SU1211508A1 - Spray attemperator of steam turbine exhaust part - Google Patents

Description

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The invention relates to energy and can be used to cool the exhaust parts of steam turbines in start-up and low flow conditions.

The purpose of the invention is to improve the reliability of the desuperheater by improving the quality of the spray and the efficiency of humidification of the steam discharged into the exhaust part of the turbine.

Fig. 1 of the invention, the scheme of the proposed desuperheater, cross section; FIG. 2 shows a section A-A in FIG. 1; FIG. 3 shows a water supply device in the form of a central transverse rib; Fig. 4 is an embodiment of the hole in the edge in the form of a nozzle (node, I in Fig. 3); Fig. 5 is a diagram of the formation of droplet flows.

The injection desuperheater is installed in the waste steam pipe 1, connecting the boiler with the exhaust turbine part (not shown) through the steam recovery device (PSbu). The steam desiccant input into the steam space of the EXHAUST 10 turbine part is made taking into account the rotor rotation through the side wall between the exhaust a pipe and a condenser tube bundle (not shown). The desuperheater includes a mixer with three successively arranged parts 2-4, respectively, confused narrowed, cylindrical, and diff Zorn and y vodopodvod present device in the form of a central transverse ribs 5 of streamlined shape, located in konfuzorkoy part mixer 2. The rib 5 is divided by a partition 6 into two chambers 7 and 8, arranged successively on xo / iiy steam, and communicated through pipelines 9 and 10 of the supply of fluid with regulating 11 and shut-off 12 organs, as well as through a common locking member 13 with a source of coolant with a condensate or a booster pump, a power unit) “The lower section of the second chamber 8 is connected to the drainage pipe- 14 via the shut-off element 15 to the condenser а (not shown) through the vapor space of the lower part.

 The cylindrical wall of the first chamber 7 has injection holes 16-18. In the second chamber 8, the walls of which form a T in a & pnut edge of the rib, the holes are filled

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in the form of slits 19, the ribs 5 are also located symmetrically on both sides in the immediate vicinity of its exit edge. Rib section

5, occupied by injection holes or slitsJ limited by visors 20 mounted on the edge 5 parallel to the surface of the confuser part 2. The holes 16-18 may be

made in the form of nozzles 21 (figure 4), the holes 16-18 of the chamber 7 are located symmetrically relative to the longitudinal axis of the rib 5 on both sides of its entrance edge and have axes forming ANGLES with it (f, g, o; |,, g, decreasing along the steam, i.e. "a :, (ig (Fig. 3), on which, together with the hole 16 located in the center of the rib 5, there are conventionally marked holes 17 and 18 of the peripheral portions of the rib 5. The location of the ISIS holes with decreasing angles along the pair between the axes of these holes and the axis of the rib 5 allows

uniform filling of the desuperheater volume with dropping moisture (Fig. 3), this is due to the fact that changing the injection angle allows to achieve different penetrating properties emanating from the orifices of the jets with the same diameter (the diameter of one is the minimum of the conditions for eliminating the risk of jet plugging). It has been established experimentally that the greatest depth of penetration of the jets is reached at an injection angle of 130. As the angle of injection decreases, the jet penetration ability decreases. So in the middle of the rib,

as the furthest from the walls of the desuperheater, the hole 16 is made at the greatest angle of injection. As the periphery of the rib 5 approaches, the corners of the openings 17 and 18 in the chamber 7 are reduced.

Injecting desuperheater operates as follows.

At start-up modes, as well as idling and low-load modes, the steam discharged from the boiler through the safety valve and the steam expander are supplied via a waste steam line 1 EO with an injection desuperheater. In this case, the locking body 15 and the total locking

The organ 13 is open, and the locking organ 12 is closed. The condensate through the pipeline 9 through the regulatory authority 11 is served in the first chamber. 7, and from there.

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through injection holes 16-18 to confusor part 2. Penetrating into a high-speed core of the steam dispersed in confusor part 2, the liquid jets are crushed and moistened.

The cooling steam pipe ejected from the desuperheater to the jet is picked up by reverse currents and, moving into the exhaust manifold, realizes heat removal,

In modes with low costs of the condensate, droplet jet torches at the outlet of injection holes 1b-18 are partially pressed by the steam flow to the walls of the rib 5 and form a film or a stream flow on them. This wall current, limited by the length of the rib with peaks 20, moves to the slots 19 and under the influence of positive pressure drop on them is diverted into the second chamber 8, and from there through the pipeline 14 through the stop valve 15 drains into the lower part of the condenser. Thus, the formation of enlarged edge moisture behind the fins 5 is eliminated, which ensures at the outlet of the desuperheater the existence of only a homogeneous finely dispersed structure of droplet jets formed by a high-speed steam flow.

When changing the parameters of steam discharged from PSB, due to

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the mode of operation of the boiler, the optimum temperature. The exhaust part of the turbine is maintained by a control system, which, acting on the regulator 11 (valve), provides the necessary flow of condensate to the first chamber 7.

As the unit is loaded, the steam discharge through the safety valve into the condenser decreases and simultaneously with the closing of the steam valve, the safety valve closes the general shut-off member 13 (valve), stopping the supply of coolant, and shut-off member 15 through the drainage duct 15. Regulator 11 and shut-off member 12 set to full open. In this state, ready for an emergency load shedding by the unit, the system remains for a period of time while the unit is turned on in the power system.

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During an emergency load shedding, when the PSbu steam valve is triggered and the steam flow through the exhaust steam line 1 is significantly higher than this value during start-up and idling modes, the protection system opens a general shut-off valve.

organ 13 and the condensate are fed simultaneously to both chambers 7 and 8, which ensures reliable cooling of the low pressure cylinder at an acceptable level.

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VNIISH (Lalaz 627/42 Circulation 399 Subscription Branch of the PPP Patent, Uzhgorod, Proektna St., 4

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Claims (4)

1. Injecting steam cooler of the EXHAUST part of a STEAM TURBINE, comprising a mixer installed in the condenser discharge pipe, in the confluent part of which there is a water supply device divided by a baffle into two chambers connected to the liquid supply pipelines with injection holes in the walls, characterized in that, in order to increase reliability in order to by improving the quality of the spray, the water supply device is made in the form of a central transverse rib, and the chambers are arranged sequentially one after the other nth in the direction of the steam, the injection holes of the first of them being located symmetrically with respect to the longitudinal axis of the rib · on both sides of its inlet edge and have axes forming angles with the axis of the rib, decreasing along the steam. 2. The desuperheater according to claim 1, which is sprayable. The opening holes of the first along the steam chamber are made in the form of nozzles. . 3. Desuperheater according to claim 1, characterized in that the injection holes of the second along the steam chamber are made in the form of slots located near the edge of the ribs. 4. Desuperheater according to claim 1, characterized in that the second chamber along the steam chamber is in communication with the lower part of the condenser. > .1