DE6604577U - USE FOR CHIMNEYS OF THERMAL POWER PLANTS - Google Patents

Description

SIEMENS AKTIENGESELLSCHAFT Akt.Z .: S 48 352 / 24k Gbm Berlin url Munich ^^ _character ^ _{64 / U89}

Skn / Tue

G S3M (6 69) D "yr" d "" Patent Office. Gtbraudifmusteratolls

Use for chimneys of thermal power plants

The innovation relates to a use for chimneys of combat or gas power plants or similar thermal Power plants whose exhaust gases have to be discharged at a greater height. Chimneys of this type usually consist of a flue gas leading Tube, depending on the chemical nature of the Gases in steel, fireclay or in acid-proof jointed special stone is created. One made in concrete or masonry outer hollow column of larger diameter represents the load-bearing structure and absorbs loads and wind forces. The lining for the flue gas routing is usually located directly on the inner wall of the outer column.

With this structure of the chimneys, the outer column is warmed up relatively evenly from the inside by the exhaust gases from the power plant and acted upon differently from the outside in terms of location and time and e.g. depending on the time of day and time of year, sunny sand etc. now warmed up, now cooled down. As a result of the even but relatively high heating inside, the leads to a substantial increase in thermal stress, which is unevenly over the length and above all Distributed over the perimeter of the chimney, it is necessary to provide iron armies, which can be considerable Mean effort and cost. The innovation avoids these disadvantages by means of an Eipsptz with the formation of an inner one Guide channel for the exhaust gases and an outer ring channel3 to Discharge of the combustion air.

The innovation is that the insert as inherently heat

- 2 ~ Akt.ZIVS * 48 552 / 24k Gbm '"

Our reference: VPA 64/1189 GM

Skn / Tue

insulating jacket is formed, but the thermal insulation of the same is reduced to a small extent in places is that under a total of only slight heat extraction from the exhaust gas flow and under only to safely avoid the risk of air filter icing sufficient heating of the fresh air locally different heat transfer values for the fresh air flow and the fresh air flow to equalize the temperature distribution caused by one-sided solar radiation can be pulled from the chimney wall. The inner one The insert forming the jacket between the air ring duct and the flue gas duct does not need to be and can be designed to be self-supporting thus, for example, made of heat-insulated sheet metal or wrought iron, asbestos cement or other in relation to the outer wall of the chimney thin-walled materials «exist.

The thermal insulation of the inner jacket can be locally extended so far reduce that a slight warming of the exhausted combustion air through the exhaust gases by one or a few degrees Celsius takes place, in order to ensure the supply of supercooled air impede. This means that the air can also be heated above the dew point caused by pressure and humidity.

The innovation is to be explained in more detail using the drawing. The figures show two exemplary embodiments in their for the New essential parts in a greatly simplified schematic representation. Same or corresponding parts are provided with the same reference symbols in both figures.

In the embodiment shown in Fig. 1 is the Lower part of a chimney illustrated in section. The outer wall of the chimney is made of masonry, Concrete or other stable materials existing coat 1 formed. An inner insert is coaxial with this jacket Sheath 2 is provided, in which the flue gases are guided upwards. The combustion air is in the cylindrical ring channel

-3- Act. Z. iS 48 "'- ^Λ ·" ^{/ η:} "-" - ■ · ^: ''"

our seals ι VPA 64/1189

Skn / Tue

η »τ VTJH

between the outer jacket 1 and the inner jacket 2 in the direction of Arrows 3 led down. The inner shell 2 consists for example of wrought iron and is with a suitable Insulation provided.

Depending on the effectiveness of the insulation and the flow speed of the combustion air drawn in, the combustion air is heated to a greater or lesser extent, ss.B * by one or more degrees. This is particularly important if the thermal power plant is sensitive to supercooled air. For example, when it comes to gas turbine systems, it is important to to avoid the supply of supercooled air. If necessary, the thermal insulation can be further reduced, in particular slightly higher warming up for steam boiler firing for example to get 10 to 15 ° 0 of the combustion air.

If necessary, the ring channel can also be subdivided into sectors or segments by means of suitable bulkheads. Also, a subdivision by cylindrical intermediate walls is conceivable in order to obtain in this W _e ise different preheated combustion air or to receive an additional air for ventilation or cooling of power plant facilities. It is based on the assumption that at greater heights, up to which the chimneys lead up, the air is cleaner than on the ground, so that dust filters of smaller dimensions are sufficient or filtering can be omitted at all.

The one in Pig. I leave illustrated embodiment the flue gases after prior heating of the working medium or the combustion air in a heat exchanger 4, the power plant and get through the pipe guide 5 into the interior of the shell 2 in the chimney. The one in the direction of arrows 3 in the ring channel Air drawn down is passed through a from the chimney to the Nacelle 6 reaching partition 7 in the air supply split into two flow paths 8 and 9, of which the flow

- 4 - Current number: S 48 352 / 24k Gbm

Our reference: VPA 64/1189 GM

Skn / Tue

way 8 leads to air preheaters and finally to the furnace while the flow path 9 for the fresh air supply in the machine house 6 can be used. The protruding on the outer jacket 1 of the chimney, only a little from the inner jacket influenced uöd thus relatively cool air is in the direction the arrows 10 deflected, while the preheated air stroking along the inner sheet metal jacket 2 continues along the pipe guide 5 flows along and assumes an ever higher temperature. If necessary, as dashed in the drawing indicated, a separate channel 9a may be provided.

When drawing in fresh air, it is advantageous to take measures to prevent smoke gases from entering the fresh air supply largely to be avoided. The embodiment shown in FIG. 2 shows possibilities for this. The suction of the Fresh air comes here for the most part at a certain distance, for example a few meters, below the chimney mouth 11. "The fresh air flows in the direction of the" arrows 12 through suitable openings 13 around the entire circumference the outer chimney jacket 1 can be distributed. By suitable guide surfaces 14, 15> 16 ensures that the smoke gases from the Chimney without going to the intake openings 13 to arrive. The wind deflectors 14, 15 »16 are here parallel to the face of the chimney mouth 11. Beyond can also be provided deeper on the chimney additional suction openings ^, for example, in half or 2/3 of the ! Lie at the chimney height. With adjustable flaps at the "chimney mouth" at the lower suction openings it can be ensured that the amount of air is distributed to the various intake points to the desired extent. Through this a possibly undesirably strong suction at the openings near the chimney can be prevented in order to reduce the risk to avoid recirculation at the chimney opening.

- 5 - act. «: ·· 3 · 4o 352 / '241c Gbm

Our reference: VPA 64/1189 GM

Skn / Tue

The ring channel for lowering the fresh air can be made so large that it is accessible. At air speeds of 5 to 10 m / sec this can be used during operation made an inspection of the chimney. If the dimensions make it difficult to walk on should, one can also think of not concentrating the inner jacket exactly, but rather off-centering it to a certain extent if move. , According to the mainly solar radiation

ύ the effect of heat on the outside of the

• In the chimney, it would be sufficient to place the inner jacket on the north

f hemisphere of the earth to the north side of the chimney

I like to have enough space on the south side for inspection

I create.

I In addition, measures can be taken to

£ to reduce the suction noise of the fresh air introduced. By

! ■ '■ the suction at great heights is in itself already a damping

i expect the suction noise. But you can do more than that

j; perform the insulation of the inner jacket in a suitable manner,

|; e.g. perforate the sheet metal insulation of steel pipes, and

j; through with relatively simple means and under little

Ij effort to reduce the noise when the air is sucked in

'or eliminate it entirely.

j 2 claims for protection

2 figures

6604573-

Claims (1)

Protection claims 1. Use for chimneys of thermal power plants with the formation of an inner duct for the exhaust gases and an outer ring channel for channeling the combustion air inside the chimney, characterized in that the insert is more heat-insulating in itself Sheath is formed, but the thermal insulation of the same is reduced in places to a small extent so far, that with a total of only slight heat extraction from the exhaust gas! and below only to safely avoid the risk of air filter freezing sufficient heating of the fresh air locally different heat transfer values for the fresh air flow and the fresh air flow to equalize those caused by one-sided solar radiation caused temperature distribution on the chimney wall can be used. 2. Use according to claim 1, characterized in that it from an outer jacket made of heat-insulated sheet metal or Wrought iron, asbestos cement or other thin-walled materials in relation to the outer casing of the chimney consists. 22.10.69 Skn / Tue