REFRIGERATOR AND CONTROL METHOD THEREOF

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application, claiming priority under 35 U.S.C. § 365 (c), of an International application No. PCT/KR2023/013628, filed on Sep. 12, 2023, which is based on and claims the benefit of a Korean patent application number 10-2022-0172049, filed on Dec. 9, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

The disclosure relates to a refrigerator and a method for controlling the same. M ore particularly, the disclosure relates to a refrigerator including a compressor with improved energy efficiency and a method for controlling the same.

2. Description of Related Art

In general, a refrigerator employing a common cooling cycle by which a refrigerant is circulated therein is to keep various food items fresh for a long time by supplying cold air into food storage compartments, the cold air generated as the refrigerant in a liquid state absorbs surrounding heat while being evaporated. Among the food storage compartments, a freezing compartment is maintained at a temperature of approximately minus 20 degrees and a refrigerating compartment is maintained at a low temperature of approximately minus 3 degrees.

In order to configure a cooling cycle, a refrigerator includes a cold air supply device. The cold air supply device includes an evaporator, an expansion device, a condenser, and a compressor. To drive the cooling cycle, the compressor is turned on to supply cold air to the storage compartment. In a case where the storage compartment temperature is sufficiently lowered, the compressor is turned off to reduce or stop the supply of cold air, and thus the temperature in the storage compartment remains at an appropriate level.

Such an on-off operation mode of the compressor continuously repeats turning the compressor on or off, causing energy loss. To reduce the energy loss, the refrigerator switches from the on-off operation mode to a continuous operation mode in which the compressor operates continuously at an appropriate revolution per minute (RPM). Because the on-off operation of the compressor causes energy loss as described above, in refrigerator compressor operation, the continuous operation mode requires to be prevented from switching back to the on-off operation mode to improve energy efficiency.

The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.

SUMMARY

Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a refrigerator and a method for controlling the same that may reduce energy loss by allowing a compressor to operate stably in a continuous operation mode even in a change in heat load applied to the refrigerator.

Another aspect of the disclosure is to provide a refrigerator and a method for controlling the same that may reduce the amount of temperature fluctuation in a storage compartment.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

In accordance with an aspect of the disclosure, a refrigerator is provided. The refrigerator includes a main body, a storage compartment formed inside the main body, a cold air supply device including a compressor and being configured to supply cold air to the storage compartment, and a controller configured to operate the compressor in an on-off operation mode, switch the compressor from the on-off operation mode to a continuous operation mode in response to a predefined condition being satisfied while the compressor operates in the on-off operation mode, determine a target revolution per minute (RPM) of the compressor as a first RPM in the on-off operation mode, operate the compressor at the first RPM in the continuous operation mode, change the target RPM of the compressor to a second RPM lower than the first RPM based on a temperature in the storage compartment being outside a preset temperature range and being lower than a reference temperature in the continuous operation mode, and change the target RPM of the compressor to a third RPM higher than the first RPM based on the temperature in the storage compartment being outside the preset temperature range and being greater than or equal to the reference temperature in the continuous operation mode.

The controller may change the target RPM of the compressor to the second RPM, based on the temperature in the storage compartment being outside the preset temperature range, being lower than the reference temperature, and being higher than an off temperature of the compressor in the continuous operation mode.

The controller may change the target RPM of the compressor to the third RPM, based on the temperature in the storage compartment being outside the preset temperature range, being greater than or equal to the reference temperature, and being lower than an on temperature of the compressor in the continuous operation mode.

The controller may switch the compressor from the continuous operation mode to the on-off operation mode, based on the temperature in the storage compartment being lower than the reference temperature and being less than or equal to an off temperature of the compressor in the continuous operation mode.

The controller may operate the compressor in the on-off operation mode at an RPM higher than the first RPM

The controller may switch the compressor from the continuous operation mode to the on-off operation mode, based on the temperature in the storage compartment being greater than or equal to the reference temperature and being greater than or equal to an on temperature of the compressor in the continuous operation mode.

The controller may operate the compressor in the on-off operation mode at an RPM higher than the first RPM.

The predefined condition may be that the compressor reaches a target operating rate range in the on-off operation mode.

The controller may operate the compressor at an n^th RPM (where n is a natural number greater than or equal to 2) lower than an (n−1)^th RPM, based on an operating rate of the compressor being less than or equal to the target operating rate range by operating the compressor at the (n−1)^th RPM in the on-off operation mode.

The controller may operate the compressor in the continuous operation mode at a value obtained by subtracting a predefined value from the (n−1)^th RPM, in response to the operating rate of the compressor reaching the target operating rate range at the (n−1)^th RPM.

The controller may operate the compressor at an n^th RPM (where n is a natural number greater than or equal to 2) higher than an (n−1)^th RPM, based on an operating rate of the compressor being higher than the target operating rate range by operating the compressor at the (n−1)^th RPM in the on-off operation mode.

The reference temperature may be set by a user, and the preset temperature range may be between a first temperature greater than the reference temperature by a predefined value and a second temperature less than the reference temperature by a predefined value.

In accordance with another aspect of the disclosure, a method performed by a refrigerator is provided. The method includes operating a compressor in an on-off operation mode to supply cold air to a storage compartment formed inside a main body of the refrigerator, determining a target revolution per minute (RPM) of the compressor as a first RPM in the on-off operation mode, switching the compressor to a continuous operation mode in response to a predefined condition being satisfied while the compressor operates in the on-off operation mode, operating the compressor at the first RPM in the continuous operation mode, changing the target RPM of the compressor to a second RPM lower than the first RPM based on a temperature in the storage compartment being outside a preset temperature range and being lower than a reference temperature in the continuous operation mode, or changing the target RPM of the compressor to a third RPM higher than the first RPM based on the temperature in the storage compartment being outside the preset temperature range and being greater than or equal to the reference temperature in the continuous operation mode.

The method may further include changing the target RPM of the compressor to the second RPM based on the temperature in the storage compartment being outside the preset temperature range, being lower than the reference temperature, and being higher than an off temperature of the compressor in the continuous operation mode.

The method may further include changing the target RPM of the compressor to the third RPM based on the temperature in the storage compartment being outside the preset temperature range, being greater than or equal to the reference temperature, and being lower than an on temperature of the compressor in the continuous operation mode.

The method may further include switching the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode, based on the temperature in the storage compartment being lower than the reference temperature and being less than or equal to an off temperature of the compressor in the continuous operation mode.

The switching of the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode includes operating the compressor in the on-off operation mode at an RPM higher than the target RPM.

The method may further include switching the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode, based on the temperature in the storage compartment being greater than or equal to the reference temperature and being greater than or equal to an on temperature of the compressor in the continuous operation mode.

The switching of the compressor from the continuous operation mode to the on-off operation mode and operating the compressor in the on-off operation mode includes operating the compressor in the on-off operation mode at an RPM higher than the target RPM.

In accordance with another aspect of the disclosure, a refrigerator is provided. The refrigerator includes a storage compartment, a cold air supply device including a compressor and being configured to supply cold air to the storage compartment, and a controller configured to operate the compressor in an on-off operation mode, switch the compressor to a continuous operation mode in response to the compressor reaching a target operating rate while the compressor operates in the on-off operation mode, determine a target revolution per minute (RPM) of the compressor as a first RPM in the on-off operation mode, operate the compressor at the first RPM in the continuous operation mode, change the target RPM of the compressor to a second RPM lower than the first RPM based on a temperature in the storage compartment being lower than a user-set temperature in the continuous operation mode, and change the target RPM of the compressor to a third RPM higher than the first RPM based on the temperature in the storage compartment being greater than or equal to the user-set temperature in the continuous operation mode.

According to an aspect of the disclosure, a refrigerator and a method for controlling the same may reduce energy loss of a compressor by allowing the compressor to operate in a continuous operation mode even when an environment of a storage compartment changes significantly.

According to an aspect of the disclosure, a refrigerator and a method for controlling the same may minimize energy loss of a compressor by reducing instances in which a continuous operation mode is switched to an on-off operation mode.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a refrigerator according to an embodiment of the disclosure;

FIG. 2 is a circuit diagram related to a cold air supply device of a refrigerator according to an embodiment of the disclosure;

FIG. 3 is a control block diagram of a refrigerator according to an embodiment of the disclosure;

FIG. 4 is a flowchart illustrating a method for controlling a refrigerator according to an embodiment of the disclosure;

FIG. 5 is a flowchart illustrating a method for controlling a refrigerator according to an embodiment of the disclosure; and

FIG. 6 is a control graph of a refrigerator according to an embodiment of the disclosure.

The same reference numerals are used to represent the same elements throughout the drawings.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

Throughout the specification, like reference numerals denote like elements or components having substantially the same functions.

The terms “includes”, “comprises”, “including”, and/or “comprising” when used in this specification, represent the presence of stated features, integers, steps, operations, elements, components or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

The term including an ordinal number such as “first”, “second”, or the like is used to distinguish one component from another and does not restrict the former component. For example, without departing from the technical spirit or essential features of the disclosure, a first element may be referred to as a second element, and a second element may also be referred to as a first element. The term “and/or” includes any and all combinations of one or more of the associated listed items.

In the disclosure, the meaning of “identical” may include similar in attribute or similar within a certain range. Also, the term “identical” means “substantially identical”. The meaning of “substantially identical” should be understood that a value falling within the margin of error in manufacturing or a value corresponding to a difference within a meaningless range with respect to a reference value is included in the range of “identical”.

Furthermore, the terms, such as “˜ part”, “˜ block”, “˜ member”, “˜ module”, etc., may refer to a unit of handling at least one function or operation. For example, the terms may refer to at least one process handled by hardware such as a field-programmable gate array (FPGA)/application specific integrated circuit (A SIC), etc., software stored in memory, or at least one processor.

The terms “front,” “rear,” “left,” “right,” etc., used in the following description are defined based on the drawings, and the shape and position of each component are not limited by these terms.

The operating principle and embodiments of the disclosure will now be described with reference to accompanying drawings.

It should be appreciated that the blocks in each flowchart and combinations of the flowcharts may be performed by one or more computer programs which include instructions. The entirety of the one or more computer programs may be stored in a single memory device or the one or more computer programs may be divided with different portions stored in different multiple memory devices.

Any of the functions or operations described herein can be processed by one processor or a combination of processors. The one processor or the combination of processors is circuitry performing processing and includes circuitry like an application processor (AP, e.g. a central processing unit (CPU)), a communication processor (CP, e.g., a modem), a graphics processing unit (GPU), a neural processing unit (NPU) (e.g., an artificial intelligence (AI) chip), a Wi-Fi™ chip, a Bluetooth™ chip, a global positioning system (GPS) chip, a near field communication (NFC) chip, connectivity chips, a sensor controller, a touch controller, a finger-print sensor controller, a display driver integrated circuit (IC), an audio CODEC chip, a universal serial bus (USB) controller, a camera controller, an image processing IC, a microprocessor unit (MPU), a system on chip (SoC), an IC, or the like.

FIG. 1 is a perspective view of a refrigerator according to an embodiment of the disclosure.

Referring to FIG. 1, a refrigerator 1 may include a main body 10, storage compartments 20 and 30 formed in the main body 10, and doors (e.g., fridge doors 21 and 22 and freezer door 31) arranged to open or close the storage compartments 20 and 30.

The main body 10 may include an inner case 11 that defines the storage compartments 20 and 30, an outer case 12 coupled onto the outer side of the inner case 11, and insulation (not shown) arranged between the inner case 11 and the outer case 12.

The inner case 11 may be formed of a plastic substance through injection molding, and the outer case 12 may be formed of a metal substance. For the insulation, urethane foam insulation may be used, and when required, used with vacuum insulation.

After the inner case 11 and the outer case 12 are coupled with each other, the urethane foam insulation may be formed by filling foamed urethane obtained by mixing urethane and a foam agent in between the inner case 11 and the outer case 12. The foamed urethane is strongly adhesive, thus reinforcing coupling power between the inner case 11 and the outer case 12, and may have sufficient strength after foaming is complete.

The main body 10 may include a middle wall 13 that makes vertical division into the storage compartments 20 and 30. The middle wall 13 may separate storage compartment 20 of the refrigerator from storage compartment 30 of the freezer.

However, a method of dividing the storage compartments 20 and 30 is not limited to what is shown in FIG. 1, but may be implemented in various known ways.

The storage compartments 20 and 30 may include the storage compartment 20 of the refrigerator formed in the upper portion of the main body 10 and the storage compartment 30 of the freezer formed in the lower portion of the main body 10. In other words, the storage compartment 30 of the freezer may be placed under the storage compartment 20 of the refrigerator.

The storage compartment 20 of the refrigerator may be maintained at temperatures of approximately 0 to 5 degrees Celsius to keep foods refrigerated. The storage compartment 30 of the freezer may be maintained at temperatures of approximately minus 30 to 0 degrees Celsius to keep foods frozen.

Shelves 23 for food items to be put thereon and containers 24 for storing food items may be provided in the storage compartment 20 of the refrigerator.

The storage compartment 20 of the refrigerator and the storage compartment 30 of the freezer may each have an open front to put in and take out foods. The open front of the storage compartment 20 of the refrigerator may be opened or closed by a pair of fridge doors 21 and 22 coupled with the main body 10. The fridge doors 21 and 22 may be rotatably coupled with the main body 10. The open front of the storage compartment 30 of the freezer may be opened or closed by a freezer door 31 sliding against the main body 10. The freezer door 31 may be shaped like a box with an open top side and may include a front plate 32 defining an exterior and a drawer 33 coupled to the rear side of the front plate 32.

However, the shape of the freezer door 31 is not limited thereto, and the freezer door 31 may have a shape rotatably coupled with the main body 10 like the fridge doors 21 and 22.

Gaskets (not shown) may be arranged on rear edges of the fridge doors 21 and 22 to seal up the space between the fridge doors 21 and 22 and the main body 10 to contain cold air of the storage compartment 20 of the refrigerator when the fridge doors 21 and 22 are closed.

The refrigerator 1 may include a cold air supply device 100 for supplying cold air into the storage compartments. The cold air supply device 100 will be described in detail below.

Meanwhile, the shape of the refrigerator 1 may not be limited to what is described above, but may have various forms, such as a top-mounted freezer (TMF) refrigerator with the freezing compartment formed in the upper portion of the main body 10 and the refrigerating compartment formed in the lower portion of the main body 10 or a side-by-side (SBS) refrigerator.

Furthermore, any type of refrigerator 1 may be used as long as it receives cold air from the cold air supply device 100.

FIG. 2 is a circuit diagram related to a cold air supply device of a refrigerator according to an embodiment of the disclosure.

Referring to FIG. 2, a cold air supply device 100 may include a compressor 110 and a condenser 120.

The compressor 110 may compress a refrigerant provided to circulate through the cold air supply device 100 to high-temperature and high-pressure gas.

The condenser 120 may condense the refrigerant compressed by the compressor 110. Specifically, the condenser 120 may phase change to a room temperature liquid by releasing heat from the high-temperature, high-pressure gaseous refrigerant compressed by the compressor 110.

The cold air supply device 100 may include an expansion device 150, which may include a capillary tube. However, the expansion device 150 is not limited to the capillary tube and may be a variety of expansion devices.

The expansion device 150 may be connected to an outlet side of the condenser 120. Being connected to the outlet side of the condenser 120 refers to being located downstream of the condenser 120 in a refrigerant flow path.

As the refrigerant flows through the expansion device 150, the refrigerant may expand and decrease in pressure. The capillary tube may be referred to as the expansion device.

The cold air supply device 100 may include an evaporator 170 connected to the outlet of the expansion device 150. The evaporator 170 may vaporize the low-pressure liquid refrigerant expanded by the expansion device 150, thereby absorbing surrounding heat. In other words, the evaporator 170 may evaporate the refrigerant.

The compressor 110, the condenser 120, the expansion device 150, and the evaporator 170 may be connected by refrigerant pipes, forming a closed loop refrigerant circuit in the refrigerator 1.

The cold air supply device 100 may be controlled by turning the compressor 110 on and off. According to an embodiment, the refrigerator 1 may control the cold air supply device 100 by turning the compressor 110 on and off. For example, by turning the compressor 110 on, the cold air supply device 100 operates to supply cold air to the storage compartments 20 and 30, and by turning the compressor 110 off, the cold air supply device 100 stops operation, and thus no cold air may be supplied to the storage compartments 20 and 30.

In addition, the refrigerator 1 may regulate the amount of cold air supplied to the storage compartments 20 and 30 by controlling a rotation frequency of the compressor 110. For example, the refrigerator 1 may increase the rotation frequency of the compressor 110 to increase the amount of cold air supplied to the storage compartments 20 and 30, or decrease the rotation frequency of the compressor 110 to reduce the amount of cold air supplied to the storage compartments 20 and 30.

FIG. 3 is a control block diagram of a refrigerator according to an embodiment of the disclosure.

Referring to FIG. 3, a refrigerator 1 according to an embodiment may further include a temperature sensor 210 and a controller 200.

The temperature sensor 210 may detect a temperature of the storage compartments 20 and 30. The temperature sensor 210 may be located adjacent to the rear wall of the inner case 11 forming the storage compartments 20 and 30, and may transmit information about the detected storage compartment temperature to the controller 200. For example, the temperature sensor 210 may be connected to an input port of the controller 200.

The controller 200 may control the cold air supply device 100 based on an outside temperature detected by the temperature sensor 210. For example, the controller 200 may perform on-off control of the compressor 110 or continuously operate the compressor 110. For example, the compressor 110 or a compressor driver (not shown) for controlling the compressor 110 may be connected to an output port of the controller 200.

The controller 200 may include a first controller and a second controller. The first controller may receive information about the temperature in the storage compartments 20 and 30 through the temperature sensor 210. The first controller and the second controller may transmit signals to each other.

The second controller may receive instructions from the first controller. For example, the second controller may receive instructions about a revolution per minute (RPM) of the compressor 110 from the first controller. The second controller may control the compressor 110. For example, the second controller may control a rotation frequency of the compressor 110 to adjust the amount of cold air supplied into the storage compartments 20 and 30.

Based on the temperature detected by the temperature sensor 210 located in the storage compartments 20 and 30, the controller 200 may adjust the RPM of the compressor 110. The controller 200 may also adjust the RPM of the compressor 110 by a set value to maintain an optimal temperature in the storage compartments 20 and 30 based on an optimal temperature for preserving food stored therein.

FIG. 4 is a flowchart illustrating a method for controlling a refrigerator according to an embodiment of the disclosure. FIG. 4 illustrates a process in which a compressor is operated in a continuous operation mode.

Referring to FIG. 4, a refrigerator 1 according to an embodiment may operate a compressor 110 in an on-off operation mode, in operation 410. The on-off operation mode refers to an operation mode in which the compressor 110 is repeatedly turned on and off. For example, the controller 200 may turn on the compressor 110 for a time t1 and then turn off the compressor 110 for a time (t2−t1). The controller 200 may keep the compressor 110 on until a temperature in the storage compartments 20 and 30 reaches an off temperature Toff, and then turn the compressor 110 off when the temperature in the storage compartments 20 and 30 reaches the off temperature. The controller 200 may turn the compressor 110 on again when the temperature in the storage compartments 20 and 30 reaches an on temperature Ton. The temperature in the storage compartments 20 and 30 may be detected by the temperature sensor 210.

For example, in a case where the on temperature Ton of the compressor 110 is 5° C. and the off temperature Toff of the compressor 110 is 0° C., the controller 200 may operate the compressor 110 until the temperature in the storage compartments 20 and 30 reaches 0° C., which is the off temperature Toff, for a time t1, and when the temperature in the storage compartments 20 and 30 reaches 0° C., the controller 200 may turn off the compressor 110. The compressor 110 may remain off until the temperature in the storage compartments 20 and 30 increases to 5° C., which is the on temperature (see FIG. 6).

As such, the operation mode in which the compressor 110 is repeatedly turned on and off is referred to as the on-off operation mode. A length of time that the compressor 110 is on and off may vary in the on-off operation mode.

During the on-off operation of the compressor 110, an operating rate of the compressor 110 may be calculated. The operating rate of the compressor 110 may be calculated by dividing a ‘compressor on time’ by the sum of the ‘compressor on time’ and a ‘compressor off time’. For example, in a case where the compressor 110 is turned on for a time t1 and turned off for a time (t2-t1), the operating rate may be t1/t2.

While operating the compressor 110 in the on-off operation mode, the controller 200 may switch the compressor 110 to the continuous operation mode in a case where a predefined condition is satisfied, or may continue to operate the compressor 110 in the on-off operation mode in a case where the predefined condition is not satisfied. The controller 200 may determine whether a predefined condition is satisfied, in operation 420. The case where the predefined condition is satisfied is described below with reference to FIGS. 5 and 6.

In this instance, the predefined condition may be that the operating rate of the compressor 110 reaches a target operating rate. For example, the target operating rate of the compressor 110 may be 70˜80%. In a case where the operating rate of the compressor 110 reaches 70˜80% range in the on-off operation mode, the controller 200 may switch an operation mode of the compressor 110 to the continuous operation mode. The controller 200 may determine a rotation frequency for the continuous operation mode during the on-off operating cycle before the predefined condition is satisfied. The rotation frequency, i.e., a target RPM, may be referred to as a first RPM.

In a case where the compressor 110 switches from the on-off operation mode to the continuous operation mode, in operation 430, the compressor 110 is operated in the continuous operation mode, in operation 440. However, while the compressor 110 is operating in the continuous operation mode, the temperature in the storage compartments 20 and 30 may deviate from a preset temperature range. The controller 200 may determine whether the temperature in the storage compartments 20 and 30 within a preset temperature range, in operation 450. For example, in a case where the door is opened or closed, hot or cold outside air may flow into the refrigerator 1, or an outside temperature changes, a heat load in the storage compartments 20 and 30 may vary, causing the temperature in the storage compartments 20 and 30 to deviate from the preset temperature range.

According to an embodiment, in a case where the temperature in the storage compartments 20 and 30 deviates from the preset temperature range while the compressor 110 is operating in the continuous operation mode, the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is lower than a reference temperature Ts, in operation 460. The controller 200 continues the continuous operation mode in a case where the temperature in the storage compartments 20 and 30 does not deviate from the preset temperature range. The reference temperature Ts may be a temperature set by a user.

The preset temperature range may be between a first temperature greater than the user-set temperature by a predefined value and a second temperature less than the user-set temperature by a predefined value. For example, in a case where the reference temperature Ts is 3° C., the predefined value may be 0.5° C. That is, the first temperature may be 3.5° C. and the second temperature may be 2.5° C. In a case where the reference temperature Ts is 3° C., the predefined value may be 1° C. That is, the first temperature may be 4.0° C. and the second temperature may be 2.0° C. However, the reference temperature Ts and the predefined value are not limited to the above examples.

The controller 200 may determine whether the temperature in the storage compartments 20 and 30 is lower than the reference temperature Ts, in a case where the temperature in the storage compartments 20 and 30 is higher than the first temperature or lower than the second temperature.

In a case where the temperature in the storage compartments 20 and 30 is determined to be lower than the reference temperature Ts, the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is less than or equal to the off temperature Toff of the compressor 110, in operation 470. For example, in a case where the temperature in the storage compartments 20 and 30 is 2° C. and the reference temperature Ts is 3° C., the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is less than or equal to the off temperature Toff of the compressor 110.

On the contrary, in a case where the temperature in the storage compartments 20 and 30 is determined to be greater than or equal to the reference temperature Ts, the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110, in operation 480. For example, in a case where the temperature in the storage compartments 20 and 30 is 4° C. and the reference temperature Ts is 3° C., the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110.

The on temperature Ton of the compressor 110 and the off temperature Toff of the compressor 110 may be determined based on the reference temperature Ts. Referring to the second graph in FIG. 6, the on temperature Ton of the compressor 110 and the off temperature Toff may be different from the reference temperature Ts by a predefined value such that the reference temperature Ts has an integral average value.

In a case where the temperature in the storage compartments 20 and 30 is lower than the reference temperature Ts but higher than the off temperature Toff of the compressor 110, the controller 200 may continue to operate the compressor 110 in the continuous operation mode. In this instance, because the temperature in the storage compartments 20 and 30 is lower than the reference temperature Ts, the controller 200 may decrease the target RPM of the compressor 110 to reduce the amount of cold air supplied to the storage compartments 20 and 30, in operation 510, thereby allowing the temperature in the storage compartments 20 and 30 to approach the reference temperature Ts. For example, in a case where the temperature in the storage compartments 20 and 30 is 2° C., the reference temperature Ts is 3° C., and the off temperature T off of the compressor 110 is 1° C., the controller 200 may reduce the target RPM of the compressor 110. In this instance, the target RPM that becomes lower than the first RPM may be referred to as a second RPM.

In addition, the target RPM of the compressor 110 may be set differently according to a difference between the temperature in the storage compartments 20 and 30 and the reference temperature Ts. For example, in a case where the temperature in the storage compartments 20 and 30 detected by the temperature sensor 210 is higher than the reference temperature Ts by 1° C. or more and less than 2° C., the controller 200 may increase the rotation frequency of the compressor 110 by 50 RPM compared to the existing frequency. In a case where the temperature in the storage compartments 20 and 30 detected by the temperature sensor 210 is higher than the reference temperature Ts by 2° C. or more and less than 3° C., the controller 200 may further increase the rotation frequency of the compressor 110 by 50 RPM in addition to the increased rotation frequency.

In a case where the temperature in the storage compartments 20 and 30 is greater than or equal to the reference temperature Ts but lower than the on temperature Ton of the compressor 110, the controller 200 may continue to operate the compressor 110 in the continuous operation mode. In this instance, because the temperature in the storage compartments 20 and 30 is greater than or equal to the reference temperature Ts, the controller 200 may increase the target RPM of the compressor 110 to increase the amount of cold air supplied to the storage compartments 20 and 30, in operation 520, thereby allowing the temperature in the storage compartments 20 and 30 to approach the reference temperature Ts. For example, in a case where the temperature in the storage compartments 20 and 30 is 4° C., the reference temperature Ts is 3° C., and the on temperature Ton of the compressor 110 is 5° C., the controller 200 may increase the target RPM of the compressor 110. In this instance, the target RPM that becomes higher than the first RPM may be referred to as a third RPM.

In addition, the target RPM of the compressor 110 may be set differently according to the difference between the temperature in the storage compartments 20 and 30 and the reference temperature Ts. For example, in a case where the temperature in the storage compartments 20 and 30 detected by the temperature sensor 210 is lower than the reference temperature Ts by 1° C. or more and less than 2° C., the controller 200 may reduce the rotation frequency of the compressor 110 by 50 RPM compared to the existing frequency. In a case where the temperature in the storage compartments 20 and 30 detected by the temperature sensor 210 is lower than the reference temperature Ts by 2° C. or more and less than 3° C., the controller 200 may further reduce the rotation frequency of the compressor 110 by 50 RPM in addition to the reduced rotation frequency.

Even in a case where the temperature in the storage compartments 20 and 30 deviates from the preset temperature range while the compressor 110 is operating in the continuous operation mode, the refrigerator 1 according to an embodiment may operate the compressor 110 in the continuous operation mode through the above method. Accordingly, energy loss caused by turning the compressor 110 on and off may be reduced. In addition, because fewer on-off operations of the compressor 110 are performed, hysteresis in the temperature change of the storage compartments 20 and 30 may be minimized.

In particular, because the rotation frequency is changed according to the amount by which the temperature in the storage compartments 20 and 30 deviates from the reference temperature Ts, the compressor 110 is less likely to switch from the continuous operation mode to the on-off operation mode.

Furthermore, the compressor 110 may be controlled based on information obtained by the temperature sensor 210 arranged in the storage compartments 20 and 30, and a separate sensor for detecting outside temperature or a temperature sensor attached to the door is not required, thereby reducing manufacturing cost of the refrigerator 1.

In a case where the temperature in the storage compartments 20 and 30 is lower than the reference temperature Ts and is less than or equal to the off temperature Toff of the compressor 110, the controller 200 may switch the compressor 110 from the continuous operation mode to the on-off operation mode. In this instance, because the inside of the storage compartments 20 and 30 may be overcooled, the controller 200 may switch the compressor 110 from the continuous operation mode to the on-off operation mode, in operation 500, by turning off the compressor 110, in operation 490. Afterwards, in a case where the compressor 110 is turned on again, the controller 200 may operate the compressor 110 at an RPM higher than the target RPM used in the continuous operation mode.

Because the controller 200 reduces the RPM of the compressor 110 to switch from the on-off operation mode to the continuous operation mode, the controller 200 increases the RPM of the compressor 110 to switch from the continuous operation mode to the on-off operation mode. For example, in a case where the temperature in the storage compartments 20 and 30 is 0° C., the reference temperature Ts is 3° C., and the off temperature Toff of the compressor 110 is 1° C., the controller 200 may turn off the compressor 110 to switch from the continuous operation mode to the on-off operation mode.

In a case where the temperature in the storage compartments 20 and 30 is greater than or equal to the reference temperature Ts and is greater than or equal to the on temperature Ton of the compressor 110, the controller 200 may switch the compressor 110 from the continuous operation mode to the on-off operation mode.

In this instance, because the temperature in the storage compartments 20 and 30 is greater than or equal to the reference temperature Ts and is greater than or equal to the on temperature Ton of the compressor 110, the controller 200 may operate the compressor 110 by increasing the RPM of the compressor 110 in the on-off operation mode.

Because the controller 200 reduces the RPM of the compressor 110 to switch from the on-off operation mode to the continuous operation mode, the controller 200 increases the RPM of the compressor 110 to switch from the continuous operation mode to the on-off operation mode. For example, in a case where the temperature in the storage compartments 20 and 30 is 6° C., the reference temperature Ts is 3° C., and the on temperature Ton of the compressor 110 is 5° C., the controller 200 may turn off the compressor 110 to switch from the continuous operation mode to the on-off operation mode.

FIG. 5 is a flowchart illustrating a method for controlling a refrigerator according to an embodiment of the disclosure. FIG. 5 illustrates a process in which the compressor 110 switches from an on-off operation mode to a continuous operation mode.

Referring to FIG. 5, a refrigerator 1 according to an embodiment may detect a temperature in storage compartments 20 and 30 using a temperature sensor 210 arranged in the storage compartments 20 and 30.

The controller 200 may determine whether the temperature in the storage compartments 20 and 30 detected by the temperature sensor 210 is greater than or equal to an on temperature Ton of the compressor 110, in operation 505. In a case where the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110, the controller 200 may determine whether the compressor 110 is in the off state. For example, in a case where the temperature in the storage compartments 20 and 30 is 6° C. and the on temperature Ton of the compressor 110 is 5° C., the controller 200 may determine whether the compressor 110 is in the off state.

In a case where the temperature in the storage compartments 20 and 30 is determined to be greater than or equal to the on temperature Ton of the compressor 110, the controller 200 may determine whether the compressor 110 is in the off state, in operation 530, and based on determining that the compressor 110 is in the off state, the controller 200 may turn on the compressor 110, in operation 550, and determine again whether the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110. Conversely, in a case where the compressor 110 is not in the off state, the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is less than or equal to an off temperature Toff of the compressor 110.

On the contrary, in determining whether the temperature in the storage compartments 20 and 30 detected by the temperature sensor 210 is greater than or equal to the on temperature Ton of the compressor 110, in a case where the temperature in the storage compartments 20 and 30 is lower than the on temperature Ton of the compressor 110, the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is less than or equal to the off temperature Toff of the compressor 110, in operation 515. For example, in a case where the temperature in the storage compartments 20 and 30 is 4° C. and the on temperature Ton of the compressor 110 is 5° C., the controller 200 may determine whether the temperature in the storage compartments 20 and 30 is less than or equal to the off temperature Toff of the compressor 110.

In a case where the temperature in the storage compartments 20 and 30 is determined to be less than or equal to the off temperature Toff of the compressor 110, the controller 200 may turn off the compressor 110 and calculate an operating rate of the compressor 110, in operation 540. In other words, the controller 200 may turn off the compressor 110 to prevent the storage compartments 20 and 30 from being overcooled. Conversely, in a case where the temperature in the storage compartments 20 and 30 is determined to be higher than the off temperature Toff of the compressor 110, the controller 200 may again determine whether the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110.

Thereafter, the controller 200 may determine whether the operating rate of the compressor 110 is within a target operating rate range, in operation 560. In a case where the operating rate is within the target operating rate range, the controller 200 may switch the on-off operation mode of the compressor 110 to the continuous operation mode, in operation 570. Once the on-off operation mode is switched to the continuous operation mode, the compressor 110 may operate in the continuous operation mode, in operation 580.

When the on-off operation mode of the compressor 110 is switched to the continuous operation mode, the controller 200 may enter the continuous operation mode while decreasing a rotation frequency of the compressor 110. For example, once the operating rate of the compressor 110 that operates in the on-off operation mode reaches the target operating rate range at the (n−1)^th RPM in the (n−1)^th cycle, the compressor 110 may be switched to and operated in the continuous operation mode at a rotation frequency in the n^th cycle obtained by subtracting a predefined value from the (n−1)^th RPM in the (n−1)^th cycle.

Because the compressor 110 is not turned off in the continuous operation mode and continues to run, in a case where the compressor 110 is operated in the continuous operation mode at the (n−1)^th RPM without reducing the rotation frequency, the inside of the storage compartments 20 and 30 may be overcooled.

In this case, the RPM of the compressor 110 at the target operating rate may be close to the target RPM in the continuous operation mode, and thus the compressor 110 may be operated in the continuous operation mode without requiring a large RPM adjustment. The controller 200 may calculate the target RPM. The target RPM may be determined in the (n−1)^th cycle immediately before the compressor 110 enters the continuous operation mode.

Based on determining that the operating rate of the compressor 110 is not within the target operating rate range, the controller 200 may continue to operate the compressor 110 in the on-off operation mode and determine whether the operating rate of the compressor 110 is higher than the target operating rate range, in operation 590.

In a case where the operating rate of the compressor 110 is determined to be higher than the target operating rate range, the controller 200 may increase the RPM of the compressor 110 to reduce the operating rate of the compressor 110, in operation 610.

Because a higher RPM of the compressor 110 causes cold air to be supplied to the storage compartments 20 and 30 more rapidly, the storage compartments 20 and 30 may be cooled more quickly. Accordingly, an operating time required to lower the temperature in the storage compartments 20 and 30 to a target temperature may be reduced. Because the operating rate may be calculated as (compressor on time)/(compressor on time+compressor off time), an increase in the RPM of the compressor 110 may reduce the operating rate. For example, in a case where the target operating rate of the compressor 110 is 70˜80% and a current operating rate of the compressor 110 is 90%, the controller 200 may increase the RPM of the compressor 110 to reduce the operating rate.

Thereafter, the controller 200 may continue to operate the compressor 110 in the on-off operation mode and determine whether the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110.

Based on determining that the operating rate of the compressor 110 is not higher than the target operating rate range, the controller 200 may reduce the RPM of the compressor 110 to increase the operating rate of the compressor 110, in operation 620.

Because reducing the RPM of the compressor 110 decreases the amount of cold air supplied to the storage compartments 20 and 30, the storage compartments 20 and 30 may be cooled slowly. Accordingly, an operating time required to lower the temperature in the storage compartments 20 and 30 to the target temperature may be increased. Because the operating rate may be calculated as (compressor on time)/(compressor on time+compressor off time), a decrease in the RPM of the compressor 110 may increase the operating rate. For example, in a case where the target operating rate of the compressor 110 is 70˜80% and a current operating rate of the compressor 110 is 50%, the controller 200 may reduce the RPM of the compressor 110 to increase the operating rate.

Thereafter, the controller 200 may continue to operate the compressor 110 in the on-off operation mode and determine whether the temperature in the storage compartments 20 and 30 is greater than or equal to the on temperature Ton of the compressor 110.

FIG. 6 is a control graph of a refrigerator according to an embodiment of the disclosure.

Referring to FIG. 6, a process is described in which an operating rate of the compressor 110 changes as a rotation frequency of the compressor 110 varies, and an on-off operation mode is switched to a continuous operation mode based on the compressor 110 reaching a target operating rate.

In FIG. 6, from top to bottom, a first graph shows an on-off state of the compressor 110 over time, a second graph shows a temperature in the storage compartments 20 and 30 over time as the compressor 110 is turned on or off, and a third graph shows a rotation frequency of the compressor 110 over time.

It is assumed that the temperature in the storage compartments 20 and 30 is within an appropriate temperature range in a case where the temperature in the storage compartments 20 and 30 is between an on temperature Ton and an off temperature Toff of the compressor 110. In addition, it is assumed that external environments of the refrigerator do not change significantly, and it is assumed that a rate and slope of any temperature rise in the storage compartments 20 and 30 when the cold air supply device 100 does not operate are the same.

The controller 200 may change the rotation frequency of the compressor 110 in each on-off cycle of the compressor 110 until the compressor 110 reaches a target operating rate. A single on-off cycle of the compressor 110 may refer to a cycle during which the compressor 110 is turned on, then turned off, and before the compressor 110 is turned on again.

It is assumed that the compressor 110 starts operating in a case where the temperature in the storage compartments 20 and 30 is the on temperature Ton of the compressor 110. The compressor 110 may be operated at a rotation frequency N1 (RPM) for a time t1. As the compressor 110 operates, the temperature in the storage compartments 20 and 30 may reach the off temperature T off of the compressor 110 after the time t1. The compressor 110 may then be turned off until the temperature in the storage compartments 20 and 30 reaches the on temperature Ton of the compressor 110. For example, the compressor 110 may remain off for a time (t2−t1).

In this instance, an operating rate of the compressor 110 is t1/t2. For example, in a case where t1 is 10 and t2 is 20, the operating rate of the compressor 110 becomes 50%. Assuming that the target operating rate of the compressor 110 is 70˜80%, the operating rate requires to be raised. Accordingly, the controller 200 may operate the compressor 110 at a lower rotation frequency in the next on-off cycle.

From a time t2 to a time t3, the controller 200 may operate the compressor 110 at a rotation frequency N2 which is lower than N1. Because the compressor 110 is operated at a lower rotation frequency than before, the amount of cold air supplied by the cold air supply device 100 to the storage compartments 20 and 30 may be reduced, and thus the temperature in the storage compartments 20 and 30 may decrease more slowly than before. Referring to the second graph in FIG. 6, which indicates the temperature in the storage compartments 20 and 30, the slope of the temperature during t2˜t3 may be smaller than during 0˜t1. Accordingly, the time required to lower the temperature in the storage compartments 20 and 30 to the off temperature Toff of the compressor 110 may be longer. For example, t3−t2 may be greater than t1. After the time t3−t2 has elapsed, the temperature in the storage compartments 20 and 30 may reach the off temperature Toff of the compressor 110. The compressor 110 may then remain off until the temperature in the storage compartments 20 and 30 reaches the on temperature Ton of the compressor 110. For example, the compressor 110 remains off for a time t4−t3. A length of the time t4−t3 during which the compressor 110 is off may be equal to or significantly close to a time t2−t1.

In this instance, the operating rate of the compressor 110 is (t3−t2)/(t4−t2). For example, in a case where t2 is 20, t3 is 35, and t4 is 45, the operating rate of the compressor 110 becomes 60% (15/25). Assuming that the target operating rate is 70˜80%, the operating rate requires to be raised. Accordingly, the controller 200 may operate the compressor 110 at a lower rotation frequency in the next on-off cycle.

From a time t4 to a time t5, the controller 200 may operate the compressor 110 at a rotation frequency N3 which is lower than N2. Because the compressor 110 is operated at a lower rotation frequency than before, the amount of cold air supplied by the cold air supply device 100 to the storage compartments 20 and 30 may be reduced, and thus the temperature in the storage compartments 20 and 30 may decrease even more slowly than before. Referring to the second graph in FIG. 6, which indicates the temperature in the storage compartments 20 and 30, the slope of the temperature during t4˜t5 may be smaller than during 0˜t1 and t2˜t3. Accordingly, the time required to lower the temperature in the storage compartments 20 and 30 to the off temperature Toff of the compressor 110 may be even longer. For example, t5−t4 may be greater than t1 and t3−t2. After the time t5−t4 has elapsed, the temperature in the storage compartments 20 and 30 may reach the off temperature Toff of the compressor 110. The compressor 110 may then remain off until the temperature in the storage compartments 20 and 30 reaches the on temperature Ton of the compressor 110. For example, the compressor 110 remains off for a time t6−t5. A length of the time t6−t5 during which the compressor 110 is off may be equal to or significantly close to a time t2−t1 and a time t4−t3.

In this case, the operating rate of the compressor 110 is (t5−t4)/(t6−t4). For example, in a case where t4 is 45, t5 is 70, and t6 is 80, the operating rate of the compressor 110 may be 71.4% (25/35). Assuming that the target operating rate of the compressor 110 is 70˜80%, it may be confirmed that the operating rate of the compressor 110 when the compressor 110 is operated at the rotation frequency N3 satisfies the target operating rate range. Accordingly, the controller 200 may switch to the continuous operation mode when turning on again the compressor 110, and operate the compressor 110 in the continuous operation mode.

Because the RPM of the compressor 110 at the target operating rate may be close to the target RPM (N4) in the continuous operation mode, the controller 200 may operate the compressor 110 without requiring a large RPM adjustment when switching to the continuous operation mode.

In addition, in a case where the controller 200 switches the compressor 110 from the on-off operation mode to the continuous operation mode, the controller 200 may enter the continuous operation mode while decreasing the rotation frequency of the compressor 110. For example, the controller 200 may operate the compressor 110 at a target RPM (N4) that is lower than the rotation frequency (N3) used for a time t5−t4. The target RPM determined in the on-off operation mode may be referred to as a first RPM. For example, in the cycle immediately before switching from the on-off mode to the continuous operation mode, the controller may determine the target RPM for the continuous operation mode, and the target RPM may be referred to as the first RPM.

Because the compressor 110 continuously runs in the continuous operation mode without being turned off, in a case where the compressor 110 is continuously operated in the continuous operation mode at the rotation frequency used in the on-off operation mode without lowering the rotation frequency, the inside of the storage compartments 20 and 30 may be overcooled.

After switching to the continuous operation mode, the controller 200 may continue to operate the compressor 110 in the continuous operation mode. Because the compressor 110 does not require to be turned on and off in the continuous operation mode, energy loss caused by turning on and off the compressor 110 may be minimized.

As the compressor 110 operates in the continuous operation mode, the controller 200 may control the compressor 110 to allow the temperature in the storage compartments 20 and 30 to reach the reference temperature Ts which is set by a user. For example, the controller 200 may control the compressor 110 to allow the temperature in the storage compartments 20 and 30 to converge to the reference temperature Ts. However, in a case where the temperature in the storage compartments 20 and 30 changes due to external environmental changes or an open door, the controller 200 may vary the target RPM (N4) of the compressor 110 as described in FIG. 4 to increase or decrease the amount of cold air supplied to the storage compartments 20 and 30. In addition, in a case where the temperature in the storage compartments 20 and 30 changes significantly, the controller 200 may switch the compressor 110 from the continuous operation mode to the on-off operation mode to respond to the surrounding environment and maintain a stable temperature in the storage compartments 20 and 30.

Accordingly, the temperature in the storage compartments 20 and 30 may remain stable without significant change, thereby preserving the quality of food stored therein. In addition, because excessive on-off operations of the compressor 110 are not performed, the energy efficiency of the refrigerator 1 and the compressor 110 may increase.

It will be appreciated that various embodiments of the disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software.

Any such software may be stored in non-transitory computer readable storage media. The non-transitory computer readable storage media store one or more computer programs (software modules), the one or more computer programs include computer-executable instructions that, when executed by one or more processors of an electronic device individually or collectively, cause the electronic device to perform a method of the disclosure.

Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like read only memory (ROM), whether erasable or rewritable or not, or in the form of memory such as, for example, random access memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a compact disk (CD), digital versatile disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a computer program or computer programs comprising instructions that, when executed, implement various embodiments of the disclosure. Accordingly, various embodiments provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program.

While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.