660MW ultra-supercritical primary reheating semi-tower boiler

Abstract

The invention discloses a 660MW ultra-supercritical primary reheating semi-tower boiler, and relates to the technical field of boilers. The invention aims to solve the problems of energy conservation, emission reduction, cost reduction and efficiency improvement of the existing ultra-supercritical unit boiler. A water cooling wall is arranged on the outer side of a boiler body, a tail separation flue is arranged on the rear portion of the upper end of the boiler body, a flue gas adjusting baffle is arranged below the tail separation flue, and an economizer outlet flue, a denitration device outlet flue and a preheater outlet flue are sequentially connected to the rear portion of the flue gas adjusting baffle from front to back. A denitration device is arranged in the denitration device outlet flue, an air preheater is arranged in the preheater outlet flue, cold primary air is heated by the air preheater and then enters a primary air pipeline, a cold secondary air duct is connected to the air preheater, and an induced draft fan is connected to the cold secondary air duct. The air preheater heats cold secondary air and then the cold secondary air enters the secondary air bellow, the over fire air bellow and the combustor secondary air nozzle through the hot secondary air duct. The invention is used for the ultra-supercritical unit.

Description

Technical Field

[0001] The present invention relates to the technical field of boilers, and particularly relates to a 660MW ultra-supercritical once-reheat semi-tower boiler. Background Art

[0002] After the 1980s, with the continuous improvement of the performance level of high-temperature and high-pressure resistant metal materials and the gradual maturity of ultra-supercritical unit technology, its reliability is close to that of subcritical units. The availability of ultra-supercritical and ultra-supercritical units at the world's advanced level can reach more than 85%, and the highest reaches 90%. However, the coal quality burned by large units in foreign power plants changes less than that in China, and generally high-quality coal is burned.

[0003] The operation practice of domestic ultra-supercritical units shows that among the problems occurring in the operation of ultra-supercritical units, except for tube bursts in evaporation systems such as water walls and deformation of spiral tube water walls, most other problems are not inherent problems of ultra-supercritical units themselves. The new generation of ultra-supercritical units adopts a large number of relatively mature technologies, and the reliability level will be further improved. However, during operation, attention should be paid not only to some special problems of ultra-supercritical units but also more to preventing problems similar to those of subcritical units. Summary of the Invention

[0004] In order to solve the problems of energy conservation, emission reduction, cost reduction, and efficiency improvement faced by existing boilers of ultra-supercritical units, the present invention further provides a 660MW ultra-supercritical once-reheat semi-tower boiler.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0006] A 660MW ultra-supercritical once-reheat semi-tower boiler includes a furnace body. A coal mill is provided on one side of the furnace body. The powder feeding pipeline of the coal mill is arranged on the furnace body. A burner is provided on the furnace body. The primary air duct is connected to the powder feeding pipeline and the primary air nozzle of the burner. A water wall is provided outside the furnace body. A tail separation flue is provided at the rear of the upper end of the furnace body. A flue gas regulating baffle is provided below the tail separation flue. The rear of the flue gas regulating baffle is successively connected with a economizer outlet flue, a denitration device outlet flue, and an air preheater outlet flue from front to back. A denitration device is provided in the denitration device outlet flue. An air preheater is provided in the air preheater outlet flue. The air preheater heats the cold primary air and then enters the primary air pipeline. A cold secondary air duct is connected to the air preheater. An induced draft fan is connected to the cold secondary air duct. The air preheater heats the cold secondary air and then enters the secondary air plenum, the overfire air plenum, and the secondary air nozzle of the burner through the hot secondary air duct.

[0007] Further, a lower furnace is provided below the furnace body, an upper furnace is provided above the furnace body, the burner is provided below the lower furnace, and the outlet ends of the secondary air plenum and the overfire air plenum are arranged in the lower furnace.

[0008] Further, the burner burns in a tangential firing mode at the four corners.

[0009] Further, the burner includes a Separated Over-Fire Air (SOFA) burner and a main burner, and the SOFA burner is arranged at a high position.

[0010] Further, a secondary superheater, a final superheater, a high-temperature reheater, and an outlet section of a low-temperature reheater are sequentially arranged in the upper furnace from bottom to top. The tail separation flue includes a front flue of the turning chamber and a rear flue of the turning chamber. The front flue of the turning chamber and the rear flue of the turning chamber are arranged in sequence from front to back. An inlet section of the low-temperature reheater is arranged in the front flue of the turning chamber, a primary superheater and an economizer are arranged in the rear flue of the turning chamber, and a divided economizer is arranged below the denitration device.

[0011] Further, the water-cooled wall includes a spiral tube water-cooled wall and a vertical tube water-cooled wall. The spiral tube water-cooled wall is connected to an intermediate mixing header, and the intermediate mixing header is connected to the vertical tube water-cooled wall in the upper furnace.

[0012] Further, the boiler feed water enters the water-cooled wall through the divided economizer and the economizer. The water-cooled wall enters the water-cooled wall outlet header through the spiral tube water-cooled wall and the vertical tube water-cooled wall. The water-cooled wall outlet header enters the separator through a connecting pipe. The working medium at the outlet of the separator enters the roof panel, the primary superheater, the secondary superheater, and the final superheater respectively through a connecting pipe, and finally enters the main steam system of the boiler; the exhaust steam from the high-pressure cylinder of the steam turbine enters the reheat steam inlet pipeline, and passes through the inlet section of the low-temperature reheater, the outlet section of the low-temperature reheater, and the high-temperature reheater to enter the reheat steam system of the boiler.

[0013] Further, the economizer is arranged in the rear flue of the turning chamber through the economizer suspension pipe, and the economizer is connected to the water-cooled wall through the economizer suspension pipe and the economizer downcomer.

[0014] Further, the secondary superheater is arranged in the upper furnace through the furnace suspension pipe, and the secondary superheater is connected to the primary superheater through the furnace suspension pipe.

[0015] Further, a primary desuperheater is respectively arranged between the primary superheater and the secondary superheater and between the secondary superheater and the final superheater, and a primary emergency desuperheater is arranged between the outlet section of the low-temperature reheater and the high-temperature reheater.

[0016] The beneficial effects included in the present invention compared with the prior art are:

[0017] The present invention provides a 660MW ultra-supercritical once-reheat semi-tower boiler. Compared with traditional tower boilers, the overall height of the boiler is reduced, the cost of steel structure and foundation treatment is reduced, and the wind and earthquake resistance ability is enhanced. At the same time, the phenomenon of furnace ash collapse and the resulting misoperation problem of the flame detection system are effectively avoided. Compared with traditional π-type boilers, the heating surface of the boiler adopts a fully hydrophobic structure, effectively preventing the tube explosion accident of the heating surface caused by the accumulation of oxide scale. At the same time, there is no turning of the flue gas in the high-temperature heating surface area, the flue gas deviation is small, and the wall temperature deviation is easier to control during load change. The boiler is an ultra-supercritical parameter variable pressure operation spiral tube coil + vertical tube coil once-through boiler, with a single furnace, once reheat, adopting the tangential firing method at the four corners, balanced draft, solid slag removal, all-steel suspension structure, and coal-fired semi-tower boiler. The furnace adopts a full membrane type spiral tube coil + vertical tube coil water wall. A flue gas regulating baffle device is arranged at the bottom of the divided flue to distribute the flue gas volume to maintain the reheat steam outlet temperature within the controlled load range. Semi-tower boiler Semi-tower boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the overall structural schematic diagram of the present invention;

[0019] Figure 2 is Figure 1 the top view of. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the following further details the invention in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] Detailed Embodiment 1: In conjunction with Figures 1 to 2 describe this embodiment. The 660MW ultra-supercritical once-reheat semi-tower boiler described in this embodiment includes a furnace body. A coal mill is provided on one side of the furnace body. The powder feeding pipeline of the coal mill is arranged on the furnace body. A burner is provided on the furnace body. The primary air duct is connected to the powder feeding pipeline and the primary air nozzle of the burner. A water wall 16 is provided outside the furnace body. A tail divided flue is provided at the rear of the upper end of the furnace body. A flue gas regulating baffle 26 is provided below the tail divided flue. The rear of the flue gas regulating baffle 26 is successively connected with a economizer outlet flue 5, a denitration device outlet flue 7 and a preheater outlet flue 9 from front to back. A denitration device 6 is provided in the denitration device outlet flue 7. An air preheater 8 is provided in the preheater outlet flue 9. The air preheater 8 heats the cold primary air and then enters the primary air pipeline. A cold secondary air duct is connected to the air preheater 8. An induced draft fan is connected to the cold secondary air duct. The air preheater 8 heats the cold secondary air and then enters the secondary air box 11, the overfire air box 12 and the secondary air nozzle of the burner through the hot secondary air duct 10.

[0022] Detailed Embodiment 2: In conjunction withFigures 1 to 2 In this embodiment, a lower furnace chamber 1 is provided below the furnace body, an upper furnace chamber 2 is provided above the furnace body, the burner is arranged below the lower furnace chamber 1, and the air outlet ends of the secondary air box 11 and the overfire air box 12 are arranged in the lower furnace chamber 1.

[0023] The technical features not disclosed in this embodiment are the same as those in the first specific embodiment.

[0024] Specific embodiment three: Figures 1 to 2 In this embodiment, the burner burns in a tangentially fired manner with four corners.

[0025] The technical features not disclosed in this embodiment are the same as those in the second specific embodiment.

[0026] Specific embodiment four: Figures 1 to 2 In this embodiment, the burner includes a SOFA burner and a main burner, and the SOFA burner is arranged at a high position.

[0027] The technical features not disclosed in this embodiment are the same as those in the third specific embodiment.

[0028] Specific embodiment five: Figures 1 to 2 In this embodiment, a secondary superheater 21, a final superheater 22, a high-temperature reheater 25 and a low-temperature reheater outlet section 24 are successively arranged in the upper furnace chamber 2 from bottom to top. The tail separating flue includes a front turning flue 3 and a rear turning flue 4. The front turning flue 3 and the rear turning flue 4 are successively arranged from front to back. A low-temperature reheater inlet section 23 is arranged in the front turning flue 3, a primary superheater 19 and an economizer 15 are arranged in the rear turning flue 4, and a divided economizer 13 is arranged below the denitration device 6.

[0029] The technical features not disclosed in this embodiment are the same as those in the second specific embodiment.

[0030] Specific embodiment six: Figures 1 to 2 In this embodiment, the water wall 16 includes a spiral tube water wall and a vertical tube water wall. The spiral tube water wall is connected to an intermediate mixing header, and the intermediate mixing header is connected to the vertical tube water wall in the upper furnace chamber.

[0031] The technical features not disclosed in this embodiment are the same as those in the fifth specific embodiment.

[0032] Specific embodiment seven: Figures 1 to 2To describe this embodiment, the boiler feed water in this embodiment enters the water wall 16 through the staged economizer 13 and the economizer 15. The water wall 16 enters the water wall outlet header through the spiral tube water wall and the vertical tube water wall. The water wall outlet header enters the separator 17 through a connecting pipe. The working medium at the outlet of the separator 17 enters the roof wall 18, the primary superheater 19, the secondary superheater 21, and the final superheater 22 respectively through connecting pipes, and finally enters the main steam system of the boiler; the exhaust steam from the high-pressure cylinder of the steam turbine enters the reheat steam inlet pipeline and enters the boiler reheat steam system after passing through the inlet section 23 of the low-temperature reheater, the outlet section 24 of the low-temperature reheater, and the high-temperature reheater 25.

[0033] The technical features not disclosed in this embodiment are the same as those in the sixth specific embodiment.

[0034] Specific Embodiment Eight: Combining Figures 1 to 2 To describe this embodiment, the economizer 14 in this embodiment is arranged in the rear flue 4 of the turning chamber through the economizer suspension pipe 15, and the economizer 14 is connected to the water wall 16 through the economizer suspension pipe 15 and the economizer downcomer.

[0035] The technical features not disclosed in this embodiment are the same as those in the seventh specific embodiment.

[0036] Specific Embodiment Nine: Combining Figures 1 to 2 To describe this embodiment, the secondary superheater 21 in this embodiment is arranged in the upper furnace 2 through the furnace suspension pipe 20, and the secondary superheater 21 is connected to the primary superheater 19 through the furnace suspension pipe 20.

[0037] The technical features not disclosed in this embodiment are the same as those in the seventh specific embodiment.

[0038] Specific Embodiment Ten: Combining Figures 1 to 2 To describe this embodiment, primary spray desuperheaters are respectively arranged between the primary superheater 19 and the secondary superheater 21 and between the secondary superheater 21 and the final superheater 22, and a primary emergency spray desuperheater is arranged between the outlet section 24 of the low-temperature reheater and the high-temperature reheater 25.

[0039] The technical features not disclosed in this embodiment are the same as those in the fifth specific embodiment.

[0040] The superheater system uses the coal-water ratio + desuperheater for temperature regulation, and the reheater system mainly uses the tail gas baffle + burner swing for regulation.

[0041] Working Principle

[0042] The flue gas flow of the present invention is as follows: lower furnace 1, upper furnace 2, front flue of the turning chamber 3, rear flue of the turning chamber 4, flue gas regulating baffle 26, economizer outlet flue 5, denitration device 6, denitration device outlet flue 7, air preheater 8, preheater outlet flue 9, and then it leaves the boiler system.

[0043] The secondary air flow of the present invention is as follows: induced draft fan, cold secondary air duct, air preheater 8, hot secondary air duct 10, secondary air box 11, overfire air box 12, and it enters the lower furnace 1 through the secondary air nozzles of the burner.

[0044] The primary steam flow of the present invention is as follows: feed water pipe, staged economizer 13, economizer 14, economizer suspension pipe 15, water wall 16, separator 17, ceiling and wall casing 18, primary superheater 19, furnace suspension pipe 20, secondary superheater 21, final superheater 22, and it enters the steam turbine through the main steam pipe.

[0045] The secondary steam flow of the present invention is as follows: reheat steam inlet pipe, inlet section of low-temperature reheater 23, outlet section of low-temperature reheater 24, high-temperature reheater 25, and it enters the steam turbine through the reheat steam outlet pipe.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A 660MW ultra-supercritical single-reheat half-tower boiler, comprising a furnace body, a coal mill is arranged on one side of the furnace body, a coal powder delivery pipeline of the coal mill is arranged on the furnace body, a burner is arranged on the furnace body, a primary air duct is connected with the coal powder delivery pipeline and the primary air nozzle of the burner, and is characterized in that: A water-cooled wall (16) is arranged on the outside of the furnace body, a tail partition flue is arranged at the rear of the upper end of the furnace body, a flue gas regulating baffle (26) is arranged below the tail partition flue, the rear of the flue gas regulating baffle (26) is connected to the economizer outlet flue (5), the denitrification device outlet flue (7) and the preheater outlet flue (9) in sequence from front to back, the denitrification device outlet flue (7) is provided with a denitrification device (6), the preheater outlet flue (9) is provided with an air preheater (8), the air preheater (8) heats the cold primary air and then enters the primary air duct, the air preheater (8) is connected to the cold secondary air duct, the cold secondary air duct is connected to the induced draft fan, the air preheater (8) heats the cold secondary air and then enters the secondary air wind box (11), the burnout air wind box (12) and the burner secondary air nozzle through the hot secondary air duct (10).

2. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 1, characterized in that: A lower furnace (1) is provided below the furnace body, an upper furnace (2) is provided above the furnace body, a burner is arranged below the lower furnace (1), and air outlet ends of a secondary air wind box (11) and a burnout air wind box (12) are arranged in the lower furnace (1).

3. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 2, characterized in that: The burner adopts a four-corner tangential combustion method.

4. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 3, characterized in that: The burner comprises a SOFA burner and a main burner, and the SOFA burner is arranged at a high position.

5. The 660MW ultra-supercritical single-reheat half-tower boiler according to claim 2, characterized in that: The upper furnace (2) is provided with a secondary superheater (21), a final superheater (22), a high-temperature reheater (25) and a low-temperature reheater outlet section (24) in sequence from bottom to top, and the tail-partitioned flue comprises a flue before the turning chamber (3) and a flue after the turning chamber (4), which are arranged in sequence from front to back, a low-temperature reheater inlet section (23) is provided in the flue before the turning chamber (3), a primary superheater (19) and an economizer (15) are provided in the flue after the turning chamber (4), and a graded economizer (13) is provided below the denitration device (6).

6. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 5, characterized in that: The water-cooled wall (16) comprises a spiral tube ring water-cooled wall and a vertical tube ring water-cooled wall. The spiral tube ring water-cooled wall is connected to the middle mixing header, and the middle mixing header is connected to the upper furnace vertical tube ring water-cooled wall.

7. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 6, characterized in that: The boiler feed water enters the water-cooled wall (16) through the staged economizer (13) and the economizer (15), the water-cooled wall (16) enters the water-cooled wall outlet header through the spiral tube ring water-cooled wall and the vertical tube ring water-cooled wall, the water-cooled wall outlet header enters the separator (17) through the connecting pipe, the outlet working medium of the separator (17) respectively enters the ceiling wall (18), the first-stage superheater (19), the second-stage superheater (21) and the final-stage superheater (22) through the connecting pipe, and finally enters the boiler main steam system; the exhaust steam of the high-pressure cylinder of the steam turbine enters the reheat steam inlet pipeline, passes through the low-temperature reheater inlet section (23), the low-temperature reheater outlet section (24) and the high-temperature reheater (25), and enters the boiler reheat steam system.

8. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 7, characterized in that: The economizer (14) is arranged in the flue (4) behind the turning chamber through an economizer suspension pipe (15), and the economizer (14) is connected to the water-cooled wall (16) through the economizer suspension pipe (15) and the economizer downcomer.

9. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 7, characterized in that: The secondary superheater (21) is arranged in the upper furnace (2) via a furnace suspension pipe (20), and the secondary superheater (21) is connected to the primary superheater (19) via the furnace suspension pipe (20).

10. A 660MW ultra-supercritical single-reheat half-tower boiler according to claim 5, characterized in that: A first-stage water spray desuperheater is provided between the first-stage superheater (19) and the second-stage superheater (21) and between the second-stage superheater (21) and the final-stage superheater (22), respectively, and a first-stage emergency water spray desuperheater is provided between the low-temperature reheater outlet section (24) and the high-temperature reheater (25).

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