JP2771590B2 - Cooling storage - Google Patents

Description

The present invention relates to a cooling storage for indirectly cooling a storage room defined inside an insulated box and maintaining the storage room at a high humidity. is there.

(B) Conventional technology As a conventional technology, Japanese Utility Model Application Laid-Open No. 60-93882 discloses that a heat insulating outer box and a thermally conductive inner box are fixedly provided with a certain space.
Cool the inner box by circulating cool air in the space between the outer box and the inner box, and make the inside of the inner box a refrigeration room, and remove the evaporator of the refrigerator for creating the cool air and the fan for circulating the cool air. Disclosed is a refrigerator structure characterized by being placed in a cool air circulation space between a box and an inner box, and being equipped with a set other than the evaporator of the refrigerator outside the outer box.

Japanese Patent Application Laid-Open No. 61-6570 discloses that a plurality of compartments which are not communicated with each other by an inner box are provided in a storage room of an outer box, an inner box, and a heat insulating box formed of a heat insulating material filled between the two boxes. A storage is disclosed in which cold air heat-exchanged by a cooler is circulated to a cool air passage by a blower and indirectly cooled in order from the uppermost compartment.

(C) Problems to be Solved by the Invention As described above, cold air is circulated through the cool air passage formed between the storage room and the heat insulating box outside the storage room, thereby cooling the inner wall surface of the storage room and indirectly. With a structure that cools the inside of the refrigerator to a low temperature using natural convection, the entire outer wall inside the refrigerator is cooled at a constant cooling temperature with almost no difference in temperature, and heat exchange with the air in the refrigerator is efficient. The cooling energy can be effectively used. In addition, since there is no forced circulation of cold air into the refrigerator, there is no cold air hitting the stored items in the refrigerator, drying of the stored items can be prevented, and the inside of the refrigerator can be maintained at a relatively high humidity for a long period of time.

However, even with such a cooling method, frost adheres to a cooler and the like in the cool air passage as the cooling operation progresses.
Also, if the inside of the refrigerator is cooled at a set temperature of 0 ° C or less,
The temperature of the inner wall surface is also 0 ° C. or less, and in such a state, frost and icing regenerate on the inner wall surface due to intrusion of outside air from the door and moisture of the stored items. Therefore, it is necessary to perform these defrosts regularly. At the time of defrosting, since the cooling operation is stopped, there is a disadvantage that the internal temperature of the refrigerator increases during that time. Therefore, it is desirable that defrosting be performed efficiently in a short time, but return to the cooling operation without leaving any frost, and such a defrosting method and its control are required.

By the way, in the above-mentioned prior art, no clear disclosure and no measures for efficient and reliable defrosting and its return control have been made with respect to defrosting of the cooler and the inner wall surface of the refrigerator.

In the indirect cooling type cooling storage, the present invention ensures not only the defrosting of the cooler and the like in the cool air passage but also the defrosting of the inner wall surface of the storage, and the defrosting and returning without defrosting. It is an object of the present invention to provide a cooling storage that achieves control.

(D) Means for Solving the Problems According to the present invention, a heat conduction box is provided inside a heat insulating box having an opening / closing door at a front opening with a space between the heat insulating box and the heat conducting box. The inside of the good conduction box is a storage room, and the space between the heat insulating material box and the good heat conduction box is a cold air passage, and the storage room is indirectly cooled in the top passage of the cold air passage. A cooling storage provided with a cooling means and an air circulating fan for performing defrosting heating means is provided below the cooling means, and the space is removed by the operation of the defrosting heating means and the air circulating fan. A temperature sensor configured to circulate the frost heat source airflow to perform defrosting of the frost adhering to the cooling means and the inner surface of the heat conduction box, and to detect the completion of the defrosting of the cooling means by a change in the temperature thereof; A temperature sensor is provided to detect the completion of defrosting of the good conductor box based on the rise in wall temperature. The former temperature sensor is provided at a position separated from the defrosting heating means of the cooling means, and the latter temperature sensor is provided on the bottom surface of the heat conduction box in which the temperature during defrost hardly increases, and the former temperature sensor and Neither of the latter temperature sensors is detected and the cooling means and the storage room are both frosted, and frost is left in the storage room where the former temperature sensor is detected but the latter is not detected. If there is, the circulating fan and the defrosting heating means are also operated to perform defrosting by circulating the defrosting heat source airflow, while defrosting remains on the cooling means where the former temperature sensor does not detect and operate. At a certain stage, when the latter temperature sensor performs the detecting operation, the air circulation fan is stopped, the defrosting heating means is operated, and the cooling means is defrosted by the defrosting heating means. Temperature When defrosting is completed, in which both the sensor and the temperature sensor detect and operate, the defrosting heating means is not operated and the circulation fan is operated to perform normal cooling operation by circulating cool air. It is.

(E) Action During defrosting, the heating means and the air circulation fan operate,
The defrost of the cooler is performed by the heating means. On the other hand, the air heated by the heating means circulates in the space between the heat conduction box and the heat insulation box by the air circulation fan. Therefore, the outer wall surface of the heat good heat box is heated by the defrosting heat source airflow, and the frost adhering to the inner wall surface of the box is removed. The end of this defrosting is performed by a temperature sensor provided in the cooling unit so as to be hardly affected by heat from the heating unit, and highly reliable defrosting end detection is performed. A temperature sensor that detects the end of defrosting of the bottom surface portion where frost is likely to remain until the end of the temperature rise that is difficult to increase, and controls the operation of the heating means and the air circulation fan so that no frost remains on the inner wall of the refrigerator. That is, the heating means and the air circulation fan are operated,
When warm air is circulating and the cooling means and the heat conduction box are being defrosted, the temperature sensor on the cooling means side operates to detect and operate. If there is frost in the heat conduction box, which has not detected a rise in the inner wall temperature, the heating means and the air circulation fan continue to operate to circulate warm air and defrost the heat conduction box. I do. However, when the temperature sensor on the heat conduction box side detects and operates first, and the temperature sensor on the cooling means side does not detect or operate, or during defrosting operation, frequent opening and closing of doors or hot items may be put in the refrigerator. If the internal temperature rises, for example, when the temperature sensor on the heat conduction box side detects and operates, the air circulation fan is stopped and the heating means is operated. Thus, after the circulation of warm air is stopped to prevent an unnecessary rise in the internal temperature, the defrosting of the cooling means is directly performed by the heat from the heating means. By appropriate control of such a heating means and a fan for air circulation, complete defrosting of the cooling means and the heat conduction box, and suppressing an increase in the temperature inside the chamber due to defrosting, and ideally not causing product damage. Defrosting can be performed.

(F) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

Reference numeral 1 denotes a cooling storage having upper and lower two-stage storage chambers 2, 3, and the entire wall surfaces 2A, 3A forming the storage chambers 2, 3 are made of a heat conductive material, for example, a metal such as stainless steel. This is formed in a box shape. Dew receiving plates 4 and 5 are provided above the storage rooms 2 and 3, respectively. The outer heat-insulating box 6 for storing the storage rooms 2 and 3 inside has an opening / closing door at the front.
7 and 7, and the top part 8 has a compressor 9 and a condenser 1
0, an external refrigeration unit such as a cooling fan 11 is installed. A cool air passage through which cool air flows through the five surfaces except the front surface of each of the storage compartments 2 and 3, ie, the upper surface, the rear surface, the left and right side surfaces, and the outer surface of the bottom surface
The storage chambers 2 and 3 are disposed and fixed in the heat insulating box 6 at an interval so that 12 is formed between the heat insulating box 6 and the inner wall surface of the heat insulating box 6. A cooler 13 and an air circulation fan 14 are disposed in the top passage 12A of the cool air passage 12, and the cool air flows out of the outlet 15 into the top passage 12A of the upper storage room 2. The outflowing cold air disperses the upper storage room 2 as shown by the arrows in the left and right side passages and the rear passage 16A, merges into the bottom passage 17 and passes through the communication port 18 to cool the lower storage room 3 first. After entering the top passage 12B, the lower storage room 3
Diverges from the left and right side passages and the back passage 16B, from the bottom passage 19 to the return passage 21 through the lower communication port 19 and upwards to the cooler.
The cold air that has been sucked into and heat exchanged is
Is circulated again. 22 is a cold air discharge passage 16A, 16
This is a vertical partition plate that separates B from the return passage 21. Also,
The upper and lower storage chambers 2 and 3 are communicated with each other by an internal drain pipe 23, and the internal drain pipe 24 is also connected from the lower storage chamber 3 to the heat insulating box 6.
It protrudes outside. Reference numeral 25 denotes a heater for defrosting mounted at the lower part of the cooler 13, which is energized at the time of defrosting and removes frost adhering to the cooler 13. At the time of general defrosting, the operation of the compressor 9 and the like is stopped and the refrigerant is not supplied, but the air circulation fan 14 continues its operation and keeps rotating, so that the air circulation fan 14 is heated by the defrosting heater 25. The defrosting heat source airflow circulates through the cool air passage 12 to warm the outer surfaces of the walls 2A and 3A of the storage rooms 2 and 3, respectively. Therefore, the removal of frost and icing adhering to the inner surfaces of the walls 2A and 3A is also performed in parallel. 26 is the surface of the cooler 13 on the cold air suction side, which is a temperature sensor for defrost release mounted at a distant position not affected by the heat from the defrost heater 25, and removes the frost of the cooler 13 Then, by detecting the temperature rise of the cooler 13 itself or a change in the temperature rise near the cooler 13, it is determined that the defrost is completed, the defrost operation is canceled, and the operation returns to the cooling operation. In addition, on the surface of the cool air discharge side of the cooler 13, where defrost recovery is determined to be the most delayed during defrost, that is, at the lowest temperature point in defrost, a temperature for defrost release is set. The sensor 27 may be mounted.

Due to the heat generated by the defrost heater 25 and the rotation of the circulation fan 14, the inner walls 2A and 3A of the storage rooms 2 and 3 are warmed by a defrost heat source airflow flowing through the outer surfaces thereof, and the inner walls 2A and 3A It removes the frost.

Here, the reason why the temperature sensors 26 and 27 for defrost release are attached to a place where the temperature of the cooler 13 is low in temperature is as follows. During the defrost operation in which the heater 25 for defrost is energized and the fan 14 for circulation rotates. The air heated by the defrost heater 25 is
As A flows from the upper part to the lower part, it exchanges heat and the inner wall 2
Defrosts frost adhering to A and 3A, discards heat, and goes downstream, the temperature becomes lower, and eventually the air temperature becomes low, which can be regarded as the lowest temperature of the inner wall surfaces 2A, 3A. Return to 13. Therefore, first, the temperature sensors 26 and 27
It is a situation to detect the lowest temperature of 3A. on the other hand,
The temperature sensors 26 and 27 are connected to the cooler 1 far from the defrost heater 25.
3 or the surface of the cooler 13 where the temperature hardly rises during defrosting.
7 is a state in which the lowest temperature of the cooler 13 is also detected.

Therefore, the lowest temperature of the cooler 13 and the lowest temperature of the inner wall surface 3A can be detected by one of the temperature sensors 26 and 27, respectively. When is set appropriately, ON / OFF control of the defrosting heater 25 is performed so as not to cause frost on the inner wall surfaces 2A and 3A, and further, defrosting of the cooler 13 can be completely performed. By the way, instead of providing the temperature sensors 26 and 27 at the lowest temperature point of the cooler 13 as in the present invention,
If there are storage chambers 2 and 3 above and below and one of the storage chambers 2 and 3 is equipped with a defrost release temperature sensor to perform defrost control, the storage chamber without a temperature sensor must be installed. If the amount of frost is large, the defrost is released before the defrosting is completed,
The storage room is defrosted poorly. It is also conceivable to attach temperature sensors to each storage room.However, since the frost formation conditions in each storage room are different, it is necessary to adjust the temperature sensor so that the defrost release temperature must be carefully set, and the number of temperature sensors Inconvenience, for example, the complexity of electrical wiring is increased. Therefore, the temperature sensor attached to the cooler 13
In addition to 26 and 27, the wall surface temperature is directly controlled to further ensure defrosting, eliminate unnecessary defrosting, reduce internal temperature rise, shorten defrosting time, and control energy-efficient defrosting. The defrost release temperature sensor 28 sensed during the defrost is attached to a portion where it is determined that the end of the defrost is performed latest at the time of defrost, that is, the lowest portion which is the lowest temperature in defrost. In addition, the defrost release temperature of the temperature sensor 28 is set slightly lower than the defrost release temperatures of the temperature sensors 26 and 27 that perform the defrost release operation on the cooler 13. Then, the return operation of these temperature sensors 26, 27, and 28, and the ON and O
By determining the relationship between the FF and the ON / OFF of the air circulation fan 14 as follows, efficient defrost control can be achieved.
That is, the following control method is used.

During the normal defrosting operation, the cooler 13 and the inner wall surfaces 2A, 3A
The frost remains on the cooler 13, and the temperature of the inner wall surfaces 2A and 3A is low. Therefore, the defrost heater 25 and the circulation fan 14
And ON operation, each generates heat, and continues rotation.

When defrosting progresses and the frost of the cooler 13 disappears, the cooler 13
The temperature sensors 26 and 27 sense the temperature rise of. On the other hand, if the frost on the inner wall surface 3A has not yet disappeared and the temperature sensor 28 is not operating, the rotation of the circulation fan 14 and
The defrosting heater 25 is controlled to continue to be energized, the defrosting heat source airflow is circulated through the cool air passage 12 to warm the inner wall surface 3A, and the defrosting is performed. Detecting the rising temperature change of the inner wall surface, the defrost is released and the heater 25 is de-energized. In this case, the circulation fan 14 keeps rotating as it prepares for the re-cooling operation, or once stops, and continues to rotate similarly.

When the regular defrosting operation is performed and the doors are frequently opened and closed during the defrosting of the cooler 13, or when a large amount of warm material is suddenly put in the refrigerator, the temperature rise of the storage room is detected in the refrigerator. The temperature sensor 28 senses the temperature of the wall surface 3A and returns. On the other hand, the temperature sensors 26 and 27 of the cooler 13 have not returned. Therefore, in such a case, the circulation fan 14 is stopped, and the heater 25 for defrost continues to be energized to defrost the cooler 13. Since the warm air generated by the heat of the defrost heater 25 does not circulate when the circulation fan 14 is stopped, there is no fear that the inside of the storage rooms 2 and 3 whose temperature is high is further increased. As described above, when control is performed using another temperature sensor 28 in addition to the temperature sensors 26 and 27 of the cooler 13, when the temperature sensors 26 and 27 are used alone, the storage temperature is further increased during the defrosting period until the temperature sensor 26 and 27 return. Room 2,
A control method that can improve the quality of the stored items 3 when the temperature becomes high and the cooling operation is resumed and smooth cooling does not proceed and energy loss can be improved when the cooling operation is resumed.

When the frost of the cooler 13 disappears and the frost of the inner wall surface 3A disappears, the respective temperature sensors 26, 27, and 28 return, and the heater 25 for defrosting is turned on. On the other hand, the operation of the circulation fan 14 is continued as it is. Ready to return to cooling operation.

The following table summarizes the above control relations in a gist.

In the above table, in the column of the defrost release temperature sensor, "low" means that the frost still remains on the inner wall surface of the cooler and the cooler, and "high" means that the cooler This means that the inner wall surface was defrosted and the temperature became high.

Next, the operation of the compressor 9 will be described.
When the circulation fan 14 is operated, the cool air heat exchanged by the cooler 13 circulates through the cool air passage 12 and the upper storage room 2 and the lower storage room 3
Indirectly cool the outer wall of the, and store the stored items at low and high temperatures. After the cooling operation for a certain period, the operation shifts to the defrosting operation. At this time, the heater 25 for defrost is energized and the fan for circulation is turned on.
Rotate 14. The frost adhering to the cooler 13 is melted by the heat of the defrost heater 25 and is gradually removed.

Since the temperature sensors 26 and 27 for defrost release are mounted on the surface of the cooler 13 which is far from the defrost heater 25 and is considered to be the lowest in temperature that is not easily affected by the heat, the defrost is performed. Does not work during frost. When the defrosting of the cooler 13 progresses and the frost disappears, the heat of the defrosting heater 25 changes from frost melting to heating of the entire cooler 13, and the temperature of the cooler 13 rises rapidly. The temperature sensors 26 and 27 first detect this change in temperature rise. Then, the air circulating in the cool air passage 12 by the circulation fan 14 is heated by the defrost heater 25. This warm air is applied to the outer surface of the wall of the upper storage room 2 and then to the lower storage room 3
By warming the outer surface of the wall, the frost and icing adhering to the inner wall surfaces of the storage rooms 2 and 3 are also melted. In this way, when the defrosting of the inner wall surface proceeds and the frost disappears, the heated air shifts to a heating action of the inner wall surface, thereby increasing the inner wall surface temperature. Then, another temperature sensor 28 for removing defrost, which is attached to the bottom surface 3C of the lower storage room 3, directly detects the rise in the temperature of the inner wall surface and operates. When either one of the two temperature sensors 26 and 27 operates in this manner, it is determined that defrosting has been completed, and the power supply to the defrosting heater 25 is turned off.
And

In the above defrosting operation condition, the defrosting of the inner wall surfaces 2A and 3A is completed, the amount of frost on the cooler 13 is large, and when it is necessary to perform the defrosting, the circulation fan 14 is stopped. Then, only the defrost heater 25 is energized, and the heat is kept until the frost of the cooler 13 disappears.

As described above, the defrosting of the cooler 13 and the inner wall surfaces 2A and 3A
The defrosting is efficiently and reliably executed while minimizing the rise in the internal temperature during defrosting.

(G) Effect of the Invention As described above, according to the present invention, the inside of the heat conduction box arranged with a space at an appropriate interval in the heat insulating box is used as a product storage room, and this space is formed as a cool air passage, A cooling means and an air circulation fan are provided in the top surface passage, and in a cooling storage for indirectly cooling the storage room by circulating cool air in this space, the defrosting of the cooling means is provided at a lower portion thereof for defrost heating. Means, and the air circulation fan is operated to circulate the defrosting heat source airflow from the defrosting heating means into the space, and to heat the outer wall surface of the heat conduction box, thereby removing frost adhering to the inner wall surface. Defrosting.
Therefore, since the cooling means and the defrosting of the inner wall surface of the refrigerator can be used together as the defrosting heat source airflow path at the time of defrosting, the cooling means and the defrosting of the inner wall surface can be performed efficiently at the same time, and the configuration becomes simple.

The cooling means is provided with a dedicated temperature sensor for detecting the completion of the defrosting, and a dedicated temperature sensor for detecting the completion of the defrosting is provided on the inner wall surface of the refrigerator. By performing appropriate ON / OFF control of the defrosting heating means and the air circulation fan according to the state, defrosting is performed so that no frost remains on the cooling means and the inner wall of the refrigerator, and the defrosting heat source air flow By performing control such as stopping the flow to the inside of the refrigerator, it is possible to perform ideal defrosting, which suppresses a rise in the temperature of the refrigerator as much as possible and prevents product damage.

Further, the temperature sensor for detecting the end of the defrost of the cooling means is provided at a place away from the defrost heating means so as not to be easily influenced by the heat of the defrost heating means, so that the defrost end is more accurately performed. The temperature sensor for detecting the end of defrosting of the heat conduction box also discharges heat from the top of the cool air passage from the top to the bottom, and the temperature rises. By installing it on the bottom of the heat conduction box, which is difficult to remove, and detecting the completion of defrosting in places where frost is likely to remain until the end, defrosting of frost attached to the heat conduction box can also be performed It is possible to carry out a highly reliable defrosting operation, for example, to complete the operation.

[Brief description of the drawings]

The drawing is a longitudinal sectional side view of the cooling storage of the present invention. 2,3… Storage room, 2A, 3A… Internal wall part, 6… Insulated box,
12 ... Cold air passage, 13 ... Cooler, 14 ... Air circulation fan, 25 ... Defrost heater, 26,27,28 ... Defrost release temperature sensor.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-185359 (JP, A) JP-A-60-79682 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25D 21/06 F25D 21/08 F25D 17/08 311

Claims (1)

(57) [Claims] 1. A heat conduction box is disposed inside a heat insulation box having an opening / closing door at a front opening thereof with a space between the heat insulation box and a storage room. In addition, a space between the heat insulating material box and the heat conducting box is formed as a cool air passage, and a cooling means and an air circulation fan for indirectly cooling the storage room in a top surface passage of the cool air passage. A defrosting heating means is provided below the cooling means, and the defrosting heat source airflow is circulated through the space by the operation of the defrosting heating means and the air circulation fan, And a temperature sensor for detecting the completion of defrosting of the cooling means by a change in the temperature thereof, and the completion of defrosting of the thermal conduction box. A temperature sensor that detects the temperature rise of the wall surface, and cools the former temperature sensor. Along with the defrosting heating means provided at a position separated from the heating means, the latter temperature sensor is provided on the bottom surface of the heat conduction box where the temperature during defrost hardly increases, and both the former temperature sensor and the latter temperature sensor are provided. Does not operate, cooling means,
If both of the storage chambers have frost residue, and if the former temperature sensor detects but the latter temperature sensor does not detect and has frost residue, the circulation fan and the defrosting heating means are both used. In the case where the operation is performed and defrosting is performed by circulating ventilation of the defrosting heat source airflow, while the former temperature sensor performs detection operation at the stage where there is frost remaining in the cooling means where the former temperature sensor does not detect and operate. The air circulation fan is stopped and the defrosting heating means is operated to perform defrosting of the cooling means by the defrosting heating means, and both the former temperature sensor and the latter temperature sensor detect and operate. A cooling storage, characterized in that when defrosting is completed, the defrosting heating means is not operated and the circulation fan is operated to perform operation control so as to perform a normal cooling operation by cooling air circulation.