Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/02—Header boxes; End plates
  • F28F9/0236—Header boxes; End plates floating elements
  • F28F9/0239—Header boxes; End plates floating elements floating header boxes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
  • F28D7/1607—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation with particular pattern of flow of the heat exchange media, e.g. change of flow direction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
  • F28D2021/0054—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for nuclear applications

Definitions

• the present invention relates to heat exchange devices and in particular those intended to cool a hot fluid which has been contaminated by radioactive substances and which leaves the enclosure of a nuclear reactor.
• hot and contaminated fluid cooling devices which use an intermediate heat exchanger.
• This type of device consists of a first heat exchanger, generally called an intermediate heat exchanger, which performs a first heat exchange, between the hot and contaminated fluid leaving the reactor and a first cooling fluid, and a second heat exchanger. heat which performs a second heat exchange between the first cooling fluid and a second cooling fluid, the latter being discharged to the outside.
• the coolant and the hot fluid which pass through a heat exchanger have different temperatures, it is often subjected to temperature gradients and transient thermal phenomena of large amplitudes during periods of normal use of the nuclear reactor and even greater when an accident occurs.
• One of the main goals of nuclear power plant designers is to make the intermediate heat exchanger as mechanically resistant as possible to the stresses imposed on it, due to differences between the deformations of the cooling fluid circulation tubes and those of the shell of the exchanger, traversed by the hot fluid.
• the present invention relates to a heat exchange device which has mechanical resistance characteristics to deformations due to the temperature gradient which are as good as those of the exchangers of the prior art and which, while comprising only one exchanger heat, has significantly improved sealing characteristics, so that this heat exchange device, with a single heat exchanger, can be placed in the backup circuits of a nuclear reactor to ensure the cooling of the hot fluid contaminated leaving the reactor enclosure by a cooling fluid, directly from the external environment, including in old nuclear power plants lacking space to house a device with two exchangers.
• the heat exchanger designed according to the invention comprises:
• - a cylindrical shell which defines a container having an inlet (outlet) connection for the coolant at one of its ends, a pair of tubular plates mounted in the container.
• One is rigidly attached to the grille.
• the other is welded and crimped to the grille over its entire periphery and defines, with a closing cover, a floating head in which is formed a connector for the outlet (entry) of the coolant, - a bundle of substantially parallel tubes.
• Some of the ends are fixed firmly to the tube plate which is rigidly fixed to the grille. Their other ends are crimped and welded over the entire thickness of the tube plate which is welded and crimped over its entire periphery to the grille.
• the outlet connection (inlet) of the coolant formed in the floating head consists at least in part of a bellows.
• the hot bellows-fluid contact which existed according to the patents of the prior art and which constituted a weak point of sealing against radioactive substances is, in the heat exchanger, according to the invention, eliminated.
• the bellows is closer along the axis of the grille of the welded tubular plate and crimped to the grille than from the top of the floating head.
• the deformations due to the temperature gradient being the greatest at the level of the contact of the tube plate and the grille, the fact that the bellows is at immediate vicinity of the tube plate ensures that the bellows will collect the most significant deformations as quickly as possible.
• the heat exchanger is more leaktight and more mechanically resistant than those of the prior art, and in particular, than those according to patents GB-A-12867222 and US- A-3850231.
• the connector associated with the bellows is on the same side of the grille as the inlet connector for the hot fluid, in particular, on the same generator of the grille. It follows that the bellows is as close as possible to the point of the hot fluid-tubular plate contact zone where the temperature gradient is maximum. By placing the bellows as close as possible to this point on the plate, we ensure an even greater effectiveness of the bellows in absorbing deformation.
• the sealing and mechanical strength characteristics of the heat exchanger according to the invention allow it to be used in a backup circuit of an enclosure of a nuclear reactor which, in the event of an accident, cools the hot contaminated fluid leaving the enclosure with a cooling fluid that can be poured directly outside.
• the heat exchanger shown comprises a shell 1 comprising a bundle of tubes 2 that are substantially straight for the passage of the cooling fluid.
• This bundle of tubes 2 which is only partially shown, is mounted between tubular plates 3.
• the tubes 2 are welded and crimped over the entire thickness of the tubular plates 3.
• the calender 1 is terminated by a head 4 in which is provided a connection 9 inlet (outlet) of the coolant.
• a head 5 is mounted floating on the grille 1.
• a connection 8 for the outlet (inlet) of the cooling fluid is provided on the floating mounted head 5.
• the connector 8 partly consists of a bellows 10.
• the connector 8, along the axis ZZ ', is closer to the tube plate 3 than to the top of the floating head 5.
• the angle formed in a plane normal to the axis ZZ 'between the projection of the axis XX' on the plane and the projection of the axis YY 'on this same plane,. Is zero .
• the bellows is thus as close as possible to the zone where the temperature gradient is maximum, which allows it to quickly absorb the deformations.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26230356

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (2)

Citations (4)

Family Cites Families (2)

• 1993
  • 1993-05-26 FR FR9306307A patent/FR2705769B1/fr not_active Expired - Lifetime
• 1994
  • 1994-11-25 RU RU96116998A patent/RU2145697C1/ru active
  • 1994-11-25 WO PCT/FR1994/001375 patent/WO1996017216A1/fr active IP Right Grant
  • 1994-11-25 EP EP95902175A patent/EP0740767B1/fr not_active Expired - Lifetime
  • 1994-11-25 SK SK919-96A patent/SK91996A3/sk unknown
  • 1994-11-25 DE DE69426781T patent/DE69426781D1/de not_active Expired - Lifetime
• 1996
  • 1996-07-22 BG BG100732A patent/BG63057B1/bg unknown

Patent Citations (4)

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