DE2262150C3

DE2262150C3 - Steam generator

Info

Publication number: DE2262150C3
Application number: DE19722262150
Authority: DE
Inventors: Günter Dipl.-Ing. 8521 Poxdorf Beese
Original assignee: Siemens AG
Current assignee: Siemens AG
Filing date: 1972-12-19
Publication date: 1976-06-10

Description

—: wird. Hier handelt es sich darum, die Wärmespannun-: will. This is about the thermal tension

gen im Rohrboden des Heizgasverteilers zu vermeiden durch die Bespülung mit siedendem Wasser, dessenconditions in the tube sheet of the heating gas distributor by flushing with boiling water, its

Die Erfindung betrifft einen Dampferzeuger, insbe- 35 Wärmeübergangswert in diesem Zustand sein Maximum hat. Es geht nicht um das Problem, die schädlichen Korrosionsprodukte im Rohrbodenbereich des Vorwärmers und des heißen Schenkels be· einem U-Rohrbündel-Dampferzeuger zu vermeiden.The invention relates to a steam generator, in particular its maximum heat transfer value in this state has. It's not about the problem of harmful corrosion products in the tube sheet area Preheater and the hot leg in a U-tube bundle steam generator.

Vorteilhafterweise verlaufen die Speisewasserrohre parallel zu den Rohren des Rohrbündels. Sie können dann mit den gleichen Befestigungsmitteln festgelegt werden. Zweckmäßig sind die Speisewasserrohre über den Rohrboden am heißen Ende verteilt, um die Strömung so gleichmäßig wie möglich zu gestallen.The feedwater pipes advantageously run parallel to the pipes of the pipe bundle. You can then be fixed with the same fasteners. The feed water pipes are expediently over distributed the tube sheet at the hot end to make the flow as even as possible.

Es erscheint empfehlenswert, den Speisewasserrohren einen mehrfach größeren Durchmesser als denIt seems advisable to give the feed water pipes a diameter several times larger than that

Claims

Patent claims:

1. Steam generator, especially for pressurized water reactors, with a flow of feed water U-tube bundle and a jacket surrounding the U-tube bundle, which is connected to the housing of the Steam generator forms a fall space, as well as with one surrounding the cold leg of the U-tube bundle Preheater, in which at least part of the feed water supplied to the steam generator flows in the direction of the tube sheet, characterized in that from the tube sheet side Exit of the preheater (20) feed water pipes (25) to the tube sheet area (26) of the hot leg of the U-tube bundle (2), whose inlet cross-section is used to adjust the flow rate is designed to be adjustable.

2. Steam generator according to claim I, characterized in that that the feedwater pipes (25) run parallel to the pipes (30) of the tube bundle (2).

3. Steam generator according to claim 1 or 2, characterized in that the feed water pipes (25) are distributed over the tube sheet (5) at the hot end.

4. Steam generator according to claim 1, 2 or 3, characterized in that the feedwater pipes (25) have a diameter several times larger than the tubes (30) of the tube bundle (2).

Especially for pressurized water reactors, with a U-tube bundle around which the feed water flows and a the jacket surrounding the U-tube bundle, which forms a fall space with the housing of the steam generator, and with a preheater enclosing the cold leg of the U-tube bundle, in which at least one Part of the feed water supplied to the steam generator flows in the direction of the tube sheet

Such a steam generator has already been proposed (DT-OS 22 32 754, in particular FIGS. 1 and 3). He has compared to another known steam generator of the U-tube bundle type (US-PS 34 83 848) Advantage that part of the feed water supplied to the steam generator in the preheater Direction of the tube sheet flows, whereby the corresponding tube sheet part is flushed and here so-called Dead water zones are largely avoided.

The present invention is concerned with the task, also in the tube sheet area of the so-called hot To give the tubes of the tube bundle, so that even with economically few tubes sufficiently large amounts of feed water can be led to the tube sheet. In this case, the inventive feature is list the inlet cross-section of these pipes to adjust the flow rate adjustable, in particular cheaper way to realize. This can mainly

Schenkels induces an intensive stream of feed water, especially by introducing air at the inlet. In this area, the invention de, but possibly also at the outlet, the cross-cut by an intense flow concentrations of the feedwater pipes by throttling on the corrosion products, which can occur in particular at hot points of the steam generator, with certainty. The invention has always proven itself
The goal is not only to improve the flow distribution, but also to reduce it

the thermal stresses in the said tube sheet area, which is also a hazard for steam generators could cause.

In a steam generator of the type mentioned at the outset, according to the invention, the stated object is thereby achieved solved that from the pipe bottom side exit of the correct amount for an optimal flow distribution adjusts.

For a more detailed explanation of the invention, an exemplary embodiment is given below with reference to the drawing described.

In Fig. 1 is schematically simplified a steam generator 1 drawn in a longitudinal section for a pressurized water reactor not shown further. the As a heat exchanger, the steam generator has a U-shaped tube bundle 2, the latter of which are symmetrical to one another lying legs 3 and 4 with their free ends in