JP5744687B2 - Deaerator - Google Patents

Description

  The present invention relates to a deaerator, and more particularly to a deaerator for a power plant.

  A deaerator for a power plant performs deaeration and heat exchange of condensate with turbine bleed steam. As a deaerator for a power plant, a spray tray deaerator is used. The spray tray type deaerator injects condensate (water supply) from the spray valve at the top of the deaeration chamber, exchanges heat by direct contact between the condensate spray particles and steam, and operates the condensate spray particles at the operating pressure. The oxygen is degassed by raising the temperature to the saturation temperature corresponding to. Furthermore, the condensate spray particles raised to the saturation temperature are caused to meander by a deaeration tray provided below the spray valve, and further degassed by contact with the rising vapor in the deaerator tray. As such a deaerator, there exists a thing of patent document 1, for example.

JP 2000-262809 JP

  In the spray tray type deaerator, when the pressure in the deaerator drops in a special operating environment such as during trial operation, the water is blown up by the flush inside the water supply outlet pipe at the bottom of the deaerator, It may damage the installed deaeration tray. In Patent Document 1, countermeasures against deaeration tray damage are taken by installing a protective member or the like. However, when a protective member is provided, its maintenance, replacement, etc. are required. If the deaeration tray itself can be deleted, the potential for damage caused by flash can be eliminated and maintenance-free can be realized.

  The objective of this invention is providing the deaerator which can exhibit sufficient deaeration performance, without a deaeration toilet.

  The present invention is characterized in that a mechanism for refining spray particles from the spray valve in the vicinity of the spray valve outlet is provided.

  As a mechanism to refine the spray particles near the spray valve outlet, for example, a structure in which high-speed steam is sprayed from the rear of the spray valve outlet, the spray particles from the spray valve are further refined, and sprayed into the deaerator body is used. It is done.

  According to the present invention, the spray particles are made finer in the vicinity of the spray valve outlet to increase the specific surface area, so that deaeration with the extracted steam can be efficiently performed, and sufficient deaeration is possible even without a deaeration toilet. It can demonstrate its performance.

The figure which shows the structure of the deaerator which is one Example of this invention. The figure which shows the relationship between the spray particle diameter which shows the effect by this invention, and temperature. The figure which shows the spray condition of spray valve exit vicinity. The figure which shows the spray condition of the spray valve exit vicinity at the time of making the spray valve outlet shape which is one Example of this invention into the waveform. The figure which shows the condition in the deaerator body when the cover board around a spray valve is not provided. The figure which shows the condition in the deaerator body at the time of providing the cover board around the spray valve which is one Example of this invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  The structure of the deaerator which is one Example of this invention is shown in FIG. Condensate condensed in the condenser passes through the condensate inlet 1 and is led to the deaerator (if necessary, the condensate is heated by the low-pressure feed water heater and then led to the deaerator). Condensate from the condensate inlet 1 is introduced as spray particles 4 into the deaerator body 3 by the spray valve 2.

  In the conventional deaerator, the spray particles 4 are heated by direct contact with the turbine extraction steam 6 introduced from the steam inlet nozzle 5 into the deaerator body 3, and the non-condensable gas (dissolved oxygen) is deaerated. . The spray particles 4 meander down the deaeration tray to promote the second deaeration.

  In the deaerator, most of the deaeration is performed by heating in the extraction steam, and if the spray particles can be made finer near the outlet of the spray valve, the specific surface area becomes large and sufficient deaeration is possible even without a tray. It is thought that it becomes. The current spray valve has a structure in which condensate is ejected in the circumferential direction as shown in FIG. 3A from a gap formed by pushing a valve element closed by a spring with the pressure of condensate inside the valve. Yes. In the spray from the spray valve having such a structure, spray particles are large, and a deaeration tray is required to ensure the deaerator performance.

  In this embodiment, as a mechanism for refining the spray particles near the outlet of the spray valve, a high-speed steam jetting part 10 that creates high-speed steam 9 installed behind the spray valve 2 is used. By spraying the high-speed steam 9 on the spray particles 4 from the spray valve 2, the spray particles 4 are further refined and dispersed in the deaerator body.

  FIG. 2 shows the relationship between the spray particle size and the temperature. The smaller the diameter of the spray particles 4, the easier it is heated from the outer surface, and the deaeration efficiency increases. Since it is heated and degassed by direct contact between the spray particles 4 and the turbine extraction steam 6, degassing efficiency is increased by further miniaturizing the spray particles 4 and increasing the specific surface area, and it is sufficient even without a degassing tray. A deaerator with deaeration performance becomes possible.

  Further, in this embodiment, as shown in FIG. 1, high-speed steam 8 is blown onto the spray particles 4 from the spray valve 2, so that the spray particles 4 in the deaerator body and the agitation 11 of the turbine extraction steam 6 are removed. Gas and heat exchange is further promoted.

  According to the present embodiment, as compared with the conventional spray toilet type deaerator, the contact area with the extracted steam is increased and the deaeration performance can be improved by making the spray particles finer. As a result, even if the deaeration tray is removed, sufficient deaeration can be performed. Therefore, the potential of deaerator damage in a special operating environment such as a trial operation (water storage is blown up by the flash inside the water supply outlet pipe 8 at the bottom of the deaerator) , The potential of damaging the deaeration tray installed in the upper part of the water storage section is reduced.

  In this embodiment, as a mechanism for refining the spray particles near the spray valve outlet, a device that further refines the spray particles near the spray valve outlet by devising the outlet structure of the spray valve is used.

  Since the outlet shape of the conventional spray valve 2 is a linear shape as shown in FIG. 3A, the condensate is in the form of a sheet near the outlet as shown in the lower part of the figure. The sheet condensate 12 is granulated after diffusion.

  In the present embodiment, as shown in FIG. 3B, the outlet shape of the spray valve 2 is changed to a wave-like outlet shape 13 so that the jet outlet is made thinner and thinner so that the spray particle diameter from the spray valve is reduced. With this wavy condensate outlet structure, the jet water can be made thinner, the spray particles near the outlet of the spray valve can be made finer, and heat exchange with the extracted steam is promoted.

  Furthermore, by combining with the above-mentioned Example 1 (spraying the high speed steam 8 from the back of the spray valve 2), further refinement of the spray particles 4 and stirring of the spray particles 4 and the turbine extraction steam 6 in the deaerator body can be achieved. Facilitates degassing and heat exchange.

  According to the present embodiment, the deaeration performance can be improved as in the first embodiment, and the potential for deaerator damage in a special operation environment such as a test operation is reduced.

  In this embodiment, a deaeration efficiency is improved by providing a cover plate near the outlet of the spray valve.

  As shown in FIG. 4A, when the cover plate is not provided, the spray particles 4 ejected from the spray valve 2 and further refined by the high-speed steam from the high-speed steam ejection section 10 are heat-exchanged with the turbine extraction steam. . However, when it adheres to the deaerator body 3 and becomes droplets 15, heat exchange with the extracted steam is not sufficiently performed, and the droplets are dropped on the water storage portion along the inner surface of the body without being deaerated.

  In this embodiment, as shown in FIG. 4B, a cover plate 14 is provided around the condensate outlet portion of the spray valve 2. Originally, undeaerated water dripping on the inner surface of the fuselage is captured on the inner surface of the cover plate 14, and high-speed steam is blown into the cover plate from the high-speed steam jetting portion 10 located behind the spray valve 2 and stirred. It becomes possible to lead to miniaturization, and it becomes possible to heat and deaerate again.

  In addition, since the opening part is provided so that the cover board 14 of a present Example may not be located in the upper part of the feed outlet pipe of the lower part of a deaerator, possibility of damage by the flash inside a feed outlet pipe is low.

  According to the present embodiment, the same effects as in the first embodiment can be obtained, and in particular, the deaeration performance can be further improved. In addition, this embodiment can be combined with the above-described embodiment 2, and in this case, the deaeration performance can be further improved.

DESCRIPTION OF SYMBOLS 1 ... Condensate inlet, 2 ... Spray valve, 3 ... Deaerator body, 4 ... Spray grain, 5 ... Steam inlet nozzle, 6 ... Turbine extraction steam, 8. ..Supply water outlet pipe, 9 ... high speed steam, 10 ... high speed steam jetting part, 11 ... state of stirring of spray particles and steam, 12 ... sheet-like condensate, 13 ... wavy Exit shape, 14 ... cover plate, 15 ... droplet.

Claims (3)

A deaerator that introduces condensate as spray particles into a deaerator body by a spray valve and heats the spray particles by direct contact with turbine bleed steam introduced into the deaerator body. And
Provide a mechanism to refine the spray particles near the outlet of the spray valve ,
The deaerator according to claim 1, wherein a high-speed steam jetting part for spraying high-speed steam near the outlet of the spray valve is provided in the deaerator body as a mechanism for refining spray particles near the spray valve outlet . According to claim 1, as a mechanism for refining the spray particle in the spray valve near the outlet, further deaerator, characterized in that the outlet shape of the spray valve and wavy. 3. The deaerator according to claim 1 , wherein a cover plate having an opening toward the lower part of the deaerator is provided in the vicinity of the spray valve outlet.

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