JP2012229884A - Cooling storehouse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling storehouse which maximally suppress a rise of a temperature in the storehouse during operation stop even if a power supply is disconnected due to maintenance and power interruption.SOLUTION: A refrigerator R for business use has a compressor 16 constituting a refrigerant circuit and an evaporator 7, cools cold air which is obtained by being heat-exchanted by the evaporator 7 by a cold-air circulating air blower 8 and circulates it to a storage chamber 3, and at a normal operation mode, controls operations of the compressor 16 and the cold-air circulating air blower 8 by a control device on the basis of the temperature in the refrigerator so that the temperature in the refrigerator reaches a prescribed temperature in a refrigerator. The control device has a prescribed preparation operation mode, and at the preparation operation mode, increases a cooling capacity of the compressor 16 more than that at the normal operation mode, and grows ice at the evaporator 7.

Description

  The present invention relates to a cold storage that circulates and cools cold air heat-exchanged with an evaporator.

  Conventionally, for example, commercial refrigerators (cooling storages) installed in kitchens such as canteens, restaurants, hotels, etc., have a heat insulating box with an open front, a compressor, a condenser (heat radiator), A cooling unit in which a refrigerant circuit is configured by connecting a decompression device (capillary tube or expansion valve) and an evaporator in a circular ring shape, and chilled air that exchanges heat with the evaporator is circulated in the cabinet by a fan for circulating cold air. Thus, the food stored in the cabinet, the cooked food (article), and the like are cooled to a predetermined temperature (see, for example, Patent Document 1).

JP 2005-180788 A

  By the way, when the maintenance (maintenance inspection / repair) of the commercial refrigerator is performed or when a planned power failure is performed in recent years, the operation of the cooling unit is stopped for a certain time. Therefore, there is a problem that the temperature in the cabinet rises and the stored food and food deteriorates.In such a case, a large amount of ice or a cold insulation agent is put into the cabinet or the food is put in another cooling storage cabinet. It needs to be transferred. Also, especially in the event of a power outage, it could not be transferred, and in the absence of a large amount of ice and cold insulation, there was no way other than using up all these ingredients.

  The present invention has been made to solve the conventional technical problems, and suppresses the rise in the internal temperature during the shutdown as much as possible even when the maintenance is performed or the power is cut off due to the power failure. It provides a cooling storage that can be used.

  In order to solve the above problems, the cooling storage of the invention of claim 1 includes a compressor and an evaporator constituting a refrigerant circuit, and cools and cools the cold air heat-exchanged with the evaporator by a cool air circulation blower. In the normal operation mode, the operation of the compressor and the cool air circulation blower is controlled by the control device so that the internal temperature becomes a predetermined internal set temperature based on the internal temperature. The control device has a predetermined preparatory operation mode. In the preparatory operation mode, the cooling capacity of the compressor is increased as compared with the normal operation mode, and ice is grown in the evaporator.

  The cooling storage of the invention of claim 2 includes a compressor and an evaporator constituting a refrigerant circuit, circulates and cools the cold air exchanged with the evaporator by a cool air circulation blower, and performs normal operation. In the mode, the operation of the compressor and the cooling air circulation fan is controlled by the control device between the upper limit temperature and the lower limit temperature set above and below the set temperature on the basis of the inside temperature. The control device has a predetermined preparatory operation mode, and in the preparatory operation mode, based on the temperature of the evaporator, the temperature of the evaporator is higher than the lower limit temperature of the evaporator, and near the lower limit temperature of the evaporator. The operation of the compressor is controlled so as to reach a certain evaporator target temperature, and the operation of the blower for circulating cold air is controlled between the upper limit temperature in the refrigerator and the lower limit temperature in the refrigerator based on the internal temperature.

  According to a third aspect of the present invention, in the above-described cooling storage, the control device controls the operation frequency of the compressor in both operation modes, stops the compressor at both lower limit temperatures, and in the preparatory operation mode, the evaporator. When the temperature of the refrigerant approaches the evaporator lower limit temperature, the cool air circulation blower is operated.

  Further, in the cooling storage of the invention of claim 4, the control device in the invention of claim 2 or claim 3 is provided with a display device, and when the temperature of the evaporator reaches the evaporator target temperature in the preparatory operation mode, A predetermined display is performed by the display device.

  The cooling storage of the invention of claim 5 includes the evaporator defrosting device in each of the above inventions, and the control device performs defrosting of the evaporator by the defrosting device at a predetermined timing in the normal operation mode. In addition, in the preparation operation mode, the defrosting of the evaporator at a predetermined timing is prohibited.

  Further, in the cooling storage of the invention of claim 6, in the above invention, in the preparatory operation mode, when the difference between the internal temperature and the temperature of the evaporator is enlarged to a predetermined value or more, the control device It is characterized by performing defrosting.

  The cooling storage of the invention of claim 7 is characterized in that, in each of the above inventions, the control device lowers the set temperature in the storage in the normal operation mode by a predetermined value in the preparation operation mode.

  The cooling storage of the invention of claim 8 is characterized in that, in each of the above inventions, the control device releases the preparation operation mode and returns to the normal operation mode when the power is cut off.

  The cooling storage of the invention of claim 9 is characterized in that, in each of the above inventions, the control device is provided with a timer, and the time for performing the preparatory operation mode can be set.

  The cooling storage of the invention of claim 10 includes a heat insulating box having a front opening in each of the above inventions, and a heat insulating door for opening and closing the opening, and the evaporator is disposed in the upper part of the storage. In addition, the cool air circulation blower is characterized in that the cool air exchanged with the evaporator is circulated in the lower cabinet, and a cooling agent can be arranged in the lower chamber of the evaporator.

  According to the first aspect of the present invention, the compressor and the evaporator constituting the refrigerant circuit are provided, and the cold air heat-exchanged with the evaporator is circulated and cooled in the cabinet by the cool air circulation blower, and in the normal operation mode. , A cooling storage cabinet in which the operation of the compressor and the cool air circulation fan is controlled by the control device so that the internal temperature becomes a predetermined internal set temperature based on the internal temperature. An operation mode is provided, and in the preparatory operation mode, the cooling capacity of the compressor is increased as compared with the normal operation mode, and ice is grown in the evaporator. By setting the apparatus in this preparatory operation mode, it is possible to sufficiently reduce the temperature of the evaporator and allow ice to grow in the evaporator before the operation of the cooling storage is stopped.

  As a result, the inside of the cabinet is cooled by the low-temperature evaporator and ice even during operation stoppage due to maintenance and planned power outages, and the rise in temperature inside the cabinet is suppressed as much as possible, and the stored articles deteriorate. It can be prevented or minimized.

  The invention of claim 2 includes a compressor and an evaporator that constitute a refrigerant circuit, and cools and cools the cool air that has exchanged heat with the evaporator by a cool air circulation blower. In the normal operation mode, Based on the internal temperature, it is a cooling storage unit that controls the operation of the compressor and the cooler circulation fan by the control device between the upper limit temperature and the lower limit temperature set above and below the set temperature in the store. The control device is provided with a predetermined preparatory operation mode, and in the preparatory operation mode, the evaporator temperature is higher than the lower limit temperature of the evaporator and is near the lower limit temperature of the evaporator based on the temperature of the evaporator. The compressor operation was controlled to reach the target temperature, and the operation of the cooling air circulation fan was controlled between the upper limit temperature and the lower limit temperature based on the internal temperature. Is implemented In addition, by setting the control device to this preparatory operation mode, before the operation of the cooling storage is stopped, the operation of the compressor is controlled by the temperature of the evaporator, and the temperature of the evaporator is lowered to near the lower limit temperature of the evaporator. In addition, it is possible to grow ice in the evaporator.

  Thus, according to the invention of claim 2, the inside of the cabinet is cooled by the low-temperature evaporator and ice during the operation stop due to the maintenance or planned power outage, and the temperature rise in the cabinet is suppressed as much as possible. Inconvenience that the stored article deteriorates can be prevented or suppressed to a minimum. Further, in the preparatory operation mode, the internal temperature is maintained at the set temperature by controlling the cool air circulation blower, so that the internal state is not overcooled and the article can be cooled and stored without any trouble. Become.

  In this case, the control device controls the operation frequency of the compressor in the both operation modes as in the invention of claim 3 and stops the compressor at the both lower limit temperatures, and the evaporator temperature becomes the evaporator lower limit in the preparation operation mode. When the temperature approaches the temperature, if the cool air circulation blower is operated, the temperature of the evaporator can be increased by raising the temperature before the temperature reaches the lower limit temperature of the evaporator. As a result, during the preparatory operation mode, the compressor can be continuously operated without being stopped, and the temperature reduction of the evaporator and the ice growth can be further promoted.

  Further, if the control device is provided with a display device as in the invention of claim 4 and the predetermined temperature is displayed by the display device when the evaporator temperature reaches the evaporator target temperature in the preparatory operation mode, the control device is used. By viewing this display, the person can recognize that the temperature of the evaporator has reached the vicinity of the evaporator target temperature in the preparatory operation mode and that preparations before the operation stop are ready.

  Further, as in the invention of claim 5, the defroster for the evaporator is provided, and the control device performs defrosting of the evaporator by the defroster at a predetermined timing in the normal operation mode, and in the preparation operation mode, If the defrosting of the evaporator at a predetermined timing is prohibited, it is possible to prevent the ice growth from being inhibited by the defrosting of the evaporator being performed during the preparation operation mode.

  However, at this time, as in the sixth aspect of the invention, the control device performs defrosting of the evaporator by the defrosting device when the difference between the internal temperature and the temperature of the evaporator increases to a predetermined value or more in the preparatory operation mode. By doing so, when the evaporator is frost blocked during the preparatory operation mode, it is possible to eliminate the detrimental effect due to the decrease in the internal cooling effect by performing defrosting.

  Further, in the preparatory operation mode, if the control device lowers the set temperature in the normal operation mode by a predetermined value in the preparatory operation mode, the temperature decrease of the evaporator and the ice growth are further promoted. It becomes possible to do.

  Further, if the control device as in the invention of claim 8 is turned off, if the preparatory operation mode is canceled and the normal operation mode is restored, the operation can be performed after the maintenance or the planned power outage is performed. When the operation is resumed, the cooling operation can be resumed without any trouble by automatically returning to the normal operation mode.

  Further, by providing a timer in the control device as in the invention of claim 9 and enabling the time for executing the preparatory operation mode to be set, the preparatory operation mode can be executed without any trouble before the maintenance or planned power outage is performed. When the planned power failure is not carried out, the normal operation mode can be automatically restored.

  Further, as in the invention of claim 10, a heat insulating box having an interior with an open front and a heat insulating door for closing the opening so as to be openable and closable, an evaporator is disposed in the upper part of the interior, and a fan for circulating cold air is provided. In the above cooling storage for circulating the cold air exchanged with the evaporator into the lower cabinet, if a cold insulation agent can be arranged in the lower compartment of the evaporator, the cooling effect can be reduced with the cold insulation during operation stoppage. Complementary, it becomes possible to effectively avoid the deterioration of the articles stored in the lower warehouse.

It is a vertical side view of a commercial refrigerator as an embodiment of a cooling storage to which the present invention is applied. It is a schematic perspective view of the cooling unit of the commercial refrigerator of FIG. It is a schematic side view of the evaporator part of the commercial refrigerator of FIG. It is a block diagram of the electric circuit of the control apparatus of the commercial refrigerator of FIG. It is a figure which shows the transition of the internal temperature and evaporator temperature in the preparatory operation mode of the control apparatus of FIG. 4, and the operating state of the compressor and the air blower for cold air circulation. It is a figure which shows transition of the evaporator temperature in the time of power OFF from the preparatory operation mode of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a longitudinal side view of a commercial refrigerator R as an embodiment of the cooling storage of the present invention, FIG. 2 is a schematic perspective view of a cooling unit 6 of the commercial refrigerator R, and FIG. 3 is a schematic side view of an evaporator 7 portion. Each is shown.

  The commercial refrigerator R according to the embodiment is installed in a kitchen of a hotel or a restaurant, for example, and the main body is constituted by the heat insulating box 1. In this heat insulation box 1, a storage chamber 3 is configured as an interior whose front is open (this opening is 2), and the front opening 2 of this storage chamber 3 can be opened and closed by a heat insulating door 4. Is blocked.

  In addition, a cooling chamber 9 to which the evaporator 7 of the cooling unit 6 and the cool air circulation blower 8 are attached is partitioned and formed by a drain pan (partition plate) 11 in the upper portion of the storage chamber 3. A cool air suction port 25 is formed at a position corresponding to the cool air circulation blower 8 at the front portion of the drain pan 11, and a cool air discharge port 30 is formed at the rear end. Then, when the cool air circulation blower 8 is operated, the cool air in the lower storage chamber 3 is sucked into the cooling chamber 9 from the cool air suction port 25 as indicated by an arrow in FIG. The cold air sucked into the cooling chamber 9 is exchanged with the evaporator 7 and then discharged from the cold air discharge port 30 located behind the cooling chamber 9 into the lower storage chamber 3. In this way, cold air is circulated in the storage chamber 3 below the cooling chamber 9 (indicated by an arrow in FIG. 1), and the interior of the storage chamber 3 is cooled.

  On the other hand, a machine room 13 is defined on the top surface of the heat insulation box 1 by a panel such as a front panel 12, and an opening 1A formed on the top surface of the heat insulation box 1 is a unit plate constituted by a heat insulation wall. 14 is occluded. On the upper surface of the unit plate 14, a compressor 16, a condenser (heat radiator) 17, and a capillary tube (decompression device) 18 that are located in the machine chamber 13 and constitute a refrigerant circuit of the cooling unit 6 together with the evaporator 7. An accumulator 20, a condenser blower 19 for cooling the condenser 17, an electrical box 21 and the like are installed. On the lower surface of the unit plate 14, an evaporator 7 located in the cooling chamber 9 in the upper part of the storage chamber 3 is provided.

  The compressor 16, the condenser 17, the capillary tube 18, the evaporator 7, and the accumulator 20 are sequentially connected in an annular manner by a refrigerant pipe to constitute a known refrigerant circuit of the cooling unit 6. The evaporator 7 is provided with a defrost heater 22 as a defrosting device for melting and removing frost (ice) growing on the evaporator 7.

  A breathable holder 23 is detachably attached to a portion located between the cold air inlet 25 and the cold air outlet 30 on the lower surface of the drain pan 11. A cooling agent (cold storage agent) 24 can be removably disposed in the holder 23, and the cooling agent 24 is held by the holder 23, and the upper part in the storage chamber 3 below the evaporator 7. Located in.

  Reference numeral 26 denotes a net shelf installed in a plurality of stages in the storage chamber 3, and foodstuffs and cooked foods (articles) are placed and stored on the net shelf 26. The net shelf 26 is detachably attached to the column 27 so that the position and interval in the vertical direction can be changed. However, even when the holder 23 is installed at the highest level, the holder 23 can carry articles on the net shelf 26. It shall be provided in a position where it is difficult to get in the way. In addition, instead of the holder 23 of the embodiment, an air-permeable base may be attached on the uppermost net shelf 26, and the cooling agent 24 may be placed on the base and placed below the evaporator 7. .

  Next, the control device (control means) 31 for the commercial refrigerator R in this embodiment will be described with reference to FIG. The control device 31 is constituted by a general-purpose microcomputer and has a timer 32 as a time limit means as its function. An input switch 33 for performing various settings and an LED display device 34 are connected to the control device 31, and these are arranged on a control panel 36 provided on the front panel 12.

  Further, at the input side of the control device 31, at least the internal temperature sensor 37 for detecting the temperature in the storage chamber 3 (internal temperature TA) and the defrosting end temperature sensor for detecting the temperature of the evaporator 7 (evaporation). Instrument temperature sensor) 38 is connected. In the embodiment, the internal temperature sensor 37 detects the temperature of the cool air sucked into the cooling chamber 9 from the storage chamber 3 as the internal temperature TA, that is, the cold air suction side of the cool air circulation fan 8, that is, the cold air inlet 25. Is provided.

  Further, on the output side of the control device 31, the compressor 16 of the cooling unit 6, the cool air circulation blower 8, the condenser blower 19 (actually a motor such as a DC motor that drives them), and a defrost heater 22 is connected. Based on the outputs of the temperature sensors 37 and 38 and the operation of the input switch 33, the control device 31 operates the operating frequencies of the compressor 16, the cool air circulation blower 8, and the condenser blower 19 by an inverter (not shown). Hz) and turn them on and off. In the embodiment, the capillary tube 18 is used as the pressure reducing device of the cooling unit 6, but an expansion valve may be used.

  Next, operation control of the commercial refrigerator R by the control device 31 will be described. The control device 31 has two operation modes, a normal operation mode and a preparation operation mode. Although the normal operation mode is executed by default, the operation mode is switched from the normal operation mode to the preparation operation mode by operating the input switch 33 or when the control device 31 is connected to a remote control device through communication. First, the normal operation mode will be described.

(1) Normal operation mode After power-on, the control device 31 executes the normal operation mode. In this normal operation mode, when the internal set temperature TSA of the storage chamber 3 is set to + 3 ° C., for example, the control device 31 sets the differential +2 deg + 5 ° C. as the internal upper limit temperature THA and the differential −2 deg +1. Set ℃ to the inside lower limit temperature TLA. And the control apparatus 31 controls the operating frequency of the compressor 16 based on the internal temperature TA which the internal temperature sensor 37 detects, and performs ON (start) -OFF (stop).

  That is, when the internal temperature TA is far from the internal set temperature TSA, the control device 31 increases the operating frequency (Hz) of the compressor 16 and decreases the operating frequency as it approaches the internal lower limit temperature TLA. Go. This suppresses so-called undershoot of the internal temperature TA. The operation frequency is controlled between the maximum frequency (MAX) and the minimum frequency (MIN). When the internal temperature TA falls to the internal lower limit temperature TLA, the control device 31 turns off (stops) the compressor 16. Thereafter, when the internal temperature TA rises and reaches the internal upper limit temperature THA, the control device 31 turns on (starts up) the compressor 16, and thereafter executes similar frequency control. In addition, after turning off the compressor 16, the control apparatus 31 prohibits starting for 5 minutes (predetermined starting stop time), for example. As a result, an overload caused by a pressure difference between the high pressure side and the low pressure side of the refrigerant circuit is avoided from being applied to the compressor 16 to protect the compressor 16 (the same applies hereinafter).

  Further, the control device 31 turns off (stops) the cool air circulation blower when the internal temperature TA falls to the internal lower limit temperature TLA, and turns on (starts) when the internal temperature TA rises to the internal upper limit temperature THA. In addition, although the operation frequency can be adjusted between the maximum frequency (MAX) and the minimum frequency (MIN), the cool air circulation blower 8 is operated at the maximum frequency (MAX) during the operation. However, the operating frequency may be adjusted similarly to the compressor 16 as described above. Further, the control device 31 intermittently operates the cool air circulation blower 8 even when the compressor 16 is stopped (OFF). Thereby, the temperature nonuniformity in the storage chamber 3 is suppressed. In the embodiment, it is assumed that the condenser blower 19 is turned ON / OFF in synchronization with ON / OFF of the compressor 16 described later.

  In this way, the control device 31 controls the internal temperature TA to the internal set temperature TSA, and cools articles such as food stored in the storage chamber 3. By such a cooling operation, frost (ice) grows in the evaporator 7. Therefore, when the time accumulated by the timer 32 reaches a predetermined defrost start time (predetermined timing), the control device 31 stops the compressor 16 and the fans 8 and 19 and turns on the defrost heater 22. (Heat generation) and defrosting of the evaporator 7 is started.

  The frost on the evaporator 7 is melted by the heating from the defrost heater 22. The drain water dripped from the evaporator 7 is received by the drain pan 11 and discarded outside. The temperature of the evaporator 7 (evaporator temperature TE) rises with the progress of defrosting, and this evaporator temperature TE is detected by the defrosting end temperature sensor 38. And when it becomes predetermined | prescribed defrost completion | finish temperature (for example, +10 degreeC etc.), it judges that the defrost of the evaporator 7 was complete | finished, and the control apparatus 31 turns off the defrost heater 22, and complete | finishes defrost. . And after predetermined draining time, the compressor 16 and each air blower 8 and 19 are started, and cooling operation is restarted.

(2) Preparatory operation mode Next, the preparatory operation mode of the control apparatus 31 is demonstrated, referring FIG.5 and FIG.6. When this preparatory operation mode is performed, the frozen coolant 24 is placed in the holder 23. Further, in the embodiment, it is assumed that maintenance is started at the time when the power is turned off in FIG. In the embodiment, the previous time from the start of the preparatory operation mode to the time when the power is turned off (for example, a predetermined time of 1 to 2 hours) and the later time until the preparatory operation mode is canceled after the time when the power is turned off. (For example, a predetermined time of 3 hours to 5 hours) can be set.

  For example, when the previous time is set to 1 hour and the subsequent time is set to 5 hours, the control device 31 is set to the preparatory operation mode by operating the input switch 33 at a time one hour before the power-off time. As a result, the one-hour preparation operation mode is performed until the power is turned off. When the power supply is actually turned off, this one hour becomes the execution time of the preparation operation mode.

  If the power is not turned off, the control device 31 cancels the preparatory operation mode and returns to the normal operation mode after 5 hours from the time when the power is assumed to be turned off. In this case, the total operation time of 1 hour (previous time) +5 hours (rear time) is the execution time of the preparation operation mode. Therefore, for example, when the maintenance is scheduled but is not performed, or when the planned power failure is not actually performed, the control device 31 automatically cancels the preparation operation mode and performs the normal operation mode. Will return to. Note that the control device 31 also sets the operation mode to the normal operation mode when the power is turned off and then returns.

  In this preparatory operation mode, the control device 31 controls the operating frequency of the compressor 16 based on the temperature of the evaporator 7 (evaporator temperature TE) detected by the defrosting end temperature sensor 38, and is turned on (started up). -Perform OFF (stop). Further, the cool air circulation blower 8 is controlled based on the internal temperature TA detected by the internal temperature sensor 37. Further, in this preparatory operation mode, the control device 31 lowers the internal set temperature TSA of the storage chamber 3 from the normal operation mode, and sets the internal set temperature TSA that was + 3 ° C. in the normal operation mode to + 2 ° C., for example.

  Further, the control device 31 also reduces the differential, sets + 3 ° C. as the upper limit temperature THA as +1 deg, and sets + 1 ° C. of differential −1 deg as the lower limit temperature TLA in the store. This is because when the compressor 16 is controlled at the internal temperature TA, the differential cannot be reduced due to the restriction of the start / stop time, but when only the cool air circulation blower 8 is controlled, there is no problem even if it is reduced. .

  When the evaporator temperature TE is far from the predetermined evaporator lower limit temperature TLE, the control device 31 increases the operation frequency (Hz) of the compressor 16 and decreases the operation frequency as it approaches the evaporator lower limit temperature TLE. I will let you. When the temperature reaches the evaporator lower limit temperature TLE, the compressor 16 is turned off (stopped). For example, the compressor 16 is turned on (started) when the temperature reaches the predetermined evaporator target temperature TSE after a predetermined start stop time elapses. Execute control to

  The evaporator lower limit temperature TLE varies depending on the refrigerant used in the refrigerant circuit, but is a temperature at which the pressure in the evaporator 7 is assumed to be negative when the temperature falls below that. When the pressure in the evaporator 7 becomes negative, problems such as intrusion of outside air into the refrigerant circuit occur. Further, the compressor 16 is also overloaded. When the refrigerant used in the embodiment is R134a, for example, the evaporator lower limit temperature TLE is set to about −25 ° C. The evaporator target temperature TSE is set to a temperature of −24 ° C. near the evaporator lower limit temperature TLE although it is higher by a predetermined value (for example, 1 deg).

  In the normal operation mode, the evaporator temperature TE is operated in a state higher than the evaporator target temperature TS. Therefore, when the normal operation mode is switched to the preparation operation mode, the operation frequency of the compressor 16 is the maximum frequency in the embodiment. Will rise. However, the maximum frequency may be switched unconditionally at the time of switching. In addition, the operation frequency lowering control is performed at the evaporator lower limit temperature TLE, but when the temperature is far from the evaporator target temperature TSE, the internal temperature TE is referred to and the operation frequency is set when the decreasing tendency is slow. You may perform control to raise. In any case, in this preparatory operation mode, the control device 31 increases the cooling capacity of the compressor 16 as compared with the normal operation mode, and the evaporator temperature TE is an evaporator whose temperature is very low near the evaporator lower limit temperature TLE. Control to set the target temperature TSE is executed.

  Further, when the internal temperature TA is far from the internal set temperature TSA, the control device 31 increases the operating frequency (Hz) of the cool air circulation blower 8 and decreases the operating frequency as it approaches the internal lower limit temperature TLA. I will let you. In the preparatory operation mode, the evaporator temperature TE is kept extremely low as described above, but undershooting of the internal temperature TA is suppressed by controlling the operation frequency of the cool air circulation blower 8. The operation frequency is also controlled between the maximum frequency (MAX) and the minimum frequency (MIN).

  When the internal temperature TA decreases to the internal lower limit temperature TLA, the control device 31 turns off (stops) the cool air circulation blower 8. Thereafter, when the internal temperature TA rises and reaches the internal upper limit temperature THA, the control device 31 turns on (starts up) the cool air circulation blower 8, and thereafter executes the same frequency control.

  Since the evaporator temperature TE is maintained at a very low temperature as described above, the cooling action by the evaporator 7 is also increased, so that the internal temperature TA reaches the internal lower limit temperature TLA at an early stage, and the cold air circulation. The blower 8 is stopped earlier than the normal operation mode. Since the cooling air circulation blower 8 is stopped, the evaporator 7 is not ventilated, so the tendency of the evaporator temperature TE to decrease sharply (X1 in FIG. 5), and frost (ice ice) around the evaporator 7 ) Will be promoted.

  When the evaporator temperature TE approaches the evaporator lower limit temperature TLE and falls to a predetermined value 0.5 deg higher than the evaporator lower limit temperature TLE, for example, the control device 31 turns on the cool air circulation blower 8 (X2 in FIG. 5). ). As a result, the ventilation to the evaporator 7 is resumed, and the evaporator temperature TE tends to increase. Therefore, the evaporator temperature TE does not decrease to the evaporator lower limit temperature TLE, and the compressor 16 is continuously operated without being stopped. Therefore, the ice growth on the evaporator 7 is further promoted.

  Further, when the evaporator temperature TE reaches the evaporator target temperature TSE, the control device 31 performs a predetermined display on the display device 34. As a result, the user is notified that the evaporator temperature TE has decreased to the target extremely low temperature (evaporator target temperature TSE).

  When the power supply OFF time is reached and the commercial refrigerator R is turned off, the compressor 16 and the fans 8 and 19 are also stopped. Although it stops, a large amount of ice is generated around the evaporator 7, so that the cold air cooled by the ice 7 and the low-temperature evaporator 7 is naturally circulated from the cold air outlet 30 and the cold air inlet 25. To descend into the lower storage chamber 3. In addition, since the cooling agent 24 is also disposed in the holder 23, the cold air cooled by the cooling agent 24 also falls into the lower storage chamber 3. Due to the natural circulation of the cold air, the rise of the temperature in the storage chamber 3 (internal temperature TA) during the stop of the cooling operation by turning off the power becomes slow.

  FIG. 6 shows the transition of the evaporator temperature TE when the power is turned off from the preparatory operation mode. As is apparent from this figure, the evaporator temperature TE rises from the power supply OFF (for example, 1:00 pm in FIG. 6), but does not change when it reaches 0 ° C. (indicated by X3 in FIG. 6). . This is the time during which the ice around the evaporator 7 is melting. The longer this time is, the slower the temperature rise of the internal temperature TA becomes, and it becomes possible to prevent or suppress the quality deterioration of articles such as foods during power OFF.

  When the power supply returns as described above, the control device 31 cancels the preparation operation mode and returns to the normal operation mode.

  Thus, the controller 31 is provided with a preparatory operation mode, and in this preparatory operation mode, the cooling capacity of the compressor 16 is increased as compared with the normal operation mode, and ice is grown in the evaporator 7. Before the maintenance or planned power outage is performed, the controller 31 is set in this preparatory operation mode, so that the compressor at the temperature of the evaporator 7 (evaporator temperature TE) before the operation of the commercial refrigerator R is stopped. 16 is controlled, the evaporator temperature TE is sufficiently lowered to near the evaporator lower limit temperature TLE, and ice can be grown in the evaporator 7.

  As a result, the storage chamber 3 is cooled by the low-temperature evaporator 7 and ice even during operation stoppage due to maintenance or planned power outage, and the temperature rise of the storage chamber 3 is suppressed as much as possible, and the stored foodstuffs It is possible to prevent or minimize the inconvenience that the article deteriorates. Further, in the preparatory operation mode, the internal temperature TA is maintained at the set temperature TSA by the control of the cool air circulation blower 8, so that the storage chamber 3 is not overcooled and the food and the like are cooled and stored without any trouble. Will be able to.

  In this case, when the evaporator temperature TE approaches the evaporator lower limit temperature TLE in the preparatory operation mode, the control device 31 operates the blower 8 for circulating cold air, and thus before the evaporator temperature TE reaches the evaporator lower limit temperature TLE. The temperature can be raised by ventilating. Thereby, during the preparatory operation mode, the compressor 16 can be continuously operated without being stopped, and the decrease in the evaporator temperature TE and the growth of ice can be further promoted.

  In addition, when the evaporator temperature TE reaches the evaporator target temperature TLE in the preparatory operation mode, the control device 31 performs a predetermined display on the display device 34. In FIG. 5, it is possible to recognize that the evaporator temperature TE has reached the vicinity of the evaporator target temperature TSE, and that preparations before the shutdown are completed.

  Further, in the preparatory operation mode, the control device 31 reduces the internal set temperature TSA in the normal operation mode by a predetermined value, so that the temperature decrease of the evaporator 7 and the ice growth can be further promoted.

  Further, when the power is cut off, the control device 31 cancels the preparatory operation mode and returns to the normal operation mode. Therefore, after the maintenance or planned power failure is performed, the normal operation mode is automatically performed when the operation is resumed. The cooling operation can be resumed without any trouble by returning to step S2.

  In addition, since the control device 31 can set the time for starting the preparatory operation mode and the time from the start of the preparatory operation mode to the cancellation, the preparatory operation mode can be set before the maintenance or planned power outage is performed. The system can be executed for the required time without any trouble, and can automatically return to the normal operation mode even when a planned power outage is not performed.

  In addition, since the cooling agent 24 can be disposed in the storage chamber 3 below the evaporator 7, the cooling agent 24 compensates for a decrease in cooling action during operation stop, and the food stored in the lower storage chamber 3 or the like. Deterioration of the article can be effectively avoided.

  Here, the control device 31 prohibits the defrosting of the evaporator 7 at the defrosting start time (predetermined timing) during the preparation operation mode. This prevents the evaporator 7 from being defrosted during the preparatory operation mode and prevents the ice growth from being inhibited, but if the ice grows too much and the inside of the cooling chamber 9 falls into a frost blockage state. Even if the cool air circulation blower 8 is operated, ventilation is not performed and the storage chamber 3 cannot be cooled.

  In this frost blockage state, the evaporator temperature TE decreases, but it can be observed that the internal temperature TA does not decrease. Therefore, when the difference between the internal temperature TA detected by the internal temperature sensor 37 and the evaporator temperature TE detected by the defrosting end temperature sensor 38 increases to a predetermined value or more, the control device 31 detects the compressor 16 and each blower 8. , 19 is stopped and the defrosting of the evaporator 7 by the defrosting heater 22 is executed. In this way, when the evaporator 7 is blocked by frost during the preparatory operation mode, the detrimental effect is eliminated, thereby eliminating the adverse effects caused by the cooling effect of the storage chamber 3 being reduced. In this case as well, the defrosting of the evaporator 7 is terminated at a predetermined defrosting end temperature as described above, and the cooling operation in the preparatory operation mode is resumed. In this case, the defrosting end temperature is higher than that in the normal operation mode. The temperature may be lower.

  In the embodiment, both the pre-time and the post-time can be set. However, only the pre-time may be set. Even in that case, it is possible to carry out the preparatory operation mode for the time required until the power is turned off. Alternatively, the power-off time can be set in the control device 31, and the previous time and the later time can be automatically set from this time. However, even in this case, the actual previous time and subsequent time can be arbitrarily changed.

R Commercial refrigerator (cooling storage)
1 Insulation box 3 Storage room (inside)
DESCRIPTION OF SYMBOLS 4 Heat insulation door 6 Cooling unit 7 Evaporator 8 Air blower for cold air 9 Cooling chamber 11 Drain pan 13 Machine room 16 Compressor 17 Condenser 18 Capillary tube 22 Defrost heater (defrost device)
23 Holder 24 Coolant 31 Control device 33 Input switch 34 Display device 37 Internal temperature sensor 38 Defrosting end temperature sensor (evaporator temperature sensor)

Claims (10)

A compressor and an evaporator constituting a refrigerant circuit are provided, and cool air that is heat-exchanged with the evaporator is circulated and cooled in the refrigerator by a cool air circulation blower. It is a cooling storehouse formed by controlling the operation of the compressor and the cool air circulation blower by a control device so that the inside temperature becomes a predetermined inside set temperature,
The control device has a predetermined preparatory operation mode, and in the preparatory operation mode, the cooling capacity of the compressor is increased as compared with the normal operation mode, and ice is grown in the evaporator. . A compressor and an evaporator constituting a refrigerant circuit are provided, and the cold air that has exchanged heat with the evaporator is circulated and cooled in the refrigerator by a fan for circulating cold air, and in the normal operation mode, It is a cooling storehouse that controls the operation of the compressor and the fan for circulating cold air by means of a control device between the upper limit temperature inside the cabinet and the lower limit temperature inside the cabinet set above and below the set temperature,
The control device has a predetermined preparation operation mode, and in the preparation operation mode, the temperature of the evaporator is higher than the lower limit temperature of the evaporator and is near the lower limit temperature of the evaporator based on the temperature of the evaporator. The operation of the compressor is controlled so as to reach an evaporator target temperature, and the operation of the blower for circulating cold air is controlled between the upper limit temperature in the store and the lower limit temperature in the store based on the temperature in the store. To cool storage. The control device controls the operation frequency of the compressor in the both operation modes, stops the compressor at the both lower limit temperatures,
3. The cooling storage according to claim 2, wherein when the temperature of the evaporator approaches the evaporator lower limit temperature in the preparatory operation mode, the cool air circulation blower is operated.   The said control apparatus is provided with the display apparatus, and when the temperature of the said evaporator reaches the said evaporator target temperature in the said preparatory operation mode, a predetermined display is performed by the said display apparatus, It is characterized by the above-mentioned. The cooling storehouse according to claim 3.   The evaporator includes a defrosting device for the evaporator, and the control device performs defrosting of the evaporator by the defrosting device at a predetermined timing in the normal operation mode, and the predetermined operation in the preparation operation mode. The cooling storage according to any one of claims 1 to 4, wherein defrosting of the evaporator at the timing of is prohibited.   The control device performs defrosting of the evaporator by the defrosting device when a difference between the internal temperature and the temperature of the evaporator is increased to a predetermined value or more in the preparation operation mode. The cooling storage box according to claim 5.   The cooling storage according to any one of claims 1 to 6, wherein the controller reduces the set temperature in the storage in the normal operation mode by a predetermined value in the preparation operation mode.   The cooling storage according to any one of claims 1 to 7, wherein when the power is cut off, the control device releases the preparation operation mode and returns to the normal operation mode.   The cooling storage according to any one of claims 1 to 8, wherein the control device includes a timer and is capable of setting a time for performing the preparatory operation mode. A heat-insulating box having a front opening in the cabinet, and a heat-insulating door that freely closes the opening;
The evaporator is disposed in the upper part of the warehouse, and the cool air circulation blower circulates the cold air heat-exchanged with the evaporator in the lower warehouse, and the cold insulator in the warehouse below the evaporator. The cooling storage according to any one of claims 1 to 9, wherein the storage can be arranged.

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