365B-SM7 英文

I—Preface
The installation and acceptance of boiler shall comply with the requirements of DL/T5190.2, Electric Power Construction and Acceptance Specification (Part 2: Boiler Unit).
The specification，which is a supplementary instruction for the special structures of the boiler, is provided only for information during the boiler erection.
In addition to relative laws and regulations, the erecting and acceptance personnel shall review carefully and familiar with this specification, boiler erection drawings and boiler structure as well as relative technical specifications in order to develop corresponding boiler erection process.
II—Major Features of the Boiler
The boiler is a circulating fluidized bed (CFB) boiler. The boiler furnace is constructed by membrane water wall and suspended on the steel structure; at the outlet of the furnace, cyclone separator is steam cooled type; the air preheater is consisted by primary air preheater and secondary air preheater, , with air flows inside the tubes and flue gas flows outside the tubes.
With high flue gas speed and large amount of recirculating material, the particle density within the furnace is very high.
Based on the abovementioned features, special attentions shall be paid to following aspects:
1.Boiler wall lining at the lower part of furnace: operation condition of this location is rough, the
operation temperature is very high and varies intensely, the boiler wall of this location is subjected to abrasion of particles, and the structure of this location are complex due to large amount of tube penetrations.
2.Construction of the anti-abrasive linings for furnace outlet and for tubes around.
3.Construction of cyclone separator outlet structure.
4.Construction of cyclone separator and material recirculating devices
III—Special Structure and Erection Requirements
1. Feeding device:
All flanges bolts connections of coal feeders should be backed with asbestos rubber to ensure sealing condition. And the sealing test should be carried out prior to the erection with the test pressure of 5000Pa.
The coal feeding pipe must align with the position reserved for pipe at the lower part of furnace front wall. Keep the gap between the coal conduit and side walls same. The thickness of casting material on two side walls should be the same and the air port of fuel spreading is symmetrical to the perpendicular bisector to prevent the sweeping and abrasion to single side wall caused by air port declining.
2. Combustion Device
(1)This boiler adopts the water-cooled air chamber and water-cooled air grid, during the erection, it
shall be make sure that the air chamber is sealed without leakage.
(2)Before laying the insulation concrete and casting material between the air nozzles, the small holes
on the air nozzles should be wrapped by plastic films or cloth to avoid the chocking. The surface of fire-resistant concrete must be smooth and without any unevenness. The connection portion between furnace wall and surroundings of the concrete should have a 10mm gap and the aluminum silicate fiber should be filled into it.
(1)The position of the air damper should match the indication. Prior to the final placement, it is
required to mark the baffle damper location on the shaft end to reflect the open/close positions. As
the primary and secondary air is guided into the furnace from the left and right sides respectively, the air damper should be designed into left and right parts, so that the open direction of air damper is consistent with the turning direction of the air duct.
(2)The buildup of the furnace wall should refer to the technical requirement in 365B-5. The selection
and construction of the anti-wearing material and the high strength anti-wearing casting material is one of the key factors to ensure the satisfactory operation of the boiler. The selected materials for this boiler should strictly follow the specified quality standard and be accepted by user according to relative index. It is recommended to have the material supplier to build up the wall to ensure the quality and performance.
3. Membrane Water Wall and Bare Tube Economizer
(1)In the transportation of membrane water wall and bare tube economizer, several times of lifting will
be required, which may cause transformation. When erected at the construction site, the membrane water wall needs to be corrected. In case of any deviation found during butt welding between membrane water wall panels or between panel and header nozzles, the tube fins should be properly cut and corrected before welding back.
(2)For all butt welds of the membrane water wall of tubes of membrane water, the side inside the
furnace must be ground to smooth to avoid local abrasion.
(3)The reinforcement frame for lifting of the membrane water wall is preferable to be installed on the
outside wall of the membrane water wall, if those reinforcement frame have to be installed on the inside wall due to the restriction of the space by other parts, all lifting lugs inside the furnace should be removed and ground to smooth after erection.
(4)Since the superheater panel is narrow and long, it is preferable to install reinforcement frame during
erection to avoid panel bending during lifting.
(5)The distance between the lower water wall of front wall and the water-cooled air chamber should
obey the drawing requirements instead of being enlarged randomly. Avoid the existence of dead zone caused by the enlarged distance between the first row of air button and the front wall, which may affect the fluidization.
4. In the installation process of secondary air duct, the position of each air tube should be corrected against the drawing requirement. After the air tubes are positioned, they should be welded together with the water wall sealing cover. The opening condition of secondary air valve should be consistent with the indicated value. The sealing cover of secondary air tube which is connected with other valve covers should be cut and trimmed at site.
5. The Anti-wearing Measures of the Tubes and Header inside the Furnace
The anchors are welded on the pipe bends and headers that are confronting with the abrasion of flue gas. The anchor surface should be cleaned completely before laying of the high-strength anti-wearing plastic material. The refractory material layer should be dense and firm with no air-pores on it. The anchors are not allowed to be exposed outside and the preparing, construction and maintenance of raw material should all obey the requirements of the material supplier. The construction of anti-wearing layer at the bottom of wing wall heat surface inside the furnace should be quite cautious. The joint part of two sides anti-wearing layers should not be left at the bottom of the platen since this part is most likely to be abraded. The right way is to build the bottom of panel as an integrated part, when the upper interface of refractory layer of lower water wall should be lower than the water wall inner side at the upper part of elbow. See 352B-5.
6. Boiler Top Construction
Top casting material shall be casted on ground before lifting and installation. Special attentions shall be paid to prevent collision during lifting, and anti-wearing casting material shall be filled for joints after
installation, and other heating surface and headers also can be installed after casting on ground.
7. Sealing Construction
（1） All the sealed fireside maze surfaces shall be filled with silica acid aluminum fiber dipped in high temperature bonding agent.
（2） All the metal expansion joints shall be seal welded to ensure the tightness.
8. Cyclone separator and the material returning device Construction
(1)Due to the limit of the transportation condition, the cyclone separator should be divided into many
pieces and assembled at site. To ensure the overall geometric dimension of the cyclone separator is very important to the performance of the cyclone separator and the safety operation. Before delivery, the cyclone separator should be trial assembled in the workshop, and the marks should be made for site splice welding. During erection, the assembly should be made based on the workshop marks, and the following requirements for dimension deviation should be satisfied.
(2)There are 2 types of air nozzles inside the material return device, which are installed at the down leg
(which faces the separator material return leg), and rise leg. The drawings shall be reviewed carefully, to avoid the mixing and errors. The holes on the nozzles shall be sealed by plastic paper or tapes before the concrete casting to prevent blockage.
(3)Anti-wearing plastic material is lined inside the steam-cooled cyclone separator, the inside casting
shall be smooth and without any crack. It is preferable to cast the anti-wearing plastic material on the ground before lifting.
After completion of its installation, the steam-cooled cyclone separator should be subjected to hydraulic test together with the other parts of the boiler proper. For installation of the votex fider, special attention should be given to the order of installation.the plane of the shell holes should be perpendicular to the centerline of the shell, and the deviation between the centers of the holes to the plane shall not exceed ±0.5.
9. For installation welding of superheater and economizer, the tube center line must be aligned; any bias is not allowed to avoid wearing of tubes. The distance between tube panel and front and rear wall shall be made based on the drawing requirements, and a large distance is not allowed in consideration of flue gas aisle
10. Air leakage on the welds on the expansion joints of the air heater is not allowed, especially of the expansion on both side of the tube box, the sealing must be guaranteed. The holes served for the lifting purpose shall be sealing welded after the installation to avoid the local erosion caused by the high pressure air which enters into the flue gas side. The distance between the tube box casing and the tube bundle shall not be too large, to avoid the flue gas aisle, and tube erosion. Staggered arrangement is applied to the air heater, expansion plate is set between the bottom tube plate and support beam. The smoothness of the expansion plate interfaces shall be guaranteed. And a firm and sealed connection between air heater lower bends and flue gas outlet duct.
11. The insulation for the air pipes and steam-water pipes is necessary, and a layer of asbestos ropes by the diameter of Φ10mm shall be applied to the coal feed pipes and ash discharge pipes of the separator, without insulation.
12. When installing the separator and material returning device, pay attention to the installing sequence. There are limit devices at the bottom of the leg. Work according to the drawings strictly to prevent rock.
13. When erecting the cyclone separator and loop seal devices, the sequence of erection shall be taken into consideration
14. In principle, all expansion guiding and anti-vibration devices shall be impact into three directions, and expansion gap shall be provided in the other direction.
15. The thermocouples shall be inserted into the furnace by 150mm, the thermocouple insert depth of the two neighboring boiler shall be the same for easy operation of the operators. The insert depth of the thermocouples at the boiler backpass should be 500mm.
16. Pre-made refractory bricks shall be lined to level off the inner cavity of all doors and holes before the covers are provide, so as to protect the cover and the casting material at the bends from wearing by recirculating material.
IV—The details of boiler drying and boiling-out please see 365B-SM8 boiler operation instruction.
Attentions: after first commissioning, one of the key points of inspection is the inspection of material return device. The recirculation material within material return device shall be totally discharged, and the foreign substance (fine particles scale off from the casted edges or debris formed during drying and boiling out process). This is an importance measure to ensure a safety operation of the material return system in the future.。