Ultralow temperature refrigeration system

Abstract

Provided is an ultra-low temperature refrigeration system capable of directly discharging frost that has been frosted in a defroster in a frosted state. A cryogenic refrigeration system (1) is provided with: a cryogenic freezer (10); an air refrigerant refrigerator (30) that cools the air in the ultra-low temperature freezer and supplies the cooled air into the ultra-low temperature freezer; and a defroster (40) that is provided in the ultra-low temperature freezer and that removes frost in air supplied from the air refrigerant refrigerator into the ultra-low temperature freezer.

Description

Technical Field

[0001] The invention relates to an ultra-low temperature freezing system. Background Art

[0002] In recent years, in ultra-low temperature freezer warehouses, a shift from binary refrigerators using Freon refrigerants to air refrigerant refrigerators is being made for the purpose of reducing Freon refrigerants as an environmental measure and saving energy by reducing fan power.

[0003] Air refrigerant freezers use air circulation that draws in air from the warehouse, compresses it, and returns the cooled air to the warehouse through adiabatic expansion. As a result, moisture contained in the air turns into frost and accumulates in the freezer and warehouse, so regular defrosting is required in the freezer and warehouse.

[0004] In connection with this, for example, the following patent document 1 discloses a structure in which a cyclone-type defroster is provided in the front stage of the freezer in an air-refrigerant freezer. According to this structure, frost contained in the air cooled in the air-refrigerant freezer is separated by the cyclone, and the frost entering the freezer is reduced. On the other hand, patent document 2 discloses defrosting using a net (filter unit).

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2006-234275 Patent Document 2: Japanese Patent Application Laid-Open No. 11-132583 Summary of the invention

[0006] Problems to be solved by the invention In the structure of the above-mentioned patent document 1 (the defroster is outside the freezer), when the filter disclosed in patent document 2 is used as the defroster, since the defroster is arranged outside the freezer, when the ambient temperature is relatively high, the frost melts and forms plate-shaped ice on the filter part, and the defroster is blocked due to clogging, and it may be impossible to defrost.

[0007] The present invention has been invented to solve the above-mentioned problems, and an object of the present invention is to provide a super-low temperature refrigeration system capable of directly discharging frost formed on a defroster in a frosted state.

[0008] Technical solutions to solve problems The ultra-low temperature refrigeration system involved in the present invention for achieving the above-mentioned purpose comprises: an ultra-low temperature freezer, which cools and stores the cooled object; an air-refrigerant freezer, which sucks in the air in the ultra-low temperature freezer and cools it, and supplies the cooled air to the ultra-low temperature freezer; and a defroster, which is arranged in the ultra-low temperature freezer and removes frost from the air supplied from the air-refrigerant freezer to the ultra-low temperature freezer.

[0009] Effects of the Invention According to the ultra-low temperature freezing system, the defroster is arranged in the ultra-low temperature freezing room, so that defrosting can be performed in a low temperature atmosphere, and frost formed in the defroster can be directly discharged in a frosted state. Therefore, it is possible to appropriately prevent the frost from melting and forming plate-shaped ice in the filter part, and the defroster is blocked due to clogging and cannot be defrosted. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a system diagram showing a cryogenic freezing system according to an embodiment of the present invention.

[0011] Figure 2 1 is a diagram showing a defroster of the cryogenic refrigeration system according to the present embodiment, and is a diagram showing a state in which frost adheres to a filter portion.

[0012] Figure 3 1 is a diagram showing a defroster of the ultra-low temperature refrigeration system according to the present embodiment, and is a diagram showing a state in which frost adhering to a filter portion falls due to its own weight.

[0013] Figure 4 It is a diagram showing a defroster according to a modified example.

[0014] Figure 5 It is a system diagram showing a cryogenic freezing system according to a modified example. DETAILED DESCRIPTION

[0015] Reference Figure 1 to Figure 3 The embodiment of the present invention is described. In the description of the drawings, the same elements are marked with the same symbols, and repeated descriptions are omitted. For the convenience of description, the dimensional ratios of the drawings are exaggerated and may be different from the actual ratios.

[0016] Figure 1 It is a system diagram showing a cryogenic freezing system 1 according to an embodiment of the present invention. Figure 2 1 is a diagram showing the defroster 40 of the cryogenic refrigeration system 1 according to the present embodiment, and is a diagram showing a state in which frost adheres to the filter portion 42 . Figure 3 The figure shows the defroster 40 of the cryogenic refrigeration system 1 according to the present embodiment, and shows how frost adhering to the filter portion 42 falls due to its own weight.

[0017] The ultra-low temperature freezing system 1 according to the present embodiment is used, for example, for cooling a pharmaceutical warehouse. In addition, the cooling object is not limited to a pharmaceutical warehouse, but can also be used for cooling a food warehouse, etc. Figure 1 As shown, the ultra-low temperature refrigeration system 1 involved in this embodiment includes: an ultra-low temperature freezer 10, which cools and stores the cooled object; a circulation passage 20, which is connected to the ultra-low temperature freezer 10 and provides air circulation; an air refrigerant refrigerator 30, which uses the air in the ultra-low temperature freezer 10 as a refrigerant and supplies cooled air to the ultra-low temperature freezer 10; and a defroster 40, which is arranged in the ultra-low temperature freezer 10 and removes frost from the air supplied from the air refrigerant refrigerator 30 to the ultra-low temperature freezer 10.

[0018] As described above, medicines are stored in the ultra-low temperature freezer 10 for cooling. In the ultra-low temperature freezer 10 for storing medicines, an automatic conveyor is used to carry in and out medicines without human operation. If frost adheres to the automatic conveyor, it may not work properly. Therefore, when the air refrigerant refrigerator 30 is used, the frost adhered to the cooled air returned to the ultra-low temperature freezer 10 must be removed by the defroster 40.

[0019] An inlet (not shown) for air circulating in the circulation passage 20 and an outlet (not shown) for blowing out the air cooled in the air refrigerant freezer 30 are arranged inside the ultra-low temperature freezer 10. The temperature inside the ultra-low temperature freezer 10 is not particularly limited, but is below -50°C. In this way, since the temperature inside the ultra-low temperature freezer 10 is ultra-low temperature, the melting of frost can be prevented in the defroster 40, and the frost can be discharged directly in a frosted state. In addition, when the temperature inside the ultra-low temperature freezer 10 is below -50°C, the frost attached to the filter section 42 will fall if it reaches a certain amount, so continuous operation can be achieved by removing the frost.

[0020] When frost is generated in the air, the temperature of the air containing moisture decreases, and moisture exceeding the saturation amount is precipitated. Here, for example, when the temperature inside the storage is -20°C to -30°C, which is higher than the temperature inside the ultra-low temperature freezer 10 involved in the present embodiment, the time of existence in the form of supercooled droplets is long, and it is easy to form large crystals by agglomeration and bonding before freezing. In contrast, the temperature inside the ultra-low temperature freezer 10 involved in the present embodiment is below -50°C, so that supercooling is easily released, and ice is precipitated before the mass increases, so frost with a small particle size can be formed. In addition, since the lower the temperature inside the ultra-low temperature freezer 10, the lower the absolute humidity, even with the same temperature difference, the amount of moisture precipitated is reduced, and relatively small frost is generated. Therefore, the frost attached to the filter unit 42 described later becomes powdery, and as described later, it can be easily discharged from the defroster 40 by wind pressure.

[0021] like Figure 1 As shown, the air-refrigerant refrigerator 30 includes a compressor 31, an expander 32, and a primary cooler 33. The compressor 31 and the expander 32 are integrated and connected to the same motor M. The air-refrigerant refrigerator 30 configures a reverse Brayton cycle.

[0022] Hereinafter, the cycle in the air-refrigerant refrigerator 30 will be described. In addition, the temperature described below is an example and is not particularly limited.

[0023] First, the air in the ultra-low temperature freezer 10 (-60°C) sucked into the air refrigerant refrigerator 30 is compressed and heated by the compressor 31 to become high-temperature and high-pressure air of 90°C. Then, the 90°C air is cooled to 40°C in the primary cooler 33 .

[0024] Next, the 40° C. air is adiabatically expanded in the expander 32 , cooled to −80° C., and the air is sent into the ultra-low temperature freezer 10 .

[0025] like Figure 1As shown, the defroster 40 is arranged in the ultra-low temperature freezer 10. Here, for example, when the defroster is arranged outside the freezer, when the ambient temperature is relatively high, the frost melts and forms plate-shaped ice in the filter part, and the defroster is blocked due to clogging, and it is possible that defrosting cannot be performed. In contrast, the defroster 40 involved in the present embodiment is arranged in the ultra-low temperature freezer 10, so it can be defrosted in a low-temperature atmosphere, and the frost frosted in the defroster 40 can be directly discharged in a frosted state. Furthermore, for example, when the defroster is arranged outside the freezer, when the ambient temperature is relatively high, the frost melts and forms plate-shaped ice in the filter part, and the defroster is blocked due to clogging, and it is possible that defrosting cannot be performed, so it is necessary to set up a heat-insulating device, and the system as a whole may be large-scale. In contrast, the defroster 40 involved in the present embodiment is arranged in the ultra-low temperature freezer 10, so it can be defrosted in a low-temperature atmosphere, and it is not necessary to perform heat-insulating equipment, which can prevent the system from being large-scale.

[0026] In the present embodiment, one defroster 40 is provided. When the air cooled to -80°C by the air-refrigerant freezer 30 is transported to the ultra-low temperature freezer 10, the defroster 40 removes frost contained in the air. The structure of the defroster 40 will be described below. The structure of the defroster 40 below is an example, and the structure of the defroster 40 is not particularly limited.

[0027] like Figure 2 , Figure 3 As shown, the defroster 40 comprises: a frame 41; a filter portion 42, which is arranged in the frame 41; a first flow path 43, which allows air from which frost is separated to circulate into the ultra-low temperature freezer 10; a first valve 44, which is arranged in the first flow path 43; a second flow path 45, which allows frost to pass when frost is discharged from the frame 41; and a second valve 46, which is arranged in the second flow path 45.

[0028] The frame 41 has an inlet 41A formed therein for taking in air containing frost cooled in the air-refrigerant refrigerator 30 .

[0029] The filter unit 42 adheres to frost contained in the air sucked from the suction port 41A and separates the frost from the air. Figure 2 , Figure 3 As shown in FIG. 1 , the filter unit 42 is arranged to extend in the horizontal direction. According to this configuration, the filter unit 42 can be provided over a wide range, so that frost can be appropriately attached to the filter unit 42 .

[0030] The filter unit 42 is configured to have numerous gaps. When air containing frost passes through the filter unit 42, Figure 2As shown, frost F is attached to the filter unit 42. On the other hand, the air after the frost is separated passes through the filter unit 42 and moves upward, and when the first valve 44 is opened, it is transported to the ultra-low temperature freezer 10 through the first flow path 43 (refer to Figure 2 That is, at this time, a normal cooling operation is performed in the ultra-low temperature freezer 10.

[0031] If the normal cooling operation is continued, when the amount of frost F attached to the filter portion 42 reaches a predetermined amount or more, as shown in FIG. Figure 3 As shown, the frost F falls to the bottom of the frame 41 due to its own weight. The fallen frost F is accumulated in the so-called powder state at the bottom. In addition, the defroster 40 may further include a dropping part that assists the frost attached to the filter part 42 to fall due to its own weight. The dropping part is not particularly limited, and an ultrasonic vibrator or a blowing part that blows out jet air can be used, but from the viewpoint of preventing clogging in the filter part 42, an ultrasonic vibrator is preferred.

[0032] Furthermore, in order to assist the frost attached to the filter portion 42 to fall due to its own weight, the air flow may be reversed (in Figure 2 The filter 42 is oriented downward to allow frost adhering to the filter portion 42 to fall off.

[0033] After a predetermined amount of frost F is accumulated on the bottom of the frame 41, Figure 3 As shown, in a state where the first valve 44 is closed and the second valve 46 is opened, the frost F can be discharged from the second flow path 45 by utilizing the wind pressure of the air sucked in from the suction port 41A. That is, the first valve 44 and the second valve 46 function as a discharge portion that discharges the frost directly to the outside in a frosted state. That is, at this time, in the ultra-low temperature freezer 10, the normal cooling operation is stopped and the defrosting operation is performed. The second valve 46 is preferably arranged in the ultra-low temperature freezer 10. Here, for example, in the case where the second valve 46 is arranged outside the ultra-low temperature freezer 10, there is a possibility that the frost melts in the second valve 46 and freezes. In the present embodiment, the second valve 46 is arranged in the ultra-low temperature freezer 10, so that the above-mentioned freezing can be prevented.

[0034] Frost released to the outside of the defroster 40 is received by, for example, a drain pan, and melted and drained by a heater or warm air provided in the drain pan, thereby preventing resublimation and facilitating defrosting.

[0035] Here, for example, when the defroster 40 is not provided in the ultra-low temperature freezer 10, when the ambient temperature is relatively high, frost attached to the filter 42 melts, ice is generated on the filter 42, and the defroster 40 is blocked and may not be defrosted.

[0036] In contrast, in the cryogenic freezing system 1 according to the present embodiment, the defroster 40 is disposed in the cryogenic freezer 10, so that defrosting can be performed in a low-temperature atmosphere, and frost formed in the defroster 40 can be directly discharged in a frosted state.

[0037] In addition, a heater unit may be installed on the filter unit 42 of the defroster 40. According to this structure, even if the frost attached to the filter unit 42 melts and forms plate-shaped ice in the filter unit 42, the ice can be melted by the heater unit, thereby preventing the defroster 40 from being blocked and failing to defrost.

[0038] The defrosting method of the defroster 40 of the ultra-low temperature freezing system 1 according to the present embodiment is described below. The defrosting method includes: an intake process, in which air with frost attached is inhaled from the intake port 41A of the frame 41; a separation process, in which frost is attached to the filter section 42 and separated from the air; a process of transporting the air separated from the frost in the filter section 42 to the ultra-low temperature freezer 10; and a discharge process, in which the frost that falls due to its own weight is directly discharged to the outside in a frosted state after the frost is attached to the filter section 42. In the discharge process, the frost is discharged from the second flow path 45 by the wind pressure of the air inhaled from the intake port 41A while the first valve 44 is closed and the second valve 46 is opened.

[0039] As described above, the ultra-low temperature freezing system 1 involved in the present embodiment includes: an ultra-low temperature freezer 10, which cools and stores the cooled object; an air refrigerant refrigerator 30, which sucks the air in the ultra-low temperature freezer 10 and cools it, and supplies the cooled air to the ultra-low temperature freezer 10; and a defroster 40, which is arranged in the ultra-low temperature freezer 10 and removes frost from the air supplied from the air refrigerant refrigerator 30 to the ultra-low temperature freezer 10. According to the ultra-low temperature freezing system 1 constructed in this way, the defroster 40 is arranged in the ultra-low temperature freezer 10, so that defrosting can be performed in a low-temperature atmosphere, and the frost frosted in the defroster 40 can be directly discharged in a frosted state. Therefore, it is possible to appropriately prevent the frost from melting and generating ice, and the defroster 40 is blocked and cannot be defrosted.

[0040] The defroster 40 has an inlet 41A for sucking air with frost attached thereto, a filter unit 42 for separating frost from air with frost attached thereto, a first flow path 43 for conveying air separated from frost in the filter unit 42 to the ultra-low temperature freezer 10, and a discharge unit for directly discharging frost dropped by its own weight in a frosted state to the outside after frost is attached to the filter unit 42. According to the ultra-low temperature freezing system 1 thus constructed, since the discharge unit is provided, defrosting can be performed automatically without human operation.

[0041] The temperature inside the cryogenic freezer 10 is -50°C or lower. According to the cryogenic freezing system 1 configured in this way, since the temperature inside the cryogenic freezer 10 is ultra-low, the defroster 40 can prevent frost from melting and can appropriately discharge frost in a frosted state.

[0042] As mentioned above, although this invention was demonstrated using embodiment, this invention is not limited to the said embodiment and modification, Various changes are possible within the scope of a claim.

[0043] For example, in the above-mentioned embodiment, if Figure 2 , Figure 3 As shown in FIG. 4 , the filter portion 42 is arranged to extend in the horizontal direction. Figure 4 As shown, the filter unit 142 may also be configured to extend in the vertical direction. According to this structure, since it is configured to be orthogonal to the traveling direction of the air, frost can be efficiently attached to the filter unit 142. In addition, the number of filter units 42 and filter units 142 provided may be any in the horizontal direction and the vertical direction, and is not limited to one.

[0044] In addition, in the above-mentioned embodiment, one air-refrigerant refrigerator 30 and one defroster 40 are provided. Figure 4 As shown, the air refrigerant refrigerator 30 and the defroster 40 may also be provided in multiple ( Figure 4 In this case, when one of the three defrosters 40 is in defrosting operation, the other defrosters stop defrosting operation (normal operation), and when the other defrosters are in defrosting operation, one defrost stops defrosting operation (normal operation). According to this structure, the defrosters 40 can be properly defrosted, and the ultra-low temperature freezer 10 can be continuously cooled.

[0045] In the above-mentioned embodiment, the discharge unit is composed of the first valve 44 and the second valve 46. However, the discharge unit may be a conveyor such as a conveyor disposed below the defroster 40, and a predetermined amount of frost may be accumulated on the conveyor and then discharged to the outside of the frame 41 by the conveyor.

[0046] This application is based on Japanese Patent Application No. 2022-140644 filed on September 5, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0047] Explanation of symbols 1 Ultra-low temperature freezing system; 10 Ultra-low temperature freezer; 20 Circulatory pathways; 30 Air refrigerant freezers; 31 compressor; 32 expander; 33 primary cooler; 40 Defroster; 41A Suction port; 42, 142 filter section; 43 first flow path; 44 first valve; 45 second flow path; 46 Second valve.

Claims

1. A cryogenic freezing system, comprising: Ultra-low temperature freezers, which cool and store the objects to be cooled; an air refrigerant refrigerator that sucks in the air in the ultra-low temperature freezer to cool it, and supplies the cooled air into the ultra-low temperature freezer; and A defroster is provided in the ultra-low temperature freezer and removes frost from the air supplied from the air-refrigerant refrigerator into the ultra-low temperature freezer.

2. The ultra-low temperature freezing system according to claim 1, wherein: The defroster is provided with a plurality of When one of the defrosters is in defrosting operation, the other defrosters stop defrosting operation. When the other defroster is performing the defrosting operation, the one defroster stops the defrosting operation.

3. The ultra-low temperature freezing system according to claim 1 or 2, wherein: The defroster has: an inlet for inhaling the air to which the frost is attached; a filter portion to which the frost adheres and to separate the frost from the air; a first flow path for conveying the air after the frost is separated in the filter section to the ultra-low temperature freezer; as well as The discharge unit discharges the frost that has fallen due to its own weight directly to the outside in a frost state after the frost has attached to the filter unit.

4. The ultra-low temperature freezing system according to claim 1 or 2, wherein: The temperature inside the ultra-low temperature freezer is below -50°C.

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