Pulse type low-temperature refrigerator

Abstract

The invention provides a cryogenic refrigerator and a method for controlling the internal temperature of the cryogenic refrigerator. The cryogenic freezer includes an inner container. The inner container defines a storage chamber. The cryogenic refrigerator includes an outer container surrounding an inner container. The outer container may define a vacuum insulated space between the outer container and the inner container. The cryogenic refrigerator includes a temperature sensor configured to measure a temperature within the storage chamber. The cryogenic refrigerator includes a controller coupled with the temperature sensor. The controller is configured to pulse an amount of coolant into the storage vessel to control a temperature within the storage vessel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims priority from U.S. non-provisional patent application No. 17 / 985,559, filed on November 11, 2022, entitled “PULSED CRYOGENFREEZER,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present specification relates to a system, device or apparatus for a cryogenic refrigerator, and a method of controlling the temperature within a cryogenic refrigerator. Background Art

[0003] Vapor-phase liquid cryogen freezers have been used for decades for long-term storage of heat-sensitive biological specimens. These freezers use a cryogenic liquid, such as a refrigerant, to store biological samples, materials, products, and the like. These freezers may have a tank of liquid cryogen, such as liquid nitrogen, located at the bottom of the freezer storage chamber, with the product stored above the tank or partially submerged in the cryogenic liquid. The freezer may be a Dewar flask, which features a double-walled vacuum insulation structure that provides a well-insulated storage chamber. Such freezers can provide storage temperatures ranging from approximately -90°C to -195°C.

[0004] The temperature in these freezers cannot be directly controlled. Instead, the temperature can be controlled by maintaining the amount of cryogenic liquid in the storage tank. The temperature of the freezer storage compartment can vary depending on the amount of liquid coolant in the freezer. In addition, immersing biological samples in cryogenic liquid may pose a risk of cross-contamination between sample containers. Even when the stored sample containers are placed in the cold vapor above the cryogenic liquid storage tank, if the freezer is overfilled with cryogenic liquid, the sample or sample container may still come into contact with or be immersed in the cryogenic liquid.

[0005] Therefore, there is a need for a system and method to manage and control the temperature within a freezer while preventing samples from being immersed in liquid coolant. Summary of the Invention

[0006] Examples described herein relate to embodiments of a freezer and a method for controlling the temperature within a cryogenic freezer. The freezer includes an outer container and an inner container within the outer container. The inner container defines a storage chamber. The freezer includes a sensor that measures the temperature within the storage chamber. The freezer may include multiple sensors that measure the temperature within the storage chamber. The freezer includes a controller coupled to a first sensor. The controller pulses a quantity of a medium into the storage chamber to control the temperature within the storage chamber. The medium may be a liquid or gaseous cryogenic refrigerant, including liquid nitrogen.

[0007] In one aspect, the present invention is embodied as a freezer. The freezer includes an outer container and an inner container. The inner container is positioned within the outer container. The inner container defines a storage chamber. The freezer includes a first sensor configured to measure a temperature within the storage chamber. The freezer includes a controller coupled to the first sensor. The controller is configured to pulse a certain amount of a medium into the storage chamber to control the temperature within the storage chamber.

[0008] These and other embodiments may optionally include one or more of the following features. The freezer may include a turntable. The turntable may be positioned in the internal container. The turntable may be configured to accommodate multiple storage areas. The first sensor may be positioned adjacent to the turntable. The first sensor may be positioned on the turntable. The second sensor may be positioned at the bottom of the turntable. The second sensor may be configured to detect or measure an amount of media within the storage chamber. The controller may be configured to pulse a certain amount of media into the storage chamber further based on the detected or measured amount of media within the storage chamber. The controller may be configured to reduce the frequency or duration of the pulses when the detected or measured amount of media within the storage chamber is greater than or equal to a threshold amount, or when the temperature is below a threshold temperature. In order to pulse a certain amount of media into the storage chamber, the controller may be configured to increase the frequency or duration of the pulses when the detected or measured amount of media within the storage chamber is less than a threshold amount and when the temperature is above a threshold temperature.

[0009] The refrigerator may also include an outlet positioned at the bottom, sidewall or other positions of the storage container to allow medium to be distributed in the sample space around the turntable. The refrigerator may also include an outlet positioned at the bottom of the storage chamber and configured to transport or disperse medium into the storage chamber. The outlet may be the end of a valve, a pipe or other outlet structures. The refrigerator may also include a medium source, which is communicated with the outlet fluid and configured to provide medium by one or more conduits and flow out from the outlet to transport or disperse medium into the storage chamber. A controller may be coupled to the medium source and the outlet. In order to allow a certain amount of medium to enter the storage container in a pulsed manner, the controller may be configured to regulate the position of the outlet valve so that the valve is opened, partially opened or closed, or to provide medium by an outlet control medium source. The medium source may be a storage container containing a medium supply portion. The medium may be a liquid cryogenic refrigerant, which includes liquid nitrogen. Liquid nitrogen may be pressurized to be transported to the outlet.

[0010] The controller may be configured to determine a time or frequency at which a certain amount of medium is pulsed into the storage container. The controller may be configured to pulse the certain amount of medium into the storage container based on the time or frequency. The controller may be configured to determine a difference between a temperature within the storage container and a set point temperature. The controller may be configured to determine a time or frequency at which a certain amount of medium is pulsed into the storage container based on the difference.

[0011] In another aspect, the present invention is embodied as a freezer that uses a liquid coolant as a refrigerant. The freezer may include an inner container defining a storage chamber. The freezer may include an outer container surrounding the inner container. The outer container may define a vacuum, thermally insulated space between the outer container and the inner and outer containers. The freezer may include a temperature sensor configured to measure a temperature within the storage chamber at a determined height. The freezer includes a controller coupled to the temperature sensor. The controller is configured to pulse a quantity of coolant into the storage container to control the temperature within the storage container. The controller may also be configured to pulse a quantity of liquid into the storage container to control the temperature within the storage container and to limit the amount of liquid that accumulates and / or collects at the bottom of the storage container.

[0012] These and other embodiments may optionally include one or more of the following features. The freezer may include a turntable positioned within the internal container. The turntable may be configured to hold a plurality of storage areas. A temperature sensor may be positioned on or adjacent to the turntable. The freezer may include a coolant level sensor positioned at a bottom of the turntable. The coolant level sensor may be configured to detect or measure an amount of coolant within the storage chamber. The controller may be configured to pulse an amount of coolant into the storage chamber further based on the detected or measured amount of coolant within the storage chamber. To pulse an amount of coolant into the storage chamber, the controller may be configured to reduce the frequency or duration of the pulses when the detected or measured amount of coolant within the storage chamber is greater than or equal to a threshold amount, or when the temperature is below a threshold temperature. The controller may also be configured to increase the frequency or duration of the pulses when the detected or measured amount of coolant within the storage chamber is less than a threshold amount, or when the temperature is above a threshold temperature.

[0013] The freezer may further include an outlet positioned at the bottom of the storage chamber. The outlet may be an outlet valve. The outlet valve may be configured to transport or disperse a coolant (e.g., a liquid coolant) into the storage chamber. The freezer may further include a coolant source that is fluidly connected to the outlet valve and is configured to provide a coolant through one or more conduits and flow out of the outlet valve to transport or disperse the medium into the storage chamber. A controller may be coupled to the coolant source and the outlet valve. In order to allow a certain amount of coolant to enter the storage container in a pulsed manner, the controller may be configured to adjust the position of the outlet valve to open, partially open, or close the outlet valve, or to control the coolant source to provide coolant until the outlet valve. The coolant source may be a storage container comprising a coolant supply that includes liquid nitrogen. The liquid nitrogen may be pressurized to be transported to the outlet valve.

[0014] In another aspect, the present invention is embodied in a method for controlling temperature within a cryogenic refrigerator. The method includes measuring or detecting, by a processor and using a temperature sensor, a temperature within a storage chamber of the cryogenic refrigerator. The method includes determining, by the processor, whether the temperature is greater than or equal to a set point temperature. The method includes pulsing, by the processor and using an outlet valve and a coolant source, a quantity of coolant into the storage chamber when the temperature is greater than or equal to the set point temperature.

[0015] These and other embodiments may optionally include one or more of the following features. The method may include measuring or detecting, by a processor and using a coolant level sensor, an amount of coolant in the storage chamber. The method may include pulsing, by a processor and using an outlet valve and a coolant source, an amount of coolant into the storage chamber based on the amount of coolant in the storage chamber. Pulsing an amount of liquid into the storage chamber may include reducing the frequency or duration of the pulses when the detected or measured amount of coolant in the storage chamber is greater than or equal to a threshold amount, or when the temperature is below a threshold temperature. Pulsing an amount of coolant into the storage chamber may include increasing the frequency or duration of the pulses when the detected or measured amount of coolant in the storage chamber is less than a threshold amount, or when the temperature is above a threshold temperature.

[0016] The method may include determining a difference between a temperature within the storage chamber and a set point temperature. The method may include determining a frequency and a timing of pulsing an amount of coolant into the storage chamber based on the difference. The method may include pulsing an amount of coolant into the storage chamber based on the timing or frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By reading the following drawings and detailed description, other systems, methods, features and advantages of the present invention will be apparent to those skilled in the art. Components shown in the drawings are not necessarily drawn to scale and may be exaggerated to better illustrate important features of the present invention.

[0018] Figure 1 is a perspective view of a cryogenic refrigerator according to one aspect of the present invention;

[0019] Figure 2 According to one aspect of the present invention Figure 1 A cross-sectional view of a cryogenic freezer;

[0020] Figure 3 According to one aspect of the present invention Figure 1 A schematic diagram of the external connection portion of the cryogenic refrigerator;

[0021] Figure 4 is the use according to one aspect of the present invention Figure 1A flowchart of an example process for controlling the temperature of a cryogenic refrigerator in FIG.

[0022] Figure 5 is the use according to one aspect of the present invention Figure 1 Flowchart of an example process for determining the frequency and timing of dielectric pulses in a cryogenic refrigerator. DETAILED DESCRIPTION

[0023] Disclosed herein are systems, devices or apparatus for refrigerators, particularly refrigerators using pulsed coolants as refrigerants, and a method for controlling the temperature within a cryogenic refrigerator system. Current refrigerator technology uses expensive heat exchangers and complex assembly processes to address the risk of materials stored in a cold storage space being exposed to liquid coolants (e.g., samples being immersed in the coolant). The coolants mentioned herein may include liquid coolants, gaseous coolants, or a combination of liquid and gaseous coolants. A pulsed coolant refrigerator eliminates the need for a heat exchanger while reducing the risk of liquid nitrogen exposure. While maintaining the temperature within the payload area of the pulsed coolant refrigerator, the pulsed coolant refrigerator also controls the coolant level within the payload area of the pulsed coolant refrigerator so that the samples within the payload area are not immersed or exposed to the coolant.

[0024] Other benefits and advantages of pulsed liquid nitrogen freezers include the ability to expand the usable storage temperature range of the pulsed liquid nitrogen freezer. For example, the usable storage temperature range can be expanded from -185°C to -195°C to -20°C to -150°C. Furthermore, pulsed liquid nitrogen freezers can be modified to couple or connect with a variety of different types of high-efficiency liquid nitrogen-based freezers. Furthermore, pulsed liquid nitrogen freezers can be configured to accommodate a variety of different types of high-efficiency liquid nitrogen-based freezers, enabling these freezers to be used in a variety of applications.

[0025] Figure 1 The figure is a perspective view of a cryogenic freezer 100. Cryogenic freezer 100 includes a dewar flask 102. Dewar flask 102 can be cylindrical or have an alternative shape. Dewar flask 102 can be a double-walled flask or container with a vacuum-insulated space between the two walls. Dewar flask 102 can be used to hold liquids at subambient temperatures. Temperature-sensitive materials, such as biological samples, can be stored at low temperatures within Dewar flask 102.

[0026] The cryogenic refrigerator 100 can have an access neck 106. The access neck 106 can be located at the top of the dewar 102 and define an access opening 108 through which the interior of the dewar 102 can be accessed. The cryogenic refrigerator 100 can have a top 110. The top 110 can include a removable plate 114 (also known as a "Dewar lid") that covers the access opening 108.

[0027] The cryogenic freezer 100 may include a housing 112. The housing 112 may be located on top of the dewar 102. A control panel 120 may be mounted on a front wall of the housing 112. The control panel 120 may include a touch screen and a display. The control panel 120 may be accessed, viewed, and / or configured. The housing 112 may house one or more electronic components. In some embodiments, one or more components may include a controller 230, such as, for example, Figure 3 shown.

[0028] Figure 2 is a cross-sectional view of a cryogenic freezer 100. The dewar 102 of the cryogenic freezer 100 may include an outer wall 204 and an inner wall 202. The outer wall 204 and / or the inner wall 202 may be made of materials including stainless steel, aluminum alloy, or other low-temperature-resistant metals or non-metals. The outer wall 204 may surround the inner wall 202. The outer wall 204 may define an enclosed space 206 within which the inner wall 202 is located. The inner wall 202 may define a storage chamber 234 in which materials, such as biological samples, may be stored at subambient temperatures, such as cryogenic temperatures. The space 206 between the outer wall 204 and the inner wall 202 may be evacuated to provide vacuum insulation. The space 206 may include other types of insulation and one or more physical inserts configured to reduce heat transfer through the space 206. In some embodiments, another form factor and insulated enclosure or container may be substituted for the vacuum-insulated dewar 102.

[0029] The access neck 106 on the top of the dewar 102 can define an access opening 108 through which the storage chamber 234 of the dewar 102 can be accessed. The top 110 of the cryogenic freezer can include a removable top panel 114 that covers the access opening 108. The top panel 114 can be insulated. The top panel 114 of the top 110 can be opened and closed to provide access to the storage chamber 234 through the access opening 108.

[0030] The cryogenic refrigerator 100 may include one or more temperature sensors 216a, 216b and / or a coolant level sensor 222. The temperature sensors 216a, 216b may be thermocouple devices. Thermocouple devices generate a voltage that is related to temperature, and this voltage can be used to measure temperature. The temperature sensor 216a may be located near the top of the cylindrical shaft 238 of the turntable 218. The temperature sensor 216a may be located at the top of the cylindrical shaft 238 of the turntable 218, which may be the hottest point within the storage chamber 234. The temperature sensor 216a may measure or detect the temperature within the storage chamber 234, and when it is located at the top of the cylindrical shaft 238 and / or at the position farthest from the cooling source, it measures or detects the hottest temperature within the storage chamber 234. The temperature sensor 216b may be located below the turntable 218. The temperature sensor 216b may be located near the bottom of the cylindrical shaft 238 of the turntable 218. In various embodiments, a temperature sensor 216b may be located at the bottom of the cylindrical shaft 238 of the turntable 218. The temperature sensor 216b may measure or detect the temperature proximate the point where the medium collects or at the bottom of the storage chamber 234. The temperature sensor 216b may also be used to measure or detect the amount of medium, such as coolant, within the storage chamber 234. For example, when the temperature sensor 216b drops below a threshold temperature, such as approximately -190°C, this may indicate that the temperature sensor 216b is submerged in a medium, such as a coolant (e.g., liquid coolant) or nitrogen, and therefore, that the payload may be in contact with or submerged in the medium. This ensures that the payload is not submerged and / or does not come into contact with the medium that may accumulate at the bottom of the storage chamber 234. One or more temperature sensors 216a, 216b may provide feedback to the controller 230, allowing the controller 230 to determine whether the payload within the storage chamber 234 is in contact with or submerged in the medium, particularly a liquid medium.

[0031] The cryogenic refrigerator 100 may include a coolant level sensor 222. The coolant level sensor 222 may measure or detect the level of the medium within the storage chamber 234. The coolant level sensor 222 may work in conjunction with the temperature sensor 216b to detect the amount or level of the medium accumulated at the bottom of the storage chamber 234 to determine whether the payload is in contact with or submerged in the medium. The coolant level sensor 222 may be coupled to the controller 230 via a connecting tube 224. The connecting tube 224 may be annular in shape. The connecting tube 224 may have an outlet 226 at the top 110.

[0032] The cryogenic refrigerator 100 may include a turntable 218. The turntable 218 may be located within the inner wall 202. The turntable 218 may accommodate multiple storage areas. These storage areas may store temperature-sensitive samples, such as biological materials. An actuator 236 may be coupled to the turntable 218. The actuator 236 may rotate, turn, move, or otherwise position the turntable 218. The turntable 218 may have a cylindrical shaft 238 that extends downwardly within the storage chamber 234. The actuator 236 may rotate the cylindrical shaft 238. In some embodiments, the temperature sensors 216a and 216b may be located on the cylindrical shaft 238 of the turntable 218 or elsewhere within the storage chamber 234. The controller 230 may control the actuator 236 to rotate or position the turntable 218 so that when the top 110 is opened, temperature-sensitive samples stored in different storage sections of the turntable 218 can be accessed. The turntable 218 can be accessed through the access opening 108 or by removing the top 110. In addition, by rotating or turning the turntable 218, the cryogenic freezer 100 can circulate air and evenly cool the interior of the storage chamber 234.

[0033] The cryogenic refrigerator 100 may include an outlet 228. This outlet may be a valve. The outlet 228 may be located at the bottom of the storage chamber 234. The outlet 228 may be connected to the controller 230 via a connecting pipe 229. The connecting pipe 229 may have an inlet 231 on the top 110. The outlet 228 may be configured to deliver or disperse a medium, such as a coolant, into the storage chamber 234. The outlet 228 may be in fluid communication with a coolant source 240 or other medium source. The coolant source 240 may be configured to provide a medium, such as a coolant, through the connecting pipe 229 and deliver or disperse the coolant or other medium from the outlet 228 into the storage chamber 234. The delivered coolant may include liquid nitrogen. In some embodiments, the delivered coolant may be a mixture of liquid and gas and / or other medium. The outlet 228 may be directed toward the bottom of the inner wall 202 to promote pulsed coolant diffusion and vaporization, thereby reducing coolant accumulation and enhancing convective heat transfer.

[0034] Figure 3 is a schematic diagram of the external connections of cryogenic refrigerator 100. Controller 230 may be a microprocessor or other electronic programmable device. Controller 230 may have an input port 242 and an output port 244. Temperature sensors 216a, 216b, coolant level sensor 222, and coolant inlet temperature sensor 246 may be in communication with controller 230 and coupled to input port 242. A coolant pulse control valve 248 and a gas bypass valve 250 may be controlled by controller 230 and coupled to output port 244.

[0035] Temperature sensor 216a can measure or detect the temperature within storage chamber 234. Controller 230 can receive the measured or detected temperature via input port 242. Temperature sensor 216a can measure the temperature at or near the hottest point within storage chamber 234. Temperature sensor 216b can measure or detect the temperature of the medium collection portion within storage chamber 234 closest to the bottom of storage chamber 234. Controller 230 can receive the measured or detected temperature via input port 242. Temperature sensor 216b can measure the temperature at or near the lowest point of storage chamber 234. Controller 230 can determine the difference between this temperature and a setpoint temperature. Based on this difference, controller 230 can determine the timing, frequency, and / or duration of pulsing coolant into storage chamber 234. In some embodiments, controller 230 can compare this temperature to a threshold temperature. The threshold value can be stored in local or external memory 254 or on a cloud server. When the temperature falls below the threshold temperature, controller 230 can reduce the timing or frequency of the pulses. When the temperature is above a threshold temperature, the controller 230 may increase the time, frequency, and / or length of the pulses.

[0036] Controller 230 can control the duration or length of the pulse. The pulse duration or length can be controlled based on the desired user operating temperature and the size of storage chamber 234. The pulse duration can be proportional to the size of storage chamber 234 and inversely proportional to the desired user operating temperature. The pulse duration can be limited based on historical control and / or usage data.

[0037] The memory 254 may be coupled to the controller 230 and store instructions executed by the controller 230. The memory 254 may include one or more of a random access memory (RAM), a read-only memory (ROM), a USB storage device, or other volatile or non-volatile memory. The memory 254 may be a non-volatile memory or data storage device, such as a hard drive, a solid-state disk drive, a hybrid disk drive, or other suitable data storage, and may further store machine-readable instructions that may be loaded and executed by the processor 104.

[0038] Temperature sensor 216b and / or coolant level sensor 222 can measure or detect the amount of a medium, such as coolant, within storage chamber 234. Controller 230 can receive the measured or detected coolant amount within storage chamber 234 via input port 242. Based on the measured or detected coolant amount within storage chamber 234, controller 230 can pulse coolant into storage chamber 234 to prevent the coolant from accumulating at the bottom of storage chamber 234 and contacting the payload. Controller 230 can compare the measured or detected coolant amount with a threshold amount. The threshold amount can be stored in local or external memory 254, or on a cloud server. When the measured or detected coolant amount within storage chamber 234 is greater than or equal to the threshold amount, controller 230 can reduce the frequency, duration, and / or length of the pulses. When the measured or detected coolant amount within storage chamber 234 is less than the threshold amount and cooling is required to maintain the temperature below the set point temperature, controller 230 can increase the frequency, duration, and / or length of the pulses.

[0039] The coolant inlet temperature sensor 246 can measure or detect the coolant temperature at the outlet of the coolant source 240 before the coolant enters the inlet 231. The controller 230 can receive the measured or detected coolant inlet temperature via the input port 242. The controller 230 can compare the detected coolant inlet temperature with the temperature of the storage chamber 234. If the coolant inlet temperature is higher than the temperature of the storage chamber 234, the controller 230 can control the gas bypass valve 250 to prevent coolant in the form of gas having a higher temperature than the storage chamber 234 from entering the storage chamber 234 during the cooling cycle. Once the coolant temperature reaches the set point temperature within the storage chamber 234, the controller 230 can control the gas bypass valve 250 to allow the coolant to enter the storage chamber 234.

[0040] The coolant pulse control valve 248 can cause coolant to enter the storage chamber 234 in a pulsed manner to control the temperature within the storage chamber 234. The controller 230 can control the coolant pulse control valve 248 to be open, partially open, or closed. In the open state, the coolant pulse control valve 248 can allow coolant to enter the cryogenic refrigerator 100 through the inlet 231. In the partially open state, the coolant pulse control valve 248 can allow less coolant to enter the cryogenic refrigerator 100 through the inlet 231 than in the open state. In the closed state, the coolant pulse control valve 248 can stop delivering coolant to the cryogenic refrigerator 100. The controller 230 can deliver coolant in a pulsed manner by switching one or more valves to an "ON" or "OPEN" state, and then to an "OFF" or "CLOSED" state, and cycling between the different states for different or equal lengths of time.

[0041] A supply line pressure reducing valve 252 may be located between the coolant source 240 and the coolant pulse control valve 248. The supply line pressure reducing valve 252 may be opened or closed to create a pressure differential between the coolant source 240 and the coolant pulse control valve 248. In the open position, the supply line pressure reducing valve 252 may release pressure to adjust the pressure differential. In the closed position, the supply line pressure reducing valve 252 may maintain the existing pressure. The pressure differential may allow a medium, such as coolant, to travel from the coolant source 240 to the coolant pulse control valve 248. In some embodiments, a pump may be used instead of the supply line pressure reducing valve 252 to pump the coolant from the coolant source 240 to the coolant pulse control valve 248.

[0042] Coolant source 240 may be a tank storing a medium, such as coolant, under pressure. The medium may be a liquid coolant, such as liquid nitrogen. During the process of delivering the coolant through the pipeline to the coolant pulse control valve 248, the coolant may evaporate. When the temperature of the gaseous coolant is higher than the temperature of the storage chamber 234, the controller 230 may control the gas bypass valve 250 to prevent the gaseous coolant, which has a temperature higher than the set point temperature, from entering the storage chamber 234. When the gaseous coolant cools to a temperature equal to or lower than the temperature of the storage chamber 234, the controller 230 may control the gas bypass valve 250 to allow the gaseous coolant or a mixture of liquid and gaseous coolant to enter the storage chamber 234. Allowing the gaseous coolant or the mixture of liquid and gaseous coolant to enter the storage chamber 234 to cool the storage chamber 234 can conserve coolant and improve overall system efficiency.

[0043] The controller 230 may be coupled to a network access device 256. The network access device 256 may include a communication port or channel, such as a dedicated short range communication (DSRC) unit, a Wi-Fi unit, a Bluetooth unit, or a wireless network. The network access device 256 may include one or more of a wireless unit, a radio frequency identification (RFID) tag or reader, or a cellular network unit for accessing a cellular network (e.g., 3G, 4G, or 5G). The network access device 256 may send data to the remote device 258 and receive data from the remote device 258. The remote device 258 may be a fixed or portable computing device, including a smartphone, a laptop, a desktop computer, a tablet computer, etc. For example, the remote device 258 may use the network access device 256 to communicate with the cryogenic freezer 100, such as to monitor and / or control the temperature and / or amount of coolant within the storage chamber 234.

[0044] The controller 230 may be coupled to a user interface 260. The user interface 260 may receive user input, such as a threshold temperature or a threshold coolant amount within the storage chamber 234. The user input may cause the controller 230 to control the frequency or timing of the coolant pulses.

[0045] The user interface 260 may provide notifications to a user or other operator, such as when the amount of coolant in the storage chamber 234 reaches or exceeds a threshold level. The user interface 260 may display statistics, such as the amount of coolant in the storage chamber 234, the frequency, length, or duration of coolant pulses delivered to the dewar 102, and / or other statistics related to filling the dewar 102 with coolant. The user interface 260 may also display alerts, such as the need to increase or decrease the frequency or duration of coolant pulses.

[0046] Figure 4 4 is a flow chart of a process 400 for controlling the temperature within the cryogenic refrigerator 100. One or more computers or one or more data processing devices, such as the controller 230, may execute the process 400. Various components of the cryogenic refrigerator 100, such as the temperature sensors 216a, 216b, the coolant level sensor 222, the outlet valve 228, the coolant source 240, and the coolant pulse control valve 248, may execute the process 400.

[0047] The cryogenic freezer 100 may obtain a set point temperature and / or threshold value for the amount of media (402). The user interface 260 may receive user input indicating a threshold level of media and / or a set point temperature. The set point temperature may indicate a temperature at which cryogenic freezing is insufficient or unable to maintain a cryogenic temperature to preserve the payload within the storage chamber 234. The threshold level of media may indicate an amount of media within the storage chamber that would come into contact with the payload stored in the storage chamber 234. The set point temperature and / or threshold level of media may be user input, preconfigured, predetermined, or otherwise obtained or determined.

[0048] The cryogenic refrigerator 100 may measure or detect the temperature within the storage chamber 234 (404). The cryogenic refrigerator 100 may use temperature sensors 216a and 216b to measure or detect the temperature within the storage chamber 234 of the cryogenic refrigerator 100. The temperature sensor 216a may be located at the top of the cylindrical shaft 238 of the turntable 218, so that the temperature sensor 216a is farthest from the medium accumulated in the storage chamber 234 and cooling the storage chamber 234, and is close to the top 110. When the top plate 114 of the top 110 is opened, ambient air can enter from the top. Therefore, the temperature sensor 216a can be exposed to the storage chamber 234 and measure or detect the highest temperature in the storage chamber 234. The temperature sensor 216b may be located at the bottom of the cylindrical shaft 238 to measure or detect the temperature at or near the medium accumulated in the storage chamber 234. In some embodiments, the controller 230 may calculate an average temperature based on the temperatures measured or detected by one or more temperature sensors 216a and 216b. Temperature can be measured, detected or calculated over a period of time or a time interval.Throughout this specification, different changes in temperature may be referred to herein as "temperature".

[0049] The cryogenic refrigerator 100 may measure or detect the level or amount of the medium within the storage chamber 234 (406). The cryogenic refrigerator 100 may use the coolant level sensor 222 and / or the temperature sensor 216b to measure or detect the level or amount of the medium within the storage chamber 234. For example, the cryogenic refrigerator 100 may detect when the medium contacts the coolant level sensor 222 to determine that the medium has exceeded a certain amount of the medium within the bottom of the storage chamber 234. In another example, when the temperature sensor 216b drops below a threshold temperature, this may indicate that the temperature sensor 216b is in contact with the medium and that the medium has reached a threshold amount at the bottom of the storage chamber 234. The cryogenic refrigerator 100 may use the measured or detected level or amount of the medium and the temperature to control the delivery of the medium to the storage chamber 234, for example, by controlling the position of one or more valves, such as the outlet valve 228, which allow the medium to flow into the storage chamber 234.

[0050] The cryogenic refrigerator 100 may determine whether the temperature is greater than or equal to a set point temperature (408). The set point temperature is the temperature or temperature range that the user desires to maintain in the storage chamber 234. The temperature sensor 216a may be located at the top of the cylindrical shaft 238 of the turntable 218. When the temperature is less than the set point temperature, this may indicate that the temperature within the storage chamber 234 is within a temperature range sufficient to maintain the desired low temperature for the payload within the storage chamber 234. The cryogenic refrigerator 100 may reduce, pause, or stop the delivery of the medium or deliver it in a pulsed manner to maintain the temperature within the storage chamber 234 (410). This may include reducing, pausing, or stopping the delivery of the medium to the storage chamber 234 or delivering it in a pulsed manner to allow the temperature within the storage chamber 234 to remain below the set point temperature without having to deliver too much medium into the storage chamber 234.

[0051] The cryogenic refrigerator 100 may reduce, pause, or stop delivering or pulsing the medium into the storage chamber 234 to prevent the payload from being submerged in the medium accumulated at the bottom of the storage chamber 234. The cryogenic refrigerator 100 may adjust the frequency or time of delivering the medium to the storage chamber 234, such as reducing the frequency or shortening the length of time. The controller 230 may control the cryogenic pulse control valve 248 and / or the outlet valve 228 to open or close at a reduced frequency, or to increase the time interval between openings of the outlet valve 228, and / or to keep the time interval open shorter. Subsequently, the cryogenic refrigerator 100 continues to monitor or detect the temperature within the storage chamber 234 (404).

[0052] Otherwise, when the temperature is greater than or equal to the set point temperature, the cryogenic refrigerator 100 may determine a time and / or frequency at which the medium is delivered to provide additional cooling (412). The time at which the medium is delivered may refer to the length of time for each pulse of the medium delivered, which is the result of one or more valves opening and then closing, and the frequency at which the medium is delivered may refer to the amount of the pulse of the medium delivered per time interval, such as per second or per hour. The initial time and / or initial frequency may be based on the size of the storage chamber 234 and the set point temperature to achieve a steady-state temperature below the set point temperature, which may be configured by the user or calculated by the controller 230. Figure 5 Further described is a process 500 for determining when and / or how often to pulse medium into the storage chamber 234. Pulsing medium into the storage chamber 234 can provide cooling and / or additional cooling to the storage chamber 234 to maintain the temperature below the set point temperature and maintain a target temperature for the payload. In various embodiments, the target temperature is a cryogenic freezing temperature.

[0053] Once the time and / or frequency of pulsing the medium into the storage chamber 234 has been determined, the cryogenic refrigerator 100 may determine whether the amount or level of the medium is greater than or equal to a threshold amount (414). When the amount or level of the medium is greater than or equal to the threshold amount, this may indicate that the payload in the storage chamber 234 is in contact with or submerged under the medium that is present or accumulating at the bottom of the storage chamber 234. When the payload is in contact with or submerged under the medium, the medium may contaminate the payload. And therefore, the cryogenic refrigerator 100 may reduce, pause, or stop the delivery or pulsing of the medium to maintain the temperature within the storage chamber 234 without causing the payload to be in contact with or submerged under the medium, as described above (410).

[0054] Otherwise, when the amount or level of the medium is below the threshold amount, the cryogenic refrigerator 100 may pulse or continue to pulse the medium into the storage chamber 234 to provide cooling or additional cooling within the storage chamber 234 (416). The cryogenic refrigerator 100 may pulse the medium into the storage chamber 234 based on a determined time and / or frequency. When the temperature is greater than or equal to the set point temperature and the amount or level of the medium is below the threshold amount, the cryogenic refrigerator 100 pulses a certain amount of the medium into the storage chamber 234. The medium pulsed in can be a liquid coolant or a mixture of gas and liquid. The controller 230 may control the coolant pulse control valve 248 to deliver the coolant to the outlet valve 228 so that the outlet valve 228 discharges the medium. The controller 230 may control the outlet valve 228 to be fully open or partially open to adjust the rate of coolant entering the storage chamber 234. For example, if the temperature is below the set point temperature, the outlet valve 228 may be partially opened to inject coolant in a pulsed manner at a slower rate. On the other hand, if the temperature is greater than or equal to the set point temperature, the outlet valve 228 may be opened more fully, injecting coolant in pulses at a faster rate. Figure 5 Further described is adjusting the amount of opening or closing of the outlet valve 228 to control the injection of the medium in a pulsed manner. In any case, the cryogenic refrigerator 100 can continue to monitor the temperature and the level or amount of the medium in the storage chamber 234 to maintain the temperature in the storage chamber 234 until the cryogenic refrigerator is deactivated (404).

[0055] Figure 5 1 is a flow chart of a process 500 for determining the timing and / or frequency of pulsing a medium into a storage chamber using the cryogenic refrigerator 100. One or more computers or one or more data processing devices, such as the controller 230, may execute the process 500. Various components of the cryogenic refrigerator 100, such as the temperature sensors 216a, 216b, the outlet valve 228, the coolant source 240, and / or the coolant pulse control valve 248, may execute the process 500.

[0056] Once the temperature within the storage chamber 234 is determined or detected, and the amount of medium is less than a threshold amount, the cryogenic refrigerator 100 may determine a difference between the temperature within the storage chamber 234 and the set point temperature (502). The difference may measure the magnitude of the excess over a target temperature range to maintain the payload within the storage chamber 234. The target temperature range may be a low-temperature temperature range. The difference may be associated with or correspond to an amount of additional cooling required to reduce the temperature below the set point temperature. For example, the greater the difference, the more additional cooling is required to cool the storage chamber 234 below the set point temperature.

[0057] After determining the difference between the temperatures within the storage chambers, the cryogenic refrigerator 100 may determine, based on the difference, when or how often to pulse a quantity of coolant into the storage chamber 234 (504). The time or frequency may be measured in pulses per hour, pulses per minute, or pulses per second. The time or frequency may be directly proportional to the difference between the temperature and the set point temperature, where the set point temperature is lower than the temperature. As the difference between the temperature and the set point temperature increases, the frequency may increase, and / or the time interval during which the pulses are "ON" may increase, for example, when the outlet valve 228 is open or partially open and discharging the medium into the storage chamber 234. And as the difference between the temperature and the set point temperature decreases, the frequency may decrease, and / or the time interval during which the pulses are "ON" may decrease.

[0058] The cryogenic refrigerator 100 may inject a certain amount of coolant (506) into the storage chamber 234 in a pulsed manner based on time or frequency. The pulsed coolant may be a liquid or a mixture of gas and liquid. The controller 230 may control the coolant pulse control valve 248 to deliver the coolant to the outlet valve 228 so that the outlet valve 228 discharges the coolant at a determined time or frequency. The controller 230 may cause the actuator to open or close the coolant pulse control valve 248 and / or the outlet valve 228 to form a pulse of medium flowing into or discharged into the storage chamber 234. The controller 230 opens the coolant pulse control valve 248 and / or the outlet valve 228 to turn the medium pulse "ON" and closes the coolant pulse control valve 248 and / or the outlet valve 228 to turn the medium pulse "OFF". The amount by which the coolant pulse control valve 248 and / or the outlet valve 228 are opened controls the flow of medium into the storage chamber 234, while the length of time the coolant pulse control valve 248 and / or the outlet valve 228 are open controls the time interval or length of the medium pulses. The controller controls the frequency and timing by cycling the coolant pulse control valve 248 and / or the outlet valve 228 between open, partially open, and / or closed positions, which creates an "on" and "off" effect of pulsing the medium into the storage chamber 234 and controls the amount of coolant and / or medium that accumulates at the bottom of the storage chamber 234 before evaporation.

[0059] The exemplary embodiments of the method / system have been disclosed in an illustrative manner. Therefore, the terms used throughout this document should be interpreted in a non-restrictive manner. Although those skilled in the art may make minor modifications to the teachings herein, it should be understood that it is intended that all such embodiments be within the scope of this granted patent that reasonably fall within the scope of this contribution to the advancement of the art, and the scope of the present invention should not be limited except in accordance with the appended claims and their equivalents.

Claims

1. A freezer comprising: outer container; an inner container positioned within the outer container and defining a storage chamber; a first sensor configured to measure a temperature within the storage chamber; as well as a controller coupled to the first sensor and configured to: A certain amount of medium is pulsed into the storage container to control the temperature in the storage container.

2. The refrigerator according to claim 1, wherein Also includes: A carousel is positioned within the inner container and is configured to hold a plurality of storage areas, wherein the first sensor is positioned adjacent the carousel.

3. The refrigerator according to claim 2, wherein: Also includes: A second sensor is positioned at the bottom of the turntable and is configured to detect or measure an amount of media within the storage chamber, wherein the controller is configured to pulse an amount of media into the storage chamber further based on the detected or measured amount of media within the storage chamber.

4. The refrigerator according to claim 3, wherein In order to make a certain amount of medium enter the storage chamber in a pulsed manner, the controller is configured as follows: When the detected or measured amount of the medium in the storage chamber is greater than or equal to a threshold amount, or when the temperature is lower than a threshold temperature, reducing the frequency or duration of the pulses; as well as When the detected or measured amount of the medium in the storage chamber is less than the threshold amount and when the temperature is higher than the threshold temperature, the frequency or the time of the pulses is increased.

5. The refrigerator according to claim 1, wherein Also includes: an outlet positioned at a bottom of the storage chamber and configured to deliver or dispense a medium into the storage chamber; as well as A medium source is in fluid communication with the outlet and is configured to provide a medium through one or more conduits and out of the outlet to deliver or disperse the medium into the storage chamber.

6. The refrigerator according to claim 5, wherein The controller is connected to the medium source and the outlet to allow a certain amount of medium to enter the storage container in a pulsed manner, and the controller is configured to: adjusting the position of the outlet valve to open, partially open, or close the outlet; or The medium source is controlled to provide the medium to the outlet valve through the outlet valve.

7. The refrigerator according to claim 5, wherein The medium source is a storage container including a medium supply, and the medium is a cryogenic refrigerant including liquid nitrogen, wherein the liquid nitrogen is pressurized for transfer to the outlet.

8. The refrigerator according to claim 1, wherein The controller is constructed as follows: A time or a frequency for pulsing a quantity of medium into the storage container is determined, wherein the controller is configured to pulse the quantity of medium into the storage container based on the time or the frequency.

9. The refrigerator according to claim 8, wherein The controller is constructed as follows: determining a difference between the temperature within the storage container and a set point temperature; as well as The time or the frequency for injecting a certain amount of medium into the storage container in a pulsed manner is determined based on the difference.

10. A refrigerator using a coolant as a refrigerant, comprising: an inner container defining a storage chamber; an outer container surrounding the inner container and defining a vacuum insulation space between the outer container and the inner container; a temperature sensor configured to measure a temperature within the storage chamber; as well as A controller is coupled to the temperature sensor and configured to: A certain amount of coolant is pulsed into the storage container to control the temperature within the storage container.

11. The refrigerator according to claim 10, wherein Also includes: A turntable is positioned within the inner container and is configured to hold a plurality of storage areas, wherein the temperature sensor is positioned adjacent to the turntable.

12. The refrigerator according to claim 11, wherein Also includes: A coolant level sensor is configured to detect or measure an amount of the coolant in the storage chamber, wherein the controller is configured to pulse an amount of coolant into the storage chamber further based on the amount of coolant detected or measured in the storage chamber.

13. The refrigerator according to claim 12, wherein: In order to allow a certain amount of coolant to enter the storage chamber in a pulsed manner, the controller is configured as follows: reducing the frequency or duration of the pulses when the detected or measured amount of the coolant within the storage chamber is greater than or equal to a threshold amount, or when the temperature is below a threshold temperature; as well as When the detected or measured amount of the coolant in the storage chamber is less than the threshold amount, or when the temperature is higher than the threshold temperature, the frequency or the time of the pulses is increased.

14. The refrigerator according to claim 10, wherein Also includes: an outlet configured to deliver or disperse coolant into the storage chamber; as well as A coolant source is in fluid communication with the outlet and is configured to provide the coolant through one or more conduits and exit from the outlet for delivery or dispersion into the storage chamber.

15. The refrigerator according to claim 14, wherein The controller is coupled to the coolant source and the outlet to allow a certain amount of coolant to enter the storage container in a pulsed manner, and the controller is configured to: adjusting the position of the outlet valve to open, partially open, or close the outlet; or The coolant source is controlled to provide the coolant through the outlet to the outlet.

16. The refrigerator according to claim 14, wherein The cryogen source is a storage container containing a supply of the cryogen, the cryogen comprising liquid nitrogen, wherein the liquid nitrogen is pressurized to facilitate transfer to the outlet.

17. A method of controlling the temperature in a cryogenic refrigerator, comprising: measuring or detecting, by a processor and using a temperature sensor, a temperature within a storage chamber of the cryogenic freezer; determining, by the processor, whether the temperature is greater than or equal to a set point temperature; as well as When the temperature is greater than or equal to the set point temperature, a quantity of coolant is pulsed into the storage chamber through the processor using an outlet and a coolant source.

18. The method according to claim 17, wherein include: measuring or detecting, by the processor and using a coolant level sensor, an amount of coolant in the storage chamber; as well as An amount of coolant is pulsed into the storage chamber through the processor using the outlet and the coolant source based on the amount of coolant in the storage chamber.

19. The method according to claim 18, characterized in that The step of pulsing a quantity of coolant into the storage chamber comprises: When the detected or measured amount of coolant within the storage chamber is greater than or equal to a threshold amount, or when the temperature is less than a threshold temperature, reducing the frequency or duration of the pulses; and When the detected or measured amount of coolant within the storage chamber is less than the threshold amount, or when the temperature is greater than the threshold temperature, the frequency or the time of the pulses is increased.

20. The method of claim 17, wherein: include: determining a difference between the temperature within the storage chamber and the set point temperature; determining a frequency or a time for pulsing a quantity of coolant into the storage chamber based on the difference; and Based on the time or the frequency, a certain amount of coolant is pulsed into the storage chamber.

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