US-12624856-B2 - Air conditioner and method for controlling an air conditioner

US12624856B2US 12624856 B2US12624856 B2US 12624856B2US-12624856-B2

Abstract

An air conditioner and a method for controlling an air conditioner are provided. The air conditioner includes an outdoor unit including a compressor and a heat exchanger; and an indoor unit connected to the outdoor unit through a gas pipe and a liquid pipe and having a heat exchanger including first and second coils branched from the gas pipe in series. The indoor unit includes first and second manifolds connected by refrigerant pipes to enable refrigerant flow to the indoor heat exchanger, an expansion valve connected in parallel to the liquid pipe, a distributor in which expansion valves are connected in series and connected by a refrigerant pipe to enable refrigerant flow to the first coil, a refrigerant flow pipe that connects the first manifold and the second coil, a gas-liquid separator installed in the refrigerant flow pipe to phase-separate the refrigerant, a bypass pipe installed between the gas pipe and the gas-liquid separator, and a control valve installed on the gas pipe.

Inventors

Beomchan Kim
Sungoh Choi
Hyeri PARK
JuSu Kim
Hyungsoon KIM

Assignees

LG ELECTRONICS INC.

Dates

Publication Date: 20260512
Application Date: 20231108
Priority Date: 20221124

Claims (13)

1 . An air conditioner, comprising: an outdoor unit including a compressor and an outdoor heat exchanger; and an indoor unit connected to the outdoor unit through a gas pipe and a liquid pipe and having an indoor heat exchanger including a first coil and a second coil which are branched from the gas pipe and connected in series, wherein the indoor unit further includes: a first manifold and a second manifold connected by refrigerant pipes to enable refrigerant flow to the indoor heat exchanger, an expansion valve connected in parallel to the liquid pipe and configured to block flow of refrigerant or expand the refrigerant to reduce a pressure thereof, a refrigerant flow pipe connected to a gas pipe side of the first manifold and the second coil, a gas-liquid separator installed on the refrigerant flow pipe to phase-separate the refrigerant, a bypass pipe installed between the gas pipe and the gas-liquid separator to bypass the gas-phase refrigerant separated in the gas-liquid separator and circulate the gas-phase refrigerant to the outdoor unit through the gas pipe, and a control valve installed on the gas pipe to block the flow of refrigerant, wherein during a cooling full load operation of the air conditioner, the refrigerant flowing from the outdoor unit through the liquid pipe sequentially passes through the first coil, the first manifold, the gas-liquid separator, the second coil, and the second manifold to circulate to the gas pipe, wherein during the cooling full load operation of the air conditioner, the control valve is opened so that gas-liquid separation occurs in the gas-liquid separator, wherein during a cooling partial load operation of the air conditioner, the refrigerant flowing from the outdoor unit through the liquid pipe sequentially passes through the first coil, the first manifold, the gas-liquid separator, the second coil, and the second manifold to circulate to the gas pipe, and wherein during the cooling partial load operation of the air conditioner, the control valve is configured to block the flow of refrigerant so that gas-liquid separation does not occur in the gas-liquid separator.
2 . The air conditioner of claim 1 , wherein the indoor unit further comprises: a distributor connected in series with the expansion valve and connected by a plurality of refrigerant supply pipes to the first coil.
3 . The air conditioner of claim 2 , wherein the refrigerant flowing from the distributor to the first coil and the refrigerant flowing from the gas-liquid separator to the second coil are configured to flow through the plurality of refrigerant supply pipes.
4 . The air conditioner of claim 1 , wherein the first coil and the second coil are configured to face each other, and wherein lower portions of the first coil and the second coil have a wider separation width than upper portions of the first coil and the second coil, and thus, the first coil and the second coil are inclined, respectively.
5 . The air conditioner of claim 4 , wherein the first manifold and the second manifold are disposed side by side with the first coil and the second coil and are configured to communicate with each other through a refrigerant pipe.
6 . The air conditioner of claim 1 , wherein first coil and the second coil are configured to operate as evaporators during a cooling operation of the air conditioner.
7 . The air conditioner of claim 1 , wherein the first coil and the second coil are configured to operate as condensers during a heating operation of the air conditioner.
8 . The air conditioner of claim 1 , wherein during a heating operation of the air conditioner, the refrigerant flowing from the outdoor unit through the gas pipe sequentially passes through the second manifold, the second coil, the gas-liquid separator, the first manifold, and the first coil to circulate to the liquid pipe.
9 . The air conditioner of claim 1 , wherein during a cooling operation of the air conditioner, two-phase refrigerant phase-changed in the expansion valve is in a first state of dryness, and wherein the two-phase refrigerant flowing in the first coil is evaporated to be in a second state of dryness.
10 . The air conditioner of claim 1 , wherein the gas-liquid separator includes: a main body; a refrigerant inflow pipe through which two-phase refrigerant flows into an upper portion of the main body; at least one refrigerant discharge pipe through which liquid-phase refrigerant is discharged from a lower portion of the main body; a separation plate which is installed in the main body to divide the main body into a first space and a second space, in which at least one through-hole is provided, and which separates gas phase and liquid-phase refrigerant among two-phase refrigerant flowing therein through the refrigerant inflow pipe to the first space and the second space, respectively; and a bypass tube that is installed in communication with the bypass pipe and bypasses the separated gas-phase refrigerant.
11 . The air conditioner of claim 10 , wherein a lower end of the refrigerant inflow pipe is positioned adjacent to the separation plate and a lower end of the bypass tube is positioned adjacent to an upper portion of the main body.
12 . The air conditioner of claim 10 , wherein the separation plate has a disk shape fixed in the main body, and distributes gas-phase refrigerant among the two-phase refrigerant flowing therein through the refrigerant inflow pipe to the first space and distributes liquid-phase refrigerant to the second space.
13 . The air conditioner of claim 10 , wherein the at least one through-hole comprises a plurality of through-holes formed in a radial direction around a central through-hole, and wherein a diameter of the plurality of through-holes increases from a center to an edge of the separation plate.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims priority under 35 U.S.C. § 119 to Korean Application No. 10-2022-0159599, filed in Korea on Nov. 24, 2022, whose entire disclosure is hereby incorporated by reference. BACKGROUND 1. Field An air conditioner and a method for controlling an air conditioner are disclosed herein. 2. Background In general, an air conditioner uses a refrigerant cycle including a compressor, a condenser, an expansion device, and an evaporator, for example, to cool or heat a room or purify air in order to create a more comfortable indoor environment for users. In particular, an air conditioner for cooling and heating a large indoor space may include an air handling unit (AHU), which is an indoor unit, and an outdoor unit. The air handling unit is a ventilation combined air conditioning unit that mixes outdoor air with indoor air, heat-exchanges the mixed air in a heat exchanger, and then supplies the mixed air to a room, is installed in an air conditioning room, or machine room, for example, provided separately from the room where the air is conditioned among buildings or houses where the air conditioner is installed, and thus, it is possible to distribute a flow of air to each space through a duct. The outdoor unit may supply refrigerant to a heat exchanger of an air handling unit using a refrigeration cycle and may include a compressor, a condenser, an expansion device, and an evaporator, for example, forming a refrigeration cycle. Korean Patent Publication No. 2021-0108240, which is hereby incorporated by reference, discloses a related art unitary type air conditioner having a square frame and an A-COIL, a lower end of which is supported an upper side of the frame. The A-COIL includes a first coil and a second coil in the air handling unit so that refrigerant flows therein and air passing through the frame exchanges heat with the refrigerant to distribute conditioned air to a room. However, in such a unitary type air conditioner, efficient operation in a partial load cycle is impossible because the cycle is configured to focus on full load without responding to performance of the load during cooling and heating operations. In addition, it is necessary to improve efficiency of not only the full load cycle but also the partial load cycle in order to satisfy annual efficiency standards of Seasonal Energy Efficiency Ratio (SEER) and Heating Seasonal Performance Factor (HSPF) of North America. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein: FIG. 1 is a schematic view of an air conditioner according to an embodiment; FIG. 2 is a perspective view of a gas-liquid separation device according to an embodiment; FIG. 3 is a plan view of a separator according to an embodiment; FIG. 4 is a perspective view illustrating a refrigerant flow structure of a gas-liquid separator according to an embodiment; FIG. 5 is a schematic view illustrating a refrigerant cycle during a cooling full load operation of an air conditioner according to an embodiment; FIG. 6 is a flowchart illustrating a cooling full load operation logic of an air conditioner according to an embodiment; FIG. 7 is a schematic view illustrating a refrigerant cycle during a cooling partial load operation of an air conditioner according to an embodiment; FIG. 8 is a flowchart illustrating a cooling partial load operation logic of an air conditioner according to an embodiment; FIG. 9 is a schematic view illustrating a refrigerant cycle during a heating operation of an air conditioner according to an embodiment; and FIG. 10 is a flowchart illustrating a heating operation logic of an air conditioner according to an embodiment. DETAILED DESCRIPTION Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments are not limited to the disclosed embodiments, and those skilled in the art who understand the spirit can easily propose other embodiments included within the scope of the same spirit by adding, deleting, changing, and supplementing components but it will be said that this is also included within the scope of the spirit. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in describing an embodiment, if it is determined that description of a related known configuration or function hinders understanding of the embodiment, description thereof is omitted. Also, terms such as first, second, A, B, (a), (b) or the like may be used herein when describing components of the embodiment of the present disclosure. Each of these terminologies is not used to define an essence, order or sequence of a corresponding component but used merely to distinguish the corresponding component from other component(s). It