Title of Invention

SEPARATOR FOR SEPARATING WATER AND STEAM

Abstract

This invention relates to Separator for a water/steam separarting apparatus. In the Prior Art generator, the wall thicknesses of pressure-carrying parts are large, which affects particularly the separators. This results in long start-up times with high start-up losses and a low-load change speed, which restricts the high flexibility of generator. The present invention provides a separator which overcomes the above mentioned disadvantages of the Prior Art. The seperator can be used in water/steam separating apparatus. In order for a separator (1) for separating water (w) and steam (D), said separator having a steam-side outlet conduit (2) and a water-side outlet conduit (3) and having a separating chamber (10) between a number of inlet conduits (5) and a swirl breaker (7) arranged upstream of the water-side outlet conduit (3), to be used to achieve the lowest possible pressure loss with a simultaneously high medim throughput and an effective separating chamber (10) is at least 5 times the internal diameter (DI) of said chamber, and theratio (K) of the overall flow cross section (F[m2]) of the inlet conduits (5) to the square of the internal diameter (DI[m]) of the separating chamber (10) is between 0.2 and 0.3. within a water/steam separating apparartus (11), the separator (1) is connected to a water-collecting tank (15) such that the top end (OK) of the latter is located beneath halfway along the length (L) of the separator (l)-calculated from the water-side, bottom end (UE) of the same.

Full Text

2 The invention relates to a separator for separating water and steam, having a steam-side outlet conduit and having a water-side outlet conduit and having a separating chamber between a number of inlet conduits and a swirl breaker arranged upstream of the water-side outlet conduit. It also relates to a water/steam separating apparatus, in particular for a continuous-flow steam generator, having at least one such separator which is connected to a water-collecting tank. DAS 1 081 474 discloses a centrifugal-force water separator in which the ratio of diameter to height is intended to be approximately 1:6 or more. Furthermore, it is known from the article by Jurgen Vollrath, entitled Dampfabscheldung bei Siedewasser und Siedeubefhitzerreaktoren, [Steam separation in boiling-water and boiling/superheating reactors], in Technische Uberwachung 9 (1968), No. 2, pages 46 to 50, to select a ratio of the diameter of a steam-side outlet conduit of a separator to the internal diameter of the separator of 52%. Furthermore, JP 1-31 23 04 A discloses a water/steam separating apparatus in which a water-collecting tank which is connected to the separator on the water side is arranged at a vertical height which is determined by the vertical height of the separator. A separator of the generic type is known, for example, from GB-A-1164996. A separator known from DE 42 42 144 Al is usually used in the evaporating system of a steam generator, in particular of a continuous-flow steam generator. Depending on the steam-generator capacity, it is often the case that a plurality of separators arranged in parallel are connected, within a water/steam separating apparatus, to a common water-collecting tank. In particular during start-up ll.l2.00 3 operation of such a continuous-flow steam generator, large quantities of water are generally produced in the evaporating system. The or each separator serves here 4 for separating water and steam, the water being guided back into the evaporator circuit and steam, as far as possible free of water droplets, being directed into a superheater. Since, in contrast to a natural-circulation steam generator, a continuous-flow steam generator is not subjected to any limited pressure, and live-steam pressures in the continuous-flow steam generator can be higher than the critical pressure of water (pcnt= 221 bar). Modern steam power plants can be operated with high steam pressures of 250 to 300 bar. High live-steam pressures are necessary in order to achieve high thermal efficiencies and thus low carbon-dioxide emissions. A particular problem here is the design of the pressure-carrying parts since such high steam pressures result in large wall thicknesses which, in turn, can reduce the temperature transmission to a considerable extent. In a continuous-flow steam generator, it is the separators in particular which are affected thereby, since in the case of load changes in variable-pressure operation, in which the steam pressure and thus also the boiling temperature in the or each separator changes linearly with the load, said separators are subjected to considerable changes in temperature. As a result, during start-up and in the case of load changes, the rate of change of temperature is limited. This, in turn, may result in undesirably long startup times with correspondingly high start-up losses and a low load-change speed, which, in turn, restricts the particularly high flexibility of the continuous-flow steam generator at least during operation with high steam pressures. The object of the invention is thus to specify a separator which is intended for a water/steam separating apparatus and which, with simultaneously low 5 pressure loss and a high degree of separation as well as the smallest possible wall thickness, is particularly thermoelastic. It is also intended to specify a suitable method of operating a water/steam separating apparatus for a continuous-flow steam generator, said separating apparatus having a number of such separators. 6 As far as the separator is concerned, the object is achieved according to the invention by the features of claim 1. For this purpose, the length of the separating chamber of said separator is at least five times the internal diameter of said chamber. In this case, the length of the separating chamber is defined by the distance between the inlet plane, which is determined by the inlet conduits of the separator, and the top edge of the swirl breaker located therebeneath. The ratio of the overall flow cross section of the inlet conduits to the square of the internal diameter of the separating chamber is between 0.2 to 0.3. The invention is based here on the finding that, in the case of a separator, in particular in the case of a cyclone separator, having a swirl breaker, the pressure loss in the separating chamber is comparatively high, whereas pressure losses caused by the steam-side outlet conduit are low. While, in the case of a cyclone separator without a swirl breaker, the considerable pressure losses occur at the inlet into the steam-side outlet conduit and in the outlet conduit itself, whereas there are only low pressure losses in the separating chamber. Taking this finding as the departure point, the invention is based on the consideration that, by virtue of the specific design of the separator, the pressure-loss components in different sections of the separator can be coordinated with one another such that, with a high medium throughput and an effective separating action, the sum thereof reaches a minimum. In this case, the pressure loss is made up of an inlet pressure-loss component and of a frictional pressure-loss component during the downward and upward flow of the water/steam mixture entering into 7 the separator and of the deflection pressure-loss component for the downward flow into the upward flow and of the inlet pressure-loss component into the steam-side outlet conduit. 8 During the operation of the separator, even in the case of a high mass flow density of M > 800kg/m2s of the medium entering into said separator, a particularly low pressure loss with a simultaneously good separating action is achieved. The mass flow density is defined here as the throughput in [kg/s] divided by the cross-sectional surface area in [m2] determined by the internal diameter in [m] of the separator and thus of the separating chamber of the same. Furthermore, the lowest possible pressure loss with the simultaneously highest possible degree of separation is achieved in that the overall cross-sectional surface area F [m2] , determined by the sum of the cross-sectional surface areas or flow cross sections of the inlet conduits, and the internal diameter DI [m] of the separator or of the separating chamber of the same satisfy the relationship F = K • DI2, where K = 0.2 to 0.3, preferably K = 0.21 to 0.26. In this case, the internal diameter DA [m] of the steam-side outlet conduit is preferably 40% to 60% of the internal diameter of the separator. In respect of the arrangement of a number of such separators within a water/steam separating apparatus, in which, for example, three or four separators are connected to the common water-collecting tank on the water side, this particularly low pressure loss with a simultaneously high degree of separation is also advantageously assisted, even with a high mass flow density of the medium of more than 800 kg/m2s, in that the top end of the water-collecting tank does not project beyond half of the axial extent of the separator. In relation to the water-side, bottom end of the separator, the top end or the top edge of the water-collecting tank should be located in this case beneath halfway along the length of the separator. As far as the method is concerned, said object is achieved according to the invention by 9 the features of claim 4. Accordingly, particularly advantageous results are achieved in the case of a continuous-flow steam generator having at least one separator if 10 if the throughput through the separator at full load of the continuous-flow steam generator is more than 630 times the square of the internal diameter of the separating chamber. Exemplary embodiments of the invention will be explained in more detail with reference to drawing in which: Figure la shows a separator having a swirl breaker, in longitudinal section, Figure lb shows the separator according to figure 1, in cross section, and Figure 2 shows a water/steam separating apparatus having a separator according to figure 1, with a water-collecting tank connected on the water side. Parts which correspond to one another are provided with the same designations in both figures, Figure 1 shows a separator or cyclone separator 1 in longitudinal section (figure la), the cross section being illustrated in figure lb. The separator 1 has a top, steam-side outlet conduit 2 and a bottom, water-side outlet conduit 3. Inlet conduits 5 which are distributed on the circumference of the separator 1 and are intended for a water/steam mixture WD which is to be separated into water W and steam D are provided beneath the steam-side outlet conduit 2, in an inflow or inlet plane E, which is located in the vicinity of the inlet opening 4 of said outlet conduit. In this case, the inlet conduits 5, on the one hand, are inclined at an angle a to the horizontal H and, on the other hand, are arranged tangentially. Beneath the inlet plane E of the inlet conduits 5, supporting brackets 7 are provided on the wall 8 of 11 the separator 1 and retain the latter in its installation position. By virtue of this arrangement of the inlet conduits 5, the water/steam mixture WD flowing into the separator 1, on the one hand, is guided downward in the direction of the base region 6 of the separator 1 12 and, on the other hand, is provided with a swirl in the process. Water W and steam D are separated here by centrifugal force, the steam D being guided away upward, and the water being guided away downward, centrally. In order to break the swirl in the water W flowing out via the outlet conduit 3, a swirl breaker 9 is provided in the base region 6 of the separator 1. Said swirl breaker prevents steam D from being entrained into the outlet conduit 3 and forms an obstacle to already separated water W being fed back into the separator 1, i.e. to a backflow into the separating chamber 10 of the same. In order to achieve the smallest possible wall thickness d of the wall 8 of the separator 1 with a simultaneously high degree of separation, the length A of the separating chamber 10 of the separator 1, said chamber being defined between the inlet plane E and the top edge B of the swirl breaker 9, is at least 5 times the internal diameter DI of the separator 1. Furthermore, the ratio K between the overall cross section F of the inlet conduits 5 and the square of the internal diameter DI of the separator 1, and thus of the separating chamber 10, is between 0.2 and 0.3, preferably between 0.21 and 0.26. In this case, the overall cross section F is determined by the sum of the individual flow cross sections f1 to fn where n = 4 in the exemplary embodiment. Furthermore, the steam-side outlet conduit 2 expediently has an internal diameter DA which is between 40% and 60% of the internal diameter DI of the separating chamber 10. In respect of the overall cross section F [m2] and of the internal diameter DI [m] of the separator 1 or separating chamber 10 and of the internal diameter DA [m] of the steam-side outlet conduit 2, the following dimensional relationships thus preferably apply: F = K • DI2 where K = 0.21 to 0.26 DA = (0.5 ± 0.1) • DI, and A > 5 • DI, 13 Figure 2 shows a water/steam separating apparatus 11 of a continuous-flow steam generator, of which only the evaporator 12 and the superheater 13 are schematically illustrated. The water/steam separating apparatus 11 comprises one or more separators 1 according to figure 1. The or each separator 1 is connected to a water-collecting tank 15 on the water side via a connecting line 14 connected to the outlet conduit 3 of said separator. The introduction of the connecting line 14 from the separator 1 into the water-collecting tank 15 expediently takes place beneath the water level WS of said tank, with the result that a calm water surface is ensured. Within the water/steam separating apparatus 11, the or each separator 1 and the water-collecting tank 15 are preferably arranged in relation to one another such that the top end or top edge OK of said tank reaches at most halfway along the length L of the separator 1. In this case, the length L is measured between the top end OE and the bottom end UE of the separator 1, Halfway along the length (1/2 L) relates to the bottom end UE of the separator, and is thus measured from there. During operation of the water/steam separating apparatus 11 of the continuous-flow steam generator, the water/steam mixture WD produced in the evaporator 12 of said generator flows, via the inlet conduits 5, into the separator 1 and is provided with a swirl there on account of the at least more or less tangential inflow. As a result of the centrifugal force thereby caused, water W and steam D are separated from one another. The separated steam D flows into the superheater 13 of the continuous-flow steam generator 13 via the steam-side outlet conduit 2 and a steamline 16 connected thereto, while the separated water W flows out into the water-collecting tank 15 via the swirl breaker 9 and the connecting line 14. In this 14 case, the internal diameter DI of the separating chamber 10 and the throughput M [kg/s] through the separator 1 in relation to the full-load operation of the continuous-flow steam generator satisfy the relationship M > 630 • DI2. 15 Using a separator 1 of such a design and arranging the same within the water/steam separating apparatus 11 of the continuous-flow steam generator, it is possible to realize steam or live-steam pressures of 250 to 300 bar with a simultaneously low pressure loss and high medium throughput and particularly effective separation. Overall, in a steam power plant operated using such a separating apparatus 11, particularly high efficiency is achieved. 16 WE CLAIM DATED THIS 12TH day of February 1. Separator for separating water and steam, having a steam-side outlet conduit (2) and having a water-side outlet conduit (3) and having a separating chamber (10) between a number of inlet conduits (5) and a swirl breaker (9) arranged upstream of the waterside outlet conduit (3), characterized in that the length (A) of the separating chamber (10) is at least five times the internal diameter (DI) of said chamber, and in that the ratio K of the overall flow cross section (F[m2]) of the inlet conduits (5) to the square of the internal diameter (DI[m]) of the separating chamber (10) is between 0.2 and 0.3. 2. Separator as claimed in claim 1, wherein the steam-side outlet conduit (2) has an internal diameter (DA) which is 40% to 60% of the internal diameter- (DI) of the separating chamber (10). 3. Water/steam separating apparatus having at least one separator as claimed in claim 1 or 2, and having a water-collecting tank (15) which is connected to the separator (1) on the water side and of which the top end (OK) is located beneath halfway along the length (L) of the separator (l)-calculated from the water-side, bottom end (UE) of the same. 4. Method of operating a water/steam separating apparatus having at least one separator (1) for a continuous-flow steam generator, in which the throughout M [Kg/s] through the separator (1) at full load of the continuous-flow steam generator and the internal diameter (DI[m]) of the separating chamber (10) satisfy the relationship M > 630.DI2. This invention relates to Separator for a water/steam separarting apparatus. In the Prior Art generator, the wall thicknesses of pressure-carrying parts are large, which affects particularly the separators. This results in long start-up times with high start-up losses and a low-load change speed, which restricts the high flexibility of generator. The present invention provides a separator which overcomes the above mentioned disadvantages of the Prior Art. The seperator can be used in water/steam separating apparatus. In order for a separator (1) for separating water (w) and steam (D), said separator having a steam-side outlet conduit (2) and a water-side outlet conduit (3) and having a separating chamber (10) between a number of inlet conduits (5) and a swirl breaker (7) arranged upstream of the water-side outlet conduit (3), to be used to achieve the lowest possible pressure loss with a simultaneously high medim throughput and an effective separating chamber (10) is at least 5 times the internal diameter (DI) of said chamber, and theratio (K) of the overall flow cross section (F[m2]) of the inlet conduits (5) to the square of the internal diameter (DI[m]) of the separating chamber (10) is between 0.2 and 0.3. within a water/steam separating apparartus (11), the separator (1) is connected to a water-collecting tank (15) such that the top end (OK) of the latter is located beneath halfway along the length (L) of the separator (l)-calculated from the water-side, bottom end (UE) of the same.

Documents:

in-pct-2001-00174-kol abstract.pdf

in-pct-2001-00174-kol claims.pdf

in-pct-2001-00174-kol correspondence.pdf

in-pct-2001-00174-kol description(complete).pdf

in-pct-2001-00174-kol drawings.pdf

in-pct-2001-00174-kol form-1.pdf

in-pct-2001-00174-kol form-18.pdf

in-pct-2001-00174-kol form-2.pdf

in-pct-2001-00174-kol form-5.pdf

in-pct-2001-00174-kol g.p.a.pdf

in-pct-2001-00174-kol latters patent.pdf

in-pct-2001-00174-kol priority document others.pdf

in-pct-2001-00174-kol priority document.pdf

IN-PCT-2001-174-KOL-(17-10-2012)-FORM-27.pdf

IN-PCT-2001-174-KOL-FORM-27.pdf

in-pct-2001-174-kol-granted-abstract.pdf

in-pct-2001-174-kol-granted-claims.pdf

in-pct-2001-174-kol-granted-description (complete).pdf

in-pct-2001-174-kol-granted-drawings.pdf

in-pct-2001-174-kol-granted-form 2.pdf

in-pct-2001-174-kol-granted-specification.pdf

IN-PCT-2001-174-KOL-OTHER PATENT DOCUMENT.pdf

in-pct-2001-174-kol-priority document.pdf

in-pct-2001-174-kol-translated copy of priority document.pdf