RU2514976C1 - Steam boiler with drumfree separation of steam - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: in a steam boiler, which comprises at least two safety valves, one safety valve is installed at the outlet of the steam reheater, and the other safety valve is arranged in the section between an external cyclone and the inlet to the steam reheater, inclusive.

EFFECT: prevention of impermissible growth of water level in a levelling drum and reduction of water level in external cyclones as a result of opening of safety valves, when pressure rises in a steam boiler with drumfree separation of steam.

3 cl, 5 dwg

Description

Technical field

The invention relates to a power system and can be used in boiler plants.

In more detail, the present invention relates to steam boilers with drumless steam separation.

Prior art

There are various schemes of drumless steam boilers, see No. SU91405, SU85772, SU892119, SU1160169, SU1291785, UA 65474.

In General, a well-known steam boiler with drumless separation is shown in figure 1 and figure 2. So, in Fig.1 and Fig.2 shows a steam boiler with drumless steam separation, which contains a surge drum 1, connected at the inlet to four external cyclones 2, connected to a superheater 3, the outlet of which are safety valves 4, while the equalization the safety valve 5 is adjacent to the drum 1. Also, the steam boiler contains an evaporation surface 6 (see figure 2); feed water circuit 7; continuous purge circuit 8.

The practice of operating a steam boiler with drumless steam separation shows that when the pressure in the steam boiler increases to the maximum permissible value, the safety valves 4 are first opened, located at the outlet of the superheater 3 to ensure that the pipes of the superheater 3 are cooled by the steam to prevent overheating of the pipes of the superheater 3 . If after opening the safety valves 4 the pressure in the boiler continues to increase, then the safety valves 5 equalize th drum 1.

Moreover, the continued increase in pressure in the steam boiler after opening the safety valves 4 at the outlet of the superheater 3 is possible for various reasons:

- malfunction (reduced steam allowance) of the valves 4;

- increased heat in the steam boiler (increase in steam capacity above the nominal value);

- clogging of the superheater pipes with 3 salts, etc.

When opening the safety valves 5 located on the equalizing drum 1, steam flows from the remote cyclones 2 to the safety valves 5 of the equalizing drum 1 through the nozzles connecting the steam volumes of the remote cyclones 2 and the equalizing drum 1. At the same time, the hydraulic resistance of these nozzles increases significantly, as a result of which there is a decrease in pressure in the equalization drum 1 and a sharp rise in water level in the equalization drum 1 (for example, a decrease in pressure in the equalization drum 1 by 0.1 atm leads to an increase in the water level by 1.0 m) and a sharp decrease in the water level in the external cyclones 2, which leads to the boiler stopping due to burnout of evaporating surfaces, as well as water entering the safety valves 5, which leads to hydraulic shock, as a result of which the safety valves 5 may fail.

The essence of the invention

An object of the present invention is to prevent an unacceptable increase in the water level in the equalization drum and to reduce the water level in the remote cyclones due to the opening of the safety valves, while increasing the pressure in the steam boiler with drumless steam separation.

Another objective of the present invention is to expand the technical capabilities of steam boilers with drumless steam separation.

Thus, the task is achieved in a known steam boiler with drumless steam separation, which contains a surge drum connected to at least one remote cyclone connected to a superheater, according to the invention, the steam boiler contains at least two safety valves, in this case, one safety valve is located at the outlet of the superheater, and another safety valve is located in the area between the remote cyclone and the entrance to the superheater, inclusive.

According to an embodiment of a steam boiler, an external cyclone is connected to the inlet of the superheater by pipes not heated by the combustion products. This allows you to avoid clogging of these pipes with salts, which is necessary for the safe operation of the steam boiler.

According to an embodiment of a steam boiler, the equalization drum is connected to an external cyclone by steam and water by pipes not heated by the combustion products. This condition is necessary for the safe operation of the steam boiler in order to avoid burnout of these pipes.

The essence of the invention lies in the transfer of safety valves from the equalization drum to the section between the external cyclone and the inlet of the superheater inclusive, as a result of which after their operation the steam does not enter the external cyclone into the equalization drum and there is no increase in the hydraulic resistance of the nozzles connecting the external cyclone and the equalization drum that does not lead to a significant change in the water level in the remote cyclone and leveling drum, and there is no sharp increase in the level odes in it.

Figures

When considering the implementation of the present invention uses narrow terminology. However, the present invention is not limited to the accepted terms and it should be borne in mind that each such term covers all equivalent elements that work in a similar way and are used to solve the same problems.

Figure 1 - steam boiler with drumless separation of steam, the prior art.

Figure 2 is a diagram of the steam boiler shown in figure 1.

Figure 3 - steam boiler with drumless steam separation when using the claimed invention.

Figure 4 is a diagram of the steam boiler shown in figure 3.

5 is an embodiment of a steam boiler circuit according to the claimed invention.

The implementation of the invention

So, figure 3 and 4 shows a steam boiler with drumless separation of steam, according to the claimed invention, which contains a balancing drum 1 connected to four external cyclones 2 connected to a superheater 3, the outlet of which are safety valves 4, while according to the claimed According to the invention, safety valves 5 are located in the area between the remote cyclones 2 and inclusive of the inlet to the superheater 3 (on the inlet manifold of the superheater 3). Also, the steam boiler contains: evaporation surface 6; feed water circuit 7; continuous purge circuit 8.

The steam boiler with drumless separation of steam, shown in figure 3 and 4, works as follows: in the process of operation of the steam boiler in the remote cyclones 2 receives steam-water mixture for separation. After separation, the steam is removed from the remote cyclones 2 through the superheater 3 to the steam consumer (not shown in the figures).

If the pressure in the steam boiler rises to the maximum permissible value, the safety valves 4 located at the outlet of the superheater 3 first open to ensure that the pipes of the superheater 3 are cooled by the steam to prevent overheating of the pipes of the superheater 3. If after opening the safety valves 4 the pressure in the steam boiler continues to increase, then the safety valves 5, which are located on the area between the remote cyclones 2 and the superheater 3, are triggered. When the safety valves are actuated, 5 pairs are discharged directly from the remote cyclone 2 to the atmosphere, while the hydraulic resistance of the nozzles connecting the remote cyclones 2 to the equalizing drum 1 does not increase, which does not lead to a significant change in the water level in the external cyclone 2 and equalizing drum 1.

The figure 5 shows a variant of the scheme of the steam boiler of low power, in which the safety valve 5 is transferred from the equalization drum 1 to the upper part of the remote cyclone 2 in the area between the remote cyclone and the entrance to the superheater, inclusive. As a result of the actuation of the safety valve 5, steam does not come from the remote cyclone to the equalization drum, as a result of which there is no significant change in the water level in the external cyclone and the equalization drum.

It is understood that the above are only two possible embodiments of the present invention. Therefore, it is obvious that the invention is not limited to the specific options that have been depicted and described above in accordance with the present invention.

Claims (3)

1. A steam boiler with drumless steam separation, which contains a surge drum connected to at least one remote cyclone connected to a superheater, characterized in that the steam boiler contains at least two safety valves, while one safety valve located at the outlet of the superheater, and another safety valve is located in the area between the remote cyclone and the entrance to the superheater, inclusive. 2. The boiler according to claim 1, in which the remote cyclone is connected to the inlet of the superheater by pipes not heated by the combustion products. 3. The boiler according to any one of claims 1 or 2, in which the equalization drum is connected to an external cyclone by steam and water by pipes not heated by the combustion products.

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