JP2017227378A - Cooling storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling storage capable of reducing power consumption.SOLUTION: A cooling storage includes a storage chamber 11, a cooling device 20 having a compressor 22, a cooler 26, an inside fan 27 for circulating and supplying cold air generated by the cooler 26 to the storage chamber 11, a defrosting heater 31 for removing frost attached to the cooler 26, and a control portion 40. The control portion 40 executes a cooling operation for cooling the inside of the storage chamber 11 by operating the compressor 22 and the inside fan 27, and a defrosting operation for removing frost attached to the cooler 26, and further the control portion 40 executes one of heater defrost for heating the cooler 26 by the defrosting heater 31, and an off-cycle defrost by stopping the compressor 22 and operating the inside fan 27, as the defrosting operation on the basis of an operation state of the compressor 22 in the cooling operation executed just before.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a cooling storage.

  In a cooling storage, what is equipped with the function to perform a defrost operation in order to remove the frost adhering to a cooler (evaporator) is known (patent document 1). Patent Document 1 describes what performs a defrosting operation by heating a cooler using a defrosting heater.

JP 2008-292019 A

  In the said structure, power consumption will increase by operating a defrost heater. Moreover, since the temperature in the storage chamber of the cooling storage increases with the operation of the defrosting heater, it is necessary to operate the cooling device in order to lower the increased temperature, which also increases the power consumption.

  This invention is completed based on the above situations, Comprising: It aims at providing the cooling storage which can reduce power consumption.

  In order to solve the above-described problems, a cooling storage of the present invention includes a storage chamber for storing stored items, a cooling device having a compressor, a cooler that generates cold air by being connected to the cooling device, and An internal fan that circulates and supplies cold air generated by a cooler into the storage chamber, a defrost heater for defrosting frost attached to the cooler, the compressor, the internal fan, and the defrost A control unit for controlling the operation of the heaters, respectively, and the control unit is performed after the cooling operation and the cooling operation for cooling the storage chamber by operating the compressor and the internal fan. And a defrosting operation for defrosting frost adhering to the cooler, respectively, and further, the control unit is based on the operation state of the compressor at the time of the cooling operation performed immediately before, By the defrost heater Characterized in that the run heater defrost heat the cooler, and either one of the off-cycle defrost operating the in-compartment fan stops the said compressor as the defrosting operation.

  In general, when the amount of frost formation on the cooler is large, the cooling efficiency is lowered, so that the operation time of the compressor becomes long. That is, it is considered that there is a correlation between the operating state of the compressor and the amount of frost formation on the cooler. In the above configuration, either heater defrost or off-cycle defrost is executed based on the operating state of the compressor. For this reason, compared with the case where a defrost operation is performed only by heater defrost, the situation where the temperature in a storage chamber rises can be suppressed. Thereby, the time which operates a cooling device can be decreased and power consumption can be reduced.

  In addition, a timing unit is provided, the timing unit is configured to count the operation time of the compressor during the cooling operation, and the control unit is configured to determine the operation time during the cooling operation performed immediately before. When the total is equal to or greater than a preset reference operation time, the heater defrost is executed as the defrosting operation, and the total operation time during the cooling operation executed immediately before is greater than the reference operation time. When it is short, the off-cycle defrost may be executed as the defrosting operation. When the operation time of the compressor is large, it is considered that there is much frost formation on the cooler. For this reason, defrosting of a cooler can be performed more reliably by performing heater defrost.

  In addition, when the compressor is stopped within a certain period before the defrosting operation is started, the control unit executes the off-cycle defrost as the defrosting operation, and the compression is performed within the certain period. When the machine does not stop, the heater defrost can be executed as the defrosting operation. When the compressor stops, it is considered that frost formation on the cooler is relatively small. For this reason, the defrosting of the cooler can be sufficiently performed by the off-cycle defrost.

  In addition, a timer unit is provided, the timer unit is configured to time the stop time of the compressor during the cooling operation, and the control unit is configured to determine the stop time of the cooling operation performed immediately before. When the total is equal to or more than a preset reference stop time, the off-cycle defrost is executed as the defrosting operation, and the sum of the stop times during the cooling operation executed immediately before is calculated from the reference stop time. If it is too short, the heater defrost may be executed as the defrosting operation. When the compressor is stopped for a long time, it is considered that there is little frost formation on the cooler. For this reason, the defrosting of the cooler can be sufficiently performed by the off-cycle defrost.

  A door that can open and close the storage chamber; and a storage chamber temperature sensor that detects a temperature in the storage chamber, wherein the temperature of the storage chamber detected by the storage chamber temperature sensor is set in advance. In the case where the number of times the detected temperature is exceeded is set as the number of times of opening and closing the door, the control unit, during the cooling operation performed immediately before, when the number of times of opening and closing the door is equal to or more than a preset reference number, The end temperature of the off-cycle defrost can be increased as compared with the case where the number is less than the reference number.

  When the door is opened and closed frequently, a lot of outside air containing a relatively high amount of moisture enters the storage chamber, so that frosting on the cooler tends to increase. Moreover, since the temperature in the storage chamber rises by opening the door, it is possible to detect opening and closing of the door by detecting the temperature in the storage chamber. For this reason, the number of times that the temperature in the storage chamber exceeds the preset door opening / closing detection temperature is defined as the door opening / closing count, and when the door opening / closing count is equal to or greater than the preset reference count, the end of the off-cycle defrost is completed. By increasing the temperature, the defrosting of the cooler can be performed more reliably.

  In addition, an operation unit may be provided, and the control unit may execute the heater defrost when the operation unit is operated. With such a configuration, the worker can execute the heater defrost at an arbitrary timing.

  ADVANTAGE OF THE INVENTION According to this invention, the cold storage which can reduce power consumption can be provided.

The front view of the cooling storehouse which concerns on Embodiment 1 of this invention Sectional view showing the internal structure of the cooling storage Block diagram showing the electrical configuration of the cooling storage Timing chart showing processing of the control unit related to the cooling operation and the defrosting operation Timing chart showing processing of control unit according to embodiment 2 Timing chart showing processing of control unit according to embodiment 3 Timing chart showing processing of control unit according to embodiment 4 Timing chart showing processing of control unit according to embodiment 5 Timing chart showing processing of control unit according to related technology 1 Timing chart showing processing of control unit according to related technology 2

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, as shown in FIG. 1, a two-door vertical refrigerator is illustrated as the cooling storage 10. As shown in FIGS. 1 and 2, the cooling storage 10 includes a heat insulation box 12 having a storage room 11 and a machine room 14 provided above the heat insulation box 12. The front surface (the left surface in FIG. 2) of the heat insulation box 12 is opened, and the opening is partitioned by a partition frame 15 extending in the horizontal direction. Thereby, the storage room 11 has two opening part 11A, 11A arranged in the up-down direction.

  Two doors 16, 16 arranged in the vertical direction are rotatably attached to the heat insulating box 12, and the opening 11 </ b> A is configured to be opened and closed by the door 16. The heat insulation box 12 is supported by legs 13 provided at the four corners of the bottom surface. In addition, a shelf board 17 is provided in the storage chamber 11 along the horizontal direction, and stored items stored in the storage room 11 can be placed on the shelf board 17. A cooling device 20 is provided in the machine room 14. The cooling device 20 (refrigeration unit) is mounted on the unit table 23 as shown in FIG. As shown in FIG. 2, the cooling device 20 includes a condenser 21 including a condenser fan 21 </ b> A and a compressor 22.

  A drain pan 24 that also serves as a cooling duct is arranged on the upper portion of the heat insulating box 12 so as to be inclined downward toward the rear (right side in FIG. 2). Thereby, a cooler chamber 25 is formed between the unit base 23 and the drain pan 24. In the cooler chamber 25, a cooler 26 is disposed, for example, so as to be attached to the lower surface of the unit table 23. The cooler 26 is circulated and connected to the cooling device 20 by a refrigerant pipe (not shown), and is configured to generate cold air when the cooling device 20 is driven. A flammable refrigerant heavier than air, such as propane or isobutane, is enclosed in the refrigerant pipe. An internal fan 27 that is driven by a motor is provided on the front side of the drain pan 24, and a cool air blow-out portion 28 is formed on the rear side of the drain pan 24.

  During the cooling operation, the compressor 22, the internal fan 27, and the condenser fan 21A are driven. By driving the internal fan 27, as shown by an arrow P1 in FIG. 2, the air in the storage chamber 11 is sucked into the cooler chamber 25, and thereafter, heat is exchanged while passing through the cooler 26. The cool air is blown out from the blowing portion 28 into the storage chamber 11 as indicated by an arrow P2. Thereby, the cool air is circulated and supplied into the storage chamber 11.

  In the cooler room 25, an internal thermistor 29 (storage room temperature sensor) is disposed above the internal fan 27. The internal thermistor 29 can detect the temperature of the air in the storage chamber 11 sucked by the internal fan 27 (and thus the temperature in the storage chamber 11). Further, since the internal thermistor 29 is arranged adjacent to the cooler 26, it can also be used as a sensor (cooler temperature sensor) for detecting the temperature of the cooler 26. Note that a defrosting thermistor 129 provided in the cooler 26 may be used as a sensor for detecting the temperature of the cooler 26. On the lower surface of the cooler 26, a defrost heater 31 made of, for example, a sheathed heater is provided. The defrost heater 31 is provided to remove frost attached to the cooler 26.

  Next, the electrical configuration of the cooling storage 10 will be described. As shown in FIG. 3, the cooling storage 10 includes a control unit 40. The control unit 40 includes a display unit 41, an operation unit 42, a storage unit 43, a timing unit 44, a compressor 22, a condenser fan 21 </ b> A, an internal fan 27, a defrost heater 31, an internal thermistor 29, and an ambient temperature thermistor 30. Are electrically connected to each other.

  For example, the control unit 40 is configured mainly by a CPU, and the storage unit 43 is configured by, for example, a ROM, a RAM, or the like. The control unit 40 executes the computer program stored in the storage unit 43 to control the operation of each device (the compressor 22, the internal fan 27, the defrosting heater 31, etc.) connected to the control unit 40. It is possible to do. In addition, although the control part 40 is accommodated in the electrical equipment box 18 (refer the broken line of FIG. 1) arrange | positioned in the machine room 14, for example, it is not limited to this.

  Moreover, the display part 41 and the operation part 42 are provided in the front surface of the electrical equipment box 18, for example. The display unit 41 is configured by, for example, a liquid crystal panel, and the operation unit 42 is configured by buttons that can be pressed. The front surface of the machine room 14 is constituted by a front cover 14A (see FIG. 1) that can be opened and closed, and the display unit 41 and the operation unit 42 are arranged on the back side of the front cover 14A. The operator can visually recognize the display unit 41 from the front through a transparent member (glass or the like) provided on the front cover 14A.

  In addition, the operator can operate the operation unit 42 by opening the front cover 14A. The operator can operate the cooling storage 10 and perform various settings (such as changing the set temperature in the storage) by operating the operation unit 42. Further, the time measuring unit 44 measures time. The ambient temperature thermistor 30 (ambient temperature sensor) is housed in, for example, the electrical box 18 as shown by the broken line in FIG. 1 and can detect the ambient temperature (outside temperature) of the cooling storage 10. Yes.

  Next, the process of the control unit 40 will be described. In the present embodiment, as shown in the timing chart of FIG. 4, a cooling operation for cooling the inside of the storage chamber 11 by operating the compressor 22 and the internal fan 27, and the cooling operation performed after the cooling operation are attached to the cooler 26. The defrosting operation for defrosting the defrosted frost is executed alternately. In addition, although a defrost operation is performed every 6 hours, for example, it is not limited to this.

  During the cooling operation, the control unit 40 executes the cooling operation with the preset internal temperature set as a target value. Specifically, the control unit 40 stops the compressor 22 and the internal fan 27 when the temperature detected by the internal thermistor 29 is lower than the internal set temperature, and the temperature detected by the internal thermistor 29 is When it becomes higher than the set temperature in the refrigerator, the compressor 22 and the internal fan 27 are driven. Thereby, the temperature in the storage chamber 11 is maintained in the vicinity of the set temperature in the warehouse. The in-compartment set temperature can be set by the operator operating the operation unit 42, and the set in-compartment set temperature is stored in the storage unit 43. Note that the internal set temperature can be set, for example, in the range of −6 ° C. to + 12 ° C., but is not limited thereto.

  In the defrosting operation, the controller 40 defrosts either the heater defrost that heats the cooler 26 by the defrost heater 31 or the off-cycle defrost that stops the compressor 22 and operates the internal fan 27. Run as driving. Although the heater defrost has a higher defrosting capacity than the off-cycle defrost, the power consumption is large. Further, the heater defrost causes a temperature rise in the storage chamber 11. For this reason, in this embodiment, when it is estimated that the amount of frost adhering to the cooler 26 is large, the heater defrost is executed, and when it is estimated that the amount of frost adhering to the cooler 26 is small, the off-cycle is performed. Defrosting shall be performed. And this inventor discovered that the quantity of the frost adhering to the cooler 26 can be estimated with the driving | running condition of the compressor 22. FIG. Specifically, if the amount of frost formation in the cooler 26 is large, the cooling efficiency of the cooler 26 is lowered, and thus it is difficult to reach the set temperature in the refrigerator by the cooling operation. In this embodiment, during the cooling operation, the compressor 22 is driven until the internal set temperature is reached. For this reason, when the amount of frost formation of the cooler 26 is large, it is considered that the operation time of the compressor 22 becomes long.

  Therefore, in the present embodiment, the control unit 40 defrosts one of the heater defrost and the off-cycle defrost based on the operation time (operation state) of the compressor 22 during the cooling operation that was executed immediately before. Run as driving. Specifically, the timer 44 measures the operation time of the compressor 22 during the cooling operation. The control unit 40 executes the heater defrost as the defrosting operation when the total operation time (T7 in FIG. 4) during the cooling operation executed immediately before is equal to or longer than a preset reference operation time. Moreover, the control part 40 performs off-cycle defrost as a defrost operation, when the sum total of the operation time (T8 + T9 of FIG. 4) in the cooling operation performed immediately before is shorter than reference | standard operation time. That is, in this embodiment, the operation time of the compressor 22 is set as a switching condition between the heater defrost and the off-cycle defrost. The reference operation time is determined in advance by a test or the like and stored in the storage unit 43. The reference operation time is set to 3 hours, for example, but is not limited to this.

  The storage unit 43 stores a defrosting end temperature at the time of heater defrosting and a defrosting end temperature at the time of off-cycle defrosting. The controller 40 completes the defrosting operation when the temperature detected by the internal thermistor 29 reaches the defrosting end temperature, and executes the next cooling operation. In addition, when performing heater defrost, after detecting defrost end temperature, the defrost heater 31 is turned off, and after the predetermined drainage time passes, the next cooling operation is performed. Instead of using the internal thermistor 29, a defrosting thermistor 129 (see FIG. 2) attached to the cooler 26 may be used.

  Next, the effect of this embodiment will be described. It is considered that the frost formation amount of the cooler 26 increases as the operation time of the compressor 22 is longer. In the above configuration, either the heater defrost or the off-cycle defrost is executed based on the operation status (operation time) of the compressor 22. For this reason, compared with the case where a defrost operation is performed only by heater defrost, the situation where the temperature in the storage chamber 11 rises can be suppressed. Thereby, the time which operates the cooling device 20 can be reduced, and power consumption can be reduced.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the present embodiment, the condition for switching between heater defrost and off-cycle defrost in the control unit 40 is different from that in the above embodiment. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. In the present embodiment, when the compressor 22 is stopped within a certain period (T10 in FIG. 5) before the defrosting operation is started, the control unit 40 determines that the frosting amount of the cooler 26 is relatively small. Judgment is made and off-cycle defrost is executed as the defrosting operation. Moreover, the control part 40 judges that the amount of frost formation of the cooler 26 is comparatively large when the compressor 22 does not stop within the fixed period T10, and performs heater defrost as a defrost operation. That is, in this embodiment, the heater defrost and the off-cycle defrost are switched based on the operation status of the compressor 22 (whether the compressor 22 is stopped). The fixed period T10 is determined in advance by a test or the like and stored in the storage unit 43. The fixed period T10 is set to 2 hours, for example, but is not limited thereto. When the compressor 22 stops, it is considered that the frost on the cooler 26 is relatively small. For this reason, the defrosting of the cooler 26 can be sufficiently performed by the off-cycle defrost.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG. In the present embodiment, the condition for switching between heater defrost and off-cycle defrost in the control unit 40 is different from that in the above embodiment. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. In the present embodiment, the timer 44 measures the stop time of the compressor 22 during the cooling operation.

  When the total stop time (T12 + T13 in FIG. 6) during the cooling operation executed immediately before is equal to or longer than a preset reference stop time, the control unit 40 has a relatively small amount of frost formation on the cooler 26. And off-cycle defrosting is performed as a defrosting operation. Further, the control unit 40 determines that the frosting amount of the cooler 26 is relatively large when the total stop time (T11 in FIG. 6) during the cooling operation executed immediately before is shorter than the reference stop time. And heater defrost is performed as a defrost operation. That is, in the present embodiment, the heater defrost and the off-cycle defrost are switched based on the operation state of the compressor 22 (stop time of the compressor 22). The reference stop time is determined in advance by a test or the like and stored in the storage unit 43. The reference stop time is set to 2 hours, for example, but is not limited to this. When the stop time of the compressor 22 is long, it is considered that frost formation on the cooler 26 is small. For this reason, the defrosting of the cooler 26 can be sufficiently performed by the off-cycle defrost.

<Embodiment 4>
Next, Embodiment 4 of the present invention will be described with reference to FIG. In the present embodiment, the processing of the control unit 40 is different from the above embodiment. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. In the present embodiment, as shown in FIG. 7, the controller 40 presets the number of times the door is opened and closed (the number of times the internal thermistor 29 has exceeded the door opening and closing detection temperature) during the cooling operation that was executed immediately before. When the number of times is equal to or greater than the reference number, the defrosting end temperature (end temperature) of the off-cycle defrost is set higher than when the number is less than the reference number. In other words, when the door opening / closing frequency is greater than or equal to a preset reference frequency, off-cycle defrosting is executed for a longer time.

  Specifically, as shown in FIG. 7, the control unit 40, when the door opening / closing frequency (one time in FIG. 7) is less than the reference frequency during the cooling operation performed immediately before, Off-cycle defrost is performed until the temperature of 29 reaches the defrosting end temperature T5. On the other hand, when the door opening / closing frequency (three times in FIG. 7) is equal to or higher than the reference frequency during the cooling operation performed immediately before, the controller 40 sets the temperature of the internal thermistor 29 to the defrosting end temperature T6. Perform off-cycle defrost until In addition, although the defrost end temperature T5 is set at 5 degreeC, for example, and the defrost end temperature T6 is set at 8 degreeC, for example, it is not limited to this and can change suitably.

  When the door 16 is frequently opened and closed, a relatively large amount of outside air enters the storage chamber 11, so that the frost on the cooler 26 tends to increase. Moreover, since the temperature in the storage chamber 11 rises by opening the door 16, it is possible to detect opening and closing of the door by detecting the temperature in the storage chamber 11. For this reason, the number of times that the temperature in the storage chamber 11 exceeds the preset door opening / closing detection temperature is defined as the door opening / closing count, and when the door opening / closing count is equal to or more than a preset reference count, the off-cycle defrosting is performed. The defrosting of the cooler can be more reliably performed by increasing the end temperature of the. On the other hand, when the door opening / closing frequency is smaller than a preset reference frequency, it is possible to suppress the temperature rise in the cabinet by lowering the end temperature of the off-cycle defrost.

<Embodiment 5>
Next, Embodiment 5 of the present invention will be described with reference to FIG. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. In the present embodiment, the operation unit 42 is provided with a function for manually executing the heater defrost. As shown in FIG. 8, the control unit 40 executes heater defrosting when the operation unit 42 is operated (see T <b> 4 in FIG. 8). With such a configuration, the worker can execute the heater defrost at an arbitrary timing. Note that the processing of the control unit 40 described in the present embodiment can be used in combination with the processing of the control unit 40 described in the above embodiments.

<Related technology 1>
In the cooling storage illustrated above, the following techniques may be employed. Related Art 1 will be described with reference to FIG. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. In Related Art 1, the number of times that the temperature in the storage chamber 11 detected by the in-compartment thermistor 29 (storage chamber temperature sensor) exceeds a preset door opening / closing detection temperature is defined as the door opening / closing frequency, The door opening / closing frequency is stored in the storage unit 43.

  As shown in FIG. 9, when the door opening / closing frequency (in FIG. 9, the door opening / closing frequency is 3 times) is equal to or more than a preset reference frequency, the control unit 40 performs the cooling operation performed immediately before. A heater defrost is performed as a defrosting operation. Moreover, the control part 40 performs off-cycle defrost as a defrost operation, when the door opening / closing frequency | count (it is 1 time in FIG. 9) is less than a reference | standard frequency | count during the cooling operation performed immediately before. The door opening / closing detection temperature and the reference count are determined in advance by a test or the like and are stored in the storage unit 43. The reference number is set to 3 times, for example, but is not limited to this. That is, in Related Art 1, the temperature of the in-compartment thermistor 29 (and thus the number of times the door is opened and closed) is set as a switching condition between the heater defrost and the off-cycle defrost.

  When the door 16 is frequently opened and closed, a relatively large amount of outside air enters the storage chamber 11, so that the frost on the cooler 26 tends to increase. Moreover, since the temperature in the storage chamber 11 rises by opening the door 16, it is possible to detect opening and closing of the door 16 by detecting the temperature in the storage chamber 11. That is, the internal thermistor 29 is used as a sensor that detects the number of times the door is opened and closed. For this reason, the number of times the temperature in the storage chamber 11 exceeds the preset door opening / closing detection temperature is set as the door opening / closing number, and the heater defrosting is executed when the door opening / closing number is equal to or more than a preset reference number. Thereby, defrosting of the cooler 26 can be performed more reliably.

  Further, when the door 16 is opened and closed, outside air enters the storage chamber 11 and the temperature of the storage chamber 11 rises. For this reason, during the cooling operation, when the detected temperature of the internal thermistor 29 is always equal to or higher than the internal set temperature, the temperature in the storage chamber 11 is unlikely to decrease as a result of a large number of opening / closing times or opening / closing times of the door 16. Can be considered. For this reason, instead of counting the number of times the door 16 is opened and closed, the door opening / closing state is estimated from the relationship between the temperature detected by the internal thermistor 29 and the internal set temperature, and the heater defrosting and off-cycle defrosting are switched based on this. May be. Specifically, when the detected temperature of the internal thermistor 29 is equal to or higher than the internal set temperature during the cooling operation, the control unit 40 executes the heater defrost as the defrosting operation, and during the cooling operation, When the detected temperature of the inner thermistor 29 is lower than the internal set temperature, the off-cycle defrost may be executed as the defrosting operation. In addition, the time when the detected temperature is lower than the set temperature is counted, and if the total time during the cooling operation is equal to or more than the preset reference time, off-cycle defrost is executed as the defrost operation. And when the sum total of the time in cooling operation is shorter than the preset reference time, it is good also as a structure which performs a heater defrost as a defrost operation.

<Related technology 2>
In the cooling storage illustrated above, the following techniques may be employed. Related Art 2 will be described with reference to FIG. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. In Related Art 2, the temperature of the cooler 26 is detected using a defrosting thermistor 129 (see FIG. 2) attached to the cooler 26. In the present embodiment, during the cooling operation, the time measuring unit 44 has a temperature detected by the defrosting thermistor 129 (cooler temperature sensor) lower than a preset cooler frost temperature (reference cooler temperature). It is assumed that the time (for example, T1 to T3 in FIG. 10) is counted. The cooler frosting temperature referred to here is a temperature at which frost is generated in the cooler 26 below this temperature (or a temperature at which frost is easily generated), and is a temperature determined in advance by a test or the like. The cooler frosting temperature is stored in the storage unit 43 and is set at 0 ° C., for example, but is not limited thereto.

  When the total time (see T1 + T2 in FIG. 10) that is lower than the cooler frosting temperature during the cooling operation that was executed immediately before is equal to or greater than a preset reference time T0, A heater defrost is performed as a defrosting operation. Moreover, the control part 40 performs off-cycle defrost as a defrost operation, when the sum total (refer T3 of FIG. 10) in the cooling operation performed immediately before is shorter than preset reference time T0. To do. The reference time T0 is a time determined in advance by a test or the like, and is stored in the storage unit 43. The reference time T0 is set to 1 hour, for example, but is not limited to this. That is, in the related art 2, the temperature of the defrosting thermistor 129 (and hence the temperature of the cooler 26) is set as the switching condition between the heater defrost and the off-cycle defrost.

  The longer the time during which the temperature of the cooler 26 is lower, the easier the frost formation on the cooler 26 occurs. It is also conceivable that the temperature of the cooler 26 is further lowered due to a decrease in heat exchange efficiency of the cooler 26 due to frost formation. For this reason, when the sum total of the time lower than the cooler frosting temperature during the cooling operation performed immediately before is equal to or more than a preset reference time T0, the heater defrost is performed to perform cooling. The defrosting of the vessel 26 can be performed more reliably.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, a two-door vertical refrigerator is illustrated as the cooling storage 10, but is not limited thereto.
(2) The switching conditions of the heater defrost and off-cycle defrost by the control unit 40 described in the above embodiments and related technologies can be used in appropriate combination. Moreover, the control part 40 performs the process (process which switches the defrost end temperature of off-cycle defrost) illustrated in the said Embodiment 4, when the conditions which perform off-cycle defrost in each said embodiment are satisfy | filled. Also good.
(3) In each of the above embodiments, the controller 40 may perform the heater defrost periodically (every predetermined time, for example, every 48 hours) regardless of the switching condition.
(4) In each of the above embodiments, a touch panel may be used as the operation unit 42.

DESCRIPTION OF SYMBOLS 10 ... Cooling storage, 11 ... Storage room, 16 ... Door, 20 ... Cooling device, 22 ... Compressor, 26 ... Cooler, 27 ... Inside fan, 29 ... Inside thermistor (stock room temperature sensor), 30 ... Ambient Temperature thermistor (ambient temperature sensor) 31 ... defrost heater 40 ... control unit 42 ... operation unit 44 ... timer

Claims (6)

A storage room for storing the storage;
A cooling device having a compressor;
A cooler that generates cold air by being connected to the cooling device;
An internal fan that circulates and supplies the cool air generated by the cooler into the storage chamber;
A defrost heater for defrosting frost adhering to the cooler;
A controller that controls the operation of the compressor, the internal fan, and the defrost heater,
The controller is
A cooling operation for cooling the storage chamber by operating the compressor and the internal fan, and a defrosting operation for defrosting frost attached to the cooler after the cooling operation are performed. It is assumed
Furthermore, the control unit
Based on the operating status of the compressor at the time of the cooling operation performed immediately before,
A cooling storage that executes either one of a heater defrost for heating the cooler by the defrost heater and an off-cycle defrost for stopping the compressor and operating the internal fan as the defrost operation. It has a timer,
The timekeeping unit is configured to time the operation time of the compressor during the cooling operation,
The controller is
When the total of the operation time during the cooling operation executed immediately before is equal to or more than a preset reference operation time, the heater defrost is executed as the defrosting operation,
The cooling storage according to claim 1, wherein the off-cycle defrost is executed as the defrosting operation when a total of the operation times during the cooling operation executed immediately before is shorter than the reference operation time. The controller is
When the compressor stops within a certain period before starting the defrosting operation, the off-cycle defrost is performed as the defrosting operation,
The cooling storage according to claim 1, wherein the heater defrost is executed as the defrosting operation when the compressor does not stop within the predetermined period. It has a timer,
The time measuring unit is configured to time the stop time of the compressor during the cooling operation,
The controller is
When the total of the stop time during the cooling operation executed immediately before is equal to or more than a preset reference stop time, the off-cycle defrost is executed as the defrost operation,
The cooling storage according to claim 1, wherein the heater defrosting is executed as the defrosting operation when a total of the stop time during the cooling operation executed immediately before is shorter than the reference stop time. A door capable of opening and closing the storage room;
A storage room temperature sensor for detecting the temperature in the storage room,
In the case where the number of times the temperature in the storage chamber detected by the storage chamber temperature sensor exceeds a preset door opening / closing detection temperature is the door opening / closing frequency,
The controller is
During the cooling operation performed immediately before, when the number of times of opening and closing the door is equal to or greater than a preset reference number, the end temperature of the off-cycle defrost is increased as compared with the case where the number of times is less than the reference number. The cooling storehouse as described in any one of Claims 1-4. It has an operation part,
The controller is
The cooling storage according to any one of claims 1 to 5, wherein the heater defrost is executed when the operation unit is operated.

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