A rear-outlet, side-inlet, multi-stage adjustable deep peak-shaving bypass flue system

Abstract

The present invention discloses a rear-exit and side-inlet multi-stage adjustable deep peak-shaving bypass flue system, comprising a bypass flue main section, a multi-section longitudinal guide box and a flue gas uniform mixer; a large-slope eccentric lead-out interface is arranged on the turning chamber, the large-slope eccentric lead-out interface is connected with the inlet of the multi-section longitudinal guide box through the bypass flue main section, a wind hood is arranged at the outlet of the multi-section longitudinal guide box, wherein one side of the inlet of the multi-section longitudinal guide box is placed on the outside of the denitrification inlet flue, one side of the outlet of the multi-section longitudinal guide box is inserted into the denitrification inlet flue, the flue gas uniform mixer is located above the multi-section longitudinal guide box, and the flue gas uniform mixer is located in the denitrification inlet flue, and the system can increase the flue gas temperature at the denitrification inlet.

Description

Technical Field

[0001] The invention belongs to the technical field of deep peak regulation, and relates to a deep peak regulation bypass flue system with rear-outlet and side-inlet and multi-stage adjustable characteristics. Background Art

[0002] Solving the increasingly serious problem of wind (light, water) abandonment, improving the absorption capacity of new energy, and striving to improve the operational flexibility of thermal power units and enhance the deep peak-shaving capacity are urgent tasks. When thermal power units have a wider load adjustment range and the load lower limit is reduced from the original 45% to 30% or even lower, the flue gas temperature at the economizer outlet is usually lower than 300°C, which cannot meet the operating requirements of the denitrification catalyst.

[0003] With the increasing requirements for thermal power flexibility transformation and deep peak load regulation, the newer 300,000 and 600,000 units have also joined the transformation. The side walls of the vertical shaft flue at the tail of the boiler of these units usually have multiple layers of soot blowers, and after the boiler part and the denitrification part are integrated into a compact design, the traditional high-temperature bypass flue can no longer be arranged. Therefore, it is necessary to develop a new deep peak load bypass flue system to increase the flue gas temperature at the denitrification inlet, so as to better serve the future flexibility transformation of thermal power units. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a rear-outlet and side-inlet multi-stage adjustable deep peak-shaving bypass flue system, which can increase the flue gas temperature at the denitrification inlet.

[0005] To achieve the above-mentioned purpose, the rear-outlet and side-inlet multi-stage adjustable depth peak-shaving bypass flue system of the present invention comprises a bypass flue main section, a multi-section longitudinal guide box and a flue gas uniform mixer;

[0006] A large-slope eccentric lead-out interface is provided on the turning chamber, and the large-slope eccentric lead-out interface is connected with the inlet of the multi-section deep guide box through the bypass flue main section, and a wind hood is provided at the outlet of the multi-section deep guide box, wherein one side of the inlet of the multi-section deep guide box is placed on the outside of the denitrification inlet flue, and one side of the outlet of the multi-section deep guide box is inserted into the denitrification inlet flue, the flue gas uniform mixer is located above the multi-section deep guide box, and the flue gas uniform mixer is located in the denitrification inlet flue.

[0007] The bypass flue main body section includes an inclined flue section and a vertical flue which are sequentially arranged along the flue gas direction.

[0008] Elbows are arranged between the inclined flue and the first expansion joint, between the inclined flue and the vertical flue, and between the vertical flue and the second expansion joint.

[0009] The angle between the inclined flue and the vertical flue is greater than or equal to 120°.

[0010] The large-slope eccentric lead-out interface is connected with the inlet of the multi-section longitudinal guide box through the shut-off door, the adjusting damper door, the first expansion joint, the bypass flue main section and the second expansion joint.

[0011] Each section of the multi-section depth guide box is provided with a multi-stage independently controlled adjustment baffle.

[0012] The mixed flue gas temperature measuring device is located above the flue gas uniform mixer, and the flue gas uniform mixer and the mixed flue gas temperature measuring device are located in the denitrification inlet flue.

[0013] It also includes a controller, which is connected with the mixed flue gas temperature measuring device, the shutoff door, the regulating damper door and the multi-stage independently controlled regulating damper.

[0014] The hood is designed in a chess piece shape.

[0015] The present invention has the following beneficial effects:

[0016] During specific operation, the rear-outlet, side-inlet, multi-stage adjustable deep peak-shaving bypass flue system described in the present invention leads out the high-temperature flue gas in the turning chamber through a large-slope eccentric lead-out interface, and the led-out flue gas flows through the bypass flue main section to the side of the denitrification inlet flue, and then is sprayed into the denitrification inlet flue through a multi-section longitudinal guide box 7, and then is evenly mixed with the main flue gas through a flue gas uniform mixer, thereby achieving the goal of raising the flue gas temperature and improving the uniformity of the temperature field distribution in the denitrification inlet flue. The structure is simple, the operation is convenient, and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 for Figure 1 Cross-section view along the AA direction;

[0019] Figure 3 It is a structural diagram of a multi-section deep flow guide box 7;

[0020] Figure 4 It is a top view of the multi-section deep flow guide box 7;

[0021] Figure 5 It is the structural diagram of the hood 9.

[0022] Among them, 1 is a large-slope eccentric lead-out interface, 2 is a shut-off door, 3 is an adjustable baffle door, 4 is the first expansion joint, 5 is the main section of the bypass flue, 5a is an elbow, 5b is an inclined flue, 5c is a vertical flue, 6 is the second expansion joint, 7 is a multi-section longitudinal guide box, 8 is a multi-stage independently controlled adjustable baffle, 9 is a wind hood, 10 is a flue gas uniform mixer, 11 is a mixed flue gas temperature measuring device, and 12 is a controller. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0024] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0025] refer to Figures 1 to 5 The rear-outlet and side-inlet multi-stage adjustable depth peak-shaving bypass flue system of the present invention comprises a shutoff door 2, an adjustable damper door 3, a first expansion joint 4, a bypass flue main section 5, a second expansion joint 6, a multi-stage longitudinal guide box 7, a multi-stage independently controlled adjustable damper 8, a flue gas uniform mixer 10, a mixed flue gas temperature measuring device 11 and a controller 12;

[0026] A large-slope eccentric lead-out interface 1 is provided on the turning chamber, and the large-slope eccentric lead-out interface 1 is connected to the inlet of the multi-stage deep guide box 7 through the shut-off door 2, the adjustable damper door 3, the first expansion joint 4, the bypass flue main section 5 and the second expansion joint 6. A wind cap 9 is provided at the outlet of the multi-stage deep guide box 7, and each section of the multi-stage deep guide box 7 is provided with a multi-stage independently controlled adjustable damper 8;

[0027] The bypass flue main section 5 includes an inclined flue 5b and a vertical flue 5c arranged in sequence along the flue gas direction, wherein elbows 5a are arranged between the inclined flue 5b and the first expansion joint 4, between the inclined flue 5b and the vertical flue 5c, and between the vertical flue 5c and the second expansion joint 6.

[0028] The angle between the oblique flue 5b and the vertical flue 5c is greater than or equal to 120°.

[0029] In addition, one side of the inlet of the multi-section deep guide box 7 is placed on the outside of the denitrification inlet flue, one side of the outlet of the multi-section deep guide box 7 is inserted into the denitrification inlet flue, the flue gas uniform mixer 10 is located above the multi-section deep guide box 7, the mixed flue gas temperature measuring device 11 is located above the flue gas uniform mixer 10, and the flue gas uniform mixer 10 and the mixed flue gas temperature measuring device 11 are located in the denitrification inlet flue. In actual operation, the high-temperature bypass flue gas depth injection distribution ratio is controlled by the multi-stage independent control adjustment baffle 8; the controller 12 is connected to the mixed flue gas temperature measuring device 11, the shut-off door 2, the adjustment baffle door 3 and the multi-stage independent control adjustment baffle 8.

[0030] The wind hood 9 adopts a chess piece-shaped design, which is beneficial to reduce wear and dust accumulation. The flue gas sprayed from the side of the wind hood 9 is preliminarily mixed with the main flue gas in the denitrification inlet flue. The mixed flue gas then flows through the flue gas mixer 10, and then is evenly mixed by the flue gas mixer 10 and then the temperature is measured by the mixed flue gas temperature measuring device 11.

[0031] The controller 12 receives the output signal of the mixed flue gas temperature measuring device 11, and uses it to automatically control the opening of the regulating damper door 3 and the multi-stage independent control regulating damper 8 to adjust the flue gas flow rate, thereby automatically adjusting the temperature uniformity of the mixed flue gas.

[0032] It should be noted that the present invention optimizes the support design by adding expansion joints to meet the requirements of the thermal displacement of the flue itself.

[0033] In addition, when site conditions permit, the flue structure is optimized and a circular bypass flue is used instead of a rectangular bypass flue. When the flow area is the same, the circular flue has the advantages of less steel usage, more flexible flue layout, and smaller flue resistance compared to the rectangular flue.

[0034] The specific working process of the present invention is:

[0035] When the unit is in low-load operation and the smoke temperature at the denitrification inlet flue does not meet the design temperature of the denitrification reactor, the shut-off door 2 is opened to lead the high-temperature flue gas in the denitrification chamber out through the large-slope eccentric lead-out interface 1, and the smoke intake amount is controlled by adjusting the damper opening of the damper door 3. The led-out flue gas flows through the bypass flue main section 5 and is sent to the side of the denitrification inlet flue. After the flow rate is adjusted by the multi-stage independently controlled damper 8, it is sent to the multi-section longitudinal guide box 7 in sections, and then sprayed into the denitrification inlet flue from the side of the wind hood 9 configured at the corresponding outlet of each section of the longitudinal guide box, and is evenly mixed with the main flue gas through the flue gas uniform mixer 10, thereby achieving the effect of increasing the smoke temperature and improving the uniformity of the temperature field distribution in the denitrification inlet flue.

[0036] The controller 12 receives the output signal of the mixed flue gas temperature measuring device 11, and uses it to automatically adjust the opening and closing of the shut-off door 2, the damper door 3, and the damper opening of the multi-stage independent control adjustment damper 8, so as to control the flow distribution of the high-temperature flue gas injected into the denitrification inlet flue, so as to achieve the purpose of improving the uniformity of the temperature field distribution in the denitrification inlet flue while increasing the flue temperature.

[0037] Finally, it should be noted that the present invention makes full use of the upper and side spaces of the denitrification inlet flue, innovatively guides the high-temperature flue gas in the boiler turning room into the denitrification inlet flue, and injects it into the denitrification inlet flue to mix with the main flue gas. The design of the flue in the system reduces the length of the horizontal flue as much as possible, which can effectively prevent a large amount of dust accumulation from having an adverse effect on the flue body and the steel structure. In addition, through the multi-section depth guide box 7, the high-temperature flue gas is injected into the denitrification inlet flue in sections and depths; at the same time, a wind hood 9 is configured, and the wind hood 9 adopts a chess piece-shaped design, which is conducive to reducing wear and dust accumulation, and the lateral smoke outlet can make the flue gas mixing more fully. The high-temperature flue gas is fully mixed with the low-temperature main flue gas through the flue gas uniform mixer 10, effectively raising the denitrification inlet flue gas temperature to the denitrification requirement and improving the uniformity of the temperature field distribution in the denitrification inlet flue. In addition, the temperature data detected by the mixed flue gas temperature measuring device 11 is used for feedback control to realize automatic adjustment of the entire system, optimize the adjustability of the system, and reduce labor costs.

Claims

1. A rear-outlet, side-inlet, multi-stage adjustable deep peak-shaving bypass flue system, characterized in that: It comprises a bypass flue main body section (5), a multi-section longitudinal guide box (7) and a flue gas uniform mixer (10); A large-slope eccentric lead-out interface (1) is provided on the turning chamber, and the large-slope eccentric lead-out interface (1) is connected to the inlet of a multi-stage longitudinal guide box (7) through a bypass flue main section (5), and a wind cap (9) is provided at the outlet of the multi-stage longitudinal guide box (7), wherein one side of the inlet of the multi-stage longitudinal guide box (7) is placed outside the denitrification inlet flue, and one side of the outlet of the multi-stage longitudinal guide box (7) is inserted into the denitrification inlet flue, and a flue gas uniform mixer (10) is located above the multi-stage longitudinal guide box (7), and the flue gas uniform mixer (10) is located in the denitrification inlet flue; The bypass flue main section (5) comprises an inclined flue (5b) and a vertical flue (5c) arranged in sequence along the direction of the flue gas; Elbows (5a) are provided between the inclined flue (5b) and the first expansion joint (4), between the inclined flue (5b) and the vertical flue (5c), and between the vertical flue (5c) and the second expansion joint (6); The angle between the oblique flue (5b) and the vertical flue (5c) is greater than or equal to 120°; The large-slope eccentric lead-out interface (1) is connected to the inlet of the multi-section longitudinal guide box (7) via the shut-off door (2), the adjustable damper door (3), the first expansion joint (4), the bypass flue main section (5) and the second expansion joint (6); Each section of the multi-section depth guide box (7) is provided with a multi-stage independently controlled adjustment baffle (8).

2. The rear-outlet, side-inlet, multi-stage adjustable deep peak-shaving bypass flue system according to claim 1 is characterized in that: The mixed flue gas temperature measuring device (11) is located above the flue gas uniform mixer (10), and the flue gas uniform mixer (10) and the mixed flue gas temperature measuring device (11) are located in the denitrification inlet flue.

3. The rear-outlet, side-inlet, multi-stage adjustable deep peak-shaving bypass flue system according to claim 2 is characterized in that: It also includes a controller (12), which is connected to the mixed smoke temperature measuring device (11), the shutoff door (2), the regulating damper door (3), and the multi-stage independently controlled regulating damper (8).

4. The rear-outlet, side-inlet, multi-stage adjustable deep peak-shaving bypass flue system according to claim 1 is characterized in that: The wind cap (9) is designed in a chess piece shape.

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