JP7201412B2 - cold storage - Google Patents

Description

The present invention relates to cold storage.

2. Description of the Related Art Conventionally, as a cooling storage, there is known a structure provided with a sensor capable of detecting opening of a door (Patent Document 1 below). Japanese Patent Laid-Open No. 2002-200003 describes a heat sensor that detects the heat (infrared rays) of a person who opens the door to detect that the door has been opened.

JP 2006-266582 A

When the door of the cold store is opened, outside air with high humidity enters the store room. When outside air containing humidity goes from the storage compartment to the cooler, frost builds up on the cooler, resulting in a decrease in cooling capacity. As in the above configuration, if the cooling storage is provided with a dedicated sensor capable of detecting that the door is opened, the opening of the door is detected and the operation of the cooling device provided in the cooling storage is controlled to cool the It is possible to suppress frost formation on the vessel. However, even in a refrigerated storage that does not have a dedicated sensor that detects when the door is opened, it is required to suppress frost formation on the cooler when the door is opened. There is room for

The present invention has been completed based on the circumstances as described above, and does not use a dedicated sensor for detecting that the door has been opened, and outside air entering the storage room causes frost to form on the cooler. The purpose is to control the situation.

In order to solve the above problems, the cooling storage of the present invention includes a box-shaped storage body having a storage room and a cooler room, a door attached to the storage body and capable of opening and closing the storage room, and the storage room. a cooling device that cools the storage chamber, a temperature sensor that detects the temperature in the storage chamber, and a control unit, and the cooling device includes a cooler housed in the cooler chamber and a cooling cycle together with the cooler and a cooling fan that sucks air in the storage chamber into the cooler chamber and supplies air that has passed through the cooler into the storage chamber, wherein the control unit controls the compressor and by operating the cooling fan, a cooling operation is performed to supply the air cooled by the cooler into the storage chamber, and further, the control unit, based on the temperature information obtained from the temperature sensor, It is characterized in that, when it is determined that the temperature in the storage chamber has risen during the cooling operation, capacity reduction processing is executed to reduce the cooling capacity of the cooling device.

When the door is opened, outside air enters the storage room, and the temperature inside the storage room rises. Therefore, when the control unit determines that the temperature inside the storage chamber has increased during the cooling operation, it determines that the door has been opened, and executes the capacity reduction process. By lowering the cooling capacity of the cooling device, it is possible to suppress the factors that cause frost on the cooler (for example, outside air entering the storage room is directed to the cooler room by the cooling fan, or the temperature of the cooler drops). It is possible to prevent frost on the cooler. As described above, in the above configuration, the temperature information acquired from the temperature sensor is used to execute the capacity reduction process. It is possible to prevent frost from forming on the cooler.

Further, the control unit may reduce the operating capacity of the cooling fan in the capacity reduction process. By lowering the operating capacity of the cooling fan, the air inside the storage room is prevented from being sucked into the cooler room, so outside air (air with relatively high humidity) that enters the storage room is directed to the cooler room. The situation can be suppressed, and the situation where the cooler is frosted can be suppressed.

Further, the control unit executes the capacity reduction process when determining that the temperature detected by the temperature sensor during the cooling operation is equal to or higher than a reference temperature. When the lowest temperature among the temperatures detected by the sensor is set as the lowest temperature, the reference temperature may be a temperature set higher than the lowest temperature by a predetermined temperature.

During the cooling operation, the temperature in the storage compartment gradually decreases, and when the door is opened during the cooling operation, outside air enters the storage compartment, and the temperature in the storage compartment rises. Therefore, the minimum temperature can be considered as the temperature in the storage compartment just before the door is opened, and the temperature detected by the temperature sensor after that is higher than the minimum temperature. For this reason, when it is determined that the temperature detected by the temperature sensor has reached or exceeded the reference temperature (minimum temperature + predetermined temperature), the capacity reduction process is executed to prevent frost from forming on the cooler when the door is opened. You can suppress the situation that sticks.

Further, a storage unit storing the minimum temperature may be provided, and the control unit may delete the minimum temperature stored in the storage unit when the compressor starts to operate. At the start of the cooling operation, the minimum temperature of the previous cooling operation can be automatically deleted. As a result, it is possible to prevent the control unit from executing the capacity reduction process with reference to the lowest temperature during the previous cooling operation.

Further, the control unit executes the capacity reduction process when it is determined that the temperature detected by the temperature sensor during the cooling operation is equal to or higher than a reference temperature. , during the cooling operation, an average value of the temperature detected by the temperature sensor over a predetermined time period is calculated for each of the predetermined time periods, and the lowest of the plurality of average values calculated by the control unit When the average value is the lowest average value, the reference temperature may be a temperature set higher than the lowest average value by a predetermined temperature.

During the cooling operation, the temperature in the storage compartment gradually decreases, and when the door is opened during the cooling operation, outside air enters the storage compartment, and the temperature in the storage compartment rises. Therefore, the lowest average value can be considered as a numerical value corresponding to the temperature in the storage compartment just before the door is opened, and thereafter the temperature detected by the temperature sensor becomes higher than the lowest average value. For this reason, when it is determined that the temperature detected by the temperature sensor exceeds the reference temperature (minimum average value + predetermined temperature), the capacity reduction process is executed to prevent frost on the cooler when the door is opened. It is possible to suppress the situation where Moreover, in the above configuration, since the capacity reduction process is executed based on the average value of the temperature detected by the temperature sensor, it is possible to reduce the effects of momentary errors of the temperature sensor, for example.

Further, a storage section storing the lowest average value may be provided, and the control section may delete the lowest average value stored in the storage section when the compressor starts to operate. At the start of the cooling operation, the lowest average value of the previous cooling operation can be automatically deleted. As a result, it is possible to prevent the control unit from executing the ability reduction process with reference to the lowest average value of the previous cooling operation.

Further, a heater that heats the cooler is provided, and the control unit executes heater defrost for defrosting frost adhered to the cooler by operating the heater, and after the heater defrost is completed After a predetermined standby time has elapsed, fan operation processing is executed to operate the cooling fan for a predetermined operation time. It can be assumed that it does not reduce the driving ability of Water droplets adhering to the cooling fan can be blown off by executing the fan operation process. Since the operability of the cooling fan is not lowered during the fan operation process, water droplets adhering to the cooling fan can be reliably blown off.

Further, the control unit is configured to perform off-cycle defrosting, which defrosts frost adhered to the cooler by stopping the compressor and operating the cooling fan. While the off-cycle defrost is being performed, the operability of the cooling fan may not be lowered. In off-cycle defrosting, the cooler can be defrosted by sending the air in the storage compartment to the cooler compartment with a cooling fan. If the operability of the cooling fan deteriorates during the off-cycle defrost, the time required for the off-cycle defrost will become longer. Therefore, during the off-cycle defrosting, the operating performance of the cooling fan is not lowered.

Further, when the control unit determines that the temperature detected by the temperature sensor is higher than 0° C., it is possible not to execute the capacity reduction process. When the temperature inside the storage compartment is higher than 0°C, frost rarely forms on the cooler. In other words, when the temperature in the storage chamber is higher than 0° C., the capacity reduction process is not executed, so the temperature in the storage chamber can be quickly lowered.

Further, an operation unit operated by a user is provided, and the control unit disables execution of the ability reduction processing from a first mode that enables execution of the ability reduction processing by operating the operation unit. A mode switching process for switching to the second mode can be executed. By setting the second mode in which the performance reduction process is disabled, for example, it is possible not to perform the performance reduction process when the storage room needs to be cooled all the time. It should be noted that "disabling performance reduction processing" means a state in which the performance execution processing is not executed even when the control unit determines that the temperature inside the storage chamber has risen.

ADVANTAGE OF THE INVENTION According to this invention, the frost on a cooler by the outside air which entered into a storage room can be suppressed, without using the sensor for exclusive use for detecting that the door opened.

1 is a perspective view of a cooling storage according to Embodiment 1 of the present invention; FIG. Sectional view showing the internal structure of the cooling storage Block diagram showing the electrical configuration of the cold storage Timing chart showing an example of the operation of the cooling device during cooling operation 4 is a flow chart showing processing of a control unit related to minimum temperature update processing; Flowchart showing processing of control unit related to capacity reduction processing Timing chart showing an example of the operation of the cooling device during heater defrost Timing chart showing an example of cooling device operation during off-cycle defrost Flowchart showing processing of the control unit related to mode switching processing Diagram showing a modification of the cooling storage Flowchart showing processing of the control unit related to minimum average value update processing Flowchart showing the processing of the control unit related to the ability reduction processing of the second embodiment Graph showing an example of temperature change over time in the storage room during cooling operation

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 10. FIG. In this embodiment, a horizontal (table-type) refrigerator is exemplified as the cooling storage 10 . The cooling storage 10 includes a horizontally long storage body 11, as shown in FIGS. The storage body 11 is a box-shaped heat-insulating box body, is mainly composed of a metal plate such as a stainless steel plate, and has a storage chamber 12 and a cooler chamber 17 . More specifically, the storage body 11 is composed of a box portion 27 that mainly configures the storage chamber 12 and a box portion 18 that mainly configures the cooler chamber 17 .

A pair of double doors 14, 14 are rotatably attached to the storage body 11 (more specifically, the box portion 27). The storage chamber 12 has an open front surface, and the opening can be opened and closed by a pair of doors 14 , 14 . Thereby, it becomes the structure which can arrange|position a stored material in the storage chamber 12 through an opening. Further, the storage body 11 is supported by four legs 15 provided on the bottom surface. A machine room 13 is arranged on the side (left side) of the storage room 12 . The cooling storage 10 has a side panel 28 (see FIG. 2) that constitutes the left side, and the machine room 13 is a space surrounded by the storage main body 11, the front panel 16 (see FIG. 1), and the side panel 28. ing. The machine room 13 can be opened and closed by a front panel 16 .

As shown in FIG. 1 , the cold storage 10 includes a cooling device 20 (cooling unit) capable of cooling the storage room 12 . The cooling device 20 includes a base 21, a compressor 22, a condenser fan 23, a condenser 24, a cooler 30, and a cooling fan 25, and each device is arranged on the base 21. Therefore, it is unitized. Specifically, a compressor 22 , a condenser fan 23 , and a condenser 24 are placed on the base 21 in this order from the back side. A lid body 19 is attached to the upper surface of the condenser 24 to cover the opening of the box portion 18 from the front, and a cooler 30 is attached to the back side of the lid body 19 in a cantilevered manner. The cooler 30 can be inserted into the inside of the box portion 18 (cooler chamber 17) from the front. The condenser fan 23 is provided on the rear side of the condenser 24 and has a function of air-cooling the condenser 24 . An electric equipment box 26 is provided on the front side of the lid body 19 . A controller 70 (see FIG. 3), which will be described later, is housed inside the electrical box 26 . It should be noted that the arrangement mode of each device constituting the cooling device 20 is not limited to the one described above.

In the cooling device 20, the compressor 22, the condenser 24, the expansion means (capillary tube and expansion valve, not shown), and the cooler 30 are circulated and connected in this order by refrigerant pipes containing refrigerant. to configure the cooling cycle. As shown in FIG. 2, the cooler 30 is covered with a pair of covers 37 and 38 made of metal plates such as stainless steel plates, and a cooler temperature sensor 41 is attached to the cover 38 . The cooler temperature sensor 41 has a function of detecting the temperature of the cooler 30 and is used to determine that defrosting is completed. A cooling fan 25 is attached to the upper portion of the cover 37 . A defrosting heater 42 (heater) made of, for example, a glass tube heater is attached to the lower end of the cover 37 .

The storage chamber 12 and the cooler chamber 17 are arranged adjacent to each other and partitioned by a partition plate 45 . The upper part of the partition plate 45 is provided with an outlet port 46 that communicates the storage chamber 12 and the cooler chamber 17, and the lower portion of the partition plate 45 is provided with a suction port 47 that communicates the storage chamber 12 and the cooler chamber 17. is provided. Further, below the cooler 30 housed in the cooler chamber 17, an internal temperature sensor 43 (temperature sensor) for detecting internal temperature (temperature inside the storage chamber) is attached. The internal temperature sensor 43 is arranged between the cooler 30 and the suction port 47, and can detect the temperature of the air (the temperature inside the storage chamber 12) flowing from the suction port 47 to the cooler 30. ing. Note that the place where the internal temperature sensor 43 is installed is not limited to the one described above, and may be installed at a position where the temperature inside the storage room 12 can be detected. For example, a thermistor can be used as each of the temperature sensors 41 and 43, but the present invention is not limited to this, and a temperature sensor other than the thermistor (for example, a thermocouple or the like) may be used.

Next, the electrical configuration of the cooling storage 10 will be described. As shown in FIG. 3 , the cold storage 10 has a control section 70 . The control unit 70 includes a display unit 71, an operation unit 72, a storage unit 73, a compressor 22, a condenser fan 23, a cooling fan 25, an internal temperature sensor 43, a cooler temperature sensor 41, a defrost heater 42, and a timer. timers 75 are electrically connected to each other.

The control unit 70 is mainly composed of a CPU, for example, and the storage unit 73 is composed of, for example, a ROM and a RAM. The control unit 70 executes a computer program stored in the storage unit 73 to operate each device (compressor 22, condenser fan 23, cooling fan 25, defrosting heater 42) connected to the control unit 70. can be controlled.

The display unit 71 and the operation unit 72 are provided on, for example, a control panel 76 (see FIG. 1) provided on the front surface of the electrical box 26 . The display unit 71 is configured by, for example, a display panel such as a liquid crystal panel, and the operation unit 72 is configured by, for example, buttons (or touch panel) that can be pressed. A user can operate the operation unit 72 by opening the front panel 16 . By operating the operation unit 72, the operator can operate the cooling storage 10 and perform various settings (such as changing the set internal temperature).

Next, processing of the control unit 70 will be described. The control unit 70 operates the compressor 22 , the cooling fan 25 , and the condenser fan 23 to perform a cooling operation of supplying the air cooled by the cooler 30 into the storage chamber 12 . By driving the cooling fan 25, the air in the storage chamber 12 is sucked from the suction port 47 into the cooler chamber 17, and then the air that has passed through the cooler 30 (the air that is heat-exchanged when passing through the cooler 30 is generated). cold air) is supplied into the storage chamber 12 from the outlet 46 . As a result, cold air is circulated into the storage compartment 12 to cool the storage compartment 12 .

In the cooling operation, when the temperature detected by the internal temperature sensor 43 is equal to or higher than the preset upper limit temperature K21, the control unit 70 operates the compressor 22, the condenser fan 23, and the cooling fan 25 to cool the refrigerator. When the temperature detected by the internal temperature sensor 43 reaches the preset lower limit temperature K22, the compressor 22, the condenser fan 23 and the cooling fan 25 are stopped. Specifically, the storage unit 73 stores a preset temperature inside the refrigerator, the upper limit temperature K21 is a temperature higher than the preset temperature inside the refrigerator by a predetermined temperature, The temperature is a predetermined temperature lower than the set temperature. By performing such a cooling operation, the temperature in the storage compartment 12 is maintained near the internal preset temperature.

Then, when the control unit 70 determines that the temperature inside the storage compartment 12 has risen during the cooling operation based on the temperature information acquired from the internal temperature sensor 43, the control unit 70 performs capacity reduction processing for reducing the operating capacity of the cooling fan 25. to run. That is, the control unit 70 reduces the cooling capacity of the cooling device 20 by reducing the operating capacity of the cooling fan 25 . More specifically, in the capacity reduction process, for example, the operating capacity is reduced by stopping the cooling fan 25 for a predetermined period of time. The operability of the cooling fan 25 may be reduced by reducing the rotational speed of the cooling fan 25, or the operability of the cooling fan 25 may be reduced by intermittently operating the cooling fan 25 that has been operating continuously. may

Next, a specific description will be given of the control related to the ability reduction process. The storage unit 73 stores the lowest temperature K1 among the temperatures detected by the internal temperature sensor 43 during the cooling operation, and the control unit 70 performs the capacity reduction process based on the lowest temperature K1. Run. When the cooling operation is started (when the operation of the compressor 22 is started), the control unit 70 erases the lowest temperature K1 (the lowest temperature during the previous cooling operation) stored in the storage unit 73, and restores the initial value of the lowest temperature K1. As the value, for example, the value of the temperature detected by the internal temperature sensor 43 at that time is stored in the storage unit 73 . Then, as shown in FIG. 5, the control unit 70 determines that the temperature detected by the internal temperature sensor 43 during the cooling operation (current temperature K2) is lower than the minimum temperature K1 stored in the storage unit 73. If so ("YES" in step S11), minimum temperature update processing is executed (step S12). In the minimum temperature update process, the control unit 70 updates the current temperature K2 as the minimum temperature K1 and stores it in the storage unit 73 . That is, the lowest temperature K1 is the lowest temperature among the temperatures detected by the temperature sensor during the cooling operation.

Note that the sampling time T9 of the internal temperature sensor 43 by the control unit 70 (the interval at which the temperature detected by the internal temperature sensor 43 is acquired) is, for example, 0.1 second, and whether or not the minimum temperature update process is performed is determined. This determination (step S11) is performed, for example, every sampling time T9, but is not limited to this. The sampling time of the inside temperature sensor 43 and the interval for determining whether or not to update the minimum temperature can be changed as appropriate.

Then, as shown in FIG. 6, when the control unit 70 determines that the temperature (current temperature K2) detected by the internal temperature sensor 43 during the cooling operation has reached or exceeded the reference temperature K4 (at step S21 "YES"), and when it is determined that the temperature detected by the internal temperature sensor 43 is 0° C. or lower ("YES" in step S22), a capacity reduction process is executed (step S23). That is, when the control unit 70 determines that the temperature detected by the internal cold storage temperature sensor 43 is higher than 0° C., the control unit 70 does not perform the capacity reduction process.

The above reference temperature K4 is a temperature set higher than the minimum temperature K1 by a predetermined temperature K3 (reference temperature K4=minimum temperature K1+predetermined temperature K3). That is, the control unit 70 determines that "the temperature inside the storage compartment 12 has risen during the cooling operation" when the current temperature K2 becomes equal to or higher than the reference temperature K4, and executes the capacity reduction process. Further, the predetermined temperature K3 is set at, for example, 1K (Kelvin), but is not limited to this and can be changed as appropriate.

It should be noted that the predetermined temperature K3 can be determined by performing tests or the like in advance. For example, when the volume of the storage chamber 12 is small, the temperature rise when the door 14 is opened is likely to increase. preferable. Also, the period during which the performance reduction process is executed (the period during which the cooling fan 25 is stopped) can be set as appropriate.

FIG. 4 will be exemplified to explain the control related to the minimum temperature update process (step S12 in FIG. 5) and the capacity reduction process (step S23 in FIG. 6). As shown in FIG. 4, when the temperature detected by the internal temperature sensor 43 reaches the upper limit temperature (see time T1), the control unit 70 starts the cooling operation (see cooling operation F1). As a result, the temperature detected by the internal cold storage temperature sensor 43 gradually decreases. Therefore, the minimum temperature K1 is updated to a smaller value each time the control unit 70 executes the minimum temperature update process at predetermined time intervals. At time T2, the door 14 is opened and the outside air enters the storage room 12, causing the temperature inside the storage room 12 to rise. Therefore, the temperature detected by the inside temperature sensor 43 at time T2 is the lowest temperature K1. Then, when the temperature in the storage compartment 12 rises and the temperature detected by the storage compartment temperature sensor 43 reaches the reference temperature K4 (time point T3), the control unit 70 executes the capacity reduction process and turns on the cooling fan. 25 is stopped for a predetermined time T4.

Further, in the present embodiment, the control unit 70 performs a defrosting operation for defrosting the cooler 30 . Examples of the defrosting operation include heater defrost and off-cycle defrost. In the heater defrost, the controller 70 stops the compressor 22, the condenser fan 23, and the cooling fan 25 and operates the defrost heater 42 to heat the cooler 30, as shown in period T5 in FIG. and defrost the frost adhering to the cooler 30. - 特許庁When the temperature detected by the cooler temperature sensor 41 reaches a preset temperature K5, the control unit 70 stops the defrosting heater 42 and terminates the heater defrosting.

Thereafter, the control unit 70 executes fan operation processing for operating the cooling fan 25 for a predetermined operating time T7 after a predetermined waiting time T6 (draining time of the cooler 30) has elapsed after the heater defrost is completed. As a result, water droplets adhering to the cooling fan 25 can be blown off. In the fan operation process, the control unit 70 keeps the rotation speed of the cooling fan 25 constant regardless of changes in the temperature inside the storage chamber 12 (the temperature detected by the internal temperature sensor 43). In other words, the control unit 70 does not lower the operability of the cooling fan 25 while executing the fan operation process. In addition, in FIG. 7, the defrosting heater 42 is intermittently operated in the heater defrost, but the defrosting heater 42 may be operated continuously.

In the off-cycle defrost, the controller 70 stops the compressor 22 and operates the cooling fan 25 to defrost the cooler 30 as shown in period T8 in FIG. The control unit 70 terminates the off-cycle defrost when the temperature detected by the cooler temperature sensor 41 reaches a preset temperature K6. Note that while the off-cycle defrosting is being performed, the control unit 70 keeps the rotation speed of the cooling fan 25 constant regardless of changes in the temperature inside the storage chamber 12 (the temperature detected by the inside temperature sensor 43). . In other words, the controller 70 does not reduce the operability of the cooling fan 25 while off-cycle defrosting is being performed.

Note that the control unit 70 executes either heater defrost or off-cycle defrost as the defrosting operation when a predetermined defrosting start condition is satisfied. The defrosting start condition is "that a certain period of time has passed since the previous defrosting operation ended" or "that a preset time has been reached", and can be set as appropriate. Further, for example, the control unit 70 executes heater defrost when the internal set temperature when the defrosting start condition is satisfied is lower than the reference value, and when the internal set temperature is higher than the reference value Power consumption is reduced by executing off-cycle defrost, but the switching condition between heater defrost and off-cycle defrost is not limited to this.

Further, as shown in FIG. 9, when the operation unit 72 of the control panel 76 is operated by the user ("YES" in step S31), the control unit 70 changes from the first mode in which the performance reduction process can be executed. A mode switching process is executed to switch to the second mode in which the ability reduction process cannot be executed (step S32). It should be noted that "disabling the performance reduction process" referred to here means that the temperature detected by the internal temperature sensor 43 (current temperature K2) is determined to be equal to or higher than the reference temperature K4 (control unit 70 determines that the temperature in the storage chamber 12 has risen), the capacity execution process is not executed.

By operating the operation unit 72 in the state of the second mode, the control unit 70 can switch from the second mode to the first mode. Further, in the present embodiment, the case where the mode switching process is executed by operating the operation unit 72 provided on the control panel 76 is exemplified, but the operation unit is not limited to this. A switch provided on a circuit board that constitutes the control unit 70 can be used as the operation unit.

Next, the effects of this embodiment will be described. According to the present embodiment, when the door 14 is opened, outside air enters the storage room 12 and the temperature inside the storage room 12 rises. Therefore, when the control unit 70 determines that the temperature in the storage chamber 12 has risen, it determines that the door 14 has opened, and executes the capacity reduction process. By reducing the operating capacity of the cooling fan 25 in the capacity reduction process, the air inside the storage room 12 is prevented from being sucked into the cooler room 17. Air with a high air temperature can be prevented from going to the cooler chamber 17, and the frost on the cooler 30 can be prevented. In this embodiment, the temperature information acquired from the internal temperature sensor 43 is used to execute the capacity reduction process. A situation in which frost forms on the cooler 30 when the door 14 is opened without using a proximity sensor that detects proximity, an infrared sensor that detects the heat (infrared rays) of a person who opens the door 14, etc. can be suppressed.

Further, the control unit 70 is configured to execute a capacity reduction process when it is determined that the temperature detected by the internal temperature sensor 43 during the cooling operation is equal to or higher than the reference temperature K4. When the lowest temperature among the temperatures detected by the temperature sensor 43 is the lowest temperature K1, the reference temperature K4 is a temperature set higher than the lowest temperature K1 by a predetermined temperature K3. During the cooling operation, the temperature in the storage chamber 12 gradually decreases, and when the door 14 is opened during the cooling operation, the outside air enters the storage chamber 12 and the temperature in the storage chamber 12 rises. Therefore, the minimum temperature K1 can be considered as the temperature in the storage compartment 12 immediately before the door 14 is opened, and the temperature detected by the internal temperature sensor 43 thereafter becomes higher than the minimum temperature K1. Therefore, when it is determined that the temperature detected by the internal temperature sensor 43 is equal to or higher than the reference temperature K4 (minimum temperature K1 + predetermined temperature K3), the capacity reduction process is executed, and the door 14 is opened. It is possible to suppress the situation where the cooler 30 is frosted immediately.

When the temperature detected by the internal temperature sensor 43 rises by a predetermined temperature (hereinafter referred to as a predetermined temperature K50) within a predetermined time (hereinafter referred to as a predetermined time T50), the controller 70 However, it is also possible to perform control such that it is determined that the door 14 is open and the ability reduction process is executed. That is, it may be determined that the door 14 is opened based on the change in temperature detected by the internal temperature sensor 43 during the predetermined time T50. However, with such control, it is difficult to appropriately set the predetermined time T50, resulting in low determination accuracy. The reason for this will be explained in detail below.

The temperature detected by the internal temperature sensor 43 may slightly fluctuate due to causes not caused by the opening of the door 14 (for example, uneven temperature of the air touching the internal temperature sensor 43). Compared with the temperature change when the door 14 is opened, the fluctuation occurs in a short period of time and is small. In other words, when the door 14 is opened, the temperature detected by the internal temperature sensor 43 slightly fluctuates (rises and falls) in the short term (due to a cause other than the opening of the door 14), but in the long term rises (due to door 14 being opened).

If the above-described predetermined time T50 (in other words, the interval at which the control unit 70 refers to the temperature detected by the internal temperature sensor 43) is set short, the control unit 70 can detect only short-term fluctuations in the temperature detected by the internal temperature sensor 43. will be referred to. In other words, since the control unit 70 does not refer to the long-term temperature change when the door 14 is opened, there is concern that it may not be possible to correctly determine that the door 14 has been opened.

If the predetermined time T50 is set long, the control unit 70 does not refer to short-term temperature changes (temperature changes not caused by the opening of the door 14), but long-term temperature changes (the A relatively large temperature rise) is referred to, so it is possible to correctly determine that the door 14 has been opened. However, since the time during which the door 14 can be opened is basically short, if the predetermined time T50 is too long, the temperature change after the door 14 is closed will also be referred to. Difficult to set. That is, the method of determining whether the door 14 is open based on the change in the temperature detected by the internal temperature sensor 43 during the predetermined time T50 is affected by the temporal change in the temperature detected by the internal temperature sensor 43, so the determination accuracy tends to be low.

On the other hand, in the present embodiment, the controller 70 determines whether the door 14 is opened based on the amount of increase (predetermined temperature K3) from the minimum temperature K1. That is, in the present embodiment, since it is determined whether or not the door 14 is opened without referring to the time, there is no influence of time change of the temperature detected by the internal temperature sensor 43, and the determination accuracy is improved. can be higher. It should be noted that the predetermined temperature K3 can be appropriately set by experimentally measuring the increase in temperature detected by the internal temperature sensor 43 when the door 14 is opened. For example, by setting the predetermined temperature K3 to a value greater than the short-term temperature rise value of the internal temperature sensor 43 (the temperature rise value not due to the opening of the door 14), the opening of the door 14 can be more easily detected. can be reliably detected.

The control unit 70 also includes a storage unit 73 that stores the minimum temperature K1, and the control unit 70 erases the minimum temperature K1 stored in the storage unit 73 when the compressor 22 starts operating. At the start of the cooling operation, the minimum temperature K1 of the previous cooling operation can be automatically deleted. As a result, it is possible to prevent the performance reduction process from being executed with reference to the lowest temperature K1 during the previous cooling operation.

The controller 70 also includes a defrost heater 42 that heats the cooler 30, and the controller 70 operates the defrost heater 42 to perform heater defrost for defrosting the cooler 30, and the heater defrost is performed. After a predetermined waiting time T6 has elapsed after the end of the cooling fan operation process, the cooling fan 25 is operated for a predetermined operating time T7. does not lower the operability of the cooling fan 25. Water droplets adhering to the cooling fan 25 can be blown off by executing the fan operation process. Since the operability of the cooling fan 25 is not lowered during the fan operation processing, water droplets adhering to the cooling fan 25 can be reliably blown off.

In addition, the control unit 70 stops the compressor 22 and operates the cooling fan 25 to perform an off-cycle defrost that defrosts frost adhered to the cooler 30. While executing the cycle defrost, the operability of the cooling fan 25 is not lowered. In the off-cycle defrosting, the cooler 30 can be defrosted by sending the air in the storage chamber 12 to the cooler chamber 17 by the cooling fan 25 . If the operability of the cooling fan 25 decreases during the off-cycle defrost, the time required for the off-cycle defrost will become longer. Therefore, during the off-cycle defrosting, the operating ability of the cooling fan 25 is kept from being lowered.

Further, when the control unit 70 determines that the temperature detected by the internal cold storage temperature sensor 43 is higher than 0° C., the control unit 70 does not perform the capacity reduction process. When the temperature in the storage room 12 is higher than 0° C., even if the air in the storage room 12 moves toward the cooler 30, the cooler 30 hardly frosts. If the internal temperature is 0° C. or lower, the capacity reduction process is executed. In other words, when the temperature in the storage chamber 12 is higher than 0° C., the capacity reduction process is not executed, so the temperature in the storage chamber 12 can be lowered quickly.

Further, an operation unit 72 operated by a user is provided, and the control unit 70 disables execution of the ability reduction process from the first mode in which the ability reduction process can be executed by operating the operation unit 72. Mode switching processing for switching to the second mode is executed. By setting the second mode that disables performance reduction processing, for example, it is possible not to execute the performance reduction processing when the storage chamber 12 needs to be cooled all the time.

A configuration that allows switching to the second mode is particularly suitable when applied to a cold storage 110 as shown in FIG. In the cooling storage 110 shown in FIG. 10 , a container 112 (for example, hotel bread) is supported on a shelf 111 provided in the storage chamber 12 , and the container 112 is allowed to pass through an opening 114 formed in a ceiling wall portion 113 of the storage main body 11 . It is possible to take out the cooling object (for example, ice cream etc.) inside. In such a configuration, it is often required to always cool the object to be cooled within the container 112 . For this reason, it is preferable to prevent the performance reduction process from being executed by setting the second mode.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIGS. 11 to 13. FIG. The same reference numerals are given to the same parts as those of the above-described embodiment, and redundant explanations are omitted. This embodiment differs from the above-described embodiment in terms of criteria for executing the ability reduction process. As shown in FIG. 11, the control unit 70 calculates an average value K10 of the temperature detected by the internal temperature sensor 43 during the cooling operation over the predetermined time T11 (step S41, average value calculation process). For example, when the sampling time T9 of the internal temperature sensor 43 is set to 0.1 seconds and the predetermined time T11 is set to 5 seconds, the average value K10 is obtained by the multiple values obtained by the internal temperature sensor 43. of the temperature data D1 (see FIG. 13), the average value of 50 temperature data D1 going back from the point in time when the average value calculation process is executed (points T21, T22, T23, T24 in FIG. 13). When determining that the calculated average value K10 is lower than the lowest average value K11 stored in the storage unit 73 ("YES" in step S42), the control unit 70 executes the lowest average value update process. (step S43). In the lowest average value update process, the control unit 70 updates the calculated average value K10 as the lowest average value K11 and stores it in the storage unit 73 .

Note that when the cooling operation is started (when the operation of the compressor 22 is started), the control unit 70 erases the lowest average value K11 (the lowest average value of the previous cooling operation) stored in the storage unit 73, As the initial value of the average value K11, for example, the value of the temperature detected by the internal chamber temperature sensor 43 at that time is stored in the storage unit 73 . That is, the lowest average value K11 is the lowest average value among the plurality of average values K10 calculated by the control unit 70. FIG. Note that the average value calculation process (step S41) and the determination process (step S42) of whether or not to execute the lowest average value update process are performed every predetermined time T11.

Then, as shown in FIG. 12, when the control unit 70 determines that the current temperature K12 detected by the internal temperature sensor 43 during the cooling operation is equal to or higher than the reference temperature K14 ("YES" in step S51). ), and when it is determined that the temperature detected by the internal temperature sensor 43 is 0° C. or lower (“YES” in step S52), the capacity reduction process is executed (step S53). In other words, the control unit 70 does not execute the capacity reduction process when it determines that the temperature detected by the internal cold storage temperature sensor 43 is higher than 0°C.

The above reference temperature K14 is a temperature set higher than the lowest average value K11 by a predetermined temperature K13 (reference temperature K14=lowest average value K11+predetermined temperature K13). That is, the control unit 70 determines that "the temperature inside the storage compartment 12 has risen during the cooling operation" when the current temperature K12 becomes equal to or higher than the reference temperature K14, and executes the capacity reduction process. Further, the predetermined temperature K13 is set at, for example, 1 K (Kelvin), but is not limited to this and can be changed as appropriate.

The predetermined temperature K13 can be determined by performing tests or the like in advance. Note that the sampling time T9 of the internal temperature sensor 43 by the control unit 70 is, for example, 0.1 seconds, and the predetermined time T11 is set to a time longer than the sampling time T9 (for example, 5 seconds). The sampling time of the internal temperature sensor 43 and the predetermined time T11 can be changed as appropriate.

Next, FIG. 13 will be exemplified to specifically explain the control related to the minimum average value update process. FIG. 13 is a graph showing an example of temperature transition in the storage compartment 12 during the cooling operation. Also, in FIG. 13, it is assumed that the average value calculation process (step S41) and the determination process (step S42) of whether or not to execute the minimum average value update process are executed at each time point T21, T22, T23, T24. do. It is also assumed that the door 14 is opened at time T30 in FIG.

As shown in FIG. 13, the temperature in the storage chamber 12 gradually decreases during the cooling operation. Therefore, while the temperature in the storage chamber 12 is gradually decreasing, the minimum average value K11 is updated to a lower value every predetermined time T11. For example, since the average value K10 for the period from time T22 to time T23 is lower than the average value K10 for the period from time T21 to time T22 in FIG. The average value K10 is stored in the storage unit 73 as the lowest average value K11, and at time T23, the average value K10 for the period from time T22 to time T23 is updated as the lowest average value K11 and stored in the storage unit 73.

Then, when the door 14 is opened at time T30, the temperature in the storage chamber 12 gradually rises. Therefore, the average value K10 for the period from time T23 to time T24 is higher than the stored lowest average value K11. That is, at time T24, the lowest average value update process is not executed. Therefore, the control unit 70 sets the average value K10 of the period from the time T22 to the time T23 to the predetermined temperature K13 as the reference temperature K14, and the temperature detected by the inside temperature sensor 43 is equal to or higher than the reference temperature K14. When it becomes, the ability decrease processing is executed.

Next, the effects of this embodiment will be described. According to the present embodiment, the temperature in the storage chamber 12 gradually decreases during the cooling operation, and when the door 14 is opened during the cooling operation, outside air enters the storage chamber 12, and the temperature in the storage chamber 12 rises. Therefore, the lowest average value K11 can be considered as a numerical value corresponding to the temperature inside the storage compartment 12 immediately before the door 14 is opened, and the temperature detected by the inside temperature sensor 43 after the door 14 is opened is the lowest. It becomes a value higher than the average value K11. Therefore, when the control unit 70 determines that the temperature detected by the internal temperature sensor 43 is equal to or higher than the reference temperature K14 (minimum average value K11+predetermined temperature K13), the capacity reduction process is executed to It is possible to suppress the frost on the cooler 30 when 14 is opened. Further, in the above configuration, the capacity reduction process is executed based on the average temperature value K10 detected by the internal temperature sensor 43, so the reference temperature K14 is determined based on the instantaneous value of the internal temperature sensor 43. Influences such as momentary errors of the inside temperature sensor 43 can be reduced compared to the case where the internal temperature sensor 43 is set.

Further, in the present embodiment, the lowest average value K11 of the previous cooling operation can be automatically deleted at the start of the cooling operation. As a result, it is possible to prevent the performance reduction process from being performed with reference to the lowest average value K11 during the previous cooling operation.

<Other embodiments>
The present invention is not limited to the embodiments explained by the above description and drawings, and the following embodiments are also included in the technical scope of the present invention.
(1) The conditions for executing the performance reduction process are not limited to those exemplified in the above embodiments. For example, the capacity reduction process may be executed based on the rate of temperature increase in the storage chamber 12 . Specifically, during the cooling operation, the control unit 70 may perform the capacity reduction process when the temperature detected by the internal cold storage temperature sensor 43 rises by a predetermined temperature within a predetermined period of time.
(2) In the above embodiment, the case where the operability of the cooling fan 25 is reduced in the capacity reduction process was exemplified, but the present invention is not limited to this. For example, the operating ability of the compressor 22 may be reduced in the ability reduction process. Since the temperature drop of the cooler 30 can be suppressed by lowering the operating capacity of the compressor 22, frost formation on the cooler 30 can be suppressed. It should be noted that "reducing the drivability of the compressor 22" referred to here means lowering the rotational speed of the compressor 22, stopping the compressor 22, and the like.

DESCRIPTION OF SYMBOLS 10... Cooling storage, 11... Storage body, 12... Storage room, 14... Door, 17... Cooler room, 20... Cooling device, 22... Compressor, 25... Cooling fan, 30... Cooler, 42... Defrosting heater (heater) 43 temperature sensor (temperature sensor) 70 control unit 72 operation unit 73 storage unit K1 minimum temperature K3, K13 predetermined temperature K4, K14 reference temperature K10 ... average value, K11 ... lowest average value, T6 ... waiting time, T7 ... operation time, T11 ... predetermined time

Claims (9)

a box-shaped storage body having a storage room and a cooler room;
a door attached to the storage body and capable of opening and closing the storage chamber;
a cooling device for cooling the storage chamber;
a temperature sensor that detects the temperature in the storage chamber;
a control unit;
The cooling device
a cooler housed in the cooler chamber;
a compressor that forms a cooling cycle together with the cooler;
a cooling fan that sucks the air in the storage chamber into the cooler chamber and supplies the air that has passed through the cooler into the storage chamber;
The control unit operates the compressor and the cooling fan to perform a cooling operation to supply the air cooled by the cooler into the storage chamber,
Furthermore, the control unit
The lowest temperature among the temperatures detected by the temperature sensor during the ON state of the compressor in the cooling operation is defined as the lowest temperature,
When the temperature detected by the temperature sensor during the ON state of the compressor in the cooling operation becomes equal to or higher than a reference temperature that is set higher than the minimum temperature by a predetermined temperature, capacity reduction processing for reducing the cooling capacity of the cooling device. Cooling storage that runs. A storage unit in which the minimum temperature is stored,
2. The cold storage according to claim 1, wherein the control unit deletes the minimum temperature stored in the storage unit when the compressor starts operating. a box-shaped storage body having a storage room and a cooler room;
a door attached to the storage body and capable of opening and closing the storage chamber;
a cooling device for cooling the storage chamber;
a temperature sensor that detects the temperature in the storage chamber;
a control unit;
The cooling device
a cooler housed in the cooler chamber;
a compressor that forms a cooling cycle together with the cooler;
a cooling fan that sucks the air in the storage chamber into the cooler chamber and supplies the air that has passed through the cooler into the storage chamber;
The control unit operates the compressor and the cooling fan to perform a cooling operation to supply the air cooled by the cooler into the storage chamber,
Furthermore, the control unit
An average value of the temperature detected by the temperature sensor during the ON state of the compressor in the cooling operation is calculated every predetermined time, and the lowest average value among the calculated average values is calculated. is the lowest average value, and
When the temperature detected by the temperature sensor during the ON state of the compressor in the cooling operation becomes equal to or higher than a reference temperature that is set higher than the lowest average value by a predetermined temperature, the ability to reduce the cooling capacity of the cooling device is lowered. Cooling storage that performs processing. A storage unit in which the lowest average value is stored,
4. The cold storage according to claim 3, wherein the control section deletes the lowest average value stored in the storage section when the compressor starts to operate. 5. The cooling storage according to any one of claims 1 to 4, wherein the controller reduces the operating capacity of the cooling fan in the capacity reduction process. A heater that heats the cooler is provided,
The control unit operates the heater to perform heater defrost for defrosting frost adhered to the cooler, and operates the cooling fan after a predetermined standby time has elapsed after the heater defrost is completed. A fan operation process is executed to operate for a predetermined operation time,
6. The cooling storage according to any one of claims 1 to 5, wherein the control unit does not lower the operability of the cooling fan while the fan operation process is being executed. The control unit is configured to perform off-cycle defrosting, which defrosts frost adhered to the cooler by stopping the compressor and operating the cooling fan,
7. The cooling storage according to any one of claims 1 to 6, wherein the control unit does not lower the operability of the cooling fan while the off-cycle defrosting is being performed. The cooling storage according to any one of claims 1 to 7, wherein the control unit does not execute the capacity reduction process when determining that the temperature detected by the temperature sensor is higher than 0°C. An operation unit operated by a user is provided,
The control unit executes mode switching processing for switching from a first mode that enables execution of the performance reduction processing to a second mode that disables execution of the performance reduction processing by operating the operation unit. A cold store according to any one of claims 1 to 8.

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