JP4845930B2 - Frozen storage device and frozen storage method - Google Patents

Description

The present invention relates to a cryopreservation apparatus for storing food in a frozen state and a method for freezing and storing the same.

Recent needs for frozen storage devices such as refrigerators for home use have been gathered in “frozen” or “frozen storage” due to changes in eating habits and lifestyles. Freezers such as food stocks are frequently used, and there is a need for larger freezers and improved quality of frozen stored foods.

Conventionally, in the case of freezing foods, first, normal temperature foods are put into a space cooled to −18 ° C., and the food temperature is cooled to a temperature equal to the space after a certain time. The food placed in a low temperature environment is cooled on the surface to form ice crystals on the food surface, and then gradually cooled down to the inside of the food. At this time, the ice crystals are not frozen in the food. It expands while pulling out, forming large needle-shaped crystals toward the center, and eventually the whole food reaches ambient temperature and freezes. At this time, since the internal structure of the food is destroyed by the needle-like crystals, there is a problem that the quality of the food once frozen and stored is lower than that of fresh food.

Therefore, as a technique for solving the above problems and improving the quality of frozen preserved foods, quick freezing for rapidly freezing foods is generally used. However, even when quick freezing is used, particularly when a large food is frozen, there is a temperature difference between the surface and the center of the food, so that it cannot always be frozen with satisfactory quality. In addition, quick freezing has a problem in that a large amount of energy is required to spray food with cryogenic cold.

In recent years, as a new high-quality freezing technology that can avoid the problem of quick freezing, the food is cooled under specific cooling conditions to maintain an unfrozen state (supercooled state) even below the freezing temperature of the food. And there is a technology to save. By preserving food in such a supercooled state, there is an advantage that it can be stored at a temperature below the freezing temperature while avoiding cooling troubles such as protein denaturation due to freezing and damage of cell tissues. Compared to the conventional quick freezing technology, the supercooled food is forcibly stimulated to release the supercooled state and produce uniform and granular fine ice crystals in the whole food, followed by quick freezing. Thus, a storage technique has been proposed that can reduce cell tissue damage and suppress quality degradation (see, for example, Patent Document 1).

In addition, in the preservation technology that creates a supercooled state by irradiating food with electromagnetic waves and cooling while suppressing freezing, the strength of the electromagnetic field is set according to the freezing temperature of the food or the temperature of the maximum ice crystal formation zone, There has been proposed a method of stopping electromagnetic waves when cooled to the temperature or lower (for example, Patent Document 2).

JP 2003-180314 A JP 2005-34089 A

However, in the technique of storing in the supercooled state described in Patent Document 1, in order to maintain the supercooled state for a long time, the food is covered in advance with a sealed container or liquid so that the food is not directly exposed to cold air. It was necessary to devise. Further, since the supercooled state is an unstable state that is easily released by a stimulus such as vibration, there is a problem that it is difficult to store in the supercooled state for a long period of time. In addition, when stored for a long time in a supercooled state, the storage temperature is relatively high, and therefore the food quality may be deteriorated due to oxidation or bacterial growth.

In addition, in the method of storing food after releasing the supercooled state, especially when supercooling is performed in a refrigerator room where several foods such as a refrigerator for home use are stored together, the cooling rate Even when food that is supercooled even if it is fast, it is always cooled at the same cooling rate even if it is put into the refrigerator compartment, so that already frozen food is left at a relatively high temperature for a long time and the frozen quality deteriorates. There was a problem to do.

Moreover, in the method of irradiating the electromagnetic wave described in Patent Document 2 to develop a supercooled state corresponding to the type of food, a complicated and large device is required to generate the electromagnetic wave. In order to prevent leakage to the outside during opening and closing, a complicated structure is required, and there is a problem that it is particularly difficult to mount on a home refrigerator.

Therefore, the present invention was made to solve the problems of the conventional food preservation method using supercooling as described above, and the object of the present invention is to perform supercooling operation and freezing according to the type of food. By adjusting the cooling rate of operation to an optimum one, a frozen storage method and a frozen storage device for storing food in a frozen state with high quality are obtained.

In the cryopreservation device according to the present invention, a storage room for storing food, a cooling means for cooling the food put in the storage room, and a supercooling that controls the cooling means to bring the food into a supercooled state. after performing the operation, and a control means for carrying out the supercooling release operation for releasing the supercooled state of the food, to implement cryopreservation oPERATION cryopreserved by cooling the food product in which said supercooled state is released, and a food type input means for inputting to said control means a type of input food in the storage compartment, said control means, said food type and based on the obtained information from the input means, when the over-cooling operation The cooling rate , the operation time of the supercooling operation, and the cooling rate during the frozen storage operation are selected from preset combinations and can be adjusted according to the selection .

According to the present invention, since it can be cooled at a cooling rate according to each food type, it is possible to suppress deterioration in quality caused by thawing the frozen stored food regardless of the type of food to be input. .

Embodiment 1 FIG.
A cryopreservation apparatus according to Embodiment 1 of the present invention that can be stored frozen through a supercooled state will be described with reference to FIGS.
FIG. 1 is a side sectional view of a so-called refrigerator that is a cryopreservation apparatus according to Embodiment 1 of the present invention.
The refrigerator 1 includes a refrigerator compartment 100 that is provided with an open / close door at the top, and a refrigerator temperature range (−18 ° C.) to a refrigerator, vegetables, chilled, soft frozen (−7 ° C.) and the like below the refrigerator compartment 100. A switching chamber 200 with a drawer door that can be switched to a temperature zone, an ice making chamber (not shown) with a drawer door arranged in parallel with the switching chamber 200, and a freezer room with a drawer door arranged at the bottom 300, the vegetable compartment 400 provided with the drawer door arrange | positioned between the freezer compartment 300, the switching room 200, and the ice making room. Further, on the door surface of the refrigerator compartment 100, an operation switch for adjusting the temperature and setting of each room, a liquid crystal display for displaying the temperature of each room, and an input for inputting the type of food to be put into the switching room 200 An operation panel 5 composed of buttons and the like is provided.

A compressor 10 constituting a refrigeration cycle is arranged outside the rear side of the refrigerator 1, and a cooler 3 constituting the refrigeration cycle is arranged inside the rear side, and further, the cold air cooled by the cooler 3 is refrigerated. A fan 2 for blowing air to the chamber 100 and the switching chamber 200 and an air passage 4 for introducing cold air cooled by the cooler 3 into the refrigerator compartment 100 are provided.

The switching chamber 200 has a storage case 201 integrated with the drawer door, the freezing chamber 300 has a storage case 301 integrated with the drawer door, and the vegetable room 400 has a storage case integrated with the drawer door. 401 are installed, and food can be stored in these cases.

Next, the flow of cold air in the refrigerator will be described. FIG. 2 is a side sectional view of the refrigerator showing the air passage configuration in the first embodiment of the present invention.
A part of the cool air cooled by the cooler 3 is blown into the freezer compartment 300. Further, the remaining cold air passes through the air passage 4 and is sent to the switching chamber 200 and the refrigerator compartment 100. The cold air flowing into the refrigerator compartment 100 passes through the refrigerator compartment return path 6 and flows into the vegetable compartment 400, and the air passing through the vegetable compartment 400 returns to the cooler 3 through the vegetable compartment return path 7.

Next, a description will be given of the switching chamber 200 having a function of preserving frozen food after it has been supercooled. FIG. 3 is a side sectional view of the switching chamber portion according to Embodiment 1 of the present invention.
The cold air passes from the air passage 4 through the switching chamber air passage 41, and is seen from the rear upper air outlet 42 provided on the upper left side of the rear as viewed from the front side of the switching chamber 200 and the ceiling air outlet 43 provided on the door-side ceiling surface 96. It is introduced into the switching chamber 200. Since the cold air flowing in from the rear upper air outlet 42 passes through the vicinity of the refrigerator compartment 100 having a relatively high temperature, the temperature is higher than the cold air flowing in from the ceiling air outlet 43. In addition, a partition wall 41a and a damper 46 are provided in the switching chamber air passage 41. By adjusting the opening / closing angle of the damper 46, the cold air distribution introduced from the rear upper outlet 42 and the ceiling outlet 43 is distributed. It is possible to change the cooling rate of the food put into the switching chamber 200 arbitrarily. Further, the cool air in the switching chamber 200 returns to the cooler 3 from the back surface suction port 44 provided in the lower right of the back surface of the switching chamber 200 and the bottom surface suction port 45 provided in the bottom surface. A surface temperature measuring device 95 such as an infrared sensor is installed near the back surface of the ceiling surface 96 of the switching chamber 200 that is not easily affected by cold air, and can detect the surface temperature of food stored in the switching chamber 200.

Next, the means for inputting the type of food and the supercooling operation will be described. 4 is a diagram showing an operation panel of the refrigerator in the first embodiment of the present invention, and FIG. 5 is a schematic diagram of a control system of the refrigerator in the first embodiment of the present invention.
When the user presses the quick freeze button 50 provided on the operation panel 5, a mode for supercooling and storing the food put in the switching chamber 200 is selected, and the supercooling operation selection display lamp 51 is lit and the user is supercooled. Is displayed. At the same time, the meat / fish selection display lamp 52 is also turned on, and an operation mode suitable for supercooling and storing meat and fish is selected. Here, when the quick freeze button 50 is pressed again, the meat / fish mode selection display lamp 52 is extinguished and the rice mode selection display lamp 53 is lit, and an operation mode suitable for supercooled and frozen rice is selected. . When the quick freeze button 50 is further pressed, the rice mode selection display lamp 53 is extinguished and the vegetable mode selection display lamp 54 is turned on, and an operation mode suitable for pre-cooling and storing the vegetables is selected.

The operation mode selected by the operation panel 5 is transmitted to the control circuit 47, and the control circuit 47 adjusts the operation of the compressor 10, the opening degree of the damper 46, the rotation of the fan 2, and the like according to the operation mode. Control the cooling rate and cooling temperature.
Further, the switching chamber 200 is refrigerated (about 3 ° C.), chilled (about 0 ° C.), soft frozen (about −5, −7, −9 ° C.), frozen by the operation panel 5 installed on the door of the refrigerator compartment 100. It is possible to switch to six temperature zones (about -17 ° C.), and the control device 47 operates the compressor 10 and the damper so as to reach the switching chamber 200 temperature set by the operation of the operation panel 5. The opening of 46 and the rotation of the fan 2 are adjusted. The temperature of the switching chamber 200 is detected by a thermistor (not shown) and transmitted to the control circuit 47.

Next, the supercooling operation will be described in detail. FIG. 6 is a graph showing a temperature change when water is frozen in the case of no supercooling operation (a) and in the case of supercooling operation (b). The vertical axis of the graph is the temperature, and the temperature increases as it goes upward. The horizontal axis is time, and the time is shown in the direction of the arrow.
The supercooled state refers to a state in which the substance is not frozen by 100% despite being below the freezing point. For example, the freezing point of water is 0 ° C. This freezing point varies depending on the substance, and tends to be lower than 0 ° C. in foods having a high salt concentration and high sugar content. In addition, the supercooled state can be canceled by applying a stimulus such as vibration or temperature change to the supercooled food.
In the present invention, a method of stimulating a supercooled food, releasing the supercooled state, and instantly freezing the whole food is called supercooled freezing.

Here, the difference between normal refrigeration and supercooled refrigeration will be described using water in a PET bottle as an example.
In the case of normal freezing, it begins to freeze from the water near the surface of the plastic bottle from the time when the freezing point is passed, and it becomes like a thin ice on the surface part, then the ice spreads toward the inside, finally The whole freezes. Ice growth occurs mainly around ice nuclei in which water molecules form a cluster of a certain size or larger. In normal freezing, ice nuclei are first formed on the surface, and then the water state The ice grows toward the inside.
In addition, in the case of quick freezing, cold air at a lower temperature than normal freezing is applied, so that ice begins to freeze from the surface and grows in the same way as normal freezing, but the internal temperature also drops rapidly, so In addition, ice nuclei are easily formed, and ice crystals are smaller than in normal freezing.

On the other hand, in the case of supercooled freezing, when freezing starts after freezing the supercooled state, ice grows in all parts of the PET bottle and ice nuclei are uniformly formed in the entire PET bottle. Ice never grows and ice nuclei are small.

Therefore, due to the difference in cooling process between normal refrigeration and supercooled refrigeration, large acicular ice crystals from the surface to the inside are formed in normal refrigeration, whereas in the case of supercooled refrigeration The difference is that evenly small granular ice crystals are formed.

Further, the temperature difference between the minimum temperature reached in the supercooling state and the freezing point as shown by the difference between the points A and B in FIG. 6B (hereinafter, the temperature difference is referred to as the degree of supercooling) is increased. By doing so, the number of ice nuclei formed at the start of freezing increases, resulting in finer ice crystals. This way of thinking is conventional and is a way of thinking that ice crystals become smaller if the passage time in the temperature zone of -1 ° C to -5 ° C, which is the maximum ice crystal formation zone, is passed in a short time. Therefore, the higher the degree of supercooling, that is, the lower the temperature reached in the supercooled state, the higher the frozen storage quality. The degree of supercooling can be increased by reducing the cooling rate.

In addition, since the food that has been once supercooled has small ice nuclei formed inside the food, it stayed in the vicinity of the maximum ice crystal formation zone (-1 ° C to -10 ° C) for a long time in the process of freezing thereafter. However, it has been confirmed that ice crystals do not enlarge.

In addition, after passing through the supercooled state, the possibility of further enlargement of ice crystals is reduced by rapid freezing in the freezing process, and it is possible to avoid food quality deterioration factors other than ice crystals such as bacteria, Furthermore, high quality freezing is possible.

Next, foods that affect frozen storage quality depending on the presence or absence of a supercooled state will be described.
FIG. 7 is a diagram showing the state of the meat tissue when the meat is frozen by normal quick freezing and supercooled freezing, and when the frozen meat is once thawed. In this way, meat, fish, and the like have their internal structure destroyed due to the formation of ice crystals during freezing, resulting in an increase in the amount of drip after thawing and a reduction in taste.

In addition, potatoes such as potatoes, which were conventionally considered unsuitable for frozen storage, normally destroy the three-dimensional structure of amylose and amylopectin that constitute starch, the main ingredient of potatoes, by the growth of ice crystals when frozen. Therefore, after thawing, it became faint and the taste was lowered.

On the other hand, since ice crystals that can be obtained by supercooling and freezing are very fine, they can be frozen with almost no destruction of the internal structure during freezing, so that deterioration of the taste after thawing can be suppressed.

Next, the effect on the refrigeration quality due to the difference in the degree of supercooling will be described. In general, when the degree of supercooling increases, the temperature can be sufficiently lowered to the inside of the food, so that the internal temperature unevenness tends to be suppressed. For example, meat is composed of fat and red meat, and is a food that easily causes uneven internal temperature. Therefore, in the case of meat, by increasing the degree of supercooling, it is possible to further reduce the amount of drip that flows out during thawing, thereby improving the quality of the refrigeration.

On the other hand, foods with a uniform internal structure such as potatoes tend not to change in taste due to the degree of supercooling. As an example, FIG. 8 shows a correlation diagram between hardness and supercooling degree measured using potato.
As can be seen from this result, it was found that potato has no correlation between the degree of supercooling and hardness, and retains the taste (in this case, texture) even when the degree of supercooling is low. In other words, in the case of potatoes, it is not necessary to increase the degree of supercooling, and it can be understood that even if the supercooling is canceled in a state where the degree of supercooling is small, it can be frozen and preserved with the texture retained. In addition, experiments have shown that potato has a higher rate of supercooling than beef, even if the cooling rate is faster.

Next, food groups that do not affect the taste depending on the presence or absence of rapid cooling after cancellation of supercooling will be described. For example, broccoli is a food that does not affect the taste depending on the presence or absence of rapid cooling after the release of supercooling. Therefore, it is possible to suppress wasteful energy consumption due to the rapid cooling operation by enabling selection so that rapid cooling is not performed by rapid cooling after cancellation of supercooling.

Next, the ease of overcooling will be described. For example, a group of foods with a uniform food composition, such as sol-gel yogurt or konjac, is likely to develop supercooling, and has a higher rate of supercooling even if the cooling rate is faster than meat. . In contrast, food groups with non-uniform food composition, such as meat with fat (mainly lipids) and red meat (mainly water and protein), have a low thermal conductivity and freezing point. Unlike other foods, temperature differences are likely to occur inside the food, so supercooling does not occur due to factors such as high cooling speed, high wind speed, low cold air temperature, etc. Things are easy to happen.

As described above, energy consumption can be reduced while maintaining high refrigeration quality by setting the optimum supercooling timing according to the food group.

Next, the operation control method of the refrigerator in Embodiment 1 which considered the relationship between the above foodstuffs and supercooling is demonstrated. FIG. 9 is a flowchart showing the supercooling operation control of the refrigerator in the first embodiment of the present invention.

First, food is put into the switching chamber 200 (S101), and the type of food is input from the operation panel 5 (S102). The input is transmitted to the control circuit 47, and the control circuit 47 sets the cooling rate A for the supercooling operation optimal for the food, the supercooling operation time t (the larger the supercooling degree, the larger the supercooling degree), and the cooling rate B for the frozen storage operation (S103 to S108, S119, S120), input of the compressor 10, the damper 46, and the fan 2 is set according to the selection, and cooling is started at the cooling rate A (S109). For example, rice is selected (S103), boiled potatoes and broccoli (S104), and beef (S107). In addition, when an operation that causes a temperature rise, such as opening and closing of a door, is detected, if the control for extending the cooling time is performed, a supercooled state can be expressed more reliably.

When the surface temperature of the food is detected by the infrared sensor 95 and the freezing temperature of the food is reached, integration of the supercooling time is started (S110), and it is detected that the food temperature is gradually decreasing (S111). . When the accumulated time has passed the supercooling operation time t (S112), the process proceeds to a supercooling release operation (stage 2) for canceling the supercooling state. If the food temperature rises before reaching the supercooling operation time t, it is recognized that the supercooled state has been released naturally, and the process proceeds to a frozen storage operation (stage 3) in which the food is frozen and stored.

In the supercooling release operation (stage 2), the cooling rate is increased and time integration is started (S113). Here again, the surface temperature of the food is detected by the infrared sensor 95 to detect that the food temperature is gradually decreasing (S114), and when the food temperature rise is detected, the supercooled state of the food is released. Judgment is made, and the process proceeds to a frozen storage operation (stage 3) in which the food is stored frozen. If the predetermined time has passed without detecting the temperature rise (S115), it is assumed that the supercooling release has failed or the supercooling state has not been reached, and the normal freezing state (a in FIG. 6) is assumed. It shifts to the freezing preservation operation (stage 3) which preserves frozen.

In the frozen storage operation (stage 3), the food is cooled at the cooling rate B (S116), and when it is detected that the preset frozen storage temperature of the switching chamber 200 has been reached (S117), the temperature of the switching chamber 200 Is controlled to be constant (S121), and the process proceeds to stage 4 where the food is stored frozen.

On the other hand, if a food type unsuitable for supercooling / freezing is entered on the operation panel 5, it is determined that supercooling operation is not necessary (S118), and further, whether or not quick freezing is performed (S119 to S120). The process proceeds to a frozen storage operation (stage 3 and stage 4) for freezing storage.

Next, the operation at each stage with respect to the operation mode selected by the control circuit 47 will be described using a timing chart. FIG. 10A shows the input state of the compressor in each operation mode of the refrigerator in the first embodiment of the present invention, and FIG. 10B shows each operation mode of the refrigerator in the first embodiment of the present invention. Shows the temperature status of food.

Supercooling operation (stage 1)
In stage 1, the charged food is cooled at the cooling rate A until the supercooling operation time t elapses after reaching the freezing temperature. At this time, in the case of a food that easily develops supercooling, the cooling rate is increased by increasing the input to the compressor 10 to a cooling rate at which supercooling is manifested instead of rapid freezing (S103, S104). As a result, when supercooled freezing is performed in a storage room where already frozen foods exist, newly added foods should be stored frozen in high quality without adversely affecting those already frozen foods. Can do. This can be applied to a cryopreservation device typified by a household refrigerator, for example, where it is difficult to increase the size of the structure, so that a cryopreservation device with high refrigeration quality can be obtained while maintaining the size of the device. In addition, in the case of foods whose frozen quality improves as the degree of supercooling increases, the supercooling operation time t is set longer to increase the degree of supercooling (S107, S108).
Although the cooling rate is adjusted here by the input of the compressor 10, the cooling rate may be adjusted by opening / closing the damper 46 and the strength of the fan 2. Further, a separate heater may be installed or the cooling rate may be adjusted using the heat of the compressor 10.

Supercooling release operation (stage 2)
Generally, the food temperature reaches 3 ° C. or more lower than the freezing point in the supercooled state, and after holding the supercooling for at least 5 seconds, the process proceeds to the stage 2 and the input of the compressor 10 is increased so that strong cold air is supplied to the food. This increases the temperature difference in the food and releases the supercooled state. The temperature of the food released from the supercooled state rises to around 0 ° C.
In addition to the method using the temperature difference as described above, the method of canceling the supercooling is a method of directly applying vibration to food using a motor or the like, or a method of using vibration of operating equipment in the refrigerator, There is a method of applying vibration directly to food without contact using sound waves.

Frozen storage operation (stage 3)
After the supercooling is released, the input of the compressor 10 is increased to cool down to the frozen storage temperature set in the switching chamber 200. However, in the case of food whose frozen quality is improved by rapid cooling after the supercooling is released. Then, quick freezing is performed by increasing the input of the compressor 10 (S103, S105, S107). In addition, in the case of foods whose refrigeration quality does not improve due to rapid cooling after canceling the supercooling, the input of the normal compressor 10 is slightly suppressed to reduce the power consumption of the refrigerator (S104, S106, S108).
In addition, in the case of foods whose frozen quality cannot be improved by freezing (S119, S120), skipping stages 1 and 2 and starting from stage 3, there is already frozen food When supercooled freezing is performed in the storage room, the newly added food can be stored frozen in high quality without adversely affecting the already frozen food. Even in cases where supercooled refrigeration is not performed (S119, S120), for foods whose frozen quality is improved by rapid cooling, rapid freezing is performed (S119). In this case, quick freezing is not performed (S120), so that it is possible to improve the freezing quality and reduce the power consumption.

Cryopreservation operation (stage 4)
Control is performed such that the input of the compressor 10 is reduced and the temperature of the switching chamber 200 becomes constant.

Note that the frozen storage temperature set in the switching chamber 200 can be arbitrarily set, so that the storage can be performed in accordance with the situation that the user wants to use.

For example, when the frozen state is stored in a range of −10 ° C. or higher after canceling the supercooling, it is possible to maintain a state where it can be easily cut with a kitchen knife in a frozen state, so that there is an advantage that it is easy for the user to use. Furthermore, since the ice crystals inside the food become fine by freezing through the supercooled state as in the method of the present invention, the effect that it becomes easier to cut than in normal freezing is also obtained. Since the storage temperature zone is below the freezing point, it can be stored for a long period of time of about 2 weeks.

For example, if the frozen state is stored in the range from -10 ° C to -15 ° C after the supercooling is released, ice crystals will be generated in a large needle shape by the normal freezing method. However, since the ice crystals inside the food become fine by freezing through the supercooled state as in the method of the present invention, there is an advantage that it can be cut with a knife even in the frozen state. Regarding the storage period, long-term storage of 2 weeks to 1 month is also possible.

For example, when frozen and stored in a temperature range of −15 ° C. or less after cancellation of supercooling, long-term storage of about one month is possible as in normal freezing. In addition, since the ice crystals inside the food become fine by freezing through the supercooled state as in the method of the present invention, cell destruction of the food due to freezing is difficult to occur, and thereby high frozen quality can be obtained.

Moreover, even if it is the same foodstuff, the ease of supercooling changes with the magnitude | sizes of a volume. A food having a large volume tends to have a large difference between the surface temperature and the center temperature in the cooling process because the distance between the surface portion and the center portion increases. In addition, since a portion close to and a portion far from the cold air outlet can be formed, the same food may be handled differently and may cause a temperature difference. Since this temperature difference becomes a factor for canceling supercooling, the larger the volume, the more difficult it is to develop supercooling and the easier it is to cancel supercooling. Therefore, in order to put a food with a large volume into a supercooled state, it is necessary to slow down the cooling rate.

As a means for detecting the volume of the food, a method for detecting the volume of the food directly by scanning the storage room with a sensor capable of detecting a distance such as an ultrasonic sensor, and a weight detection means for detecting the weight in the storage room; A method of calculating the volume from the rough density data of each food and the weight of the food by combining means for discriminating the type of food can be considered. Moreover, the method of inputting a volume and a weight from an operation panel may be used.

In addition, the merit of the storage method that has been frozen after releasing the supercooled state has been described so far, but as a frozen storage device, the function that can operate the storage method that stores in the supercooled state or the normal storage method The user may be allowed to select arbitrarily.

Further, as the food surface temperature detection means, it is also possible to use a device other than the infrared sensor, for example, an electric field sensor to determine the state of the supercooled product.

In the case of using an infrared sensor, the infrared sensor is installed on the wall surface of the space where the storage case 201 is provided, and is movable so that the entire interior of the storage case 201 can be seen, or the entire interior of the storage case 201 can be viewed as an array sensor. It can be so. As the installation position, for example, it is possible to see the whole by installing it on the back surface of the switching chamber 200 and looking over the storage case 201 obliquely from above.
When entering the supercooling mode, the infrared sensor detects the surface temperature of the food in the storage case 201 and calculates the core temperature therefrom.

When an electric field sensor is used, the electric field sensor is installed in a space where the storage case 201 is provided. The electrode part of the electric field sensor may have any shape as long as it is made of metal. For example, in order to easily attach the storage case 201 to the storage case 201, the foil can be attached along the unevenness of the storage case 201 as long as it is foil-shaped. By making the plate thicker than the foil, it is possible to obtain an electrode that is less likely to break during attachment. Further, it is non-contact type and may be installed anywhere as long as it is a wall surface of the space in which the storage case 201 is provided, and can be measured even if there is another substance such as a plastic plate between the substance to be measured.
The output of the electric field sensor changes depending on the dielectric constant inside the food. Compared to when the food is unfrozen or supercooled and the water is liquid, when the supercooling is released and ice crystals are generated, the dielectric constant is greatly reduced. To do.

Moreover, you may make it the structure which measures the temperature of a foodstuff directly with a thermometer other than using the above apparatuses.

Moreover, although the means which uses the damper 46 as a temperature control means of the switching chamber 200 was demonstrated, the heater in the surrounding wall of the switching chamber 200 is provided, for example, and the temperature in the switching chamber 200 is adjusted by adjusting the input of a heater. You may use the method to do.

In addition, the method of canceling and storing the frozen state after the occurrence of supercooling has been described so far. However, an operation mode for storing while maintaining the supercooled state may be provided.

Until now, as a means for recognizing the type of food, the method of inputting the food types summarized in several from the operation panel has been described, but for example, foods selected with the buttons by providing buttons for various foods A method of selecting an operation mode according to the method may be used. In that case, it is sufficient to select the operation mode with the slowest cooling rate among the selected foods, so that the supercooled state can be surely exhibited.

In addition, IC tags that record the producer, production area, harvest date, etc. on the food are attached to the food or food package, and means for recognizing the type of food from the IC tag may be used. . At that time, the food weight can also be detected by recording the weight of the food on the IC tag.

Further, a supercooling maintenance mode that is maintained in a supercooled state may be selected from the operation panel 5. For example, when the supercooling maintenance mode is selected and water is maintained in a supercooled state, the water can be made into a sherbet shape by taking out from the refrigerator while being maintained and pouring into a glass. Thereby, a new food texture can be obtained or it can be used as one of the cooking means.
If the supercooling maintenance mode is installed in a product not normally used, the supercooling maintenance mode may be selected by performing a special operation on the operation panel 5, for example, by simultaneously pressing a plurality of buttons. .

In the first embodiment of the present invention, the configuration in which the cooling room is supercooled and frozen is described in the switching room 200, but the function of developing supercooling is that of the refrigerator room 100, the freezer room 300, the vegetable room 400, and the ice making room 500. You may provide in any part.

The sectional side view of the refrigerator in Embodiment 1 of this invention. The sectional side view which shows the air path structure of the refrigerator in Embodiment 1 of this invention. The sectional side view of the switch room periphery of the refrigerator in Embodiment 1 of this invention. The figure which shows the operation panel of the refrigerator in Embodiment 1 of this invention. The schematic of the control system of the refrigerator in Embodiment 1 of this invention. The graph which showed the temperature change when water freezes with no supercooling operation (a) and with supercooling operation (b). The figure which showed the state of the meat structure | tissue when meat was frozen by normal quick freezing and supercooled freezing, and the meat once frozen was thawed. Correlation diagram between the hardness of thawing potatoes and the degree of supercooling after supercooled freezing. The flowchart which shows the supercooling driving | operation control of the refrigerator in Embodiment 1 of this invention. The timing chart which shows the relationship between the input state of the compressor in each operation mode of the refrigerator in Embodiment 1 of this invention, and the temperature of a foodstuff.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator, 2 fan, 3 cooler, 4 air path, 5 operation panel, 6 return path for refrigerator compartment, 7 return path for vegetable room, 10 compressor, 41 switching room air path, 41a partition wall, 42 back upper side blowing Mouth, 43 Ceiling outlet, 44 Back lower suction port, 45 Bottom suction port, 46 Damper, 47 Control circuit, 50 Quick freeze button, 51 Supercooling operation selection display lamp, 52 Meat / fish selection display lamp, 53 Rice Selection display lamp, 54 Vegetable selection display lamp, 95 Infrared sensor, 96 Ceiling surface, 100 Refrigeration room, 200 Switching room, 201 Storage case, 300 Freezing room, 301 Freezing case, 400 Vegetable room, 401 Vegetable case.

Claims (10)

A storage chamber for storing food, and a cooling means for cooling the food charged in the storage chamber;
After performing the supercooling operation to control the cooling means to bring the food into a supercooled state, the supercooling release operation to release the supercooled state of the food is performed , and the food that has been released from the supercooled state and control means for implementing the cryopreservation OPERATION cryopreserved cooling,
Food type input means for inputting the type of food put into the storage room to the control means,
Said control means based on the information obtained from the food type input means, the cooling rate during the supercooling operation, the cooling rate during operation time and the freezer storage operation of the over-cooling operation, is set in advance A cryopreservation device characterized by being selected from a combination and adjusting according to the selection . Comprising temperature detecting means for detecting the surface temperature of the food introduced into the storage room;
When the temperature detecting means detects that the surface temperature of the food has increased during the supercooling operation or the supercooling release operation , the control means starts from the supercooling operation or the supercooling release operation. The cryopreservation apparatus according to claim 1, wherein the transition to the cryopreservation operation is performed. Comprising a volume detection means for detecting the volume of food put into the storage room;
Wherein, cryopreservation apparatus according to claim 1 or claim 2, characterized in that adjusting the cooling rate of the volume on the basis of the information obtained from the sensing means when the over-cooling operation. Comprising weight detecting means for detecting the weight of the food put into the storage room;
The volume detection means, a weight of the food detected by the weight detection means, based on information obtained from the food type input means, according to claim 3, characterized in that to estimate the volume of the introduced food The cryopreservation device according to 1. The frozen storage apparatus according to any one of claims 1 to 4 , wherein the food type input means includes an operation panel capable of selecting a type of food. The cryopreservation apparatus according to claim 5 , wherein the operation panel has a function of inputting a volume of food. The cryopreservation apparatus according to claim 5 , wherein the operation panel has a function of inputting a weight of food. The frozen food storage device according to any one of claims 1 to 7 , wherein the food type input means automatically recognizes the food type. After performing the over-cooling operation that was thrown into the storage compartment food supercooled, conducted supercooling release operation for releasing the supercooled state of the food, cooling the food product in which the supercooled state is released A cryopreservation method for carrying out a cryopreservation operation for cryopreserving ,
A first step of inputting a type of food put into the storage room;
Based on the type of the input food, a second cooling rate selected during the supercooling operation, an operation time during the supercooling operation, and a cooling rate during the frozen storage operation are selected from preset combinations. Steps,
A third step of performing the supercooling operation at the selected cooling rate at the time of the supercooling operation and the operation time of the supercooling operation;
A fourth step of performing the supercooling operation cancellation operation;
And a fifth step of performing the frozen storage operation at the selected cooling rate during the frozen storage operation . The refrigeration according to claim 9, wherein when the surface temperature of the food is detected to be increased in the third step or the fourth step, the process proceeds to the fifth step. Preservation method.

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