Flow tripper in combination with spacer deflector
    1.
    发明授权
    Flow tripper in combination with spacer deflector 失效
    流动脱扣器与间隔导流器组合

    公开(公告)号:US4999153A

    公开(公告)日:1991-03-12

    申请号:US497803

    申请日:1990-03-21

    IPC分类号: G21C3/322

    CPC分类号: G21C3/322 Y02E30/31 Y02E30/38

    摘要: A combination of flow trippers with spacer deflectors in the two phase steam/water region of a fuel bundle in a boiling water reactor is disclosed. Spacers with deflectors are placed immediately above the flow trippers. The flow trippers are located on either an inside channel wall surrounding the fuel bundle or the outside of water chambers within the fuel bundle. Additional flow trippers may be located adjacent to the spacers, above the flow trippers that are below the spacers. The spacers are provided with deflector skirts overlying the flow trippers. In operation of the fuel bundle, excess water flows in the two phase region in a film on the unheated inside walls of the fuel channel or the outside walls of the water chambers. The film flow is perturbed by the flow trippers and is deflected toward the fuel rods. The overlying deflector skirts or tabs on the spacers further deflect the liquid toward the fuel rods to improve cooling and to increase the power generation capability of the fuel bundle. A preferred embodiment includes deflector tabs at the top of the spacer for further deflecting the stripped water layer towards the fuel rods. The synergistic combination of flow trippers and spacer deflector skirts and tabs provide better cooling than would be predicted by adding the separate effects of flow trippers, deflector skirts and flow tabs.

    摘要翻译: 公开了一种在沸水反应器中的燃料束的两相蒸汽/水区域中具有隔离导流器的流动脱扣器的组合。 带偏转器的间隔物立即放置在流量跳闸的上方。 流动脱扣器位于围绕燃料束的内部通道壁或燃料束内的水室外部。 额外的流动脱扣器可以位于邻近间隔件的上方,位于间隔件下方的流动脱扣器上方。 间隔件设置有覆盖流量跳闸器的偏转裙。 在燃料束的操作中,过量的水在燃料通道的未加热的内壁或水室的外壁的膜中的两相区域中流动。 膜流被流动跳闸扰乱,并朝向燃料​​棒偏转。 垫片上的覆盖偏转器裙部或突片进一步使液体朝向燃料棒偏转,以改善冷却并增加燃料束的发电能力。 优选的实施例包括位于间隔件顶部的偏转片,用于进一步使剥离的水层偏向燃料棒。 流量跳闸器和间隔板偏转器裙板和凸片的协同组合提供比通过添加流动跳闸器,偏转器裙板和流动凸片的单独效果预测的更好的冷却。

    Axially shaped channel and integral flow trippers
    2.
    发明授权
    Axially shaped channel and integral flow trippers 失效
    轴向通道和积分流量跳闸

    公开(公告)号:US4749543A

    公开(公告)日:1988-06-07

    申请号:US29508

    申请日:1987-03-24

    IPC分类号: G21C3/322 G21C3/324 G21C3/34

    摘要: An improved channel is disclosed which has a reduced average thickness in its upper portion. The lesser average thickness corresponds to a lower pressure difference acting on the channel sides, over the upper portion of the channel. The reduction in average thickness is accomplished by cutting flow trippers into the inner surface of the channel walls and/or cutting grooves into the outer surface of the channel. The axial variation of channel average thickness increases water volume adjacent to the upper part of the channel to provide increased neutron moderation, to minimize the steam void reactivity coefficient, and to provide a greater cold shutdown margin. The material removed to produce the flow trippers increases the cross-sectional area inside the channel and reduces pressure drop in the upper portion of the channel. The flow trippers divert water flowing on the channel walls to the fuel rods adjacent to the channel walls, permitting higher reactor power operation. The flow trippers also permit operation at lower flow rates.

    Two-phase pressure drop reduction BWR assembly design
    3.
    发明授权
    Two-phase pressure drop reduction BWR assembly design 失效
    两相压降机组BWR装配设计

    公开(公告)号:US5112570A

    公开(公告)日:1992-05-12

    申请号:US176975

    申请日:1988-04-04

    摘要: In a boiling water reactor having discrete bundles of fuel rods confined within channel enclosed fuel assemblies, an improved fuel design of bundles of fuel rods interior of the channels is disclosed. Specifically, partial length rods are utilized which extend from the bottom of the channel only part way to the top of the channel. These partial length rods are symmetrically distributed throughout the fuel bundle with the preferred disposition being in the second row of the bundle of fuel rods from the channel wall. The symmetrical distribution of the partial length rods is at spaced apart locations one from another. During shutdown of the reactor, an improved cold shutdown margin is produced at the top of the fuel assembly due to the improved moderator-to-fuel ratio and reduction in plutonium formation at the upper portion of the bundle. Shutdown control rod worth is improved due to greater moderator-to-fuel ratio and a longer thermal neutron diffusion length. During power reactor operation, the partial length fuel rods improve flow distributions above the ends of the partial length rods by channeling steam in the open interstitial area between rods above the ends of the partial length rods.

    Axially shaped channel and integral flow trippers

    公开(公告)号:USRE33818E

    公开(公告)日:1992-02-11

    申请号:US534812

    申请日:1990-06-06

    IPC分类号: G21C3/322 G21C3/324

    摘要: An improved channel is disclosed which has a reduced average thickness in its upper portion. The lesser average thickness corresponds to a lower pressure difference acting on the channel sides, over the upper portion of the channel. The reduction in average thickness is accomplished by cutting flow trippers into the inner surface of the channel walls and/or cutting grooves into the outer surface of the channel. The axial variation of channel average thickness increases water volume adjacent to the upper part of the channel to provide increased neutron moderation, to minimize the steam void reactivity coefficient, and to provide a greater cold shutdown margin. The material removed to produce the flow trippers increases the cross-sectional area inside the channel and reduces pressure drop in the upper portion of the channel. The flow trippers divert water flowing on the channel walls to the fuel rods adjacent to the channel walls, permitting higher reactor power operation. The flow trippers also permit operation at lower flow rates.

    Two-phase pressure drop reduction BWR assembly design

    公开(公告)号:US5017332A

    公开(公告)日:1991-05-21

    申请号:US375646

    申请日:1989-07-03

    IPC分类号: G21C3/30 G21C3/322 G21C3/328

    摘要: In a boiling water reactor having discrete bundles of fuel rods confined within channel enclosed fuel assemblies, an improved fuel design of bundles of fuel rods interior of the channels is disclosed. Specifically, partial length rods are utilized which extend from the bottom of the channel only part way to the top of the channel. These partial length rods are shortened with respect to the remaining rods and are symmetrically distributed throughout the fuel bundle with the preferred disposition being in the second row of the bundle of fuel rods from the channel wall. The symmetrical distribution of the partial length rods is at spaced apart locations one from another. The partial length rods extend from the bottom of the fuel bundle and terminate within the boiling region. during shutdown of the reactor, an improved cold shutdown margin is produced at the top of the fuel assembly due to the improved moderator-to-fuel ratio and reduction in plutonium formation at the upper portion of the bundle. Shutdown control rod worth is improved due to greater moderator-to-fuel ratio and a longer thermal neutron diffusion length. During power reator operation, the partial length fuel rods improve flow distribution above the ends of the partial length rods by channeling steam in the open interstitial area between rods above the ends of the partial length rods. This enables a high slip ratio of steam with respect to water and increases the density of the moderating water about the remaining rods in the upper region of the bundle at power operation. The total pressure drop is reduced, permitting more fuel rods in the design or a larger fuel rod diameter. The ratio of two-phase pressure drop to single phase pressure drop also is reduced, tending to increase the threshold for thermal hydraulic instability or coupled nucler-thermal-hydraulic instability. Rod spacers and bundle tie plates are provided with larger apertures overlying the partial length rods for further channeling of the steam and reduction of two-phase pressure drop. Most importantly and during full reactor power output, the pressure drop in the two-phase region of the bundle is reduced without substantial corresponding degradation of the fuel assemblies thermal limits. These features permit designs with larger fuel rod diameter than are possible without part length rods and results in a net increase in fuel assembly uranium weight with the larger fuel rod diameter more than compensating for the weight removed by shortening some of the fuel rods.

    Lower tie plate debris catcher for a nuclear reactor
    6.
    发明授权
    Lower tie plate debris catcher for a nuclear reactor 失效
    用于核反应堆的较低的夹板碎片捕获器

    公开(公告)号:US5488634A

    公开(公告)日:1996-01-30

    申请号:US194357

    申请日:1994-02-10

    摘要: A unitary one-piece lower tie plate grid has a lower portion and an upper portion for supporting the fuel rods. The lower tie plate grid includes cylindrical boss portions extending upwardly from the lower grid portion and arranged in square matrices for receiving the lower end plugs of the fuel rods. Web portions extending upwardly from the lower tie plate portion interconnect the boss portions along the sides of the matrices. The lower grid portion includes a plurality of openings which open into the flow spaces defined by the convex portions of the bosses and the webs within each square matrix of the upper portion of the tie plate. Coolant flows through the openings into the flow spaces for further flow upwardly about the fuel rods. The openings are radiussed adjacent their lower ends and have divergent side walls downstream of a throat area to define a flow venturi.

    摘要翻译: 一体的单件下连接板格架具有用于支撑燃料棒的下部和上部。 下连接板网格包括从下格栅部分向上延伸的圆柱形凸台部分,并且以方形矩阵布置以接收燃料棒的下端塞。 从下连接板部分向上延伸的网部分沿着矩阵的侧面互连凸起部分。 下格栅部分包括多个开口,这些开口通过凸起部分的凸部和连接板上部的每个正方形矩阵内的腹板限定的流动空间。 冷却剂流过开口进入流动空间,以进一步在燃料棒周围向上流动。 开口在其下端附近被辐射,并且在喉部区域下游具有发散的侧壁以限定流量文丘里管。

    Lower tie plate strainers for boiling water reactors
    7.
    发明授权
    Lower tie plate strainers for boiling water reactors 失效
    用于沸水反应堆的下连接板过滤器

    公开(公告)号:US5384814A

    公开(公告)日:1995-01-24

    申请号:US44687

    申请日:1993-04-12

    摘要: In a boiling water reactor fuel bundle, a three dimensional debris catching grid construction is placed within the flow volume defined by the lower tie plate assembly between the inlet nozzle and upper fuel rod supporting grid. A perforated plate is utilized having round holes as small consistent with the prevention of inadvertent closure due crudding and a hole pitch consistent with mechanical integrity requirements. The perforated plate is placed in a three dimensional construction such as a dome, cylinder, pyramid, inverted pyramid or corrugated construction spanning the flow volume of the lower tie plate assembly. As a consequence of this three dimensional grid construction, the total flow through area of the perforations in the metal plate does not introduce appreciable pressure drop in the lower tie plate assembly between the inlet nozzle and the rod supporting grid. Fluid movement at the debris restraining holes of the grid construction has a low flow velocity and a change in flow direction before passing through the holes to discourage debris from finding its way through the grid holes. Finally, it is possible to incorporate debris traps within the flow volume of the lower tie plate assembly that can cause trapping and subsequent removal of trapped debris upon fuel bundle replacement.

    摘要翻译: 在沸水反应堆燃料束中,三维碎屑捕获栅格结构放置在由入口喷嘴和上燃料棒支撑栅之间的下连接板组件限定的流动体积内。 使用多孔板,其圆形孔小,防止由于粗糙度而导致的无意闭合,以及与机械完整性要求一致的孔间距。 多孔板被放置在三维结构中,例如圆顶,圆柱体,金字塔,倒金字塔或波纹结构,跨越下拉板组件的流动体积。 作为这种三维格栅结构的结果,金属板中的穿孔面积的总流量不会在入口喷嘴和支撑杆之间的下连接板组件中引入明显的压降。 格栅结构的碎屑限制孔处的流体运动在通过孔之前具有低流速和流动方向的变化,以阻止碎屑通过栅格孔。 最后,可以将碎屑收集器结合在下连接板组件的流动体积内,这可以导致在燃料束更换时捕获和随后的捕获的碎屑的去除。

    Lower tie plate strainers including double corrugated strainers for
boiling water reactors
    8.
    发明授权
    Lower tie plate strainers including double corrugated strainers for boiling water reactors 失效
    下层连接板过滤器,包括用于沸水反应堆的双波纹过滤器

    公开(公告)号:US5483564A

    公开(公告)日:1996-01-09

    申请号:US196738

    申请日:1994-02-15

    摘要: In a boiling water reactor fuel bundle, a three dimensional debris catching grid construction is placed within the flow volume defined by the lower tie plate assembly between the inlet nozzle and upper fuel rod supporting grid. A perforated plate is utilized having round holes as small consistent with the prevention of inadvertent closure due crudding and a hole pitch consistent with mechanical integrity requirements. The perforated plate is placed in a three dimensional construction such as a dome, cylinder, pyramid, inverted pyramid or corrugated construction spanning the flow volume of the lower tie plate assembly. As a consequence of this three dimensional grid construction, the total flow through area of the perforations in the metal plate does not introduce appreciable pressure drop in the lower tie plate assembly between the inlet nozzle and the rod supporting grid. Fluid movement at the debris restraining holes of the grid construction has a low flow velocity and a change in flow direction before passing through the holes to discourage debris from finding its way through the grid holes. Finally, it is possible to incorporate debris traps within the flow volume of the lower tie plate assembly that can cause trapping and subsequent removal of trapped debris upon fuel bundle replacement. A double corrugated plate having large holes in the lower plate and smaller holes in the upper plate is utilized to trap debris.

    摘要翻译: 在沸水反应堆燃料束中,三维碎屑捕获栅格结构放置在由入口喷嘴和上燃料棒支撑栅之间的下连接板组件限定的流动体积内。 使用多孔板,其圆形孔小,防止由于粗糙度而导致的无意闭合,以及与机械完整性要求一致的孔间距。 多孔板被放置在三维结构中,例如圆顶,圆柱体,金字塔,倒金字塔或波纹结构,跨越下拉板组件的流动体积。 作为这种三维格栅结构的结果,金属板中的穿孔面积的总流量不会在入口喷嘴和支撑杆之间的下连接板组件中引入明显的压降。 格栅结构的碎屑限制孔处的流体运动在通过孔之前具有低流速和流动方向的变化,以阻止碎屑通过栅格孔。 最后,可以将碎屑收集器结合在下连接板组件的流动体积内,这可以导致在燃料束更换时捕获和随后的捕获的碎屑的去除。 在下板中具有大孔的双层波纹板和上板中的较小孔用于捕集碎屑。

    Upper tie plate for boiling water nuclear reactor
    9.
    发明授权
    Upper tie plate for boiling water nuclear reactor 失效
    沸水核反应堆上层板

    公开(公告)号:US5002724A

    公开(公告)日:1991-03-26

    申请号:US399107

    申请日:1989-08-28

    IPC分类号: G21C3/33 G21C3/324

    摘要: An improved upper tie plate is disclosed in a fuel bundle for a boiling water nuclear reactor. The tie plate resides in a fuel bundle including an upper tie plate, a lower tie plate, a matrix of sealed fuel rods supported therebetween, and a surrounding channel. Both the lower tie plate and the improved upper tie plate have two functions; they support the fuel rods in vertical upstanding relation between the tie plates and interior of the channel and permit the passage of moderating coolant through the channel from the bottom of the channel to the top of the channel. This moderating coolant enters through the lower tie plate in the liquid form, passes into the matrix of upstanding fuel rods where steam is generated and exits outwardly through the improved upper tie plate as a water steam mixture at the top of the fuel bundle. The improvement includes the support of the channel directly from the fuel bundle lifting bail for transmission of load directly to the bail instead of a cantilevered support through the tie plate. This direct support enables cutting away a portion of the matrix overlying the fuel rods for reduction of pressure drop in the escaping steam/water phase from the fuel bundle. Additionally, this alignment enables raising of the points of tie plate support for longer fuel rod length. Improved fuel bundle performance results.

    Composite spacer with Inconel grid and Zircaloy band

    公开(公告)号:US5089221A

    公开(公告)日:1992-02-18

    申请号:US603046

    申请日:1990-10-25

    IPC分类号: G21C3/34 G21C3/344 G21C3/348

    摘要: An improved spacer is disclosed which contains an Inconel grid and a Zircaloy surrounding band. The Inconel grid can be fabricated from the extremely thin and highly elastic spring metal utilizing a modification of a prior art cell construction that includes paired inwardly bent vertical spring legs with cantilevered and rod encircling upper and lower arm pairs. The spring legs extend at spaced apart locations between the upper and lower arm pairs and have a medial spring rod contacting portion for biasing the rods into stops on the rod encircling arm pairs. The springs at the upper and lower ends are provided with spring dimple stops to prevent over stressing of the spring during assembly or handling of the fuel bundle into which the spacer is incorporated. The rod encircling arm pairs have an offset from center where the two arms meet at their distal ends to complete encirclement of the rods. This offset from center enables the cells to be fastened in cell pairs at their respective embracing arms. The cell pairs can in turn be manipulated as a unit to define the necessary types of spacer grids required for any particular grid construction. A preferred grid construction for a ten by ten fuel rod matrix is disclosed including a grid filling all rod lattice positions for the bottom of a fuel bundle, a grid enabling the placement of a water rod of varying diameter, and finally a grid defining missing lattice positions for overlying partial length rods and permitting upward venting of steam with minimum pressure drop. An all Zircaloy band is disclosed for surrounding containment of the Inconel grid. The band consists of two or four segments. Apertures are provided in the band at the corners, and portions of the corner Inconel cells project into these apertures, keying the Inconel grid to the Zircaloy band. The band is welded into continuous encircling relation. There results a spacer with an Inconel grid and surrounding Zircaloy band having minimum pressure drop and minimum neutron absorption useful with a high density fuel rod matrix required in modern fuel bundle design.