KR101644703B1 - An air conditioner and Method of controlling the same - Google Patents

Abstract

The present invention relates to an air conditioner and a control method thereof. An air conditioner according to one aspect of the present invention includes: a load sensing unit for sensing a load amount operated in an indoor unit; A control unit for determining an amount of refrigerant necessary for driving the indoor unit based on the measured load on the load sensing unit; And an outdoor heat exchanger for exchanging heat with the refrigerant flowing into the indoor unit and storing or discharging the refrigerant to the indoor unit; A sensing unit provided on the refrigerant channel of the outdoor heat exchanger for sensing an amount of refrigerant stored in the outdoor heat exchanger; And a valve driving unit for driving a valve device for adjusting a flow direction of a refrigerant flowing in the outdoor heat exchanger in response to an instruction from the control unit, wherein the control unit detects the indoor load amount sensed by the load sensing unit, And the opening degree of the valve device is controlled by driving the valve driving section on the basis of the information on the refrigerant storage amount.

Description

[0001] The present invention relates to an air conditioner and a control method thereof,

The present invention relates to an air conditioner and a control method thereof.

The air conditioner is a device for keeping the air in a predetermined space in a most suitable condition according to the purpose of use and purpose. Generally, the air conditioner includes a compressor, a condenser, an expansion device, and an evaporator, and a refrigerant cycle for compressing, condensing, expanding, and evaporating the refrigerant is driven to cool or heat the predetermined space .

The predetermined space may be variously proposed depending on the place where the air conditioner is used. For example, when the air conditioner is installed in a home or an office, the predetermined space may be an indoor space of a house or a building. On the other hand, when the air conditioner is disposed in a car, the predetermined space may be a boarding space on which a person boarded.

When the air conditioner performs the 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. On the other hand, when the air conditioner performs the heating operation, the indoor heat exchanger functions as a condenser and the outdoor heat exchanger functions as an evaporator.

1 is a view showing a configuration of a conventional outdoor heat exchanger.

1, a conventional outdoor heat exchanger 1 is provided with a plurality of refrigerant tubes 2 arranged in a plurality of rows, and an end portion of the refrigerant tube 2 connected to the refrigerant tubes 2, And a header 4 for branching the refrigerant to the coupling plate 3 and the refrigerant pipe 2 or for coupling the refrigerant passing through the refrigerant pipe 2 to each other.

The outdoor heat exchanger (1) further includes a return tube (7) for switching the flow direction of the refrigerant from one refrigerant pipe (2) to another refrigerant pipe. For example, the return tube 7 can change the flow direction of the refrigerant from the refrigerant pipe 1 located in the first row to the refrigerant pipe located in the second row among the two rows of the refrigerant pipes 2.

The outdoor heat exchanger (1) further includes a plurality of distributors (5, 6). Wherein the plurality of distributors (5, 6) are provided with a first distributor (5) for branching and introducing refrigerant into at least a part of the refrigerant tubes of the plurality of refrigerant tubes (2) And a second distributor (6) for branching and introducing the refrigerant into the pipe.

In such an outdoor heat exchanger 1, the flow direction of the refrigerant is opposite to that in the cooling and heating operation.

For example, when the air conditioner performs cooling operation, the outdoor heat exchanger 1 functions as a condenser (see a solid line arrow).

In detail, the high-pressure refrigerant compressed in the compressor flows into the header 4, is branched into a plurality of refrigerant tubes 2, and is heat-exchanged with the outdoor air while flowing in the refrigerant tube 2. The heat-exchanged refrigerant is mixed in the first distributor (5) and the second distributor (6) and flows to the indoor heat exchanger side.

On the other hand, when the air conditioner performs the heating operation, the outdoor heat exchanger 1 functions as an evaporator (see the dotted arrow).

In detail, the refrigerant condensed in the indoor heat exchanger is decompressed while passing through the expansion device, and can be introduced into the outdoor heat exchanger (1). The refrigerant is branched from the inlet side of the outdoor heat exchanger 1 to the first distributor 5 and the second distributor 6 and flows into the refrigerant pipe 2 through a plurality of branch pipes connected to the respective distributors .

At this time, the refrigerant is heat-exchanged with the outdoor air during the flow of the refrigerant through the refrigerant pipe (2), and the heat-exchanged refrigerant can be joined to the header (4) and flow to the compressor side.

When the air conditioner is driven, the amount of refrigerant required varies depending on the load amount to be operated in the indoor unit. In particular, since the amount of refrigerant required at the time of low load operation is smaller than the amount of refrigerant required at the maximum load reflected in the system design, the amount of excess refrigerant has a problem of lowering the cooling efficiency at the time of low load operation.

Although a method of installing a separate reservoir for storing the excess refrigerant has been proposed, there is a problem that the amount and state of the refrigerant stored in the reservoir can not be grasped.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an air conditioner having improved cooling efficiency.

According to an aspect of the present invention, there is provided a load sensing apparatus comprising: a load sensing unit for sensing a load operating on an indoor unit; A control unit for determining an amount of refrigerant necessary for driving the indoor unit based on the measured load on the load sensing unit; And an outdoor heat exchanger for exchanging heat with the refrigerant flowing into the indoor unit and storing or discharging the refrigerant to the indoor unit; A sensing unit provided on the refrigerant channel of the outdoor heat exchanger for sensing an amount of refrigerant stored in the outdoor heat exchanger; And a valve driving unit for driving a valve device for adjusting a flow direction of a refrigerant flowing in the outdoor heat exchanger in response to an instruction from the control unit, wherein the control unit detects the indoor load amount sensed by the load sensing unit, And the opening of the valve device is controlled through driving of the valve driving section on the basis of the information on the stored refrigerant amount.

According to another aspect of the present invention, there is provided an air conditioner comprising: Detecting a load value operated in the indoor unit through a load sensing unit; Determining whether the refrigerant circulating in the outdoor heat exchanger is stored according to the sensed load value; Sensing an amount of refrigerant stored in the outdoor heat exchanger through a sensing unit; And controlling the controller to determine whether the refrigerant stored in the outdoor heat exchanger is discharged according to the sensed amount of refrigerant.

According to the present invention, when the air conditioner is in the cooling operation and the heating operation, the amount of the refrigerant performing the cycle can be adjusted according to the amount of load operated in the indoor unit, so that the cooling and heating efficiency can be improved.

Further, there is an advantage that the amount of the refrigerant performing the cycle can be reduced by storing the heat-exchanged refrigerant in the outdoor heat exchanger.

Further, since the outdoor heat exchanger includes the temperature sensor and the sensing sensor, the amount and state of the refrigerant stored in the outdoor heat exchanger can be grasped, and the refrigerant control can be clearly performed.

1 is a view showing a configuration of a conventional outdoor heat exchanger.
2 is a system diagram showing a configuration of an air conditioner according to an embodiment of the present invention.
3 is a view showing a main configuration of an outdoor heat exchanger according to an embodiment of the present invention.
4 is an enlarged view of a lower header of an outdoor heat exchanger according to an embodiment of the present invention;
5 is an enlarged view of a lower header of an outdoor heat exchanger according to a second embodiment of the present invention.
6 is a block diagram of an air conditioner according to the present invention.
7 is a flowchart of a refrigerant control method according to an embodiment of the present invention.
8 is a flowchart of a refrigerant control method according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

FIG. 2 is a system diagram showing the configuration of an air conditioner according to an embodiment of the present invention. FIG. 3 is a view showing a main configuration of an outdoor heat exchanger according to an embodiment of the present invention. FIG. 3 is an enlarged view of a lower header of the outdoor heat exchanger according to FIG.

Referring to FIG. 2, the air conditioner 10 according to the embodiment of the present invention includes an outdoor unit arranged outdoors and an indoor unit arranged in the room. The indoor unit includes an indoor heat exchanger that exchanges heat with air in the indoor space. Fig. 2 shows the configuration of the outdoor unit.

The air conditioner (10) is provided with a plurality of compressors (110, 112), an oil separator (110, 120) disposed at an outlet side of the plurality of compressors (110, 120) for separating oil from refrigerant discharged from the plurality of compressors 120, 122).

The plurality of compressors 110 and 112 include a first compressor 110 and a second compressor 112 connected in parallel. Discharge temperature sensors 114 for sensing the temperature of the compressed refrigerant may be provided at the outlet sides of the first compressor 110 and the second compressor 112, respectively.

The oil separators 120 and 122 include a first oil separator 120 disposed at an outlet side of the first compressor 110 and a second oil separator 122 disposed at an outlet side of the second compressor 112 ).

The air conditioner 10 includes a recovery flow path 116 for recovering oil from the oil separators 120 and 122 to the compressors 110 and 112. The recovery flow path 116 extends from the respective outlet sides of the first and second oil separators 120 and is connected to the inlet side piping of the first and second compressors 110 and 112.

A dryer 127 and a capillary 128 may be installed in the recovery flow path 116.

A high pressure sensor 125 for sensing a discharge high pressure of the refrigerant discharged from the compressors 110 and 112 and a refrigerant passing through the high pressure sensor 125 are connected to the outdoor heat exchanger 200 or indoor unit The flow switching unit 130 is provided. For example, the flow switching unit 130 may include a four-way valve.

When the air conditioner performs the cooling operation, the refrigerant flows into the outdoor heat exchanger (200) from the flow switching unit (130). On the other hand, when the air conditioner performs the heating operation, the refrigerant flows from the flow switching unit 130 to the indoor heat exchanger side of the indoor unit (not shown).

When the air conditioner is in the cooling operation mode, the refrigerant condensed in the outdoor heat exchanger 200 passes through the main expansion valve 260 (the electronic expansion valve), and the main expansion valve 260 is fully opened, The pressure reducing action is not performed. That is, the main expansion valve 260 may be installed on the outlet side of the outdoor heat exchanger 200 on the basis of cooling operation.

The refrigerant passing through the main expansion valve (260) passes through the heat sink (265). The heat dissipation plate 265 may be provided in an electrical unit provided with a heat generating component.

For example, the heat generating component may include an intelligent power module (IPM). The IPM is understood as a module provided with a power MOSFET for controlling electric power, a drive circuit for a power device such as an IGBT, and a protection circuit for a magnetic protection function.

The condensed refrigerant is coupled to the heat sink 265 to cool the heat generating component.

The air conditioner 10 is provided with a supercooling heat exchanger 270 through which the refrigerant flowing through the heat dissipating plate 265 flows and a supercooling distributor 271 provided at the inlet side of the supercooling heat exchanger 270 for branching the refrigerant . The supercooling heat exchanger 270 functions as an intermediate heat exchanger in which the first refrigerant circulating through the system and the refrigerant (second refrigerant) of a part of the first refrigerant are branched and then heat-exchanged.

Here, the first refrigerant is a refrigerant flowing into the supercooling heat exchanger 270 through the supercooling distributor 271, and may be supercooled by the second refrigerant. On the other hand, the second refrigerant can absorb heat from the first refrigerant.

The air conditioner (10) includes a supercooling flow path (273) provided at an outlet side of the supercooling heat exchanger (270) to branch the second refrigerant from the first refrigerant. The supercooling flow path 273 is provided with a supercooling expansion device 275 for reducing the pressure of the second refrigerant. The supercooling expansion device 275 may include an EEV (Electric Expansion Valve).

The second refrigerant in the supercooling passage 273 flows into the supercooling heat exchanger 270 and is heat-exchanged with the first refrigerant, and then flows to the inlet side of the gas-liquid separator 280. The air conditioner (10) further includes a supercooling discharge temperature sensor (276) for sensing the temperature of the second refrigerant that has passed through the supercooling heat exchanger (270).

The gas-liquid separator 280 separates the gaseous refrigerant before the refrigerant is introduced into the compressors 110 and 112. The separated gaseous refrigerant can be introduced into the compressors 110 and 112.

In the process of driving the refrigeration cycle, the evaporated refrigerant may be introduced into the gas-liquid separator 280 through the flow switching unit 130. At this time, the evaporated refrigerant passes through the supercooling heat exchanger 270 2 refrigerant and flows into the gas-liquid separator 280.

The inlet side of the gas-liquid separator 280 may be provided with a suction temperature sensor 282 for sensing the temperature of the refrigerant to be sucked into the compressors 110 and 112.

Meanwhile, the first refrigerant passing through the supercooling heat exchanger (270) may be introduced into the indoor unit through the indoor unit connecting pipe (279). The air conditioner (10) is provided with an outlet pipe (24) which is provided at an outlet side of the supercooling heat exchanger (270) and which has a liquid pipe temperature Sensor 278 is further included.

Hereinafter, the outdoor heat exchanger 200 and its peripheral structure will be described.

The air conditioner 10 is provided with a first inlet pipe 201a connected to one side of the outdoor heat exchanger 200 from the flow switching unit 130 and a second inlet pipe 201b connected to the main expansion pipe 201a from the other side of the outdoor heat exchanger 200, And a second inlet / outlet pipe 201b extending to the device 260 is included.

The first inlet pipe 201a is connected to the upper portion of the header 205 and the second inlet pipe 201b is connected to the lower portion of the header 205, 205b.

During the cooling operation of the air conditioner 10, the refrigerant flows into the outdoor heat exchanger 200 through the first inlet / outlet pipe 201a and flows through the second inlet / outlet pipe 201b to the outdoor heat exchanger 200 .

On the other hand, at the time of heating operation of the air conditioner 10, the refrigerant flows into the outdoor heat exchanger 200 through the second inlet / outlet pipe 201b and flows through the first heat exchanger 201a And is discharged from the apparatus 200.

The outdoor heat exchanger 200 includes a refrigerant pipe 201 having a plurality of rows and a plurality of stages. For example, the refrigerant pipe 201 may be provided in a plurality of rows so as to form two rows in the lateral direction and a plurality of rows in the longitudinal direction, and a plurality of the refrigerant pipes 201 may be spaced apart from each other.

The plurality of refrigerant pipes 202 may be bent and extended. For example, referring to FIG. 3, the plurality of refrigerant pipes 202 may be configured to extend rearwardly of the ground and then forward again. In this case, the plurality of refrigerant pipes 202 may have a U shape.

The outdoor heat exchanger (200) further includes a coupling plate (203) for supporting the refrigerant pipe (201). The coupling plate 203 includes a first plate 203a for supporting one side of the refrigerant pipe 202 having a bent shape and a second plate 203b for supporting the other side. The first plate 203a and the second plate 203b are elongated in the vertical direction.

The outdoor heat exchanger 200 further includes a return pipe 204 coupled to an end of the plurality of refrigerant pipes 202 for guiding the refrigerant flowing through the refrigerant pipe 202 to the other refrigerant pipe 202 . The return pipe 204 is provided with a plurality of return pipes 204 and is coupled to one side of the first plate 203a and the second plate 203b.

The outdoor heat exchanger (200) further includes a header (205) forming a space for the refrigerant to flow. The header 205 branches or introduces the refrigerant into the plurality of refrigerant pipes 202 depending on the cooling or heating operation of the air conditioner 10, And may be configured to join the refrigerant. The header 205 is elongated in the vertical direction corresponding to the extending direction of the first plate 203a.

A plurality of coolant inlet pipes 232 extend between the header 205 and the first plate 203a. The plurality of refrigerant inlet pipes 232 extend from the header 205 and are connected to a refrigerant pipe 202 supported by the first plate 203a. The plurality of coolant inflow pipes 232 may be spaced apart from each other in the vertical direction.

During the cooling operation of the air conditioner 10, the refrigerant in the header 205 may flow into the refrigerant pipe 202 through the plurality of refrigerant inlet pipes 232. On the other hand, in the heating operation of the air conditioner 10, the refrigerant of the refrigerant pipe 202 may flow into the header 205 through the refrigerant inlet pipe 232.

The outdoor heat exchanger 200 includes a plurality of refrigerant inlet pipes 232 extending from the lower header 205b to the plurality of refrigerant pipes 202. The plurality of refrigerant inflow pipes 232 include a lowermost inflow pipe 232a disposed at the lowest position and a plurality of upper inflow pipes 232b disposed above the lowest inflow pipe 232a.

The plurality of refrigerant inflow pipes 232 are provided with a temperature sensor 290 installed in each of the plurality of refrigerant inflow pipes 232 to sense the temperature of the refrigerant flowing through the refrigerant inflow pipe 232 . The temperature sensor 290 includes a first temperature sensor 291 disposed inside the lowermost inlet pipe 232a and a plurality of temperature sensors 292 and 298 provided in the plurality of upper inlet pipes 232b. . That is, the temperature sensor 290 is installed on the flow path through which the refrigerant flows in the plurality of refrigerant inlet pipes 232.

The temperature sensor 290 senses the temperature of the refrigerant flowing in the refrigerant inflow pipe to determine the state and the level of the refrigerant, which will be described later.

Meanwhile, the temperature sensor 290 may be provided inside the lower header 205b. At this time, the temperature sensor 290 may be provided in a plurality of spaced apart from the bottom surface of the lower header 205b upward. The temperature sensor 290 is provided on a flow path through which the refrigerant flows in the lower header 205b.

Also, the temperature sensor 290 may be provided inside the refrigerant pipe 202. In this case, the temperature sensor 290 may be provided with a plurality of temperature sensors 290 spaced a certain distance upward with respect to the lowermost end of the refrigerant pipe 202.

5 is an enlarged view of a lower header of an outdoor heat exchanger according to a second embodiment of the present invention.

Referring to FIG. 5, a water level sensor 300 may be provided inside the lower header 205b to detect the level of the refrigerant stored in the lower header 205b. The level sensor 300 includes a first level sensor 301 disposed on the lowermost side of the lower header 205b and a plurality of level sensors 302 and 308 disposed on the upper side of the first level sensor 301 . The water level sensor 300 may be installed up to the inner most end of the lower header 205b. When the refrigerant is stored in the lower portion of the outdoor heat exchanger 200, the level sensor 300 senses the level of the refrigerant stored in the lower header 205b and senses the amount of the refrigerant.

Any one of the temperature sensor 290 and the water level sensor 300 may be included in the outdoor heat exchanger 200 and both the temperature sensor 290 and the water level sensor 300 may be connected to the outdoor heat exchanger 200 As shown in Fig.

The functions and effects of the temperature sensor 290 and the water level sensor 300 will be described later.

The air conditioner (10) further includes a plurality of distributors (210, 220) for branching and introducing the refrigerant to the outdoor heat exchanger (200) based on the heating operation. The plurality of distributors 210 and 220 include a first distributor 210 and a second distributor 220.

The air conditioner 10 is connected to the first distribution pipe 211 and the second distribution pipe 212 branched from the second inlet pipe 201b to the first distributor 210 and the second distributor 220, The first distribution pipe 211 and the second distribution pipe 221 may be extended from the branching unit 201c to the first distributor 210 and the second distributor 220. [ have.

The air conditioner 10 includes a first valve unit 215 installed in the first distribution pipe 211 and capable of controlling the amount of refrigerant flowing through the first distribution pipe 211, And a second valve device 225 installed in the second distribution pipe 221 and capable of controlling the amount of refrigerant flowing through the second distribution pipe 221.

The first valve device 215 and the second valve device 225 may include an electronic expansion valve capable of controlling opening degree.

The air conditioner 10 further includes a plurality of capillary tubes 207 extending from the first distributor 210 and the second distributor 220 to the plurality of refrigerant pipes 202. The refrigerant is branched into the first distributor 210 and the second distributor 220 during the heating operation of the air conditioner 10 and flows through the plurality of capillary tubes 207 to the refrigerant pipe 202 Flow.

The air conditioner 10 further includes a branch pipe 209 connecting the plurality of capillary tubes 207 to the refrigerant pipe 202. The branch pipe 209 branches the refrigerant flowing through the capillary tube 207 in two directions and branches the refrigerant into one refrigerant pipe 202 and another refrigerant pipe 202. For example, the branch tube 209 may include a branch tube having a Y-shape. A plurality of branch tubes 209 may be provided corresponding to the number of the capillary tubes 207.

The refrigerant flowing into the refrigerant pipe 202 through the plurality of capillary tubes 207 connected to the first distributor 210 undergoes heat exchange and then flows into the header 205, As shown in FIG. The refrigerant flowing into the refrigerant pipe 202 through the plurality of capillary tubes 207 connected to the second distributor 220 is heat-exchanged and then flows into the lower header 205b of the header 205 .

That is, the header 205 includes an upper header 205a communicating with the first distributor 210 and a lower header 205b communicating with the second distributor 220. 3, a virtual partition line l1 for partitioning the upper header 205a and the lower header 205b is displayed.

The air conditioner 10 further includes a check valve 240 installed between the upper header 205a and the lower header 205b. The check valve 240 permits refrigerant flow from the lower header 205b to the upper header 205a and limits refrigerant flow from the upper header 205a to the lower header 205b.

The refrigerant flowing into the refrigerant pipe 202 through the second distributor 220 flows into the lower header 205b after the heat exchange and the check valve 240 And may flow into the upper header 205b. The refrigerant flowing into the refrigerant pipe 202 through the first distributor 210 flows into the upper header 205a after heat exchange and is joined to the refrigerant flowing from the lower header 205b, 1 < / RTI > inlet / outlet pipe 201a.

The air conditioner 10 further includes a connection pipe 230 extending from one point of the first distribution pipe 211 to the lower header 205b. The connection pipe 230 may be provided with a third valve device 235 for controlling the flow rate of the refrigerant in the connection pipe 230. For example, the third valve device 235 may include a solenoid valve capable of ON / OFF control or an electronic expansion valve capable of adjusting opening degree.

The refrigerant that has flowed from the first distributor 210 to the first distribution pipe 211 may be introduced into the lower header 205b through the connection pipe 230 during the cooling operation of the air conditioner 10. [ have.

Hereinafter, the refrigerant flow in the air conditioner 10 during the heating operation and the cooling operation of the air conditioner will be described with reference to Figs. 2 and 3. Fig.

First, when the air conditioner performs the heating operation, the high-temperature and high-pressure refrigerant compressed by the first and second compressors 110 and 112 is separated from the oil while passing through the first and second oil separators 120 and 122, And returns to the first and second compressors (110, 112) through the recovery flow path (116). The refrigerant from which the oil is separated flows through the flow switching unit 130 to the indoor unit side.

The refrigerant flowing into the indoor unit is condensed in the indoor heat exchanger, and the condensed refrigerant flows into the supercooling heat exchanger (270) through the indoor unit connecting pipe (279). At this time, a part of the refrigerant is branched into the supercooling flow path 273, is depressurized in the supercooling expansion device 275, and can be introduced into the supercooling heat exchanger 270.

Therefore, the condensed refrigerant and the refrigerant flowing through the supercooling flow path 273 are heat-exchanged with each other, so that the condensed refrigerant can be supercooled.

The supercooling refrigerant passing through the supercooling heat exchanger 270 may be reduced in pressure in the main expansion valve 260 by cooling the heat generating component of the electric unit through the heat dissipating plate 265.

The decompressed refrigerant may be branched into the first distribution pipe 211 and the second distribution pipe 221 from the branched portion 201c and may be respectively introduced into the first distributor 210 and the second distributor 220 . At this time, the first valve device 215 and the second valve device 225 can be opened beyond the set opening degree. For example, the first valve device 215 and the second valve device 225 may be fully opened.

The refrigerant flowing into the first distributor 210 flows into the refrigerant pipe 202 through the plurality of capillary tubes 207 and flows into the upper header 205a after heat exchange. The refrigerant flowing into the second distributor 220 flows into the refrigerant pipe 202 through the plurality of capillary tubes 207 and flows into the lower header 205b after heat exchange. At this time, the refrigerant can be evaporated in the process of heat exchange.

The refrigerant flowing into the lower header 205b flows into the upper header 205a and is mixed with the refrigerant flowing into the upper header 205a. At this time, the refrigerant in the lower header 205b can flow to the upper header 205a via the check valve 240 (see the dotted arrow).

The gaseous refrigerant may be discharged to the first inlet / outlet pipe 201a connected to the upper header 205a. The gaseous refrigerant introduced into the gas-liquid separator 280 through the flow switching unit 130 and separated from the gas- The refrigerant can be sucked into the first and second compressors 110 and 112. This cycle can be repeated.

In this way, the refrigerant can be introduced into the outdoor heat exchanger 200 through the first and second distributors 210 and 220 during the heating operation of the air conditioner 10, The heat exchanging can be performed using both the flow path on the side of the first distributor 220 and the flow path on the second distributor 220 side.

Therefore, the refrigerant flow path in the outdoor heat exchanger 200 is shortened, while the number of paths branched to the outdoor heat exchanger 200 is increased. As a result, it is possible to reduce the pressure loss of the refrigerant and thereby prevent the evaporation pressure from being lowered, thereby improving the evaporation efficiency.

Next, when the air conditioner performs the cooling operation, the high-temperature and high-pressure refrigerant compressed by the first and second compressors 110 and 112 flows through the first and second oil separators 120 and 122, Return to the first and second compressors (110, 112) through the recovery flow path (116). The refrigerant separated from the oil flows to the first inlet / outlet pipe 201a through the flow switching unit 130 and flows into the header 205 of the outdoor heat exchanger 200. [

The refrigerant flowing into the header 205 is present in the upper header 205a and limited by the check valve 240 to the lower header 205b.

The refrigerant in the upper header 205a flows into the refrigerant pipe 202 fixed to the first plate 203a through the plurality of refrigerant inlet pipes 232. [ The refrigerant in the refrigerant pipe 202 flows to the plurality of capillary tubes 207 through the branch pipe 209 after heat exchange. At this time, the refrigerant can be firstly condensed in the process of heat exchange.

The refrigerant of the plurality of capillary tubes 207 is mixed in the first distributor 210 and flows into the lower header 205b through the first distribution pipe 211 and the connection pipe 230. At this time, the first valve device 215 is closed, and the refrigerant is restricted from flowing to the branched portion 201c. Then, the third valve device 235 is turned on or opened beyond the set opening to allow the refrigerant to flow to the connecting pipe 230.

The refrigerant flowing into the lower header 205b flows into the plurality of refrigerant pipes 202 fixed to the first plate 203a via the plurality of refrigerant inlet pipes 232. [ The refrigerant can be secondarily condensed in the process of flowing through the plurality of refrigerant pipes 202.

The second condensed refrigerant flows into the second distributor 220 through the branch pipe 209 and the plurality of capillary tubes 207. [ The refrigerant of the second distributor 220 flows through the second distribution pipe 221 and the branched portion 201c to flow through the second inlet and outlet flow passage 201b and is discharged from the outdoor heat exchanger 200 .

The refrigerant discharged from the outdoor heat exchanger 200 may flow to the indoor unit through the heat dissipating plate 265 and the supercooling heat exchanger 270. After the refrigerant expands and evaporates in the indoor unit, the refrigerant can be sucked into the first and second compressors 110 and 120 through the flow switching unit 130 and the gas-liquid separator 280. This cycle can be repeated.

The refrigerant flowing into the outdoor heat exchanger 200 is first condensed in the refrigerant pipe 202 connected to the upper header 205a during the cooling operation of the air conditioner 10, The refrigerant flow path becomes long while the number of paths branched to the refrigerant pipe 202 is reduced by secondary condensation in the refrigerant pipe 202 connected to the refrigerant pipe 205b. As a result, it is possible to increase the flow rate of the refrigerant, thereby reducing the condensation pressure and improving the condensation efficiency.

On the other hand, the amount of the refrigerant performing the refrigerant cycle varies depending on the amount of load operated in the indoor unit. Accordingly, in the present embodiment, the refrigerant is stored in the lower portion of the outdoor heat exchanger 200, and the refrigerant thus stored is controlled.

FIG. 6 is a block diagram of an air conditioner according to the present invention, and FIG. 7 is a flowchart of a refrigerant control method according to an embodiment of the present invention.

6, the air conditioner 10 may include a control unit 20, an indoor load sensing unit 30, a sensor unit 40, a valve driving unit 50, and a memory 60. The components shown in Fig. 6 are not essential for realizing the air conditioner, and can have more or fewer components than the components listed above in the air conditioner 10 described in this specification.

More specifically, the load sensing unit 30 among the components senses a load operating in the indoor unit. Accordingly, the controller 20 controls the refrigerant stored or heat-exchanged in the outdoor heat exchanger 200 through the sensed load.

The sensor unit 40 may include a temperature sensor 290 and a water level sensor 300 provided in the outdoor heat exchanger 200. The control unit 20 controls the valve driving unit 50 in comparison with a preset value stored in the memory 60 through a measured value sensed by the sensor unit 40.

The valve driving part 50 includes a first valve driving part 51 for adjusting the opening degree of the first valve device 215, a second valve driving part 52 for adjusting the opening degree of the second valve device 225, And a third valve driving part 53 for adjusting the opening degree of the third valve device 236. The valve driving unit 50 independently opens and closes each valve device 215, 225, and 236 according to a command from the controller 20, and adjusts the opening degree.

In the memory 60, set values are input. For example, the set value may be a temperature value of the heat exchanged refrigerant, a set value of a load operating in the indoor unit for storing the refrigerant, and refrigerant storage amount values for turning off the third valve unit 236.

Hereinafter, a method of storing and controlling the refrigerant will be described.

For convenience of explanation, a case where the air conditioner performs cooling operation will be described as an example.

Referring to FIG. 7, the controller 20 detects a load value operated in the indoor unit through the load sensing unit 30 (S100). The detected load value is compared with the set load value stored in the memory.

The set load value refers to an indoor unit load value requiring circulation of a refrigerant over a certain range. In other words, the reference value for discharging all the heat-exchanged refrigerant without storing the refrigerant in the outdoor heat exchanger 200 means. Accordingly, when the detected load amount is higher than the set load value, the outdoor heat exchanger 200 operates to discharge the heat-exchanged refrigerant by a predetermined amount or more. When the sensed load amount is lower than the set load amount value, The outdoor heat exchanger (200) stores refrigerant equal to or more than a set amount of the heat exchanged refrigerant and discharges only a part of the refrigerant from the outdoor heat exchanger (200).

In this way, since the amount of the refrigerant performing the cycle is controlled according to the value of the load operated in the indoor unit, the amount of the refrigerant can be reduced, thereby increasing the cooling efficiency.

For example, if the predetermined indoor unit load value is 50%, if the load on the indoor unit is 50% or less, the outdoor heat exchanger 200 stores a part of the heat-exchanged refrigerant in the outdoor heat exchanger 200 . However, if the load of the indoor unit exceeds 50%, the outdoor heat exchanger 200 does not store the refrigerant any more, but discharges the stored refrigerant and the heat-exchanged refrigerant.

The control unit 20 controls the first valve unit 50 and the second valve unit 50 via the valve driving unit 50. In this case, when the sensed value of the indoor unit load is higher than the predetermined value, The first valve device 215 is closed, the second valve device 225 is opened, and the third valve device 236 is opened (S200).

The first valve device 215 is closed and the second valve device 225 is opened and the third valve device 236 is opened for the refrigerant flow in the outdoor heat exchanger 200 Explain.

The refrigerant flowing into the upper header 205a flows into the refrigerant pipe 202 fixed to the first plate 203a through the plurality of refrigerant inlet pipes 232. [ The refrigerant in the refrigerant pipe 202 flows to the plurality of capillary tubes 207 through the branch pipe 209 after heat exchange. The refrigerant of the plurality of capillary tubes 207 is mixed in the first distributor 210 and flows into the lower header 205b through the first distribution pipe 211 and the connection pipe 230 do. Because the third valve device 235 is open, it allows the refrigerant to flow to the connection pipe 230.

The refrigerant flowing into the lower header 205b flows into the plurality of refrigerant pipes 202 fixed to the first plate 203a via the plurality of refrigerant inlet pipes 232. [ The refrigerant can be secondarily condensed in the process of flowing through the plurality of refrigerant pipes 202.

The second condensed refrigerant flows into the second distributor 220 through the branch pipe 209 and the plurality of capillary tubes 207. [ The refrigerant of the second distributor 220 flows through the second distribution pipe 221 and the branched portion 201c to flow through the second inlet and outlet flow passage 201b and is discharged from the outdoor heat exchanger 200 .

However, when the sensed value of the indoor unit load is lower than the pre-set value, a relatively small amount of refrigerant is required for driving the indoor unit. Therefore, only a part of the heat-exchanged refrigerant is discharged from the outdoor heat exchanger 200, Is stored in the heat exchanger (200).

The control unit 20 controls the valve driving unit 50 so that the first valve unit 215 is opened and the second valve unit 225 is closed and the third valve unit 236 is opened (S120).

The first valve device 215 is opened and the second valve device 225 is closed and the third valve device 236 is opened for the refrigerant flow in the outdoor heat exchanger 200 Explain.

The refrigerant flowing into the upper header 205a flows into the refrigerant pipe 202 fixed to the first plate 203a through the plurality of refrigerant inlet pipes 232. [ The refrigerant in the refrigerant pipe 202 flows to the plurality of capillary tubes 207 through the branch pipe 209 after heat exchange. The refrigerant of the plurality of capillary tubes 207 is mixed in the first distributor 210 and flows into the lower header 205b through the first distribution pipe 211 and the connection pipe 230 do. Because the third valve device 235 is open, it allows the refrigerant to flow to the connection pipe 230.

Since the first valve device 215 is also opened, a part of the refrigerant flows into the connection pipe 230, and a part of the refrigerant is discharged from the outdoor heat exchanger 200.

The refrigerant flowing into the lower header 205b flows into the plurality of refrigerant pipes 202 fixed to the first plate 203a via the plurality of refrigerant inlet pipes 232. [ The refrigerant can be secondarily condensed in the process of flowing through the plurality of refrigerant pipes 202.

The second condensed refrigerant flows into the second distributor 220 through the branch pipe 209 and the plurality of capillary tubes 207. [ The refrigerant in the second distributor 220 flows through the second inlet pipe 201b through the second distribution pipe 221 and the branch pipe 201c. However, since the second valve device 221 is closed, the refrigerant flowing into the second inlet / outlet flow path 201b is prevented from being discharged from the outdoor heat exchanger 200.

In other words, a part of the primary condensed refrigerant is discharged from the outdoor heat exchanger 200, and the remaining part is stored between the lower header 205b and the second inlet-outlet flow passage 201b. Therefore, the outdoor heat exchanger 200 serves as a refrigerant reservoir for storing the refrigerant.

On the other hand, the refrigerant stored in the lower portion of the outdoor heat exchanger (200) has a limited amount of refrigerant in the outdoor heat exchanger (200), so that it must be discharged from the outdoor heat exchanger (200). Therefore, the process of detecting the amount of refrigerant stored in the outdoor heat exchanger 200 will be described below.

First, the temperature of the stored refrigerant is sensed (S140).

The stored refrigerant is stored through sufficient undercooling. Therefore, as shown in FIG. 4, the refrigerant is stored from the lowest position of the lower header 205b by gravity. Therefore, the temperature at the point where the refrigerant is located and the point at which the refrigerant does not exist are different from each other.

When the refrigerant storage amount is determined through the temperature sensor 290, the first temperature sensor 291 disposed at the lowermost end of the lowermost inlet pipe or the lower header 205b may initially be operated at a lower temperature . Therefore, a difference of more than a predetermined value is generated between the temperature detected by the first temperature sensor 291 and the temperature detected by the second temperature sensor 292. When the refrigerant is continuously stored, it can be sensed that the refrigerant is stored up to a temperature sensor provided at a point where a difference of more than a predetermined value among the plurality of temperature sensors 290 is generated. The temperature difference value at the position where the refrigerant is not located and the temperature difference value at the position where the refrigerant is located may be preset and stored in the memory 60.

For example, assuming that the preset value is 20, if the value of the temperature sensor is detected as -20 at the point A and the degree of 1 is detected at the point B, the difference value exceeds 20, which is the preset value, It is possible to detect that the liquid refrigerant has been stored to a point between the point and the point B.

Accordingly, the subcooling degree and the refrigerant amount of the refrigerant stored through the sensors 290 and 300 are determined (S160). If the amount of stored refrigerant exceeds the preset value in step S180, the controller 20 opens the third valve unit 235 through the third valve driving unit 53 (step S190) And the stored refrigerant is discharged from the outdoor heat exchanger (200).

The first valve device 215 is opened, the second valve device 225 is closed, and the third valve device 236 is kept in the opened state, The subcooled refrigerant is continuously stored in the lower portion of the outdoor heat exchanger (200).

Meanwhile, since the temperature and the degree of supercooling of the stored refrigerant are measured through the temperature sensor 190, the state of the refrigerant stored in the outdoor heat exchanger 200 can be confirmed.

8 is a flowchart of a refrigerant control method according to a second embodiment of the present invention.

Referring to FIG. 8, the amount of refrigerant stored may be confirmed through the level sensor 300. As described above, the water level sensor 300 is provided at a certain distance in the height direction of the lower header 205b to sense the level of the refrigerant, thereby determining the amount of refrigerant stored in the outdoor heat exchanger 200 have.

Therefore, instead of sensing the temperature of the first embodiment (S140), by sensing the liquid level of the liquid refrigerant through the liquid level sensor 300 (S240), the amount of liquid refrigerant flowing into the lower header 205b .

Claims (14)

A load detecting unit for detecting a load amount operated in the indoor unit;
A control unit for determining an amount of refrigerant necessary for driving the indoor unit based on the measured load on the load sensing unit;
An outdoor heat exchanger for exchanging heat with refrigerant flowing into the indoor unit and storing or discharging the refrigerant to the indoor unit;
A valve device provided on the refrigerant flow space of the outdoor heat exchanger for adjusting a flow direction of the refrigerant; And
And a sensing unit provided on the refrigerant channel of the outdoor heat exchanger for sensing an amount of refrigerant stored in the outdoor heat exchanger,
Wherein the control unit controls the opening degree of the valve unit based on the indoor load detected by the load sensing unit and the refrigerant storage amount sensed by the sensing unit.
The method according to claim 1,
The outdoor heat exchanger
A refrigerant pipe provided with a plurality of rows and through which the refrigerant flows;
A header for branching or laminating the refrigerant; And
And a plurality of refrigerant inlet pipes extending from the header to the plurality of refrigerant pipes,
A lowermost inlet pipe disposed at the lowest position in the plurality of refrigerant inlet pipes; And a plurality of upper inflow pipes arranged above the lowermost inflow pipe.
The method according to claim 1,
Wherein,
Wherein the control unit controls the opening degree of the valve unit to store the refrigerant in the outdoor heat exchanger when the load on the indoor unit is less than a preset range,
And the valve device is controlled to discharge the refrigerant stored in the outdoor heat exchanger when the amount of load operated in the indoor unit exceeds a predetermined range.
3. The method of claim 2,
Wherein the sensing unit includes a temperature sensor for sensing the temperature of the refrigerant stored in the outdoor heat exchanger.
5. The method of claim 4,
The temperature sensor
A first temperature sensor disposed in the upper inflow pipe; And
And a plurality of temperature sensors disposed in the lowermost inlet pipe,
Wherein an amount of refrigerant stored in the outdoor heat exchanger is sensed through a temperature difference sensed by the first temperature sensor and the plurality of temperature sensors.
The method according to claim 1,
And the sensing unit includes a water level sensor for sensing the level of the refrigerant.
The method according to claim 6,
The level sensor
A first water level sensor disposed on the lowermost side of the outdoor heat exchanger; And
And a plurality of water level sensors disposed on the upper side of the first water level sensor,
Wherein the amount of refrigerant stored in the outdoor heat exchanger is sensed through the level of the refrigerant sensed by the first temperature sensor and the plurality of water level sensors.
The method according to claim 1,
Further comprising a memory for storing information on a set value and an indoor load value for discharging the refrigerant stored in the outdoor heat exchanger,
Wherein the control unit compares the value stored in the memory with the value stored in the memory, and determines whether the refrigerant stored in the outdoor heat exchanger is discharged.
The cooling operation being driven in the indoor unit;
Detecting a load value operated in the indoor unit through a load sensing unit;
Determining whether the refrigerant circulating in the outdoor heat exchanger is stored according to the sensed load value;
Sensing an amount of refrigerant stored in the outdoor heat exchanger through a sensing unit;
And controlling the controller to determine whether the refrigerant stored in the outdoor heat exchanger is discharged according to the sensed amount of the refrigerant.
10. The method of claim 9,
Wherein,
Wherein the control unit is configured to discharge a predetermined amount or more of the refrigerant flowing through the outdoor heat exchanger when the load value sensed through the load sensing unit is higher than the set load value,
Wherein when the detected load value is lower than the set load value, the refrigerant is stored in a predetermined amount or more of the refrigerant flowing through the outdoor heat exchanger, and only the refrigerant is partially discharged.
11. The method of claim 10,
Further comprising a valve device provided on the refrigerant passage of the outdoor heat exchanger to adjust the flow direction of the refrigerant,
Wherein,
Wherein the control unit controls the storage and discharge of the refrigerant by driving the valve unit.
10. The method of claim 9,
The sensing unit includes:
And a temperature sensor provided on the refrigerant passage of the outdoor heat exchanger for sensing the temperature of the refrigerant,
And the amount of refrigerant stored in the outdoor heat exchanger is sensed through the temperature value of the refrigerant sensed by the temperature sensor.
10. The method of claim 9,
The sensing unit includes:
And a water level sensor provided on the refrigerant channel of the outdoor heat exchanger for sensing the level of the refrigerant,
And the amount of refrigerant stored in the outdoor heat exchanger is sensed through the level value of the refrigerant sensed by the water level sensor.
10. The method of claim 9,
Wherein,
The refrigerant discharged from the outdoor heat exchanger is discharged when the amount of refrigerant detected by the sensing unit exceeds a predetermined range,
Wherein the refrigerant flowing through the outdoor heat exchanger is stored in the outdoor heat exchanger when the amount of refrigerant detected by the sensing unit is lower than a predetermined range.

Images