Cooling system and corresponding methods

Abstract

The invention relates to a method for cooling system (300) for providing liquefied helium (I), the cooling system comprising: a hydrogen liquefying subsystem (301) and a helium cooling subsystem (302), wherein the hydrogen liquefying subsystem is configured to receive gaseous hydrogen (a) and, downstream, provide liquefied hydrogen (b), wherein the helium cooling subsystem is configured to receive gaseous helium (k) and provide, downstream, liquefied or supercritical helium (I), the hydrogen liquefying subsystem (301) and the helium cooling subsystem (302, 402), together, comprising a plurality of heat exchangers (111-116, 211-217, 314b, 317) and a phase separator (320), wherein a first group of the plurality of the heat exchangers and the phase separator are assigned to the hydrogen cooling subsystem, wherein a second group of the plurality of the heat exchangers is assigned to the helium cooling subsystem, wherein one or more shared heat exchangers (317) of the plurality of heat exchangers are comprised in both the first group of heat exchangers and the second group of heat exchangers, and wherein the cooling system (300) is configured to provide the liquefied or supercritical helium (I), preferably for cooling a target system (240).

Description

[0001] The present invention relates to a cooling system, comprising a hydrogen liquefying subsystem and a helium cooling subsystem, preferably for cooling a target system like a data center operated by quantum computing a corresponding system, to a method for cooling a target system and to a method for providing a cooling system.Background

[0002] The development of quantum computing moves forward and is used, e.g., in data centers such as to provide great computing power. This technology, however, requires cryogenic cooling down to 4.5 K and below. While this requirement is still low for smaller quantum computers and can be met by cryocoolers, with further development and larger quantum computers or data centers using it, the requirements for cooling will increase. This will significantly increase the cryogenic cooling capacity to be installed for such a quantum computing system.

[0003] Such data centers and other applications, however often must be in operation around the clock. This is difficult to achieve with cryogenic refrigeration systems. Such complex refrigeration systems suffer minor interruptions from time to time due to equipment failures, especially power outages.

[0004] Thus, an object of the present invention is to provide a way to provide an efficient and / or reliable way of cooling targets like data centers.Disclosure of the invention

[0005] This object is achieved by providing a cooling system and corresponding methods with the features of the independent claims. Embodiments of the invention are the subject of the dependent claims and of the description that follows.

[0006] The invention relates to cooling systems for cooling target systems like data centers based on quantum computing, and to a corresponding method for cooling a target system as well as a method for providing (or manufacturing) such cooling system. As mentioned before, the development of quantum computing moves forward and is used, e.g., in data centers such as to provide great computing power. This technology, however, requires cryogenic cooling down to 4.5 K and below. While this requirement is still low for smaller quantum computers and can be met by cryocoolers, with further development and larger quantum computers or data centers using it, the requirements for cooling will increase. This will significantly increase the cryogenic cooling capacity to be installed for such a quantum computing system.

[0007] As also mentioned, cryogenic refrigeration systems are complex systems suffering minor interruptions from time to time due to equipment failures, especially power outages. Multiple cryocoolers could be used, but would be too inefficient. A way for providing sufficient cooling is, thus, a helium cooling or liquefying system, in particular closed-loop cryogenic helium refrigerators.

[0008] It has now turned out that efficiency and reliability of the helium cooling system can be improved by, at least partially, integrating it with a hydrogen liquefying system. Hydrogen has a great potential as a clean energy carrier. It is a very light gas and cryogenic liquefaction increases the density significantly and it is a competitive solution for distribution of hydrogen in larger quantities.

[0009] Such data centers and other applications, however often must be in operation around the clock. This is difficult to achieve with cryogenic refrigeration systems. Such complex refrigeration systems suffer minor interruptions from time to time due to equipment failures, especially power outages.

[0010] To a large extent, the clean energy will be generated by means of photovoltaics and wind power. Both energy sources, however, vary over the course of a day and over weeks. Cryogenic systems are very sensitive to load variations as they have a limited capacity range and can only respond slowly so as not to disrupt the temperature profile.

[0011] By combination or integration of helium and hydrogen cooling (liquefying) systems, however, the advantages of both can be used, while avoiding or at least reducing their disadvantages.

[0012] A cooling system according to the present invention comprises a hydrogen liquefying subsystem and a helium cooling subsystem. The hydrogen liquefying subsystem is configured to receive gaseous hydrogen and, downstream, provide liquefied hydrogen. The helium cooling subsystem is configured to receive gaseous helium and provide, downstream, liquefied or supercritical helium.

[0013] The hydrogen liquefying subsystem and the helium cooling subsystem, together, comprise a plurality of heat exchangers and a phase separator. A first group of the plurality of the heat exchangers and the phase separator are assigned to the hydrogen cooling subsystem, and a second group of the plurality of the heat exchangers is assigned to the helium cooling subsystem. The phase separator can also be assigned to the helium cooling subsystem, such that the phase separator is shared between the hydrogen co liquefying subsystem and the helium cooling subsystem.

[0014] It is noted that the heat exchangers of the first group are typically arranged as subsequent cooling stages, in each of with the received hydrogen is cooled down further. The phase separator is typically arranged after the last cooling stage, i.e., the last heat exchanger of the first group through which the hydrogen is led.

[0015] Similarly, the heat exchangers of the second group are typically arranged as subsequent cooling stages, in each of with the received helium is cooled down further. The phase separator, if used here, is typically not arranged after the last cooling stage but in-between two of the cooling stages.

[0016] One or more shared heat exchangers of the plurality of heat exchangers are comprised in both the first group of heat exchangers and the second group of heat exchangers. In other words, out of the plurality of heat exchangers of the entire cooling system, one or more of them are shared heat exchangers, which are shared between the hydrogen liquefying subsystem and the helium cooling subsystem, i.e., these are assigned to both subsystems.

[0017] Further, the cooling system is configured to provide the liquefied or supercritical helium, preferably for cooling a target system like a data center operated by quantum computing. It is noted that the cooling system can also comprise a storage tank for the liquefied or supercritical helium. Further, it is noted that both subsystems, the hydrogen liquefying subsystem and the helium cooling subsystem, are configured as closed-loop-systems where parts of the cooled hydrogen or helium is fed back and used to cool down the respective medium at an earlier stage upstream.

[0018] In addition, it is noted that when it is referred to the media hydrogen and helium, these do not necessarily have be 100% pure hydrogen or helium; rather, some amount of impurities can also be present.

[0019] In this way, i.e., with sharing one or more heat exchangers, cooling capacity can be transferred between the hydrogen liquefying subsystem and the helium cooling subsystem. Depending on the number of shared heat exchangers, both, most of the hydrogen liquefying subsystem and the helium cooling subsystem can correspond to a standard hydrogen liquefying system and a standard helium cooling system, respectively. It is just the gas streams to be guided accordingly via the shared heat exchanger. For the helium cooling subsystem, an additional heat exchanger, in addition to a standard helium cooling system might be used in order to better match the temperature profile.

[0020] In an embodiment, the cooling system further comprises two nitrogen cooling subsystems, wherein a first one of the two nitrogen cooling subsystems is assigned to the hydrogen liquefying subsystem and wherein a second one of the two nitrogen cooling subsystems is assigned to the helium cooling subsystem. For both, the hydrogen liquefying subsystem and the helium cooling subsystem, the respective nitrogen cooling subsystem is correlated with one or more heat exchangers of the respective groups. In other words, only some of the plurality of heat exchangers are shared and each of the hydrogen liquefying subsystem and the helium cooling subsystem still has its own heat exchangers. Thus, the cooling system can also be referred to as partially integrated system.

[0021] In an embodiment, the one or one of the more shared heat exchangers is arranged directly upstream the phase separator, i.e., there is no further heat exchanger arranged in the stream between the shared one and the phase separated. In this way, cooling capacities can be shared or transferred very efficiently between the hydrogen liquefying subsystem and the helium cooling subsystem.

[0022] It is noted that also other heat exchangers can be the one shared heat exchanger and also more than one shared heat exchangers can be provided.

[0023] In an embodiment, the second group of heat exchangers comprises all heat exchangers of the first group of heat exchangers. In addition, the second group of heat exchangers can comprise all of the plurality of heat exchangers. It is noted that helium cooling typically requires more heat exchangers or stages of heat exchangers than hydrogen cooling or liquefying; thus, there can be heat exchangers that are only used for the helium cooling subsystem but not for the hydrogen liquefying subsystem.

[0024] In an embodiment, the cooling system further comprises a nitrogen cooling subsystem, wherein the nitrogen cooling subsystem is assigned to both the hydrogen liquefying subsystem and the helium cooling subsystem. Preferably, at least one of the first group of heat exchangers is assigned to the nitrogen cooling subsystem.

[0025] Such cooling system can also be referred to as fully integrated system. Such fully integrated solution is more efficient than two fully separate (stand-alone) hydrogen liquefying and helium cooling systems, and has lower investment costs than the stand-alone systems and also than the partially integrated solution, as the number of heat exchanger blocks and vacuum boxes can be reduced. However, this solution might be more demanding in terms of process design, heat exchanger design and controls.

[0026] In an embodiment, the cooling system further comprises a storage tank for liquefied hydrogen and a fuel cell system. The cooling system is configured to supply liquefied hydrogen from the storage tank (typically after re-gasifying and warming) to the fuel cell system and generate electrical power. Preferably, the cooling system further is configured to operate at least a part of the helium cooling subsystem by means of the generated electrical power. In this way, power failures or energy outages can be bridged efficiently.

[0027] Hydrogen is an energy carrier and can be stored in large quantities as a liquid. In the event of a power outage vaporized hydrogen can be used in a fuel cell to generate emergency power for operating the helium cooling subsystem and, thus, the continued cooling of, e.g., the data center or another target system. This ensures continuous operation of the data center. The data center cooling load is a constant load throughout the year. This or another constant load can be used as a steady partial load in the hydrogen liquefaction process especially during night. This allows continuous operation of the hydrogen liquefier with varying clean energy supply.

[0028] For a given load, the total power consumption for hydrogen liquefaction increases with this partially integrated design. However, production losses during load transients can be significantly reduced. Synergies, particularly on the utility side, will result in lower investment costs.

[0029] Further advantages and embodiments of the invention will be apparent from the description and the accompanying drawing. The invention is illustrated schematically by means of embodiments in the drawing and is described below with reference to the drawing.

[0030] Short description of the figures Fig. 1illustrates a hydrogen liquefying system for explaining a background of the invention; Fig. 2illustrates a helium cooling system for explaining a background of the invention; Fig. 3illustrate a cooling system according to an embodiment of the invention; and Fig. 4illustrate a cooling system according to another embodiment of the invention. Detailed description of the figures

[0031] Fig. 1 schematically illustrates an exemplary hydrogen liquefying system 100 for explaining a background of the invention. The hydrogen liquefying system 100 comprises a plurality of heat exchangers 111, 112, 113, 114, 115, 116, 117, and a phase separator 120. These heat exchangers 111, 112, 113, 114, 115, 116, 117 are arranged in cooling stages and gaseous hydrogen, which is received as stream a at, e.g., a hydrogen input, is guided through heat exchanger 111 and heat exchanger 112.

[0032] Further, the hydrogen stream a is guided through, e.g., an adsorber 124 and again through heat exchanger 112.

[0033] Further downstream the hydrogen stream a is guided through the heat exchangers 113, 114, 115, 116 and 117, then via an ejector 123 and through the phase separator 120 to a valve 125, from which liquefied hydrogen can be received as stream b at, e.g., a hydrogen output. The liquefied hydrogen can be provided to a storage tank, for example. Via the ejector 123 gaseous hydrogen from, for example, the mentioned storage tank, be re-injected into the stream.

[0034] The ejector 123 could also be replaced by a Joule-Thomson valve, for example. Both can be used to throttle the gas in the Joule-Thomson zone to reduce to the gas temperature. The ejector has the additional benefit to compress a side stream to an elevated pressure.

[0035] In addition, gaseous hydrogen, which is received as stream c is guided through heat exchangers 111, 112, 113, 114, 115, 116 and 117 and, via a valve 126, into the phase separator 120. Hydrogen, in particular gaseous hydrogen, from the phase separator 120 is guided back through the heat exchangers 117, 116, 115, 114, 113 and 111 (heat exchanger 112 is omitted in this case) in inverse direction and is received as stream d.

[0036] From hydrogen stream d, a partial stream e is diverted after the heat exchanger 113 and before the heat exchanger 114, is guided, via a valve 127, through an expander 121, through heat exchanger 115, through a further expander 122 and then guided back through the heat exchangers 116, 115, 114, 113 and 111 (heat exchanger 112 is omitted in this case). The streams d and e can, e.g., after compression, again be used as stream c, i.e., in a cycle. This cycle is a refrigeration cycle to cool down the heat exchangers.

[0037] In addition, a nitrogen cooling subsystem 130 is provided. Here, nitrogen, in particular, liquid nitrogen, is received as stream f and guided via a valve 132 into a phase separator 131 where a part g of the nitrogen stream f is diverted and guided through heat exchangers 112 and 111, and the remaining second part h of the nitrogen stream f is re-joined to the first part g between the heat exchangers 112 and 111. This nitrogen cooling subsystem 130 is used for pre-cooling.

[0038] Note that hydrogen streams are shown as solid lines, and nitrogen streams are shown as dash-dotted lines.

[0039] It is noted that all components shown here, i.e. the heat exchangers 111, 121, 113, 114, 115, 116 and 117, the phase separator 120, the expanders 121, 122, the ejector 123, the adsorber 124, the valves 125, 126 and 127 as well as the nitrogen cooling subsystem 130 comprising the phase separator 131 and the valve 132 can be encompassed by a housing for evacuation; vacuum pumps are then also provided.

[0040] Fig. 2 schematically illustrates an exemplary helium cooling system 200 for explaining a background of the invention. The helium cooling system 200 comprises a plurality of heat exchangers 211, 212, 213, 214, 215, 216, 217. These heat exchangers 211, 212, 213, 214, 215, 216, 217 are arranged in cooling stages and gaseous helium, which is received as stream k at, e.g., a helium input, is guided through heat exchanger 211, 212, 213, 214, 215, 216, 217 and then via a valve 223 so as to receive liquefied or supercritical helium as stream I at, e.g., a helium output. The liquefied helium can be provided to a storage tank, for example, and / or be used to cool a target system 240 or another application.

[0041] Any remaining, in particular, gaseous helium, which is, e.g., obtained during cooling the target system 240, is guided back through the heat exchangers 217, 216, 215, 214, 213 and 211 (heat exchanger 212 is omitted in this case) in inverse direction and is received as stream m.

[0042] In addition, from helium stream k, a partial stream n is diverted after the heat exchanger 213 and before the heat exchanger 214, is guided, via a valve 224, through an expander 221, through heat exchanger 215, through a further expander 222 and is then re-joined with stream m between the heat exchangers 216 and 217. Reference numeral 226 illustrates cooling power at a higher temperature (e.g. 70 K, or between 50 K and 80 K) to cool e.g. the shield in the target system. Valves 224 and 225 control the shield cooling temperature. Further, from helium stream k, a partial stream o is diverted after the heat exchanger 214 and before the heat exchanger 215, is guided, via a valve 225 and injected to and joined with partial stream n between vales 224 and 226, i.e. before the partial stream n is guided through the expanders.

[0043] The stream m can, e.g., after compression, again be joined with stream k i.e., in a (partial) cycle. This (partial) cycle is a refrigeration cycle to cool down the heat exchangers.

[0044] In addition, a nitrogen cooling subsystem 230 is provided. Here, nitrogen, in particular, liquid nitrogen, is received as stream p and guided via a valve 232 into a phase separator 231 where a part q of the nitrogen stream p is diverted and guided through heat exchangers 212 and 211, and the remaining second part r of the nitrogen stream p is re-joined to the first part q between the heat exchangers 212 and 211. This nitrogen cooling subsystem 230 is used for pre-cooling.

[0045] It is noted that all components shown here, i.e. the heat exchangers 211, 221, 213, 214, 215, 216 and 217, expanders 221, 222, the valves 223, 224, 225, 226 as well as the nitrogen cooling subsystem 230 comprising the phase separator 231 and the valve 232 can be encompassed by a housing for evacuation; vacuum pumps are then also provided.

[0046] Note that helium streams are shown as dotted lines, and nitrogen streams are shown as dash-dotted lines.

[0047] Fig. 3 schematically illustrates cooling system 300 according to an embodiment of the invention. The cooling system 300 comprises a hydrogen liquefying subsystem 301 and a helium cooling subsystem 302. The cooling system 300 is a partially integrated system as mentioned above; in particular, a helium cooling system like helium cooling system 200 of Fig. 2 is partially integrated into a hydrogen liquefying system like hydrogen cooling system 100 of Fig. 1. This results in the helium cooling and hydrogen liquefying systems being subsystems of the entire cooling system 300.

[0048] The hydrogen liquefying subsystem 301 can, basically, correspond to the hydrogen cooling system 100 of Fig. 1 and the helium cooling subsystem 302 can, basically, correspond to the helium cooling system 200 of Fig. 2. However, there are some differences. Thus, only differences to the individual cooling or liquefying systems of Figs. 1 and 2 will be described. Same or essentially the same components will have the same reference numerals, similar components will have like or similar reference numerals.

[0049] The hydrogen liquefying subsystem 301 and the helium cooling subsystem 302, together, comprise a plurality of heat exchangers and a phase separator 320; these heat exchangers are heat exchangers 111, 112, 113, 114, 115, 116, 211, 212, 213, 214, 314b, 215, 216, 217. All of these heat exchangers form part of the entire cooling system 300.

[0050] Compared to the individual hydrogen liquefying system 100 of Fig. 1, in the hydrogen liquefying subsystem 301, the heat exchanger 117 is replaced by the heat exchanger 317, and the phase separator 120 is replaced by phase separator 320. Within the hydrogen liquefying subsystem 301, the functions of heat exchanger 317 and phase separator 320 correspond to the functions of heat exchanger 117 and phase separator 120, respectively. However, the heat exchanger 317 is larger so as also be able allow the helium streams k, m be guided through it. Similarly, the phase separator 320 is larger so as also be able allow the helium streams k, m be guided through it.

[0051] The helium cooling subsystem 302 comprises the same heat exchangers as the helium cooling system 200 of Fig. 2, i.e., 211, 212, 213, 214, 215, 216, 217. In addition, however, the heat exchanger 317 is also part of the helium cooling subsystem 302, i.e., heat exchanger 317 is a shared heat exchanger. Further, an additional heat exchanger 314b is provided in the helium cooling subsystem 302 in order to better match temperature profiles. In particular, the additional heat exchanger 314b is provided downstream (with respect to stream k) the heat exchanger 214, and heat exchanger 317 is provided downstream the heat exchanger 314b, and before the phase separator 320. The phase separator 320 in turn is provided upstream (with respect to stream k) the heat exchanger 215.

[0052] In this way, additional and / or larger and / or modified heat exchangers and phase separator are required. However, other heat exchangers, in turn, can, for example, be built smaller. In addition, synergistic effects can be used as mentioned above.

[0053] The cooling system 300 further comprises the nitrogen cooling subsystem 130 and the nitrogen cooling subsystem 230, which are assigned to the hydrogen liquefying subsystem 301 and the helium cooling subsystem 302, respectively, and which correspond to the nitrogen cooling subsystems of Figs. 1 and 2, respectively.

[0054] It is noted that the cooling system 300 shown in Fig. 3, based on the hydrogen liquefying system 100 of Fig. 1 and the helium cooling system 200 of Fig. 2, is only exemplary. Such cooling system having hydrogen liquefying and helium cooling subsystems sharing a heat exchanger and preferably a phase separator can also be based on individual hydrogen liquefying and helium cooling system of different design, e.g., having different numbers of heat exchangers and / or different paths of the hydrogen and helium streams through the heat exchangers and other components. Also, other and / or more heat exchangers can be shared.

[0055] Further, the cooling system 300 comprises a storage tank 350 for storing at least part of the liquefied hydrogen b, and a fuel cell system 352. Hydrogen from this storage tank 350 can be re-gasified, warmed and provided to the fuel cell system 352 in order to generate electrical power, which be used to operate the helium cooling subsystem 302 in case of power failure, for example.

[0056] Fig. 4 schematically illustrates cooling system 400 according to another embodiment of the invention. The cooling system 400 comprises a hydrogen liquefying subsystem 401 and a helium cooling subsystem 402. The cooling system 400 is a fully integrated system as mentioned above; in particular, a helium cooling system like helium cooling system 200 of Fig. 2 is fully (i.e. as much possible) integrated into a hydrogen liquefying system like hydrogen cooling system 100 of Fig. 1. This results in the helium cooling and hydrogen liquefying systems being subsystems of the entire cooling system 400.

[0057] The hydrogen liquefying subsystem 401 can, basically, correspond to the hydrogen liquefying system 100 of Fig. 1; in addition, the hydrogen liquefying subsystem 401 can, basically, correspond to the hydrogen liquefying subsystem 301 of Fig. 3. The helium cooling subsystem 302 can, at least with respect to the media streams, correspond to the helium cooling system 200 of Fig. 2. However, there are some differences. Thus, only differences to the individual cooling systems of Figs. 1 and 2 and the subcooling systems of Fig. 3 will be described. Same or essentially the same components will have the same reference numerals, similar components will have like or similar reference numerals.

[0058] The hydrogen liquefying subsystem 401 and the helium cooling subsystem 402, together, comprise a plurality of heat exchangers and a phase separator 420; these heat exchangers are heat exchangers 411, 412, 413, 414, 415, 416, 417, 215, 216, 217. All of these heat exchangers form part of the entire cooling system 400.

[0059] Compared to the individual hydrogen liquefying system 100 of Fig. 1, in the hydrogen liquefying subsystem 401, the heat exchangers 111 to 117 are replaced by the heat exchangers 411 to 417, and the phase separator 120 is replaced by phase separator 420. Within the hydrogen liquefying subsystem 301, the functions of exchangers 411 to 417 and phase separator 420 correspond to the functions of heat exchangers 111 to 117 and phase separator 120, respectively. However, the heat exchangers 411 to 417 are larger so as also be able allow the helium streams k, m be guided through it. Similarly, the phase separator 420 is larger so as also be able allow the helium streams k, m be guided through it.

[0060] The helium cooling subsystem 402 comprises the same heat exchangers as the helium cooling system 200 of Fig. 2, i.e., 215, 216, 217. In addition, however, the heat exchangers 411 to 417 are also part of the helium cooling subsystem 402, i.e., heat exchangers 411 to 417 are shared heat exchangers.

[0061] In this way, additional and / or larger and / or modified heat exchangers and phase separator are required. However, many other heat exchangers, in turn, can, for example, be built smaller or be omitted. In addition, synergistic effects can be used as mentioned above.

[0062] The cooling system 400 further comprises a nitrogen cooling subsystem 430, which is assigned to the hydrogen liquefying subsystem 401 and the helium cooling subsystem 402. Basically, the nitrogen cooling subsystem 430 can correspond to the nitrogen cooling subsystem 130 of Figs. 1, 3, respectively. However, the nitrogen cooling subsystem 430 can be built larger in order to manage to efficiently cool the additional streams, hydrogen and helium.

[0063] It is noted that the cooling system 400 shown in Fig. 4 is only exemplary. Such cooling system having hydrogen liquefying and helium cooling subsystems sharing heat exchangers and preferably a phase separator can also be based on individual hydrogen liquefying and helium cooling system of different design, then having different numbers of heat exchangers and / or different paths of the hydrogen and helium streams through the heat exchangers and other components.

[0064] Further, the cooling system 400 comprises a storage tank 450 for storing at least part of the liquefied hydrogen b, and a fuel cell system 452. Hydrogen from this storage tank 450 can be re-gasified, warmed and provided to the fuel cell system 452 in order to generate electrical power, which be used to operate the helium cooling subsystem 402 in case of power failure, for example.

Examples

Embodiment Construction

[0031]Fig. 1 schematically illustrates an exemplary hydrogen liquefying system 100 for explaining a background of the invention. The hydrogen liquefying system 100 comprises a plurality of heat exchangers 111, 112, 113, 114, 115, 116, 117, and a phase separator 120. These heat exchangers 111, 112, 113, 114, 115, 116, 117 are arranged in cooling stages and gaseous hydrogen, which is received as stream a at, e.g., a hydrogen input, is guided through heat exchanger 111 and heat exchanger 112.

[0032]Further, the hydrogen stream a is guided through, e.g., an adsorber 124 and again through heat exchanger 112.

[0033]Further downstream the hydrogen stream a is guided through the heat exchangers 113, 114, 115, 116 and 117, then via an ejector 123 and through the phase separator 120 to a valve 125, from which liquefied hydrogen can be received as stream b at, e.g., a hydrogen output. The liquefied hydrogen can be provided to a storage tank, for example. Via the ejector 123 gaseous hydrogen from...

[0001] The present invention relates to a cooling system, comprising a hydrogen liquefying subsystem and a helium cooling subsystem, preferably for cooling a target system like a data center operated by quantum computing a corresponding system, to a method for cooling a target system and to a method for providing a cooling system.Background

[0002] The development of quantum computing moves forward and is used, e.g., in data centers such as to provide great computing power. This technology, however, requires cryogenic cooling down to 4.5 K and below. While this requirement is still low for smaller quantum computers and can be met by cryocoolers, with further development and larger quantum computers or data centers using it, the requirements for cooling will increase. This will significantly increase the cryogenic cooling capacity to be installed for such a quantum computing system.

[0003] Such data centers and other applications, however often must be in operation around the clock. This is difficult to achieve with cryogenic refrigeration systems. Such complex refrigeration systems suffer minor interruptions from time to time due to equipment failures, especially power outages.

[0004] Thus, an object of the present invention is to provide a way to provide an efficient and / or reliable way of cooling targets like data centers.Disclosure of the invention

[0005] This object is achieved by providing a cooling system and corresponding methods with the features of the independent claims. Embodiments of the invention are the subject of the dependent claims and of the description that follows.

[0006] The invention relates to cooling systems for cooling target systems like data centers based on quantum computing, and to a corresponding method for cooling a target system as well as a method for providing (or manufacturing) such cooling system. As mentioned before, the development of quantum computing moves forward and is used, e.g., in data centers such as to provide great computing power. This technology, however, requires cryogenic cooling down to 4.5 K and below. While this requirement is still low for smaller quantum computers and can be met by cryocoolers, with further development and larger quantum computers or data centers using it, the requirements for cooling will increase. This will significantly increase the cryogenic cooling capacity to be installed for such a quantum computing system.

[0007] As also mentioned, cryogenic refrigeration systems are complex systems suffering minor interruptions from time to time due to equipment failures, especially power outages. Multiple cryocoolers could be used, but would be too inefficient. A way for providing sufficient cooling is, thus, a helium cooling or liquefying system, in particular closed-loop cryogenic helium refrigerators.

[0008] It has now turned out that efficiency and reliability of the helium cooling system can be improved by, at least partially, integrating it with a hydrogen liquefying system. Hydrogen has a great potential as a clean energy carrier. It is a very light gas and cryogenic liquefaction increases the density significantly and it is a competitive solution for distribution of hydrogen in larger quantities.

[0009] Such data centers and other applications, however often must be in operation around the clock. This is difficult to achieve with cryogenic refrigeration systems. Such complex refrigeration systems suffer minor interruptions from time to time due to equipment failures, especially power outages.

[0010] To a large extent, the clean energy will be generated by means of photovoltaics and wind power. Both energy sources, however, vary over the course of a day and over weeks. Cryogenic systems are very sensitive to load variations as they have a limited capacity range and can only respond slowly so as not to disrupt the temperature profile.

[0011] By combination or integration of helium and hydrogen cooling (liquefying) systems, however, the advantages of both can be used, while avoiding or at least reducing their disadvantages.

[0012] A cooling system according to the present invention comprises a hydrogen liquefying subsystem and a helium cooling subsystem. The hydrogen liquefying subsystem is configured to receive gaseous hydrogen and, downstream, provide liquefied hydrogen. The helium cooling subsystem is configured to receive gaseous helium and provide, downstream, liquefied or supercritical helium.

[0013] The hydrogen liquefying subsystem and the helium cooling subsystem, together, comprise a plurality of heat exchangers and a phase separator. A first group of the plurality of the heat exchangers and the phase separator are assigned to the hydrogen cooling subsystem, and a second group of the plurality of the heat exchangers is assigned to the helium cooling subsystem. The phase separator can also be assigned to the helium cooling subsystem, such that the phase separator is shared between the hydrogen co liquefying subsystem and the helium cooling subsystem.

[0014] It is noted that the heat exchangers of the first group are typically arranged as subsequent cooling stages, in each of with the received hydrogen is cooled down further. The phase separator is typically arranged after the last cooling stage, i.e., the last heat exchanger of the first group through which the hydrogen is led.

[0015] Similarly, the heat exchangers of the second group are typically arranged as subsequent cooling stages, in each of with the received helium is cooled down further. The phase separator, if used here, is typically not arranged after the last cooling stage but in-between two of the cooling stages.

[0016] One or more shared heat exchangers of the plurality of heat exchangers are comprised in both the first group of heat exchangers and the second group of heat exchangers. In other words, out of the plurality of heat exchangers of the entire cooling system, one or more of them are shared heat exchangers, which are shared between the hydrogen liquefying subsystem and the helium cooling subsystem, i.e., these are assigned to both subsystems.

[0017] Further, the cooling system is configured to provide the liquefied or supercritical helium, preferably for cooling a target system like a data center operated by quantum computing. It is noted that the cooling system can also comprise a storage tank for the liquefied or supercritical helium. Further, it is noted that both subsystems, the hydrogen liquefying subsystem and the helium cooling subsystem, are configured as closed-loop-systems where parts of the cooled hydrogen or helium is fed back and used to cool down the respective medium at an earlier stage upstream.

[0018] In addition, it is noted that when it is referred to the media hydrogen and helium, these do not necessarily have be 100% pure hydrogen or helium; rather, some amount of impurities can also be present.

[0019] In this way, i.e., with sharing one or more heat exchangers, cooling capacity can be transferred between the hydrogen liquefying subsystem and the helium cooling subsystem. Depending on the number of shared heat exchangers, both, most of the hydrogen liquefying subsystem and the helium cooling subsystem can correspond to a standard hydrogen liquefying system and a standard helium cooling system, respectively. It is just the gas streams to be guided accordingly via the shared heat exchanger. For the helium cooling subsystem, an additional heat exchanger, in addition to a standard helium cooling system might be used in order to better match the temperature profile.

[0020] In an embodiment, the cooling system further comprises two nitrogen cooling subsystems, wherein a first one of the two nitrogen cooling subsystems is assigned to the hydrogen liquefying subsystem and wherein a second one of the two nitrogen cooling subsystems is assigned to the helium cooling subsystem. For both, the hydrogen liquefying subsystem and the helium cooling subsystem, the respective nitrogen cooling subsystem is correlated with one or more heat exchangers of the respective groups. In other words, only some of the plurality of heat exchangers are shared and each of the hydrogen liquefying subsystem and the helium cooling subsystem still has its own heat exchangers. Thus, the cooling system can also be referred to as partially integrated system.

[0021] In an embodiment, the one or one of the more shared heat exchangers is arranged directly upstream the phase separator, i.e., there is no further heat exchanger arranged in the stream between the shared one and the phase separated. In this way, cooling capacities can be shared or transferred very efficiently between the hydrogen liquefying subsystem and the helium cooling subsystem.

[0022] It is noted that also other heat exchangers can be the one shared heat exchanger and also more than one shared heat exchangers can be provided.

[0023] In an embodiment, the second group of heat exchangers comprises all heat exchangers of the first group of heat exchangers. In addition, the second group of heat exchangers can comprise all of the plurality of heat exchangers. It is noted that helium cooling typically requires more heat exchangers or stages of heat exchangers than hydrogen cooling or liquefying; thus, there can be heat exchangers that are only used for the helium cooling subsystem but not for the hydrogen liquefying subsystem.

[0024] In an embodiment, the cooling system further comprises a nitrogen cooling subsystem, wherein the nitrogen cooling subsystem is assigned to both the hydrogen liquefying subsystem and the helium cooling subsystem. Preferably, at least one of the first group of heat exchangers is assigned to the nitrogen cooling subsystem.

[0025] Such cooling system can also be referred to as fully integrated system. Such fully integrated solution is more efficient than two fully separate (stand-alone) hydrogen liquefying and helium cooling systems, and has lower investment costs than the stand-alone systems and also than the partially integrated solution, as the number of heat exchanger blocks and vacuum boxes can be reduced. However, this solution might be more demanding in terms of process design, heat exchanger design and controls.

[0026] In an embodiment, the cooling system further comprises a storage tank for liquefied hydrogen and a fuel cell system. The cooling system is configured to supply liquefied hydrogen from the storage tank (typically after re-gasifying and warming) to the fuel cell system and generate electrical power. Preferably, the cooling system further is configured to operate at least a part of the helium cooling subsystem by means of the generated electrical power. In this way, power failures or energy outages can be bridged efficiently.

[0027] Hydrogen is an energy carrier and can be stored in large quantities as a liquid. In the event of a power outage vaporized hydrogen can be used in a fuel cell to generate emergency power for operating the helium cooling subsystem and, thus, the continued cooling of, e.g., the data center or another target system. This ensures continuous operation of the data center. The data center cooling load is a constant load throughout the year. This or another constant load can be used as a steady partial load in the hydrogen liquefaction process especially during night. This allows continuous operation of the hydrogen liquefier with varying clean energy supply.

[0028] For a given load, the total power consumption for hydrogen liquefaction increases with this partially integrated design. However, production losses during load transients can be significantly reduced. Synergies, particularly on the utility side, will result in lower investment costs.

[0029] Further advantages and embodiments of the invention will be apparent from the description and the accompanying drawing. The invention is illustrated schematically by means of embodiments in the drawing and is described below with reference to the drawing.

[0030] Short description of the figures Fig. 1illustrates a hydrogen liquefying system for explaining a background of the invention; Fig. 2illustrates a helium cooling system for explaining a background of the invention; Fig. 3illustrate a cooling system according to an embodiment of the invention; and Fig. 4illustrate a cooling system according to another embodiment of the invention. Detailed description of the figures

[0031] Fig. 1 schematically illustrates an exemplary hydrogen liquefying system 100 for explaining a background of the invention. The hydrogen liquefying system 100 comprises a plurality of heat exchangers 111, 112, 113, 114, 115, 116, 117, and a phase separator 120. These heat exchangers 111, 112, 113, 114, 115, 116, 117 are arranged in cooling stages and gaseous hydrogen, which is received as stream a at, e.g., a hydrogen input, is guided through heat exchanger 111 and heat exchanger 112.

[0032] Further, the hydrogen stream a is guided through, e.g., an adsorber 124 and again through heat exchanger 112.

[0033] Further downstream the hydrogen stream a is guided through the heat exchangers 113, 114, 115, 116 and 117, then via an ejector 123 and through the phase separator 120 to a valve 125, from which liquefied hydrogen can be received as stream b at, e.g., a hydrogen output. The liquefied hydrogen can be provided to a storage tank, for example. Via the ejector 123 gaseous hydrogen from, for example, the mentioned storage tank, be re-injected into the stream.

[0034] The ejector 123 could also be replaced by a Joule-Thomson valve, for example. Both can be used to throttle the gas in the Joule-Thomson zone to reduce to the gas temperature. The ejector has the additional benefit to compress a side stream to an elevated pressure.

[0035] In addition, gaseous hydrogen, which is received as stream c is guided through heat exchangers 111, 112, 113, 114, 115, 116 and 117 and, via a valve 126, into the phase separator 120. Hydrogen, in particular gaseous hydrogen, from the phase separator 120 is guided back through the heat exchangers 117, 116, 115, 114, 113 and 111 (heat exchanger 112 is omitted in this case) in inverse direction and is received as stream d.

[0036] From hydrogen stream d, a partial stream e is diverted after the heat exchanger 113 and before the heat exchanger 114, is guided, via a valve 127, through an expander 121, through heat exchanger 115, through a further expander 122 and then guided back through the heat exchangers 116, 115, 114, 113 and 111 (heat exchanger 112 is omitted in this case). The streams d and e can, e.g., after compression, again be used as stream c, i.e., in a cycle. This cycle is a refrigeration cycle to cool down the heat exchangers.

[0037] In addition, a nitrogen cooling subsystem 130 is provided. Here, nitrogen, in particular, liquid nitrogen, is received as stream f and guided via a valve 132 into a phase separator 131 where a part g of the nitrogen stream f is diverted and guided through heat exchangers 112 and 111, and the remaining second part h of the nitrogen stream f is re-joined to the first part g between the heat exchangers 112 and 111. This nitrogen cooling subsystem 130 is used for pre-cooling.

[0038] Note that hydrogen streams are shown as solid lines, and nitrogen streams are shown as dash-dotted lines.

[0039] It is noted that all components shown here, i.e. the heat exchangers 111, 121, 113, 114, 115, 116 and 117, the phase separator 120, the expanders 121, 122, the ejector 123, the adsorber 124, the valves 125, 126 and 127 as well as the nitrogen cooling subsystem 130 comprising the phase separator 131 and the valve 132 can be encompassed by a housing for evacuation; vacuum pumps are then also provided.

[0040] Fig. 2 schematically illustrates an exemplary helium cooling system 200 for explaining a background of the invention. The helium cooling system 200 comprises a plurality of heat exchangers 211, 212, 213, 214, 215, 216, 217. These heat exchangers 211, 212, 213, 214, 215, 216, 217 are arranged in cooling stages and gaseous helium, which is received as stream k at, e.g., a helium input, is guided through heat exchanger 211, 212, 213, 214, 215, 216, 217 and then via a valve 223 so as to receive liquefied or supercritical helium as stream I at, e.g., a helium output. The liquefied helium can be provided to a storage tank, for example, and / or be used to cool a target system 240 or another application.

[0041] Any remaining, in particular, gaseous helium, which is, e.g., obtained during cooling the target system 240, is guided back through the heat exchangers 217, 216, 215, 214, 213 and 211 (heat exchanger 212 is omitted in this case) in inverse direction and is received as stream m.

[0042] In addition, from helium stream k, a partial stream n is diverted after the heat exchanger 213 and before the heat exchanger 214, is guided, via a valve 224, through an expander 221, through heat exchanger 215, through a further expander 222 and is then re-joined with stream m between the heat exchangers 216 and 217. Reference numeral 226 illustrates cooling power at a higher temperature (e.g. 70 K, or between 50 K and 80 K) to cool e.g. the shield in the target system. Valves 224 and 225 control the shield cooling temperature. Further, from helium stream k, a partial stream o is diverted after the heat exchanger 214 and before the heat exchanger 215, is guided, via a valve 225 and injected to and joined with partial stream n between vales 224 and 226, i.e. before the partial stream n is guided through the expanders.

[0043] The stream m can, e.g., after compression, again be joined with stream k i.e., in a (partial) cycle. This (partial) cycle is a refrigeration cycle to cool down the heat exchangers.

[0044] In addition, a nitrogen cooling subsystem 230 is provided. Here, nitrogen, in particular, liquid nitrogen, is received as stream p and guided via a valve 232 into a phase separator 231 where a part q of the nitrogen stream p is diverted and guided through heat exchangers 212 and 211, and the remaining second part r of the nitrogen stream p is re-joined to the first part q between the heat exchangers 212 and 211. This nitrogen cooling subsystem 230 is used for pre-cooling.

[0045] It is noted that all components shown here, i.e. the heat exchangers 211, 221, 213, 214, 215, 216 and 217, expanders 221, 222, the valves 223, 224, 225, 226 as well as the nitrogen cooling subsystem 230 comprising the phase separator 231 and the valve 232 can be encompassed by a housing for evacuation; vacuum pumps are then also provided.

[0046] Note that helium streams are shown as dotted lines, and nitrogen streams are shown as dash-dotted lines.

[0047] Fig. 3 schematically illustrates cooling system 300 according to an embodiment of the invention. The cooling system 300 comprises a hydrogen liquefying subsystem 301 and a helium cooling subsystem 302. The cooling system 300 is a partially integrated system as mentioned above; in particular, a helium cooling system like helium cooling system 200 of Fig. 2 is partially integrated into a hydrogen liquefying system like hydrogen cooling system 100 of Fig. 1. This results in the helium cooling and hydrogen liquefying systems being subsystems of the entire cooling system 300.

[0048] The hydrogen liquefying subsystem 301 can, basically, correspond to the hydrogen cooling system 100 of Fig. 1 and the helium cooling subsystem 302 can, basically, correspond to the helium cooling system 200 of Fig. 2. However, there are some differences. Thus, only differences to the individual cooling or liquefying systems of Figs. 1 and 2 will be described. Same or essentially the same components will have the same reference numerals, similar components will have like or similar reference numerals.

[0049] The hydrogen liquefying subsystem 301 and the helium cooling subsystem 302, together, comprise a plurality of heat exchangers and a phase separator 320; these heat exchangers are heat exchangers 111, 112, 113, 114, 115, 116, 211, 212, 213, 214, 314b, 215, 216, 217. All of these heat exchangers form part of the entire cooling system 300.

[0050] Compared to the individual hydrogen liquefying system 100 of Fig. 1, in the hydrogen liquefying subsystem 301, the heat exchanger 117 is replaced by the heat exchanger 317, and the phase separator 120 is replaced by phase separator 320. Within the hydrogen liquefying subsystem 301, the functions of heat exchanger 317 and phase separator 320 correspond to the functions of heat exchanger 117 and phase separator 120, respectively. However, the heat exchanger 317 is larger so as also be able allow the helium streams k, m be guided through it. Similarly, the phase separator 320 is larger so as also be able allow the helium streams k, m be guided through it.

[0051] The helium cooling subsystem 302 comprises the same heat exchangers as the helium cooling system 200 of Fig. 2, i.e., 211, 212, 213, 214, 215, 216, 217. In addition, however, the heat exchanger 317 is also part of the helium cooling subsystem 302, i.e., heat exchanger 317 is a shared heat exchanger. Further, an additional heat exchanger 314b is provided in the helium cooling subsystem 302 in order to better match temperature profiles. In particular, the additional heat exchanger 314b is provided downstream (with respect to stream k) the heat exchanger 214, and heat exchanger 317 is provided downstream the heat exchanger 314b, and before the phase separator 320. The phase separator 320 in turn is provided upstream (with respect to stream k) the heat exchanger 215.

[0052] In this way, additional and / or larger and / or modified heat exchangers and phase separator are required. However, other heat exchangers, in turn, can, for example, be built smaller. In addition, synergistic effects can be used as mentioned above.

[0053] The cooling system 300 further comprises the nitrogen cooling subsystem 130 and the nitrogen cooling subsystem 230, which are assigned to the hydrogen liquefying subsystem 301 and the helium cooling subsystem 302, respectively, and which correspond to the nitrogen cooling subsystems of Figs. 1 and 2, respectively.

[0054] It is noted that the cooling system 300 shown in Fig. 3, based on the hydrogen liquefying system 100 of Fig. 1 and the helium cooling system 200 of Fig. 2, is only exemplary. Such cooling system having hydrogen liquefying and helium cooling subsystems sharing a heat exchanger and preferably a phase separator can also be based on individual hydrogen liquefying and helium cooling system of different design, e.g., having different numbers of heat exchangers and / or different paths of the hydrogen and helium streams through the heat exchangers and other components. Also, other and / or more heat exchangers can be shared.

[0055] Further, the cooling system 300 comprises a storage tank 350 for storing at least part of the liquefied hydrogen b, and a fuel cell system 352. Hydrogen from this storage tank 350 can be re-gasified, warmed and provided to the fuel cell system 352 in order to generate electrical power, which be used to operate the helium cooling subsystem 302 in case of power failure, for example.

[0056] Fig. 4 schematically illustrates cooling system 400 according to another embodiment of the invention. The cooling system 400 comprises a hydrogen liquefying subsystem 401 and a helium cooling subsystem 402. The cooling system 400 is a fully integrated system as mentioned above; in particular, a helium cooling system like helium cooling system 200 of Fig. 2 is fully (i.e. as much possible) integrated into a hydrogen liquefying system like hydrogen cooling system 100 of Fig. 1. This results in the helium cooling and hydrogen liquefying systems being subsystems of the entire cooling system 400.

[0057] The hydrogen liquefying subsystem 401 can, basically, correspond to the hydrogen liquefying system 100 of Fig. 1; in addition, the hydrogen liquefying subsystem 401 can, basically, correspond to the hydrogen liquefying subsystem 301 of Fig. 3. The helium cooling subsystem 302 can, at least with respect to the media streams, correspond to the helium cooling system 200 of Fig. 2. However, there are some differences. Thus, only differences to the individual cooling systems of Figs. 1 and 2 and the subcooling systems of Fig. 3 will be described. Same or essentially the same components will have the same reference numerals, similar components will have like or similar reference numerals.

[0058] The hydrogen liquefying subsystem 401 and the helium cooling subsystem 402, together, comprise a plurality of heat exchangers and a phase separator 420; these heat exchangers are heat exchangers 411, 412, 413, 414, 415, 416, 417, 215, 216, 217. All of these heat exchangers form part of the entire cooling system 400.

[0059] Compared to the individual hydrogen liquefying system 100 of Fig. 1, in the hydrogen liquefying subsystem 401, the heat exchangers 111 to 117 are replaced by the heat exchangers 411 to 417, and the phase separator 120 is replaced by phase separator 420. Within the hydrogen liquefying subsystem 301, the functions of exchangers 411 to 417 and phase separator 420 correspond to the functions of heat exchangers 111 to 117 and phase separator 120, respectively. However, the heat exchangers 411 to 417 are larger so as also be able allow the helium streams k, m be guided through it. Similarly, the phase separator 420 is larger so as also be able allow the helium streams k, m be guided through it.

[0060] The helium cooling subsystem 402 comprises the same heat exchangers as the helium cooling system 200 of Fig. 2, i.e., 215, 216, 217. In addition, however, the heat exchangers 411 to 417 are also part of the helium cooling subsystem 402, i.e., heat exchangers 411 to 417 are shared heat exchangers.

[0061] In this way, additional and / or larger and / or modified heat exchangers and phase separator are required. However, many other heat exchangers, in turn, can, for example, be built smaller or be omitted. In addition, synergistic effects can be used as mentioned above.

[0062] The cooling system 400 further comprises a nitrogen cooling subsystem 430, which is assigned to the hydrogen liquefying subsystem 401 and the helium cooling subsystem 402. Basically, the nitrogen cooling subsystem 430 can correspond to the nitrogen cooling subsystem 130 of Figs. 1, 3, respectively. However, the nitrogen cooling subsystem 430 can be built larger in order to manage to efficiently cool the additional streams, hydrogen and helium.

[0063] It is noted that the cooling system 400 shown in Fig. 4 is only exemplary. Such cooling system having hydrogen liquefying and helium cooling subsystems sharing heat exchangers and preferably a phase separator can also be based on individual hydrogen liquefying and helium cooling system of different design, then having different numbers of heat exchangers and / or different paths of the hydrogen and helium streams through the heat exchangers and other components.

[0064] Further, the cooling system 400 comprises a storage tank 450 for storing at least part of the liquefied hydrogen b, and a fuel cell system 452. Hydrogen from this storage tank 450 can be re-gasified, warmed and provided to the fuel cell system 452 in order to generate electrical power, which be used to operate the helium cooling subsystem 402 in case of power failure, for example.

Examples

Embodiment Construction

[0031]Fig. 1 schematically illustrates an exemplary hydrogen liquefying system 100 for explaining a background of the invention. The hydrogen liquefying system 100 comprises a plurality of heat exchangers 111, 112, 113, 114, 115, 116, 117, and a phase separator 120. These heat exchangers 111, 112, 113, 114, 115, 116, 117 are arranged in cooling stages and gaseous hydrogen, which is received as stream a at, e.g., a hydrogen input, is guided through heat exchanger 111 and heat exchanger 112.

[0032]Further, the hydrogen stream a is guided through, e.g., an adsorber 124 and again through heat exchanger 112.

[0033]Further downstream the hydrogen stream a is guided through the heat exchangers 113, 114, 115, 116 and 117, then via an ejector 123 and through the phase separator 120 to a valve 125, from which liquefied hydrogen can be received as stream b at, e.g., a hydrogen output. The liquefied hydrogen can be provided to a storage tank, for example. Via the ejector 123 gaseous hydrogen from...

Claims

1. A cooling system (300, 400) for providing liquefied or supercritical helium (I), the cooling system comprising: a hydrogen liquefying subsystem (301, 401) and a helium cooling subsystem (302, 402), wherein the hydrogen cooling subsystem is configured to receive gaseous hydrogen (a) and, downstream, provide liquefied hydrogen (b), wherein the helium cooling subsystem is configured to receive gaseous helium (k) and provide, downstream, liquefied or supercritical helium (I), the hydrogen liquefying subsystem (301, 401) and the helium cooling subsystem (302, 402), together, comprising a plurality of heat exchangers (111-116, 211-217, 314b, 317, 411-417) and a phase separator (320, 420), wherein a first group of the plurality of the heat exchangers and the phase separator are assigned to the hydrogen liquefying subsystem, wherein a second group of the plurality of the heat exchangers are assigned to the helium cooling subsystem, wherein one or more shared heat exchangers (317, 411-417) of the plurality of heat exchangers are comprised in both the first group of heat exchangers and the second group of heat exchangers, and wherein the cooling system (300, 400) is configured to provide the liquefied or supercritical helium (I), preferably for cooling a target system (240).

2. The cooling system (300) of claim 1, further comprising two nitrogen cooling subsystems (130, 230), wherein a first one of the two nitrogen cooling subsystems is assigned to the hydrogen liquefying subsystem and wherein a second one of the two nitrogen cooling subsystems is assigned to the helium cooling subsystem.

3. The cooling system (300) of claim 1 or 2, wherein the one or one of the more shared heat exchangers is arranged directly upstream the phase separator.

4. The cooling system (400) of claim 1, wherein the second group of heat exchangers comprises all heat exchangers of the first group of heat exchangers, preferably, wherein the second group of heat exchangers comprises all of the plurality of heat exchangers.

5. The cooling system (400) of claim 4, further comprising a nitrogen cooling subsystem (430), wherein the nitrogen cooling subsystem is assigned to both the hydrogen liquefying subsystem and the helium cooling subsystem.

6. The cooling system (400) of claim 5, wherein at least one of the first group of heat exchangers is assigned to the nitrogen cooling subsystem.

7. The cooling system (300, 400) of any one of the preceding claims, further comprising a storage tank (350, 450) for liquefied hydrogen, and a fuel cell system (352, 452), wherein the cooling system is configured to supply liquefied hydrogen, preferably re-gasified and warmed, from the storage tank to the fuel cell system and generate electrical power.

8. The cooling system (300, 400) of claim 7, configured to operate at least a part of the helium cooling subsystem (302, 402) by means of the generated electrical power.

9. A method for cooling a target system (240), comprising: receiving, in a hydrogen liquefying subsystem (301, 401), gaseous hydrogen (a) and, downstream, provide liquefied hydrogen (b); receiving, in a helium cooling subsystem (302, 402), gaseous helium (k) and provide, downstream, liquefied or supercritical helium (I); and providing the liquefied or supercritical helium (I) for cooling the target system (240), wherein the hydrogen liquefying subsystem (301, 401) and the helium cooling subsystem (302, 402), together, comprise a plurality of heat exchangers (111-116, 211-217, 314b, 317, 411-417) and a phase separator (320, 420), wherein a first group of the plurality of the heat exchangers and the phase separator are assigned to the hydrogen cooling subsystem, wherein a second group of the plurality of the heat exchangers is assigned to the helium cooling subsystem, and wherein one or more shared heat exchangers (317, 411-417) of the plurality of heat exchangers are comprised in both the first group of heat exchangers and the second group of heat exchangers.

10. The method of claim 9, comprising operating the cooling system (300, 400) of any one of claims 1 to 8.

11. The method of claim 9 or 10, wherein the target system comprises a data center, wherein the data center, preferably, is operated by and / or comprises quantum computing machines.

12. A method for providing a cooling system (300, 400) for providing liquefied or supercritical helium (I), the cooling system comprising: a hydrogen liquefying subsystem (301, 401) and a helium cooling subsystem (302, 402), wherein the hydrogen liquefying subsystem is configured to receive gaseous hydrogen (a) and, downstream, provide liquefied hydrogen (b), wherein the helium cooling subsystem is configured to receive gaseous helium (k) and provide, downstream, liquefied or supercritical helium (I), wherein the hydrogen liquefying subsystem (301, 401) and the helium cooling subsystem (302, 402) are at least partially integrated into one another, such that the hydrogen liquefying subsystem (301, 401) and the helium cooling subsystem (302, 402), together, comprise a plurality of heat exchangers (111-116, 211-217, 314b, 317, 411-417) and a phase separator (320, 420), wherein a first group of the plurality of the heat exchangers and the phase separator are assigned to the hydrogen liquefying subsystem, wherein a second group of the plurality of the heat exchangers is assigned to the helium cooling subsystem, and such that one or more shared heat exchangers (317, 411-417) of the plurality of heat exchangers are comprised in both the first group of heat exchangers and the second group of heat exchangers.

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