DE1950502A1 - Steam generators and other heated heat exchangers - Google Patents

Description

P4392

Sulzer Brothers Aktiengesellschaft, Winterthur / Switzerland

Steam generator and other heated heat exchangers

The invention relates to a steam generator or other heated heat exchanger with at least one cylindrical vortex combustion chamber in which a nearly stoichiometric Mixture of fuel oil and / or gas is burned with air, and the flue gas duct connected to it, are housed in the heating surfaces.

Such steam generators are known in which the combustion takes place in large vortex combustion chambers, a considerable part of the heat of combustion being disposed on the walls of the combustion chamber Radiant heating surfaces is added. The already relatively strongly cooled exhaust gases are then fed to the contact heating surfaces. The large combustion chambers of these Steam generators take up a lot of space, they require

ORlGtNAL INSPECTEO 109817/0819

furthermore, due to deflagrations that may occur, a Wide-span, strong support structure and are therefore expensive parts of the boiler.

There are also cyclones and smelting combustion chambers known, in which at increased power density in strong Vortex springs are preferably burned with coal dust. The mouth of these cyclones is constricted, so that larger, still unburned coal particles or slag particles be held back by centrifugal force in the cyclone while the flame guests beat out through the mouth in a ; lined with radiant heating surfaces

then
Afterburning chamber, in which the combustion is finished first

In these known boilers, the combustion chamber loads are medium of the order of magnitude 6 IQ kcal / m h ata. Higher combustion chamber loads of up to 2 · 10 keal / m h ata can be achieved with flame tube boilers,

It is the object of the invention to make steam generators and heated heat exchangers as well as the heating surfaces essential to downsize and reduce the costs sta.

^ "10 9817/0819 _oRlGlNAL inspected

This task is accomplished by the fact that the eddy

combustion chamber for a combustion chamber load of more than

7 3

10 kcal / m «h« ata is designed and that the flue gas with the heating surfaces with the suppression of any radiant combustion chambers directly to the vortex combustion chamber connected.

Combustion chambers with a similarly high combustion chamber load are known in gas turbine systems, especially in aircraft engines. In these, the combustion chamber wall cooled by a stream of air that is added to the burning gas mixture. The high combustion chamber load is achieved on the one hand because of the use of volatile fuels and on the other hand because of a very high combustion air excess, which is in the limits of 1.2 to 3, while in systems according to the invention Almost stoichiometric combustion, i.e. an excess of air of about 1.02 is aimed for and achieved. In systems in which the invention is to be used, such known combustion chambers would not be portable, on the one hand because of the high exhaust gas losses, on the other hand because of the low gas outlet temperature, which is a significant Enlargement of the heating surface would result and

109817/0819 ^omm ^ inspected

.Only because of the high residual oxygen content, which would lead _{to excessive SO 3 formation if sulfur-containing fuels were burned.}

It would be conceivable to use the afterburning chamber in boilers with cyclone combustion chambers with conventional combustion chamber loading to suppress. However, this would lead to very large and correspondingly expensive cyclone combustion chambers. so it has surprisingly been shown that by using the above-mentioned, significantly higher heat load, a closed Effective area occurs: The surface becomes unproductive and dangerous looking step into higher power density of the vortex combustion chamber is reduced relative to the volume and thus the heat dissipation to the outside is greatly reduced. Because of the smaller losses, the combustion temperature rises together with that in the vortex combustion chamber scored. high turbulence - leads to faster combustion, which ultimately leads to the initially required higher power density is made possible.

The invention is shown schematically in longitudinal section, for example, on the basis of one in the drawing Forced once-through steam generator shown in more detail.

The steam generator has a vertical flue gas 1, which is welded together from four sides

10 9817/0819 ORIGINAL INSPECTED

Vertical tubes formed walls 2 is limited. The vertical tubes are based on a square Frame forming distributor 3. They open into a analog square collector 4. A floor 5 with insulation 6 closes off the flue 1 at the bottom. Above it is via connecting surfaces that run like a pyramid 7 connected to a chimney 8.

In the flue 1 between two collectors 10 and 11 are parallel-connected, horizontal pipe coils arranged. Vertical pipe coils 13, which, connected in parallel, are attached to two collectors 14 and 15, hang above these are connected. The collector 10 is supplied with working fluid of supercritical pressure via a line 16, which flows through the horizontal coils 12 and from the collector 11 via a connecting line 17 in the Distributor 3 arrives. After flowing through the wall pipes, the working medium exits the collector 4 via a

Connection line 18 into the collector 14 and from there through the coils 13 to the collector 15, from which it is guided by means of a live steam line 19 to the steam consumer . ; . ■

In each of the four side walls is below the

109817/0819 «■« · «.» * ««

19S0502 t

• Coiled tubes 12 each with a vortex combustion chamber 20 horizontally oriented axis connected. The vortex combustion chambers 20 consist of a ceramic-lined, cylindrical muffle 21 and the actual burner 22 arranged coaxially therewith.

According to the invention, the vortex combustion chamber is for a

7 3

Combustion chamber load of more than 10 kcal / m -hata designed, that is, the actual burner 22 is dimensioned and constructed so that the in the cylindrical muff el Amount of heat released every hour at atmospheric pressure based on the internal volume of the cylindrical muffle, measured from the burner mouth to an imaginary

7 3 level spanning the outlet opening, 10 kcal / m

amounts to. ''

The vortex burners arranged in opposite walls lie on a common axis. This has the particular advantage that the one Most of the flame radiation emitted from the combustion chamber falls into the opposite combustion chamber, which increases the combustion temperature there. Vice versa, Radiation from the other combustion chamber also increases the temperature in one. Due to the alignment on the axis

- - 109817/0819 _0RiewM . , nspected

.of the combustion chambers is also that of direct flame radiation exposed wall area reduced. The free space in the flue gas between the vortex combustion chambers 20 "Despite the flame radiation acting on the free wall parts, it cannot work with a radiation combustion chamber be confused because the combustion is still completed within the vortex combustion chambers 20.

The ceramic lining of the cylindrical muffle of the vortex combustion chambers 20 takes on the inner surface practically the temperature of the burning gases. Because of the poor thermal conductivity of the ceramic and additional Insulation, the vortex combustion chamber can be operated up to a considerable size without external cooling. The burn thus runs, which is very essential for the success of the invention, practically adiabatic. An additional ™

Lich means to achieve the highest possible combustion temperature lies in the high level of preheating of the combustion air. This / is practically limited by the fact that it is cumbersome would be, the combustion air leading parts of the burner 22 through a third medium, e.g. through working medium, to cool.

As can be seen from the drawing, the

109817/0 8Ί9 originally inspected

19b0502

.Invention the additional advantage that the flue gas regardless of the dimensioning of combustion chambers based solely on the requirements of optimal heat transfer can be measured in the contact heating surfaces. The constrictions known in conventional boilers, Noses etc. are thus unnecessary. Another advantage of the invention is that the thermally highly stressed pipes because of the uniform heating over the entire circumference and thanks to the unconstrained suspension suffer only moderate thermal stresses. This allows the tubes to be very heavily loaded, which leads to a reduction in the heating surface.

ORIGINAL INSPECTED

7/08 19

Claims (6)

Claims Steam generator or other heated heat exchanger, characterized in that that at least one cylindrical vortex combustion chamber is provided, that this combustion chamber is used to burn an almost stoichiometric mixture of fuel oil and / or gas with air is suitable, that the vortex combustion chamber (20) has such a volume that at atmospheric pressure and during the combustion of the amount of fuel required for full load at least 10 kcal / m ^{3 are} released per hour and that immediately, i.e. avoiding a radiation-heated Heating surfaces having space, to the vortex combustion chamber a heated by contact heating surfaces having a flue gas duct is connected. 2. Steam generator or other heated heat exchanger according to claim 1, characterized in that the walls (21) of the vortex combustion chamber (20) are designed with oxide ceramics. 3. Steam generator or other heated heat exchanger according to claim 1, characterized in that the Walls (21) of the vortex combustion chamber (20) are uncooled. ORiGfNAL INSPECTED 109817/0819 4. Steam generator or other heated heat exchanger after. Claim 1, characterized in that the .Walls (21) of the vortex combustion chamber (20) are insulated to reduce heat loss. 5.. Steam generator or other heated heat exchanger according to claim 1 with an even number of vortex combustion chambers, characterized in that the vortex combustion chambers (20) in pairs, - coaxially opposite one another are arranged at one end of the flue gas duct (1). 6. Steam generator or other heated heat exchanger according to claim 1 -. ee ■, characterized in that the length of the muffle is 0.5-2 times the inner diameter of the muffle .. ORIGINAL INSPECTED 109817/0819