33 is a capillary tube, 52, 53
is an electromagnetic two-way valve. The compressor 30, the four-way electromagnetic valve 58, the outdoor heat exchanger 32, the capillary tube 33, and the two-way electromagnetic valves 52 and 53 constitute the outdoor unit 1. Further, 36 and 37 are indoor heat exchangers of the indoor units 2 and 3, respectively.

In FIG. 8, during heating operation of the indoor unit 2, the high-pressure, high-temperature gaseous refrigerant discharged from the compressor 30 enters the indoor heat exchanger 36 via the electromagnetic four-way valve 58. At 36, the gaseous refrigerant and the air sucked in by an indoor fan (not shown in Fig. 8) perform a heat exchange action, and the refrigerant changes its state by taking away the heat of condensation from the air, and becomes a liquid refrigerant. Conversely, the air receives heat from the refrigerant and is warmed. In other words, the indoor unit 2 takes in cold air and blows out warm air.

Further, the liquefied refrigerant is sent to the capillary tube 33 through the electromagnetic two-way valve 52. In the capillary tube 33,
It acts as a heat insulator and expands to become a low-pressure, low-temperature liquid refrigerant, but this liquid refrigerant is sent to the outdoor heat exchanger 32, where it performs heat exchange again and removes evaporation heat from the outdoor air. It undergoes a change of state and becomes gaseous. This gaseous refrigerant is sucked into the compressor 30 through the electromagnetic four-way valve 58.

The above explanation corresponds to the operating state of only the indoor unit 2 in FIG. 3 mentioned above.

Next, as described in FIG.
A case will be described in which the indoor units 2 and 3 are both driven by a compressor motor that performs polar operation. In this case, like the indoor heat exchanger 36,
The high-pressure, high-temperature gaseous refrigerant performs a heat exchange action in the indoor heat exchanger 37, and loses condensation heat. Therefore, a large amount of condensation heat is removed from the refrigerant compared to the case shown in FIG. 3, the high pressure becomes lower, and the condenser capacity increases from the viewpoint of the refrigeration cycle. This allows the operation described in FIG. 4 to be executed.

Next, the portion of the control circuit that controls the heating operation of the air conditioner of this invention as described above will be explained based on FIG. In this Figure 9,
R and S indicate the R phase and S phase of the power supply, respectively, and a series circuit with the normally open contact 57-1 of the relay 57 and the outdoor fan motor 49 is connected between the R phase and the S phase. A normally open contact 55-1 of the relay 55 is connected in parallel to the normally open contact 57-1.

Further, between the R phase and the S phase, a series circuit is provided between the normally open contact 57-2 of the relay 57 and the 2-pole compressor motor 50, and the normally open contact 55-2 of the relay 55 and the 4-pole compressor motor 50. 51, a series circuit between the normally open contact 60-1 of the relay 60 and the electromagnetic two-way valve 52,
Normally open contact 62-1 of relay 62 and electromagnetic two-way valve 53
A series circuit between the normally open contact 60-2 of the relay 60, a normally open contact 62-2 of the relay 62, and the relay 54 are connected.

In addition, a parallel circuit of normally open contact 60-3 of relay 60 and normally open contact 62-2 of relay 62, a series circuit of B contact 56-2 of timed relay 56, and relay 55 are connected between the R phase and S phase. has been done. b contact 5
6-2 is a time-limited relay 56 that is opened after a certain period of time has elapsed after being energized.

This time-limited relay 56 is the normally open contact 5 of the relay 54.
The time relay 5 is connected in series with 4-1 between the R phase and the S phase.
A series circuit of the a contact 56-1 of No. 6 and the relay 57 is connected. Point a 56-1 is a time relay 56
It closes after a certain period of time after it is energized.

Furthermore, a series circuit of a cooling/heating changeover switch 63 and an electromagnetic four-way valve 58 is connected between the R phase and the S phase. Between the R phase and the S phase, the operation switch 64
A series circuit of a thermostat 65 and a relay 60 is connected in parallel with the indoor fan motor 59. An operation switch 64, a thermostat 65, an indoor fan motor 59, and a relay 60 are provided within the indoor unit 2.

In the indoor unit 3, R
A series circuit of an operation switch 66 and an indoor fan motor 61 is connected between the phase and S phase, and a series circuit of a thermostat 67 and a relay 62 is connected in parallel with the indoor fan motor 61.

Next, the operation of the control circuit shown in FIG. 9 will be explained. When performing heating operation, the cooling/heating changeover switch 63 is turned on. As a result, the electromagnetic four-way valve 58
is excited. Here, when the indoor unit 2 is put into heating operation, the operation switch 64 in this indoor unit 2 is turned on. When the operation switch 64 is turned on, the indoor fan motor 59 rotates.
Next, when thermostat 65 is turned on, relay 60 is energized. As a result, normally open contact 6
0-1 to 60-3 are closed.

By closing the normally open contact 60-1, the electromagnetic two-way valve 52 is energized. In addition, the normally open contact 60
-3 is closed, the b contact 56 of the time relay 56
-2 (remains closed), the relay 55 is energized. By energizing the relay 55, its normally open contact 5
5-1 and 55-2 are closed. This normally open contact 5
5-2 is closed, the four-pole compressor motor 51 rotates. At the same time, the outdoor fan motor 49 rotates by closing the normally open contact 55-1.

In this state, in the refrigeration cycle shown in FIG. A four-way electromagnetic valve 58 and a compressor 30 form a refrigeration cycle for heating operation, and the compressor 30 performs four-pole operation with a four-pole compressor motor 51.
only performs heating operation.

Next, when the indoor unit 3 is operated for heating at the same time as the indoor unit 2 is operated (the state shown in FIG. 4), the operation switch 66 and thermostat 67 of the indoor unit 3 are turned on in the same manner as in the case of the indoor unit 2. By turning on the operation switch 66, the indoor fan motor 61 rotates, and by turning on the thermostat 67, the relay 62 is excited. By energizing the relay 62, its normally open contacts 62-1 to 62-3 are both closed.

By closing the normally open contact 62-1, the electromagnetic two-way valve 53 is energized. Also, since the indoor unit 2 is in operation, the normally open contacts 60-2 and 6
2-2 are connected in series, and the relay 54 is excited. When the relay 54 is energized, its normally open contact 54-1 is closed, and the time relay 56 is energized. Even after the time relay 56 is energized, the A point contact 56-1 remains open within a certain delay time, and the B contact 56-2 is also closed within a certain delay time, so that the relay 55 It remains energized.

While the relay 55 is in an excited state, its normally open contacts 55-1 and 55-2 are closed, so that the four-pole compressor motor 51 is rotating. The relay 57 is not excited, so its normally open contacts 57-1 and 57-2 are not open, so that the two-pole compressor motor 50 is not energized.
The compressor 30 is in four-pole operation even when the indoor units 2 and 3 are in operation.

In other words, in this state, as already mentioned, two indoor units 2 and 3 are being operated, and in terms of the refrigeration cycle, the number of condensers has doubled, and the high pressure has decreased. Naturally, the load applied to the compressor 30 becomes smaller, and in FIG. 7, the load point changes from A to B.

Next, after a certain time has elapsed, the time relay 56
The a-contact 56-2 of the compressor 30 is closed and the b-contact 56-1 is opened. Therefore, the four-pole compressor motor 51 is de-energized, the two-pole compressor motor 50 is energized, and the compressor 30 performs two-pole operation.

As detailed above, according to the air conditioner of this invention, a single outdoor air conditioner can perform cooling operation and heating operation by switching the solenoid four-way valve, and has a compressor motor that can switch the number of poles. a unit, a plurality of indoor units connected to the outdoor unit, means for generating a predetermined delay time when switching the number of poles of the compressor motor due to load fluctuations of the indoor unit, and The gist of the above is that the outdoor unit is operated to increase its condensing capacity, and then the number of poles of the compressor motor is changed. Even if the operation is impossible, with this invention it is possible to switch to two-pole operation, and the usable temperature,
This eliminates the problem that humidity conditions are determined, making it difficult for users to use.

[Brief explanation of the drawing]

Figure 1 shows the range of possible and impossible switching of the compressor motor from 4 poles to 2 poles in a conventional air conditioner, and Figure 2 shows the single-phase power supply in a conventional air conditioner. Figures 3 to 5 show the torque-rotation speed curves of a 4-pole and 2-pole compressor motor of an embodiment of the air conditioner of this invention, respectively. FIG. 6 is a diagram for explaining the process of switching from four poles to two poles in the air conditioner of this invention, and shows the range in which switching from four poles to two poles is possible and impossible; Figure 7 is a diagram showing the four-pole and two-pole torque-rotational speed curves of the single-phase power supply compressor motor in the air conditioner of this invention, and Figure 8 is a diagram showing an embodiment of the air conditioner of this invention. FIG. 9 is a refrigerant circuit diagram showing a refrigeration cycle, and is a circuit diagram of a control circuit that performs switching control between a four-pole compressor motor and a two-pole compressor motor in the air conditioner of this invention. 1... Outdoor unit, 1A, 30... Compressor,
2, 3... Indoor unit, 32... Outdoor heat exchanger, 33... Capillary tube, 36, 37...
...Indoor heat exchanger, 49...Outdoor fan, 50...
...Two-pole compressor motor, 51... Four-pole compressor motor, 52, 53... Solenoid two-way valve, 54, 5
5, 57, 60, 62... Relay, 56... Timed relay, 58... Solenoid four-way valve, 59, 61... Indoor fan motor, 63... Cooling/heating changeover switch, 6
4, 65...operation switch, 65...thermostat.

Claims (1)

[Scope of utility model registration request] One outdoor unit with a compressor motor that can perform cooling and heating operations by switching a four-way electromagnetic valve and has a switchable number of poles, and multiple indoor units connected to this outdoor unit. and a means for generating a predetermined delay time when switching the number of poles of the compressor motor due to load fluctuations in the indoor unit, and an operation so as to reduce the load torque relative to the compressor motor torque within this delay time. An air conditioner comprising: means for switching the number of poles of the compressor motor after switching the number of poles of the compressor motor.