Cooling storage

Abstract

To maintain a constant temperature property of an in-storage temperature without regard to the temperature outside the storage.SOLUTION: In the case where an in-storage temperature TR is between a setting temperature upper limit value TH and a setting temperature lower limit value TL set sandwiching a setting temperature TO, constant temperature control can be executed for controlling in such a manner that the in-storage temperature TR is maintained at the setting temperature TO by controlling the rotational frequency of a compressor 30 and ON / OFF of a temperature rising heater 50. When transiting from the constant temperature control to a defrosting operation, in the case where an outside-storage temperature TOUT is equal to or greater than a first threshold value T1, before starting the defrosting operation, a before defrosting cooling operation is executed for lowering the in-storage temperature TR to the setting temperature lower limit value TL.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a refrigerated storage facility. [Background technology]

[0002] For example, when storing medicines in a refrigerated storage facility, the allowable temperature range may be narrow. In this case, it is necessary to make the temperature change inside the storage facility smaller than usual. The refrigerated storage facility described in Patent Document 1 below executes control to prevent a decrease in constant temperature (hereinafter referred to as constant temperature control). This constant temperature control controls the rotation speed of the compressor and the power supply rate of the heater that heats the storage facility, thereby allowing the compressor to operate continuously and preventing the compressor from stopping. This is because if the compressor is stopped, it cannot be started again for a certain period of time, which would result in large temperature changes inside the storage facility.

[0003] The constant temperature control in Patent Document 1 is configured to operate a heater to raise the temperature inside the refrigerator when the temperature inside the refrigerator falls below a set temperature, and to continue operating the compressor to reduce temperature changes inside the refrigerator. Furthermore, for example, when the temperature outside the refrigerator (outside air temperature) is low, the degree of drop in the temperature inside the refrigerator may be large even if the compressor rotation speed is reduced to the minimum rotation speed. Patent Document 1 below is configured to operate a heater to reduce the degree of drop in temperature in such cases. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-180726 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, even when the constant temperature control described in Patent Document 1 is used, depending on the temperature outside the refrigerator, there is a risk that the temperature may deviate significantly from the desired temperature range. Furthermore, in refrigerated storage refrigerators, in order to remove frost from the evaporator, the compressor is periodically stopped and the heater is activated to heat the evaporator, thereby performing a so-called defrosting operation. When this defrosting operation is performed, the compressor is stopped. However, as described above, a specific time is required before the compressor can be activated again. Therefore, for example, when the outside air temperature is high, there is a risk that the temperature inside the refrigerator may rise too high before the specific time has elapsed. In other words, if the temperature deviates significantly from the desired temperature range using constant temperature control, there is a risk that the temperature may exceed the allowable temperature range for the objects stored inside the refrigerator.

[0006] The present invention has been made in consideration of such circumstances, and its object is to provide a refrigerated storage cabinet that can maintain a constant temperature inside the cabinet regardless of the temperature outside the cabinet. [Means for solving the problem]

[0007] In order to solve the above problems, the refrigerated storage facility disclosed in the present application has the following structure. (1) A refrigerated storage facility for keeping objects cold, a refrigeration circuit including a variable speed compressor and an evaporator for cooling the interior of the refrigerator; a heating heater for raising the temperature inside the cabinet; an inside temperature sensor and an outside temperature sensor for detecting the inside temperature and the outside temperature, respectively; A control device that controls the cooling storage facility; Equipped with The control device has a cold insulation operation execution unit that keeps the interior of the refrigerator cold and a defrosting operation execution unit that defrosts the evaporator, The cold storage operation execution unit a constant temperature control execution unit that controls the number of rotations of the compressor and the ON / OFF of the heating heater when the inside temperature is between a set temperature upper limit value and a set temperature lower limit value that are set on either side of the set temperature, thereby controlling the inside temperature to be maintained at the set temperature; a pre-defrost cooling operation execution unit that, when the outside-compartment temperature is equal to or higher than a first threshold value, reduces the inside-compartment temperature to the set temperature lower limit value before starting the defrosting operation by the defrosting operation execution unit; 10. A cooling storage facility comprising:

[0008] The defrosting operation is terminated, for example, when the minimum stop time, which is the time required to restart the compressor, has elapsed and the temperature of the evaporator or the temperature near the evaporator has reached the set temperature. However, when the temperature outside the refrigerator is relatively high, the temperature inside the refrigerator tends to rise easily, and the temperature inside the refrigerator may exceed the set upper limit temperature before the minimum stop time has elapsed. Furthermore, there is a risk that the temperature inside the refrigerator may reach or exceed not only the set upper limit temperature, but also the upper limit of the temperature range allowed for the object being kept cold by the refrigerator.

[0009] In contrast, the refrigerated storage cabinet disclosed in the present application is configured to lower the internal temperature before starting a defrosting operation when the external temperature is equal to or higher than a first threshold, which is a predetermined temperature. Specifically, the refrigerated storage cabinet disclosed in the present application normally maintains the internal temperature near a set temperature through constant temperature control, but when the external temperature is high, the internal temperature is lowered to the lower limit of the set temperature before starting a defrosting operation. Therefore, the refrigerated storage cabinet disclosed in the present application can lower the internal temperature during a defrosting operation when the external temperature is high, thereby preventing the internal temperature from reaching the upper limit of the allowable temperature range for the object.

[0010] Furthermore, the cooling storage cabinet having the above-described configuration can be configured in various ways as shown below.

[0011] (2) The cold storage operation execution unit has an internal temperature drop control execution unit that increases the internal temperature when the internal temperature drops below the set temperature lower limit value, The cooling storage container according to claim (1), wherein the constant temperature control execution unit increases the set temperature lower limit when the outside temperature is equal to or lower than a second threshold value compared to when the outside temperature is higher than the second threshold value.

[0012] When the outside temperature is low, the cooling capacity of the refrigerated storage cabinet is higher than when the outside temperature is not low. Although the refrigerated storage cabinet disclosed herein is configured to perform constant temperature control, even when the heater capacity is increased during constant temperature control (for example, when the heater's power supply rate is increased), the cooling capacity is higher and the inside temperature may drop to the lower limit of the set temperature. When the cooling capacity is increased in this way, the temperature near the outlet of the duct (evaporator chamber) in which the evaporator is located tends to be lower than the center of the cabinet. In particular, when the inside temperature sensor is installed near the intake port of the evaporator, the inside temperature is measured at the position farthest from the outlet, which may result in the area near the outlet becoming excessively cold. In contrast, in a refrigerated storage facility with this configuration, when the temperature outside the facility is low, the set temperature lower limit is set higher than normal, so that the system switches from constant temperature control to control when the temperature inside the facility drops at an early stage, preventing the cooling capacity from becoming too high and the temperature inside the facility from dropping too much.

[0013] (3) The cooling storage facility is equipped with an internal fan to circulate the air inside the storage facility. The refrigerated storage facility described in (1) or (2) above, wherein the constant temperature control execution unit operates the internal fan at a lower speed when the outside temperature is equal to or lower than a third threshold value compared to when the outside temperature is higher than the third threshold value.

[0014] Generally, when the compressor is operating, the internal fan rotates at high speed to efficiently circulate the cold air. On the other hand, in a refrigerated storage cabinet with this configuration, the internal fan rotates at low speed when the external temperature is low, thereby preventing excessive cooling near the outlet, as described above.

[0015] (4) The cooling storage according to (3), wherein the third threshold value is the upper limit of the set temperature.

[0016] A refrigerated storage cabinet with this configuration has a third threshold value for switching the internal fan from high speed to low speed operation, and when the temperature outside the cabinet is likely to become lower than the temperature inside the cabinet, the fan is switched to low speed operation, effectively suppressing a drop in the internal temperature.

[0017] (5) The cold storage operation execution unit has an internal temperature drop control execution unit that increases the internal temperature when the internal temperature drops below the set temperature lower limit value, The cooling storage facility according to any one of claims (1) to (4), wherein the control execution unit for when the inside temperature drops stops the compressor and activates the heating heater when the outside temperature is lower than a fourth threshold, and stops the compressor and the heating heater when the outside temperature is equal to or higher than the fourth threshold.

[0018] Even in the refrigerated storage cabinet disclosed herein, which performs constant temperature control, if the internal temperature drops too much below the set lower limit, the compressor is stopped and the heater is activated to quickly raise the internal temperature. However, when the external temperature is high, the internal temperature is likely to rise. Therefore, as mentioned above, there is a risk that the internal temperature will reach the set upper limit before the minimum compressor stop time has elapsed, and will reach the upper limit of the allowable temperature range for the object before the minimum stop time has elapsed. In contrast, this configuration of refrigerated storage cabinet does not activate the heater when the external temperature is high, even if the internal temperature falls below the set lower limit. In other words, a situation in which the internal temperature drops due to the external temperature is unlikely, and the internal temperature is gradually raised. Therefore, this configuration of refrigerated storage cabinet can prevent the internal temperature from exceeding the set upper limit. Furthermore, this configuration of refrigerated storage cabinet extends the time that both the compressor and heater are stopped, thereby improving energy-saving performance.

[0019] (6) A refrigerated storage facility according to paragraph (5), wherein the cold storage operation execution unit resumes constant temperature control by the constant temperature control execution unit when the minimum stop time, which is the time required to restart the compressor after stopping it, has elapsed during the control by the control execution unit when the internal temperature drops, and when the internal temperature reaches the set temperature upper limit value.

[0020] A refrigerated storage facility with this configuration can prevent the temperature inside the facility from exceeding the set upper temperature limit, and can extend the time that both the compressor and heater are stopped, thereby effectively improving energy-saving performance.

[0021] (7) The cooling storage according to (5) or (6), wherein the fourth threshold value is the set temperature.

[0022] In a refrigerated storage cabinet with this configuration, a fourth threshold value is specified to switch the heater ON or OFF during control when the internal temperature drops, and this threshold value is set as the set temperature. With a refrigerated storage cabinet with this configuration, the internal temperature does not drop significantly even if the compressor is stopped and the heater is not operated, so it is possible to avoid a situation where the internal temperature drops outside the control range of constant temperature control.

[0023] (8) A refrigerated storage facility according to any one of paragraphs (1) to (7), wherein the control device has an abnormality cold storage operation execution unit that operates the compressor when the temperature outside the storage facility is higher than the set temperature when an abnormality is detected in the storage facility temperature sensor, and stops the compressor when the temperature outside the storage facility is equal to or lower than the set temperature.

[0024] In a refrigerated storage cabinet with this configuration, even if an abnormality occurs in the internal temperature sensor, the compressor is stopped if the external temperature is lower than the set temperature, thereby preventing the internal temperature from dropping. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a refrigerated storage cabinet that can maintain a constant temperature inside the cabinet regardless of the temperature outside the cabinet. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a front view of a medicine showcase (refrigerated storage) according to an embodiment of the present invention; [Figure 2] Front cross-sectional view of a medicine showcase [Figure 3] Side cross-sectional view of a medicine showcase [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the inside of the evaporator chamber in FIG. [Figure 5] Functional block diagram of the control device equipped in the medicine showcase [Figure 6] A diagram summarizing the controls executed during cold storage operation [Figure 7] Constant temperature control timing chart [Figure 8]A diagram showing the change in temperature inside the refrigerator depending on whether or not pre-defrost cooling operation is performed [Figure 9] FIG. 6 is a flowchart of a cooling operation program executed by the control device shown in FIG. [Figure 10] Flowchart of the subroutine for controlling low temperatures inside the cabinet [Figure 11] FIG. 6 is a flowchart of a defrosting operation program executed by the control device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0027] <Configuration of refrigerated storage facility> A refrigerated storage cabinet according to an embodiment of the present invention is a medicine showcase 10, and the configuration of the medicine showcase 10 will be described with reference to FIGS. 1 to 4. The medicine showcase 10 of this embodiment is designed to keep medicines cold and allows the medicines to be viewed from the outside. Specifically, as shown in FIG. 1, the medicine showcase 10 of this embodiment includes a storage cabinet main body 12 formed of an insulated box with an open front, a pair of left and right sliding glass doors 14 that open and close the front opening of the storage cabinet main body 12, and a machine room 16 located below the storage cabinet main body 12. Multiple shelves can be installed horizontally within the storage cabinet main body 12, and medicines can be placed on the shelves. Note that in some of the drawings, the symbols F, B, L, R, U, and D are used to indicate directions, respectively representing the front side (front), rear side (rear), left side, right side, upper side, and lower side when viewing the medicine showcase 10 from the front.

[0028] As shown in Figures 2 and 3, the machine room 16 houses a part of the cooling device (refrigeration circuit) 18, an electrical box 20, etc. The electrical box 20 houses a control device 22 (see Figure 5) that controls the medicine showcase 10, and the control device 22 is connected to an operation box 24 provided at the upper end of the front side of the storage cabinet main body 12. A user of the medicine showcase 10 can operate an operation unit 24A (see Figure 1) provided on the operation box 24 to perform various operations such as setting a target temperature inside the cabinet. In the following explanation, the set target temperature will be referred to as the set temperature T O Let us call it this.

[0029] The cooling device 18 and its peripheral configuration will be described with reference to FIGS. 2 to 4. The cooling device 18 includes a compressor 30, a condenser 32, a condenser fan 34, an evaporator 36, and the like. The compressor 30, the condenser 32, and the condenser fan 34 are housed in the machine room 16, and the evaporator 36 is attached to the underside of the ceiling wall 12A inside the storage body 12 and is housed in an evaporator chamber R1, which is a space formed by the ceiling wall 12A and a cooling duct 40, which will be described next. The cooling duct 40 separates the evaporator chamber R1 from the storage chamber R2, which occupies the majority of the storage body 12. The compressor 30, the condenser 32, and the condenser fan 34 housed in the machine room 16 and the evaporator 36 housed in the storage body 12 are connected to each other by a refrigerant pipe for circulation.

[0030] The cooling duct 40 covers the evaporator 36 from below and also functions as a drain pan that receives defrost water, which is water obtained when frost adhering to the evaporator 36 melts. As shown in Figures 3 and 4, the cooling duct 40 has a substantially flat bottom wall 40A that slopes downward toward the rear, and a rear wall 40B that rises slightly upward from the rear edge of the bottom wall 40A.

[0031] As shown in Figures 2 to 4, two intake ports 40C for drawing air into the evaporator chamber R1 are formed in the front portion of the bottom wall 40A. The rear wall 40B is spaced forward from the rear wall 12B of the storage cabinet main body 12, and an air outlet 40D is formed between the rear wall 40B and the rear wall 12B of the storage cabinet main body 12. In addition, a drain groove 40E with a U-shaped cross section is formed integrally with the rear wall 40B, extending from approximately the center in the left-right direction toward the rear. A drain pipe is provided inside the rear wall 12B of the storage cabinet main body 12, and defrost water received by the cooling duct 40 is discharged from the drain groove 40E via the drain pipe to the outside of the storage cabinet.

[0032] An internal fan 42 is attached above the intake port 40C of the cooling duct 40. When the internal fan 42 is operated, air in the storage compartment R2 is drawn into the evaporator compartment R1 through the intake port 40D, and the drawn air is cooled by the evaporator 36 and blown out from the outlet 40D. A thermistor 44 is attached above the internal fan 42. This thermistor 44 measures the temperature inside the storage compartment R2 (internal temperature T R Hereinafter, this thermistor 44 will be referred to as an inside thermistor (inside temperature sensor).

[0033] 2 to 4, a duct member 46 is attached to the rear wall 12B of the storage cabinet main body 12, and a rear duct extending in the vertical direction is formed between the rear wall 12B and the duct member 46. In other words, the air (cold air) blown out from the air outlet 40D of the evaporator chamber R1 is sent to the rear duct. As shown in FIG. 2, a number of vent holes 46A are formed in the duct member 46, and the cold air is blown out forward from the vent holes 46A and sent onto each of the shelves mentioned above.

[0034] A heater 50 for raising the temperature inside the refrigerator is provided in the rear duct. More specifically, as shown in Figures 2 and 3, the heater 50 is disposed in a serpentine shape on the surface of the rear wall 12B.

[0035] As shown in Fig. 4, a thermistor 52 is provided below the evaporator 36 near the air outlet 40D. The thermistor 52 senses the air temperature T D Hereinafter, this thermistor 52 will be referred to as a defrosting thermistor, and the air temperature TD will be referred to as an evaporator temperature.

[0036] <Control in refrigerated storage> The control device 22 is mainly a computer having a CPU, ROM, and RAM, and is connected to the compressor 30 and condenser fan 34 of the cooling device 18, the inside fan 42, the heating heater 50, the inside thermistor 44, the defrosting thermistor 52, etc., and controls these connected devices by executing various programs stored in the ROM. Note that the medicine showcase 10 of this embodiment is mounted on a control board in the operation box 24 and is configured to control the outside temperature T OUT The external thermistor 54 is also connected to the control device 22.

[0037] (1) Cooling operation First, the cold storage operation executed by the control device 22 will be described with reference to Figs. 6 and 7. The medicines to be kept cold by the medicine showcase 10 of this embodiment must be kept within a narrow tolerance range of, for example, 2°C to 8°C, and strict temperature control is required. For this reason, the medicine showcase 10 of this embodiment is designed to keep the medicines at a set temperature T O If the temperature is within the specified temperature range (control area) set for the R The set temperature T O In detail, the constant temperature control is performed to maintain a constant temperature by bringing the temperature of the inside of the storage unit close to T R When the time t is within the control region, the rotation speed of the compressor 30 is controlled, and the power supply rate (the ratio of the time that the power is supplied to a certain unit time) of the temperature raising heater 50 is controlled. Once the compressor 30 is stopped, it is stopped for a specific time (minimum stop time t DIn view of this, the constant temperature control is performed by continuously operating the compressor 30 without stopping it, and the internal temperature T R Set the temperature T O Specifically, for example, as shown in FIG. 7, the lower the inside temperature, the lower the rotation speed of the compressor 30 is controlled, and the higher the power supply rate of the heater 50 (the ratio of the time when the heater 50 is powered on to a certain unit time) is controlled, thereby controlling the inside temperature T R Set the temperature T O approaching the set temperature T O It maintains this.

[0038] In this embodiment, the control area is a set temperature T O The upper limit (set temperature upper limit) TH is determined for the set temperature T O Add the additional temperature ΔTH to determine the lower limit (lower limit of set temperature) TL and set temperature T O It is determined by subtracting the subtraction temperature ΔTL from

[0039] In addition, the internal temperature T R If the temperature T is higher than the upper limit TH, the compressor 30 is operated, and the condenser fan 34 and the internal fan 42 are operated at high speeds to quickly raise the internal temperature T R The control for high temperature inside the refrigerator is performed so that the temperature T is within the control range. O and the internal temperature T R As the difference between the temperature and the temperature inside the refrigerator is large, the refrigerator operates at the maximum rotation speed, as shown in Fig. 7. On the other hand, the temperature inside the refrigerator T R If the temperature T is lower than the lower limit value TL, the compressor 30 and the condenser fan 34 are stopped and the heating heater 50 is energized to raise the internal temperature T RIn this low temperature control, the internal fan 42 is switched to a slower operation speed than that in the constant temperature control and the high temperature control. The low temperature control is performed for a minimum stop time t D and the internal temperature T R When the temperature reaches the upper limit TH of the control range, the temperature returns to constant temperature control.

[0040] However, with only the above control, the outside temperature T OUT Depending on the temperature, there is a risk that the temperature may also deviate from the allowable temperature of the medicine after it has deviated from the control range. OUT Controls to deal with this are also being implemented.

[0041] When the outside temperature is low, the cooling capacity is higher than when the outside temperature is not low. The medicine showcase 10 of this embodiment is configured to perform constant temperature control, but even when the capacity of the heating heater 50 is increased in constant temperature control, the cooling capacity of the compressor 30 operating at the minimum rotation speed is higher, and the inside temperature T R In this way, when the cooling capacity is increased, the temperature near the outlet 40D of the evaporator chamber R1 tends to be lower than the temperature at the center of the cabinet. In particular, since the in-cabinet thermistor 44 is provided near the inlet 40D in the medicine showcase 10 of this embodiment, the in-cabinet temperature T R Therefore, there is a risk that the vicinity of the air outlet 40D may become excessively cooled.

[0042] In contrast, the medicine showcase 10 of this embodiment is OUT When the temperature outside the refrigerator T is equal to or lower than a threshold temperature T1 (for example, an upper limit value TH), the lower limit value TL of the control range is set higher than usual, as shown in FIG. OUTWhen the temperature T is equal to or lower than the threshold temperature T1, the subtraction temperature ΔTL is reduced. OUT If the temperature is greater than the threshold temperature T1, ΔTL1 (for example, 1.0 K) is used, and the temperature outside the chamber T OUT is equal to or lower than the threshold temperature T1, the temperature is set to ΔTL2 (for example, 0.5K).

[0043] In addition, in the constant temperature control, the inside fan 42 is operated at high speed, but the outside temperature T OUT When the temperature T1 is equal to or lower than the threshold temperature T1, the internal fan 42 is switched to low-speed operation. The threshold (third threshold) for switching the operating speed of the internal fan 42 is set to be the same as the threshold (second threshold) for changing the lower limit value TL of the control range, but they may be set to different values. Furthermore, the second and third thresholds are set to be the same as the upper limit value T H It is possible to set it to a value different from

[0044] As mentioned above, the outside temperature T OUT When the temperature T is relatively low, the constant temperature control is switched to the low temperature control at an early stage, and the fan 42 is operated at a low speed to prevent the cooling capacity from becoming too high. R This prevents the value from dropping too much.

[0045] In addition, in the medicine showcase 10 of this embodiment, the internal temperature T R If the temperature drops below the lower limit TL of the control range, the internal temperature T R In order to increase the temperature T OUT If the temperature inside the cabinet is high, R The compressor 30 is stopped for a minimum time t D Since it cannot be resumed until the minimum stop time t D Before the temperature inside the cabinet T R may reach the upper limit value TH and further reach the upper limit of the allowable temperature range of the chemical.

[0046] The medicine showcase 10 of this embodiment is OUT is the threshold temperature T2 (for example, the set temperature T O ) or higher, the internal temperature T R Even if the outside temperature T falls below the lower limit TL, the heater 50 is not operated. OUT The internal temperature T R It is difficult to imagine a situation where the temperature inside the cabinet T R Therefore, in the medicine showcase 10 of this embodiment, the inside temperature T R This can prevent a situation in which the upper limit value TH of the control range is exceeded. Furthermore, the medicine showcase 10 of this embodiment extends the time during which the compressor 30, the condenser fan 34, and the heating heater 50 are stopped, thereby improving energy-saving performance.

[0047] (2) Defrosting operation When the above-mentioned cold-keeping operation is performed, frost forms on the evaporators 36. Therefore, the control device 22 is configured to perform a defrosting operation to defrost the evaporators 36 every time the cold-keeping operation is performed for a predetermined period (for example, six hours). This defrosting operation is a so-called off-cycle defrosting method, and is a method of defrosting using the above-mentioned internal fan 42. When this defrosting operation is started, the control device 22 normally stops the compressor 30 and the condenser fan 34 and operates the internal fan 42 to defrost the evaporators 36. Then, the control device 22 determines the minimum stop time t of the compressor 30, and D The evaporator temperature T D is the threshold temperature T D0 When this occurs, it is determined that defrosting of the evaporator 36 has been completed, and the defrosting operation is terminated, and the above-described cooling operation is resumed.

[0048] However, the outside temperature T OUT is relatively high, the internal temperature T R As shown by the broken line in FIG. 8, the minimum stop time tD Before the evaporator temperature T D is the threshold temperature T D0 When the internal temperature T R may exceed the upper limit TH, or even exceed the upper limit of the temperature range allowed for the chemical.

[0049] Therefore, the medicine showcase 10 of this embodiment is OUT is equal to or higher than a predetermined threshold temperature T3 (for example, 20°C, corresponding to the first threshold), the internal temperature T R In detail, the medicine showcase 10 of this embodiment is configured to perform a pre-defrost cooling operation to lower the internal temperature T R is controlled to the set temperature T O The temperature outside the cabinet is maintained at T OUT If the temperature inside the refrigerator is high, the pre-defrost cooling operation reduces the temperature inside the refrigerator to T R Therefore, according to the medicine showcase 10 of this embodiment, the defrosting operation is started after the outside temperature T OUT During defrosting operation when the temperature inside the refrigerator is high, the temperature T R This can lower the temperature point reached by the object, thereby preventing the object from reaching the upper limit of its allowable temperature range.

[0050] (3) Cooling operation in case of abnormality In the medicine showcase 10 of this embodiment, when an abnormality is detected in the inside thermistor 44, an abnormality cold storage operation is executed as a countermeasure control. OUT Specifically, the ON / OFF of the compressor 30 is controlled based on the outside temperature T OUT is the set temperature T O If the temperature is higher than the outside temperature T OUT is the set temperature T O If the temperature is equal to or lower than the temperature TR is the set temperature T O It is controlled so as not to deviate significantly from the

[0051] <Example of a control program> The above-mentioned cold-storage operation and defrosting operation are performed, for example, by executing a cold-storage operation program whose flowchart is shown in Fig. 9 and a defrosting operation program whose flowchart is shown in Fig. 11. Normally, the cold-storage operation program is repeatedly executed at short time intervals, and when the cooling operation program has been executed continuously for a predetermined time (for example, 6 hours), the defrosting operation program is executed. The cold-storage operation program and the defrosting operation program will be described in order below.

[0052] In the cold storage operation program, first, in step 1 (hereinafter sometimes abbreviated as "S1"; the same applies to other steps), the inside temperature T R It is determined whether the internal temperature T is equal to or lower than the upper limit TH of the control range. R If the internal temperature T is higher than the upper limit value TH, the high temperature internal temperature control is executed in S2. R If the internal temperature T is equal to or greater than the upper limit value TH, the flag value of the low temperature flag FL is checked in S3. This low temperature flag FL, which will be explained later, is changed from 0 to 1 when the internal temperature control is started, and is returned from 1 to 0 when the internal temperature control is completed. If the flag value of the low temperature flag FL is 0 in S3, the internal temperature T R is greater than the lower limit TL of the control region.

[0053] In S4, the temperature inside the cabinet T R If the temperature T is greater than the lower limit TL, constant temperature control is performed in S5 and below. OUT It is determined whether the temperature outside the cabinet T is equal to or lower than the threshold temperature T1. OUTIf the temperature outside the refrigerator T is not equal to or lower than the threshold temperature T1, the upper limit TH and the lower limit TL of the control range are determined in S6 as usual, and the internal fan 42 is operated at high speed in S7. OUT If the temperature T is lower than the threshold temperature T1, the upper limit TH and lower limit TL of the control region are determined in S8. At this time, the lower limit TL is determined to be larger than the lower limit in S6. In addition, the internal fan 42 is operated at a low speed in S9. In either case, the rotation speed of the compressor 30 and the power supply rate of the heating heater 50 are controlled in S10.

[0054] In addition, if the flag value of the low temperature flag FL is 1 in S3, or if the internal temperature T R If the temperature difference is equal to or less than the lower limit TL, low temperature inside refrigerator control is executed in S11. This low temperature inside refrigerator control is performed by executing a low temperature inside refrigerator control subroutine shown in the flowchart of FIG.

[0055] As described above, the low temperature inside temperature control stops the compressor 30. Therefore, in the low temperature inside temperature control subroutine, first, in S21, the minimum stop time t of the compressor 30 after the compressor 30 has stopped, in other words, after the low temperature inside temperature control has started, is calculated. D It is determined whether the minimum stop time t has elapsed. D If the time has not elapsed, the compressor 30 and the condenser fan 34 are stopped, and the internal fan 42 is operated at a low speed in S22.

[0056] Next, in S23, the outside temperature T OUT is the threshold temperature T2 (for example, the set temperature T O ) or higher. OUT If the temperature is lower than the threshold temperature T2, the heater 50 is turned on in S24. OUT If the temperature T is equal to or higher than the threshold temperature T2, the heater 50 is turned off in S25. Subsequently, in S25, the flag value of the low temperature flag FL is set to 1, and the low temperature inside refrigerator control subroutine is ended.

[0057] In S21, the minimum stopping time t D If the time has elapsed, the internal temperature T R It is determined whether the internal temperature T is equal to or greater than the upper limit TH of the control range. R If the internal temperature T is smaller than the upper limit value TH, the process from S22 onwards is carried out to continue the low temperature internal control. R becomes equal to or greater than the upper limit value TH, the process of ending the low temperature internal temperature control is performed. Specifically, the heating heater 50 is turned off in S28, and the flag value of the low temperature flag FL is returned to 0 in S29, and the low temperature internal temperature control subroutine is ended. When this low temperature internal temperature control subroutine is ended, one cycle of the cooling operation program is ended.

[0058] Next, the defrosting operation control program will be described. In the defrosting operation program, first, in S31, the outside temperature T OUT It is determined whether the temperature outside the refrigerator T is equal to or higher than the threshold temperature T3. OUT is lower than the threshold temperature T3, steps S32 to S33 are skipped, and defrosting operation is performed in step S34 and thereafter. Specifically, in step S34, the compressor 30 and the condenser fan 34 are stopped, and the internal fan 42 is operated at a high speed. Next, in step S35, the minimum stop time t of the compressor 30 is set. D Wait until the minimum stop time t D After the time has elapsed, in S36, the evaporator temperature T detected by the defrosting thermistor 52 is D is the threshold temperature T D0 It is determined whether the evaporator temperature T D is the threshold temperature T D0 When this occurs, the defrosting operation ends.

[0059] In S31, the outside temperature T OUT If the temperature T is equal to or higher than the threshold temperature T3, the pre-defrost cooling operation is performed in S32. RWait until the temperature inside the chamber reaches the lower limit TL of the control region, and then R When the temperature falls to or below the lower limit TL, the defrosting operation is started in step S34. When the defrosting operation is completed, the cold-keeping operation program is executed again, and the cold-keeping operation is resumed.

[0060] <Controller functional configuration> The control device 22 that performs the above-described control has a functional configuration as shown in the block diagram of Fig. 5 and includes various functional units. Specifically, the control device 22 includes a cold storage operation execution unit 80 that executes the above-described cold storage operation program to perform the cold storage operation, and a defrosting operation execution unit 82 that executes the defrosting operation program to perform the defrosting operation. The control device 22 also includes an abnormality cold storage operation execution unit 84 that executes the above-described abnormality cold storage operation, although the program is not shown in the figure.

[0061] The above-mentioned cold storage operation execution unit 80 is R is the set temperature T O When the temperature inside the cabinet T is within the set temperature range (control area) R is the set temperature T O a constant temperature control execution unit 86 that performs constant temperature control to maintain the temperature T R When the temperature inside the chamber T is higher than the control range of the constant temperature control R A high temperature control execution unit 88 is a part that performs high temperature control to reduce the internal temperature T R When the internal temperature T is lower than the control range of the constant temperature control R and a low inside temperature control execution unit (low inside temperature control execution unit) 90 which is a unit that performs low inside temperature control to increase the temperature. The constant temperature control execution unit 86 is configured to include a unit that executes S5 to S10 of the cold storage operation program, the high inside temperature control execution unit 88 is configured to include a unit that executes S2 of the cold storage operation program, and the low inside temperature control execution unit 90 is configured to include a unit that executes a low inside temperature control subroutine.

[0062] The constant temperature control execution unit 86 has a low outside temperature handling unit 92 that handles cases where the outside temperature is low, and this low outside temperature handling unit 92 is configured to include parts that execute S5, S8, and S9 of the cold storage operation program. The low inside temperature control execution unit 90 has a high outside temperature handling unit 94 that handles cases where the outside temperature is high, and this high outside temperature handling unit 94 is configured to include parts that execute S23 and S25 of the low inside temperature control subroutine.

[0063] In addition, the cold storage operation execution unit 80 is configured to OUT is high, before the defrosting operation execution unit 82 starts the defrosting operation, R to the lower limit value TL in the control region. The pre-defrost cooling operation execution unit 96 is configured to include a part that executes S31 to S33 of the defrosting operation program.

[0064] <Effects of refrigerated storage> The medicine showcase 10 of the present embodiment configured as described above has the pre-defrost cooling operation execution unit 96, the low outside temperature countermeasure unit 92, and the high outside temperature countermeasure unit 94, and thereby can control the outside temperature T OUT Regardless of the temperature inside the cabinet, T R This makes it possible to maintain a constant temperature, allowing for the appropriate storage of objects that require strict temperature control, such as medicines.

[0065] <Other embodiments> The present invention is not limited to the above-described embodiment, and can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. For example, the following embodiments are also included within the technical scope of the present invention.

[0066] In the above embodiment, the threshold value (third threshold value) for switching the operating speed of the internal fan 42 and the threshold value (second threshold value) for changing the lower limit value TL of the control region are the upper limit value TH of the control region, but are not limited to this.

[0067] In the above embodiment, the second threshold value and the third threshold value are the same value, but they can also be set to different values.

[0068] In the above embodiment, the constant temperature control is performed using the heating heater 50 for heating the interior of the refrigerator. However, a defrost heater for defrosting the evaporator 36 may be provided and used for the constant temperature control.

[0069] In the constant temperature control in the above embodiment, it is not specifically described what is the basis for varying the control of the rotation speed of the compressor 30 and the control of the power supply rate of the heating heater 50, but various conventional methods can be adopted.

[0070] In the above embodiment, a medicine showcase is used as an example of a refrigerated storage cabinet, but the present invention is not limited to a showcase and can be used in any medicine storage cabinet whose interior cannot be seen. Furthermore, the present invention is not limited to medicine, and can be used in various showcases, refrigerators, and freezers.

[0071] 10...Medicinal showcase (refrigerated storage cabinet), 18...Cooling device (refrigeration circuit), 22...Control device, 30...Compressor, 36...Evaporator, 42...Interior fan, 44...Interior thermistor (interior temperature sensor), 50...Heating heater, 52...Defrosting thermistor, 54...Exterior thermistor (exterior temperature sensor), 80...Cooling operation execution unit, 82...Defrosting operation execution unit, 84...Cooling operation execution unit under abnormal conditions, 86...Constant temperature control execution unit, 90...Interior low temperature control execution unit (interior temperature drop control execution unit), 96...Pre-defrost cooling operation execution unit

Claims

1. A refrigerated storage facility for keeping objects cold, a refrigeration circuit including a variable speed compressor and an evaporator for cooling the interior of the refrigerator; a heating heater for raising the temperature inside the cabinet; an inside temperature sensor and an outside temperature sensor for detecting the inside temperature and the outside temperature, respectively; A control device that controls the cooling storage facility; Equipped with The control device has a cold insulation operation execution unit that keeps the interior of the refrigerator cold and a defrosting operation execution unit that defrosts the evaporator, The cold storage operation execution unit a constant temperature control execution unit that controls the rotation speed of the compressor and ON / OFF of the heating heater when the inside temperature is between a set temperature upper limit value and a set temperature lower limit value that are set on either side of the set temperature, thereby controlling the inside temperature to be maintained at the set temperature; a pre-defrost cooling operation execution unit that, when the outside-compartment temperature is equal to or higher than a first threshold, reduces the inside-compartment temperature to the set temperature lower limit value before starting the defrosting operation by the defrosting operation execution unit; 10. A cooling storage facility comprising:

2. The cold storage operation execution unit has an internal temperature drop control execution unit that increases the internal temperature when the internal temperature drops below the set temperature lower limit value, The refrigerated storage facility according to claim 1, wherein the constant temperature control execution unit increases the set temperature lower limit value when the outside temperature is equal to or lower than a second threshold value compared to when the outside temperature is higher than the second threshold value.

3. The cooling storage cabinet is equipped with an internal fan that circulates air inside the cabinet, 3. The refrigerated storage facility according to claim 1, wherein the constant temperature control execution unit operates the internal fan at a lower speed when the outside temperature is equal to or lower than a third threshold value compared to when the outside temperature is higher than the third threshold value.

4. The refrigerated storage facility according to claim 3 , wherein the third threshold value is the set temperature upper limit value.

5. The cold storage operation execution unit has an internal temperature drop control execution unit that increases the internal temperature when the internal temperature drops below the set temperature lower limit value, 3. The refrigerated storage facility according to claim 1, wherein the control execution unit for when the internal temperature drops stops the compressor and activates the heating heater when the external temperature is lower than a fourth threshold, and stops the compressor and the heating heater when the external temperature is equal to or higher than the fourth threshold.

6. 6. The refrigerated storage facility according to claim 5, wherein the cold storage operation execution unit resumes constant temperature control by the constant temperature control execution unit when a minimum stop time, which is the time required to restart the compressor after stopping it, has elapsed during the control by the control execution unit when the internal temperature drops, and the internal temperature has reached the set temperature upper limit value.

7. The refrigerated storage facility according to claim 5 , wherein the fourth threshold value is the set temperature.

8. 3. The refrigerated storage facility according to claim 1, wherein the control device has an abnormality cold storage operation execution unit that operates the compressor when the outside temperature is higher than the set temperature and stops the compressor when the outside temperature is equal to or lower than the set temperature when an abnormality is detected in the inside temperature sensor.

Images