JPS5817558B2 - Fixed bed high pressure vaporization generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a generator for fixed bed high pressure vaporization of granular fuel with a vaporization medium containing free oxygen.

The generator furnace for fixed-bed high-pressure vaporization of granular fuel is constructed with double walls in order to direct the effects of temperature and pressure to the tower side.

The annular chamber thus formed is filled with high-pressure boiling water at a slightly higher pressure than the inner chamber of the generator.

The inner wall therefore takes on the action of temperature, and the outer wall, which has a temperature slightly below the boiling point of water, takes on the action of pressure.

This principle makes it possible to construct the inner wall relatively thin, which is subjected to only a slight pressure during normal use.

This division of roles is due to the release process, especially during the rapid depressurization of the system during a failure, as a result of the re-evaporation of the water in the annular chamber, which creates a pressure differential of several atmospheres between the water jacket and the reactor inner chamber. Particularly restricted.

To avoid damage due to inward bulge of the inner wall, the inner wall must be designed for an external overpressure of approximately 0.2 to 0.4 MPa.

When the diameter of the generating furnace is large, the above-mentioned differential pressure requires a considerably thick inner wall, and for example, when the diameter of the generating furnace is 4 m, the wall thickness of the inner wall already exceeds 20 mm.

These internal walls are subject to severe corrosion, especially depending on the lignite used, and in some areas of the furnace chest this corrosion can reach wear rates of several millimeters per year.

The generator can be equipped with a refractory lining to inhibit corrosion.

The disadvantages of such a lining are that the effective cross-sectional area of the generator is reduced and that there is a risk of slag formation in the generator due to the extremely high temperature inside the brickwork.

Therefore, brick masonry was abandoned and attempts were made to prevent corrosion of the inner walls by cladding or overlaying with special steel plates.

Not only are such solutions expensive, but the results achieved are not always satisfactory.

Although the causes of corrosion have not been fully resolved, there is no doubt that high material temperatures and material stresses accelerate corrosion.

An object of the present invention is to provide a fixed-bed high-pressure vaporization furnace with less corrosion of the metal inner wall and a longer service life.

The present invention is based on the problem of developing a fixed-bed high-pressure gasification generator with metal inner walls, which guarantees a sufficient service life and in which the temperature and temperature difference of the inner walls and the stress of the material are significantly suppressed.

The solution according to the present invention is that the high-temperature inner wall of the generating furnace is not a cylinder made of iron plates as in the past, but consists of rectangular channels welded together and arranged vertically, and the inner wall and the pressure-resistant outer wall of the generating furnace are constructed in this way. It is characterized by an annular gap remaining between the two.

Thanks to the solution of the invention, even with large generator diameters, the wall thickness of the inner walls, in particular of the partition between the ice chamber and the generator chamber, can be made slightly smaller compared to the required wall thickness of the cylindrical iron wall. I can do it.

The solution according to the invention also provides an auxiliary internal water circulation at the height of the hot zone of the generator, in which case in the rectangular conduits the bundle of steam generation by heating from the internal chamber of the gas generator, water rises; It descends in the annular chamber remaining between the conduit and the outer wall.

The reduction in wall thickness is accompanied by a significant reduction in the temperature difference in the material of the inner wall and, with it, in the thermal stresses that occur.

The auxiliary internal water circulation facilitates heat transfer between the inner wall and the contained water, ensuring that the temperature of the inner wall does not significantly exceed the water temperature under all conditions of use.

In the current structure, the high heat loads that occur with local and temporal variations can lead to film evaporation, which in turn leads to significant overheating of the iron plates and high thermal stresses, which can be suppressed by the above.

In addition, the inner wall of the generating furnace can be stiffened by the welded belly plate and intermediate plate.

In this way, the solution according to the invention eliminates the corrosion-promoting factors mentioned above.

1 to 4, the invention will now be explained with reference to two embodiments. According to FIG. 1, the conventional laminated plates are installed at a height of about 30,001 nrIl from the top of the grid in areas where the heat load on the inner wall is particularly high. Taut.

Alternatively, the inner wall iron plate 1 is replaced with a thin inner wall iron plate 1 made of an unstrung iron plate with a thickness of about 25 mm.

In the first embodiment, an angle-shaped member 3 is welded to the outside of the inner wall iron plate 1, as shown in FIG.

The angles are also welded on the outside to form a closed rectangular conduit.

The top and bottom of the conduit are open.

An annular gap 9 remains between the outer edge of the angle member 3 and the generator outer wall 2.

The annular gap 9 is also open at the top and bottom.

For installation in an existing generator, a thin inner wall steel plate 1 is prefabricated as segments together with angle members 3, inserted into the generator through an opening 5 in the head or bottom of the generator, and a welded seam 6 6 is inserted into the generator. welded together to create a closed wall shell.

The invention will now be described with reference to other embodiments.

According to FIG. 3, the inner wall steel plate 1 is stiffened by inserting the welded belly plate 4 and intermediate plate 5.

FIG. 4 shows the connection to the inner wall 7 of the compact structure outside the area of high thermal load for two embodiments.

Insert the pre-prepared supplementary inner wall iron plate appropriately and weld it longitudinally as shown in Fig. 2 or 3.

An annular portion 8 is welded between the compact inner wall 7 and the supplementary inner wall iron plate 1 as a connecting member.

The inner wall iron plate 1 can be equipped with a special proportion plate.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the generating furnace. FIG. 2 is a sectional view taken along line A-A in FIG. 1 for Example 1. 3 is a sectional view taken along the line A-A in FIG. 1 for Example 2. FIG. FIG. 4 shows a detailed view of E in FIG. Main part names and reference numbers, 1...Inner wall, 2...Outer wall, 9...
...Annular gap, 10... Guide path.

Claims (1)

[Scope of Claims] 1. A generating furnace for fixed-bed high-pressure vaporization of granular fuel using a polymeric vaporization medium containing free oxygen, consisting of an inner wall and an outer wall, in which boiling water flows through an annular chamber formed by the inner and outer walls ( In order to obtain suitable auxiliary internal water circulation, the inner walls 1 are welded to each other in the high temperature zone of the generating furnace and are arranged vertically, consisting of rectangular channels 10 with an open bottom -F, and the inner wall 1 and the outer wall 2 are connected to each other. A generating furnace characterized in that there is an annular gap 9 between them. 2. A generating furnace according to claim 1, characterized in that the inner wall of the generating furnace is supplemented by a welded belly plate 4 and an intermediate plate 5. Generator 1,