Boiler overhaul technology summary

Looking at the white smoke from the #1 boiler, the mood can not be calm for a long time. For today, all leaders and combatants have worked hard for more than 50 days. Looking back at each day of the overhaul, it’s vivid. In order to do a good job in this anti-wear and explosion-proof work, everyone actively participated in the anti-wear inspection, carefully inspect each pipe, each weld, carefully and carefully. First of all, I would like to thank Tianwei Maintenance Company for its anti-wear and explosion-proof group. It is that they have worked tirelessly and hard, and made a great contribution to the a-level maintenance of Jinneng boiler. In order to set the target for the work, in addition to a large number of inspections during the day, data will be organized at night. As an ordinary laborer, there is no rhetoric and no magnificent vows. All trivial and tiny work has turned into a safe haven for boilers. Despite this tiredness, when we looked at the boiler once the water pressure was successful and the ignition was successful, a sense of accomplishment was long in the heart. All the hard work, all the efforts are not the result of successful ignition and safe operation? Work is hard, and it takes a lot of work to do it. When you are involved in it, there is also fun!

First, the main problems and maintenance measures found in the #1 boiler in the a-level maintenance:

1, #1 furnace plasma burner is seriously worn

2. During the overhaul, it was found that part of the soot blower was severely burned and 28 parts need to be replaced.

3, the inner liner of the steam drum crack

All ring welds are ground and strengthened.

4. The first screen of the left side of the separator screen superheater, the 19th pallet of the first number of the first two sheets and the right clamping tube. An anti-wear block has been added.

5. During the anti-wear and explosion-proof inspection process of the boiler, it was found that some of the tubes in the outlet section of the final reheater had scale phenomenon, and then the metal professional cut tube sampling analysis was carried out for the 12cr1mov three-stage spheroidization. Install some thermal control points for real-time monitoring.

6. The steam pipe crack found by metal inspection:

1) After the screen passes through the exit header, the right side of the steam pipe, the three-way weld seam, two places

After the screen passes through the exit header, the right side of the steam pipe, the third half of the weld

After the screen passes through the exit header, the right side of the steam pipe, the three-way weld, the second half of the weld

2) After the screen passes through the outlet header, the left side of the steam pipe, the three-way weld

After the screen passes through the exit header, the left side of the steam pipe, the tee weld, the back of the weld, 1/3 week

3) Screen reheater inlet header left 1 guide steam pipe tee weld length of about 1/4 week, depth of about 4mm; width of about 8mm, two places

Screen reheater inlet header left 1 guide steam pipe tee weld

4) Screen reheater inlet header right 2 guide steam pipe tee, partial grinding

Screen re-inlet header right side steam pipe-2 three-way sanding

5) Screen reheater inlet header The right 1 guide steam pipe tee weld fills up, about 100mm long, 20mm wide and about 10mm deep.

Screen re-inlet header right side steam pipe-1 three-way weld seam to fill

6) The third-stage weld of the right-hand re-inlet header is drilled for about half a week and the depth is about 8mm.

7) The third-stage weld of the right-hand re-export header of the final-stage re-export box is about 100mm long, 20mm wide and about 10mm deep.

The third-stage weld seam of the right-hand re-export header

8) The left-side steam guide tube three-way weld seam of the last-stage inlet and outlet header is about 1/3 week long, about 10mm deep; about 20mm wide.

Last stage inlet and outlet header left side steam pipe tee

9) The third-stage weld of the right-hand inlet and outlet header is trimmed, and the whole circle is about 25mm deep.

The last stage of the inlet and outlet box, the right side of the steam pipe, the three-way weld

7, anti-wear spraying project:
According to the results of the heating surface inspection, the spraying adopts targeted and preventive measures to spray protection against the blower area of ​​the boiler heating surface and the coke area of ​​the burner and the corrosive area of ​​the water wall. The total area of ​​#1 heated surface spraying is 1268.87 square meters. The spraying work is completed as planned. Through the implementation of this spraying project, the corrosion resistance and wear of the pipes in the main area of ​​the heating surface of the boiler are further enhanced, and the service life of the furnace tube is further improved.

8. Soot blower maintenance project:
#1Boiler soot blower overhaul main contents include: 154 sets of soot blower intake valve disassembly grinding and flange seal replacement; 154 sets of soot blower walking box front and rear bearing refueling; 28 sets of furnace soot blower disassembly and burning sleeve Cartridge replacement, specifically b4, b5, b14, b13, b11, c11, c7, c6, c4, c5, d7, d9, d10, d12, d14, d17, d2, d4, e1, e3, e4, e5, e6 , e10, e12, e18, e17, e16; among them, 10 sets of soot blower gearbox disintegration inspection, long blowing 4 sets l16, r23, l23, l24, short blowing 4 sets c8, c17, d8, d17, air preheater 2 sets of soot blowers, at1, at2; wherein the gearbox is replaced by a wear turbine. The soot blower decompression station gas source main pipe upper regulating valve, electric shut-off valve, safety valve, manual valve all carry out physical inspection and grinding, and the process adjustment and setting value setting.
Through the overhaul of this soot blower, the performance of the entire soot blower system and equipment is improved than before the repair, and the stability and safety of the equipment are improved.
9, #1 furnace a-level maintenance and replacement project:

1) The rear smoke well 48.2m furnace left 7th, 64th economizer intermediate header connection pipe horizontal middle section each take 1m, specification: φ51*6.5, material: sa-210c #1 furnace 45.4 meters left rear smoke Well Economizer Middle Union Box Hand Hole Cover Fillet Weld, Union: φ219*35 Material: 106b
13) Replace the elbow and the welding joint with the sewage pipe in the fixed discharge container.
Note: Each pipe has two welds.
A total of 46 tubes were replaced during this inspection, including chemical sampling.
10, burner maintenance project burner main repair is 20 burner repair welding, plasma burner three-stage amplification inner sleeve repair welding and increase wear-resistant aggregate. In addition, the burner is overheated and replaced. Through these inspections, the burner wear is treated, the use time is extended, and the overheated portion is treated.
11. Other items:
In addition, the heating surface desuperheater was overhauled, and the right reheater desuperheater, superheater level, and secondary desuperheater were sampled. No damage was found. After 2 years of operation, the nozzles of the desuperheater were relatively good.