RU1791692C - System preventing pollution of stream turbine condenser - Google Patents

Abstract

Steam turbine condenser pollution prevention system. The invention relates to a power system and can be used to prevent pollution of steam turbine condensers. The filter in the form of a perforated cone, placed B in the pressure pipe of the condenser, is directed by the base of the cone towards the flow of cooling water. Inside the cone there are built-in flat radial partitions, dividing it into two sections: -n1 volume into compartments, each of which is equipped with a sector damper at the entrance and an autonomous contamination removal line at the exit. 1 C.p. f-ls, 2 ill.

Description

The present invention relates to the field of power engineering and can be used to prevent pollution of steam turbine condensers. The impurities are deposited in the condenser tubes and clog their inlet portions in the tube plates, which causes an increase in the hydraulic resistance of the condenser, a decrease in the vacuum in it, and ultimately a deterioration in the efficiency and reliability of the steam turbine units. Condensation-cooling water filters. tori located on the coastal pumping room, do not provide its effective cleaning. This is due to the partial passage of pollution through them, as well as the fact that colonies of various types of molluscum are very often disconnected between these filters and the condenser in long circulating circulating water supply systems. A fresh cooling water filter directly in front of the turbine condenser. When porous rubber balls are used to clean condenser tubes, the filter in front of the condenser is an essential element of this ball cleaning. These filters work under specific conditions of increased cooling water consumption (for example, on a 300 MW turbine, the water consumption per filter is about 18 thousand m / h), various pollution (stones, pieces of ice and wood, shells, fish, leaves long algae, etc.), significant water velocities (2-3 m / s) and in the absence of a specially designed place for the filter. In addition, during operation, zlzposy infusions of large quantities of sludge, leaves, river and water are possible with cooling water, capable of completely clogging holes in the filtering surface in a matter of seconds. This is going to

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a sharp decrease in the flow of cooling water entering the condenser and, as a consequence, an emergency shutdown of the turbine, which is unacceptable. Therefore, such filters must have a reliable system for cleaning the filter surface.

Also known is a preventive system. no pollution of the condenser 1 containing a filter in the form of a perforated cone located in the condenser cooling water conduit with a mechanism for cleaning it during operation, made in the form of a pump and two nozzle systems, the first of which is placed tangentially to the axis of the conduit in front of the top of the cone, and the second rotating nozzles - inside the cone, perpendicular to its lateral surface.

The disadvantage of this system (prototype), in addition to the considerable length and high hydraulic resistance of the filter, is a complicated and uneconomical method of washing. Operating experience has shown that the washing system with pressure nozzles is not reliable.

The aim of the proposed invention is to increase efficiency and reliability, as well as reducing metal consumption. . The goal is achieved in that in the system for preventing pollution of the condenser of a steam turbine containing a filter surface located in the pressure conduit in the perforated cone truss, a device for cleaning it during operation and a line for removing impurities, according to the invention, the filter surface is directed towards the flow with the base of the cone , and inside the cone are built flat radial partitions that divide its internal volume into compartments, each of which is equipped with a sector bed at the water inlet Coy with a radial axis of rotation, and on an output - pipe connected battery line to remove contaminants from the discharge conduit of the condenser. The taper angle of the filter surface is advantageously carried out in the range from 15 to 35 °.

Causal relationship; with the above distinguishing features and purpose, the cone is divided into compartments with flat radial baffles, the base directed towards the flow, conditions are created for the efficiency of the crawling of the garbage BODA moving through the flow through the unloading door and atatmsmuyu LMZ in a continuous circulation conduit. In case of extreme situations (leaf fall, storm, ice drift), in which an unintended supply of leaves, algae, sludge, etc., is possible, sectorial dampers with a radial axis of rotation are installed at the inlet of the compartments, which provide alternate washing of the compartments with a reverse

BODIES.

With such a decontamination scheme

0 there is no need to use as a prototype a complex system of washing the filter surface with power water flowing out under pressure from nozzles, which requires the installation of a special pump, vrz5 (a collector with radial pipes for supplying water to the nozzles, an electric or hydraulic motor that provides this rotation, a filter for washing power water to prevent clogging of nozzles, as well as tangentially placed nozzles for swirling the flow. Obviously, the rejection of these elements, some of which are often failure, increase reliability

5 systems. Its economy is enhanced by eliminating the cost of operating an additional pump, reducing hydraulic resistance and other factors. The implementation of the filter with a taper angle of

0 recommended ranges from 15 to 35 ° compared with an angle of 8-12 °, as with previously used domestic filters (see analog), leads to a decrease in its length and metal consumption and the corresponding

5 reduce capital costs. All these activities contribute to the achievement of goals.

In FIG. 1 schematically shows in side section a condenser of a steam turbine,

0 equipped with the proposed pollution control system; figure 2 is a view along arrow A of the inlet section of the conical filter.

Condenser 1 with tubes 2, pipe

5 with a board 3, pressure A and drain 5 water conduits is equipped with a filter located directly in front of it in the pressure water conduit, having a conical filter surface 6 with holes 7 and a base 8 directed towards the water flow. Inside the cone there are built-in radial partitions 9, dividing its internal volume into compartments 10 with dampers 11 having an actuator 12 and a radial axis 5 along the gate 13, at the inlet and nozzles 14 connected to the lines 15 to remove pollution at the outlet. The porous balls 16 are for cleaning the condenser tubes, the mesh 17 for them. es-livani st., pump 13 - dl supported: s them

closed loop circulation. A water-jet ejector 19 can be used with a working rim pipe 20 mounted on the bypass lines 15. It is designed to further reduce the pressure in the compartment 10 at a low pressure of water into the water conduit 4.

The system operates as follows. Cooling water enters the condenser 1 through the discharge conduit 4 and is discharged through the drain 5. When it passes through the opening 7, the impurities contained therein are separated on the filter surface 6 and carried by the flow moving along this surface to the nozzles 14 through which they enter line 15 and further into the water conduit 5 after the sharm-catching net 17 along the flow. However, some types of pollution (especially with an increase in the concentration of debris in the water, are delayed on the inner surface of the cone, which leads to gradual clogging of the holes 7 and an increase in the pressure drop on the filter surface. When the value of this drop reaches the maximum permissible value, a signal is given to alternate rotation by 90 ° of the shutters 11, carried out with the help of the actuator 12. At the same time, the filtering surface of each compartment 10 is cleaned up with the return water flow and the pollution is removed through the same lines 15. В In case of need, simultaneously turning the damper 11 of one of the compartments 10, a water-jet ejector is switched on on the lines 15 corresponding to this compartment. After removing the impurities and reducing the filter resistance to the calculated value, the damper is returned to its initial position along the flow direction, at which their influence on hydraulic resistance the filter is minimal.

Studies conducted at the VTI hydraulic bench showed (test report is attached) that removing contaminants from the filter surface by creating a backflow through the openings with the shutter closed is much more efficient than removing contaminants with pressure jets from its clean side, like the analog and prototype. When the shutter moves, debris particles pressed to the surface undergo alternating influences of the flow, which contribute to their separation from the surface and drift into the line for specific pollution.

Ispjdovzim showed. that with an increase in the angle between the generatrix and the height of the cone (the taper angle of the comic filter) from 15 to 30 °, the ratio of the total

the area of the holes to the cross-sectional area of the pipeline decreases sharply, and the coefficient of resistance, irrespective of the direction of flow, changes insignificantly (by 10-12%).

With an increase in the angle a and a corresponding decrease in the length of the filter, the efficiency of the effect of vortex flows on the separation of pollution from the surface and its washing increases. In addition, the filter with an angle of c-25-300 has a significantly lower metal consumption compared to the analogue and prototype, which were performed with d 10-12 °. With decreasing angle, the total area of the openings of the filtering surface also decreases, on which, in direct proportion, the cross-sectional area depends on the area to be removed from the soil. The latter, in turn, at a given pressure drop between the water conduits determines the flow rate of cooling water bypassing the condenser, which affects the efficiency of the system. The difference between the conduits is determined by the hydraulic resistance of the condenser and, under nominal conditions, is about 4 mW.

Thus, the implementation of this proposal makes it possible to abandon the use of washing the filter surface with power water using a complex and unreliable rotating collector with pressure nozzles, equipped with an electric or 5-hydraulic drive, seals, pressure pump; power water filter and so on. Instead of all these elements, when the cone is positioned with the base facing the flow, rotary dampers are installed, upon closing of which, for several seconds, the filter surface is washed away with water backwash, after which the damper is returned to its original position. Reliability: the 5th ability of the rotary mechanism of the dampers is incomparably higher than the hydraulic washing systems, and the costs associated with bypassing an insignificant water flow rate (3-4%) through the lines for removing impurities other than the condenser are less than for hydraulic washing, the use of which oh also leads to an increase in the total hydraulic resistance of the filter.

Claims (2)

5 The advantage of this system is its spaciousness and the ability to self-cleaning HUio filter; e czg1 surface during operation. The inclusion of rotary water heat pumps is only offered in extreme situations with an excessive increase in the content of cooling water pollution usually occurring during periods of high water, leaf fall, strong wind, etc. The system is devoid of rotating parts, additional filter pumps, which guarantees its reliability. It is introduced at large power units manufactured at the S. Kirov Kharkov Turbine Plant (PO Turboatom). SUMMARY OF THE INVENTION 1. A system for preventing pollution of a condenser of a steam turbine, comprising a perforated cone filter arranged in a pressure conduit of cooling water, a device for cleaning it during operation and a line for removing contaminants, characterized in that, in order to increase economy and reliability, the base of the perforated cone is directed towards the flow of cooling water, the inner volume of the cone is equipped with flat radial partitions that divide it into compartments, each of which at the inlet of the flow of the cooling hearth has a sector damper with a radial axis of rotation, and at the outlet there is a pipe in communication with the mucous conduit of the condenser. 2. Pop 1 system with in that, in order to reduce the metal consumption, the opening angle of the cone is 15-35 °.