JP5957761B2 - Cooling storage - Google Patents

Description

  The present invention relates to a cold storage comprising a freezer compartment and a refrigerator compartment partitioned by a partition wall.

  Conventionally, in this kind of cold storage having a freezing room and a refrigerating room, for example, a compressor, a condenser, a refrigerating room evaporator connected via a capillary tube, and a freezing connected via another capillary tube. A refrigerant circuit is composed of the chamber evaporator. And after radiating the refrigerant | coolant discharged from the compressor with a condenser, the refrigerator compartment evaporator to which one capillary tube was connected via the three-way valve, or the freezer compartment evaporator to which the other capillary tube was connected The refrigeration cycle was evaporated in each of these and returned to the compressor.

  In this case, the capillary tubes connected to the respective evaporators are configured with arbitrary diameters and lengths, thereby setting the evaporation temperatures in the respective evaporators and setting the predetermined temperatures in the refrigerator compartment and the freezer compartment, respectively. Cool to the temperature zone.

  In addition, the refrigerator temperature chamber and the freezer compartment are each provided with an internal temperature sensor for detecting the internal temperature, and the control of the three-way valve and the compressor is performed so that each indoor is within the set cooling temperature range. (For example, refer to Patent Document 1).

Japanese Patent No. 3922891

  Here, the freezing room and the refrigerating room are each configured by partitioning the inside of the heat insulation box with a partition wall, the freezing room is cooled to a freezing temperature range of, for example, about −20 ° C., and the refrigerating room has a refrigerating temperature of about + 4 ° C. Cooled to area. Of course, this partition wall is made of a material having heat insulation properties, but since it is inevitably cooled by the freezer compartment, the surface on the refrigerator compartment side is at a lower temperature than the refrigerator compartment.

  For this reason, moisture that has entered the refrigerator compartment from the outside or moisture that has evaporated from the stored articles adheres to the surface of the partition wall on the refrigerator compartment side with condensation. In particular, when the refrigerator compartment is configured below the freezer compartment, the dew drops into the refrigerator compartment below, and the stored articles are contaminated.

  Therefore, by attaching and heating a cold room condensation prevention heater (electric heater) on the cold wall side surface (inside) of the partition wall from the past, the temperature of the cold wall side surface of the partition wall is not lowered, Measures to prevent dew condensation have been taken, but since it was always energized, it was against energy saving.

  This invention is made in order to solve the conventional technical subject which concerns, and provides the cooling storage which can control accurately electricity supply of the heater which heats the surface at the side of the refrigerator compartment of a partition wall. Objective.

In order to solve the above-mentioned problems, the cooling storage of the invention of claim 1 is formed by partitioning a freezing room and a refrigeration room below it with a partition wall. To the output of a freezer temperature sensor and a refrigerator temperature sensor for detecting the temperature of the freezer compartment and the refrigerator compartment, an outside air temperature sensor for detecting the outside air temperature, and the output of the freezer temperature sensor and the refrigerator compartment temperature sensor, respectively. Control means for controlling the energization of the heater based on the temperature difference between the freezer compartment and the refrigeration room detected by each temperature sensor, and when the temperature difference is small, the control means And controlling the energization rate of the heater in a direction to increase when the outside air temperature detected by the outside air temperature sensor is high based on the output of the outside air temperature sensor .

Furthermore, in the cooling storage of the invention according to claim 2 , in the above invention, the control means sends the heater to the heater when the temperature difference between the freezer compartment and the refrigerator compartment is smaller than a predetermined value and the outside air temperature is a predetermined low temperature or less. This is characterized in that the energization of is stopped.

And the cooling storage of the invention of claim 3 has the freezer compartment evaporator which cools a freezer compartment in each above-mentioned invention, and the refrigerator compartment evaporator which cools a refrigerator compartment, respectively, and has cooled refrigerant compressed with a compressor, respectively Each chamber is cooled by being distributed and supplied to the freezer evaporator and the refrigerator refrigerator through the decompression means.

  Condensation on the surface on the refrigerator compartment side of the partition wall that separates the refrigerator compartment and the refrigerator compartment is caused by the cooling action from the refrigerator compartment, so it is affected by the temperature difference between the refrigerator compartment and the refrigerator compartment. The smaller the is, the less likely it is to occur.

  Accordingly, in the first aspect of the invention, in a cooling storage formed by partitioning the freezer compartment and the lower refrigerator compartment with a partition wall, a heater for heating the surface of the partition wall on the refrigerator compartment side, and the freezer compartment And a freezer compartment temperature sensor and a refrigerator compartment temperature sensor for detecting the temperature of the refrigerator compartment, respectively, and a control means for controlling the energization of the heater based on the output of each temperature sensor, which is detected by each temperature sensor. Based on the temperature difference between the freezer compartment and the refrigerator compartment, when the temperature difference is small, the heater energization rate is controlled in the direction of decreasing, so the temperature difference between the freezer compartment and the refrigerator compartment is small and the partition wall is refrigerated. In a situation where condensation is unlikely to occur on the room side surface, the energization rate of the heater is lowered by the control means.

  Thereby, it is possible to reduce the power consumption of the heater while effectively eliminating the condensation on the surface of the partition wall on the refrigerator compartment side. Moreover, since the load in a refrigerator compartment is also suppressed, these can contribute to energy saving.

  On the other hand, when the outside air temperature of the cooling storage is high, the absolute humidity increases, and the moisture contained in the air entering the refrigerator compartment increases, so that condensation tends to occur on the surface of the partition wall on the refrigerator compartment side.

Therefore, the invention of claim 1 is provided with an outside air temperature sensor for detecting the outside air temperature in addition to the above invention, and the control means raises the outside air temperature detected by the outside air temperature sensor based on the output of the outside air temperature sensor. Since the heater energization rate is controlled by the direction, the heater energization rate is kept low in situations where the outside air temperature is low, and the outside air temperature rises and condensation tends to occur on the surface of the partition wall on the refrigerator compartment side. In this case, the energization rate of the heater is increased by the control means. Accordingly, it is possible to more accurately reduce the power consumption of the heater while effectively eliminating the condensation on the surface of the partition wall on the refrigerator compartment side, and further energy saving can be realized. .

Further, in the invention of claim 2 , in addition to the above-mentioned invention, the control means supplies power to the heater when the temperature difference between the freezer compartment and the refrigerator compartment is smaller than a predetermined value and the outside air temperature is not more than a predetermined low temperature. Therefore, it is possible to achieve further energy saving by cutting off the power to the heater in a situation where condensation on the surface of the partition wall on the refrigerator compartment side is least likely to occur.

In this case, as in the third aspect of the invention, in the cooling storage that cools the freezing room and the refrigerating room by the freezing room evaporator and the refrigerating room evaporator, respectively, the freezing room and the refrigerating room are accurately cooled to the respective cooling temperature ranges. However, the above inventions are particularly effective in such a cooling storage.

It is a perspective view of the state where the door of the cooling storage which applied the present invention was opened. It is a vertical side view of the cooling storage of FIG. It is an enlarged view of the drain pan part of FIG. It is a refrigerant circuit figure of the cooling storage of FIG. It is a block diagram of the electric circuit of the control apparatus of the cooling storage of FIG. It is a flowchart explaining the normal cooling operation which the control apparatus of FIG. 5 performs. It is a figure explaining the electricity supply rate control of the refrigerator compartment condensation prevention heater in the control apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1: has shown the perspective view of the state which open | released the door of the cooling storage 1 to which this invention is applied. The cooling storage 1 according to the embodiment is a vertical commercial refrigerator-freezer installed in a kitchen of a hotel or a restaurant, and includes a heat insulating box 2 that opens to the front.

  In the cooling storage 1 of FIG. 1, a freezer compartment (F) 3 and a refrigerator compartment (R) 4 as storage compartments are formed by partitioning the inside of the heat insulation box 2 with heat insulating partition walls 2A and 2B. Yes. In this embodiment, the upper portion of the heat insulating box 2 is divided into left and right by a partition wall 2A, and one side (in this case, the left side in FIG. 1) partitioned by the partition wall 2A is further vertically moved by a partition wall 2B. By dividing into two, the upper part of one side (toward the left side) in the heat insulating box 2 is the freezer compartment 3, and the other part (toward the right side) is continuous from the upper part to the lower part (the lower side of the freezer room 3). The refrigeration chamber 4 is configured such that the upper left freezing chamber 3 and the other refrigeration chambers 4 are configured to be incapable of circulating cold air. That is, the lower refrigerator compartment 4 is configured below the freezer compartment 3 and the partition walls 2A, 2B.

  The front opening of the freezer compartment 3 is closed so as to be freely opened and closed by a heat insulating door 8 pivotally supported on one side upper part of the heat insulating box 2, and the front opening of the refrigerator compartment 4 is opened in addition to the heat insulating box 2. The heat insulating doors 9 are pivotally supported independently on the side upper part, the other side lower part, and the one side lower part, respectively, so that they can be opened and closed. Thereby, the front opening of the heat insulation box 2 is closed by two sets of double doors 8, 9, 9, 9 provided at the top and bottom so as to be freely opened and closed.

  In addition, 10 in the figure is for partitioning the front opening of the heat insulating box 2 up and down at the same height as the partition wall 2B, so that the doors 8 and 9 are in close contact with each other when the doors 8 and 9 are closed. It is a partition.

  The freezer compartment evaporator 5 which comprises the cooling device 16 of the cooling storage 1 is arrange | positioned at the upper part of the freezer compartment 3, This freezer compartment evaporator 5 and the freezer compartment blower 7F (FIG. 7) attached to the front side vicinity. 5), the inside of the freezer compartment 3 is cooled to a predetermined freezer compartment cooling temperature range. Further, a refrigeration room evaporator 6 constituting the cooling device 16 is also arranged at the upper part of the refrigeration room 4, and the refrigeration room is blown by the refrigeration room evaporator 6 and a refrigeration room blower 7R attached in the vicinity of the front side thereof. The inside of 4 is cooled to a predetermined refrigerator compartment cooling temperature range. In addition, arrangement | positioning and volume ratio of the freezer compartment 3 and the refrigerator compartment 4 are not limited to this, The flow of cold air should just be made impossible mutually.

  Here, FIG. 2 shows a vertical side view of the cooling storage 1 on the side of the refrigeration room 4 located on the other side (right side) of the heat insulation box 2, in which the refrigeration room evaporator 6 and the refrigeration room. 20 attached below the blower 7R is made of aluminum for partitioning the cooling chamber 21 where the refrigerator compartment evaporator 6 is disposed and the refrigerator compartment 4 to receive and discharge drain water from the refrigerator compartment evaporator 6. The drain pan. The detailed structure of the drain pan 20 is shown in the enlarged view of FIG. In this figure, reference numeral 50 denotes a resin evaporator cover disposed below the drain pan 20. The drain pan 20 and the evaporator cover 50 are open at the rear. Further, the refrigerator compartment fan 7R is housed in the fan case 55, and the drain pan 20 and the evaporator cover 50 corresponding to the lower side of the refrigerator compartment fan 7R are opened, and particularly the part corresponding to the refrigerator compartment fan 7R. The evaporator cover 50 is a slit-shaped fan cover 50A. Then, the cold air sucked into the cooling chamber 21 from the inside of the refrigerator compartment 4 by the refrigerator compartment fan 7 </ b> R exchanges heat with the refrigerator compartment evaporator 6, and then is discharged into the refrigerator compartment 4 from the rear of the cooling chamber 21.

  The drain pan 20, the evaporator cover 50, the fan case 55, and the cooling chamber 21 are configured in the same manner for the freezer evaporator 5 and the freezer blower 7F in the freezer compartment 3, although not shown.

  A machine room 12 is defined on the top surface of the heat insulation box 2 by a panel 11 constituting a front surface, both side surfaces, and a rear surface, and the evaporators 5, 6 are contained in the machine room 12. At the same time, a compressor 13 and a condenser 14 that constitute the cooling device 16 and a condenser blower 15 and the like are disposed.

  The freezer compartment evaporator 5 is provided with a freezer compartment defrosting heater 46 for melting the frost on the freezer compartment evaporator 5 and performing defrosting. A freezer compartment defrosting temperature sensor 41 for detecting the recovery temperature (for example, + 10 ° C.) is attached. Further, the drain pan 20 located below the freezer evaporator 5 has a freezer drain pan heater 48 (FIG. 5) that functions as an ice melting heater that melts or contributes to the freezing of the drain pan 20 and the freezer blower 7F. Is attached to the fan case 55 to which the freezer compartment fan 7F is attached, and a freezer compartment fan case heater 49 that functions as an ice melting and melting heater that also melts or contributes to freezing of the freezer compartment fan 7F. It is attached.

  On the other hand, the refrigerator compartment evaporator 6 is provided with a refrigerator compartment defrost heater 47 for melting and defrosting the frost on the refrigerator compartment evaporator 6, and further, a predetermined frost of the refrigerator compartment evaporator 6. A refrigerating room defrosting temperature sensor 42 for detecting the recovery temperature (for example, + 10 ° C.) is attached. Further, on the back (lower) surface of the drain pan 20 located on the lower side of the refrigerating room evaporator 6, the refrigerating room drain pan functioning as a freezing and melting heater that melts or contributes to the freezing of the drain pan 20 and the refrigerating room blower 7R. The fan case 55 to which the heater 51 is attached and the refrigerator compartment fan 7R is attached to the refrigerator compartment fan case heater that also functions as an ice melting and melting heater that melts or contributes to the melting of the refrigerator compartment fan 7R. 52 is attached.

  Furthermore, a refrigerator compartment condensation prevention heater 53 as a heater in the present invention is attached to the inside of the surface of the partition walls 2A, 2B on the refrigerator compartment 4 side. The refrigerating room condensation prevention heater 53 is a heater that heats the surface of the partition walls 2A and 2B on the side of the refrigerating room 4 and by the cooling action from the freezer compartment 3 having a low temperature, the refrigerating room 4 side of the partition walls 2A and 2B. This prevents the occurrence of condensation on the surface.

  Here, the refrigerant circuit of the cooling storage 1 will be described with reference to the refrigerant circuit diagram of FIG. 4. A condenser 14 is connected to the refrigerant discharge side of the compressor 13, and a freezer compartment evaporator 5 that cools the freezer compartment 3 and a refrigerator compartment evaporator that cools the refrigerator compartment 4 are disposed downstream of the condenser 14. 6 are connected via capillary tubes 18 and 19 as decompression means. Each capillary tube 18 and 19 is selected to have an arbitrary diameter and length in consideration of the evaporation temperature in the freezer compartment 3 or the refrigerator compartment 4.

  In this embodiment, the refrigerant compressed by the compressor 13 is passed through the capillary tube 18 through the capillary tube 18 by the three-way valve 17 as a flow path switching means for controlling the refrigerant supply to the evaporators 5 and 6. Alternatively, it can be distributed and supplied to the refrigerator compartment evaporator 6 via the capillary tube 19. That is, by switching and controlling the three-way valve 17, the refrigerant is selectively supplied to only one of the evaporators 5 and 6, and both the freezer evaporator 5 and the refrigerator compartment evaporator 6 are supplied. The state of supplying the refrigerant can be realized.

  In this embodiment, when the refrigerant is supplied to only one of the evaporators 5 and 6 by the three-way valve 17, the temperature of the chamber in which the supplied evaporator is provided is always predetermined. It is assumed that the cooling temperature is deviated from the cooling temperature range in time and the flow of refrigerant into the deviating evaporator 5 or 6 is stopped (thermo-off).

  And the refrigerant | coolant piping 22 and 23 connected to the refrigerant | coolant outflow side of each evaporator 5 and 6 is arrange | positioned so that heat exchange with each corresponding capillary tube 18 and 19 is carried out, The edge part serves as the junction part 24. Connected. The junction 24 is connected to a suction pipe 25 that returns the refrigerant that has flowed out of the evaporators 5 and 6 and returned to the compressor 13.

  Next, the control apparatus 40 which comprises the control means of the cooling storage 1 is demonstrated with reference to the block diagram of the electric circuit of FIG. The control device 40 is constituted by a general-purpose microcomputer, and includes a memory 26 as a storage unit, and has a timer 27 as a time limit unit as its function.

  On the input side of the control device 40, a control panel (input means) 28 that can arbitrarily set the set temperatures TF and TR of the freezer compartment 3 and the refrigerator compartment 4 and a cooling temperature range including the set temperature, a freezer A freezer temperature sensor (freezer temperature detection means; storage room temperature sensor) 29 for detecting the temperature of the room 3 and a refrigerating room temperature sensor (refrigeration room temperature detection means. Storage room temperature sensor) for detecting the temperature of the refrigerating room 4. 30 and an outside air temperature sensor (outside air temperature detecting means) 32 for detecting the outside air temperature are connected. The control panel 28 can arbitrarily set the set temperature TF of the freezer compartment 3 within a freezing temperature range of, for example, −22 ° C. to −18 ° C. centering on −20 ° C., and the set temperature TR of the refrigerator compartment 4. Can be arbitrarily set within a refrigeration temperature range of, for example, + 2 ° C. to + 6 ° C., centering on + 4 ° C. In addition to the above, the control panel 28 can change various settings, and also includes a display (alarm means) for displaying various information and alarms.

  Moreover, the compressor 13, the three-way valve 17, the freezer compartment blower 7F, the refrigerating compartment blower 7R, and the condenser blower 15 are connected to the output side of the control device 40. In this embodiment, the compressor 13 (compressor motor) is connected via the inverter device 31, whereby the control device 40 sets the operation frequency of the compressor 13 in addition to the operation and stop of the compressor 13. It can be arbitrarily controlled linearly between the lower limit value (G1: for example 30 Hz) and the upper limit value (G2: for example 80 Hz).

  Further, on the input side of the control device 40, the freezing room defrosting return temperature sensor 41, the refrigerating room defrosting return temperature sensor 42, the freezing room blower current transformer 43 for detecting the energization current of the freezing room blower 7F, A cold room blower current transformer 44 is connected to detect the energization current of the cold room blower 7R. Furthermore, on the output side of the control device 40, the freezer compartment defrost heater 46, the refrigerator compartment defrost heater 47, the refrigerator compartment condensation prevention heater 53, the freezer compartment drain pan heater 48, and the freezer compartment fan case heater 49. The refrigerator compartment drain pan heater 51 and the refrigerator compartment fan case heater 52 are connected.

  In the embodiment, the control device 40 can control the duty ratio of the heaters 46, 47, 48, 49, 51, 52, 53 between 0% and 100% using a semiconductor switching element. That is, the control device 40 stops the compressor 13 every predetermined time during the normal cooling operation described later, and energizes both defrost heaters 46 and 47, both drain pan heaters 48 and 51, and both fan case heaters 49 and 52. The defrosting operation of both evaporators 5 and 6 is executed. And if the temperature of each evaporator 5 and 6 rises to predetermined defrosting return temperature, a defrost operation will be complete | finished. Further, the control device 40 energizes the refrigerating room condensation prevention heater 53 to prevent the occurrence of condensation on the surface of the partition walls 2A, 2B on the refrigerating room 4 side. The control of the refrigerator compartment condensation prevention heater 53 will be described in detail later.

  With the above configuration, the operation of the cooling storage 1 of the embodiment will be described next with reference to the flowchart.

(1) Normal cooling operation When the power is turned on, the control device 40 starts the normal cooling operation by operating the compressor 13 and each of the fans 7F, 7R, and 15. The flowchart of FIG. 6 shows this normal cooling operation, and the control device 40 controls the compressor 13 and the three-way valve 17 so that each of the freezer compartment 3 and the refrigerator compartment 4 falls within the cooling temperature range by this normal cooling operation. Do.

  That is, when the set temperature TF (for example, −20 ° C.) of the freezer compartment 3 is set by the control panel 28, the freezer compartment cooling temperature range is set within a range above and below the set temperature TF including the set temperature TF. The In this case, the freezer compartment cooling temperature range is, for example, a temperature range between the freezer compartment lower limit temperature TFL (set temperature TF-2 ° C.) and the freezer compartment upper limit temperature TFH (set temperature TF + 2 ° C.). Similarly, when the set temperature TR (for example, + 4 ° C.) of the refrigerator compartment 4 is set on the control panel 28, the refrigerator compartment cooling temperature range is set within the range above and below the preset temperature TR including the preset temperature TR. . In this case, the refrigerating room cooling temperature range is, for example, a temperature range of the refrigerating room lower limit temperature TRL (set temperature TR-2 ° C.) or higher and the refrigerating room upper limit temperature TRH (set temperature TR + 2 ° C.) or lower. The differential temperature (2 ° C.) can be changed by the control panel 28.

  Assuming that the three-way valve 17 is in a state of supplying refrigerant to both the evaporators 5 and 6, the high-temperature refrigerant discharged from the compressor 13 is condensed by the condenser 14 and then refrigerated via the three-way valve 17. The flow is divided and flows into the capillary tube 18 on the chamber evaporator 5 side and the capillary tube 19 on the refrigerator compartment evaporator 6 side. The refrigerant decompressed by the capillary tubes 18 and 19 flows into the corresponding evaporators 5 and 6, respectively, where they evaporate and exhibit a cooling action.

  Further, when each blower 7F, 7R is operated, cold air is sucked from the freezer compartment 3 and the refrigerator compartment 4 below and discharged to the evaporators 5 and 6 at the rear. The cold air exchanges heat with the evaporators 5 and 6, and after cooling, is discharged from the back of the drain pan 20 into the chambers 3 and 4. Thereby, the inside of the freezer compartment 3 and the refrigerator compartment 4 are each cooled.

  The low-temperature refrigerant evaporated in the evaporators 5 and 6 flows out of the evaporators 5 and 6 and then flows into the refrigerant pipes 22 and 23, respectively, where the relatively high temperature refrigerant flows in the capillary tubes 18 and 19. After the heat exchange, the merging portion 24 joins and returns to the compressor 13 through the suction pipe 25.

  The controller 40 determines whether or not the temperature of the freezer compartment 3 detected by the freezer temperature sensor 29 in step S1 of FIG. 6 is equal to or higher than the freezer compartment upper limit temperature TFH (set temperature TF + 2 ° C.). Next, it is determined whether the temperature of the refrigerator compartment 4 detected by the refrigerator compartment temperature sensor 30 is equal to or higher than the refrigerator compartment upper limit temperature TRH (set temperature TR + 2 ° C.). If so, the process proceeds to step S11 and the three-way valve 17 is turned on. Control is performed so that the refrigerant flows through both the evaporators 5 and 6. In step S11, the control device 40 determines the operation amount from the PID calculation result based on the deviation e between the current temperature of the freezer compartment 3 and the refrigerator compartment 4 and the set temperature TF, TR (in the freezer compartment and the refrigerator compartment). The operation frequency of the compressor 13 is controlled (PID control).

  When the temperature of the refrigerator compartment 4 is lower than the refrigerator upper limit temperature TRH in step S8, the control device 40 proceeds to step S9, determines whether or not the temperature of the refrigerator compartment 4 is equal to or lower than the refrigerator compartment lower limit temperature TRL. In some cases, the process proceeds to step S13, and the three-way valve 17 is switched to a state in which only the freezer evaporator 5 is allowed to flow. Further, the compressor 13 performs PID control based on the temperature of the freezer compartment 3. If the temperature of the refrigerator compartment 4 is higher than the refrigerator compartment lower limit temperature TRL in step S9, the control device 40 proceeds to step S10 and determines whether or not the refrigerant is currently being cooled by flowing the refrigerant into the refrigerator compartment evaporator 6, If it is flowing (that is, while the temperature is being lowered to the lower limit temperature), the process proceeds to step S11. If it is not flowing (that is, the temperature is being increased to the upper limit temperature), the process proceeds to step S13.

  When the temperature of the freezer compartment 3 is lower than the freezer upper limit temperature TFH (set temperature TF + 2 ° C.) in step S1 of FIG. 6, the process proceeds to step S2, and the temperature of the freezer compartment 3 is changed to the freezer compartment lower limit temperature TFL (set temperature TF-2). If it is below, the process proceeds to step S4, and it is determined whether the temperature of the refrigerating room 4 is equal to or higher than the refrigerating room upper limit temperature TRH (set temperature TR + 2 ° C.). Then, the three-way valve 17 is controlled so as to allow the refrigerant to flow only into the refrigerator compartment evaporator 6. In step S <b> 12, the control device 40 performs PID control on the operating frequency of the compressor 13 based on the temperature of the refrigerator compartment 4.

  If the temperature of the refrigerator compartment 4 is lower than the refrigerator upper limit temperature TRH in step S4, the control device 40 proceeds to step S5, determines whether or not the temperature of the refrigerator compartment 4 is equal to or lower than the refrigerator compartment lower limit temperature TRL. In this case, the process proceeds to step S7, where the three-way valve 17 is closed so that no refrigerant flows through any of the evaporators, and the compressor 13 is stopped. When the temperature of the refrigerator compartment 4 is higher than the refrigerator compartment lower limit temperature TRL in step S5, the control device 40 proceeds to step S6 and determines whether or not the refrigerant is currently cooled by flowing the refrigerant into the refrigerator compartment evaporator 6, If it is flowing (that is, while the temperature is being lowered to the lower limit temperature), the process proceeds to step S12. If it is not flowing (that is, the temperature is being increased to the upper limit temperature), the process proceeds to step S7.

  When the temperature of the freezer compartment 3 is higher than the freezer compartment lower limit temperature TFL (set temperature TF-2 ° C.) in step S2, the control device 40 proceeds to step S3 and is currently cooling by flowing the refrigerant into the freezer compartment evaporator 5. If it is flowing (that is, while the temperature is being lowered to the lower limit temperature), the process proceeds to step S8. If not flowing (that is, the temperature is being raised to the upper limit temperature), the process proceeds to step S4. move on. By controlling the compressor 13 and the three-way valve 17 as described above, the control device 40 allows the temperatures of the freezer compartment 3 and the refrigerator compartment 4 to be within the freezer compartment cooling temperature range (set temperature TF: −22 ° C. centering on −20 ° C. -18 ° C range) and refrigerator compartment cooling temperature range (set temperature TR: 2 ° C to + 6 ° C centered on + 4 ° C).

(2) Control of the refrigerator compartment condensation prevention heater As described above, the control device 40 controls the freezer compartment 3 to the freezer compartment cooling temperature range and the refrigerator compartment 4 to the refrigerator compartment cooling temperature range. 2A and 2B receive a cooling action from the freezer compartment 3 whose temperature is lower than that of the refrigerator compartment 4, and the surface of the refrigerator compartment 4 side becomes lower than the temperature of the refrigerator compartment 4. Therefore, as it is, moisture in the air (outside air) that has entered the refrigerating chamber 4 when the heat insulating door 9 is opened and water that has evaporated from the articles stored in the refrigerating chamber 4 are on the refrigerating chamber 4 side of the partition walls 2A and 2B. It adheres to the surface as condensation. Since this dew eventually drops as a drop in the freezer compartment 4 and the lower refrigerator compartment 4 formed on the lower side of the partition walls 2A and 2B (the entire lower part), it is stored in the lower refrigerator compartment 4. Will be soiled with dew.

  On the other hand, the dew condensation on the surfaces of the partition walls 2A, 2B partitioning the freezer compartment 3 and the refrigerator compartment 4 on the side of the refrigerator compartment 4 is caused by the cooling action from the freezer compartment 3, so It is affected by the temperature difference with the chamber 4 and is less likely to occur as the temperature difference is smaller. Further, when the outside temperature of the cooling storage 1 is high, the absolute humidity increases, and the moisture contained in the air entering the refrigerator compartment 4 also increases, so dew condensation occurs on the surface of the partition walls 2A, 2B on the refrigerator compartment 4 side. It becomes easy to do.

  Therefore, the control device 40 energizes the refrigerating room condensation prevention heater 53 to generate heat so that the temperature of the surfaces of the partition walls 2A and 2B on the refrigerating room 4 side does not drop. 40 is not always energized, but in the embodiment, based on the outputs of the freezer temperature sensor 29, the refrigerator temperature sensor 30, and the outside air temperature sensor 32, the temperature of the freezer 3 and the refrigerator temperature detected by the freezer temperature sensor 29. Based on the difference (temperature difference) between the temperature of the refrigerating chamber 4 detected by the sensor 30 and the outside air temperature detected by the outside air temperature sensor 32, the outside air is reduced in the direction of decreasing when the temperature difference between the freezer compartment 3 and the refrigerating chamber 4 is small. When the temperature is high, the energization rate of the refrigerator compartment condensation prevention heater 53 is controlled in the direction of increasing.

  Specifically, the energization rate is changed as shown in FIG. FIG. 7 is a table in which data relating to the energization rate of the refrigerator compartment condensation prevention heater 53 set in advance in the memory 26 of the control device 40 is stored. In the case of the embodiment, when the outside air temperature is + 25 ° C. (predetermined low temperature) or less, the control device 40 has a temperature difference between the freezer compartment 3 and the refrigerator compartment 4 (temperature of the refrigerator compartment 4 (R) −temperature of the refrigerator compartment 3). (F). The same applies hereinafter) is 27 ° C. or higher, the energization rate of the refrigerator-dew condensation prevention heater 53 is set to 60%. Moreover, when a temperature difference is 10 degreeC or more and less than 27 degreeC, an electricity supply rate is reduced to 30%. Further, when the temperature difference is less than 10 ° C. (predetermined value), the energization rate is further reduced to 0%. That is, when the temperature difference is smaller than 10 ° C. (predetermined value) and the outside air temperature is + 25 ° C. (predetermined low temperature) or less, the control device 40 stops energizing the cold room dew condensation prevention heater 53 (non-energized) ).

  When the outside air temperature is higher than + 25 ° C. and lower than + 35 ° C., and the temperature difference between the freezer compartment 3 and the refrigerator compartment 4 is 27 ° C. or more, the energization rate of the refrigerator compartment condensation prevention heater 53 is set to 80%. Moreover, when a temperature difference is 10 degreeC or more and less than 27 degreeC, an electricity supply rate is reduced to 50%. Furthermore, when the temperature difference is less than 10 ° C., the energization rate is further reduced to 20%. That is, the energization rate is increased as a whole as compared with when the outside air temperature is + 25 ° C. or lower.

  Further, when the outside air temperature is + 35 ° C. or higher, and the temperature difference between the freezer compartment 3 and the refrigerator compartment 4 is 27 ° C. or higher, the energization rate of the refrigerator compartment dew condensation prevention heater 53 is set to 100%, that is, continuous energization. Moreover, when a temperature difference is 10 degreeC or more and less than 27 degreeC, an electricity supply rate is reduced to 70%. Furthermore, when the temperature difference is less than 10 ° C., the energization rate is further reduced to 40%. That is, the overall energization rate is increased as compared to when the outside air temperature is higher than + 25 ° C. and lower than + 35 ° C.

  As described above, in the present invention, the control device 40 is based on the temperature difference between the freezer compartment 3 and the refrigerator compartment 4 detected by the freezer compartment temperature sensor 29 and the refrigerator compartment temperature sensor 30, and when the temperature difference is small, the refrigerator compartment is lowered. Since the power supply rate of the dew condensation prevention heater 53 is controlled, the temperature difference between the freezer compartment 3 and the refrigerator compartment 4 is small, and it is difficult for condensation to occur on the surface of the partition walls 2A and 2B on the refrigerator compartment 4 side. As a result, the control device 40 reduces the energization rate of the refrigerating room condensation prevention heater 53.

  Accordingly, it is possible to reduce power consumption of the refrigerator compartment dew condensation prevention heater 53 while effectively eliminating condensation on the surface of the partition walls 2A and 2B on the refrigerator compartment 4 side. Moreover, since the load in the refrigerator compartment 4 (heat generation of the heater 53) is also suppressed accordingly, it is possible to contribute to energy saving.

  Further, since the controller 40 controls the energization rate of the refrigerator compartment dew condensation prevention heater 53 in a direction to increase when the outside air temperature detected by the outside air temperature sensor 32 is high, the refrigerator cold room condensation prevention heater in a situation where the outside air temperature is low. When the energization rate of the refrigerating room dew condensation prevention heater 53 is increased when the outside air temperature becomes high and condensation easily occurs on the surface of the partition walls 2A and 2B on the refrigerating room 4 side. Will be. As a result, it is possible to more accurately reduce the power consumption of the refrigerating room dew condensation prevention heater 53 while effectively eliminating the dew condensation on the surface of the partition walls 2A and 2B on the refrigerating room 4 side. Can be realized.

  Further, when the temperature difference between the freezer compartment 3 and the refrigerator compartment 4 is smaller than a predetermined value (the above 10 ° C.) and the outside air temperature is a predetermined low temperature (the above + 25 ° C.) or less, the control device 40 Since the power supply to the dew condensation prevention heater 53 is stopped, the power supply to the refrigerating room dew condensation prevention heater 53 is cut off in a situation where condensation on the surface of the partition walls 2A and 2B on the side of the refrigerating room 4 is most unlikely to occur. Energy saving can be achieved.

  Moreover, in the cooling storage 1 which cools the freezer compartment 3 and the refrigerator compartment 4 by the freezer evaporator 5 and the refrigerator compartment evaporator 6 like an Example, respectively, the freezer compartment 3 and the refrigerator compartment 4 are in each cooling temperature range. It will be cooled accurately. Therefore, controlling the energization rate of the refrigerator compartment condensation prevention heater 53 based on the temperature difference as in the present invention is extremely effective in terms of energy saving.

  In the embodiment, the energization rate of the refrigerator compartment condensation prevention heater 53 is controlled on the basis of both the temperature difference between the freezer compartment 3 and the refrigerator compartment 4 and the outside air temperature. Only the temperature difference between the refrigerator compartment 4 and the refrigerator compartment 4 may be used. In the invention of claim 4, only the outside air temperature may be used.

  Further, in the embodiment, the present invention has been described with the cooling storages in which the freezing room evaporator 5 and the refrigerating room evaporator 6 are disposed in the freezing room 3 and the refrigerating room 4, respectively, but the invention other than claim 5 is not limited thereto. Instead, the cool air exchanged with a single evaporator may be supplied to, for example, a freezing room, and the cold air whose supply amount is adjusted by a damper or the like may be supplied to the refrigerating room. In that case, each chamber is cooled by a single evaporator. In such a case, supply / stop of the refrigerant to the evaporator is also included in the present invention by performing operation / stop of the compressor 13. Shall.

  Moreover, although the freezer compartment 3 was comprised only in the upper left toward the inside of the heat insulation box 2 in the Example, not only that but the inside of the heat insulation box 2 was completely divided up and down by the horizontal partition wall, The present invention is also effective for a cooling storage room in which the refrigerator compartment is vertically defined.

  Further, in the embodiment, the semiconductor energization rate of the refrigerating room condensation prevention heater 53 is duty-controlled using a semiconductor switching element. However, the present invention is not limited to this, and the energization may be controlled on and off using a normal relay or the like. . However, in that case, considering the limitation on the number of ON / OFF times of the relay, for example, it is preferable to control the energization rate by energizing for several minutes (or enough) of 2 hours, and to secure a certain switching interval. .

DESCRIPTION OF SYMBOLS 1 Cooling storage 2 Heat insulation box 2A, 2B Partition wall 3 Freezer room 4 Refrigerating room 5 Freezer room evaporator 6 Cold room evaporator 8, 9 Thermal insulation door 13 Compressor 14 Condenser 17 Three-way valve 18, 19 Capillary tube 29 Freezer room Temperature sensor (freezer temperature detection means)
30 Cold room temperature sensor (refrigeration room temperature detection means)
32 Outside temperature sensor (outside temperature detection means)
40 Control device (control means)
53 Refrigerating Room Condensation Prevention Heater (Heater)

Claims (3)

In the cold storage compartment formed by partitioning the freezer compartment and the refrigerator compartment below it with partition walls,
A heater for heating the surface of the partition wall on the refrigerator compartment side;
A freezer temperature sensor and a refrigerating room temperature sensor for detecting temperatures of the freezing room and the refrigerating room, respectively ;
An outside temperature sensor for detecting the outside temperature;
Control means for controlling energization of the heater based on outputs of the freezer temperature sensor and the refrigerator temperature sensor;
The control means controls the energization rate of the heater in a decreasing direction when the temperature difference is small, based on the temperature difference between the freezer compartment and the refrigerator compartment detected by the temperature sensors, and outputs the output of the outside temperature sensor. Based on this , the cooling storage is characterized in that the energization rate of the heater is controlled in a direction to increase when the outside air temperature detected by the outside air temperature sensor is high . The said control means stops the electricity supply to the said heater, when the temperature difference of the said freezer compartment and a refrigerator compartment is smaller than predetermined value, and external temperature is below a predetermined low temperature. The cooling storage according to 1 . A freezer compartment evaporator that cools the freezer compartment and a refrigerator compartment evaporator that cools the refrigerator compartment, and the refrigerant compressed by the compressor is evaporated through the decompression means, respectively. The cooling storage according to claim 1 or 2 , wherein each chamber is cooled by being distributed and supplied to a vessel.

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