JP2010266123A - Cooling storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress dew condensation in a storage chamber with a higher internal set temperature while minimizing power consumption. <P>SOLUTION: The cooling storage is equipped with a duct heater 40 attached to an air duct 30 to raise a temperature in a refrigeration chamber 12, an ambient temperature sensor 57 detecting an ambient temperature, and a heater control part 50 controlling a heating value of the duct heater 40. The heater control part 50 is composed of a comparison part 51 comparing a refrigeration chamber set temperature TR and a freezing chamber set temperature TF and sending out a calculation instruction signal when the difference reaches a predetermined value or larger, a temperature difference calculating part 52 calculating the difference of the ambient temperature and the refrigeration chamber set temperature TR when the calculation instruction signal is received, and an energization rate control part 53 carrying out control so that an energization rate to the duct heater 40 becomes larger as a calculated value becomes smaller on the basis of the calculated value of the temperature difference calculating part 52. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cold storage having a plurality of storage rooms having different internal set temperatures.

  An example of this type of cold storage is a refrigerator-freezer. A refrigerator-freezer is divided into a refrigerator compartment and a freezer compartment by a heat-insulating partition wall in the body consisting of a heat insulation box, and each compartment has a cooler and a cooling fan that constitute a part of the refrigeration cycle. It is an equipped structure, and in each room, the internal temperature detected by the internal temperature sensor is compared with the predetermined internal temperature, and whether the internal temperature is higher or lower than the preset temperature. Thus, the cooling operation and the stop thereof are repeated, and each chamber is maintained substantially at the set temperature inside the chamber (see, for example, Patent Document 1).

JP 2000-220939 A

In this type of refrigerator / freezer, if the temperature difference between the refrigerator compartment and the freezer compartment is large, the cold temperature of the freezer compartment is transmitted to the refrigerator compartment through the partition wall, and the surface temperature of the partition wall facing the refrigerator compartment is lowered. Cheap. On the other hand, the smaller the difference between the ambient temperature at the position where the refrigerator / freezer is installed and the set temperature in the refrigerator compartment, the less the heat enters from the outside and the temperature inside the refrigerator compartment is less likely to rise. There is a problem that the stop time becomes long, that is, the refrigeration room is likely to become high humidity by suppressing frost formation in the cooler, and condensation is likely to occur on the surface of the partition wall on the cold room side described above at a low temperature. there were.
The present invention has been completed based on the above circumstances, and an object thereof is to suppress dew condensation in a storage room having a higher internal set temperature while suppressing power consumption as much as possible.

  According to the present invention, a plurality of storage chambers are formed by partitioning a heat insulating partition wall in a storage body composed of a heat insulating box, and each storage chamber has the same structure as a cooler constituting a part of a refrigeration cycle. A cooling fan that generates a circulating flow in the storage chamber while passing through the cooler is provided, and a set temperature inside the store that is different from each other is set. By repeatedly executing or stopping the cooling operation of the cooler according to whether the internal temperature detected in step 1 is higher or lower than the corresponding internal set temperature, the internal temperature becomes the corresponding internal set temperature. In a cooling storage that is maintained, a heater provided in the storage chamber to raise the temperature of the storage chamber having a higher internal set temperature, and an ambient temperature sensor that detects the ambient temperature at the installation location of the cooling storage When, On the condition that the difference between the lower chamber set temperature and the lower chamber set temperature is a predetermined value or more, the smaller the difference is based on the difference between the ambient temperature and the higher chamber set temperature, the above And heater control means for controlling the heater so as to increase the amount of heat generated.

When the difference between the higher chamber set temperature and the lower chamber set temperature is greater than or equal to the specified value, that is, the surface of the partition wall facing the storage chamber with the higher chamber set temperature (the storage chamber on the high temperature side) However, when it is considered that the adjacent room is in a low temperature state due to the cold, the heater provided in the high temperature side storage room generates heat during the cooling operation. As a result, the time during which the cooling operation is performed increases because the internal temperature of the storage room rises, and the internal humidity of the high temperature side storage room is reduced due to the dehumidifying effect of the internal air passing through the cooler. Decreases and condensation on the partition wall of the high temperature side storage room is prevented.
Here, the smaller the difference between the ambient temperature and the set temperature inside the storage room on the high temperature side, the smaller the temperature rise in the storage room on the high temperature side due to heat penetration from the outside of the storage room. Conversely, if the difference between the ambient temperature and the set temperature inside the storage room on the high temperature side becomes large, the temperature rise in the storage room on the high temperature side due to heat intrusion from outside the container increases, and the heater There is a circumstance that the subsidy due to the heat generation of is less. Therefore, in the present invention, the smaller the difference between the ambient temperature and the set temperature in the storage room on the high temperature side, the larger the heating value of the heater, that is, to obtain the heating value of the heater as required. Power is kept to a minimum. In addition, if the heater generates too much heat and the storage chamber is excessively heated, the cooling operation time becomes too long and extra power is required to operate the refrigeration system. Excessive cooling operation is also prevented.
As a result, it is possible to suppress dew condensation in the storage room having a higher internal set temperature while suppressing power consumption as much as possible.

The following configuration may also be used.
(1) The heater control means compares the higher chamber set temperature with the lower chamber set temperature and sends a calculation instruction signal when the difference is equal to or greater than a predetermined value; A temperature difference calculation unit that calculates a difference between an ambient temperature and a higher internal set temperature when a calculation instruction signal is received, and based on the calculated value of the temperature difference calculation unit, the smaller the calculated value, And an energization rate control unit that controls the energization rate to be large.
When the comparison unit recognizes that the difference between the higher chamber set temperature and the lower chamber set temperature is a predetermined value or more, the difference between the ambient temperature and the higher chamber set temperature is calculated, Based on the calculated value, control is performed such that the smaller the calculated value, the greater the energization rate to the heater.

(2) An air duct that also serves as a drain pan is stretched on the ceiling of each storage chamber to form a cooler chamber that houses the cooler, and the cooling fan is mounted on the air duct. During the cooling operation, cold air generated by heat exchange with the cooler is circulated and supplied into the storage chamber as the cooling fan is driven, while the cooler is heated by a defrost heater attached to the cooler. A defrosting operation for removing frost is performed, and a duct heater that generates heat during the defrosting operation is mounted in the vicinity of the position of the cooling fan in the air duct. The duct heater is the heater provided to raise the temperature of the storage chamber having a higher internal set temperature.
The duct heater is provided in an air duct constituting the cooler chamber and functions to defrost the vicinity of the cooling fan by generating heat during the defrosting operation. During the cooling operation, the duct heater can be heated to raise the temperature of the high-temperature storage chamber in order to prevent condensation.

(3) An air duct that also serves as a drain pan is stretched on the ceiling of each storage chamber to form a cooler chamber in which the cooler is accommodated, and the cooling fan is driven during the cooling operation. The cool air generated by heat exchange with the cooler is circulated and supplied into the storage chamber, while the cooler is equipped with a defrost heater, and the cooler is heated by the defrost heater to remove frost. The frost operation is performed, and the defrost heater is the heater provided to raise the temperature of the storage chamber having a higher internal set temperature.
The defrost heater is attached to the cooler and functions to remove frost adhering to the cooler by generating heat during the defrost operation. During the cooling operation, the defrost heater can generate heat, so that the temperature of the storage chamber on the high temperature side can be raised so as to prevent condensation by sandwiching the air duct. Since the defrost heater indispensable for the cooling storage that enables the defrost operation is also used as the heater for increasing the temperature of the storage room, it can contribute to cost reduction.

  ADVANTAGE OF THE INVENTION According to this invention, after suppressing power consumption as much as possible, the dew condensation in the store room with a higher internal set temperature can be suppressed.

Front view of a refrigerator-freezer according to an embodiment of the present invention Longitudinal section showing the refrigerator compartment side Air duct top view Block diagram of heater energization control mechanism Graph showing heater energization rate Flow chart of heater energization control

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, a four-door refrigerator-freezer is illustrated.
As shown in FIGS. 1 and 2, the refrigerator / freezer has a main body 10 made of a slightly vertically long heat insulating box with a front opening. Inside the main body 10, a heat insulating partition wall is provided at the center in the frontage direction. 11 is provided, the refrigerator compartment 12 is formed in the right side seen from the front, and the freezer compartment 13 is formed in the left side. A double-spread type heat insulating door 14 is attached to the front opening of the main body 10 in two upper and lower stages. The main body 10 is supported by four illustrated legs 15 arranged on the bottom surface, and a machine room 16 is formed on the upper surface of the main body 10 by being surrounded by a panel.

In the machine room 16, independent refrigeration units 20 are provided corresponding to the refrigerator compartment 12 and the freezer compartment 13, respectively. Taking the refrigerator compartment 12 side as an example, the refrigeration unit 20 includes an air-cooled condenser 24 and the like in which a compressor 23 and a condenser fan 24A are attached to the upper surface of a heat-insulating base 21 having a flat square shape. While the refrigeration apparatus 22 is mounted, a cooler 25 is suspended and attached to the lower surface side, and the refrigeration apparatus 22 and the cooler 25 are circulated and connected by a refrigerant pipe. The cooler 25 is attached in an oblique posture with the back side slightly lowered.
On the other hand, a window hole 18 that is slightly smaller than the base 21 is formed at the bottom surface of the machine room 16, in other words, at a position near the far end of the ceiling wall 12 </ b> A of the refrigerator compartment 12, and the base 21 of the refrigeration unit 20 described above. However, it is attached by closing the window hole 18 while passing the cooler 25 through the lower surface side of the window hole 18.

  A synthetic resin air duct 30 also serving as a drain pan is stretched on the lower surface side of the window hole 18 in the ceiling portion of the refrigerator compartment 12, and a cooler chamber 31 is formed above the air duct 30. . The bottom surface of the air duct 30 is formed so as to have a downward slope (substantially the same as the inclination angle of the cooler 25) toward the inner edge (right side in FIG. 2). A suction port 32 is provided. Each suction port 32 is equipped with a cooling fan 34 composed of a fan motor, and a lattice-shaped fan cover 35 is attached to the suction port 32. An air outlet 36 is formed between the inner edge of the air duct 30 and the back wall of the refrigerator compartment 12.

When the cooling fan 34 is driven while operating the refrigeration apparatus 22 (the compressor 23 and the condenser fan 24A), the air in the refrigerator compartment 12 is sucked into the cooler compartment 31 from the suction port 32 by the cooling fan 34. Cold air is generated by heat exchange while the air flows through the cooler 25, and the cold air is blown out from the outlet 36 along the inner surface of the refrigerator compartment 12. Is circulated and supplied so that the inside of the refrigerator compartment 12 is cooled.
In addition, the structure of the cooler chamber 31 on the freezer compartment 13 side, the arrangement structure of the freezer unit 20, and the circulation and circulation mode of air are the same as those on the refrigerator compartment 12 side.

The basic cooling operation is performed as follows. The refrigerator compartment 12 and the freezer compartment 13 are each provided with an internal temperature sensor 27 for detecting the internal temperature, and these are disposed, for example, upstream of the cooler 25 in each cooler chamber 31. On the other hand, in a setting unit (not shown), the set temperature TR in the refrigerator compartment 12 (hereinafter also referred to as the refrigerator compartment set temperature TR) and the set temperature TF in the freezer compartment 13 (hereinafter also referred to as the freezer compartment set temperature TF). For example, in the refrigerator compartment 12, “5 ° C.” is set, and in the freezer compartment 13, “−25 ° C.” is set.
When the cooling fan 34 is driven in each of the refrigerator compartment 12 and the freezer compartment 13 and the internal temperature detected by the internal temperature sensor 27 rises to the upper limit values of the set temperatures TR and TF, the corresponding refrigeration unit. 20 compressor 23 is operated and the compressor 23 is stopped when the set temperature TR, TF is lowered to the lower limit value. By repeating this operation, the internal temperatures of the refrigerator compartment 12 and the freezer compartment 13 are changed. The temperature is substantially maintained at the set temperatures TR and TF.

Moreover, in order to remove the frost adhering to each cooler 25 grade | etc., A defrost operation is performed suitably. Therefore, as shown in FIG. 2, a defrost heater 29 including a sheathed heater is provided on the lower surface of the cooler 25.
On the other hand, a metal plate 38 such as an aluminum plate is stretched in a region extending from the position corresponding to the lower side of the cooler 25 on the upper surface of the air duct 30 to the mounting position of the cooling fan 34.
On the metal plate 38, a duct heater 40 comprising a cord heater is mounted to heat the vicinity of the cooling fan 34. Specifically, as shown in FIG. 3, the cooler 25 in each cooling fan 34 (suction port 32). It is wired in such a way that it surrounds a little more than half of the side.

  The defrosting operation is basically performed by energizing the defrosting heater 29 and heating the cooler 25 with the refrigeration apparatus 22 (the compressor 23 and the condenser fan 24A) and the cooling fan 34 stopped. After the melted defrost water is received by the air duct 30 and flows down, it is led from the drain pipe 30A protruding at the lower position of the air duct 30 to the drain channel 42 provided on the back side of the refrigerator body 10. It is drained. At this time, the duct heater 40 is also energized to generate heat, and mainly defrosting in the vicinity of the cooling fan 34 (fan cover 35) is performed. The duct heater 40 is temporarily de-energized before the cooling operation is started.

In the present embodiment, means for preventing condensation on the surface of the partition wall 11 facing the refrigerator compartment 12 is taken. Specifically, on the condition that the difference between the refrigerator compartment set temperature TR and the freezer compartment set temperature TF is equal to or higher than a predetermined temperature (for example, 10 K), the ambient temperature at the installation position of the refrigerator-freezer and the refrigerator The energization to the duct heater 40 is controlled according to the difference from the room set temperature TR.
Therefore, a heater control unit 50 equipped with a microcomputer, a timer and the like is provided. On the input side of the heater control unit 50, a refrigeration room set temperature take-in unit 55 that takes in a preset refrigeration room set temperature TR and a freezer compartment set temperature take-in unit 56 that takes in a preset freezer room set temperature TF. And the ambient temperature sensor 57 which detects the ambient temperature of the installation position of the said refrigerator-freezer is connected. In addition, an operation state detection unit 58 that sends a signal according to the operation state of the refrigerated freezer is connected to the input side.

The heater control unit 50 includes a comparison unit 51, a temperature difference calculation unit 52, and an energization rate control unit 53. The comparison unit 51 includes the refrigerating room set temperature TR fetched from the refrigerating room set temperature taking-in unit 55 and the freezer compartment set temperature taking-in unit 56 when the cooling operation is started by the operation state detecting unit 58. Is compared with the freezer compartment set temperature TF taken in, and the calculation function signal is transmitted when the freezer compartment set temperature TR is higher than the freezer compartment set temperature TF by a predetermined value (10K) or more.
When the calculation instruction signal is output from the comparison unit 51, the temperature difference calculation unit 52 and the ambient temperature detected by the ambient temperature sensor 57 and the refrigerator compartment set temperature fetched from the refrigerator compartment set temperature fetch unit 55 described above. Calculate the difference from TR.

The energization rate control unit 53 determines the energization rate according to the temperature difference calculated by the temperature difference calculation unit 52, and applies the determined energization rate to the duct heater 40.
The energization rate E (%) is, for example, that E seconds are turned on in 100 seconds and (100-E) seconds are turned off, and has a five-step pattern from “0%” to “40%”. As the difference D between the ambient temperature and the refrigerating room set temperature TR is smaller, a pattern having a larger energization rate E is set. Specifically, as shown in the graph of FIG. 5, E (energization rate) = 40 when D (temperature difference) <0, E = 30 when 0 ≦ D <5, and 5 ≦ D <10. When E = 20, 10 ≦ D <15, E = 10, and when D ≧ 15, E = 0.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. When it is time to complete the defrosting operation and start the cooling operation, the refrigerator compartment set temperature take-in portion 55 takes in the refrigerator compartment set temperature TR, and the freezer compartment set temperature take-in portion 56 takes in the freezer compartment set temperature TF, respectively. Then, the comparison unit 51 compares the set temperatures TR and TF. If the refrigerator compartment set temperature TR is greater than the freezer compartment set temperature TF by a predetermined value (10K) or more, a calculation instruction signal is sent to the temperature difference calculation unit 52.
On the contrary, if the difference between the set temperatures TR and TF is less than 10K, the duct heater 40 is not energized. If the difference between the set temperatures TR and TF of the refrigerator compartment 12 and the freezer compartment 13 is small, the surface temperature of the partition wall 11 facing the refrigerator compartment 12 is less likely to be lowered due to the cold on the freezer compartment 13 side, and therefore dew condensation occurs. In order to prevent this, it is not necessary to raise the temperature in the refrigerator compartment 12.
At the start of the cooling operation, after the refrigeration apparatus 22 is started, the cooling fan 34 is driven with a delay of a predetermined time to suppress a sudden rise in the internal temperature.

  As described above, when the difference between the set temperatures TR and TF of the refrigerator compartment 12 and the freezer compartment 13 is large and the temperature difference calculation unit 52 receives the calculation instruction signal, the temperature difference calculation unit 52 detects it by the ambient temperature sensor 57. A difference D between the ambient temperature thus obtained and the refrigerating room set temperature TR taken in by the refrigerating room set temperature taking-in portion 55 is calculated. Then, the energization rate control unit 53 determines the energization rate E corresponding to the calculated temperature difference D, and the duct heater 40 is energized by the determined energization rate E during the cooling operation. Become.

  During the cooling operation, in the refrigerator compartment 12, when the internal temperature rises to the upper limit value of the refrigerator compartment set temperature TR, the cooling operation by the cooler 25 is executed, and when it falls to the lower limit value of the preset temperature TR, the cooling operation is stopped. This operation is repeated, but when the duct heater 40 is energized as described above, the air duct 30 stretched on the ceiling of the refrigerator compartment 12 is heated, so that the internal temperature of the refrigerator compartment 12 rises. As a result, the time during which the cooling operation is performed becomes longer. The fact that the cooling operation is executed means that the internal air circulates and circulates in the refrigerator compartment 12 while passing through the cooler 25 in a low temperature state. During this time, the defrosting effect is obtained by frosting the cooler 25. In other words, the humidity in the refrigerator compartment 12 is reduced, and as a result, condensation on the surface of the partition wall 11 facing the refrigerator compartment 12 is suppressed.

  As described above, according to the present embodiment, when the difference between the set temperature TR in the refrigerator compartment 12 and the set temperature TF in the freezer compartment 13 is a predetermined value (10K) or more, that is, the refrigerator compartment 12 is faced. When the surface of the partition wall 11 is considered to be in a low temperature state due to the influence of the cold on the freezer compartment 13 side, it is stretched to form the cooler chamber 31 at the ceiling of the refrigerator compartment 12 during the cooling operation. The duct heater 40 mounted on the air duct 30 is energized to heat the air duct 30. As a result, the internal temperature of the refrigerator compartment 12 rises, so that the time during which the cooling operation is performed becomes long, and the internal humidity of the refrigerator compartment 12 decreases due to the dehumidification effect that accompanies the passage of the internal air through the cooler 25. In addition, condensation on the partition wall 11 on the refrigerator compartment 12 side is prevented.

Here, the smaller the difference between the ambient temperature and the refrigerating room set temperature TR, the smaller the temperature rise of the refrigerating room 12 due to heat intrusion from the outside of the cabinet. Therefore, more assistance from the heat generated by the duct heater 40 is necessary. If the difference between the temperature and the set temperature TR of the refrigerator compartment becomes large, the temperature rise on the side of the refrigerator compartment 12 due to the heat intrusion from the outside of the cabinet increases, and there is a situation that the assistance due to the heat generated by the duct heater 40 can be reduced.
Therefore, in the present embodiment, the smaller the difference between the ambient temperature and the refrigerator compartment set temperature TR, the higher the energization rate for the duct heater 40 and the greater the amount of heat generated, that is, the amount of heat generated by the duct heater 40 as required. In this way, power consumption is kept to a minimum. In addition, if the duct heater 40 generates too much heat and the inside of the refrigerator compartment 12 is excessively heated, the cooling operation execution time becomes too long, and extra power for operating the refrigeration apparatus 22 is required. In this embodiment, excessive cooling operation is also prevented.
As a result, it is possible to suppress dew condensation on the partition wall 11 facing the refrigerator compartment 12 while suppressing power consumption as much as possible.

<Embodiment 2>
In the above embodiment, the duct heater 40 attached to the air duct 30 stretched to form the cooler chamber 31 in the ceiling portion of the refrigerator compartment 12 is used as means for assisting the temperature rise of the refrigerator compartment 12, In the second embodiment, as shown by the chain line in FIGS. 2 and 4, it is used to heat the cooler 25 during the defrosting operation so as to be applied to a refrigerator-freezer that is not equipped with the duct heater 40 described above. A defrosting heater 29 is employed as a heater for assisting temperature increase. Other structures including the heater control unit 50 are the same as those in the first embodiment.

  The operation of the second embodiment will be briefly described as follows. The difference between the set temperature TR in the refrigerator compartment 12 and the set temperature TF in the freezer compartment 13 is not less than a predetermined value (10K), and the surface of the partition wall 11 facing the refrigerator compartment 12 is considered to be in a low temperature state. During the cooling operation, the defrost heater 29 attached to the cooler 25 is energized to generate heat. Thereby, since the internal temperature of the refrigerator compartment 12 rises across the air duct 30, the time for which the cooling operation is executed is lengthened, and the refrigerator compartment is also caused by the dehumidifying effect accompanying the passage of the internal air through the cooler 25. The humidity in the cabinet 12 is reduced, and condensation on the partition wall 11 on the refrigerator compartment 12 side is prevented.

Further, when the defrost heater 29 is caused to generate heat, the energization rate is similarly controlled so as to obtain a heat generation amount of the defrost heater 29 as necessary. The power consumption is suppressed as much as possible, and the refrigerator room 12 is faced. It is possible to suppress condensation on the partition wall 11.
In the second embodiment, in particular, the defrost heater 29, which is essential for a refrigerator-freezer having a defrosting operation function, is also used as a heater for assisting the temperature increase, which can contribute to cost reduction.

<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.
(1) In the above embodiment, the case where the energization rate to the heater for raising the temperature (duct heater or defrost heater) is determined only at the timing when the cooling operation is started. The energization rate may be reviewed at each time interval. Further, the energization rate may be determined immediately before the cooling operation is started.
(2) In the above embodiment, the change of the energization rate for the heater for assisting the temperature increase is illustrated over five stages, but the number of stages is arbitrary. Further, the relationship between the energization rate and the difference between the ambient temperature and the refrigerator compartment set temperature is not limited to that exemplified in the above embodiment, but can be arbitrarily selected according to conditions such as the usage form of the cooling storage.

(3) The difference between the refrigerator compartment set temperature and the freezer compartment set temperature for determining whether or not the heater energization control is necessary is not limited to 10K exemplified in the above embodiment, and can be arbitrarily set.
(4) As a means for controlling the heat generation amount of the heater for assisting temperature increase, other means such as changing the power supplied to the heater in addition to changing the energization rate to the heater exemplified in the above embodiment. May be used.
(5) As the temperature increase assist heater, another heater may be prepared in addition to the duct heater and the defrost heater exemplified in the above embodiment.

(6) In the above embodiment, the type in which the refrigeration chamber and the freezer compartment are individually equipped with independent refrigeration cycles is exemplified. However, in the present invention, each cooler of the refrigerator compartment and the freezer compartment is a compressor. Are connected to a common refrigeration apparatus, and a valve mechanism for switching the flow of refrigerant to each cooler is provided. Each cooler is operated by a valve mechanism in a state where the compressor is operated. The present invention can be similarly applied to a type in which execution and stop of the cooling operation are controlled in accordance with the circulation and stop of the refrigerant to the cooler.
(7) Further, the present invention is not limited to the refrigerator-freezer exemplified in the above embodiment, and is generally applied to a cooling storehouse in which a plurality of storage chambers are formed in the main body and can be cooled to different set temperatures. Applicable.

  DESCRIPTION OF SYMBOLS 10 ... Main body (storage main body) 11 ... Partition wall 12 ... Refrigeration room (storage room with higher set temperature in the storage) 13 ... Freezing room (storage room with lower set temperature in the storage) 20 ... Refrigeration unit 22 ... Freezing Apparatus 25 ... Cooler 27 ... Inside temperature sensor 29 ... Defrost heater 30 ... Air duct 31 ... Cooler chamber 32 ... Suction port 34 ... Cooling fan 36 ... Air outlet 40 ... Duct heater 50 ... Heater control section (heater control means) 51 ... Comparison part 52 ... Temperature difference calculation part 53 ... Conductivity control part 55 ... Refrigerating room set temperature taking part 56 ... Freezer room setting temperature taking part 57 ... Ambient temperature sensor TR ... Refrigerating room set temperature TF ... Freezer room setting temperature

Claims (4)

A plurality of storage chambers are formed in the storage body consisting of a heat insulating box by dividing by a heat insulating partition wall, and each storage chamber passes through a cooler constituting a part of the refrigeration cycle and the same cooler. However, a cooling fan that generates a circulation flow in the storage chamber is provided, and a set temperature in the cabinet that is different from each other is set.
In each storage room, by repeatedly executing or stopping the cooling operation of the cooler according to whether the internal temperature detected by the internal temperature sensor is higher or lower than the corresponding internal set temperature, In the cooling storage where the inside is maintained at the corresponding internal set temperature,
A heater provided in the storage chamber to raise the temperature of the storage chamber having a higher internal set temperature;
An ambient temperature sensor for detecting the ambient temperature at the installation location of the cooling storage;
On the condition that the difference between the higher chamber set temperature and the lower chamber set temperature is a predetermined value or more, the smaller the difference based on the difference between the ambient temperature and the higher chamber set temperature, the more Heater control means for controlling the heating value of the heater to increase,
The cooling storage characterized by comprising. The heater control means includes
A comparison unit that compares the higher chamber set temperature and the lower chamber set temperature and sends a calculation instruction signal when the difference is equal to or greater than a predetermined value;
A temperature difference calculation unit that calculates the difference between the ambient temperature and the higher internal set temperature when receiving the calculation instruction signal;
An energization rate control unit that controls the energization rate to the heater to be larger as the calculated value is smaller based on the calculated value of the temperature difference calculating unit;
The cooling storage according to claim 1, comprising: An air duct that also serves as a drain pan is stretched on the ceiling of each storage chamber to form a cooler chamber that houses the cooler, and the cooling fan is attached to the air duct to perform cooling operation. Sometimes, as the cooling fan is driven, cold air generated by heat exchange with the cooler is circulated and supplied into the storage chamber, while the defrost heater attached to the cooler is heated to form frost. A defrosting operation for removing air is performed, and a duct heater that generates heat at the time of the defrosting operation is mounted in the vicinity of the position of the cooling fan in the air duct. And
The cooling storage according to claim 1 or 2, wherein the duct heater is the heater provided to raise the temperature in the storage chamber having a higher internal set temperature. An air duct that also functions as a drain pan is stretched on the ceiling of each storage chamber to form a cooler chamber that houses the cooler. During the cooling operation, the cooler and the heat are While the cold air generated by replacement is circulated and supplied into the storage chamber, a defrosting operation is performed in which a defrost heater is attached to the cooler and the cooler is heated by the defrost heater to remove frost. Which is supposed to be done,
The cooling depot according to claim 1 or 2, wherein the defrosting heater is the heater provided to raise the temperature in the storage chamber having a higher internal set temperature.

Images