KR20220045359A - Multi-air conditioner for heating and cooling operations - Google Patents

Abstract

The present invention provides a multi-air conditioner for both air conditioning and heating operations, which comprises: at least one indoor unit for both air conditioning and heating operations including an indoor heat exchanger; and an outdoor unit for both air conditioning and heating operations including a compressor, a plurality of outdoor heat exchangers, and a switching unit disposed on a discharge side of the compressor and switching a flow of refrigerant. In the plurality of outdoor heat exchangers of the outdoor unit for both air conditioning and heating operations, one end is connected to the switching unit, wherein the one end is provided with a defrost control valve for controlling an amount of opening during defrosting operation of the outdoor heat exchanger. Therefore, the present invention has effects of operating heating and defrosting together by installing a plurality of outdoor heat exchangers to perform divisional defrosting, and improving the heat exchange efficiency by conducting heat exchange during defrosting in a two-phase region.

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 split defrosting by installing a valve at an outlet of each heat exchanger of 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

In the case of heating the room as described above, when the temperature of the outdoor air is very low, frost is formed on the heat exchanger due to heat absorption generated in the heat exchanger of the outdoor unit.

Such frost reduces the efficiency of the outdoor heat exchanger, and a defrosting operation to remove it is performed to remove the frost and remove the frost.

As an example, in Korean Patent Laid-Open Patent Publication No. 10-2010-0096553, a high-temperature/high-pressure steam refrigerant is flowed to a heat exchanger to be defrosted, thereby removing the formed frost. At this time, when a plurality of outdoor heat exchangers are installed, continuous heating can be performed while performing divisional defrosting through the upper/lower hot gas valves.

However, the gaseous refrigerant enters the heat exchanger to be split defrost and heat exchanges without passing through the two-phase region, resulting in poor heat exchange efficiency. To compensate for this, the amount of refrigerant required for defrosting is increased, and the amount of refrigerant circulating to the indoor side is reduced accordingly, resulting in a problem in that heating performance is reduced.

Korean Patent Publication No. 10-2010-0096553 (published on September 02, 2010)

A first object of the present invention is to install a plurality of outdoor heat exchangers and perform divisional defrosting, so that heating and defrosting are realized together. It provides a coordinator.

A second object of the present invention is to provide a heating/cooling multi-air conditioner capable of improving heat exchange efficiency by adding a device for forming a pressure gradient in each heat exchanger in order to conduct heat exchange during defrosting in a two-phase region.

A third object of the present invention is to provide a heating/cooling multi-air conditioner capable of securing continuous heating performance by performing heat exchange in a two-phase region during divisional defrosting to prevent inflow of additional refrigerant and increase a refrigerant flow rate toward an indoor unit.

For two-phase heat exchange during split defrosting, which is a subject of the present invention, the present invention provides at least one indoor unit for heating and cooling, including an indoor heat exchanger; and a compressor, a plurality of outdoor heat exchangers, and a switching unit disposed on a discharge side of the compressor to switch a flow of refrigerant; Including, one end of the plurality of outdoor heat exchangers of the outdoor unit for heating and cooling is connected to the switching unit, and a defrosting control valve for controlling an opening amount during a defrosting operation of the outdoor heat exchanger is formed at one end of the outdoor heat exchanger. provide a coordinator.

The outdoor unit for heating and cooling includes a first heat exchanger having one end connected to the switching unit and another end connected to the indoor heat exchanger, and one end connected/blockable to the other end of the first heat exchanger, the other end being the It may include a second heat exchanger connected to the indoor heat exchanger.

The defrost control valve may include a first defrost valve formed at one end of the first heat exchanger to control an opening amount during a defrosting operation of the first heat exchanger; and a second defrost valve formed at one end of the second heat exchanger to control an opening amount during a defrosting operation of the second heat exchanger.

The outdoor unit for heating and cooling may include a first connection pipe connecting the other end of the first heat exchanger and one end of the second heat exchanger in series; and a first connection valve disposed on the first connection pipe and configured to turn on/off a mechanical connection between the first heat exchanger and the second heat exchanger.

The first defrost valve and the second defrost valve may be fully opened in a heating operation and a cooling operation.

The air conditioning multi-air conditioner may further include an accumulator that collects refrigerant from the first and second heat exchangers or the indoor heat exchanger and provides the refrigerant to the compressor.

An opening amount of the first defrost valve and the second defrost valve may be determined according to a suction temperature of the accumulator during a defrosting operation of the first heat exchanger and the second heat exchanger.

The heating/cooling multi-air conditioner calculates a degree of refrigerant superheat according to the suction temperature of the accumulator during defrosting of the first heat exchanger and the second heat exchanger, and the first defrost valve and the first defrost valve according to the refrigerant superheat 2 The opening degree of the defrost valve can be varied.

The heating/cooling multi-air conditioner may reduce the opening amount of the defrost valve of the currently defrosting heat exchanger among the first and second heat exchangers currently defrosting when the refrigerant superheat degree is greater than a predetermined range.

During the defrosting operation, a lower defrosting mode in which the refrigerant discharged from the compressor flows into the second heat exchanger while evaporating the refrigerant in the first heat exchanger to defrost the second heat exchanger, and The upper defrost mode of performing the defrosting of the first heat exchanger by flowing the refrigerant discharged from the compressor to the first heat exchanger while evaporating the refrigerant in the second heat exchanger may be alternately performed.

Controls the opening amount of the second defrost valve in the lower defrost mode, the first defrost valve is fully opened, and controls the opening amount of the first defrost valve in the upper defrost mode, and the second defrost valve is can be fully open.

The heating/cooling multi-outdoor unit may include: a suction temperature sensor configured to periodically read an inlet temperature of the accumulator; It may further include a pipe temperature sensor that periodically reads the pipe temperature of the first and second heat exchangers.

The air-conditioning multi outdoor unit includes a first hot gas pipe connecting the discharge side of the compressor and the other end of the first heat exchanger; a second hot gas pipe connecting the discharge side of the compressor and the other end of the second heat exchanger; a first hot gas valve installed on the first hot gas pipe to flow the refrigerant of the compressor to the first heat exchanger; and a second hot gas valve installed on the second hot gas pipe to flow the refrigerant of the compressor to the first heat exchanger.

In the lower defrost mode, the second hot gas valve is opened to condense a portion of the refrigerant discharged from the compressor in the second heat exchanger, and in the upper defrost mode, the first hot gas valve is opened to A portion of the discharged refrigerant may be condensed in the first heat exchanger.

In the upper defrost mode and the lower defrost mode, by controlling the opening degrees of the first defrost valve and the second defrost valve, the refrigerant flowing in the first heat exchanger and the second heat exchanger can exchange heat while changing phase. .

In the upper defrost mode and the lower defrost mode, the amount of opening of the first defrost valve and the second defrost valve may be controlled according to the suction temperature of the accumulator to concentrate the refrigerant into the indoor heat exchanger.

Through the above solution, the present invention can operate to implement heating and defrost together by installing a plurality of outdoor heat exchangers and performing divisional defrosting, and can improve heat exchange efficiency by conducting heat exchange during defrosting in a two-phase region. there is.

In addition, heat exchange efficiency may be improved by adding a device for forming a pressure gradient in each of the heat exchangers in order to conduct heat exchange during defrosting in the two-phase region.

In addition, heat exchange is performed in the two-phase region during the split defrosting to prevent an additional refrigerant inflow and increase the refrigerant flow rate toward the indoor unit to secure continuous heating performance.

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 a heating operation.
FIG. 4 is a flowchart for the divided defrosting of the heating/cooling multi-air conditioner of FIG. 1 .
FIG. 5 is an operation diagram illustrating an operating state of the heating/cooling multi-air conditioner of FIG. 1 during an upper divisional defrosting operation.
6 is an operation diagram illustrating an operating state of the heating/cooling multi-air conditioner of FIG. 1 during the lower division defrosting operation.
7 is a graph illustrating a heat exchange effect according to the operation of FIGS. 5 and 6 .

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 specifically stated otherwise 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/cooling multi-air conditioner 100 includes at least one heating/cooling indoor unit (B) and an outdoor unit (A) for heating/cooling.

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.

The hot gas units 73 and 75 for bypassing the refrigerant discharged from the compressor 53 without going through the four-way valve 62 are connected to the bonding unit 57 . In addition, the joint portion 57 is connected to the four-way valve 62 and the third discharge pipe (68).

The outdoor heat exchangers A1 and A2 are connected to the four-way valve 62 by the outdoor heat exchanger-the four-way valve connecting pipe 71 . In the outdoor heat exchangers A1 and A2, 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 exchangers A1 and A2. In the heating/cooling multi-air conditioner 100 , the outdoor heat exchangers A1 and A2 are used as condensers during the cooling operation, and the outdoor heat exchangers A1 and A2 are used as the evaporators during the heating operation.

The outdoor heat exchanger (A1, A2) is connected to the four-way valve 62 and the outdoor heat exchanger-the four-way valve connecting pipe 71 for allowing the refrigerant to flow therebetween. The outdoor heat exchanger-the four-way valve connecting pipe 71 connects the first outdoor heat exchanger A1 with the four-way valve 62, the first outdoor heat exchanger-the four-way valve connecting pipe 28, and the second outdoor heat exchanger ( A2) and the second outdoor heat exchanger connecting the four-way valve 62 to the four-way valve connecting pipe 29 are included. The outdoor heat exchanger-the four-way valve connecting pipe 71 connected from the four-way valve 62 is branched into the first outdoor heat exchanger- four-way valve connecting pipe 28 and the second outdoor heat exchanger- four-way valve connecting pipe 29 .

A check valve is disposed in the second outdoor heat exchanger-the four-way valve connecting pipe 29, and the check valve is configured to allow the refrigerant supplied from the outdoor heat exchanger- four-way valve connecting pipe 71 to pass through the second outdoor heat exchanger—the four-way valve. It blocks the inflow into the connecting pipe (29).

A variable pass pipe 74 connecting the first outdoor heat exchanger pipe 76 and the second outdoor heat exchanger-the four-way valve connecting pipe 29 is further disposed, and the variable pass valve 82 is connected to the variable pass pipe 74. ) may be further disposed.

The variable pass valve 82 may be selectively operated. When the variable pass valve 82 is opened, the refrigerant flowing along the first outdoor heat exchanger pipe 76 passes through the variable pass pipe 74 and the variable pass valve 82, and the four-way valve ( 62) can be guided.

When the variable pass valve 82 is closed, the refrigerant supplied through the first outdoor heat exchanger pipe 76 flows to the first outdoor heat exchanger A1 during a heating operation.

When the variable pass valve 82 is closed, the refrigerant that has passed through the first outdoor heat exchanger A1 flows to the liquid connection pipe 72 through the first outdoor heat exchanger pipe 76 during the cooling operation.

On the other hand, a first defrost expansion valve 28 for controlling the output pressure during the defrosting operation of the first outdoor heat exchanger A1 is formed on the first outdoor heat exchanger-the four-way valve connecting pipe 28, and the second A second defrost expansion valve 29 for controlling the output pressure of the second outdoor heat exchanger A2 during the defrosting operation is formed on the outdoor heat exchanger-the four-way valve connecting pipe 29 .

The first defrost expansion valve 28 and the second defrost expansion valve 29 are formed at one end of the corresponding outdoor heat exchanger and selectively operate during the defrosting operation to control the output pressure of the corresponding outdoor heat exchanger (A1, A2). By doing so, it is possible to induce a phase change of the refrigerant in the outdoor heat exchangers A1 and A2 in the defrosting operation.

The first defrost expansion valve 28 and the second defrost expansion valve 29 may be an electronic expansion valve (EEV) capable of adjusting an opening value according to an input signal.

At this time, the output end of the first outdoor heat exchanger (A1) and the second outdoor heat exchanger (A2), that is, the first defrost expansion valve 28 and the second defrost expansion valve 29 are formed at one end of the temperature sensor. can be formed.

The opening values of the first defrost expansion valve 28 and the second defrost expansion valve 29 may be determined according to the suction temperature of the ampululator 52 , that is, the temperature value of the refrigerant flowing into the indoor unit B.

The outdoor expansion valves 65 and 67 expand the refrigerant flowing into the outdoor heat exchangers A1 and A2 during the heating operation. During the cooling operation, the outdoor expansion valves 65 and 67 pass through the refrigerant without expanding it. As the outdoor expansion valves 65 and 67, an electronic expansion valve (EEV) capable of adjusting an opening value according to an input signal may be used.

The outdoor expansion valves 65 and 67 include a first outdoor expansion valve 65 that expands the refrigerant flowing into the first outdoor heat exchanger A1, and a second outdoor expansion valve 65 that expands the refrigerant flowing into the second outdoor heat exchanger A2. 2 It includes an outdoor expansion valve (67).

The first outdoor expansion valve 65 and the second outdoor expansion valve 67 are formed at the other ends of the corresponding outdoor heat exchangers A1 and A2 and are connected to the liquid pipe connection pipe 72 . During the heating operation, the refrigerant condensed in the indoor unit B is supplied to the first outdoor expansion valve 65 and the second outdoor expansion valve 67 .

In order to be connected to the first outdoor expansion valve 65 and the second outdoor expansion valve 67 , the liquid pipe connection pipe 72 is branched, and is connected to the first outdoor expansion valve 65 and the second outdoor expansion valve 67 . each is connected The first outdoor expansion valve 65 and the second outdoor expansion valve 67 are arranged in parallel.

A pipe connecting the first outdoor expansion valve 65 and the first outdoor heat exchanger A1 is defined as a first outdoor heat exchanger pipe 76 . A pipe connecting the second outdoor expansion valve 66 and the second outdoor heat exchanger A2 is defined as a second outdoor heat exchanger pipe 77 .

The accumulator 52 provides refrigerant to the compressor 53 . The accumulator 52 is disposed on the suction side of the compressor 53 and is connected to the four-way valve 62 . A temperature sensor 93 may be formed at the inlet side of the amuculator 52 to measure the suction temperature of the amuculator 52 , that is, the temperature of the refrigerant flowing into the indoor unit B .

Meanwhile, a pipe connecting the outdoor expansion valves 65 and 67 and the supercooling unit 66 among the liquid pipe connection pipe 72 may be defined as a supercooling liquid pipe connection pipe.

The four-way valve 62 is provided at the outlet side of the first and second compressors 53 and 54, and switches the flow path of the refrigerant flowing in the outdoor unit A. The four-way valve 62 appropriately switches the flow paths of the refrigerant discharged from the first and second compressors 53 and 54 in accordance with the cooling/heating operation of the air conditioner 100 .

The four-way valve 62 according to this embodiment sends the refrigerant discharged from the first and second compressors 53 and 54 to the outdoor heat exchangers A1 and A2, or flows in the outdoor heat exchangers A1 and A2. The refrigerant is sent to the first and second compressors 53 and 54 through the accumulator 52, or the refrigerant discharged from the first and second compressors 53 and 54 is sent to the engine connection pipe 75, or the engine The refrigerant introduced from the connection pipe 75 is discharged to the first and second compressors 53 and 54 through the accumulator 52 .

Also, during the heating operation, the four-way valve 62 on the side of the outdoor unit A for heating operation sends the refrigerant flowing into the outdoor heat exchangers A1 and A2 to the first and second compressors 53 and 54 .

The air conditioner 100 according to the present embodiment may include hot gas units 73 and 79 in which a portion of the refrigerant compressed in the first and second compressors 53 and 54 flows. A portion of the high-temperature and high-pressure refrigerant compressed by the first and second compressors 53 and 54 may pass through the hot gas bypass pipes 73 and 79 and may be introduced into the outdoor heat exchangers A1 and A2.

The hot gas units 73 and 79 include hot gas bypass pipes 73 and 79 and hot gas valves 63 and 69 for bypassing the refrigerant.

In this embodiment, a first hot gas bypass pipe 73 connecting the first outdoor heat exchanger pipe 76 and the lamination part 57 is disposed. One end of the first hot gas bypass pipe 73 is connected to the first outdoor heat exchanger pipe 76 , and the other end is connected to the lamination part 57 . A second hot gas bypass pipe 79 connecting the second outdoor heat exchanger pipe 77 and the lamination unit 57 is disposed. One end of the second hot gas bypass pipe (79) is connected to the first outdoor heat exchanger pipe (77), and the other end is connected to the lamination part (57).

A first hot gas valve 63 is disposed in the first hot gas bypass pipe 73 , and a second hot gas valve 69 is disposed in the second hot gas bypass pipe 79 . As the hot gas valves 63 and 69, a solenoid valve capable of adjusting the opening degree is used, and an on/off valve may be used.

The first hot gas bypass pipe 73 and the second hot gas bypass pipe 79 may be connected to the compressor discharge pipe 55, respectively, but in this embodiment, after lamination, the compressor discharges through one pipe It is connected to the pipe (55).

A supercooling unit 66 may be disposed in the liquid pipe connection pipe 72 .

The supercooling unit 66 is bypassed in the supercooling heat exchanger 66a, the liquid pipe connection pipe 72, and the supercooling bypass pipe 66b connected to the supercooling heat exchanger 66a, and the supercooling bypass pipe ( A supercooling expansion valve (66c) disposed in 66b) and selectively expanding the flowing refrigerant, a supercooling-compressor connection pipe (89) connecting the supercooling heat exchanger (66a) and the compressor (53), and a supercooling-compressor connection It is disposed in the pipe 89 and includes a supercooling-compressor expansion valve 91 for selectively expanding the flowing refrigerant.

The supercooling unit 66 according to the present embodiment further includes an accumulator bypass pipe connecting the accumulator 52 and the supercooling-compressor connecting pipe, and the accumulator bypass pipe is configured to receive the refrigerant of the accumulator 52 as the accumulator bypass pipe. Provided to the supercooling-compressor connection pipe (89).

A supercooling bypass valve 90 is further disposed in the accumulator bypass pipe.

The supercooling expansion valve 66c expands the liquid refrigerant and provides it to the supercooling heat exchanger 66a, and the expanded refrigerant is evaporated in the supercooling heat exchanger 66a to cool the supercooling heat exchanger 66a. The liquid refrigerant flowing to the outdoor heat exchangers A1 and A2 through the liquid pipe connection pipe 72 may be cooled while passing through the supercooling heat exchanger 66a. The supercooling expansion valve 66c is selectively actuated and can control the temperature of the liquid refrigerant.

When the supercooling expansion valve 66c is operated, the supercooling-compressor expansion valve 91 is opened and the refrigerant flows to the first and second compressors 53 and 54 .

The subcooling expansion valve 66c is selectively actuated, and can provide liquid refrigerant of the accumulator 52 to the subcooling-compressor expansion valve 91 .

The supercooling-compressor expansion valve 91 is selectively operated and expands the refrigerant to lower the temperature of the refrigerant supplied to the first and second compressors 53 and 54 . When the first and second compressors 53 and 54 exceed the normal operating temperature range, the refrigerant expanded in the supercooling-compressor expansion valve 91 may be evaporated in the first and second compressors 53 and 54, and , it is possible to lower the temperature of the first and second compressors 53 and 54 through this.

On the other hand, the air conditioner 100 according to this embodiment may further include a pressure sensor for measuring the pressure of the refrigerant, a temperature sensor for measuring the temperature of the refrigerant, and a strainer for removing foreign substances present in the refrigerant flowing through the refrigerant pipe. can

Meanwhile, each of the indoor units B for heating and cooling includes an indoor heat exchanger 11 , an indoor electronic expansion valve 12 , and an indoor unit fan 15 . The indoor electromagnetic expansion valve 12 is installed on the indoor connecting pipe connecting the indoor heat exchanger 11 and the engine connecting pipe 75 or the liquid pipe connecting pipe 72 .

In addition, temperature sensors may be installed to sense the temperature of the refrigerant discharged from the indoor units B for heating and cooling. Also, a temperature sensor (not shown) for measuring the indoor temperature may be installed in the indoor heat exchanger 11 .

The air conditioning multi-air conditioner may further include a distributor (not shown) between the outdoor unit A and the indoor unit B of FIG. 1 .

When the distributor is included, simultaneous operation or individual operation of the plurality of outdoor units (A) and the plurality of indoor units (B) is possible.

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

2 shows the operation of the heating/cooling multi-air conditioner 100 and the flow of the refrigerant during 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 . , flows into the outdoor heat exchangers (A1, A2). The high-pressure liquid refrigerant condensed through the series connection through the bypass pipe 74 of the outdoor heat exchangers A1 and A2 flows into the liquid pipe connection pipe 72 through the supercooling device 66 . The refrigerant discharged from the liquid pipe connecting pipe 72 through the indoor connecting pipe is expanded in the indoor electronic expansion valve 12 and then evaporated in the indoor heat exchanger 11, and the low-pressure gas refrigerant is transferred through the indoor connecting pipe to the engine connecting pipe. After it flows into (75), it is sucked into the first and second compressors (53, 54) through the accumulator (52).

Here, during the cooling operation, the first and second defrost expansion valves 28 and 29 are fully opened and the refrigerant transferred from the compressors 53 and 54 or the outdoor heat exchanger A1 in front flows as it is.

3 shows the operation of the heating/cooling multi-air conditioner 100 and the flow of the refrigerant during 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 passes through the high-pressure gas pipe 63 and is condensed in the indoor heat exchangers 11 through the indoor connection pipe. Thereafter, the refrigerant is discharged through the liquid pipe connection pipe 72, expanded in the outdoor electromagnetic expansion valves 65 and 67, and then evaporated in the first and second outdoor heat exchangers A1 and A2. 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 .

On the other hand, when the outdoor temperature is low, the heating operation is continued and the operating load of the indoor unit B is high. dew condensation occurs.

Such implantation lowers the heat exchange efficiency of the heat exchangers A1 and A2, and a defrosting operation is performed to remove the implantation.

For example, when the humidity in winter is very high, when the heating operation is selected, when the outdoor unit A is driven as an evaporator because the humidity is very high in the outdoor unit, the piping temperature around the heat exchangers A1 and A2 is 0 degrees or less. , if the current temperature is lower than the dew point temperature, the condensed water may freeze. When such a state continues for a long time, the drainage becomes unstable, ice grows, and the heat exchange efficiency decreases.

In this case, when the operating load of the indoor unit B is still required, the divided defrosting operation may be performed by alternating the plurality of heat exchangers A1 and A2 .

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 internal temperature of the indoor unit B, the external temperature of the outdoor unit A, the temperature of one end of the heat exchangers A1 and A2 of the outdoor unit A, and the temperature of the inlet end of the accumulator 52, and By receiving input information such as an operation mode, the inverter driving of each valve of the indoor unit B and the outdoor unit A and the compressor 53 may be performed accordingly.

The control unit may be installed in the outdoor unit A, but differently, 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.

Hereinafter, a divided defrosting operation will be described with reference to FIGS. 4 to 7 .

4 is a flowchart for the divided defrosting of the heating and cooling multi air conditioner of FIG. 1 , FIG. 5 is an operation diagram showing the operating state of the heating and cooling multi air conditioner of FIG. 1 during the upper division defrosting operation, and FIG. 6 is the lower division defrosting It is an operation diagram showing the operating state of the heating/cooling multi-air conditioner of FIG. 1 during operation, and FIG. 7 is a graph showing the heat exchange effect according to the operation of FIGS. 5 and 7 .

Referring to FIG. 4 , the control unit receives a simple user's driving selection command, and receives information on the current indoor temperature and outdoor temperature from temperature sensors disposed in the indoor unit B and the outdoor unit A.

The controller drives the inverters of each valve and the compressor 53 based on the received indoor and outdoor temperatures, the pipe temperature of the outdoor unit heat exchanger, and the user's operation selection information to perform the heating mode operation.

At this time, the controller detects and reads the pipe temperature of the heat exchangers A1 and A2 of the outdoor unit A ( S10 ).

When the piping temperature of the heat exchangers A1 and A2 of the outdoor unit A is lower than the first threshold value (S20), it is determined that the conception of the outdoor unit A has started and the defrosting mode is entered (S30).

일 수 있으나, 이에 한정되는 것은 아니다. In this case, the first threshold value is 0

may be, but is not limited thereto.

The control unit also obtains outdoor humidity information, the pipe temperature of the outdoor unit (A) heat exchangers (A1, A2) meets below zero, calculates the dew point temperature based on the current pipe temperature and humidity, and the current pipe temperature When is lower than the calculated dew point temperature, it is determined that dew has entered a state, that is, an implantation state, and the defrost mode can be entered.

When entering the defrosting mode, it is possible to perform divided defrosting by dividing the defrosting of the upper and lower heat exchangers while maintaining the heating operation.

First, the upper divisional defrost starts as shown in FIG. 5 (S40).

The control unit controls the first external electronic expansion valve 65 in real time to perform a defrosting operation of the first heat exchanger A1 disposed on the upper part in the general heating operation to provide a high temperature and high pressure to the first heat exchanger A1 in real time. drain the refrigerant

Specifically, the high-pressure gas refrigerant discharged from the first and second compressors 53 and 54 flows through the first and second discharge pipes, flows into the four-way valve 62 , and flows into the indoor heat exchanger 11 . The high-temperature and high-pressure liquid refrigerant condensed in the indoor heat exchanger 11 is injected into the second heat exchanger A2 of the outdoor unit through the second electromagnetic expansion valve 67, heat exchanges, and evaporates, thereby operating a heating cycle.

At this time, the second defrost expansion valve 29 is fully opened to provide the low-temperature and low-pressure gas refrigerant evaporated from the second heat exchanger A2 to the accumulator 52 . The low-temperature gas refrigerant discharged to one end of the second heat exchanger A2 for upper defrosting is recovered to the compressors 53 and 54 through the accumulator 52 .

At this time, the first electromagnetic expansion valve 65 is closed to block the refrigerant flow from the indoor unit B to the outdoor first heat exchanger A1.

Meanwhile, the defrosting of the first heat exchanger A1 may be performed by opening the lower first hot gas valve 63 . Specifically, a portion of the refrigerant discharged from the compressors 53 and 54 is provided to the first heat exchanger A1 through the first hot gas pipe 73 .

The control unit detects the suction temperature of the accumulator 52 and determines the degree of superheat of the refrigerant (S50). That is, the degree of superheat of the refrigerant is determined by calculating the difference between the suction temperature and the saturation temperature of the accumulator 52 , and accordingly, the degree of opening of the first defrost expansion valve 28 is controlled.

Specifically, when the degree of superheat is greater than or equal to a predetermined range, it is determined that the refrigerant flowing for the heating operation of the indoor unit B is insufficient.

The amount of gaseous refrigerant injected into the first heat exchanger A1 is reduced according to the determination of the refrigerant shortage, and such control of the refrigerant amount can be compensated by controlling the degree of opening and closing of the first defrost expansion valve 28 .

That is, if the degree of opening of the first defrost expansion valve 28 is reduced, the pressure difference between the input end and the output end of the first heat exchanger A1 becomes very large, and by this pressure gradient, the phase in the first heat exchanger A1 is Conversion takes place and more enthalpy changes, resulting in refrigerant condensation (S60).

Accordingly, while a small amount of refrigerant flows, it is recovered to the compressors 53 and 54 through the accumulator 52 again while removing the implantation of the first heat exchanger A1 by a sufficiently large amount of change in enthalpy.

As such, when the heat exchangers A1 and A2 are formed in one outdoor unit A, the heat exchanger A2 of some layers is driven as an evaporator for heating driving, while in the other part, a defrosting mode is performed to continuously heating is possible.

When the upper defrost is finished, the lower defrost is performed (S70).

When the lower defrost starts, 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 flows into the four-way valve 62 to heat exchange indoors. It flows into the group (B). The high-temperature and high-pressure liquid refrigerant condensed in the indoor heat exchanger (B) is injected into the first heat exchanger (A1) of the outdoor unit (A) through the first electromagnetic expansion valve (65), heat exchanges, and evaporates, thereby operating a heating cycle.

At this time, the first defrost expansion valve 28 is fully opened to provide the low-temperature and low-pressure gas refrigerant evaporated from the first heat exchanger A1 to the accumulator 52 and is recovered to the compressors 53 and 54 .

At this time, the second electromagnetic expansion valve 66 is closed for lower defrosting to block the refrigerant flow from the indoor unit B to the outdoor second heat exchanger A2.

Defrosting of the second heat exchanger A2 may be performed by opening the lower second hot gas valve 69 . Specifically, a portion of the high-temperature and high-pressure refrigerant discharged from the compressors 53 and 54 passes through the second hot gas pipe 79 and removes the second heat exchanger A2 from forming the second heat exchanger A2 while again passing through the accumulator 52 to the compressor 53 , 54) are recovered.

The control unit detects the suction temperature of the accumulator 52 and determines the degree of superheat of the refrigerant (S80). That is, the degree of superheat of the refrigerant is determined by calculating the difference between the suction temperature and the saturation temperature of the accumulator 52 , and accordingly, the degree of opening of the second defrost expansion valve 29 is controlled.

Specifically, when the degree of superheat is greater than or equal to a predetermined range, it is determined that the refrigerant flowing for the heating operation of the indoor unit B is insufficient.

The amount of gas-phase refrigerant injected into the second heat exchanger A2 required for defrosting is reduced according to such refrigerant shortage determination, and the control of this amount of refrigerant is compensated by controlling the degree of opening and closing of the second defrost expansion valve 29. can

That is, if the degree of opening of the second defrost expansion valve 29 is lowered, the pressure difference between the input end and the output end of the second heat exchanger A2 becomes very large, and by this pressure gradient, the phase in the second heat exchanger A2 is Conversion occurs and more enthalpy is changed to cause condensation of the refrigerant (S90).

That is, as shown in FIG. 7 , by adding expansion valves 28 and 29 implementing a pressure gradient to the output ends of the outdoor heat exchangers A1 and A2, compared to the conventional structure in which the expansion valve is not formed at the output end of the heat exchanger. The amount of change in enthalpy between the inlets and outlets of the heat exchangers A1 and A2 can be greatly increased.

That is, by greatly increasing the pressure gradient of the inlet and outlet of the defrosting heat exchangers A1 and A2, a phase change occurs due to heat exchange while the refrigerant flows in the heat exchanger, so that defrosting is possible with only a small amount of refrigerant.

Therefore, while a small amount of refrigerant flows and the enthalpy is removed by a sufficiently large amount of change in enthalpy, it is recovered to the compressors 53 and 54 through the accumulator 52 again.

As described above, the outdoor heat exchangers A1 and A2 of the present invention can be formed as a plurality of heat exchangers that can be separated/connected from each other, and divided defrosting can be performed alternately according to external and internal conditions and the load of the indoor unit B, and the indoor unit ( Defrosting can be performed while ensuring the refrigerant amount of B).

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
B: indoor unit 53, 54: compressor
52: accumulator A1, A2: outdoor heat exchanger
65, 67: first, second electromagnetic expansion valve 62: four-way valve
28, 29: first and second defrost expansion valves

Claims (16)

at least one air-conditioning/air-conditioning indoor unit including an indoor heat exchanger; and
an outdoor unit for heating and cooling, including a compressor, a plurality of outdoor heat exchangers, and a switching unit disposed on a discharge side of the compressor to switch a flow of refrigerant;
including,
The plurality of outdoor heat exchangers of the outdoor unit for heating and cooling are connected to one end of the switching unit, and a defrosting control valve for controlling an opening amount during a defrosting operation of the outdoor heat exchanger is formed at one end of the outdoor heat exchanger. According to claim 1,
The air conditioning combined outdoor unit,
a first heat exchanger having one end connected to the switching unit and the other end connected to the indoor heat exchanger; and
A second heat exchanger having one end connected to/blocking from the other end of the first heat exchanger and the other end connected to the indoor heat exchanger.
Air conditioning multi-air conditioner comprising a. 3. The method of claim 2,
The defrost control valve is
a first defrost valve formed at one end of the first heat exchanger to control an opening degree during a defrosting operation of the first heat exchanger; and
A second defrost valve formed at one end of the second heat exchanger to control an opening degree during a defrosting operation of the second heat exchanger.
Air conditioning multi-air conditioner comprising a. 4. The method of claim 3,
The air conditioning combined outdoor unit,
a first connection pipe connecting the other end of the first heat exchanger in series with one end of the second heat exchanger; and
A first connection valve disposed on the first connection pipe and configured to turn on/off a mechanical connection between the first heat exchanger and the second heat exchanger
Air conditioning multi-air conditioner, characterized in that it further comprises. 4. The method of claim 3,
The heating and cooling multi-air conditioner, characterized in that the first defrost valve and the second defrost valve are fully opened in a heating operation and a cooling operation. 4. The method of claim 3,
The heating/cooling multi-air conditioner further comprises an accumulator that collects refrigerant from the first and second heat exchangers or indoor heat exchangers and provides the refrigerant to the compressor. 7. The method of claim 6,
The opening degree of the first defrost valve and the second defrost valve is determined according to the suction temperature of the accumulator during the defrosting operation of the first heat exchanger and the second heat exchanger. 4. The method of claim 3,
The heating and cooling multi air conditioner
During the defrosting operation of the first heat exchanger and the second heat exchanger, the refrigerant superheat degree is calculated according to the suction temperature of the accumulator, and the opening degree of the first defrost valve and the second defrost valve according to the refrigerant superheat degree Air conditioning multi-air conditioner characterized in that the variable. 9. The method of claim 8,
The heating and cooling multi air conditioner
When the degree of superheat of the refrigerant is greater than a predetermined range, the amount of opening of the defrost valve of the currently defrosting heat exchanger among the first and second heat exchangers currently defrosting is reduced. 10. The method of claim 9,
During the defrosting operation, a lower defrosting mode in which the refrigerant discharged from the compressor flows into the second heat exchanger while evaporating the refrigerant in the first heat exchanger to defrost the second heat exchanger, and the Air conditioning and cooling, characterized in that the upper defrost mode of performing the defrosting of the first heat exchanger by flowing the refrigerant discharged from the compressor to the first heat exchanger while evaporating the refrigerant in a second heat exchanger is alternately performed Multi air conditioner. 11. The method of claim 10,
Controls the opening amount of the second defrost valve in the lower defrost mode, the first defrost valve is fully opened, and controls the opening amount of the first defrost valve in the upper defrost mode, and the second defrost valve is Air conditioning multi-air conditioner characterized in that it is fully open. 12. The method of claim 11,
The heating and cooling multi-outdoor unit
The outdoor unit for heating and cooling includes a suction temperature sensor for periodically reading an inlet temperature of the accumulator;
A pipe temperature sensor that periodically reads pipe temperatures of the first and second heat exchangers
Air conditioning multi-air conditioner, characterized in that it further comprises. 13. The method of claim 12,
The heating and cooling multi-outdoor unit
a first hot gas pipe connecting the discharge side of the compressor and the other end of the first heat exchanger;
a second hot gas pipe connecting the discharge side of the compressor and the other end of the second heat exchanger;
a first hot gas valve installed on the first hot gas pipe to flow the refrigerant of the compressor to the first heat exchanger; and
a second hot gas valve installed on the second hot gas pipe to flow the refrigerant of the compressor to the first heat exchanger
Air conditioning multi-air conditioner, characterized in that it further comprises. 14. The method of claim 13,
In the lower defrost mode, the second hot gas valve is opened to condense a portion of the refrigerant discharged from the compressor in the second heat exchanger,
In the upper defrost mode, the first hot gas valve is opened to condense a portion of the refrigerant discharged from the compressor in the first heat exchanger. 15. The method of claim 14,
In the upper defrost mode and the lower defrost mode, by controlling the opening degrees of the first defrost valve and the second defrost valve, the refrigerant flowing in the first heat exchanger and the second heat exchanger performs heat exchange while changing the phase. Heating and cooling multi air conditioner. 16. The method of claim 15,
In the upper defrost mode and the lower defrost mode, the amount of opening of the first defrost valve and the second defrost valve is controlled according to the suction temperature of the accumulator to concentrate the refrigerant into the indoor heat exchanger. energy.

Images