JP6022503B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device for cooling an object to be cooled such as a food pack by immersing it in cooling water.

  This type of cooling device is known, for example, from US Pat. The cooling device of Patent Literature 1 includes a water tank that stores cooling water and a cooling unit that cools the cooling water in the water tank. The cooling means consists of a refrigerator in which a compressor (compressor), a condenser (condenser), an expansion part (capillary tube), and an evaporator (evaporator) are connected by refrigerant piping. The evaporator is wound around the outer surface of the water tank. It is fixed in the state. When the refrigerant liquid evaporates in the evaporator, the cooling water stored in the water tank is cooled, and the object to be cooled can be cooled by immersing the object to be cooled such as a can drink in the cooling water. Moreover, the cooling device of patent document 1 is provided with the to-be-cooled object amount detection means which detects the quantity of the to-be-cooled object immersed in the cooling water. The cooling object amount detection means comprises a water level detection device that detects the cooling water level, and is based on the difference between the water level before the cooling object is immersed in the cooling water and the water level after the cooling object is immersed. Then, the amount (volume) of the object to be cooled is detected. As the amount of the object to be cooled detected by the detecting means increases, the output of the flowing water generator for generating flowing water in the water tank is set to increase.

  In the cooling device according to the present invention, the cooling water is cooled to freeze a part thereof, and an ice layer is formed in the water tank. In this regard, for example, a chiller of Patent Document 2 is known. The cold water machine of Patent Document 2 is for a water tank (cooling tank) that stores drinking water, an evaporation pipe that is wound around the peripheral side wall of the water tank, a temperature sensor (thermostat) that detects the temperature of the drinking water, and a compressor. And a timer switch for controlling the power supply state. When drinking water is poured into the aquarium and the chiller is started, the drinking water is cooled by the evaporation pipe, and the water temperature eventually decreases to a predetermined low temperature (freezing temperature) at which an ice layer can be formed on the inner surface of the aquarium. . When a predetermined time elapses from this point, the timer switch is opened to stop the power supply to the compressor, and the cooling of the cold water by the evaporation pipe is stopped. Thus, if the cooling time after the water temperature is lowered to the freezing temperature is made constant, a constant amount of ice layer can be formed regardless of the initial temperature of the drinking water injected into the aquarium.

JP-A-9-324973 (paragraph numbers 0014, 0096, FIG. 1, FIG. 21) Japanese Patent Publication No.53-545

  When the ice layer control method according to Patent Document 2 is applied to the cooling device of Patent Document 1 that stores cooling water in the water tank, the water temperature of the original cooling water injected into the water tank when the cooling device is activated. Regardless, a certain amount of ice layer can be formed. However, when cooling the cooling water whose temperature has been increased by immersing the object to be cooled, applying the control method of Patent Document 2 may cause excess or deficiency in the ice layer. That is, when the object to be cooled is immersed, the amount of increase in the temperature of the cooling water and the melting amount of the ice layer accompanying the increase in the water temperature vary depending on the amount of the object to be cooled. The more, the more the water temperature rises and the amount of ice layer melting increases. That is, the remaining amount of the ice layer is not constant at the time when the cooling water in which the object to be cooled is immersed is cooled again and the water temperature falls to a predetermined low temperature (freezing temperature). Therefore, if the control method of Patent Document 2 in which the cooling time after reaching the freezing temperature is made constant is adopted, when the remaining amount of the ice layer is large, the ice layer may grow excessively. On the other hand, when the remaining amount of ice layer is zero or close to it, the cooling time for forming the ice layer is insufficient, and the ice layer is sufficient to cool the next object to be cooled. May not be formed.

  An object of the present invention is to allow an ice layer to be formed in a water tank without excess or deficiency when the cooling water whose temperature has risen is cooled again in a cooling device that cools an object to be cooled in cooling water. Is to make it.

  The cooling device according to the present invention includes a water tank 1 for storing cooling water, a cooling means 3 for cooling the cooling water in the water tank 1, a temperature sensor 35 for detecting the water temperature T of the cooling water in the water tank 1, and the water tank 1. A cooling object amount detecting means 42 for detecting the amount of the cooling object immersed in the cooling water therein and a cooling control unit 40 for controlling the cooling means 3 are provided. The cooling control unit 40 operates as an operation mode of the cooling means 3 in a normal mode in which a part of the cooling water is frozen to form an ice layer in the water tank 1, and a cooling water temperature T is set higher than the normal mode. And a suppression mode for holding the temperature lower than the reference temperature T1. In the normal mode, the cooling control unit 40 switches the operation mode to the suppression mode when a predetermined switching time L1 elapses from the time when the water temperature T decreases to the reference temperature T1. In the suppression mode, when the water temperature T rises and exceeds the reference temperature T1, the cooling control unit 40 switches the operation mode to the normal mode. When the water temperature T rises and exceeds the reference temperature T1, the to-be-cooled object amount detection means 42 performs a detection process on the assumption that the to-be-cooled object is immersed in the cooling water, and the switching time according to the detected amount of the to-be-cooled object. L1 is set.

  Specifically, when the cooled object amount detection means 42 detects a small amount of the cooled object, the switching time L1 is set shorter than when a large amount of the cooled object is detected.

  The amount-of-cooled object detection means 42 rises to a determination temperature T2 where the water temperature T is higher than the reference temperature T1 from when the coolant temperature T exceeds the reference temperature T1 until a predetermined determination time L2 elapses. In such a case, it is determined that the amount of the object to be cooled is large, and if the water temperature T does not rise to the determination temperature T2, it can be determined that the amount of the object to be cooled is small.

  In the present invention, when the switching time L1 elapses from the time when the cooling water temperature T decreases to the reference temperature T1, the operation mode of the cooling means 3 is switched from the normal mode to the suppression mode, and then the amount-of-cooled object detection means 42 is detected. The switching time L1 is set according to the amount of the object to be cooled. Specifically, the switching time L1 is set shorter when the cooled object amount detection means 42 detects a small amount of cooled object than when a large amount of cooled object is detected. According to this, when the amount of the object to be cooled is small and the remaining amount of the ice layer is large, the operation time in the normal mode, that is, the cooling time for forming the ice layer is shortened, Growth can be prevented. In this case, even if the operation time in the normal mode is short, the ice layer can be grown up to an amount sufficient to cool the object to be immersed next. On the other hand, when the amount of objects to be cooled is large and the remaining amount of ice layer is small, the operation time in the normal mode should be longer than when the remaining amount of ice layer is large, and the ice layer should be grown sufficiently Can do. Therefore, it is possible to prevent the ice layer from being insufficient when the next object to be cooled is cooled. As described above, according to the present invention, when the cooling water whose water temperature has increased due to the immersion of the object to be cooled is cooled again, the cooling time for forming the ice layer is optimized according to the amount of the object to be cooled. Thus, an ice layer can be formed in the water tank 1 without excess or deficiency.

  The amount-of-cooled object detection means 42 rises to a determination temperature T2 where the water temperature T is higher than the reference temperature T1 from when the coolant temperature T exceeds the reference temperature T1 until a predetermined determination time L2 elapses. In such a case, it is determined that the amount of the object to be cooled is large, and if the water temperature T does not rise to the determination temperature T2, it can be determined that the amount of the object to be cooled is small. As described above, when the object to be cooled detection unit 42 is based on the coolant temperature T, it is possible to determine the amount of heat of the object to be cooled, and to detect only the volume of the object to be cooled (Patent Document 1). The cooling time for forming the ice layer can be made more appropriate as compared with the case where the object amount detecting means (1) is adopted. That is, even if the volume of the object to be cooled immersed in the cooling water is the same, if the temperature of the object to be cooled is different, the range of increase in the water temperature and the remaining amount of the ice layer are different. However, according to conventional cooling object amount detection means based only on the volume of the object to be cooled, if the volume of the object to be cooled is the same, it depends on the temperature of the object to be cooled (the amount of remaining ice layer). Instead, the same switching time is set. On the other hand, according to the object-to-be-cooled amount detection means 42 of the present invention, even if the object to be cooled has the same volume, when the object to be cooled has a low temperature (the remaining amount of ice layer is large), By setting the switching time L1 to be shorter than when the temperature of the cooling object is high (the remaining amount of the ice layer is small), and shortening the operation time in the normal mode, that is, the cooling time for forming the ice layer, Excessive ice layer growth can be prevented. Thus, according to the to-be-cooled object amount detection means 42 of the present invention for determining the amount of heat of the to-be-cooled object, the cooling time for forming the ice layer is made more appropriate, and there is no excess or deficiency in the water tank 1. An ice layer can be formed more reliably. Moreover, according to the to-be-cooled object amount detection means 42 of the present invention, it is possible to reliably determine the amount of the to-be-cooled object during the determination time L2 and prevent the determination process from taking a long time.

It is a schematic block diagram of the cooling device which concerns on embodiment of this invention. It is a perspective view of a cooling device. It is a cross-sectional top view of the water tank of a cooling device. It is a block diagram which shows the control structure of a cooling device. It is a flowchart for demonstrating the control method of a cooling device. It is a flowchart for demonstrating the control method of a cooling device. It is a timing chart for demonstrating the control method of a cooling device. It is a timing chart for demonstrating the control method of a cooling device.

(Embodiment) FIGS. 1-8 shows embodiment of the cooling device based on this invention. 1 and 2, the cooling device includes a water tank 1 for storing cooling water, a housing 2 disposed below the water tank 1, a cooling means 3 for cooling the cooling water in the water tank 1, and the like. The water tank 1 is formed of a heat insulating box having an opening on the upper surface, and an operation unit 4 for a user to operate the cooling device is provided on the outer surface thereof. The housing 2 is formed of a box body having the same longitudinal and lateral dimensions as the water tank 1, and a machine room 5 is formed therein. An intake port fitted with a louver 6 is formed on the side wall of the housing 2, and outside air is introduced into the machine room 5 through the intake port. In addition, a large number of vent holes are formed in the plurality of side walls of the housing 2.

  In FIG. 1, the cooling unit 3 supplies a compressor 8, a condenser 9, an expansion valve 10, and an evaporator 11 connected in a circular manner by a refrigerant pipe 12, and supplies heat exchange air to the condenser 9. Condensing fan 15 and the like. The evaporator 11 is built in the water tank 1, and the coolant stored in the water tank 1 is cooled by evaporating the refrigerant liquid in the evaporator 11. A dryer 16 is disposed between the condenser 9 and the expansion valve 10 in the refrigerant pipe 12, and an accumulator 17 is disposed between the evaporator 11 and the compressor 8. The compressor 8, the condenser 9, the expansion valve 10, the condenser fan 15, the dryer 16, and the accumulator 17 are accommodated in the machine room 5 in the housing 2.

  In FIG. 3, the water tank 1 is composed of an outer box 20, an inner box 21 accommodated in the outer box 20 with a space, and a heat insulating material 22 filled between both boxes 20, 21. Cooling water can be stored inside the inner box 21. The refrigerant pipe constituting the evaporator 11 is arranged in a wound state surrounding the peripheral side wall of the inner box 21 from the outer surface side (the heat insulating material 22 side), and further arranged in a meandering state on the outer surface side of the bottom wall of the inner box 21. ing. As the refrigerant liquid evaporates in the evaporator 11, the cooling water is cooled through the wall surface of the inner box 21, and an ice layer is formed on the inner surface of the inner box 21.

  Inside the inner box 21, a protective plate 24 is arranged at a certain distance from each side wall of the inner box 21. Each protection plate 24 includes a large number of water passages 25 that allow the passage of cooling water (see FIG. 2), and the water level of the cooling water is the same inside and outside the protection plate 24. By immersing the object to be cooled in the cooling water in the space surrounded by the four protective plates 24, it can be cooled and stored. Examples of the object to be cooled in the present embodiment include packed foods that are prepared by heating and cooking liquid foods such as soups and stews. If this packed food is immersed in cooling water containing an ice layer, quickly cooled, and stored while immersed, the propagation of germs and the like can be suppressed while maintaining the freshness until the food is provided. The protection plate 24 prevents the ice layer on the inner surface of the inner box 21 from growing excessively and becoming an obstacle when the object to be cooled is immersed.

  The cooling device according to the present embodiment includes a pair of circulation means 27 for forming a water flow between the inner box 21 and the protection plate 24. In FIG. 1, each circulation means 27 includes a cooling water suction port 28 and a discharge port 29 disposed on the inner surface side of the side wall of the inner box 21, a cooling water circulation channel 30 that connects the suction port 28 and the discharge port 29, and The pump 31 is disposed in the middle of the circulating water channel 30 and accommodated in the machine room 5. The suction port 28 is disposed at the lower part of the side wall of the inner box 21, and the discharge port 29 is disposed at the upper part of the side wall. When the pump 31 is driven, the cooling water in the inner box 21 is sucked into the circulation water channel 30 from the suction port 28 and discharged from the discharge port 29 into the inner box 21.

  In FIG. 3, the discharge port 29 protrudes from the side wall of the inner box 21 toward the inner surface, and opens in the horizontal direction along the side wall. The cooling water is discharged from the discharge port 29 in the horizontal direction, whereby a spiral water flow is formed between the inner box 21 and the protection plate 24. Thus, if a water flow is formed between the inner box 21 and the protective plate 24, the heat exchange efficiency between the side wall of the inner box 21 cooled by the evaporator 11 and the cooling water can be improved. The protection plate 24 also serves to prevent the discharge port 29 from being damaged by separating the discharge port 29 from the object to be cooled. Specifically, when the object to be cooled stored in a container such as a mesh basket is immersed, the protection plate 24 can prevent the container from colliding with the discharge port 29 and damaging the discharge port 29.

  In FIG. 1, a drain port 34 for draining the cooling water in the inner box 21 is provided at the bottom of the water tank 1. In addition, a temperature sensor 35 that detects the water temperature T of the cooling water in the water tank 1 is fixed to the lower portion of the side wall of the inner box 21 so as to protrude from the side wall to the inner surface side. When such an arrangement is adopted, the temperature sensor 35 is moved away from the inner box 21 that is directly cooled by the evaporator 11, the influence of the low temperature of the inner box 21 is suppressed, and the actual temperature of the cooling water is accurately detected. be able to.

  The control configuration of the cooling device according to this embodiment is shown in the block diagram of FIG. In this block diagram, reference numeral 40 denotes a cooling control unit that controls the compressor 8 and the condenser fan 15 of the cooling means 3 and the pump 31 of the circulation means 27. The cooling control unit 40 includes a cooling water temperature T detected by the temperature sensor 35, an elapsed time L measured by the time measuring means 41 built in the cooling device, and a determination result of the cooled object amount detecting means 42 described later. Control each device based on

  The cooling control unit 40 has a normal mode in which a part of the cooling water is frozen to form an ice layer on the inner surface of the inner box 21 as the operation mode of the cooling means 3, and the cooling water temperature T is higher than the normal mode. And a suppression mode to be held. In the normal mode, even if the coolant temperature T decreases to 0 ° C., the operation of the compressor 8 and the condenser fan 15 is continued to grow an ice layer on the inner surface of the inner box 21.

  If the normal mode is continued for a long time, the ice layer on the inner surface of the inner box 21 grows and reaches the protection plate 24, and the water inlet 25 of the protection plate 24 is blocked by the ice layer. Therefore, the cooling control unit 40 switches the operation mode to the suppression mode under a certain condition described later to prevent excessive ice layer growth. In the suppression mode, the water temperature T of the cooling water is maintained at a temperature slightly higher than the temperature at which the cooling water freezes, that is, 0 ° C. In the present embodiment, the water temperature T is maintained at 1 ± 0.5 ° C. by the on / off control of the compressor 8 and the condenser fan 15.

  Switching from the normal mode to the suppression mode is performed based on the coolant temperature T detected by the temperature sensor 35 and the elapsed time L measured by the time measuring means 41. Specifically, the cooling water is cooled in the normal mode, and the time counting by the time measuring means 41 is started when the water temperature T is lowered to a predetermined reference temperature T1. Then, when the elapsed time L from the start of timing reaches the switching time L1, the operation mode is switched from the normal mode to the suppression mode. The reference temperature T1 is set to a temperature slightly higher than the cooling water temperature zone (1 ± 0.5 ° C.) in the suppression mode. In the present embodiment, the reference temperature T1 is set to 2 ° C. The switching time L1 is a variable selected from among the initial switching time L10, the first switching time L11, and the second switching time L12. Details of this will be described later.

  A processing procedure performed by the cooling control unit 40 and the amount-of-cooled object detection means 42 will be described with reference to flowcharts shown in FIGS. 5 and 6 and timing charts shown in FIGS. 7 and 8. When normal temperature cooling water (tap water) is injected into the water tank 1 and the cooling device is activated by the operation of the operation unit 4 (time point t0), the cooling control unit 40 sets the operation mode to the normal mode (step). S1), operation of the compressor 8 and the condenser fan 15 is started. In addition to starting the cooling device directly by operating the operation unit 4, it is possible to set the cooling device to start at the start time designated by the user using the operation unit 4. Alternatively, it is possible to immerse and cool the object to be cooled at the use start time specified by the operation unit 4, that is, a state where a sufficient amount of ice layer is formed in the water tank 1. In addition, the startup time of the cooling device can be calculated backward, and the cooling device can be set to start at that time.

  When the normal temperature cooling water is cooled by the cooling means 3 (evaporator 11) and the water temperature T falls to a predetermined circulation start temperature T0 (time t1, YES in step S2), the cooling control unit 40 causes the circulation means 27 to pump. 31 is driven (step S3), and a water flow is formed between the inner box 21 and the protection plate 24. In this embodiment, the circulation start temperature T0 is set to 10 ° C.

  When the cooling water is further cooled and the water temperature T becomes equal to or lower than the reference temperature T1 (2 ° C.) (time t2, YES in step S4), the switching time L1 is set to the initial switching time L10 (step S5), and time measuring means Time counting by 41 is started (step S6). In this embodiment, the initial switching time L10 is set to 120 minutes. The initial setting (step S5) of the switching time L1 can be performed at an arbitrary timing from the time point t0 to the time point t2.

  When elapsed time L from the start of timing reaches switching time L1 (initial switching time L10) (at time t3, YES in step S7), cooling control unit 40 switches the operation mode to the suppression mode (step S8). At this time t3, a part of the cooling water in the water tank 1 freezes, and a sufficient amount of ice layer is formed on the inner surface of the inner box 21 to cool the object to be cooled. Further, the water temperature T detected by the temperature sensor 35 is 0 ° C., and is below the lower limit temperature (0.5 ° C.) of the temperature control range (1 ± 0.5 ° C.) in the suppression mode. The unit 40 stops the operation of the compressor 8 and the condenser fan 15.

  In the suppression mode, the water temperature T of the cooling water is maintained at 1 ± 0.5 ° C. Specifically, when the water temperature T rises to the upper limit temperature (1.5 ° C.), the operation of the compressor 8 and the condenser fan 15 is started, and when the water temperature T falls to the lower limit temperature (0.5 ° C.), the compression occurs. The operation of the machine 8 and the condenser fan 15 is stopped. Further, in the suppression mode, the continuous operation time of the compressor 8 is measured by the time measuring means 41, and when this time reaches the preset maximum time, the water temperature T is lowered to the lower limit temperature (0.5 ° C.). Even if not, the operation of the compressor 8 and the condenser fan 15 is stopped. In the present embodiment, this maximum time is set to 120 minutes. In this way, during operation in the suppression mode, the water temperature T is maintained at 1 ± 0.5 ° C. Therefore, unless there is an external factor such as immersion of the object to be cooled, the water temperature T is equal to the reference temperature T1 (2 ° C. ) Will not rise.

  When the water temperature T exceeds the reference temperature T1 (time t4, YES in step S9), it is considered that the object to be cooled is immersed in the cooling water, and the cooling control unit 40 switches the operation mode to the normal mode (step S10). At the same time, the amount-of-cooled object detection means 42 starts the detection process. The to-be-cooled object amount detecting means 42 determines the amount of the to-be-cooled object immersed in the cooling water, and sets the switching time L1 according to the determination result.

  Specifically, the to-be-cooled object amount detecting means 42 first resets the time measuring means 41 at time t4 and starts time measurement (step S11). If the water temperature T rises to a determination temperature T2 higher than the reference temperature T1 before the elapsed time L from the start of time reaches the predetermined determination time L2 (NO in step S13, YES in step S12), The coolant amount detection means 42 determines that the amount of objects to be cooled is large, and sets the switching time L1 to the first switching time L11 (step S14). On the other hand, if the elapsed time L reaches the determination time L2 before the water temperature T reaches the determination temperature T2 (NO in step S12, YES in step S13), the amount-of-cooled object detection means 42 indicates that the amount of object to be cooled is small. Determination is made and the switching time L1 is set to a second switching time L12 that is shorter than the first switching time L11 (step S15). FIG. 7 is a timing chart when the amount of objects to be cooled is large, and FIG. 8 is a timing chart when the amount of objects to be cooled is small. In the present embodiment, the determination temperature T2 is set to 4 ° C., the determination time L2 is set to 10 minutes, the first switching time L11 is set to 120 minutes, and the second switching time L12 is set to 60 minutes.

  The reason why the second switching time L12 is set shorter than the first switching time L11 is that when the amount of the object to be cooled is small, the increase in the water temperature when this is immersed is small, and the melting amount of the ice layer is small. This is because there are few. If the remaining amount of ice layer is large, even if the switching time L1 is set to the short second switching time L12 and the operation time in the normal mode, that is, the cooling time for forming the ice layer is shortened, the ice layer is immersed next. The ice layer can be grown to an amount sufficient to cool the object to be cooled. If the remaining time of the ice layer is large and the operation time in the normal mode is shortened, it is possible to prevent the ice layer from growing excessively so as to block the water passage 25 of the protection plate 24. On the other hand, when the amount of the object to be cooled is large and the remaining amount of the ice layer is small, the switching time L1 is set to the long first switching time L11 and the operation time in the normal mode is lengthened, thereby It can be grown sufficiently. Therefore, it is possible to prevent the ice layer from being insufficient when the next object to be cooled is cooled. As described above, according to the present embodiment, when the cooling water whose temperature has risen due to the immersion of the object to be cooled is cooled again, the cooling time for forming the ice layer is optimized according to the amount of the object to be cooled. Thus, an ice layer can be formed in the water tank 1 without excess or deficiency.

  The cooling water whose water temperature T exceeds the reference temperature T1 is cooled in the normal mode together with the object to be cooled. When the water temperature T decreases again to the reference temperature T1 (time t5, YES in step S16), the cooling control unit 40 resets the time measuring means 41 and starts timekeeping (step S17). If the water temperature T exceeds the reference temperature T1 before the elapsed time L reaches the switching time L1 (the first switching time L11 or the second switching time L12) (NO in step S19, YES in step S18), the next to-be-cooled Assuming that the object has been immersed, the to-be-cooled object amount detection means 42 starts the determination processing after step S11.

  On the other hand, as shown in the timing charts of FIGS. 7 and 8, the water temperature T does not exceed the reference temperature T1 (NO in step S18), that is, the elapsed time L is not immersed in the next object to be cooled. When the switching time L1 is reached (time t6, YES in step S19), the cooling control unit 40 switches the operation mode to the suppression mode (step S20), returns to step S9, and continues to the next mode while continuing the suppression mode. Wait for the immersion. When the water temperature T is higher than the lower limit temperature (0.5 ° C.) in the suppression mode at the time point t6, the operation of the compressor 8 and the condenser fan 15 is continued, and when the water temperature T is equal to or lower than the lower limit temperature, the compressor 8 and the condenser fan 15 are stopped. The timing charts of FIGS. 7 and 8 show the latter case. Instead of the above setting, the operation of the compressor 8 and the condenser fan 15 can be set to stop unconditionally when the operation mode is switched to the suppression mode.

  The to-be-cooled object amount detection means 42 according to the above embodiment is based on whether or not the coolant temperature T detected by the temperature sensor 35 rises from the reference temperature T1 to the determination temperature T2 within the determination time L2. Although the amount of the object to be cooled is determined, the present invention is not limited to this. For example, the determination time L2 is abandoned, and the maximum value of the water temperature T, that is, the water temperature T at the time when the water temperature T starts to decrease is detected, and this maximum value is compared with the determination temperature T2. Some can be determined. Alternatively, the time length from the time point t4 to the time point t5 in the timing charts of FIGS. 7 and 8, that is, the cooling water temperature T required to decrease to the reference temperature T1 again after exceeding the reference temperature T1. Time is measured, and when the time is equal to or greater than the reference, it can be determined that there are many objects to be cooled, and when the time is less than the reference, it can be determined that there are few objects to be cooled. Further, the determination result by the object-to-be-cooled amount detection means 42 does not have to be in two stages of “large” and “small”, the amount of the object to be cooled is determined in three or more stages, and the switching time L1 corresponding to each stage is set. It can also be set. Of course, in this case, the switching time L1 is set to a shorter time as the amount of the object to be cooled is smaller.

  In the suppression mode, the output (operating frequency) of the compressor 8 can be controlled in place of the on / off control of the compressor 8 or in combination with the on / off control. The evaporator 11 can be disposed on the inner surface side of the inner box 21. In this case, the evaporator 11 may be in contact with the wall surface of the inner box 21 or may be separated from the wall surface. When the evaporator 11 is disposed on the inner surface side of the inner box 21, an ice layer is formed around the evaporator 11. In the present invention, the ice layer includes both those formed along the inner surface of the water tank 1 and those formed around the evaporator 11 (cooling means 3). The cooling means 3 may be a thermoelectric element such as a Peltier element other than the refrigerator including the evaporator 11.

  The cooling water stored in the water tank 1 is not limited to the tap water used in the above embodiment, and may be seawater (salt water) having a freezing point lower than 0 ° C. In the present invention, the cooling water includes not only pure water but also an aqueous solution in which various solutes are dissolved in water. Examples of the object to be cooled in the present invention include fresh foods such as meat, fish and vegetables, canned drinks and bottled drinks in addition to the packed foods shown in the above embodiment. Further, the object to be cooled does not need to be in direct contact with the cooling water, and can be immersed in a sealed container or the like so as not to touch the cooling water.

DESCRIPTION OF SYMBOLS 1 Water tank 3 Cooling means 8 Compressor 11 Evaporator 15 Condenser fan 27 Circulation means 31 Pump 35 Temperature sensor 40 Cooling control part 41 Timing means 42 Cooled object amount detection means

Claims (3)

A water tank (1) for storing cooling water, a cooling means (3) for cooling the cooling water in the water tank (1), and a temperature sensor (35) for detecting the water temperature (T) of the cooling water in the water tank (1). And a cooled object amount detecting means (42) for detecting the amount of the cooled object immersed in the cooling water in the water tank (1), and a cooling controller (40) for controlling the cooling means (3). And
The cooling control unit (40) sets, as an operation mode of the cooling means (3), a normal mode in which a part of the cooling water is frozen to form an ice layer in the water tank (1), and a cooling water temperature (T). A suppression mode for maintaining the temperature higher than the normal mode and lower than the predetermined reference temperature (T1),
In the normal mode, the cooling control unit (40) switches the operation mode to the suppression mode when a predetermined switching time (L1) has elapsed from the time when the water temperature (T) has decreased to the reference temperature (T1). ,
In the suppression mode, the cooling control unit (40) switches the operation mode to the normal mode when the water temperature (T) rises and exceeds the reference temperature (T1).
When the water temperature (T) rises and exceeds the reference temperature (T1), the object to be cooled detection means (42) performs a detection process on the assumption that the object to be cooled is immersed in the cooling water. A cooling device characterized by setting a switching time (L1) according to the amount.   The cooling device according to claim 1, wherein when the amount-of-cooled object detection means (42) detects a small amount of the object to be cooled, the switching time (L1) is set shorter than when a large amount of the object to be cooled is detected.   The to-be-cooled object amount detection means (42) is configured such that the water temperature (T) is the reference between the time when the coolant temperature (T) exceeds the reference temperature (T1) and the predetermined determination time (L2) elapses. When the temperature rises to a determination temperature (T2) higher than the temperature (T1), it is determined that the amount of the object to be cooled is large, and when the water temperature (T) does not increase to the determination temperature (T2), the object to be cooled The cooling device according to claim 2, wherein the amount is determined to be a small amount.

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