CN216113986U

CN216113986U - Device for improving steam blowpipe coefficient of ultra-supercritical boiler

Info

Publication number: CN216113986U
Application number: CN202122752178.XU
Authority: CN
Inventors: 王林; 牛佩; 杨博; 高景辉; 何信林; 孟颖琪
Original assignee: Xian Thermal Power Research Institute Co Ltd
Current assignee: Xian Thermal Power Research Institute Co Ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-03-22
Anticipated expiration: 2031-11-10

Abstract

The utility model discloses a device for improving the steam blow pipe coefficient of an ultra supercritical boiler, which comprises a water wall, a water storage tank, a steam-water separator, a superheater, a blow door, a reheater, a silencer, a reheater relief valve, a superheater relief valve and a drainage flash tank, wherein the water wall is provided with a water inlet pipe and a water outlet pipe; the demineralized water pipeline is communicated with an inlet of a steam-water separator through a water-cooled wall, a steam outlet of the steam-water separator is communicated with an inlet of a superheater, an outlet of the superheater is divided into two paths, one path of the demineralized water pipeline is communicated with an inlet of a reheater through a blow door, the other path of the demineralized water pipeline is communicated with an inlet of a hydrophobic flash tank through a heat relief valve, an outlet of the reheater is divided into two paths, one path of the reheater is communicated with the outside atmosphere through a silencer, the other path of the reheater is communicated with an inlet of the hydrophobic flash tank through the pressure relief valve of the reheater, a water outlet of the steam-water separator is communicated with an inlet of the hydrophobic flash tank, and the device can effectively solve the problem that the steam blow pipe coefficient of a high-parameter ultra-supercritical unit boiler is low.

Description

Device for improving steam blowpipe coefficient of ultra-supercritical boiler

Technical Field

The utility model relates to a purging device, in particular to a device for improving the steam blowing pipe coefficient of an ultra-supercritical boiler.

Background

Impurities such as welding slag, rusty scale, dust and the like exist in a steam-water pipeline of a boiler of a newly-built thermal power generating unit, and steam purging is needed before the boiler is put into use. The boiler steam blowpipe refers to that foreign matters and impurities in pipelines of steam heating surfaces such as a newly-built boiler superheater and a reheater are blown out of a boiler by using high-temperature and high-pressure steam, so that the cleanliness of the pipelines is ensured, and the blades of a steam turbine are prevented from being damaged by impact of impurity particles.

In recent years, as the steam temperature and pressure parameters of a power station boiler are continuously improved, the pipe diameters of heating surfaces of a superheater and a reheater are gradually thickened, and when a new boiler steam blowing pipe is built, the problems that the blowing pipe coefficients of the superheater and the reheater are small and even the blowing pipe is unqualified are often encountered. The reason for this is that after the blowing door is opened, the emptying pipe cannot rapidly discharge the pressure at the outlet of the heating surface, so that the pressure drop of the heating surface is small in the blowing process, and the steam momentum cannot meet the blowing requirement.

If a pressure relief emptying pipeline is additionally arranged at the outlet of the heating surface, the pressure relief speed is greatly increased, the pressure drop of the heating surface in the blowing process is increased, and the blowing pipe coefficient is effectively improved.

In engineering practice, the ratio of the pressure difference between the inlet and outlet of a certain heating surface of a boiler to the pressure difference between the inlet and outlet of the heating surface under the working condition of maximum evaporation capacity is obtained, and the obtained ratio is the blow pipe coefficient of the heating surface. It is recognized in industry specifications that an effective steam lance should have a lance coefficient (expressed as K) greater than 1.0. In recent years, ultra-supercritical units with high parameters (main steam temperature of 620 ℃ or higher and main steam pressure of 31MPa or higher) and large capacity are rapidly developed and become the main power of electric power infrastructure, the problems that the blowing coefficient is still low due to the fact that the blowing pressure is often increased on site are solved, and the device capable of improving the boiler steam blowing coefficient is extremely necessary.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provides a device for improving the steam blowing pipe coefficient of an ultra-supercritical boiler, which can effectively solve the problem that the steam blowing pipe coefficient of a high-parameter ultra-supercritical unit boiler is low.

In order to achieve the purpose, the device for improving the steam blowing pipe coefficient of the ultra-supercritical boiler comprises a water-cooled wall, a water storage tank, a steam-water separator, a superheater, a blowing door, a reheater, a silencer, a reheater pressure release valve, a superheater pressure release valve and a drainage flash tank;

the demineralized water pipeline is communicated with an inlet of the steam-water separator through a water-cooled wall, a steam outlet of the steam-water separator is communicated with an inlet of a superheater, an outlet of the superheater is divided into two paths, wherein one path is communicated with an inlet of a reheater through a blow door, the other path is communicated with an inlet of a hydrophobic flash tank through a heat relief valve, an outlet of the reheater is divided into two paths, one path is communicated with the outside atmosphere through a silencer, the other path is communicated with an inlet of the hydrophobic flash tank through the reheater relief valve, and a water outlet of the steam-water separator is communicated with an inlet of the hydrophobic flash tank.

The bottom outlet of the drainage flash tank is communicated with a condensed water tank.

The steam-water separator is of a cylindrical structure.

The water storage tank is a long cylindrical container.

The hydrophobic flash tank is a steel cylindrical container.

The silencer is an open cylindrical device.

The condensed water tank is a steel tank-shaped container.

The superheater pressure release valve is an electric valve.

The utility model has the following beneficial effects:

when the device for improving the steam blowing pipe coefficient of the ultra-supercritical boiler is specifically operated, the superheater is firstly blown in the first stage, and the blowing pipe coefficient is further increased by using the superheater pressure release valve in the blowing process, so that the blowing pipe quality is improved; and purging the reheater in the second stage, wherein in the purging process, the blowing pipe coefficient is further increased by using the superheater relief valve and the reheater relief valve, and the blowing pipe quality is improved so as to solve the problem that the steam blowing pipe coefficient of the high-parameter ultra-supercritical unit boiler is low.

Drawings

FIG. 1 is a block diagram of the present invention.

Wherein, 1 is a water wall, 2 is a water storage tank, 3 is a steam-water separator, 4 is a superheater, 5 is a blow door, 6 is a reheater, 7 is a silencer, 8 is a reheater relief valve, 9 is a superheater relief valve, 10 is a drainage flash vessel, and 11 is a condensate tank.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the utility model. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to fig. 1, the device for improving the steam blowing pipe coefficient of the ultra supercritical boiler comprises a water wall 1, a water storage tank 2, a steam-water separator 3, a superheater 4, a blow-by door 5, a reheater 6, a silencer 7, a reheater relief valve 8, a superheater relief valve 9, a drain flash tank 10 and a condensate water tank 11;

the demineralized water pipeline is communicated with an inlet of the steam-water separator 3 through the water-cooled wall 1, a steam exhaust port of the steam-water separator 3 is communicated with an inlet of the superheater 4, an outlet of the superheater 4 is divided into two paths, one path is communicated with an inlet of the reheater 6 through the blowing door 5, the other path is communicated with an inlet of the drain flash tank 10 through the heater relief valve 9, an outlet of the reheater 6 is divided into two paths, one path is communicated with the outside atmosphere through the silencer 7, the other path is communicated with an inlet of the drain flash tank 10 through the reheater relief valve 8, a water outlet of the steam-water separator 3 is communicated with an inlet of the drain flash tank 10, and a bottom outlet of the drain flash tank 10 is communicated with the condensed water tank 11.

The steam-water separator 3 is of a cylindrical structure, the water storage tank 2 is a long cylindrical container, the drain flash tank 10 is a steel cylindrical container, the superheater decompression valve 9 is an electric valve, the reheater decompression valve 8 is an electric valve, the silencer 7 is an open cylindrical device, and the condensate tank 11 is a steel cylindrical container.

The working process of the utility model is as follows:

the desalted water enters the water wall 1 to absorb heat and evaporate, saturated steam is formed at the outlet of the water wall 1, then the steam and the liquid are separated through the steam-water separator 3, wherein the steam enters the superheater 4 to continuously absorb heat to form superheated steam, and the separated water enters the water storage tank 2 and finally is discharged into the drainage flash tank 10 and the condensed water tank 11.

After the boiler is ignited, fuel is gradually added, and when the steam temperature and the steam pressure at the steam-water separator 3 reach required values, steam purging of the heating surface can be started.

The superheater 4 is firstly purged in the first stage, and the specific process is as follows:

1) there is no pressure relief valve. And (3) opening a blow-on door 5, allowing high-temperature and high-pressure steam to rapidly flow through the heating surface of the superheater 4 from the steam-water separator 3 and the superheater 4 and to be discharged to the atmosphere through a reheater 6 and a silencer 7, and strongly washing the inner wall of a pipe on the heating surface by high-speed airflow so as to carry impurities out of the boiler by the steam. When the steam pressure at the steam-water separator 3 is reduced to a required value, closing the blow door 5 and ending the primary blow pipe; adding fuel, and when the steam pressure rises to the required value again, carrying out next blow pipe.

2) There is a pressure relief valve. After the superheater 4 is purged for a plurality of times, coarse particle impurities are basically cleaned and discharged out of the boiler, and then purging can further increase the blow pipe coefficient by using a superheater pressure relief valve 9, so that the blow pipe quality is improved. The specific operation is as follows: when the steam pressure at the steam-water separator 3 is increased to a set value, the blow-on door 5 and the superheater decompression valve 9 are opened simultaneously, the steam output by the superheater 4 is discharged into the hydrophobic flash tank 10 rapidly, the steam pressure is reduced rapidly, the pressure difference between the inlet and the outlet of the superheater 4 is increased rapidly, and the blow pipe coefficient of the superheater 4 is increased simultaneously to obtain better purging quality.

The second stage purges the reheater 6, and the specific process is as follows:

1) there is no pressure relief valve. And opening the blow-on door 5, allowing high-temperature and high-pressure steam to rapidly flow through the heating surfaces of the superheater 4 and the reheater 6 from the steam-water separator 3 and the superheater 4 and to be discharged to the atmosphere through the silencer 7, and performing strong scouring on the inner wall of the pipe of each heating surface by high-speed airflow so as to carry impurities out of the boiler by the steam. And when the steam pressure at the steam-water separator 3 is reduced to a required value, closing the blow door 5 and finishing one-time blowing. After that, the boiler ensures combustion, and when the steam pressure is increased to a required value, the next blow pipe can be carried out.

2) There is a pressure relief valve. After the superheater 4 and the reheater 6 are purged for a plurality of times, coarse particle impurities are basically cleaned and discharged out of the boiler, and then purging can further increase the blow pipe coefficient by using a superheater pressure release valve 9 and a reheater pressure release valve 8, so that the blow pipe quality is improved. The specific operation is as follows: when the steam pressure at the steam-water separator 3 rises to a set value, the blow-on door 5 and the superheater decompression valve 9 are opened simultaneously, the steam output by the superheater 4 is discharged into the drainage flash tank 10 rapidly, the steam pressure is reduced rapidly, the pressure difference between the inlet and the outlet of the superheater 4 is increased rapidly, and the blow pipe coefficient of the superheater 4 is increased simultaneously. After purging for a plurality of times, the superheater relief valve 9 is closed, and during blowing, the reheater relief valve 8 is opened, so that the pressure at the outlet of the reheater 6 is rapidly reduced, the pressure drop of the reheater 6 is increased, and the superheater 4 and the reheater 6 can obtain a higher blowing pipe coefficient and better purging quality.

Claims

1. A device for improving the steam blow pipe coefficient of an ultra-supercritical boiler is characterized by comprising a water wall (1), a water storage tank (2), a steam-water separator (3), a superheater (4), a blow door (5), a reheater (6), a silencer (7), a reheater pressure release valve (8), a superheater pressure release valve (9) and a drainage flash tank (10);

the demineralized water pipeline is communicated with an inlet of a steam-water separator (3) through a water-cooled wall (1), a steam exhaust port of the steam-water separator (3) is communicated with an inlet of a superheater (4), an outlet of the superheater (4) is divided into two paths, one path of the demineralized water pipeline is communicated with an inlet of a reheater (6) through a blow-by door (5), the other path of the demineralized water pipeline is communicated with an inlet of a hydrophobic flash tank (10) through a thermal-tank pressure release valve (9), an outlet of the reheater (6) is divided into two paths, one path of the demineralized water pipeline is communicated with the outside atmosphere through a silencer (7), the other path of the demineralized water pipeline is communicated with an inlet of the hydrophobic flash tank (10) through a reheater pressure release valve (8), and a water outlet of the steam-water separator (3) is communicated with an inlet of the hydrophobic flash tank (10).

2. The device for improving the steam blowpipe coefficient of the ultra-supercritical boiler according to claim 1, wherein a condensed water tank (11) is communicated with the bottom outlet of the hydrophobic flash tank (10).

3. The device for improving the steam blowpipe coefficient of the ultra-supercritical boiler as claimed in claim 1, wherein the steam-water separator (3) is of a cylindrical structure.

4. An arrangement for increasing the steam blowpipe coefficient of an ultra supercritical boiler as defined in claim 1 wherein the water holding tank (2) is a long cylindrical vessel.

5. The apparatus for increasing the steam blowpipe coefficient of an ultra supercritical boiler as set forth in claim 1, wherein the hydrophobic flash tank (10) is a steel cylindrical vessel.

6. An arrangement for increasing the steam blowpipe coefficient of an ultra supercritical boiler as defined in claim 1 wherein the silencer (7) is an open cylindrical device.

7. The apparatus for increasing the steam blowpipe coefficient of an ultra supercritical boiler as set forth in claim 2, wherein the condensate tank (11) is a steel can-like container.

8. The device for improving the steam blowpipe coefficient of an ultra-supercritical boiler according to claim 1, characterized in that the superheater pressure relief valve (9) is an electrically operated valve.