RU2805709C1 - System for removing steam-air mixture in low-pressure heater - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention can be used in low-pressure heaters having a removable pipe system as part of a steam turbine at a power plant. The system for removing the steam-air mixture in the low-pressure heater includes removable pipe system 3, guide baffles 4 and fixed housing 9. A part of the removable tube bundle of the heater is selected, connected to the outlet pipe of steam-air mixture 2, which is limited in height by the penultimate and last guide partitions 4, and on the side by the installation of shield 5. Coaxially with shield 5, flanged cover 6 is installed by welding, connected to flange 7, into which pipe 8 is inserted with hinges installed at the ends of the pipe. The hinges are designed to compensate for thermal expansion of pipe system 3 relative to heater body 9, as well as to seal the gap between flange 7 and cover 10. Steam-air mixture outlet pipe 2 is welded on cover 10.

EFFECT: increased efficiency of air vapor mixture removal.

1 cl, 6 dwg

Description

The invention relates to the field of power engineering, namely to turbine construction, and can be used in the design of new and reconstruction (modernization) of existing heaters of a low-pressure regeneration system having a removable pipe system (low-pressure heaters (LPH) and stuffing box heaters (SP)), in as part of steam turbine units (STU) at a power plant.

The design of heaters for a low-pressure regeneration system is known from the prior art, taken as a prototype, which is a shell-and-tube apparatus with a removable pipe system with guide baffles, in which the steam-air mixture (SAM) is removed from the steam space through a pipe located in the lower part of the housing (“ Heat exchangers for power plants”, edited by Yu.M. Brodov, Ekaterinburg, 2003, p. 250, Fig. 3.20).

To understand the essence of the claimed invention, Fig. Figure 1 shows a typical design of a heater for a low-pressure regeneration system, which is a shell-and-tube apparatus with a removable pipe system 3 with guide baffles 4, in which PVA is removed from the steam space through a pipe located in the lower part of the housing. The disadvantage of the known solutions is that some part of the working steam, the so-called idle steam leaks 13, passing through the gap 12 between the edge of the guide partitions 4 of the pipe system and the heater body 9, bypassing the tube bundle, is removed together with the steam-air mixture, and from part of the tube bundle , located under the last guide partition, the steam-air mixture is not removed at all. This reduces the efficiency of the heater and increases the underheating (temperature pressure) of the main condensate.

A vertical shell-and-tube heater is also known, including a distribution water chamber with inlet and outlet pipes for heated water, a housing with a steam inlet pipe, an outlet for its condensate and a PVA outlet pipe, a pipe system with guide baffles, a surface-type air cooler (Invention “Vertical heater”, patent No. 2366859, published 09/10/2009, Bulletin No. 25). The disadvantage of the invention is that it does not disclose the essence of installing a steam-air mixture outlet pipe in a housing with a removable pipe system to ensure the assembly and operation of the apparatus.

The technical problem to which the claimed invention is aimed is to eliminate the shortcomings of known solutions: idle leaks of working steam in the heater body, which bypass the tube bundle and are removed together with the PVA, a large volume of working steam in the PVA composition and the lack of effective organization of steam movement in the lower part tube bundle located under the last guide baffle.

The technical result of the invention is to increase the efficiency of PVA removal by minimizing or eliminating completely idle steam leaks in the designs of heaters with a removable pipe system and the inclusion of the heat exchange surface of the lower part of the tube bundle, located under the last guide partition, into operation.

The technical result is achieved by changing the PVA movement pattern through the use of the claimed steam-air mixture exhaust system in a low-pressure heater with a removable pipe system 3, guide baffles 4 and a fixed heater body 9, characterized in that a part of the removable pipe bundle of the heater is allocated, connected to the PVA outlet pipe 2 , which is limited in height by the penultimate and last guide partitions 4, and on the side by installing a shield 5, coaxially with which a flanged cover 6 is installed by welding, connected to a flange 7 into which a pipe 8 is inserted with hinges installed at the ends of the pipe, made to compensate for thermal extensions of the pipe system 3 relative to the heater body 9, as well as to seal the gap between the flange 7 and the cover 10, in which the PVA outlet pipe 2 is installed for welding.

An analysis of the level of technology carried out by the applicant and including a search of patent and scientific and technical sources of information, as well as the identification of sources containing information about analogues of the claimed invention, did not reveal a technical solution characterized by features identical or equivalent to those proposed.

The found invention “Vertical heater” according to patent No. 2366859 represents only a general disclosure of a solution for removing the steam-air mixture without disclosing the essence of installing a branch pipe for removing the steam-air mixture, which does not deprive the novelty of the particular disclosure of the claimed system for removing the steam-air mixture in a low-pressure heater.

Determination from the list of identified analogues of the prototype as the closest technical solution in terms of the set of features made it possible to determine in the claimed device a set of essential distinctive features in relation to the technical result and set out in the claims below.

Consequently, the claimed invention meets the patentability criterion of “novelty”.

To check the proposed technical solution for compliance with the patentability criterion of the invention “inventive step”, an additional search was carried out using information known from the prior art. The search results showed that the proposed invention does not clearly follow from the prior art for a specialist. Moreover, as can be seen from the description, in order to achieve the desired technical result, the applicant introduced fundamental and non-obvious design changes to the steam-air mixture exhaust system in the low-pressure heater, and also provided it with new elements and connections.

Consequently, the claimed invention meets the patentability criterion of “inventive step”.

The essence of the claimed technical solution is illustrated by the following figures, which depict:

fig. 1 is a general view of the known design of a low-pressure heater;

fig. 2 - view A of the known design of a low-pressure heater, made on an enlarged scale of 1:10;

fig. 3 - main view of the low-pressure heater in which the claimed invention is implemented;

fig. 4 - view B of a low-pressure heater in which the claimed invention is implemented, made on an enlarged scale of 1:10;

fig. 5 - B-B section of the low-pressure heater, made on an enlarged scale of 1:10;

fig. 6 - view D, which shows an approximation of part of the section B-B of the low-pressure heater, characterizing the claimed invention.

The following positions are indicated in the attached figures:

1 - steam inlet pipe;

2 - PVA outlet pipe;

3 - removable pipe system;

4 - guide partitions;

5 - shield;

6 - flanged cover;

7 - flange;

8 - pipe with hinges;

9 - heater body;

10 - cover;

11 - pipe;

12 - gap between the heater body and the pipe system;

13 - idle leaks of working steam.

The claimed system for removing the steam-air mixture is illustrated using the example of its implementation in a low-pressure heater. The low-pressure heater includes a housing 9, a distribution water chamber with inlet and outlet pipes for heated water, a steam inlet pipe 1, an outlet for its condensate, a removable pipe system 3 with guide baffles 4 (Fig. 3) and the claimed PVA drainage system. The steam-air mixture exhaust system consists of a dedicated part of the removable tube bundle of the heater, connected to the steam-air mixture exhaust pipe 2, which is limited in height by the penultimate and last guide partitions 4, and on the side by installing a shield 5. Coaxial to the shield 5, a flanged cover 6 is installed by welding, connected with a flange 7 into which the pipe 8 is inserted. At the ends of the pipe 8 there are hinges that serve to compensate for thermal expansion of the pipe system 3 relative to the heater body 9, while simultaneously sealing the gap between the flange 7 and the cover 10, in which the PVA outlet pipe 2 is installed for welding .

The claimed invention works as follows.

The heated water through the inlet pipe enters the inlet part of the distribution water chamber, from where it is directed into the pipes of the heat exchange surface of the first stroke and through the rotating chamber through the pipes of the second stroke it enters the outlet part of the distribution water chamber and then through the pipe it is removed from the heater. As water moves through the pipes, it is heated by the heat generated by steam condensation. The working steam enters the heater housing 9 through the steam inlet pipe 1, condenses on the tubes of the tube bundle, and the resulting heating steam condensate flows into the lower part of the housing 9 and is removed from it. Most of the steam makes longitudinal-transverse movements along the tube bundle along the guide partitions 4, and part of the steam rushes through the annular gap between the body 9 and the guide partitions 4, which cannot be excluded to ensure the assembly of the heater, into the PVA outlet pipe past the tube bundle. The steam-air mixture exhaust system, which includes an installed shield 5 and a system of pipes connected to it, prevents the removal of working steam from the heater. The steam passes through the tube bundle, condenses on it and enters a dedicated part of the removable tube bundle, connected to the PVA outlet pipe 2, limited in height by the penultimate and last guide partitions 4, and on the side by the installation of a shield 5, where the process of steam condensation is completed and the steam-air mixture is discharged from the heater body.

Thus, the above information indicates that the following set of conditions are met when using the invention:

the means embodying the claimed invention during its implementation is used in turbine construction, namely in the production of low-pressure heaters and stuffing box heaters;

the means embodying the claimed invention during its implementation is capable of achieving the technical result envisaged by the applicant.

Consequently, the proposed technical solution meets the patentability criterion of “industrial applicability”.

Claims (1)

A system for removing the steam-air mixture in a low-pressure heater, including a removable pipe system 3, guide baffles 4 and a fixed housing 9, characterized in that a part of the removable pipe bundle of the heater is separated, connected to the outlet pipe for the steam-air mixture 2, which is limited in height by the penultimate and last guides partitions 4, and on the side by installing a shield 5, coaxially with which a flanged cover 6 is installed by welding, connected to a flange 7, into which a pipe 8 is inserted with hinges installed at the ends of the pipe, made to compensate for the thermal expansion of the pipe system 3 relative to the heater body 9, and also to seal the gap between flange 7 and cover 10, in which the steam-air mixture outlet pipe 2 is installed for welding.