JP2004116840A - Cooling storage shed - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further inexpensively cope with heating quantity control of a heating means for preventing dew condensation. <P>SOLUTION: An outside air temperature sensor is installed on a refrigerant pipe in the outlet vicinity of a condenser in a refrigerating plant, and commonly uses an originally arranged sensor for detecting failure of the refrigerating plant. Since a flow of a refrigerant is hardly caused when stopping the refrigerating plant such as before starting the refrigerating plant or until the refrigerating plant is driven again (in the timing A) after finishing defrosting operation, a temperature of the refrigerant pipe in the outlet vicinity of the condenser becomes equal to an outside air temperature. Thus, a detecting temperature of the outside air temperature sensor at refrigerating plant stopping time is taken in a control means as the outside air temperature, and a power supply rate to a dew condensation preventive heater is controlled according to a difference between this outside air temperature and a shed inside temperature, and a surface temperature of the port edge of an inlet-outlet is maintained at a temperature causing no dew condensation. The dew condensation can be surely prevented while restraining waste of electric power, and an existing temperature sensor is used in common as the outside air temperature sensor to inexpensively cope with the control. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling storage provided with a heating unit for preventing dew condensation.
[0002]
[Prior art]
For example, in a four-door refrigerator, four doorways are formed by mounting a cross-shaped heat-insulating partition frame at the front opening of a refrigerator body made of an insulated box. It is a structure that can be mounted. On the other hand, the rim of each entrance is easily cooled by cold air inside the refrigerator, and dew condensation may occur on the surface facing the outside.Therefore, a heater is arranged on the back side to heat the front side of the rim and condensate Try to prevent.
Here, the possibility of condensation varies depending on conditions such as the temperature and humidity of the outside air. However, if the heater is always in a constant heat generation state, power may be wasted. Therefore, conventionally, a sensor for detecting the outside air temperature or the outside air humidity is provided, and the power supply rate to the heater, that is, the amount of heat generated by the heater is controlled based on the detected temperature or the detected humidity, so that power consumption is suppressed. There has been proposed a device that reliably prevents dew condensation (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-6-3034
[Problems to be solved by the invention]
However, in the conventional device, it is necessary to provide a sensor for detecting the outside air temperature and the outside air humidity for the purpose of preventing dew condensation, and it is not always preferable from the viewpoint of cost reduction.
The present invention has been completed based on the above circumstances, and an object of the present invention is to make it possible to control the heating amount of a heating means for preventing dew condensation at a lower cost.
[0005]
[Means for Solving the Problems]
As means for achieving the above object, the invention according to claim 1 is characterized in that an opening which is opened and closed by a door is formed in a storage body made of an insulated box, and a dew condensation preventing opening is formed inside a rim of the opening. In a cooling storage provided with a heating unit and provided with a control unit for controlling a heating amount of the heating unit based on the outside air temperature, a temperature of a condenser in a refrigerating device provided in the cooling storage is detected. It is characterized in that a temperature sensor is provided, and an outside air temperature detecting means for outputting a detection temperature of the temperature sensor when the refrigeration apparatus is stopped to the control means as an outside air temperature is provided.
According to a second aspect of the present invention, in the device according to the first aspect, the control unit detects the abnormality of the refrigeration apparatus based on a temperature detected by the temperature sensor when the refrigeration apparatus is driven. The feature is that it has a function of reducing the amount of heating.
[0006]
Function and Effect of the Invention
<Invention of claim 1>
The temperature sensor provided on the condenser detects that the condenser temperature has risen when the filter originally mounted on the condenser has clogged or the condenser fan has failed, and thus detects abnormalities. Used to acknowledge occurrence. On the other hand, when the refrigerating apparatus is stopped, such as before the refrigerating apparatus is started or before the refrigerating apparatus is restarted after the defrosting operation is completed, the temperature of the condenser is reduced due to almost no refrigerant flow. It will be comparable to temperature.
Therefore, the temperature detected by the temperature sensor when the refrigerating device is stopped is taken into the control means as the outside air temperature, and the amount of heating of the heating means is controlled in accordance with the outside air temperature so that the surface temperature of the edge of the opening does not condense. Maintain at temperature.
As described above, it is possible to prevent the dew condensation while suppressing the waste of electric power. In addition, the temperature sensor for detecting the outside air temperature is also used as the existing temperature sensor for detecting the temperature of the condenser, so new parts are provided. There is no need for this, and it can be handled at low cost.
[0007]
<Invention of Claim 2>
During the operation of the refrigeration system, the temperature sensor is used to detect an abnormality of the refrigeration system. When an abnormality of the refrigerating device is recognized, the heating amount of the heating means is controlled to decrease (including no heating amount). When the refrigerating device is abnormal, the proper cooling function is not exhibited, and thus the inside of the refrigerator is insufficiently cooled.However, a decrease in the heating amount of the heating means may cause an excessive rise in the surface temperature of the opening. In addition, the heat load in the refrigerator is suppressed, and the rise in the refrigerator temperature can be reduced.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a four-door refrigerator will be described with reference to FIGS.
In FIGS. 1 and 2, reference numeral 10 denotes a refrigerator body composed of an insulating box having an open front surface, and the insulating box is formed of urethane foam resin between an outer box and an inner box assembled at intervals. It is formed by filling a heat insulating material. In the opening 11 of the refrigerator body 10, a partition frame 12 in which a horizontal frame 12 </ b> A and a vertical frame 12 </ b> B are assembled in a cross is fitted to form four doors 13. It is mounted so that it can be opened and closed dynamically.
[0009]
For example, taking the horizontal frame 12A as an example, as shown in FIG. 3, the partition frame 12 forms a channel shape that is slightly larger than the inside of the exterior plate 20 made of a magnetic metal plate such as a stainless steel plate. An interior plate 21 made of a synthetic resin is fitted and formed into a rectangular tube shape, and is similarly formed by filling the inside with a heat insulating material 22 made of urethane foam resin.
Each of the above-mentioned entrances and exits 13 is formed such that two of the four edges are formed by the partition frame 12 and the remaining two sides are formed by the opening 11 of the refrigerator main body 10, and when the heat insulating door 14 is closed. The magnet packing 15 attached to the peripheral edge on the back side of the heat insulating door 14 is brought into close contact with the entire periphery of the edge of the corresponding entrance 13.
[0010]
On the other hand, the refrigerator of the present embodiment is provided with a refrigerating device 40. As schematically shown in FIG. 4, the refrigeration apparatus 40 has a structure in which a compressor 41, a condenser 42, a dryer 43, an expansion valve 44, and a cooler 45 (evaporator) are circulated by a refrigerant pipe 46. I have. Then, as shown in FIG. 7, when the compressor 41 is driven together with the condenser fan, cool air is generated in the vicinity of the cooler 45, and the cool air is blown into the refrigerator by the fan in the refrigerator. The inside of the refrigerator is cooled to a predetermined temperature.
In addition, the defrosting operation is appropriately performed, and therefore, the cooler 45 is equipped with a defrost heater, and the defrost heater is heated while the refrigerating device 40 and the like are stopped, so that the defrost heater is heated. Is being done.
[0011]
On the back surface of the front surface 24 of the exterior panel 20 in the partition frame 12, a dew condensation prevention heater 25 for preventing dew condensation on the surface of the front surface 24 is provided.
Although a heater for preventing dew condensation may be similarly provided on the back side of the opening 11 of the refrigerator body 10, a description will be given below of the dew condensation preventing heater 25 provided on the partition frame 12 side.
Basically, the amount of heat generated by the dew condensation prevention heater 25 is controlled in order to effectively prevent dew condensation while suppressing power consumption.
[0012]
Therefore, as shown in FIG. 5, a control means 50 having a microcomputer, a timer 51 and the like is provided. The input side of the control means 50 is connected to an outside air temperature sensor 52 for detecting the outside air temperature, an inside temperature sensor 53 for detecting the inside temperature, and an operation control unit 54 of the refrigerator.
In particular, as shown in FIG. 4, the outside air temperature sensor 52 is mounted on the refrigerant pipe 46 near the outlet of the condenser 42, and also serves as a sensor originally provided for detecting a failure or the like of the refrigeration system 40. . Therefore, during the operation of the refrigeration apparatus 40, the outside air temperature sensor 52 is used for failure detection. For example, when it is detected that a state of a certain temperature or more has continued for a certain time or more, the filter provided in the condenser 42 is used. It is considered that there has been an abnormality in which the condensing capacity has decreased due to clogging or a failure of the condenser fan, and this is displayed on the error display section 55. Further, when it is detected that the state below the certain temperature has continued for more than a certain time, it is considered that an abnormality such as a failure of the compressor 41 has occurred, and the error is displayed on the error display unit 55 in the same manner.
[0013]
On the other hand, the control means 50 can receive the signal from the operation control unit 54 of the refrigerator as described above, and, as described later in detail, from the time the power is turned on until the normal operation is started. Between the predetermined timing and the draining time after the defrosting operation is completed (for example, two minutes after the defrosting heater is turned off (timing A in FIG. 7)). The detected temperature is taken in as the outside air temperature.
That is, at both timings described above, since the refrigerant hardly flows in the refrigerant pipe 46, the temperature of the refrigerant pipe 46 near the outlet of the condenser 42 becomes equal to the outside air temperature. Therefore, the detected temperature is taken in as the outside air temperature.
[0014]
Then, the control means 50 calculates a difference between the taken-in outside air temperature and the inside temperature detected by the inside temperature sensor 53, and sets a duty ratio according to the temperature difference. It has a function of applying the set duty ratio to the dew condensation prevention heater 25 via 56. The duty ratio has a multi-step pattern of, for example, 100%, 80%,..., 20%, and the larger the difference between the outside air temperature and the inside temperature, the larger the duty ratio is set. It has become.
Further, the control means 50 has a function of forcibly reducing the energization rate to the dew condensation prevention heater 25 when an abnormality is recognized during the operation of the refrigeration apparatus 40 as described above. When the abnormality is recognized, the energization rate is halved, and when an abnormality such as a failure of the compressor 41 is recognized, the energization is stopped.
[0015]
Subsequently, the operation of the present embodiment will be described with reference to FIGS.
When the power is turned on, first, the outside air temperature is detected by the outside air temperature sensor 52, the inside temperature is detected by the inside temperature sensor 53, and the temperature difference is calculated. The current is supplied to the dew condensation prevention heater 25 at the set energization rate, and the edge of the entrance 13 is heated with a corresponding amount of heat. Subsequently, normal operation is started by driving the refrigerating device 40 (compressor 41, condenser fan) and the internal fan.
[0016]
When the normal operation is continued, the inside of the refrigerator is gradually cooled, and the difference from the outside air temperature increases, so that the duty ratio is changed at an appropriate timing after the normal operation is started. For this purpose, the inside temperature is newly detected, the difference between the temperature and the outside air temperature taken in earlier is recalculated, and the duty ratio is changed according to the calculated value. It is energized by the new energization rate. Similarly, the edge of the entrance 13 is heated with a corresponding calorific value.
[0017]
On the other hand, a defrosting operation is appropriately performed. As shown in FIG. 7, the defrosting operation is performed by stopping the driving of the refrigerating device 40 (compressor 41, condenser fan) and the internal fan, and supplying power to the defrosting heater. When the predetermined defrosting operation is completed, the defrosting heater is turned off, a draining time of about 5.5 minutes is provided, and then the forced continuous operation in which only the refrigerating device 40 (the compressor 41 and the condenser fan) is driven. Is performed for about 5 minutes, after which normal operation is resumed.
During this time, after the defrosting operation is completed, at timing A when two minutes have elapsed after the drainage time, the outside air temperature and the inside temperature are detected again, and the temperature difference is calculated again, and the calculated value is calculated. The duty ratio is accordingly changed, and the dew condensation prevention heater 25 is energized at the new duty ratio. The next normal operation will be started in a state where the rim of the entrance 13 is heated with a corresponding calorific value.
[0018]
During normal operation, the outside air temperature sensor 52 is used for detecting an abnormality of the refrigerating device 40. For example, when an abnormality of a decrease in condensing capacity is recognized, this is displayed on the error display unit 55, and The power supply rate to the dew condensation prevention heater 25 is reduced by half. When an abnormality such as a failure of the compressor 41 is recognized, the error is displayed on the error display section 55 and the power supply to the dew condensation prevention heater 25 is stopped.
When the refrigerating device 40 is abnormal, the proper cooling function is not exerted, and thus the inside of the refrigerator is also insufficiently cooled. The rise is prevented, and the heat load to the inside of the refrigerator is also suppressed, so that the rise in the temperature in the refrigerator can be suppressed to a small value.
[0019]
As described above, according to the present embodiment, the rim of the entrance 13 is heated to a required temperature while changing the energization rate to the dew condensation prevention heater 25 based on the difference between the outside air temperature and the inside temperature. As a result, it is possible to reliably prevent dew condensation while suppressing wasteful consumption of power. Moreover, since the outside air temperature sensor 52 is also used as an existing temperature sensor for detecting the temperature near the outlet of the condenser 42 in order to determine the abnormality of the refrigerating device 40, there is no need to provide new parts and the cost can be reduced. It becomes possible.
[0020]
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and furthermore, besides the following, within the scope not departing from the gist. Can be implemented with various modifications.
(1) As means for controlling the amount of heat generated by the heater, other means such as changing the power supply to the heater may be used in addition to changing the power supply rate to the heater exemplified in the above embodiment.
(2) The present invention can be widely applied to all cooling storages in which a heating means for preventing dew condensation is provided at an opening such as an entrance.
[Brief description of the drawings]
1 is an external perspective view of a refrigerator according to one embodiment of the present invention; FIG. 2 is a perspective view of a heat insulating box; FIG. 3 is an enlarged cross-sectional view taken along line XX of FIG. 2; FIG. FIG. 5 is a block diagram showing a control system of the dew condensation prevention heater. FIG. 6 is a flowchart for explaining a control operation of the dew condensation prevention heater. FIG. 7 is a timing chart thereof.
DESCRIPTION OF SYMBOLS 10 ... Refrigerator main body 11 ... Opening 12 ... Partition frame 13 ... Doorway 14 ... Insulated door 25 ... Condensation prevention heater 40 ... Refrigerator 41 ... Compressor 42 ... Condenser 46 ... Refrigerant piping 50 ... Control means 51 ... Timer 52 ... Outside air temperature Sensor 53: Internal temperature sensor 54: Operation control unit 55: Error display unit 56: Duty ratio adjustment unit

Claims (2)

An opening that is opened and closed by a door is formed in the storage box body made of an insulated box, and a heating unit for preventing dew condensation is provided inside the rim of the opening, and the heating unit is controlled based on the outside air temperature. In a cooling storage provided with control means for controlling the amount of heating,
A temperature sensor is provided for detecting a temperature of a condenser in the refrigeration apparatus provided in the cooling storage, and an outside air temperature detection for outputting the detected temperature of the temperature sensor when the refrigeration apparatus is stopped to the control means as an outside air temperature. Cooling storage, characterized in that means are provided. The control means has a function of reducing a heating amount of the heating means when an abnormality of the refrigerating apparatus is recognized from a temperature detected by the temperature sensor when the refrigerating apparatus is driven. The cold storage according to claim 1.

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