KR20060126808A - A cooling device and its control method - Google Patents

Abstract

This invention relates to a cooling device (1) which enables a decrease of the energy consumption cost of the user as a consequence of a decrease in the number of defrost procedures which is performed by taking into consideration the temperature of freshfood compartment (T1) during the defrost process taking place when the doors (4) are closed.

Description

Cooling device and its control method {A COOLING DEVICE AND ITS CONTROL METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device and a control method thereof, and to a cooling device and a control method thereof which can improve productivity by avoiding unnecessary defrosting when the door is closed.

In the compartment in which the evaporator is located in the cooling system, the moisture in that environment forms frost on the evaporator surface because the evaporator has the coldest surface. Defrost formed on the surface of the evaporator needs to be removed periodically through the defrost process. The period of the defrost process is determined by a defrost control algorithm, which is based on parameters such as the amount of frost formed on the evaporator, the number of times the refrigerator door is opened or closed, or the defrost occurring within a predetermined fixed time frame. . Cooling efficiency is improved if frost formation is avoided through defrosting. However, since the defrost process requires high energy consumption, the cost of the increased energy consumption is borne by the consumer. Therefore, energy consumption can be reduced by optimizing many defrost processes and their timing.

The amount of frost formed on the evaporator surface is directly proportional to the humidity in the air circulated in the cooling system. High humidity increases the amount of frost formed. If the refrigerator door is left open for a long time, the humidity circulating in the air is constantly reduced since no air is introduced into the refrigerator from the outside. In this case, it takes longer for frost to form on the evaporator surface. Various defrosting methods have been developed to reduce energy consumption when refrigerator doors are closed for a long time.

In US Pat. No. 4,297,852, a second defrost method is started if the refrigerator door is not frequently opened. In this method, the defrost is determined according to the ratio of the time the door is kept open to the time the door is kept closed.

 In EP patent application EP1070925, a second defrost method is started when the refrigerator door is closed for a long time. In this method defrost is determined based on the difference between the temperature of the evaporator and the interior space of the refrigerator.

The present invention is to implement a cooling system and its control method for adjusting the defrost time in order to reduce the energy consumption cost of the user.

The present invention for achieving the above object, the refrigerator compartment for storing food and beverages, the freezer compartment for freezing the food, one or more doors (compressor) to open and close the refrigerator compartment and the freezer compartment (compressor, performing a cooling cycle, heat energy) An evaporator that absorbs and cools the internal space of the following cooling device, a defroster which removes frost formed in the evaporator, a thermometer measuring a temperature inside the refrigerating chamber, one or more doors that are turned on when the door is opened and turned off when the door is closed. In the cooling device including a memory for storing information such as a switch, defrost algorithm, the next defrost time,

Determine the operating time of the defroster according to a fixed or variable defrost algorithm, and if the door is not opened after the previous defrost process, the defroster until the temperature of the refrigerating chamber exceeds a preset limit temperature value. It characterized in that it comprises a control card for delaying the operation time of the predetermined waiting time.

In addition, the control method of the cooling apparatus according to the present invention for achieving the above object comprises the steps of determining the next defrost time (zd) after the defrost process; Determining whether a door of the cooling device is open; Delaying the defrost process until the next defrost time zd if the door is open; Performing a defrost process by the operation of the defrost unit; Returning to determining the next defrost time zd; Comparing the temperature (T1) of the refrigerating compartment and the threshold temperature value (Ts) of the refrigerating compartment, measured by a thermometer, if the door is not opened; If the temperature T1 of the refrigerating compartment is lower than the threshold temperature value Ts of the refrigerating compartment, returning to the step of determining whether the door is closed; When the temperature T1 of the refrigerating compartment is higher than the limit temperature value Ts of the refrigerating compartment, the time length z1 at which the temperature of the refrigerating compartment is maintained above the limit temperature value Ts of the refrigerating compartment and the limit heating time of the refrigerating compartment comparing (zs); If the time length z1 at which the temperature of the refrigerating compartment is maintained at or above the threshold temperature value Ts of the refrigerating compartment is smaller than the limit heating time zs of the refrigerating compartment, determining whether the door 4 is closed. Returning; If the time length z1 at which the temperature of the refrigerating chamber is maintained above the threshold temperature value Ts of the refrigerating chamber is greater than the limit heating time zs of the refrigerating chamber, defrosting is performed by an operation of the defrost unit. step; And returning to determining the next defrost time.

In one embodiment of the present invention, the control method of the above-mentioned cooling apparatus includes a time length z1 at which the temperature of the refrigerating chamber is maintained above the limit temperature value Ts of the refrigerating chamber and the limit heating time zs of the refrigerating chamber. After the step of comparing

If the length of time z1 at which the temperature of the refrigerating chamber is maintained above the limit temperature value Ts of the refrigerating chamber is greater than the limit heating time zs of the refrigerating chamber, the minimum between two consecutive defrost processes when the door is closed. Determining whether the time length z3 has elapsed; When the door is closed, returning to the step of determining whether the door is closed if the minimum time length (z3) between two successive defrost processes has not elapsed; And when the door is closed, performing a defrost process by an operation of the defrost unit when the minimum time length z3 between two consecutive defrost processes has elapsed.

In another embodiment of the present invention, the control method of the above-mentioned cooling apparatus is, after the step of determining whether or not the door is opened,

If it is determined that the door has been kept open, determining whether the next defrost time zd has been reached; If the next defrost time zd has not been reached, delaying the defrost process until a later defrost time zd is reached; If the next defrost time zd is reached, delaying the defrost process for an additional defrost delay time z2; And performing a defrost process by the operation of the defrost unit.

The cooling apparatus of the present invention and its control method for achieving the above object are explained by the accompanying drawings;

1 is a conceptual diagram of a cooling apparatus according to the present invention.

2 is a flowchart showing a control method of a cooling apparatus according to the present invention.

3 and 4 is a flow chart showing another application of the cooling apparatus control method according to the present invention.

Each component of each figure is given an individual reference numeral as follows.

1-chiller

2-refrigerator

3-freezer

4-door

5-compressor

6-evaporator

7-Defrost

8-thermometer

9-control card

10-memory

11-door switch

Referring to Figure 1, the cooling device 1 according to the present invention is preferably a refrigerator without frost, a refrigerating chamber (2) for storing food and beverages, a freezer (3) for freezing and storing the food, the One or more doors (4) for opening and closing the refrigerating compartment and the freezing compartment (2, 3), the compressor (5) to help carry out the cooling cycle, the evaporator (6) to absorb the heat energy to cool the internal space of the cooling device (1) ), A defroster 7 for removing frost formed in the evaporator 6, a thermometer 8 for measuring the temperature inside the refrigerating chamber 2, one or more doors that are opened when the door is opened and blocked when the door is closed. The operating time of the defroster 7 is determined according to the door switch 11, a fixed or variable defrost algorithm, and if the door is not opened after the immediately defrost process, the temperature of the refrigerating chamber 2 is preset. Exceed the set limit temperature Control card 9 for delaying the operation time of the defrost unit 7 for a predetermined waiting time until, and a memory 10 for storing information such as defrost algorithm, the next defrost time.

The control card 9 controls the state of the door 4 covering the refrigerating compartment and the freezing compartment 2, 3 after the defrosting process is performed in the defrost unit 7 through the position of the door switch 11. To track. The next defrost time determined by the defrost algorithm is stored in the memory 10. If the door 4 is opened before the next defrost time, that is, the door switch 11 is turned on, the defrost process is performed at a preset time. If the door 4 continues to be closed, that is, the door switch 11 is always kept off, the defrost process is delayed by the control card 9. The information collected by the thermometer 8 is continuously controlled. If the temperature of the refrigerating chamber 2 does not exceed the limit temperature value, the defrost process is not performed. If the temperature of the refrigerating chamber (2) exceeds the threshold temperature value and maintained above the threshold temperature value for a predetermined time, the control card (9) operates the defroster 7 to perform the defrost process. . As the time for which the temperature of the refrigerating chamber 2 is maintained above the threshold temperature value increases, the amount of frost formed in the evaporator 6 increases, which means that a defrost process is required.

For the description of the control method of the cooling device 1 according to the present invention, the following reference numerals are used.

zd: Next defrost time

T1: temperature of the refrigerating chamber 2

Ts: limit temperature value of the refrigerating compartment (2)

z1: length of time for which the temperature of the refrigerating chamber 2 is maintained above the limit temperature value Ts of the refrigerating chamber 2.

zs: limit heating time of the refrigerating compartment (2)

z2: Defrost additional delay time

z3: Minimum time length between two defrosting processes when the door (4) is closed

Limit temperature value Ts of the refrigerating compartment 2, limit heating time zs of the refrigerating compartment 2, additional defrost time delay z2 and the minimum time between two defrosting processes when the door 4 is closed. The length z3 is determined by the manufacturer and written on the memory 10.

The defrosting process of the cooling device 1 is controlled as follows.

When the defrost process is performed, the next defrost time zd is calculated (101).

Determine whether door 4 is open (102).

If the door (4) is open (103), wait until the next defrost time;

Defrost process is performed by the operation of the defrost unit (7),

Thereafter proceeds to step 101 where the next defrost time is calculated (101).

If the door 4 is not open, the temperature T1 of the refrigerating compartment 2 measured by the thermometer 8 is compared with the limit temperature value Ts of the refrigerating compartment 2 (104).

If the temperature T1 of the refrigerating compartment 2 is lower than the threshold temperature value Ts of the refrigerating compartment 2, the process proceeds to step 102 of determining whether the door 4 is closed.

If the temperature T1 of the refrigerating compartment 2 is higher than the limit temperature value Ts of the refrigerating compartment 2, the time length z1 at which the temperature of the refrigerating compartment is maintained above the limit temperature value Ts of the refrigerating compartment 2. And the critical heating time zs of the refrigerating chamber 2 are compared (105).

The door 4 is closed if the time length z1 at which the temperature of the refrigerating compartment is kept above the threshold temperature value Ts of the refrigerating compartment is less than the limit heating time zs of the refrigerating compartment 2. The determination proceeds to step 102.

-If the time length z1 at which the temperature of the refrigerating chamber is maintained above the threshold temperature value Ts of the refrigerating chamber is greater than the limit heating time zs of the refrigerating chamber 2, Defrost process is performed by (106).

Then proceed to step 101 of calculating the next defrost time.

In another embodiment of the present invention, in order to avoid cycles in which defrosting is carried out continuously, the minimum time length z3 required to occur between two successive defrosting processes when the door 4 is closed is determined. The door switch when the door 4 is in the closed position, until the door is slightly opened or when hot food enters the cooling device 1 or cooling is insufficient due to an obstacle (gas leak, etc.) 11 is pressed. If the temperature T1 of the refrigerating compartment is always maintained above the limit temperature value Ts of the refrigerating compartment 2, there is a possibility that the defrost cycle is continuously performed. In order to avoid this, in addition to the above steps, the time length z1 at which the temperature of the refrigerating chamber 2 is maintained above the limit temperature value Ts of the refrigerating chamber 2 and the limit heating of the refrigerating chamber 2 After the step 105 of comparing the time zs, the following steps are further performed.

If the length of time z1 at which the temperature of the refrigerating chamber 2 is kept above the limit temperature value Ts of the refrigerating chamber 2 is greater than the limit heating time zs of the refrigerating chamber 2, the door 4 When it is closed, it is determined whether the minimum time length z3 between two successive defrost processes has elapsed (201).

If the minimum time length (z3) between the two successive defrost processes has not elapsed when the door 4 is closed, the process proceeds to step 102 of controlling whether or not the door 4 is closed,

If the minimum time length z3 between the two successive defrost processes has elapsed when the door 4 is closed, the defrost process is performed by the operation of the defrost unit 7 (106).

In another embodiment according to the invention, after step 102 of determining whether the door is closed, if it is determined that the door 4 has been kept open,

Check whether the next defrost time zd has been reached (301),

If the next defrost time zd has not been reached, the defrost process is delayed until the next defrost time zd is reached (103);

If the next defrost time zd has been reached, the defrost process is delayed for an additional defrost delay time z2 (302).

The defrost process is then performed by operation of the defrost unit 7 (106).

In the case of the cooling device 1 of the present invention, since the humidifier no longer increases while the door 4 is kept closed, the need for frost and defrost formed on the evaporator 6 is more than in normal operating conditions. Occurs at long time intervals. If the door 4 is closed, the defrosting process is performed in consideration of the temperature T1 of the refrigerating chamber, thereby implementing a less defrosting process and providing a user with a reduction in energy consumption cost.

Claims (4)

Refrigerator (2) for storing food and beverages, freezer (3) for storing the food, one or more doors (4) for opening and closing the refrigerator and freezer (2, 3), the compressor for performing the cooling cycle ( 5), an evaporator 6 for absorbing thermal energy to cool the internal space of the following cooling device 1, a defroster 7 for removing frost formed in the evaporator, and a temperature for measuring the temperature inside the refrigerating chamber 2 Cooling apparatus 1 comprising a thermometer 8, at least one door switch 11 that is turned on when the door is opened and turned off when the door is closed, and a memory 10 for storing information such as defrost algorithms, next defrost time, etc. ), The operating time of the defrost unit 7 is determined according to a fixed or variable defrost algorithm, and if the door is not opened after the previous defrost process, the temperature of the refrigerating chamber 2 may exceed a preset limit temperature value. And a control card (9) for delaying the operation time of the defroster (7) for a preset waiting time until the defroster (7). In the control method of the cooling apparatus 1 of Claim 1, Determining (101) the next defrost time zd after the defrost process; Determining (102) whether the door (4) of the cooling device (1) is open; Delaying (103) the defrost process until the next defrost time (zd) if the door (4) is open; Performing a defrost process by the operation of the defrost unit (106); Returning to step 101, determining the next defrost time zd; Comparing (104) the temperature (T1) of the refrigerator compartment measured by the thermometer (8) and the threshold temperature value (Ts) of the refrigerator compartment (2) if the door (4) is not open; If the temperature T1 of the refrigerating compartment is lower than the limit temperature value Ts of the refrigerating compartment 2, returning to step 102 of determining whether the door 4 is closed; When the temperature T1 of the refrigerating compartment is higher than the limit temperature value Ts of the refrigerating compartment 2, the length of time z1 at which the temperature of the refrigerating compartment is maintained above the limit temperature value Ts of the refrigerating compartment 2 and Comparing (105) a limit heating time (zs) of the refrigerating compartment (2); If the time length z1 at which the temperature of the refrigerating chamber is maintained above the threshold temperature value Ts of the refrigerating chamber 2 is smaller than the limit heating time zs of the refrigerating chamber 2, the door 4 is closed. Returning to determining 102 whether there is; When the time length z1 at which the temperature of the refrigerating chamber is maintained above the limit temperature value Ts of the refrigerating chamber 2 is greater than the limit heating time zs of the refrigerating chamber 2, the defrost unit 7 Performing 106 a defrost process by operation; And Returning to step 101, determining the next defrost time; Control method of the cooling device (1) comprising a. The method of claim 2, After step 105 of comparing the length of time z1 at which the temperature of the refrigerating compartment is maintained above the threshold temperature value Ts of the refrigerating compartment 2 and the limit heating time zs of the refrigerating compartment 2, When the time length z1 at which the temperature of the refrigerating chamber 2 is maintained above the limit temperature value Ts of the refrigerating chamber 2 is greater than the limit heating time zs of the refrigerating chamber 2, the door 4 Determining whether the minimum time length (z3) between two consecutive defrost processes has elapsed when it is closed (201); When the door (4) is closed, returning (102) to determining whether the door (4) is closed if the minimum time length (z3) between the two successive defrost processes has not elapsed; And When the door (4) is closed, performing a defrost process by an operation of the defrost unit (7) if a minimum time length (z3) between two successive defrost processes has elapsed; Control method of the cooling device (1) characterized in that it further comprises. The method according to claim 2 or 3, After the step 102 of determining whether the door 4 is open is performed, If it is determined that the door 4 has been kept open, determining (301) whether the next defrost time (zd) has been reached; If the next defrost time (zd) has not been reached, delaying (103) the delay until the subsequent defrost time (zd) is reached; If the next defrost time zd has been reached, delaying the defrost process for an additional defrost delay time z2 (302); And A step (106) of performing a defrost process by the operation of the defrost unit (7); Control method of the cooling device (1) characterized in that it further comprises.

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