CN113251509B

CN113251509B - Air conditioning apparatus

Info

Publication number: CN113251509B
Application number: CN202011576531.7A
Authority: CN
Inventors: 金珏中; 宋致雨; 申一隆; 史容澈
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2020-01-28
Filing date: 2020-12-28
Publication date: 2023-03-31
Anticipated expiration: 2040-12-28
Also published as: CN113251509A; KR20210096522A; DE102021200238A1; US20210231317A1

Abstract

The air conditioning apparatus of the present invention includes: an outdoor unit in which a refrigerant circulates; an indoor unit in which water circulates; a heat exchanger device that connects the outdoor unit and the indoor unit and exchanges heat between the refrigerant and the water; a first internal pipe through which a refrigerant in a high-pressure state flows, the first internal pipe connecting the outdoor unit and the heat exchanger; a second internal pipe through which the refrigerant in a low-pressure state flows, the second internal pipe connecting the outdoor unit and the heat exchanger; and a third internal pipe connecting the outdoor unit and the heat exchange device, wherein a liquid refrigerant flows through the third internal pipe, the heat exchange device includes a bypass pipe bypassing the second internal pipe, and a flow rate control valve provided in the bypass pipe.

Description

Air conditioning apparatus

Technical Field

The present invention relates to an air conditioning apparatus.

Background

An air conditioning apparatus is a device for maintaining air in a predetermined space in an optimum state according to the use and purpose. Generally, the air conditioning device may include a compressor, a condenser, an expansion device, and an evaporator, and may cool or heat the prescribed space by driving a refrigeration cycle for performing compression, condensation, expansion, and evaporation processes of a refrigerant.

The predetermined space may be various scenes depending on the place of use of the air conditioning apparatus. For example, the air-conditioning apparatus may be installed in a house or an office.

When the air-conditioning apparatus performs a cooling operation, the outdoor heat exchanger provided in the outdoor unit functions as a condenser, and the indoor heat exchanger provided in the indoor unit functions as an evaporator. In contrast, in the case where the air conditioning device performs a heating operation, the indoor heat exchanger functions as a condenser, and the outdoor heat exchanger functions as an evaporator.

In recent years, in accordance with environmental protection policies, there is a tendency to limit the types of refrigerants used in air-conditioning apparatuses and to reduce the amount of refrigerants used.

In order to reduce the amount of refrigerant used, a technique has been proposed in which cooling or heating is performed by exchanging heat between the refrigerant and a predetermined fluid. As an example, the predetermined fluid may include water.

The following prior art documents relate to a system for performing cooling or heating by heat exchange between a refrigerant and water.

1. Authorization number: japanese patent publication No. 5279919

2. The invention name is as follows: air conditioning apparatus

The air conditioning apparatus of the above-mentioned conventional document includes an outdoor unit, a heat medium relay unit, and an indoor unit.

The heat medium converter includes: a heat exchanger; a fastening device located on an upstream side of the heat exchanger; and a refrigerant flow path changing device located on a downstream side of the heat exchanger. When the cooling operation is performed, the refrigerant flow changing device is connected to a refrigerant pipe through which a refrigerant in a low temperature state flows.

However, according to this conventional document, since the flow switching portion is always connected to the low-pressure gas pipe, there is a risk that the plate heat exchanger is frozen if a leak occurs in an Expansion Valve (EEV) of the plate heat exchanger in a non-operating state.

In addition, when one plate heat exchanger functions as an evaporator, the other plate heat exchanger functions as a condenser, and a plurality of indoor units simultaneously perform heating main bodies performing heating operation, there is a risk that the evaporation temperature of the plate heat exchanger functioning as an evaporator becomes zero, and frost cracking occurs.

Disclosure of Invention

The invention provides an air conditioner which can prevent water from freezing on a water flow path of a heat exchanger when heating-based simultaneous operation is performed.

The invention provides an air conditioner capable of forming the evaporation temperature of a heat exchanger to be more than 0 ℃ regardless of the outdoor temperature.

Further, an air conditioner is provided which can increase the flow rate of a compressor regardless of the evaporation temperature of a heat exchanger provided in an outdoor unit.

According to the air conditioning apparatus of an aspect of the present invention, the pressure of the low pressure gas pipe may be adjusted by the flow rate adjustment valve to prevent the occurrence of frost crack in a heat exchanger that performs heat exchange for performing a cooling operation of the indoor unit when a heating-based simultaneous operation is performed.

An air conditioning device according to an embodiment of the present invention may include: an outdoor unit in which a refrigerant circulates; an indoor unit in which water circulates; a heat exchange device for connecting the outdoor unit and the indoor unit and exchanging heat between the refrigerant and water; a first internal pipe for connecting the outdoor unit and the heat exchanger, wherein the refrigerant in a high-pressure state flows through the first internal pipe; a second internal pipe for connecting the outdoor unit and the heat exchanger, wherein the refrigerant in a low-pressure state flows through the second internal pipe; and a third internal pipe for connecting the outdoor unit and the heat exchanger, wherein a liquid refrigerant flows through the third internal pipe.

The heat exchanger may further include a bypass pipe that bypasses the second inner pipe, and a flow rate adjustment valve provided in the bypass pipe.

The heat exchange device may include: a branch portion that is one end of the bypass pipe connected to the second internal pipe; and a junction portion which is the other end of the bypass pipe connected to the second internal pipe.

The heat exchange device may further include a valve disposed between the branch portion and the confluence portion.

The second internal pipe may be provided with a pressure sensor that may measure a pressure of the refrigerant before flowing out of the branch portion.

The valve may be closed when the heating-based simultaneous operation is performed.

The opening degree of the flow rate adjustment valve may be adjusted so that the pressure measured by the pressure sensor falls within a pressure range between a first pressure P1 and a second pressure P2.

The opening degree of the flow rate adjustment valve may be decreased if the pressure measured by the pressure sensor is less than a first pressure P1, and may be increased if the pressure measured by the pressure sensor exceeds a second pressure P2.

The evaporation temperature of the second internal pipe based on the first pressure P1 may exceed 0 ℃.

When the heating operation is performed, the valve may be opened, and the flow rate adjustment valve may be opened at a maximum opening degree.

The heat exchange device may include: a first heat exchanger and a second heat exchanger; a first branch pipe and a second branch pipe that branch from the first inner pipe, respectively; and a third branch pipe and a fourth branch pipe that branch from the second inner pipe, respectively.

The method can comprise the following steps: first valves provided to the first branch pipe and the second branch pipe, respectively; and second valves provided to the third branch pipe and the fourth branch pipe, respectively.

The method can comprise the following steps: a first refrigerant pipe and a second refrigerant pipe that branch from the third internal pipe, respectively; a first expansion valve provided in the first refrigerant pipe; and a second expansion valve provided in the second refrigerant pipe.

The method can also comprise the following steps: a first common gas pipe to which the first branch pipe and the third branch pipe are connected; a fifth branch pipe for connecting the third branch pipe and the second internal pipe; a first bypass valve provided in the fifth branch pipe; a second common gas pipe to which the second branch pipe and the fourth branch pipe are connected; a sixth branch pipe for connecting the fourth branch pipe and the second internal pipe; and a second bypass valve provided in the sixth branch pipe.

Each of the heat exchangers may include: a refrigerant flow path through which a refrigerant flows; and a water flow path through which water flows so as to exchange heat with the refrigerant in the refrigerant flow path, and the water flowing through the water flow path can flow toward the indoor unit.

Drawings

Fig. 1 is a schematic diagram showing a configuration of an air-conditioning apparatus according to an embodiment of the present invention.

Fig. 2 is a circuit diagram showing the configuration of an air conditioner according to an embodiment of the present invention.

Fig. 3 is a circuit diagram showing a state in which the refrigerant and water flow through the heat exchanger when the air conditioner according to the embodiment of the present invention performs the heating operation.

Fig. 4 is a circuit diagram showing a state in which refrigerant and water flow through the heat exchanging device when the air conditioning apparatus according to the embodiment of the present invention performs the heating-based simultaneous operation.

Fig. 5 is a circuit diagram showing a state in which the refrigerant and water flow through the heat exchanging device when the air conditioning apparatus according to the embodiment of the present invention performs the cooling operation.

Fig. 6 is a circuit diagram showing a state of flow of the refrigerant and water in the heat exchanging device when the air conditioning apparatus according to the embodiment of the present invention performs the cooling-based simultaneous operation.

Fig. 7 is a graph showing a setting range of the pressure sensor value of the air-conditioning apparatus according to the embodiment of the present invention.

Detailed Description

In the following, some embodiments of the invention are explained in detail by means of exemplary drawings. Note that, when reference numerals are given to components in each drawing, the same components are denoted by the same reference numerals as much as possible although they are denoted by different drawings. In describing the embodiments of the present invention, detailed descriptions of related well-known structures or functions will be omitted when it is judged that the understanding of the embodiments of the present invention is hindered.

In describing the components of the embodiments of the present invention, terms such as first, second, and A, B, (a), (b), and the like may be used. The above terms are only used to distinguish the above-mentioned components from other components, and the nature, order, sequence, and the like of the corresponding components are not limited by the above terms. When it is stated that a certain component is "connected", "coupled" or "connected" to another component, it is to be understood that the component may be directly connected or coupled to the other component, and another component may be "connected", "coupled" or "coupled" between the components.

Fig. 1 is a schematic diagram showing the configuration of an air-conditioning apparatus according to an embodiment of the present invention, and fig. 2 is a circuit diagram showing the configuration of the air-conditioning apparatus according to the embodiment of the present invention.

Referring to fig. 1 and 2, an air conditioner 1 according to an embodiment of the present invention may include an outdoor unit 200, an indoor unit 50, and a heat exchange device 100 connected to the outdoor unit 200 and the indoor unit 50.

The outdoor unit 200 and the heat exchange device 100 may be connected to allow a first fluid to flow. As an example, the first fluid may comprise a refrigerant.

The refrigerant can flow through the refrigerant side flow path of the heat exchanger provided in the heat exchange device 100 and the outdoor unit 200.

The outdoor unit 200 includes: a plurality of

compressors

240, 242; and

oil separators

241 and 243 disposed on outlet sides of the plurality of

compressors

240 and 242 and separating oil from the refrigerant discharged from the plurality of

compressors

240 and 242.

The plurality of

compressors

240, 242 includes a first compressor 240 and a second compressor 242 connected in parallel. The

oil separators

241 and 243 include: a first oil separator 241 disposed on an outlet side of the first compressor 240; and a second oil separator 243 disposed on an outlet side of the second compressor 242.

The outdoor unit 200 includes a recovery flow path 245, and the recovery flow path 245 is used to recover oil from the

oil separators

241 and 243 to the

compressors

240 and 242. That is, the recovery flow path 245 extends from the first oil separator 241 toward the first compressor 240, and extends from the second oil separator 243 toward the second compressor 242.

Flow switching

parts

260 and 262 are provided on outlet sides of the

oil separators

241 and 243, and the

flow switching parts

260 and 262 guide the refrigerants discharged from the

compressors

240 and 242 to the outdoor heat exchange device 200 or the indoor unit side.

For example, the

flow switching parts

260 and 262 may include a first flow switching part 260 and a second flow switching part 262.

When the air conditioning apparatus performs a cooling operation, the refrigerant flows into the outdoor heat exchange apparatus 210 from the

flow switching parts

260 and 262. Conversely, when the air-conditioning apparatus performs a heating operation, the refrigerant flows from the

flow switching units

260 and 262 to the indoor heat exchanger side of the indoor unit.

The outdoor unit 200 is provided with a gas-liquid separator 250 connected to the inlet sides of the plurality of

compressors

240 and 242.

The gas-liquid separator 250 is configured to separate the gaseous refrigerant before the refrigerant flows into the

compressors

240 and 242. The separated gaseous refrigerant may flow into the

compressors

240, 242.

When the air conditioner performs the cooling operation, the refrigerant having passed through the outdoor heat exchange device 210 may flow into the third outdoor unit connection pipe 27.

The outdoor heat exchanging apparatus 210 includes a plurality of

heat exchanging parts

211, 212 and an outdoor fan 218. The plurality of

heat exchange portions

211, 212 include a first heat exchange portion 211 and a second heat exchange portion 212 connected in parallel.

Further, the outdoor heat exchange device 210 includes a variable flow path 220, and the variable flow path 220 guides a flow of the refrigerant from the outlet side of the first heat exchange portion 211 toward the inlet side of the second heat exchange portion 212. The variable flow path 220 extends from a first outlet pipe 230 (which is an outlet-side pipe of the first heat exchange unit 211) to an inlet pipe 212a (which is an inlet-side pipe of the second heat exchange unit 212).

The outdoor heat exchanger 210 is provided with a first valve 222, and the first valve 222 is provided in the variable flow path 220 to selectively block the flow of the refrigerant. The refrigerant passing through the first heat exchange portion 211 selectively flows into the second heat exchange portion 212 according to whether the first valve 222 is opened/closed.

Specifically, when the first valve 222 is in an open or open state, the refrigerant passing through the first heat exchange portion 211 flows through the variable flow path 220 to the inlet pipe 212a, and exchanges heat in the second heat exchange portion 212. After that, the refrigerant having passed through the second heat exchange portion 212 flows into the third outdoor unit connection pipe 27 through the second outlet pipe 231.

On the other hand, if the first valve 222 is closed or closed, the refrigerant passing through the first heat exchange portion 211 flows into the third outdoor unit connection pipe 27 through the first outlet pipe 230.

The first outlet pipe 230 is provided with a second valve 232 for regulating the flow of the refrigerant, and the second outlet pipe 231 is provided with a third valve 233 for regulating the flow of the refrigerant. The second valve 232 and the third valve 233 may be connected in parallel.

When the second valve 232 is in an open state or the opening degree thereof is increased, the amount of the refrigerant flowing through the first outlet pipe 230 is increased. When the third valve 233 is opened or the opening degree thereof is increased, the amount of the refrigerant flowing through the second outlet pipe 231 is increased.

The second Valve 232 and the third Valve 233 may include Electronic Expansion Valves (EEV).

The electronic expansion valve is capable of reducing the pressure of refrigerant passing through the expansion valve by adjusting the opening degree thereof. For example, when the expansion valve is in a fully open state (full-open state), the refrigerant may pass through the expansion valve without being decompressed, and when the opening degree of the expansion valve is decreased, the refrigerant may be decompressed. The degree of pressure reduction of the refrigerant increases as the opening degree decreases.

The first outlet pipe 230 and the second outlet pipe 231 are converged and connected to the third outdoor unit connection pipe 27.

The air conditioning device 1 may further include: and outdoor

unit connection pipes

21, 25, and 27 for connecting the outdoor unit 200 and the heat exchange device 100.

The outdoor

unit connection pipe

21, 25, and 27 may include: a first outdoor unit connection pipe 21 which is a gas pipe (high-pressure gas pipe) for flowing a high-pressure gas refrigerant; a second outdoor unit connection pipe 25 which is a gas pipe (low-pressure gas pipe) for flowing a low-pressure gas refrigerant; and a third outdoor unit connection pipe 27, which is a liquid pipe for flowing a liquid refrigerant.

That is, the outdoor unit 200 and the heat exchange device 100 have a "three-pipe connection structure" in which a refrigerant can circulate through the outdoor unit 200 via the three

connection pipes

21, 25, and 27.

The heat exchanger 100 may be connected to the three outdoor

unit connection pipes

21, 25, and 27 by providing three

internal pipes

11, 15, and 17, and the three

internal pipes

11, 15, and 17 may circulate a refrigerant through the outdoor unit 200 and the heat exchanger 100.

The heat exchange device 100 and the indoor unit 50 may be connected to allow a second fluid to flow. As an example, the second fluid may comprise water.

The water may flow through the water flow path of the heat exchanger provided in the heat exchanger device 100 and the outdoor unit 200.

The heat exchange device 100 may include a plurality of

heat exchangers

140, 141. As an example, the heat exchanger may comprise a plate heat exchanger. In the present specification, a plurality means two or more.

The indoor unit 50 may include a plurality of

indoor units

60 and 70. It should be noted that, in the present embodiment, the number of the

indoor units

60 and 70 is not limited, and fig. 1 shows a case where two

indoor units

60 and 70 are connected to the heat exchange device 100 as an example.

The

indoor units

60 and 70 may include a first indoor unit 60 and a second indoor unit 70.

The air conditioning device 1 may further include: and

pipes

30 and 35 for connecting the heat exchange device 100 and the indoor unit 50.

The piping 30, 35 may include: and a first indoor unit connection pipe 30 and a second indoor unit connection pipe 35 for connecting the heat exchange device 100 to the

indoor units

60 and 70, respectively.

Water may be circulated through the heat exchange device 100 and the indoor unit 50 via the indoor

unit connection pipes

30 and 35.

Of course, if the number of indoor units is increased, the number of pipes for connecting the heat exchange device 100 and the indoor units is increased.

With this configuration, the refrigerant circulating through the outdoor unit 200 and the heat exchanger 100 and the water circulating through the heat exchanger 100 and the indoor unit 50 exchange heat with each other through the

heat exchangers

140 and 141 provided in the heat exchanger 100.

The water cooled or heated by the heat exchange can exchange heat with the

indoor heat exchangers

61 and 71 provided in the indoor units 50, and thus can cool or heat the indoor space.

The number of the

heat exchangers

140 and 141 may be the same as the number of the

indoor units

60 and 70. Alternatively, two or more indoor units may be connected to one heat exchanger.

The heat exchanger 100 will be described in detail below.

The heat exchange device 100 may include a first heat exchanger 140 and a second heat exchanger 141, and the first heat exchanger 140 and the second heat exchanger 141 may be connected to each

indoor unit

60 and 70 to enable fluid to flow.

The first heat exchanger 140 and the second heat exchanger 141 may be formed in the same structure.

As an example, each of the

heat exchangers

140 and 141 may include a plate-shaped heat exchanger, and may be configured such that water flow paths and refrigerant flow paths are alternately stacked.

Each of the

heat exchangers

140, 141 may include a

refrigerant flow path

140a, 141a and a

water flow path

140b, 141b.

The

refrigerant flow paths

140a and 141a are connected to the outdoor unit 200 so as to allow a fluid to flow therethrough, and the refrigerant discharged from the outdoor unit 200 may flow into the

refrigerant flow paths

140a and 141a, and the refrigerant passing through the

refrigerant flow paths

140a and 141a may flow into the outdoor unit 200.

The

water flow paths

140b and 141b are connected to the

indoor units

60 and 70, respectively, and water discharged from each

indoor unit

60 and 70 can flow into the

water flow paths

140b and 141b, and water having passed through the

water flow paths

140b and 141b can flow into the

indoor units

60 and 70, respectively.

The heat exchange device 100 may include: a first branch pipe 101 and a second branch pipe 102 branched from the first internal pipe 11.

For example, the refrigerant in a high pressure state may flow through the first branch pipe 101 and the second branch pipe 102. Therefore, the first branch pipe 101 and the second branch pipe 102 may be named as high-pressure pipes.

First valves

103, 104 may be provided in the first branch pipe 101 and the second branch pipe 102.

However, it is clear that the number of branch pipes branching from the first internal pipe 11 is not limited.

The heat exchange apparatus 100 may include: a third branch pipe 105 and a fourth branch pipe 106 branched from the second internal pipe 15.

As an example, the refrigerant in a low pressure state may flow in the third branch pipe 105 and the fourth branch pipe 106. Therefore, the third branch pipe 105 and the fourth branch pipe 106 may be named as low-pressure pipes.

Second valves

107, 108 may be provided in the third branch pipe 105 and the fourth branch pipe 106.

However, it should be clear that the number of branch pipes branched from the second internal pipe 15 is not limited.

On the other hand, the second internal pipe 15 may further include a flow rate adjustment valve 161.

For example, a valve 163 may be provided in the second internal pipe 15, and the flow rate adjustment valve 161 may be provided in parallel with the valve 163. The valve 163 may be a solenoid valve.

In detail, the flow rate adjustment valve 161 may be provided in a bypass pipe 162 branched from the second internal pipe 15, and the valve 163 may be provided between a branching portion 162a (which is an inlet side of the bypass pipe 162) and a merging portion 162b (which is an outlet side of the bypass pipe 162).

For example, the bypass pipe 162 may be connected to the second inner pipe 15 at the branch portion 162a and the junction portion 162b, and at least a part of the refrigerant flowing through the second inner pipe 15 may flow to the bypass pipe 162.

The evaporation pressure of the second internal pipe 15 can be controlled by controlling the amount of the refrigerant that passes through the flow rate adjustment valve 161 and flows through the second internal pipe 15.

Further, the second internal pipe 15 may further include: a pressure sensor 164 for measuring the pressure in the second internal pipe 15.

For example, the pressure sensor 164 may be provided on an outlet side of the second internal pipe 15. Specifically, the pressure sensor 164 may be provided between the

branch pipes

105 and 106 of the second internal pipe 15 and the flow rate control valve 161.

The heat exchange apparatus 100 may include: a first common gas pipe 111 to which the first branch pipe 101 and the third branch pipe 105 are connected; and a second common gas pipe 112 to which the second branch pipe 102 and the fourth branch pipe 106 are connected.

The first common gas pipe 111 may be connected to one end of a refrigerant flow path of each of the

heat exchangers

140, 141.

The

refrigerant pipes

121 and 122 may be connected to the other ends of the refrigerant passages of the

heat exchangers

140 and 141.

A first refrigerant pipe 121 may be connected to the first heat exchanger 140, and a second refrigerant pipe 122 may be connected to the second heat exchanger 141.

A first expansion valve 123 may be provided in the first refrigerant pipe 121, and a second expansion valve 124 may be provided in the second refrigerant pipe 122.

The first refrigerant pipe 121 and the second refrigerant pipe 122 may be connected to the third internal pipe 17.

As an example, each of the

Expansion valves

123, 124 may include an Electronic Expansion Valve (EEV).

The heat exchange device 100 may further include: and a fifth branch pipe 113 for connecting the third branch pipe 105 and the second internal pipe 15.

The fifth branch pipe 113 bypasses the refrigerant around the second valve 107 of the third branch pipe 105. A first regulating valve 114 may be provided in the fifth branch pipe 113.

The heat exchange device 100 may further include: and a sixth branch pipe 115 for connecting the fourth branch pipe 106 and the second internal pipe 15.

The sixth branch pipe 115 bypasses the refrigerant around the second valve 1108 of the fourth branch pipe 106. A second regulating valve 116 may be provided in the sixth branch pipe 115.

The first regulating valve 114 and the second regulating valve 116 are valves capable of regulating the flow rate of the refrigerant. That is, the regulating

valves

114 and 116 may be electronic expansion valves whose opening degrees can be regulated.

On the other hand, each of the indoor

unit connection pipes

30 and 35 may include a heat

exchanger inflow pipe

31 and 36 and a heat

exchanger outflow pipe

32 and 37.

A

pump

151, 152 may be provided at each of the heat

exchanger inflow pipes

31, 36.

Each of the heat

exchanger inflow pipes

31, 36 and the heat

exchanger outflow pipes

32, 37 may be connected to each of the

indoor heat exchangers

61, 71.

The heat

exchanger inlet pipes

31 and 36 may function as indoor unit inlet pipes with respect to the

indoor heat exchangers

61 and 71, and the heat

exchanger outlet pipes

32 and 37 may function as indoor unit outlet pipes with respect to the

indoor heat exchangers

61 and 71.

Fig. 3 is a circuit diagram showing the flow state of the refrigerant and water in the heat exchanger when the air conditioner according to the embodiment of the present invention performs the heating operation.

Referring to fig. 3, when the air conditioning device 1 performs a heating operation, high-pressure gaseous refrigerant compressed by the

compressors

240 and 242 of the outdoor unit 200 may flow through the first outdoor unit connecting pipe 21 and the first inner pipe 11, and then may be branched toward the first branch pipe 101 and the second branch pipe 102.

When the air-conditioning apparatus 1 performs a heating operation, the

first valves

103 and 104 of the first branch pipe 101 and the second branch pipe 102 are opened, and the

second valves

107 and 108 of the third branch pipe 105 and the

fourth branch pipes

105 and 106 are closed. In addition, the first bypass valve 114 and the second bypass valve 116 are closed.

The refrigerant branched toward the first branch pipe 101 flows along the first common gas pipe 111, and then flows toward the refrigerant flow path 140a of the first heat exchanger 140.

The refrigerant branched toward the second branch pipe 102 flows along the second common gas pipe 112 and then flows to the refrigerant flow path 141a of the second heat exchanger 141.

In this embodiment, the

heat exchangers

140 and 141 may function as condensers when the air-conditioning apparatus 1 performs a heating operation.

When the air-conditioning apparatus 1 performs the heating operation, the first expansion valve 123 and the second expansion valve 124 are opened.

The refrigerant having passed through the

refrigerant flow paths

140a, 141a of the

heat exchangers

140, 141 passes through the

expansion valves

123, 124, and then flows into the third internal pipe 17.

The refrigerant discharged into the third internal pipe 17 can flow into the outdoor unit 200 and be sucked into the

compressors

240 and 242. For example, the refrigerant passing through the third outdoor unit connection pipe 27 may flow to the outdoor heat exchange device 210.

The refrigerant, which has passed through the outdoor heat exchange device 210 and has undergone heat exchange, may pass through the second flow switching part 262 and flow into the plurality of

compressors

240 and 242. The high-pressure refrigerant compressed by the plurality of

compressors

240 and 242 flows to the heat exchange device 100 again through the first outdoor unit connection pipe 21.

On the other hand, the water flowing through the water flow path of each of the

heat exchangers

140 and 141 is heated by heat exchange with the refrigerant, and the heated water is supplied to each of the

indoor heat exchangers

61 and 71 to perform heating.

On the other hand, during the operation of each of the

heat exchangers

140 and 141 during the heating operation, the valve 163 is opened, and the flow rate adjustment valve 161 can be opened by adjusting the opening degree thereof to the maximum.

That is, the amount of the refrigerant flowing through the second inner pipe 15 can be maximized.

The simultaneous operation of the air-conditioning apparatus based on heating refers to a case where a plurality of indoor units perform heating operation, and one of the

heat exchangers

140 and 141 may perform heat exchange for heating, while the remaining one may perform heat exchange for cooling.

For example, in the operation of the first heat exchanger 140, as described above, the first valve 103 of the first branch pipe 101 is opened, the second valve 107 of the third branch pipe 105 is closed, and the first expansion valve 123 is opened, so that the refrigerant flows as in the heating operation.

However, the first valve 104 of the second branch pipe 102 is closed, and the second valve 108 of the fourth branch pipe 106 and the second expansion valve 124 are opened. Furthermore, the

bypass valves

114, 116 are closed.

That is, the refrigerant branched from the third internal pipe 17 and distributed to the second refrigerant pipe 122 may be decompressed into a low-pressure refrigerant while passing through the second expansion valve 124.

The decompressed refrigerant exchanges heat with water along the refrigerant flow path of the second heat exchanger 141 to be evaporated, and then flows to the second common gas pipe 122. The refrigerant flowing into the second common gas pipe 122 flows into the second inner pipe 15 through the fourth branch pipe 106.

At this time, the refrigerant flowing into the outdoor unit 200 also flows in the same manner as in the case where the air-conditioning apparatus 1 performs the heating operation.

On the other hand, when the air-conditioning apparatus 1 performs a simultaneous operation for heating, the evaporation temperature of a heat exchanger that performs heat exchange for cooling may fall below 0 ℃, and thus there is a risk of occurrence of frost cracking.

Therefore, the pressure loss can be compensated for by the flow rate adjusting valve 161 provided in the second internal pipe 17, and the evaporation pressure in the second internal pipe 17 can be increased.

That is, when the air-conditioning apparatus 1 performs the simultaneous operation for heating, the valve 163 may be closed and only the flow rate adjustment valve 161 may be opened, thereby adjusting the amount of the refrigerant flowing through the second internal pipe 17.

As an example, the amount of the refrigerant may be adjusted such that the evaporation temperature based on the pressure measured by the pressure sensor 164 exceeds 0 ℃.

Fig. 5 is a circuit diagram showing a flow state of the refrigerant and water in the heat exchanger when the air conditioner according to the embodiment of the present invention performs the cooling operation, and fig. 6 is a circuit diagram showing a flow state of the refrigerant and water in the heat exchanger when the air conditioner according to the embodiment of the present invention performs the cooling-based simultaneous operation.

Referring to fig. 5, when the air-conditioning apparatus 1 performs the cooling operation, the high-pressure liquid refrigerant condensed in the outdoor heat exchanger 210 of the outdoor unit 200 may flow through the third outdoor unit connection pipe 27 and the third internal pipe 17, and then be distributed to the first refrigerant pipe 121 and the second refrigerant pipe 122.

Since the

expansion valves

123, 124 provided in the first refrigerant pipe 121 and the second refrigerant pipe 122 are opened at a predetermined opening degree, the refrigerant is decompressed into a low-pressure refrigerant while passing through the

expansion valves

123, 124.

The refrigerant having been depressurized can flow along the

refrigerant flow paths

140a and 141a of the

heat exchangers

140 and 141, and can be evaporated by exchanging heat with water.

That is, when the air conditioning device 1 performs the cooling operation, the

heat exchangers

140 and 141 may function as evaporators.

During the cooling operation of the air conditioning apparatus 1, the

first valves

103, 104 of the first branch pipe 101 and the second branch pipe 102 are closed, and the

second valves

107, 108 of the third branch pipe 105 and the fourth branch pipe 106 are opened. In addition, the

bypass valves

114, 116 are closed.

Therefore, the refrigerant passing through the

refrigerant flow paths

140a, 141a of the

heat exchangers

140, 141 flows toward the

common gas pipes

111, 112.

The refrigerant flowing through each of the

common gas pipes

111 and 112 flows through the third branch pipe 105 and the fourth branch pipe 106, and then flows into the second inner pipe 15.

The refrigerant discharged to the second internal pipe 15 may flow into the outdoor unit 200 and be sucked into the

compressors

240 and 242. The high-pressure refrigerant compressed by the

compressors

240 and 242 is condensed by the outdoor heat exchanger 210, and the condensed liquid refrigerant may flow along the third outdoor unit connection pipe 27 again.

On the other hand, since the flow of water is the same as that described in fig. 3, a detailed description thereof will be omitted.

On the other hand, fig. 6 is a circuit diagram showing the flow state of the refrigerant and water in the heat exchanging device when the air conditioning apparatus according to the embodiment of the present invention performs the cooling-based simultaneous operation.

That is, one of the

heat exchangers

140 and 141 may perform heat exchange for heating, and the remaining one may perform heat exchange for cooling. In this case, as described with reference to fig. 5, the operation of the outdoor unit 200 may be the same as that during the cooling operation.

On the other hand, while the

heat exchangers

140 and 141 are operating during the cooling operation, the valve 163 is opened, and the flow rate adjustment valve 161 can be opened by adjusting the opening degree thereof to the maximum.

On the other hand, fig. 7 is a graph showing a setting section of the pressure sensor value of the air-conditioning apparatus according to the embodiment of the present invention.

Referring to fig. 7, it can be confirmed that the opening degree of the flow rate adjustment valve 161 can be controlled by the pressure or temperature of the low pressure gas pipe, i.e., the second internal pipe 25.

Specifically, the flow rate adjustment valve 161 may adjust the amount of the refrigerant such that the pressure measured by the pressure sensor 164 belongs to a predetermined pressure range. The predetermined pressure interval may be an interval between the first pressure P1 and the second pressure P2.

For example, if the pressure measured by the pressure sensor 164 is lower than the first pressure P1, the opening degree of the flow rate control valve 161 is decreased, and if the pressure measured by the pressure sensor 164 exceeds the second pressure P2, the opening degree of the flow rate control valve 161 is increased.

The reference for the predetermined pressure range is a range in which the temperature of the refrigerant based on the pressure exceeds 0 ℃.

Specifically, the first pressure P1 is a pressure at which the evaporation temperature of the second internal pipe 25 based on the first pressure P1 exceeds 0 ℃. That is, the evaporation temperature T1 of the second internal pipe 25 based on the first pressure P1 may be greater than 0 ℃.

In order to operate the heat exchange device 100, the second internal pipe 25 needs to function as a low-pressure gas pipe, and therefore, the pressure can be kept at a predetermined pressure or lower. That is, the pressure measured by the pressure sensor 164 may be the second pressure P2 or less.

For example, the first pressure P1 may be about 740kPaG, and the second pressure P2 may be about 800 kPaG.

According to the embodiments of the present invention, it is possible to prevent: when the simultaneous operation by heating is performed, the evaporation pressure of the heat exchanger provided in the outdoor unit is lowered by the low-temperature outdoor environment, and thus the evaporation pressure of the heat exchanger provided in the heat exchange device is also lowered together, thereby causing a phenomenon of frost cracking.

Further, the flow rate of the low-pressure gas pipe is adjusted to maintain the evaporation temperature of the low-pressure gas pipe at 0 ℃ or higher, thereby preventing the heat exchanger provided in the heat exchanger from freezing.

Further, since the flow rate of the compressor can be increased without being affected by the evaporation pressure of the heat exchanger provided in the outdoor unit, a decrease in heating efficiency can be prevented.

Claims

1. An air conditioning device, comprising:

an outdoor unit in which a refrigerant circulates;

an indoor unit in which water circulates; and

a heat exchange device for connecting the outdoor unit and the indoor unit and exchanging heat between the refrigerant and the water,

the heat exchange device includes:

a first internal pipe through which a refrigerant in a high-pressure state flows, the first internal pipe connecting the outdoor unit and the heat exchanger;

a second internal pipe through which a low-pressure refrigerant flows, the second internal pipe connecting the outdoor unit and the heat exchanger;

a third internal pipe through which the liquid refrigerant flows, the third internal pipe connecting the outdoor unit and the heat exchanger;

a bypass pipe that bypasses the second inner pipe, and a flow rate adjustment valve that is provided in the bypass pipe and adjusts the flow of refrigerant so as to prevent the indoor unit from freezing when the indoor unit is operated while heating is mainly performed;

a branch portion that is connected to the second internal pipe as one end of the bypass pipe;

a junction portion that is connected to the second internal pipe as the other end of the bypass pipe; and

and a valve disposed in the second internal pipe and provided between the branch portion and the junction portion.

2. The air conditioning device according to claim 1,

a pressure sensor is provided in the second internal pipe.

3. The air conditioning device according to claim 2,

the pressure sensor measures a pressure of the refrigerant before branching from the branching portion.

4. The air conditioning device according to claim 2,

the valve is closed when the heating is mainly performed and the operation is performed.

5. The air conditioning device according to claim 2,

the flow rate control valve adjusts the opening degree thereof such that the pressure measured by the pressure sensor falls within a pressure range between a first pressure (P1) and a second pressure (P2).

6. The air conditioning device according to claim 5,

if the pressure measured by the pressure sensor is less than a first pressure (P1), the opening of the flow rate regulating valve is reduced,

if the pressure measured by the pressure sensor is greater than a second pressure (P2), the opening of the flow rate control valve is increased.

7. The air conditioning device according to claim 6,

the evaporation temperature of the second internal pipe based on the first pressure (P1) is greater than 0 ℃.

8. The air conditioning device according to claim 1,

when the heating operation is performed, the valve is opened, and the flow rate adjustment valve is opened at the maximum opening degree.

9. The air conditioning device according to claim 1,

the heat exchange device includes:

a first heat exchanger and a second heat exchanger;

a first branch pipe and a second branch pipe branching from the first internal pipe, respectively; and

and a third branch pipe and a fourth branch pipe which branch from the second inner pipe.

10. The air conditioning device according to claim 9, comprising:

first valves respectively arranged on the first branch pipe and the second branch pipe; and

and second valves respectively provided to the third branch pipe and the fourth branch pipe.

11. The air conditioning device according to claim 1, further comprising:

a first refrigerant pipe and a second refrigerant pipe branching from the third internal pipe, respectively;

a first expansion valve provided in the first refrigerant pipe; and

and a second expansion valve provided in the second refrigerant pipe.

12. The air conditioning device according to claim 9, further comprising:

a first common gas pipe to which the first branch pipe and the third branch pipe are connected;

a fifth branch pipe connecting the third branch pipe and the second internal pipe;

the first bypass valve is arranged on the fifth branch pipe;

a second common gas pipe to which the second branch pipe and the fourth branch pipe are connected;

a sixth branch pipe connecting the fourth branch pipe and the second internal pipe; and

and a second bypass valve provided in the sixth branch pipe.

13. The air conditioning device according to claim 9,

the first and second heat exchangers include:

a refrigerant flow path through which a refrigerant flows; and

a water flow path through which water flows to exchange heat with the refrigerant in the refrigerant flow path,

the water flowing through the water flow path flows to the indoor unit.