Scalable thermal energy recycling for cryogenic systems

Abstract

Systems and techniques are provided that facilitate scalable thermal energy recycling for cryogenic systems. In various embodiments, the system can include at least one cryostat. In various aspects, the system can further include a heat battery coupled to the at least one cryostat by a heat exchange system. In various cases, the heat battery can be configured to store thermal energy extracted from the at least one cryostat or to supply thermal energy to the at least one cryostat.

Description

[Background technology]

[0001] The present disclosure relates to cryogenic systems, and more particularly to scalable thermal energy recycling for cryogenic systems.

[0002] Because quantum processors rely on extremely low temperatures for proper operation, such quantum processors may be implemented within a cryostat. During a cooling cycle, the cryostat may consume input electrical energy to transfer thermal energy outside the cryostat. During an active warming cycle, the cryostat may consume input electrical energy to transfer thermal energy to the cryostat. During a passive warming cycle, the cryostat may avoid consuming input electrical energy at the expense of longer warming times. In any case, the energy or time spent cooling or warming the cryostat may be considered a cost of operating the cryostat. As quantum processors and the cryostats that house them scale up in size, such costs may accumulate significantly, which may be undesirable.

[0003] Therefore, systems or techniques that can address one or more of these technical problems would be desirable. Summary of the Invention

[0004] The following presents a summary to provide a basic understanding of one or more embodiments of the invention. This summary is not intended to identify key or critical elements or to delineate the scope of any particular embodiments or the claims. Its sole purpose is to present concepts in a simplified form as a prelude to the more detailed description that is presented later. In one or more embodiments described herein, a device, system, method, or apparatus that can facilitate scalable thermal energy recycling for cryogenic systems is described.

[0005] According to one or more embodiments, a system is provided. In various aspects, the system can include at least one cryostat. In various cases, the system can include a heat battery coupled to the at least one cryostat by a heat exchange system. In various cases, the heat battery can be configured to store thermal energy extracted from the at least one cryostat or to supply thermal energy to the at least one cryostat. In various aspects, the heat battery can be thermally insulated from an ambient environment surrounding the at least one cryostat by a vacuum chamber, a heat shield, or by underground installation. In various cases, the heat battery can include a plurality of thermally insulated cells that can each be coupled to the at least one cryostat via a plurality of actuatable flow valves of the heat exchange system.

[0006] According to one or more embodiments, a method is provided. In various aspects, the method can include opening, via one or more controllers, one or more first flow valves of heat exchange piping, wherein the heat exchange piping can couple a cryostat to a heat battery, and wherein a first cell of the heat battery can be thermally integrated with the cryostat when the one or more first flow valves are open. In various cases, the method can further include circulating a heat exchange fluid between the cryostat and the first cell via a pump and through the heat exchange piping until a temperature of the cryostat is within a threshold margin of a temperature of the first cell.

[0007] According to one or more embodiments, a device is provided. In various aspects, the device can include a heat battery suspended in a vacuum chamber. In various cases, the device can further include heat exchange tubing that can couple the heat battery to an exterior of the vacuum chamber.

[0008] Various other details of the various embodiments described herein are provided in the following sections:

[0009] Item 1: A system comprising: at least one cryostat; and a thermal battery coupled to the at least one cryostat by a heat exchange system, wherein the thermal battery is configured to store thermal energy extracted from the at least one cryostat or to supply thermal energy to the at least one cryostat.

[0010] Item 2: The system of any preceding item, wherein the thermal battery is thermally isolated from the ambient environment surrounding the at least one cryostat by a vacuum chamber, by a heat shield, or by underground installation.

[0011] Item 3: The system of any preceding item, wherein the at least one cryostat is colder than the heat battery, and the heat exchange system is configured to circulate a heat exchange fluid between the at least one cryostat and the heat battery, the circulation configured to cause the heat exchange fluid to absorb energy from the heat battery and deposit the energy in the at least one cryostat.

[0012] Item 4: The system of any preceding item, wherein the at least one cryostat is below 5 Kelvin.

[0013] Item 5: The system of any preceding item, wherein the at least one cryostat is warmer than the heat battery, and the heat exchange system is configured to circulate a heat exchange fluid between the at least one cryostat and the heat battery, the circulation being configured to cause the heat exchange fluid to absorb energy from the at least one cryostat and deposit the energy in the heat battery.

[0014] Item 6: The system of any preceding item, wherein the at least one cryostat is at room temperature.

[0015] Item 7: The system of any preceding item, wherein the thermal battery has a plurality of thermally insulated cells each coupled to the at least one cryostat via a plurality of actuatable flow valves of the heat exchange system.

[0016] Item 8: The system of any preceding item, wherein the plurality of actuatable flow valves are configured to operate in an alternating manner such that at most one of the plurality of thermally isolated cells is thermally coupled to the at least one cryostat at a time.

[0017] Item 9: The system of any preceding item, wherein two or more of the plurality of thermally isolated cells have different masses or different heat capacities from one another.

[0018] Item 10: The system of any preceding item, wherein the cryostat houses a quantum processor.

[0019] In various embodiments, any combination of one or more of any of items 1-10 can be implemented.

[0020] Item 11: A method comprising: opening, via one or more controllers, one or more first flow valves of heat exchange piping, wherein the heat exchange piping couples a cryostat to a thermal battery, wherein a first cell of the thermal battery is thermally integrated with the cryostat when the one or more first flow valves are open; and circulating, via a pump and through the heat exchange piping, a heat exchange fluid between the cryostat and the first cell until the temperature of the cryostat is within a threshold margin of the temperature of the first cell.

[0021] Item 12: The method of any preceding item, further comprising: in response to determining that the temperature of the cryostat is within the threshold margin of the temperature of the first cell, stopping the circulation of the heat exchange fluid between the cryostat and the first cell via the pump; and closing the one or more first flow valves of the heat exchange piping via the one or more controllers, wherein the first cell of the thermal battery is thermally isolated from the cryostat when the one or more first flow valves are closed.

[0022] Item 13: The method of any preceding item, further comprising: opening one or more second flow valves of the heat exchange piping via the one or more controllers in response to closing the one or more first flow valves, wherein a second cell of the thermal battery is thermally integrated with the cryostat when the one or more second flow valves are open; and circulating the heat exchange fluid between the cryostat and the second cell via the pump and through the heat exchange piping.

[0023] Item 14: The method of any preceding item, wherein the first cell and the second cell have different masses or different heat capacities.

[0024] Item 15: The method of any preceding item, wherein the temperature of the cryostat is less than the temperature of the first cell such that circulation of the heat exchange fluid between the cryostat and the first cell causes the cryostat to heat and the first cell to cool.

[0025] Item 16: The method of any preceding item, wherein the temperature of the cryostat is higher than the temperature of the first cell such that circulation of the heat exchange fluid between the cryostat and the first cell causes the cryostat to cool and the first cell to heat.

[0026] In various embodiments, any combination of any one or more of items 11-16 can be implemented.

[0027] Item 17: A device comprising: a heat battery suspended in a vacuum chamber; and heat exchange piping coupling the heat battery to an exterior of the vacuum chamber.

[0028] Item 18: The device of any preceding item, wherein the thermal battery has a copper spherical mass.

[0029] Item 19: The device of any preceding item, wherein the thermal battery has at least two cells, the at least two cells having different masses or different heat capacities from each other.

[0030] Item 20: The device of any preceding item, wherein the heat exchange piping comprises vacuum insulated pipe.

[0031] In various embodiments, any combination of one or more of any of items 17-20 can be implemented. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a structural diagram of an example, non-limiting system for facilitating scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein.

[0033] [Figure 2] FIG. 1 is an example, non-limiting block diagram illustrating how pre-warming via a thermal battery can affect the temperature of a cryostat, according to one or more embodiments described herein.

[0034] [Figure 3] FIG. 1 is an example, non-limiting block diagram illustrating how pre-cooling via a thermal battery can affect the temperature of a cryostat, according to one or more embodiments described herein.

[0035] [Figure 4] FIG. 1 is a structural diagram of an example, non-limiting embodiment of a thermal battery suspended in a vacuum chamber to facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein.

[0036] [Figure 5] FIG. 1 is a flow diagram of an example, non-limiting method for facilitating scalable thermal energy recycling for a cryogenic system, according to one or more embodiments described herein.

[0037] [Figure 6] FIG. 1 is a structural diagram of an example, non-limiting embodiment of a multi-cell thermal battery that facilitates scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein.

[0038] [Figure 7] FIG. 1 is a flow diagram of an example, non-limiting method involving a multi-cell thermal battery facilitating scalable thermal energy recycling for a cryogenic system, according to one or more embodiments described herein.

[0039] [Figure 8] FIG. 1 is a flow diagram of an example, non-limiting method for facilitating scalable thermal energy recycling for a cryogenic system, according to one or more embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0040] The following detailed description is exemplary only and is not intended to limit the embodiments or the application or uses of the embodiments, nor is it intended to be bound by any expressed or implied information presented in the preceding Background or Summary sections or in the Detailed Description section.

[0041] One or more embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a more thorough understanding of one or more embodiments. It will be apparent, however, that in various cases one or more embodiments may be practiced without these specific details.

[0042] A quantum processor can be any suitable device that can implement or otherwise comprise any suitable number and type of qubit architecture. Various non-limiting examples of such qubit architectures can include quantum dots, spin qubits, or superconducting qubits (e.g., transmons or other qubits composed of Josephson junctions). Generally, quantum processors cannot achieve proper operation or functionality above cryogenic temperatures. Therefore, to achieve proper operation, such quantum processors can be implemented in a cryostat.

[0043] A cryostat can be any suitable device capable of cooling an interior region or enclosure of the cryostat to a cryogenic temperature (e.g., via any suitable cryogenic refrigeration technique). During a cooling cycle, the cryostat can consume input electrical energy to transfer thermal energy to the exterior of the interior region or enclosure of the cryostat (e.g., to cool the interior region or enclosure of the cryostat from room temperature to a cryogenic temperature so that any quantum processor housed within the cryostat may operate). For example, the cryostat can include any suitable number of cryogenic compressors capable of circulating a cryogen through a refrigeration cycle, and such cryogenic compressors can be driven by the input electrical energy. Similarly, during an active warming cycle, the cryostat can consume input electrical energy to transfer thermal energy to the interior region or enclosure of the cryostat (e.g., to heat the interior region or enclosure of the cryostat from a cryogenic temperature to room temperature so that any quantum processor housed within the cryostat may be repaired, inspected, or upgraded). For example, a cryostat can include any suitable number of heaters (e.g., heating coils) capable of supplying heat to an interior region or housing of the cryostat, and such heaters can be powered by input electrical energy. In contrast, during a passive warming cycle, the cryostat can avoid consuming input electrical energy at the expense of a longer warming time. For example, a passive warming cycle can involve turning the cryostat off and on and waiting for the cryostat to naturally warm to room temperature as a result of heat transfer from the surrounding environment. However, because the cryostat can be significantly thermally insulated, such a passive warming cycle can take orders of magnitude longer than an active warming cycle.

[0044] Moreover, as the inventors of the various embodiments described herein recognized, electrical energy used to remove heat from the cryostat may be lost to the ambient environment surrounding the cryostat during warming. For laboratory-scale cryostats, this loss may be considered acceptable. However, for large-scale or industrial-scale cryogenic quantum computing server spaces with multiple large cryostats, such loss may be considered unacceptable.

[0045] In other words, the energy or time spent cooling or warming a cryostat can be considered a cost of operating the cryostat. As quantum processors and the cryostats that house them scale up in size, such costs can accumulate prohibitively, which can be undesirable. For example, a cryostat that houses a quantum processor that includes tens or dozens of qubit architectures may require much less energy and time to cool or warm than a cryostat that instead houses a quantum processor that includes hundreds, thousands, or even millions of qubit architectures.

[0046] Therefore, systems or techniques that can address one or more of these technical problems would be desirable.

[0047] Various embodiments described herein may address one or more of these technical problems. In particular, various embodiments described herein may provide systems or techniques that can facilitate scalable thermal energy recycling for cryogenic systems. More specifically, the inventors of various embodiments described herein recognize that when existing techniques are implemented, the electrical energy consumed by a cryostat and the thermal energy operated by the cryostat during a cooling or warming cycle are ultimately lost as waste heat to the ambient environment surrounding the cryostat. Furthermore, the inventors recognize that such waste heat may be considered non-reusable because the ambient environment may be considered an expansive thermal reservoir that does not undergo temperature change in response to such waste heat, or that undergoes at most a negligible temperature change (e.g., below any suitable threshold margin). As described herein, the inventors have devised various techniques for recycling the thermal energy associated with a cryostat so that such lost or non-reusable waste heat can be reduced, and so that the time or electrical energy consumed during a cooling or warming cycle can be correspondingly reduced.

[0048] For example, assume that the interior region or enclosure of a cryostat begins at room temperature. In such a case, it may be desirable to perform a cooling cycle on the cryostat. If the cooling cycle is performed according to existing techniques, electrical energy may be consumed by the cryostat's cryogenic compressor to remove thermal energy from the interior region or enclosure, and both such consumed electrical energy and such removed thermal energy may be discharged to the ambient environment where they are effectively lost or cannot be reused. After such a cooling cycle, the interior region or enclosure of the cryostat may be at a cryogenic temperature. Therefore, it may be desirable to eventually perform a warming cycle on the cryostat. If a warming cycle (which may be active or passive) is performed according to existing techniques, new thermal energy may be injected into the interior region or enclosure so that it once again returns to room temperature. At some point, it may be desirable to perform another cooling cycle. However, during such another cooling cycle, the new thermal energy injected during the warming cycle may be removed by the cryogenic compressor and discharged to the ambient environment where it is lost or cannot be reused. In this way, the cooling and warming cycles may be considered to cancel or otherwise waste the thermal work performed by each other. Moreover, alternating between cooling and warming cycles in accordance with existing techniques may increase the amount of lost or non-reusable waste heat, which may correspondingly increase the amount of time or electrical energy consumed during such alternation.

[0049] To remedy this technical problem, the inventors have devised various techniques, as described herein, that can reuse or otherwise recycle at least a portion of the thermal energy manipulated by the cryostat.

[0050] Indeed, various embodiments described herein may include coupling a heat battery to a cryostat. In various aspects, a temperature difference may exist between the heat battery and the cryostat. Accordingly, a heat exchange fluid may be circulated or cycled between the heat battery and the cryostat to facilitate heat transfer. For example, if the heat battery is at a higher temperature than the cryostat, circulation of the heat exchange fluid may cause thermal energy (e.g., heat) to be absorbed from the heat battery and released to the cryostat, which may correspondingly lower the temperature of the heat battery and increase the temperature of the cryostat. Such heat transfer may be considered pre-warming the cryostat prior to the cryostat performing a warming cycle. As another example, if the heat battery is instead at a lower temperature than the cryostat, circulation of the heat exchange fluid may cause thermal energy to be absorbed from the cryostat and released to the heat battery, which may correspondingly increase the temperature of the heat battery and decrease the temperature of the cryostat. Such heat transfer may be considered to pre-cool the cryostat prior to the cryostat performing a cooling cycle.

[0051] In other words, the heat battery may be considered in some cases to supply thermal energy to the cryostat, or in other cases to extract thermal energy from the cryostat. Note that in either case, the temperature of the heat battery (unlike the temperature of the surrounding environment) may change measurably (e.g., by more than any suitable threshold margin) as it supplies or extracts thermal energy from the cryostat. Due to such measurable changes in temperature, the heat battery may be considered to be able to store or recycle at least some thermal work performed during a previous cooling cycle or a previous warming cycle.

[0052] Thus, when a thermal battery is implemented as described herein, at least some thermal work that would otherwise be lost to the ambient environment can instead be recycled to perform pre-cooling or pre-warming of the cryostat. As described herein, such recycled thermal work can reduce the total amount of electrical energy required to complete a subsequent cooling cycle of the cryostat; the total amount of electrical energy required to complete a subsequent active warming cycle of the cryostat; or the total amount of time required to complete a subsequent passive warming cycle of the cryostat. In other words, various embodiments described herein can reduce the total amount of time or the total amount of input energy required to operate the cryostat.

[0053] More specifically, various embodiments described herein may include a cryostat, a thermal battery, and a heat exchange system. In various aspects, the cryostat may house or otherwise store any suitable number of quantum processors of any suitable type.

[0054] In various instances, the heat battery can be any suitable tangible object whose temperature can measurably change in response to receiving or supplying thermal energy from or to the cryostat. As a non-limiting example, the heat battery can be a chunk of metal (e.g., copper) having any suitable mass, size, or shape. In various cases, the heat battery can be thermally isolated from the ambient environment surrounding the cryostat. As a non-limiting example, the heat battery can be vacuum insulated by being suspended (e.g., in the manner of a chandelier) within any suitable vacuum chamber. Such vacuum insulation can help reduce or prevent heat transfer from occurring between the heat battery and the ambient environment. Moreover, in various aspects, the interior or exterior surfaces of the vacuum chamber can be lined with any suitable thermal barrier (e.g., heat shield material, insulating material), which can further help reduce or prevent heat transfer from occurring between the heat battery and the ambient environment. Additionally, in various cases, the vacuum chamber may be located underground, which may further help reduce or prevent heat transfer from occurring between the thermal battery and the surrounding environment.

[0055] In any case, the heat battery can be coupled to the cryostat via a heat exchange system. In various embodiments, the heat exchange system can include a pump, which pumps a working fluid (e.g., helium 3 ( 3 He) or helium 4( 4The system may also include piping through which the heat battery (He) may be propelled or circulated. In various cases, the piping and pumps, like the heat battery, may be thermally isolated from the surrounding environment (e.g., via vacuum insulation, via a thermal barrier such as a heat shield material or insulating material, or via underground installation). In various cases, the piping may extend through the heat battery (e.g., inside the heat battery) from an inlet end of the heat battery to an outlet end of the heat battery. In various cases, the piping may further extend from an outlet end of the heat battery to an inlet end of the cryostat. In various aspects, the piping may further extend through the cryostat (e.g., inside the cryostat) from an inlet end of the cryostat to an outlet end of the cryostat. In various cases, the piping may further extend from an outlet end of the cryostat to an inlet end of the heat battery. Thus, the piping may be considered to form a closed loop between the cryostat and the heat battery.

[0056] In various embodiments, a pump in a heat exchange system may propel or circulate the working fluid through a closed loop formed by the piping of the heat exchange system. If the temperature of the cryostat is different from the temperature of the heat battery (and if the average temperature of the working fluid is between these two temperatures), propelling or circulating the working fluid may cause heat transfer to occur between the heat battery and the cryostat, and such heat transfer may cease when the pump stops propelling or circulating the working fluid.

[0057] For example, assume that the heat battery begins at a lower temperature than the cryostat. In such a case, propulsion or circulation of the working fluid can cause the working fluid to be at a higher temperature than the heat battery as it passes through the heat battery, and such propulsion or circulation can likewise cause the working fluid to be at a lower temperature than the cryostat as it passes through the cryostat. Thus, the working fluid can absorb thermal energy as it passes through the cryostat, thereby lowering the temperature of the cryostat, and the working fluid can release that thermal energy as it passes through the heat battery, thereby raising the temperature of the heat battery. At some point, propulsion or circulation of the working fluid can cause the temperature of the cryostat to equal (or otherwise fall within any suitable threshold margin of) that of the heat battery. At such point, heat transfer from the cryostat to the heat battery can be stopped or otherwise reduced, despite any further propulsion or circulation of the working fluid. Therefore, at such time, the pump of the heat exchange system can stop propelling or circulating the working fluid and the cryogenic compressor of the cryostat can be started to further reduce the temperature of the cryostat. In other words, if the heat battery starts at a lower temperature than the cryostat, the propelling or circulating of the working fluid can be considered to perform pre-cooling for the cryostat, which can then perform the remainder of the refrigeration cycle after such pre-cooling.

[0058] As another example, suppose the heat battery instead starts at a higher temperature than the cryostat. In such a case, propulsion or circulation of the working fluid can cause the working fluid to be at a lower temperature than the heat battery as it passes through the heat battery, and such propulsion or circulation can similarly cause the working fluid to be at a higher temperature than the cryostat as it passes through the cryostat. Thus, the working fluid can absorb thermal energy as it passes through the heat battery, thereby lowering the temperature of the heat battery, and the working fluid can release that thermal energy as it passes through the cryostat, thereby raising the temperature of the cryostat. As above, propulsion or circulation of the working fluid can, at some point, cause the temperature of the cryostat to equal (or otherwise fall within any suitable threshold margin of) the temperature of the heat battery. At such point, heat transfer from the heat battery to the cryostat can be stopped or otherwise reduced, despite any further propulsion or circulation of the working fluid. Therefore, at such time, the pumps of the heat exchange system can stop propelling or circulating the working fluid and the heating coils of the cryostat can be activated to further increase the temperature of the cryostat. In other words, if the heat battery starts at a higher temperature than the cryostat, the propelling or circulating of the working fluid can be considered to perform pre-warming on the cryostat, and the cryostat can perform the remainder of the warming cycle after such pre-warming.

[0059] It should be noted that in any case, the heat battery and piping of the heat exchange system may be thermally isolated from the ambient environment, such that no, or at most negligible, heat transfer occurs between the heat battery and the ambient environment when working fluid is not being propelled or circulated through the piping. Thus, if a heat battery is used to perform pre-warming for the cryostat, such pre-warming may lower the temperature of the heat battery, and the lack of measurable heat transfer between the heat battery and the ambient environment may cause the temperature of the heat battery to remain lowered until it is desired to perform a subsequent cooling cycle for the cryostat. At that point, the heat battery may be used to perform pre-cooling for the cryostat, and the subsequent cooling cycle may then be performed. Similarly, if a heat battery is used to perform pre-cooling for the cryostat, such pre-cooling may raise the temperature of the heat battery, and the lack of measurable heat transfer between the heat battery and the ambient environment may cause the temperature of the heat battery to remain elevated until it is desired to perform a subsequent warming cycle for the cryostat. At that point, the thermal battery can be used to perform a pre-warming for the cryostat, and a subsequent warming cycle can then be performed.

[0060] Thus, pre-cooling as described herein can transfer thermal energy outside the cryostat and store it in a thermal battery, which can reduce the time or total amount of electrical energy input required to complete a cooling cycle of the cryostat (e.g., the pump of the heat exchange system can consume less electrical energy per unit time than the cryogenic compressor of the cryostat). Conversely, pre-warming as described herein can allow such stored thermal energy to be subsequently transferred out of the heat battery and back to the cryostat, which can reduce the time or total amount of electrical energy input required to complete a warming cycle of the cryostat (e.g., the pump of the heat exchange system can consume less electrical energy per unit time than the heating coil of the cryostat; the pump of the heat exchange system can heat the cryostat faster than passive warming). In other words, the heat battery can be thought of as storing or recycling at least some thermal work previously performed by the cryostat during a preceding warming or cooling cycle, thereby reducing the amount of thermal work the cryostat performs in a subsequent cooling or warming cycle. Therefore, implementation of a heat battery as described herein can help reduce the costs (e.g., time or electrical energy input) associated with operating a cryostat.

[0061] Thus far, the heat battery has been described as exhibiting a single-stage structure (e.g., as being one continuous chunk of metal). However, this is merely a non-limiting example. In various aspects, the heat battery can instead exhibit a multi-stage structure. In such cases, the heat battery can be composed of multiple heat cells, where each heat cell can be a separate chunk of metal having any suitable mass, size, shape, or chemical composition, and the multiple heat cells can be thermally isolated from one another. For example, each of such multiple heat cells can be thermally insulated by a respective vacuum chamber, a respective thermal barrier, or a respective underground installation.

[0062] In various aspects, the piping of the heat exchange system can include a plurality of actuatable valves, each of which can correspond to a plurality of heat cells. When an actuatable valve corresponding to a given heat cell is open, working fluid can flow through the given heat cell. In such a case, the given heat cell can be considered thermally integrated with the cryostat. In other words, when the actuatable valve corresponding to the given heat cell is open, measurable heat transfer can occur between the cryostat and the given heat cell in response to the pump propelling or circulating the working fluid. Conversely, when the actuatable valve corresponding to the given heat cell is closed, working fluid can be prevented from flowing through the given heat cell. In such a case, the given heat cell can be considered thermally isolated from the cryostat. In other words, when the actuatable valve corresponding to the given heat cell is closed, no heat transfer, or at most negligible heat transfer, can occur between the cryostat and the given heat cell in response to the pump propelling or circulating the working fluid.

[0063] In various cases, the actuatable valves can be configured to alternately operate so that at most one of the heat cells can be thermally integrated with the cryostat at any given time. In such cases, one of the heat cells currently thermally integrated with the cryostat can be used to perform pre-warming or pre-cooling on the cryostat. Moreover, in response to the temperature of the cryostat becoming equal to (or otherwise within any suitable threshold margin of) the temperature of the heat cell, the actuatable valves can be operated to thermally isolate the heat cell from the cryostat and to thermally integrate a different one of the heat cells with the cryostat. That different heat cell can then be used to continue such pre-warming or pre-cooling of the cryostat.

[0064] Various embodiments described herein can be utilized to solve problems that are highly technical in nature (e.g., to facilitate scalable thermal energy recycling for cryogenic systems), and such embodiments are not abstract, not merely laws of nature, not merely natural phenomena, and cannot be implemented as a set of mental acts by humans. Instead, various embodiments described herein include tangible thermal-fluid-related structures / architectures or methodologies related to such tangible thermal-fluid-related structures / architectures that can be implemented to reduce the time or electrical energy consumed by a cryostat during a cooling or warming cycle.

[0065] In fact, as mentioned above, when a cryostat operates according to existing techniques, the electrical energy consumed and the thermal energy manipulated by the cryostat during cooling and warming cycles is ultimately lost as waste heat to the ambient environment surrounding the cryostat. Ultimately, a warming cycle may involve injecting thermal energy into the cryostat, and a cooling cycle may involve expelling that thermal energy to the ambient environment where it is lost or unavailable for reuse. In other words, a cooling cycle may be considered to waste the thermal work performed during the preceding warming cycle, and a warming cycle may similarly be considered to waste the thermal work performed during the preceding cooling cycle. Such waste may increase the total amount of time or electrical energy consumed by the cryostat, which may be undesirable.

[0066] Various embodiments described herein can address such technical issues. Specifically, the systems or techniques described herein can include coupling a heat battery to a cryostat, where the heat battery can be thermally isolated (e.g., via vacuum insulation, via a thermal barrier, via underground installation) from the ambient environment surrounding the cryostat. In various aspects, the heat battery and the cryostat can be at different temperatures (e.g., one at room temperature and the other at cryogenic temperatures). Thus, a working fluid (e.g., 3 He, 4Circulating the working fluid (He) can cause a measurable heat transfer between the cryostat and the heat battery. In the case where the heat battery is initially cooler than the cryostat, circulating the working fluid can transfer thermal energy from the cryostat to the heat battery, thereby increasing the temperature of the heat battery and decreasing the temperature of the cryostat. This can be considered pre-cooling the cryostat. After such pre-cooling, the cryostat can perform a cooling cycle, which can consume less time or electrical energy than it would otherwise have consumed (e.g., because the cryostat may have been pre-cooled, the cryostat cooling cycle can be responsible for traversing a smaller temperature range than it would have had to traverse in the absence of pre-cooling). Similarly, in the case where the heat battery is initially warmer than the cryostat, circulating the working fluid can transfer thermal energy from the heat battery to the cryostat, thereby decreasing the temperature of the heat battery and increasing the temperature of the cryostat. This can be considered pre-warming the cryostat. After such pre-warming, the cryostat can perform a warming cycle, which can consume less time or electrical energy than it would have otherwise consumed (e.g., because the cryostat may have been pre-warmed, the cryostat's warming cycle can be responsible for traversing a smaller temperature range than it would have had to traverse in the absence of pre-warming).

[0067] As a non-limiting example, assume that the heat battery starts at room temperature and the cryostat starts at a cryogenic temperature (e.g., the cryostat may have last completed a cooling cycle rather than a warming cycle). In such a case, the heat battery may be used to perform a pre-warming, which may increase the temperature of the cryostat, and this may reduce the temperature of the heat battery below room temperature. After such pre-warming, the cryostat may perform a warming cycle to bring it to room temperature. Again, such a warming cycle may consume less time or electrical energy than it would have otherwise consumed due to the pre-warming. Here, at this point, the cryostat may be at room temperature, but the heat battery may have remained below room temperature because it may be thermally isolated from the ambient environment. Thus, when it is desired for the cryostat to return to cryogenic temperature, the heat battery can be used to perform a pre-cooling, which can reduce the temperature of the cryostat below room temperature, and this can increase the temperature of the heat battery (although the heat battery may still be below room temperature). After such pre-cooling, the cryostat can perform a cooling cycle to return to cryogenic temperature. Again, such a cooling cycle can consume less time or electrical energy than would otherwise be consumed due to the pre-cooling. Note that at such a point, the heat battery can again be considered to be at a higher temperature than the cryostat, so that pre-warming can be performed again once more if desired. In this manner, the heat battery can be implemented to perform multiple iterations of pre-warming and pre-cooling on the cryostat, each iteration reducing the total time or electrical energy required to perform the subsequent cooling or warming cycle by some non-zero amount.

[0068] The various embodiments described herein enable cryostats to consume less time or electrical energy during cooling or warming cycles compared to existing techniques, and therefore certainly constitute concrete and demonstrable technical improvements in the field of cryogenic systems.

[0069] It should be understood that the drawings and disclosure herein illustrate non-limiting examples of various embodiments. It should be further understood that the figures are not necessarily drawn to scale.

[0070] 1 illustrates a structural diagram of an exemplary, non-limiting system 100 that can facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein. As shown, the system 100 can include a cryostat 102, a thermal battery 104, or a heat exchange system 106.

[0071] In various embodiments, the cryostat 102 can be any suitable type of cryostat. As a non-limiting example, the cryostat 102 can be a closed-cycle cryostat. As another non-limiting example, the cryostat 102 can be a continuous-flow cryostat. As yet another non-limiting example, the cryostat 102 can be a multi-stage cryostat.

[0072] In various embodiments, cryostat 102 may store or otherwise accommodate any suitable number of quantum processors of any suitable type. As a non-limiting example, cryostat 102 may store or otherwise accommodate any suitable quantum processor implementing a quantum dot qubit architecture. As another non-limiting example, cryostat 102 may store or otherwise accommodate any suitable quantum processor implementing a spin qubit architecture. As yet another non-limiting example, cryostat 102 may store or otherwise accommodate any suitable quantum processor implementing a superconducting qubit architecture.

[0073] In various cases, cryostat 102 can be configured to perform cooling or warming cycles. During a cooling cycle, cryostat 102 can reduce its temperature (e.g., via a cryogenic compressor circulating a cryogen) to cryogenic levels (e.g., to tens of Kelvin, to less than 5 Kelvin, to just a few milliKelvin) for the purpose of operating the quantum processor housed in cryostat 102. In contrast, during a warming cycle, cryostat 102 can increase its temperature (e.g., via a heating coil or via passive ambient heat transfer) to room temperature levels (e.g., to about 300 Kelvin) for the purpose of performing maintenance tasks (e.g., repair, upgrade, replacement) on the quantum processor housed in cryostat 102.

[0074] In various aspects, thermal battery 104 can be any suitable tangible object having any suitable size, shape, or chemical composition whose temperature can measurably change (e.g., increase or decrease by any suitable threshold margin) in response to receiving thermal energy from or supplying thermal energy to cryostat 102. As a non-limiting example, thermal battery 104 can be a metal object having any suitable dimensions, any suitable mass, and any suitable heat capacity.

[0075] In various cases, the thermal battery 104 can be thermally isolated from the ambient environment surrounding the cryostat 102 via any suitable thermal insulation technique such that no heat transfer, or at most negligible heat transfer (e.g., below any suitable threshold amount) occurs between the thermal battery 104 and the ambient environment. As a non-limiting example, the thermal battery 104 can be suspended within a vacuum chamber such that the thermal battery 104 can be considered vacuum-insulated from the ambient environment. Such vacuum insulation can be considered to increase the amount of thermal resistance between the thermal battery 104 and the ambient environment. As another non-limiting example, the vacuum chamber in which the thermal battery 104 can be suspended can be equipped, internally or externally, with any suitable thermal barrier, such as a heat shield or a layer of insulating material. Such a thermal barrier can be considered to further increase the amount of thermal resistance between the thermal battery 104 and the ambient environment. As yet another non-limiting example, the vacuum chamber in which the thermal battery 104 can be suspended can be positioned, located, or otherwise installed underground. Such underground installation may be considered to even further increase the amount of thermal resistance between the thermal battery 104 and the surrounding environment. In various instances, any other suitable thermal isolation techniques may be implemented for the thermal battery 104 so as to increase the amount of thermal resistance between the thermal battery 104 and the surrounding environment, and thus so that no, or at most negligible, heat transfer can occur between the thermal battery 104 and the surrounding environment.

[0076] In various embodiments, the thermal battery 104 can be coupled to the cryostat 102 by a heat exchange system 106. In various cases, the heat exchange system 106 can include heat exchange piping 108. In various cases, the heat exchange piping 108 can be configured to carry any suitable heat exchange fluid, such as 3 He, 4The heat exchange piping 108 may be any suitable type of piping, tube, or conduit through which the heat exchange fluid (He) may flow. In various aspects, the heat exchange piping 108 may be thermally isolated from the ambient environment such that no, or at most negligible (e.g., less than any suitable threshold amount thereof) heat transfer occurs between the ambient environment and the heat exchange fluid that may flow through the heat exchange piping 108. As a non-limiting example, the heat exchange piping 108 may be or otherwise include vacuum-insulated piping, which may increase the amount of thermal resistance between the heat exchange fluid and the ambient environment. As another non-limiting example, the heat exchange piping 108 may include or otherwise be equipped with any suitable thermal barrier, such as a heat shield or insulating material, which may further increase the amount of thermal resistance between the heat exchange fluid and the ambient environment. As yet another non-limiting example, the heat exchange piping 108 may be positioned, located, or otherwise installed underground, which may even further increase the amount of thermal resistance between the heat exchange fluid and the ambient environment. In various instances, any other suitable thermal insulation techniques can be implemented for the heat exchange piping 108 to increase the amount of thermal resistance between the heat exchange fluid and the surrounding environment, and thus to ensure that no heat transfer, or at most negligible heat transfer, occurs between the heat exchange fluid and the surrounding environment.

[0077] In any case, the heat exchange piping 108 can form a closed loop between the cryostat 102 and the heat battery 104. Indeed, in various embodiments, the heat exchange piping 108 can extend or otherwise feed through the interior of the heat battery 104 and similarly through the interior of the cryostat 102. More specifically, as shown, the heat exchange piping 108 can extend or otherwise feed: from an inlet 110 of the heat battery 104 to an outlet 112 of the heat battery 104; from the outlet 112 of the heat battery 104 to an inlet 114 of the cryostat 102; from the inlet 114 of the cryostat 102 to an outlet 116 of the cryostat 102; and from the outlet 116 of the cryostat 102 to the inlet 110 of the heat battery 104.

[0078] In various embodiments, the heat exchange system 106 can further include a heat exchange pump 118. While Figure 1 depicts the heat exchange system 106 as having a single heat exchange pump (e.g., one instance of 118), this is merely a non-limiting example for ease of illustration. In various cases, the heat exchange system 106 can include any suitable number of heat exchange pumps.

[0079] In various instances, the heat exchange pump 118 may be any suitable device capable of circulating or otherwise propelling a heat exchange fluid through the closed loop formed by the heat exchange piping 108. In the non-limiting example shown in FIG. 1 , the direction in which the heat exchange fluid may be circulated or propelled by the heat exchange pump 118 may be indicated by the reference numeral 120. Accordingly, the heat exchange pump 118 may thus circulate the heat exchange fluid from the inlet 110 of the heat battery 104 to the outlet 112 of the heat battery 104, to the inlet 114 of the cryostat 102, to the outlet 116 of the cryostat 102, and back to the inlet 110 of the heat battery 104.

[0080] In various embodiments, a temperature difference may exist between the heat battery 104 and the cryostat 102. In other words, the temperature of the heat battery 104 may initially differ from the temperature of the cryostat 102. In the presence of such a temperature difference, the circulation or propulsion of heat exchange fluid through the heat exchange piping 108 may result in a measurable heat transfer between the cryostat 102 and the heat battery 104.

[0081] As a non-limiting example, assume that the heat battery 104 is initially at a higher temperature than the cryostat 102. In such a case, the heat exchange pump 118 may circulate or propel the heat exchange fluid through the heat exchange tubing 108 in the direction indicated by the reference numeral 120. Such circulation or propulsion, in various cases, may cause the heat exchange fluid to be at a lower temperature than the heat battery 104 as it passes through the heat battery 104. Therefore, as the heat exchange fluid flows through the heat battery 104, the heat exchange fluid may absorb thermal energy (e.g., heat) from the heat battery 104, thereby decreasing the temperature of the heat battery 104 and increasing the temperature of the heat exchange fluid. Moreover, such circulation or propulsion, in various cases, may cause the heat exchange fluid to be at a higher temperature than the cryostat 102 as it passes through the cryostat 102. Thus, as the heat exchange fluid flows through the cryostat 102, the heat exchange fluid can release thermal energy (e.g., heat) to the cryostat 102, thereby increasing the temperature of the cryostat 102 and decreasing the temperature of the heat exchange fluid. In this manner, the heat exchange system 106 can be thought of as transferring thermal energy from the heat battery 104 to the cryostat 102. In various cases, this can be referred to as pre-warming the cryostat 102.

[0082] As another non-limiting example, assume that the heat battery 104 is initially at a lower temperature than the cryostat 102. In such a case, the heat exchange pump 118 may circulate or propel the heat exchange fluid through the heat exchange piping 108 in the direction indicated by the reference numeral 120. Such circulation or propulsion, in various cases, may cause the heat exchange fluid to be at a lower temperature than the cryostat 102 as it passes through the cryostat 102. Therefore, as the heat exchange fluid flows through the cryostat 102, the heat exchange fluid may absorb thermal energy (e.g., heat) from the cryostat 102, thereby decreasing the temperature of the cryostat 102 and increasing the temperature of the heat exchange fluid. Furthermore, such circulation or propulsion, in various cases, may cause the heat exchange fluid to be at a higher temperature than the heat battery 104 as it passes through the heat battery 104. Thus, as the heat exchange fluid flows through the heat battery 104, the heat exchange fluid can release thermal energy (e.g., heat) to the heat battery 104, thereby increasing the temperature of the heat battery 104 and decreasing the temperature of the heat exchange fluid. In this manner, the heat exchange system 106 can be thought of as transferring thermal energy from the cryostat 102 to the heat battery 104. In various cases, this can be referred to as pre-cooling the cryostat 102.

[0083] In various embodiments, pre-warming of the cryostat 102 can be accelerated prior to performing a warming cycle of the cryostat 102, and such pre-warming can cause such a warming cycle to consume less time or electrical energy than it would otherwise consume. This is further described with respect to FIG.

[0084] FIG. 2 shows an example, non-limiting block diagram 200 illustrating how pre-warming via a thermal battery 104 can affect the temperature of a cryostat 102, according to one or more embodiments described herein.

[0085] In various embodiments, in order for a quantum processor housed by or otherwise contained within cryostat 102 to operate properly, cryostat 102 may need to be at an operating temperature 202. By way of non-limiting example, operating temperature 202 may be less than or equal to 5 Kelvin (e.g., on the order of milliKelvin). Conversely, in order for maintenance tasks to be performed on a quantum processor housed by or otherwise contained within cryostat 102, cryostat 102 may need to be at room temperature 204. By way of non-limiting example, room temperature 204 may be approximately 300 Kelvin.

[0086] In various aspects, assume that the cryostat 102 is currently at an operating temperature 202, further assume that it is desired to bring the cryostat 102 to room temperature 204, and further assume that the temperature of the heat battery 104 is currently higher than the operating temperature 202. In such a case, the heat battery 104 and the heat exchange system 106 may be implemented to perform a pre-warming process 206 for the cryostat 102. In various instances, the pre-warming process 206 may involve the heat exchange pump 118 circulating or otherwise propelling a heat exchange fluid through the heat exchange piping 108. Because the temperature of the heat battery 104 may currently be higher than the temperature of the cryostat 102, such circulation or propulsion may cause the heat exchange fluid to absorb thermal energy from the heat battery 104 and deposit the thermal energy in the cryostat 102. Therefore, the pre-warming process 206 may lower the temperature of the heat battery 104 and increase the temperature of the cryostat 102. In various aspects, the pre-warming process 206 may, at some point, cause the temperature of the thermal battery 104 to equalize or otherwise be within any suitable threshold margin of the temperature of the cryostat 102. At such point, there may no longer be a temperature difference between the thermal battery 104 and the cryostat 102, and therefore, the heat exchange fluid may be considered no longer capable of transferring heat from the thermal battery 104 to the cryostat 102. In other words, the pre-warming process 206 may be considered complete at such point.

[0087] In various aspects, upon completion of the pre-warming process 206, the temperature of the cryostat 102 may be considered to be at an intermediate temperature 208, where the intermediate temperature 208 may be any suitable temperature that is higher than the operating temperature 202 and lower than the room temperature 204. In various instances, the temperature of the thermal battery 104 may also be considered to be at the intermediate temperature 208, since upon completion of the pre-warming process 206, there may no longer be a temperature difference between the thermal battery 104 and the cryostat 102. In various cases, the intermediate temperature 208 may be approximated as follows:

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[0088] In various embodiments, after completion of the pre-warming process 206, the cryostat 102 can perform a partial warming cycle 210. In various cases, the partial warming cycle 210 can be active, in which case various heating coils of the cryostat 102 can be activated. In various other cases, the partial warming cycle 210 can be passive, in which case the cryostat 102 can be slowly warmed by heat transfer with the surrounding environment. In either case, the partial warming cycle 210 can bring the temperature of the cryostat 102 from the intermediate temperature 208 to room temperature 204. Contrast this with a full warming cycle that would instead have brought the cryostat 102 from the operating temperature 202 to room temperature 204 (e.g., in the absence of the thermal battery 104 and without the pre-warming process 206). In other words, the partial warming cycle 210 may be referred to as "partial" because it may traverse a smaller temperature range than a full warming cycle would have traversed (e.g., the difference between the room temperature 204 and the intermediate temperature 208 may be smaller than the difference between the room temperature 204 and the operating temperature 202).

[0089] In various aspects, the pre-warming process 206 may cause the cryostat 102 to consume less time or electrical energy during warming. More specifically, the pre-warming process 206 may consume some non-zero amount of time and electrical energy. In particular, the heat exchange pump 118 may circulate or propel a heat exchange fluid in response to input electrical energy, and the circulation or propulsion of the heat exchange fluid may require some amount of time to bring the cryostat 102 from the operating temperature 202 to the intermediate temperature 208. However, the amount of electrical energy consumed during the pre-warming process 206 may be lower (e.g., in some cases, orders of magnitude lower) than the amount of electrical energy that would be consumed if the cryostat 102 instead utilized active heating to bring the cryostat 102 from the operating temperature 202 to the intermediate temperature 208 (e.g., the heat exchange pump 118 may be less energetically expensive than the heating coils of the cryostat 102). In other words, when the partial warming cycle 210 is active, the total amount of electrical energy consumed by the pre-warming process 206 and by the partial warming cycle 210 may be lower than the total amount of electrical energy that would have been consumed by a full warming cycle instead. That is, the electrical energy saved by the cryostat 102 by performing the partial warming cycle 210 rather than a full active warming cycle may be higher than the electrical energy consumed by the heat exchange pump 118 during the pre-warming process 206.

[0090] Similarly, the amount of time consumed during the pre-warming process 206 may be lower (e.g., by orders of magnitude lower, in some cases) than the amount of time that would have been consumed if the cryostat 102 had instead utilized passive warming to bring the cryostat 102 from the operating temperature 202 to the intermediate temperature 208 (e.g., the heat exchange pump 118 may heat the cryostat 102 faster than ambient heat transfer). In other words, if the partial warming cycle 210 is passive, the total amount of time consumed by the pre-warming process 206 and by the partial warming cycle 210 may be lower than the total amount of time that would have been consumed by a full warming cycle instead. That is, the time saved by the cryostat 102 by performing the partial warming cycle 210 rather than a full passive warming cycle may be higher than the time consumed by the heat exchange pump 118 during the pre-warming process 206.

[0091] In various embodiments, pre-cooling of the cryostat 102 can be accelerated prior to the execution of a cooling cycle of the cryostat 102, and such pre-cooling can cause such cooling cycle to consume less time or electrical energy than it would otherwise consume. This is further described with respect to FIG.

[0092] FIG. 3 shows an example, non-limiting block diagram 300 illustrating how pre-cooling via a thermal battery 104 can affect the temperature of a cryostat 102, according to one or more embodiments described herein.

[0093] As mentioned above, the cryostat 102 may need to be at an operating temperature 202 for the quantum processor stored within the cryostat 102 to operate properly, and the cryostat 102 may alternatively need to be at room temperature 204 for maintenance tasks to be performed on the quantum processor stored within the cryostat 102.

[0094] In various aspects, assume that the cryostat 102 is currently at room temperature 204, further assume that it is desired to bring the cryostat 102 to the operating temperature 202, and further assume that the temperature of the heat battery 104 is currently lower than room temperature 204. In such a case, the heat battery 104 and the heat exchange system 106 may be implemented to perform a pre-cooling process 302 for the cryostat 102. In various instances, the pre-cooling process 302 may involve the heat exchange pump 118 circulating or otherwise propelling a heat exchange fluid through the heat exchange piping 108. Because the temperature of the heat battery 104 may currently be lower than the temperature of the cryostat 102, such circulation or propulsion may cause the heat exchange fluid to absorb thermal energy from the cryostat 102 and deposit the thermal energy in the heat battery 104. Therefore, the pre-cooling process 302 may increase the temperature of the heat battery 104 and decrease the temperature of the cryostat 102. In various aspects, the pre-cooling process 302 may, at some point, cause the temperature of the thermal battery 104 to equal or otherwise be within any suitable threshold margin of the temperature of the cryostat 102. At such point, there may no longer be a temperature difference between the thermal battery 104 and the cryostat 102, and therefore, the heat exchange fluid may be considered no longer capable of transferring heat from the cryostat 102 to the thermal battery 104. In other words, the pre-cooling process 302 may be considered complete at such point.

[0095] In various aspects, upon completion of the pre-cooling process 302, the temperature of the cryostat 102 may be considered to be at an intermediate temperature 304, where the intermediate temperature 304 may be any suitable temperature that is higher than the operating temperature 202 and lower than the room temperature 204. In various instances, the temperature of the thermal battery 104 may also be considered to be at the intermediate temperature 304, since upon completion of the pre-cooling process 302, there may no longer be a temperature difference between the thermal battery 104 and the cryostat 102. In various cases, the intermediate temperature 304 may be approximated as follows:

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[0096] In various aspects, after completing the pre-cooling process 302, the cryostat 102 may perform a partial cooling cycle 306. In various instances, the partial cooling cycle 306 may involve starting various cryogenic compressors of the cryostat 102. In various cases, the partial cooling cycle 306 may bring the temperature of the cryostat 102 from the intermediate temperature 304 to the operating temperature 202. Contrast this with a full cooling cycle that would instead have brought the cryostat 102 from room temperature 204 to the operating temperature 202 (e.g., in the absence of the thermal battery 104 and without the pre-cooling process 302). In other words, the partial cooling cycle 306 may be referred to as “partial” because it may traverse a smaller temperature range than a full cooling cycle would have traversed (e.g., the difference between the operating temperature 202 and the intermediate temperature 304 may be smaller than the difference between the operating temperature 202 and the room temperature 304).

[0097] In various aspects, the pre-chilling process 302 may cause the cryostat 102 to consume less electrical energy during cooling. More specifically, the pre-chilling process 302 may consume some non-zero amount of electrical energy. In particular, the heat exchange pump 118 may circulate or propel a heat exchange fluid in response to input electrical energy. However, the amount of electrical energy consumed during the pre-chilling process 302 may be lower (e.g., in some cases, orders of magnitude lower) than the amount of electrical energy that would have been consumed if the cryostat 102 had instead utilized a refrigeration cycle to bring the cryostat 102 from room temperature 204 to the intermediate temperature 304 (e.g., the heat exchange pump 118 may actually be less energetically expensive than the cryogenic compressor of the cryostat 102). In other words, the total amount of electrical energy consumed by the pre-chilling process 302 and by the partial refrigeration cycle 306 may be lower than the total amount of electrical energy that would have been consumed by a full refrigeration cycle instead. In further other words, the electrical energy saved by the cryostat 102 by performing a partial cooling cycle 306 rather than a full cooling cycle may be higher than the electrical energy consumed by the heat exchange pump 118 during the pre-cooling process 302.

[0098] Thus, implementation of the thermal battery 104 and heat exchange system 106 as described herein may allow the cryostat 102 to consume less time or electrical energy during warming and cooling cycles.

[0099] To help further understand the various energy saving benefits of the thermal battery 104 and heat exchange system 106, consider the following non-limiting example.

[0100] Assume that the cryostat 102 has just completed a cooling cycle. Thus, the cryostat 102 may be at operating temperature 202. Additionally, assume that the thermal battery 104 is currently at room temperature 204. In such a case, the thermal battery 104 may be warmer than the cryostat 102, and thus the thermal battery 104 may be used to perform pre-warming on the cryostat 102. Such pre-warming may increase the temperature of the cryostat 102 and decrease the temperature of the thermal battery 104 until both the cryostat 102 and the thermal battery 104 are at a first intermediate temperature, where such first intermediate temperature is higher than the operating temperature 202 but lower than room temperature 204. At such point, the cryostat 102 may perform a partial warming cycle, whereby the cryostat 102 may now be at room temperature 204. As explained above, such a partial warming cycle may be less expensive (eg, in terms of time or electrical energy) than a full warming cycle.

[0101] In various aspects, the thermal battery 104 and heat exchange system 106 can be thermally isolated from the ambient environment so that the thermal battery 104 can be maintained at (or otherwise vary at most negligibly from) the first intermediate temperature for any suitable amount of time (e.g., in some cases, over days, weeks, or even months). In other words, pre-warming can be considered to cause the thermal battery 104 to store some of the “coldness” that the cryostat 102 previously had when it was at the operating temperature 202.

[0102] In any case, because the heat battery 104 may be at a first intermediate temperature and the cryostat 102 may be at room temperature 204, the heat battery 104 may be cooler than the cryostat 102 at this point. Thus, if desired, the heat battery 104 may be used to perform pre-cooling on the cryostat 102. Such pre-cooling may decrease the temperature of the cryostat 102 and increase the temperature of the heat battery 104 until both the cryostat 102 and the heat battery 104 are at a second intermediate temperature, which may be higher than the first intermediate temperature but lower than room temperature 204. At such point, the cryostat 102 may perform a partial cooling cycle, which may bring the cryostat 102 back to the operating temperature 202. As explained above, such a partial cooling cycle may be less expensive than a full cooling cycle.

[0103] As mentioned above, because the thermal battery 104 and heat exchange system 106 can be thermally isolated from the ambient environment, the thermal battery 104 can be maintained at (or otherwise vary at most negligibly from) the second intermediate temperature for any suitable amount of time. That is, pre-cooling can be considered to cause the thermal battery 104 to store some of the heat that the cryostat 102 previously had when it was at room temperature 204.

[0104] In any case, the heat battery 104 may once again be warmer than the cryostat 102 because the heat battery 104 may be at the second intermediate temperature and the cryostat 102 may be at the operating temperature 202. Thus, if desired, the heat battery 104 may be used to perform pre-warming on the cryostat 102. Such pre-warming may increase the temperature of the cryostat 102 and decrease the temperature of the heat battery 104 until both the cryostat 102 and the heat battery 104 are at a third intermediate temperature, which may be higher than the operating temperature 202 but lower than the second intermediate temperature. At such point, the cryostat 102 may again perform a partial warming cycle, which may bring the cryostat 102 once again to room temperature 204. As noted above, such a partial warming cycle may be less expensive than a full warming cycle.

[0105] Such pre-warming and pre-cooling processes can be repeated in this manner as desired.

[0106] In this manner, the thermal battery 104 and the heat exchange system 106 may be utilized to perform multiple sequential iterations of pre-warming and pre-cooling of the cryostat 102, each such iteration storing some "cold" or some heat previously stored in the cryostat 102, where such stored "cold" or stored heat can reduce the amount of time or electrical energy consumed by the cryostat 102 during a subsequent warming or cooling cycle. In other words, the thermal battery 104 and the heat exchange system 106 may be viewed as recycling or otherwise reusing some of the thermal work that the cryostat 102 performed in a previous cooling or warming cycle, where such recycled or reused thermal work can be used to reduce or otherwise offset the cost of operating the cryostat 102 during a subsequent warming or cooling cycle.

[0107] 4 illustrates a structural diagram 400 of an example, non-limiting embodiment of a thermal battery suspended in a vacuum chamber that can facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein. In other words, FIG. 4 illustrates an example, non-limiting embodiment of a thermal battery 104.

[0108] In various embodiments, as mentioned above, the thermal battery 104 can be any suitable tangible object capable of receiving or releasing thermal energy. In some aspects, the thermal battery 104 can be a continuous chunk of metal having any suitable mass or any suitable heat capacity. As a non-limiting example, the thermal battery 104 can be a 500 kilogram continuous chunk of copper, while in various other cases, the thermal battery 104 can be composed of any other suitable metal. Indeed, in some cases, the thermal battery 104 can be composed of any suitable combination of metals.

[0109] In various instances, the thermal battery 104 can have or otherwise appear any suitable size, shape, or dimensions. As a non-limiting example, the thermal battery 104 can be spherical. Ultimately, a sphere can be considered a geometric shape with a minimized surface area to volume ratio. Thus, by shaping the thermal battery 104 as a sphere, the outgoing heat flux can be reduced or otherwise minimized across the surface area of ​​the thermal battery 104. Such reduced or minimized outgoing heat flux can thus help to better thermally isolate the thermal battery 104 from the surrounding environment.

[0110] In various aspects, as shown, the heat battery 104 can be suspended in the vacuum chamber 402. In various instances, the heat battery 104 can be suspended within the vacuum chamber 402 via any suitable suspension technique. By way of non-limiting example, the heat battery 104 can be suspended like a chandelier or otherwise secured in the vacuum chamber 402. In any case, the vacuum chamber 402 can be evacuated of air or other gases to reduce or otherwise eliminate convective heat transfer from affecting the surface area of ​​the heat battery 104. Such reduced or eliminated convective heat transfer can further reduce the outgoing heat flux across the surface area of ​​the heat battery 104, thereby helping to further thermally isolate the heat battery 104 from the surrounding environment.

[0111] 4 depicts vacuum chamber 402 as having or otherwise exhibiting a linear shape, this is merely a non-limiting example for ease of illustration. In various cases, vacuum chamber 402 can have or otherwise exhibit any suitable size, any suitable shape, or any suitable dimensions (e.g., any suitable thickness).

[0112] In various embodiments, an exterior portion of the vacuum chamber 402 can be coated, lined, clad, or otherwise protected by an external thermal barrier 404. In various cases, the external thermal barrier 404 can include any suitable heat shielding material, which can help reduce radiative heat transfer to the interior or exterior of the vacuum chamber 402. As some non-limiting examples, such heat shielding materials can include steel, aluminum, or copper. In various other cases, the external thermal barrier 404 can include any suitable insulating material, which can help reduce convective heat transfer to the interior or exterior of the vacuum chamber 402. As some non-limiting examples, such insulating materials can include fiberglass, polyurethane, multi-layer aluminized Mylar, or glass wool. In some cases, the external thermal barrier 404 can include any suitable combination of heat shielding or insulating materials. In any case, the external thermal barrier 404 can help further reduce the outgoing heat flux across the surface area of ​​the thermal battery 104, thereby helping to further thermally isolate the thermal battery 104 from the surrounding environment.

[0113] 4 depicts the external thermal barrier 404 as having or otherwise exhibiting a linear shape, this is merely a non-limiting example for ease of illustration. In various cases, the external thermal barrier 404 can have or otherwise exhibit any suitable size, any suitable shape, or any suitable dimensions (e.g., any suitable thickness).

[0114] In various embodiments, the interior portion of the vacuum chamber 402 can be coated, lined, covered, or otherwise protected by an internal thermal barrier 406. In various cases, the internal thermal barrier 406 can include any suitable heat shielding material (e.g., steel, aluminum, copper), which can help reduce radiative heat transfer to the interior or exterior of the vacuum chamber 402. In various other cases, the internal thermal barrier 406 can include any suitable insulating material (e.g., fiberglass, polyurethane, multi-layer aluminized Mylar, glass wool), which can help reduce convective heat transfer to the interior or exterior of the vacuum chamber 402. In some cases, the internal thermal barrier 406 can include any suitable combination of heat shielding or insulating materials. In any case, the internal thermal barrier 406 can help further reduce the outgoing heat flux across the surface area of ​​the thermal battery 104, thereby helping to further thermally isolate the thermal battery 104 from the ambient environment.

[0115] 4 depicts the internal thermal barrier 406 as having or otherwise exhibiting a linear shape, this is merely a non-limiting example for ease of illustration. In various cases, the internal thermal barrier 406 can have or otherwise exhibit any suitable size, any suitable shape, or any suitable dimensions (e.g., any suitable thickness).

[0116] Although not explicitly shown in FIG. 4 , the thermal battery 104 may be coated, lined, covered, wrapped, or otherwise protected by any other suitable thermal barrier (e.g., by any suitable combination of heat shielding or insulating materials) to help further reduce the outgoing heat flux across the surface area of ​​the thermal battery 104, thereby helping to further thermally isolate the thermal battery 104 from the surrounding environment.

[0117] In various embodiments, after exiting the outlet 116 of the cryostat 102, the heat exchange piping 108 can pass through the external thermal barrier 404, the walls of the vacuum chamber 402, and the internal thermal barrier 406 to reach the inlet 110 of the heat battery 104. In various instances, as shown, the heat exchange piping 108 can pass through the heat battery 104 to connect the inlet 110 to the outlet 112. More specifically, the heat exchange piping 108 can, in various cases, snake or bend (e.g., in any suitable manner or layout) through the interior of the heat battery 104, as shown. In various embodiments, such snakes or bends can be considered to increase the amount of surface area of ​​the heat exchange piping 108 in thermal contact with the heat battery 104. In various instances, such increased surface area can help increase the rate of heat transfer that can occur between the heat battery 104 and the heat exchange fluid flowing through the heat exchange piping 108. In any case, as shown, the heat exchange piping 108 can extend from the outlet 112, back through the inner thermal barrier 406, back through the wall of the vacuum chamber 402, and back through the outer thermal barrier 404, and the heat exchange piping 108 can then lead to the inlet 114 of the cryostat 102.

[0118] In some cases, the heat exchange piping 108 may be considered to couple the thermal battery 104 to the exterior or outside of the vacuum chamber 402 .

[0119] FIG. 5 illustrates a flow diagram of an example, non-limiting method 500 that can facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein.

[0120] In various embodiments, action 502 can include coupling a cryostat (e.g., 102) to a heat battery (e.g., 104) by a heat exchange system (e.g., 106). In various cases, the heat battery can be thermally insulated (e.g., thermally isolated) from the ambient environment surrounding the cryostat. By way of non-limiting example, the heat battery can be suspended in a vacuum chamber (e.g., 402). As another non-limiting example, the vacuum chamber can be lined with a heat shield or insulating material (e.g., 404, 406). As yet another non-limiting example, the vacuum chamber can be located underground.

[0121] In various embodiments, act 504 pumps a heat exchange fluid (e.g., 118) between the cryostat and the thermal battery via a pump (e.g., 118) in the heat exchange system. 3 He, 4 The heat battery may include circulating a heat exchange fluid (He) between the cryostat and the cryostat. In various cases, the temperature of the heat battery may be higher than the temperature of the cryostat. In such cases, the circulation of the heat exchange fluid may heat or otherwise warm the cryostat and may cool or otherwise chill the heat battery. In various other cases, the temperature of the heat battery may instead be lower than the temperature of the cryostat. In such cases, the circulation of the heat exchange fluid may cool or chill the cryostat and may heat or warm the heat battery.

[0122] To this point, the disclosure herein has primarily described the thermal battery 104 as exhibiting a single-cell architecture (e.g., as being a contiguous chunk of metal). This is merely a non-limiting example for ease of illustration and description. In various other embodiments, the thermal battery 104 may instead exhibit a multi-cell architecture (e.g., may instead be composed of multiple separate contiguous chunks of metal). Various non-limiting aspects of such other embodiments are described with respect to FIG. 6.

[0123] Figure 6 illustrates a structural diagram 600 of an example, non-limiting embodiment of a multi-cell thermal battery that can facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein. That is, Figure 6 illustrates a non-limiting, example embodiment of a thermal battery 104, where the thermal battery 104 exhibits a multi-cell architecture.

[0124] In various embodiments, thermal battery 104 can include multiple heat cells. As shown, Figure 6 depicts thermal battery 104 as including three separate heat cells: heat cell 104(1), heat cell 104(2), and heat cell 104(3). However, this is merely a non-limiting example for ease of illustration. In various aspects, the multiple heat cells can include any other suitable number of heat cells (e.g., can include two or more heat cells).

[0125] In various aspects, the heat cells of thermal battery 104 can be any suitable tangible object capable of receiving or releasing thermal energy. As a non-limiting example, heat cell 104(1) can be a first continuous chunk of metal (e.g., copper) having any suitable mass, any suitable heat capacity, any suitable size, any suitable shape (e.g., spherical), or any suitable dimensions. As another non-limiting example, heat cell 104(2) can be a second continuous chunk of metal having any suitable mass, any suitable heat capacity, any suitable size, any suitable shape, or any suitable dimensions. As yet another non-limiting example, heat cell 104(3) can be a third continuous chunk of metal having any suitable mass, any suitable heat capacity, any suitable size, any suitable shape, or any suitable dimensions. In some cases, the heat cells can have different masses from one another (e.g., the mass of heat cell 104(1) can be different from the mass of heat cell 104(2), which can be different from the mass of heat cell 104(3)). Similarly, in various embodiments, the heat cells can have different heat capacities from one another (e.g., heat cell 104(1) can be constructed from a different metal than heat cell 104(2), which can be constructed from a different metal than heat cell 104(3)). Furthermore, in various instances, the heat cells can have different shapes, sizes, or dimensions from one another (e.g., heat cell 104(1) can be a different size, shape, or dimensions from heat cell 104(2), which can be a different size, shape, or dimensions from heat cell 104(3)).

[0126] In various embodiments, as shown, each of the plurality of heat cells can be suspended in vacuum chamber 602. As a non-limiting example, heat cell 104(1) can be suspended, hung, or otherwise affixed within a first chamber of vacuum chamber 602, which can be evacuated of air or other gas to help further thermally isolate heat cell 104(1) from the ambient environment. As another non-limiting example, heat cell 104(2) can be suspended, hung, or otherwise affixed within a second chamber of vacuum chamber 602, which can be evacuated of air or other gas to help further thermally isolate heat cell 104(2) from the ambient environment. As yet another non-limiting example, heat cell 104(3) can be suspended, hung, or otherwise secured within a third compartment of vacuum chamber 602, which can be evacuated of air or other gases to help further thermally isolate heat cell 104(3) from the ambient environment.

[0127] 6 depicts heat cell 104(1), heat cell 104(2), and heat cell 104(3) as each being within a separate respective compartment of vacuum chamber 602, but this is by way of non-limiting example only. In various embodiments, heat cell 104(1), heat cell 104(2), and heat cell 104(3) can all be suspended, hung, or otherwise affixed within the same compartment of vacuum chamber 602.

[0128] 6 depicts vacuum chamber 602 as having or otherwise exhibiting a linear shape, this is merely a non-limiting example for ease of illustration. In various cases, vacuum chamber 602 can have or otherwise exhibit any suitable size, any suitable shape, or any suitable dimensions (e.g., any suitable thickness).

[0129] In various aspects, an exterior portion of vacuum chamber 602 can be coated, lined, covered, or otherwise protected by an external thermal barrier 604. In various cases, external thermal barrier 604 can be similar to external thermal barrier 404 described above (e.g., any suitable type of heat-shielding material or any suitable combination of thermally insulating materials). Thus, external thermal barrier 604 can help to further thermally isolate heat cell 104(1), heat cell 104(2), and heat cell 104(3) from the surrounding environment.

[0130] In various embodiments, the interior portion of vacuum chamber 602 can be coated, lined, covered, or otherwise protected by any suitable internal thermal barrier. For example, the first compartment of vacuum chamber 602 can be coated, lined, covered, or otherwise protected by internal thermal barrier 606(1). In various cases, internal thermal barrier 606(1) can be similar to internal thermal barrier 406 described above (e.g., any suitable combination of any suitable type of thermally insulating or heat-insulating material). Thus, internal thermal barrier 606(1) can help to further thermally isolate heat cell 104(1) from the ambient environment. Similarly, the second compartment of vacuum chamber 602 can be coated, lined, covered, or otherwise protected by internal thermal barrier 606(2). In various cases, internal thermal barrier 606(2) can be similar to internal thermal barrier 406 described above (e.g., any suitable combination of any suitable type of thermally insulating or heat-insulating material). Thus, the internal thermal barrier 606(2) can help to further thermally isolate the heat cell 104(2) from the ambient environment. Similarly, the third compartment of the vacuum chamber 602 can be coated, lined, covered, or otherwise protected by an internal thermal barrier 606(3). In various cases, the internal thermal barrier 606(3) can be similar to the internal thermal barrier 406 described above (e.g., any suitable type of heat-shielding material or any suitable combination of thermally insulating materials). Thus, the internal thermal barrier 606(3) can help to further thermally isolate the heat cell 104(3) from the ambient environment.

[0131] Although not explicitly shown in FIG. 6, any of the plurality of heat cells may be coated, lined, covered, wrapped, or otherwise protected by any other suitable thermal barrier (e.g., by any suitable combination of heat shielding or insulating materials) to help further thermally isolate the plurality of heat cells from the ambient environment.

[0132] In various embodiments, as shown, a first section of piping can branch off from heat exchange piping 108 at a location downstream of cryostat 102 but upstream of heat battery 104. In various cases, the first section of piping can pass through external thermal barrier 604, the wall of vacuum chamber 602, and internal thermal barrier 606(1) to reach inlet 110(1) of heat cell 104(1). In various cases, as shown, the first section of piping can pass through heat cell 104(1) (e.g., in a serpentine or meandering manner) to connect inlet 110(1) to outlet 112(1) of heat cell 104(1). In various embodiments, as shown, the first section of piping can extend from outlet 112(1), back through internal thermal barrier 606(1), back through the wall of vacuum chamber 602, and back through external thermal barrier 604. The first section of piping may then rejoin the heat exchange piping 108 at a location downstream of the heat battery 104 but upstream of the cryostat 102 .

[0133] Similarly, a second section of piping can branch off from heat exchange piping 108 at a location downstream of cryostat 102 but upstream of heat battery 104. In various embodiments, the second section of piping can pass through external thermal barrier 604, the wall of vacuum chamber 602, and internal thermal barrier 606(2) to reach inlet 110(2) of heat cell 104(2). In various cases, as shown, the second section of piping can pass through heat cell 104(2) (e.g., in a serpentine or meandering manner) to connect inlet 110(2) to outlet 112(2) of heat cell 104(2). In various cases, as shown, the second section of piping can extend from outlet 112(2), back through internal thermal barrier 606(2), back through the wall of vacuum chamber 602, and back through external thermal barrier 604. The second section of piping may then rejoin the heat exchange piping 108 at a location downstream of the heat battery 104 but upstream of the cryostat 102 .

[0134] Similarly, a third section of piping can branch off from heat exchange piping 108 at a location downstream of cryostat 102 but upstream of heat battery 104. In various embodiments, the third section of piping can pass through external thermal barrier 604, the walls of vacuum chamber 602, and internal thermal barrier 606(3) to reach inlet 110(3) of heat cell 104(3). In various cases, as shown, the third section of piping can pass through heat cell 104(3) (e.g., in a serpentine or meandering manner) to connect inlet 110(3) to outlet 112(3) of heat cell 104(3). In various cases, as shown, the third section of piping can extend from outlet 112(3), back through internal thermal barrier 606(3), back through the walls of vacuum chamber 602, and back through external thermal barrier 604. The third section of piping may then rejoin the heat exchange piping 108 at a location downstream of the heat battery 104 but upstream of the cryostat 102 .

[0135] In other words, as shown in FIG. 6, each of the multiple heat cells that make up the thermal battery 104 can be considered to be coupled together by heat exchange piping 108 in a parallel spatial arrangement, as opposed to being coupled together in a series spatial arrangement.

[0136] Additionally, in various embodiments, the heat exchange system 106 can include multiple actuatable valves, each corresponding to a respective one of the heat cells. In various aspects, such multiple actuatable valves can be configured to control whether or not heat exchange fluid can flow through each of the multiple heat cells.

[0137] As a non-limiting example, the first section of piping extending through heat cell 104(1) may include actuatable valve 608(1) and actuatable valve 610(1). In various cases, actuatable valve 608(1) and actuatable valve 610(1) may be any suitable electronically controllable valve (e.g., a ball valve, a butterfly valve, a gate valve) that can be toggled between an open state and a closed state. In various cases, as shown, actuatable valve 608(1) may be positioned along the first section of piping at a location upstream of inlet 110(1). In contrast, actuatable valve 610(1) may be positioned along the first section of piping at a location downstream of outlet 112(1). Thus, when both actuatable valve 608(1) and actuatable valve 610(1) are open, they may permit heat exchange fluid from the remainder of heat exchange system 106 to flow through heat cell 104(1). In such a case, heat cell 104(1) may be considered to be thermally integrated with cryostat 102 (e.g., when both actuatable valve 608(1) and actuatable valve 610(1) are open, a heat exchange fluid may facilitate measurable heat transfer between heat cell 104(1) and cryostat 102). In contrast, when both actuatable valve 608(1) and actuatable valve 610(1) are closed, they may prevent heat exchange fluid from the rest of heat exchange system 106 from flowing through heat cell 104(1). In such a case, heat cell 104(1) may be considered to be thermally isolated from cryostat 102 (e.g., when both actuatable valve 608(1) and actuatable valve 610(1) are closed, a heat exchange fluid may not facilitate measurable heat transfer between heat cell 104(1) and cryostat 102).

[0138] As another non-limiting example, the second section of piping extending through heat cell 104(2) can include actuatable valve 608(2) and actuatable valve 610(2). As described above, actuatable valve 608(2) and actuatable valve 610(2) can be any suitable electronically controllable valve (e.g., ball valve, butterfly valve, gate valve) that can be toggled between an open state and a closed state. In various embodiments, as shown, actuatable valve 608(2) can be positioned along the second section of piping at a location upstream of inlet 110(2). In contrast, actuatable valve 610(2) can be positioned along the second section of piping at a location downstream of outlet 112(2). Thus, when both actuatable valve 608(2) and actuatable valve 610(2) are open, they can permit heat exchange fluid from the remainder of heat exchange system 106 to flow through heat cell 104(2). In such a case, heat cell 104(2) may be considered to be thermally integrated with cryostat 102 (e.g., when both actuatable valve 608(2) and actuatable valve 610(2) are open, a heat exchange fluid may facilitate measurable heat transfer between heat cell 104(2) and cryostat 102). In contrast, when both actuatable valve 608(2) and actuatable valve 610(2) are closed, they may prevent heat exchange fluid from the rest of heat exchange system 106 from flowing through heat cell 104(2). In such a case, heat cell 104(2) may be considered to be thermally isolated from cryostat 102 (e.g., when both actuatable valve 608(2) and actuatable valve 610(2) are closed, a heat exchange fluid may not facilitate measurable heat transfer between heat cell 104(2) and cryostat 102).

[0139] As yet another non-limiting example, the third section of piping extending through heat cell 104(3) can include actuatable valve 608(3) and actuatable valve 610(3). As above, actuatable valve 608(3) and actuatable valve 610(3) can be any suitable electronically controllable valve (e.g., ball valve, butterfly valve, gate valve) that can be toggled between an open state and a closed state. In various embodiments, as shown, actuatable valve 608(3) can be positioned along the third section of piping at a location upstream of inlet 110(3). In contrast, actuatable valve 610(3) can be positioned along the third section of piping at a location downstream of outlet 112(3). Thus, when both actuatable valve 608(3) and actuatable valve 610(3) are open, they can permit heat exchange fluid from the remainder of heat exchange system 106 to flow through heat cell 104(3). In such a case, heat cell 104(3) may be considered to be thermally integrated with cryostat 102 (e.g., when both actuatable valve 608(3) and actuatable valve 610(3) are open, a heat exchange fluid may facilitate measurable heat transfer between heat cell 104(3) and cryostat 102). In contrast, when both actuatable valve 608(3) and actuatable valve 610(3) are closed, they may prevent heat exchange fluid from the rest of heat exchange system 106 from flowing through heat cell 104(3). In such a case, heat cell 104(3) may be considered to be thermally isolated from cryostat 102 (e.g., when both actuatable valve 608(3) and actuatable valve 610(3) are closed, a heat exchange fluid may not facilitate measurable heat transfer between heat cell 104(3) and cryostat 102).

[0140] In various embodiments, the actuatable valves can alternately operate relative to one another such that at most one of the plurality of heat cells is thermally integrated with cryostat 102 at any given time, and the remainder of the plurality of heat cells is thermally isolated from cryostat 102 at that given time. As a non-limiting example, when actuatable valve 608(1) and actuatable valve 610(1) are open, the remaining actuatable valves (e.g., 608(2), 610(2), 608(3), 610(3)) can be closed. In such a case, heat cell 104(1) can be thermally integrated with cryostat 102, and the remaining of the plurality of heat cells (e.g., 104(2), 104(3)) can be thermally isolated from cryostat 102. As another non-limiting example, when actuatable valve 608(2) and actuatable valve 610(2) are open, the remaining actuatable valves (e.g., 608(1), 610(1), 608(3), 610(3)) can be closed. In such a case, heat cell 104(2) can be thermally integrated with cryostat 102, and the remaining heat cells (e.g., 104(1), 104(3)) can be thermally isolated from cryostat 102. As yet another non-limiting example, when actuatable valve 608(3) and actuatable valve 610(3) are open, the remaining actuatable valves (e.g., 608(1), 610(1), 608(2), 610(2)) can be closed. In such a case, heat cell 104(3) may be thermally integrated with cryostat 102, and the remaining heat cells (e.g., 104(1), 104(2)) may be thermally isolated from cryostat 102.

[0141] In various aspects, the heat exchange pump 118 can circulate or propel a heat exchange fluid between the cryostat 102 and a particular heat cell that is currently thermally integrated with the cryostat 102. At some point, the temperature of the cryostat 102 can equalize (or otherwise fall within any suitable threshold margin of) the temperature of that particular heat cell. At such point, an actuatable valve corresponding to that particular heat cell can be closed, thereby causing that particular heat cell to now be thermally isolated from the cryostat 102. Moreover, at such point, an actuatable valve corresponding to some other heat cell can be opened, thereby causing that other heat cell to now be thermally integrated with the cryostat 102. Thus, the heat exchange pump 118 can circulate or propel a heat exchange fluid between the cryostat 102 and that other heat cell. By implementing multiple heat cells in this manner, multiple heat cells can be used sequentially to pre-warm or pre-cool the cryostat 102, thereby collectively providing a greater magnitude of pre-warming or pre-cooling.

[0142] Indeed, in some cases, the mass, heat capacity, or initial temperature of multiple heat cells can be varied (e.g., different from one another) to customize or adjust the magnitude of pre-warming or pre-cooling as desired.

[0143] As mentioned above, the plurality of actuatable valves (e.g., 608(1), 608(2), 608(3), 610(1), 610(2), 610(3)) may be electronically remotely controllable. In other words, the plurality of actuatable valves may be considered to include or otherwise be implemented with any suitable number of any suitable type of electronic controller (e.g., any suitable computer processor, any suitable microprocessor, any suitable microcontroller). More specifically, the plurality of actuatable valves may be toggled (e.g., actuated) between open and closed states by such electronic controllers. For example, such an electronic controller may send an “open” signal to each one of the plurality of actuatable valves, thereby opening that one of the plurality of actuatable valves. As another example, such an electronic controller may send a “close” signal to each other one of the plurality of actuatable valves, thereby closing that one of the plurality of actuatable valves. In some cases, each of the plurality of actuatable valves may be considered to include or otherwise be implemented with its own separate electronic controller, while in other cases, two or more of the plurality of actuatable valves may be considered to include or otherwise be implemented with a shared electronic controller.

[0144] FIG. 7 illustrates a flow diagram of an example, non-limiting method 700 involving a multi-cell thermal battery that can facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein.

[0145] In various embodiments, action 702 can include coupling a cryostat (e.g., 102) to a thermal battery (e.g., 104) by heat exchange piping (e.g., 108). In various aspects, the thermal battery can include multiple isolated cells (e.g., 104(1), 104(2), 104(3)), which can be arranged in parallel with one another, as opposed to in series with one another. In various instances, the multiple isolated cells can be coupled to the cryostat via multiple flow valves (e.g., 608(1), 608(2), 608(3), 610(1), 610(2), 610(3)) on each of the heat exchange piping.

[0146] In various cases, action 704 can include actuating a plurality of flow valves to all be in a closed state, which in various embodiments can thermally isolate each of the plurality of isolated cells from the cryostat.

[0147] In various cases, act 706 may include determining whether any of the plurality of insulated cells have not yet been used to cool (or heat, if applicable) the cryostat. If so (e.g., if all of the plurality of insulated cells have already been used to cool (or heat) the cryostat), method 700 may end at act 708. If not (e.g., if at least one of the plurality of insulated cells has not yet been used to cool (or heat) the cryostat), method 700 may proceed to act 710.

[0148] In various embodiments, act 710 can include selecting one of the multiple insulated cells (e.g., 104(2)) that is not already being used to cool (or heat, if applicable) the cryostat.

[0149] In various cases, action 712 may include opening one or more of the plurality of flow valves (e.g., 608(2), 610(2)) such that the selected isolated cell is thermally integrated with the cryostat and the remainder of the plurality of isolated cells (e.g., 104(1), 104(3)) remain thermally isolated from the cryostat.

[0150] In various cases, act 714 may include transferring a heat exchange fluid (e.g., 3 He, 4 He). Such circulation can cause the heat exchange fluid to facilitate heat transfer between the cryostat and the selected insulated cell (e.g., if the selected insulated cell is warmer than the cryostat, such circulation can cool the selected insulated cell and heat the cryostat; if the selected insulated cell is instead colder than the cryostat, such circulation can heat the selected insulated cell and cool the cryostat).

[0151] In various embodiments, act 716 can include stopping the circulation of the heat exchange fluid and closing one or more of the flow valves when the temperature of the cryostat is within a threshold margin of the temperature of the isolated cells (e.g., as determined via any suitable thermometer or thermocouple). In various cases, this can cause the selected isolated cells to now be thermally isolated from the cryostat. In various cases, method 700 can return to act 706.

[0152] FIG. 8 illustrates a flow diagram of an example, non-limiting method 800 that can facilitate scalable thermal energy recycling for cryogenic systems, according to one or more embodiments described herein.

[0153] In various embodiments, action 802 can include, via one or more controllers (e.g., via any suitable computer processor), opening one or more first flow valves (e.g., 608(1), 610(1)) of heat exchange piping (e.g., 108), which can couple the cryostat (e.g., 102) to the thermal battery (e.g., 104). In various cases, a first cell (e.g., 104(1)) of the thermal battery can be thermally integrated with the cryostat when the one or more first flow valves are open.

[0154] In various aspects, act 804 may include pumping a heat exchange fluid (e.g., 118) between the cryostat (e.g., 102) and the first cell (e.g., 104(1)) via a pump (e.g., 118) and through heat exchange piping (e.g., 108) until the temperature of the cryostat (e.g., 102) is within a threshold margin of the temperature of the first cell (e.g., 104(1)). 3 He, 4 This can include circulating a mixture of 10 ...

[0155] In various instances, action 806 may include stopping the circulation of heat exchange fluid between the cryostat (e.g., 102) and the first cell (e.g., 104(1)) via the pump (e.g., 118) in response to determining that the temperature of the cryostat (e.g., 102) is within a threshold margin of the temperature of the first cell (e.g., 104(1)). In some cases, such a determination may be based on a temperature measurement captured by any suitable thermometer, thermocouple, or temperature sensor.

[0156] In various embodiments, action 808 can include closing, via one or more controllers, one or more first flow valves (e.g., 608(1), 610(1)) of the heat exchange piping. In various instances, the first cell (e.g., 104(1)) of the thermal battery can be thermally isolated from the cryostat (e.g., 102) when the one or more first flow valves (e.g., 608(1), 610(1)) are closed.

[0157] In various cases, action 810 can include, via one or more controllers, opening one or more second flow valves (e.g., 608(2), 610(2)) of the heat exchange piping in response to closing one or more first flow valves (e.g., 608(1), 610(1)), such that a second cell (e.g., 104(2)) of the thermal battery can be thermally integrated with the cryostat (e.g., 102) when the one or more second flow valves (e.g., 608(2), 610(2)) are open.

[0158] In various embodiments, action 812 can include circulating a heat exchange fluid between the cryostat (e.g., 102) and the second cell (e.g., 104(2)) via a pump (e.g., 118) and through heat exchange piping (e.g., 108).

[0159] Although not explicitly shown in FIG. 8, the first cell (eg, 104(1)) and the second cell (eg, 104(2)) can have different masses or different heat capacities.

[0160] Although not explicitly shown in FIG. 8 , the temperature of the cryostat (e.g., 102) can be less than the temperature of the first cell (e.g., 104(1)) such that circulation of a heat exchange fluid between the cryostat (e.g., 102) and the first cell (e.g., 104(1)) can cause the cryostat (e.g., 102) to heat and the first cell (e.g., 104(1)) to cool.

[0161] Although not explicitly shown in FIG. 8 , the temperature of the cryostat (e.g., 102) can be greater than the temperature of the first cell (e.g., 104(1)) such that circulation of a heat exchange fluid between the cryostat (e.g., 102) and the first cell (e.g., 104(1)) can cause the cryostat (e.g., 102) to cool and the first cell (e.g., 104(1)) to heat.

[0162] Various other embodiments described herein can include a device that can include a heat battery (e.g., 104) suspended in a vacuum chamber (e.g., 402 or 602); and heat exchange piping (e.g., 108) that can couple the heat battery to the exterior of the vacuum chamber. In various aspects, the heat battery can include a copper spherical mass. In various cases, the heat battery can include at least two cells (e.g., 104(1), 104(2), 104(3)), and the at least two cells can have different masses or different heat capacities from one another. In various cases, the heat exchange piping can include vacuum-insulated pipe.

[0163] Accordingly, various embodiments described herein can facilitate scalable thermal energy recycling of cryogenic systems by coupling a heat battery to such cryogenic systems. In various aspects, the heat battery can be viewed as storing at least some thermal work previously performed by the cryogenic system in a previous warming or cooling cycle, and such stored thermal work can be dissipated by the heat battery to reduce the costs (e.g., time, electrical energy input) required to perform a subsequent cooling or warming cycle. Thus, various embodiments described herein certainly constitute a tangible and demonstrable improvement in the field of cryogenic systems.

[0164] While the disclosure herein primarily describes a single cryostat (e.g., 102) coupled to a thermal battery (e.g., 104), this is merely a non-limiting example for ease of illustration and description. In various embodiments, any suitable number of cryostats (e.g., two or more cryostats, at least one cryostat) can be coupled to any given thermal battery.

[0165] The disclosure herein describes non-limiting examples of various embodiments of the subject innovation. For ease of description or explanation, various portions of the disclosure herein utilize the term "each" when discussing various embodiments of the subject innovation. Such use of the term "each" is a non-limiting example. In other words, when the disclosure herein provides a description that applies to "each" of any particular object or component, it should be understood that this is a non-limiting example of various embodiments of the subject innovation, and it should be further understood that in various other embodiments of the subject innovation, such a description may apply to fewer than "each" of that particular object or component.

[0166] The flowcharts and structures in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, devices, or computer program products according to various embodiments described herein. In this regard, each block in the flowcharts may represent a module, segment, or portion of instructions, including one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions noted in the blocks may occur in a different order than that noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially simultaneously, depending on the functionality involved, or the blocks may sometimes be executed in the reverse order. It should also be noted that each block of the flowchart diagrams, and combinations of blocks in the flowchart diagrams, may be implemented by a dedicated hardware-based system that performs the specified functions or acts, or executes a combination of dedicated hardware and computer instructions.

[0167] Additionally, the term "or" is intended to mean an inclusive "or," rather than an exclusive "or." That is, unless otherwise specified or clear from the context, "X utilizes A or B" is intended to mean any of the natural inclusive permutations. That is, "X utilizes A or B" is satisfied under any of the foregoing cases if X utilizes A; if X utilizes B; or if X utilizes both A and B. As used herein, the term "and / or" is intended to have the same meaning as "or." Moreover, the articles "a" and "an," as used in the specification of the present subject matter and the accompanying drawings, should generally be construed to mean "one or more," unless otherwise specified or clear from the context to refer to the singular form. As used herein, the terms "example" and / or "exemplary" are used to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter described herein is not limited to such examples. Additionally, any aspect or design described herein as "example" and / or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs, and is not intended to exclude equivalent exemplary structures and techniques known to those skilled in the art.

[0168] What has been described above includes merely examples of systems, methods, devices, or apparatus. Of course, for purposes of describing one or more embodiments, it is not possible to describe every conceivable combination of components or method operations, but one of ordinary skill in the art may recognize that many further combinations or permutations of one or more embodiments are possible. Furthermore, to the extent that the terms "includes," "has," "possesses," and the like are used in the detailed description, claims, appendices, or drawings, such terms are intended to be inclusive in the same manner as the term "comprising," as "comprising" is interpreted when used as a transitional term in a claim.

[0169] The description of various embodiments has been presented for purposes of illustration and is not intended to be exhaustive or limited to the embodiments described herein. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein has been selected to best explain the principles of the embodiments, practical applications, or technical improvements over technologies found in the market, or to enable others skilled in the art to understand the embodiments described herein.

Claims

1. at least one cryostat; and a heat battery coupled to the at least one cryostat by a heat exchange system, wherein the heat battery is configured to store thermal energy extracted from the at least one cryostat or to supply thermal energy to the at least one cryostat; A system comprising:

2. 10. The system of claim 1, wherein the thermal battery is thermally isolated from the ambient environment surrounding the at least one cryostat by a vacuum chamber, by a heat shield, or by underground installation.

3. 10. The system of claim 1, wherein the at least one cryostat is colder than the heat battery, and the heat exchange system is configured to circulate a heat exchange fluid between the at least one cryostat and the heat battery, the circulation being configured to cause the heat exchange fluid to absorb energy from the heat battery and deposit the energy in the at least one cryostat.

4. The system of claim 3 , wherein the at least one cryostat is below 5 Kelvin.

5. 10. The system of claim 1, wherein the at least one cryostat is warmer than the heat battery, and the heat exchange system is configured to circulate a heat exchange fluid between the at least one cryostat and the heat battery, the circulation being configured to cause the heat exchange fluid to absorb energy from the at least one cryostat and deposit the energy in the heat battery.

6. The system of claim 5 , wherein the at least one cryostat is at room temperature.

7. 10. The system of claim 1, wherein the thermal battery comprises a plurality of thermally insulated cells each coupled to the at least one cryostat via a plurality of actuatable flow valves of the heat exchange system.

8. 8. The system of claim 7, wherein the plurality of actuatable flow valves are configured to operate in an alternating manner such that at most one of the plurality of thermally isolated cells is thermally coupled to the at least one cryostat at a time.

9. The system of claim 7 , wherein two or more of the plurality of thermally isolated cells have different masses or different heat capacities from one another.

10. The system of claim 7 , wherein the cryostat houses a quantum processor.

11. opening, via one or more controllers, one or more first flow valves of heat exchange piping, wherein the heat exchange piping couples a cryostat to a heat battery, wherein a first cell of the heat battery is thermally integrated with the cryostat when the one or more first flow valves are open; and circulating a heat exchange fluid between the cryostat and the first cell via a pump and through the heat exchange piping until the temperature of the cryostat is within a threshold margin of the temperature of the first cell. A method comprising:

12. in response to determining that the temperature of the cryostat is within the threshold margin of the temperature of the first cell, stopping circulation of the heat exchange fluid between the cryostat and the first cell via the pump; and closing the one or more first flow valves of the heat exchange piping via the one or more controllers, wherein the first cell of the thermal battery is thermally isolated from the cryostat when the one or more first flow valves are closed; The method of claim 11 further comprising:

13. opening, via the one or more controllers, one or more second flow valves of the heat exchange piping in response to closing the one or more first flow valves, wherein a second cell of the thermal battery is thermally integrated with the cryostat when the one or more second flow valves are open; and circulating the heat exchange fluid between the cryostat and the second cell via the pump and through the heat exchange piping. The method of claim 12 further comprising:

14. The method of claim 13 , wherein the first cell and the second cell have different masses or different heat capacities.

15. 15. The method of any one of preceding claims 11 to 14, wherein the temperature of the cryostat is less than the temperature of the first cell such that circulation of the heat exchange fluid between the cryostat and the first cell causes the cryostat to heat and the first cell to cool.

16. 16. The method of any one of preceding claims 11 to 15, wherein the temperature of the cryostat is higher than the temperature of the first cell such that circulation of the heat exchange fluid between the cryostat and the first cell causes the cryostat to cool and the first cell to heat.

17. a thermal battery suspended in a vacuum chamber; and Heat exchange tubing coupling the thermal battery to the exterior of the vacuum chamber A device comprising:

18. 20. The device of claim 17, wherein the thermal battery comprises a copper spherical mass.

19. A device according to any one of the preceding claims 17 to 18, wherein the thermal battery comprises at least two cells, the at least two cells having different masses or different heat capacities from each other.

20. A device according to any one of the preceding claims 17 to 19, wherein the heat exchange piping comprises a vacuum insulated pipe.

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