CN103032884A

CN103032884A - Sealing device of rotary air pre-heater

Info

Publication number: CN103032884A
Application number: CN2012105875903A
Authority: CN
Inventors: 黄辉
Original assignee: ZHOU LINDI
Current assignee: ZHOU LINDI
Priority date: 2012-12-31
Filing date: 2012-12-31
Publication date: 2013-04-10

Abstract

The invention belongs to the energy-saving field and in particular discloses a sealing device of a rotary air pre-heater which is used for a thermal power plant. The sealing device comprises flexible sealing elements which are arranged on a radial fan-shaped plate and an axial sealing plate, wherein the flexible sealing elements are air bags; the width of the air bags is equal to radial distance and axial distance of adjacent two partition plates of a rotator; after the air bags are aerated, one partition plate contacts with the sealing surfaces of the air bags in an extruded manner at every rotary moment of the rotator; and after the air bags are deflated, the sealing surfaces of the air bags are separated from the partition plates of the rotator. According to the sealing device of the rotary air pre-heater disclosed by the invention, an air leakage rate of the air pre-heater can be reduced to an extra-low level; and the operating economy of a boiler can be remarkably improved.

Description

A kind of sealing device of rotary regenerative air preheater

Technical field

The invention belongs to energy-saving field, be specially a kind of sealing device for the thermal power plant rotary regenerative air preheater.

Background technology

Progressively increase along with thermal power plant's single-machine capacity, trisector air heater obtains large-scale application, directly the leaking out of the type air preheater (radially leak out, axially leak out, bypass leak out) problem is the principal element that affects unit economy always, thereby how improves the research emphasis that its performance of leaking out has become a lot of researchers.

Directly leaking out of the type air preheater causes that at contact-making surface pressure difference and rotor and fanning strip gap pressure reduction is larger by the various flows moving medium, and inleakage is larger; The gap is larger, and it is larger to leak out.Thereby how to reduce pressure differential and rotor and the fanning strip gap of various flows moving medium on contact-making surface, become many researchers' research direction, many patents have also been delivered, after being applied in the production, some patented technologies also obtained preferably economic benefit, such as double seal system patent, elastic packing sheet devices patent, auto-compensation gap patent, the flexible contact type sealing patent etc. of leaking out.

Present applied sealing patented technology thinking is diaphragm seal to be installed on the dividing plate of rotor modulus storehouse lattice (radially and/or axially), by automatic adjusting or cold conditions preset clearance method, reach and reduce rotor dividing plate and fanning strip gap, thereby reduce the air-heater leakage amount.But these methods are limited to the minimizing amplitude of air-heater leakage amount, and have difficult, the problems such as seal clearance is difficult to control, the remarkable increase of inleakage of changing after diaphragm seal weares and teares.

Summary of the invention

The object of the invention is to overcome above-mentioned deficiency; a kind of sealing device of rotary regenerative air preheater is provided; its technology thoughtcast of breaking the normal procedure; adopt air bag as potted component; and potted component only is installed in radially on the fanning strip and axial sealing plate; thereby any moment that guarantees rotor has a modelling storehouse lattice dividing plate to contact with potted component, realizes the zero clearance sealing of various flows moving medium intersection.

For realizing above-mentioned technical purpose, scheme provided by the invention is: a kind of sealing device of rotary regenerative air preheater, comprise the flexible sealing element that is installed on the radially fanning strip and axial sealing plate, wherein, described flexible sealing element is air bag, its width is slightly wider than the adjacent two dividing plate radial spacings of rotor and axial spacing respectively, and any moment of rotor has a dividing plate to contact with the sealing surface extruding of air bag behind the airbag aeration, and sealing surface and rotor dividing plate break away from behind the air bag deflation.

And the air sac sealing face on the described radially fanning strip is fan-shaped or analogous shape, the rectangular or analogous shape of air sac sealing face on the described axial sealing plate.

And the outer surface of described air bag has wear-resistant material layer, insulation material layer and adiabator layer from outside to inside successively.

And described wear-resistant material layer is stainless steel cloth or other wear-resisting spray paints, and described insulation material layer is ceramic fiber cloth, and described adiabator layer is glass fabric.

And the radial and axial described air bag inner surface that is positioned at the air preheater hot junction is the fluorine adhesive plaster; The radially described air bag inner surface that is positioned at air preheater cold-end air is silica gel cloth.

And described air bag is communicated with seal fan by the air inlet pipe with inflation control valve, and described air bag is communicated with the exhaust pass of air preheater by the bleeder pipe with vent valve.

And described air inlet pipe arranges Pressure gauge.

And the work of described inflation control valve is controlled by the DCS control system.DCS is the abbreviation of scattered control system (Distributed Control System), and domestic general custom is called Distributed Control System.It is a multi-level computer system take communication network as tie that is comprised of process control level and process monitoring level, combine computer (Computer), communication (Communication), show (CRT) and control 4C technology such as (Control), its basic thought is decentralised control, centralized operation, differentiated control, flexible configuration, configuration convenience.

The present invention can be down to air leak rate of air preheater an extremely low level, can significantly improve Boiler Economical Operation; Can make the installation of air pre-heater sealing element and change operation to become simple, convenient, and to air preheater radially after fanning strip and the axial sealing plate structure optimization, the air preheater of also can realizing not stopping transport is changed potted component; Also can make air preheater under any boiler output operating mode, realize the radial and axial zero sealing of leaking out.

Description of drawings

Fig. 1 is that the present invention is at the structural representation of inflated condition.

Fig. 2 is that the present invention is at the structural representation of air bag deflation state.

Fig. 3 is the schematic diagram that the present invention contacts with the extruding of rotor dividing plate in the inflated condition lower sealing surface.

Fig. 4 is that the present invention is at the schematic diagram of air bag deflation state lower sealing surface and the disengaging of rotor dividing plate.

Fig. 5 is the structural representation of system of the present invention.

Fig. 6 is the cutaway view of A-A face among Fig. 4.

Wherein, 1, the air bag border, 2, sealing surface, 3, axial sealing plate, 4, hot junction fanning strip radially, 5, dividing plate, 6, air bag, 7, Pressure gauge, 8, the inflation limb pipe, 9, the venting branched pipe, 10, the inflation control valve, 11, vent valve, 12, cold junction fanning strip radially.

The specific embodiment

The invention will be further described below in conjunction with drawings and Examples.

Present embodiment provides a kind of sealing device of rotary regenerative air preheater, comprise the flexible sealing element that is installed on the radially fanning strip 4 and axial sealing plate 3, as depicted in figs. 1 and 2, described soft potted component is air bag 6, and its width is slightly wider than rotor adjacent two dividing plates 5 radial spacings and axial spacing respectively.Thereby the sectional dimension that the fanning strip of air bag 6 be used for to be installed only needs than bigger get final product in adjacent two dividing plates, 5 cross sections, can make the air of current air preheater and flue gas intersection fanning strip reduced cross-sectional closely half.Radially fanning strip 4 and axial sealing plate 3 and dividing plate 5 assemblage gaps and required sealing height, rotor axial dividing plate 5 and axial sealing plate 3 gaps and required sealing height, the pre-allowance of rotor thermal expansion and adjacent two dividing plates 5 of rotor are radially, the parameter design such as axial spacing is processed into structure shown in Fig. 1 design sketch according to air preheater rotor under the cold conditions, open some holes on air bag border 1 and be used for being connected with the bolt of fanning strip 4 and axial sealing plate 3, guarantee its tightness during connection.In addition, the potted component among the present invention only is installed in radially on the fanning strip and axial sealing plate 3, carry out Optimal Structure Designing after, when not stopping transport air preheater, can realize the replacing to its potted component.

Any moment of rotor has a dividing plate 5 to contact with sealing surface 2 extruding of air bag 6 after air bag 6 inflations, as shown in Figure 3, after air bag 6 inflations, radially, axially air sac sealing face 2 abundant expansions are " bubbling " shape, contact with 5 extruding of rotor dividing plate, the sealing surface 2 of air bag consists of barrier jointly with dividing plate 5, blocked the both sides flow media because of the leakage current that pressure differential forms, eliminated air preheater radially, axial air leakage phenomena.After air bag 6 inflation, air sac sealing face 2 and the 5 Contact frictions of rotor dividing plate cause that rotary electric machine power consumption recruitment estimates by following formula:

Figure 2012105875903100002DEST_PATH_IMAGE001

(1)

,

Radially, axial seal face 2 causes the motor power consumption recruitment, the w of unit with dividing plate 5 contact frictions;

Sealing surface 2 causes that with dividing plate 5 contact frictions motor power consumption increases total amount, the w of unit;

,

The separate unit air preheater radially, axially air bag 6 quantity are respectively 6 and 3;

,

Radially, axial seal face 2 and dividing plate 5 coefficient of frictions;

Air preheater rotor service cycle, the s of unit;

,

Radially, axial air bag 6 the blowing pressures, the pa of unit;

,

Air preheater rotor dividing plate 5 radially, axial width, the m of unit;

, Be respectively air preheater rotor dividing plate 5 internal diameters and external diameter, the m of unit;

The air preheater rotor height, the m of unit.

Take the 125MW unit as example, get

, , ,

,

, ,

Calculate

,

, air bag 6 causes favourable turn total power consumption recruitment with the maximal friction of rotor

, current increment is 1.3A.

As shown in Figure 4, after air bag 6 venting, sealing surface 2 is " shrivelled " shape, and this moment, sealing surface 2 broke away from rotor dividing plate 5, and rotor can expeditely rotate.

Further, described in the such scheme radially the air sac sealing face 2 on the fanning strip 4 be fan-shaped or analogous shape, air sac sealing the face 2 rectangular or analogous shapes on the described axial dividing plate 5.

Further, the outer surface at air bag described in the such scheme 6 has wear-resistant material layer, insulation material layer and adiabator layer from outside to inside successively.

Further, be stainless steel cloth or other wear-resisting spray paints at wear-resistant material layer described in the such scheme, described insulation material layer is ceramic fiber cloth, described adiabator layer is glass fabric.

Further, the material of air bag 6 can be used for reference resistant to elevated temperatures non-metal expansion joint material composition on the power plant boiler flue in such scheme, adopts high temperature resistant, anticorrosion, high compactness flexible rubber cloth.Radial and axial described air bag 6 inner surfaces that are positioned at the air preheater hot junction are the fluorine adhesive plaster; Radially described air bag 6 inner surfaces that are positioned at air preheater cold-end air are silica gel cloth.

After adding heat insulation, insulation material, the radial and axial air bag 6 in hot junction can be for a long time normally uses under 400 ℃ and above high temperature; Cold junction radially air bag 6 also can be for a long time normally uses under 300 ℃ and above high temperature.

Further, be communicated with the female pipe of seal fan by the air inlet pipe with inflation control valve 10 at air bag described in the such scheme 6, described air bag 6 is communicated with the exhaust pass of air preheater by the bleeder pipe with vent valve 11.During inflation, can export female Guan Yinyi road from seal fan and inflate female pipe to the air preheat applicator platform, through inflation control valve 10 source of the gas be introduced successively air preheater air bag 6 inner chambers by inflation limb pipe 8 again.During venting, close inflation control valve 10 on the inflation limb pipe 8, open vent valve 11, utilize air preheater exhaust pass negative pressure that air bag 6 inner chambers are evacuated to " shrivelled " attitude.

Further, controlled by the DCS control system in the work of the control valve 10 of inflation described in the such scheme.Utilize the DCS control system to write pressure and automatically adjust logic, only need the required pressure target value of input, the adjustment that can realize inflating control valve 10 auto-open-closes.

Step during use is: the zero sealing → pressure adjustment → air bag deflation that leaks out of airbag aeration → pressure adjustment → air bag.Prevent that the control program that inleakage increases after the air preheater rotor thermal expansion from being: the one, described air bag height is reserved the rotor thermal expansion amount, and the 2nd, regulate described air bag inflation pressure.

Claims

1. the sealing device of a rotary regenerative air preheater, comprise the flexible sealing element that is installed on the radially fanning strip and axial sealing plate, it is characterized in that: described soft potted component is air bag, its width is slightly wider than the adjacent two dividing plate radial spacings of rotor and axial spacing respectively, any moment of rotor has a dividing plate to contact with the sealing surface extruding of air bag behind the airbag aeration, and sealing surface and rotor dividing plate break away from behind the air bag deflation.

2. the sealing device of a kind of rotary regenerative air preheater according to claim 1, it is characterized in that: the air sac sealing face on the described radially fanning strip is fan-shaped, and the air sac sealing face on the described axial sealing plate is rectangular.

3. the sealing device of a kind of rotary regenerative air preheater according to claim 1 and 2, it is characterized in that: the outer surface of described air bag has wear-resistant material layer, insulation material layer and adiabator layer from outside to inside successively.

4. the sealing device of a kind of rotary regenerative air preheater according to claim 3, it is characterized in that: described wear-resistant material layer is stainless steel cloth, and described insulation material layer is ceramic fiber cloth, and described adiabator layer is glass fabric.

5. according to claim 1 and 2 or the sealing device of 4 described a kind of rotary regenerative air preheaters, it is characterized in that: the radial and axial described air bag inner surface that is positioned at the air preheater hot junction is the fluorine adhesive plaster; The radially described air bag inner surface that is positioned at air preheater cold-end air is silica gel cloth.

6. the sealing device of a kind of rotary regenerative air preheater according to claim 1, it is characterized in that: described air bag is communicated with the female pipe of seal fan by the air inlet pipe with inflation control valve, and described air bag is communicated with the exhaust pass of air preheater by the bleeder pipe with vent valve.

7. the sealing device of a kind of rotary regenerative air preheater according to claim 6, it is characterized in that: described air inlet pipe arranges Pressure gauge.

8. the sealing device of a kind of rotary regenerative air preheater according to claim 6, it is characterized in that: the work of described inflation control valve is controlled by the DCS control system.