Sootblower and sootblowing system

Abstract

The present invention discloses a sootblower and a sootblowing system. The sootblower comprises a lower sootblowing part and an air duct connected to the air inlet of the lower sootblowing part, a Laval nozzle hole is arranged between the air inlet and the air outlet of the lower sootblowing part, and an upper sootblowing part whose air inlet is connected to the air duct, a Laval nozzle hole is arranged between the air inlet and the air outlet of the upper sootblowing part. The sootblower sprays sootblowing jets with compressed air in multiple directions, and the compressed air with a certain pressure and flow rate rolls up the accumulated ash, destroys the sedimentation equilibrium state of the original accumulated ash, and forces the accumulated ash to become a turbulent state and flow away with the flow of flue gas, thereby removing the accumulated ash. In the sootblowing system, the sootblower is arranged in an array inside the slope section and the horizontal section of the flue, and can operate normally in a high-temperature environment without cooling, which is simple and convenient.

Description

Technical Field

[0001] The invention relates to the technical field of boiler sootblowing, and in particular to a sootblower and a sootblowing system. Background Art

[0002] There has been no better solution to the ash accumulation at the flame corner of a power plant boiler. If the ash accumulation at the flame corner is serious, the high-pass and high-resuspended pipes will be buried in the ash, causing high-temperature ash corrosion, and forming corrosion pits on the pipe walls at the lower ends of the high-pass and high-resuspended pipes, resulting in thinning of the pipe walls. Pipes must be inspected and replaced regularly, which will increase the cost of equipment maintenance. At the same time, in extreme cases, when the ash thickness reaches a certain level, the ash will suddenly flow back into the furnace like an avalanche under the disturbance of the flue gas, which may cause the boiler fire extinguishing protection action to start, causing a sudden shutdown accident. Therefore, it is imperative to clean the ash at the boiler's flame corner, but because the flue gas temperature at the boiler's flame corner is relatively high, the high temperature and corrosion resistance requirements of the sootblowing equipment materials need to be higher, resulting in a relatively high cost of sootblowing equipment and certain defects. Summary of the invention

[0003] The present invention provides a soot blower, which aims to not only realize the soot blowing function efficiently and economically, but also effectively avoid the soot blower from being blocked, thereby ensuring the normal use of the soot blower.

[0004] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0005] A sootblower comprises a lower sootblowing part and an air passage communicating with an air inlet of the lower sootblowing part, wherein a Laval spray hole is arranged between the air inlet and the air outlet of the lower sootblowing part for communication.

[0006] Preferably, it further comprises an upper soot blowing portion whose air inlet is connected to the air duct, and a Laval spray hole is arranged between the air inlet and the air outlet of the upper soot blowing portion for communication.

[0007] Preferably, the flow resistance of the upper sootblowing part is greater than the flow resistance of the lower sootblowing part.

[0008] Based on the above technical features, when the soot blower is not in working state, the settled ash in the flue gas will enter the soot blower through the air outlet of the upper soot blowing part or the lower soot blowing part. When the settled ash blocks the air outlet of the upper and lower soot blowing parts, the pressure increases when the soot blower is started. The air outlet of the lower soot blowing part has increased flow resistance due to the blockage, while the air outlet flow resistance of the upper soot blowing part becomes smaller. At this time, compressed air is sucked out of the soot blower from the upper soot blowing part, and the dust in the soot blower is continuously cleaned until the lower soot blowing part is blown through, thereby achieving the purpose of self-cleaning the dust accumulated inside the soot blower.

[0009] Preferably, in the sootblower, the throat diameter of the Laval nozzle hole of the lower sootblowing part is 5×5 to 10×10 mm, and the throat diameter of the Laval nozzle hole of the upper sootblowing part is 2×5 to 5×10 mm.

[0010] Based on the above technical features, the flow velocity of the airflow can be accelerated, thereby achieving strong blowing of the accumulated dust, thereby improving the working performance of the soot blower.

[0011] Preferably, the number of air outlets of the upper and lower sootblowing parts is 4 to 8.

[0012] Based on the above technical features, the upper soot blowing part and the lower soot blowing part can spray airflow from different directions, which can strongly flush the accumulated soot at different positions, greatly improving the soot blowing effect.

[0013] Preferably, the sootblower further comprises a chassis, the lower sootblowing part is arranged on the chassis, and the chassis is provided with a plurality of mounting holes.

[0014] Based on the above technical features, the setting of the fixed installation holes facilitates the good fixation and installation of the soot blower.

[0015] Preferably, a sonicator is provided in the air passage, and is arranged in the airflow direction of the upper soot blowing part 2 and the lower soot blowing part 3 .

[0016] Based on the above technical features, through the auxiliary superposition of sonicators, compressed air is used as the energy source of sound waves. The high-strength titanium metal diaphragm self-oscillates under the action of the compressed air source and generates resonance in the harmonic cavity, converting the potential energy of compressed air into low-frequency sound energy, and transmitting the sound energy to the corresponding ash accumulation points through the air medium, so that the sound waves have the effect of "acoustic fatigue" on the ash and slag. Due to the repeated action of the sound wave oscillation, the extrusion cyclic changing load applied to the ash and slag reaches a certain number of cyclic stresses, and the structure of the ash and slag is destroyed due to fatigue, and then the ash and slag is removed from the surface of the attached body due to gravity or the fluid medium, thereby improving the cleaning effect.

[0017] The present invention also provides a sootblowing system, comprising a high-pressure driving air source, an air supply main pipe and a control device, and a plurality of the above-mentioned sootblowers, wherein the sootblowers are arranged in an array.

[0018] The beneficial effects of the present invention are:

[0019] The sootblower sprays sootblowing jets with compressed air in multiple directions. The compressed air with a certain pressure and flow rate rolls up the accumulated ash, destroys the original sedimentation equilibrium state of the accumulated ash, and forces the accumulated ash to become a turbulent state and flow away with the flow of flue gas, thereby achieving the purpose of removing the accumulated ash. In addition, the unique design of the air outlets of the upper and lower sootblowing parts can not only effectively remove the accumulated ash on the inner wall of the pipeline, but also realize the self-cleaning function, ensuring the normal operation of the sootblower, and having the characteristics of simple structure, high efficiency and economy. The sootblower in the sootblowing system is arranged in an array inside the slope section and the horizontal section of the flue, and can operate normally in a high-temperature environment without cooling, which is simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 This is a schematic structural diagram of a soot blower according to Embodiment 1 of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the upper soot blowing part of the first embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the structure of the lower soot blowing part of the first embodiment of the present invention;

[0024] Figure 4 and Figure 5 This is a working principle diagram of a flat hole according to Embodiment 1 of the present invention;

[0025] Figure 6 This is a diagram of the air pressure analysis of a flat hole according to the first embodiment of the present invention.

[0026] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0027] 1-air duct; 2-upper soot blowing section; 3-lower soot blowing section; 4-chassis; 5-upper air outlet; 6-lower air outlet; 7-installation hole. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-3 As shown, this embodiment is a sootblower, comprising an upper sootblowing part 2 and a lower sootblowing part 3, wherein the upper sootblowing part 2 comprises an upper air inlet and an upper air outlet 5, and the lower sootblowing part 3 comprises a lower air inlet and a lower air outlet 6, wherein the upper air inlet 5 and the lower air inlet 6 are connected to the same air duct 1. The upper sootblowing part 2, the lower sootblowing part 3 and the air duct 1 are integrally formed, which greatly improves the mechanical strength thereof, thereby greatly extending the service life of the sootblower.

[0030] The upper soot blowing part 2 and the lower soot blowing part 3 are both disc-shaped, and the upper soot blowing part 2 and the lower soot blowing part 3 are arranged to form concentric circles, and the airway 1 is arranged at the center of the circle.

[0031] The upper soot blowing part 2 is evenly provided with 4 to 8 upper air outlets 5 in the circumferential direction. The upper air inlet and the upper air outlet 5 are connected by a flat hole provided in the upper soot blowing part 3. The flat hole is a Laval nozzle hole, and the throat diameter of the flat hole is set to 2×5 to 5×10 mm.

[0032] The lower soot blowing part 3 is evenly provided with 4 to 8 lower air outlets 6 in the circumferential direction, and the lower air inlet and the lower air outlet 6 are connected by a flat hole provided in the lower soot blowing part 3, and the flat hole is a Laval spray hole, and the throat diameter of the flat hole is set to be 5×5 to 10×10 mm. The upper soot blowing part 2 and the lower soot blowing part 3 can spray airflow from different directions, and can strongly flush the accumulated soot at different positions, which greatly improves the soot blowing effect.

[0033] The purpose of the flat hole is to accelerate the airflow, and even to transform the subsonic airflow into the supersonic airflow. Figure 4 and Figure 5 The compressed air in the flat hole is ejected backward through the jet nozzle and enters A1 of the nozzle. The movement of compressed air follows the principle that "when the fluid moves in the tube, the flow velocity is high where the cross section is small, and the flow velocity is low where the cross section is large", so the airflow is constantly accelerated. When it reaches the narrow throat A kr When the flow rate w kr It has increased and even exceeded the speed of sound. However, when the transonic fluid is moving, it no longer follows the principle of "the flow velocity is high where the cross section is small, and the flow velocity is low where the cross section is large", but on the contrary, the larger the cross section, the faster the flow velocity. In A2, the speed of the airflow is further accelerated, sometimes equivalent to several times the speed of sound, thus generating a huge jet. The flat hole actually acts as a "flow velocity amplifier", and the thrust of the jet is amplified.

[0034] In order to analyze the influence of the design of external back pressure on the airflow of the flat hole, it is assumed that the ambient pressure outside the outlet section is p a remains constant, while the stagnation pressure P0 at the nozzle inlet section can change. When the total pressure changes, the gas pressure p at the nozzle outlet section eAccording to the relative size of and, the best state of the gas flow in the nozzle is that the ambient pressure outside the outlet section is equal to the gas pressure on the nozzle outlet section, that is, p a =p e .

[0035] The gas is fully expanded in the flat hole, which is the optimal expansion state of the flat hole, also known as the design state. Figure 6 The main characteristics of this flow are:

[0036] 1) The flat pore throat reaches a critical state, and the outlet flow is a high-speed jet or supersonic, that is, Ma>1;

[0037] 2) After the fluid flows out of the nozzle, it neither expands nor compresses, but is a parallel jet;

[0038] 3) Since the flow in the tube is a high-speed jet or supersonic, when a small disturbance occurs in the external environment, the propagation speed of the disturbance is lower than the flow speed, and the disturbance cannot be transmitted into the flat hole.

[0039] The flow resistance of the upper sootblowing part 2 is greater than that of the lower sootblowing part 3. Specifically, the flow resistance between the upper air inlet and the upper air outlet 5 is greater than the flow resistance between the lower air inlet and the lower air outlet 6. When the sootblower is not in operation, the settled ash in the flue gas will enter the sootblower through the upper air outlet or the lower air outlet. When the settled ash blocks the upper and lower air outlets, the pressure increases when the sootblower is started. The flow resistance of the lower air outlet 6 increases due to being blocked, and the flow resistance of the upper sootblowing part 2 becomes smaller. At this time, the compressed air is ejected from the upper sootblowing part 2 to suck the dust in the sootblower, and the dust in the sootblower is continuously cleaned until the lower sootblowing part 3 is blown through, thereby achieving the purpose of self-cleaning the dust accumulated inside the sootblower.

[0040] The sootblower also includes a sonicator, which is provided in both the upper sootblowing part 2 and the lower sootblowing part 3, and is provided in the airflow direction of the upper sootblowing part 2 and the lower sootblowing part 3. By auxiliary superposition of the sonicator, compressed air is used as the energy source of the sound wave, and the high-strength titanium metal diaphragm self-excites under the action of the compressed air source, and resonates in the resonant cavity, converting the potential energy of the compressed air into low-frequency sound energy, and transmitting the sound energy to the corresponding ash accumulation point through the air medium, so that the sound wave plays the role of "acoustic fatigue" on the ash and slag. Due to the repeated action of the sonic wave oscillation, the load of the extrusion cycle change applied to the ash and slag reaches a certain number of cyclic stresses, and the structure of the ash and slag is destroyed due to fatigue, and then the ash and slag is removed from the surface of the attachment due to gravity or fluid medium, thereby improving the cleaning effect.

[0041] The soot blower is also provided with a chassis 4, the lower soot blowing part is provided on the chassis 4, and the chassis 4 is provided with mounting holes 7, so as to facilitate good fixing and mounting of the soot blower.

[0042] Embodiment 2

[0043] A sootblowing system comprises a high-pressure driving air source, an air supply main pipe, a control device, and the sootblower described in Example 1, wherein the control device issues instructions to control the high-pressure driving air source to generate an airflow, and the airflow passes through the air supply main pipe and enters the Laval jet sootblower to perform sootblowing. The control device may be an industrial computer.

[0044] The soot blower is made of alloy material and has the characteristics of high temperature resistance and corrosion resistance. When in use, the laminated disc soot blower is installed in the boiler of a coal-fired power plant and arranged in an array at the slope section and horizontal section of the flame folding angle. The airway is connected to compressed air and driven by compressed air. The soot blower cooperates with the automatic control system to remove the soot accumulated in the flame folding angle in an intermittent or continuous manner. The soot blower is composed of two layers of soot blowing holes, and soot blowing jets are ejected in different directions with compressed air. The airflow is accelerated through the throat and ejected in the form of a high-speed jet. The compressed air with a certain pressure and flow rate rolls up the soot, destroying the original soot sedimentation equilibrium state, and sucking the soot to form turbulence, so that the soot is carried away by the flowing flue gas, so as to achieve the purpose of removing the soot. On this basis, a sonicator can be superimposed to use the characteristics of sonic waves to assist in clearing the soot.

[0045] The present invention has a reasonable structural design. It is arranged in an array inside the slope section and the horizontal section of the flue and can operate normally in a high-temperature environment without cooling. The unique design of the upper and lower layers can not only effectively remove the accumulated dust on the inner wall of the pipeline, but also realize the self-cleaning function, thereby ensuring the normal operation of the soot blower. It has the characteristics of simple structure, high efficiency and economy.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0047] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A soot blower, characterized in that: It includes a lower soot blowing part and an air duct connected to the air inlet of the lower soot blowing part, a Laval spray hole is arranged between the air inlet and the air outlet of the lower soot blowing part, and also includes an upper soot blowing part whose air inlet is connected to the air duct, and a Laval spray hole is arranged between the air inlet and the air outlet of the upper soot blowing part; The flow resistance of the upper soot blowing part is greater than the flow resistance of the lower soot blowing part; The upper soot blowing part is evenly provided with 4 to 8 air outlets in the circumferential direction; The lower soot blowing part is evenly provided with 4 to 8 air outlets in the circumferential direction; The aperture of the air outlet of the upper soot blowing part is smaller than that of the air outlet of the lower soot blowing part. The throat diameter of the Laval nozzle of the upper soot blowing part is 2×5~5×10mm; the throat diameter of the Laval nozzle of the lower soot blowing part is 5×5~10×10mm.

2. The sootblower according to claim 1, characterized in that: The upper and lower sootblowing parts are stacked.

3. The sootblower according to claim 1, characterized in that: The upper soot blowing part and the lower soot blowing part are concentric circles, and the air channel is arranged at the center of the circle.

4. The sootblower according to claim 1, characterized in that: The sootblower further comprises a chassis, the lower sootblowing part is arranged on the chassis, and the chassis is provided with a plurality of mounting holes.

5. The sootblower according to claim 1, characterized in that: A sonicator is also provided, and the sonicator is arranged in the air flow direction of the upper sootblowing part and the lower sootblowing part.

6. A sootblowing system, comprising a high-pressure driving air source, an air supply main pipe and a control device, characterized in that: It also includes a soot blower as described in any one of claims 1 to 5.

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