JP4575281B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator that uses a cooling fan to cool a refrigerator compartment.

  In recent years, an evaporator for cooling a refrigerator (hereinafter referred to as “first evaporator”) and an evaporator for cooling a freezer (hereinafter referred to as “second evaporator”) are used, and a switching valve is used. There has been proposed a refrigerator having a refrigeration cycle in which a refrigerant is circulated between a refrigerator compartment and a freezer compartment in the refrigerator, and alternately cooling the refrigerator compartment and the freezer compartment (see, for example, Patent Document 1). In this way, by alternately cooling the refrigerator compartment and the freezer compartment, it becomes possible to set the evaporation temperature of each evaporator relatively high, so that the efficiency of the refrigeration cycle can be improved and power saving operation is performed. Can also be performed.

In this refrigerator, when the freezer compartment is being cooled, the refrigeration cooler circulation fan is rotated to sublimate the frost attached to the first evaporator to perform defrosting, and the moisture is used to remove the frost. It is configured to maintain high humidity. This refrigerated cold air circulation fan rotates continuously until reaching a predetermined temperature, for example, 3 ° C. or higher, which can be regarded as the completion of defrosting of the first evaporator. If this defrosting is not completed, it does not shift to cooling of the refrigerator compartment.
JP 2002-303474 A

  However, for example, when the refrigerator is installed at a low temperature such as in winter, the temperature rise is slow even if the first evaporator is defrosted by the rotation of the refrigeration cooler circulation fan. It took a long time to shift to cooling of the room, and there was a possibility that the temperature of the refrigerating room would rise. Further, in the form in which the first evaporator is disposed in the vicinity of the second evaporator or the freezer compartment having a relatively low temperature, in particular, the temperature rise of the first evaporator becomes dull. The cooling to the refrigerator compartment is delayed, the temperature of the refrigerator compartment is likely to rise, and there is a risk of adversely affecting the stored food.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a refrigerator capable of reliably removing frost attached to an evaporator for cooling a refrigerator.

A feature according to the embodiment of the present invention is that a cooling operation for alternately cooling the refrigerator compartment and the freezer compartment by having a first evaporator for cooling the refrigerator compartment and a second evaporator for cooling the freezer compartment is performed. In the refrigerator to be performed, a heater that removes frost attached to the first evaporator, and a cool air that circulates in the refrigerating chamber during the cooling operation of the freezer, and the heater is also driven when the first evaporator is heated. A refrigerating room cool air circulation fan that removes frost adhering to the evaporator 1, and the refrigerating room cold air circulation fan supplies cooling air to the refrigerating room during driving of the refrigerating room and during cooling operation of the freezing room. drive and heater when circulating the Ri Do different rotational speed between the drive in the case of heating the first evaporator, heater need outermost reduced from the start of the cooling run of at least the freezing chamber defrosting of the first evaporator It is turned on after a lapse of time.

  ADVANTAGE OF THE INVENTION According to this invention, the refrigerator which can remove frost attached to the evaporator for cooling room cooling reliably can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of a refrigerator 1 according to an embodiment of the present invention, with the left side facing the front of the refrigerator 1 and the right side facing the back. As shown in FIG. 1, the refrigerator 1 includes an outer box 2 made of iron plate, an inner box 3 made of plastic, and a heat insulating material 4 made of, for example, urethane foam and filled with foam between them. In the refrigerator 1, a refrigerated storage room 5, a switching room 6, a vegetable room 7, and a frozen storage room 8 are provided in order from the top. An ice making chamber (not shown) is provided next to the switching chamber 6 (on the front side of the switching chamber in FIG. 1) so as to be arranged on the right side when viewed from the front of the refrigerator 1. Moreover, between the refrigerated storage room 5 and the switching room 6, between the switching room 6 and the vegetable room 7, and between the vegetable room 7 and the frozen storage room 8 are partitioned by heat insulating partition walls 9a and 9b, respectively. .

  A first evaporator 10 is located behind the vegetable compartment 7, and a cold air circulation fan (hereinafter referred to as “first cooling fan”) 11 for circulating cold air inside the refrigerator compartment behind the switching chamber 6. Is arranged. When the first cooling fan 11 is driven, the cold air cooled by the first evaporator 10 passes through the first air duct 12 provided behind the refrigerated storage chamber 5 as indicated by an arrow. And supplied to the vegetable compartment 7 via the second air duct 13. Thereby, it is set as the structure by which the refrigerator compartment 5 and the vegetable compartment 7 are cooled.

  Behind the first evaporator 10, a second evaporator 14 is further provided by being partitioned by a heat insulating partition wall 9c. The cold air cooled by the second evaporator 14 is stored frozen as indicated by an arrow by a freezing room cold air circulation fan (hereinafter referred to as “second cooling fan”) 35 not shown in FIG. It is supplied to the chamber 8 and an ice making chamber (not shown).

  The temperature in the refrigerator compartment 5 is detected by a refrigerator compartment sensor 15 provided on the wall surface of the refrigerator compartment 5. The temperature in the freezer compartment 8 is detected by a freezer sensor 16 provided on the wall surface of the freezer compartment 8. These detected temperatures are transmitted to a control unit (not shown) and used for temperature control of the refrigerator 1. In addition, the V sensor 17 provided in the back surface of the vegetable compartment 7 detects the temperature in the vegetable compartment 7, and the bottom surface which is not shown in figure so that the inside of the vegetable compartment 7 may be maintained at preset temperature, for example, 5 degreeC here. The heater energization control is performed.

  A machine room 18 is formed at the bottom of the refrigerator 1, and a compressor 19, an evaporating dish 20 that evaporates by receiving defrost water, and the like are disposed therein. The defrosted water for evaporating in the evaporating dish 20 is collected via the eaves 21a and the drainage hose 21b provided from the first evaporator 10 and the second evaporator 14 toward the evaporating dish 20. .

  Between the first evaporator 10 and the vegetable compartment 7, a heater (hereinafter referred to as “R heater”) that melts and removes frost attached to the first evaporator 10 by heating the first evaporator 10. 22) Here, an aluminum foil heater is provided. The air circulated by the first evaporator 10 circulates in the vegetable compartment 7 and flows from the upstream side which is the lower side of the first evaporator 10 to the downstream side which is the upper side. At this time, since the air is heated by the R heater 22 and flows from the upstream side to the downstream side of the first evaporator 10, defrosting of the first evaporator 10 is promoted. A refrigeration defrost sensor 23 (hereinafter referred to as “RD sensor”) is provided on the upper portion of the first evaporator 10, and the piping temperature of the first evaporator 10 is detected.

  Further, the eave 21a is provided with an eaves heater 24a, here an aluminum foil heater, on the back surface of the eave 21a, and the drain hose 21b is surrounded by a drain hose 21b, An aluminum foil heater is wound so that the defrost water passing through the trough 21a and the drain hose 21b is not frozen. The R heater 22 may be any type of heater such as a pipe heater or a glass tube heater.

  FIG. 2 is a diagram showing a refrigeration cycle 30 of the refrigerator 1 in the embodiment of the present invention. As shown in FIG. 2, the compressor 19, the condenser 31, the switching valve 32, the refrigerator compartment capillary tube 33, the first evaporator 10, the first cooling fan 11, the freezer compartment capillary tube 34, the second compartment The refrigeration cycle 30 is configured by sequentially connecting the evaporator 14, the second cooling fan 35, the accumulator 36, and the check valve 37.

  According to this configuration, the refrigerating room capillary tube 33, the cooling operation of the refrigerating room via the first evaporator 10 by the switching valve 32, the freezing room capillary tube 34, the second evaporator 14, the accumulator 36, The system is switched to the cooling operation of the freezer compartment via the check valve 37, and is configured to alternately cool the two systems of the refrigerator compartment system such as the refrigerator compartment 5 and the freezer compartment system such as the refrigerator compartment 8. is doing.

  FIG. 3 is a flowchart showing a flow of defrosting in the refrigerator 1 according to the embodiment of the present invention. First, a rough flow of defrosting in the refrigerator compartment will be described with reference to FIG. Here, the refrigerated room includes the refrigerated storage room 5 or the vegetable room 7, and the freezing room includes the switching room 6 or the frozen storage room 8.

  As shown in FIG. 3, in order to remove frost attached to the first evaporator 10, it is first determined whether or not the cooling operation of the refrigerating room has shifted to the cooling operation of the freezing room (ST1). This determination is made based on conditions such as whether the freezer compartment has reached −18 ° C. or higher, or whether the refrigerator compartment has been cooled for 20 minutes or longer.

  4 shows the detected temperature of the refrigerator compartment sensor (hereinafter referred to as “R sensor”) 15, the detected temperature of the RD sensor 23, and the detected temperature of the freezer compartment sensor (hereinafter referred to as “F sensor”) 16 from the top. It is a time chart which shows a motion and ON and OFF of the 1st cooling fan 11 and the R heater 22. FIG. The temperature detected by each sensor indicates that among the items of each sensor, the upper part is high and the lower part is low. For example, in the term of the RD sensor 23, the leftmost column indicates that the temperature is decreasing.

  FIG. 4 shows that time has passed from the left to the right. Portions (A, B, C, D) separated by the vertical axis of the dotted line indicate the cooling operation time of the refrigerator compartment or the cooling operation time of the freezer compartment. For example, in FIG. Indicates that driving is taking place.

  On the other hand, the dotted line α on the horizontal axis drawn in the R sensor column indicates that the energization start temperature of the R heater 22 is the Ron temperature at which the cooling operation of the refrigerator compartment is started and the current temperature in the refrigerator compartment (R sensor 15 The difference from the detected temperature). This difference is set to 0.5 ° C., for example. When this temperature is exceeded, the R heater 22 is energized as described later. A double line on the vertical axis indicating this point is represented by a. An alternate long and short dash line β drawn in the column of the RD sensor 23 is a line indicating 3 ° C. This 3 ° C. is a temperature at which it can be considered that the defrosting is completed, and is set as a condition for turning off the R heater 22.

  As shown in FIG. 4, in the column A, the detected temperatures of the R sensor 15 and the RD sensor 23 are decreasing, indicating that an operation for cooling the refrigerator compartment is being performed. Since the cooling operation of the room is not performed, the F sensor 16 indicates that the temperature in the freezer compartment is rising. During the cooling operation of the refrigerator compartment, the first cooling fan 11 is turned on to cool the refrigerator compartment by circulating the cool air from the first evaporator 10 to the refrigerator compartment.

  When the transition condition for the cooling operation of the freezer compartment as described above is satisfied, the first cooling fan 11 is switched to the low-speed operation and starts the cooling operation of the freezer compartment (ST2). The low speed operation mentioned here refers to a state in which, for example, when the normal rotational speed is 1900 rpm, the rotational speed is decreased from 1600 to 1700 rpm, for example. As described above, by operating the first cooling fan 11 even during the cooling operation of the freezer compartment, the frost adhering to the first evaporator 10 is sublimated as indicated by the arrow γ in FIG. It is possible to increase the humidity of the refrigerator compartment ("moisture operation"). In this state, the R sensor 15 and the RD sensor 23 detect how the temperature in the freezer compartment gradually decreases as indicated by the F sensor 16 while the temperature in the refrigerator compartment gradually increases. In FIG. 4 and subsequent figures, the “first cooling fan 11” is referred to as “R fan” for convenience.

  Next, it is determined whether or not the first cooling fan 11 has operated at a low speed for 20 minutes or more (ST3). Twenty minutes, which is the determination criterion, is a minimum time required for defrosting the first evaporator 10. If 20 minutes have not elapsed, the first cooling fan 11 is continuously operated at a low speed. When 20 minutes have elapsed, the difference between the Ron temperature (for example, 4 ° C.) at which the cooling operation of the refrigerator compartment is started and the current temperature in the refrigerator compartment (detected temperature of the R sensor 15) is the energization of the R heater 22. It is determined whether the temperature is higher than the start temperature (for example, 0.5 ° C.) (ST4). At this time, when the difference between the Ron temperature and the R sensor 15 is larger than the energization start temperature of the R heater 22, that is, when the temperature in the refrigerator compartment is low, the air to be heat exchanged even if the first cooling fan is rotated. Since the temperature is low, the temperature rise of the first evaporator 10 becomes dull, and it may take a long time to shift to the cooling operation of the refrigerator compartment. Therefore, the first evaporator 10 is heated by turning on the R heater 22 to promote defrosting (ST5). That is, when the time chart of the R heater 22 described in the lowermost stage of FIG. 4 is viewed, the R heater 22 is turned on at the double line a. In this case, by not turning on the R heater 22 from the beginning of the cooling operation of the freezer compartment, it is possible to prevent the temperature of the refrigerator compartment from being inadvertently increased. Further, when the temperature rise slows down, since the outside air temperature is low and the temperature in the refrigerator compartment has risen to, for example, 1 ° C. or more, it is effective to energize the R heater 22 after a predetermined time. The evaporator can be heated and power consumption can be reduced.

  Further, when the detected temperature of the RD sensor 23 is 3 ° C. or higher, it is assumed that the defrosting is completed (ST6), and the R heater 22 is turned off (ST7). A dotted line b in FIG. 4 indicates a point in time when the determination is made. That is, the R heater 22 is turned on for a time Δ between the double line a and the dotted line b. When the R heater 22 is turned on only during this time Δ, the temperature detected by the RD sensor 23, which is a refrigeration defrost sensor, rapidly increases and exceeds 3 ° C. near the dotted line b. Thus, the frost attached to the first evaporator 10 is surely sublimated.

  When the temperature detected by the RD sensor 23 reaches 3 ° C. or higher, it is determined whether or not the cooling operation for the freezer compartment has shifted to the cooling operation for the refrigerator compartment (ST8). This determination is made based on conditions such as whether or not the Ron temperature at which the cooling operation of the refrigerator compartment is started, or whether or not the freezer is cooled for 40 minutes or more. When it is determined that the cooling operation has been shifted to the refrigerating room, the first cooling fan 11 that has been operated at a low speed returns to the normal operation (ST9), and the refrigerating room is cooled again. In this manner, the cooling operation of the refrigerator compartment and the cooling operation of the freezer compartment are alternately repeated.

  On the other hand, if it is determined that the cooling operation of the refrigerator compartment has not been shifted, the first cooling fan 11 is further operated at a low speed for a predetermined time (for example, 1 minute) (ST10). This is for rotating the first cooling fan for a predetermined time to disperse the residual heat and make the temperature of the evaporator uniform. . However, if there is a request for the cooling operation of the refrigerator compartment even if the predetermined time has not elapsed, the cooling of the refrigerator compartment is prioritized. After the predetermined time has elapsed, it is not necessary to rotate the first cooling fan any more. Therefore, the first cooling fan 11 is stopped (ST11), and it is determined whether or not the cooling room cooling operation has been started again. (ST12). The criteria for determination are the same as in step 8. When it is determined that the cooling operation has been shifted to the refrigerator compartment, the first cooling fan 11 that has been operated at a low speed returns to the normal operation (ST9).

  FIG. 5 shows the temperature change of each sensor and the first cooling fan 11 and the R heater when a hot dish, for example, is put in the freezer compartment during the cooling operation of the freezer compartment and the temperature in the freezer compartment rises rapidly. It is a time chart which shows ON and OFF.

  For example, when the temperature in the refrigerating chamber suddenly increases at the time point c shown in FIG. 5, the R sensor 15 reacts and the R heater 22 is turned on. In this case, it can be seen that the temperature detected by the RD sensor 23 does not follow the change in temperature in the refrigerator compartment detected by the R sensor 15. However, as the R heater 22 is turned on and the first cooling fan 11 continues to operate, the frost adhering to the first evaporator 10 sublimates early, and the temperature of the RD sensor 23 increases. If it becomes 3 degreeC or more, it will transfer to the cooling operation of a refrigerator compartment from the cooling operation of the freezer compartment until now. By doing in this way, even if the temperature in the refrigerator compartment suddenly rises, it is possible to make a fine response that can be shifted to the cooling operation of the refrigerator compartment at an early stage, food stored in the refrigerator Etc. can be prevented.

  FIG. 6 shows a case where the door 5a is opened and closed immediately after the first cooling fan 11 is operated at a low speed ("moisture operation"), or, for example, a hot dish is left as it is, and the temperature in the refrigerator compartment rapidly increases. 6 is a time chart showing temperature changes of each sensor and ON / OFF of the first cooling fan 11 and the R heater.

  In this case, since the temperature in the refrigerator compartment rises, it is necessary to shorten the ON time of the R heater 22 in consideration of the temperature rise detected by the R sensor 15 and the RD sensor 23 thereafter. Therefore, the timing at which the R heater 22 is turned on is delayed (waiting for the R heater 22 to be energized), and then the R heater 22 is energized only for a short period of time until steps 4 to 7 in the flowchart shown in FIG. Can be completed in a short time. By doing in this way, even if the temperature in the refrigerator compartment suddenly rises, it is possible to make a fine response that can be shifted to the cooling operation of the refrigerator compartment at an early stage, food stored in the refrigerator Etc. can be prevented.

  FIG. 7 shows, for example, the temperature change of each sensor when the external environment of the refrigerator 1 is at low room temperature and the temperature in the refrigerator compartment detected by the R sensor 15 does not rise easily, and the first cooling fan 11 and the R heater. It is a time chart which shows ON and OFF.

  In this case, if the temperature in the refrigerator compartment detected by the R sensor 15 is difficult to rise, the temperature rise of the RD sensor 23 also becomes slow, and a lot of frost adheres to the first evaporator 10, so that the first The cooling performance of the evaporator 10 may be reduced. In view of this, a predetermined time (for example, 180 minutes) is used to divide the time and shift from the cooling operation of the freezer compartment to the cooling operation of the refrigerator compartment. Whether the energization start temperature of the R heater 22 in the flowchart shown in FIG. 3 is larger than the difference between the Ron temperature at which the cooling operation of the refrigerating room is started and the current temperature in the refrigerating room (detected temperature of the R sensor 15). At the time of determination (ST4), the energization start temperature of the R heater 22 is smaller than the difference between the Ron temperature at which the cooling operation of the refrigerator compartment is still started and the temperature in the refrigerator compartment at the present time. After determining whether (for example, 180 minutes) has elapsed (ST13), if it has elapsed, the R heater 22 is forcibly turned on.

  By doing in this way, the refrigerator which can remove reliably the frost adhering to the evaporator (1st evaporator) 10 for the refrigerator compartment 10 or the basket 21 can be provided.

It is a schematic sectional drawing of the refrigerator which concerns on embodiment of this invention. It is a figure which shows the refrigerating cycle of the refrigerator in embodiment of this invention. It is a flowchart which shows the flow of the defrost in the refrigerator of embodiment of this invention. It is a time chart which shows the movement of the detection temperature of each sensor, and ON and OFF of a 1st cooling fan and R heater. It is a time chart which shows the temperature change of each sensor and ON / OFF of a 1st cooling fan and R heater when the temperature in the refrigerator compartment during cooling operation of a freezer compartment rises rapidly. It is a time chart which shows the temperature change of each sensor and ON / OFF of a 1st cooling fan and R heater when the temperature in a refrigerator compartment rises rapidly immediately after a 1st cooling fan is drive | operated at low speed. It is a time chart which shows the temperature change of each sensor when the temperature in the refrigerator compartment is hard to rise, and ON / OFF of a 1st cooling fan and R heater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator 10 1st evaporator 11 1st cooling fan 15 Cold room sensor (R sensor)
16 Freezer compartment sensor (F sensor)
22 R heater 23 RD sensor

Claims (6)

In a refrigerator having a first evaporator for cooling the refrigerator compartment and a second evaporator for cooling the freezer compartment and performing a cooling operation for alternately cooling the refrigerator compartment and the freezer compartment,
A heater for removing frost adhering to the first evaporator;
Cold air is circulated in the refrigerator compartment during the cooling operation of the freezer compartment, and the heater is also driven when the first evaporator is heated to remove frost adhering to the first evaporator. With fans,
Equipped with a,
The cold air circulation fan for the refrigerator compartment is driven when the refrigerator is cooled, when the refrigerator is cooled, when the cold air is circulated through the refrigerator, and when the heater heats the first evaporator. The number of revolutions differs between the drive and
The heater is turned on at least after a predetermined time required for defrosting the first evaporator from the start of the cooling operation of the freezer;
A refrigerator characterized by. The heater, refrigerator of claim 1 Symbol mounting, characterized in that the first evaporator is OFF when a certain temperature. The heater, refrigerator according to claim 1 or claim 2, characterized in that it is OFF after a predetermined time. The refrigerator according to any one of claims 1 to 3 , wherein the cold air circulation fan for the refrigerator compartment is driven even after the heater is turned off. When the heater is turned ON, claims 1 to 4, characterized in that it comprises a trough heater for heating the first evaporator and the first trough through which the defrost water coming from the evaporator The refrigerator in any one of. The drainage hose heater which heats the drainage hose through which the defrost water discharged from the first evaporator and the first evaporator passes when the heater is turned on. Item 6. The refrigerator according to any one of Items 5 .

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