A reverse Brayton cycle multi-temperature zone cryogenic storage

Abstract

This utility model discloses a reverse Brayton cycle multi-temperature zone low-temperature cold storage, including a circulating refrigeration unit and a cold storage box. The internal cavity of the cold storage box is divided into multiple compartments by multiple partitions. The circulating refrigeration unit and the cold storage box are connected by air supply ducts and return air ducts, which run through and extend to each compartment of the cold storage box. Each air supply duct has an air outlet at the corresponding position of each compartment, and each air outlet is equipped with an electric damper. Each return air duct has a return air outlet at the corresponding position of each compartment. The air inlet of the air supply duct is connected to the air supply end of the circulating refrigeration unit, and the air return end of the return air duct is connected to the return end of the circulating refrigeration unit. This utility model has the advantages of achieving individual and precise temperature control of each compartment, realizing the function of multiple temperature zones in a single low-temperature cold storage, effectively reducing defrosting time and defrosting energy consumption, and ensuring stable temperature inside the cold storage box.

Description

Technical Field

[0001] This utility model relates to the field of cold storage technology, specifically a reverse Brayton cycle multi-temperature zone low-temperature cold storage. Background Technology

[0002] Cold storage facilities are mainly used as constant-temperature refrigeration equipment for food, dairy products, meat, aquatic products, and special medicines. With the development of refrigeration equipment, the reverse Brayton cycle refrigeration system has been applied to refrigeration equipment due to its energy-saving and environmental protection advantages. For example, patent publication number CN112484330A discloses a Brayton refrigeration cycle low-temperature chamber, which specifically discloses a chamber body, a regenerator for heat exchange between low-temperature nitrogen and high-temperature nitrogen, a compressor, an expander, an aftercooler, a cooler, and a high-speed motor; it can achieve low-temperature storage below -80℃.

[0003] Traditional low-temperature cold storage facilities typically consist of a single unit. Patent publication number CN118442752A discloses a parallel-type medical ultra-low temperature cold storage facility and its assembly method. The cold storage unit has multiple partitions inside its cavity, dividing it into several independent compartments. The refrigeration unit is connected in parallel to each compartment through air supply and return ducts, providing the effect of storage in multiple independent compartments. However, it suffers from problems such as a single temperature within the cold storage, inability to achieve multi-temperature zones, low refrigeration efficiency, and high energy consumption. Utility Model Content

[0004] The technical problem this invention aims to solve is to overcome existing defects and provide a reverse Brayton cycle multi-temperature zone cryogenic cold storage, enabling individual and precise temperature control of each compartment, allowing a single cryogenic cold storage to function as multiple temperature zones, and meeting various customer needs; the cryogenic cold storage has high refrigeration efficiency; it can reduce the impact on the power grid when the circulating refrigeration unit starts up, and can reduce the energy consumption of the cryogenic cold storage; it can effectively reduce defrosting time and defrosting energy consumption, reduce the impact of defrosting on the temperature inside the compartment, and ensure stable temperature inside the cold storage box; it can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a reverse Brayton cycle multi-temperature zone low-temperature storage unit, comprising a circulating refrigeration unit and a cold storage box, wherein the cold storage box is provided with multiple partitions, and the internal cavity of the cold storage box is divided into multiple compartments by the multiple partitions; the circulating refrigeration unit and the cold storage box are connected by an air supply duct and a return air duct, the air supply duct and the return air duct penetrate and extend to each compartment of the cold storage box, the air supply duct is provided with an air supply port at the corresponding position of each compartment, and each air supply port is provided with an electric damper, the return air duct is provided with a return air port at the corresponding position of each compartment; the air inlet end of the air supply duct is connected to the air supply end of the circulating refrigeration unit, and the air return end of the return air duct is connected to the return end of the circulating refrigeration unit.

[0006] Furthermore, the circulating refrigeration unit is a reverse Brayton cycle refrigeration system. The circulating refrigeration unit includes a refrigeration unit, an aftercooler, a regenerator, a cooling unit, and an insulated box. The refrigeration unit includes a compressor and an expander synchronously driven by a high-speed motor. The compressor, expander, aftercooler, regenerator, and cooling unit are circulated and connected by pipes. The cooling unit is fixedly installed inside the insulated box. The insulated box is equipped with a refrigeration fan. An air supply port is opened on the outer wall of the insulated box at the position corresponding to the fan blades of the refrigeration fan. A return port is also provided on the outer wall of the insulated box. The air inlet end of the air supply pipe is connected to the air supply port of the insulated box, and the air return end of the return air pipe is connected to the return port of the insulated box.

[0007] Furthermore, the insulation box is equipped with an air guide hood located at the upper end of the cooler, and the fan blades of the refrigeration fan are located inside the air guide hood. The air inlet end of the air supply duct passes through the air supply port and is connected to the air guide hood; the return port of the insulation box is located below the cooler.

[0008] Furthermore, the bottom of the cooler is equipped with a defrosting heater, and the return air duct is equipped with an electric damper on the pipe wall between the cold storage box and the insulation box.

[0009] Furthermore, the outer wall of the aftercooler is provided with cooling fan one and cooling fan two, which are used to blow ambient air toward the aftercooler; cooling fan one and cooling fan two are arranged vertically.

[0010] Furthermore, the circulating refrigeration unit also includes an insulation box II, and a regenerator is disposed inside the insulation box II.

[0011] Compared with the prior art, the beneficial effects of this utility model are: (1) This reverse Brayton cycle multi-temperature zone low-temperature warehouse has various compartments in the cold storage box connected in parallel through air supply pipes and return air pipes. Each air supply outlet on the air supply pipe is equipped with an electric damper. The air supply volume of each compartment can be adjusted by controlling the opening of the electric damper, thereby adjusting the temperature of each compartment and realizing individual and precise temperature control of each compartment. This enables a low-temperature warehouse to have multiple temperature zones, meeting the various needs of customers. (2) The air guide hood above the cooler is equipped with the fan blades of the refrigeration fan. The refrigeration fan draws out the cold air in the insulation box, pressurizes it and sends it to each compartment of the cold storage box to improve the refrigeration efficiency of the low temperature storage. (3) By adopting the optimized configuration of refrigeration host and dual cooling fans, the impact on the power grid when the circulating refrigeration unit starts up can be reduced, and the energy consumption of the low temperature warehouse can be reduced. (4) Before defrosting with the cooler, use its own cold storage to continue cooling each compartment of the cold storage box, and then use the defrost heater to heat and defrost, which can effectively reduce defrosting time and defrosting energy consumption. When defrosting, close the electric damper 1 and electric damper 2 of all compartments, and set the cooler and the cold storage box separately, which can effectively reduce the impact of defrosting on the temperature inside the compartment and ensure the temperature inside the cold storage box is stable. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the circulating refrigeration unit structure of this utility model; Figure 3 This is a schematic diagram of the internal structure of the insulated box of this utility model; Figure 4 This is a schematic diagram of the internal structure of the cold storage box of this utility model; Figure 5 This is a schematic diagram of the multi-temperature zone low-temperature storage structure of this utility model.

[0013] In the diagram: 1. Circulating refrigeration unit; 2. Cold storage box body; 21. Partition; 22. Compartment; 3. Refrigeration unit; 31. Compressor; 311. Inlet; 312. Outlet; 32. Expander; 321. Expansion inlet; 322. Expansion outlet; 4. Aftercooler; 41. Cooling fan one; 42. Cooling fan two; 5. Regenerator; 51. High temperature inlet; 52. High temperature outlet; 53. Low temperature inlet; 54. Low temperature outlet; 6. Refrigeration unit; 7. Air supply duct; 71. Air outlet; 72. Electric damper one; 8. Return air duct; 81. Return air outlet; 82. Electric damper two; 9. Insulation box one; 10. Refrigeration fan; 11. Air guide hood; 12. Defrosting heater; 13. Insulation box two. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0015] Please see Figure 1-5This utility model provides a technical solution: a reverse Brayton cycle multi-temperature zone low-temperature cold storage, including a circulating refrigeration unit 1 and a cold storage box 2. Multiple partitions 21 are vertically arranged along the length of the cold storage box 2, dividing the internal cavity of the cold storage box 2 into multiple compartments 22. In this embodiment, each compartment 22 is equipped with a temperature sensor. The circulating refrigeration unit 1 and the cold storage box 2 are connected by an air supply duct 7 and a return air duct 8. The air supply duct 7 and the return air duct 8 penetrate and extend into each compartment 22 within the cold storage box 2. Each air supply duct 7 has an air outlet 71 at a position corresponding to each compartment 22, and each air outlet 71 is equipped with an electric damper 72. Each return air duct 8 has a return air outlet 81 at a position corresponding to each compartment 22. The air inlet of the air supply duct 7 is connected to the air supply end of the circulating refrigeration unit 1, and the return air end of the return air duct 8 is connected to the return flow end of the circulating refrigeration unit 1. The circulating refrigeration unit 1 provides cooling capacity to each compartment 22 in the cold storage box 2. The compartments 22 in the cold storage box 2 are connected in parallel, and each air outlet 71 of the air supply duct 7 is equipped with an electric damper 72. In this embodiment, the opening degree of the electric damper 72 can be controlled independently. By controlling the electric damper 72, the temperature of each compartment 22 can be precisely controlled individually, so that different compartments 22 have different temperatures.

[0016] The circulating refrigeration unit 1 is a reverse Brayton cycle refrigeration system. The circulating refrigeration unit 1 includes a refrigeration host 3, an aftercooler 4, a regenerator 5, a cooler 6, and an insulation box 9. The refrigeration host 3 includes a compressor 31 and an expander 32 synchronously driven by a high-speed motor. The compressor 31 and the expander 32 of the refrigeration host 3 start and stop synchronously. The compressor 31, the expander 32, the aftercooler 4, the regenerator 5, and the cooler 6 are connected in a circulating manner through pipelines. The exhaust port 312 of the compressor 31 is connected to the inlet of the aftercooler 4 through a pipeline. The outlet of the aftercooler 4 is connected to the high-temperature inlet 51 of the regenerator 5 through a pipeline. The high-temperature outlet 52 of the regenerator 5 is connected to the expansion inlet 321 of the expander 32 through a pipeline. The expansion outlet 322 of the expander 32 is connected to the inlet of the cooler 6 through a pipeline. The outlet of the cooler 6 is connected to the low-temperature inlet 53 of the regenerator 5 through a pipeline. The low-temperature outlet 54 of the regenerator 5 is connected to the suction port 311 of the compressor 31 through a pipeline. The cooler 6 is fixedly installed inside the insulation box 9. The insulation box 9 is equipped with a refrigeration fan 10, and an air supply port is opened on the outer wall of the insulation box 9 at the position corresponding to the fan blades of the refrigeration fan 10. An air guide shroud 11 is provided above the cooler 6 inside the insulation box 9. In this embodiment, the refrigeration fan 10 is a centrifugal fan, and the fan blades of the refrigeration fan 10 are located inside the air guide shroud 11. The air inlet end of the air supply duct 7 passes through the air supply port and connects to the air guide shroud 11. A return port is opened on the outer wall of the insulation box 9 below the cooler 6. The return end of the return air duct 8 is connected to the return port of the insulation box 9. An electric damper 82 is provided on the pipe wall of the return air duct 8 between the cold storage box 2 and the insulation box 9. A defrost heater 12 is provided at the bottom of the cooler 6. The outer wall of the aftercooler 4 is provided with a cooling fan 41 and a cooling fan 42, which are used to blow ambient air toward the aftercooler 4; the cooling fan 41 and the cooling fan 42 are arranged vertically; the circulating refrigeration unit 1 also includes an insulation box 13, and the regenerator 5 is installed inside the insulation box 13.

[0017] Working principle: After the compressor 31 compresses the refrigerant, it is sent from its discharge port 312 to the inlet of the aftercooler 4. The aftercooler 4 cools the refrigerant and then it flows from its outlet to the high-temperature inlet 51 of the regenerator 5. The regenerator 5 further cools the refrigerant and then it flows from its high-temperature outlet 52 to the expansion inlet 321 of the expander 32. The expander 32 expands, depressurizes, and cools the refrigerant and then it flows from its expansion outlet 322 to the inlet of the cooler 6. The cooler 6 provides cooling capacity to the insulation box 9. The cold air inside the insulation box 9 is extracted and pressurized by the refrigeration fan 10 and then flows through the air supply duct. The air duct 7 delivers cold air to each compartment 22 of the cold storage box 2, thereby cooling each compartment 22. The temperature of each compartment 22 can be precisely controlled individually by controlling the corresponding electric damper 72. The air inside each compartment 22 is returned to the insulation box 9 through the air supply duct 7 and the return air inlet 81. After the working fluid in the cooler 6 absorbs heat and is heated, it flows through its outlet to the low temperature inlet 53 of the regenerator 5, and then through the low temperature outlet 54 of the regenerator 5 to the suction port 311 of the compressor 31 for cyclic cooling.

[0018] The specific operating steps of the circulating refrigeration unit 1 are as follows: Upon startup, the refrigeration unit 3 runs at its lowest speed n1 (rpm) for m1 minutes. Then, cooling fan 41 and refrigeration fan 10 begin operation, with 20000 ≤ n1 ≤ 30000 rpm and 1 ≤ m1 ≤ 10. After the refrigeration unit 3 runs for m2 minutes, it begins to increase to speed n2, and cooling fan 42 starts operating, with 30000 ≤ n2 ≤ 40000 rpm and 10 ≤ m2 ≤ 30. After the refrigeration unit 3 runs for m3 minutes, it begins to increase to speed n3, with 40000 ≤ n3 ≤ 50000 rpm and 40 ≤ m3 ≤ 60. After the refrigeration unit 3 runs for m4 minutes, it reaches its rated speed n4, with 60000 ≤ n4 ≤ 100000 rpm and 50 ≤ m4 ≤ 100000 rpm. 400; When the temperature of all compartments 22 in the cold storage unit 2 reaches 2℃ lower than the set temperature, the speed of the refrigeration unit 3 decreases by n5 revolutions per m5 minutes, 200≤n5≤1000, 2≤m5≤30. When the speed of the refrigeration unit 3 decreases to half of the rated speed n4, the cooling fan 1 41 is turned off, and only the cooling fan 2 42 runs, until the refrigeration unit 3 decreases to the minimum speed n1. When the refrigeration unit 3 runs for more than P minutes and still cannot reach the requirements of compartment 22, 40≤P≤100, the refrigeration unit 3 starts to increase by n5 revolutions per m5 minutes. When the speed of the refrigeration unit 3 rises to 60% of its rated speed, the turned-off cooling fan 1 41 is turned on, and both cooling fan 1 41 and cooling fan 2 42 run. When the refrigeration unit 3 runs at its rated speed n4 for more than the system-set time W minutes to reach the required temperature of compartment 22, and 60≤W≤150, it is determined that the chiller 6 needs to be defrosted. The temperature of all compartments 22 is reduced to 2°C lower than the set temperature. The refrigeration unit 3 begins to reduce its speed. When it drops to half of the rated speed n4, one of the cooling fans is shut down. After the refrigeration unit 3 stops for a period of time, the other cooling fan is stopped. At this time, the refrigeration fan 10 continues to run, using the chiller 6's own cold storage to continue cooling the compartments 22. When the temperature of the chiller 6 drops to the same level as the temperature inside the compartments 22, all electric dampers 1 72 and 2 82 are closed. The defrosting heater 12 begins to heat and defrost. After defrosting, the refrigeration unit 3 operates in the same way as when it was started. Electric dampers 1 72 and 2 82 remain closed until the temperature of the chiller 6 is lower than the temperature inside the compartments 22. Then, electric dampers 1 72 and 2 82 are opened to continue normal refrigeration.

[0019] The reverse Brayton cycle multi-temperature zone low-temperature storage disclosed in this embodiment has various compartments 22 within the cold storage body 2 interconnected in parallel via air supply ducts 7 and return air ducts 8. Each air outlet 71 on the air supply duct 7 is equipped with an electric damper 72. The opening degree of the electric damper 72 can be controlled to adjust the air volume of each compartment 22, thereby adjusting the temperature of each compartment 22 and achieving individual and precise temperature control of each compartment 22. This allows a single low-temperature storage unit to function as multiple temperature zones, meeting various customer needs. The air guide hood 11 above the refrigeration unit 6 contains the blades of a refrigeration fan 10. The refrigeration fan 10 draws and pressurizes the cold air from the insulation box 9 and sends it to the cold storage unit. Within each compartment 22 of the cold storage unit 2, the refrigeration efficiency of the low-temperature storage is improved. By adopting an optimized configuration of the refrigeration unit 3 and dual cooling fans, the impact on the power grid when the circulating refrigeration unit 1 starts up can be reduced, and the energy consumption of the low-temperature storage can be reduced. Before defrosting, the cooler 6 uses its own cold storage to continue cooling each compartment 22 of the cold storage unit 2, and then uses the defrost heater 12 to heat and defrost, which can effectively reduce defrosting time and defrosting energy consumption. During defrosting, the electric dampers 72 and 82 of all compartments 22 are closed, and the cooler 6 is set separately from the cold storage unit 2, which can effectively reduce the impact of defrosting on the temperature inside the compartments 22 and ensure the temperature stability inside the cold storage unit 2.

[0020] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reverse Brayton cycle multi-temperature zone low-temperature cold storage, comprising a circulating refrigeration unit and a cold storage enclosure, characterized in that: The cold storage unit has multiple partitions inside, dividing the internal cavity into multiple compartments. The circulating refrigeration unit is connected to the cold storage unit via air supply ducts and return air ducts, which run through and extend into each compartment of the cold storage unit. Each air supply duct has an air outlet at the location corresponding to each compartment, and each air outlet is equipped with an electric damper. Each return air duct has a return air outlet at the location corresponding to each compartment. The air inlet of the air supply duct is connected to the air supply end of the circulating refrigeration unit, and the air return end of the return air duct is connected to the return end of the circulating refrigeration unit.

2. The reverse Brayton cycle multi-temperature zone cryogenic storage facility according to claim 1, characterized in that: The circulating refrigeration unit is a reverse Brayton cycle refrigeration system. The circulating refrigeration unit includes a refrigeration unit, an aftercooler, a regenerator, a cooling unit, and an insulated box. The refrigeration unit includes a compressor and an expander synchronously driven by a high-speed motor. The compressor, expander, aftercooler, regenerator, and cooling unit are connected in a circulating manner through pipes. The cooling unit is fixedly installed inside the insulated box. The insulated box is equipped with a refrigeration fan. An air supply port is opened on the outer wall of the insulated box at the position corresponding to the fan blade. A return port is also provided on the outer wall of the insulated box. The air inlet end of the air supply pipe is connected to the air supply port of the insulated box, and the air return end of the return air pipe is connected to the return port of the insulated box.

3. The reverse Brayton cycle multi-temperature zone cryogenic chamber according to claim 2, characterized in that: The insulation box is equipped with an air guide hood at the upper end of the cooler, and the fan blades of the refrigeration fan are located inside the air guide hood. The air inlet end of the air supply duct passes through the air supply port and is connected to the air guide hood. The return port of the insulation box is located below the cooler.

4. A reverse Brayton cycle multi-temperature zone cryogenic chamber according to claim 2, characterized in that: The bottom of the cooler is equipped with a defrosting heater, and the return air duct is located on the pipe wall between the cold storage box and the insulation box 1, and is equipped with an electric damper 2.

5. A reverse Brayton cycle multi-temperature zone cryogenic chamber according to claim 2, characterized in that: The outer wall of the aftercooler is equipped with a cooling fan 1 and a cooling fan 2, which are used to blow ambient air toward the aftercooler; the cooling fan 1 and the cooling fan 2 are arranged vertically.

6. A reverse Brayton cycle multi-temperature zone cryogenic chamber according to claim 2, characterized in that: The circulating refrigeration unit also includes an insulation box II, and a regenerator is installed inside the insulation box II.

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