RU2328044C2 - Core inlet chamber - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: device can be applied in monoblock nuclear steam generating plants with preferred liquid metal heat carrier in the first circuit. Core inlet chamber includes vessel bottom, vertical mating shell, knife edges at the bottom, annular plate with inlets and cylindrical sleeves for heat carrier input, lower core grid. Inlet chamber features distributor in the form of upper elliptic bottom with central hole of diameter not less than the diameter of lower core grid, placed axisymmetrically to the vessel bottom, at the distance allowing heat carrier speed to surpass heat carrier speed in the inlet cylindrical sleeves. Displacers are placed in the obtained annular volume, so that they form curvilinear diffuser channels butted to each other at their outputs in the diameter of the central hole.

EFFECT: reduced dimensions, volume and mass of heat carrier in the inlet chamber.

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Description

The field of technology.

The invention relates to a monoblock nuclear steam generating units (YAPPU) with predominant use in the first circuit of a liquid metal coolant.

The level of technology.

Famous one-piece YPPU firm "Babcock and Wilcox" D.F. Romanov and others. "Ship nuclear steam generating installations", L., publishing house "Sudostroenie", 1967, p. 82, Fig. 32a, in which the entrance chamber is formed by an elliptical the bottom of the housing JAPPU, the lower lattice of the active zone and the baffle mounted on the aforementioned bottom. The coolant is supplied from the pumps to the chamber through four horizontal inlet pipes of the vertical shell of the partition. Next, the coolant changes the direction of motion by 90 °, lowers down, washing the bottom, again changes the direction of motion by 180 ° (possibly with a separation of the jet) and enters the throttle-leveling device located in the chamber in front of the active zone. The purpose of this device is to equalize the unevenness of the flow at the inlet to the chamber and ensure a uniform velocity field at the entrance to the active zone, since a sharp change in the direction of flow of the coolant not only increases the hydraulic resistance of the path, but also leads to the formation of vertical vortices that distort the flow structure and creating significant non-uniformity of the coolant velocity at the entrance to the core.

The disadvantages of the aforementioned design of the entrance chamber of the core are significant dimensions and a large volume of coolant in it. This design of the entrance chamber of the active zone in a monoblock design of the IAPP is the closest technical solution of the known and therefore taken as a prototype.

Disclosure of the invention.

An object of the present invention is to provide a compact core input chamber.

The objective of the invention is the optimal profiling of the coolant path in the input chamber of the active zone, making it possible to significantly reduce the size and volume of the said chamber and the mass of the coolant in it.

The technical result of the invention is to reduce hydraulic losses, hydraulic flow unevenness at the entrance to the reactor core, and a decrease in the mass of the coolant in the input chamber of the core.

The specified result is achieved by the fact that the said chamber is equipped with a guide apparatus made in the form of two elliptical bottoms arranged axisymmetrically and forming an annular volume, and displacers located in the annular volume so that they form curved channels-diffusers of the heat carrier path.

One guide surface of the mentioned coolant path is the inner surface of the elliptical bottom of the solid reactor vessel, the other bounding and guide surface of the coolant path is the outer surface of the upper elliptical bottom of a smaller diameter, having a Central hole equal to the diameter of the lower lattice of the active zone. The upper elliptical bottom in diameter of the central hole is attached to the landing shell of the core, which, in turn, is attached, for example, by welding, to support ribs mounted on the bottom of the body and to the horizontal horizontal plate of the chamber. The height of the upper elliptical bottom is increased due to the cylindrical shell attached at one end to the bottom and the other to an annular plate, in which there are round holes for installing pump fittings. The chamber thus formed has a maximum cross section in its upper part, which gradually decreases to the minimum necessary cross section at the exit. In the plan, between the holes in the annular plate there are displacers, each of which occupies the entire height between the elliptical bottoms, having a maximum width in its upper part in the tangential direction and a minimum at the exit, at the boundary of the central hole in the upper elliptical bottom, forming curved channel diffusers of the path coolant. As a result, the average speeds in each cross section are close to each other; therefore, hydraulic losses in the diffuser channels are minimal. At the outlet, the diffuser channels form an annular collector with a diameter no smaller than the outer diameter of the lower core of the core, and provide a uniform supply of coolant to the inlet chamber along the entire perimeter of the free volume.

A brief description of the drawings.

The invention is illustrated by drawings:

Figure 1 is a longitudinal section of the input chamber of the active zone;

Figure 2 is a top view.

The entrance chamber of the active zone is formed by the bottom of the housing 1, the upper elliptical bottom 2 with a cylindrical insert 3 and an axial hole 4, a baffle consisting of a vertical landing shell 5, mounted on the supporting ribs 6, and an annular plate 7 with inlet holes 8 into which the cylindrical sleeves 9, as well as displacers 10, forming the side surfaces of the diffuser channel 11. In the central part, the inlet chamber is limited by the lower lattice 12 of the active zone. In the volume between the elliptical bottom 2, the annular plate 7 and the shell 5 is placed a block of displacers 13.

The implementation of the invention.

The entrance chamber of the active zone is equipped with a guide annular channel formed by two curved surfaces belonging to two elliptical bottoms located axisymmetrically at some distance from each other. The upper elliptical bottom has in the center a circular hole with a diameter not less than the diameter of the lower lattice of the active zone, and is attached to a vertical landing shell, which, in turn, is mounted on supporting ribs mounted on the bottom of the body. The outer edge of the upper elliptical bottom is attached to a horizontal annular plate. Preliminarily, displacers are fixed on the upper elliptical bottom, which, after installing the bottom in the proposed design, form the pressure part of the inlet chamber of the active zone in the form of several curved diffuser channels that are joined at the inlet at the diameter of the central hole in the said upper bottom, providing a radial coolant supply throughout the perimeter of the inlet chamber under the core of the core.

Claims (1)

The entrance chamber of the active zone, containing the bottom of the housing, a vertical landing shell, support ribs on the bottom, an annular plate with inlet openings and cylindrical sleeves installed therein for supplying coolant, a lower core of the active zone, characterized in that the entrance chamber of the active zone is equipped with a guide apparatus in the form of an upper elliptical bottom with a central hole with a diameter not less than the diameter of the lower lattice of the active zone, located axisymmetrically with the bottom of the body at a distance from it, about ensuring the speed of the coolant at the outlet is not greater than the speed in the cylindrical sleeves of the inlet openings, and the displacers are located in the formed annular volume so that they form curvilinear diffuser channels that are joined at the outlet to each other at the diameter of the central hole.

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