Upper pipe base of low-pressure depressurization water reactor fuel assembly
Technical Field
The utility model relates to the field of nuclear fuel diversion, in particular to an upper pipe seat of a pressure-drop pressurized water reactor fuel assembly.
Background
The fuel assembly of pressurized water nuclear reactor consists of guide pipe parts, instrument pipe parts, grillwork, several fuel rods, upper and lower pipe seats, etc. The upper pipe seat is an important component of the framework of the fuel assembly and is a main bearing part which directly influences the safety of the fuel assembly during operation, transportation and in-pile operation. The top nozzle is located at the uppermost end of the fuel assembly and serves as an important interface component, the structural design of which has a direct influence on the operability of the fuel assembly and the compatibility of the in-stack structure and plays a role in preventing the fuel rods from escaping from the top of the assembly. In addition, the upper nozzle is located at the core coolant outlet, which has an important influence on the uniformity of the core outlet coolant flow distribution and the overall fuel assembly pressure drop.
The strength characteristic and the resistance characteristic are key performance indexes concerned in the design of the upper pipe seat structure, and the strength characteristic is used for judging whether the upper pipe seat structure is complete under different working conditions or not so as to ensure the safety of the upper pipe seat. And the thermal property of resistance characteristic direct relation fuel, if the upper nozzle support resistance coefficient is great, then there is great pressure drop in upper and lower both sides of upper nozzle support grating, need provide bigger main pump lift just can make the mobility of coolant satisfy the design requirement, be unfavorable for the economic nature of reactor.
Accordingly, there remains a need in the art for improvements.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the problem of poor pressure drop characteristic of the existing upper pipe seat partition plate.
In order to achieve the purpose, the utility model adopts the following technical scheme:
the utility model provides a low-pressure depressurization water reactor fuel assembly upper pipe seat, which comprises:
the upper tube seat lattice plate is arranged in a rectangular shape, and a plurality of through holes are formed in the upper tube seat lattice plate;
the through holes comprise a first-class water hole, a second-class water hole, a third-class water hole and a guide hole;
the upper pipe seat grid plate comprises four square grid plate units which are arranged in a central symmetry manner;
the plurality of water flow holes of the same type are arranged at two mutually vertical center lines of the upper tube base grating plate;
the second-type water flow holes are arranged at two diagonal lines of the upper tube base grid plate;
the three types of water flow holes are arranged in the area between the two diagonal lines and the middle line of the upper tube base grid plate;
the guide holes comprise inner ring guide holes arranged in a square matrix around the center of the upper tube seat grid, outer ring guide holes arranged around the outer parts of the inner ring guide holes and instrument tube holes arranged at the center of the upper tube seat grid;
and the supporting frame is used for being fixedly connected with the outer side of the side edge of the upper tube base lattice plate.
Furthermore, 8 inner ring guide holes are formed, 8 inner ring guide holes surround the outer side of the instrument tube hole, and 8 inner ring guide holes and the instrument tube hole form a 3 x 3 square matrix together.
Furthermore, 16 outer ring guide holes are formed, and the 16 outer ring guide holes uniformly surround the outer side of the inner ring guide hole.
Furthermore, ribs are arranged between every two adjacent through holes.
The utility model has the beneficial effects that: through the optimal design to upper tube base grating geometry, a novel discharge orifice arrangement mode is proposed. The water flowing holes are arranged in a mode of symmetrically arranging opposite side middle point connecting lines and opposite side angle lines in the horizontal and vertical directions relative to the upper pipe seat grid plate. Can realize higher grating flow area ratio under the prerequisite of ensureing structural strength to make the upper tube seat pressure drop can keep at lower level, help promoting its economic nature.
Drawings
FIG. 1 is a schematic view of the base structure of the upper tube base provided by the present invention;
FIG. 2 is a top plan view of an upper tube grid provided by the present invention;
FIG. 3 is a top view of an upper nozzle panel unit provided by the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.
As shown in fig. 1 to 3, the present invention provides an upper pipe seat of a low-pressure depressurization water reactor fuel assembly, comprising:
the upper tube seat grid plate 1 is arranged in a rectangular shape and is provided with a plurality of through holes;
the through holes comprise a first-class water flowing hole 6, a second-class water flowing hole 7, a third-class water flowing hole 8 and a guide hole;
the upper pipe seat grid plate comprises four square grid plate units which are arranged in a central symmetry manner;
a plurality of water flow holes 6 of the same type are arranged at two mutually vertical center lines of the upper tube base grid plate 1;
a plurality of second-type water flow holes 7 are arranged at two diagonal lines of the upper tube base grid plate 1;
a plurality of the three types of water flow holes 8 are arranged in the area between two diagonals and a midline of the upper tube base grid plate 1;
the guide holes comprise inner ring guide holes 4 arranged in a square matrix around the center of the upper tube seat grid plate, outer ring guide holes 5 arranged outside the inner ring guide holes 4 in a surrounding mode, and instrument tube holes 3 arranged at the center of the upper tube seat grid plate 1;
and the supporting frame 2 is used for being fixedly connected with the outer side of the side edge of the upper tube base lattice plate 1.
Furthermore, 8 inner ring guide holes 4 are arranged, 8 inner ring guide holes 4 surround the outer side of the instrument tube hole 3, and 8 inner ring guide holes 4 and the instrument tube hole 3 jointly form a 3 × 3 square matrix.
Furthermore, 16 outer ring guide holes 5 are arranged, and the 16 outer ring guide holes 5 uniformly surround the outer side of the inner ring guide hole 4.
Furthermore, a rib 9 is arranged between every two adjacent through holes.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the utility model. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.