Method And System For Reducing Thermal Leak By Decoupling A Thermal Interface
20210199372 · 2021-07-01
Inventors
Cpc classification
F25B30/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25D13/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25D29/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25B2500/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F25D19/006
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
The present disclosure relates to issues that may arise from power loss in temperature control systems, such as a heat pump or thermal engine. According to the present disclosure, a temperature control system may comprise a temperature-controlling device configured to control a temperature-controlled unit. The temperature-controlling device and the temperature-controlling device may be thermally connectable through a thermal path connector. The thermal path connector may be actuatable, wherein actuation of the thermal path connector breaks the thermal path between the temperature-controlling device and the temperature-controlled unit, wherein the break limits temperature leak. Actuation may occur during power loss, which may allow for sustained temperatures without additional power.
Claims
1. A temperature control system comprising: a temperature-controlled unit; a temperature-controlling device configured to control a temperature of the temperature-controlled unit, wherein the temperature controlling device is connectable to a power source; a thermal path connector comprising: an actuatable connector comprising a first end comprising a first thermal interface connectable to the temperature-controlled unit; a second end comprising a second thermal interface connectable to the temperature-controlling device; and an actuation mechanism configured to actuate the actuatable connector based on predefined parameters, wherein actuation of the actuatable connector controls connection of one or both the first thermal interface to the temperature-controlled unit and the second thermal interface and the temperature-controlling device, and wherein when connected, a thermal path between the temperature-controlled unit and the temperature-controlling device is continuous, and wherein when one or both the first thermal interface and the second thermal interface is disconnected, the thermal path is broken.
2. The system of claim 1, wherein actuation of the thermal path connector occurs with power loss.
3. The system of claim 2, wherein the temperature control system comprises a power detector configured to detect power loss, wherein the power detector prompts actuation of the thermal path connector.
4. The system of claim 1, wherein the temperature-controlled unit comprises a plurality of zones, wherein temperature of each zone is independently controllable.
5. The system of claim 1, wherein the temperature-controlling device comprises a thermodynamic engine.
6. The system of claim 1, wherein the temperature-controlled unit comprises: a containing portion comprising: a cavity comprising at least a first containing wall to contain a load, wherein the temperature-controlling device directly or indirectly controls a load temperature when the load is located within the cavity, an opening configured to receive the load into the cavity; and a lid comprising a movable cover configured to control access to the opening, wherein a closed position of the lid limits passive temperature change within the cavity.
7. The system of claim 6, wherein one or both the lid and the opening further comprises rigid bellows configured to limit passive temperature change within the cavity.
8. The system of claim 6, wherein the temperature-controlled unit further comprises a second containing wall, wherein the second containing wall surrounds the first containing wall.
9. The system of claim 8, wherein a space between the first containing wall and the second containing wall comprises a vacuum jacket.
10. The system of claim 1, wherein the temperature control system is configured to operate in one or both microgravity or zero gravity conditions.
11. The system of claim 1, wherein the actuatable connector comprises a thermal strap.
12. A thermal path connector comprising: an actuatable connector comprising a first end comprising a first thermal interface connectable to a temperature-controlled unit; a second end comprising a second thermal interface connectable to a temperature-controlling device; and an actuation mechanism configured to actuate the actuatable connector based on predefined parameters, wherein actuation of the actuatable connector controls connection of one or both the first thermal interface to the temperature-controlled unit and the second thermal interface and the temperature-controlling device, and wherein when connected a thermal path between the temperature-controlled unit and the temperature-controlling device is continuous, and wherein when one or both the first thermal interface and the second thermal interface is disconnected, the thermal path is broken.
13. The thermal path connector of claim 12, wherein the thermal path connector comprises a pivot mechanism connected to the actuatable connector, wherein actuation of the actuatable connector occurs by pivoting the thermal path connector and wherein pivoting disconnects one or both the first thermal interface and the second thermal interface.
14. The thermal path connector of claim 12, wherein breaking the thermal path limits passive temperature change of the temperature-controlled unit.
15. The thermal path connector of claim 12, wherein actuation of the actuatable connector occurs with power loss.
16. The thermal path connector of claim 12, wherein a resting state of the thermal path connector disconnects one or both the first thermal interface to the temperature-controlled unit and the second thermal interface and the temperature-controlling device.
17. The thermal path connector of claim 12, wherein the actuatable connector comprises a thermal strap.
18. A temperature control system comprising: a temperature-controlled unit; a plurality of temperature-controlling devices connectable to a power source, wherein each of the plurality of temperature-controlling devices is configured to control temperature of the temperature-controlled unit when connected to the power source; and a first thermal path connector comprising: a first actuatable connector comprising: a first end comprising a first thermal interface connectable to the temperature-controlled unit, a second end comprising a second thermal interface connectable to at least a first portion of the plurality of temperature-controlling devices, and a first actuation mechanism configured to actuate the first actuatable connector based on predefined parameters, wherein actuation of the first actuatable connector controls connection of one or both the first thermal interface and the second thermal interface, and wherein when both the first thermal interface and the second thermal interface are connected a thermal path between the temperature-controlled unit and at least the first portion of temperature-controlling devices is continuous, and wherein when one or both the first thermal interface and the second thermal interface is disconnected, the thermal path is broken.
19. The system of claim 18, further comprising a second thermal path connector comprising: a second actuatable connector comprising: a third end comprising a first thermal interface connectable to the temperature-controlled unit, a fourth end comprising a second thermal interface connectable to at least a second portion of the plurality of temperature-controlling devices, and a second actuation mechanism configured to actuate the second actuatable connector based on predefined parameters, wherein actuation of the actuatable connector controls connection of one or both the third thermal interface and the fourth thermal interface, and wherein when both the second thermal interface and the fourth thermal interface are connected a thermal path between the temperature-controlled unit and at least the second portion of temperature-controlling devices is continuous, and wherein when one or both the third thermal interface and the fourth thermal interface is disconnected, the thermal path is broken.
20. The system of claim 18, wherein breaking the thermal path limits passive temperature change of the temperature-controlled unit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings that are incorporated in and constitute a part of this specification illustrate several embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure:
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DETAILED DESCRIPTION
[0064] In the following sections, detailed descriptions of examples and methods of the disclosure will be given. The description of both preferred and alternative examples, though thorough, are exemplary only, and it is understood to those skilled in the art that variations, modifications, and alterations may be apparent. It is therefore to be understood that the examples do not limit the broadness of the aspects of the underlying disclosure as defined by the claims.
Glossary
[0065] Temperature-Controlled Unit: as used herein refers to the portion of the temperature control system that is targeted for temperature control. In some embodiments, the temperature-controlled unit may operate without power. The temperature-controlled unit may slow heat transfer sufficient to allow for controlled temperature retention within the temperature threshold. In some implementations, the temperature-controlled unit may transmit information indicating the expiration period of the integrity of the temperature within the temperature-controlled unit after a disconnection with a power source. In some aspects, a temperature-controlled unit may comprise a container configured to hold a load, wherein the container may comprise an opening, lid, and cavity. The opening may accept a load into the cavity, and the lid may control access to the opening and cavity. [0066] Temperature Controlling Device: as used herein refers to a device directly or indirectly thermally connectable to a temperature-controlled unit such as through the thermal path connector. When the thermal path is continuous, a temperature-controlling device may heat or cool the temperature-controlled unit. As non-limiting examples, a temperature control system may comprise a Stirling engine cryocooler, a heat pump, a thermal engine, thermoelectric plates, or a solid-state cooler. [0067] Flexible Bellows: as used herein refers to a connector mechanism that may change in length or orientation when subjected to outside force. [0068] Rigid Bellows: as used herein refers to a pleated edge that limits leak of heat or cold. In some embodiments, rigid bellows may comprise edge-welded bellows. In some aspects, rigid bellows may be located on a perimeter of one or both a lid of a temperature-controlled unit and an opening of a temperature-controlled unit. The lid and opening of a temperature-controlled unit may be particularly susceptible to temperature leak. [0069] Temperature Control System: as used herein refers to a system configured to control a temperature of a load. In some aspects, a temperature control system may comprise a temperature-controlling device thermally connectable to a temperature-controlled unit, wherein connection may be controlled at least in part by a thermal path connector. In some embodiments, a temperature control system may comprise a power source. In some implementations, a temperature control system may be connected to an external power source, such as power from a space station, manufacturing plant, or space craft, as non-limiting examples. [0070] Temperature Leak: as used herein refers to a loss of temperature control. For example, where a temperature-controlling device may cool a temperature-controlled unit, a temperature leak may comprise heat gain. Where a temperature-controlling device may heat a temperature-controlling device, a temperature leak may comprise heat loss. Temperature leak may occur passively with or without power, such as at connection points within a TCS. Temperature leak may occur during loss of power when temperature equilibrium may naturally shift temperature from a temperature-controlled unit back to a temperature-controlling device. [0071] Heat or heating: as used herein refers to a temperature warmer than another temperature in the temperature control system. The term heat is used relative to the term cold. For example, heat may comprise −70 degrees C. and cold may comprise −80 degrees C. [0072] Cold or cooling: as used herein refers to a temperature cooler than another temperature in the temperature control system. The term cold is used relative to the term heat. For example, cold may comprise 75 degrees C. and heat may comprise 80 degrees C. [0073] Conductive Interface: as used herein refers to a connection point along a thermal path. In some embodiments, a conductive interface may occur in one or more locations along the thermal path. As non-limiting examples, conductive interfaces may be located at the junction between a thermal strap and a cryocooler finger, at the junction between a heat sink and a thermal bar. [0074] Thermal Path: as used herein refers to a path that allows for a thermal connection between a temperature-controlling device and temperature-controlled unit. In some aspects, a thermal path connector controls continuity of the thermal path. [0075] Thermal Path Connector (thermal path connector): as used herein refers to a moveable conductive piece that connects the thermal path between the temperature-controlling device and the temperature-controlled unit. In some embodiments, the thermal path connector may disconnect or be disconnectable from the temperature-controlling device or temperature-controlled unit at a conductive interface wherein disconnecting breaks the thermal path between the temperature-controlling device and the temperature-controlled unit. In some aspects, the conductive interface may be located at one or more locations such as between the thermal path connector and the temperature-controlling device, between the thermal path connector and the temperature-controlled unit, within the thermal path connector, or any combination thereof. In some aspects, such as with a Stirling engine, a thermal path connector may be continuous through a thermal strap of flexible material between a heat sink and cryocooler finger. In some embodiments, a thermal path connector may comprise a rigid bar with limited flexibility. In some implementations, such as with thermoelectric plates, a thermal path connector may comprise semiconductor pillars. [0076] Load: as used herein refers to an object or container that may be directly or indirectly temperature controlled by a temperature control system. In some aspects, a load may be directly connected to the temperature control system. In some embodiments, a load may be indirectly controlled by placing it in a container directly controlled by the temperature control system. A load may be indirectly controlled by a temperature-controlled unit that is directly or indirectly connected by a thermal path connector to a temperature-controlling device. In some implementations, a temperature-controlled unit may comprise a container that may accept a load.
[0077] Referring now to
[0078] In some embodiments, a power supply may exist as a live connection to a larger source of energy. In some implementations, the power supply may be portable. For example, a removeable battery with insertable prongs may be attached to the top of the temperature control system 100. This may be useful in applications where connections may impede the use of the temperature control system in aspects of motion, such as rotation around the outside of a satellite.
[0079] Referring now to
[0080] In some aspects, where the object may be cooled, the heat input side may occur at a conductive interface, and the heat output side may occur through the temperature-controlled unit 210. In some embodiments, where the object may be heated, the heat output side may occur into temperature-controlled unit 210, and the heat input side may occur at a conductive interface, wherein the thermal path connector 230 and the passive heat exchanger 215 may be reversed in location. In some aspects, the temperature-controlled unit 210 may be surrounded by a vacuum jacket 255, which may provide insulation. In some embodiments, the temperature-controlled unit 210 may be surround by phase change material, which may act as a thermal energy battery. In some implementations, a thermal energy battery may store and release thermal energy, which may allow for more efficient storage and release of energy than if no thermal energy battery was in place.
[0081] In some embodiments, a power sensor may discern between intentional and expected power loss. For example, if the power source is removed intentionally, the intended result may be to return to ambient temperature, and a break in the thermal path may delay that process. In some implementations, power loss intended to allow for a temperature leak may maintain continuity of the thermal path. Power loss that is unintentional or power loss that is still intended to maintain a temperature may trigger actuation of a thermal path connector.
[0082] In some aspects, terminating power may occur at a different rate, which may allow the power sensor to distinguish between intentional and unintentional power loss. In some embodiments, manual power loss may provide an option to prevent the actuator power sources from providing power to the actuator. As non-limiting examples, a temperature control system 200 may be used to maintain temperatures for space flight hardware, heat exchangers, and cold trap condensers.
[0083] Referring now to
[0084] Referring now to
[0085] In some embodiments, the bellows 225 may affect the power requirements for actuation. For example, the resting state of the bellows may be in the compressed configuration for breaking the conductive surface 235, which may lower the power requirements to actuate the thermal path connector 230, as the bellows 225 may act as a spring. As non-limiting examples, actuation may be performed by linear or rotary actuators, solenoids, stepper, servo, DC motor, or BLDC driven. In some embodiments, other elements (e.g., actuating pins) are utilized to lock or hold the temperature-controlling device connector 220 in a position where it does not contact thermal path connector 230 or otherwise contact the temperature-controlled unit 210.
[0086] Referring now to
[0087] In some embodiments, the temperature-controlled unit 310 may comprise a container 350, which may be surrounded by a vacuum jacket 355. The container portion may comprise a cavity and an opening configured to accept a load into the cavity. The container 350 may comprise a lid that is a movable cover configured to control access to the opening. One or both the lid and opening may comprise material and features that may limit temperature leak, such as rigid bellows 365, insulation, or temperature-specific materials.
[0088] In some implementations, the thermal path connector 330 may penetrate the vacuum jacket 355 as it connects to the temperature-controlled unit 310. In some aspects, a plurality of conductive surfaces may connect to the thermal path connector 330 to disseminate the transferred thermal energy into the temperature-controlled unit 310. In some embodiments, the dispersion of this thermal energy may be supplemented by a convection device 340. This convection device 340 may assist in circulating radiated thermal energy emitting from the surfaces within the temperature-controlled unit 310. In some implementations, the conductive surfaces may come in contact with fluids comprising predefined thermophysical properties. These thermophysical properties may allow the fluid to store thermal energy to allow for energy dissipation over time without requiring a thermal source or power connection to supply thermal energy.
[0089] Referring now to
[0090] For example, as a power sensor detects a loss of power, the temperature control system 400 may utilize the final traces of power stored as capacitance to activate the actuation mechanism 418. The actuation mechanism 418 may adjust the position of the thermal path connector 430 to disrupt the thermal path. In some embodiments, the actuation mechanism 418 may actuate the thermal path connector back to the connected position, reestablishing continuity of the thermal path when power is reconnected to the temperature control system 400.
[0091] Referring now to
[0092] Referring now to
[0093] Referring now to
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[0096] In some aspects, actuation of the temperature-controlled unit 710 may be performed with linear steppers or servo actuators. For example, one or more linear solenoids, electromagnets, and similar may be used. In some implementations, separating the conductive interface may not be linear. For example, the gap may occur by rotating one or both the thermal path connector and the temperature-controlled unit 710, wherein 2-axis displacement plus rotation off-axis may further limit radiative transfer by changing the view factor between the two faces.
[0097] In some embodiments, a temperature control system may utilize an array of temperature-controlled unit 710 that may allow for more precise temperature control of a load. For example, a plurality of temperature-controlled unit 710 may be thermally connected to a load at various positions. The different positions may require different temperatures or may have different temperature sensitivity. In some aspects, the array may be arranged based on the unique cooling or heating needs of a system.
[0098] As an illustrative example, a satellite may be built to spin at a predefined speed, wherein the spin may limit exposure of any one portion of the satellite to solar radiation. An array of temperature-controlled unit 710 may be arranged around the satellite, wherein the conductive interfaces of each temperature-controlled unit 710 may engage when the portion of the satellite it controls is exposed to a threshold level of solar radiation and disengage when the exposure falls below the threshold level.
[0099] Referring now to
[0100] The temperature control system 800 may comprise a power sensor 860, which may monitor power levels. The power sensor 860 may detect when a power level falls below a predefined threshold level, wherein detection may cause activation of the pivot mechanism 822. In some implementations, the power sensor 860 may be configured to detect unexpected loss of power, wherein intentional disconnection of the temperature control system 800 may not trigger activation of the pivot mechanism 822.
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[0107] As shown, the actuator mechanism 1118 may be located outside the vacuum jacket 1155. In some embodiments, flexible bellows 1125 may attach the thermal path connector 1130 to the actuator mechanism 1118. Though shown within the flexible bellows 1125, a vacuum jacket 1155 may be more inclusive and may surround one or more of the thermal path connector 1130, the actuator mechanism 1118, or temperature-controlling device 1105. In some implementations, the flexible bellows 1125 may act as a spring, wherein the resting position allows for a normally open configuration.
[0108] Referring now to
[0109] Referring now to
[0110] For example, the phase change material may be cooled to a predefined temperature, such as −70° C., 230° C., or 0° C., as non-limiting examples. When the power is disconnected, the phase change material may maintain a predefined temperature within the temperature-controlled unit 1210 for a predetermined amount of time, such as 2 hours, 4 days, or 36 hours, as non-limiting examples. In some aspects, the phase change material may be located within smaller containers, sleeves, or sacs within the container 1250 of the temperature-controlled unit 1210.
[0111] In some implementations, the phase change material may be removeable. For example, a composite material may be more conducive to maintaining a lower temperature within the temperature-controlled unit 1210. A viscous liquid may be substituted for the composite material as a different load is introduced into the temperature-controlled unit 1210 and the temperature requirements change. In some embodiments, the walls of the container 1250 may be hollow. In some implementations, hollow walls within the container 1250 may allow for the presence of phase change material. In some aspects, the walls of the container 1250 may enclose the phase change material to prevent interaction with the load inserted within the temperature-controlled unit 1210.
[0112] Referring now to
[0113] Referring now to
[0114] Referring now to
[0115] Referring now to
[0116] In some implementations, the temperature-controlled unit may utilize rigid bellows 1465 to reduce heat loss from the temperature-controlled unit 1410 interacting with the ambient temperature. In some aspects, the temperature-controlled unit may comprise a plurality of conductive surfaces 1435 to bring phase change material to the predefined temperature. In some embodiments, the temperature-controlled unit may comprise a continuous conductive surface 1435 that extends to the placement of the phase change material to facilitate equal thermal energy distribution. In some implementations, the conductive surface 1435 may extend to a vertical orientation to increase the efficiency of distributing thermal energy to the phase change material.
[0117] Referring now to
[0118] Referring now to
[0119] In some aspects, the visual indicator 1670 may provide information detailing the estimated time until the temperature threshold within the temperature-controlled unit is compromised. In some embodiments, this visual indicator 1670 may utilize low quantities of energy to inscribe an energy independent message on the visual indicator 1670. For example, the visual indicator 1670 may utilize electronic ink that retains a form memory after its initial creation via electrical impulse. In some implementations, the visual indicator 1670 may possess lights to indicate power connection and power loss.
[0120] Referring now to
[0121] As an illustrative example, a satellite may be built to spin at a predefined speed, wherein the spin may limit exposure of any one portion of the satellite to solar radiation. An array of temperature-controlled unit 1710 may be arranged around the satellite, wherein the conductive interfaces of each temperature-controlled unit 1710 may engage when the portion of the satellite it controls is exposed to a threshold level of solar radiation and disengage when the exposure falls below the threshold level.
[0122] Referring now to
[0123] In some implementations, separate temperature-controlling devices may independently control each temperature-controlled unit zone 1810, 1811. In some aspects, a temperature-controlling device may control multiple temperature-controlled unit zones 1810, 1811. A temperature-controlling device may cycle through temperature control states, such as heating, cooling, and off states, depending on the predefined target temperatures of the temperature-controlled unit and temperature-controlled unit zones 1810, 1811.
[0124] Referring now to
[0125] Referring now to
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CONCLUSION
[0127] A number of embodiments of the present disclosure have been described. While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any disclosures or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the present disclosure.
[0128] Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination or in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in combination in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.
[0129] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous.
[0130] Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
[0131] Thus, particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order show, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the claimed disclosure.