JP2005331139A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerator capable of keeping cooling performance of an evaporator by preventing frost from being chronically remaining in defrosting operation, and inhibiting the temperature rise of a storage chamber. <P>SOLUTION: The power is distributed to a defrosting heater on the basis of a specific period S1 to conduct the defrosting operation S2, the power distribution to the defrosting heater is cut off and terminated when a temperature sensor 52 detects a temperature higher than a defrost termination temperature S3, S4, a compressor 41 is stopped until a specific time is passed after the termination of the defrosting operation S5, S8, S10, and the defrost termination temperature or period of the next defrosting operation is adjusted on the basis of the temperature detected by the temperature sensor 52 within the specific time or after the lapse of a specific time S6, S7, S9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigerator that performs a defrosting operation using a defrosting heater.

  Conventionally, in order to prevent the cooling performance from being deteriorated due to frost formation on the evaporator, the defrost heater is energized at a predetermined cycle of the cooling operation, for example, a predetermined cycle obtained by integrating the operation time of the compressor to evaporate. A defrosting operation is performed to defrost the vessel. In this case, in the defrosting operation, when the evaporator reaches the defrosting end temperature, for example, 10 ° C. or higher, it is assumed that all the attached frost has melted and removed, and the energization to the defrosting heater is shut off. The defrosting operation was terminated (for example, Patent Document 1).

On the other hand, if the compressor is operated immediately after the defrosting operation, abnormal noise is generated in the accumulator due to the pressure balance in the refrigeration cycle. Therefore, the compressor is started for a predetermined time, for example, 6 minutes after the defrosting is completed. (For example, refer to Patent Document 2).
JP-A-8-261629 JP 2004-240404 A

  However, between the end of the defrosting operation and the operation of the compressor, even if the defrosting heater is de-energized, there is a prisoner that raises the temperature in the vicinity of the evaporator and the storage chamber due to the residual heat. In this case, it is possible to set the defrosting end temperature of the defrosting heater to a lower temperature, for example, about 8 ° C. in consideration of the temperature rise due to this residual heat, but the amount and type of stored food, Alternatively, when the amount of frost formation is large due to the frequency of opening and closing the door, the remaining defrost is not fully melted and may remain. If there is some residual frost, there is little effect on the cooling performance, but if the residual frost increases by setting the defrosting end temperature low, cooling by the evaporator will be hindered and the performance will deteriorate significantly. Occurs.

  The present invention takes the above-mentioned problems into consideration, and provides a refrigerator that prevents the generation of chronic residual frost in the defrosting operation, maintains the cooling performance of the evaporator, and suppresses the temperature rise of the storage room. For the purpose.

  In order to solve the above problems, a refrigerator according to the present invention detects a refrigeration cycle in which a compressor, a condenser, and an evaporator are sequentially connected, a defrost heater that heats the evaporator, and the evaporator or the vicinity thereof. The defrosting operation of the evaporator, which is provided with a temperature sensor and energizes the defrosting heater based on a predetermined cooling operation cycle, is performed when the temperature sensor detects a temperature equal to or higher than the defrosting end temperature. The compressor is stopped for a predetermined time after completion of the defrosting operation, and the next defrosting operation is removed based on the temperature detected by the temperature sensor within or after the predetermined time. The frost end temperature or the cycle is adjusted.

  According to the above invention, since the remaining frost state after the completion of the defrosting operation is detected by the detected temperature of the temperature sensor and used as control information for the next defrosting operation, an increase in the remaining frost can be prevented. The cooling performance of the evaporator can be maintained. Moreover, it becomes possible to set low defrost end temperature using the residual heat of a defrost heater, and can suppress the temperature rise of a storage chamber.

  An embodiment of the present invention will be described. As shown in FIG. 4, which is a longitudinal sectional view of the refrigerator according to the present invention, the refrigerator main body 1 has a refrigerator compartment 3 in order from the top in a heat insulating box 2 filled with a heat insulating material between the outer box and the inner box. The vegetable room 4, the switching room 5, and the freezing room 6. Although not shown in particular, an ice making chamber is provided with the switching chamber 5. The front opening of the main body 1 is provided with doors 7 to 10 that sequentially close the storage chambers 3 to 6 in an openable manner.

  The refrigerator compartment 3 and the vegetable compartment 4 are maintained in a temperature range of approximately 1 to 5 degrees based on the temperature detected by the temperature sensor 54 (hereinafter referred to as R sensor) attached to the back of the refrigerator compartment 3, Are partitioned by a partition plate 11. A refrigeration room evaporator 44 (hereinafter referred to as “R EVA”) is provided on the back of the vegetable compartment 4, and a refrigeration room fan 18 (hereinafter referred to as “R fan”) is provided on the top thereof. Yes. When the R fan 18 is operated, the cold air generated by the R evaporator 44 is supplied to the refrigerating chamber 3 to cool the chambers 3 and 4, and the cooled cold air is returned to the R evaporator 44 again and heated. It is supposed to be replaced.

  On the other hand, the freezing room 6 including the ice making room and the switching room 5 are partitioned by a heat insulating partition wall 16, and the freezing room 6 is detected by a freezing temperature sensor 55 (hereinafter referred to as an F sensor). Therefore, the switching chamber 5 is controlled to be held in various set temperature zones. On the back surfaces of the switching chamber 5 and the freezer compartment 6, there is provided a freezer compartment evaporator 47 (hereinafter referred to as F EVA) whose evaporation temperature is set lower than that of the R evaporator 44, and in the upper part thereof, a freezer compartment fan 19 is provided. (Hereinafter referred to as F fan). When the F fan 19 is operated, the cold air generated by the F EVA 47 is supplied to the switching chamber 5 and the freezing chamber 6 to cool each chamber, and the cooled cold air is again heat-exchanged by the F EVA 47. It has become so. Further, the F-eva 47 is provided with a defrost heater 20 that performs defrosting, and the defrost heater 20 includes a pipe heater, a glass tube heater, and the like.

  The vegetable room 4, the switching room 5, and the ice making room are partitioned by a heat insulating partition wall 17, and the refrigeration room 3 and the vegetable room 4, the switching room 5, the ice making room, and the freezing room 6 each have a flow of cold air. Independent.

  A machine room 30 is provided at the bottom of the back surface of the main body 1. A compressor 41, a heat dissipating fan 31 that radiates heat from the compressor 41 (hereinafter referred to as “C fan”), and an outside air temperature sensor 53 that detects the outside air temperature. Is provided. In addition, on the back surface of the machine room 30, power is supplied to each electrical component based on the outside air temperature sensor 53, the R sensor 54, the F sensor 55, the temperature detected by an RD sensor 51, which will be described later, and the like. A control device 50 is provided.

  In the refrigeration cycle 40 according to the present invention, as shown in FIG. 5 which is a schematic diagram, a condenser 45 and a three-way valve 42 which is a flow path switching device are sequentially connected to the discharge side of the compressor 41. A freezing capillary tube 46 (hereinafter referred to as F capillary tube), a pipe connecting F evaporator 47 and an accumulator 48 in order are connected to one of the outlet sides of 42, and a second capillary tube 43 (hereinafter referred to as “capillary tube”) is connected to the other. , R capillary tube) and a pipe connecting R EVA 44 are connected. The outlet side piping of the R EVA is connected to the inlet side of the F EVA 47, and the outlet side piping of the accumulator 48 is connected to the suction side of the compressor 41.

  The outlet piping of the R evaporator 44 is provided with a refrigeration defrost sensor 51 (hereinafter referred to as an RD sensor) for detecting the piping temperature of the R evaporator 44, and the accumulator 48 has an outlet piping temperature of the F evaporator 47. Is provided with a defrosting sensor 52 for refrigeration (hereinafter referred to as FD sensor).

  When the detected temperature of the R sensor 54 becomes an ON temperature, for example, 5 ° C. or more, the refrigerator 3 and the vegetable compartment 4 are cooled by operating the three-way valve 41 so that the refrigerant flows to the R EVA 44 side (hereinafter referred to as R cooling mode). Called). On the other hand, when the detected temperature of the F sensor 55 becomes an ON temperature, for example, −18 ° C. or more, the freezer compartment 6 and the like are cooled by operating the three-way valve so that the refrigerant flows to the F EVA 47 side (hereinafter referred to as F cooling mode). Called). In the R cooling mode, the R fan 18 is rotated to supply cold air to the refrigerator compartment 3, and the F fan 19 is stopped. In the F cooling mode, the F fan 19 is rotated to supply cold air to the freezer compartment 6, and the R fan 18 detects the temperature of the RD sensor 51 at a predetermined temperature, for example, 3 ° C. or higher for defrosting the R evaporator 44. Rotate until it reaches. In this way, the refrigeration chamber 3, the vegetable chamber 4, the switching chamber 5, the ice making chamber, and the freezing chamber 6 are maintained at appropriate temperatures by sequentially switching the R cooling mode and the F cooling mode alternately.

  Next, the defrosting operation of the F EVA 47 will be described with reference to FIGS. 1 to 3. FIG. 1 is a flowchart showing an embodiment of the present invention, FIG. 2 is a graph showing a temperature change of F EVA when there is little residual frost in the defrosting operation, and FIG. 3 is in the defrosting operation. It is a graph which shows the temperature change of F EVA when there are many residual frosts.

As shown in FIG. 1, step 1, to detect whether the defrosting start timing (S1), if the timing of defrosting, the process proceeds to Step 2 at the timing of t _a shown in FIG. 2 and 3 Then, the compressor 41 is stopped, and the defrosting operation is performed in which the defrost heater 20 is energized to heat the F evaporator 47 (S2). Here, the timing of the defrosting in this embodiment is a predetermined cooling operation cycle that assumes that the cooling performance is deteriorated due to the frost formation of the F EVA 47, for example, the accumulated operation time of the compressor is 8 hours. This is the time when the F cooling mode has been completed. In the F cooling mode before the defrosting operation, in order to suppress the temperature rise of the freezer compartment 6 and the like due to the defrosting, the end set temperature of the F cooling mode is lowered stepwise to force the freezer compartment 6 and the like. Perform precooling operation to cool.

In step 3, it is detected whether or not the F EVA 47 has been defrosted. Specifically, it is detected whether or not the detected temperature of the FD sensor 52 has reached the defrosting end temperature or higher (S3), and if it has reached the defrosting end temperature or higher, the defrosting is completed or thereafter and considered when defrosting is completed by the residual heat, and terminates the defrosting operation proceeds to step 4 at the timing of t _b shown in FIG. 2,3 (S4). Here, if the initial setting of the defrosting end temperature is a normal amount of frosting by experiment, it is considered that the F evacuation 47 rises in temperature due to the residual heat after the energization of the defrosting heater 20 is finished and there is no residual frost. A relatively low set temperature, for example, 8 ° C. is set.

In step 4, the energization of the defrosting heater 20 is cut off, but the compressor 41 is stopped until a predetermined time, for example, 6 minutes elapses, in step 5, due to the pressure balance of the refrigeration cycle 40 and the like. .
In step 5, as described above, it is detected whether or not a predetermined time has elapsed (S5), and if not, the process proceeds to step 6 (S6).

  In step 6, whether or not the residual frost has disappeared, specifically, whether or not the detected temperature of the FD sensor 52 has reached a relatively high adjustment temperature, for example, 10 ° C. or higher, which can be regarded as having no residual frost by experiments. Is detected (S6).

As shown in FIG. 2, the normal frost formation amount, specifically if the state does not remain residual frost free or almost at the timing of t _b, be ended energization of defrosting heater 20, the The detected temperature of the FD sensor 52 rises above the adjustment temperature due to the residual heat.

  Therefore, since defrosting can be reliably performed by the subsequent residual heat without setting the defrosting end temperature high, the defrosting end temperature in the next defrosting operation is set low (S7).

  Note that the defrosting end temperature may be kept at an initial setting (for example, 8 ° C.), or the defrosting end temperature may be decreased by 0.2 ° C. for each defrosting operation. Further, the determination in step 6 may be after the elapse of the predetermined time because the F-evapor 47 does not immediately drop in temperature even when the compressor 41 is started after the elapse of the predetermined time in step 5.

  In this case, since the defrosting in a predetermined cycle is completed, the temperature increase of the storage chamber due to the defrosting can be reduced by delaying the defrosting timing. Specifically, the predetermined cycle is lengthened. Here, when the set operation time of the compressor 41 is changed from 8 hours to 12 hours, or when the F cooling mode ends twice after 8 hours have elapsed. The predetermined cycle is lengthened by various methods such as shifting to a defrosting operation. Note that either one or both of the defrosting end temperature setting and the predetermined cycle setting may be performed.

Now, in step 8, for detecting whether the elapsed predetermined time from the timing of t _b in the same manner as Step 5 (S8). After a lapse of a predetermined time, the compressor 41 is activated the flow proceeds to step 10 it is determined that may be, to resume operation of the compressor 41 at the timing of t _c, the process proceeds to the normal cooling mode (S10) .

On the other hand, if the detected temperature of the FD sensor 52 does not rise to the regulated temperature within a predetermined time (t _{b to} t _c ) as shown in FIG. A high frost end temperature is set (S9).

Since when frost formation amount of F evaporator 47 is high by the state of food and door opening, Zanshimo amount at the timing of t _b is large and to Zanshimo even with residual heat of the defrosting heater 20, the Zanshimo As a result, the temperature rise of the F EVA 47 is slowed down, and the FD sensor 52 cannot detect a temperature higher than the adjustment temperature. In such a case, if the defrosting operation is continued while the defrosting end temperature is set lower than usual, the residual frost increases and the cooling performance of the F-evaporator 47 is remarkably lowered.

  Therefore, when the detected temperature of the FD sensor 52 does not rise to the control temperature, the next defrosting end temperature is set to a high value, for example, 10 ° C., so that the defrosting of the F EVA 47 is performed in the next defrosting operation. Make sure to prevent deterioration of cooling performance due to residual frost. In addition, the setting of defrost end temperature may raise defrost end temperature by 0.2 degreeC, for example for every defrost operation.

  In the above case, since the amount of frost formation is large, it is possible to prevent residual frost by shortening the defrosting start timing and decreasing the amount of frost formation per defrost operation. Specifically, the predetermined cycle is shortened. Here, the set time of the operation integration time of the compressor 41 is changed from 8 hours to 4 hours, and after 4 hours, the defrosting operation is immediately performed. The predetermined period is shortened by various methods. Note that either one or both of the defrosting end temperature setting and the predetermined cycle setting may be performed.

If the setting is After completion, to resume the operation of the compressor 41 at the timing of t _c, the process moves to the normal cooling mode (S10), the process returns to step 1 so as to repeat these control.

  As described above, according to the present invention, after the defrosting operation is finished, the compressor 41 is not started until a predetermined time elapses, and the remaining frost state after the defrosting operation is detected by the detected temperature of the temperature sensor. Since it is utilized as control information for the next defrosting operation, an increase in residual frost can be prevented, and the cooling performance of the F EVA 47 can be maintained. Moreover, it becomes possible to set low defrost end temperature by utilizing the residual heat of the defrost heater 20, and it can suppress the temperature rise of the freezer compartment 6 grade | etc.,.

  Further, according to the present invention, when the FD sensor 52 detects a temperature equal to or higher than the adjustment temperature set higher than the defrosting end temperature within a predetermined time or after the elapse of time, the defrosting end of the next defrosting operation is completed. Since the temperature is set low or the cycle is set long, even if the defrost end temperature is set low, the F evaporator 47 is heated by the remaining heat after the energization of the defrost heater 20 is completed. Therefore, it is possible to suppress an increase in temperature of the freezer compartment 6 and the like while preventing a decrease in cooling performance due to the influence of residual frost.

  Furthermore, according to the present invention, if the temperature sensor cannot detect a temperature equal to or higher than the adjustment temperature set higher than the defrosting end temperature within a predetermined time or after the elapse of time, the defrosting end temperature of the next defrosting operation is detected. Is set high, or the cycle of the defrosting operation is set short, so even if the amount of remaining frost in F EVA 47 increases due to setting the defrosting end temperature low, it is surely removed in the next defrosting operation. The frost can be completed, and a decrease in cooling performance due to the influence of residual frost can be prevented.

  The above-described configuration is an embodiment of the present invention, and various changes can be made. In the present embodiment, the R eva 44 has been described in the defrosting method by the rotation of the R fan 18, but the R eva 44 also performs the defrosting operation by the defrost heater in the same manner as the F eva 47, and the defrosting end temperature of the present invention. May be adjusted. In addition, the refrigeration cycle 40 is not limited to the configuration described in the present embodiment, but a so-called parallel cycle in which an R EVA 44 and an F EVA 47 are connected in parallel, a cycle using a two-stage compressor, or a single evaporator. It may be a one-evaporation system that cools the refrigerating room 3 or the freezing room 6 by using it. Furthermore, it is preferable to appropriately change the defrosting timing, the defrosting end temperature, the method for adjusting the defrosting end temperature, the adjustment temperature, the adjustment of the predetermined cycle, and the like.

  The present invention can be applied to various refrigerators equipped with a defrosting operation using a defrosting heater.

It is a flowchart which shows one Embodiment of this invention. It is a graph which shows the temperature change of F EVA when there is little residual frost in a defrost operation. It is a graph which shows the temperature change of F EVA when there is much residual frost in a defrost operation. It is a longitudinal section showing a refrigerator which is one embodiment of the present invention. It is the schematic which shows the refrigerating cycle which is one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigerator main body 3 ... Refrigeration room 6 ... Freezer room 18 ... R fan 19 ... F fan 20 ... Defrost heater 40 ... Refrigeration cycle 41 ... Compressor 42 ... Three-way valve 44 ... R EVA 47 ... F EVA 50 ... Control device 51 ... RD sensor 52 ... FD sensor 53 ... Outside air temperature sensor 54 ... R sensor 55 ... F sensor

Claims (3)

A refrigeration cycle in which a compressor, a condenser, and an evaporator are sequentially connected; a defrost heater that heats the evaporator; and a temperature sensor that detects the evaporator or the vicinity thereof.
The defrosting operation of the evaporator, which is performed by energizing the defrosting heater based on the predetermined cooling operation cycle, ends when the temperature sensor detects a temperature equal to or higher than the defrosting end temperature and shuts off the energization to the defrosting heater. The compressor is stopped for a predetermined time after the completion of the defrosting operation,
A refrigerator characterized in that the defrosting end temperature or the cycle of the next defrosting operation is adjusted based on the temperature detected by the temperature sensor within or after the predetermined time. If the temperature sensor detects a temperature equal to or higher than the control temperature set higher than the defrost end temperature within or after the specified time, set the defrost end temperature for the next defrost operation low or set the cycle longer. The refrigerator according to claim 1. If the temperature sensor cannot detect a temperature that is higher than the control temperature set higher than the defrost end temperature within or after the specified time, set the defrost end temperature for the next defrost operation higher or set the cycle shorter. The refrigerator according to claim 1.

Images