RU75455U1 - SCREEN - Google Patents

Abstract

The utility model relates to the field of power engineering and can be used in steam generators and boiler building.

The objective of the utility model is to ensure the reliability of framing screen pipes through the use of the collector effect and reduce temperature unevenness in the pipes.

A screen, mainly plane-parallel, with an end supply and outlet of steam, consisting of inlet and outlet headers connected by a bundle of heated pipes, of which the framing pipe is connected to the output manifold of the first steam outlet from the collector, while the framing pipe is connected to the blind end of the inlet manifold.

Description

The utility model relates to the field of power engineering and can be used in steam generators and boiler building.

Known plane-parallel screens, consisting of input and output collectors connected by a beam of heated pipes. Steam is supplied and discharged to the ends of the input and output collectors, the second ends are muffled.

(see "Steam Generators", Moscow, Energoatomizdat, 1985, edited by A. Kovalev, pp. 308-310 and "Steam Boilers of High Power", Industry Catalog, Moscow, USSR Ministry of Heavy Engineering, 1990, p. 39).

The geometric contour of each screen is composed of the longest and most heated flue gas framing pipe and the shortest and placed on the way already partially cooled gases of the inner pipe. All other pipes are inside this circuit.

With the end supply of steam to the screens with the most common “P” scheme, all pipes work at approximately the same pressure drop.

With a large overheating of the metal relative to other pipes, the framing pipe works due to the increased hydraulic resistance (the longest in comparison with other pipes) and, therefore, with a lower consumption of steam through it.

In addition to the mentioned factors, the overheating of the metal of the framing pipes is also determined by the conditions for washing it in the pipe circuit with the hottest flue gases.

Therefore, on the screens of boilers of power units, great damage to these heat-stressed pipes is observed.

A screen with a shortening of the longest first three or four pipes in the screens was selected as a prototype (see. "Steam Generators", M. Energoatomizdat, 1985, edited by A. Kovalev, p. 314).

The disadvantage of the prototype is a large temperature scan along the pipes of the screens, the reduced reliability of the pipes, including framing due to overheating of the metal.

The objective of the utility model is to ensure the reliability of framing heat-stressed screens through the use of collector differential pressure and reduce temperature unevenness in the pipes.

The essence of the utility model

The object of the utility model is a screen, mainly plane-parallel, with an end supply and steam outlet, consisting of inlet and outlet manifolds connected by a bundle of heated pipes, of which the framing pipe is connected to the output manifold of the first steam outlet from the collector, while the framing pipe is connected to the blind end of the intake manifold.

In operation, the most acceptable solution is the mutual transfer of the framing and inner pipes to the inlet manifold. Then the framing pipe connected to the blind end works under a large available differential, and the shortest inner pipe connected first to the distribution of the medium from the input manifold, with a smaller available differential.

Thus, the temperature non-uniformity in these pipes will significantly decrease.

This allows you to increase the reliability of the screens, reduce the temperature scan through the pipes of the superheater.

Utility Model Implementation

Figure 1 presents the screen with the proposed connection of the framing pipe to the input manifold.

Figure 2 - plot of the distribution of the differential pressure across the screen pipes before switching the framing pipe to the blind end of the inlet manifold.

Figure 3 - plot of the distribution of the differential pressure across the pipes of the screen after attaching the framing pipe to the blind end of the inlet manifold.

The screen contains:

1 - a bunch of pipes;

2 - input collector;

3 - output collector;

4 - distribution pipe;

5 - collecting pipeline;

6 - framing pipe;

7 - an internal pipe;

8 - disposable pressure drop across the framing pipe of the screen;

9 - disposable differential pressure across the inner tube of the screen;

10 - disposable pressure drop along the middle pipe of the screen;

11 - collector pressure drop at the blank end of the inlet manifold;

12 - collector pressure drop at the blank end of the output manifold.

The device operates as follows: the steam from the distribution pipe 4 enters the inlet manifold 2 and is distributed along the bundle of pipes 1. After heating with flue gases, the steam is sent to the outlet manifold 3 and then to the collecting pipe 5.

In the process of steam distribution, the framing pipe 6, connected to the blind end of the inlet manifold 2, already operates under a large available differential pressure 8 by the value of the collector differential pressure. The inner tube 7 in the contour of the screen, while remaining connected to the end of the inlet manifold, operates under a constant disposable pressure drop 9.

The disposable differential across the middle pipe 10 and the collector differential pressure of the output manifold 12 remain unchanged.

Industrial applicability

The utility model can be implemented both on the basis of commercially available high-power steam generators, and on operated domestic boilers, the superheaters of which are particularly in need of reducing temperature unevenness.

Claims (1)

A screen, mainly plane-parallel, with an end supply and outlet of steam, consisting of input and output headers connected by a bundle of heated pipes, of which the framing pipe is connected to the output manifold of the first steam output from the collector, characterized in that the framing pipe is connected to the blind end of the input collector.