JP4189299B2 - Cooling storage - Google Patents

Description

  The present invention relates to a cooling storage of a type that is cooled to different cooling temperatures by a cooling device in which a plurality of storage chambers are individually provided.

In a commercial refrigerator-freezer, the inside of the main body made of a heat insulating box is partitioned by a heat insulating wall to be divided into a freezing room and a refrigerating room, and the freezing room is cooled to about −20 ° C. and the refrigerating room is cooled to about 5 ° C., respectively. . Here, for example, in a domestic refrigerator-freezer, a cooling system is adopted in which a single cooling unit is provided and a part of the cold air circulating in the freezer compartment is distributed to the refrigerator compartment. In particular, when the volume of the refrigeration chamber is large, the inefficiency becomes remarkable. Therefore, cooling units are individually mounted for refrigeration and freezing (see, for example, Patent Document 1).
On the other hand, in this type of commercial refrigerator-freezer, a defrosting operation is performed using a heater, and depending on the model, the above-mentioned defrosting may be performed when the freezer compartment or the refrigerator compartment is excessively cooled. Some have a function of increasing and recovering the internal temperature using a heater.

  More specifically, the refrigerator / freezer having the above-described functions will be described. As shown in FIG. 7, the refrigerator compartment 1A and the refrigerator compartment 1B are individually equipped with cooling units 2A and 2B, while the two compartments 1A and 1B are equipped with the refrigerator units 1A and 1B. Are provided with internal temperature sensors 3A and 3B for detecting the internal temperature. In addition, defrost heaters 4A and 4B are attached to the evaporators of the cooling units 2A and 2B, and defrost temperature sensors 5A and 5B for detecting the temperature of the evaporator are attached to the evaporators. In addition, a common control board 6 equipped with a microcomputer or the like is installed in an electrical box provided in any one of the cooling units, and the internal temperature sensors 3A and 3B are provided on the input side of the control board 6. Both defrosting temperature sensors 5A and 5B are connected to both cooling units 2A and 2B (compressor) and both defrosting heaters 4A and 4B on the output side.

And in each of the refrigerator compartment 1A and the freezer compartment 1B, depending on whether the internal temperature detected by the internal temperature sensors 3A, 3B is higher or lower than a predetermined set temperature, the corresponding cooling units 2A, 2B Operation and stop are controlled, and the chambers 1A and 1B are maintained substantially at the set temperature. On the other hand, in both chambers 1A and 1B, a defrosting operation is appropriately performed by a 24-hour timer or a switch operation, which energizes the defrosting heaters 4A and 4B while the cooling units 2A and 2B are stopped to evaporate. This is done by heating the vessel. During the defrosting operation, if the detection temperature of the defrosting temperature sensors 5A and 5B rises to a predetermined defrosting completion temperature (for example, 20 ° C for the refrigerator compartment 1A, 35 ° C for the freezer compartment 1B), the defrosting is performed. It is considered that the defrosting operation is completed.
Similarly, in both chambers 1A and 1B, if the temperature detected by the internal temperature sensors 3A and 3B is lowered to a predetermined supercooling temperature (for example, each set temperature -5K), it is determined that there is an excessive cooling state and the corresponding defrost heater When the 4A and 4B are energized to increase the internal temperature and the supercooled state is removed, the energization to the defrosting heaters 4A and 4B is stopped.
No. 8-7337

In the above, the cooling units 2A and 2B and the defrosting heaters 4A and 4B are individually arranged in the refrigerating room 1A and the freezing room 1B, whereas the control board 6 is equipped with a common one and wired. And other incidental structures are being simplified, which may cause the following problems. For example, there is an erroneous connection of the sensor to the control board 6, and this possibility cannot be denied at the time of repair after shipment, regardless of the factory shipment.
For example, as shown by the broken arrow in FIG. 7, the internal temperature sensor 3 </ b> A equipped in the refrigerator compartment 1 </ b> A is connected to the input port 7 </ b> B of the internal temperature sensor 3 </ b> B on the freezer compartment 1 </ b> B side in the control board 6. Conversely, the internal temperature sensor 3B equipped in the freezer compartment 1B may be connected to the input port 7A of the internal temperature sensor 3A on the refrigerator compartment 1A side.

When such an erroneous connection occurs, during the cooling operation, on the freezer compartment 1B side, the internal temperature on the opposite refrigerator compartment 1A side is input, and the freezer compartment 1B side is in order to lower it to the set temperature. Although the cooling unit 2B is operated, the actual internal temperature of the freezer compartment 1B is not reflected in the control. Therefore, the operation of the cooling unit 2B is continued and the inside of the freezer compartment 1B is cooled below the set temperature.
On the other hand, in the refrigerator compartment 1A side, the internal temperature of the freezer compartment 1B side is input, and since the internal compartment temperature is being cooled as described above, the refrigerator compartment 1A side is considered to be in an excessively cooled state, In order to repair it, the defrost heater 4A on the refrigerator compartment 1A side is energized. However, what is detected is the internal temperature of the freezer compartment 1B, which is in a state of decreasing as described above, so that it is not recognized that the temperature of the refrigerator compartment 1A has been raised, and the defrost heater The energization to 4A is continued continuously, and the situation where the so-called heater goes out of control is caused. As a result, the heater itself and peripheral members may be damaged.

Even if the sensor is properly connected, the heater may run away as described above even when accurate information cannot be obtained from the sensor due to a failure or the like. Therefore, depending on the model, a temperature fuse is interposed in the energization line to the defrosting heaters 4A and 4B, and when the ambient temperature of the temperature fuse rises to a predetermined value, it is blown to provide means for protecting the defrosting heaters 4A and 4B. Some have been taken, but nonetheless, a new thermal fuse must be replaced to restart.
The present invention has been completed based on the above circumstances, and an object of the present invention is to prevent runaway of the defrost heater.

  As means for achieving the above-mentioned object, the invention of claim 1 includes a plurality of storage chambers that are partitioned in a body in a heat-insulating state, a cooling device mounted for each storage chamber, Connected to an internal temperature sensor for detecting internal temperature, an evaporator in each cooling device or a defrost heater disposed in the vicinity thereof, each cooling device, each defrost heater, and each internal temperature sensor Each of the storage chambers is controlled at different cooling temperatures by controlling the operation and stop of the corresponding cooling device based on the temperature detected by the internal temperature sensor. The defrosting operation is performed by energizing the defrost heater while the cooling device is stopped for each of the storage chambers, and the temperature detected by the internal temperature sensor is a predetermined excess. When the temperature falls to the cold temperature, In the cooling storage provided with a function of energizing the corresponding defrosting heater as being in a cool state, if any one of the temperature sensors in the entire chamber detects a predetermined stop temperature or higher, It is characterized in that a heater control means for stopping energization to the defrosting heater is provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, a defrosting temperature sensor that detects the temperature of each of the evaporators or the vicinity thereof is provided and connected to the controller, and the defrosting operation is performed during the defrosting operation. When the temperature detected by the frost temperature sensor rises to a predetermined defrosting completion temperature, the defrosting operation is deemed complete and the defrosting operation is terminated. One of the frost temperature sensors is characterized by having a function of stopping energization to all the defrost heaters when a predetermined stop temperature or higher is detected.

The invention of claim 3 is characterized in that, in the invention of claim 2, the stop temperature related to the internal temperature sensor and the stop temperature related to the defrost temperature sensor are set to the same temperature. .
According to a fourth aspect of the present invention, in the apparatus according to any one of the first to third aspects, the defrost heater is equipped with a temperature fuse that is blown when an ambient temperature reaches a predetermined temperature or more, and the stop The temperature is characterized in that the temperature fuse is set to a temperature value before cutting.

<Invention of Claim 1>
During operation, the temperature detected by the internal temperature sensor is monitored, and if any one of the detected temperatures is equal to or higher than the stop temperature, the power supply to all defrost heaters is cut off. In other words, even if the temperature in one cabinet reaches a higher stop temperature than can normally be taken, it is considered that the energization time to the defrost heater has become unnecessarily long due to sensor misconnection, etc. The energization is forcibly stopped, and the runaway of the defrost heater is prevented in advance. Therefore, the defrosting heater itself is prevented from burning out and surrounding members are not damaged.

<Invention of Claim 2>
During operation, the temperature detected by the total defrost temperature sensor is monitored, and if any one of the detected temperatures is equal to or higher than the stop temperature, the energization to all the defrost heaters is cut off. In other words, if the temperature of the evaporator or its vicinity reaches a higher stop temperature than can normally be taken, the energization time to the defrost heater becomes unnecessarily long due to a sensor misconnection or the like. Therefore, energization is forcibly stopped, and the runaway of the defrosting heater is prevented.
This is also effective for ensuring prevention of runaway of the defrost heater when the detected temperature cannot be properly obtained from the internal temperature sensor for some reason.

<Invention of Claim 3>
Since the stop temperature related to the internal temperature sensor and the stop temperature related to the defrost temperature sensor are set to the same temperature, the control system is simplified.
<Invention of Claim 4>
When the defrost heater is equipped with a thermal fuse, the energization to the defrost heater is stopped before it is disconnected. Re-operation is possible without replacing the thermal fuse.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. In this embodiment, the case where the present invention is applied to a commercial refrigerator-freezer is illustrated.
The refrigerator-freezer is, for example, a four-door type, and includes a main body 10 made of a heat insulating box having a front surface opened as shown in FIG. 1, and the front opening is partitioned into a cross to form four doorways. The approximately 1/4 internal space corresponding to the entrance on the upper right portion when viewed from the front is partitioned by a heat insulating partition wall to be the freezing room 11B, and the remaining approximately 3/4 area is the refrigerating room 11A. (See FIG. 2). Each doorway is provided with a heat insulating door 12 that can swing open and close.

On the upper surface of the main body 10, a machine room 13 is configured by, for example, a panel 13 </ b> A standing around. As shown in FIG. 2, openings 14 are formed at positions corresponding to the ceiling walls of the refrigerating room 11 </ b> A and the freezing room 11 </ b> B on the upper surface of the main body 10 which is the bottom surface of the machine room 13. The cooling unit 15 is mounted individually.
In the following description, the refrigerating room 11A side and the freezing room 11B side often have a common structure, and therefore, structural members having the same function are used, but the common structural members have the same reference numerals. In particular, when it is desired to distinguish between the refrigerator compartment 11A side and the freezer compartment 11B side, a suffix “A” or “B” is attached to each symbol.

The cooling unit 15 includes a compressor 16, a condenser 17 with a condenser fan 18, an expansion valve (not shown), and an evaporator 20 circulated through a refrigerant pipe to form a refrigeration circuit. A heat-insulating unit base 21 that covers the portion 14 is mounted, and the evaporator 20 among the constituent members of the cooling unit 15 is attached to the lower surface side of the unit base 21 and the other constituent members are attached to the upper surface side. Yes.
On the other hand, a drain pan 23 that also serves as a cooling duct is stretched downwardly toward the back of the ceiling of the refrigerating chamber 11A and the freezing chamber 11B, and an evaporator chamber 24 is formed between the unit base 21 and the unit. Yes. A suction port 25 is provided on the upper side of the drain pan 23, a cooling fan 26 is provided, and a discharge port 27 is formed on the lower side.

In the refrigerator compartment 11A and the freezer compartment 11B, an internal temperature sensor 29 for detecting the internal temperature is provided, for example, in the vicinity of the suction port 25.
Further, a defrost heater 30 for heating and defrosting the evaporator 20 is mounted on the lower surface side of each evaporator 20, and the temperature of the evaporator 20 is detected and removed on the upper side. A defrosting temperature sensor 31 for determining whether or not frost has been completed is attached.
On the front surface of the machine room 13, there is provided an operation panel 33 capable of individually setting the set temperatures of the refrigerating room 11A and the freezing room 11B. The operation panel 33 is provided with a display unit, and the refrigerating room 11A. And the temperature inside the freezer compartment 11B, various alarms, and the like can be displayed.

The cooling operation and the defrosting operation are executed based on a predetermined program. For this reason, an electrical box 35 is installed in the unit base 21 of one cooling unit 15 (for example, the cooling unit 15B on the freezing room 11B side), and a microcomputer in which the above-described program is stored therein as shown in FIG. 37 is equipped with a control board 38 on which 37 is mounted.
The internal temperature sensors 29A and 29B and the defrost temperature sensors 31A and 31B on the refrigerator compartment 11A side and the freezer compartment 11B side are connected to the input part of the control board 38, respectively. On the other hand, cooling units 15A and 15B (compressors 16A and 16B), cooling fans 26A and 26B, and defrosting heaters 30A and 30B on the refrigerator compartment 11A side and the freezer compartment 11B side are connected to the output unit.
The control board 38 is also connected to the operation panel 33.

As a basic operation, when the cooling unit 15 (compressor 16) and the cooling fan 26 are driven, the air in the refrigerating room 11A (the freezing room 11B) is sucked in as shown in the arrow of FIG. The cold air sucked into the evaporator chamber 24 from 25 and generated by heat exchange while passing through the evaporator 20 is circulated so as to be blown out from the discharge port 27 to the refrigerating chamber 11A (freezer chamber 11B). Thereby, the inside of the refrigerator compartment 11A (freezer compartment 11B) is cooled.
During this time, the operation and stop of the corresponding cooling unit 15 (compressor 16) and cooling fan 26 are controlled according to whether the internal temperature detected by the internal temperature sensor 29 is higher or lower than a predetermined set temperature. Thus, the chambers 11A and 11B are maintained at substantially the set temperature.

In the refrigerator compartment 11A and the freezer compartment 11B, a defrosting operation is appropriately performed by operating a 24-hour timer and a defrosting switch provided on the operation panel 33, respectively. This is performed by energizing the defrost heater 30 and heating the evaporator 20 in a state where the cooling unit 15 (compressor 16) and the cooling fan 26 are stopped. During the defrosting operation, the defrosting is completed when the temperature detected by the defrosting temperature sensor 31 rises to a predetermined defrosting completion temperature (for example, 20 ° C. for the refrigerator compartment 11A and 35 ° C. for the freezer compartment 11B). It is considered that the defrosting operation is terminated.
In addition, in the refrigerator compartment 11A and the freezer compartment 11B, if the temperature detected by the internal temperature sensor 29 falls to a predetermined supercooling temperature (for example, each set temperature -5K), it is determined that the cooling state is excessive and the corresponding side is excluded. The frost heater 30 is energized to increase the internal temperature (internal temperature increase). When the supercooled state is removed, the power supply to the defrost heater 30 is stopped.

In this embodiment, measures are taken to prevent runaway of the defrost heater 30 due to erroneous connection of the internal temperature sensor 29.
Therefore, a program for performing heater control as shown in FIG. 4 is added. In short, when the refrigerator-freezer is operated, the detected temperature of both the internal temperature sensors 29A and 29B, more precisely, the detected temperature input to both the input ports 40A and 40B of the internal temperature sensors 29A and 29B is captured. When any one of the detected temperatures rises to a predetermined stop temperature or higher, energization to both defrost heaters 30A and 30B is stopped.

Here, the stop temperature of the present embodiment is set to “45 ° C.”. This “45 ° C.” indicates that it is higher than the internal temperature that the refrigerator compartment 11A or the freezer compartment 11B can take when it is normally operated including the defrosting operation.
On the other hand, in the experiment, when the internal temperature was measured when the defrost heater 30 was continuously energized and burned out, it was confirmed to be 50 ° C. or higher. Therefore, “45 ° C.” means the internal temperature before the defrost heater 30 is burned out.
In addition, this type of defrost heater 30 is equipped with a temperature fuse that is cut when the ambient temperature reaches a predetermined temperature or more, and protects the defrost heater 30 from burning out. "Is also the temperature at which the thermal fuse is held before it is blown.

Next, the operation of this embodiment will be described.
For example, when performing maintenance close to an overhaul or changing the installation of a refrigerator-freezer, the electrical wiring may be temporarily removed and reconnected, and the connection may be incorrect. For example, as shown in FIG. 5, the internal temperature sensor 29A provided in the refrigerating room 11A is connected to the input port 40B of the internal temperature sensor 29B on the side of the freezing room 11B on the control board 38. The internal temperature sensor 29B equipped in 11B may be connected to the input port 40A of the internal temperature sensor 29A on the refrigerator compartment 11A side.

When such an erroneous connection occurs, during the cooling operation, the freezer compartment 11B side receives the internal temperature of the opposite refrigerator compartment 11A side, and the freezer compartment 11B side in order to lower it to the set temperature. Although the cooling unit 15B (compressor 16B) and the cooling fan 26B are operated, the actual internal temperature of the freezer compartment 11B is not reflected in the control, so the operation of the cooling unit 15B and the cooling fan 26B is continued, and the freezer compartment 11B is cooled below the set temperature.
Conversely, in the refrigerator compartment 11A side, the internal temperature of the freezer compartment 11B side is input, and since the internal compartment temperature is being cooled as described above, the refrigerator compartment 11A side is considered to be in an excessively cooled state, In order to repair it, the defrost heater 30A on the side of the refrigerator compartment 11A is energized. However, what is detected is the internal temperature of the freezer compartment 11B, which is in a state of decreasing as described above, and it is not recognized that the temperature of the refrigerator compartment 11A has been raised, and the defrost heater The energization to 30A is continued. If it is left as it is, it leads to the runaway of the so-called defrosting heater 30A.

  Therefore, in this embodiment, after the refrigerator-freezer is operated, as shown in FIG. 4, the temperatures detected by the internal temperature sensors 29A and 29B are seen, and the defrost heater 30A is energized as described above. If it continues, the internal temperature by the side of the refrigerator compartment 11A will rise gradually, ie, the detection temperature of the internal temperature sensor 29A will rise, and if the detection temperature reaches "45 degreeC" which is stop temperature, both defrosting Energization of the heater 30, the defrost heater 30A on the side of the refrigerator compartment 11A that was actually energized, is stopped. Therefore, the defrosting heater 30A is not burned out and the surrounding members are not damaged. Moreover, before the temperature fuse with which the defrost heater 30A was equipped blows, electricity supply to the defrost heater 30A will be stopped.

The operation is continued even after the energization to the defrosting heater 30A is stopped as described above. In the meantime, the temperature rise on the refrigerator compartment 11A side is stopped, but the cooling continues further on the refrigerator compartment 11B side. Here, in this type of refrigerator-freezer, normally, both the refrigerator compartment 11A and the freezer compartment 11B issue an over-temperature alarm when the internal temperature of the refrigerator falls to a predetermined temperature. Therefore, here, the detected temperature on the freezer compartment 11B side is further lowered, and this is taken in as the refrigerator temperature on the refrigerator compartment 11A side. Is issued. This allows the user to know that there was at least some trouble.
In addition, you may make it issue the alarm to the effect that there exists a misconnection directly using the signal which forcibly stops the defrost heater 30 as mentioned above.

  As described above, according to the present embodiment, the temperature detected by both the internal temperature sensors 29A and 29B is monitored, and when either one becomes equal to or higher than the stop temperature, the energization to both the defrost heaters 30A and 30B is cut off. By such simple means, it is possible to prevent the defrost heater 30 from running away. Therefore, it is possible to prevent the defrosting heater 30 itself from being burned out and the surrounding members from being damaged. Further, it is possible to avoid disconnection of the thermal fuse provided in the defrosting heater 30, and the thermal fuse can be restarted without replacement.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the second embodiment, when the heater control program is further improved and the refrigerator-freezer is operated, the detected temperatures of both defrosting temperature sensors 31A and 31B are detected in addition to the detected temperatures of the internal temperature sensors 29A and 29B. When one of the detected temperatures rises to a predetermined stop temperature (45 ° C.) or higher, energization to both defrost heaters 30A and 30B is stopped.

  As described above, when the temperature detected by the defrost temperature sensor 31, that is, the temperature of the evaporator 20 reaches the defrost completion temperature (20 ° C. in the refrigerator compartment 11 A, 35 ° C. in the freezer compartment 11 B), the defrost is completed. However, if the detected temperature (temperature of the evaporator 20) is higher than the defrosting completion temperature such as “45 ° C.”, it is excessive in this case except for the defrosting operation. When the defrost heater 30 is energized to recover from the cold state, it is considered that the defrost heater 30 is about to run out of control. Energization to the heater 30A is stopped.

When the defrost heater 30 is continuously energized more than necessary, in the same room, the temperature of the evaporator 20 is usually higher than the internal temperature in the same room, so the temperature of the evaporator 20 is the internal temperature. Before reaching the stop temperature, the power supply to the defrost heater 30 is stopped based on the stop temperature. By stopping energization of the defrost heater 30 at a timing earlier than when depending on the internal temperature, burning of the defrost heater 30 and damage to surrounding members can be prevented more reliably. Of course, cutting of the thermal fuse is also prevented.
Further, it is also effective for guaranteeing the prevention of runaway of the defrost heater 30 when the detected temperature cannot be properly obtained from the internal temperature sensor 29 for some reason.
Note that the stop temperature related to the defrost temperature sensor 31 may be set to a value different from the stop temperature related to the internal temperature sensor 29 and viewed separately.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) Depending on the model, a drain heater that also serves as a duct is equipped with a duct heater, and the duct heater is operated in synchronism with the defrosting heater during defrosting operation or temperature rise in the cabinet. The present invention can be similarly applied.
(2) The present invention can also be applied to an apparatus provided with three or more storage chambers cooled to different cooling temperatures by individual cooling units.

(3) “45 ° C.” applied to the stop temperature related to the internal temperature sensor and the stop temperature related to the defrost temperature sensor is merely an example, and is optimal depending on the type of defrost heater and other conditions. What is necessary is just to set the temperature value.
(4) There is a type that controls the end of defrosting with the passage of time by a timer, but the present invention is also applicable to such a type.

1 is an external perspective view of a refrigerator-freezer according to Embodiment 1 of the present invention. Sectional view of the cooling unit installation Block diagram of operation control mechanism Flow chart showing heater control operation Block diagram of operation control mechanism in case of incorrect connection The flowchart which shows the operation | movement of the heater control which concerns on Embodiment 2. FIG. Block diagram of conventional operation control mechanism

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Main body 11A ... Refrigeration room (storage room) 11B ... Freezing room (storage room) 15, 15A, 15B ... Cooling unit (cooling device) 16, 16A, 16B ... Compressor 20 ... Evaporator 29, 29A, 29B ... Warehouse Internal temperature sensor 30, 30A, 30B ... defrost heater 31, 31A, 31B ... defrost temperature sensor 38 ... control board (control device) 40A, 40B ... input port

Claims (4)

A plurality of storage chambers formed in a thermally insulated state in the body,
A cooling device attached to each storage room;
An internal temperature sensor for detecting the internal temperature of each storage room;
A defrost heater disposed in the evaporator or in the vicinity thereof in each cooling device;
A single control device connected to each cooling device, each defrost heater and each internal temperature sensor;
Each of the storage rooms is maintained at a different cooling temperature by controlling the operation and stop of the corresponding cooling device based on the detection temperature of the internal temperature sensor,
For each of the storage chambers, when the cooling device is stopped and the defrost heater is energized, defrosting operation is performed, and when the temperature detected by the internal temperature sensor is lowered to a predetermined supercooling temperature. In a cooling storage with a function of energizing the corresponding defrost heater as being in an excessively cooled state,
Cooling, characterized in that heater control means is provided for stopping energization of all the defrosting heaters when one of the all-in-house temperature sensors detects a predetermined stop temperature or more. Storage. When a defrost temperature sensor for detecting the temperature of each evaporator or the vicinity thereof is provided and connected to the control device, and the temperature detected by the defrost temperature sensor rises to a predetermined defrost completion temperature during the defrost operation It is considered that the defrosting has been completed and has a function to end the defrosting operation,
The heater control means has a function of stopping energization of all the defrosting heaters when one of the total defrosting temperature sensors detects a predetermined stop temperature or more. The cooling storage according to claim 1, wherein The cooling storage according to claim 2, wherein the stop temperature related to the internal temperature sensor and the stop temperature related to the defrost temperature sensor are set to the same temperature. The defrost heater is equipped with a temperature fuse that is cut when the ambient temperature reaches a predetermined value or more, and the stop temperature is set to a temperature value before the temperature fuse is cut. The cooling storage box according to any one of claims 1 to 3.

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