Cryogenic storage system

Abstract

An embodiment of a cryogenic storage system includes a housing further including a chamber having a front opening closable by an outer door and a rear wall opposite the front opening, one or more outlets defined in the rear wall, and one or more inlets defined in the chamber closer to the front opening than the rear wall. In addition, the cryogenic storage system includes a refrigeration module operably coupled to the chamber. The refrigeration module includes an evaporator positioned vertically higher than the chamber, a blower configured to generate an airflow in thermal communication with the evaporator, and a piping configured to circulate the airflow between the chamber and the evaporator via an inlet and an outlet such that the airflow is directed through the outlet into the chamber, then from the chamber into the inlet to cool the chamber.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to U.S. Application Serial No. 18 / 585,725 (Agency Docket No. T11063910940US.1(0455.2) entitled "COMPRESSOR CONTROL PROCESS FOR VARIABLE CASCADE REFRIGERATION SYSTEM" and naming Thomas A. Schoeppner, Alex Roberts, and Trace A. Lydick as inventors and Trane Technologies Life Sciences LLC as applicant) and U.S. Application Serial No. 18 / 585,642 (Agency Docket No. T11063910930US.1(0454.4) entitled "DEFROST FAN CONTROL" and naming Thomas A. Schoeppner, Alex Roberts, Trace A. Lydick, and M.J. Donnelly as applicants. J. Donnelly is named as the inventor, and Trane Technologies Life Sciences LLC is named as the applicant. Each of these applications was filed on the same day as the present application, and the entire contents of these applications are incorporated herein by reference. Technical Field The present disclosure generally relates to a cryogenic storage system. Background Art

[0002] Cryogenic storage systems, such as refrigerators and freezers, can be used to store goods or other materials at temperatures below ambient conditions. For life science products and materials, such as vaccines, biological specimens, and other related materials, cryogenic storage systems are crucial for maintaining the required environmental parameters (such as temperature and relative humidity) to avoid degradation or damage.

[0003] Cryogenic storage systems can achieve temperatures within their internal storage chambers that are significantly lower than the surrounding ambient temperature. For example, some cryogenic storage systems may be designed to achieve and maintain so-called "ultra-low" temperatures. Consequently, the features and components of such cryogenic storage systems require careful design to ensure optimal performance and operating efficiency at such low temperatures. Summary of the Invention

[0004] Some embodiments disclosed herein relate to a cryogenic storage system. In some embodiments, the cryogenic storage system includes a housing, the housing further comprising: a chamber having a front opening closable by an outer door and a rear wall opposite the front opening, one or more outlets defined in the rear wall, and one or more inlets defined in the chamber closer to the front opening than the rear wall. In addition, the cryogenic storage system includes a refrigeration module operably coupled to the chamber. The refrigeration module includes an evaporator vertically positioned higher than the chamber, a blower configured to generate an airflow in thermal communication with the evaporator, and a duct system configured to circulate an airflow between the chamber and the evaporator via one or more inlets and one or more outlets, so that the airflow is guided into the chamber through the one or more outlets and then into the inlet from the chamber to cool the chamber.

[0005] Some embodiments disclosed herein relate to a method. In some embodiments, the method includes (a) generating an airflow with a blower of a refrigeration module, the refrigeration module being operably coupled to a chamber of a cryogenic storage system. In addition, the method includes (b) cooling the airflow with an evaporator of the refrigeration module, the evaporator being vertically positioned above the chamber. In addition, the method includes (c) directing the airflow into the chamber through one or more outlets positioned along a rear wall of the chamber and then exiting the chamber through one or more inlets defined in the chamber to cool the chamber, the rear wall being opposite a front opening of the chamber, and the one or more inlets being positioned closer to the front opening than the rear wall.

[0006] Some embodiments disclosed herein relate to a cryogenic storage system. In some embodiments, the cryogenic storage system includes a housing, the housing further comprising a chamber having a front opening. Furthermore, the housing includes a door frame extending around the front opening, the door frame further comprising: a first door stop defining a first sealing surface; and a second door stop defining a second sealing surface adjacent to the first sealing surface along an edge of the front opening. The second door stop is parallel to and discontinuous with the first door stop, such that the first and second door stops are configured to thermally contract independently of each other. Furthermore, the cryogenic storage system includes a refrigeration module configured to generate airflow through the chamber to reduce the temperature of the chamber to below -50°C. Furthermore, the cryogenic storage system includes an outer door configured to selectively close the front opening. The outer door has a door seal comprising a plurality of sealing projections configured to engage with the door frame, such that a first portion of the sealing projections is configured to engage the first door stop, and a second portion of the sealing projections is configured to engage the second door stop.

[0007] Some embodiments disclosed herein relate to a method. In some embodiments, the method includes (a) engaging a first sealing surface of a first door stop of a door frame extending at least partially around a front opening of a chamber of a low-temperature storage system with a first portion of a plurality of sealing protrusions of a door seal connected to an outer door. In addition, the method includes (b) engaging a second sealing surface of a second door stop of the door frame with a second portion of a plurality of sealing protrusions of the door seal, the second door stop being parallel to and adjacent to the first door stop along an edge of the front opening, the second door stop being discontinuous with the first door stop, such that the first door stop and the second door stop are configured to thermally shrink independently of each other. In addition, the method also includes (c) directing an airflow from a refrigeration module through the chamber to cool the chamber to below -50°C.

[0008] Some embodiments disclosed herein relate to a cryogenic storage system. In some embodiments, the cryogenic storage system includes a housing, the housing further comprising: a chamber having a front opening closable by an outer door and a rear wall opposite the front opening; one or more outlets defined in the rear wall; and an intake duct positioned in an upper portion of the chamber, the intake duct having one or more openings defined therein, the intake duct being at least partially formed by a tray that is removably inserted into the chamber from the front opening. In addition, the cryogenic storage system includes a refrigeration module operably coupled to the chamber, the refrigeration module being configured to generate an airflow that is directed from the one or more outlets into the chamber and then from the chamber into the one or more inlets of the intake duct to cool the chamber to below -50°C.

[0009] Some embodiments disclosed herein relate to a method. In some embodiments, the method includes (a) inserting a tray into an upper portion of a chamber of a cryogenic storage system to at least partially define an intake duct in the chamber. The tray has one or more inlets defined therein, which are configured to connect the chamber to the intake duct fluid, and the chamber includes a rear wall having one or more outlets defined therein. In addition, the method includes (b) operably connecting a refrigeration module to the chamber. The refrigeration module has a blower and an evaporator, arranged so that the blower is configured to generate an airflow from the evaporator and into the chamber via one or more outlets, and then from the chamber via one or more inlets to the intake duct to cool the chamber to below -50°C.

[0010] The embodiments described herein include combinations of features and characteristics that are intended to address various shortcomings associated with some existing devices, systems, and methods. The foregoing provides a fairly broad overview of the features and technical features of the disclosed embodiments in order to better understand the following specific embodiments. After reading the following specific embodiments and referring to the accompanying drawings, the various characteristics and features described above, as well as other features, will be apparent to those skilled in the art. It should be understood that the present disclosure can be easily used as a basis for modifying or designing other structures to achieve the same purpose as the disclosed embodiments. It should also be recognized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a detailed description of various embodiments, reference will now be made to the accompanying drawings, in which:

[0012] Figure 1 is a perspective view of a cryogenic storage system according to some embodiments disclosed herein.

[0013] Figure 2 According to some embodiments disclosed herein Figure 1 Another perspective view of a cryogenic storage system showing an exterior door opened to reveal an interior storage chamber therein.

[0014] Figure 3 According to some embodiments disclosed herein Figure 2 Front view of the cryogenic storage system.

[0015] Figure 4 According to some embodiments disclosed herein Figure 1 Schematic diagram of the climate control components of a cryogenic storage system.

[0016] Figure 5 According to some embodiments disclosed herein Figure 1 An enlarged partial side cross-sectional view of a cryogenic storage system illustrating airflow between an internal storage chamber and an evaporator.

[0017] Figure 6 According to some embodiments disclosed herein Figure 1 An enlarged perspective view of the internal storage chamber of a cryogenic storage system.

[0018] Figure 7 According to some embodiments disclosed herein Figure 1 Another enlarged perspective view of the internal storage chamber of the cryogenic storage system.

[0019] Figure 8 According to some embodiments disclosed herein Figure 1 An enlarged partial side cross-sectional view of a portion of a suction piping of a cryogenic storage system.

[0020] Figure 9 According to some embodiments disclosed herein Figure 1 An enlarged perspective view of an interior storage chamber of a cryogenic storage system showing a tray pulled out of the interior storage chamber, the tray at least partially defining Figure 8 suction pipe.

[0021] Figure 10 According to some embodiments disclosed herein Figure 9 A perspective view of a portion of a tray.

[0022] Figure 11 According to some embodiments disclosed herein, a temperature sensor is maintained at Figure 9 A perspective view of a bracket on a tray;

[0023] Figure 12 According to some embodiments disclosed herein Figure 1 An enlarged perspective view of a portion of a door frame of a low-temperature storage system;

[0024] Figure 13 According to some embodiments disclosed herein Figure 1 an enlarged perspective view of a portion of a door seal on an outer door of a cryogenic storage system;

[0025] Figure 14 According to some embodiments disclosed herein Figure 12 Door frame and Figure 13 The door seals engage each other to seal Figure 1 A side sectional view of an internal storage chamber of a cryogenic storage system;

[0026] Figure 15 According to some embodiments disclosed herein Figure 12 An exploded view of a portion of a door frame;

[0027] Figure 16 According to some embodiments disclosed herein, Figure 1 a top perspective view of a shelf within an interior storage chamber of a low-temperature storage chamber;

[0028] Figure 17 According to some embodiments disclosed herein Figure 16 A bottom perspective view of a shelf;

[0029] Figure 18 According to some embodiments disclosed herein Figure 1 An enlarged perspective view of a shelf support assembly within an interior storage chamber of a cryogenic storage system;

[0030] Figure 19 FIG. 1 is a diagram showing the connection between the bracket and the Figure 18 an enlarged cross-sectional view of the engagement between the support rails of the shelf support assembly;

[0031] Figure 20 According to some embodiments disclosed herein, Figure 18 a front view of one of the shelves on the shelf support assembly;

[0032] Figure 21 and 22 According to some embodiments disclosed herein Figure 20 An enlarged cross-sectional view of a shelf supported on Figure 18 on one of the brackets of the shelf support assembly;

[0033] Figure 23 According to some embodiments disclosed herein Figure 4 a perspective view of an interstage heat exchanger of a climate control assembly;

[0034] Figure 24 According to some embodiments disclosed herein Figure 1 a front view of a user interface of a cryogenic storage system; and

[0035] Figure 25 According to some embodiments disclosed herein Figure 24 A perspective view of the user interface. DETAILED DESCRIPTION

[0036] Cryogenic storage systems can be used to store degradable materials, such as life science products and materials. Some cryogenic storage systems are designed to achieve and maintain temperatures of -20°C, -50°C, -70°C, or below, and in some cases, -80°C. However, achieving and maintaining such low temperatures within a chamber surrounded by ambient, traditional room temperature conditions can require careful design to ensure reliable and efficient operation.

[0037] Therefore, embodiments disclosed herein relate to cryogenic storage systems that utilize forced air convection in an internal chamber to achieve and maintain low temperatures (e.g., ultra-low temperatures) for products stored therein. In some embodiments, the cryogenic storage system can utilize forced convection via a refrigerated air flow through the chamber to achieve and / or maintain the desired temperature therein. In some embodiments, the refrigeration system of the cryogenic storage system can be constructed and positioned to control and utilize the upward flow of natural heat convection in the chamber to achieve improved operating efficiency. In some embodiments, the cryogenic storage system may include enhanced door seals that are configured to withstand extreme temperature differences between the interior of the cold chamber and the surrounding environment, thereby further improving performance and operating efficiency. In some embodiments, the cryogenic storage system may include alternative or additional features that can further improve its reliability, performance, and / or efficiency during operation. Therefore, by using embodiments disclosed herein, the cryogenic storage system can more consistently and reliably achieve and maintain the desired temperature of the stored products, which is particularly important for degradable materials such as life science products.

[0038] Now refer to Figure 1-3 , shows a cryogenic storage system 10 according to some embodiments. The cryogenic storage system 10 can be configured to store degradable products (such as life science products and materials) at a temperature below the freezing point of water (e.g., 0°C or 32°F) or lower (e.g., below -20°C, below -40°C, below -70°C, below -80°C, etc.). Therefore, the cryogenic storage system 10 may be more simply referred to as a "freezer" herein. In some embodiments, the freezer can be configured to store products at ultra-low temperatures below -50°C. However, it should be understood that other embodiments of the cryogenic storage system 10 can be configured to store products at temperatures above the freezing point of water.

[0039] Generally speaking, the cryogenic storage system 10 includes a housing 15 that defines one or more internal storage chambers 12 (or more simply, "chambers" or "chambers") therein. The housing 15 can be relatively compact, so that the cryogenic storage system 10 can be transportable or relatively portable. Thus, the cryogenic storage system 12 can be easily moved or transported between rooms in a facility or between completely different facilities.

[0040] exist Figure 2 and Figure 3 In the embodiment shown in FIG, the housing 15 includes a separate chamber 12 accessible via an outer door 14. Specifically, the chamber 12 may include a front opening 13 that is closable by the outer door 14 during operation. Thus, the chamber 12 is at least partially defined by the outer door 14. When the door 14 is closed, the front opening 13 is blocked or covered. Figure 1), the chamber 12 is isolated from the surrounding environment 5 or is substantially closed, when the door 14 is opened ( Figure 2 and Figure 3 ), the chamber 12 is exposed to the surrounding environment 5 via the front opening 13. In some embodiments, the cryogenic storage system 10 can define a plurality of separate chambers 12, which can be accessed via an outer door 14 or multiple outer doors 14.

[0041] like Figure 2 and Figure 3 As shown in FIG, the chamber 12 can have one or more (e.g., a plurality) of inner doors 17 positioned therein that are configured to at least partially close the front opening 13 independently of the outer door 14. The one or more inner doors 17 can provide an additional barrier (i.e., in addition to the outer door 14) to minimize air exchange between the chamber 12 and the surrounding environment 5 when the outer door 14 is open. The number and arrangement of the inner doors 17 can correspond to the shelves or other tissue support structures (e.g., shelf 210) inserted into the chamber 12 so that a user can open the inner door 17 associated with a specific storage location (e.g., a specific shelf 210).

[0042] In addition, the cryogenic storage system 10 includes a climate control assembly or system 100 operably coupled to the chamber 12. Specifically, the chamber 12 can be conditioned by a separate climate control assembly 100 that is configured to achieve and / or maintain a desired temperature (or temperature range) within the chamber 12 during operation. The climate control assembly 100 can include a vapor compression refrigeration system or module (or more simply, a "refrigeration module") that circulates one or more refrigerants to exchange heat between the chamber 12 and the environment 5 during operation. In some embodiments, the climate control assembly 100 can include a cascade refrigeration module having multiple staged refrigerant circuits that are in thermal communication with each other and configured to achieve and / or maintain a low temperature within the chamber 12 during operation. Accordingly, the climate control assembly 100 may be referred to herein as a "refrigeration module" 100.

[0043] The housing 15 can define or include a first portion or upper portion 18 and a second portion or lower portion 16, with the second portion or lower portion 16 being positioned vertically below and lower than the upper portion 18. The refrigeration module 100 can generally define the upper portion 18, and the chamber 12 can generally define the lower portion 16. Thus, the refrigeration module 100 (or at least a majority thereof) can be positioned vertically above the chamber 12, or even vertically above the chamber 12. In some embodiments, the refrigeration module 100 (and / or at least a portion of the upper portion 18) can be easily removed and replaced on the lower portion 16 of the housing 15 (e.g., to facilitate replacement of the refrigeration module 100 in the event of a failure). According to some embodiments, additional features of the chamber 12 and the refrigeration module 100 are provided herein.

[0044] Furthermore, in some embodiments, the position of the refrigeration module 100 relative to the chamber 12 and the lower portion 16 of the housing 15 can vary. For example, in some embodiments, the refrigeration module 100 (or a portion thereof) can be positioned along a lateral side or back of the lower portion 16 of the housing 15, or possibly even along the bottom side of the lower portion 16 of the housing 15.

[0045] The freezer 10 can operate using electricity supplied from a line power source (e.g., a local power grid). In addition, the freezer 10 can include (or be coupled to) one or more backup batteries, capacitors, generators, and the like (collectively, "backup power sources," not shown) to ensure that the freezer 10 (or one or more components or subsystems thereof) remains operational when the line power source fails. In some embodiments, the one or more backup power sources can operate one or more sensors (e.g., temperature sensor 128) and a user interface (e.g., user interface 300 described herein) of the freezer 10, but the remainder of the freezer 10 may become inoperable when the line power source loses power or fails.

[0046] Figure 4 A schematic diagram of a refrigeration module 100 of a freezer 10 according to some embodiments is shown. As previously described, in some embodiments, the refrigeration module 100 is configured to circulate a refrigerant (or refrigerants) to cool the chamber 12 during operation. Specifically, the climate control assembly 100 can include a so-called cascade refrigeration assembly that includes a plurality of separate, staged refrigerant circuits 113, 121 that are thermally coupled to one another for transferring heat between the chamber 12 and the ambient environment 5. In some embodiments, the refrigeration module 100 can be configured to achieve and / or maintain low temperatures (e.g., "ultra-low" temperatures as previously described) in the chamber 12.

[0047] like Figure 4As shown in FIG, the refrigeration module 100 may include a first refrigeration stage 102 (or more simply referred to as "first stage" 102) having a first refrigerant circuit 113 circulating a first refrigerant and a second refrigeration stage 104 (or more simply referred to as "second stage" 104) having a second refrigerant circuit 121 circulating a second refrigerant. The first refrigerant and the second refrigerant may include any suitable refrigerant or combination of refrigerants, such as one or more chlorofluorocarbons, hydrochlorofluorocarbons, hydrocarbons, ammonia, and the like. The first refrigerant and the second refrigerant may be selected such that, at operating pressures of the first refrigerant circuit 113 and the second refrigerant circuit 121, the saturated condensing temperature range of the second refrigerant (in the second refrigerant circuit 121) overlaps with the saturated evaporating temperature of the first refrigerant (in the first refrigerant circuit 113) in an interstage heat exchanger (e.g., the interstage heat exchanger 114 described herein), such that each of the first refrigerant and the second refrigerant may experience a change in enthalpy when thermally interacting with each other during operation (e.g., via the interstage heat exchanger 114 described herein).

[0048] Generally speaking, during operation, the refrigeration module 100 can circulate a first refrigerant and a second refrigerant through the first refrigerant circuit 113 and the second refrigerant circuit 121, respectively, to transfer heat from the chamber 12 to the ambient environment 5. Heat can be transferred between the first refrigerant and the second refrigerant via the interstage heat exchanger 114, which is coupled to and part of each of the first refrigerant circuit 113 and the second refrigerant circuit 121.

[0049] More specifically, the first refrigerant circuit 113 can circulate the first refrigerant between the first-stage compressor 112 (or more simply referred to as "compressor" 112), the condenser 110, the first-stage expansion valve 116 (or more simply referred to as "expansion valve" or "valve" 116), and the interstage heat exchanger 114 to transfer heat from the second refrigerant circuit 121 to the ambient environment 5. Specifically, the compressor 112 can compress the first refrigerant and output the compressed first refrigerant to the condenser 110. Due to the heat exchange within the interstage heat exchanger 114, the first refrigerant flowing to and through the compressor 112 may be in (or substantially in) a vapor state. The condenser 110 may include a heat exchanger (or a collection of heat exchangers) configured to cool the first refrigerant by transferring heat from the first refrigerant to the ambient environment 5 via convection, radiation, and / or any other suitable heat transfer mode. For example, in Figure 4In the embodiment shown in FIG, a blower or fan 118 can generate an airflow 117 that is in thermal contact with the first refrigerant via the condenser 110, such that during operation, the first refrigerant transfers heat to the airflow 117 and cools, thereby condensing or partially condensing the vapor into a liquid. The heated airflow 117 can flow outward and away from the condenser 110 and into the ambient environment 5. For example, in some embodiments, as Figure 1 and Figure 2 , airflow 117 can at least partially exit housing 15 from vents 119 positioned on a top or upper surface of housing 15 (e.g., along a top or upper surface of upper portion 18 of housing 15). In some embodiments, condenser 110 can transfer heat from the first refrigerant to ambient environment 5 via natural convection and / or radiation, in addition to or in lieu of forced convection via airflow 117. Thus, in some embodiments, fan 118 can be omitted.

[0050] Liquid (or at least partially liquid) first refrigerant may be discharged from condenser 110 and then expanded through expansion valve 116 to at least partially evaporate and further cool the first refrigerant. Thereafter, the cooled first refrigerant flows into interstage heat exchanger 114.

[0051] In the interstage heat exchanger 114, heat is transferred from the second refrigerant flowing through the second refrigerant circuit 121 to the first refrigerant, causing the first refrigerant to change phase (or substantially change phase) from liquid to vapor in the interstage heat exchanger 114. Therefore, the interstage heat exchanger 114 can serve as an evaporator for the first refrigerant in the first refrigerant circuit 113. The heated and vaporized (or partially vaporized) first refrigerant is then discharged from the interstage heat exchanger 114 and flows back to the first stage compressor 112 to restart the above cycle. According to the refrigeration module 100 ( Figure 22 ), further details of the interstage heat exchanger 114 are described herein for at least some embodiments of the present invention.

[0052] Still refer to Figure 4The second refrigerant circuit 121 can circulate the second refrigerant between the second-stage compressor 120 (or more simply referred to as "compressor" 120), the interstage heat exchanger 114, the second-stage expansion valve 122 (or more simply referred to as "expansion valve" or "valve" 122), and the evaporator 124 to transfer heat from the chamber 12 to the first refrigerant circuit 113. Specifically, the compressor 120 can compress the second refrigerant and output the compressed second refrigerant to the interstage heat exchanger 114. Due to the heat exchange within the evaporator 124, the second refrigerant flowing to the compressor 120 and through the compressor 112 may be in (or substantially in) a vapor state. Within the interstage heat exchanger 114, heat can be transferred from the second refrigerant to the first refrigerant as described above. As a result, within the interstage heat exchanger 114, the second refrigerant can be cooled, condensing or partially condensing from a vapor to a liquid. Therefore, the interstage heat exchanger 114 can serve as a condenser for the second refrigerant in the first refrigerant circuit 121.

[0053] Liquid (or at least partially liquid) second refrigerant may be discharged from interstage heat exchanger 114 and then expanded through expansion valve 122 to at least partially vaporize and further cool the second refrigerant. Thereafter, the cooled second refrigerant flows into evaporator 124.

[0054] The evaporator 124 is a heat exchanger configured to transfer heat from the chamber 12 to the second refrigerant. Specifically, the cooled second refrigerant flows through a coil 126, which is thermally exposed to the airflow 50 in the evaporator 124 (e.g., such that the airflow 50 is in thermal communication with the evaporator 124), thereby transferring heat from the airflow 50 to the second refrigerant, thereby causing the second refrigerant to undergo a phase change (or a substantial phase change) from a liquid to a vapor. The airflow 50 can be generated by a blower or fan 36 in fluid communication with the ductwork 30, which is configured to direct the airflow 50 between the chamber 12 and the evaporator 124 during operation. Specifically, the ductwork 30 includes a suction duct 32 configured to direct the airflow 50 from the chamber 12 to the evaporator 124, and a discharge duct 34 configured to direct the airflow 50 from the evaporator 124 to the chamber 12. The blower 36 may be located along or adjacent to the discharge duct 34 ; however, other locations for the blower 36 (eg, in the intake duct, in the chamber 12 , etc.) are also contemplated herein.

[0055] Still refer to Figure 4During operation, the refrigeration module 100 can significantly reduce the temperature in the chamber 12. As previously described, the refrigeration module 100 can be configured to achieve and / or maintain ultra-low temperatures (e.g., below -50°C) in the chamber 12 while the ambient environment 5 remains at normal room conditions (e.g., in some examples, a temperature within the range of approximately 18-24°C (approximately 65-75°F) and a relative humidity level within the range of approximately 30-60%). In some embodiments, the ambient environment 5 can include a temperature below normal room conditions (e.g., below 18°C ​​or 65°F), but may still be higher than the temperature in the chamber 12. Air at a higher temperature than the chamber 12 may also include a greater relative humidity value than that in the chamber 12. Thus, when the exterior door 14 is opened, relatively warm and humid air from the ambient environment 5 may flow into the generally cooler chamber 12 and ultimately form ice therein. Of particular note, the airflow 50 circulating between the evaporator 124 and the chamber 12 may cause ice to form on the coils 126 of the evaporator 124, which may reduce the heat transfer function of the evaporator 124. Therefore, the refrigeration module 100 may periodically perform a defrost operation to remove ice accumulated on the coils 126. The defrost operation may include a so-called "hot gas bypass" and / or a separate supplemental heat source.

[0056] For example, in some embodiments, the refrigeration module 100 can utilize a hot gas bypass to defrost the evaporator 124 during operation. Specifically, the second refrigerant circuit 121 can include a bypass line 123 configured to recirculate compressed second refrigerant discharged from the compressor 120 back to the evaporator 124 in a bypass of the interstage heat exchanger 114 and the expansion valve 122. Specifically, a valve 127 can be positioned along the defrost bypass line 123 to control the flow of the second refrigerant along the line. During defrost operation, the expansion valve 122 can be closed to prevent (or at least limit) the flow of the second refrigerant from the interstage heat exchanger 114 to the evaporator 124, and the valve 127 can be opened to initiate the flow of compressed and relatively warm second refrigerant from the compressor 120 back to the evaporator 124, thereby melting ice accumulated on the coil 126.

[0057] In some embodiments, the refrigeration module 100 can defrost the coil 126 of the evaporator 124 via other methods. For example, a separate supplemental heat source (e.g., a resistive heating element) can be positioned near the coil 126 to melt accumulated ice. In some embodiments, the separate heat source can include a heat-generating component (e.g., a resistive heater or other suitable heating device or component) positioned outside the housing 150 (e.g., attached to an outer surface of the housing 15), with the supplemental heat being transferred to the coil 126 via a conductive medium (e.g., a heat pipe, a steam chamber, etc.). Thus, in some embodiments, the defrost bypass line 123 can be omitted from the second refrigerant circuit 121. In other embodiments, particularly where a separate refrigeration circuit is used, the circuit can be provided with a three-way switching valve to allow the refrigerant flow direction to be reversed, thereby causing the evaporator 124 to function as a condenser.

[0058] Performing a defrost operation may also require adding an additional heat source to the system, thereby causing the air surrounding the evaporator to warm. For example, it is important to allow ice melted from the evaporator 124 to be collected and drained from the refrigeration assembly 100 before refreezing. Therefore, in some embodiments, the heater 129 (e.g., a resistive heater) may be configured to heat a drain pan 131 (see FIG. 1 ) positioned at least partially below the evaporator 124. Figure 5 ) to prevent the melt water from refreezing while being drained from the system. The heater 129 can be coupled to or integrated with the drain pan 131. Due to the operation of the heater 129, heat can be added to the air around the coil 126.

[0059] The controller 40 may be communicatively coupled (via any suitable wired and / or wireless connection) to various components of the refrigeration module 100 (e.g., compressors 112, 120, condenser 110, expansion valves 116, 122, valve 127, etc.). As described in more detail herein, the controller 40 may at least partially direct or control the operation of the refrigeration module 100 during operation. The controller 40 may be (or may be incorporated into) the primary or main controller for the chiller 10, or the controller 40 may be a stand-alone controller 40 for controlling the refrigeration module 100 or a portion thereof. Regardless, the controller 40 may be described and referred to herein as a portion of the refrigeration module 100, and more generally, the chiller 10 ( Figure 1-3 ) part.

[0060] The controller 40 may include one or more computing devices, such as a computer, tablet computer, smartphone, server, circuit board, or other one or more computing devices or one or more systems.

[0061] The processor 42 may include any suitable processing device or a collection of processing devices. In some embodiments, the processor 42 may include a microcontroller, a central processing unit (CPU), a graphics processing unit (GPU), a timing controller (TCON), a scaler unit, or some combination thereof. During operation, the processor 42 executes machine-readable instructions (such as machine-readable instructions 46) stored on the memory 44, thereby causing the processor 42 to perform some or all of the actions attributed to the controller 40 herein. Typically, the processor 42 acquires, decodes, and executes instructions (e.g., machine-readable instructions 46). In addition, the processor 42 may also perform other actions, such as making determinations, detecting conditions or values, and transmitting signals. If the processor 42 assists another component in performing a function, it can be said that the processor 42 causes the component to perform the function.

[0062] The memory 44 may be any suitable device or collection of devices for storing digital information, including data and machine-readable instructions, such as the machine-readable instructions 46. For example, the memory 44 may include volatile storage, such as random access memory (RAM), non-volatile storage, such as flash memory, read-only memory (ROM), etc., or a combination of volatile and non-volatile storage. Data read or written by the processor 42 when executing the machine-readable instructions 46 may also be stored on the memory 44. The memory 44 may include a "non-transitory machine-readable medium," where the term "non-transitory" does not include or encompass transient propagating signals.

[0063] The processor 42 may include one processing device or multiple processing devices distributed within the controller 40 (or communicatively coupled to the controller 80), or more broadly distributed within the refrigeration module 100 and / or the freezer 10 ( Figure 1-3 Likewise, the memory 44 may include a memory device or a plurality of memory devices distributed within the controller 40 (or communicatively coupled to the controller 40), or more broadly distributed within the refrigeration module 100 and / or the freezer 10 ( Figure 1-3 ). Thus, the controller 40 may include components distributed throughout the climate control assembly 100 and / or the freezer 10 ( Figure 1-3 ) in a separate "controller".

[0064] The controller 40 may be communicatively coupled to one or more components of the refrigeration module 100 (eg, via one or more wired and / or wireless connections). Figure 4As shown in FIG, controller 40 can be communicatively coupled to compressors 112 and 120, valves 116, 122, and 127, blowers 118 and 36, or some subset thereof. During operation, controller 40 can control the operating conditions of the components of climate control assembly 100. For example, controller 40 can change the operating conditions of one or both of compressors 112, 120 and / or blowers 118, 36, such as by activating, deactivating, and / or changing the operating speed of one or both of compressors 112, 120 and / or blowers 118, 36 during operation. Similarly, controller 40 can change the operating conditions of one or more of valves 116, 122, 127, such as by changing their positions (e.g., open, closed, or some position therebetween). In some embodiments, controller 40 can change the operating conditions of one or both of compressors 112, 120 and / or one or more of valves 116, 122, 127 to achieve or maintain a desired temperature in chamber 12.

[0065] In some embodiments, a temperature sensor 128 can be in fluid communication with the airflow 50. Specifically, the temperature sensor 128 can be positioned along the intake duct 32 (or elsewhere in the duct system 30 and / or chamber 12). Without being limited to this or any other theory, the airflow 50 entering the intake duct 32 may be heated due to contact with the chamber 12 (and the product stored therein). Thus, the intake duct 32 can represent the location where the airflow 50 reaches its maximum average temperature during operation. Therefore, placing the temperature sensor 128 in the intake duct 32 can allow the controller 40 to control the refrigeration module 100 based on the highest average temperature of the airflow 50 during operation. However, it should be understood that other locations for the temperature sensor 128 are also contemplated herein, such as directly within the chamber 12, in the discharge duct 34, etc. Furthermore, in other embodiments, multiple temperature sensors (e.g., the temperature sensor 128) can be positioned throughout the chamber system 12, the duct system 30, or elsewhere.

[0066] The controller 40 can be communicatively coupled to the temperature sensor 128 (or multiple temperature sensors 128) and can be configured to control the operating conditions of the refrigeration module 100 (or its components) during operation based at least in part on the output from the temperature sensor 128. For example, the controller 40 can activate or deactivate the refrigeration module 100 (or a portion thereof) based on the output from the temperature sensor 128. Specifically, the controller 40 can activate the compressors 112, 120 and the blowers 36, 118 to circulate the first and second refrigerants through the first and second refrigerant circuits 113, 121, respectively, at least in part in response to the output from the temperature sensor 128 indicating that the temperature in the suction line 32 is above a target value, as described above. Conversely, the controller 40 can deactivate the compressors 112, 120 and the blowers 36, 118 to stop the circulation of the first and second refrigerants through the first and second refrigerant circuits 113, 121, respectively, at least in part in response to the output from the temperature sensor 128 indicating that the temperature in the suction line 32 is below a target value, as described above. Furthermore, controller 40 may adjust the positions of valves 116 , 122 and / or the operating speeds of compressors 112 , 120 and / or blowers 36 , 118 to actively vary the cooling capacity of refrigeration module 100 based at least in part on output from temperature sensor 128 .

[0067] Figure 5 Shown is a freezer 10 ( Figure 1-3 ) of some embodiments of the present invention, the air flow 50 passes through the chamber 12, the duct system 30 and the evaporator 124 ( Figure 4 ). Specifically, Figure 5 A side cross-sectional view of the freezer 10 is shown, however, it should be noted that some features have been simplified or obscured by additional cross-hatching to simplify the drawing and focus on example paths for airflow 50 according to some embodiments. Figure 5 , the evaporator 124 and the blower 36 can be co-located in an enclosure 150 formed in the upper portion 18 of the housing 15. The enclosure 150 can be positioned vertically above the chamber 12. If the airflow 50 is stopped by deactivating the blower 36, the enclosure 150 can substantially define the volume of air that will be heated as part of the defrost operation described above.

[0068] The exhaust duct 34 (of the duct system 30) may include an exhaust manifold 130 positioned adjacent the chamber 12. Specifically, the chamber 12 may have a rear wall 134 opposite the front opening 13, which separates the exhaust manifold 130 from the chamber 12. A pair of side walls 135 may extend laterally between the rear wall 134 and the front opening 13 (at Figure 5Only one side wall 135 is visible in the cross-section of FIG. 1 ). Thus, the exhaust manifold 130 can be defined in the housing 15 behind the rear portion or rear side of the chamber 12. The rear wall 134 can include one or more (e.g., one or more) outlets 136 defined therein that are configured to place the chamber 12 in fluid communication with the exhaust manifold 130 during operation. Figure 6 The plurality of outlets 136 may comprise a plurality of elongated slots that are generally elongated in a horizontal or transverse direction (eg, substantially perpendicular to the direction of gravity) and have an elongated pill-like shape. However, any suitable shape and arrangement of the outlets 136 is contemplated herein.

[0069] Reference again Figure 5 , the suction duct 32 (of the duct system 30) can include a suction manifold 140 positioned at the upper end 12a of the chamber 12. The upper end 12a of the chamber 12 can be a vertical upper end (e.g., relative to the direction of gravity) and can include the end of the chamber 12 closest to the enclosure 150 (and the evaporator 124 and the blower 36). The suction manifold 140 can be in fluid communication with the chamber 12 via one or more (e.g., one or more) inlets 142. Therefore, the inlet 142 can be positioned in the upper portion of the chamber 12, near the upper end 12a. In addition, in a lateral or horizontal direction within the chamber 12 (e.g., perpendicular to the direction of gravity), the inlet 142 can be positioned closer to the front opening 13 and the door 14 than the rear wall 134. Brief Reference Figure 7 In some embodiments, the inlet 142 may be shaped similarly to the plurality of outlets 136 and, therefore, may be formed as an elongated pill-shaped slot (however, as with the outlets 136, other shapes are also contemplated).

[0070] Reference again Figure 5 , the suction manifold 140 can be in fluid communication with the enclosure 150 via the suction port 152, and the discharge manifold 130 can be in fluid communication with the enclosure 150 via the discharge port 154. The suction manifold 140, the suction port 152, and a first portion of the enclosure 150 (e.g., a portion upstream of the blower 36) can collectively define the suction duct 32 of the duct system 30, while the discharge manifold 130, the discharge duct 154, and a second portion of the enclosure 150 (e.g., a portion including and downstream of the blower 36) can define the discharge duct 34 of the duct system 30. Figure 4 As shown in .

[0071] The arrangement of the manifolds 130, 140, outlets 136, and inlet 142 in the chamber 12 promotes a front-to-back and vertically upward flow direction of the airflow 50 in the chamber 12 during operation. Specifically, the blower 36 can discharge the airflow 50 vertically downward through the discharge port 154 and into the discharge manifold 130. Thereafter, the airflow 50 can flow out of the discharge manifold 130 and into the chamber 12 via the plurality of outlets 136. Figure 5 , the airflow 50 changes direction as it flows from the discharge port 154 to the discharge manifold 130, specifically, the direction changes from vertical to lateral and then from lateral to vertical as it flows from the discharge port 154 into the discharge manifold 130. The plurality of outlets 136 can be shaped, numbered, and arranged so as to exert sufficient back pressure on the discharge manifold 130 to provide a relatively smooth outflow of the airflow 50 through the plurality of outlets 36. The direction of the airflow 50 entering the chamber 12 via the plurality of outlets 136 on the rear wall 134 can be generally horizontal or lateral. Thus, the overall direction of the airflow 50 can be horizontal or lateral in the chamber 12, from the rear wall 134 toward the front opening 13 (or door 14). In addition, the airflow 50 can flow generally vertically upward in the chamber 12 toward the plurality of inlets 142. Due to the rear-to-front lateral direction of the airflow 50 described above, a majority of the airflow 50 can flow in the chamber 12 between the front opening 13 and the outer door 14 (as well as the outer door 142). Figure 2 and Figure 3 17) or the vicinity of the inner door 17 shown in FIG.

[0072] After entering the suction manifold 140 via the plurality of inlets 142, the direction of the airflow 50 may change from vertical to horizontal or lateral and may proceed through the suction manifold 140 to the suction port 152. The airflow 50 may then change direction again from lateral to vertical in the suction port 152 and may proceed vertically through the suction port 152 into the enclosure 150. After entering the enclosure 150, the airflow 50 may again change direction from vertical to lateral in order to traverse the enclosure 150 through, over, and / or through the evaporator 124. As the airflow 50 thermally engages the evaporator 24, heat from the airflow 50 is transferred to the second refrigerant ( Figure 4 ), thereby reducing the temperature of the airflow 50. Thereafter, the cooled airflow 50 is drawn into the blower 36 to restart the above cycle.

[0073] Without being limited to this or any other theory, heat within the chamber 12 may tend to rise vertically via natural convection (i.e., independent of the airflow 50). Thus, placing the evaporator 124 vertically above the chamber 12 in the chamber 150 can take advantage of this natural heat migration, thereby more effectively promoting the flow of relatively warm air toward the evaporator 124. More specifically, the vertically upward direction of the airflow 50 within the chamber 12 can work in conjunction with natural convection to more effectively sweep relatively warm air out of the chamber 12 and toward the evaporator 124 via the intake duct 32. Thus, the overall arrangement of the evaporator 124, chamber 12, and ductwork 30 more effectively removes heat from the chamber 12, thereby more efficiently and reliably reducing the temperature therein. Furthermore, again without being limited to this or any other theory, the multiple directional changes of the airflow 50 as it travels from the enclosure 150 into the chamber 12, from the chamber 12 to the enclosure 150, and through the enclosure 150 itself can be configured to limit or minimize unintentional mixing of air in the chamber 12 and the enclosure 150 when the blower 36 is not operating (e.g., during a defrost operation).

[0074] Now refer to Figure 5 and Figure 7-10 , the suction manifold 140 can be at least partially formed or defined by a tray 160 that is removably insertable into the chamber 12 at (or near) the upper end 12a. Specifically, the tray 160 can have a flat base 162 and one or more side walls 164 extending orthogonally away from the base 162. The tray 160 can be inserted into the chamber 12 so that the base 162 extends substantially laterally or horizontally and so that the one or more side walls 164 extend generally vertically upward from the base 162. Moreover, when the tray 160 is inserted into the chamber 12, the base 162 and side walls 164 of the tray 160 and the upper end 12a of the chamber 12 can define the suction manifold 140 in the chamber 12, and the inlet 142 can be positioned along the base 162.

[0075] like Figure 8-10 As shown, the temperature sensor 128 can be secured to the tray 160 via a bracket 166. Specifically, the bracket 166 is mounted to the base 162 within the intake manifold 140 such that the airflow 50, after flowing into the plurality of inlets 142, flows over and / or around the temperature sensor 128 within the intake manifold 140. As previously discussed, the airflow 50, after flowing through the chambers 12 (and engaging with the product stored therein), is likely to be at the highest average temperature within the intake manifold 140. Thus, by placing the temperature sensor 128 in the intake manifold 140 via the bracket 166 mounted to the tray 160, the temperature sensor 128 can provide a "worst case" measurement of the temperature of the airflow 50 so that the controller 40 ( Figure 4) The operation of the refrigeration module 100 can be more conservatively controlled to ensure the desired temperature in the chamber 12 during operation.

[0076] Furthermore, mounting the temperature sensor 128 to the base 162 of the tray 160 can simplify the process of inspecting, calibrating, maintaining, installing, or removing the temperature sensor 128 (collectively referred to as "maintenance activities"). Figure 9 and Figure 10 As best shown in FIG, the tray 160 can be slid out of the front opening 13 of the chamber 12 to expose at least a portion of the base 162. Because the bracket 166 and the temperature sensor 128 are placed along the base 162 near the plurality of inlets 142, as shown in FIG. Figure 9 As shown in , even though the tray 160 is partially withdrawn from the front opening 13 of the chamber 12, the bracket 166 and the sensor 128 can be fully exposed to the outside of the chamber 12 to facilitate maintenance activities such as clearing frost from the pipes.

[0077] Now refer to Figure 11 In some embodiments, the bracket 166 can include a longitudinal axis 165 (or more simply referred to as "axis" 165), a first end 166a, and a second end 166b opposite the first end 166a, such that the ends 166a, 166b are spaced apart from each other along the axis 165. In addition, the bracket 166 includes a planar base 168 extending axially between the ends 166a, 166b relative to the axis 165. The base 168 can include a rectangular plate elongated along the axis 165.

[0078] A pair of mounting ears 170, 172 extend orthogonally outwardly from the base plate 168 in a radial direction relative to the axis 165. Specifically, the first mounting ear 170 can be positioned at the first end 166a and the second mounting ear 172 can be positioned at the second end 166b. Thus, the mounting ears 170, 172 can be axially spaced apart along the axis 165. In some embodiments, the mounting ears 170, 172 can be formed by folding or bending portions of the base plate 168 vertically upward. Thus, in some embodiments, the mounting ears 170, 172 can be integrally formed with the base plate 168, thereby defining a one-piece, unitary body therewith. The base plate 168 can be secured to the base 162 ( Figure 7-9 ), such that the pair of mounting ears 170 , 172 extend orthogonally away from (and vertically upwardly from) the base 160 of the bracket 166 , thereby more centrally placing the sensor 128 within the suction manifold 140 during operation.

[0079] Each mounting ear 170, 172 may include one or more connection holes 174 extending therethrough. The one or more connection holes 174 in each mounting ear 170, 172 may be aligned (e.g., in an axial direction relative to the axis 165) with a corresponding one of the one or more connection holes 174 extending through the other mounting ear 170, 172. Figure 11 The embodiment of the bracket 166 shown in FIG can be configured to hold two sensors (e.g., the temperature sensor 128 and / or another sensor for measuring temperature or another parameter, such as a temporary sensor for calibration purposes). Accordingly, each mounting ear 170 includes a pair of connection holes 174 extending therethrough.

[0080] A grommet 176 can be inserted through each connection hole 174 to engage with and support a portion of a corresponding sensor during operation. Specifically, in some embodiments, each grommet 176 can include a plurality of support fingers 178 extending in a plane oriented generally radially relative to axis 165 that can engage the body of a sensor (e.g., temperature sensor 128) and suspend it within the corresponding connection hole 174.

[0081] Reference Figure 3 、 12 The housing 15 may include a door jamb 180 at least partially surrounding the front opening 13 into the chamber 12, and the outer door 14 may include a door seal 190 configured to engage with the door jamb 180 to seal the chamber 12 from the surrounding environment 5 when the outer door 14 is closed. Figure 1 ). The door frame 180 may include a pair of door stops, namely a first door stop 182 and a second door stop 184. The door stops 182, 184 may be more simply referred to herein as "stops" 182, 184. In addition, the door seal 190 includes a plurality of sealing protrusions 192 configured to sealingly engage the first stop 182 and the second stop 184 of the door frame 180 to seal or isolate the chamber 12 from the ambient environment 5.

[0082] As previously described, the door jamb 180 (which may be referred to herein as a "mullion") may include a first stop 182 and a second stop 184. The stops 182, 184 may extend adjacent to and parallel to each other along each edge of the front opening 13. The stops 182, 184 may also be discontinuous with each other to allow for independent thermal expansion during operation, as explained in more detail below. The first stop 182 may be referred to herein as an "inner" stop because the first stop 182 is positioned proximate to the front opening 13. Additionally, the second stop 184 may be referred to herein as an "outer" stop because the second stop 184 is positioned outside of the first stop 182 relative to the front opening 13. Thus, the inner stop 182 is positioned between the front opening 13 and the outer stop 184, which may be positioned around the first stop 182.

[0083] Specific reference Figure 3 , the shape of the front opening 13 can be a quadrilateral (e.g., a rectangle). Therefore, the door frame 180, in particular the stops 182, 184, can also have a corresponding rectangular shape to conform to the rectangular shape of the front opening 13. Specifically, the stops 182, 184 of the door frame 180 can include separate elongated linear segments to conform to the rectangular shape of the front opening 13. The stops 182, 184 can each have an upper segment 182a, 184a, a lower segment 182b, 184b, and a pair of vertically oriented side segments 182c, 184c. The side segments 182c, 184c can extend vertically between the upper segments 182a, 184a and the lower segments 182b, 184b, respectively. The upper segments 182a, 182b may extend substantially parallel to one another, the lower segments 182b, 184b may extend substantially parallel to one another, and the side segments 182c, 184c may all extend substantially parallel to one another.

[0084] Now refer to Figure 14 Along each of the sections 182a, 184a, 182b, 184b, 182c, 184c, the stops 182, 184 can be separate, distinct, and discontinuous individual components. Thus, each of the stops 182, 184 can be configured to thermally expand or contract independently of the other. As will be described in greater detail below, the independent expansion / contraction of the stops 182, 184 can prevent or at least reduce the risk of deformation (e.g., warping) of the door jamb 180, which could result in a loss of sealing engagement with the door seal 190 during operation.

[0085] Each segment 182a, 182b, 182c, 182d of the inner stopper 182 can include a first or inner side 181 and a second or outer side 183, with the inner side 181 being closer to the front opening 13 than the outer side 183. A sealing surface 185 extends between the sides 181, 183. The sealing surface 185 can include a substantially flat surface configured to engage with one or more sealing protrusions 192 of the door seal 190 during operation. Similarly, each segment 184a, 184b, 184c, 184d of the outer stopper 182 can include a first or inner side 187 and a second or outer side 189, with the inner side 187 being closer to the front opening 13 than the outer side 189. A sealing surface 186 extends between the sides 187, 189. The sealing surface 186 can include a substantially flat surface configured to engage with one or more sealing protrusions 192 of the door seal 190 during operation.

[0086] An elongated connecting member 191 can be inserted between the inner stop 182 and the outer stop 184 (along each of the segments 182a, 182b, 182c and 184a, 184b, 184c, respectively). Specifically, the outer side 183 of the inner stop 182 and the inner side 187 of the outer stop 184 can be connected to the elongated connecting member 191 via a tongue-and-groove joint. Specifically, the outer side 183 of the inner stop 182 and the inner side 187 of the outer stop 184 can each form a groove, and the connecting member 191, which is formed as an elongated plate, can form suitable tongues that can be inserted into the grooves formed on the sides 183, 187 of the stops 182, 184, respectively. However, it should be understood that the connection may be alternatively constructed, such as in some embodiments by forming a groove on the end of the connecting member 191 that receives a "tongue" formed on the ends 183, 187 of the stops 182, 184.

[0087] Additionally, similar tongue-and-groove joints can be formed around the front opening 13 between the stops 182, 184 and the structure of the housing 15. Specifically, the inner side 181 of the inner stop 182 and the outer side 189 of the outer stop 184 can be grooved to receive a tongue 188 formed on the housing 15. Similar to the connection between the connecting member 191 and the sides 183, 187 of the stops 182, 184, respectively, the connection between the sides 181, 189 of the stops 182, 184, respectively, and the housing 15 can be alternatively configured. For example, the housing 15 can be formed with "grooves" to receive "tongues" formed on the ends 181, 189 of the stops 182, 184.

[0088] The connection between the stops 182, 184, the connecting member 191, and the housing 15 (e.g., via the tongue 188) can allow the stops 182, 184 to be longitudinally movable relative to the connecting member 191, the housing 15, and each other during operation (e.g., in the longitudinal direction). Figure 14 Thus, during operation, each segment 182a, 182b, 182c of the inner door stop 182 can expand or contract (e.g., along their lengths) relative to the corresponding segment 184a, 184b, 184c of the outer door stop 184.

[0089] Various materials can be used to form the stops 182, 184 and the connecting member 191 along each segment 182a, 184a and 182b, 184b and 182c, 184c. For example, the inner stop 182, the outer stop 184, and the connecting member 191 can include a suitable polymer such as fiber reinforced plastic (FRP), thermoplastic, ultra-high molecular weight (UHMW) polyethylene, or some combination thereof. However, other materials and material combinations are also contemplated herein. In some embodiments, the stops 182, 184 can be formed from different materials or different material combinations.

[0090] In some embodiments, the material selected for the stops 182, 184 can be selected based on its thermal contraction or thermal expansion characteristics. For example, the materials 182, 184 can be formed of a material selected to ensure that the sealing surfaces 185, 186 are substantially flat when they are placed under the expected temperature gradient associated with the operation of the freezer 10 with the outer door 14 closed. Figure 1-3 ).

[0091] Now refer to Figure 15 , an L-shaped corner member 193 may be connected between the door stops 182, 184 at the intersection of the sections 182a, 182b, 182c, 184a, 184b, 184c. Specifically, Figure 15 A partial exploded view of the door stop 180 is shown at one of the intersections of the upper sections 182a, 184a and the side sections 182c, 184c of the door stops 182, 184, respectively. Figure 15, an L-shaped corner member 193 is shown spanning between the elongated connecting members 191 extending along the segments 182a, 184a to complete the corner. Additionally, the L-shaped corner member 193 can form tongues that are received within grooves formed at the sides 183, 187 at the intersection. The segments 182a, 184a, 182c, 184c can have angled or mitered cuts to form 90° angles at their corners / intersections. Without being limited to this or any other theory, the L-shape of the corner member 193 can help prevent separation of the segments 182a, 184a, 182c, 184c at the mitered corner due to temperature changes of the segments 182a, 184a, 182c, 184c over time. It should be understood that similar L-shaped corner members 193 can be used to Figure 15 Segments 182a, 184a and segments 182b, 184b are connected to side segments 182c, 184c at the other corners of door stop 180 in a similar manner as shown in FIG.

[0092] As previously mentioned, the freezer 10 ( Figure 1-3 ) can be configured to achieve and / or maintain (e.g., via the refrigeration module 100) ultra-low temperatures (e.g., -50°C or below) within the chamber 12, despite the ambient environment 5 being under typical indoor conditions. Consequently, when the outer door 14 is closed, the interior side 181 of the inner stopper 182 may be exposed to the ultra-low temperature, while the exterior side 189 of the outer stopper 184 may be exposed to the ambient environment 5. Due to this extreme temperature difference (e.g., approximately 100°C in some cases), the inner stopper 182 may experience significant thermal contraction relative to the outer stopper 184. However, the connection between the stops 182, 184, the connecting member 191, and the housing 15 is configured to allow the inner stopper 182 (particularly the segments 182a, 182b, 182c) to thermally contract (e.g., in the longitudinal direction) without applying compression or other strain to the outer stopper 184 (particularly the segments 184a, 184b, 184c). Thus, thermal contraction of the inner stopper 182 may not cause deformation of the sealing surface 186 of the outer stopper 184 , thereby maintaining the sealing engagement between the sealing surface 186 and the corresponding sealing protrusion 192 of the door seal 190 .

[0093] Reference again Figure 3 and Figure 13The door seal 190 may have a generally rectangular shape to correspond to the rectangular shape of the stoppers 182, 184 of the door frame 180. Specifically, the door seal 190 may have an upper section 190a, a lower section 190b, and a pair of vertically oriented side sections 190c. The side sections 190c may extend vertically between the upper section 190a and the lower section 190b. A plurality of sealing protrusions 192 may extend along each of the sections 190a, 190b, 190c.

[0094] Reference again Figure 14 Along each segment 190a, 190b, 190c, a sealing protrusion 192 can engage with a sealing surface 185, 186 of a stopper 182, 184 of the door jamb 180, respectively, to seal the chamber 12 from the ambient environment 5 when the outer door 14 is closed. Specifically, each segment 190a, 190b, 190c can include a common base 194, and a plurality of sealing members 192 can be formed on a first side 194a of the base 194 and protrude outward therefrom. A plurality of connectors 195 are formed on a second side 194b of the base 194, opposite the first side 194a, and protrude outward therefrom.

[0095] As from Figure 13 and 14 As will be appreciated, each sealing projection 192 can have an arcuate convex shape (e.g., when not in contact with the sealing surfaces 185, 186 of the stoppers 182, 184, respectively) (sometimes referred to as a spherical seal); however, other shapes and curvatures (e.g., rectangular cross-section, triangular cross-section, flaps, etc.) are also contemplated. The plurality of sealing projections 192 can be hollow or semi-hollow such that they can at least partially deform or flatten when in contact with the respective sealing surfaces 185, 186 to facilitate sealing contact therewith.

[0096] Each of the plurality of sealing protrusions 192 can form a separate seal with the door frame, thereby creating redundancy in the sealing contact between the door seal 190 and the door frame 180. Specifically, a first portion of the sealing protrusion 192 can engage with the sealing surface 185 of the inner stopper 182, while the remaining second portion of the sealing protrusion 192 can engage with the sealing surface 186 of the outer stopper 184 around the door frame 180. Figure 14In the illustrated embodiment, the door seal 190 includes a total of four (4) sealing protrusions 192 on each segment 190a, 190b, 190c, wherein two (2) of the sealing protrusions 192 are configured to engage the sealing surface 185 of the inner stop 182, and the remaining two (2) of the sealing protrusions 192 are configured to engage the sealing surface 186 of the outer stop 184. Thus, the sealing engagement between the door seal 190 and the inner stop 182 via the separate sealing protrusions 192 can be independent of the sealing engagement between the door seal 190 and the outer stop 184.

[0097] Still refer to Figure 14 , the connector 195 can include an arrow-shaped cross-section including a pair of inclined surfaces 197 that diverge outwardly from each other to define a pair of shoulders 199. For each segment 190a, 190b, 190c, the connector 195 can extend along the length of the base 194. The outer door 14 can include a plurality of cavities 200, each having a corresponding opening 202 formed therein. The inner diameter of the opening 202 can be narrower than the inner width or diameter of the corresponding cavity 200. The cavity 200 can receive the connector 195 therein via the opening 202 to secure the door seal 190 to the interior side of the outer door 14, as shown. Specifically, the dimensions of the narrow opening 202 can be designed such that when the connector 195 is inserted therein, the inclined surface 197 of each connector 195 deflects and deforms inwardly until the shoulder 199 advances into the cavity 200 and through the opening 202, at which point the inclined surface 197 can diverge outwardly to its normal state so that the shoulder 199 can prevent or at least limit the connector 195 from exiting the cavity 200 through the narrow opening 202.

[0098] The base 194, sealing protrusion 192, and connector 195 of each segment 190a, 190b, 190c can each be formed as a single-piece, unitary body. In some embodiments, each segment 190a, 190b, 190c of the door seal 190 can be formed from a resilient material, such as an elastomeric material (e.g., natural or synthetic rubber). Thus, the segments 190a, 190b, 190c of the door seal 190 can be flexible to facilitate sealing engagement between the sealing protrusion 192 and the sealing surfaces 185, 186 of the stoppers 182, 184, as well as insertion of the connector 195 through the opening 202 of the cavity 200, as described herein.

[0099] Again a brief reference Figure 5In some embodiments, a similar frame and sealing assembly 19 may be disposed between the upper portion 18 and the lower portion 16 of the housing 15 to seal the enclosure 150 from the surrounding environment 5. Thus, the frame and sealing assembly 19 disposed between the portions 18, 16 of the housing 15 for sealing the enclosure 150 may be configured similarly to the frame and sealing assembly 19 of the housing 15. Figure 14 The door seal 190 and surround 180 shown in and described herein are the same or similar.

[0100] Reference again Figure 5 and Figure 6 , a plurality of shelves 210 may be positioned in the chamber 12 of the freezer 10 ( Figure 1-3 ) to support products (such as life science products and materials) therein. Figure 5 , the shelves 210 may be supported in the chamber 12 such that the outer perimeter of the shelves 210 is spaced apart from the inner walls of the chamber 12, thereby allowing the airflow 50 to flow vertically upward around the shelves 210 in the chamber 12. As will be described in greater detail herein, the shelves 210 may be supported in the chamber 12 via corresponding shelf support assemblies 250 to ensure adequate spacing for the airflow 50.

[0101] Now refer to Figure 16 and 17 Each shelf 210 is a generally rectangular member having a top side 212 and a bottom side 214. Furthermore, the shelf 210 includes a front end 210a and a rear end 210b, and a pair of side surfaces 216 extending between the ends 210a, 210b. The front end 210a, the rear end 210b, and the pair of side surfaces 216 together define an outer perimeter of the shelf 210.

[0102] The retaining wall 218 extends upward (e.g., orthogonally upward) from the top side 212 along the pair of side faces 216 and the rear end 210b. The retaining wall 218 can be configured to prevent product from hanging over the side faces 216 and the rear end 210b (which can partially block the vertical flow of the airflow 50 during operation, such as Figure 3 ). In addition, a handle 219 may be formed on the front end 210a, which extends downward (e.g., orthogonally downward) from the bottom side 214. The handle 219 can be grasped by a user to facilitate insertion and removal of the shelf 210 into and from the chamber 12.

[0103] In some embodiments, the retaining walls 218 and the handle 219 can form a single, unitary body with the main body of the shelf 210. For example, a single piece of sheet metal can be used to construct the main portion or body of the shelf 210. Three adjacent edges of the sheet metal can be bent upward along the top side 212 to form the retaining walls 218, and the remaining edge of the sheet metal can be bent downward along the bottom side 214 to form the handle 219.

[0104] like Figure 17 As shown in FIG, a pair of centering posts 220 are secured to the bottom side 214 of the shelf 210. The posts 220 may extend linearly between the sides 216 and be spaced apart from one another between the front end 210a and the rear end 210b.

[0105] Reference again Figure 6 , each shelf 210 can be supported in the chamber 12 using a shelf support assembly 250. Specifically, the shelf support assembly 250 can include one or more vertically oriented support rails 252 (or more simply "rails" 252) mounted to the side walls 135 in the chamber 12. Each side wall 135 can include a pair of rails 252 that extend parallel to each other and are horizontally spaced apart between the rear wall 134 and the front opening 13.

[0106] Now refer to Figure 18 and 19 The shelf support assembly 250 may further include one or more support brackets 260 ( Figure 18 ) (or more simply referred to as "brackets" 260) to support the shelves 210 in the chamber 12 in turn. Each shelf 210 can be arranged along a pair of side surfaces 216 ( Figure 20 ) are supported on two brackets 260. In addition, each bracket 260 can be engaged with the pair of rails 252 along one of the corresponding side walls 135 in the chamber 12 so that the bracket 260 horizontally spans between the pair of rails 252.

[0107] Each bracket 260 includes a U-shaped saddle 266 having a first end 266a, a second end 266b opposite the first end 266a, and an upper planar support surface 267 extending between the ends 266a, 266b (e.g., horizontally between the ends 266a, 266b). A hook assembly 262 is connected to each end 266a, 266b and is configured to engage one of the rails 252. Specifically, each rail 252 includes a plurality of vertically spaced slots (or holes) 254. The hook assembly 262 of the support bracket 260 can be inserted into a corresponding slot 254 in the rail 252, thereby hanging the bracket 260 on the rail 252 (e.g., as shown in FIG. 2 ). Figure 18 ).

[0108] Each hook component 262 can have an inclined surface 264 adjacent to the upper planar support surface 267. Specifically, the inclined surface 264 can be inclined downward toward the support surface 267. Figure 18 and 19As shown in FIG, the inclined surface 264 may be a planar surface; however, in some embodiments, the inclined surface 264 may have some non-linear curvature.

[0109] Now refer to Figure 20 , each shelf 210 can be supported on a pair of brackets 260, each of which is supported on the pair of rails 252 on a corresponding one of the side walls 135 in the chamber 12, as previously described. The engagement between the shelf 210 and the pair of brackets 260 can cause the shelf 210 to be laterally centered (or substantially centered) in the chamber 12, such that the outer periphery of the shelf 210 (including the ends 210a, 210b, the sides 216) is spaced apart from the inner walls of the chamber 12 (including the rear wall 134, the side walls 135, and the front opening 13 (or the inner surface of the inner door 17), thereby allowing the airflow 50 to flow vertically upward in the chamber 12, as previously described ( Figure 5 ).

[0110] For example, Figure 21 As shown in FIG, the inclined surface 264 ( Figure 18 and 19 ) can facilitate centering the shelf 210 laterally or horizontally between the side walls 135 such that the side 216 is laterally spaced from the side walls 135 in the chamber 12. Thus, if the shelf 210 is inserted off-center between the side walls 135, the bottom side 214 of the shelf 210 can engage the inclined surface 264 on the bracket 260 (e.g., on the corresponding side 216) such that the shelf 210 can slide downwardly along the inclined surface 264 via gravity to land on the upper planar support surface 267.

[0111] In addition, if Figure 22 , when the shelf 210 is inserted into the chamber 12 and supported on the bracket 260, the saddle 266 of the bracket 260 can be received between the pair of centering posts 220. Thus, due to the contact between the centering posts 220 and the saddle 266 of the bracket 260, the slidable range of the shelf 210 in the lateral or horizontal direction between the front opening 13 and the rear wall 134 is limited. In addition, via the engagement between the centering posts 220 and the saddle 266 of the bracket 260, the front end 210a and the rear end 210b of the shelf 210 are respectively spaced (and possibly centered) between the front opening 13 (or the inner surface of the inner door 17 and / or the outer door 14) and the rear wall 134.

[0112] As previously described, the climate control assembly 100 may include a cascade refrigeration module having a plurality of separate staged refrigerant circuits 113, 121 that are interconnected via interstage heat exchangers 114 ( Figure 3) are thermally coupled to each other. The interstage heat exchanger 114 may include any suitable heat exchanger type, such as a shell and tube type, a double tube type, a plate type heat exchanger, etc. For example, Figure 23 An example of an interstage heat exchanger 114 configured as a plate heat exchanger, particularly a brazed plate heat exchanger, is shown according to some embodiments.

[0113] according to Figure 23 The interstage heat exchanger 114 includes a generally rectangular shell 270. Specifically, the shell 270 is generally cuboid in shape, having a first side 270a, a second side 270b, a third side 270c, and a fourth side 270d. The first side 270a and the second side 270b are spaced apart from each other along a first axis 275, while the third side 270c and the fourth side 270d are spaced apart from each other along a second axis 277 that is orthogonal to the first axis 275. The shell 270 is elongated along the first axis 275 relative to the second axis 277, and thus the first axis 275 may be referred to as the "major axis" and the second axis 277 may be referred to as the "minor axis." The shell 270 is positioned such that the major axis 275 is generally aligned with the transverse or horizontal direction, and the minor axis 277 is generally aligned with the vertical direction. Therefore, the first side 270a may be referred to as the upper side 270a, the second side 270b may be referred to as the lower side 270b, and the sides 270c and 270d may be referred to as the lateral sides.

[0114] The housing 270 includes a first inlet 272, a first outlet 274, a second inlet 276, and a second outlet 278. The first inlet 272 is positioned near the intersection of the first side 270a and the fourth side 270d, the first outlet 274 is positioned near the intersection of the first side 270a and the third side 270c, the second inlet 276 is positioned near the intersection of the third side 270c and the second side 270b, and the second outlet 278 is positioned near the intersection of the second side 270b and the fourth side 270d. Thus, the first inlet 272 and the first outlet 274 are axially spaced apart from each other relative to the major axis 275, and the second inlet 276 and the second outlet 278 are axially spaced apart from each other relative to the major axis 275. Furthermore, the first inlet 272 and the second outlet 278 are axially spaced apart from each other relative to the minor axis 277, and the first outlet 274 and the second inlet 276 are axially spaced apart from each other relative to the minor axis 277. Thus, the first inlet 272 and the first outlet 274 are positioned vertically above the second outlet 278 and the second inlet 276 , respectively.

[0115] The first inlet 272 and the first outlet 274 are in fluid communication with each other via a first fluid circuit (not shown) defined in the housing 270, and the second inlet 276 and the second outlet 278 are in fluid communication with each other via a second fluid circuit (not shown) defined in the housing 270. The first fluid circuit (not shown) and the second fluid circuit (not shown) are separated. Thus, the fluids flowing along the first fluid circuit (not shown) and the second fluid circuit (not shown) do not mix or otherwise come into physical contact with each other within the housing 270. However, the first fluid circuit (not shown) and the second fluid circuit (not shown) are in thermal contact with each other via an inner wall or barrier within the housing 270, so that heat can be transferred between them within the housing 270 during operation.

[0116] Now refer to Figure 3 and Figure 23 During operation, the first inlet 272, the first outlet 274, and the first fluid circuit (not shown) are connected as part of the first refrigerant circuit 113 of the refrigeration module 100, while the second inlet 276, the second outlet 278, and the second fluid circuit (not shown) are connected as part of the second refrigerant circuit 121 of the refrigeration module 100. Specifically, the first inlet 272 is connected to a first inlet line 280, which includes the portion of the first refrigerant circuit 113 extending from the expansion valve 116 to the interstage heat exchanger 114. Furthermore, the first outlet 274 is connected to a first outlet line 282, which includes the portion of the first refrigerant circuit 113 extending from the interstage heat exchanger 114 to the compressor 112. Furthermore, the second inlet 276 is connected to a second inlet line 284, which includes the portion of the second refrigerant circuit 121 extending from the compressor 120 to the interstage heat exchanger 114. Furthermore, the second outlet 278 is connected to a second outlet line 286 including a portion of the second refrigerant circuit 121 extending from the interstage heat exchanger 114 to the valve 122 .

[0117] Thus, during operation, although the first and second fluid circuits (not shown) may take circuitous or even tortuous paths through the shell 270 of the interstage heat exchanger 114, the general flow direction of the first refrigerant in the shell 270 of the interstage heat exchanger 114 is from the fourth side 270d to the third side 270c, and the general flow direction of the second refrigerant in the shell 270 of the interstage heat exchanger 114 is from the third side 270c to the fourth side 270d. Thus, the first and second refrigerants in the first and second refrigerant circuits 113, 121, respectively, flow through the shell 270 of the interstage heat exchanger 114 in a countercurrent arrangement.

[0118] As previously described, the first refrigerant in the first refrigerant circuit 113 can undergo a phase change (or a substantial phase change) from a liquid to a vapor in the interstage heat exchanger 114. Thus, when the first refrigerant flows into the first inlet 272 via the first inlet line 280, the first refrigerant can be in a (or substantially) liquid state, and when it flows out of the first outlet 274 via the first outlet line 282, the first refrigerant can be in a (or substantially) vapor state. Conversely, as previously described, the second refrigerant in the second refrigerant circuit 121 can undergo a phase change (or a substantial phase change) from a vapor to a liquid in the interstage heat exchanger 114. Thus, when the second refrigerant flows into the second inlet 276 via the second inlet line 284, the second refrigerant can be in a (or substantially) vapor state, and when it flows out of the second outlet 278 via the second outlet line 286, the second refrigerant can be in a (or substantially) liquid state.

[0119] Without being limited to this or any other theory, placing the second inlet 276 and the second outlet 278 vertically lower than the first inlet 272 and the first outlet 274 can help ensure a higher concentration of liquid in the second refrigerant exiting the shell 270 via the second outlet 278. Specifically, because the major axis 275 is oriented substantially horizontally and the minor axis 277 is oriented substantially vertically, the second outlet 278 is positioned along the vertically lower side of the shell 270. Therefore, as the second refrigerant condenses into liquid in the interstage heat exchanger 114, the condensed liquid tends to accumulate in the lower portion of the shell 270 via gravity. In addition, the overall flow momentum of the second refrigerant in the second fluid circuit (not shown) tends to accumulate the second refrigerant liquid toward the outlet side of the shell 270, which, as previously described, corresponds to the fourth side 270d for the second refrigerant. Therefore, placing the second inlet 276 and the second outlet 278 vertically below the first outlet 274 and the first inlet 272, respectively, helps ensure that the condensed liquid of the second refrigerant has a higher concentration at the second outlet 278, thereby improving the reliability and efficiency of the refrigeration module 100 during operation.

[0120] Furthermore, again without being limited to this or any other theory, vertically positioning the first inlet 272 and the first outlet 274 at a higher position than the second inlet 276 and the second outlet 278 can help ensure a higher concentration of vapor in the first refrigerant exiting the shell 270 via the first outlet 274. Specifically, because the major axis 275 is oriented substantially horizontally and the minor axis 277 is oriented substantially vertically, the first outlet 274 is positioned along the vertically higher side of the shell 270. Thus, as the first refrigerant undergoes a phase change to vapor in the interstage heat exchanger 114, the vapor tends to rise and accumulate in the vertically higher portion of the shell 270. Thus, vertically positioning the first inlet 272 and the first outlet 274 above the second outlet 278 and the second inlet 276, respectively, helps ensure a higher concentration of vaporized first refrigerant at the first outlet 274, thereby improving the reliability and efficiency of the refrigeration module 100 during operation.

[0121] Reference again Figure 1 and Figure 2 , the user interface 300 can be mounted to the housing 15. Specifically, the user interface 300 can be mounted to the outer door 14 so that the user can easily access the user interface 300 during operation. In some embodiments, the user interface 300 can include a controller 40 ( Figure 4 ). Thus, the user interface 300 may be configured to convey information from the controller 40 to a user and / or receive user input for the controller 40 during operation.

[0122] Now refer to Figure 24 and 25 , the user interface 300 may include a housing 302 that protrudes outwardly from the exterior door 14 along a central axis 305 (or more simply referred to as the "axis" 305) from a base 302a to a terminal end 302b. The housing 302 includes a plurality of side surfaces 304a, 304b, 304c, 304d extending from the base 302a to the terminal end 302b. The housing 302 may have a truncated pyramid shape such that there are a total of four (4) side surfaces 304a, 304b, 304c, 304d that taper inwardly toward the axis 305 when moving from the base 302a to the terminal end 302b, and each side surface 304a, 304b, 304c, 304d may have a generally trapezoidal shape. The shell 302 can be oriented on the outer door 14 so that the side surfaces 304a, 304b, 304c, 304d include a top side surface 304a positioned along the top side of the shell 302, a bottom side surface 304b positioned along the bottom side of the shell 302, and a pair of lateral side surfaces 304c, 304d located on opposite lateral sides of the shell 302, which extend generally vertically between the top side surface 304a and the bottom side surface 304b.

[0123] An electronic display 310 can be positioned on terminal 302b of housing 302 and configured to present information related to the operation of freezer 10. Electronic display 310 can include any suitable type of electronic display (e.g., a liquid crystal display, a light emitting diode display, a plasma display, etc.) and may or may not include a touch-sensitive display. During operation, a user can receive information related to the operation of freezer 10 and / or make input related to the operation of freezer 10 via user interface 300, and in particular electronic display 310.

[0124] One or more of the side surfaces 304a, 304b, 304c, 304d may include vents, ports, or other openings configured to allow air to flow into and out of the housing 302 to cool the electronic components contained therein. Figure 23 and 24 In the embodiment shown in FIG, the bottom side surface 304b includes a plurality of ports 312 disposed thereon.

[0125] In addition, if Figure 24 and 25 As shown in , lateral side surfaces 304c and 304d may include indicator lights 306 that are configured to illuminate so as to visually alert a user to the operating status of freezer 10 (or components thereof). Indicator lights 306 may include a transparent or translucent cover through which light can shine. Indicator lights 306 may utilize any suitable one or more lighting devices or components, such as light emitting diodes (LEDs), incandescent lighting devices, etc. In some embodiments, indicator lights 306 may include an edge-lit light guide in which one or more light emitters illuminate the peripheral edge of the light guide, and surface defects on the light guide (and / or one or more coatings or one or more covers attached to the light guide by a suitable adhesive or mechanical attachment) may cause light to escape and be visible on the exterior of indicator lights 306. In various embodiments, other lighting systems and / or one or more lighting devices for indicator lights 306 are also contemplated.

[0126] During operation, the indicator light 306 can be activated or deactivated, or can output a specific color and / or light pulse, based on the operating state of the freezer 10 (or its components). The operating state of the freezer 10 that can be indicated by the indicator light 306 can include, among other things, an indication that the refrigeration module 100 is operating or not operating, an indication that there is a system error associated with the freezer 10 (or its components or subsystems, such as the refrigeration module 100), an indication that the outer door 14 is open and / or an indication that the door seal 190 has malfunctioned, etc.

[0127] In some embodiments, indicator light 306 can be configured to output different colors of light, such as green, red, and yellow. In some embodiments, a controller (e.g., controller 40 as described above) can be configured to actuate or energize indicator light 306 to emit colored light patterns to indicate a particular operating state of freezer 10. For example, in some embodiments, indicator light 306 can output light patterns according to the operating state of freezer 10 as shown in Table 1 below. Table 1

[0128] In some embodiments, the controller (e.g., in some embodiments, the controller 40) can be configured to actuate or energize the indicator light 306 to emit a single color combination so as to output a range of colors (e.g., various combinations of red, green, blue, or other primary colors) during operation. For example, in some embodiments, the indicator light 306 can be configured to output various combinations of red, green, and blue light that can provide up to 16,777,216 different unique output colors, thereby increasing the number of unique operating states of the freezer 10 that can be visually indicated by the indicator light 306 during operation. Additionally, in some embodiments, the indicator light 306 can be configured to emit pulsed or scanned light emissions (e.g., light that pulses or scans along the length of the indicator light 306 along the corresponding lateral side surface 304c) to indicate one or more operating states of the freezer 10.

[0129] Regardless of the specific operating condition or operating status indicated by indicator light 306, the use of indicator light 306 can provide a visual cue to a user within the line of sight of freezer 10, thereby allowing the user to take more immediate action when necessary or desired. In addition, the tapered orientation of lateral side surfaces 304c, 304d can orient indicator light 306 so that it is more easily visible from a wider range of positions relative to freezer 10 (particularly exterior door 14). Thus, a user can see the light emitted by indicator light 306 from a greater percentage (up to and including 100%) of the room in which freezer 10 is stored.

[0130] As explained above and reiterated below, the present disclosure includes, but is not limited to, the following example embodiments.

[0131] Option 1: A low-temperature storage system comprises: a shell, the shell including: a chamber having a front opening closable by an outer door and a rear wall opposite to the front opening; one or more outlets defined in the rear wall; one or more inlets defined in the chamber closer to the front opening than the rear wall; and a refrigeration module operably connected to the chamber, the refrigeration module including: an evaporator vertically positioned higher than the chamber; a blower configured to generate an airflow in thermal communication with the evaporator; and a duct system configured to circulate an airflow between the chamber and the evaporator via one or more inlets and one or more outlets, so that the airflow is guided into the chamber through the one or more outlets and then enters the one or more inlets from the chamber to cool the chamber.

[0132] Option 2: A cryogenic storage system according to any option, wherein the duct system includes an intake duct configured to direct airflow from one or more inlets to the evaporator, the intake duct being at least partially formed by a tray that is removably insertable into the chamber from the front opening.

[0133] Option 3: The low-temperature storage system according to any of the options further includes a temperature sensor positioned in the intake duct and mounted to the tray so that the temperature sensor is exposed when the tray is withdrawn from the chamber, and wherein the refrigeration module includes a controller communicatively coupled to the temperature sensor, wherein the controller is configured to control the operating state of components of the refrigeration module based at least in part on output from the temperature sensor.

[0134] Option 4: A low-temperature storage system according to any of the options, wherein the refrigeration module includes a cascade refrigeration module, which includes: a first refrigerant circuit, which is configured to circulate a first refrigerant to exchange heat with the ambient environment around the shell; a second refrigerant circuit, which is configured to circulate a second refrigerant to exchange heat with the chamber, wherein the evaporator is positioned along the second refrigerant circuit; and an interstage heat exchanger thermally coupled between the first refrigerant circuit and the second refrigerant circuit, which is configured to transfer heat between the first refrigerant and the second refrigerant.

[0135] Option 5: The cryogenic storage system according to any one of the options, wherein the refrigeration module is configured to reduce the temperature within the chamber to below -50°C via the air flow.

[0136] Option 6: A cryogenic storage system according to any of the options, wherein the interstage heat exchanger includes a brazed plate heat exchanger, the brazed plate heat exchanger including a slender body, the slender body defining: a first inlet and a first outlet connected to a first refrigerant circuit; and a second inlet and a second outlet connected to a second refrigerant circuit, wherein the body is substantially horizontally oriented such that: the first inlet and the second outlet are positioned proximate a first lateral side of the body; the second inlet and the first outlet are positioned proximate a second lateral side of the body, the second lateral side being opposite to the first lateral side; the second inlet is vertically positioned lower than the first outlet; and the second outlet is vertically positioned lower than the first inlet.

[0137] Option 7: A low-temperature storage system according to any of the options, wherein the shell further includes: a door frame extending around the front opening, the door frame including: a first door stop defining a first sealing surface; a second door stop defining a second sealing surface, the second door stop being parallel to the first door stop and discontinuous with the first door stop, so that the first door stop and the second door stop are configured to heat shrink independently of each other.

[0138] Option 8: A low-temperature storage system according to any option, wherein the outer door has a door seal, which includes a plurality of sealing protrusions configured to engage with the door frame, such that a first portion of the sealing protrusion is configured to engage a first sealing surface and a second portion of the sealing protrusion is configured to engage a second sealing surface.

[0139] Option 9: A low-temperature storage system according to any option, wherein the first door stop and the second door stop include one or more slender sections, wherein the door frame further includes a slender connecting member, which is arranged between the corresponding sections of the first door stop and the second door stop, so that the corresponding sections of the first door stop and the second door stop are configured to expand longitudinally or contract longitudinally relative to the slender connecting member.

[0140] Option 10: The cryogenic storage system of any one of the options, wherein the elongated connecting member is engaged between corresponding sections of the first door stop and the second door stop by a tongue-and-groove joint.

[0141] Option 11: The low-temperature storage system according to any option further includes a user interface mounted to the outer door, wherein the user interface protrudes outward from the outer door so that the user interface includes: a terminal; a plurality of side surfaces extending between the terminal and the outer door; an electronic display positioned on the terminal; and an indicator light positioned on one of the plurality of side surfaces, the indicator light being configured to emit light corresponding to the operating status of the refrigeration module.

[0142] Option 12: A cryogenic storage system according to any option, wherein the chamber includes a pair of side walls extending laterally between a front opening and a rear wall, and wherein the cryogenic storage system further includes: a shelf positioned within the chamber, the shelf including an outer periphery; and a shelf support positioned within the chamber, configured to support the shelf so that the outer periphery is spaced apart from the pair of side walls, the rear wall, and the front opening.

[0143] Option 13: The cryogenic storage system of any one of the options, wherein the shelf support comprises one or more inclined surfaces configured to align the outer periphery of the shelf away from the pair of side walls.

[0144] Option 14: A low-temperature storage system according to any option, wherein the shelf includes a top side and a bottom side opposite the top side, wherein the bottom side includes a pair of centering posts configured to engage with the shelf support to keep the outer periphery of the shelf away from the rear wall and the front opening within the chamber.

[0145] Option 15: A method comprising: (a) generating an airflow with a blower of a refrigeration module operably connected to a chamber of a cryogenic storage system; (b) cooling the airflow with an evaporator of the refrigeration module, the evaporator being vertically positioned above the chamber; and (c) directing the airflow into the chamber through one or more outlets positioned along a rear wall of the chamber and then out of the chamber through one or more inlets defined in the chamber to cool the chamber, the rear wall being opposite to a front opening of the chamber and the one or more inlets being positioned closer to the front opening than the rear wall.

[0146] Option 16: The method of any option, wherein (c) comprises directing the airflow out of the chamber through one or more inlets into an intake duct at least partially defined by a tray that is removably insertable into an upper portion of the chamber.

[0147] Option 17: The method of any of the options, further comprising: (d) directing airflow over a temperature sensor mounted to the tray; and (e) controlling an operating state of components of the refrigeration module based at least in part on output from the temperature sensor.

[0148] Option 18: The method according to any option further includes: (f) circulating the first refrigerant in a first refrigerant circuit of the refrigeration module; (g) circulating the second refrigerant in a second refrigerant circuit of the refrigeration module, wherein the evaporator is positioned along the second refrigerant circuit; and (h) exchanging heat between the first refrigerant and the second refrigerant using an interstage heat exchanger.

[0149] Option 19: A method according to any option, wherein the interstage heat exchanger includes a brazing plate, and wherein (h) includes: (h1) causing the first refrigerant to flow laterally between a first inlet and a first outlet in the interstage heat exchanger; and (h2) causing the second refrigerant to flow laterally between a second inlet and a second outlet in the interstage heat exchanger, the second inlet and the second outlet being vertically positioned lower than the first outlet and the first inlet, respectively.

[0150] Option 20: The method according to any option further includes: (i) sealing the front opening of the chamber by engaging a door seal on the outer door with a door frame positioned around the front opening to seal the chamber from the surrounding environment, wherein the door frame includes: a first door stop defining a first sealing surface; and a second door stop defining a second sealing surface, the second door stop being parallel to the first door stop and discontinuous with the first door stop, so that the first door stop and the second door stop are configured to heat shrink independently of each other.

[0151] Option 21: A method according to any option, wherein the door seal includes a plurality of sealing protrusions, and wherein (i) further includes: (i1) engaging a first portion of the plurality of sealing protrusions with a first sealing surface; and (i2) engaging a second portion of the plurality of sealing protrusions with a second sealing surface.

[0152] Option 22: A method according to any option, wherein the chamber includes a pair of side walls extending laterally between the front opening and the rear wall, and wherein the method further includes centering the shelf in the chamber with a shelf support so that the outer periphery of the shelf is spaced apart from the pair of side walls, the rear wall and the front opening.

[0153] Scheme 23: A low-temperature storage system comprises: a shell, the shell comprising: a chamber having a front opening; a door frame extending around the front opening, the door frame comprising: a first door stop defining a first sealing surface; and a second door stop defining a second sealing surface, the second sealing surface being adjacent to the first sealing surface along an edge of the front opening, the second door stop being parallel to the first door stop and discontinuous with the first door stop, such that the first door stop and the second door stop are configured to thermally shrink independently of each other; a refrigeration module configured to generate an airflow through the chamber to reduce the temperature of the chamber to below -50°C; and an outer door configured to selectively close the front opening, the outer door having a door seal comprising a plurality of sealing protrusions, the sealing protrusions being configured to engage with the door frame, such that a first portion of the sealing protrusion is configured to engage the first door stop and a second portion of the sealing protrusion is configured to engage the second door stop.

[0154] Option 24: A low-temperature storage system according to any option, wherein the first door stop and the second door stop each include one or more slender sections, wherein the door frame further includes a slender connecting member, which is connected between the corresponding sections of the first door stop and the second door stop, so that the corresponding sections of the first door stop and the second door stop are configured to expand longitudinally or contract longitudinally relative to the slender connecting member.

[0155] Option 25: The cryogenic storage system of any one of the options, wherein the elongated connecting member is engaged between the first door stop and the second door stop by a tongue-and-groove joint.

[0156] Option 26: The low-temperature storage system according to any option further includes a piping system configured to direct the airflow into the chamber via one or more outlets positioned on the rear wall of the chamber, and to direct the airflow out of the chamber via one or more inlets positioned in the chamber closer to the front opening than the rear wall.

[0157] Option 27: The cryogenic storage system of any one of the options, wherein the one or more inlets are formed in a tray that is removably insertable into the upper portion of the chamber.

[0158] Embodiment 28: The cryogenic storage system of any embodiment, wherein the tray at least partially defines a suction duct of the ductwork.

[0159] Embodiment 29: The cryogenic storage system of any embodiment, wherein the refrigeration module includes an evaporator configured to cool the airflow, wherein the evaporator is vertically positioned above the chamber in the housing.

[0160] Option 30: The cryogenic storage system according to any of the options further includes a temperature sensor positioned in the intake duct and mounted to the tray so that the tray is withdrawn from the chamber to expose the temperature sensor, wherein the refrigeration module includes a controller communicatively coupled to the temperature sensor, and wherein the controller is configured to control the operating state of components of the refrigeration module based at least in part on the output of the temperature sensor.

[0161] Option 31: The low-temperature storage system according to any option further includes a user interface mounted to the outer door, wherein the user interface protrudes outward from the outer door, so that the user interface includes: a terminal; a plurality of side surfaces extending between the terminal and the outer door; an electronic display positioned on the terminal; and an indicator light positioned on one of the plurality of side surfaces, the indicator light being configured to emit light corresponding to the operating status of the refrigeration module.

[0162] Option 32: A low-temperature storage system according to any option, wherein the chamber includes a pair of side walls extending laterally between a front opening and a rear wall, wherein the system further includes: a shelf positioned within the chamber, the shelf including an outer periphery; and a shelf support positioned within the chamber, configured to support the shelf so that the outer periphery is spaced apart from the pair of side walls, the rear wall, and the front opening.

[0163] Option 33: A low-temperature storage system according to any option, wherein the shelf support includes one or more inclined surfaces that are configured to direct the outer periphery of the shelf away from the pair of side walls, wherein the shelf includes a top side and a bottom side opposite the top side, and wherein the bottom side includes a pair of centering posts that are configured to engage with the shelf support to direct the outer periphery of the shelf away from the rear wall and front opening within the chamber.

[0164] Option 34: A method comprising: (a) engaging a first sealing surface of a first door stop of a door frame extending at least partially around a front opening of a chamber of a low-temperature storage system with a first portion of a plurality of sealing protrusions of a door seal connected to an outer door; (b) engaging a second sealing surface of a second door stop of the door frame with a second portion of a plurality of sealing protrusions of the door seal, the second door stop being parallel to and adjacent to the first door stop along an edge of the front opening, and the second door stop being discontinuous with the first door stop such that the first door stop and the second stop are configured to thermally shrink independently of each other; and (c) directing an airflow from a refrigeration module through the chamber to cool the chamber to below -50°C.

[0165] Option 35: A method according to any option, wherein the first door stop and the second door stop each include one or more slender sections, wherein the door frame further includes a slender connecting member connecting between the corresponding sections of the first door stop and the second door stop, and wherein the method further includes: (d) longitudinally contracting the first section of the first door stop; and (e) during (d), sliding the section of the first door stop along the connecting member.

[0166] Embodiment 36: The method of any embodiment, wherein the respective sections of the first door stop and the second door stop are connected to the connecting member via a tongue and groove joint.

[0167] Option 37: A method according to any option, wherein (c) further comprises: directing the airflow into the chamber through one or more outlets positioned along the rear wall of the chamber, and then directing the airflow out of the chamber through one or more inlets defined in the chamber, the rear wall being opposite to the front opening of the chamber, and the one or more inlets being positioned closer to the front opening than the rear wall.

[0168] Option 38: The method of any option, further comprising: (f) allowing airflow to flow through the interior side of the door seal during (e); and (g) allowing the exterior side of the door seal to contact the ambient environment during (e).

[0169] Embodiment 39: The method of any embodiment, wherein (c) further comprises directing at least a portion of the airflow vertically around an outer periphery of a shelf positioned in the chamber.

[0170] Option 40: The method according to any option further includes: (h) circulating the first refrigerant in a first refrigerant circuit of the refrigeration module; (i) circulating the second refrigerant in a second refrigerant circuit of the refrigeration module to cool the airflow, wherein the second refrigerant circuit includes an evaporator vertically positioned above the chamber, the evaporator being configured to cool the airflow; and (h) exchanging heat between the first refrigerant and the second refrigerant using an interstage heat exchanger.

[0171] Scheme 41: A low-temperature storage system comprises: a shell, the shell comprising: a chamber having a front opening closable by an outer door and a rear wall opposite to the front opening; one or more outlets defined in the rear wall; an intake duct having one or more inlets defined therein, the inlets being positioned in an upper portion of the chamber, the intake duct being at least partially formed by a tray that is removably inserted into the chamber from the front opening; and a refrigeration module operably connected to the chamber, the refrigeration module being configured to generate an airflow that is directed from the one or more outlets into the chamber and then from the chamber into the one or more inlets of the intake duct to cool the chamber to below -50°C.

[0172] Option 42: The low-temperature storage system according to any option further includes a temperature sensor positioned in the intake duct and mounted to the tray so that the temperature sensor is exposed outside the chamber when the tray is withdrawn from the front opening of the chamber, wherein the refrigeration module includes a controller communicatively coupled to the temperature sensor, and wherein the controller is configured to control the operating state of the components of the refrigeration module based at least in part on the output from the temperature sensor.

[0173] Embodiment 43: The cryogenic storage system of any embodiment, wherein the refrigeration module includes an evaporator configured to reduce the temperature of the airflow, and wherein the evaporator is vertically positioned above the chamber.

[0174] Option 44: A low-temperature storage system according to any option, wherein the refrigeration module includes: a first refrigerant circuit, which is configured to circulate the first refrigerant to exchange heat with the ambient environment around the shell; a second refrigerant circuit, which is configured to circulate the second refrigerant to exchange heat with the chamber, wherein the evaporator is positioned along the second refrigerant circuit; and an interstage heat exchanger thermally coupled between the first refrigerant circuit and the second refrigerant circuit, which is configured to transfer heat between the first refrigerant and the second refrigerant.

[0175] Option 45: A cryogenic storage system according to any of the options, wherein the interstage heat exchanger includes a brazed plate heat exchanger comprising a slender body, the slender body defining: a first inlet and a first outlet connected to a first refrigerant circuit; a second inlet and a second outlet connected to a second refrigerant circuit, wherein the body is substantially horizontally oriented such that: the first inlet and the second outlet are positioned proximate a first lateral side of the body; the second inlet and the first outlet are positioned proximate a second lateral side of the body, the second lateral side being opposite to the first lateral side; the second inlet is vertically positioned lower than the first outlet; and the second outlet is vertically positioned lower than the first inlet.

[0176] Option 46: A low-temperature storage system according to any option, wherein the shell further includes: a door frame extending at least partially around the front opening, the door frame including: a first door stop defining a first sealing surface; and a second door stop defining a second sealing surface, the second door stop being parallel to the first door stop and discontinuous with the first door stop, so that the first door stop and the second door stop are configured to heat shrink independently of each other.

[0177] Option 47: A low-temperature storage system according to any option, wherein the outer door has a door seal, which includes a plurality of sealing protrusions, and the door seal is configured to engage with the door frame, so that the first portion of the plurality of sealing protrusions is configured to engage the first sealing surface, and the second portion of the plurality of sealing protrusions is configured to engage the second sealing surface.

[0178] Option 48: The low-temperature storage system according to any option further includes a user interface mounted to the outer door, wherein the user interface protrudes outward from the outer door, so that the user interface includes: a terminal; a plurality of side surfaces extending between the terminal and the outer door; an electronic display positioned on the terminal; and an indicator light positioned on one of the plurality of side surfaces, the indicator light being configured to emit light corresponding to the operating status of the refrigeration module.

[0179] Option 49: The cryogenic storage system of any one of the options, wherein the plurality of side surfaces taper inwardly as they extend outwardly from the outer door to the terminal.

[0180] Embodiment 50: The cryogenic storage system according to any embodiment, wherein the interface assembly has a truncated pyramid shape such that the plurality of side surfaces have a trapezoidal shape.

[0181] Option 51: A low-temperature storage system according to any option, wherein the chamber includes a pair of side walls extending laterally between a front opening and a rear wall, wherein the system further includes: a shelf positioned within the chamber, the shelf including an outer periphery; and a shelf support positioned in the chamber, which is configured to support the shelf so that the outer periphery is spaced apart from the pair of side walls, the rear wall and the front opening.

[0182] Option 52: A low-temperature storage system according to any option, wherein the shelf support includes one or more inclined surfaces that are configured to direct the outer periphery of the shelf away from the pair of side walls, wherein the shelf includes a top side and a bottom side opposite the top side, wherein the bottom side includes a pair of centering posts that are configured to engage with the shelf support to direct the outer periphery of the shelf away from the rear wall and the front opening within the chamber.

[0183] Scheme 53: A method comprising: (a) inserting a tray into an upper portion of a chamber of a cryogenic storage system to at least partially define an intake duct in the chamber, the tray defining one or more inlets configured to connect the chamber to fluid communication with the intake duct, and the chamber comprising a rear wall defining a plurality of outlets; and (b) operably connecting a refrigeration module to the chamber, the refrigeration module having a blower and an evaporator, the blower and evaporator being arranged such that the blower is configured to generate an airflow that flows from the evaporator into the chamber via one or more outlets and then from the chamber via one or more inlets to the intake duct to cool the chamber to below -50°C.

[0184] Embodiment 54: The method of any embodiment, further comprising: (c) controlling an operating state of components of the refrigeration module based at least in part on an output of a temperature sensor positioned in the suction duct and mounted to the tray.

[0185] Option 55: The method according to any option, further comprising: (d) withdrawing the tray from the front opening of the chamber; and (e) exposing the temperature sensor to the outside of the chamber due to (d).

[0186] Option 56: The method of any option, wherein the one or more inlets are closer to the front opening than to the rear wall.

[0187] Option 57: The method according to any option further includes: (f) circulating the first refrigerant in a first refrigerant circuit of the refrigeration module; (g) circulating the second refrigerant in a second refrigerant circuit of the refrigeration module, wherein the evaporator is positioned along the second refrigerant circuit; and (h) exchanging heat between the first refrigerant and the second refrigerant using an interstage heat exchanger.

[0188] Embodiment 58: The method of any embodiment, wherein the evaporator is positioned vertically above the chamber.

[0189] Therefore, embodiments disclosed herein relate to cryogenic storage systems that utilize forced air convection in an internal chamber to achieve and maintain low temperatures (e.g., ultra-low temperatures) for products stored therein. In some embodiments, the cryogenic storage system can utilize forced convection via a refrigerated air flow through the chamber to achieve and / or maintain the desired temperature therein. In some embodiments, the refrigeration system of the cryogenic storage system can be constructed and positioned to control and utilize the upward flow of natural heat convection in the chamber to achieve improved operating efficiency. In some embodiments, the cryogenic storage system may include enhanced door seals that are configured to withstand extreme temperature differences between the interior of the cold chamber and the surrounding environment, thereby further improving performance and operating efficiency. In some embodiments, the cryogenic storage system may include alternative or additional features that can further improve its reliability, performance, and / or efficiency during operation. Therefore, by using embodiments disclosed herein, the cryogenic storage system can more consistently and reliably achieve and maintain the desired temperature of the stored products, which is particularly important for degradable materials such as life science products.

[0190] The foregoing discussion describes various exemplary embodiments. However, those skilled in the art will appreciate that the examples disclosed herein have broad application, and that the discussion of any embodiment is merely an example of that embodiment and does not imply that the scope of the present disclosure, including the claims, is limited to that embodiment.

[0191] The accompanying drawings are not necessarily drawn to scale. Some features and components herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown for the sake of clarity and conciseness.

[0192] In the discussion herein and in the claims, the terms "including" and "comprising" are used in an open-ended manner and, therefore, should be interpreted as meaning "including, but not limited to." Furthermore, the terms "couple" or "couples" are intended to indicate either an indirect or direct connection. Thus, if a first device is coupled to a second device, that connection may be through a direct connection between the two devices, or through an indirect connection established via other devices, components, nodes, and connections. Furthermore, as used herein, the terms "axial" and "axially" generally refer to directions along or parallel to a given axis (e.g., the central axis of a body or port), while the terms "radial" and "radially" generally refer to directions perpendicular to a given axis. For example, an axial distance refers to a distance measured along or parallel to an axis, and a radial distance refers to a distance measured perpendicular to an axis. Furthermore, when used herein (including in the claims), when referring to a value, the words "about," "substantially," "approximately," and the like mean within a range of ±10% of the stated value.

[0193] Although exemplary embodiments have been shown and described, modifications thereof may be made by those skilled in the art without departing from the scope or teachings herein. The embodiments described herein are intended to be exemplary only and not restrictive. Many variations and modifications of the systems, devices, and processes described herein are possible and are within the scope of this disclosure. Therefore, the scope of protection is not limited to the embodiments described herein, but is limited only by the following claims, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The statement of identifiers such as (a), (b), (c) or (1), (2), (3) before the steps in a method claim is not intended to nor does it specify a particular order of the steps, but is used to simplify subsequent references to those steps.

Claims

1. A low-temperature storage system comprising: A housing, comprising: a chamber having a front opening closable by an outer door and a rear wall opposite the front opening; one or more outlets defined in the rear wall; and one or more inlets defined in the chamber, the one or more inlets being closer to the front opening than to the rear wall; and a refrigeration module operably coupled to the chamber, the refrigeration module comprising: an evaporator positioned vertically above the chamber; a blower configured to generate an air flow in thermal communication with the evaporator; and and a duct system configured to circulate the airflow between the chamber and the evaporator via the one or more inlets and the one or more outlets, such that the airflow is directed into the chamber through the one or more outlets and then from the chamber into the one or more inlets to cool the chamber.

2. The low temperature storage system according to claim 1, characterized in that The ducting includes an intake duct configured to direct the airflow from the one or more inlets to the evaporator, the intake duct being at least partially formed by a tray that is removably insertable into the chamber from the front opening.

3. The low temperature storage system according to claim 2, characterized in that Also included is a temperature sensor positioned in the intake duct and mounted to the tray so as to be exposed upon ejection of the tray from the chamber, and wherein the refrigeration module includes a controller communicatively coupled to the temperature sensor, wherein the controller is configured to control an operating state of components of the refrigeration module based at least in part on an output from the temperature sensor.

4. The low temperature storage system according to claim 1, characterized in that The refrigeration module includes a cascade refrigeration module, and the cascade refrigeration module includes: a first refrigerant circuit configured to circulate a first refrigerant to exchange heat with an ambient environment around the housing; a second refrigerant circuit configured to circulate a second refrigerant to exchange heat with the chamber, wherein the evaporator is positioned along the second refrigerant circuit; and An interstage heat exchanger is thermally coupled between the first refrigerant circuit and the second refrigerant circuit and is configured to transfer heat between the first refrigerant and the second refrigerant.

5. The low temperature storage system according to claim 4, characterized in that The refrigeration module is configured to reduce the temperature within the chamber to below -50°C via the air flow.

6. The low temperature storage system according to claim 4, characterized in that The interstage heat exchanger comprises a brazed plate heat exchanger including an elongated body defining: a first inlet and a first outlet connected to a first refrigerant circuit; and a second inlet and a second outlet, the second inlet and the second outlet being connected to the second refrigerant circuit, wherein the body is oriented substantially horizontally such that: the first inlet and the second outlet being positioned proximate a first lateral side of the body; the second inlet and the first outlet being positioned proximate a second lateral side of the body, the second lateral side being opposite the first lateral side; the second inlet is positioned vertically lower than the first outlet; and The second outlet is positioned vertically lower than the first inlet.

7. The low temperature storage system according to claim 1, characterized in that The housing further comprises: A door frame extending around the front opening, the door frame comprising: a first door stop defining a first sealing surface; and A second door stop defines a second sealing surface, the second door stop being parallel to and discontinuous with the first door stop such that the first and second door stops are configured to heat shrink independently of each other.

8. The low temperature storage system according to claim 7, characterized in that The exterior door has a door seal including a plurality of sealing projections configured to engage the door jamb such that a first portion of the sealing projections is configured to engage the first sealing surface and a second portion of the sealing projections is configured to engage the second sealing surface.

9. The low temperature storage system according to claim 8, characterized in that The first door stop and the second door stop include one or more slender sections, wherein the door frame further includes a slender connecting member, which is arranged between the corresponding sections of the first door stop and the second door stop, so that the corresponding sections of the first door stop and the second door stop are configured to expand longitudinally or contract longitudinally relative to the slender connecting member.

10. The low temperature storage system according to claim 9, characterized in that The elongated connecting member is engaged between corresponding sections of the first and second door stops via a tongue-and-groove joint.

11. The low temperature storage system according to claim 1, characterized in that Also included is a user interface mounted to the exterior door, wherein the user interface projects outwardly from the exterior door such that the user interface includes: terminal; a plurality of side surfaces extending between the terminal end and the exterior door; an electronic display positioned on the terminal; and An indicator light is positioned on one of the plurality of side surfaces and is configured to emit light corresponding to an operating status of the refrigeration module.

12. The low temperature storage system according to claim 1, characterized in that The chamber includes a pair of side walls extending laterally between the front opening and the rear wall, and wherein the cryogenic storage system further comprises: a shelf positioned within the chamber, the shelf including an outer perimeter; and A shelf support is positioned in the chamber, the shelf support configured to support the shelf such that the outer perimeter is spaced apart from the pair of side walls, the rear wall, and the front opening.

13. The low temperature storage system according to claim 12, characterized in that The shelf support includes one or more inclined surfaces configured to direct an outer perimeter of the shelf away from the pair of side walls.

14. The low temperature storage system according to claim 13, characterized in that The shelf includes a top side and a bottom side opposite the top side, wherein the bottom side includes a pair of centering posts configured to engage the shelf support to direct the outer periphery of the shelf away from the rear wall and the front opening within the chamber.

15. A method comprising: (a) generating an air flow with a blower of a refrigeration module, the refrigeration module being operably coupled to the chamber of the cryogenic storage system; (b) cooling the airflow using an evaporator of the refrigeration module, the evaporator being vertically positioned above the chamber; (c) directing the airflow into the chamber through one or more outlets positioned along a rear wall of the chamber and then out of the chamber through one or more inlets defined in the chamber to cool the chamber, the rear wall being opposite a front opening of the chamber and the one or more inlets being positioned closer to the front opening than the rear wall.

16. The method according to claim 15, characterized in that (c) comprising directing the airflow out of the chamber through the one or more inlets into an intake duct at least partially defined by a tray removably insertable into an upper portion of the chamber.

17. The method according to claim 16, characterized in that Also includes: (d) directing the airflow over a temperature sensor mounted to the tray; as well as (e) controlling an operating state of a component of the refrigeration module based at least in part on output from the temperature sensor.

18. The method according to claim 15, characterized in that Also includes: (f) circulating a first refrigerant in a first refrigerant circuit of the refrigeration module; (g) circulating a second refrigerant in a second refrigerant circuit of the refrigeration module, wherein the evaporator is positioned along the second refrigerant circuit; and (h) exchanging heat between the first refrigerant and the second refrigerant using an interstage heat exchanger.

19. The method according to claim 18, characterized in that The interstage heat exchanger comprises brazing plates, and wherein (h) comprises: (h1) causing the first refrigerant to flow transversely between a first inlet and a first outlet in the interstage heat exchanger; and (h2) causing the second refrigerant to flow transversely between a second inlet and a second outlet in the interstage heat exchanger, the second inlet and the second outlet being vertically positioned lower than the first outlet and the first inlet, respectively.

20. The method according to claim 15, wherein Also includes: (i) sealing the front opening of the chamber to seal the chamber from the surrounding environment by engaging a door seal on the outer door with a door jamb positioned around the front opening, wherein the door jamb comprises: a first door stop defining a first sealing surface; and A second door stop defines a second sealing surface, the second door stop being parallel to and discontinuous with the first door stop such that the first and second door stops are configured to heat shrink independently of each other.

21. The method according to claim 20, characterized in that The door seal comprises a plurality of sealing protrusions, and wherein (i) further comprises: (i1) engaging a first portion of the plurality of sealing protrusions with the first sealing surface; and (i2) Engaging a second portion of the plurality of sealing protrusions with the second sealing surface.

22. The method according to claim 15, wherein The chamber includes a pair of side walls extending laterally between the front opening and the rear wall, and wherein the method further includes centering a shelf in the chamber with a shelf support such that an outer periphery of the shelf is spaced apart from the pair of side walls, the rear wall, and the front opening.

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