US3873419A - Flow-throttling orifice nozzle - Google Patents

Flow-throttling orifice nozzle Download PDF

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Publication number
US3873419A
US3873419A US268330A US26833072A US3873419A US 3873419 A US3873419 A US 3873419A US 268330 A US268330 A US 268330A US 26833072 A US26833072 A US 26833072A US 3873419 A US3873419 A US 3873419A
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US
United States
Prior art keywords
housing
orifices
high pressure
elongated
spaced
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US268330A
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English (en)
Inventor
Harold L Sletten
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Boeing North American Inc
Original Assignee
Rockwell International Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rockwell International Corp filed Critical Rockwell International Corp
Priority to US268330A priority Critical patent/US3873419A/en
Priority to CA172,342A priority patent/CA987799A/en
Priority to GB2615173A priority patent/GB1403650A/en
Priority to FR7320436A priority patent/FR2191215B3/fr
Priority to JP48067001A priority patent/JPS4951635A/ja
Priority to SE7309112*A priority patent/SE372365B/xx
Priority to DE19732333839 priority patent/DE2333839A1/de
Application granted granted Critical
Publication of US3873419A publication Critical patent/US3873419A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C3/00—Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements
    • G21C3/30—Assemblies of a number of fuel elements in the form of a rigid unit
    • G21C3/32—Bundles of parallel pin-, rod-, or tube-shaped fuel elements
    • G21C3/322—Means to influence the coolant flow through or around the bundles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors

Definitions

  • ABSTRACT A series-parallel-flow type throttling apparatus to restrict coolant flow to certain fuel assemblies of a nuclear reactor is comprised of an axial extension nozzle of the fuel assembly, the nozzle having a series of concentric tubes with parallel-flow orifice holes in each tube.
  • the throttling device must dissipate most of the high pressure energy in order to limit flow rate to the low power fuel assemblies and at the same time provide sufficient flow area and parallel flow paths to minimize the chance of plugging the entrance to the fuel assemblies.
  • fourthv and fifth orifice plates each have more and more apertures therein as they progress sequentially down the conduit.
  • This device is primarily a means to prevent the cavitation of liquids within a conduit.
  • the axes of the orifice are displaced radially and circumferentially about the plate centers so as to be in misalignment with the axes of the orifices in adjacent plates.
  • the object ofthe device is primarily to minimize the pressure drop while preventing cavitation.
  • the instant invention maximizes pressure drop to maintain lovi flow through a fuel assembly.
  • US. Pat. No. 3.368.946 provides a means to cool a fuel assembly in a nuclear reactor. Flow enters the region of the fuel elements in a path parallel to the length of the fuel elements. Flow enters a central opening axially aligned with the fuel elements and impacts a parabolically shaped inner body, the narrow crown being positioned adjacent the inlet so that the fuel impacts the parabolic object and is diverted along the axial length of the body, thus directing or diverting the coolant flow substantially radially towards the surrounding fuel elements.
  • a perforated cylinder outwardly of the concentrically aligned fuel elements provides an outlet path for the coolant flow passing through the fuel element rods.
  • the coolant flow flows through the inner space of the fuel body in a partly longitudinal and partly transverse direction. It is important to note that there is a little pressure drop in the foregoing device. The system would not dissipate high pressure or act to throttle the incoming flow, as does the present invention.
  • the entering coolant subsequently enters through the perforations in the first inner cylinder into an annular space formed by the first inner cylinder and an adjacent perforated cylinder inwardly positioned.
  • the second perforated cylinder has a series of aligned apertures therethrough, the apertures being axially positioned opposite to the perforations in the first inner cylinder so that the coolant flow must again traverse the entire annulus formed by the first inner cylinder and the second inner cylinder.
  • the coolant cools the entire periphery of the second inner cylinder, and so on.
  • the entire assembly protects the inner cylinder housing the television camera from the high temperatures surrounding the camera.
  • the cooling system does not throttle or lessen the incoming fluid pressure as does the apparatus of the instant invention.
  • the system is used primarily to shield a television camera from a thermal and radiation environment.
  • a particular type of flow throttling device herein described has specific design characteristics that satisfy the requirements that are peculiar to certain types of fuel assemblies such the radial blanket type offuel assemblies associated with the fast breeder reactor. These fuel assemblies have low power relative to the primary fuel assemblies of the reactor and obtain their supply of coolant from a common source, which is the high pressure plenum chamber.
  • the present invention provides a throttling device that dissipates most of this high pressure energy inherent in the high pressure plenum in order to limit the flow rate to these fuel assemblies and at the same time provide sufficient flow area and parallel flow paths to minimize the chance of plugging the entrance to the fuel assembly.
  • this throttling device which consists of a number of concentric tubes with orifice holes therein.
  • the tube diameters are chosen to provide an annular space or chamber for flow between adjacent tubes. This space is closed at the ends and all flow must pass in series through one tube to the next from outside the nozzle to inside of the innermost tube where it flows axially to cool the nuclear fuel elements in the interior of the fuel assembly.
  • the apertures in each of the concentric tubes adjacent one another are not aligned, requiring that the fluid make at least two turns and travel a maximum distance axially and circumferentially in the annular space or chamber between tubes.
  • the net result of the nonaligned holes in each of the concentric tubes is that the flow is turned first upwardly between the outer tube and the middle tube, then downwardly between the middle tube and the inner tube. which would add hydraulic resistance to satisfy specific pressure drop and flow rate requirements.
  • the essential feature of the invention is that it utilizes concentric cylindrical shells as an integral part of an inlet nozzle for a nuclear fuel assembly to provide series and parallel flow throttling.
  • An advantage over the prior art is the ability to dissipate high pressure energy through the throttling device while maintaining the pressure high in the chamber surrounding the device.
  • Still another advantage over the prior art is realized in that the multiple concentric tube concept will add stiffness in handling to an extension nozzle of a fuel assembly and therefore will give the assembly more lateral support.
  • FIG. 1 is an overall view of a fuel assembly with a nozzle extension attached thereto;
  • FIG. 2 is a cross sectional view of the nozzle extension. the extension being immersed in a high pressure plenum chamber between a pair of grid plates;
  • FIG. 3 is a developed view of a typical throttling de' vice with three tube sections representing each of three concentric tubes. each developed tube section having apertures therein that are non-aligned when compared to an adjacent tube section; and
  • Fl(i. 4 is a Cross sectional view of an alternative em bodiment illustrating another array of orifices in each concentric tube.
  • the fuel assembly generally designated as is comprised of a fuel assembly housing 12. which generally encases fuel elements consisting of a bundle of fuel rods.
  • the fuel assembly 10 is further comprised of an extension nozzle generally designated as 14. which is metallurgically bonded or otherwise fixed to the fuel assembly housing at joint 11.
  • the extension nozzle 14 positioned between the grid plates 16 and 18, makes up approximately onesixth of the total fuel assembly length.
  • the relative nozzle length need not be limited to the foregoing example.
  • the fuel assemblies, less the extension nozzle herein described. are well known in the art.
  • FIG. 2 illustrates the elongated housing or extension nozzle 14 which extends through an upper grid plate 16, through bearing sleeve 13.
  • the bottom 15 of extension nozzle 14 extends through a lower grid plate 18, through bearing sleeve 19.
  • the base 15 of extension nozzle 14 terminates adjacent a base plate 21.
  • the extension nozzle is keyed in position by a pin 29 connected to base plate 21.
  • the nozzle 14, comprised of an outer concentric tube or housing 22, has in an ordered array. a series of orifices 23 therein equidistantly spaced about the periphery of outer tube 22. lnwardly of and spaced from outer tube 22 is a middle concentric tube 24.
  • Middle tube 24 has a series of orifices 25 through the tube, the orifices being equidistantly spaced about the periphery of tube 24 in ordered arrays.
  • An inner concentric tube 26 is spaced from the middle tube 24, the inner tube 26 having a similar series of orifices 27 through the inner tube 26.
  • Each of the concentric tubes 22, 24, and 26 are so positioned in housing 14 so that each orifice 23, 25, and 27 does not align one with another.
  • the space between the upper grid plate 16 and the lower grid plate 18 defines a high pressure plenum chamber 20 which is normally filled, for example. with liquid sodium, liquid sodium being an excellent medium for carrying away heat generated by the nuclear reactor.
  • the high pressure plenum chamber 20 maintains a total pressure differential of approximately 100 psi relative to the pressure above or at the outlet of fuel assembly 1.0. The pressure differential then must be compensated for in order to properly cool the fuel element assemblies 10.
  • Liquid sodium coolant enters through the outer concentric tube 22 through orifices 23. Since the orifices 23 do not align with the orifices 25 in the middle concentric tube 24, the coolant fluid must then either traverse axially upwardly or downwardly to traverse across the middle tube 24.
  • the fluid must then again either traverse axially upwardly or down wardly to find access to orifices 27 in the inner tube 26.
  • the number and size of the orifices in each concentric tube 22. 24, and 26 are so configured as to dissipate ap proximately percent ofthe pressure energy available from the high pressure plenum 20. For example.
  • each tube would have 24 4 inch holes and five 3/16 inch holes in each of the concentric tubes 22, 24, and 26.
  • approximately 95 percent of the lOU psi is dissipated through the fuel assembly extension 14.
  • each of the concentric tubes 22, 24, and 26 clearly show the hole patterns in ordered array in each of the concentric tubes.
  • orifices 23 in the outer tube 22 do not align with the orifices 25 in the middle tube 24.
  • the orifices in the middle tube do not align with the orifices 27 in the inner tube 26 when viewed through the same direction, for example, the 60 angular position in each of the concentric tubes.
  • liquid sodium is forced to traverse axially in series from one annular gap to another annular gap defined by the concentric tubes.
  • the tortuous path thus dissipates the pressure in the high pressure plenum chamber 20.
  • the orifices 30, 32, and 34 are the smaller orifices in each of the concentric tubes 22, 24, and 26.
  • the reduction in size of the orifices 30, 32, and 34 is a means to arrive at the total area of opening or number of orifices necessary to dissipate the high pressure.
  • the hole size distribution is relatively non-critical as long as there are sufficient numbers of orifices to minimize the chances of plugging, yet dissipate the pressure energy.
  • the groups of orifices 45, 47, and 49 are arrayed in sections or groups, for example, the group of orifices 45 in outer concentric tube 44 are positioned towards the bottom of the tube 44 to cause the liquid sodium from high pressure plenum chamber 42 to traverse axially upwardly towards the group of orifices 47 positioned near the top of the concentric middle tube 46, the fluid then subsequently turns downwardly to traterse through the group of orifices 49 near the bottom of the inner tube 48.
  • the liquid sodium is caused to move unidirectionally axially and in series between the annular space defined by the concentric tubes 44, 46, and 48.
  • the extension nozzle 40 offers an advantage in that the groups of orifices 47 in the middle concentric tube 46 may be displaced axially farther from the groups of orifices 45 and 49 in the outer tube 44 and the inner tube 48, by mechanically translating tube 46 tnot shown) axially between tubes 44 and 48. A yalving action is thus provided to either increase or decrease the flow through the throttling device.
  • the extension 40 may act as a flow control valve.
  • nozzle extension hereinabove described need not be limited to three concentric tubes, obviously, two or more tubes may be utilized while remaining within the scope of this invention.
  • a flow-throttling nozzle communicating said coolant flow from said high pressure plenum chamber of said reactor through said nozzle to an array of fuel elements of said relatively low power fuel assembly.
  • said fuel elements being located downstream from the coolant flow leaving said nozzle, while dissipating a high pressure differential between said plenum chamber and said array of fuel elements so as to substantially reduce the rate of coolant flow from said plenum chamber through said nozzle to said array of fuel elements, said nozzle comprising:
  • a first elongated housing spaced between a pair of grid plates, said grid plates defining said high pressure plenum chamber, said housing forming a plurality of orifices therethrough, said orifices extending around said housing in spaced and ordered arrays, and
  • At least a second elongated housing spaced from and positioned within said first housing to provide a continuous annular space defining a continuous fluid flow path within said annulus of said nozzle, said second housing forming a plurality of orifices therethrough, said orifices extending around said housing in spaced, ordered arrays, said arrays being positioned out of alignment in both an axial and circumferential direction with respect to said arrays of said orifices as defined by said first elongated housing,
  • a flow throttling device for use in a nuclear reactor to dissipate a high pressure differential between a plenum chamber and an array of fuel elements comprising:
  • a first elongated housing spaced between a pair of grid plates, said grid plates defining a high pressure plenum chamber, said housing forming a plurality of orifices therethrough, said orifices extending completely around said housing in equidistantly spaced and ordered arrays,
  • a second elongated housing spaced from and positioned within said first housing, said second housing forming a plurality or orifices therethrough, said orifices extending completely around said housing in equidistantly spaced, ordered arrays, said arrays being positioned out of alignment with said arrays ofsaid orifices defined by said first elongated housing, and
  • a third elongated housing spaced from and positioned within said second elongated housing, said third housing forming a plurality of orifices therethrough, said orifices extending completely around said housing in equidistantly spaced, ordered arrays, said arrays being positioned out of alignment with said arrays of orifices in said second elongated housing, whereby fluid is caused to follow a tortuous path in series from said first elongated housing through said third elongated housing, thereby dissipating said high pressure differential between said high pressure plenum and said array of fuel elements.
  • a flow-throttling device for use in a nuclear reactor to dissipate a high pressure differential between a plenum chamber and an array of fuel elements comprising:
  • a first elongated housing spaced between a pair of grid plates.
  • said grid plates defining a high pressure plenum chamber, said housing forming a plurality of orifices therethrough. said orifices extending around said housing in spaced and ordered arrays.
  • At least a second elongated housing spaced from and positioned within said first housing to provide an annular space defining a fluid flow path.
  • said second housing forming a plurality of orifices therethrough. said orifices extending around said housing in spaced. ordered arrays. said arrays being positioned out of alignment with said arrays of said orifices defined by said first elongated housing, whereby fluid is caused to follow a tortuous path in series from said first elongated housing circumferentially and axially through said annular space and then through said second elongated housing. thereby dissipating said high pressure differential between said high pressure plenum and said array of fuel elements.
  • said flow-throttling device further comprising an annular sleeve spaced from and surrounding said first elongated housing. said sleeve being connected to one of said grid plates at its base. said annular sleeve extending axially part way over said first elongated housing to further restrict flow of said fluid into said first housing.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Structure Of Emergency Protection For Nuclear Reactors (AREA)
  • Pipe Accessories (AREA)
US268330A 1972-07-03 1972-07-03 Flow-throttling orifice nozzle Expired - Lifetime US3873419A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US268330A US3873419A (en) 1972-07-03 1972-07-03 Flow-throttling orifice nozzle
CA172,342A CA987799A (en) 1972-07-03 1973-05-24 Flow-throttling orifice nozzle
GB2615173A GB1403650A (en) 1972-07-03 1973-06-01 Nuclear reactor having a flow-throttling orifice device
FR7320436A FR2191215B3 (enrdf_load_stackoverflow) 1972-07-03 1973-06-05
JP48067001A JPS4951635A (enrdf_load_stackoverflow) 1972-07-03 1973-06-15
SE7309112*A SE372365B (enrdf_load_stackoverflow) 1972-07-03 1973-06-28
DE19732333839 DE2333839A1 (de) 1972-07-03 1973-07-03 Stroemungsdrosseleinrichtung

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Application Number Priority Date Filing Date Title
US268330A US3873419A (en) 1972-07-03 1972-07-03 Flow-throttling orifice nozzle

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US3873419A true US3873419A (en) 1975-03-25

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US268330A Expired - Lifetime US3873419A (en) 1972-07-03 1972-07-03 Flow-throttling orifice nozzle

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US (1) US3873419A (enrdf_load_stackoverflow)
JP (1) JPS4951635A (enrdf_load_stackoverflow)
CA (1) CA987799A (enrdf_load_stackoverflow)
DE (1) DE2333839A1 (enrdf_load_stackoverflow)
FR (1) FR2191215B3 (enrdf_load_stackoverflow)
GB (1) GB1403650A (enrdf_load_stackoverflow)
SE (1) SE372365B (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993539A (en) * 1974-04-16 1976-11-23 The United States Of America As Represented By The United States Energy Research And Development Administration Method and device for measuring fluid flow
US4016035A (en) * 1974-06-12 1977-04-05 Commissariat A L'energie Atomique Fuel assembly support column for a nuclear reactor diagrid
US4036690A (en) * 1974-12-31 1977-07-19 United Kingdom Atomic Energy Authority Nuclear reactor fuel element assemblies
US4038136A (en) * 1974-06-11 1977-07-26 Commissariat A L'energie Atomique Support structure for the lateral neutron shield system of a fast reactor core
US4298432A (en) * 1979-03-19 1981-11-03 Kraftwerk Union Aktiengesellschaft Device for holding gas-cooled fuel assemblies of nuclear reactors
US4303474A (en) * 1977-03-01 1981-12-01 General Atomic Company Nuclear reactor core assembly
US4526745A (en) * 1981-08-25 1985-07-02 Ab Asea-Atom Fuel assembly with a water flow separated from the fuel rods
US5383227A (en) * 1993-08-23 1995-01-17 Siemens Power Corporation Method for modifying existing transition pieces in bottom entry nuclear fuel assemblies for reducing coolant pressure drop
US5513233A (en) * 1993-07-08 1996-04-30 Hitachi, Ltd. Nuclear reactor
US5617457A (en) * 1993-03-16 1997-04-01 Siemens Aktiengesellschaft Pressurized-water reactor with individually adapted pressure distribution in the coolant
US20040096026A1 (en) * 2002-11-18 2004-05-20 Hwang Choe Apparatus and methods for optimizing reactor core coolant flow distributions
US6778209B1 (en) * 1997-09-26 2004-08-17 Diamond Power International, Inc. Furnace video camera apparatus

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2284170A1 (fr) * 1974-09-03 1976-04-02 Commissariat Energie Atomique Structure de reduction des courants de convection a l'interieur de la cuve d'un reacteur nucleaire
GB2091932B (en) * 1981-01-23 1984-05-02 Westinghouse Electric Corp Nuclear reactor having fuel assemblies with controllable coolant flow therethrough
JPH0643522Y2 (ja) * 1986-11-29 1994-11-14 カヤバ工業株式会社 可変ポンプの流量制御装置
SE467899B (sv) * 1991-02-05 1992-09-28 Asea Atom Ab Braenslepatron foer en kaernreaktor av tryckvattentyp
JP2011106526A (ja) * 2009-11-13 2011-06-02 Tlv Co Ltd フロート式スチームトラップ

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3235465A (en) * 1961-05-16 1966-02-15 Atomic Power Dev Ass Inc Fuel element hold-down arrangement for nuclear reactors
US3281326A (en) * 1962-03-09 1966-10-25 Hargo Bernt Torsten Allan Fuel element for nuclear reactors
US3368946A (en) * 1964-03-04 1968-02-13 Alfa Laval Ab Fuel assembly
US3373082A (en) * 1965-01-20 1968-03-12 Alfa Laval Ab Control of nuclear power reactor
US3383287A (en) * 1965-06-15 1968-05-14 Atomic Energy Authority Uk Nuclear reactor core support structure

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3235465A (en) * 1961-05-16 1966-02-15 Atomic Power Dev Ass Inc Fuel element hold-down arrangement for nuclear reactors
US3281326A (en) * 1962-03-09 1966-10-25 Hargo Bernt Torsten Allan Fuel element for nuclear reactors
US3368946A (en) * 1964-03-04 1968-02-13 Alfa Laval Ab Fuel assembly
US3373082A (en) * 1965-01-20 1968-03-12 Alfa Laval Ab Control of nuclear power reactor
US3383287A (en) * 1965-06-15 1968-05-14 Atomic Energy Authority Uk Nuclear reactor core support structure

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993539A (en) * 1974-04-16 1976-11-23 The United States Of America As Represented By The United States Energy Research And Development Administration Method and device for measuring fluid flow
US4038136A (en) * 1974-06-11 1977-07-26 Commissariat A L'energie Atomique Support structure for the lateral neutron shield system of a fast reactor core
US4016035A (en) * 1974-06-12 1977-04-05 Commissariat A L'energie Atomique Fuel assembly support column for a nuclear reactor diagrid
US4036690A (en) * 1974-12-31 1977-07-19 United Kingdom Atomic Energy Authority Nuclear reactor fuel element assemblies
US4303474A (en) * 1977-03-01 1981-12-01 General Atomic Company Nuclear reactor core assembly
US4298432A (en) * 1979-03-19 1981-11-03 Kraftwerk Union Aktiengesellschaft Device for holding gas-cooled fuel assemblies of nuclear reactors
US4526745A (en) * 1981-08-25 1985-07-02 Ab Asea-Atom Fuel assembly with a water flow separated from the fuel rods
US5617457A (en) * 1993-03-16 1997-04-01 Siemens Aktiengesellschaft Pressurized-water reactor with individually adapted pressure distribution in the coolant
US5513233A (en) * 1993-07-08 1996-04-30 Hitachi, Ltd. Nuclear reactor
US5383227A (en) * 1993-08-23 1995-01-17 Siemens Power Corporation Method for modifying existing transition pieces in bottom entry nuclear fuel assemblies for reducing coolant pressure drop
US6778209B1 (en) * 1997-09-26 2004-08-17 Diamond Power International, Inc. Furnace video camera apparatus
US20040096026A1 (en) * 2002-11-18 2004-05-20 Hwang Choe Apparatus and methods for optimizing reactor core coolant flow distributions

Also Published As

Publication number Publication date
GB1403650A (en) 1975-08-28
FR2191215A1 (enrdf_load_stackoverflow) 1974-02-01
FR2191215B3 (enrdf_load_stackoverflow) 1976-05-21
SE372365B (enrdf_load_stackoverflow) 1974-12-16
DE2333839A1 (de) 1974-03-07
JPS4951635A (enrdf_load_stackoverflow) 1974-05-20
CA987799A (en) 1976-04-20

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