Patent ID: 12247732

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The basic concept of the disclosure is that the swirl vanes are no longer attached, as before, to an existing pipe wall, which has the abovementioned disadvantages. Each swirl vane is now already connected to a pipe segment and to a shaft segment. When the shaft segments are then attached to their shaft segment holder, the pipe segments join together to form the pipe section. As a result, the time-consuming positioning and fixing, for example by affixing the swirl vanes to the pipe section, is advantageously avoided. It is then particularly advantageous if the steam boiler water separator is produced on site and not in a workshop. It is very particularly advantageous if the steam boiler water separator is produced as it were in situ, in other words when a liquid separator or a water separator needs to be replaced in a steam boiler and a new liquid separator replaces the worn old one. The steam boiler water separator is usually then not placed in the steam boiler as a complete unit because the dimensions of a steam boiler water separator are usually too large for access to a dome of the steam boiler, for example access through a manhole. A swirl vane with a pipe segment already attached thereto and a shaft segment attached thereto is dimensioned such that it fits through a manhole of the relevant steam boiler. In the dome inside the steam boiler, the individual swirl vanes are connected positively and detachably with their shaft segments to the shaft segment holder. A pipe section is thus also formed from the pipe segments. A steam boiler water separator is thus produced particularly simply which is already positioned in a pipe section. The production time for a steam boiler water separator is accordingly considerably reduced. In addition, the manual positioning of the swirl vanes on the pipe wall is avoided such that quality-impairing deformation is avoided by the in-situ welding of the swirl vanes to a pipe wall in the steam boiler.

The steam boiler water separator is particularly advantageously used when it is replaced as a replacement steam boiler water separator in an environment which is hazardous to people, for example in a nuclear power plant steam boiler. People should only spend a limited amount of time there such that the steam boiler water separator, i.e. in this case a nuclear power plant steam boiler water separator, is produced as quickly as possible and replaced quickly.

A development of the steam boiler water separator provides that a first closure element is connected to a first end face of the shaft segment holder and a second closure element is connected to a second end face of the shaft segment holder, that each closure element has a circular groove with an open side facing the respective end face, that a respective radially outer groove wall of the grooves engages over a subzone of the shaft segments. It is hereby advantageous that the individual axial ends of the shaft segments of an end face are placed in a groove of a closure element. The axially outer groove wall thus engages over the axial ends. The axial ends are in this way protected particularly well from force exerted by the flow of steam through the steam boiler water separator. Wear is correspondingly minimized.

A particularly simple way of connecting the closure elements to the end faces is characterized in that the closure elements are screwed into the end face of the shaft segment holder. For this purpose, a closure element has, for example, an external thread which is screwed into a corresponding internal thread on the shaft segment holder.

A further alternative embodiment of the steam boiler water separator is characterized in that each shaft segment has a molding, in that the shaft segment holder has guide grooves which are arranged in the longitudinal direction of the shaft segment holder on the radially outer surface of the latter, and in that a positive connection is produced between each shaft segment and the shaft segment holder by a respective molding/guide groove combination. A particularly simple positive connection between the shaft segments and the shaft segment holder is possible in this way. Preferred positive-locking shapes are, for example, dovetail or mushroom-shaped grooves in the shaft segment holder with a correspondingly shaped molding on the shaft segments. It is also within the concept of the disclosure that the grooves or the moldings are also arranged on the respective other component in order to produce a molding/guide groove combination.

A further alternative embodiment of the steam boiler water separator provides that adjacent components of the components shaft segments, pipe segments, shaft segment holders, and/or closure elements are connected to one another undetachably in their position by securing means. Two adjacent components can be connected, in order to be secured in position or in order to be secured against the component coming loose from its position, by a large number of technical options, for example by spot welds, weld seams, adhesive bonding, bolts, or rivets. A particularly simple, time-saving, and at the same time secure securing option for use in a replacement situation or within a steam boiler is the placement of spot welds or weld seams which connect two adjacent components to each other.

The object is also achieved by a steam boiler through which steam flows vertically, with a primary water separator which is arranged in an upper dome zone, viewed geodetically, wherein the primary water separator has a number of vertically extending pipe sections, wherein a steam boiler water separator is arranged in at least some of the pipe sections. The steam boiler provides a specific installation situation for the steam boiler water separator, in particular in a nuclear power plant. This means that the steam boiler water separator is produced only within the confined space of the dome of the steam boiler. The abovedescribed advantages are accordingly particularly important when the steam boiler water separator is produced inside a steam boiler dome.

For particularly simple production of the steam boiler with a steam boiler water separator, it is provided that the dome zone has a manhole, that the dimensions and form of the components shaft segments, pipe segments, shaft segment holders, and/or closure elements are adapted to the clear width of the manhole such that these components can be introduced into the dome zone from outside the dome zone. In this way, a steam boiler water separator can be produced using just a few components prefabricated in a workshop with appropriate precision and be inserted into its intended installation location in the steam boiler.

A preferred alternative embodiment of the steam boiler is use as a nuclear power plant steam boiler.

The object is additionally achieved by a method for producing a steam boiler water separator according to the disclosure, comprising the following method steps:

Connecting the first closure element to the shaft segment holder

Positively connecting the shaft segments of the water separator segments to the shaft segment holder such that the pipe section is formed by the pipe segments and such that the swirl vanes are arranged at their structurally intended positions,

Connecting the second closure element to the shaft segment holder such that the axial positions of the shaft segments between the first and the second closure element are fixed.

In this way, a steam boiler water separator is produced particularly simply and quickly with just a few method steps according to the disclosure. In particular in the case of in-situ production, i.e. production which does not take place in a workshop context, the method steps according to the disclosure ensure a high quality of a steam boiler water separator, whilst the swirl vanes additionally are subject to no risk, or just a small risk, of deformation of faulty positioning of the swirl vanes during production.

The method according to the disclosure for producing a steam boiler water separator can also comprise the following subsequent additional method step:

Attaching the securing means in each case to adjacent components of the components shaft segments, pipe segments, shaft segment holders, and/or closure elements.

In this alternative embodiment, the position and the connection of adjacent components are additionally ensured by the securing means.

Thus, in the method for producing a steam boiler water separator, the securing can be effected by respective adjacent components of the components shaft segments, pipe segments, shaft segment holders, and/or closure elements being connected to one another by spot welds or weld seams as the securing means.

A further alternative embodiment of the method for producing a steam boiler water separator in a dome zone of a steam boiler provides the following additional step:

Introducing the components shaft segments, pipe segments, shaft segment holders, and/or closure elements through the manhole into the dome zone.

The purpose of this alternative embodiment of the method is to produce a steam boiler water separator in a specific installation situation, which usually needs to be done as quickly as possible, wherein the quality of the steam boiler water separator cannot be impaired.

FIG.1shows an exploded drawing of a water separator10as an exemplary embodiment for a steam boiler liquid separator which is intended for installation as a replacement liquid separator in a primary steam boiler of a nuclear power plant. In the example chosen, the liquid medium which flows through the steam boiler is water which is heated during the flow through the steam boiler to form water vapor as steam. The water separator10shown has a first12, a second14, a third16, and a fourth water separator segment18which all have the same structure. The water separator segments12,14,16,18are arranged symmetrically about a holder with a center axis which lies longitudinally on a notional axis of symmetry of the water separator10. The holder here has a shaft segment holder20, a first closure element22, and second closure element24.

The structure of a water separator segment will be explained in detail below by way of example at a first water separator segment12.

The first water separator segment12has a curved first swirl vane26to which a first shaft segment28is attached on its side facing the shaft segment holder20. A first pipe segment30is connected to the first swirl vane26on the side facing away from the shaft segment holder20. In the chosen exemplary embodiment, the water separator10has precisely four water separator segments which have the same structure with pipe segments30, swirl vanes26, and shaft segments28. After assembly of the water separator10, the four pipe segments28produce a complete pipe section. In the exemplary embodiment, each pipe segment30represents a quarter, or 90°, of the circumference of the pipe wall at the pipe section. In the chosen example, the shaft segments28also represent a quarter, or 90°, of the circumference and, when assembled, form a shaft pipe section. The first shaft segment28has, on its side facing the shaft segment holder20, a dovetail molding32which is formed over the complete length of a longitudinal extent of the first shaft segment28of the first water separator segment12. A total of four dovetail grooves, with dimensions which are adapted to the moldings on the shaft segments, are introduced into the shaft segment holder20over its longitudinal extent. Thus, for example, the first molding can be pushed longitudinally into a first groove and in this way connected positively to the shaft segment holder20. The procedure of pushing the moldings into the grooves is indicated in this Figure in the form of a plurality of lines42. The lengths of the shaft segment holder20and the shaft segments28are here matched to one another, i.e. have the same length in the chosen example.

In addition, the first closure element22has, on its end face facing the shaft segment holder20, a thread36which can be screwed into a corresponding mating thread on a first end face38of the shaft segment holder20. The mating thread cannot, however, be seen in this view. In addition, a circular groove40is incorporated on the first end face38into the material of the first closure element22, wherein the clear width of the first circular groove40is adapted to the radial thickness of the material of the shaft segments. The region of the shaft segments which is arranged in the circular groove after assembly is positioned and fixed in this way. Another end face of the first closure element22is configured with a streamlined shape such that steam which occurs on the other end face is guided around the first closure element22and the holder as a whole with as minimal loss of pressure as possible.

In addition, the second closure element24has, on its end face facing the shaft segment holder20, an external thread44which can be screwed into an internal thread46in a second end face48of the shaft segment holder20. A second circular groove50, which has a comparable configuration and function to the first circular groove40, is introduced on this end face of the second closure element24. Those regions of the shaft segments28which lie in the second circular groove50when assembled are also positioned and fixed there. A further end face of the second closure element24is configured as the diffusor element52, which results in a further minimization of the loss of pressure in the flow of steam over the water separator10.

The first22and the second closure element24fix all the water separator segments12,14,16,18in a structurally predetermined axial and radial position at or on the shaft segment holder20.

FIG.2shows a 3D view of the assembled water separator10, for which reason the same reference numerals are used for the same components as in the description ofFIG.1. It can also be clearly seen inFIG.2that the pipe segments30of the individual water separator segments12,14,16,18as a whole produce a pipe section in which the swirl vanes26are arranged. It can also be seen from the Figure that adjacent components, for example the first pipe segment20of the first water separator segment12and the adjacent pipe segment30of the second water separator segment14, form a common joining surface54at which they lie flat against each other and at which the two components can be welded together by means of a weld seam as a securing means.

FIG.3shows a cross-section through a geodetically upper part of a steam boiler60in the primary cooling circuit of a nuclear power plant with installed water separators10. In the example shown, the steam boiler has a height of approximately 17 m and a diameter of approximately 4 m and a cooling medium, namely water, flows up through it from below. The cooling medium is heated and changes into the vapor phase as it flows through. Only an upper part of the steam boiler60, a so-called dome, dome zone, or steam boiler dome62, in which the cooling medium is already in the vapor phase, is shown in the Figure. A two-stage primary water separator64, which has a plurality of vertically arranged first pipes66(two of which can be seen in the cross-section), is shown in the steam boiler dome62. In each of the first pipes66, a water separator10has been introduced as a steam boiler liquid separator according to the disclosure as the second stage of the two-stage primary water separator64. To do this, an end face of an end of the pipe section of the water separator10is connected, for example welded, to an end face at the end of a second pipe68. In addition, an external diameter of the second pipe68and the water separator10is smaller (800 millimeters in the example chosen but typically between 600 mm and 1100 mm) than a clear diameter of the first pipe66. In this way, the second pipe68can, with the water separator10attached thereto, be pushed into the first pipe66from below and to be precise as far as a position in which the pipe section of the water separator10is situated entirely in the first pipe66. The steam boiler dome62can be accessed, for example for repair or maintenance work, by incorporating a manhole (not shown in the Figure) into a steam boiler wall70. The manhole is closed by a manhole cover while the steam boiler60is operating normally but can be opened temporarily for the said repair or maintenance work. A typical diameter for such a manhole is 500 mm to 600 mm.

Repair work which may be required on the steam boiler60consists of replacing the water separator or separators10. After operation for a certain period of time, the material of the water separator can become worn or removed by the water separator being subjected to steam and water droplets such that the water separator can be destroyed or at least have limited functionality. It is, however, often not readily possible to replace the original water separator with a water separator10because an external diameter of the replacement water separator as the water separator10is larger than the clear diameter of the manhole through which the water separator10would have to pass into the steam boiler dome. The water separator10according to the disclosure is particularly suited to this use as a steam boiler liquid separator and is installed in the steam boiler60as follows. A more resistant material can here be chosen as the material for the water separator10than that of the original water separator, for example stainless steel or high-alloy special steels with a relatively high content of chrome, vanadium, or other metals. In addition, plating the components and in particular the swirl vanes26with, for example, austenitic steels can also be considered for increasing the resistance of the water separator10to wear. Plasma spray coating the components and in particular the swirl vanes26is also provided as a further alternative for increasing the resistance of the water separator10to wear.

It is assumed that the original water separator which needs to be removed from the steam boiler dome because of its state of wear, for example using a separation method such as sawing, flame-cutting, or grinding off the original water separator from the second pipe68and separating the original water separator from the first pipe66. The original water separator is then broken down further such that the individual segments can be taken out of the steam boiler dome62through the manhole. The new water separator10can, however, not be introduced into the steam boiler dome62in an assembled state. This is because the diameter of the water separator10is larger than the clear width of the manhole. According to the disclosure, the water separator10has, however, a plurality of components. In the example shown, there are seven components which each have dimensions that allow them to be moved through the manhole. In this way, all the required components of the water separator10are first introduced into the steam boiler dome62through the manhole. In a first working step, the first closure element22is there first screwed into the mating thread of the shaft segment holder20with its thread36. In a further working step, the first water separator segment12is inserted with its first molding32into the free end face of the first groove34and displaced in the first groove34until the first shaft segment28bears against a groove base of the circular groove40. This working step is repeated for the second14, the third16, and the fourth water separator segment18until they are arranged in the further grooves34, assigned thereto, or longitudinal grooves in the shaft segment holder20and are in this way connected positively to the latter. In an additional working step, the second closure element24is screwed into the internal thread46of the shaft segment holder20with its external thread44until a groove base of the second circular groove40is tensioned against the shaft segments28. In this way, the individual shaft segments are held and tensioned fixedly at their structurally intended positions between the first22and the second closure element24. In the example shown, in a subsequent working step all the adjacent components are welded to one another, i.e. connected to one another undetachably, by weld seams. The touching sides of the first30and second pipe section are thus, for example, connected by a weld seam, or alternatively the closure element22is welded to the first shaft segment28by a weld seam.