JPH10205853A - Multi-chamber type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-chamber type air conditioner in which capacity can be controlled so as to meet load regardless of high or low load by a simple constitution and control and a highly efficient operation having no excessive deficiency in capacity can be done within a wide load range. SOLUTION: According to the provision of start and stop control means 37 of a plurality of compressors, when the total load of indoor machines 29a, 29b, 29c, and 29d is larger than the set value of a high load side, a constant rate compressor 20 with small capacity is started or stopped and a constant rate compressor 21 with large capacity is continuously operated. When the total load is located between the set value of the high load side and the set value of a low load side, the constant rate compressor 20 with small capacity and the constant rate compressor 21 with large capacity are alternately started and stopped. Further, a controller 37 for starting/stopping compressor is provided, and when the total load is smaller than the set value of the low load side, the constant rate compressor 20 with small capacity is stated or stopped and the constant rate compressor 21 with large capacity is stopped.

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 control of the capacity of an outdoor unit.

[0002]

2. Description of the Related Art FIG. 7 is a system configuration diagram of a conventional multi-room air conditioner disclosed 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 the outdoor heat exchanger, 5 is the accumulator 6 is the first compressor 1 and the second
These are oil equalizing pipes for making the level of refrigerating machine oil in the compressor 2 the same, and these are accommodated in the outdoor unit 7. 8a,
Units 8b, 8c and 8d are indoor pressure reducing devices 9a, 9b, 9c and 9d each having a fully closed function and indoor heat exchangers 10a, 10b, 10c and 10d.

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, 8c, 8d
And the outdoor unit 7 include a gas-side main pipe 11 and a liquid-side main pipe 12.
And the gas side branch pipe 11 branched from the gas side main pipe 11
a, 11b, 11c, 11d and liquid side branch pipes 12a, 12
b, 12c, and 12d.

Next, the operation of the conventional multi-room air conditioner will be described. The refrigerant discharged from the first compressor 1 and the second compressor is sent to the outdoor heat exchanger 4 through the check valves 3a and 3b to be condensed and liquefied, and the liquid main pipe 12 and the liquid branch pipes 12a and 12b are condensed and liquefied. , 12c, 12d to the indoor units 8a, 8b, 8c, 8d. Here, the pressure is reduced by the indoor-side pressure reducing devices 9a, 9b, 9c, 9d, evaporated by the indoor-side heat exchangers 10a, 10b, 10c, 10d, gasified to contribute to cooling, and gas-side branch pipes 11a, 11b, 11
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 the conventional multi-room air conditioner, the first compressor 1 and the second compressor 2 capable of converting two poles to four poles are provided.
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.

[0008]

However, in such a conventional multi-chamber air conditioner, step control using a pole-changing compressor is performed. Needs to be changed, and the number of times of switching increases, which complicates the control.

The capacity ratio between the first compressor 1 and the second compressor 2 is set at 2: 3, and each compressor is capable of converting two poles to four poles. Control (2HP to 10HP, ie, 20
%, 30%, 40%,..., 100% operation), but when an intermediate capacity between these stages is required, for example, when operating a 3.5HP indoor unit. Although the capacity control of 35% is required, since the step control is performed every 10%, the first compressor 1 is stopped and the second compressor 2 is operated with four poles 3HP (30%)
In operation, the capacity of the outdoor unit of 3.5 HP cannot be satisfied and the capacity becomes insufficient. In 4HP (40%) operation in which the first compressor 1 is operated with two poles and the second compressor 2 is stopped, Since the capacity becomes excessive, it is necessary to reduce the capacity by excessively reducing the pressure with a pressure reducing device, and there is a problem that the operating efficiency is reduced.

The present invention has been made to solve the conventional problems. With a simple configuration and control, it is possible to control the capacity in accordance with the load irrespective of the size of the load. An object of the present invention is to provide a multi-room air conditioner that can be operated efficiently without problems.

[0011]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention comprises a large-capacity constant-speed compressor and a small-capacity constant-speed compressor. Comparing the corresponding set value on the high load side and the set value on the low load side corresponding to the capacity of the small capacity constant speed compressor, and starting / stopping the large capacity and small capacity constant speed compressor according to the comparison result. Accordingly, even in any load condition, a wide range of capacity control can be performed with simple control, and highly efficient operation can be performed.

When the total load is smaller than the low load side set value and the difference between the total load and the low load side set value is large,
By operating the bypass valve connecting the discharge system and the suction system in the opening direction to adjust the bypass amount of the discharge gas to the suction system, fine performance control can be performed even when the load is small. Furthermore, by adjusting the bypass amount according to the difference between the total load and the set value, it is possible to control the capacity over a wide range, and when the bypass amount is excessive, switching to control of the number of compressors is performed. ,
High-efficiency operation can be performed while preventing a decrease in efficiency due to an increase in bypass amount.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large capacity constant speed compressor,
An outdoor unit consisting of a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, and an outdoor restrictor, and a plurality of indoor units consisting of an indoor exchanger and an indoor restrictor are connected to form a refrigerant circuit. The load substantially equivalent to the operating capacity of the large-capacity constant-speed compressor is set to a high-load side set value, the load substantially equivalent to the operating capacity of the small-capacity constant-speed compressor is set to a low-load side set value, A total load detecting unit that detects a total load of the indoor unit, a load comparing unit that compares the total load, the high load side set value, and the low load side set value, based on a result compared by the load comparing unit When the total load is larger than the high load side set value, the small capacity constant speed compressor starts and stops, and the large capacity constant speed compressor operates continuously, and the total load is the high load. If the set value is halfway between the low set value and the low load set value, The constant-speed compressor and the large-capacity constant-speed compressor alternately start and stop, and when the total load is smaller than the set value on the off-load side, the large-capacity constant-speed compressor is stopped, and the small-capacity constant speed compressor is stopped. A plurality of compressor start / stop control means for starting / stopping the high-speed compressor is provided.

A bypass pipe having a bypass valve for connecting a discharge system and a suction system of the large-capacity constant-speed compressor and the small-capacity constant-speed compressor is provided, and when a total load is smaller than a low load side set value. A system in which a small-capacity constant-speed compressor is continuously operated, and a large-capacity constant-speed compressor is stopped, and system capacity control means is provided for opening and closing the bypass valve according to a difference between the total load and a low load side set value. It is.

When the total load is larger than the high load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor operate continuously, and the difference between the total load and the high load side set value is obtained. The bypass valve is opened and closed according to the above, and when the total load is between the high load side set value and the low load side set value, the small capacity constant speed compressor is stopped, and the large capacity constant speed compressor is Continuous operation, and opens and closes the bypass valve according to the difference between the total load and the high load side set value, and when the total load is smaller than the low load side set value, the small capacity constant speed compressor continuously operates. ,
The large-capacity constant-speed compressor is provided with system capability means for stopping and opening and closing the bypass valve according to the difference between the total load and the set value on the high load side.

When the total load is larger than the high load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor operate continuously, and according to the difference between the total load and the high load side set value. When the difference between the total load and the set value on the high load side is equal to or more than a predetermined value, the bypass valve is closed, the small capacity constant speed compressor starts and stops, and the large capacity constant speed When the compressor is continuously operated and the total load is between the high load side set value and the low load side set value, the small capacity constant speed compressor is stopped and the large capacity constant speed compressor is continuously operated. Opening and closing the bypass valve according to the difference between the total load and the high load side set value, and closing the bypass valve when the difference between the total load and the high load side set value is equal to or greater than a predetermined value. , The small-capacity constant-speed compressor and the large-capacity constant-speed compressor start and stop alternately. If smaller than the value is continuous operation small capacity constant speed compressor, and large constant speed compressor stops,
And a system capacity control means for opening and closing the bypass valve according to the difference between the total load and the set value on the high load side.

When the total load is smaller than the low load side set value, the large capacity constant speed compressor is stopped, the small capacity constant speed compressor is continuously operated, and the difference between the total load and the low load side set value is satisfied. When the bypass valve is opened and closed according to the difference and the total load is smaller than a predetermined value, the system is provided with system capacity control means for stopping the large capacity constant speed compressor and starting and stopping the small capacity constant speed compressor. Things.

When the total load is between the high load side set value and the low load side set value and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the small capacity constant The operation start of the high-speed compressor and the operation stop of the large-capacity constant-speed compressor are almost simultaneously performed, and the operation stop of the small-capacity constant-speed compressor and the operation start of the large-capacity constant-speed compressor are almost simultaneous. It is to be.

When the total load is intermediate between the high load side set value and the unload side set value, and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the total load is reduced. Accordingly, the ratio of the operation time of the small capacity constant speed compressor to the operation time of the large capacity constant speed compressor is controlled.

According to the present invention having the above-described structure, the total load of the indoor unit is detected, and the preset high load set value, the preset stop load set value, and the total load are compared to determine the total load. Is larger than the set value on the high-load side, the large-capacity constant-speed compressor is continuously operated, and the small-capacity constant-speed compressor is operated or stopped by controlling the total load.
In the case of a relatively large load, the operation corresponding to the capacity can be performed. When the total load is between the high load side set value and the low load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor are alternately started and stopped, and each compressor is started and stopped. In the case of a moderate load, it is possible to operate with the capacity corresponding to the medium load. When the total load is smaller than the set value on the unload side, the large capacity constant speed compressor is stopped, and the small capacity constant speed compressor is controlled to operate or stop according to the magnitude of the total load, so that the relatively small load is controlled. In the case of, operation of the capacity corresponding to it becomes possible, and continuous capacity control is possible under a wide range of load conditions by simple control of the number of operating compressors, without excess or deficiency of capacity,
Highly efficient operation is always possible. Also, a bypass pipe having a bypass valve connecting the discharge system and the suction system is provided,
By operating the bypass valve in the opening direction when the difference between the total load and the low load side set value is large, when the total load is smaller than the low load side set value, stopping the large capacity constant speed compressor, By continuously operating the small-capacity constant-speed compressor and adjusting the bypass amount of the discharge gas to the suction system, the amount of refrigerant circulating in the refrigeration cycle is reduced, enabling fine-grained capacity control even when the load is small. .

When the total load is larger than the high load side set value, the small capacity constant speed compressor and the large capacity constant speed compressor are continuously operated, and the difference between the total load and the high load side set value is large. In this case, by operating the bypass in the opening direction and adjusting the bypass amount of the discharge gas to the suction system,
Reducing the amount of refrigerant circulating in the refrigeration cycle enables fine-grained capacity control, and when the difference exceeds a certain value, starts and stops the small-capacity constant-speed compressor and continuously operates the large-capacity constant-speed compressor. Accordingly, it is possible to perform capacity control that can follow a large load change. Further, when the total load is smaller than the predetermined value, the large capacity constant speed compressor is stopped, and the system is provided with a system capacity control means for starting and stopping the small capacity constant speed compressor. The capacity can be reliably controlled even with the load, and the efficiency does not decrease with an increase in the bypass amount.

In the case of alternate operation of the small-capacity constant-speed compressor and the large-capacity constant-speed compressor, the operation of the small-capacity constant-speed compressor /
By making the stop and the stop / run of the large-capacity constant-speed compressor almost simultaneously, there is no large pressure fluctuation at the time of switching of the compressor, so that there is no loss of performance or input due to starting and stopping. is there.

If the total load is between the high load side set value and the unloaded side set value, the small capacity constant speed compressor and the large capacity constant speed compressor alternately start and stop, and By controlling the ratio of the operating time of the small-capacity constant-speed compressor to the large-capacity constant-speed compressor, the load corresponding to the capacity of the large-capacity constant-speed compressor can be reduced. Thus, continuous and fine-grained capability control can be performed.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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 numeral 20 denotes a small-capacity constant-speed compressor having a small capacity and a capacity of 4HP. . Reference numeral 21 denotes a large-capacity constant-speed compressor having a large capacity,
The ability is 6HP.

Reference numerals 22a and 22b denote small capacity constant speed compressors 20.
Alternatively, when one of the large-capacity constant-speed compressors 21 is operating and the other is stopped, a check valve for preventing refrigerant from stagnating in the stopped compressor, 23 is a four-way valve, and 24 is outdoor heat exchange. vessel,
25 is an accumulator, 26 is a small capacity constant speed compressor 20
Oil equalizing pipe for equalizing the refrigerating machine oil level in the large capacity constant speed compressor 21 with an outdoor expansion valve (an outdoor expansion device)
These are stored in an outdoor unit (outdoor unit) 28.

Numerals 29a, 29b, 29c and 29d denote indoor units (indoor units) which are indoor expansion valves (indoor expansion devices) 30a, 30b, 30c, 30c, respectively, each having a fully closed function.
30d and indoor heat exchangers 31a, 31b, 31c, 31
d. In addition, the indoor units 29a, 29
b, 29c, 29d and the outdoor unit 28 are connected to the gas-side main pipe 32, the liquid-side main pipe 33, the gas branch pipes 32a, 32b, 32c, 32d branched from the gas-side main pipe 32, and the liquid-side branch pipes 33a, 33b, 33c, 33d. Is communicated by

Reference numerals 34a, 34b, 34c and 34d denote room temperature sensors for measuring the room temperature of each of the indoor units 29a, 29b, 29c and 29d, and the output is sent to the total load detecting means 35. Here, the total load of the indoor unit during operation can be detected and calculated. Reference numeral 36 denotes a load comparing unit that compares the total load calculated by the total load detecting unit 35 with a preset high load side set value and a low load side set value. 37 is a small capacity constant speed compressor 20 based on the comparison result of the load comparing means 36.
And a plurality of compressor start / stop control means for controlling the operation and stop of the large capacity constant speed compressor 21.

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

The refrigerant discharged from the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 is supplied to the check valves 22a, 22
b, is sent to the outdoor heat exchanger 24 through the check valve 23 and condensed and liquefied, and passes through the outdoor expansion valve 27, the liquid main pipe 33, and the liquid branch pipes 33a, 33b, 33c, 33d to form the indoor unit 29a. , 29b, 29c, and 29d. The pressure is further reduced by the indoor expansion valves 30a, 30b, 30c, 30d, and the indoor heat exchangers 31a, 31b, 31c, 31 are reduced.
d, it is gasified by contributing to cooling, and the gas side branch pipe 3
2a, 32b, 32c, 32d, and gas-side main pipe 3
2, the air is sent to the outdoor unit 28, passes through the four-way valve 23 and the accumulator 25, and returns to the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 for circulation.

On the other hand, each of the indoor units 29a, 29b, 2
The room temperature of 9c, 29d is the room temperature sensor 34a, 34b, 3
The values measured at 4c and 34d are sent to the total load detecting means 25 for detecting the total load. Here, the calculation of equation (1) is performed from the difference between the preset target set temperature of each indoor unit and the room temperature and the capacity (the number of HPs) of the operating indoor units, and the total load is calculated.

The total load = 数 the number of HPs in the operating indoor unit × (room temperature−target set temperature) Equation (1) Further, a load (equivalent to 6 HP) corresponding to the operating capacity of the large capacity constant speed compressor 21 is set on the high load side. And the load corresponding to the operating capacity of the small capacity constant speed compressor 20 (equivalent to 4HP)
Is set as the low load side set value. Then, based on the comparison result between the total load calculated by the total load detection means 35 and the set high load side set value and low load side set value, the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 Control running and stopping. This will be described with reference to the operation control flowchart shown in FIG.

The magnitude of the total load detected by the total load detecting means 35 and the set value on the high load side are judged (40), and if it is large, the large capacity constant speed compressor 21 (6HP) is continuously operated to reduce the small capacity. The constant speed compressor 20 (4HP) controls the operation / stop so that the value of the total load is large or small and the pressure is in an appropriate pressure range (4.
1). By doing so, the control can respond to a load in the range of 6HP to 10HP.

If the total load is smaller than the set value on the high load side, the total load, the set value on the low load side, and the magnitude are determined (4).
2) In a large case, the large-capacity constant-speed compressor 21 and the small-capacity constant-speed compressor 20 are alternately operated so that the value of the total load is large or small and the pressure range is appropriate.
The control corresponding to the load in the range of HP becomes possible (4.
3).

That is, here, the small capacity constant speed compressor 2
By controlling the ratio of the operating time of the compressor 21 to 0 and the large capacity constant speed compressor 21, it is possible to continuously and finely control the capacity of 4HP to 6HP.

Further, when the total load is smaller than the set value on the low load side, the large capacity constant speed compressor 21 is stopped, and the small capacity constant speed compressor 20 is changed to the magnitude of the total load value or an appropriate pressure range. By controlling the operation / stop to become 0HP ~
Capability control corresponding to a load in the range of 4HP becomes possible (44).

On the other hand, in the case of the alternating operation of the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21, when the small-capacity constant-speed compressor 20 starts operating and when the large-capacity constant-speed compressor 21 stops operating. At approximately the same time, large pressure fluctuations do not occur when the compressor is switched, so that the pressure of the refrigeration cycle is substantially maintained. Will be gone.

As described above, simple control of the number of operating two constant-speed compressors having different capacities makes it possible to operate in a wide range of load (here, 0 HP to 10 HP), and the capacity is excessive or insufficient. The operation can always be performed with a high-efficiency cycle without the occurrence of a problem. In particular, in this embodiment, 4H
In the range of P to 6HP, the small capacity constant speed compressor 20
By operating the compressor 21 and the large-capacity constant-speed compressor 21 alternately in accordance with the load, it is possible to perform almost continuous and fine-grained capacity control, and to realize a highly efficient operation that always responds to load fluctuations.

In this embodiment, the small capacity constant speed compressor 2
Although 0 has been described as 4HP and large-capacity constant-speed compressor 21 has been described as 6HP, the present invention is not limited to this, and any combination of capacities is included in the present invention.

Further, in this embodiment, the total load detecting means 35
Has been described as the total load in equation (1), but the same applies to a load calculated only as the HP number of the driving machine or a load calculated from the difference between the outside air temperature and the room.
These are included in the present invention.

(Embodiment 2) FIG. 3 is a system configuration diagram of a multi-room type air conditioner according to Embodiment 2 of the present invention. The description is omitted.

Here, the discharge pipe 50, the accumulator 25 and the four-way valve 2 between the check valves 22a and 22b and the four-way valve 23 are used.
The suction pipe 51 is connected through a bypass valve 52. Further, based on the comparison result of the load comparing means 36, the system capacity control means 53 for controlling the operation and stop of the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21 and controlling the opening of the bypass valve 52 is controlled. Provided.

Here, based on the comparison result between the total load calculated by the total load detecting means 35 and the preset high load side set value and low load side set value, the small capacity constant speed compressor 20 and The operation and stop of the large-capacity constant-speed compressor 21 and the opening of the bypass valve 52 are controlled. This will be described with reference to an operation control flowchart shown in FIG. Here, the same reference numerals are given to those showing the same flow as FIG. 2, and the description is omitted.

If the total load detected by the total load detecting means 35 is smaller than the high load side set value, the magnitude of the total load and the low load side set value is determined (42), and the total load is set to the low load side. If it is smaller than the set value, the large capacity constant speed compressor 21 is stopped and the small capacity constant speed compressor 20 is continuously operated (53). Further, the magnitude of the value of the total load is determined (54), and when the total load increases, the bypass valve 52 is operated in the opening direction (5).
5) When the total load decreases, the bypass valve 52 is operated in the opening direction (56). In this way, when the load decreases, the discharge gas of the small-capacity constant-speed compressor 20 is transferred from the discharge pipe 50 through the bypass valve 52 to the suction pipe 5.
1, the capacity can be reduced by reducing the amount of refrigerant circulating to the refrigeration cycle.

That is, when the total load is smaller than the set value on the low load side, continuous and fine capacity control can be performed by controlling the opening degree of the bypass valve 52 instead of operating / stopping the small capacity constant speed compressor. Stable operation can be performed without large fluctuations in capacity due to operation / stop of the compressor.

On the other hand, the magnitude of the value of the total load is determined (5
4) If it is smaller than a predetermined value, the large-capacity constant-speed compressor is stopped, and only the small-capacity constant-speed compressor starts and stops so that the value of the total load is large or small and the pressure is within an appropriate pressure range. With this configuration, the capacity can be reliably controlled even with a small load that cannot be controlled by the bypass, and the efficiency does not decrease as the bypass amount increases.

(Embodiment 3) FIG. 5 is a flowchart showing operation control of a multi-room air conditioner according to Embodiment 3 of the present invention.
Also, the system configuration diagram shown here is the same as FIG. 3,
Description is omitted, and control of each compressor and control of the bypass valve 52 will be described.

The total load detected by the total load detecting means 35, the set value on the high load side, and the magnitude are determined (60). If the magnitude is large, the large capacity constant speed compressor 21 (6HP) and the small capacity constant speed compressor 21 are determined. 20 (4HP) is operated continuously (61). Further, the magnitude of the value of the total load is determined (62), and when the total load increases, the bypass valve 52 is operated in the closing direction (6).
3) When the total load decreases, the bypass valve 52 is operated in the opening direction (64). By doing so, the capacity control by the bypass valve bypass 52 is added, and the simultaneous operation of the small-capacity constant-speed compressor 20 and the large-capacity constant-speed compressor 21 is particularly suitable for the case where the capacity is slightly excessive. Capability control becomes possible.

Next, when the total load is smaller than the high load side set value, the total load, the low load side set value and the magnitude are determined (6).
5) If large, the large-capacity constant-speed compressor 21 is continuously operated, and the small-capacity constant-speed compressor 20 is stopped (66).

Further, the magnitude of the value of the total load is determined (6).
7) When the total load increases, the bypass valve 52 is operated in the closing direction (68), and when the total load decreases, the bypass valve 52 is operated in the opening direction (69).

Also in this case, since the capacity control by the bypass valve 52 is added, the operation of only the large-capacity constant-speed compressor 21 makes it possible to perform the capacity control particularly suitable when the capacity is slightly excessive. Become.

Next, when the total load is smaller than the low load side set value, the large capacity constant speed compressor 21 is stopped, and the small capacity constant speed compressor 20 is continuously operated (70). Further, the magnitude of the value of the total load is determined (71), and when the total load increases, the bypass valve 52 is operated in the closing direction (72). When the total load decreases, the bypass valve 52 is opened. (73). By doing so, even when the total load is smaller than the low load side set value, the operation of the small capacity constant speed compressor
By controlling the opening degree of the bypass valve 52 instead of stopping and controlling the capacity, fine capacity control can be performed even in the case of a small load, so that the operation corresponding to the load can be performed in a wider range.

As described above, in addition to the control of the number of operating compressors, the capacity control by the bypass valve 52 is added.
It is possible to perform detailed performance control over a wide range from HP to 10HP.

(Embodiment 4) FIG. 6 is a flowchart showing the operation control of a multi-room air conditioner according to Embodiment 4 of the present invention.
Also, the system configuration diagram shown here is the same as FIG. 3,
Description is omitted, and control of each compressor and control of the bypass valve 52 will be described.

The magnitude of the total load detected by the total load detecting means 35 and the set value on the high load side are judged (60). If the magnitude is large, the large capacity constant speed compressor 21 (6HP) and the small capacity constant speed compression are used. The machine 20 (4HP) is operated continuously (61). Further, the magnitude of the value of the total load is determined (62), and when the total load increases, the bypass valve 52 is operated in the closing direction (6).
3) If the total load decreases, the bypass valve 52 is operated in the opening direction (64). Here, the difference between the total load and the set value on the high load side is compared (80), and if the difference is equal to or more than a certain value, the large capacity constant speed compressor 21 (6HP) and the small capacity constant speed compressor 21 are continued. 20 (4HP) is operated continuously, and the bypass valve 52 is operated. On the other hand, when the difference between the total load and the set value on the high load side is equal to or less than a predetermined value, the large capacity constant speed compressor is continuously operated, and the small capacity constant speed compressor 20 is operated by changing the value of the total load or an appropriate value. The operation / stop is controlled to be in the pressure range (66). By doing so, 6HP ~
In addition to the control capable of coping with the load in the range of 10 HP, the capacity control by the bypass valve 52 is added, so that the small capacity constant speed compressor 20 and the large capacity constant speed compressor 21
In the simultaneous operation of the above, particularly suitable capacity control can be performed when the capacity is slightly excessive, and the load range used by the bypass valve 52 is set. Since the control is switched to the control, it is possible to prevent a decrease in efficiency caused by an excessive amount of bypass, and it is possible to always operate in an optimal cycle corresponding to the load.

Next, when the total load is smaller than the high load side set value, the total load, the low load side set value and the magnitude are determined (6).
5) If large, the large-capacity constant-speed compressor 21 is continuously operated, and the small-capacity constant-speed compressor 20 is stopped (66).

Further, the magnitude of the value of the total load is determined (6).
7) When the total load increases, the bypass valve 52 is operated in the closing direction (68), and when the total load decreases, the bypass valve 52 is operated in the opening direction (69). Here, the difference between the total load and the set value on the high load side is compared (82), and if the difference is equal to or more than a certain value, the large capacity constant speed compressor 21 (6) is continued.
HP) is operated continuously, and the bypass valve 52 is operated. On the other hand, when the difference between the total load and the set value on the high load side is equal to or less than a certain value, the large capacity constant speed compressor 21 and the small capacity constant speed compressor 20 are set to the magnitude of the total load value or the appropriate pressure range. (83).

By doing so, as before, 4
In addition to the control capable of coping with the load in the range of HP to 6HP, the capacity control by the bypass valve 52 is added, so that the operation with only the large-capacity constant-speed compressor 21 has a slightly excessive capacity in the case of the operating condition. In addition, particularly suitable capacity control becomes possible, and furthermore, by setting a load range using the bypass valve 52 and switching to control of the number of compressors when the bypass amount increases, the bypass amount is determined to be excessive. As a result, the efficiency can be prevented from lowering, and the compressor can always be operated with the optimum number of compressors and cycles corresponding to the load.

Next, when the total load is smaller than the low load side set value, the large capacity constant speed compressor 21 is stopped, and the small capacity constant speed compressor 20 is continuously operated (70). Further, the magnitude of the value of the total load is determined (71), and when the total load increases, the bypass valve 52 is operated in the closing direction (72). When the total load decreases, the bypass valve 52 is opened. (73). By doing so, even when the total load is smaller than the low load side set value, the operation of the small capacity constant speed compressor
By controlling the opening degree of the bypass valve 52 instead of stopping and controlling the performance, even in the case of a small load, fine performance control can be performed, so that the load can be operated in a wider range.

As described above, in addition to controlling the number of operating compressors, the capacity control by the bypass valve 52 is added.
It is possible to finely control the capacity in a wide range from HP to 10HP, and when the bypass amount is excessive, the control is switched to the control of the number of compressors. The compressor can always be operated with a highly efficient number of compressors.

[0061]

As described above, in the multi-room air conditioner according to the present invention, the total load of the indoor unit is compared with the set value on the high load side and the set value on the low load side, and the large capacity is set according to the comparison result. By operating / stopping the constant-speed compressor and the small-capacity constant-speed compressor, it is possible to operate in response to load fluctuations with a simple control of the number of operating units, and it is possible to continuously control the capacity even under all load conditions, There is no excess or shortage, and highly efficient operation is always possible.

A bypass pipe having a bypass valve for connecting the discharge system and the suction system is provided, and when the total load is smaller than the low load side set value and the difference between the total load and the low load side set value is large, By operating the bypass valve in the opening direction, when the total load is smaller than the low load side set value, by adjusting the bypass amount to the discharge gas suction system, the refrigerant circulation amount of the refrigeration cycle is reduced, and the load is reduced. Is small, it is possible to perform fine-grained capability control.

Further, even when the total load is larger than the high load side set value, the amount of refrigerant circulating in the refrigeration cycle can be reduced by adjusting the bypass amount of the discharge gas to the suction system, thereby enabling finer capacity control. In addition, when the bypass amount is excessive, the control is switched to the control of the number of compressors, so that it is possible to always operate the compressor with a high efficiency number of compressors while preventing a decrease in efficiency due to an increase in the bypass amount. It has a great effect.

[Brief description of the drawings]

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

FIG. 2 is a control flowchart of the multi-room air conditioner according to the first embodiment of the present invention.

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

FIG. 4 is a control flowchart of a multi-room air conditioner according to Embodiment 2 of the present invention.

FIG. 5 is a control flowchart of a multi-room air conditioner according to Embodiment 3 of the present invention.

FIG. 6 is a control flowchart of a multi-room air conditioner according to a fourth embodiment of the present invention.

FIG. 7 is a system configuration diagram of a conventional multi-room air conditioner.

[Explanation of symbols]

 Reference Signs List 20 small capacity constant speed compressor 21 large capacity constant speed compressor 22a, 22b check valve 23 four-way valve 24 outdoor heat exchanger 25 accumulator 26 oil leveling pipe 27 outdoor expansion valve 28 outdoor unit 29a, 29b, 29c, 29d indoor Unit 30a, 30b, 30c, 30d Indoor expansion valve 31a, 31b, 31c, 31d Indoor heat exchanger 32 Gas main pipe 32a, 32b, 32c, 32d Gas side branch pipe 33 Liquid main pipe 33a, 33b, 33c, 33d Liquid side branch pipes 34a, 34b, 34c, 34d Room temperature sensor 35 Total load detection means 36 Load comparison means 37 Multiple compressor start / stop control means 50 Discharge pipe 51 Suction pipe 52 Bypass valve 53 System capacity control means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Takashi Kaneko 4-5-2-5 Takaida Hondori, Higashi-Osaka-shi, Osaka Matsushita Refrigerating Machinery Co., Ltd. (72) Michimi Kusaka Michimi Kusaka, Takaida-Hondori, Osaka 4-5-2-5 Matsushita Refrigeration Machine Co., Ltd.

Claims (7)

[Claims] 1. An outdoor unit comprising a large-capacity constant-speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger and an outdoor throttle device, and an indoor heat exchanger and an indoor throttle device. A refrigerant circuit is formed by connecting a plurality of indoor units, and a load substantially corresponding to the operation capacity of the large-capacity constant-speed compressor is set to a high-load side set value, and substantially corresponds to the operation capacity of the small-capacity constant-speed compressor. A load to be set as a low load side set value, a total load detecting means for detecting a total load of the plurality of indoor units, and a load comparing means for setting the total load to the high load side set value and comparing the low load side set value And, if the total load is larger than the high load side set value based on the result compared by the load comparing means,
The small capacity constant speed compressor starts and stops, and the large capacity constant speed compressor operates continuously, and when the total load is between the high load side set value and the low load side set value, The small-capacity constant-speed compressor and the large-capacity constant-speed compressor alternately start and stop, and when the total load is smaller than a low-load-side set value, the large-capacity constant-speed compressor is stopped, and A multi-room air conditioner provided with a plurality of compressor start / stop control means for starting / stopping a small capacity constant speed compressor. 2. A large-capacity constant-speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor restrictor, a discharge of the large-capacity constant-speed compressor and the small-capacity constant-speed compressor. An outdoor unit comprising a bypass pipe having a bypass valve connecting the system and the intake system, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion device are connected to form a refrigerant circuit, and the large-capacity constant-speed compression is performed. A load substantially corresponding to the operation capacity of the unit is set to a high load side, a load substantially corresponding to the operation capacity of the small capacity constant speed compressor is set to a low load side, and a total load of the plurality of indoor units is detected. Total load detection means, load comparison means for comparing the total load with the high load side set value and the low load side set value, and the total load based on the result of comparison by the load comparison means. If it is larger than the side set value, the small capacity is constant When the high-speed compressor starts and stops, and the large-capacity constant-speed compressor operates continuously, and the total load is between the high-load side set value and the low-load side set value, the small-capacity constant When the high-speed compressor and the large-capacity constant-speed compressor alternately start and stop, and when the total load is smaller than the low-load-side set value, the large-capacity constant-speed compressor is stopped and the small-capacity constant speed compressor is stopped. A multi-room air conditioner comprising a system capacity control means for continuously operating a high speed compressor and opening and closing the bypass valve in accordance with a difference between the total load and the low load side set value. 3. A large-capacity constant-speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor restrictor, a discharge of the large-capacity constant-speed compressor and the small-capacity constant-speed compressor. An outdoor unit consisting of a bypass pipe having a bypass valve connecting the system and the suction system, and a plurality of indoor units consisting of an indoor heat exchanger and an indoor expansion device are connected to form a refrigerant circuit, and the large-capacity constant-speed compression is performed. The load load substantially equivalent to the operating capacity is set to a high load side, the load substantially equivalent to the operating capacity of the small capacity constant speed compressor is set to a low load side, and the total load of the plurality of indoor units is set. A total load detecting unit that detects the load, a load comparing unit that compares the total load with the high load side set value and the low load side set value, and the total load based on a result compared by the load comparing unit. If it is larger than the set value on the load side, The constant-speed compressor and the large-capacity constant-speed compressor operate continuously, and open and close the bypass valve according to a difference between the total load and the high load side set value. When the load-side set value and the low-load side set value are intermediate, the small-capacity constant-speed compressor stops, the large-capacity constant-speed compressor operates continuously, and the total load and the high-load side are set. The bypass valve is opened and closed according to a difference from a set value, and when the total load is smaller than the low load side set value, the large capacity constant speed compressor is stopped, and the small capacity constant speed compression is performed. A multi-room air conditioner comprising a system capacity control means for continuously operating the air conditioner and opening and closing the bypass valve according to the difference between the total load and the low load side set value. 4. A large-capacity constant-speed compressor, a small-capacity constant-speed compressor, a four-way valve, an outdoor heat exchanger, an outdoor restrictor, a discharge of the large-capacity constant-speed compressor and the small-capacity constant-speed compressor. An outdoor unit comprising a bypass pipe having a bypass valve connecting the system and the intake system, and a plurality of indoor units comprising an indoor heat exchanger and an indoor expansion device are connected to form a refrigerant circuit, and the large-capacity constant-speed compression is performed. A load substantially corresponding to the operating capacity of the unit is set to a high load side value, a load substantially corresponding to the operating capacity of the small capacity constant speed compressor is set to a low load side set value, and a total load of the plurality of indoor units is detected. A total load detection unit, a load comparison unit that compares the total load with a high load side set value and a low load side set value, and the total load is set to the high load side set value based on a result compared by the load comparison unit. If it is larger, the small capacity constant speed compressor and And the large-capacity constant-speed compressor operates continuously, and opens and closes the bypass valve according to the difference between the total load and the high load side set value, and furthermore, the total load and the high load side set value. When the difference becomes equal to or less than a predetermined value, the small capacity constant speed compressor starts and stops, the large capacity constant speed compressor operates continuously, the bypass valve closes, and the total load decreases. When the intermediate value is between the high load side set value and the low load side set value, the small capacity constant speed compressor is stopped, the large capacity constant speed compressor is continuously operated, and the total load and the high load When the difference between the total load and the high load side set value is equal to or less than a predetermined value, the small capacity constant speed compressor is opened and closed. And the large capacity constant speed compressor alternately start and stop, the bypass valve is closed, and When the total load is smaller than the low load side set value, the large capacity constant speed compressor is stopped, and the small capacity constant speed compressor is continuously operated, and the total load and the low load side set value are set. A multi-room air conditioner provided with system capacity control means for opening and closing the bypass valve according to the difference between the air conditioner and the air conditioner. 5. When the total load is smaller than the low load side set value, the large capacity constant speed compressor is stopped, the small capacity constant speed compressor is continuously operated, and the total load and the low load side set value are set. A system that opens and closes the bypass valve in accordance with the difference between the above and when the total load is smaller than a predetermined value, the large-capacity constant-speed compressor stops, and the small-capacity constant-speed compressor starts and stops. The multi-room air conditioner according to claim 2 or 4, further comprising capacity control means. 6. When the total load is intermediate between the high load side set value and the low load side set value and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the small capacity The start of operation of the constant-speed compressor and the stop of the operation of the large-capacity constant-speed compressor are substantially simultaneous, and the stop of the operation of the small-capacity constant-speed compressor and the start of operation of the large-capacity constant-speed compressor are substantially the same. The multi-room air conditioner according to any one of claims 1, 2, 4, and 5, wherein the air conditioner is at the same time. 7. When the total load is intermediate between the high load side set value and the low load side set value and the small capacity constant speed compressor and the large capacity constant speed compressor start and stop alternately, the total load is 6. The multiple according to claim 1, wherein the ratio of the operation time of the small capacity constant speed compressor to the operation time of the large capacity constant speed compressor is controlled in accordance with the following. Room type air conditioner.