EP0886743B1 - Water separation system - Google Patents

Abstract

The invention relates to a water separation system (1) which is used to separate water from a water/steam mixture (G) and comprises at least one inlet pipe (4) arranged at the periphery of a container (2) and an outlet pipe (6), provided above the inlet pipe (4), for steam (D'). To obtain the highest separation quality, a separation device (14), preferably in the form of a bent pipe (10, 10'), for a partial steam current (D, D') is connected on the inlet side and in parallel to the container (2).

Description

The invention relates to a water separation system for Separate water from a water-steam mixture with at least an inlet pipe arranged on the circumference of a container and provided with one above the inlet pipe Outlet pipe for steam.

Such, e.g. from the German published application DE 42 42144 A1 known water separation system with a water separator usually becomes one in the evaporation system Continuous or forced flow steam generator used. He is used to separate water from a water / water-steam mixture at the end of a heating surface called an evaporator of the steam generator. This is to avoid that Water gets into the subsequent superheater heating surfaces. A such disturbance of the medium-side loading of the heating surface inlets leads to different due to heating Mass flows in the heating surfaces. The result Different cooling conditions can lead to impermissible excess temperatures and thus damage to the pipes of the heating surfaces to lead.

That is usually tangential via the inclined inlet pipes water / water / steam mixture flowing into the water separator is in a container as a result of a combination separated from the effects of gravity and centrifugal force. Here the water is separated from the container walls and flows down while the steam due to the inclination of the inlet pipes first led down and then on a flow reversal in the separator in the upper area of the tank is subtracted.

With increasing steam content and increasing steam generator load however, it narrows due to the ratio of downward flow and upward flow defined fluidic Cross section so that the speeds of the mixture proportions increase and the pressure loss increases. As a result of the comparatively high speed of the water / water-steam mixture water droplets are carried away by the steam, the quality of separation decreases increasingly. With increasing number the outlet conditions of the Mixture beam increasingly disturbed.

A water separation system is known from FR-A-961 953, with a container on the inlet side Disconnecting device for a partial steam flow upstream is.

The invention has for its object a water separation system with a particularly high separation quality.

This task is the beginning of a water separation system mentioned type according to the invention solved in that the Container on the inlet side to separate a partial steam flow a pipe bend is upstream, one of which Steam partial flow line branches.

The invention is based on the consideration of an existing one Fluid separator through a pre-separation to relieve a partial steam flow.

By means of this upstream of the container of the water separation system and arranged parallel to this separator is using the pressure differential across the tank of the water separation system before the actual one Water separator steam is withdrawn from the water separator outflowing steam can be added. Here the centrifugal force effect in the pipe bend is used, whereby in Area of water-steam stratification in the pipe bend a subset of the steam is drawn off.

To maintain centrifugal separation inside the container to get, is the or each inlet pipe on the circumference of the container at an angle of inclination and / or arranged tangentially.

The inflow to the upstream separation device can done from above or from below. Therefore, the pipe bend the separator curved up or down his. Especially in the case of an inflow from below a drainage of the upstream separation device for Container of the water separator may be provided. To do this the steam partial flow line connected a drainage line and / or a drainage vessel in the partial steam flow line be switched.

In the case of an upwardly curved pipe bend, the upstream The separating device is the end of the pipe bend Steam partial flow line expediently branches while in the case of a downwardly curved pipe bend, the one facing it End of the steam flow line preferably siphon-like is trained.

The connection of the steam lines from the water separator tank and the disconnecting device upstream of this can be directly behind the water separator or in one higher-level collection system. The outlet pipe and the steam partial flow line are then with one another or with connected to the common collection system.

The advantages achieved with the invention are in particular in that due to one on the inflow side of the separator separated and run parallel to this Partial steam flow the pressure loss in the water separation system decreased. As a result of the resulting reduced The steam flow to the actual separator is reduced Vapor speed in the separator, so that an entrainment of Drops of water in the separated steam flow is avoided.

The formation of the separation device in the form of a pipe bend with connected steam partial flow line in addition, particularly small dimensions and small wall thicknesses the actual separator. This in turn leads to a particularly low total pressure drop in the water separation system and due to the small wall thicknesses to one particularly favorable behavior with temperature changes.

Figur 1

ein Wasserabscheidesystem mit einem nach oben gekrümmten Eintritts-Rohrbogen,

Figur 2

ein Wasserabscheidesystem gemäß Figur 1 mit einem nach unten gekrümmten und einem nach oben gekrümmten Eintritts-Rohrbogen, und

Figuren 3

im Ausschnitt einen Schnitt entlang der Linie III-III in Figur 2 mit einem syphonartig ausgebildeten Rohrbogen.

Embodiments of the invention are explained in more detail with reference to a drawing. In it show:

Figure 1

a water separation system with an upwardly curved inlet pipe bend,

Figure 2

a water separation system according to Figure 1 with a downward and an upward curved inlet pipe bend, and

Figures 3

in detail a section along the line III-III in Figure 2 with a siphon-shaped pipe bend.

Corresponding parts are in all figures with the provided with the same reference numerals.

The water separation system 1 according to FIG. 1 comprises a closed one Container 2 with an obliquely arranged Inlet tube 4 and an axially extending Outlet pipe 6 and also an axial water drain 8. Instead of the axial outlet pipe 6, several, e.g. extractor pipes running at an angle or radially his.

On the inflow side, the inlet pipe 4 goes into an upwardly curved one Elbow 10 over, together with one in the bend area steam partial flow line 12 connected to the container 2 upstream and parallel to this Separating device 14 forms. The steam partial flow line 12 is connected to the outlet pipe 6, which is in a vapor collection system 16 opens.

When the water separating system 1 is operating, a water / water / steam mixture flows G over the pipe bend 10 of the inlet pipe 4 into the container 2. The inflow of the pipe bend 10 takes place from above. By means of the separating device 14 is a partial steam flow D upstream of the container 2 Elbow 10 and the partial steam flow line 12 is withdrawn and fed to the steam system 16 behind the container 2. Here the centrifugal effect in the pipe bend 10 is used, in which Area of a water-steam stratification formed in the pipe bend 10 a subset of steam separated per unit of time becomes. The steam partial flow D arises accordingly Pressure conditions in the water separation system 1, i.e. in the container 2 and in the parallel or steam partial flow line 12, on.

The remaining water / water-steam mixture G 'overflows the inlet pipe 4 into the container 2. As a result of the enema Beam impact on walls 18 of container 2 forms a surge S, which with the speed conditions in Balance is there. Would the burden of high Vapor percentage increase, so that would be separated in the container 2 Take steam stream D 'water drops with you. This is through the upstream disconnection device 14 avoided.

The separation of water from the water / water-steam mixture G 'takes place on the walls 18 of the container 2, if that Water / water-vapor mixture G 'preferably inclined over it and tangentially arranged inlet pipe 4 flows. The Steam is initially due to the inclination of the inlet pipes 4 led downwards and after a flow reversal in the container 2 deducted axially above. The flow is through the Curve 20 shown. With increasing steam content and increasing The flow cross-section narrows under load Q so that the flow rate increases and the pressure loss increases. The separation quality would now get worse, because droplets are carried away at high speeds become. By running the partial steam flow D in parallel the container 2 this is avoided since the container 2 guided steam quantity and thus also the steam speed is now comparatively small.

In Figure 2, the container 2 is shown with two inlet pipes 4. While the one shown on the right side of the figure Elbow 10 is curved upwards, is on the tube bend 10 'shown on the left side of the figure is curved downward. Branched into the end facing the pipe bend 10 Partial steam flow line 12 is a drainage vessel 22 switched, which via a drainage line 23 with the lower region of the container 2 is connected. The drainage of the downward curved pipe bend 10 'takes place over a siphon 24 which is part of the steam partial flow line 12 '. The siphon 24 is also via a drainage line 25 connected to the lower area of the container 2. The Siphon-like configuration of the pipe bend 10 ' The end of the partial steam flow line 12 'is in FIG. 3 shown.

The partial steam flow lines 12, 12 'are to the outlet pipe 6 connected. As dashed on the left side of Figure 2 shown, the steam partial flow line 12 'can also be connected directly to the steam collection system 16. To the Influence pressure loss in the steam partial flow line 12 ', a throttle or a valve 26 is connected in this.

Although several arranged around the circumference of the container 2 Inlet pipes 4 with any combination from the top and downwardly curved pipe bends 10, 10 'may be provided can, the number of inlet pipes 4 should be limited to a few be because with an increasing number of inlet pipes 4 the Run-out ratios of that represented by curve 20 Beam is disturbed.

By branching off a partial steam flow D, D 'before the actual one Separator by means of the separator 14 is due to favorable flow conditions in the container 2 a achieved particularly high separation quality. Further can be special small dimensions of the water separation system 1 can be selected, so that particularly favorable conditions with regard to Temperature changes are given. Furthermore, the pressure loss in the water separation system 1, especially in full load operation, particularly low.

Claims (7)

1. Water separating system for separating water from a water vapour mixture (G) having at least one inlet tube (4) arranged on the periphery of a vessel (2) and having an outlet tube (6) for steam (D') provided above the inlet tube (4), characterized in that for the separation of a steam part stream (D, D'), a tube bend (10, 10') from which a steam part-stream line (12, 12') branches off, is connected upstream of the vessel (2) on the inlet side.
2. Water separating system according to Claim 1, characterized in that the or each inlet tube (4) is arranged so as to run obliquely.
3. Water separating system according to Claim 1 or 2, characterized in that the tube bend (10, 10') is curved upwards or downwards.
4. Water separating system according to one of Claims 1 to 3, characterized in that a water drainage line (23, 25) is connected to the steam part-stream line (12, 12').
5. Water separating system according to one of Claims 1 to 4, characterized in that a water drainage container (22) is connected into the steam part-stream line (12).
6. Water separating system according to one of Claims 1 to 5, characterized in that that end of the steam part-stream line (12') which faces the tube bend (10') is of siphon-like design.
7. Water separating system according to one of Claims 1 to 6, characterized in that the outlet tube (6) and the steam part-stream line (12, 12') are connected to a common steam-collection system (16).

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