KR20220027563A - Multi-air conditioner for heating and cooling operations - Google Patents

Abstract

In accordance with the present invention, provided is a cooling/heating multi-air conditioner including: at least one cooling/heating indoor unit individually including an indoor heat exchanger; a cooling/heating outdoor unit including a compressor, an outdoor heat exchanger and a switching unit placed on a discharge side of the compressor to switch a flow of a refrigerant; and a distributor placed between the cooling/heating outdoor unit and the cooling/heating indoor unit to distribute the refrigerant to the cooling/heating indoor unit in accordance with the cooling or heating driving mode. The distributor includes: a low-pressure valve group releasing a low-temperature gas refrigerant from an indoor connection pipe connected to the cooling/heating indoor unit; and a high-pressure valve group releasing a high-temperature gas refrigerant to the indoor connection pipe connected to the cooling/heating indoor unit. Therefore, the present invention can provide a structure parallelly using at least two high-pressure and low-pressure valves to one single indoor unit connection port in a refrigerant distributor of a cooling/heating multi air conditioner using high-pressure and low-pressure valves. Moreover, a plurality of high-pressure and low-pressure valves connecting high-pressure and low-pressure pipes to the indoor unit are parallelly applied, and are selectively opened in accordance with a driving load, thus actively controlling the density of the refrigerant.

Description

Multi-air conditioner for heating and cooling operations }

The present invention relates to a heating/cooling multi-air conditioner, and more particularly, to a heating/cooling multi-air conditioner capable of variably distributing refrigerant by placing a plurality of valves in a high-pressure gas pipe and a low-pressure gas pipe connected to an outdoor unit.

In general, a multi-type air conditioner connects a plurality of indoor units to one outdoor unit, and uses each of the plurality of indoor units as a cooling unit or a heater while using the outdoor unit in common.

Recently, a plurality of outdoor units are connected and used in parallel to effectively respond to a cooling or heating load according to the number of indoor units operated.

A multi-air conditioner according to the related art includes a plurality of outdoor units, a plurality of indoor units, and a refrigerant pipe connecting the plurality of outdoor units and indoor units, wherein the plurality of outdoor units are a main outdoor unit and a plurality of sub units. It consists of an outdoor unit.

Each of the plurality of outdoor units includes a compressor for compressing low-temperature and low-pressure gaseous refrigerant to high-temperature and high-pressure, an outdoor heat exchanger for exchanging the circulated refrigerant with outdoor air, and a four-way valve for switching the refrigerant flow according to cooling or heating operation. is installed An expansion mechanism and an indoor heat exchanger for exchanging the circulated refrigerant with indoor air are installed in each of the plurality of indoor units.

In the multi-air conditioner according to the prior art configured as described above, the refrigerant compressed by the compressors of the main outdoor unit and the sub outdoor unit is sent to the outdoor heat exchanger by the four-way valve during the cooling operation, and the refrigerant passing through the outdoor heat exchanger is After being condensed by heat exchange with air, it is sent to the expansion device. The refrigerant expanded by the expansion mechanism flows into the indoor heat exchanger and evaporates while absorbing heat from the indoor air to cool the room.

Meanwhile, during the heating operation, the flow path is switched in the four-way valve, and the refrigerant discharged from the compressor sequentially passes through the four-way valve, an indoor heat exchanger, an outdoor linear expansion valve (LEV), and an outdoor heat exchanger. to heat

For example, Japanese Laid-Open Patent Publication JP2018-087688A discloses an air conditioner that changes refrigerant discharged from a compressor to a liquid refrigerant through an outdoor heat exchanger and flows it to a plurality of indoor heat exchangers. In this prior art, one high-pressure valve and one low-pressure valve are connected to a connection port for one indoor unit.

Such a method is a very general connection method, and is selectively opened according to an operation mode to provide a corresponding refrigerant to a connection port of the indoor unit.

However, according to such a connection method, when the flow rate of the refrigerant increases or decreases as the operating capacity varies, the pressure loss in the corresponding valve increases, which causes a decrease in system operating efficiency.

Japanese Patent Laid-Open Patent JP2018-087688A (published date: June 07, 2018)

A first object of the present invention is to provide a structure in which two or more high-pressure and low-pressure valves are used in parallel to one indoor unit connection port in a refrigerant distributor of a heating/cooling multi-air conditioner using a high-pressure valve and a low-pressure valve.

The second object of the present invention is to apply a plurality of high-pressure and low-pressure valves in parallel to connect high-pressure and low-pressure pipes and indoor units, and selectively open them according to the operating load, thereby actively controlling the density of the refrigerant. It provides a coordinator.

A third object of the present invention is to provide a heating/cooling multi-air conditioner capable of real-time control by periodically sensing indoor and outdoor temperatures and calculating a driving load by controlling a combined flow rate value of a low-pressure valve or a high-pressure valve.

In order to control a refrigerant pressure loss according to an indoor heating/cooling load, which is an object of the present invention, the present invention provides at least one combined heating/cooling indoor unit each including an indoor heat exchanger; an outdoor unit for heating and cooling, including a compressor, an outdoor heat exchanger, and a switching unit disposed on a discharge side of the compressor to switch a flow of refrigerant; and a distributor disposed between the outdoor unit for heating and cooling and the indoor unit for heating and cooling to distribute the refrigerant to the indoor unit for heating and cooling according to the cooling or heating operation mode, wherein the distributor is connected to the indoor unit for heating and cooling. Provided is a heating/cooling multi-air conditioner including a low-pressure valve group for flowing a low-pressure gas refrigerant from a pipe, and a high-pressure valve group for flowing a high-pressure gas refrigerant through an indoor connection pipe connected to the indoor unit for heating and cooling.

The low pressure valve group may include a plurality of low pressure valves, and the high pressure valve group may include a plurality of high pressure valves.

A plurality of low pressure valves of the low pressure valve group may be connected in parallel to each other, and a plurality of high pressure valves of the high pressure valve group may be connected in parallel with each other.

The distributor includes a liquid header; a low-pressure gas header; It may further include a high-pressure gas header through which a refrigerant having a higher pressure than that of the refrigerant in the low-pressure gas header flows.

The low-pressure valve group may selectively connect the indoor connection pipe and the low-pressure gas header, and the high-pressure valve group may selectively connect the indoor connection pipe and the high-pressure gas header.

The number of the valves to be opened in the low pressure valve group and the high pressure valve group may be determined according to an operating load.

The driving load may be determined according to the user's driving mode selection information and indoor and outdoor temperatures.

When the user's operation mode is a cooling operation, at least one low-pressure valve of the low-pressure valve group is opened, and when the user's operation mode is a heating operation, at least one high-pressure valve of the high-pressure valve group can be opened there is.

The plurality of low pressure valves of the low pressure valve group may be identical to each other, and the plurality of high pressure valves of the high pressure valve group may be identical to each other.

The plurality of low pressure valves of the low pressure valve group and the plurality of high pressure valves of the high pressure valve group may be installed in the same number.

When the operating load increases, the number of the low-pressure valves and the high-pressure valves that are opened may increase.

It may further include a temperature sensor for detecting the temperature of the refrigerant flowing in the indoor unit for heating and cooling.

The temperature sensor may be disposed at a connection port of the indoor unit for heating and cooling.

When the user's operation mode selection information is received, the number of the low-pressure valves or the high-pressure valves to be initially opened is determined and opened, and the number of the low-pressure valves or the high-pressure valves to be opened is adjusted by periodically calculating the operation load. can

The low pressure valve or the high pressure valve opened in a previous cycle may be closed or further opened by periodically reading the indoor temperature and the outdoor temperature to calculate the operating load.

When the operating load of the current cycle increases by a threshold value or more than the operating load of the previous cycle, the number of the low-pressure valves or the high-pressure valves to be opened may be increased.

When the operating load of the current cycle increases by more than a threshold value compared to the operating load of the previous cycle, the number of the low-pressure valves or the high-pressure valves that are connected and opened in parallel of the low-pressure valve group or the high-pressure valve group increases to increase the density of the refrigerant can increase

Through the above solution means, the present invention can provide a structure in which two or more high-pressure valves and low-pressure valves are used in parallel to one indoor unit connection port in a refrigerant distributor of a heating/cooling multi-air conditioner using a high-pressure valve and a low-pressure valve. there is.

In addition, a plurality of high-pressure valves and low-pressure valves connecting the high-pressure pipe and the low-pressure pipe and the indoor unit are applied in parallel and selectively opened according to the operating load, thereby actively controlling the flow rate of the refrigerant.

And, it is possible to adjust the density of the refrigerant in real time by selectively opening the low-pressure valve or the high-pressure valve according to the calculation of the operating load by periodically sensing indoor and outdoor temperatures, thereby minimizing the pressure loss of the refrigerant and improving the operating efficiency. can

1 is a schematic configuration diagram of a heating/cooling multi-air conditioner according to an embodiment of the present invention.
FIG. 2 is an operation diagram illustrating an operating state of the heating/cooling multi-air conditioner of FIG. 1 during a cooling operation.
3 is an operation diagram illustrating an operating state of the heating/cooling multi-air conditioner of FIG. 1 during heating operation.
FIG. 4 shows a detailed configuration of a refrigerant distributor of the air conditioning multi-air conditioner of FIG. 1 .
5 is a flowchart for controlling the refrigerant distributor according to the conditions of the heating/cooling multi-air conditioner of FIG. 1 .
6A and 6B are graphs illustrating an effect of opening a low-pressure valve and a high-pressure valve of a refrigerant distributor according to an operation mode.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between components and other components. Spatially relative terms should be understood as terms including different directions of components during use or operation in addition to the directions shown in the drawings. For example, when a component shown in the drawing is turned over, a component described as "beneath" or "beneath" of another component may be placed "above" of the other component. can Accordingly, the exemplary term “below” may include both directions below and above. Components may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless otherwise specified in the phrase. As used herein, "comprises" and/or "comprising" means that a referenced component, step and/or action excludes the presence or addition of one or more other components, steps and/or actions. I never do that.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

In the drawings, the thickness or size of each component is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component do not fully reflect the actual size or area.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a schematic configuration diagram of a heating/cooling multi-air conditioner according to an embodiment of the present invention.

Referring to FIG. 1 , a heating/cooling multi-air conditioner 100 according to an embodiment of the present invention is shown. The heating and cooling multi-air conditioner 100 includes first and second heating and cooling indoor units B1 and B2, a heating and cooling outdoor unit A and a distributor C.

The outdoor unit A for heating and cooling includes first and second compressors 53 and 54 , an outdoor heat exchanger 51 , an outdoor heat exchanger fan 61 , and a switching unit. Here, the switching unit includes a four-way valve 62 . The suction portions of the first and second compressors 53 and 54 are connected by a common accumulator 52 . The first compressor 53 may be an inverter compressor capable of varying the compression capacity of the refrigerant, and the second compressor 54 may be a constant speed compressor having a constant compression capacity of the refrigerant.

The first and second discharge pipes 55 and 56 are connected to the discharge portions of the first and second compressors 53 and 54 , and the first and second discharge pipes 55 and 56 are connected to the laminating unit 57 . The first and second oil separators 58 and 59 are provided in the first and second discharge pipes 55 and 56 to recover oil from the refrigerant discharged from the first and second compressors 53 and 54. each is installed. In the first and second oil separators 58 and 59 , the oil separated from the first and second oil separators 58 and 59 is guided to the suction part of the first and second compressors 53 and 54 , the first , 2 oil return pipes 30 and 31 are connected.

A high-pressure gas pipe 63 through which the refrigerant discharged from the first and second compressors 53 and 54 is bypassed without passing through the four-way valve 62 is connected to the bonding unit 57 . In addition, the joint portion 57 is connected to the four-way valve 57 and the third discharge pipe (68).

The outdoor heat exchanger 51 is connected to the four-way valve 62 by the first connection pipe 71 . In the outdoor heat exchanger 51, the refrigerant is condensed or evaporated by heat exchange with the outside air. At this time, in order to facilitate heat exchange, the outdoor fan 61 introduces air into the outdoor heat exchanger 51 . In the heating/cooling multi-air conditioner 100 , the outdoor heat exchanger 51 is used as a condenser during a cooling operation, and the outdoor heat exchanger 51 is used as an evaporator during a heating operation.

On the liquid pipe 72 connecting the outdoor heat exchanger 51 and the distributor C, an outdoor electromagnetic expansion valve 65 and a supercooling device 66 are installed. The outdoor electronic vane valve 65 expands the refrigerant during operation of the entire heating room or simultaneous operation of the heating main body. The supercooling device 66 cools the refrigerant moving to the distributor C during the operation of the entire cooling room or the simultaneous operation of the cooling main body. The outdoor electromagnetic expansion valve 74 expands the refrigerant condensed in the first and second indoor heat exchangers 11 and 21 before being introduced into the outdoor heat exchanger 51 during operation of the entire heating room or the simultaneous operation of the heating main body. The supercooling device 66 includes a supercooler 66a installed to surround a part of the liquid pipe 72 and a portion of the refrigerant that is disposed between the supercooler 66a and the distributor C and moves to the distributor C. The bypass pipe 66b for bypassing the inside of the subcooler 66a, the electromagnetic expansion valve 66c installed in the bypass pipe 66b, and the supercooler 66a and the third discharge pipe 64 are connected and a recovery pipe 66d.

The distributor (C) is disposed between the combined heating and cooling outdoor unit (A) and the first and second heating and cooling indoor units (B1) and (B2), and the first and second combined heating and cooling indoor units ( Allocate to B1)(B2).

Although two indoor units are illustrated and described, the present invention is not limited thereto, and a larger number of indoor units may be connected.

The distributor C includes a high-pressure gas header 81 , a low-pressure gas header 82 , a liquid header 83 , and control valve groups C1 and C2 .

The first and second heating and cooling indoor units B1 and B2 are respectively the first and second indoor heat exchangers 11 and 21, the first and second indoor electronic expansion valves 12 and 22 and the first, 2 indoor unit fans 15 and 25 are included. The first and second indoor electronic expansion valves 12 and 22 are first and second indoor connecting pipes 13 connecting the first and second indoor heat exchangers 11 and 21 with the high-pressure gas header 81 . ) (23).

In addition, first and second temperature sensors 16 and 26 may be installed to sense the temperature of the refrigerant discharged from the first and second heating and cooling indoor units B1 and B2. Here, the first and second temperature sensors 16 and 26 are the fifth, sixth, and indoor connecting pipes 14 connecting the first and second indoor heat exchangers 11 and 21 and the low-pressure gas header 82 . ) (24). In addition, a temperature sensor (not shown) for measuring an indoor temperature may also be installed in the first and second indoor heat exchangers 11 and 21 .

The high-pressure gas header 81 is connected to one side of the high-pressure gas pipe 63 and the first and second indoor heat exchangers 11 and 21 of the laminating unit 57 , respectively. In addition, the low-pressure gas header 82 is connected to the suction pipe 64 through the low-pressure gas pipe 75 , and is connected to the other side of the first and second indoor heat exchangers 11 and 21 . The liquid header 83 is connected to one side of the supercooling device 66 and the first and second indoor heat exchangers 11 and 21, respectively. The high-pressure gas header 81, the low-pressure gas header 82, and the liquid header 83 include a high-pressure gas pipe 63', a low-pressure gas pipe 75', and a liquid pipe 72' of other outdoor units (not shown). Each may be further connected. A low pressure valve group C2 is formed on the fifth and sixth indoor connecting pipes 14 and 24 to be connected to the low pressure gas header 82, and the fifth and sixth indoor connecting pipes 14 and 24 are formed. A high-pressure valve group C1 is formed on the top to be connected to the high-pressure gas header 81 .

The configuration of the low pressure valve group (C2) and the high pressure valve group (C1) will be described in detail later.

A bypass pipe (not shown) may be further installed between the high-pressure gas header 81 and the low-pressure gas header 82 .

Hereinafter, the operation of the heating/cooling multi-air conditioner shown in FIG. 1 and the flow of the refrigerant will be described with reference to FIGS. 2 to 3 .

2 shows the operation of the heating/cooling multi-air conditioner 100 and the flow of the refrigerant according to the cooling operation. The high-pressure gas refrigerant discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes 55 and 56 and passes through the third discharge pipe 68 and the four-way valve 62 . , is introduced into the outdoor heat exchanger (51). The high-pressure liquid refrigerant condensed in the outdoor heat exchanger 51 flows into the liquid header 83 through the supercooling device 66 . The refrigerant discharged from the liquid header 83 through the first and second indoor connecting pipes 13 and 23 is expanded by the first and second indoor electronic expansion valves 12 and 22, and then the first and second It evaporates in the indoor heat exchangers 11 and 21 and flows into the low pressure gas header 82 through the low pressure valve group C2 through the fifth, sixth, and indoor connecting pipes 14 and 24 . The low-pressure gas refrigerant discharged from the low-pressure gas header 82 is introduced into the suction/discharge pipe 64 and is then sucked into the first and second compressors 53 and 54 through the accumulator 52 .

Here, during the cooling operation, a predetermined number of valves among the plurality of low pressure valves 85a and 85b of the low pressure valve group C1 are opened in consideration of the cooling load.

Accordingly, the control of the low pressure valve group C2 will be described in detail later.

3 shows the operation of the heating/cooling multi-air conditioner 100 and the flow of the refrigerant during the heating operation. The refrigerant of the high-pressure gas discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes 55 and 56 and does not flow into the four-way valve 62 , but does not flow into the four-way valve 62 . It is introduced into the high-pressure gas header 81 through the high-pressure gas pipe 63 . The refrigerant discharged from the high-pressure gas header 81 through the fifth and sixth indoor connecting pipes 14 and 24 through the high-pressure valve group C1 is the first and second indoor heat exchangers 11 and 21 . is condensed in Thereafter, the refrigerant flows into the liquid header 83 , is discharged through the liquid pipe 72 , expands in the outdoor electromagnetic expansion valve 65 , and then evaporates in the outdoor heat exchanger 51 . The low-temperature, low-pressure gas refrigerant flows into the suction pipe 64 through the four-way valve 62 , and is then sucked into the first and second compressors 53 and 54 through the accumulator 52 .

During operation of the entire heating room, a predetermined number of valves among the plurality of high-pressure valves 84a and 84b of the high-pressure valve group C1 are opened in consideration of the heating load.

The control of the high-pressure valve group C1 according to this will be described in detail later.

Hereinafter, the valve group control according to the cooling/heating load of the distributor of the present invention will be described in detail with reference to FIGS. 4 to 6 .

4 is a view showing a detailed configuration of the refrigerant distributor of the heating/cooling multi-air conditioner of FIG. 1, FIG. 5 is a flowchart for controlling the refrigerant distributor according to the conditions of the heating/cooling multi-air conditioner of FIG. 1, and FIGS. 6A and 6B is a graph showing the opening effect of the low-pressure valve and the high-pressure valve of the refrigerant distributor according to the operation mode.

The control of the valve group of the refrigerant distributor (C) of the heating/cooling multi-air conditioner of the present invention opens a specific number of valves according to the indoor and outdoor conditions, that is, the indoor and outdoor temperature, and the user selects a specific mode by opening a certain number of valves. It is a control method for improving the operating efficiency by controlling the density of the refrigerant.

To this end, temperature sensors (not shown) may be further installed in order to detect the temperature of the refrigerant flowing in from the first and second heating and cooling indoor units B1 and B2 according to the embodiment of the present invention. Here, the temperature sensors are installed on the first and second indoor connecting pipes 13 and 23 .

Accordingly, temperature sensors are disposed in the first and second indoor connecting pipes 13 and 23, the fifth and sixth indoor connecting pipes 14 and 24, and the first and second heat exchangers 11 and 21, respectively. The temperature of the corresponding location may be transmitted to the control unit.

In addition, the distributor (C) connects the fifth and sixth indoor connecting pipes 14 and 24 with the low pressure gas header 82 through the low pressure valve group C2, and the fifth and sixth indoor connecting pipes (14) and (24) are connected to the high-pressure gas header 81 via the high-pressure valve group (C1).

In this case, in each of the valve groups C1/C2, a plurality of valves 84a, 84b/85a, 85b may be connected in parallel.

The plurality of valves 84a, 84b/85a, 85b constituting each valve group C1/C2 may be disposed in the same number, but is not limited thereto.

Preferably, the number of valves included in the low pressure valve group C2 may be greater than the number of valves included in the high pressure valve group C1.

Also, each valve of each valve group C1/C2 may have the same capacity, but is not limited thereto, and valves 84a , 84b , 85a , 85b having different capacities may be connected to each other.

Each valve group (C1/ C2) is periodically opened by opening a specific number of valves (84a, 84b, 85a, 85b) among the plurality of valves (84a, 84b, 85a, 85b) under the control of the controller at the same time to flow the refrigerant The number of valves (84a, 84b, 85a, 85b) that are opened or closed by the can be varied.

In order to perform such detailed operation, the air conditioning multi-air conditioner 100 according to the embodiment of the present invention may include a controller (not shown).

The control unit periodically reads the indoor unit (B1) and (B2) connection ports and the temperature inside the indoor unit (B1) and (B2), receives input information such as the user's operation mode and set temperature, and calculates the current heating and cooling load. Calculate the required refrigerant flow rate and refrigerant pressure loss, and determine the required number of distributor (C) valves.

Specifically, when the cooling and heating load is very large and the required flow rate of the refrigerant is increased, if the flow rate is made to flow through one valve, the pressure loss of the flowing refrigerant is increased.

To prevent this, when the flow rate of the refrigerant required is calculated and the flow rate is passed through the plurality of valves 84a, 84b, 85a, 85b, the density of the refrigerant is increased. To this end, by simultaneously opening the plurality of parallel-connected valves (84a, 84b, 85a, 85b), it is possible to increase the density of the refrigerant and reduce the pressure loss while securing the refrigerant flow rate.

The control unit may be installed in the outdoor unit A, but, unlike this, may be implemented as a processor in the manager management system. Alternatively, a controller for performing operation according to the selected detailed mode may be disposed in the outdoor unit A, and a main control unit transmitting and receiving the same may be installed in the manager management system.

A detailed description of various modifications of the control unit will be omitted.

The control unit receives a simple user's operation selection command, and receives the current indoor temperature and the connection port temperature of the heat exchanger of the indoor units B1 and B2 from the temperature sensors 16 and 26 disposed in the indoor unit B and the outdoor unit A. and information about the outdoor temperature.

The controller calculates a driving load of the selected driving mode based on the received indoor and outdoor temperatures and the user's driving selection information.

The control unit operates the respective valves 63 , 64 , 65 , 66 , 67 , 68 , C1 , and C2 of the air conditioning multi-air conditioner 100 and the operation of the compressors 53 , 54 and the accumulator 52 according to the operation mode. , to control sensor operation, etc.

Specifically, referring to FIG. 5 , the heating/cooling multi-air conditioner 100 according to the embodiment of the present invention starts operation while receiving a user's driving selection command (S10).

That is, when the user selects the operation mode of the indoor unit B installed in a specific space, the controller (not shown) installed in the outdoor unit A starts operation in the corresponding operation mode.

The user may select the operation of the indoor unit B in a specific space as cooling or heating according to the user's intention.

Upon receiving such a user's driving selection command, the controller receives information on the current indoor temperature and outdoor temperature from the temperature sensor 81 disposed in the indoor unit B and the outdoor unit A ( S20 ).

In this case, the controller calculates the driving load, that is, the driving capacity, based on the received indoor and outdoor temperatures and the user's driving selection information ( S30 ).

First, when the user's operation selection command is cooling operation, the controller calculates the cooling load according to the indoor temperature, the indoor unit connection port temperature, the outdoor temperature, and the set temperature, and calculates the refrigerant flow rate required for the cooling load.

The control unit drives the compressor by setting the frequencies of the compressors 53 and 54 according to the calculated refrigerant flow rate, and calculates a refrigerant pressure loss for the refrigerant flow rate.

The control unit determines the number of low pressure valves 85a and 85b of the low pressure valve group C2 to be opened according to the magnitude of the refrigerant pressure loss.

Specifically, as the cooling load increases, the refrigerant pressure loss increases, so that more valves 85a and 85b are selected to open.

At this time, the number and selection of the low pressure valves 85a and 85b themselves can be specified depending on the case where both the low pressure valves 85a and 85b have the same flow rate or when the low pressure valves 85a and 85b have different flow rates. .

The control unit performs a cooling operation while opening the selected number of low-pressure valves 85a and 85b (S40).

Such a cooling operation is the same as that shown in FIG. 2 , and a corresponding number of low-pressure valves are opened at the same time to flow the low-pressure refrigerant at the same time, thereby reducing the pressure loss of the refrigerant.

That is, the refrigerant of the high-pressure high-temperature gas discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes, passes through the four-way valve 62 , and passes through the first connection pipe 71 to the outdoor unit It flows into the first heat exchanger (A1) of (A). At this time, the first connection valve 82 is opened so that the first heat exchanger A1 and the second heat exchanger A2 are connected in series with each other so that the refrigerant flowing through the first heat exchanger A1 is transferred to the second heat exchanger A2. It heats up again and is further condensed. The condensed high-pressure liquid refrigerant passes through the distributor (C) through a supercooling device (not shown), and the refrigerant discharged through the first and second indoor connecting pipes (13, 23) is expanded by the indoor electronic expansion valve (12). Then, through the third and fourth indoor connecting pipes 14 and 24 through the plurality of low pressure valves 85a and 85b which are evaporated in the indoor heat exchangers 11 and opened to a low-temperature and low-pressure gas state, the suction and discharge pipes ( 77), it is sucked into the first and second compressors 53 and 54 through the accumulator 52.

Next, the control unit periodically receives the indoor and outdoor temperatures and repeats the above operation (S50).

Specifically, the current operating load is calculated by reading both the indoor temperature and the outdoor temperature and the pipe temperature of the connection ports of the indoor units B1 and B2 in the current cycle (S60).

At this time, when the operating load is larger or smaller than the operating load of the previous cycle, the number of valves 85a and 85b of the distributor C that is opened when the corresponding deviation is greater than or equal to the threshold value is adjusted.

Specifically, when the deviation is less than the threshold, the number of valves currently open is maintained, and when the deviation is equal to or greater than the threshold, the valves 85a and 85b to be further opened or closed are determined according to the deviation.

By opening or closing the recrystallized number of valves 85a and 85b again, the density of the refrigerant flowing from the indoor units B1 and B2 is changed and the refrigerant pressure loss is reduced (S70).

By periodically performing such an operation, the pressure loss of the refrigerant can be reduced in real time, thereby improving operating efficiency.

That is, referring to FIG. 6A , during the cooling operation, as the operating capacity, ie, the cooling load, increases, the pressure loss of the refrigerant becomes very large.

As the pressure loss of the refrigerant increases, the operating efficiency decreases.

When a plurality of low-pressure valves 85a and 85b are opened, the pressure loss of the refrigerant is rapidly reduced. This is because by increasing the density of the refrigerant, the pressure loss can be remarkably reduced even if the flow rate is the same.

Accordingly, by periodically calculating the operating load and controlling the density of the refrigerant by opening the plurality of valves 85a and 85b when the corresponding operating load becomes very large, the operating efficiency can be significantly increased.

Meanwhile, when the user selects the heating operation, the control unit may calculate the heating load in the heating operation mode based on the user's operation selection information, the indoor temperature, the temperature of the input/output ports of the indoor units B1 and B2, and the outdoor temperature information. .

Such an operation is the same as that of FIG. 5 above, and the required refrigerant flow rate is calculated according to the calculated heating load, and the number of valves 84a and 84b to be opened in the high-pressure valve group C1 can be selected.

The control unit may perform a heating operation by opening the selected valves 84a and 84b, and such heating operation is performed in the same manner as illustrated in FIG. 3 .

That is, the refrigerant of the high-pressure gas discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes and flows into the four-way valve 62 to close the selected plurality of high-pressure valves 84a and 84b. through the indoor heat exchanger (B). The high-temperature and high-pressure liquid refrigerant condensed in the indoor heat exchanger (B) passes through the indoor electronic expansion valve (12) and the first and second electromagnetic expansion valves (65, 66) in the first heat exchanger (A1) of the outdoor unit (A). ) and the second heat exchanger (A2) are injected in parallel to heat exchange and evaporate.

In such a heating operation, a pressure loss occurs depending on the heating load, as shown in FIG. 6b, and when the heating load is very large, a plurality of valves 84a and 84b are opened to reduce the pressure loss and increase the operating efficiency. there is.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and in the technical field to which the present invention belongs, without departing from the gist of the present invention as claimed in the claims Various modifications may be made by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

100: air conditioning multi-air conditioner A: outdoor unit heat exchanger
C: distributor C2: low pressure valve group
C1: high pressure valve group 84a, 84b: high pressure valve
85a, 85b: Low pressure valve B: Indoor unit (B1, B2)
53, 54: Compressor 52: Accumulator
65, 66, 67: first, second, third electromagnetic expansion valve 62: four-way valve

Claims (17)

at least one air-conditioning/heating/cooling indoor unit each including an indoor heat exchanger;
an outdoor unit for heating and cooling, including a compressor, an outdoor heat exchanger, and a switching unit disposed on a discharge side of the compressor to switch a flow of refrigerant; and
and a distributor disposed between the heating and cooling outdoor unit and the heating and cooling indoor unit to distribute the refrigerant to the cooling and heating indoor unit according to the cooling or heating operation mode;
The distributor is
A low-pressure valve group for flowing a low-pressure gas refrigerant from an indoor connection pipe connected to the indoor unit for heating and cooling, and
A high-pressure valve group that flows a high-pressure gas refrigerant through an indoor connection pipe connected to the indoor unit for heating and cooling.
Air conditioning multi-air conditioner that includes. The method of claim 1,
The low-pressure valve group includes a plurality of low-pressure valves, and the high-pressure valve group includes a plurality of high-pressure valves. 3. The method of claim 2,
A plurality of low-pressure valves of the low-pressure valve group are connected in parallel with each other, and a plurality of high-pressure valves of the high-pressure valve group are connected in parallel with each other. 4. The method of claim 3,
the distributor
a liquid header;
a low-pressure gas header;
The air conditioning multi-air conditioner according to claim 1, further comprising a high-pressure gas header through which a refrigerant having a higher pressure than that of the refrigerant in the low-pressure gas header flows. 5. The method of claim 4,
The low pressure valve group selectively connects the indoor connection pipe and the low pressure gas header,
The high-pressure valve group selectively connects the indoor connection pipe and the high-pressure gas header. 5. The method of claim 4,
The low-pressure valve group and the high-pressure valve group are air-conditioning multi-air conditioner, characterized in that the number of valves to be opened is determined according to the operating load. 7. The method of claim 6,
The heating and cooling multi-air conditioner, characterized in that the operation load is determined according to the user's operation mode selection information and indoor and outdoor temperatures. 8. The method of claim 7,
When the user's operation mode is a cooling operation, at least one low pressure valve of the low pressure valve group is opened,
When the user's operation mode is a heating operation, at least one high-pressure valve of the high-pressure valve group is opened. 9. The method of claim 8,
The plurality of low-pressure valves of the low-pressure valve group are identical to each other, and the plurality of high-pressure valves of the high-pressure valve group are identical to each other. 10. The method of claim 9,
A plurality of low-pressure valves of the low-pressure valve group and a plurality of high-pressure valves of the high-pressure valve group are installed in the same number. 10. The method of claim 9,
When the operating load increases, the number of the low-pressure valve and the high-pressure valve that are opened increases. 10. The method of claim 9,
The heating and cooling multi-air conditioner further comprising a temperature sensor for detecting the temperature of the refrigerant flowing in the indoor unit for heating and cooling. 13. The method of claim 12,
The temperature sensor is a heating/cooling multi-air conditioner, characterized in that it is disposed on a connection port of the indoor unit for heating and cooling. 13. The method of claim 12,
When the user's operation mode selection information is received, the number of the low pressure valve or the high pressure valve to be initially opened is determined and opened,
The heating and cooling multi-air conditioner, characterized in that the number of the low-pressure valve or the high-pressure valve to be opened is adjusted by periodically calculating the operating load. 14. The method of claim 13,
The air conditioner according to claim 1, wherein the low pressure valve or the high pressure valve opened in a previous cycle is closed or further opened by periodically reading the indoor temperature and the outdoor temperature to calculate the operating load. 14. The method of claim 13,
When the operating load of the current cycle increases by more than a threshold value than the operating load of the previous cycle, the heating/cooling multi-air conditioner, characterized in that the adjustment is made to increase the number of the low-pressure valve or the high-pressure valve to be opened. 14. The method of claim 13,
When the operating load of the current cycle increases by more than a threshold value compared to the operating load of the previous cycle, the number of the low-pressure valves or the high-pressure valves connected and opened in parallel of the low-pressure valve group or the high-pressure valve group increases to increase the density of the refrigerant Air conditioning multi-air conditioner characterized in that it raises.

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