JP6654921B2 - Cold thawing equipment - Google Patents

Description

  The present invention relates to a cold thawing apparatus corresponding to freezing, frozen storage, thawing and refrigerated storage.

  Foods such as fish and meat are frozen in a freezer for the purpose of maintaining quality and are stored frozen. The frozen food is then thawed at the time of sale or processing, and is refrigerated if necessary.

  When the food is frozen and stored frozen, and then thawed and refrigerated, temperature control for maintaining the quality and performing cold thawing is important. In addition, it is necessary to set a thawing schedule so that food can be provided in a timely manner.

  For example, as a general method of maintaining quality, when freezing food, by reducing the size of ice crystals generated in the cells of the food, cell destruction due to the formation of ice crystals is reduced, and the flow of drip is suppressed. , There is a method of maintaining the taste of food. In order to reduce cell destruction, it is necessary to pass through the maximum ice crystal formation temperature zone as short as possible in both freezing and thawing. The maximum ice crystal formation temperature range is a temperature range in which the generation of ice crystals is greatest, and varies depending on the object to be cooled and thawed, but is, for example, in the range of −2 to −10 ° C.

  For this reason, at present, instead of slow freezing, which freezes the object over time, the subject is placed in a lower temperature environment than slow freezing, and the rapid refrigeration technology that freezes in a shorter time than slow freezing has been developed. Development is progressing, and quality is maintained by quick freezing. For example, the passage time in the maximum ice crystal formation temperature zone in slow freezing is about one to several hours, whereas the passage time in the maximum ice crystal formation temperature zone in rapid freezing is about 6 to 30 minutes. It can be seen that the use of freezing can reduce cell destruction due to the formation of ice crystals as compared with the case of using slow freezing.

  On the other hand, the development of thawing technology is behind the development of freezing technology, and the development of rapid thawing instead of slow thawing is urgent. When quick-thawing frozen foods, running water thawing or natural thawing is common. On the other hand, as a thawing method considering the quality, there is a method of thawing at a low temperature such as a refrigeration temperature, but the thawing time becomes long.

  In addition, when thawing frozen food, it is generally necessary to transfer from a freezer to a refrigerator or other equipment. Then, a series of flows from freezing to thawing are not controlled continuously, but are controlled independently. In addition, the quality of food is degraded due to a change in temperature due to the transfer from the freezing device to the defrosting device.

  A highly versatile system capable of freezing to thawing has also been studied (for example, see Patent Document 1). However, each facility and each control are independent, and no consideration is given to controlling thawing using data accumulated during freezing.

Patent No. 3071659

  As described above, the development of the thawing technique has not been advanced, and it has conventionally been difficult to thaw a frozen object such as a frozen food in a short time without deteriorating its quality after freezing. Further, a series of flows from freezing to thawing are independently performed by separate devices of a freezer and a thaw, and are not continuously controlled. Therefore, a plurality of devices are required, the quality of the object to be thawed is degraded, and the work load of the worker such as transfer from the freezer to the thaw is heavy.

  Accordingly, the present invention enables freezing, freezing, thawing, and refrigeration of an object by utilizing the reversibility of thawing and thawing from coagulation and freezing of ice in a single cold thawing apparatus, It is an object of the present invention to provide a cold thawing apparatus which prevents deterioration of the quality of an object, enables setting of thawing time during freezing, and realizes this series of temperature control in a shorter time than before.

The cold-thaw apparatus according to the present invention, between the freezing and refrigerated storage of the object to be cold-thawed, a cold-thaw storage that can be stored, a heat exchanger that supplies cold or warm heat in the cold-thaw storage, A plurality of temperature sensors for measuring the temperature of the cold thawing chamber and the object; a temperature data storage unit for storing temperature data for associating a temperature value measured by the temperature sensor with a measurement time; and the heat exchanger Calorie data storage unit for storing calorie data relating the amount of cold or warm heat supplied and the time supplied, and a heat exchanger control capable of controlling the heat exchanger in a series of processes from freezing to thawing The heat exchanger control unit, the heat exchanger control unit, the amount of heat corresponding to the amount of cold heat supplied to the cold thawing cabinet during the freezing of the object, as the amount of warm heat required for thawing the object, the amount of heat, when thawing, Supply the warm heat of the amount To control the exchanger.

  According to the present invention, while freezing, freezing and preserving, thawing and refrigerated preservation of an object are enabled in one apparatus, the quality of the object is prevented from deteriorating, and this series of operations is performed in a shorter time than before. Temperature control can be realized.

It is a schematic diagram explaining the composition of the cold thawing device concerning a 1st embodiment. It is the schematic explaining the space of the cold thawing warehouse of the cold thawing apparatus of FIG. 1, a heat exchange room, and the partition provided between them. It is a block diagram explaining an example of a heat pump. It is the schematic explaining the position of the fan coil in the partition of the cold thawing apparatus of FIG. It is a figure explaining arrangement | positioning of the shelf to the cold thawing warehouse of the cold thawing apparatus of FIG. FIG. 6 is a diagram for explaining the shelf of FIG. 5, the installation position of a temperature sensor on the shelf, and the arrangement position of an object. It is the schematic explaining the cardboard box which is an example of an object. It is the schematic explaining the installation position of the temperature sensor on a shelf, and the arrangement position of the cardboard box on a shelf. FIG. 2 is a schematic diagram illustrating a distributor used in the cold thawing apparatus of FIG. 1. FIG. 2 is a graph showing a temperature change when an object is cold-thawed by the cold-thaw apparatus of FIG. 1. It is a graph showing the temperature change in the maximum ice crystal formation zone of an object when the object is frozen by slow freezing. It is a graph showing the temperature change of the object after passing through the maximum ice crystal formation zone when the object is frozen. It is a flowchart explaining the processing of the supply calorie control method in the case of thawing an object. It is a figure explaining the determination method of the unit thawing time of the supply heat quantity control method, and the determination method of the supply heat quantity. It is a graph showing the temperature change of the target object when the target object is rapidly thawed, and the temperature change of the atmosphere temperature in a cold thawing storage. It is a flowchart explaining a process of a temperature gradient control method. It is a flowchart explaining the process of an individual temperature control method. It is a graph showing the temperature change in the case of controlling only thawing, and the supply amount of warm heat. It is a schematic diagram explaining the composition of the cold thawing device concerning a 2nd embodiment. 20 is a graph illustrating a temperature change when the target is cold-thawed by the cold-thaw apparatus of FIG. 19. It is a graph showing the temperature change in the maximum ice crystal formation zone of an object when the object is frozen by rapid freezing. It is a schematic diagram explaining the composition of the cold thawing device concerning a modification. It is a schematic diagram when an electrode (ground electrodes on the top and bottom, discharge electrodes in the middle) is installed in a cold thawing cabinet. It is a graph showing the temperature characteristic of supercooling.

  Hereinafter, a cold thawing apparatus according to an embodiment of the present invention will be described. The cold thawing apparatus according to the embodiment has a freezing function, a freezing storage function, a thawing function, a refrigerated storage function and a temperature control function, and freezes, freezes, thaws and refrigerated storage of an object from coagulation and freezing of ice. It is a device that can be performed in a single cold thawing device by utilizing the reversibility of thawing and thawing. The target of cold thawing is a substance containing water, and the typical ones are foods such as fish, meat, fruits and vegetables, but also other items such as fresh flowers, seeds, artificial fertilized embryos of humans and livestock, and isolated organs for transplantation , Blood differentiated cells, microorganisms for bioreactors, and the like. The target object is stored in a storage container (including a paper bag or the like) of, for example, cardboard or vinyl chloride, and may include the container.

  Typical freezing methods include "slow freezing" in which the passage time of the maximum ice crystal formation zone is long and "quick freezing" in which the passage time of the maximum ice crystal formation band is short. Specifically, "slow freezing" is a method of freezing a low-priced object such as a processed product mainly in an environment of -20 to -30 ° C or higher. It is about one to several hours. On the other hand, the "rapid freezing" is a method of freezing an object for maintaining high price and freshness in an environment of -30 ° C or less, and the passage time of the maximum ice crystal formation zone is 6 to 30 minutes. It is about.

  In the following description, the cold thawing apparatus according to the first embodiment is an apparatus that freezes and defrosts by “slow freezing”. On the other hand, the cold thawing apparatus according to the second embodiment is an apparatus for freezing and thawing by “rapid freezing”.

[First Embodiment]
<Cold thawing apparatus 1A, heat exchange chamber 20, cold thawing box 10>
1 and 2 show a schematic configuration example of a cold thawing apparatus 1A according to a first embodiment of the present invention. The cold thawing apparatus 1A is provided with a cold thawing chamber 10 in which an object 2 to be cooled and thawed is installed, and a heat exchange chamber in which a heat pump 21 which is a heat exchanger for performing heat supply for freezing, freezing storage, thawing, and refrigeration storage is installed. 20, a partition 30 provided between the cold thawing storage 10 and the heat exchange chamber 20, and a cold thawing control device 40 for controlling the temperature related to cold thawing.

《Heat pump 21》
The heat pump 21 is a heat exchanger having a refrigeration function, a refrigeration storage function, a thawing function, and a refrigeration storage function, and is, for example, a brine heat pump that can supply warm and cold heat. The cold heat supplied by the heat pump 21 is a cold heat of −30 ° C. or more.

  This heat pump 21 is connected to a cold / thaw control device 40, and the supply of cold or warm heat is controlled by the cold / thaw control device 40. Specifically, the heat pump 21 supplies cold heat to the cold thawing box 10 so that the temperature of the cold thawing box 10 becomes suitable for freezing during freezing. Warm heat is supplied to the cold / thaw storage 10 so as to be as it is. Further, the heat pump 21 supplies cold heat to the cold-thaw storage 10 so that the temperature of the cold-thaw storage 10 becomes suitable for storage during frozen storage and refrigerated storage.

  The heat pump 21 has a calorie sensor (not shown), and measures the calorie to be supplied by the calorie sensor. The supplied heat amount measured by the heat amount sensor is stored in the heat amount data storage unit 43 as heat amount data by the heat pump control unit 41 described later.

  FIG. 3 is a configuration diagram illustrating an example of the heat pump 21. The heat pump 21 has a compressor and an expansion valve, and compresses, condenses, and expands the refrigerant by using heat input from the outside air, and generates cold or warm heat according to the control of the cold / thaw control device 40. The heat pump 21 of the example illustrated in FIG. 3 can switch between the supply of cold heat and the supply of warm heat by using a four-way valve. Note that the exhaust heat is the exhaust heat of the factory's warm wastewater and the factory's exhaust gas outside the cold / thaw apparatus 1. Further, heat such as well water may be used.

  Here, the heat pump 21 will be described as an example of the heat exchanger, but the heat pump is not limited to the heat pump, and may be any heat exchanger that can supply cold and warm heat.

<< cold thawing storage 10 >>
As shown in FIG. 1, a fan coil 11 for heat supply is provided on the side of the partition 30 at the side of the cold / thaw compartment 10, and cold or warm heat from the heat pump 21 is supplied to the cold / thaw cabinet 10 via the fan coil 11. Is done. Thereby, the inside of the cold thawing box 10 is adjusted to a temperature suitable for freezing, thawing or storage. For example, the fan coil 11 is provided at a position 31 of the partition wall 30 as shown in FIGS. FIG. 4C is a diagram showing the installation position of the fan coil of the cooling and thawing apparatus according to the second embodiment, which will be used in the following description.
Further, a plurality of temperature sensors 12 for measuring the temperature in the cold thawing cabinet 10 and the temperature of the object 2 are arranged in the cold thawing cabinet 10. Specifically, an example of the temperature sensor 12, which will be described later with reference to FIG. 6, is a gas thermometer, an infrared thermography, or the like, but a sensor capable of digital measurement is preferable. The temperature control in the cold / thaw storage 10 is performed by the cold / thaw control device 40 according to the measurement value of the temperature sensor 12.

  Note that the size of the cold thawing box 10 is not limited, and can be set to various sizes according to the purpose. In addition, in the example shown in FIGS. 1 to 3, the cold thawing chamber 10 and the heat exchange chamber 20 are formed adjacent to each other with the partition wall 30 interposed therebetween, but are separated while being connected by a pipe or duct for heat supply. It may be formed in a state.

(Shelf 61, cardboard box 22)
When arranging the objects 2 in the cold thawing box 10, as shown in FIG. 5, a shelf 61 is set on a gantry 60 of the cold thawing box 10, and a plurality of objects 2 are aligned and mounted on the shelf 61. May be installed. For example, the shelf 61 is configured to support a plurality of shelves 64 on which the object 2 can be placed by columns 62 and beams 63. The shelf board 64 is desirably provided with a hole 65 to facilitate heat transfer between the object 2 and the space. When the objects 2 are arranged on the shelf board 64, as shown in FIG. 6, it is preferable that a space is provided between each of the objects 2 arranged and placed. These spaces become passages for cold heat during freezing, frozen storage, and refrigerated storage, and become passages for warm heat during thawing.

  When the cold thawing apparatus 1A is used in a factory, a market, or the like, as shown in FIGS. 6 and 7, an object to be subjected to cold thawing and a container such as a cardboard box 22 in which the object is stored may be used as the object 2. Good. In this case, the cardboard boxes 22 in which the objects 2 are stored are arranged on the respective shelves 64.

  For example, as shown in FIG. 7, when an object is put in a cardboard box 22 having a bonding portion 23 in the middle, even if a space is created on the upper surface side in the cardboard box 22, the object is placed on the bottom side of the cardboard box 22. Is heavy because the object 2 exists. Therefore, at the time of cold thawing, cool air collects on the bottom side of the cardboard box 22. Therefore, in order to freeze or thaw as much as possible without unevenness, the cardboard box 22 is placed so that there is a space on the upper surface, the bottom surface, and the side surface of the shelf board 64 as shown in FIG. 6, and as shown in FIG. The shelf board 64 is provided with a hole 65 so that the total area thereof is as large as possible, so that the cardboard box 22 contacts cold air as much as possible during freezing, and the cardboard box 22 where cold air gathers during thawing. It is desirable to promote heat transfer by warm air also from below.

  The shelf 61 may be made of any material that can withstand the weight of the object 2.

(Temperature sensor)
In the cold thawing, the temperature unevenness in the cold thawing chamber 10 leads to the deterioration of the quality of the object 2. Furthermore, when a plurality of objects 2 are to be cold-thawed, it is desirable to control the temperature after making the temperatures of the objects 2 uniform. Therefore, it is necessary to measure the temperature at a plurality of locations in the cold thawing cabinet 10 and to measure the temperature at each location in order to prevent temperature unevenness in the cold thawing cabinet 10.

  For example, as shown in FIG. 6, an infrared thermography 66 and a thermometer 67 are installed as the temperature sensor 12 on the pillar 62, the beam 63, the shelf 64, and the like, and the temperature of the cardboard box 22 is measured. The temperature measured by the infrared thermography 66 and the thermometer 67 is stored in the temperature data storage unit 44 as temperature data by the temperature control unit 42.

  In the cardboard box 22, the space temperature tends to enter from the central bonding portion 23, and the temperature of the bonding portion 23 in the box tends to be lower during freezing and higher during thawing as compared with other portions. Therefore, when the cardboard box 22 is placed on the shelf 61 as the target object 2 and the thermometer 67 is installed below the cardboard box 22, the central part 23 is avoided and the position 24 of the cardboard box 22 is avoided. Is installed at the position of the shelf plate 64 corresponding to. That is, the thermometer 67 is attached to the shelf board 64 at a position 24 in contact with the cardboard box 22 at several positions 24 away from the bonding section 23 symmetrical to the bonding section 23 on the lower side of the cardboard box 22. The temperature of the shelf 64 on the lower side of the box 22 is measured.

  Although description using illustration is omitted, the temperature data stored in the temperature data storage unit 44 may be a display screen representing a temperature distribution and may be displayable on a display. Thus, a fan guide, a flow rate adjusting guide, a distributor system, and the like used for heat flow adjustment are installed in the cold thawing box 10, and the amount of heat supplied to each position in the cold thawing box 10 is adjusted to increase or decrease. It is possible to minimize the temperature difference between the high and low surface temperatures of the inside 10 and the object 2.

(Distributor 13)
When a plurality of objects 2 are to be cold-thawed in the cold-thawing apparatus 1A, in order to prevent the quality of the objects 2 from deteriorating and to shorten the time for cold-thawing, as shown in FIG. The distributor 13 may be installed in the inside. By using the distributor 13, the flow of cold or warm heat in the space around the object 2 is promoted, and at the same time, the heat or cold heat is applied to the object 2 slowly and uniformly so as not to have an adverse effect. To form a simple flow. Thereby, it is possible to prevent the quality of the target object 2 from deteriorating and shorten the cold thawing time.

  Specifically, as shown in FIG. 9, the cold / thaw storage 10 includes a distributor 13 through which cool air or warm air can flow evenly, a plurality of nozzles 132, a pipe 133, an outlet 134, and the like. The nozzles 132 and the pipes 133 are arranged, for example, at intervals so as to be uniform on the columns 62, the beams 63, or the shelf boards 64. Cooling or warming heat supplied from the heat pump 21 via the distributor 13 flows out of the outlet 134 provided in the pipe 133 into the space around the object 2.

  When temperature unevenness occurs on the surface of the object 2 during the freezing or thawing process, the supply amount of warm air supplied to the outlet 134 near the portion where the unevenness has occurred among the plurality of outlets 134 is increased or decreased. Thereby, the flow of cold air or warm air can be controlled, and unevenness of freezing or thawing can be suppressed.

  The method of blowing cold and warm heat using the distributor 13 is suitable as a method of allowing the plurality of objects 2 to pass through without causing temperature unevenness during freezing, particularly in the maximum ice crystal formation temperature zone.

  Although illustration is omitted, a fan or a guide valve is installed in the cold / thaw chamber 10 so as to increase or decrease the supply of the amount of heat of the cool air or the warm air to the location where the temperature unevenness of the target object 2 is present. It may be.

  Further, if necessary, an amount of air containing cold air corresponding to the amount of air sent from the heat exchange chamber 20 to the cold-thawing chamber 10 is taken out of the cold-thawing chamber 10 and the pressure in the cold-thawing chamber 10 is reduced. It is possible to adjust. The cool air may be stored in, for example, an ice heat storage tank 135 or the like, and the air containing the cool air in the ice heat storage tank 135 may be used for a condenser of the heat pump 21 or supplied to an air conditioner or another refrigeration device.

<Cold thawing control device 40>
As shown in FIG. 1, the cold / thaw control device 40 includes a heat pump control unit 41 and a temperature control unit 42, and executes a series of temperature control of cold / thaw and storage (freezing, freezing storage, thawing, refrigeration storage). Further, the cold / thawing control device 40 includes a calorie data storage unit 43 for storing calorie data supplied by the heat pump 21 to the cold / thawing cabinet 10, and a temperature data storage unit 44 for storing temperature data measured by the temperature sensor 12. .

  FIG. 10 shows the temperature characteristics of the object 2 during cold thawing. As shown in FIG. 10, the temperature range at the time of cold thawing is “frozen region” for performing refrigeration control, “freezing storage region” for performing frozen storage control, “thawing region” for performing thawing control, and refrigeration. The area is divided into four areas of “refrigerated storage area” for controlling the storage.

  When the surface of the object 2 reaches the freezing temperature tc after the start of freezing, the water contained therein starts freezing. When the freezing starts, the temperature of the object 2 decreases more slowly from the freezing temperature tc to the lower limit temperature ts of the maximum ice crystal formation zone than the temperature decreasing rate up to that time. The temperature range from the freezing temperature tc to the lower limit temperature ts of the maximum ice crystal formation zone is the maximum ice crystal formation zone, and the maximum ice crystal formation band is at the maximum. After passing through the maximum ice crystal formation zone, the temperature decreases mainly due to the specific heat of ice, and the temperature of the object 2 rapidly decreases to the freezing storage temperature and is stored frozen.

  Although each temperature differs depending on the type of the target object 2, in the present embodiment, the freezing temperature (target set temperature) tc is −2 ° C., and the maximum ice crystal formation zone lower limit temperature ts is −10 ° C. Here, the freezing temperature is a temperature at which freezing of the object 2 starts, and the target set temperature is a target temperature when the object 2 is refrigerated and stored. Here, the freezing temperature, the target set temperature, and Are both -2 ° C.

  In the description of the temperature control, a first preset temperature tp (omitted in FIG. 10), which will be described later, is −5 ° C., and a second preset temperature tpp is −3 ° C. Note that the preset temperature is a set temperature used as a reference for temperature control as compared with the temperature of the object 2, and two points of the first preset temperature tp and the second preset temperature tpp are not essential, and any one of them is required. One point may be set.

  The heat pump control unit 41 controls the heat pump 21 so as to supply cold heat for freezing the object 2 into the cold / thaw storage 10 during freezing (a period of the freezing region). Further, the heat pump control unit 41 supplies cold heat for freezing or refrigerated storage of the target object 2 in the cold / thaw storage 10 during frozen storage and refrigerated storage (the period of the frozen storage region and the period of the refrigerated storage region). The heat pump 21 is controlled to perform the operation. Further, the heat pump control unit 41 controls the heat pump 21 so as to supply warm heat for rapidly thawing the object 2 into the cold thawing box 10 as needed during thawing (period of the thawing region).

  In addition, the heat pump control unit 41 stores, in the heat amount data storage unit 43, heat amount data indicating the relationship between the value of the heat amount supplied to the cold thawing cabinet 10 by the heat pump 21 and time.

  The temperature control unit 42 stores, in the temperature data storage unit 44, temperature data indicating the relationship between the value of the temperature measured by the temperature sensor 12 and time.

<< Frozen area (from the start of freezing to the passage of the maximum ice crystal formation zone) >>
With reference to FIG. 11, a description will be given of the temperature characteristics in the maximum ice crystal generation zone and the control in the maximum ice crystal generation zone during freezing (slow freezing). FIG. 11 is a detailed explanatory diagram of a portion A-1 in the temperature characteristic of FIG.

  In this refrigeration control, the heat pump control unit 41 controls the heat pump 21 to supply cold heat. For example, the heat pump control unit 41 controls the heat pump 21 so as to supply a predetermined amount of cold heat at the beginning of freezing, and then controls the heat pump 21 in accordance with the temperature of the object 2 and the temperature in the cold thawing chamber 10 acquired from the temperature control unit 42. Can be adjusted.

  When the heat pump 21 supplies cold heat to start freezing the object 2, when the surface of the object 2 becomes 0 ° C. or less, the surface moisture starts to freeze. As shown in FIG. 11, the temperature of the target object 2 decreases over time, and the freezing of the target object 2 proceeds from the surface when the target object 2 reaches the freezing temperature tc. Thereafter, the inside of the object 2 freezes due to the heat transfer of the cold to the inside of the object 2.

  Here, after reaching the freezing temperature tc, the speed at which the temperature of the object 2 decreases becomes slow due to solidification of the water inside the object 2. At approximately the middle (temperature tm) of the maximum ice crystal formation zone (between tc and ts), the temperature-time characteristic changes its direction, and the temperature decreases.

  When much (about 50%) of the water in the object 2 freezes, the temperature of the object 2 decreases more rapidly, and the temperature rapidly decreases mainly due to the specific heat of the ice.

  Specifically, as shown in FIG. 11, the angle α (α1 to α8) between the line connecting the two points at the predetermined time interval h1 and the horizontal line is obtained in the temperature characteristic of the object 2. As for the object 2, the freezing of the water starts in earnest from the vicinity where the temperature becomes K1. The angle α gradually decreases as α1> α2> α3> α4 when the temperature is near K1 to near K2. After the temperature reaches K2, the angle α gradually increases as α4 <α5 <α6 <α7 <α8. As described above, it is possible to grasp the change in the state inside the target object 2 from the temperature change of the target object 2, and the heat pump control unit 41 can control the heat pump 21 in accordance with the change.

  For example, the heat pump control unit 41 acquires the temperature of the object 2 and the ambient temperature of the cold thawing chamber 10 from the temperature control unit 42, and specifically, sets the difference between them to be large, By controlling the heat pump 21 that increases the supply amount of, it is possible to quickly pass through the maximum ice crystal formation zone. Thereby, the refrigerating speed can be increased to prevent the quality of the object 2 from deteriorating due to freezing.

  In addition, when the expected temperature characteristics are not maintained, it is desirable to consider maintenance of the cold thawing apparatus.

  If the determined time interval h1 is short and the characteristic of the temperature change cannot be clearly obtained, if necessary, for example, the angle between the line connecting the separation points corresponding to twice or three times the time interval h1 and the angle of the horizontal line May be measured to grasp its characteristics.

  Further, the timing for obtaining the angle α between the line connecting the two points at the predetermined time interval h1 and the horizontal line does not need to be at each time interval h1, but can be obtained at each shorter time interval to obtain the accuracy of temperature control. Can be improved.

<< Frozen area (after passing through the maximum ice crystal formation zone) and frozen storage area >>
With reference to FIG. 12, a description will be given of temperature characteristics during freezing and frozen storage after passing through the maximum ice crystal formation zone, and control during this period. FIG. 12 is a detailed explanatory diagram of a portion B of the temperature characteristic in FIG. In FIG. 12, the temperature ty is a frozen storage temperature expected at the time of frozen storage.

  In the freezing process, when it is predicted that the direction of the freezing temperature characteristic deviates from the original temperature characteristic (solid line) in the direction of d (broken line) and does not reach the expected freezing storage temperature ty, the heat pump control unit 41 performs the cooling operation. The heat pump 21 is controlled so as to increase the supply amount. Specifically, as shown in an example shown in FIG. 12, the heat pump control unit 41 compares the point K3 with the point K3 ″ with respect to the angle β1 obtained between the point K3 and the preceding point K3 ′ based on the point K3. When the angle β2 obtained in the above is greatly reduced, it is predicted that the expected frozen storage temperature ty will not be reached.

  When the object 2 approaches the target frozen storage temperature ty, the temperature change of the object 2 becomes gentle, and when the temperature of the object 2 reaches the frozen storage temperature ty, the refrigeration control ends and the process shifts to the refrigeration storage control. At the time of frozen storage, the heat pump control unit 41 reduces the supply amount of cold heat to the cold / thaw storage 10, and the object is stored at the target frozen storage temperature ty. Since the cold heat supplied during the freezing storage is supplied at a temperature higher than the freezing storage temperature ty, the temperature of the target object 2 may deviate from the frozen storage temperature ty higher. In that case, cold is supplied to return the temperature of the object 2 to the frozen storage temperature ty, and the object 2 is stored at the frozen storage temperature ty. That is, as shown in FIG. 12, when the direction of the temperature characteristic rises from the original temperature characteristic (solid line) to the direction of e (dashed line), the heat pump control unit 41 returns to the predetermined frozen storage temperature by the predetermined temperature. The heat pump 21 is controlled so as to increase the supply of cold heat at a temperature. Specifically, when the angle β3 obtained with respect to the horizontal line is equal to or greater than a predetermined angle, the heat pump control unit 41 predicts that the temperature characteristic has deviated from the original temperature characteristic.

  In addition, it is confirmed that the user is walking a predetermined temperature characteristic so that the user can grasp the temperature characteristic. In these controls, if the temperature characteristics deviate significantly from the expected temperature characteristics, it is desirable to consider maintenance.

《Thaw area》
In the thawing region, the heat pump control unit 41 executes the thawing control based on the data collected in the freezing region. As a method of thawing control, there are a "supply calorie control method", a "temperature gradient control method", an "ambient temperature control method", and an "individual temperature control method". In addition, the heat pump control unit 41 performs thawing control by combining these plural methods.

(Supply heat control method)
With reference to FIG. 13 and FIG. 14, a supply heat amount control method which is a control method at the time of thawing will be described. The supplied heat amount control method is a method of using the value of the amount of heat used for freezing for controlling the supply of heat amount during thawing, and is a control in the thawing region in FIG. FIG. 13 is a flowchart illustrating the processing of the supplied heat amount control method. FIG. 14 is a diagram illustrating the thawing time, the amount of heat supplied and the temperature characteristics during freezing, and the temperature characteristics during thawing.

As shown in FIG. 13, at the time of thawing, the heat pump control unit 41 divides the set thawing time L by a predetermined value N to obtain a unit thawing time _Hi (= L / N) (S01). In decompression control, the heat pump control unit 41, wherein the amount of heat supplied to the cold thawing chamber 10 is calculated for each thawing time H _i found, controls the heat pump 21 to supply warm heat of the calculated amount of heat. Here, as shown in FIG. 14, illustrating the defrosting time L, as divided into first defrosting time H ₁ ~ N-th thawing time H _N time intervals Hr. Then, the first thawing time H ₁ supplies a first quantity of heat, the second thawing time for the next H _2, to supply the heat newly obtained. The thawing time after (H ₃ ~H _N) repeated supply and calculation of a new heat.

First, the heat pump controller 41 are the first thawing time processing of H _1, and i = 1 (S02).

The heat pump control unit 41 extracts the total heat amount Wfc supplied during the freezing of the object 2 from the heat amount data stored in the heat amount data storage unit 43, divides the total heat amount Wfc by a value N, and performs a first thawing time. The amount of heat Wt ₁ (= Wfc / N) to be supplied to the cold-thaw storage 10 at H ₁ is determined (S 03).

In the first defrosting time H _1, the heat pump control unit 41 to supply warm heat of heat Wt _1, to control the heat pump 21 (S04). Incidentally, the heat pump control unit 41 during this first defrosting time H _1, the warm heat of the heat Wt1, to average supplied at a temperature that is set in advance to control the heat pump 21.

Subsequently, i is incremented (i = i + 1) to execute the processing of the next decompression time (S05). For example, when i = 2, the second process of the defrosting time H ₂ is executed. At this time, the amount of heat Wf1 supplied up to the freezing time T1 is averagely supplied at a predetermined temperature to Wf1 / (N-1) during the time H2. Further, for example, when i = 3, the processing of the third decompression time H ₃ is executed.

In the i-th thawing time H _i , the heat pump control unit 41 acquires the current temperature T _i of the target object 2 from the temperature control unit 42 and, during freezing, from the start of freezing until the target object 2 becomes T _i. the total heat Wf _i spent extracted from heat data of heat data storage unit 43, the amount of heat supplied to the total heat Wf _i divided by the value (N-i), the cold thawing chamber 10 to the i thawing time H _i Wt _i (= Wf _i / (N−i)) is obtained (S06).

Further, in the i defrosting time H _i, the heat pump control unit 41 to supply warm heat of heat Wt _i, to control the heat pump 21 (S07). In this case, the heat pump control unit 41, between the first i defrosting time H _i, so that the average supplied warm heat of heat Wt _i at a predetermined temperature, to control the heat pump 21.

At the timing when the i thawing time H _i is completed, the heat pump control unit 41 acquires the temperature T of the current object 2 from the temperature control unit 42 compares the temperature T and the first preset temperature tp (S08) . The first preset temperature tp is set to, for example, −5 ° C. or −4 ° C. When the T _i has reached the first preset temperature tp, the heat pump controller 41 from the temperature control unit 42, shown in the display make the transition to the supply heat quantity control processing in the second pre-set temperature tpp.

If T _i ≧ tp is not satisfied (NO in step S08), heat pump control unit 41 repeats the processing in steps S05 to S08. At this time, the heat pump control unit 41 can use the temperature acquired in step S08 in the process of step S06 as the current temperature Ti of the target object 2.

On the other hand, if Ti ≧ tp (YES in step S08), heat pump control unit 41 sets heat amount Wt _i as heat amount Wt to be supplied thereafter (S09). Further, the heat pump control unit 41 increments i (S10). Further, the heat pump control unit 41 controls the heat pump 21 so as to supply the warm heat Wt (S11).

Thereafter, the heat pump controller 41, for each time interval H _r, acquires the temperature Ti of the current object 2 from the temperature control unit 42 compares the temperature Ti and the second preset temperature tpp (S12).

  If Ti ≧ tpp is not satisfied (NO in step S12), the heat pump control unit 41 repeats the processing in steps S09 to S10. The second preset temperature tpp is set to, for example, −3 ° C.

  On the other hand, if Ti ≧ tpp (YES in step S12), the supply of warm heat from the temperature control unit 42 to the heat pump control unit 41 is stopped, and the heat control unit 41 converges to the target set temperature tc (for example, −2 ° C.). The supplied heat amount control process as the defrosting control process is terminated (S13).

  After that, the heat pump control unit 41 executes a process of refrigeration storage control.

  As described above, when the thawing time L is set, the heat pump control unit 41 uses the value of the amount of heat supplied in the freezing for thawing, so that the thawing is properly completed within the set thawing time L. Can be controlled.

(Temperature gradient control method)
With reference to FIG. 15 and FIG. 16, a description will be given of a temperature gradient control method which is a control method at the time of thawing. The temperature gradient control method performs thawing control more precisely than the supplied heat amount control method based on the temperature-time characteristic (temperature change) at the time of thawing, and thus is executed in combination with the supplied heat amount control method described above with reference to FIG. This is a method of controlling heat supply according to a temperature change of the object 2 during thawing. Specifically, when steps S01 to S08 shown in the flowchart of FIG. 13 are executed in the supply heat amount control method, the gradient of the temperature change of the temperature-time characteristic (temperature change) at the time of thawing is simultaneously measured. In S08, if the first preset temperature tp is −5 ° C., there is a possibility that the temperature of the line connecting the two points becomes 45 °. Therefore, the first preset temperature tp is set to a temperature higher than the temperature at which the temperature becomes 45 °.

  FIG. 15 is a detailed explanatory diagram of a portion C in the temperature characteristic of FIG. 10, and shows a temperature change (thaw temperature characteristic) of the object 2 in the case of rapid thawing and a temperature change in the cold thawing room 10 (cold thawing room). Internal atmosphere temperature characteristics). FIG. 16 is a flowchart illustrating processing of the temperature gradient control method.

  In the case of using the temperature gradient control method, the heat pump control unit 41 performs the supply heat amount control when the inclination γ of a line connecting two measurement points at a predetermined time interval h3 described below reaches 45 degrees in the supply heat amount control method. The method ends, and the temperature gradient control process starts. Start the temperature gradient control. The heat pump controller 41 acquires the temperature of the object 2 from the temperature controller 42 (S21). The temperature acquired here has a temperature characteristic as shown in FIG.

  Further, the heat pump control unit 41 obtains a slope γ of a line connecting two measurement points at a predetermined time interval h3 from the acquired temperature (S22). The time interval h3 is, for example, a time interval from about 10 seconds to 5 minutes.

  When the inclination γ is obtained, the heat pump control unit 41 determines whether the obtained inclination γ is 45 ° or less (S23).

  If the obtained inclination γ is not equal to or smaller than 45 ° (NO in S23), the heat pump control unit 41 controls the heat pump 21 so as to supply the warm heat while maintaining the supplied heat amount, and repeats the processing of steps S21 to S23 (S24). ). That is, the heat pump control unit 41 controls so as to supply the warm heat of the heat amount (Wti (S07)) obtained in step S06 of the flowchart of FIG.

  On the other hand, when the obtained inclination γ is equal to or smaller than 45 ° (YES in S23), the heat pump controller 41 corrects the supplied heat amount Wti according to the inclination, and corrects the corrected heat amount Wγ (= Wti × (γ / 45 °). )), The heat pump 21 is controlled to supply the warm heat (S25). The point at which the inclination γ is 45 ° is the temperature at which the change in ice of the object 2 is such that the melting of ice becomes dominant due to the rise in specific heat, and is in the maximum ice crystal formation zone.

  Further, the heat pump control unit 41 obtains the temperature of the target object 2 after supplying the warm heat with the corrected heat amount Wγ from the temperature control unit 42 (S26).

  The heat pump controller 41 compares the obtained temperature with the target set temperature tc (S27).

  If the acquired temperature is not equal to or higher than the target set temperature tc (NO in S27), the heat pump control unit 41 returns to Step S25 and repeats the processing in Steps S25 to S27.

  On the other hand, when the acquired temperature is equal to or higher than the target set temperature tc (YES in S27), the heat pump control unit 41 stops the supply of warm heat and ends the control of the temperature gradient method (S28).

  As described above, the heat pump control unit 41 determines the amount of heat to be used for thawing according to the temperature gradient of the object 2, thereby preventing an excessive rise in the temperature of the object 2 during thawing and reducing the deterioration of quality. be able to.

(Ambient temperature control method)
An atmosphere temperature control method will be described with reference to FIG. The atmosphere temperature control method is a method that is executed in combination with the above-described heat supply amount control method or the temperature gradient control method, and is a method of controlling heat supply according to the atmosphere temperature of the cold thawing box 10 during thawing.

Specifically, when the atmosphere temperature control method is combined with the supply heat quantity control method, the heat pump control unit 41 executes the atmosphere control method and the supply heat quantity control method in parallel, and executes When the temperature rise of the atmosphere is 0 ° C. or more, and the temperature change once becomes gentle and then the temperature rise is detected again, or the temperature in the cold thawing box 10 is changed to the second preset temperature tpp by the supply heat quantity control method. Alternatively, the supply of warm heat is stopped at a timing that occurs earlier than the timing (S11 in FIG. 13) at which it is determined that the temperature has become higher than the target set temperature tc.
When the atmosphere temperature control method is combined with the temperature gradient control method, the heat pump control unit 41 executes the atmosphere control method and the temperature gradient control method in parallel, and performs the temperature control of the atmosphere of the cold-thaw storage 10 by the atmosphere temperature control method. When the temperature rise is 0 ° C. or more and the temperature change once becomes moderate, the temperature rise is detected again, or the temperature of the object 2 is increased to the second preset temperature tpp or the target temperature by the temperature gradient control method. The supply of warming heat is stopped at a timing that occurs earlier than any of the timings (S27 in FIG. 16) at which it is determined that it has become larger than tc.

  When executing the atmosphere temperature control method, the heat pump control unit 41 acquires the atmosphere temperature in the cold thawing room 10 from the temperature control unit 42. Further, the heat pump control unit 41 determines the inclination δ of a line connecting measurement points at predetermined time intervals h3 (for example, 1 minute, 3 minutes, 5 minutes, etc.) based on the acquired temperature characteristics of the ambient temperature in the cold thawing box 10. (Δ1, δ2, δ3, δ4 ...) are measured.

  When the slope δ of the line approaches the balance between the warming heat to be supplied and the cool heat emitted from the object 2 and the angle δ decreases and then increases again, the heat pump control unit 41 stops supplying the warming heat. As in the example shown in FIG. 15, after gradually decreasing to δ1> δ2> δ3, the gradient δ increases to δ3 <δ4. Therefore, by detecting the increase in the slope δ, it is possible to detect the timing at which the temperature once rises gradually after the ambient temperature becomes 0 ° C. or higher and then rises again. Further, after stopping the supply of the warm heat, the heat pump control unit 41 switches to the supply of the cool heat so as to converge to the set target set temperature tc, and executes the refrigeration process.

  In this way, the heat pump control unit 41 stops supply of warm heat used for thawing after the ambient temperature once becomes moderate at 0 ° C. or higher, and then increases the temperature of the target object 2 due to the temperature rise. Quality can be reduced. For example, in the present control method, when the amount of warming heat supplied to the thawing is large, the heat of melting of ice in the object 2 and the amount of heat of the atmosphere in the cold thawing cabinet 10 are not balanced, and This is effective when the ambient temperature rises.

(Individual temperature control method)
The individual temperature control method will be described with reference to FIGS. The individual temperature control method is a method that is executed in combination with the above-described supply heat amount control method or the temperature gradient control method. When a plurality of objects 2 are simultaneously thawed, thawing of each object 2 is prevented, and thawing is performed. This is a method of controlling the temperature so as to proceed uniformly. FIG. 17 is a flowchart illustrating the processing of the individual temperature control method.

  Specifically, for example, when combined with the temperature gradient control method, whether or not the temperature of any one of the objects 2 has reached, for example, the second preset temperature tpp between steps S26 and S27 in the flowchart of FIG. And if the temperature of any one of the objects 2 has reached the second preset temperature tpp, the individual temperature control method is executed. Here, the second preliminary set temperature tpp is close to the target set temperature tc and lower than the target set temperature tc.

  As shown in the flowchart of FIG. 17, the heat pump control unit 41 acquires the temperatures of the plurality of objects 2 (S31). Further, as shown in FIG. 15, the heat pump control unit 41 obtains an inclination γ between a straight line connecting two points at a predetermined time interval h3 of the temperature of each object 2 and a horizontal line (S32). Note that FIG. 15 shows only the temperature characteristics of the measurement values obtained by one temperature sensor. However, when the individual temperature control method is executed, a plurality of temperature characteristics exist because the inclination is obtained from the measurement values obtained by a plurality of temperature sensors. Will be.

The heat pump controller 41 compares the plurality of slopes γ obtained for each object 2 with a first predetermined value, and reduces the supply of warm heat to the object 2 having a slope γ larger than the first predetermined value (S33). , S34).
In addition, the heat pump control unit 41 compares the plurality of slopes γ obtained for each object 2 with a second predetermined value, and increases the supply of warm heat to the object whose inclination γ is larger than the second predetermined value ( S35, S36).

  Then, the heat pump control unit 41 acquires the temperatures of the plurality of objects 2 (S37). Further, the heat pump control unit 41 determines whether or not the temperature difference between the plurality of objects 2 is within a predetermined range (S38).

  If it is within the predetermined range (YES in S38), heat pump control unit 41 ends the individual temperature control process. If it is not within the predetermined range (NO in S38), the process returns to step S31, and the processes in steps S31 to S38 are repeated.

  As described above, when simultaneously thawing a plurality of objects 2, the heat pump control unit 41 supplies heat so that the temperature change of each object 2 becomes uniform, thereby increasing the temperature rise in the plurality of objects 2. Uniformization can be achieved, and uneven thawing can be prevented. Here, the temperature can be made uniform using the distributor 13 described above with reference to FIG.

  In the individual temperature control, even if the temperature is lower than the second preset temperature tpp, for example, the first preset temperature tp, the set temperature is determined to make the temperatures of the plurality of objects 2 uniform. I can do it.

(Correction coefficient)
When the target object 2 is stored in the storage container, the corrugated cardboard or resin, which is a material thereof, is a buffer material against pressure and a buffer material against heat. Therefore, there is a time delay in the heat transfer to the object 2 in the storage container with respect to the change in the atmosphere due to the heat. Therefore, it is preferable to set a correction coefficient that takes into account the time delay of heat transfer, and control the temperature using the correction coefficient.

  Note that the time delay varies depending on the size, shape, and the like of the storage container as well as the type, size, shape, and the like of the target object 2. Therefore, for a plurality of objects 2, cold thawing data corresponding to various storage containers are accumulated, and a correction coefficient obtained for each condition is set from them.

  In addition, it is desirable to introduce an integrated data application control that can accumulate and accumulate a time delay record for each storage container in the temperature control so that it can be used at the next cold thawing.

(Control only for thawing)
In addition, the cold thawing apparatus 1A is capable of controlling the entire process from freezing to refrigeration after thawing as a series of steps from freezing to thawing with a single cold thawing device. Even if there is no data, it can be handled. In this case, the amount of cold stored in the object 2 is calculated, and thawing is performed using the calculated amount of heat as basic data. This control will be described with reference to FIG. FIG. 18 is a diagram illustrating the temperature characteristics of the target object 2 and the supply amount of warm heat by the heat pump 21 when the control of only the thawing is performed.

  Specifically, the heat pump control unit 41 calculates the amount of cold heat W held by the object 2 from the amount of ice held by the object 2 and the temperature.

When the temperature of the target object 2 is 0 ° C., the cooling energy W ₀ held by the target object 2 is roughly calculated and is represented by the following equation (1).
W ₀ = (M · X / 100) · [C · (| T | − | t |) + (<Y / 100> · C · | t |) + (<Z / 100> · I)] ( 1)
M: object weight (kg)
X: water content of target object (%)
t: Freezing temperature of the object (° C)
T: Temperature at which the object was frozen (° C)
C: Specific heat of ice (kJ / kg)
I: Heat of melting of ice (kJ / kg)
Y: Percentage of ice that has reached 0 ° C out of the target ice (%)
Z: Percentage (%) of ice melted to 0 ° C. of target ice (Y + Z = 100)

  The values of M, X, C, Y, Z, and I are obtained for each type of target. These values can be obtained by using the accumulated data obtained in the process of the control, and can be appropriately updated to higher values according to the update of the accumulated data.

Therefore, if the freezing temperature of the object 2 is tc, and the ratio of the amount of the melted ice in the object 2 at tc is Zc%, the amount of heat W required for thawing by tc is as shown in equation (2). Desired.
W = (M · X / 100) · [C · (| T | − | tc |) + (<Zc / 100> · I)] (2)

  The heat pump controller 41 controls the heat pump 21 so as to divide the heat amount W by the thawing time L and supply the heat amount per time (W / L) to the cold thawing box 10. After that, the heat pump control unit 41 acquires the temperature of the object 2 and measures the angle ε between a line connecting two points at a predetermined time interval h4 and a horizontal line. A point P1 at which the angle ε becomes 45 degrees is a point at which the phase of the ice contained in the object 2 mainly melts from a state where the temperature change of the specific heat is dominant. / L of heat.

  Thereafter, the heat pump control unit 41 supplies warm heat by applying the above-described temperature gradient control method. That is, with respect to the supplied heat amount (W / L) at the time point P1, the heat amount Wε (= (W / L) · (ε) corrected using the angle ε between the line connecting the two points of the measured temperature and the horizontal line. / 45)), the amount of heat to be supplied is reduced.

  Then, at the time point P2 when the temperature of the object 2 reaches the second preset temperature tpp, the supply of heat is stopped, the thawing control is ended, and the refrigeration storage control is started.

(Principle of cold thawing control)
In this way, when performing the cold thawing with one cold thawing apparatus 1A, utilizing the reversibility of water solidifying and freezing on ice, and then thawing from ice through the thawing process, that is, utilizing the reversibility of freezing and thawing, Utilizing the positional reversibility of freezing and thawing in the object 2 due to the difference in thermal conductivity between ice and water of the object 2 and the temperature-time characteristics of the cold thawing of the object 2 by synthesizing those characteristics, Cold thawing can proceed. The thermal conductivity of water at 0 ° C. is 0.569 W / mK, and the thermal conductivity of ice at 0 ° C. is 2.2 W / mK.

  During freezing, the surface of the object 2 is cooled by freezing and cooling, and a temperature difference occurs between the surface of the object 2 and the core. In the rapid freezing, since the thermal conductivity of the moisture inside the object 2 is low, a large temperature difference is provided in the rapid freezing, and the cold heat is forcibly delivered to the core and the freezing proceeds.

  Also, when thawing, heat is given to provide a temperature difference between the surface of the object 2 and the core, and the high thermal conductivity of ice is used. Increase the temperature of the soft core ice to speed up melting. When the core ice melts, the thermal conductivity of water decreases, so the amount of heat reaching the core decreases, preventing an excessive rise in temperature of the core and simultaneously increasing the temperature of the ice around the core of the object And a lot of heat is used for melting. The heat of solidification of water and the heat of melting of ice are the same, and the specific heat of ice is the same if the temperature is the same between freezing and thawing. Then, utilizing the reversibility of freezing and thawing, the amount of heat used during freezing is added as a warming amount during thawing to promote thawing. On the other hand, there is a large difference in thermal conductivity between water and ice. As the freezing of the object progresses, heat conduction to the core of the object becomes easier, and the amount of cold required for freezing decreases. At the time of thawing, when an appropriate warming heat is applied, the temperature rises not only on the surface of the object but also on the core, and the melting starts. Then, at the same time as the volume of the object 2 that increases in temperature increases, the amount of heat required for the temperature increase and melting of the object 2 increases. Since the characteristics appear in the temperature characteristics of the object 2, the amount of warming heat supplied for thawing is supplied by utilizing the temperature characteristics of the object, and thawing is advanced.

  If the freezing time is long, the central portion of the object 2 also freezes on ice as hard as the surface of the object 2. At this time, even if a large amount of high-temperature warming heat is supplied, only the surface of the object 2 melts to increase the moisture, heat conduction to the core deteriorates, and only the surface is thawed and the ice remaining on the core remains. And remains hard. Therefore, at the time of rapid thawing, the supply of warm heat must be performed according to appropriate control.

  Both freezing and thawing proceed according to the correlation between the ambient temperature and the amount of heat of the object to be thawed. By using the same apparatus for freezing and thawing while keeping the heat capacity (size) of the cold thawing chamber 10 constant, the amount of heat used during freezing does not excessively melt only the surface of the object 2, but basically Uses reversibility to allow thawing. On the other hand, when different devices are used for freezing and thawing, the heat capacity of the device changes and reversibility is not established.

  In addition, in the case of the electrode installation described below, the electric energy supplied from the electrode is extremely small compared to the warm energy supplied from the atmosphere for thawing by the cold thawing device, Has no significant effect.

<Effect of cold thawing device 1A>
As described above, in the cold thawing apparatus 1A according to the first embodiment, the temperature of the cold thawing box 10 can be appropriately controlled. Specifically, rapid thawing can be realized by controlling the heat supply for thawing according to the value of the amount of heat supplied by freezing. In addition, by controlling the heat supply for thawing according to the temperature change of the object 2, the quality deterioration of the object 2 can be reduced. Furthermore, in the case of thawing a plurality of objects 2, by controlling the heat supply for thawing in accordance with the temperature of each object 2, the thawing time of each object 2 is prevented from varying and the quality of the object 2 is reduced. Degradation can be reduced, and rapid thawing can be realized.

[Second embodiment]
FIG. 19 shows a schematic configuration example of a cold thawing apparatus 1B according to the second embodiment of the present invention. The cold thawing apparatus 1B is different from the cold thawing apparatus 1A described above with reference to FIG. 1 in that instead of the heat pump 21 for freezing, thawing, and preserving, a freezing / freezing preserving apparatus is used as a heat exchanger in the heat exchange chamber 20. And a heat pump 21b for thawing and refrigeration storage. The cooling / thawing control device 40 includes a freezing and refrigeration storage function control unit 41a and a heat pump control unit 41b. The heat pump 21 of the cold thawing apparatus 1A according to the first embodiment can supply the cold heat and the warm heat, but the cool heat that can be supplied is the cold heat of −30 ° C. or more. In contrast, in the cold thawing apparatus 1B according to the second embodiment, the functional unit 21a can supply cold heat of −30 ° C. or less.

  Therefore, the freezing / thawing device 1B is controlled by the freezing / freezing / saving function control unit 41a during freezing and freezing / saving, and the freezing / freezing / saving function unit 21a is connected to the cold / thaw storage 10 via the fan coil 11a. Supply cold heat. In addition, the thawing apparatus 1B is controlled by the heat pump control unit 41b during thawing and refrigeration storage, and the heat pump 21b for thawing and refrigeration storage supplies warm and cold heat to the cold thawing box 10 via the fan coil 11b. Supply. Further, the fan coils 11a and 11b are arranged at the positions of 31a and 31b of the partition wall 30, as shown in FIG.

  FIG. 20 shows temperature characteristics of the object 2 during cold thawing. FIG. 21 shows temperature characteristics (A-2 in FIG. 20) in the maximum ice crystal formation zone during freezing (rapid freezing).

  The freezing / freezing storage function control unit 41a controls the function unit 21a to supply cold heat. For example, the freezing / freezing storage function control unit 41a controls the function unit 21a so as to supply a predetermined amount of cold heat at the beginning of freezing, and thereafter, the object 2 and the inside of the cold thawing room 10 acquired from the temperature control unit 42. The supply amount of cold heat can be adjusted according to the temperature.

  When the freezing of the object 2 is started by the functional unit 21a supplying cold heat of −30 ° C. or less, as shown in FIG. 21, after the object 2 reaches the freezing temperature tc, the object 2 is cooled. The speed at which the temperature decreases becomes slow due to the generation of heat of solidification due to the solidification of the water inside the object 2. At approximately the middle (temperature tn) of the maximum ice crystal formation zone (between tc and ts), the temperature-time characteristic changes its direction, and the temperature rapidly decreases.

  As shown in FIG. 11, in the temperature characteristic of the object 2, the angle θ (θ1 to θ6) between the line connecting the two points at the predetermined time interval h5 and the horizontal line is obtained as in the slow freezing. The angle θ gradually decreases as θ1> θ2> θ3. Also, it gradually increases as θ4 <θ5 <θ6. As described above, it is possible to grasp the change in the state of the object 2 from the temperature change of the object 2, and the freezing / freezing storage function control unit 41a controls the function unit 21a in accordance with the change. Can be.

  For example, the freezing / freezing storage function control unit 41a acquires the temperature of the object 2 and the ambient temperature of the cold thawing room 10 from the temperature control unit 42, and specifically, so that the difference becomes large, By controlling the freezing / freezing / saving function unit 21a for increasing the supply amount by the freezing / freezing / saving function control unit 41a, it is possible to quickly pass through the maximum ice crystal generation zone. This can prevent the quality of the object 2 from deteriorating due to freezing.

  Since the cold thawing apparatus 1B can supply cold heat of −30 ° C. or less into the cold thawing chamber 10 during freezing, rapid freezing is possible as shown in FIGS. Therefore, compared to the case of slow freezing described above with reference to FIG. 10, the freezing time can be reduced, and the passage time through the maximum ice crystal formation zone can be reduced. That is, deterioration of the quality of the object due to freezing can be reduced more than in the case of slow freezing.

  In the control in the cold thawing apparatus 1B, the freezing / freezing storage function control unit 41a controls the processing of the cold heat supply during freezing and freezing storage, and the heat pump control unit 41b controls the hot heat supply or the cold heat supply for the cold storage during thawing and refrigeration storage. The control is the same as the control in the cold thawing apparatus 1A except that the processing is controlled and the temperature of the cold heat supplied during freezing is different. That is, in the cold thawing apparatus 1B, similarly to the cold thawing apparatus 1A, the temperature data and the calorie data are stored at the time of freezing, and the thawing control is executed by the above-described supply calorie control method using the temperature data and the calorie data. I do. Also in the cold thawing apparatus 1B, thawing control can be executed by combining a temperature gradient control method, an ambient temperature control method, an individual temperature control method and the like.

  As described above, in the cold thawing apparatus 1B according to the second embodiment, the temperature of the cold thawing box 10 can be appropriately controlled. Specifically, rapid thawing can be realized by controlling the heat supply for thawing according to the value of the amount of heat supplied by freezing. In addition, by controlling the heat supply for thawing according to the temperature change of the target object 2, the quality deterioration of the target object 2 can be reduced. Furthermore, when a plurality of objects 2 are to be thawed, the heat supply for thawing is controlled in accordance with the temperature of each object 2 to prevent a variation in the thawing time of each object 2 and the quality of the objects 2 Degradation can be reduced, and rapid thawing can be realized.

[Modification]
(Add electrode)
FIG. 22 shows a schematic configuration example of a cold thawing apparatus 1C according to a modified example of the present invention. The cold thawing apparatus 1C includes a ground electrode 14a and a discharge electrode 14b in the cold thawing chamber 10 and controls the electrodes 14 (14a, 14b), as compared with the cold thawing apparatus 1B described above with reference to FIG. A different point is that an electrode control unit 45 is provided.

  As the ground electrode 14a and the discharge electrode 14b, the shelf plate 64 of the shelf 61 on which the object 2 is arranged may be used as the ground electrode 14a and the discharge electrode 14b, as shown in an example in FIG. The shapes of the electrodes 14a and 14b are not limited.

  The electrode control unit 45 can apply a voltage to the electrode 14a and discharge it from the start of freezing to the passage of the maximum ice crystal formation zone and from the start of thawing to refrigeration, for example. By the discharge, for example, the following effects can be obtained.

  (1) When refrigeration is promoted by heat transfer from the surface of the object 2, the inside of the object 2 is maintained at a substantially uniform temperature higher than the surroundings by energization, and the surface of the object 2 is By generating a temperature difference between the parts, it is possible to prevent the supercooling state from being partially generated among a large number of objects 2 installed in the cold thawing chamber 10, and to perform a uniform freezing. Enables to maintain various quality.

  (2) During freezing, in the cold / thaw storage 10, the freezing temperature is reduced by heat supplied by the functional unit 21a, and the temperature difference between the surface of the object 2 and the core is secured by discharging. Then, the application of the voltage to the electrode 14 is stopped in a state where the difference between the ambient temperature in the cold thawing chamber 10 and the temperature of the core of the object 2 is secured, and the quick freezing effect can be generated.

  (3) Air existing in the space between the object 2 and the discharge electrode 14b is an insulator, and when a voltage is applied to the electrode 14, a large current does not flow and a minute current flows. Therefore, the amount of Joule heat generated by energization in the object 2 is extremely small as compared with the amount of heat supplied from the functional unit 21a. Therefore, mist is supplied into the atmosphere of the cold thawing chamber to the extent that no discharge is generated between the object 2 and the surroundings, the current flowing between the electrodes is increased, and the temperature of the core of the object 2 rises, and melting occurs. Can be further accelerated. It is to be noted that a voltage can be applied between the electrodes according to the situation of the target object 2 so that the core does not freeze.

  The cold thawing apparatus 1C shown in FIG. 22 includes the electrode 14 and the electrode control unit 45 in the cold thawing apparatus 1B having the functional unit 21a and the heat pump 21b, but the cold thawing apparatus 1A having only the heat pump 21 shown in FIG. A configuration including the electrode 14 and the electrode control unit 45 may be employed. The other control at the time of cold thawing is the same as the control described in the first embodiment.

(Super cooling)
By setting the object 2 in a supercooled state during freezing, the ice crystals in the cells can be made small and fine. As a result, it is possible to maintain the quality of the object 2 without breaking the cell membrane and without drip. In the supercooling refrigeration control, the temperature inside the cold thawing chamber 10 is uniformly and slowly lowered by using the individual temperature control to cause the supercooling, and also, after the supercooling occurs and the supercooling is broken. Eliminates supercooling by rapid temperature drop. Therefore, it is necessary to detect the occurrence of supercooling by precise temperature measurement and determine the timing at which the supercooling is eliminated. For example, a distributor shown in FIG. 9 can be used to uniformly adjust the temperature in the cold / thaw storage 10.

  FIG. 24 shows the temperature characteristics of supercooling. In FIG. 24A, a point K1 is a point at which the supercooling is released. After the release of the supercooling, the temperature rapidly rises due to the coagulation of water, but after the point K2, the temperature drops in the process of freezing again. .

  FIG. 24B is an enlarged view of the temperature characteristic at the time of eliminating supercooling in FIG. In the supercooling refrigeration control, a temperature gradient control method is used by using a gradient between a horizontal line and a line connecting the temperatures measured at a time interval h8 (for example, several seconds) as shown in FIG. When the cooling is released, the temperature rises instantaneously. Therefore, in addition to the temperature gradient control method, it is possible to use one or both of a temperature change speed measurement method for observing a temperature change speed.

  In the temperature gradient control method, as shown in FIG. 25B, measurement is performed at time intervals of h8, and angles q (q1 to q6) between the measured two points and the horizontal line are obtained. At this time, q2 is an example in which it becomes 0 °. Next, when the temperature rises rapidly, q3 is inverted to the opposite angle to q1. That is, q1 formed an angle in the + direction with respect to the horizontal line, while q3 formed an angle in the-direction with respect to the horizontal line. Toward freezing, the angle is still in the negative direction, although the required angle q4 decreases. Thereafter, q5 and q6 whose angles are reversed in the + direction are obtained again (q5 <q6), and the angles increase with rapid freezing. In other words, since the inversion of the angle in the + direction and the inversion of the-direction occur twice, this can be sensed and the occurrence of supercooling can be known.

  In the temperature change speed measurement method, the temperature goes in the minus direction, then goes in the plus direction, and again goes in the minus direction. By measuring the change in the direction and the speed of the temperature change, it is possible to sense the overcooling and detect the magnitude of the temperature change. That is, at the point K1 at which the supercooling is released, the temperature greatly changes from the minus direction to the plus direction, but the temperature change per time increases. At point K2, again towards cooling, the temperature decreases. The value of the temperature change at that time is smaller than that at the time when the supercooling is released.

  In the supercooling refrigeration control, one of or a combination of the temperature gradient control method and the temperature change speed measurement method is used to detect the occurrence and release of the supercooling. After the cancellation of the supercooling, the thawing control is executed as described in the first embodiment.

(Other variations)
When warm air is supplied to the cold thawing apparatus by the heat exchanger, mist is supplied to the cold thawing apparatus simultaneously or intermittently in addition to the supplied warm air. By utilizing both the amount of heat of the warm air and the latent heat of condensation when the mist is liquefied, higher speed rapid thawing is possible. Further, by adding mist, when the surface temperature of the object 2 becomes higher than the thawing temperature (freezing temperature), the mist that adheres to the surface of the object 2 and condenses and freezes once liquefies, and the liquefied mist Further evaporates, and has an effect of suppressing an excessive rise in temperature of the object 2 by the heat of fusion and the heat of evaporation.

  Further, the cold thawing apparatus can be incorporated in a general refrigerator and freezer.

  Further, the ice may be sequentially melted inward by heat conduction from the surface of the object 2 by supplying warm air by a heat exchanger by incorporating the air in a general microwave oven, and then cooking may be performed in the microwave oven. . At this time, even if all the ice of the object 2 is not melted, the heat left in the object 2 can be melted by heat conduction in the object 2 by warm air or energy of a microwave oven. An integrated cold thawing device that adds mist in addition to warm air, promotes rapid thawing from the surface of the object 2, and enables thawing with a microwave oven.

  As described above, the present invention has been described using the embodiment, but the present invention is not limited to the embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims.

1A, 1B, 1C: Cold thawing device 2: Object 10: Cold thawing cabinet 11, 11a, 11b: Fan coil 12: Temperature sensor 20: Heat exchange chamber 21, 21b: Heat pump (heat exchanger)
21a… Function part for freezing and freezing and preservation (heat exchanger)
Reference numeral 22: Corrugated cardboard box 23: Laminating unit 30: Partition wall 40: Cold / thawing control device 41, 41b: Heat pump control unit (heat exchanger control unit)
41a: Freezing / freezing storage function control unit (heat exchanger control unit)
42 temperature control unit 43 calorific value data storage unit 44 temperature data storage unit 60 pedestal 61 shelf shelf 62 pillar 63 beam 64 shelf plate 65 hole 66 infrared thermography (temperature sensor)
67 ... thermometer (temperature sensor)

Claims (1)

A cold-thaw storage that can store the objects to be cold-thawed from freezing to thawing through thawing,
A heat exchanger that supplies cold or warm heat in the cold / thaw chamber,
A heat exchanger control unit that can control the heat exchanger in a series of processes from freezing to thawing through thawing,
Equipped with a,
The heat exchanger control unit obtains a heat amount corresponding to the heat amount of the cold heat supplied to the cold-thaw storage during the freezing of the object as the heat amount of the warm heat necessary for the thawing of the object. A cold thawing apparatus characterized by controlling a heat exchanger to supply heat .

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