EP-4200572-B1 - REFRIGERATOR AND CONTROL METHOD THEREOF

EP4200572B1EP 4200572 B1EP4200572 B1EP 4200572B1EP-4200572-B1

Inventors

LEE, SANGIL
Hu, Jinseok
Ahn, Buhwan
SHIN, Seonggu

Dates

Publication Date: 20260513
Application Date: 20210617

Claims (13)

A method for controlling a refrigerator, the refrigerator comprising a refrigerating room evaporator, a freezing room evaporator, a reciprocating compressor configured to supply refrigerant to each of the refrigerating room evaporator and the freezing room evaporator and using the refrigerant as a lubricant for a piston, a voltage detector configured to detect a driving voltage applied to the compressor, a current detector configured to detect a driving current applied to the compressor, and a refrigerant control valve configured to control the refrigerant flowing from the compressor to each of the refrigerating room evaporator and the freezing room evaporator, the method comprising: determining whether a condition of a refrigerant recovery operation is satisfied, wherein the refrigerant recovery operation is an operation for recovering the refrigerant from at least one of the refrigerating room evaporator or the freezing room evaporator; when the condition of the refrigerant recovery operation is satisfied, performing the refrigerant recovery operation and detecting a driving power value applied to the compressor based on the detected driving current and driving voltage; comparing a first driving power value of the compressor with a second driving power value of the compressor in real time, wherein the first driving power value is a driving power value at a first time point corresponding to a start time point of the refrigerant recovery operation and the second driving power value is a driving power value at a time point of the refrigerant recovery operation after the first time point; and determining a second time point of the refrigerant recovery operation at which a ratio of the first driving power value and the second driving power value is lower than a preset ratio as an end time point of the refrigerant recovery operation.
The method of claim 1, further comprising: determining whether a minimum refrigerant recovery operation time period is elapsed, wherein the comparing the first driving power value with the second driving power value is performed after the elapse of the minimum refrigerant recovery operation time period, and wherein the minimum refrigerant recovery operation time period is defined as a minimum value of an operation time period of the compressor to prevent abrasion of the reciprocating piston.
The method of claim 1, wherein, when the second time point does not arrive before a preset maximum refrigerant recovery operation time elapses, the determining of the end time point of the refrigerant recovery operation determines an end time of the maximum refrigerant recovery operation time as the end time of the refrigerant recovery operation.
The method of claim 1, wherein the second time point is an initial time point of the refrigerant recovery operation at which the ratio of the first driving power value and the second driving power value is lower than the preset ratio.
The method of claim 1, wherein when a predetermined abnormal operation occurs in the compressor, the determining of the end time point of the refrigerant recovery operation determines a time point at which the abnormal operation occurs as an end time point of the refrigerant recovery operation regardless of a result of comparing the first driving power value with the second driving power value.
The method of claim 1, further comprising: storing the first driving power value prior to the comparing the first driving power value with the second driving power value.
The method of claim 1, wherein a time interval between the start time point and the end time point is changed based on the driving power value of the compressor.
The method of claim 1, wherein a pressure and a temperature of the refrigerating room evaporator are higher than a pressure and a temperature of the freezing room evaporator and wherein the refrigerant recovery operation is performed after the second cooling operation, when a first cooling operation, by the refrigerating room evaporator, and a second cooling operation, by the freezing room evaporator, are sequentially performed.
The method of claim 1, wherein, in the refrigerant recovery operation, the refrigerant control valve is closed and the compressor is driven to recover the refrigerant remaining in the at least one of the refrigerating room evaporator or the freezing room evaporator.
The method of claim 1, wherein the refrigerant recovery operation is performed when the compressor performs a continuous operation and an intermittent operation.
A refrigerator, comprising: a compressor (100) configured to compress refrigerant; a voltage detector (630) configured to detect a driving voltage applied to the compressor (100); a current detector (620) configured to detect a driving current applied to the compressor (100); a condenser (110) configured to condense the refrigerant compressed by the compressor (100); a refrigerating room expansion valve (132) and a freezing room expansion valve (134) configured to decompress the refrigerant condensed by the compressor (100) and expand the refrigerant, a refrigerating room evaporator (122) and a freezing room evaporator (124) configured to evaporate the refrigerant expanded by the refrigerating room expansion valve (132) and the freezing room expansion valve (134) and generate cold air; a refrigerant control valve (130) configured to adjust the refrigerant flowing from the condenser (110) toward each of the refrigerating room evaporator (122) and the freezing room evaporator (124); a controller (180) configured to control the compressor (100) and the refrigerant control valve, wherein the controller (180) is configured to: determine whether a condition of a refrigerant recovery operation is satisfied, wherein the refrigerant recovery operation is an operation for recovering the refrigerant from at least one of the refrigerating room evaporator or the freezing room evaporator; perform the refrigerant recovery operation and detect a driving power value applied to the compressor (100) based on the detected driving current and driving voltage, when the condition of the refrigerant recovery operation is satisfied; compare a first driving power value of the compressor (100) with a second driving power value of the compressor (100) in real time, wherein the first driving power value is a driving power value at a first time point corresponding to a start time point of the refrigerant recovery operation and the second driving power value is a driving power value at a time point of the refrigerant recovery operation after the first time point; and determine a second time point of the refrigerant recovery operation at which a ratio between the first driving power value and the second driving power value is lower than a preset ratio as an end time point of the refrigerant recovery operation.
The refrigerator of claim 11, wherein the controller (180) is configured to compare the first driving power value with the second driving power value after driving the compressor (100) for a minimum refrigerant recovery operation time period and wherein the minimum refrigerant recovery operation time period is defined as a minimum value of an operation time period of the compressor (100) to prevent abrasion of the reciprocating piston.
The refrigerator of claim 11, wherein the controller (180) is configured to determine, when the second time point does not arrive before a preset maximum refrigerant recovery operation time elapses, an end time of the maximum refrigerant recovery operation time as the end time of the refrigerant recovery operation.

Description

[Technical Field] The present invention relates to a refrigerator performing a refrigerant recovery operation to recover refrigerant, that is, a pump down operation, and a control method thereof. [Background Art] A refrigerator is an apparatus to prevent spoilage and deterioration by cooling objects to be cooled (hereinafter; referred to as "food") such as food, drugs, and cosmetics. The refrigerator includes a storage portion in which food is stored and a cooling device to cool the storage portion. The cooling device may include a compressor, a condenser, a refrigerant control valve, an expansion valve (e.g., a capillary pipe), and an evaporator through which the refrigerant is circulated. The refrigerator may include a 1COMP-1EVA system to cool both a freezing room (an F-room) and a refrigerating room (an R-room) using a compressor and an evaporator and may include a 1COMP-2EVA system to independently cool the freezing room and the refrigerating room using a compressor and two evaporators. In this case, the two evaporators include a freezing room evaporator to cool the freezing room and a refrigerating room evaporator to cool the refrigerating room. The refrigerator including the 1COMP-2EVA system to independently cool the freezing room and the refrigerating room connects the freezing room evaporator and the refrigerating room evaporator in parallel and independently cools the freezing room and the refrigerating room. The refrigerator including the 1COMP-2EVA system in related art repeats refrigerating room operation, freezing room operation, and refrigerant recovery operation and independently cools the refrigerating room and the freezing room. The refrigerating room operation is an operation in which the refrigerant passes through the refrigerating room evaporator and the refrigerating room evaporator cools the refrigerating room. The freezing room operation is an operation in which the refrigerant passes through the freezing room evaporator and the freezing room evaporator cools the freezing room. The refrigerant recovery operation, that is, the pump down operation, is an operation in which refrigerant control valve (i.e., a 3 way valve) is adjusted to block flow of the refrigerant to each of the refrigerating room evaporator and the freezing room evaporator while a compressor is operated, and the refrigerant remaining in the refrigerating room evaporator and the refrigerant remaining in the freezing room evaporator are recovered to the compressor. The refrigerant recovery operation is performed between the freezing room operation and the refrigerating room operation. When the refrigerant recovery operation is performed between the freezing room operation and the refrigerating room operation, the refrigerant from the freezing room evaporator having relatively lower pressure and temperature than those of the refrigerating room evaporator is recovered to the condenser, is supplied to the refrigerating room evaporator during the operation of the refrigerating room, the refrigerant from the condenser quickly flows to the refrigerating room evaporator. When the refrigerating room is operated, sufficient amount of refrigerant flows to the refrigerating room evaporator to quickly cool the refrigerating room. Meanwhile, Korean Patent Publication No. 10-2007-031656 discloses a method for controlling a refrigerator comprising, when refrigerant is recovered from a refrigerating room evaporator or a freezing room evaporator, smoothly recovering the refrigerant remaining in the refrigerating room evaporator or the freezing room evaporator by driving a refrigerating room fan or a freezing room fan. In the above-described related art patent, the refrigerator performs the refrigerant recovery operation for a fixed period of time. However, when the refrigerator performs the refrigerant recovery operation for the fixed period of time, there is a problem in that a performance of the refrigerant recovery operation varies depending on the operation conditions of the refrigerator. That is, the performance of the refrigerant recovery operation varies depending on a power of the compressor. When the refrigerant recovery operation is performed for the fixed period of time, the refrigerant is not recovered properly when a cooling power is low and an excessive amount of power is supplied when the cooling power is high. Therefore, in the above-described related art patent, the refrigerant recovery operation may not be efficiently performed. Document EP 1 106 943 A2 is considered to show the closest prior art and discloses a refrigerator and a temperature based control of a refrigerant recovery operation. The documents KR 2008 0103854 A and US 2006/048530 A1 are related prior art documents. [Invention] [Technical Problem] The invention is specified by the independent claims. Preferred embodiments are defined in the dependent claims. In the following description, although numerous features may be designated as optional, it is never