Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
  • F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
  • F25J1/005—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by expansion of a gaseous refrigerant stream with extraction of work
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
  • F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
  • F25J1/0052—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by vaporising a liquid refrigerant stream
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/006—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
  • F25J1/0062—Light or noble gases, mixtures thereof
  • F25J1/0065—Helium
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
  • F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
  • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
  • F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
  • F25J1/0275—Construction and layout of liquefaction equipments, e.g. valves, machines adapted for special use of the liquefaction unit, e.g. portable or transportable devices
  • F25J1/0276—Laboratory or other miniature devices
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/16—Receivers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
  • F25B2700/04—Refrigerant level
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/06—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point using expanders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/14—External refrigeration with work-producing gas expansion loop
  • F25J2270/16—External refrigeration with work-producing gas expansion loop with mutliple gas expansion loops of the same refrigerant
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2270/00—Refrigeration techniques used
  • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
  • F25J2270/912—Liquefaction cycle of a low-boiling (feed) gas in a cryocooler, i.e. in a closed-loop refrigerator

Definitions

• the invention relates to a refrigeration method of a fluid, for example helium, for supplying a fluid consumer, as well as a corresponding installation.
• the fluid cyclically circulates successively through a compression stage, a pre-cooling stage and / or fluid cooling stage, and an interface for supplying the consumer with fluid and collect fluid from the consumer.
• This type of process is particularly suitable when the consumer needs a substantially constant heat load, that is to say when the thermal power to be supplied by the refrigeration process is almost constant over time.
• a reactor used in the field of controlled fusion comprises superconducting elements cooled with liquid helium.
• a pulsed thermal load varying substantially sinusoidal in time, is necessary in order not to damage the aforementioned superconducting elements. It therefore appears that, in this application in particular, the aforementioned conventional method can not be used without significant over-dimensioning of the various components of the installation to implement it.
• the document FR 1540391 describes a method for maintaining very low temperature electrical appliances using a fluid subjected to a compression stage, an expansion and cooling stage in order to be partially liquefied in a reservoir intended to maintain a balance of phase of the fluid at a target temperature.
• the tank supplies electrical appliances for cooling. This system is unsuited to applications undergoing thermal load variations required by the consumer since the flow rates are subject to significant variations (to the compression stage and the expansion and cooling stage).
• the invention aims to overcome this drawback by proposing a method of refrigerating a fluid to adapt to thermally variable loads over time.
• the invention relates to a refrigeration method of a fluid of the aforementioned type, characterized in that a first portion of the fluid from the pre-cooling stage and / or cooling is selectively directed to the interface, a second part of the fluid is returned selectively to the pre-cooling stage and / or cooling depending on whether the heat load required by the consumer is low or high, a third part of the fluid being cooled and directed to a battery designed to selectively store this fluid or to deliver, depending on whether the heat load required by the consumer is low or high, a quantity of fluid already stored in order to cool the first fluid part directed towards the interface, the first part of the fluid supplying directly the interface without passing through the accumulator.
• the accumulator can store cold fluid when the thermal load to be supplied is low, that is to say to store in the accumulation means a specific thermal load and to deliver, by heat exchange, at least a portion of this charge stored in fluid for the interface.
• the amount of fluid returned to the pre-cooling and / or cooling stage is adjusted by at least one controlled bypass valve, for example by means of a pressure sensor.
• the amount of cold fluid supplied to the interface is therefore adjusted dynamically by the bypass valve according to the needs of the user.
• the fluid from the pre-cooling and / or cooling stage circulates through an expansion turbine.
• the first part of the fluid from the pre-cooling and / or cooling stage exchanges heat energy with the fluid delivered by the accumulator.
• the fluid from the pre-cooling and / or cooling stage exchanges the heat energy with the fluid coming from the interface and / or with the second fluid part from the precooling stage and / or cooling.
• the second and / or third portion of the fluid from the pre-cooling and / or cooling stage exchanges heat energy with the fluid coming from the interface.
• the second fluid portion from the pre-cooling stage and / or cooling is expanded through an expansion valve.
• the first portion of the fluid from the pre-cooling and / or cooling stage exchanges heat energy with a first fraction of the fluid from the expansion valve.
• a second fraction of the fluid from the expansion valve is intended to supply the accumulator.
• the fluid delivered by the accumulator is returned to the pre-cooling and / or cooling stage.
• the invention furthermore relates to a refrigeration installation of a fluid, for example helium, for implementing the method according to the invention, comprising an interface equipped with fluid inlet and outlet members intended respectively for supplying a consumer with fluid and collecting fluid from the consumer, a fluid compression stage coming from the interface, at least one pre-cooling stage and / or cooling the fluid coming from the interface and / or fluid from the compression stage, characterized in that it comprises a damping stage comprising a supply pipe connecting the pre-cooling and / or cooling stage to the fluid inlet members of the interface a discharge pipe connecting the fluid outlet members of the interface to the pre-cooling and / or cooling stage, and a first bypass pipe connecting the supply pipe.
• a fluid for example helium
• the damping stage further comprising a second bypass line, connecting the supply line to the discharge pipe, and equipped with accumulator, a first heat exchanger being arranged to exchange heat energy between the fluid from the accumulator and the fluid flowing in the supply pipe.
• the supply pipe is equipped with an expansion turbine, arranged upstream of the first bypass pipe.
• the supply pipe is equipped with a second heat exchanger disposed upstream of the expansion turbine, so as to exchange heat energy between the discharge pipe and the supply pipe.
• the supply pipe is equipped with a third heat exchanger disposed downstream of the expansion turbine, so as to exchange heat energy between the discharge pipe and the supply pipe.
• the first bypass line connects the supply line, at a point between the expansion turbine and the third heat exchanger, to the discharge pipe at a point between the third heat exchanger and the second heat exchanger.
• the first bypass pipe connects the supply pipe, at a point between the expansion turbine and the third heat exchanger, to the discharge pipe at a point between the second heat exchanger and the pre-cooling stage and / or cooling, the first bypass line passing through the second heat exchanger, the bypass valve being disposed downstream of the second heat exchanger.
• the first branch pipe connects the supply pipe, at a point situated downstream of the third heat exchanger, to the discharge pipe at a point situated between the second heat exchanger and the pre-cooling and / or cooling stage, the first bypass pipe successively passing through the third heat exchanger and the second heat exchanger and being equipped with a first bypass valve located upstream of the third heat exchanger and a second bypass valve located downstream of the second heat exchanger.
• the second bypass pipe is equipped with an expansion valve disposed between the third exchanger and the accumulator.
• the damping stage comprises a third bypass pipe designed to deflect a portion of the fluid from the expansion valve, the third pipe passing through the first heat exchanger and being connected to the discharge pipe.
• the accumulator inside which the first heat exchanger is arranged so as to exchange heat energy between the fluid passing through the first exchanger and the fluid contained in the accumulator.
• the interface comprises an enclosure equipped with fluid inlet and outlet means, the supply pipe being equipped with a controlled valve arranged upstream of the fluid inlet members, the valve being controlled, for example via a fluid level sensor inside the enclosure.
• the first, second and third portions of fluid from the pre-cooling and / or cooling stage are obtained by selective branching of at least a portion of the fluid assembly from the pre-cooling stage. and / or cooling.
• the second part of the fluid coming from the pre-cooling and / or cooling stage is obtained by a selective bypass of a part of fluid coming from the pre-cooling and / or cooling stage intended for selectively supplying the interface (first part of the fluid) and / or the accumulator (third part of the fluid) (that is to say that the second fluid part is removed from all the fluid coming from the stage compression).
• the third part of the fluid coming from the pre-cooling and / or cooling stage is obtained by a selective bypass of a part of the fluid coming from the pre-cooling stage and / or cooling for selectively directly supplying the interface (1) (that is to say that the third part of the fluid is removed from the first fluid).
• the accumulator comprises for example a vacuum insulated cryogenic tank, for example housed in the pre-cooling and / or cooling stage.
• Figure 1 is a schematic overview of the installation
• Figure 2 is a schematic view of the damping stage of the installation;
• Figures 3 and 4 are views corresponding to Figure 1, two embodiments.
• FIG. 1 A helium refrigeration installation according to the invention is described in FIG.
• this installation comprises an interface 1 in the form of a cold box or of an enclosure equipped with an inlet and a fluid outlet 2.
• the cold box 1 makes it possible to exchange a heat load with a fluid intended for a consumer constituted, for example, by a cooling circuit for superconducting elements of a controlled fusion reactor.
• the installation comprises a compression stage 4 of the fluid coming from the interface 1, a pre-cooling stage 5 and a cooling stage 6 of the fluid. These stages are known from the prior art and will therefore be briefly described below.
• the compression stage 4 compresses the helium from the lower stage, namely the pre-cooling stage 5 and bring the helium to a room temperature.
• Helium at high pressure that is to say at a pressure of between 15 and 20 bar is fed to the precooling stage 5 where it is cooled, in brazed aluminum plate exchangers 7, 8, by the cold helium from the lower stage, that is to say the cooling stage 6.
• the pre-cooling is completed by a heat exchange with liquid nitrogen.
• the cooling of the helium continues in the cooling stage 6, via a plurality of exchangers of the aforementioned type and by cryogenic expansion turbines 9 arranged in parallel. For each expansion turbine 9, part of the high-pressure helium flow is withdrawn and relaxed at the average pressure of the cycle.
• the number of expansion turbines 9 varies between 2 or 4 for a refrigerator of high power.
• the pre-cooling stage brings the helium to the lower stage, that is to say to a damping stage 10, at a temperature of about 20 Kelvin.
• the damping stage 10 will now be described in more detail with reference to FIGS. 2 to 4.
• This stage 10 includes a supply pipe 11 in which the cold fluid flows from the cooling stage 6 to the interface 1, and a discharge pipe 12 for bringing the hot fluid from the interface 1 to the cooling stage 6.
• the helium flowing in the feed pipe 1 1 passes successively, in the direction of flow, a second heat exchanger 13, a control valve 14, an expansion turbine 15, a third heat exchanger 16, a first exchanger 17 and a controlled valve 18, for example by means of a sensor 19 of the helium level within the chamber 1.
• the helium flowing in the discharge pipe 12 passes successively in the direction of flow, the third heat exchanger 16 and the second heat exchanger 13, and is then returned to the cooling stage 6.
• the damping stage 10 further comprises a first bypass pipe 21 for directing the fluid from the expansion turbine 15 to the discharge pipe 12, between the second and third heat exchangers 13, 16.
• the first pipe branch 21 is equipped with a bypass valve 22 controlled, for example by means of a pressure sensor 23. The pressure measurement is performed by this sensor 23 at a point in the supply line 1 1 downstream of the expansion turbine 15 and upstream of the third heat exchanger 16.
• a second bypass pipe 24 makes it possible to deflect a portion of the fluid coming from the third heat exchanger 16.
• the helium flowing in the second channel passes through an expansion valve 25, part of the helium stream coming from this valve 25 then being directed into an accumulator 26, another part passing through the first heat exchanger 17 and then being brought back into the discharge pipe 12, into a point located between the valve 20 and the third heat exchanger 16.
• the fluid stored in the accumulator 26 is also directed towards the first heat exchanger 17 and then directed towards the discharge pipe 12, at a point situated between the valve 20 and the third heat exchanger 16.
• the accumulator 26 is likely to contain helium both in liquid form but also in gaseous form.
• An exhaust pipe 27 makes it possible to evacuate the gases towards the discharge pipe 12, at a point thereof located upstream of the third heat exchanger 16.
• the heat exchangers 13, 16, 17 make it possible to cool or heat the fluids passing through them, the hot fluids and the cold fluids being arranged to flow countercurrently relative to each other in each of the exchangers.
• the helium flowing in the supply line 11 is cooled successively as it passes through the second, third and first exchangers 13, 16, 17.
• the temperature of the helium flowing in the discharge pipe 12 increases as it passes through the second and third heat exchangers 13, 16, and that of the helium from the second bypass pipe 24 or the other.
• accumulator 26 increases as it passes through the first exchanger 17.
• the operation of the damping stage 10 is as follows.
• the controlled bypass valve 22 is mainly open so that a large part of the fluid from the expansion turbine 15 is returned to the cooling stage 6. A small part of the flow of cold helium is fed to the interface 1 by the supply line 11. A certain amount of helium from the part of the aforementioned flow is stored in the accumulator 26, the rest being directed to the discharge pipe 12.
• the bypass valve 22 When the heat load absorbed by the consumer is large, the bypass valve 22 is mainly closed so that the majority of the fluid is directed towards the interface 1. This has the effect to increase the available thermal load for the consumer at interface 1.
• the cold fluid stored by the accumulator 26 is delivered and passes through the first heat exchanger 17, so as to cool the fluid of the supply pipe 11 directed towards the interface 1, thereby increasing the heat load provided. to the consumer.
• FIG. 3 An alternative embodiment of the invention is shown in Figure 3, only the positions of the first branch pipe 21 and the bypass valve 22 having been modified.
• the first branch pipe 21 connects the supply line 1 1, at a point located between the expansion turbine 15 and the third heat exchanger 16, to the discharge pipe 12, at a point situated between the second heat exchanger 13 and the cooling stage 6, the first bypass pipe 21 passing through the second heat exchanger 13, the bypass valve 22 being disposed downstream of the second heat exchanger 13.
• This embodiment avoids a reduction in the efficiency of the second heat exchanger 13.
• the efficiency of a heat exchanger may be reduced during the passage of a fluid having a liquid phase and a phase gas.
• the bypass valve 22 generating an expansion and, therefore, a cooling of the fluid passing through it, the fluid disposed behind the bypass valve 22 may be in two-phase form, depending on the operating conditions.
• the valve 22 thus disposed downstream of the heat exchanger 13 makes it possible not to modify the state of the fluid before passing through this exchanger.
• Another variant embodiment is shown in FIG.
• the first bypass pipe 21 connects the supply pipe 1 1, at a point located downstream of the third heat exchanger 16, to the discharge pipe 12, at a point situated between the second heat exchanger 13 and the cooling stage 6, the first bypass pipe 21 passing successively through the third heat exchanger 16 and the second heat exchanger 13 and being equipped with a first bypass valve 28 situated upstream of the third heat exchanger 16 and a second bypass 29 located downstream of the second heat exchanger 13.
• the second and third heat exchangers 13, 16 are generally grouped together in one and the same heat exchange block. Such a provision bypass valves allows to connect these valves 28, 29 outside the heat exchange block, which is more convenient installation, while ensuring that the fluid passing through each of the exchangers 13, 16 is not two-phase.
• bypass valve could be controlled by a temperature sensor or by any means making it possible to measure a parameter representative of the consumer's needs.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Clinical Laboratory Science (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Pipeline Systems (AREA)

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Publications (3)

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Cited By (7)

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• 2007
  • 2007-08-03 FR FR0756926A patent/FR2919713B1/fr not_active Expired - Fee Related
• 2008
  • 2008-07-28 JP JP2010518720A patent/JP5149381B2/ja active Active
  • 2008-07-28 EP EP08827838.7A patent/EP2185873B1/de active Active
  • 2008-07-28 WO PCT/FR2008/051415 patent/WO2009024705A2/fr active Application Filing

Non-Patent Citations (1)

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