SK283901B6 - Steam generator feeding node - Google Patents

Abstract

The present invention relates to a steam generator feeding node comprising an enclosed chamber (1) with inlet water pipes (2), built-in pipe connections (4) with shaped pipes ((5) inserted therein. The shaped pipes (5), being provided on their circumference with channels (6), pass through the enclosed chamber (1) and have their outlet in outer space extending about the enclosed chamber (1), whereby the ratio of said channel (6) cross sections and internal cross section of the shaped pipe (5) ranges within 0.7 to 1.8.

Description

Technical field

The invention relates to a steam generator power node, in particular a horizontal design for nuclear power plants.

BACKGROUND OF THE INVENTION

The supply water distributions inside the steam generators, in particular of the horizontal design for nuclear power plants, are provided either inside the bundle of heat exchanger tubes or above the bundle of heat exchanger tubes.

In the case of distributions carried out inside the tube bundle, this is a solution with one horizontal tube equipped with spouts and connected to the supply supply pipe. The horizontal, generally very rigid pipe is firmly fixed to the support system inside the steam generator and thus also satisfactorily secured against vibration. However, this embodiment of the distribution system has the disadvantage that it is inaccessible and thus irreparable. This finally showed a number of practical experiences.

The supply water distributions in the design above the tube bundle inside the horizontal steam generator are principally provided with one or two horizontally oriented supply tubes connected to the supply water supply and the outgoing groups of supply water distribution pipes that are introduced into the longitudinal gaps of the tube bundle and connected to either perforated water outlet pipes or one or more chambers with openings which are again located in the longitudinal gaps in the tube bundle.

In the case of solutions with feed-water chambers in the form of flow-through boxes with rectifying construction of feed-water flow, there is no mixing of cold feed-water with hot water from the outside of the chambers - boxes in the box, but up to the box. Super-emergency power supply, when very cold water, heat shocks with little favorable reaction to heat exchanger tubes is conveyed to the steam generator through one and the same distribution system.

SUMMARY OF THE INVENTION

These drawbacks are overcome by a steam generator supply node formed by a closed chamber with water inlet ducts and outlet openings equipped with sleeves with an embedded shaped tube provided on the outer perimeter of at least two channels and opening the other end into the external space around the closed chamber in such an arrangement that the circumference of the shaped tube and the inner cross-section of the shaped tube is in the range of 0.7 to 1.8.

Advantageously, in such a cross-sectional arrangement, the very cold feed water flowing at the super-emergency feed of the steam generator or the relatively cold feed water flowing at the start of the steam generator through the hot water inlet ducts located around the enclosure is present first inside the closed chamber. shaped tubes. Thus, warmer water always emerges from the nozzles than the incoming feed water and the tubes of the steam generator tube bundle are not exposed to large thermal shocks from the outlet water of the nozzle. This ultimately contributes to ensuring the long-term integrity of the heat exchanger tubes and thus enhancing the nuclear safety of the nuclear power plant.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of a generator power node is shown in the attached figure.

DETAILED DESCRIPTION OF THE INVENTION

In a horizontal steam generator, a bundle of horizontally oriented heat exchanger tubes is positioned so as to form several vertically oriented gaps along its length. In these gaps are closed chambers 1 connected to the water inlet pipe 2 and equipped with outlet openings 3 to which are connected the sockets 4 with built-in shaped tubes 5 provided on the outer circumference in the exemplary embodiment with six channels 6 and opening the other end into the outer space around of the closed chamber 1 in such an arrangement that the ratio of the cross-sections of the channels 6 formed on the periphery of the shaped tube 5 and the inner cross-section of the shaped tube 5 is in the exemplary embodiment 1,1. In the area of the relative cross-sections thus performed, the super-emergency feeding of the steam generator with very cold water than during the start-up of the steam generator under normal operating conditions with a cooler feed water supply than the water temperature around the closed chambers 1 and thus around the tube bundle The warmer feedwater then flows in the closed chamber 1 and the tube bundle compared to the feedwater temperature of the feed system and the water inlet pipes 2. This leads to suppression of thermal shocks on the tube bundle tubes and contributes significantly to the long term integrity of the heat exchanger tubes of the steam generator.

Claims (1)

PATENT CLAIMS I. A steam generator feed node formed by a closed chamber with water inlet ducts and outlet openings equipped with sleeves with an embedded shaped tube provided on the outer perimeter with at least two channels and opening the other end into the outer space around the closed chamber, characterized in that (6) formed on the periphery of the shaped tube (5) and the inner cross-section of the shaped tube (5) is in the range of 0.7 to 1.8.