摘要:
Embodiments of a bottom nozzle of a nuclear fuel assembly provided with flow holes by utilizing a layered aircraft airfoil structure are provided. The bottom nozzle not only increases efficiency of filtering foreign substances by minimizing a size of the flow holes by constituting a shape of flow holes into cross stripes but also prevents coolant water flow velocity drop through prevention of coolant water pressure drop by constituting a lateral sectional shape of the grid frames constituting the cross stripes into an aircraft airfoil type.
摘要:
A joint structure between a top nozzle and a guide thimble of a nuclear fuel assembly and, more particularly, a structure for joining an inner-extension tube, the top nozzle and the guide thimble. When an inner-extension tube head, which is provided as a means for facilitating removal of the top nozzle of the nuclear fuel assembly from the guide thimble, is removed from an inner-extension tube body to separate the top nozzle from the nuclear fuel assembly, the inner-extension tube body is prevented from undesirably rotating, so that the guide thimble and the inner-extension tube body can maintain the joined state.
摘要:
Disclosed herein is a joint structure between a top nozzle and a guide thimble. The joint structure includes an outer guide post, an inner-extension tube head, an inner-extension tube body, a wedge and the guide thimble. The outer guide post is provided with an external thread formed on a lower end thereof. The inner-extension tube head includes an annular retaining part formed on an upper end thereof. An internal thread is formed on a medial portion of the inner-extension tube head. An external thread is formed on each of upper and lower ends of the inner-extension tube body. A stop protrusion is provided under a lower end of the wedge. The wedge is welded to the inner-extension tube body after the top nozzle has been joined with the guide thimble. A stop protrusion receiving depression is formed in the guide thimble.
摘要:
Disclosed is a spacer grid assembly with mixing vanes supporting fuel rods of nuclear fuel assemblies and mixing coolant that flows around the fuel rods, and more particularly, a spacer grid equipped with mixing vanes that mix coolant flowing around fuel rods.The spacer grid with hydraulically balanced mixing vane patterns, in the spacer grid equipped with a strip dividing a plurality of unit grid cells and a plurality of springs, protruded in uniform directions of vertical and horizontal directions on a grid surface of the strip and supporting nuclear fuel rods, which includes: a plurality of mixing vanes protruded to the downstream of coolant on an upper end of the inner grid surface, wherein positions and directions of the mixing vanes are formed in regular patterns on the spacer grid. Thus, it can minimize coolant flow induced vibration of the spacer grid by balancing hydraulic load generated by the mixing vanes, around the center of the spacer grids.
摘要:
Disclosed herein is a hold-down spring unit for a top nozzle of a nuclear fuel assembly. The hold-down spring unit is coupled to the upper end of the top nozzle of the nuclear fuel assembly. The hold-down spring unit includes a first spring which acts against a hold-down force with respect to the nuclear fuel assembly under start-up conditions or hot full power conditions of a nuclear reactor, and a second spring which acts against a hold-down force with respect to the nuclear fuel assembly under start-up conditions of the nuclear reactor. The present invention reduces the hold-down margin under start-up conditions or hot full power conditions, thus enhancing the mechanical and structural stability of the nuclear fuel assembly.
摘要:
The present invention relates to an anti-fretting wear spacer grid having a plurality of canoe-shaped springs formed thereon, wherein each of the canoe-shaped springs includes: a fuel rod-contacting part having a flat surface having a predetermined longitudinal length so as to have linear contact with the fuel rod; a curved face-connecting part formed on the upper and lower portions of the fuel rod-contacting part; a leg-connecting part formed on the end portion of the curved face-connecting part; and legs each being formed of a plate shape having a predetermined length and connecting the both sides of the leg-connecting part with one unit grid cell surface.
摘要:
Disclosed is a photo-electrode for a dye-sensitized solar cell comprising a conductive substrate; a meso-porous metal oxide thin film formed on the surface of the conductive substrate; a porous film formed on the meso-porous metal oxide thin film and comprising metal oxide nanoparticles; and a photosensitive dye adsorbed on the surface of the porous film; and a process for preparation thereof.
摘要:
Provided are an electrolyte composition of a dye-sensitized solar cell, a manufacturing method thereof, and a dye-sensitized solar cell comprising the composition. The composition comprises a polyvinylidene fluoride (PVDF) based high polymer and titanium dioxide nanoparticles serving as an inorganic material based filler. Using the PVDF based high polymer in the composition can solidify the composition, and this solidification can contribute to the flexibility of a solar cell. Also, the inorganic material based filler, i.e., the titanium dioxide nanoparticles, can reinforce the collection and retention of an aqueous component comprising iodide ions, which are carriers within the electrolyte. Accordingly, compared to typical high polymer based electrolyte solutions, excellent photoelectric conversion efficiency can be achieved with the above electrolyte composition.
摘要:
A cathode active material for a lithium secondary cell used in a cellular phone is disclosed. The cathode active material for the lithium secondary cell and the method the same having a high capacity and a long lifetime, different from LiCoO2 and LiMn2O4, Li(Ni, Co)O2, and V-system oxide that has been researched as the active material for substituting LiCoO2 are provided. The cathode active material for the lithium secondary cell in the next formula 1 is obtained by heating or chemically treating diadochite [Fe2(PO4)(SO4)(OH).6H2O] that is the mineral containing PO43−, SO42−, and OH−. LiaFebMc(PO4)x(SO4)y(OH)z (1) In the formula, M is at least one element selected from a radical consisting of Mg, Ti, Cr, Mn, Co, Ni, Cu, Zn, Al, and Si, with 0≦a, c≦0.5, 1≦b≦2, 0.5≦x, y, z≦1.5.
摘要:
The present invention provides a new organic-inorganic (PDMcT+PANI)/V2O5 composites electrode material in which two different organic polymers are intercalated into the V2O5 interlayer, which shows higher discharge capacity than each isolated polymers and V2O5. Therefore, it can be used as a cathode in secondary lithium battery.