JPH0712417A - Air conditioner - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an air conditioner with excellent reliability that can respond to various changes in the required capacity of a plurality of indoor units and can always perform stable operation. [Structure] A plurality of indoor units are pipe-connected to a heat source unit via a distribution unit. The heat source unit is provided with a plurality of main water heat exchangers as a heat source side heat exchanger and a sub water heat exchanger having a smaller capacity than the main water heat exchanger, and a plurality of refrigerant flow paths to these water heat exchangers. Provide a two-way valve. Then, the pressure of the refrigerant discharged from the compressor is detected, and each two-way valve is opened / closed according to the detected pressure. By opening / closing each of the two-way valves, each of the main water heat exchanger and the sub water heat exchanger is selectively used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner provided with a heat source unit, a distribution unit, and a plurality of indoor units, each of which can simultaneously perform cooling and heating operations.

[0002]

2. Description of the Related Art In a multi-type air conditioner in which a plurality of indoor units are connected to a heat source unit via a distribution unit, a heat source unit is provided with a heat source side heat exchanger, for example, a plurality of water heat exchangers. By selectively using the exchanger, it is possible to meet the required capacity of each indoor unit.

[0003]

[Problems to be Solved by the Invention] There are various types and capacities of a plurality of indoor units, and their diversification tends to be more and more advanced. Along with this, the required capacity of each indoor unit changes variously. For this reason, it is becoming difficult to adequately cope with changes in the required capacity by merely using each water heat exchanger selectively.

The present invention takes the above circumstances into consideration,
It is an object of the present invention to provide an air conditioner which is capable of sufficiently responding to various changes in the required capacity of a plurality of indoor units and which is always reliable and excellent in reliability.

[0005]

The air conditioner according to the first aspect of the present invention includes a discharge port of a compressor, a four-way valve, main water heat exchangers, flow rate adjusting valves, decompressors for cooling, and indoor heat exchange. Of the compressor, the two-way valve for each cooling cycle, and the suction port of the compressor in order, and the auxiliary water heat exchanger in parallel with the four-way valve and each of the main water heat exchangers. Refrigeration by sequentially connecting the discharge port, two-way valve for each heating cycle, each indoor heat exchanger, each flow control valve, pressure reducing device for heating, each main water heat exchanger, four-way valve, and suction port of the compressor. Make up a cycle.

The air conditioner of the second invention comprises a discharge port of a compressor, a four-way valve, each water heat exchanger, each flow control valve, each cooling decompressor, each indoor heat exchanger, and each cooling cycle two. The one-way valve and the suction port of the compressor are sequentially connected by piping, and a bypass pipe is partially connected in parallel to one of the water heat exchangers, and the discharge port of the compressor and each heating device are connected. Two-way valve for cycle, each indoor heat exchanger, each flow control valve, pressure reducer for heating,
The water heat exchanger, the four-way valve, and the suction port of the compressor are sequentially connected by piping to form a refrigeration cycle.

The air conditioner of the third aspect of the invention comprises means for comparing one of the indoor units with the required cooling capacity and the required heating capacity for determining one of the cooling system operation mode and the heating system operation mode, and the cooling system. When determining the operation mode, the refrigerant discharged from the compressor is passed through at least one of the main water heat exchangers or the sub water heat exchanger, and the refrigerant passing through the water heat exchanger is exchanged with the indoor heat of the indoor unit on the cooling request side. And returns to the compressor, a part of the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is transferred to the indoor unit of the indoor unit on the cooling request side. A means for performing simultaneous cooling / warming operation of the cooling system by merging with the flow of refrigerant to the heat exchanger, and when determining the heating system operation mode, the refrigerant discharged from the compressor is used for indoor heat of the indoor unit on the heating request side. Pass through the exchanger,
The refrigerant passing through the indoor heat exchanger is passed through at least one of the main water heat exchangers and returned to the compressor, and a part of the refrigerant passing through the indoor heat exchanger of the indoor unit on the heating request side is transferred to the cooling request side. Means for returning to the compressor by passing through the indoor heat exchanger of the indoor unit, and executing cold / warm operation of the heating system.

The air conditioner of the fourth aspect of the present invention comprises means for comparing one of the indoor units with the required cooling capacity and the required heating capacity to determine one of the cooling system operation mode and the heating system operation mode, and the cooling system. At the time of determining the operation mode, the refrigerant discharged from the compressor is passed through at least one of the water heat exchangers or a part of the one water heat exchanger, and the refrigerant passing through the water heat exchangers of the indoor unit on the cooling request side is passed. The refrigerant is passed through the indoor heat exchanger and returned to the compressor, and a part of the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is transferred to the room on the cooling request side. A unit that joins the flow of the refrigerant to the indoor heat exchanger of the unit to execute the cooling / warming operation of the cooling system, and the refrigerant discharged from the compressor of the indoor unit on the heating request side when the heating system operation mode is determined. Through the indoor heat exchanger, The refrigerant that has passed through the exchanger is passed through at least one of the water heat exchangers and returned to the compressor, and a part of the refrigerant that has passed through the indoor heat exchanger of the indoor unit on the heating request side is indoors in the indoor unit on the cooling request side. And a means for returning to the compressor through the heat exchanger and executing the cold / warm operation of the heating system.

In addition to the configuration of the third aspect of the invention, the air conditioner of the fifth aspect of the invention includes a plurality of means for detecting the pressure of the refrigerant discharged from the compressor and a plurality of cooling / warming simultaneous operations of the cooling system. If the indoor unit simultaneously performs the cooling operation, when the detected pressure is equal to or higher than the set value, the flow of the refrigerant to each main water heat exchanger is selectively controlled according to the detected pressure, and when the detected pressure is equal to or lower than the set value. A means for circulating the refrigerant only in the auxiliary water heat exchanger to cut off the refrigerant flow to each main water heat exchanger,
In the simultaneous cooling / warming operation of the cooling system, if one indoor unit independently executes the cooling operation, when the detected pressure is equal to or higher than the set value, the circulation of the refrigerant to each main water heat exchanger is performed according to the detected pressure. Selective control, when the detected pressure is less than or equal to a set value and the state continues for a predetermined time, a means for causing the refrigerant to flow only to the auxiliary water heat exchangers and cutting off the refrigerant flow to each main water heat exchanger. Prepare

In addition to the structure of the fourth aspect of the invention, the air conditioner of the sixth aspect of the invention includes a plurality of means for detecting the pressure of the refrigerant discharged from the compressor and a plurality of cooling / warming simultaneous operations of the cooling system. If the indoor units simultaneously execute the cooling operation, the refrigerant flow to each water heat exchanger is selectively controlled according to the detected pressure when the detected pressure is equal to or higher than the set value, and 1 is set when the detected pressure is equal to or lower than the set value. A means for circulating the refrigerant only in a part of one of the water heat exchangers to block the circulation of the refrigerant to the other water heat exchanger, and one indoor unit independently performs the cooling operation during simultaneous cooling / warming operation of the cooling system. If it is executed, the flow of the refrigerant to each water heat exchanger is selectively controlled according to the detected pressure when the detected pressure is equal to or higher than the set value, and one is set when the state where the detected pressure is equal to or lower than the set value is continued for a predetermined time. Refrigerant only on a part of the water heat exchanger By threaded comprises means for blocking the flow of refrigerant to the other water heat exchanger.

[0011]

In the air conditioner of the first invention, the compressor discharge port, the four-way valve, each main water heat exchanger, each flow control valve, each cooling decompressor, each indoor heat exchanger, each cooling cycle The two-way valve and the suction port of the compressor are sequentially connected by piping, and the auxiliary water heat exchanger is connected by piping in parallel with the four-way valve and each main water heat exchanger to form a cooling cycle. In addition, the discharge port of the compressor, the two-way valve for each heating cycle, each indoor heat exchanger, each flow rate control valve, the heating decompressor, each main water heat exchanger, the four-way valve, and the suction port of the compressor in sequence. Connect the pipes to form a heating cycle.

In the air conditioner of the second invention, the discharge port of the compressor, the four-way valve, each water heat exchanger, each flow rate adjusting valve, each cooling decompressor, each indoor heat exchanger, and each cooling cycle dual A one-way valve and a suction port of a compressor are sequentially connected by piping, and a bypass pipe is partially connected in parallel to one of the water heat exchangers to form a cooling cycle. In addition, the discharge port of the compressor, the two-way valve for each heating cycle, each indoor heat exchanger, each flow control valve, the heating pressure reducer, each water heat exchanger, the four-way valve, and the suction port of the compressor are sequentially piped. Connect and form a heating cycle.

In the air conditioner of the third aspect of the present invention, one of the cooling system operation mode and the heating system operation mode is determined by comparing the required cooling capacity and the required heating capacity of each indoor unit. When the cooling system operation mode is determined, the refrigerant discharged from the compressor is passed through at least one of the main water heat exchangers or the sub water heat exchangers, and the refrigerant passing through the water heat exchangers is fed into the indoor unit of the cooling request side. While passing through the heat exchanger and returning to the compressor, a part of the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is transferred to the indoor unit on the cooling request side. The cooling / warming simultaneous operation of the cooling system is executed by merging with the flow of the refrigerant to the indoor heat exchanger. When the heating system operation mode is determined, the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is passed through at least one of the main water heat exchangers. Cooling / Warming of the heating system is returned to the compressor, and part of the refrigerant that has passed through the indoor heat exchanger of the indoor unit on the heating request side is returned to the compressor by passing through the indoor heat exchanger of the indoor unit on the cooling request side. Carry out driving.

In the air conditioner of the fourth aspect of the present invention, one of the cooling system operation mode and the heating system operation mode is determined by comparing the required cooling capacity and the required heating capacity of each indoor unit. When the cooling system operation mode is determined, the refrigerant discharged from the compressor is passed through at least one of the water heat exchangers or a part of the water heat exchangers, and the refrigerant passing through the water heat exchangers is cooled to the indoor unit on the cooling request side. While returning to the compressor through the indoor heat exchanger, a part of the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is cooled on the cooling request side. The cooling / warming operation of the cooling system is executed by merging with the flow of the refrigerant to the indoor heat exchanger of the indoor unit. When the heating system operation mode is determined, the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is passed through at least one of the water heat exchangers for compression. Cooling / warm operation of the heating system while returning it to the compressor and returning some of the refrigerant that has passed through the indoor heat exchanger of the indoor unit on the heating request side to the compressor through the indoor heat exchanger of the indoor unit on the cooling request side. To execute.

In the air conditioner of the fifth aspect of the present invention, when the plurality of indoor units simultaneously perform the cooling operation during the simultaneous cooling / warming operation of the cooling system, when the pressure of the refrigerant discharged from the compressor is equal to or higher than the set value, the discharged refrigerant is discharged. Selectively controls the circulation of the refrigerant to each main water heat exchanger according to the pressure, and when the discharge refrigerant pressure is less than or equal to the set value, the refrigerant is circulated only to the auxiliary water heat exchanger and the refrigerant to each main water heat exchanger. Cut off distribution. Cooling system /
If one indoor unit performs the cooling operation independently during the warm simultaneous operation, the refrigerant flow to each main water heat exchanger is selectively controlled according to the detected pressure when the compressor discharge refrigerant pressure is equal to or higher than the set value. When the pressure of the discharged refrigerant is equal to or lower than the set value for a predetermined time, the refrigerant is circulated only in the auxiliary water heat exchangers and the refrigerant is blocked from flowing to each main water heat exchanger.

In the air conditioner of the sixth aspect of the present invention, when the plurality of indoor units simultaneously perform the cooling operation during the simultaneous cooling / warming operation of the cooling system, when the pressure of the refrigerant discharged from the compressor is equal to or higher than the set value, the refrigerant discharged from the compressor is discharged. The flow of the refrigerant to each water heat exchanger is selectively controlled according to the pressure, and when the discharge refrigerant pressure is equal to or less than the set value, the refrigerant is circulated to only one part of the water heat exchanger and the other water heat exchangers. Block the flow of refrigerant. When one indoor unit independently performs cooling operation during simultaneous cooling / warming operation of the cooling system, when the refrigerant discharge pressure of the compressor is equal to or higher than the set value, the refrigerant for each main water heat exchanger is corresponding to the refrigerant discharge pressure. Is selectively controlled, and when the discharge refrigerant pressure is equal to or lower than the set value, the refrigerant is circulated to only a part of one water heat exchanger and the refrigerant is blocked from flowing to the other water heat exchangers.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a distribution unit B is connected to a heat source unit A through three pipes W, G and S, and a plurality of indoor units C ₁ , C ₂ and C are connected to the distribution unit B.
Connect ₃ and C ₄ by piping. Liquid refrigerant passes through the pipe W, high-pressure gas refrigerant passes through the pipe G, and low-pressure gas refrigerant passes through the pipe S.

The heat source unit A has a compressor 1. The compressor 1 has two variable capacity compressors 1a and 1b housed in a common casing. This compressor 1
The discharge port of a is connected to the high pressure side pipe 2, and the discharge port of the compressor 1b is connected to the high pressure side pipe 2 via the check valve 3. Further, the low-pressure side pipe 20 is connected to the suction ports of the compressors 1a and 1b.

A main water heat exchanger 5a, which is a heat source side heat exchanger, is connected to the high pressure side pipe 2 through a neutral side flow passage of a four way valve 4.
5b and 5c are respectively connected to one end, and the other ends of the main water heat exchangers 5a, 5b and 5c are connected via two-way valves 6, 7 and 8, respectively, and further, a check valve 9, a two-way valve 10 and a receiving valve. A liquid valve (liquid tank) 11 and a dryer 12 are sequentially connected to a packed valve 13. A series circuit of a two-way valve 14, a heating expansion valve 15, and a check valve 16 is connected in parallel with the series circuit of the check valve 9 and the two-way valve 10.

A packed valve 18 is connected to the high pressure side pipe 2 via a dryer 17.

An accumulator 21 is attached to the low pressure side pipe 20.
And the service valve 23 is connected via the dryer 22.

A pressure sensor 25 is attached to the high-pressure side pipe 2 via a capillary tube 24. Main water heat exchanger 5a,
One end of each of 5b and 5c is connected to the pipe between the accumulator 21 and the dryer 22 via the switching side flow path of the four-way valve 4. A capillary tube 26 is connected to the four-way valve 4 in order to apply an operating pressure.

The packed valve 13 is connected to a pipe W, and the pipe W has an electronic flow rate adjusting valve (pulse motor valve; hereinafter abbreviated as PMV) 41, 51, 6 of the distribution unit B.
1, 71 through the cooling expansion valves 42, 52, 62, 72
Connect. Check valves 43, 53, 63, 73 are connected in parallel with the expansion valves 42, 52, 62, 72, respectively.

The expansion valves 42, 52, 62, 72 are provided with indoor heat exchangers 44, 5 of the indoor units C ₁ , C ₂ , C ₃ , C ₄ , respectively.
4, 64 and 74 are connected.

In the indoor heat exchangers 44, 54, 64, 74,
Two-way valves 45, 55, 6 for cooling cycle of distribution unit B
The pipe S is connected through 5,75. This pipe S is connected to the service valve 23.

In the indoor heat exchangers 44, 54, 64, 74,
Two-way valves 46, 56, 6 for heating cycle of distribution unit B
The pipe G is connected via 6,76. This pipe G is connected to the packed valve 18.

One end of the auxiliary water heat exchanger 5d is connected to the high-pressure side pipe 2 through a parallel circuit of the two-way valve 27 and the capillary tube 28, and the other end of the auxiliary water heat exchanger 5d is connected to the check valve 9.
To the two-way valve 10. Auxiliary water heat exchanger 5
The capacity of d is smaller than that of the main water heat exchangers 5a, 5b, 5c.

A water supply unit 30 is provided in each of the main water heat exchangers 5a, 5b, 5c and the sub water heat exchanger 5d through a water pipe.
Connect. Each water heat exchanger 5a, 5b, 5c, 5d is
This is for exchanging the heat of the inflowing refrigerant and the heat of the water supplied from the water supply unit 30, and is of a double pipe type in which a pipe through which the refrigerant passes and a pipe through which the water passes are arranged coaxially.

The control circuit is shown in FIG.

The outdoor unit A includes an outdoor control section 100 composed of a microcomputer and its peripheral circuits. In the outdoor control unit 100, the inverter circuit 101,
102, four-way valve 4, two-way valve 6, 7, 8, 10, 14, 2
7, the pressure sensor 25, and the water supply unit 30 are connected.

The inverter circuits 101 and 102 rectify the voltage of the AC power supply 103, convert it into a voltage of a predetermined frequency (and level) according to a command from the outdoor control unit 100, and output it. This output is compressor motor 1aM, 1bM
Drive power.

The distribution unit B has a multi-control unit 110 composed of a microcomputer and its peripheral circuits. PMV 41, 51, 6
1,71, two-way valve for cooling cycle 45,55,65,7
5, and two-way valves 46, 56, 66, 7 for heating cycle
Connect 6

The indoor units C ₁ , C ₂ , C ₃ and C ₄ are
An indoor control unit 120 including a microcomputer and its peripheral circuits is provided. These indoor control units 12
0, a remote control type operation unit (hereinafter abbreviated as a remote controller) 121 and an indoor temperature sensor 122.
Connect.

A multi-control unit 110 is connected to the outdoor control unit 100 by a signal line, and each multi-control unit 110 is connected to each indoor control unit 120 by a signal line.

Each indoor control section 120 has the following functional means.

[1] Means for sending to the multi-control unit 110 a request for the cooling operation mode or a request for the heating operation mode based on the operation of the remote controller 121.

[2] The multi-control unit 110 uses the difference between the room temperature set by the remote controller 121 and the temperature detected by the room temperature sensor 122 as the required cooling capacity (in the cooling operation mode) or the required heating capacity (in the heating operation mode). Means to send to.

The multi-control unit 110 and the outdoor control unit 10
0 has the following functional means.

[1] Indoor units C ₁ , C ₂ , C ₃ , C
Means for determining either one of the cooling system operation mode and the heating system operation mode by comparing the total required cooling capacity and the total required heating capacity of _{4 above} . For example, if the total required cooling capacity is larger than the total required heating capacity, the cooling system operation mode is determined. If the total required heating capacity is approximately the same as or larger than the total required cooling capacity, the heating system operation mode is determined.

[2] When determining the cooling system operation mode, the refrigerant discharged from the compressors 1a, 1b is used as the main water heat exchangers 5a, 5b, 5c.
Through at least one of the sub-water heat exchanger 5d, the refrigerant having passed through the water heat exchanger is passed through the indoor heat exchanger of the indoor unit on the cooling request side and returned to the compressors 1a, 1b,
Part of the refrigerant discharged from the compressors 1a and 1b is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is transferred to the indoor heat exchanger of the indoor unit on the cooling request side. Means to join the flow and execute simultaneous cooling / warming operation of the cooling system.

[3] Means for controlling the number of operating compressors 1a and 1b and the operating frequency (the output frequency of the inverter circuits 101 and 102) in accordance with the total required cooling capacity during the simultaneous cooling / warming operation of the cooling system.

[4] In the simultaneous cooling / warming operation of the cooling system, when a plurality of indoor units simultaneously perform the cooling operation, when the detected pressure Pd of the pressure sensor 25 is equal to or higher than the set value P _2, the detected pressure Pd is determined. Main water heat exchangers 5a, 5b, 5c
Is selectively controlled (open / close control of the two-way valves 6, 7, and 8), and when the detected pressure Pd is equal to or less than the set value P ₂ , the refrigerant is circulated only through the auxiliary water heat exchanger 5d to generate the main water heat. Means for interrupting the flow of the refrigerant to the exchangers 5a, 5b, 5c.

[5] In the simultaneous cooling / warming operation of the cooling system, 1
When the two indoor units independently perform the cooling operation, when the pressure Pd detected by the pressure sensor 25 is equal to or higher than the set value P ₁ , the main water heat exchangers 5a, 5b, 5c corresponding to the detected pressure Pd.
When the detected pressure Pd is kept below the set value P ₁ for a predetermined time t ₁ by selectively controlling the flow of the refrigerant to the main water heat exchangers 5a and 5d, the refrigerant is flowed only to the auxiliary water heat exchanger 5d.
Means for blocking the flow of the refrigerant to b and 5c.

[6] When determining the heating system operation mode, the refrigerant discharged from the compressors 1a and 1b is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is subjected to main water heat exchange. At least one of the reactors 5a, 5b, 5c or the auxiliary water heat exchanger 5d is returned to the compressors 1a, 1b, and a part of the refrigerant passing through the indoor heat exchanger of the indoor unit on the heating request side is cooled on the cooling request side. Means for returning to the compressors 1a, 1b through the indoor heat exchanger of the indoor unit, and executing the cold / warm operation of the heating system.

[7] Means for controlling the number of operating compressors 1a and 1b and the operating frequency in accordance with the total required heating capacity during simultaneous cooling / warming operation of the heating system.

[8] During simultaneous cold / warm operation of the heating system, the main water heat exchanger 5 is responsive to the pressure Pd detected by the pressure sensor 25.
Means for selectively controlling the flow of the refrigerant to the a, 5b, and 5c and cutting off the flow of the refrigerant to the auxiliary water heat exchanger 5d.

Next, the operation of the above configuration will be described.

It is assumed that the indoor unit C ₁ is in the cooling operation mode, the indoor unit C ₂ is in the cooling operation mode, the indoor unit C ₃ is in the heating operation mode, and the indoor unit C ₄ is not in operation. Then, it is assumed that the total required cooling capacity is larger than the total required heating capacity.

In this case, the cooling system operation mode is determined,
The four-way valve 4 of the heat source unit A is in the neutral position, at least one of the two-way valves 6, 7, 8 or the two-way valve 27 is open,
The two-way valve 10 opens and the two-way valve 14 closes.

In the distribution unit B, PMVs 41, 51,
61 is opened and the PMV 71 is closed, and among the two-way valves 45, 55, 65, 75 for the cooling cycle, the two-way valves 45, 55 corresponding to the indoor unit on the cooling request side are opened and the two-way valves 65, 75 are closed. , And two-way valve for heating cycle 4
Of the 6, 56, 66, 76, the two-way valve 66 corresponding to the indoor unit on the heating request side opens and the two-way valves 46, 56, 76 are opened.
Closes.

In FIG. 1, the closed valve is shown in black.

Therefore, the refrigerant discharged from the compressors 1a and 1b passes through the four-way valve 4 and the main water heat exchangers 5a and 5b.
At least one of b and 5c or the auxiliary water heat exchanger 5d flows. The refrigerant passing through the water heat exchanger passes through the indoor heat exchangers 44 and 54 of the indoor units C ₁ and C ₂ on the cooling request side and returns to the compressors 1a and 1b. At the same time, part of the refrigerant discharged from the compressors 1a and 1b is partially heated by the indoor unit C on the heating request side.
_The refrigerant that has flowed to the indoor heat exchanger 64 of 3 and has passed through the indoor heat exchanger 64 joins the flow of the refrigerant to the indoor heat exchangers 44 and 54 on the cooling request side.

That is, at least one of the main water heat exchangers 5a, 5b and 5c or the sub water heat exchanger 5d is a condenser, the indoor heat exchangers 44 and 54 are evaporators, and the indoor heat exchanger 64 is a condenser. Functioning, cooling operation with indoor units C ₁ and C ₂ ,
A heating operation is performed in the indoor unit C ₃ .

In this case, the indoor units C ₁ and C on the cooling side
Part of the heat absorbed by ₂ will be used as the heat for heating the indoor unit C ₃ on the heating side.

By the way, when the number of operating cooling side indoor units is two or more, the control shown in FIG. 3 is performed. That is, the detected pressure Pd of the pressure sensor 25 (compressors 1a, 1b
Is the set value P ₂ (for example, 17 kg / cm ² )
In the normal cooling load as the above, it executes the control pattern SPV1, in the small cooling load sensing pressure Pd is below the set value P ₂ executes a control pattern of SPV2.

In the control pattern of SPV1, the detected pressure P
The two-way valves 6 and 7 are opened and closed according to d, thereby selectively controlling the flow of the refrigerant to the main water heat exchangers 5a and 5b, and the two-way valve 8 is opened to supply the refrigerant to the main water heat exchanger 5c. Distribute. The two-way valve 27 is closed to shut off the flow of the refrigerant to the auxiliary water heat exchanger 5d.

In the control pattern of SPV2, the two-way valve 6,
7 and 8 are closed to block the flow of the refrigerant to the main water heat exchangers 5a, 5b and 5c, and the two-way valve 27 is opened to flow the refrigerant only to the auxiliary water heat exchanger 5d. In executing the control pattern of SPV2, the detected pressure Pd is set to the set value P ₄ (for example,
When the detected pressure Pd exceeds the set value P ₄ , the process is continued when the pressure is 23 Kg / cm ² ) or less, and the control pattern of SPV1 is started.

Thus, the plurality of main water heat exchangers 5a, 5
In addition to b, 5c, a sub-water heat exchanger 5d having a smaller capacity than that of the main water heat exchanger is provided, and the main water heat exchangers 5a, 5b, 5c are selectively used for normal cooling load. A subwater heat exchanger 5 that works and has a small capacity for small cooling loads.
By operating only d, it is possible to maintain the optimum condensing capacity commensurate with the cooling load.

The number of operating cooling side indoor units is 1
In the case of a table, the control shown in FIG. 4 is performed. That is, the control pattern of SPV3 is executed in the normal cooling load where the detected pressure Pd is equal to or higher than the set value P ¹ (for example, 10 kg / cm ² ), and that state is set in the small cooling load where the detected pressure Pd is equal to or lower than the set value P _1. Continues for a predetermined time t ₁ (for example, 3 minutes) based on the time count t, the control pattern of SPV4 is executed.

In the control pattern of SPV3, the detected pressure P
The two-way valves 6 and 7 are opened and closed according to d, thereby selectively controlling the flow of the refrigerant to the main water heat exchangers 5a and 5b, and the two-way valve 8 is opened to supply the refrigerant to the main water heat exchanger 5c. Distribute. The two-way valve 27 is closed to shut off the flow of the refrigerant to the auxiliary water heat exchanger 5d.

In the control pattern of SPV4, the two-way valve 6,
7 and 8 are closed to block the flow of the refrigerant to the main water heat exchangers 5a, 5b and 5c, and the two-way valve 27 is opened to flow the refrigerant only to the auxiliary water heat exchanger 5d. In executing the control pattern of SPV4, the detected pressure Pd is set to the set value P ₃ (for example,
18 kg / cm ²⁾ continuously in the following cases, and ends when the sensed pressure Pd exceeds the set value P ₃ moves to control the pattern of SPV3.

Thus, the main water heat exchangers 5a, 5b, 5c are selectively operated for the normal cooling load, and only the sub-water heat exchanger 5d having a small capacity is operated for the small cooling load. , The optimum condensing capacity corresponding to the cooling load can be maintained. Note that the cooling load is originally small during the isolated operation, and therefore tends to easily enter the control pattern of the SPV 4 using the auxiliary water heat exchanger 5d. Therefore, the predetermined time t
The factor of ₁ is added to reduce the water heat exchanger capacity only when the small cooling load is certain.

Therefore, even if the types and capacities of the indoor units tend to diversify, various changes in the required capacity of each indoor unit can be sufficiently dealt with, and stable operation is always possible.

Regarding the switching of the water heat exchanger capacity,
Since it is performed by opening and closing the two-way valve 27 instead of switching the four-way valve 4, there is no sudden refrigerant flow between the high pressure side and the low pressure side unlike when switching the four-way valve 4, and therefore unpleasant refrigerant noise is generated. Can be prevented. Particularly, since the heat source unit A is installed in the building, it is important to prevent unpleasant noise from the viewpoint of reliability.

Next, it is assumed that the request of the indoor unit C ₁ is the heating operation mode, the request of the indoor unit C ₂ is the heating operation mode, the request of the indoor unit C ₃ is the cooling operation mode, and the operation of the indoor unit C ₄ is stopped. . Then, it is assumed that the total required heating capacity is substantially the same as or larger than the total required cooling capacity.

In this case, the heating system operation mode is determined,
The four-way valve 4 of the heat source unit A is switched, and the two-way valves 6, 7,
8 or at least one or two-way valve 27 open,
0 closes and the two-way valve 14 opens.

In the distribution unit B, PMVs 41, 51,
61 is opened and the PMV 71 is closed, and the two-way valves 46, 56 corresponding to the indoor unit on the heating request side of the two-way valves 46, 56, 66, 76 for the heating cycle are opened and the two-way valves 66, 76 are closed. , And the two-way valve 45 for the cooling cycle,
Of the 55, 65 and 75, the two-way valve 65 corresponding to the indoor unit on the cooling request side is opened and the two-way valves 45, 55 and 75 are closed.

Therefore, the refrigerant discharged from the compressors 1a, 1b flows into the indoor heat exchangers 44, 54 of the indoor units C ₁ , C ₂ on the heating request side, and the refrigerant passing through the indoor heat exchangers 44, 54 is the main water. At least one of the heat exchangers 5a, 5b, 5c or the sub-water heat exchanger 5d is passed through, and further, the four-way valve 4 is returned to the compressors 1a, 1b. At the same time, the indoor heat exchanger 4
A part of the refrigerant passing through 4, 54 flows into the indoor heat exchanger 64 of the indoor unit C ₃ on the cooling request side, and the indoor heat exchanger 64
After passing through, the refrigerant returns to the compressors 1a and 1b.

That is, the indoor heat exchangers 44 and 54 are condensers, at least one of the main water heat exchangers 5a, 5b and 5c or the sub water heat exchanger 5d is an evaporator, and the indoor heat exchanger 64 is an evaporator. The indoor units C ₁ and C ₂ perform heating operation and the indoor unit C ₃ performs cooling operation.

In this case, the heat absorption of the cooling side indoor unit C ₃ is used as the heating heat of the heating side indoor units C ₁ and C ₂ .

Further, the two-way valves 6, 7, 8 are opened and closed according to the pressure Pd detected by the pressure sensor 25, thereby selectively controlling the flow of the refrigerant to the main water heat exchangers 5a, 5b, 5c. The two-way valve 27 is closed to shut off the flow of the refrigerant to the auxiliary water heat exchanger 5d.

In this way, the main water heat exchangers 5a, 5b, 5
By selectively operating c, it is possible to maintain the optimum evaporation capacity commensurate with the heating load.

Next, a second embodiment of the present invention will be described. In the drawings, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

Here, as shown in FIG. 5, one end of the bypass 80 is connected to the middle portion of the main water heat exchanger 5c, and the other end of the bypass 80 is connected between the two-way valve 8 and the check valve 9. Connect to the tube. Then, the two-way valve 81 is provided in the bypass 80.
With the adoption of the bypass 80 and the two-way valve 81, the first
The auxiliary water heat exchanger 5d, the two-way valve 27, and the capillary tube 28 in the embodiment are removed.

The control circuit has a two-way valve 8 instead of the two-way valve 27.
1 is provided, and other configurations are the same as those in FIG.

The operation will be described. The flow chart showing the control is shown in FIG. 3 except that the two-way valve 27 is replaced with the two-way valve 81.
And the same as FIG.

When the number of operating cooling side indoor units is two or more, the pressure Pd detected by the pressure sensor 25 (the compressor 1a,
1b discharge refrigerant pressure) is set value P ₂ (for example, 17 kg / cm
In the normal cooling load as a ²⁾ or more, performs the control pattern SPV1, in the small cooling load sensing pressure Pd is below the set value P ₂ executes a control pattern of SPV2.

In the control pattern of SPV1, the detected pressure P
The two-way valves 6 and 7 are opened and closed according to d, thereby selectively controlling the flow of the refrigerant to the main water heat exchangers 5a and 5b, and the two-way valve 8 is opened to supply the refrigerant to the main water heat exchanger 5c. Distribute. The two-way valve 81 is closed to shut off the bypass 80.

In the control pattern of SPV2, the two-way valve 6,
7, 8 are closed to block the flow of the refrigerant to the main water heat exchangers 5a, 5b, 5c, and the two-way valve 81 is opened to bypass 80.
To conduct. When the bypass 80 is conducted, the refrigerant flows only in a part of the main water heat exchanger 5c. The execution of the control pattern of SPV2 continues when the detected pressure Pd is less than or equal to the set value P ₄ (for example, 23 kg / cm ² ), and ends when the detected pressure Pd exceeds the set value P ₄ and the control of SPV1 is performed. Move on to the pattern.

As described above, by selectively operating the main water heat exchangers 5a, 5b, 5c for the normal cooling load and by operating only a part of the main water heat exchanger 5c for the small cooling load, It is possible to maintain the optimum condensing capacity corresponding to the cooling load.

The number of operating cooling-side indoor units is 1
In the case of stand-alone operation, SPV3 is applied under normal cooling load where the detected pressure Pd exceeds the set value P ¹ (for example, 10 kg / cm ² ).
Control pattern is executed, and the detected pressure Pd is the set value P.
_With a small cooling load of ₁ or less, the control pattern of SPV4 is executed when the state continues for a predetermined time t ₁ (for example, 3 minutes) based on the time count t.

In the control pattern of SPV3, the detected pressure P
The two-way valves 6 and 7 are opened and closed according to d, thereby selectively controlling the flow of the refrigerant to the main water heat exchangers 5a and 5b, and the two-way valve 8 is opened to supply the refrigerant to the main water heat exchanger 5c. Distribute. The two-way valve 81 is closed to shut off the bypass 80.

In the control pattern of SPV4, the two-way valve 6,
7, 8 are closed to block the flow of the refrigerant to the main water heat exchangers 5a, 5b, 5c, and the two-way valve 81 is opened to bypass 80.
To conduct. When the bypass 80 is conducted, the refrigerant flows only in a part of the main water heat exchanger 5c. Execution of the control pattern of the SPV4 continues when the sensed pressure Pd is equal to or less than the set value P ₃ (e.g. 18 Kg / cm ^2), control ends when the sensed pressure Pd exceeds the set value P ₃ SPV3 Move on to the pattern.

Thus, the plurality of main water heat exchangers 5a, 5
In addition to the provision of b and 5c, a part of one of the main water heat exchangers can be used, and the main water heat exchangers 5a, 5b and 5c are selectively operated for normal cooling load, By operating only a part of the main water heat exchanger 5c with respect to the cooling load, it is possible to maintain the optimum condensing capacity corresponding to the cooling load. Note that the cooling load is originally small during the isolated operation, and therefore tends to easily enter the control pattern of the SPV 4 that uses only a part of the main water heat exchanger 5c. Therefore, the water heat exchanger capacity is reduced only when the small cooling load is certain by adding a determination factor for the predetermined time t ₁ .

Therefore, even if the types and capacities of the indoor units tend to be diversified, various changes in the required capacity of each indoor unit can be sufficiently dealt with, and stable operation can always be performed.

Regarding the switching of the water heat exchanger capacity,
Since it is performed by opening and closing the two-way valve 81 instead of switching the four-way valve 4, there is no abrupt refrigerant flow between the high pressure side and the low pressure side unlike when switching the four-way valve 4, and therefore unpleasant refrigerant noise is generated. Can be prevented. Particularly, since the heat source unit A is installed in the building, it is important to prevent unpleasant noise from the viewpoint of reliability.

[0088]

As described above, according to the present invention, the air conditioners of claim 1, claim 3, and claim 5 have a plurality of main water heat exchangers and a main water heat exchanger thereof. Since a sub-water heat exchanger with a small capacity is provided, it is possible to sufficiently cope with various changes in the required capacity of multiple indoor units,
Stable operation is always possible and reliability is improved.

The air conditioners of claim 2, claim 4, and claim 6 are provided with a plurality of main water heat exchangers, and one of the main water heat exchangers is selectively used. Therefore, it is possible to sufficiently cope with various changes in the required capacity of the plurality of indoor units, and it is possible to always perform stable operation and improve reliability.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a control circuit according to the first embodiment.

FIG. 3 is a flowchart for explaining the operation of the first embodiment when operating a plurality of units.

FIG. 4 is a flowchart for explaining the operation of the first embodiment during islanding.

FIG. 5 is a configuration diagram of a refrigeration cycle according to a second embodiment of the present invention.

[Explanation of symbols]

A ... Heat source unit, B ... Distribution unit, C ₁ , C ₂ , C
₃ ... Indoor unit, 1a, 1b ... Compressor, 2 ... High-pressure side piping, 20 ... Low-pressure side piping, 4 ... Four-way valve, 5a, 5b, 5c
... Main water heat exchanger, 5d ... Sub water heat exchanger, 44,54,6
4, 74 ... Indoor heat exchanger, 25 ... Pressure sensor.

Claims (6)

[Claims] 1. A compressor, a four-way valve, a plurality of main water heat exchangers,
Auxiliary water heat exchanger with smaller capacity than these main water heat exchangers,
A heat source unit provided with a heating pressure reducer, a plurality of flow rate control valves, a plurality of cooling pressure reducers, a plurality of cooling cycle two-way valves, and a distribution unit having a plurality of heating cycle two-way valves, respectively. Multiple indoor units with indoor heat exchanger, compressor discharge port, four-way valve, each main water heat exchanger, each flow control valve, each cooling decompressor, each indoor heat exchanger, each cooling cycle two Connect the one-way valve and the suction port of the compressor in order, and connect the four-way valve and each main water heat exchanger in parallel with the auxiliary water heat exchanger, and connect the compressor discharge port and each heating cycle. Two-way valve, each indoor heat exchanger, each flow control valve, heating decompressor, each main water heat exchanger, four-way valve, and a refrigeration cycle in which the suction ports of the compressor are sequentially connected by piping. And an air conditioner. 2. A heat source unit provided with a compressor, a four-way valve, a plurality of water heat exchangers, a heating decompressor, a plurality of flow control valves, a plurality of cooling decompressors, and a plurality of cooling cycle two-way valves. , A distribution unit provided with a plurality of heating cycle two-way valves, a plurality of indoor units each having an indoor heat exchanger, a compressor discharge port, a four-way valve, each water heat exchanger, each flow control valve, Each cooling decompressor, each indoor heat exchanger, each two-way valve for each cooling cycle, and the suction port of the compressor are connected in order by piping, and one of the water heat exchangers is partially connected. By-pass pipes are connected in parallel to each other, and the discharge port of the compressor, two-way valve for each heating cycle, each indoor heat exchanger, each flow control valve,
An air conditioner comprising: a heating decompressor, water heat exchangers, a four-way valve, and a refrigeration cycle in which suction ports of a compressor are sequentially connected by piping. 3. A compressor, a four-way valve, a plurality of main water heat exchangers,
Auxiliary water heat exchanger with smaller capacity than these main water heat exchangers,
A heat source unit provided with a heating pressure reducer, a plurality of flow rate control valves, a plurality of cooling pressure reducers, a plurality of cooling cycle two-way valves, and a distribution unit having a plurality of heating cycle two-way valves, respectively. A plurality of indoor units that have an indoor heat exchanger and make a request for either cooling or heating, and the required cooling capacity and required heating capacity of each indoor unit are compared, and the cooling system operation mode and heating system operation are performed. Means for determining one of the modes, and when determining the cooling system operation mode, the refrigerant discharged from the compressor is passed through at least one of the main water heat exchangers or the auxiliary water heat exchanger,
The refrigerant passed through the water heat exchanger is returned to the compressor by passing through the indoor heat exchanger of the indoor unit on the cooling request side, and a part of the refrigerant discharged from the compressor is transferred to the indoor heat exchanger of the indoor unit on the heating request side. Through the indoor heat exchanger to join the flow of the refrigerant to the indoor heat exchanger of the indoor unit on the cooling request side to execute the cooling / warming simultaneous operation of the cooling system and the heating system operation mode. At the time of determination, the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is passed through at least one of the main water heat exchangers and returned to the compressor. A means for performing a cooling / warming operation of the heating system by passing a part of the refrigerant passing through the indoor heat exchanger of the indoor unit on the heating request side through the indoor heat exchanger of the indoor unit on the cooling request side to the compressor. An air conditioner characterized by having and. 4. A heat source unit having a compressor, a four-way valve, a plurality of water heat exchangers, a heating decompressor, a plurality of flow rate adjusting valves, a plurality of cooling decompressors, and a plurality of cooling cycle two-way valves. , A distribution unit provided with a plurality of two-way valves for heating cycles, a plurality of indoor units each having an indoor heat exchanger, and a cooling system operation mode comparing the required cooling capacity and the required heating capacity of each indoor unit. And a means for determining one of the heating system operation modes, and at the time of determining the cooling system operation mode, the refrigerant discharged from the compressor is passed through at least one of the water heat exchangers or a part of the one water heat exchanger, The refrigerant passed through the water heat exchanger is returned to the compressor by passing through the indoor heat exchanger of the indoor unit on the cooling request side, and a part of the refrigerant discharged from the compressor is transferred to the indoor heat exchanger of the indoor unit on the heating request side. Through the indoor heat exchange The refrigerant that has passed through is combined with the refrigerant flow to the indoor heat exchanger of the indoor unit on the cooling request side, and means for executing the cooling / warming operation of the cooling system, and the discharge of the compressor when the heating system operation mode is determined. The refrigerant is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is passed through at least one of the water heat exchangers to be returned to the compressor. A part of the refrigerant that has passed through the indoor heat exchanger is passed through the indoor heat exchanger of the indoor unit on the cooling request side and returned to the compressor, and means for executing cold / warm operation of the heating system is provided. An air conditioner. 5. A compressor, a four-way valve, a plurality of main water heat exchangers,
Auxiliary water heat exchanger with smaller capacity than these main water heat exchangers,
A heat source unit provided with a heating pressure reducer, a plurality of flow rate control valves, a plurality of cooling pressure reducers, a plurality of cooling cycle two-way valves, and a distribution unit having a plurality of heating cycle two-way valves, respectively. A plurality of indoor units that have an indoor heat exchanger and make a request for either cooling or heating, and the required cooling capacity and required heating capacity of each indoor unit are compared, and the cooling system operation mode and heating system operation are performed. Means for determining one of the modes, and when determining the cooling system operation mode, the refrigerant discharged from the compressor is passed through at least one of the main water heat exchangers or the auxiliary water heat exchanger,
The refrigerant passed through the water heat exchanger is returned to the compressor by passing through the indoor heat exchanger of the indoor unit on the cooling request side, and a part of the refrigerant discharged from the compressor is transferred to the indoor heat exchanger of the indoor unit on the heating request side. Through the indoor heat exchanger to join the flow of the refrigerant to the indoor heat exchanger of the indoor unit on the cooling request side to execute the cooling / warming simultaneous operation of the cooling system and the heating system operation mode. At the time of determination, the refrigerant discharged from the compressor is passed through the indoor heat exchanger of the indoor unit on the heating request side, and the refrigerant passing through the indoor heat exchanger is passed through at least one of the main water heat exchangers and returned to the compressor. A means for performing a cooling / warming simultaneous operation of the heating system by passing a part of the refrigerant passing through the indoor heat exchanger of the indoor unit on the heating request side through the indoor heat exchanger of the indoor unit on the cooling request side to the compressor. The pressure of the refrigerant discharged from the compressor. And a plurality of indoor units simultaneously perform cooling operation during simultaneous cooling / warming operation of the cooling system, when the detected pressure is equal to or higher than a set value, the refrigerant for each main water heat exchanger is corresponding to the detected pressure. The flow of refrigerant is selectively controlled, and when the detected pressure is less than the set value, the refrigerant is circulated only to the auxiliary water heat exchanger to shut off the refrigerant flow to each main water heat exchanger, and the cooling / heating of the cooling system. In the simultaneous operation, if one indoor unit independently executes the cooling operation, when the detected pressure is equal to or higher than the set value, the refrigerant flow to each main water heat exchanger is selectively controlled according to the detected pressure to detect the detected pressure. Is equal to or less than a set value and when the state continues for a predetermined time, it is provided with means for cutting off the circulation of the refrigerant to each main water heat exchanger by circulating the refrigerant only in the auxiliary water heat exchanger. An air conditioner. 6. A heat source unit provided with a compressor, a four-way valve, a plurality of water heat exchangers, a heating decompressor, a plurality of flow rate adjusting valves, a plurality of cooling decompressors, and a plurality of cooling cycle two-way valves. , A distribution unit provided with a plurality of two-way valves for heating cycles, a plurality of indoor units each having an indoor heat exchanger, and a cooling system operation mode comparing the required cooling capacity and the required heating capacity of each indoor unit. And a means for determining one of the heating system operation modes, and at the time of determining the cooling system operation mode, the refrigerant discharged from the compressor is provided in at least one of the water heat exchangers or a part of the water heat exchanger connected to the bypass pipe. Pass the refrigerant through the water heat exchanger and return it to the compressor by passing it through the indoor heat exchanger of the indoor unit on the cooling request side, and part of the refrigerant discharged from the compressor is exchanged with the indoor heat of the indoor unit on the heating request side. Pass it through A means for joining the refrigerant that has passed through the indoor heat exchanger with the refrigerant flow to the indoor heat exchanger of the indoor unit on the cooling request side, and the refrigerant discharged from the compressor when the heating system operation mode is determined. Of the refrigerant that has passed through the indoor heat exchanger, passes through the indoor heat exchanger through at least one of the water heat exchangers, and returns to the compressor. A means for returning a part of the refrigerant to the compressor by passing it through the indoor heat exchanger of the indoor unit on the cooling request side, a means for detecting the pressure of the refrigerant discharged from the compressor, and a plurality of means for simultaneous cooling / warming operation of the cooling system. If the indoor unit of 5 simultaneously executes the cooling operation, when the detected pressure is equal to or higher than the set value, the flow of the refrigerant to each water heat exchanger is selectively controlled according to the detected pressure, and when the detected pressure is equal to or lower than the set value. Part of one water heat exchanger If the unit performs the cooling operation independently during the simultaneous cooling / warming operation of the cooling system, a means for circulating the refrigerant only for the minutes to cut off the refrigerant flow to other water heat exchangers When the pressure is above the set value, the flow of the refrigerant to each water heat exchanger is selectively controlled according to the detected pressure, and when the detected pressure is below the set value and the state continues for a predetermined time, one water heat exchange An air conditioner, comprising: a means for circulating the refrigerant only in a part of the vessel to block the circulation of the refrigerant to other water heat exchangers.