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EP-4742271-A1 - MODULAR VESSEL ASSEMBLY

EP4742271A1EP 4742271 A1EP4742271 A1EP 4742271A1EP-4742271-A1

Abstract

A modular vessel assembly defining an internal chamber suitable to maintain a vacuum within the chamber to support a magnetically confined plasma. The present modular assembly is formed from a plurality of annular modular sections arranged in abutting contact as a stack of annular rings extending around a central axis of the chamber. A sealing arrangement is provided at the interface between the modules of the stack to create a fluid seal configured to maintain at least a partial vacuum within the chamber. The present modular vessel assembly is suitable for use as a confinement vessel within a fusion reactor such as a tokamak.

Inventors

  • VERHOEVEN, Roel

Assignees

  • UK Fusion Energy Ltd

Dates

Publication Date
20260513
Application Date
20251006

Claims (15)

  1. A modular vessel assembly comprising: a stack of annular modules stacked along a longitudinal axis of the assembly so as to at least partially define an internal vacuum chamber; and a sealing arrangement configured to create a fluid seal between the annular modules for maintaining at least a partial vacuum within the internal vacuum chamber, wherein each annular module comprises a structural portion configured to support a structural load transmitted axially through the stack.
  2. The assembly as claimed in claim 1 wherein the sealing arrangement comprises one or more sealing devices mounted respectively to the modules and configured to extend between axially neighbouring modules of the stack.
  3. The assembly as claimed in claim 2 wherein each sealing device is mounted at the structural portion of a respective one of the modules and is configured to contact the structural portion of a respective axially neighbouring module of the stack, optionally, wherein each sealing device comprises: a biasing member having a first end region sealingly connected to the module to which the sealing device is mounted and a second end region; and a sealing shoe sealingly connected at the second end region of the biasing member; wherein the sealing shoe is provided in sealing engagement with the respective axially neighbouring module of the stack, the biasing member configured to apply a biasing force to the sealing shoe to bias the sealing shoe into contact to provide a fluid seal between the modules of the stack.
  4. The assembly as claimed in any preceding claim, wherein each annular module comprises an annular abutment portion in contact with a respective adjacent annular abutment portion of an axially neighbouring annular module of the stack, wherein the structural portions of the modules are configured to transmit the structural load between the respective abutment portions of the modules.
  5. The assembly as claimed in claim 4, wherein the abutment portions of at least one pair of axially neighbouring modules comprise a first annular extension provided on one of the pair of modules, and a second annular extension provided on the other of the pair of modules, wherein the first and second annular extensions are radially offset relative to each other so as to axially overlap; optionally, wherein at least one of the first and second annular extensions comprises one or a combination of: an annular step; an annular flange; an annular ridge; and at least one castellation, e.g. wherein the first annular extension comprises an annular step and the second annular extension comprises an annular flange positioned radially inboard of an axially extending wall portion of the annular step of the first annular extension such that the respective annular flange and the annular wall portion of axially neighbouring modules of the stack axially overlap.
  6. The assembly as claimed in claims 4 or 5, wherein the annular extensions of at least one pair of axially neighbouring modules comprise corresponding chamfered surfaces aligned oblique to the longitudinal axis and arranged so as to contact one another to aid alignment of the modules as they are assembled axially to form the stack.
  7. The assembly as claimed in any preceding claim further comprising a locking mechanism configured to selectively lock axially neighbouring pairs of annular modules of the stack together.
  8. The assembly as claimed in claim 7, wherein the locking mechanism comprises a first part provided at one module of the pair of modules, and a second part provided at the other module of the pair of modules, the first and second parts configured for releasable engagement with each other to provide the axial lock; optionally, wherein the first and second parts comprise respective first and second recesses and the locking mechanism further comprises an annular toothed ring mounted at least partially within a cavity defined by the first and second recesses, the toothed ring capable of rotation in a circumferential direction around the longitudinal axis within the cavity; optionally, wherein the assembly further comprises a drive mechanism coupled to the toothed ring to provide rotational drive to the ring.
  9. The assembly as claimed in any preceding claim, wherein the stack of annular modules is toroidal.
  10. The assembly as claimed in claim 9 further comprising an elongate core module aligned with the longitudinal axis, a first end of the core module provided at and/or in part defining a first axial end of the chamber and/or the vessel and a second axial end of the core module provided at and/or defining a second axial end of the chamber and/or the vessel; optionally, wherein the assembly is configured such that the elongate core module is removable from the stack independently of the other modules.
  11. The assembly as claimed in claim 10 wherein the stack comprises: at least one first end module provided in contact with the first end of the core module; at least one second end module provided in contact with the second end of the core module; and at least one intermediate module positioned axially intermediate of the first and second end modules; and optionally wherein the annular modules comprise a plurality of intermediate annular modules positioned axially between the first and second end modules.
  12. A plasma confinement device, such as a tokamak, comprising a modular vessel assembly as claimed in any one of claims 9 to 11, the plasma confinement device configured to maintain a magnetically confined plasma within the internal vacuum chamber of the modular vessel assembly; optionally, wherein the plasma confinement device comprises: one or more field coils for controlling the plasma, e.g. including one or more poloidal field coils and/or one or more toroidal field coils extending around the internal vacuum chamber; and/or a central solenoid aligned with the longitudinal axis.
  13. The plasma confinement device as claimed in claim 12, wherein the stack defines at least one of: a first wall of the internal vacuum chamber; and at least one divertor configured to extract heat and/or fusion products from a fusion reaction.
  14. The plasma confinement device as claimed in claims 12 or 13 wherein at least one of the annular modules comprises one or more of: a breeder blanket arrangement, e.g. comprising a plurality of breeder blanket modules; one or more plasma facing components, e.g. a section of a first wall of the vacuum chamber; a cooling arrangement configured to supply and/or circulate a coolant for cooling at least part of the respective annular module, e.g. comprising a coolant manifold configured to supply coolant to or receive coolant from a plurality of cooling devices of the cooling arrangement; and one or more field coils for controlling the plasma.
  15. A method of assembling a modular vessel assembly comprising: providing a plurality of annular modules; stacking the modules on top of one another along a longitudinal axis of the assembly such that the modules at least partially define an internal vacuum chamber; and sealing between the modules via a sealing arrangement to create a fluid seal configured to maintain at least a partial vacuum within the internal vacuum chamber, wherein a structural portion of each of the modules is configured to support a structural load transmitted at least axially through the stack of modules; optionally, wherein the method further comprises: translating a first module of the stack of modules along the longitudinal axis away from the remaining modules in the stack; undertaking maintenance, inspection and/or repair of the first module; and reforming the stack of modules via translating the first module or a replacement first module along the longitudinal axis to the remaining modules in the stack.

Description

Field of invention The present invention relates to a modular vessel assembly defining an internal chamber, and in particular although not exclusively, to a vessel assembly and chamber configured to confine a plasma suitable to support a fusion reaction. Background Fusion power is the subject of extensive research and development due to its potential to provide clean, safe and cost-efficient electricity via abundant sources of the necessary hydrogen isotope fuel (such as sea water, which contains deuterium). A fusion reactor is adapted to harvest energy released from the fusion of isotopes of hydrogen that are collided together to form heavier nuclei and release large amounts of energy in the process. The heat from such reactions may be used to generate electricity using steam turbines and the like. The fusion reaction is typically undertaken and controlled within a reactor device, such as a tokamak, that is adapted to create specifically orientated magnetic fields that confine and control the plasma within the reactor internal chamber of the high structural integrity vessel. Such vessels are designed to maintain an internal vacuum and be compatible for use with the powerful magnetic fields generated by the external confinement magnets and a central solenoid that drives circulation of the plasma within the chamber (whilst also facilitating start-up and shutdown of the plasma). These vacuum vessels are typically manufactured from panels of stainless steel that are welded together to form a unitary vessel having a toroidal shape configuration. Plasma within the fusion reaction is formed from a super-heated gas and is a collection of positively charged ions and negatively charged electrons. The plasma is an electrically conductive fluid that is responsive to electric and magnetic fields within which the fusion reaction occurs between the atomic isotopes. The walls of a plasma confining vessel are adapted to withstand significant thermal load, magnetic distortions, electromagnetic forces and energetic particle bombardment. The extreme operating conditions of confinement vessels such as those used in tokamaks, require regular maintenance to avoid operational failures. As will be appreciated, maintenance is complicated by the high radiation environment created by the deuterium/tritium fusion reaction phase of operation. Additionally, due to the unpredictable behaviour of the plasma and the fine tolerances for achieving energy efficient fusion reactions, device shutdown and reaction process restarts are to be minimised. Accordingly, there remains a need for improvements to vacuum vessels and specifically vessels suitable to confine a plasma. Summary of the invention It is an objective of the present invention to provide a vacuum vessel suitable for use to confine highly energetic plasma and in particular, a plasma configured as a fluid medium to enable and support a fusion reaction. It is a further specific objective to provide a vacuum vessel that may be serviced and maintained including repair and maintenance of the structural integrity of the vessel and associated sub-modules including all regions of the vessel including radially inner and radially outer wall sections. The objectives are achieved via a modular vessel assembly according to the present concept that comprises an internal chamber in which individual modules of the vessel assembly are separate annular segments divided in planes aligned perpendicular to a longitudinal axis of the vessel. Such modules or segments may be stacked together axially as a unitary structure and sealed via a plurality of sealing devices provided at the respective interfaces between the modules. Such a modular construction greatly facilitates inspection, servicing, maintenance and repair of both the vessel and other functional components, assemblies, devices and mechanisms associated and forming part of a plasma confinement device such as a tokamak, stellarators and the like. Specifically, the present modules and components may be removed, repaired, serviced and/or replaced with fewer disconnection and reconnection steps relative to existing vessels. The modules of the present vessel assembly and respective sealing devices comprise a generally annular configuration to be consistent/compatible with the toroidal shaped reaction chamber. That is and preferably, the modules of the present vessel assembly have a configuration being a torus, in particular a ring torus, often referred to as a doughnut in which the chamber extends in a circumferential direction around a central core or region. The present vessel is formed from annular modules that may be considered to comprises ring-like shape configurations that are stackable vertically on top of one another in axial abutment contact. The present sealing devices are similarly annular and extend the full 360° circumferential length at the axial interface between the modules so as to couple the modules as a unitary structure via respec