JP2012255640A - Cooling method and implement, and device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contact freezer capable of freezing a filet or lump of fish meat in a roller or a tray to be of favorable quality although a conventional contact freezer has been mainly used for freezing a processed food formed into a regular hexahedron or a rectangular parallelpiped providing a high contact rate.SOLUTION: A high contact rate can be obtained even by an infinite fish meat by forming a water layer on the surface to drive out the air in the gap formed with a heat absorbing plate. A structure is employed in which an alcohol water solution which keeps direct contact with the rear surface of the heat absorbing plate, a heat radiation fin extended in the thickness direction, and a balloon which includes air to contact with the lower end of the fin are provided, thereby allowing the utilization of the latent heat of the fusion of ice at a freezing point because of an alcohol concentration. Consequently, a heat capacity can be sufficiently increased even by a small metal plate, and furthermore, the ice can be melted down to the lower part of a cold storage material because of the heat radiation fin. In addition, since the air in the balloon absorbs the amount of an increase in volume when freezing a water solution, the cold storage material can be sealed up in a container. An object can be freezed in favorable quality by a large cold heat amount and low thermal resistance in a stable and a uniform manner.

Description

  Technical fields related to cooling.

  At present, contact freezers are used for freezing processed foods that have been formed into cubes or cuboids. However, the contact freezer is rarely used for freezing irregularly shaped foods such as meat and fish because the contact ratio obtained by dividing the area contacting the endothermic plate by the surface area is low. In the conventional contact freezing method, a refrigerant is circulated in a tube brought into contact with a thin heat absorption plate to be brought into contact with the heat absorption plate at around -50 ° C., and the object to be frozen is directly brought into contact without packaging and frozen. Similarly, some households use a contact freezing effect by providing a cold storage material on the back surface of the freezing plate in the freezer compartment. Patent Document 1 describes that the refrigerant is condensed from the evaporator in the freezer compartment using the latent heat of fusion at the time of defrosting the evaporator for the refrigerator compartment. Patent Document 2 discloses means for holding a regenerator in a freezer compartment.

  JP 2008-45847 A   JP 2010-43830 A

  There is a demand for means that can realize freezing with high quality at low cost with a small amount of electricity used in a conventional freezer for homes and restaurants.

  The first means is a contact freezer provided with a metal endothermic plate, in which a thin liquid layer is formed on the surface of the object to be frozen or the surface of the packaging means is dry, and a thin liquid is formed on the surface. The object to be frozen having a layer or the surface of the packaging means is brought into contact with an endothermic plate having a cooling capacity equal to or greater than the heat of solidification of the amount of water to be frozen to be frozen.

  The main reason for the low versatility of contact freezers is that the shape of the food is indeterminate and the contact rate with the endothermic plate is low, and often the food is packaged and frozen. This is because a certain resin film has a large thermal resistance and cannot be cooled at a sufficient speed. However, since the heat absorption plate made of metal is sufficiently low in heat resistance compared to ice, if the heat capacity on the heat absorption side is sufficiently larger than the amount of heat necessary for freezing the object to be frozen, the contact rate must be considered. Cooling can be performed at the fastest speed compared to other cooling methods. Foods such as meat and fish are elastic, and when placed on a flat endothermic plate, they deform along the endothermic plate. However, when the surface of the food is dry, an air layer is formed in the gap between the heat absorbing plate and the food, and the actual contact rate is extremely lowered. Therefore, when freezing, it is frozen without packaging means, wrapped with a very thin resin film, or wrapped with metal foil to form a thin layer of water, saline solution, oil, etc. on the surface of food or packaging As a result, the air in the gap between the food and the heat absorbing plate can be expelled to ensure a high contact rate. In addition, if the surface water layer is too thin when food is brought into direct contact with the endothermic plate, the food may stick to the endothermic plate and damage the food when peeled off. However, the food surface can be protected by appropriately thickening the water layer.

  The second means is characterized in that a cold storage material made of a solution having a freezing point depressing action is provided in direct contact with the metal heat-absorbing plate back surface, and heat-radiating fins extending in the thickness direction are provided on the heat-absorbing plate back surface.

  A conventional freezing plate with a cold storage material (container containing a cold storage agent) uses a resin container between the metal plate and the cold storage agent to isolate the cold storage agent and has a large thermal resistance. Can not get a good effect. The reason for this is that food is usually frozen from the surface, and ice progresses to the inside. In the case of the plate, it is composed of food, metal plate, resin container, and cold storage agent, and the center of the food always transfers heat through the frozen surface ice after the start of freezing, so heat transfer between the food and cold storage agent If the heat transfer coefficient of the medium is less than the heat transfer coefficient of the surface ice of the food, the heat transfer will have a high-order lag thermal time constant, and if the heat capacity of the metal plate is small, the rate of heat absorption of the food will be resin. Limited by the heat transfer coefficient of the container wall. However, the heat capacity or cold heat capacity described here is the product of specific gravity, specific heat, and temperature difference. The thermal time constant is a product of heat capacity and thermal resistance (reciprocal of product of heat transfer coefficient and surface area). Therefore, a freezing plate having a sufficiently large heat capacity and a low thermal resistance is desired. In order to solve this problem, there is a method of sufficiently increasing the heat capacity of the metal plate part, but the latent heat of moisture contained in the food is large, and the temperature difference from the freezing temperature is small at the freezer temperature of the domestic refrigerator. For this reason, the weight of the metal plate becomes very large. Therefore, the total weight can be greatly reduced by freezing a solution having a freezing point depressing action as a cold storage agent and using the latent heat of fusion. Furthermore, the concentration of the solution is adjusted so that it is frozen at a temperature as low as possible below 0 ° C. Therefore, unlike pure water, there is no specific gravity change due to the solution temperature, and the ice is melted by absorbing heat from the top surface. In many cases, ice is attached to the wall surface, and the ice attached to the lower wall surface cannot be melted by heat transfer by convection. When pure water is used, convection is generated at the time of melting, but the melting temperature is 0 ° C., and it cannot be below −2 ° C., which is the average freezing temperature of food, and cannot be used as an endothermic agent for freezing. This problem could be solved by disposing heat radiating fins in the thickness direction.

  The third means is characterized in that a container for storing air in an airtight manner is provided in the lower part of the container.

  In addition, when the solution is an aqueous solution, it is difficult to make a sealed container because the volume of the solution expands when ice is generated during freezing. If air is simply introduced to absorb the volume expansion, the air accumulates in the upper part of the container, so that the heat dissipation effect from the upper surface of the container having the highest temperature is greatly hindered. In view of this, the problem was solved by placing air in an airtight container having a variable volume below the heat dissipating fins.

  In a fourth means, a metal freezing lid is brought into contact with the heat sink of the freezer and pre-cooled, and is brought into contact with the object to be frozen from the direction opposite to the heat sink, and between the drop lid and the heat sink. In addition, a spacer slightly thinner than the thickness of the object to be frozen is provided.

  A pre-cooled metal cooling lid with a large amount of cold heat is brought into contact with the upper surface of the food, and is sandwiched between the heat-absorbing plate from the lower surface and the dropping lid to absorb heat, thereby freezing at a higher speed. However, in order to increase the heat amount of the drop lid, the weight must be increased. However, it was found that the amount of drip after thawing increases when pressure is applied to deform the food when frozen. Therefore, by providing a spacer slightly thinner than the thickness of the frozen material, it was possible to minimize the deformation of the food and realize high quality freezing.

  The fifth means is characterized in that a stepped spacer is provided on or on the side surface of the heat absorbing plate, and a support member is provided on the side surface of the drop lid that is supported by the bearing portion of the stepped spacer and supports the drop lid.

  A step-like spacer is provided on the heat absorption plate or on the side, and the height can be adjusted simply by moving the drop lid back and forth by providing a support to support the drop lid on the side of the drop lid. it can. Furthermore, the storage space for spacers of various thicknesses can be saved.

  The sixth means is characterized in that the spacer is made of a far-infrared absorbing material, or a far-infrared absorbing material is provided on the inner wall surface of the spacer.

  Many freezer walls are made of resin and easily absorb far-infrared rays that are emitted when the food surface layer is frozen. However, the contact freezer uses metal for the heat-absorbing plate and reflects the far-infrared rays so that the food surface The freezing speed is reduced by returning to. Therefore, since far infrared rays are absorbed by materials other than metal, the problem was solved by providing a layer of a material other than metal on the inner wall surface of the spacer.

  In a seventh means, in a contact freezer having a cooling means provided in a refrigerator or a freezer, the heat associated with the heat absorption during cooling is ice or a mixture of ice and liquid as a cold storage material, and It is characterized in that it is dissipated by contacting the cold storage material.

  By dissipating the heat at the time of cooling of the contact freezer provided with the cooling means to the ice in the warehouse or the mixture of ice and liquid, a large heat absorption can be realized by utilizing the latent heat of ice. Moreover, the temperature at the time of releasing the latent heat of ice is 0 ° C. in pure water, which is much lower than the temperature of the air outside the refrigerator used by the refrigerator condenser, and the specific heat of ice and water is larger than that of air. Therefore, the endothermic plate temperature of the contact freezer can be significantly lowered than the inside temperature, and high-quality freezing can be realized.

  In the eighth means, in the refrigerator or freezer provided with the contact freezer in the refrigerator that reverses the refrigeration cycle at the time of defrosting the evaporator, the frost that has formed on the evaporator during the defrosting operation is stored in the cold storage material. And the flow of the refrigerant is switched from the condenser outside the warehouse to the evaporator of the contact freezer provided in the warehouse with a valve to cool the endothermic plate in the warehouse.

  Dissipation of refrigerant from the contact freezer with an evaporator provided in the refrigerator is performed using the latent heat of melting of the ice that has formed on the evaporator in the refrigerator or freezer. It can be performed.

  The ninth means is characterized in that means for estimating the amount of frost formation is provided, and the defrosting operation is started when the cooling capacity necessary for contact freezing is reached.

  Prediction of the amount of frost formation on the evaporator is currently controlled by defrosting at regular defrost intervals or by integrating the opening and closing of doors. Further, a temperature sensor provided in the evaporator is used to predict the amount of temperature change within a certain time. It is possible to predict whether or not the amount of frost formation necessary for contact freezing has been reached using these prediction means, and at the same time to release heat from the cooling means provided in the contact freezer.

  By forming a thin liquid layer on the object to be frozen and its packaging surface, it is possible to expel the air layer in the gap with the heat absorbing plate of the contact freezer and greatly improve the contact rate. Moreover, a heat absorption board can be made low temperature significantly by providing a cooling means in a contact freezer and radiating heat to the ice in a refrigerator or a freezer. If latent heat at the time of defrosting is used, power consumption can be reduced.

Cross-sectional explanatory drawing explaining a freezing instrument Explanatory drawing explaining a freezing device Explanatory drawing explaining a freezing device Cross-sectional explanatory drawing explaining a freezing device Explanatory drawing of a refrigerator with a freezing device Cross-sectional explanatory drawing explaining a freezing device Explanatory drawing explaining the freezing apparatus provided with the spacer 7 is a top plan view of FIG. Cross-sectional illustration of a contact freezer with spacers Top view of spacer Cross-sectional explanatory drawing of Peltier unit and cold storage material Graph of drip rate due to difference in contact refrigerant Graph of drip rate with and without surface water layer Graph of drip rate with and without pressure deformation Graph showing concentration and freezing point of ethanol aqueous solution

  A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional explanatory view illustrating a contact freezing apparatus for meat and seafood according to the present invention. 101 is a metal heat-absorbing plate with a mirror finish on the upper surface, 102 is a cool storage agent, 103 is a wall surface of a cool storage material, 104 is a heat radiation fin, 105 is a balun, and 106 is air. 12, FIG. 13 and FIG. 14 are a cylindrical shape having a diameter of about 1 cm and a height of about 1 cm after mixing Takano tofu in a powder of 7% by weight with respect to the weight of water in a 1.5% by weight agar aqueous solution. The sample molded with a die is used as a drip measurement sample, and the weight is measured. After freezing naked without using a packaging means such as a bag under each experimental condition, it is 220G · The mixture was centrifuged for 40 minutes, thawed, weighed again, and the difference between the initial weight and the weight after centrifugal thawing divided by the initial weight was compared as the drip rate. FIG. 13 shows a sample for measurement which was left indoors for 30 minutes to dry the surface. One was wetted with a cotton swab and the surface layer was pre-cooled in a -60 ° C. freezer. The aluminum plate was frozen by contact. FIG. 15 is a graph showing the concentration and freezing point of an aqueous ethanol solution.

  The freezing apparatus of this embodiment is a contact freezing apparatus that is used at a relatively high temperature around −20 ° C., such as a freezer for a household refrigerator or a freezer for a restaurant. By using a 22% by weight aqueous ethanol solution as the cold storage agent (102), a freezing agent having a freezing point near -15 ° C is obtained. Unlike the pure water of 4 ° C. close-packed filling, this aqueous solution has a higher density of liquid at a lower temperature. Therefore, when heat is absorbed from the upper part, sufficient diffusion of heat due to convection cannot be expected. However, by providing the heat dissipating fins (104), the ice adhering to the generated lower part can be melted to transfer the heat to the lower part, and the remaining unmelted is reduced, so that the heat absorption capacity that can be practically used is increased. Can do. In addition, by providing an aluminum vapor deposition balun (105) containing air (106) below the heat dissipating fin (104), it absorbs the volume expansion caused by the formation of ice in the aqueous solution, so that the endothermic plate is not deformed. The aqueous solution can be sealed in the container. Moreover, air can be kept in the lower part for a long period of time by putting air in the aluminum vapor deposition balun with high airtightness. As a method of use, the freezing agent (102) is frozen by putting the freezing instrument into a freezer compartment of a domestic refrigerator near -20 ° C. Wash the fish that has been put down into three sheets, drain lightly, and in a state where a water film is formed on the surface layer, freeze it by making contact with a metal heat absorption plate (101) with the skin side facing up and the meat side mirror-finished . After freezing, remove the frozen product from the heat sink with a wooden spatula. Then, after vacuum packaging, it is stored in a freezer. In this case, the fish meat may be wrapped with a packaging resin film, and a few drops of low melting point edible oil such as corn oil, coconut oil or walnut oil may be dropped on the heat absorbing plate (101) and then frozen by contacting with the heat absorbing plate. . The contact rate was increased by forming a thin layer of liquid on the surface, and the drip rate decreased when a water layer was formed as shown in FIG. Moreover, when using at lower temperature, it is set as the cool storage agent density | concentration which becomes a freezing point temperature about 5 to 10 degreeC higher than use temperature by FIG.

  A second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is an explanatory view showing a refrigerant cycle of the freezing apparatus of the present invention. 201 is a condenser, 202 is a check valve, 203 is a switching valve, 204 is a capillary, 205 is a check valve, 206 is a capillary, 207 is a main evaporator, 208 is an auxiliary condenser, 209 is a switching valve, and 210 is a compression valve , 211 is a four-way valve, 212 is a switching valve, and 213 is a freezing evaporator. FIG. 5 is an explanatory diagram of a refrigerator provided with a freezing device. Reference numeral 501 denotes a refrigerating room, 502 denotes a freezing room, 503 denotes an ice making room, 504 denotes a front operation panel, and 505 denotes a freezing storage room. FIG. 6 is a cross-sectional explanatory view of the refrigerator evaporator and the freezing condenser of FIGS. 2 and 5. Reference numeral 601 denotes a freezing chamber lid, 602 denotes an endothermic metal plate, 603 denotes a freezing evaporator, 604 denotes ice, and 605 denotes an auxiliary condenser. FIG. 12 shows the drip rate due to the difference in the cooling medium in contact with the object to be frozen. ■ is the drip rate of one side of a pre-cooled resin plate that is frozen by contact, □ is the drip rate of one side of a pre-cooled 400 g aluminum plate that is frozen by contact, and ▲ is a drip that is frozen by immersion in ethanol brine The rate, Δ, is the drip rate immersed in ice slurry and frozen.

  In this embodiment, the contact freezer of FIG. 6 is provided in the freezer compartment (502) in the refrigerator of FIG. The freezer compartment (502) shares a ventilation path with the freezer storage room (505) and is always kept at substantially the same temperature as the freezer storage. The lid (601) of the freezer compartment (502) is provided on the lower right floor in the refrigerator compartment (501), and the endothermic metal plate (602) whose mirror surface is processed inside the lid (601) and the refrigerant shown in FIG. Refrigeration evaporators (603, 213) for evaporating the refrigerant of the cycle, and ice (604) and auxiliary condensers (605, 208) are provided at the lower part of the freezing chamber. When it is determined that the main evaporator (207) has been frosted by integrating the number of times the door of the refrigerator is opened and closed, the switching valve (212) and the switching valve (203) are also switched at the same time when the four-way valve (211) is switched. The main evaporator is defrosted by flowing hot gas, and at the same time, the refrigerant is evaporated by the freezing evaporators (213, 603) to cool the endothermic metal plate (602) to a low temperature. The endothermic metal plate can increase the initial heat absorption rate by giving the heat capacity as large as possible. Once the food surface layer is frozen, the ice has a thermal conductivity four times that of water, so that the freezing time can be shortened. Further, when the defrosting of the main evaporator is completed, the refrigeration evaporator (213, 603) is continuously cooled by switching the switching valve (209) and flowing hot gas to the auxiliary condenser (208, 605). Can do. As shown in FIG. 12, in the temperature range lower than −20 ° C., the metal plate contact freezing has less drip than the freezing on the resin plate, and the value is close to that of freezing ice slurry or freezing without packaging. Obtained.

  A third embodiment of the present invention will be described with reference to the drawings. FIG. 3 is an explanatory view showing a refrigerant cycle of another freezing apparatus. 301 is a refrigerator condenser, 302 is a refrigerator evaporator, 303 is a capillary, 304 is a defrosting condenser, 305 is an auxiliary condenser, 306 is a capillary, 307 is a freezing evaporator, and 308 is a compressor for a freezer , 309 is a switching valve, 310 is a heat exchanger, and 311 is a refrigerated employment compressor. FIG. 4 is a cross-sectional explanatory view of the refrigerator evaporator, the heat exchanger, the defrosting condenser, and the refrigeration condenser of FIG. 401 is an evaporator + heat exchanger + condenser, 402 is a frost receiver, 403 is ice, 404 is a condenser, and 405 is a drain pipe. FIG. 5 is an explanatory diagram of a refrigerator provided with a freezing device.

  In this embodiment, the refrigerant cycle of FIG. 3 is incorporated in the refrigerator of FIG. 5, and the defrosting condenser (304) and the evaporator (302) are mounted on the same heat exchange fin (310), and the refrigerator of FIG. It is an evaporator + heat exchanger + condenser (401). During normal operation, the compressor (311) is operated, and the inside of the refrigerator is cooled by the evaporator (302). When frost is formed on 401, the compressor (308) is operated, hot gas flows into the condenser section (304), is heated through the heat exchanger (310), and is defrosted. At the same time, the refrigerant evaporates in the refrigeration evaporator (307), and a heat absorption plate (not shown) in contact with the evaporator (307) is cooled.

  A fourth embodiment of the present invention will be described with reference to the drawings. FIG. 5 is an explanatory diagram of a refrigerator provided with a freezing device. FIG. 7 is an explanatory side view for explaining a freezing device and a spacer provided in the freezer compartment of FIG. 701 is a wooden handle, 702 is a heat insulating material, 703 is a support rod, 704 is a metal plate, 705 is an object to be cooled, 706 is a stepped spacer, and 707 is an endothermic metal plate. FIG. 8 is a top plan view of FIG. Reference numeral 801 denotes a support rod, 802 denotes a stepped spacer, 803 denotes a wooden handle, 804 denotes a single-sided heat insulating metal plate, and 805 denotes an endothermic metal plate. FIG. 14 is a graph in which a 50 g resin plate is placed on one side and subjected to pressure deformation, and the other is contact frozen without placing a resin plate and the drip rate is compared.

  This form shows an example of the spacer provided in the contact freezer. As shown in FIG. 14, when the pressure is applied until it is deformed, the drip increases, so that it should be prevented from being deformed as much as possible. Therefore, by providing the spacers in FIGS. 7 and 8, the height can be adjusted by simply shifting the position back and forth, and a large heat capacity, that is, a heavy metal plate (704, 804) is dropped and a lid is placed on the top of the food (705). Even if they are brought into contact with each other, a large deformation is prevented, and a faster freezing rate is realized by cooling from the upper and lower surfaces, and high-quality freezing becomes possible.

  A fifth embodiment of the present invention will be described with reference to the drawings. FIG. 5 is an explanatory diagram of a refrigerator provided with a freezing device. FIG. 9 is an explanatory side sectional view for explaining the spacer provided on the heat absorbing plate (1101) of FIG. Reference numeral 901 denotes a positioning hole, 902 denotes a spacer, and 903 denotes a positioning through bar. FIG. 10 is a top plan view of FIG. Reference numeral 1001 denotes a positioning hole, 1002 denotes a spacer, and 1003 denotes a resin film. FIG. 11 is a cross-sectional explanatory view of a contact freezing apparatus using a Peltier unit provided in the freezer compartment of FIG. 1101 is a heat absorption plate, 1102 is a Peltier unit, 1103 is a temperature sensor, 1104 is a heat dissipation plate, 1105 is a cold storage agent, 1106 is a cold storage material wall surface, 1107 is a heat dissipation fin, 1108 is a balun, and 1109 is air.

  In this embodiment, a contact freezing apparatus and a spacer using a Peltier unit provided in the freezer compartment of FIG. By using aluminum spacers (902, 1002) with thicknesses of 4 mm, 8 mm, 16 mm, and 32 mm on the heat absorbing plate (1101) in an overlapping manner with the penetrating rod (903) and the positioning holes (901, 1001), up to 4-60 mm The thickness can be adjusted. By contacting food with the surface of the spacer (902, 1002) where the resin film is not applied, contact with the three surfaces of the metal drop lid (not shown) and the lower heat absorption plate (1101) from the top. The rate can be increased. In addition, by sticking the resin film (1003), it is possible to absorb the reflection of the far infrared rays emitted from the metal surface when the food surface is frozen, and the amount of the reflected far infrared rays returning to the food can be reduced.

  Can be used for freezing food, cells and organs.

101, 602, 707, 805, 1101, 1104 Endothermic plate 102, 1105 Cold storage agent 103, 1106 Cold storage wall surface 104, 1107 Radiation fin 105, 1108 Balun 106, 1109 Air 201, 208, 301, 304, 305, 404, 605 Condenser 202, 205 Check valve 203, 209, 212, 309 Switching valve 204, 206, 303, 306 Capillary 207, 213, 302, 307, 603 Evaporator 210, 308, 311 Compressor 211 Four-way valve 310 Heat exchanger 401 Evaporator + Heat exchanger + Condenser 402 Frost receiver 403, 604 Ice 405 Drain pipe 501 Refrigeration room 502 Freezer room 503 Ice making room 504 Front operation panel 505 Freezer storage room 601 Freezing room wall surface 701, 803 Wooden handle 702 Insulation 703, 80 Support rods 704, 804 Single-sided heat insulating metal plate 705 Objects to be cooled 706, 802, 902, 1002 Spacers 901, 1001 Positioning holes 903 Positioning through rods 1003 Resin film 1102 Peltier unit 1103 Temperature sensor Re Drip rate ■ One side on pre-cooled resin plate The drip rate of the one that was frozen by contact □ The drip rate that was frozen by contact with one side of a pre-cooled 400 g aluminum plate ▲ The drip rate that was frozen by immersion in ethanol brine △ Dipped in ice slurry and frozen Drip rate

Claims (9)

  A contact freezer provided with a metal heat-absorbing plate that has a thin liquid layer on the surface and a thin liquid layer on the surface when the object to be frozen or the surface of the packaging means is dry A cooling method and an apparatus therefor, wherein the object or the packaging means surface is frozen by bringing it into contact with a heat absorbing plate having a heat capacity equal to or greater than the heat of solidification of the amount of water to be frozen.   2. The cooling method and apparatus according to claim 1, wherein a cold storage material made of a solution having a freezing point depressing action is provided in direct contact with the rear surface of the metal heat absorbing plate, and a heat dissipating fin extending in the thickness direction is provided on the rear surface of the heat absorbing plate. .   The cooling method and apparatus according to claim 2, wherein a container for storing air in an airtight manner is provided in a lower part of the container.   A contact freezer in which a metal drop lid is brought into contact with the endothermic plate of the freezer and pre-cooled to contact the object to be frozen from the direction facing the endothermic plate, and the thickness of the object to be frozen is between the drop lid and the endothermic plate. 4. The cooling method and apparatus according to claim 1, 2 or 3, wherein a spacer that is slightly thinner is provided.   The cooling method according to claim 4, wherein a stepped spacer is provided on the heat absorbing plate or on a side surface, and a support member is provided on the side surface of the drop lid that is supported by the bearing portion of the stepped spacer and supports the drop lid. That instrument.   6. The cooling method and apparatus according to claim 4 or 5, wherein the spacer is made of a far-infrared absorbing material, or a far-infrared absorbing material is provided on the inner wall surface of the spacer.   In a contact freezer having a cooling means provided in a refrigerator or freezer, the heat associated with the absorption of heat during cooling is ice or a mixture of ice and liquid in the freezer as a cold storage material, and the heat dissipation means is brought into contact with the cold storage material. The cooling method and apparatus according to claim 1, 2, 3, 4, 5 or 6, wherein heat is radiated.   In a refrigerator or freezer provided with a contact freezer in a refrigerator that reverses the refrigeration cycle during defrosting of the evaporator, during the defrosting operation, the frost formed on the evaporator is used as a regenerator and the flow of refrigerant is reduced. The heat absorption plate in the warehouse is cooled by switching from a condenser outside the warehouse to an evaporator of a contact freezer provided in the warehouse by a valve. 8. The cooling method and apparatus according to 7.   9. The cooling method and apparatus according to claim 8, wherein means for estimating the amount of frost formation is provided, and the defrosting operation is started when the cooling capacity required for contact freezing is reached.

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