JPH11201564A - Multiroom type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe and highly efficient multiroom type air conditioner where trouble does not occur at control of capacity by enabling the capacity control of constant velocity compressor. SOLUTION: In the case where proper operation pressure at air conditioning operation is t and that the air conditioner is operated within the range of proper operation pressure, the operation capacity of constant velocity compressors 20, 21, 22, and 23 are kept as it is, and in the case where it is outside the range of a proper operation pressure value, the operation capacity is increased or decreased so that it may come to the proper operation pressure, and besides in the case where the operation capacity increased, indoor throttle devices 32a, 32b, 32c, and 32d, or an outdoor throttling device 29, or both throttle devices are operated in open direction, and also in the case where the operation capacity decreases, the indoor throttling devices 32a, 32b, 32c, and 32d, or the outdoor throttling device 29, or both throttling devices are operated in the close direction, whereby the excessive pressure drop to lower pressure or excessive pressure rise to higher pressure or the like can be avoided, and it becomes possible to perform safe and highly efficient continuous operation with proper pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner equipped with a plurality of compressors, and more particularly, to a compressor capacity control of an outdoor unit.

[0002]

2. Description of the Related Art FIG. 5 is a system configuration diagram of a conventional multi-room air conditioner described in Japanese Patent Application Laid-Open No. 63-295880, wherein 1 is a first compressor having a small capacity and capable of converting the number of poles. And the ability can control 4HP and 2HP. 2
Is a second compressor having a large capacity and capable of converting the number of poles. The capacity is controllable at 6HP and 3HP.

When one of the first and second compressors 1 and 2 is operated and the other is stopped, check valves 3a and 3b prevent the refrigerant from stagnating in the stopped compressor. Is an outdoor heat exchanger, 5 is an accumulator, 6 is an oil equalizing pipe for making the level of refrigerating machine oil in the first compressor 1 and the second compressor 2 the same, and these are accommodated in the outdoor unit 7.

[0004] Reference numerals 8a, 8b, 8c, and 8d denote indoor units, which are indoor side expansion devices 9a, 9 each having a fully closed function.
b, 9c, 9d and indoor heat exchangers 10a, 10b, 10
c, 10d.

Here, the indoor units 8a and 8c have a capacity of 3
The capacity of the indoor units 8b and 8d is 2HP.

The indoor units 8a, 8b, 8
The gas-side main pipe 11, the liquid-side main pipe 12, and the gas-side branch pipes 11a, 11b, 11c, 11d branched from the gas-side main pipe 11, and the liquid-side branch pipe 12a,
They are communicated by 12b, 12c and 12d.

Next, the operation of the conventional multi-room air conditioner will be described below. The refrigerant discharged from the first compressor 1 and the second compressor 2 is sent to the outdoor heat exchanger 4 through the check valves 3a and 3b to be condensed and liquefied, and to be condensed and liquefied. It is sent to the indoor units 8a, 8b, 8c, 8d through 12b, 12c, 12d. Here, the pressure is reduced by the indoor-side expansion devices 9a, 9b, 9c, and 9d, evaporated in the indoor-side heat exchangers 10a, 10b, 10c, and 10d, and gasified by contributing to cooling, and the gas-side branch pipes 11a, 11b, and 11 are formed.
c, 11d and the gas-side main pipe 11 are sent to the outdoor unit 7 and returned from the accumulator 5 to the first compressor 1 and the second compressor to circulate.

Here, for example, the indoor units 8a, 8
When the indoor unit 8a having a capacity of 3HP stops operating while four b, 8c, and 8d are operating, the indoor operating capacity becomes 70%, and the number of poles of the second compressor 2 having a capacity of 6HP is reduced. The capacity of the outdoor unit 7 is reduced to 7HP (70%) by halving the capacity of the second compressor 2 from two poles to four poles.
Thus, the outdoor unit capacity corresponding to the indoor operation capacity can be output.

According to this conventional multi-chamber air conditioner, the first compressor 1 and the second compressor 2 capable of converting two poles to four poles respectively.
The capacity ratio of 2 to 3 (4HP for 2 poles to 6HP for 4 poles, 2H for 4 poles)
P to 3HP), the capacity can be controlled in eight stages, and a plurality of different horsepower indoor units can be operated individually,
Even if the operating capacity changes, the capacity of the outdoor unit can be easily adjusted to the operating capacity of the indoor unit, so that the system configuration is simplified and efficient operation can be realized.

[0010]

However, in such a conventional multi-room air conditioner, when the number of operating compressors or the number of poles is changed in accordance with the increase or decrease of the load of each indoor unit, Since the capacity of the compressor was relatively large and the compressor capacity was changed in units of HP, when the number of compressors was changed, the amount of circulating refrigerant rapidly increased and decreased, and the original opening degree control of the expansion device did not follow the amount of circulation. Despite the large fluctuations in high and low pressure of the refrigeration cycle and an increase in compressor capacity, transient efficiency decline or capacity shortage occurred, or the pressure exceeded the operating range of the compressor. Hunting, such as returning to the capacity of the compressor, and a problem that the protection device operates to stop the compressor.

Further, a method has been devised in which the compressor is driven by an inverter to avoid a sudden change in the amount of circulation, and to perform fine capacity control and to operate safely at high and low pressures. However, there is a problem that the inverter becomes expensive. Was.

The present invention solves these conventional problems. The capacity of a constant-speed compressor can be controlled in accordance with the load by a simple configuration and control. An object of the present invention is to provide a multi-room air conditioner capable of safe and highly efficient operation without hunting or protection stop due to shortage or high / low pressure fluctuation.

[0013]

In order to achieve this object, the present invention sets an appropriate operating pressure during the cooling and heating operation, and when operating within a range of the appropriate operating pressure, a constant speed compressor is provided. The operating capacity is maintained as it is, and when the operating capacity is outside the range of the appropriate operating pressure value, the operating capacity is increased or decreased so as to obtain an appropriate operating pressure, and when the operating capacity increases, the indoor throttle device or If the outdoor throttle device or both throttle devices are operated in the closing direction, and if the operating capacity decreases, by operating the indoor throttle device or the outdoor throttle device or both throttle devices in the closing direction, excessive Low pressure drop and high pressure rise can be avoided, and safe and efficient continuous operation can be performed at an appropriate pressure.

By setting the range of the proper operating pressure after changing the compressor capacity to be wider for a certain period of time, even if the pressure falls outside the proper operating pressure range with respect to the high and low pressure fluctuations after changing the compressor capacity, Since the compressor capacity is not changed until the valve opening control reaches the appropriate value, hunting of the capacity can be prevented even if the compressor is out of the range of the appropriate operating pressure for a certain period of time.

Also, by maintaining the operating capacity of the constant speed compressor for a predetermined period of time after the compressor capacity is changed, the high and low pressure fluctuations after the compressor capacity change are also out of the proper operating pressure range. The compressor capacity is not changed until the opening control of the expansion valve reaches the appropriate value even if the pressure becomes, preventing hunting of the capacity even if the operating pressure is out of the range. it can.

Further, when the operating pressure is outside the range of the appropriate operating pressure, the operating capacity of the constant speed compressor is increased or decreased so that the compressor can be operated within the range of the appropriate operating pressure, and the range of the appropriate operating pressure is adjusted to the fixed operating pressure. Hunting can be prevented from occurring in a wide operating range from a small capacity to a large capacity by setting the speed compressor to be wider as the capacity change ratio is larger.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention relates to an outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion device, and an indoor heat exchanger. A plurality of indoor units including an indoor-side expansion device are connected to form a refrigerant circuit, and a proper operating pressure on a low-pressure side of the constant-speed compressor is set during cooling, and a high-pressure side of the constant-speed compressor is set during heating. Set an appropriate operating pressure, if operating within the range of the appropriate operating pressure, maintain the operating capacity of the constant speed compressor as it is, if outside the range of the appropriate operating pressure value The operating capacity of the constant speed compressor is increased or decreased so that the operating capacity can be operated within the range of the appropriate operating pressure, and when the operating capacity of the constant speed compressor increases, the indoor-side expansion device or the chamber Operate the outer restrictor or both restrictors in the opening direction and When the operating capacity of the constant speed compressor is reduced, a control device for operating the indoor-side expansion device, the outdoor-side expansion device, or both the expansion devices in the closing direction is provided, and the constant-speed compressor is provided. When the refrigerant circulation amount fluctuates due to a sudden change in the operating capacity, it is possible to forcibly set an appropriate throttle opening in advance, so that there is no delay in the operation of the expansion valve and excessive low pressure It is possible to avoid a drop or a high pressure rise, and it is possible to perform safe and highly efficient continuous operation at an appropriate pressure.

According to a second aspect of the present invention, the control device includes:
When the operating capacity of the constant-speed compressor increases, the indoor-side expansion device or the outdoor-side expansion device or both of the expansion devices are opened in an opening direction that is substantially proportional to a change in the operating capacity of the constant-speed compressor. When the operating capacity of the constant-speed compressor is reduced, the indoor-side expansion device, the outdoor-side expansion device, or both expansion devices are substantially proportional to the operating capacity change of the constant-speed compressor. When the operating capacity change rate of the constant speed compressor is large, the refrigerant circulating amount increases and decreases relatively relatively, and the pressure fluctuation increases. Therefore, it is possible to forcibly set an appropriate throttle opening in advance, so that there is no delay in the operation of the expansion valve, and it is possible to perform safe and highly efficient continuous operation at an appropriate pressure. Become.

According to a third aspect of the present invention, there is provided an outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion valve. A refrigerant circuit is configured by connecting the indoor units of the above, the proper operating pressure on the low pressure side of the constant speed compressor is set during cooling, and the proper operating pressure on the high pressure side of the constant speed compressor is set during heating,
When operating within the range of the appropriate operating pressure, the operating capacity of the constant speed compressor is maintained as is, and when the operating capacity is outside the range of the appropriate operating pressure value, the range of the appropriate operating pressure is maintained. A control device is provided for increasing or decreasing the operating capacity of the constant speed compressor so that the compressor can be operated within, and for setting the range of the appropriate operating pressure after the increase or decrease wide for a certain period of time. For high and low pressure fluctuations, the compressor capacity switching value is set wider than the normal proper operating pressure range, so that the opening control of the indoor or outdoor expansion valve reaches a state appropriate for the circulation amount, Since the compressor capacity is not changed until the appropriate pressure is reached, hunting due to compressor capacity switching can be prevented.

According to a fourth aspect of the present invention, there is provided an outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion valve. A refrigerant circuit is configured by connecting the indoor units of the above, the proper operating pressure on the low pressure side of the constant speed compressor is set during cooling, and the proper operating pressure on the high pressure side of the constant speed compressor is set during heating,
When operating within the range of the appropriate operating pressure, the operating capacity of the constant speed compressor is maintained as is, and when the operating capacity is outside the range of the appropriate operating pressure value, the range of the appropriate operating pressure is maintained. A control device for increasing or decreasing the operating capacity of the constant-speed compressor so that the compressor can operate within the predetermined speed, and maintaining the operating capacity of the constant-speed compressor for a predetermined period of time. Even if the pressure falls outside the appropriate operating pressure range for the subsequent high-low pressure fluctuation, the compressor capacity is not changed until the pressure reaches the appropriate value by controlling the opening of the indoor or outdoor expansion valve. Even if the pressure falls outside the range of the proper operating pressure, it is possible to prevent the occurrence of hunting due to the switching of the compressor capacity.

According to a fifth aspect of the present invention, the control device increases or decreases the operating capacity of the constant speed compressor, and increases or decreases the operating capacity of the constant speed compressor. Operate both throttle devices in the opening direction,
Further, when the operating capacity of the constant speed compressor decreases, the indoor-side expansion device or the outdoor-side expansion device or both expansion devices are operated in the closing direction. Even if the operating pressure falls outside the appropriate operating pressure range, the indoor or outdoor expansion valve can be forcibly set to an appropriate throttle opening degree, so that the operation of the expansion valve is delayed. Therefore, an excessively low pressure drop or an excessively high pressure drop can be avoided, and a safe and highly efficient continuous operation can be performed at an appropriate pressure.

According to a sixth aspect of the present invention, there is provided an outdoor unit including a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger, an outdoor expansion device, and an outdoor fan, and an indoor heat exchanger and an indoor expansion device. A plurality of indoor units including an indoor fan are connected to form a refrigerant circuit, and a proper operating pressure on the low pressure side of the constant speed compressor is set during cooling, and a proper operating pressure on the high pressure side of the constant speed compressor is used during heating. Set the pressure, if operating within the range of the appropriate operating pressure, maintain the operating capacity of the constant speed compressor as it is, if outside the range of the appropriate operating pressure value, A control device that increases or decreases the operating capacity of the constant speed compressor so as to operate within the range of the appropriate operating pressure, and sets the range of the appropriate operating pressure wider as the rate of change in the capacity of the constant speed compressor increases. Provided, the capacity change is large. In such a case, the pressure fluctuation after the capacity change becomes larger, so that it is out of the proper operating pressure range, and the hunting is likely to occur repeatedly by changing the compressor capacity. It becomes easy to enter, and it is possible to perform safe and highly efficient continuous operation at an appropriate pressure.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a multi-room air conditioner according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a system configuration diagram of a multi-room air conditioner according to Embodiment 1 of the present invention.
Reference numerals 1, 22, and 23 denote constant speed compressors, each having a capacity of 5HP.

Reference numerals 24a, 24b, 24c and 24d denote non-return valves for preventing refrigerant from stagnating in a stopped one of the constant speed compressors 20, 21, 22 and 23, 25 a four-way valve, and 26 an outdoor side. A heat exchanger, 27 is an accumulator, 28 is an oil equalizing pipe for equalizing the refrigerating machine oil level of the constant speed compressors 20, 21, 22, 23, and 29 is an outdoor expansion valve, which are housed in the outdoor unit 30. ing.

Reference numerals 31a, 31b, 31c and 31d denote indoor units, which are indoor expansion valves 32 each having a fully closed function.
a, 32b, 32c, 32d and the indoor heat exchanger 33a,
33b, 33c, and 33d.

The indoor units 31a, 31b,
31c, 31d and the outdoor unit 30 are connected to the gas side main pipe 34.
The gas-side branch pipes 34a, 34b, 34c, 34d branched from the liquid-side main pipe 35 and the gas-side main pipe 34 communicate with the liquid-side branch pipes 35a, 35b, 35c, 35d.

Numeral 36 denotes constant speed compressors 20, 21 and 2.
A discharge pressure sensor for detecting discharge pressures of 2, 23;
Is a suction pressure sensor for detecting the suction pressure of the constant speed compressors 20, 21, 22, 23. Reference numeral 38 denotes a pressure detector which receives signals from the discharge pressure sensor 36 and the suction pressure sensor 37 and detects the discharge pressure and the suction pressure.

Numeral 39 denotes constant speed compressors 20, 21, 22, 2
Compressor capacity control for detecting the operating capacity of the compressor 3 and controlling the operating capacity by comparing the values of the discharge pressure and the suction pressure sent from the pressure detector 38 with the proper operating pressure set in advance. Device.

Reference numeral 40 denotes a signal of the operating capacity of the constant speed compressors 20, 21, 22, 23 from the compressor capacity control device 39, and when the operating capacity is changed, the outdoor expansion valve 2 is operated.
9, and the indoor expansion valves 32a, 32b, 32c, 32
This is an expansion valve control device at the time of a capacity change for opening and closing d.

Next, the operation of the multi-room air conditioner will be described by taking a cooling operation as an example.

When, for example, three of the constant speed compressors 20, 21, 22, 23 are operating and one is stopped,
When the indoor units 31a, 31b, 31c, 31d are in operation, the refrigerant discharged from the constant speed compressors 20, 21, 22, 23 is supplied to the check valves 24a, 24b, 24c, 24.
d and the condensed liquid is sent to the outdoor heat exchanger 26 through the four-way valve 25, and is then condensed and liquefied.
5. It is sent to the indoor units 31a, 31b, 31c, 31d through the liquid side branch pipes 35a, 35b, 35c, 35d.

Further, the indoor expansion valves 32a, 32b, 32
c, 32d, and the indoor heat exchangers 33a, 33
b, 33c, 33d, evaporates and contributes to cooling, is gasified, is sent to the outdoor unit 30 through the gas side branch pipes 34a, 34b, 34c, 34d and the gas side main pipe 34, and the four-way valve 25, the accumulator 27, return to the constant speed compressors 20, 21, 22, 23 and circulate.

On the other hand, the constant speed compressors 20, 21, 22, 2
3 (15 HP in this case), the signal of the suction pressure detected by the suction pressure sensor 37, and the signal of the discharge pressure detected by the discharge pressure sensor 36 are converted into numerical values of the suction pressure and the discharge pressure by the pressure detector 38. The suction pressure is sent to the compressor capacity control device 39 and is compared with a preset proper operating pressure range and a suction pressure value. If the suction pressure is equal to or lower than the proper operating pressure, the constant speed compressor 20, 21,
22 and 23 compressor operating capacity is reduced.

More specifically, a signal is output from the compressor capacity control device 39 to further stop the operation of one of the constant-speed compressors 20, 21, 22, and 23, and reduce the number of operating units (capacity) to two. (10HP). Further, a signal indicating that the number of operating units (capacity) has been reduced from three units (15 HP) to two units (10 HP) from the compressor capacity control unit 39 is sent to the expansion valve control unit 40 at the time of capacity change. Here, the indoor expansion valves 32a, 32
For example, b, 32c, and 32d are forcibly operated in the closing direction by an opening based on (Equation 1), for example.

(Equation 1) Expansion valve opening change amount = (compressor operation capacity after capacity change / compressor operation capacity before capacity change-1) × each indoor expansion valve opening before capacity change × constant ( The change amount of the opening degree of the expansion valve <0 indicates the closing direction. In this manner, the constant speed compressors 20, 21, 22, 22
When the operating number (capacity) of the 23 immediately decreases from 3 units (15 HP) to 2 units (10 HP), the refrigerant circulation amount sharply decreases, the suction pressure transiently increases excessively, and the proper operating pressure The number of operating units (capacity) does not return to three units (15 HP) again transiently beyond the range, and the number of operating units (capacity) decreases and the indoor expansion valves 32a, 32b,
Since the suction pressure after the number of operated units (capacity) is changed to an appropriate operating pressure by operating the units 32c and 32d appropriately in the closing direction, it is possible to immediately operate at an appropriate high-efficiency pressure and to maintain a constant pressure. The hunting phenomenon that repeatedly increases and decreases the operating number (capacity) of the high-speed compressors 20, 21, 22, 23 does not occur.

The constant speed compressors 20, 21, 22, 2
The operating number (capacity) of 3 is from 2 (10HP) to 1 (5
HP), the amount of change in the opening degree of the expansion valve is relatively large as shown in (Equation 1), and the two units (10H
In response to the 50% decrease in the circulation amount of the refrigerant from P) to one (5HP), relatively more opening operation of the indoor expansion valve is possible. In this case as well, the suction pressure after the capacity change is reduced. Since the operating pressure can be set to an appropriate value, it is possible to immediately operate at an appropriate high-efficiency pressure, and the hunting phenomenon does not occur.

Although the case where the suction pressure during the cooling operation is equal to or higher than the proper operation pressure is not described here, the difference is that the compressor operation capacity of the constant speed compressors 20, 21, 22, and 23 is increased. Only, and the description is omitted.

Although the heating operation has not been described here, during the heating operation, the range of the preset proper operating pressure is compared with the value of the discharge pressure to determine that the discharge pressure is lower than the proper operating pressure. , The constant speed compressor 2
When the operating capacity of the compressors 0, 21, 22, and 23 is increased and the discharge pressure is equal to or higher than the appropriate operating pressure, the only difference is that the operating capacity of the compressor is reduced.

(Embodiment 2) FIG. 2 is a system configuration diagram of a multi-room air conditioner according to Embodiment 2 of the present invention.
Components having the same configuration and the same function as those described above are denoted by the same reference numerals, and description thereof will be omitted.

Here, the constant speed compressors 20, 21 and 2 are used.
A capacity change pressure setting device having a function of changing an appropriate operation pressure for a certain period of time when the number of operating units (capacities) of the units 2 and 23 changes.

That is, taking the case of the cooling operation as an example,
The operating number (capacity) of the constant speed compressors 20, 21, 22, 23, the signal of the suction pressure detected by the suction pressure sensor 37, and the signal of the discharge pressure detected by the discharge pressure sensor 36 are determined by the suction detector 38. , Is converted to a numerical value of the discharge pressure, sent to the compressor capacity control device 39, and compared with a preset proper operating pressure. If the suction pressure is equal to or less than the proper operating pressure, the number of operating compressors (capacity) ) To decrease.

Further, the constant speed compressors 20, 21, 22, 2
For example, when one of the three compressors is in operation and one of the compressors is stopped, the compressor capacity control device 39 sends a signal to the constant speed compressors 20 and 2.
The operation of any one of the compressors 1, 22, and 23 is stopped, and the number of operated units (capacity) is changed to two units (10HP). Furthermore, the number of operating units (capacity) is 3
The signal reduced from the number of units (15 HP) to two units (10 HP) is sent to the pressure change-time pressure setting device 50.

Here, according to the operating number (capacity) of the constant speed compressors 20, 21, 22, 23 sent from the compressor capacity control device 39, and the value of the suction pressure sent from the pressure detector 38. For example, based on (Equation 2), the range of the appropriate operating pressure after the capacity change is set to be wide for a certain period of time.

(Equation 2) Appropriate operating pressure after change in capacity = appropriate operating pressure before change in capacity × constant Constant> 1 By doing so, the constant speed compressors 20, 21, 22, 22 are obtained.
23 operating units (capacity) are, for example, 3 units (15HP)
If the pressure instantaneously decreases to 2 units (10 HP), the refrigerant circulation amount sharply decreases, and the suction pressure transiently increases too much.
Even when the proper operating pressure is exceeded, the proper operating pressure range can be set wide for a certain period of time by the pressure change-time pressure setting device 50.
Since the number of operating units (capacity) of 2, 23 can be maintained at 2 units (10 HP), the number of operating units (capacity) does not return to 3 units (15 HP) again, but the number of operating units is repeatedly increased and decreased. No hunting phenomenon occurs.

This also means that the constant speed compressors 20, 2
Number of operating units (capacity) of 1, 22, 23 is 2 (10HP)
The same applies to the case where the number increases from 3 to 15 units (15 HP),
In this case, the discharge pressure increases and the suction pressure decreases. Also in this case, the appropriate operating pressure range can be set wider for a certain period of time by the displacement setting pressure setting device 40. , 22, and 23 can maintain the number of operating units (capacity) of three (15 HP), so that the number of operating units (capacity) does not return to two units (10 HP) again, and the number of operating units is repeatedly increased and decreased. Such a hunting phenomenon does not occur.

Further, after a lapse of a certain period of time after the number of operating units (capacity) has decreased, the transient increase in the suction pressure subsides due to expansion valve control (not shown) or the like, and falls within the proper operating pressure range. Therefore, even if the pressure is returned to the normal proper operating pressure range, problems such as an increase in the number of operating units (capacity) do not occur again, and appropriate high-efficiency operation can be performed.

Although the case where the suction pressure during the cooling operation is equal to or higher than the proper operation pressure has not been described here, the difference is that the compressor operating capacity of the constant speed compressors 20, 21, 22, and 23 is increased. Only, and the description is omitted.

Although the description of the heating operation is not given here, during the heating operation, the range of the preset proper operating pressure is compared with the value of the discharge pressure to determine that the discharge pressure is lower than the proper operating pressure. , The constant speed compressor 2
When the operating capacity of the compressors 0, 21, 22, and 23 is increased and the discharge pressure is equal to or higher than the appropriate operating pressure, the only difference is that the operating capacity of the compressor is reduced.

(Embodiment 3) FIG. 3 is a system configuration diagram of a multi-room air conditioner according to Embodiment 3 of the present invention.
Components having the same configuration and the same function as those described above are denoted by the same reference numerals, and description thereof will be omitted.

Here, the constant speed compressors 20, 21 and 22
When the number of operating units (capacity) changes, the number of operating units (capacity) after the change has a function to maintain the changed number of operating units (capacity) for a certain period of time.

Further, when the operation capacity signal of the constant speed compressors 20, 21, 22, 23 is received from the compressor capacity control device 38, the outdoor expansion valve 29,
A capacity change expansion valve control device 40 for opening and closing the indoor expansion valves 32a, 32b, 32c, 32d is also provided.

More specifically, when the cooling operation is taken as an example, the operating number (capacity) of the constant speed compressors 20, 21, 22, 23, the signal of the suction pressure detected by the suction pressure sensor 37, and the discharge pressure The signal of the discharge pressure detected by the sensor 36 is converted into numerical values of the suction pressure and the discharge pressure by the pressure detector 38, sent to the compressor displacement control device 39, and compared with a preset proper operating pressure. If the pressure is lower than the proper operating pressure, the number of operating compressors (capacity) is reduced.

For example, the constant speed compressors 20, 21 and
For example, when one of the units 2 and 23 is stopped while one is operating, the compressor capacity control unit 39 sends a signal to the constant speed compressor 2
The operation of any one of the compressors 0, 21, 22, and 23 is stopped, and the number of operated units (capacity) is changed to two units (10 HP).
In addition, the number of operating units (capacity)
Sends the signal reduced from 3 units (15 HP) to 2 units (10 HP) to the capacity change-time capacity setting device 60.

In the capacity change time capacity setting device 60, the constant speed compressors 20 and 2 sent from the compressor capacity control device 39 are provided.
A certain time after a change in the number of operation (capacity) of 1, 22, 23,
A signal for maintaining the number of operating units (capacity) is transmitted to the compressor capacity control device 39.
Return to

The compressor capacity control device 39 performs control so as not to change the operating capacity of the constant speed compressors 20, 21, 22, 23 while receiving the signal. Thereafter, after a certain period of time, the displacement control is performed in accordance with the range of the proper operating pressure in accordance with the suction pressure and the discharge pressure of the pressure detector 38. In this manner, the constant speed compressors 20, 21, 2
For example, the number of operating units (capacity) of 2, 23 is three (15H
(P) to two units (10HP) instantaneously, the refrigerant circulating amount sharply decreases, the suction pressure transiently rises too much, and even when the proper operating pressure is exceeded, the capacity change occurs when the capacity changes. The time capacity setting device 60 allows the constant speed compressor 2
The operating numbers (capacities) of 0, 21, 22, and 23 are two (10
HP) can be maintained, so that the number of operating units (capacity) is not changed by exceeding the transient proper operating pressure, and the hunting phenomenon of repeatedly increasing and decreasing the number of operating units (capacity) does not occur.

Further, by sending a signal indicating a decrease in the number of operating units (capacity) from the compressor displacement control device 39 to the displacement change expansion valve control device 40, the indoor expansion valve 32a,
Since 32b, 32c, and 32d are forcibly operated in the closing direction by an appropriate opening degree, the suction pressure after the change in the number of operated units (capacity) can be set to an appropriate operating pressure sooner, so that highly efficient operation is achieved. It is possible.

This is because the compressors 20, 21 and 21 are fixed speed.
Number of operating units (capacity) of 2, 23 is 2 (10HP) to 3
The same applies to the case where the pressure increases to 15 units (15 HP). In this case, the discharge pressure increases and the suction pressure decreases.
The operating number (capacity) of 21, 22, 23 is 3 (15H
P) can be maintained, so that the number of operating units (operating capacity) is not changed by exceeding the appropriate operating pressure, and the number of operating units of the constant speed compressors 20, 21, 22, and 23 is repeatedly increased and decreased. No hunting phenomenon occurs.

Although the case where the suction pressure during the cooling operation is equal to or higher than the proper operation pressure is not described here, the difference is that the compressor operating capacity of the constant speed compressors 20, 21, 22, and 23 is increased. Only, and the description is omitted.

Although the heating operation has not been described here, during the heating operation, a predetermined range of the proper operating pressure is compared with the value of the discharge pressure, and the discharge pressure is set to be equal to or less than the proper operating pressure. , The constant speed compressor 2
When the operating capacity of the compressors 0, 21, 22, and 23 is increased and the discharge pressure is equal to or higher than the appropriate operating pressure, the only difference is that the operating capacity of the compressor is reduced.

(Embodiment 4) FIG. 4 is a system configuration diagram of a multi-room air conditioner according to Embodiment 4 of the present invention.
Components having the same configuration and the same function as described above are denoted by the same reference numerals, and description thereof is omitted.

Here, the constant speed compressors 20, 21 and 22
An appropriate operating pressure setting device 70 having a function of maintaining the operating number (capacity) after the change for a certain period of time when the number of operating units (capacity) 2 and 23 changes.

More specifically, taking the cooling operation as an example, the operating number (capacity) of the constant speed compressors 20, 21, 22, 23, the signal of the suction pressure detected by the suction pressure sensor 37, and the discharge pressure The signal of the discharge pressure detected by the sensor 36 is converted into numerical values of the suction pressure and the discharge pressure by the pressure detector 38 and sent to the compressor displacement control device 39, where the proper operation pressure set by the proper operation pressure setting device 70 and If the suction pressure is equal to or lower than the proper operating pressure, the number of operating compressors (capacity) is reduced.

Here, the proper operating pressure setting device 70
Is set, for example, to the value shown in (Table 1).

[0065]

[Table 1]

That is, the constant speed compressors 20, 21 and
When the operating number (capacity) of 2, 23 is one (5HP),
The appropriate suction pressure range is as wide as 400 kPa, and two units (1
0HP), 3 units (15HP), and 4 units (20HP), as the number of operating units (capacity) increases, the appropriate suction pressure range is narrowed.

By doing so, the constant speed compressor 20,
When the operating number (capacity) of the units 21, 22, and 23 is instantaneously reduced from two units (10HP) to one unit (5HP), the refrigerant circulation amount sharply decreases (approximately half), and the suction pressure transients. Increase is greater. Therefore, even when the pressure exceeds the proper suction pressure, the constant speed compressors 20, 21, 22, 2
Since the number of operating units (operating) of No. 3 can be maintained at one unit (5HP), the number of operating units (capacity) is again set to two units (10H).
There is no return to P), and the hunting phenomenon of repeatedly increasing and decreasing the number of operating units (capacity) does not occur.

The constant speed compressors 20, 21, 22, 2
For example, when the operating number (capacity) of 3 is reduced from 4 units (20 HP) to 3 units (15 HP), the decrease in the refrigerant circulation amount is about 25%, which is not so sharp, and thus the transient of the suction pressure. The rise is not large. Therefore, in such a case, even if an appropriate pressure in a relatively narrow range is set at the suction pressure at which the refrigeration cycle can operate efficiently,
The hunting phenomenon of repeatedly increasing and decreasing the number of operating units (capacity) does not occur, and high-efficiency operation and operation with a compressor capacity corresponding to the required capacity can be performed.

This also means that the constant speed compressors 20, 2
The operating number (operating capacity) of 1, 22, 23 is 1 (5H
The same applies to the case where the number increases from P) to two units (10 HP). Compared with the case where the number increases from three units (15 HP) to four units (20 HP), the refrigerant circulation amount sharply increases, and the transient of the suction pressure. Is greater. Therefore, even when the suction pressure is lower than the appropriate suction pressure, the operating number (capacity) of the constant speed compressors 20, 21, 22, and 23 can be maintained at two (10HP) by setting the appropriate suction pressure wider. Therefore, the number of operating units (capacity) does not return to one (5HP) again, and the hunting phenomenon of repeatedly increasing and decreasing the number of operating units (capacity) does not occur.

The constant speed compressors 20, 21, 22, 2
For example, when the number of operating units (operating capacity) of the three
When the pressure decreases from P) to four units (20HP), the increase in the amount of circulating refrigerant is about 35%, which is not so sharp, and the transient decrease in the suction pressure is not large. Therefore, in such a case, by setting an appropriate pressure within a relatively narrow range with a suction pressure capable of operating the refrigeration cycle efficiently, the number of compressors (capacity according to the required efficiency and high efficiency operation) is set. ).

Although the case where the suction pressure during the cooling operation is equal to or higher than the proper operation pressure is not described here, the difference is that the compressor operating capacity of the constant speed compressors 20, 21, 22, and 23 is increased. Only, and the description is omitted.

Although the description of the heating operation is not given here, during the heating operation, the range of the proper operating pressure set in advance is compared with the value of the discharge pressure, and the discharge pressure is lower than the proper operating pressure. , The constant speed compressor 2
When the operating capacity of the compressors 0, 21, 22, and 23 is increased and the discharge pressure is equal to or higher than the appropriate operating pressure, the only difference is that the operating capacity of the compressor is reduced.

Further, here, an example is shown in which the proper operating pressure of the suction pressure is set during the cooling operation and the proper operating pressure of the discharge pressure is set during the heating operation. However, both the suction and discharge pressures are used during the cooling and heating operations. When the pressure is set to an appropriate pressure, the same effect is obtained in a similar manner, and this case is also included in the present invention.

Further, as the compressor, not only a constant speed compressor but also a variable speed compressor having an ability control means such as an extreme variable compressor or a cylinder bypass, or a variable speed compressor using an inverter can be used. The case where is used is also included in the present invention.

[0075]

As described above, according to the first aspect of the present invention, when operating within the range of the proper operating pressure during the cooling / heating operation, the operating capacity of the constant speed compressor is maintained as it is. If the operating pressure is outside the range of the appropriate operating pressure value, the operating capacity of the constant speed compressor is increased or decreased, and if the operating capacity is increased, the indoor expansion device, the outdoor expansion device, or both expansion devices are installed. When the operation is performed in the opening direction and the operating capacity is reduced, a control device is provided to operate the indoor-side expansion device, the outdoor-side expansion device, or both the expansion devices in the closing direction. When the refrigerant circulation amount increases or decreases due to a change in operating capacity, it is possible to forcibly set an appropriate throttle opening in advance, so that there is no delay in the operation of the expansion valve. Can avoid rising It can be performed safely and high efficiency continuous operation at an appropriate pressure to become.

The invention described in claim 2 is the first invention.
In addition to the invention described in the above, the indoor-side expansion device or the outdoor-side expansion device or both expansion devices are operated in the opening direction by an opening degree substantially proportional to a change in the operating capacity of the constant-speed compressor, and the constant-speed compressor When the operating capacity of the compressor decreases, the indoor-side expansion device, the outdoor-side expansion device, or both expansion devices are operated in the closing direction by an opening degree substantially proportional to the change in the operating capacity of the constant-speed compressor. When the operating capacity change rate of the compressor is large, the amount of refrigerant circulating increases and decreases relatively greatly, and the pressure fluctuation becomes large. For this reason, it is necessary to forcibly set an appropriate throttle opening in advance according to the operating capacity change. Therefore, there is no delay in the operation of the expansion valve, and a safe and highly efficient continuous operation can be performed at an appropriate pressure.

Further, according to the third aspect of the present invention, the operating capacity of the constant speed compressor is increased or decreased so that the compressor can be operated within the proper operating pressure range when the operating pressure is out of the proper operating pressure range. A control device is provided to set the range of the appropriate operating pressure after the increase / decrease for a certain period of time, so the compressor capacity switching value is set wider than the normal appropriate operating pressure range for high / low pressure fluctuations after the compressor capacity is changed. Therefore, the compressor capacity is not changed until the opening degree control of the indoor side or outdoor side expansion valve reaches a state corresponding to the circulation amount and reaches the normal appropriate pressure. Hunting can be prevented from occurring.

Further, the invention according to claim 4 is provided with a control device for maintaining the operating capacity of the constant speed compressor for a fixed time set in advance when the operating pressure is outside the range of the proper operating pressure value. Even if the pressure falls outside the appropriate operating pressure range for the high and low pressure fluctuations after the compressor capacity change, the compressor capacity is maintained until the pressure reaches the appropriate value by controlling the opening of the indoor or outdoor expansion valve. Since no change is made, it is possible to prevent occurrence of hunting due to compressor capacity switching even if the operating pressure falls outside the range of the proper operating pressure.

According to a fifth aspect of the present invention, in the capacity control device, when the operating capacity of the constant speed compressor is increased or decreased, and when the operating capacity is increased, the indoor throttle device or the outdoor throttle device or Both throttle devices are operated in the opening direction, and when the operating capacity of the constant speed compressor is reduced, the indoor throttle device or the outdoor throttle device or both throttle devices are operated in the closing direction. Even if the pressure falls outside the proper operating pressure range with respect to the high / low pressure fluctuation after the compressor capacity change, the indoor or outdoor expansion valve can be forcibly set to an appropriate throttle opening degree. There is no delay in the operation of the expansion valve, an excessively low pressure drop or a high pressure rise can be avoided, and a safe and efficient continuous operation can be performed at an appropriate pressure.

According to a sixth aspect of the present invention, when the operating pressure is out of the range of the appropriate operating pressure, the operating capacity of the constant speed compressor is increased or decreased so that the operating capacity can be maintained within the range of the appropriate operating pressure. A control device that sets the pressure range wider as the capacity change ratio of the constant speed compressor is larger is provided.If the capacity change is large, the pressure change after the capacity change becomes larger, Although it is out of the range, hunting is likely to occur repeatedly with repeated compressor capacity changes, but this makes it easy to enter the proper operating pressure range even after compressor capacity changes, and performs safe and efficient continuous operation at appropriate pressure. This has a great effect, for example, is possible.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of Embodiment 1 of a multi-room air conditioner according to the present invention.

FIG. 2 is a system configuration diagram of Embodiment 2 of the multi-room air conditioner according to the present invention.

FIG. 3 is a system configuration diagram of Embodiment 3 of the multi-room air conditioner according to the present invention.

FIG. 4 is a system configuration diagram of Embodiment 4 of the multi-room air conditioner according to the present invention.

FIG. 5 is a system configuration diagram of a conventional multi-room air conditioner.

[Explanation of symbols]

 20, 21, 22, 23 Constant speed compressors 24a, 24b Check valve 25 Four-way valve 26 Outdoor heat exchanger 27 Accumulator 28 Oil leveling pipe 29 Outdoor expansion valve 30 Outdoor unit 31a, 31b, 31c, 31d Indoor unit 32a, 32b, 32c, 32d Indoor expansion valve 33a, 33b, 33c, 33d Indoor heat exchanger 34 Gas-side main pipe 34a, 34b, 34c, 34d Gas-side branch pipe 35 Liquid-side main pipe 35a, 35b, 35c, 35d Liquid-side Branch pipe 36 Discharge pressure sensor 37 Suction pressure sensor 38 Pressure detector 39 Compressor capacity control device 40 Capacity change expansion valve control device 50 Capacity change pressure setting device 60 Capacity change time capacity setting device 70 Proper operating pressure setting device

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michimi Kusaka 4-5-2-5 Takaidahondori, Higashiosaka-shi, Osaka Matsushita Refrigeration Co., Ltd.

Claims (6)

[Claims] An outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion device, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion device are connected. Constitute a refrigerant circuit, set the proper operating pressure on the low pressure side of the constant speed compressor during cooling, set the proper operating pressure on the high pressure side of the constant speed compressor during heating, within the range of the proper operating pressure When operating at, the operating capacity of the constant speed compressor is maintained as it is, and when it is out of the range of the appropriate operating pressure value, the operating capacity is maintained within the range of the appropriate operating pressure. Increase or decrease the operating capacity of the constant speed compressor, and
When the operating capacity of the constant-speed compressor increases, the indoor-side expansion device or the outdoor-side expansion device or both expansion devices are operated in the opening direction, and the operating capacity of the constant-speed compressor decreases. In some cases, a multi-room air conditioner is provided with a control device for operating the indoor expansion device, the outdoor expansion device, or both expansion devices in a closing direction. 2. The control device according to claim 1, wherein when the operating capacity of the constant-speed compressor increases, the control unit changes the indoor-side expansion device, the outdoor-side expansion device, or both of the expansion devices to change the operating capacity of the constant-speed compressor. When the operating capacity of the constant speed compressor decreases, the indoor-side expansion device, the outdoor-side expansion device, or both of the expansion devices are operated at the constant speed. The multi-room air conditioner according to claim 1, wherein the compressor is operated in the closing direction by an opening substantially proportional to a change in the operating capacity of the compressor. 3. An outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion valve. Constitute a refrigerant circuit, set the proper operating pressure on the low pressure side of the constant speed compressor during cooling, set the proper operating pressure on the high pressure side of the constant speed compressor during heating, within the range of the proper operating pressure When operating at, the operating capacity of the constant speed compressor is maintained as it is, and when it is out of the range of the appropriate operating pressure value, the operating capacity is maintained within the range of the appropriate operating pressure. A multi-chamber type wherein a control device is provided for increasing or decreasing the operating capacity of the constant speed compressor, and for setting the range of the appropriate operating pressure after increasing or decreasing the operating capacity of the constant speed compressor wide for a certain period of time. Air conditioner. 4. An outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion valve are connected. Constitute a refrigerant circuit, set the proper operating pressure on the low pressure side of the constant speed compressor during cooling, set the proper operating pressure on the high pressure side of the constant speed compressor during heating, within the range of the proper operating pressure When operating at, the operating capacity of the constant speed compressor is maintained as it is, and when it is out of the range of the appropriate operating pressure value, the operating capacity is maintained within the range of the appropriate operating pressure. A control device for increasing or decreasing the operating capacity of the constant-speed compressor and maintaining the operating capacity of the constant-speed compressor for a preset fixed time after increasing or decreasing the operating capacity of the constant-speed compressor is provided. Multi-room air conditioner. 5. The control device according to claim 1, wherein when increasing or decreasing the operating capacity of the constant speed compressor, when the operating capacity increases,
The indoor-side expansion device or the outdoor-side expansion device or both expansion devices are operated in the opening direction, and when the operating capacity of the constant-speed compressor decreases, the indoor-side expansion device or the outdoor-side expansion device is reduced. 5. The multi-room air conditioner according to claim 3, wherein both the throttle devices are operated in the closing direction. 6. 6. An outdoor unit comprising a plurality of constant speed compressors, a four-way valve, an outdoor heat exchanger and an outdoor expansion device, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion device are connected. Constitute a refrigerant circuit, set the proper operating pressure on the low pressure side of the constant speed compressor during cooling, set the proper operating pressure on the high pressure side of the constant speed compressor during heating, within the range of the proper operating pressure When operating at, the operating capacity of the constant speed compressor is maintained as it is, and when it is out of the range of the appropriate operating pressure value, the operating capacity is maintained within the range of the appropriate operating pressure. Increase or decrease the operating capacity of the constant speed compressor, and
A multi-room air conditioner, further comprising a control device for setting the range of the appropriate operating pressure to be wider as the rate of change in capacity of the constant speed compressor is larger.