JP2006071248A - Cooling storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the start of a compressor in restarting cooling operation after defrosting operation. <P>SOLUTION: An ambient temperature of a refrigerator detected by an ambient temperature sensor 35 is compared with a set temperature Y°C at a timing T of starting the next defrosting operation after the lapse of a predetermined X time from a starting time D1 of the last defrosting operation, and the start of defrosting operation is put off when the ambient temperature is higher than the set temperature. The defrosting operation is started first when the ambient temperature becomes lower than the set temperature (D2). As the ambient temperature is low, and the increase of load is kept low when the compressor 18 is started to restart the cooling operation after the termination of defrosting operation (timing t), the compressor 18 can be properly started, and continuously the cooling operation can be performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to control of a defrosting operation in a cooling storage.

In a commercial refrigerator or the like, a defrosting operation is performed several times (for example, every 6 hours) in a day using a 24-hour timer or the like (see, for example, Patent Document 1). The defrosting operation is performed by stopping the compressor constituting the refrigeration cycle and energizing and heating the heater provided in the cooler. During this time, when the temperature of the cooler is detected by the defrosting temperature sensor and reaches a predetermined temperature, it is considered that the defrosting has been completed, the heater is cut, and then the compressor is driven to resume the cooling operation. It has become.
JP-A-8-285441

Conventionally, since the defrosting operation is simply performed at regular time intervals, there are the following problems. That is, during the defrosting operation, since the cooler is heated by the heater as described above, the low-pressure pressure in the refrigeration circuit increases, and a large starting torque is required when the compressor is started. At this time, if the ambient temperature of the refrigerator is high, there is a circumstance that a larger load is applied. Therefore, if the ambient temperature is high at the timing when the defrosting operation is completed and the compressor is restarted, the compressor may not be started due to insufficient torque.
The present invention has been completed based on the above circumstances, and an object of the present invention is to ensure that the compressor is started when the cooling operation is resumed after the defrosting operation.

  As means for achieving the above object, the invention of claim 1 is characterized in that the refrigerant is supplied to the cooler by driving the compressor in the refrigeration cycle, and the cold air generated by heat exchange with the cooler is stored in the refrigerator. A cooling operation for cooling by circulation is performed, and a defrosting operation for removing frost by heating the cooler while the compressor is stopped is performed during the cooling operation. The cooling storage is characterized in that the temperature detection means for detecting the ambient temperature of the cooling storage is provided, and the control means for determining the defrosting operation mode based on the temperature detected by the temperature detection means is provided. Have

According to a second aspect of the present invention, in the first aspect, the defrosting operation mode is a start time of the defrosting operation, and the defrosting operation is not started at a time when the detected temperature is equal to or higher than a predetermined value. Is characterized in that the start time is determined.
According to a third aspect of the present invention, the defrosting operation is not started and the detected temperature is predetermined when the detected temperature is equal to or higher than a predetermined value at the scheduled start time of the defrosting operation. It is characterized in that the defrosting operation is started when it falls below.
According to a fourth aspect of the present invention, in the second aspect, in the case where the defrosting operation is performed a plurality of times in a constant cycle within one day, the ambient temperature on the day before the operating day of the cooling storage is set at predetermined intervals. This is characterized in that the start time of the defrosting operation is determined so that the time when the detected temperature is maximum and the maximum value of the detected temperature is taken is at the center of the cycle of the defrosting operation.

According to a fifth aspect of the present invention, in the first aspect, the defrosting operation mode is an execution time of the defrosting operation, and the execution time is shortened when the detected temperature is equal to or higher than a predetermined value. However, it has characteristics.
According to a sixth aspect of the present invention, in the apparatus according to the fifth aspect, the defrosting operation is performed a plurality of times in one day, while the temperature of the cooler is detected during the defrosting operation to detect the cooler temperature. In the case where heating of the cooler is stopped when a predetermined defrosting end temperature is reached, the ambient temperature on the day before the operating day of the cooling storage is detected and stored every predetermined time, and the defrosting operation is performed. In the case where the detected temperature at the start time is equal to or higher than a predetermined value, the defrosting end temperature related to the defrosting operation is set to be changed to be low.

According to a seventh aspect of the invention, in the fifth aspect, the defrosting operation is performed a plurality of times in one day, while the temperature of the cooler is detected during the defrosting operation to detect the cooler temperature. In the case where the heating of the cooler is stopped when a predetermined defrosting end temperature is reached, it is close to the time when the ambient temperature takes the minimum value in the non-business hours or the day before the operating day of the cooling storage. The defrosting operation executed at the time is characterized in that the defrosting end temperature is set higher than others.
The invention of claim 8 is characterized in that, in the invention of claim 4, claim 6 or claim 7, the detected temperature at each time is a predetermined number of integrated values.

<Invention of Claim 1>
When restarting the cooling operation after the defrosting operation and starting the compressor, if the ambient temperature of the cooling storage is high, the load may increase and cause a start failure of the compressor.
Therefore, in the first aspect of the present invention, the mode of the defrosting operation is determined based on the ambient temperature. For example, the load is reduced based on the increase in the low pressure in the refrigeration circuit and the total load caused by the ambient temperature. The defrosting operation is performed in such a manner. As a result, the compressor is reliably started to restart the cooling operation.

<Invention of Claim 2>
When the ambient temperature is equal to or higher than the predetermined temperature, the defrosting operation is not performed, and the defrosting operation is executed at a low temperature. Therefore, when the compressor is started when the cooling operation is restarted after the defrosting operation, the ambient temperature is low, and the load is reduced accordingly, so that the start of the compressor is ensured.
<Invention of Claim 3>
At the time when the defrosting operation is scheduled to start, if the ambient temperature of the cooling storage is greater than or equal to a predetermined value, it is postponed that the defrosting operation is started. When the compressor is started to resume the cooling operation after the defrosting operation is completed, the ambient temperature is surely low.

<Invention of Claim 4>
Based on the ambient temperature data of the previous day, the start time of the defrosting operation is set so as not to overlap the maximum value of the ambient temperature. Similarly, when the compressor is started to restart the cooling operation after the defrosting operation is completed, the ambient temperature is low.
In addition, with regard to the cooling storage, if the installation location is different, or if the business form of the installed restaurant or the like, and therefore the use form, is different, the change characteristics of the ambient temperature may be different. In the invention of claim 4, since it is based on the ambient temperature data of the previous day at the place where the cooling storage is actually placed, each cooling storage having different installation locations or different usage forms is handled with the same control. be able to. Even in the same refrigerated storage, the ambient temperature change characteristics may change, such as when the air temperature is turned off outside business hours in summer, etc., and the ambient temperature becomes higher than during busy hours, etc. Based on the temperature data, it is possible to respond accurately even when the change characteristics of the ambient temperature change due to the change of seasons.

<Invention of Claim 5>
When the ambient temperature is equal to or higher than the predetermined temperature, the defrosting operation is entered, but the execution time is shortened. That is, the shortening of the heating time suppresses the rise in the temperature of the cooler, and consequently the rise in the low pressure in the refrigeration circuit, thereby reducing the total load and ensuring the start of the compressor.
<Invention of Claim 6>
If the ambient temperature at the start time of the defrosting operation is greater than or equal to a predetermined value based on the ambient temperature data of the previous day, the defrosting end temperature related to the defrosting operation is set low. Therefore, in the defrosting operation, the heating time is shortened, and as a result, the increase of the low pressure in the refrigeration circuit is suppressed, and the total load can be reduced.
In addition, because it is based on the ambient temperature data of the previous day, it is possible to respond to the individual cooling storage units with different installation locations and usage patterns with the same control. Even if the change characteristics of the change, it can be handled accurately.

<Invention of Claim 7>
If the ambient temperature is likely to be high, the defrosting end temperature is set low to reduce the heating time of the cooler, which in turn suppresses the increase in low-pressure pressure in the refrigeration circuit. Reduction is achieved. That is, control is performed to give priority to the start of the compressor.
On the other hand, in the defrosting operation that is performed when the ambient temperature is considered to be low due to detection during non-business hours or the previous day, the defrosting end temperature is set high, so the heating time is long and the cooler is hot. Thus, frost formation is reliably removed not only in the cooler but also in the peripheral portion. As the cooler becomes hot, the low-pressure pressure also rises, but since the ambient temperature is low, this is also suppressed to a small total load, and there is no problem in starting the compressor. That is, when the ambient temperature is low, defrost priority control is performed in which complete defrosting is performed by increasing the defrosting end temperature.
<Invention of Claim 8>
In order to obtain the change data of the ambient temperature of the previous day, the integrated value was used as the detected temperature at each time, so if there was a sudden temperature change, it was absorbed and more accurate as the ambient temperature change data. You can get things.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the refrigerator according to the present embodiment has a refrigerator main body 10 composed of a vertically long heat insulating box with a front opening, and is supported by four legs 11 provided on the bottom surface. It is a storage room 12. A heat insulating door 13 is attached to the opening of the front surface of the storage chamber 12 so as to be swingable. A refrigeration unit 15 is installed on the upper surface of the main body 10 so as to close the window hole 14 opened in the ceiling wall. The refrigeration unit 15 is mounted with a refrigeration device 17 including a compressor 18, a condenser 19 with a fan 19A, and the like mounted on the upper surface of the heat insulating base 16, and a cooler 20 suspended from the lower surface side. The refrigeration apparatus 17 and the cooler 20 are circulated and connected by a refrigerant pipe to form a known refrigeration cycle.

A drain pan 22 also serving as an air duct is stretched on the lower surface side of the window hole 14 in the ceiling portion of the storage chamber 12, and a cooler chamber 23 is formed above the drain pan 22. The cooler chamber 23 accommodates the cooler 20 described above, and a suction port 24 is provided on the front side (left side in FIG. 1) of the drain pan 22 and a cooling fan 25 is provided. Is provided with an air outlet 26.
For the defrosting operation, a defrosting heater 27 is attached to the cooler 20, and a drainage channel 28 connected to the outlet 22 </ b> A of the drain pan 22 is formed in the wall surface of the main body 10.

  The operation of the refrigerator is controlled based on a predetermined program. Therefore, as shown in FIG. 2, a control device 30 including a microcomputer, a timer 31 and the like and storing the program is provided. ing. Connected to the input side of the control device 30 are an internal temperature sensor 33 that detects the internal temperature and a defrost temperature sensor 34 that functions to detect the temperature of the cooler 20 and to determine that the defrosting is complete. Has been. On the other hand, the compressor 18, the condenser fan 19A, the cooling fan 25, and the defrost heater 27 in the refrigeration apparatus 17 are connected to the output side.

  The basic operation will be described. In the cooling operation, the cooling fan 25 is driven while the compressor 18 and the condenser fan 19 </ b> A in the refrigeration apparatus 17 are operated, and the indoor air in the storage chamber 12 is sucked into the suction port 24 by the cooling fan 25. Is sucked into the cooler chamber 23, and cold air is generated by heat exchange while the air flows through the cooler 20, and the cold air is blown out from the outlet 26 along the inner surface of the storage chamber 12. Thus, cold air is circulated and supplied into the storage chamber 12. Meanwhile, the internal temperature is detected by the internal temperature sensor 33, and the compressor 18, the condenser fan 19A, and the cooling fan 25 are driven based on whether the detected temperature is higher or lower than a predetermined set temperature. Alternatively, the interior of the storage chamber 12 is maintained substantially at the set temperature by being stopped.

  During the cooling operation, as will be described in detail later, a defrosting operation is performed to remove frost attached to the cooler 20 and the like. This defrosting operation is performed by energizing and heating the defrost heater 27 with the compressor 18, the condenser fan 19 </ b> A, and the cooling fan 25 stopped, and the defrost water is received by the drain pan 22. After that, the water is drained out of the warehouse through the drainage channel 28 provided in the wall surface of the main body 10. If it is determined that the defrosting has been completed by the temperature detected by the defrosting temperature sensor 34, the defrosting heater 27 is de-energized, the defrosting operation is terminated, and the cooling operation is resumed.

In this embodiment, when restarting the cooling operation after the defrosting operation, the operation program is improved in order to reliably start the compressor 18. In short, when the ambient temperature at the installation position of the refrigerator is equal to or higher than a predetermined temperature at the scheduled start timing of the defrosting operation, the defrosting operation is not started and the defrosting is not performed until the ambient temperature decreases. Control is performed so that operation is started. Therefore, an ambient temperature sensor 35 is provided as means for detecting the ambient temperature, and is connected to the input side of the control device 30.
In this embodiment, the defrosting operation is basically executed every X hours (for example, 6 hours). Moreover, the set temperature Y ° C. of the ambient temperature that determines the suitability of the start of the defrosting operation is determined as follows. That is, as shown in FIG. 3, the ambient temperature at which the compressor 18 cannot be started, that is, the starting limit temperature is obtained empirically, and in view of providing a detection error and a margin, a predetermined temperature is determined from the starting limit temperature. The set temperature Y ° C. described above is set at a low temperature.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. 4 and the timing chart of FIG.
When the cooling operation is executed in step S10 and X hours have elapsed from the start time D1 of the previous defrosting operation (step S11 is “Yes”: timing T), the detected temperature detected by the ambient temperature sensor 35 is the set temperature Y. Compared to ° C. For example, when the timing T is busy during the day, the ambient temperature of the refrigerator placed in the kitchen tends to increase due to an increase in the amount of firearms used in the kitchen. Therefore, when the detected temperature of the ambient temperature is equal to or higher than the set temperature Y ° C. (Step S12 is “No”), the defrosting operation is not started and the cooling operation is continued.

  As shown in comparison with FIG. 5B, when the defrosting operation is started at the timing T described above, the cooler 20 is heated by the defrost heater 27, so that the low pressure in the refrigeration circuit is reduced. When the compressor 18 is restarted to rise and return to the cooling operation, there is a circumstance that a large starting torque is required. At this time, if the ambient temperature of the refrigerator is high, a larger load is applied and the compression is performed. There is concern that the machine 18 cannot be restarted. In addition, during the defrosting operation, if the ambient temperature is high, the amount of heat entering the cabinet also increases, and the door 13 often opens and closes during busy periods, so the chamber temperature tends to rise, and as described above If the compressor 18 cannot be started, the internal temperature rises significantly as indicated by the broken characteristic line, which may damage the stored items.

On the other hand, in this embodiment, when the detected temperature of the ambient temperature at the timing T is equal to or higher than the set temperature Y ° C. as described above, the compressor 18 is restarted when the defrosting operation is finished and the cooling operation is restarted. Considering that there is a possibility that it cannot be performed, the cooling operation is continued without switching to the defrosting operation (step S10).
After that, for example, when the busy time ends and the α time has elapsed from the above timing T, when the detected temperature of the ambient temperature falls below the set temperature Y ° C. (step S12 is “Yes”), the defrosting operation is performed in step S13. Be started. That is, the defrosting operation is started when (X + α) time has elapsed from the previous defrosting start time D1 (time D2).

  The defrosting operation is performed by energizing and heating the defrosting heater 27 in a state where the compressor 18, the condenser fan 19A, and the cooling fan 25 are stopped. In the meantime, the temperature of the cooler 20 is detected by the defrost temperature sensor 34. When the temperature of the cooler 20 rises to a predetermined temperature, it is considered that the defrosting is finished, and the defrost heater 27 is turned off, and then the predetermined temperature is reached. The defrosting operation is finished after the water draining time (step S14), and the process proceeds to the cooling operation of step S10. At this time, first, a pre-cooling operation in which only the compressor 18 and the condenser fan 19A are started is performed, and the cooling fan 25 is started after a predetermined time delay, whereby the cooling operation is resumed in earnest.

Although the low temperature pressure in the refrigeration circuit is increasing at the timing t when the cooling operation is restarted, specifically, the precooling operation is started, the ambient temperature is lower than the set temperature Y ° C. The increase in load is kept small, and the compressor 18 is started well.
In addition, since the defrosting operation is started when the ambient temperature becomes low after the end of the busy period, the amount of heat entering the cabinet can be suppressed, the rise in the cabinet temperature can be suppressed, and defrosting can be performed. After the completion, the pre-cooling operation is promptly performed with the start-up of the compressor 18 as described above, so that the internal temperature tends to decrease. That is, the internal temperature does not rise excessively.

When the cooling operation is continued and X hours have elapsed from the start time D2 of the previous defrosting operation (step S11 is “Yes”: time D3), the detected temperature of the ambient temperature sensor 35 is again compared with the set temperature Y ° C. If the detected temperature of the ambient temperature is lower than the set temperature Y ° C. (eg, “Yes” in step S12), for example, because it is out of the busy time, the defrosting operation is started in step S13.
When the defrosting operation is completed in the same manner as described above, the cooling operation is resumed following the pre-cooling operation, but the compressor 18 is started well due to the low ambient temperature.
Thereafter, the operation control described above is repeatedly performed.

As described above, in the first embodiment, at the time when the defrosting operation is scheduled to start, if the ambient temperature of the refrigerator is equal to or higher than the set temperature Y ° C, it is postponed that the defrosting operation is started, and then the ambient temperature is set. The defrosting operation starts only after the temperature falls below. Therefore, when the compressor 18 is started to restart the cooling operation after the defrosting operation is finished, an increase in load is suppressed in a situation where the ambient temperature is low, and the compressor 18 is started well. The cooling operation can be continued.
In addition, since the defrosting operation is started when the ambient temperature becomes low, the amount of heat intrusion into the chamber is suppressed, the rise in the chamber temperature is also suppressed, and the compression is performed as described above after the defrosting is completed. As the cooling operation (pre-cooling operation) is promptly performed with the startup of the machine 18, the internal temperature tends to decrease. That is, the internal temperature does not rise excessively, and thus it is reliably prevented that the stored item is damaged.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, the start time of the defrosting operation is determined based on the ambient temperature of the refrigerator as in the first embodiment, but the specific means are different.
As already mentioned, the ambient temperature of a commercial refrigerator installed in a restaurant kitchen etc. depends on the business type of the restaurant, but tends to peak at a specific time, such as during busy hours. Yes, if the defrosting operation is executed at this time, the start-up may fail when the compressor 18 is started to restart the cooling operation.

In the second embodiment, based on the ambient temperature data of the previous day, the start time is shifted and set so that the start time of the defrosting operation does not overlap with the vicinity of the peak of the ambient temperature.
Therefore, as shown in FIG. 6, the ambient temperature sensor 35 that detects the ambient temperature of the refrigerator, the storage means 40 that stores the detected temperature, and the start time of the defrosting operation are determined based on the stored data. The start time determination means 41 is provided, and the start time determined by the determination means is rewritten to an operation program including a defrosting operation. The defrosting operation is executed four times every 6 hours in one day.

Specifically, the ambient temperature data of the previous day detected by the ambient temperature sensor 35 is stored in the storage unit 40. The data is, for example, the ambient temperature detected every 30 minutes from 0 o'clock to 23:30 on the previous day, as shown in FIG.
When the last data is taken in at 23:30 on the previous day, the start time determining means 41 captures the time when the maximum temperature of the previous day was taken, and that time is from the start of one defrosting operation. All four start times are determined so as to come to the center of one cycle (6 hours) until the start of the next defrosting operation.

For example, as shown in FIG. 7, when the maximum value of the ambient temperature (for example, 35 ° C.) is detected at 20:30, the maximum value is taken so that the same time comes to the center of the defrost cycle. The time 17:30 and 23:30, 3 hours before and after 20:30, were determined as the start time of the defrosting operation, and 6:30 were sequentially placed from 17:30. Minutes and 5:30 are determined as the remaining start times.
The four start times determined in this way are rewritten into the operation program immediately before, for example, 0:00 of the day.

  Therefore, the defrosting operation is started at 5:30, 11:30, 17:30, and 23:30 on the day. The contents of the defrosting operation are the same as those described in the first embodiment, and after the completion, the compressor 18 is started to restart the cooling operation. Here, the start time of the defrosting operation in the vicinity where the ambient temperature reaches the maximum value is large before and after the time when the ambient temperature reaches the maximum value (20:30), such as 17:30 or 23:30. Since it is set to be distributed at a distance, the ambient temperature at the end of each defrosting operation is at a relatively low temperature such as 20 to 25 ° C., the increase in load is suppressed small, and the compressor 18 is good. Will be launched.

  According to the second embodiment, the start time of the defrosting operation is set so as not to overlap with the vicinity of the peak of the ambient temperature, based on the ambient temperature data of the previous day. Therefore, as in the first embodiment, when the compressor 18 is started to finish the defrosting operation and restart the cooling operation, the increase in load is suppressed to be small in a situation where the ambient temperature is low. 18 can be started well and can continue to the cooling operation. Similarly, since the defrosting operation is started when the ambient temperature becomes low, the rise in the internal temperature is also suppressed, and after the defrosting is completed, the cooling operation (precooling operation) is performed with the start of the compressor 18. By being carried out promptly, the internal temperature tends to decrease, thereby preventing an excessive increase in the internal temperature and surely preventing the stored item from being damaged.

  In addition, when the compressor 18 is started to restart the cooling operation, the high-temperature protection device does not operate unnecessarily because the high-pressure pressure of the refrigeration circuit is low because the ambient temperature is low. Further, the current of the compressor 18 becomes small and the current protection device does not operate unnecessarily, and the accompanying effects such as reduction of power consumption can be obtained.

As for the refrigerator, if the installation location is different, or the business form of the installed restaurant, that is, the use form, the ambient temperature change characteristics may be different. In this embodiment, the refrigerator is actually placed. Since the start time of the defrosting operation is determined based on the ambient temperature data of the previous day at the new location, it is possible to cope with the same control for each refrigerator having a different installation location or different usage pattern.
Furthermore, even in the same refrigerator, the time when the ambient temperature peaks may change, such as when the ambient temperature becomes higher than during busy hours due to, for example, turning off air conditioning outside of business hours in summer, etc. Based on the ambient temperature data, it is possible to accurately cope with changes in ambient temperature change characteristics due to changes in seasons.

<Embodiment 3>
The third embodiment should also be referred to as a modification of the second embodiment. In the second embodiment, the ambient temperature data of the previous day is obtained by a pin spot at a specific time, whereas in the third embodiment, the ambient temperature data is obtained by the integrated value. .
Specifically, as shown by a chain line in FIG. 6, an integration unit 43 is interposed between the ambient temperature sensor 35 and the storage unit 40. The integration means 43 integrates 30 detected temperatures every minute for the first 30 minutes each time the hour comes from 0 o'clock, 1 o'clock, 2 o'clock, and so on. The integrated value is stored in the storage means 40 as the detected temperature at that time.

When the data for 23 o'clock of the previous day is taken in, the start time determination means 41 captures the time when the maximum value of the integrated value of the ambient temperature of the previous day is taken, and that time is the next from the start of one defrosting operation. All four start times are determined so as to come to the center of one cycle (6 hours) until the start of the defrosting operation.
Specifically, it is assumed to be four times, the time obtained by subtracting 3 hours from the time when the maximum value of the integrated value of the ambient temperature is taken, and the time obtained by subtracting 6 hours from that time until the numerical value is 0 or positive. . In addition, when only 3 times are obtained by the above calculation, the time obtained by adding 3 hours to the time of taking the maximum integrated value is set to 4 times for convenience.
For example, if the time when the maximum integrated value is taken is 21:00, the start time of the defrosting operation is 4 times, 18:00, 12:00, 6:00, and 0:00.
The four start times determined in this way are rewritten into the operation program immediately before, for example, 0:00 of the day.

Subsequent actions and effects are the same as those in the second embodiment.
Especially in the third embodiment, in order to obtain the change data of the ambient temperature on the previous day, since the integrated value within a predetermined time is set as the detected temperature at each time, this is absorbed when there is a sudden temperature change, More accurate data on changes in ambient temperature can be obtained.

<Embodiment 4>
A fourth embodiment of the present invention will be described with reference to FIGS.
In the fourth embodiment, when the cooling operation is restarted after the defrosting operation, it is the same that the compressor 18 is surely started, but the specific means are different.
As described above, the start-up failure of the compressor 18 is a concern because the low-pressure pressure in the refrigeration circuit increases as the cooler 20 is heated by the defrost heater 27 during the defrosting operation. This is because the load increases when the ambient temperature is high.
Therefore, the basic idea of the fourth embodiment is that when the ambient temperature is high, the defrosting time is shortened, that is, the heating time by the defrosting heater 27 is shortened to increase the temperature of the cooler 20, and thus the low pressure in the refrigeration circuit. The increase in pressure is suppressed, and the total load is reduced, so that the compressor 18 is reliably started.

The defrosting operation will be described again with additional information. The defrosting operation is performed by energizing and heating the defrosting heater 27 in a state where the compressor 18, the condenser fan 19 </ b> A, and the cooling fan 25 are stopped. Done. During this time, if the temperature of the cooler 20 is detected by the defrost temperature sensor 34 and the temperature of the cooler 20 rises to 0 ° C., the frost formation on the cooler 20 can be regarded as melted. However, there is frost on the periphery of the cooler 20, for example, the cooling fan 25 (fan cover), etc. In order to remove this frost, energization to the defrost heater 27 is continued for a while and the temperature rises. The surrounding frost is melted by the heat radiation from the cooler 20. And if the time when the temperature of the cooler 20 rises to a predetermined value has elapsed, it is considered that the surrounding frost has melted by that time.
Therefore, depending on the model, if it is detected that the temperature of the cooler 20 has reached, for example, 35 ° C., it is considered that frost has been removed from the cooler 20 including its peripheral portion, and The energization is turned off, and the defrosting operation is completed after a predetermined draining time. After that, a pre-cooling operation in which only the compressor 18 and the condenser fan 19A are started is performed, and the cooling fan 25 is started after a predetermined time delay, so that the cooling operation is resumed in earnest.

  In the fourth embodiment, it is assumed that the defrosting operation is executed four times within a day, for example, at predetermined times (5 o'clock, 11 o'clock, 17 o'clock and 23 o'clock) every 6 hours. ing. And the detection temperature of the cooler 20, in order to stop energization to the defrost heater 27, what is called defrost end temperature is provided with normal 35 degreeC and 20 degreeC lower than that, Program of each defrost operation Can be set individually. If the defrosting end temperature is lower, 20 ° C., the energization time to the defrosting heater 27 is shortened, the temperature rise of the cooler 20 is suppressed, and consequently the low pressure of the refrigeration circuit is also increased. It will be suppressed.

In particular, based on the ambient temperature data of the refrigerator installation location, the defrosting end temperature is set to a normal 35 ° C. only when the ambient temperature is low, and when the ambient temperature is high, the defrosting is completed. The temperature is set to 20 ° C.
Therefore, as shown in FIG. 8, the ambient temperature sensor 35 for detecting the ambient temperature of the refrigerator, the storage means 40 for storing the detected temperature, and the defrosting end temperature in each defrosting operation based on the stored data. And a defrosting end temperature determining means 45 for determining the defrosting end temperature determined by the determining means 45 are set in each defrosting operation program in the operation program.

Specifically, the ambient temperature data of the previous day detected by the ambient temperature sensor 35 is stored in the storage unit 40. For example, as in the second embodiment, the data is the ambient temperature detected every 30 minutes from 0 o'clock to 23:30 on the previous day, as shown in FIG. 9.
When the last data is taken in at 23:30 on the previous day, the defrosting end temperature determining means 45 catches the time when the minimum value of the ambient temperature of the previous day is taken and starts at a time close to that time 1 For defrosting operation twice or twice, the defrosting end temperature is set to 35 ° C, and for the other two or three defrosting operations, the defrosting end temperature is set to 20 ° C. The

  As shown in the figure, the ambient temperature usually tends to be high during business hours in which a firearm or the like is used in the kitchen and low outside business hours. And, for example, if the minimum value of the ambient temperature is detected at 8 o'clock, in the two defrosting operations that start at 5 o'clock and 11 o'clock, the defrosting end temperature is set to 35 ° C, and the other two times For the defrosting operation that starts at 17:00 and 23:00, the defrosting end temperature is set to 20 ° C. This setting is made for the driving program immediately before 0:00 of the day, for example.

  When the defrosting operation is performed four times on the same day, the defrosting operation that is started at 17:00 and 23:00, particularly during business hours, is performed as follows. As described above, the defrosting operation is performed by energizing and heating the defrosting heater 27 while the compressor 18 (condenser fan 19A) and the cooling fan 25 are stopped. Meanwhile, the temperature of the cooler 20 is detected by the defrost temperature sensor 34, and the defrost heater 27 is turned off particularly when the temperature of the cooler 20 rises to 20 ° C. (defrost end temperature). Thereafter, the defrosting operation is completed after a predetermined draining time. After that, the operation is shifted to the cooling operation. First, a pre-cooling operation in which only the compressor 18 (condenser fan 19A) is started is performed, and the cooling fan 25 is started after a predetermined time delay, so that the cooling operation is performed in earnest. Will be resumed.

  During the two defrosting operations, the ambient temperature is high because it is during business hours. On the other hand, in these two defrosting operations, the defrosting end temperature is set to 20 ° C., so the heating time of the cooler 20 by the defrost heater 27 is shortened, and the temperature of the cooler 20 rises. As a result, an increase in the low pressure in the refrigeration circuit can be suppressed. As a result, the total load can be reduced, and the compressor 18 can be started well when the cooling operation is resumed. In short, when the ambient temperature is high, for example, even if the defrosting of the peripheral portion of the cooler 20 is left uncontrolled, the temperature rise of the cooler 20, that is, the rise of the low pressure is suppressed, and the start of the compressor 18 is given priority. Is done.

  On the other hand, in the other two defrosting operations, since the defrosting end temperature is set to 35 ° C., the heating time is long and the cooler 20 becomes high temperature. Frost is reliably removed. As the cooler 20 becomes hot, the low pressure increases, but the ambient temperature is low. Therefore, the total load is also kept small, and there is no problem in starting the compressor 18. That is, when the ambient temperature is low, defrost priority control is performed in which complete defrosting is performed by raising the defrosting end temperature.

Note that the ambient temperature usually increases during business hours as exemplified above, so it may be sufficient if the defrost end temperature is set low during the defrosting operation during business hours. However, the ambient temperature may be higher during non-business hours than during business hours due to, for example, turning off air conditioning outside business hours in summer, etc., so that defrosting is completed only during defrosting during business hours. If the temperature is set to be low, the compressor 18 may not be able to be started after the defrosting operation is finished outside business hours when the ambient temperature is high.
In this regard, in this embodiment, based on the ambient temperature data of the previous day, the low defrost pressure of the refrigeration circuit is set by setting the defrosting end temperature to 20 ° C. when the ambient temperature is high regardless of the business hours during the business hours. Therefore, after the defrosting operation is completed four times, the compressor 18 can be started up satisfactorily.

<Related technology 1>
Related Art 1 will be described with reference to FIGS. 10 and 11.
First, an operation during a normal defrosting operation will be described with reference to FIG. Defrosting is started by energizing the defrosting heater 27 in a state where the compressor 18 and the cooling fan 25 are stopped. The heat of the defrost heater 27 is initially used to melt the frost formation of the cooler 20, and the frost is melted while the temperature of the cooler 20 gradually increases. When the temperature reaches around 0 ° C., the state of the cooler 20 stops at 0 ° C. because frost changes to water. When the frost of the cooler 20 becomes completely water, the cooler 20 becomes a heat source this time, and while the temperature gradually rises, the heat dissipates and warms the peripheral parts of the cooler 20 such as the fan cover of the cooling fan 25 to form frost. Melt. And if it detects that the temperature of the cooler 20 became 35 degreeC (it is arbitrary with a machine), electricity supply to the defrost heater 27 will be cut | disconnected and defrost will be complete | finished. After that, after 10 minutes (arbitrary) draining time, the precooling operation for cooling the cooler 20 is performed by starting the compressor 18 with the cooling fan 25 stopped, and cooling is performed after 5 minutes (arbitrary). The fan 25 is activated and the cooling operation is resumed.

By the way, the frost of the fan cover or the like is melted by the heat of the cooler 20 as described above. To completely melt the frost, the temperature of the cooler 20 is increased after the frost of the cooler 20 is melted. A certain amount of time is required until 35 ° C. is detected. If the temperature reaches 35 ° C. quickly and the defrosting is completed, the frost cannot be melted without the heat of the cooler 20 being transmitted to the fan cover. Therefore, the number of watts of the defrost heater 27 is suppressed, and the cooler 20 is slowly heated to gain time.
However, this method, on the other hand, results in heating the cooler 20 for an unnecessarily long time, so that the low-pressure pressure in the refrigeration circuit increases, and a so-called load increases when starting the compressor 18 to restart the cooling operation. There was a case where it could not be started due to hanging.

Therefore, in the related technique 1, as shown in FIG. 10A, the number of W of the defrost heater 27 can be switched between large and small by the PWM method or the like. The smaller W number is the same as the conventionally used W number.
When defrosting is started, initially, the W number of the defrost heater 27 is increased. If it does so, as shown to the same figure (B), the frost of the cooler 20 will be thawed at high speed, ie, a short time. When the frost of the cooler 20 melts and the cooler 20 temperature reaches 2 ° C., the W number of the defrost heater 27 is switched to a smaller value. As a result, the temperature of the cooler 20 rises while taking a certain amount of time as in the conventional case. During this time, the frost around the cooler 20 is melted, and when the temperature of the cooler 20 reaches 35 ° C., the removal is performed. The energization to the frost heater 27 is cut off.

That is, in the related art 1, it takes time for the cooler 20 to rise from 0 ° C. to 35 ° C. in order to melt the frost around the fan cover or the like. Regardless of the time, it is made in view of the fact that the temperature of the cooler 20 is sufficiently melted as long as the temperature of the cooler 20 reaches 35 ° C. In the latter half, which contributes to the defrosting of the surroundings, the temperature is increased over a certain amount of time by changing to a small W number. As a result, the entire defrosting time (heater energization time) can be shortened by the amount of time required to remove the frost formation on the cooler 20.
As a result, the cooler 20 is not heated more than necessary, the increase in the low pressure of the refrigeration circuit is suppressed, the starting failure of the compressor 18 is not caused, and the increase in the internal temperature is also suppressed. be able to.

<Related technology 2>
Next, related technology 2 will be described with reference to FIGS.
In the related technique 2, as described above, in the refrigerator in which the defrosting operation is performed a plurality of times at predetermined time intervals in the day, it is unnecessary based on the information on the number of times the refrigerator door is opened and closed. In this case, it is intended not to perform the defrosting operation.
Conventionally, as described above, a defrosting operation is performed a plurality of times every several hours in a day using a 24-hour timer or the like, but frost growth is not taken into consideration, and therefore Although there is a case where defrosting operation is performed even though there is almost no frost formation, there is a problem that not only wasteful electric power is consumed but also an unnecessary temperature rise is added to stored foods and the like.

  Here, in the refrigerator, when the door is opened, air containing moisture enters the cabinet and adheres to the cooler as frost when dehumidified. Therefore, if the door is opened and closed frequently, the air containing a large amount of moisture enters the cabinet, so that the growth of frost becomes intense. Conversely, if the number of opening and closing is small, the growth of frost is small. That is, the open / close state of the door can be used as a measure for measuring the frost growth state, and in Related Technology 2, the necessity of the defrosting operation is determined based on the number of times of opening / closing the door.

  This will be specifically described. In particular, in the description of the drawings, portions having the same functions as those of the first embodiment are appropriately given the same reference numerals. As shown in FIG. 12, the refrigerator is provided with two upper and lower doors 13 at the entrance of the front surface of the main body 10, and a drain pan 22 that also serves as a duct is stretched on the ceiling in the main body 10, thereby cooling the cooler chamber 23. Is formed, and the cooler 20 is accommodated therein, and is circulated and connected to the refrigeration apparatus 17 installed on the upper surface of the main body 10 to constitute a refrigeration cycle. A cooling fan 25 is installed at the end on the near side of the duct 22, and an outlet 26 is opened on the back side. The refrigerator is operated based on a program stored in the control device in the electrical box 50, and the refrigerator is located at a position facing the air blowing area A of the cooling fan 25 on the ceiling surface of the cooler chamber 23. An internal temperature sensor 33 that detects the temperature is provided.

  The cooling operation is performed by driving the compressor 18 of the refrigeration apparatus 17, and the internal air is sucked into the cooler chamber 23 by the cooling fan 25 and generated by heat exchange while flowing through the cooler 20. The chilled air is circulated and circulated so as to be blown out from the outlet 26 into the cabinet. Meanwhile, the internal temperature is detected by the internal temperature sensor 33, and the compressor 18 and the cooling fan 25 are driven or stopped based on whether the detected temperature is higher or lower than a predetermined set temperature. As shown in FIG. 13, the interior of the cabinet is maintained at a substantially set temperature. In the middle of this cooling operation, for example, the start timing of the defrosting operation is set four times every 6 hours in one day. For example, the defrosting operation is performed by energizing and heating the defrosting heater 27 provided in the cooler 20 in a state where the compressor 18 and the cooling fan 25 are stopped. When it is detected by the defrost temperature sensor 34 that the temperature of the cooler 20 has risen above a predetermined level, it is considered that the defrost has been completed including the surroundings, and the defrost heater 27 is de-energized and the defrost operation is completed. Then, the cooling operation is resumed.

In the related technique 2, as described above, whether or not the defrosting operation is necessary is determined based on the number of times the door 13 is opened and closed. Therefore, a door opening / closing detection device is provided. This detection device detects opening and closing of the door 13 by a change in the internal temperature.
As shown in FIG. 13, when the refrigerator door 13 is in a closed state, the compressor 18 (cooling fan 25) is repeatedly turned on and off so that the inside temperature becomes the set temperature. While the inside temperature is lowered and is turned off, it rises due to heat intrusion from the outside. Here, when the door 13 is opened, high-temperature air directly enters the interior, so that the temperature rises more rapidly than when the door 13 is closed. Thereafter, when the door 13 is closed, the temperature rise stops and starts to fall. Opening / closing of the door 13 is detected by capturing this rapid temperature change.

More specifically, the internal temperature sensor 33 detects the internal temperature and always calculates the gradient of the temperature change. If this inclination exceeds a certain level, it is detected that there is a sudden rise in the internal temperature, that is, the door 13 is opened. After that, when the gradient turns negative (when the temperature starts to decrease), it is detected that the door 13 is closed, and it is counted that the door 13 has been opened and closed once and is input to the counter.
Note that the refrigerator for business use is usually made of a stainless material, and a large amount of food is always stored in the refrigerator, that is, the heat capacity in the refrigerator is considerably large. On the other hand, the heat capacity of the air (outside air) flowing into the cabinet when the door 13 is opened is small.
However, as shown in FIG. 12, since the internal temperature sensor 33 is arranged to face the air blowing area A of the cooling fan 25, the temperature of the inflowing air can be detected with high sensitivity and a sudden temperature rise can be detected. After that, when the door 13 is closed, the internal heat capacity is large as described above, and the temperature is not increased. Therefore, the air having a low heat capacity is cooled at once. The decrease in temperature is slightly slower than the above increase in temperature, but has a considerable slope.
As a result, the rise and fall of the internal temperature can be accurately detected, and can be recognized as the opening / closing operation of the door 13.

An example of operation control will be described with reference to FIG. As described above, when the opening / closing operation of the door 13 is detected, it is input to the counter each time. Moreover, the opening / closing frequency | count of the door 13 considered to be frosting more than fixed is set (n times).
When the power is turned on, the counter is reset, and then the cooling operation is performed as described above. Meanwhile, if opening / closing of the door 13 is detected, it is counted by a counter. When the cooling operation progresses and the start timing of the predetermined defrosting operation comes, the number of times of opening and closing the door 13 counted so far is compared with the set value n. The defrosting operation is carried out. After completion, the cooling operation is resumed after the counter is reset.

On the other hand, if the opening / closing frequency of the door 13 is less than the set value n at the start timing of the defrosting operation, the cooling operation is continued with the defrosting operation skipped once. The counter is not reset, and the count continues to wait for the start timing of the next defrosting operation.
That is, in the related technique 2, when the frost formation is small and the defrosting is unnecessary, the execution of the defrosting operation can be canceled, so that it is possible to prevent wasteful power consumption and temperature rise in the cabinet. it can.

  As shown in FIG. 15, a dedicated temperature sensor 52 for detecting opening / closing of the door 13 may be provided at the upper edge of the entrance / exit 13 </ b> A of the refrigerator body 10. At this position, it is easy to be affected by heat outside the cabinet when the door 13 is opened, and the temperature change when the door 13 is opened and closed can be greatly measured. Therefore, the detection accuracy of opening and closing of the door 13 is improved.

Moreover, you may make it detect the influence degree of the heat | fever penetration | invasion into a store | warehouse | chamber other than the detection of the opening / closing operation | movement of the door 13 by the information from the chamber temperature sensor 33. FIG.
The detection method of the influence level memorizes the temperature when the door 13 is opened. After the temperature rises as the door 13 opens, the temperature of the door 13 that is memorized decreases when the door 13 is closed. The time required for the temperature to drop to the opening temperature is stored as an influence level.
This time becomes longer as the temperature difference between the ambient temperature and the inside of the warehouse is larger, because there is more heat penetration, and conversely, it becomes shorter when the temperature difference is small. The longer the opening time, the longer the influence time, while the shorter the opening time, the shorter the influence time, reflecting the time when the door 13 is open and the heat has entered. Therefore, the time of the influence degree can be used as a standard for knowing the total amount of heat intrusion by opening and closing the door 13 once.

  With regard to this related technology 2, the time of the above influence degree indicates the amount of heat penetration, but in general, moisture also penetrates at the same time as heat, so it is used as a guide for indicating the amount of moisture penetration into the chamber. You can also Accordingly, this degree of influence is accumulated every hour, and if it is not equal to or greater than a certain threshold value, it is determined that the amount of frost formation is small, and the defrosting operation is not started even at the start timing of the defrosting operation. If the defrosting operation is performed only when the threshold value is exceeded, unnecessary defrosting operation can be avoided, which is effective for energy saving and food protection in the warehouse.

Further, the opening / closing information of the door 13 described above can be used for the following.
Depending on the model, there is a type in which the cooling fan 25 is continuously driven during the cooling operation. However, if the opening operation of the door 13 can be detected, for example, the refrigeration apparatus 17 is stopped when the door 13 is opened. The cooling fan 25 can be controlled to stop when it is. As a result, it is possible to prevent the cool air from being discharged to the outside of the storage.
If the refrigerator is equipped with an inverter compressor and a condenser whose capacity can be controlled, for example, during busy hours such as lunchtime or dinnertime, that is, when the door 13 is frequently opened and closed, cooling is performed so that the inside temperature can be maintained. It can also be used for control such as increasing capacity.

If the number of times the door 13 is opened is large, the amount of air flowing into the cabinet is large, and it is considered that there is much frost formation. Therefore, in such a case, it is possible to control to shorten the time interval for performing the defrosting operation. .
Conversely, when many doors 13 are opened, there is also an idea that it is better not to enter the defrosting operation, that is, it may be used to postpone the defrosting operation. When the temperature in the kitchen is high, if the door 13 is frequently opened and closed, the cooling capacity cannot catch up, and the internal temperature may increase steadily, but this overlaps with the defrosting time during which the refrigeration apparatus 17 is stopped. This is because the rise in the internal temperature is further accelerated.

<Related technology 3>
Related Art 3 will be described with reference to FIGS. 16 and 17.
In Related Art 3, the set temperature of the internal temperature during the cooling operation is adjusted based on the number of times of opening / closing the door of the refrigerator.
As described above, during the control operation of the cooling operation, the refrigeration apparatus 17 (compressor 18) is repeatedly turned on and off so that the internal temperature is substantially maintained at a predetermined set temperature. At this time, as shown in FIG. 16, if the door 13 is frequently opened and closed, even if the refrigeration apparatus 17 continues to be turned on, the internal temperature continues to rise due to insufficient cooling capacity, and the stored food, etc. There is a risk of problems in maintaining quality.
In this related technique 3, the opening / closing state of the door 13 on the previous day is memorized, and in a time zone where the number of times of opening and closing is high, the set temperature is automatically lowered slightly before that time zone, and the internal temperature rises. Also, the temperature around the original set temperature is maintained. The opening / closing operation of the door 13 is detected based on a change in the internal temperature as in the case of the related technique 2.

A specific implementation method is as follows.
First, as shown in FIG. 17A, on the first day of the previous day, the number of times the door 13 is opened and closed every hour is detected and stored. Then, on the day, as shown in FIG. 5B, based on the above data, the set temperature is restored to the original temperature at a time before a time when the number of times of opening / closing per hour becomes a certain value (threshold) or more. Change to a lower temperature (L) than the value. When it becomes a time zone in which the number of times of opening and closing is less than the threshold, the set temperature is returned to the original value (H).
By storing data related to the number of times the door 13 is opened and closed the previous day, a time zone in which the internal temperature is likely not to be maintained is foreseen, and on that day, the internal temperature is automatically changed to a low value before that time is reached. As a result, the internal temperature is prevented from rising beyond the original set temperature.

Also in this related technique 3, it is possible to use the degree of influence obtained from the information from the internal temperature sensor 33 described in the related technique 2. If the time of this influence degree is changed, it will become a standard which knows the total amount of heat penetration by opening and closing the door 13 once.
Therefore, the time of influence is accumulated every hour and stored for 24 hours, and based on this, the magnitude of the substantial influence of opening and closing the door 13 in one day is obtained for each hour. And in the time zone that exceeds the threshold, it is judged that there is a possibility that the cooling does not catch up because the amount of heat intrusion is large and the internal temperature rises above the set value. Control to lower. Then, even if there is a large amount of heat intrusion by opening and closing the door 13, the original set temperature can be maintained, which is effective for protecting food in the cabinet.

<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) The time interval for performing the defrosting operation is not limited to the 6 hours exemplified in the above embodiment, and can be set to any time.
(2) In a refrigerator, a condenser temperature sensor is attached to the condenser and is used to detect the temperature of the refrigerant to monitor the presence or absence of an abnormality in the refrigeration apparatus. Since it may be considered that there is a certain temperature difference with the ambient temperature at the installation position, a condenser temperature sensor may be used to detect the ambient temperature.
(3) In the first embodiment, if the time for starting the first defrosting is delayed by α hours, the next time for starting the defrosting is held after (X−α) time obtained by subtracting the α time from the predetermined time interval X hours. You may make it come. That is, the start time of the basic defrosting operation may be determined and shifted if necessary at each time.

(4) In the fourth embodiment, in order to obtain the change data of the ambient temperature on the previous day, as in the third embodiment, the integrated value within a predetermined time may be used as the detected temperature for each time.
(5) In the fourth embodiment, the ambient temperature at the time when the defrosting operation is started is directly read, and the defrosting end temperature may be changed depending on whether the temperature is higher or lower than a predetermined temperature. .
(6) If it is the said method, it is also possible to set defrost end temperature based on the ambient temperature of the day.
(7) The set value of the defrosting end temperature is arbitrarily set according to the model or the like, and therefore, the set value for change is also selected accordingly.
(8) Stopping energization of the heater, that is, the end timing of the defrosting operation may be controlled by the time after the start of the defrosting operation. In this case, the execution time of the defrosting operation is selected as long and short and set.

The longitudinal cross-sectional view of the refrigerator which concerns on Embodiment 1 of this invention Block diagram of operation control mechanism Illustration of ambient temperature setting temperature Operation flowchart (A) Timing chart of operation, (B) Timing chart of comparative example The block diagram which shows the means to determine the start time of the defrost operation which concerns on Embodiment 2. FIG. Explanatory drawing which shows the relationship between ambient temperature and the start time of a defrost operation The block diagram which shows the means to determine the defrost completion | finish temperature of Embodiment 4. Explanatory drawing which shows the relationship between ambient temperature and defrost end temperature (A) The graph which shows the W number of the defrost heater which concerns on related technology 1, (B) The graph which shows the process of the defrost driving | operation. (A) The graph which shows the W number of the defrost heater which concerns on a comparative example with related technology 1, (B) The graph which shows the process of the defrost operation Vertical sectional view of the refrigerator according to Related Technology 2 Explanatory diagram showing changes in internal temperature as door opens and closes Operation flowchart Partial longitudinal sectional view of an example with a temperature sensor dedicated to door open / close detection Explanatory drawing explaining the influence which the door opening and closing gives to the temperature in a warehouse regarding related technology 3 (A) A graph showing the number of times the door is opened and closed, (B) A graph explaining a change in the set temperature in the cabinet

Explanation of symbols

  DESCRIPTION OF SYMBOLS 17 ... Refrigeration apparatus 18 ... Compressor 20 ... Cooler 25 ... Cooling fan 27 ... Defrost heater 30 ... Control device (control means) 33 ... Interior temperature sensor 34 ... Defrost temperature sensor 35 ... Ambient temperature sensor (Temperature detection means) 40 ... Storage means 41 ... Start time determining means 43 ... Integrating means 45 ... Defrosting end temperature determining means

Claims (8)

A refrigerant is supplied to the cooler by driving the compressor in the refrigeration cycle, and a cooling operation is performed by cooling and circulating the cold air generated by heat exchange with the cooler, and this cooling operation. In the middle of the cooling storage where the defrosting operation is performed to remove frost by heating the cooler while the compressor is stopped,
A cooling storage, comprising temperature detection means for detecting the ambient temperature of the cooling storage, and provided with control means for determining a defrosting operation mode based on the temperature detected by the temperature detection means. The defrosting operation mode is a start time of the defrosting operation, and the start time is determined so that the defrosting operation is not started at a time when the detected temperature is equal to or higher than a predetermined temperature. Refrigerated storage as described. The defrosting operation is not started when the detected temperature is higher than or equal to a predetermined value at the scheduled start time of the defrosting operation, and the defrosting operation is started when the detected temperature is lower than a predetermined value. The cooling storage box according to claim 2. When the defrosting operation is performed a plurality of times in a certain cycle within one day, the ambient temperature on the day before the operating day of the cooling storage is detected and stored every predetermined time, and the maximum value of the detected temperature is taken The cooling storage according to claim 2, wherein the start time of the defrosting operation is determined so as to come to the center of the cycle of the defrosting operation. The cooling storage according to claim 1, wherein the defrosting operation mode is an execution time of the defrosting operation, and the execution time is shortened when the detected temperature is equal to or higher than a predetermined value. While the defrosting operation is performed a plurality of times in one day, the temperature of the cooler is detected during the defrosting operation, and the cooler is heated when the cooler temperature reaches a predetermined defrosting end temperature. In what is to be stopped, the ambient temperature on the day before the operating day of the cooling storage is detected and stored every predetermined time, and if the detected temperature at the start time of the defrosting operation is equal to or higher than the predetermined temperature, The cooling storage according to claim 5, wherein the defrosting end temperature related to the frost operation is set to be low. While the defrosting operation is performed a plurality of times in one day, the temperature of the cooler is detected during the defrosting operation, and the cooler is heated when the cooler temperature reaches a predetermined defrosting end temperature. In the defrosting operation that is executed at a time close to the time when the ambient temperature takes the minimum value in the non-business hours or the day before the operating day of the cooling storage, the defrosting end temperature is The cooling storage according to claim 5, wherein the cooling storage is set higher than the others. The cooling storage according to claim 4, 6 or 7, wherein the detected temperature at each time is an integrated value of a predetermined number of times.

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