Intelligent ash removal device and method for waste heat boiler

Abstract

The application provides a smart waste heat boiler ash removal device and method, the ash removal device is used for waste heat boiler, and the ash removal device comprises a spraying and brushing device, a plurality of groups of spray gas headers, a transmission device, a spray gas grading valve and a spray gas hose; the transmission device is arranged at one end of the spraying and brushing device in the extension direction of the spraying and brushing device outside the shell; each group of spray gas headers corresponds to one transmission device; the spray gas grading valve corresponding to each group of spray gas headers is connected with the spray gas header through the spray gas hose; and different groups of spray gas headers are arranged above and below the same vertical plane. The method comprises the following steps: monitoring the waste heat boiler flue gas temperature drop and resistance drop; when the flue gas temperature drop and resistance drop are within the set normal threshold range, the ash removal work is periodically performed at a fixed frequency, and it is judged whether the heat exchange tube bundle has accumulated ash; and once the accumulated ash appears, the ash removal is started. The application can remove the stubborn accumulated ash on the surface of the heat exchange tube to the greatest extent and has good ash removal effect.

Description

Technical Field

[0001] The present application relates to the technical field of dust accumulation treatment, and in particular to an intelligent waste heat boiler dust cleaning device and method. Background Art

[0002] Converter (BOF) flue gas is characterized by high temperatures (up to 1600°C) and high dust content (80-150 g / Nm³). The main components of this dust are iron oxides (FeO, Fe₂O₃), iron powder, CaO, SiO₂, MnO, and MgO. Currently, the main methods for recovering converter gas are wet gas recovery (OG) and dry gas recovery (LT). Both methods suffer from the inability to recover waste heat from the medium and low-temperature sections of the converter flue gas (below 900°C). Therefore, using waste heat boilers to recover waste heat from these sections, thereby increasing converter steam production per ton of steel, is a key measure to improve converter steelmaking energy efficiency.

[0003] However, dust from the converter flue gas easily forms a highly adhesive ash layer on the heat exchange surfaces of the waste heat boiler (HRSG), particularly in the convection tube bundle area of ​​the HRSG. This ash layer forms an insulating barrier on the heating surface, reducing heat exchange efficiency and significantly reducing steam production per ton of steel. In severe cases, ash accumulation can clog the heat exchange surfaces of the flue gas system, causing the converter and HRSG systems to malfunction. HRSG ash accumulation also impairs the cooling effect of the converter flue gas, leading to excessively high temperatures and compromising dust removal and converter gas yield.

[0004] At present, the common disadvantages of converter gas recovery, whether it is the OG method or the LT method, are that the waste heat in the medium and low temperature sections (below 900°C) of the converter flue gas is not recovered, and there is currently no effective measure for the ash layer.

[0005] For heat exchange equipment with dusty flue gas from other devices, the existing cleaning methods are as follows: Shutdown cleaning: It is necessary to shut down the machine and manually enter the confined space for operation, which is time-consuming and has high safety risks, and is not conducive to the continuous production of the device. Mechanical vibration cleaning: A vibration device is added to the area prone to dust accumulation, such as the front side of the convection tube bundle; however, the disadvantage is that the impact force of the vibration hammer decays significantly with distance, and the dust accumulation in the tube bundle far away from the hammer head is difficult to remove, and there are dead corners for cleaning. The cleaning effect is poor for nano-scale, highly cemented, and sticky dust; and in addition, the vibration of the equipment is prone to generate electric sparks, which is not suitable for working environments with flammable and explosive gases. Gas pulse purging: The shock wave decays quickly and can remove local dust accumulation to a certain extent. It is difficult to effectively remove dead corners inside dense tube bundles, or highly viscous dust accumulation, plated dust, or slag layers. Acoustic resonance cleaning: The sound energy intensity generated by conventional acoustic wave cleaners is usually between 140 and 155 decibels, which is less effective for viscous, severely scaled or hardened ash deposits; the effective distance is limited, and the noise is relatively loud during operation.

[0006] Therefore, the current cleaning methods all have their own defects, especially for dead corners or severely scaled ash accumulation, which is difficult to effectively remove, and thus difficult to be directly applied to the heat exchange surface of the waste heat boiler. Summary of the Invention

[0007] The present application provides an intelligent waste heat boiler ash cleaning device and method, which can be used to solve the technical problem that ash accumulation in dead corners or severe scaling is difficult to effectively remove.

[0008] The present application provides an intelligent waste heat boiler dust cleaning device, which is used for a waste heat boiler. The waste heat boiler includes multiple groups of heat exchange tubes and a shell, wherein a single group of heat exchange tubes extends horizontally, and different groups of heat exchange tubes are arranged at intervals in the vertical direction; the outer layer of the waste heat boiler is the shell;

[0009] The dust cleaning device includes a spray brush device, a blowing air conveying system, and a transmission device;

[0010] The spray brush device includes a nozzle and a brushing device. The spray brush device is arranged on the spray air pipeline. The spray air is sprayed from the nozzle along the spray air pipeline in the spray air delivery system. A transmission device is provided at one end of the spray air pipeline along the axis of the heat exchange tube. The transmission device is used to drive the spray brush device to move back and forth along the axis of the heat exchange tube.

[0011] Each group of heat exchange tubes corresponds to its own transmission device, that is, different groups of heat exchange tubes can be cleaned separately.

[0012] The dust cleaning device also includes a monitoring and control module, which includes a controller, a temperature sensor and a pressure sensor. The controller controls the brushing device, the air blowing system and the transmission device according to the values ​​of the temperature sensor and the pressure sensor.

[0013] Furthermore, the included angle α between the nozzle and the cross section of the blowing gas pipe where the nozzle is located ranges from 15° to 45°; the included angle β between the nozzle and the longitudinal axis of the cross section where the nozzle is located ranges from 60° to 120°.

[0014] Furthermore, the injection gas pipeline includes an injection gas main pipe and an injection gas branch pipe;

[0015] The axis of the injection gas main pipe is parallel to the axis of the heat exchange tube, one or more injection gas branch pipes are vertically connected to the injection gas main pipe, and the plane formed by the injection gas branch pipe and the injection gas main pipe is parallel to the axis of the heat exchange tube, wherein the spray brush device is provided at the injection gas branch pipe, and the brushing device is provided corresponding to the heat exchange tube;

[0016] A transmission device is provided at one end of the blowing air pipeline extending along the axis of the heat exchange tube.

[0017] Further, the brushing device is arranged at the blowing gas pipeline through a sleeve.

[0018] The specific position of the brushing device is arranged according to the ash deposition condition. In one possible mode, multiple brushing devices are arranged at different positions of the blowing gas branch pipeline in an up-down mode; multiple brushing devices are arranged on one blowing gas branch pipeline.

[0019] In the case of flammable and explosive smoke, the brushing device is a ceramic brush, and the ceramic material has the advantage of insulation.

[0020] Further, the brushing device includes two types: type I blowing brushing device and type II blowing brushing device; wherein the type I blowing brushing device is used for blowing and brushing single-layer heat exchange pipes, that is, one heat exchange pipe corresponds to one blowing gas main pipe; the type II blowing brushing device is used for blowing and brushing double-layer heat exchange pipes at the same time, that is, only one blowing gas main pipe is arranged between two heat exchange pipes.

[0021] Further, the blowing gas conveying system further includes a blowing gas grading valve, a blowing gas hose and a blowing gas header pipe;

[0022] The blowing gas header pipe is connected with multiple blowing gas main pipes;

[0023] The blowing gas grading valve and the blowing gas header pipe are connected through the blowing gas hose.

[0024] Further, a sealing element is arranged between the blowing gas pipeline and the shell of the waste heat boiler, and the sealing element includes an expansion sealing element and a fixed sealing element; wherein the fixed sealing element connects the shell and the blowing gas pipeline; the expansion sealing element connects the fixed sealing element and the blowing gas pipeline, and the expansion sealing element can expand and contract with the movement of the transmission device and the blowing gas pipeline.

[0025] Further, a temperature measuring point is arranged at the inlet of the heat exchange pipe, and a temperature measuring point is arranged at the outlet of the heat exchange pipe; a pressure measuring point is arranged at the inlet of the heat exchange pipe, and a pressure measuring point is arranged at the outlet of the heat exchange pipe.

[0026] Further, the blowing gas includes dust-removed flue gas.

[0027] The present application also provides a smart waste heat boiler ash removal method, and the method is realized by the device provided in the present application; the method includes:

[0028] The monitoring and control module specifically, each inlet gas temperature measuring point, outlet flue gas temperature measuring point, pressure inlet measuring point and pressure outlet measuring point are monitored in real time, and the temperature drop and resistance drop of the waste heat boiler flue gas are monitored;

[0029] When the temperature drop and resistance drop of the flue gas are within the set normal threshold range, the ash removal work is periodically performed at a fixed frequency, and it is judged whether the heat exchange tube bundle exists ash deposition condition;

[0030] Once ash accumulation occurs, start cleaning until the flue gas temperature and resistance drop return to normal thresholds.

[0031] Furthermore, if any value of the flue gas temperature drop and the resistance drop of a certain stage of heat exchange tube exceeds 15% of the normal threshold, it is considered that there is ash accumulation;

[0032] If it is determined that dust accumulation exists, the control blow gas classification valve and transmission device are opened for dust cleaning: the corresponding blow gas classification valve is opened, the blow gas enters the spray brush device and is sprayed out through the nozzle; the transmission device drives the blow gas main pipe to move horizontally, thereby driving the brush sweeping device to move horizontally.

[0033] Furthermore, periodic soot blowing or group cleaning is performed during the overall soot cleaning process. The group cleaning process includes:

[0034] The first-stage spray air classification valve on the top layer is opened first, and the brushing device is moved horizontally under the drive of the transmission device. After reaching the set number of reciprocating times, the second-stage spray air classification valve is opened and sprayed; and so on, until all heat exchangers are cleaned.

[0035] Furthermore, when the dust accumulation is serious, a bottom-up group cleaning method is adopted. First, the lowest layer of the injection air classification valve is opened, and the brushing device is moved horizontally under the drive of the transmission device. After reaching the set number of reciprocating times, it moves upward step by step until all the heat exchangers with serious dust accumulation are cleaned, and then cleaning is carried out from top to bottom.

[0036] The dust cleaning device provided in the present application includes a spray brush device and a transmission device, wherein the spray brush device includes a combination module of several brush sweeping devices + nozzles, and the transmission device can drive the spray brush device to move along the length direction of the heat exchange tube. This composite dust cleaning method combines the ability of the brush sweeping device to loosen sticky and highly adhesive dust accumulation, and the blowing effect on the residual dust accumulation on the surface of multiple heat exchange tubes in the column where the spray brushing point is located. The spray brush device reciprocates along the axial direction of the heat exchange tube, which is conducive to the effective peeling of stubborn dust accumulation or slag layer, and there is no dead angle for cleaning. In addition, the brush sweeping device is wear-resistant, high-temperature resistant, and insulated, which can avoid static electricity from generating electric sparks, thereby achieving an explosion-proof effect.

[0037] The nozzle's spray angle is set relative to the heat exchange tube axis; the nozzle's spray angle is set relative to the tube's circumference. This expands airflow coverage: The spray angle allows airflow to cover a wider area of ​​the heat exchange tube, reducing dead spots. Inducing secondary airflow: Oblique spraying more effectively induces surrounding flue gas, increasing the total amount of cleaning airflow. Improving spray energy utilization: Oblique spraying reduces the ineffective energy loss of direct impact, extending the effective cleaning time of the spray airflow and expanding airflow coverage.

[0038] Gradual control and spraying from top to bottom can guide the dust to fall, which is more in line with the law of dust sedimentation, reduces secondary adsorption, and improves the thoroughness of cleaning. In addition, graded control may allow cleaning layer by layer, reduce system resistance fluctuations, and maintain stable operation.

[0039] When the dust accumulation is serious, a bottom-up blowing scheme is adopted to first remove the lower layer of dust to leave a falling channel for the upper layer of dust.

[0040] Compared with nitrogen, the use of clean flue gas after dust removal as the injection gas can reduce the consumption of nitrogen and other gases, thereby reducing costs. On the other hand, it can reduce the impact on the components of the converter flue gas, such as avoiding affecting the CO content and calorific value of the flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of the converter flue gas purification and waste heat recovery process provided by the present invention;

[0042] Figure 2 Schematic diagram of the heat exchange tubes and dust cleaning spraying device of a certain stage heat exchanger of the converter waste heat boiler provided by the present invention;

[0043] Figure 3 A schematic top view of the heat exchange tubes and dust cleaning spraying device of a certain stage heat exchanger of a converter waste heat boiler provided by the present invention;

[0044] Figure 4 This is a schematic diagram of a blowing and brushing device for cleaning ash from a waste heat boiler;

[0045] Figure 5 This is a partial schematic diagram of a Type I blowing device (blowing single-layer heat exchange tubes);

[0046] Figure 6 This is a partial schematic diagram of the Type II blowing device (blowing double-layer heat exchange tubes).

[0047] The meanings of the accompanying drawings are: 1 converter; 2 flue gas; 3 cooling flue; 4 waste heat boiler: 40 heat exchange tube; 41 brushing device: 410 injection gas main pipe, 411 injection gas branch pipe, 412 collar, 413 brushing device, 414 nozzle; 42 fixed seal; 43 telescopic seal; 44 injection gas header pipe; 45 transmission device; 46 injection gas grading valve; 47 injection gas hose; 48 heat exchange tube support plate; 49 shell; 491 inlet gas temperature measuring point; 492 pressure inlet measuring point; 493 outlet flue gas temperature measuring point; 494 pressure outlet measuring point; 5 dust removal device; 6 injection gas storage tank; 7 injection gas main valve. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0049] The following first introduces the embodiments of the present application with reference to the accompanying drawings.

[0050] like Figures 2 to 6 As shown, the waste heat boiler 4 includes multiple groups of heat exchange tubes 40, heat exchange tube support plates 48, and a shell 49; a brushing device 41 for cleaning the heat exchange tubes, a fixed seal 42, a telescopic seal 43, multiple groups of injection air header pipes 44, a transmission device 45, an injection air classification valve 46, and an injection air hose 47 are also provided;

[0051] The heat exchange tubes 40 of a single group extend horizontally, and different groups of heat exchange tubes 40 are spaced apart in the vertical direction; multiple heat exchange tube support plates 48 are vertically arranged, interspersed with multiple groups of heat exchange tubes 40; the heat exchange tube support plates 48 are evenly spaced apart;

[0052] A transmission device 45 is provided on the outer side of the housing 49 at one end in the extension direction of the brushing device 41;

[0053] Each group of injection air header pipes 44 corresponds to a transmission device 45; each group of injection air header pipes 44 has its own corresponding injection air classification valve 46 connected to the injection air header pipe 44 through an injection air hose 47; different groups of injection air header pipes 44 are arranged in the same vertical plane.

[0054] A telescopic seal 43 and a fixed seal 42 are further provided between the transmission device 45 and the spray brush device 41; wherein the fixed seal 42 is provided at the junction of the housing 49 and the spray brush device 41; the telescopic seal 43 is provided between the fixed seal 42 and the transmission device 45 and can be extended and retracted with the lateral movement of the transmission device 45;

[0055] Among them, the transmission device 45 is used to drive the horizontal displacement of the spray brush device 41; the fixed seal 42 and the telescopic seal 43 ensure the sealing of the waste heat boiler 4 in the process of driving the displacement of the spray brush device 41, realize double sealing, and ensure the isolation of the flue gas from the atmospheric environment; at the same time, the telescopic seal 43 is used to absorb the horizontal displacement of the spray brush device 41; the blowing air hose 47 is used to fix the connection between the blowing air pipeline and the spray brush device 41, and ensure the flexibility of the horizontal displacement of the spray brush device 41; when the flue gas is a flammable and explosive gas such as converter flue gas, the blowing gas is nitrogen.

[0056] like Figures 2 to 6 As shown, the spray brushing device 41 includes a spray air main pipe 410, a spray air branch pipe 411, a collar 412, a brushing device 413, and a nozzle 414.

[0057] The injection gas header pipe 44 is connected to multiple injection gas main pipes 410;

[0058] There are multiple injection air main pipes 410, which are horizontally arranged between the heat exchange tubes 40. The injection air main pipes 410 and the heat exchange tubes 40 have the same extension direction. At least one injection air main pipe 410 is arranged between two adjacent heat exchange tubes 40. It should be noted that in some places with serious dust accumulation or a single heat exchange tube 40 at the top layer, a separate injection air main pipe 410 is corresponding.

[0059] A plurality of injection gas branch pipes 411 are vertically arranged at intervals on the injection gas main pipe 410; the injection gas main pipe 410 and the injection gas branch pipes 411 form a crisscross layout; at least one injection gas branch pipe 411 is arranged between two adjacent heat exchange tube support plates 48;

[0060] Multiple collars 412 are arranged at intervals on the air blowing branch pipe 411; each collar 412 is fixed with a brushing device 413; a nozzle 414 is arranged next to the brushing device 413;

[0061] like Figures 2 to 6 As shown, the heat exchange tube support plate 48 divides the heat exchange tube length into several smaller intervals. Figure 2 The dimension "S" in the figure means that the spraying points of the spraying device can be set to multiple locations to realize the short-stroke reciprocating motion of the spraying device. While achieving the soot cleaning effect, it reduces the space occupied by the reciprocating motion of the spraying device outside the boiler.

[0062] The spray brush device 41 includes two types: type I blowing brush device and type II blowing brush device; type I blowing brush device is used to blow single-layer heat exchange tubes, that is, each blowing air main pipe 410 corresponds to one heat exchange tube; type II blowing brush device is used to blow double-layer heat exchange tubes at the same time, that is, only one blowing air main pipe 410 is set between two heat exchange tubes; the specific structural setting method is detailed in Figure 5 and Figure 6 . Figure 5 and Figure 6 The brushing device + nozzle shown is a preferred embodiment. This composite cleaning method combines the brushing device's ability to loosen sticky and highly adhesive dust deposits with the effect of blowing residual dust deposits on the surfaces of multiple heat exchange tubes in the column where the spraying point is located. The spraying device 41 reciprocates along the axial direction of the heat exchange tube, which is conducive to effectively peeling off stubborn dust or slag layers, eliminating blind spots in cleaning. In addition, in situations where flammable and explosive flue gases are present, the brushing device is a ceramic brush, and the ceramic material has the advantage of insulation. Ceramic brushes are wear-resistant, high-temperature resistant, and insulating, and can prevent static electricity from generating sparks, thereby achieving an explosion-proof effect.

[0063] The transmission device 45 can be driven by air pressure, a hydraulic cylinder or a motor, and can specifically be driven by a screw drive, a wire rope drive, a sprocket chain drive or the like to drive the spray brush device 41 to move back and forth.

[0064] The range of the spray angle α between the nozzle 414 and the axis of the heat exchange tube is shown in FIG. Figure 5 , Figure 6 is 15°~ 45°, preferably 30°; the blowing angle β of the nozzle 414 with the cross section of the heat exchange tube is in the range of Figure 5 , Figure 6 is 60°~ 120°, preferably 90°.

[0065] This arrangement of the nozzle has the following advantages:

[0066] The blowing range of the airflow is expanded, and the dead angle of dust removal is reduced:

[0067] The blowing angle α of the nozzle with the axis of the heat exchange tube strengthens the blowing effect on the surface of the column of multiple heat exchange tubes; the blowing angle β of the nozzle with the cross section of the heat exchange tube increases the blowing range in the length direction of the heat exchange tube. The airflow enters the heat exchange tube bundle space in a non-vertical direction, guides the airflow to adhere and diffuse along the wall surface of the heat exchange tube, and forms a wider blowing coverage, effectively avoiding the dust accumulation on the heat exchange tube.

[0068] The airflow induction and mixing effect are enhanced:

[0069] The oblique blowing airflow produces a strong vortex effect and entrains more secondary airflow, inducing the surrounding flue gas to participate in the dust removal process. Due to the good injection efficiency of oblique blowing, the total kinetic energy of the dust removal airflow is increased.

[0070] The airflow is allowed to diffuse to the surface of the heat exchange tube with less kinetic energy loss, reducing the invalid energy loss of direct impact. Under the same blowing pressure, the effective dust removal time of the oblique blowing airflow is prolonged, and the energy utilization rate is improved.

[0071] An inlet gas temperature measuring point 491 is arranged at the inlet of the heat exchange tube, and an outlet flue gas temperature measuring point 493 is arranged at the outlet of the heat exchange tube; a pressure inlet measuring point 492 is arranged at the inlet of the heat exchange tube, and a pressure outlet measuring point 494 is arranged at the outlet of the heat exchange tube;

[0072] See Figure 1 , the flue gas 2 discharged from the converter 1 enters the waste heat boiler 4 after passing through the cooling flue 3 to further recover heat, and the outlet flue gas enters the dust removal device and then enters the subsequent process.

[0073] Preferably, the relatively clean flue gas after dust removal is used as the blowing gas, and the blowing gas is nitrogen. Specifically, the flue gas after dust removal is introduced after the dust removal device 5, compressed and stored in the blowing gas storage tank 6, and then the flue gas is used for blowing.

[0074] Preferably, the blowing gas grading valve 46 is a shock wave generating valve, and the gas in the reused blowing gas storage tank 6 is stored at a pressure of 0.6~0.8 MPa. When dust blowing operation is needed, the high-pressure gas is quickly released through the shock wave generating valve to form a strong shock wave airflow at the nozzle 414 to blow away the dust and impurities on the surface of the heat exchange tube 40.

[0075] In some embodiments, the brushing gas main is also provided with a brushing device.

[0076] This application also provides an intelligent waste heat boiler ash cleaning method, which is implemented based on the device provided in this application;

[0077] Each inlet gas temperature measuring point 491, outlet flue gas temperature measuring point 493, pressure inlet measuring point 492, and pressure outlet measuring point 494 are monitored in real time to monitor the flue gas temperature drop and pressure drop of the waste heat boiler;

[0078] When the flue gas temperature drop and resistance drop are within the set normal threshold range, the automatic blowing program is set to periodically perform dust cleaning at a fixed frequency, and at the same time determine whether there is dust accumulation in the heat exchange tube bundle;

[0079] Once ash accumulation occurs, start cleaning until the flue gas temperature and resistance drop return to normal thresholds.

[0080] If any value of the flue gas temperature drop and the resistance drop of a certain stage of heat exchange tube exceeds 15% of the normal threshold, it is considered that ash accumulation exists.

[0081] If dust accumulation is detected, the air grading valve 46 and the transmission device 45 are controlled to open for dust removal. Specifically, the corresponding air grading valve 46 is opened, and the air enters the brushing device 41 and is ejected outward through the nozzle 414. The transmission device 45 drives the air main pipe 410 to move horizontally, thereby driving the brushing device 413 to move horizontally.

[0082] For example, if the temperature and resistance drop between the inlet and outlet of a heat exchanger at a certain stage exceed 15% of the set temperature, it is determined that dust accumulation may exist in that heat exchanger, and the injection air grading valve 46 and transmission device 45 of that stage are activated. When the temperature and resistance drop parameters return to normal, the injection air grading valve 46 and transmission device 45 of that stage are deactivated.

[0083] Generally speaking, the low-temperature heat exchange section is the part with more serious dust accumulation. Take the last-stage heat exchanger as an example: set the exhaust gas temperature of this stage heat exchanger to 180℃ and the resistance drop to 120Pa at the initial operation stage; at a certain stage of the operation process, the exhaust gas temperature of this stage heat exchanger is 215℃ and the resistance drop is 160Pa, then it is judged that the equipment has dust accumulation, and the dust accumulation program needs to be started and the frequency of soot blowing needs to be increased.

[0084] Perform soot blowing periodically, or perform soot cleaning in groups during the overall soot cleaning process.

[0085] The injection system also includes an injection gas main valve and an injection gas grading valve. The injection gas grading valve is used to control the injection from top to bottom.

[0086] The topmost, first-stage air-spraying grading valve opens first. Driven by a transmission mechanism, the brushing device 413 moves horizontally. After a set number of reciprocating cycles, the second-stage air-spraying grading valve opens again and begins brushing. This process repeats until all heat exchangers have been cleaned. This brushing method guides dust downward, better aligning with dust settling patterns, reducing secondary adsorption and improving thoroughness of cleaning. Furthermore, graded control allows for layer-by-layer cleaning, reducing fluctuations in flue gas system resistance and maintaining stable operation.

[0087] Preferably, when dust accumulation is severe, a bottom-up group cleaning method is adopted. First, the lowest level of the injection air classification valve is opened. Then, driven by the transmission device, the brushing device 413 is moved horizontally. After reaching a set number of reciprocating cycles, the brushing device 413 is moved upward step by step until all the heat exchangers with severe dust accumulation have been cleaned. Then, the dust is cleaned from top to bottom. The lower layer of dust is removed first to leave a channel for the upper layer of dust to fall, preventing the upper layer of dust from falling into the lower heat exchange tubes and causing blockage.

[0088] The device and method provided in this application can be applied to a variety of scenarios, including converter flue gas, electric furnace flue gas, sintering flue gas, etc. in the steel and metallurgical industry; calcium carbide furnace flue gas; coal-fired / power generation boiler flue gas in the power and energy industry; coal gasification flue gas; cement and glass production kiln flue gas in the building materials industry; waste incineration and solid waste treatment flue gas; non-ferrous metal smelting flue gas, etc.

[0089] This application is particularly suitable for cleaning of bare tubes, longitudinal straight fin tubes, and in-line arranged boiler (heat exchanger) heat exchange tube bundles in toxic, flammable and explosive environments, high dust content, and stubborn dust accumulation.

[0090] The above-described embodiments of the present application do not constitute a limitation on the scope of protection of the present application.

Claims

1. An intelligent waste heat boiler ash cleaning device, characterized in that: The dust cleaning device is used for a waste heat boiler (4), the waste heat boiler (4) comprising a plurality of groups of heat exchange tubes (40) and a shell (49), wherein a single group of heat exchange tubes (40) extends transversely, and different groups of heat exchange tubes (40) are arranged at intervals in the vertical direction; the outer layer of the waste heat boiler (4) is the shell (49); The dust cleaning device includes a brushing device (41), a blowing air delivery system, and a transmission device (45); The spray brush device (41) includes a nozzle (414) and a brushing device (413), the spray gas is sprayed from the nozzle (414) along the spray gas pipeline in the spray gas delivery system, and the transmission device (45) is used to drive the spray brush device (41) to move back and forth along the axial extension direction of the heat exchange tube (40); The injection gas pipeline includes an injection gas main pipe (410) and an injection gas branch pipe (411); The axis of the injection gas main pipe (410) is parallel to the axis of the heat exchange tube (40), one or more injection gas branch pipes (411) are vertically connected to the injection gas main pipe (410), and the plane formed by the injection gas branch pipes (411) and the injection gas main pipe (410) is parallel to the axis of the heat exchange tube (40), wherein the spray brush device is arranged at the injection gas branch pipe, and the brushing device (413) is arranged corresponding to the heat exchange tube; A transmission device (45) is provided at one end of the injection air pipeline extending in the axial direction of the heat exchange tube (40); The brushing device (413) is arranged on the blowing air branch pipe through a collar; The dust cleaning device further includes a monitoring and control module, the monitoring and control module including a controller, a temperature sensor and a pressure sensor, the controller controlling the brushing device (41), the air blowing conveying system and the transmission device (45) according to the values ​​of the temperature sensor and the pressure sensor; The included angle α between the nozzle (414) and the cross section of the blowing gas pipe where the nozzle (414) is located ranges from 15° to 45°; the included angle β between the nozzle (414) and the longitudinal axis of the cross section where the nozzle (414) is located ranges from 60° to 120°; The injection gas includes the flue gas after dust removal.

2. The dust cleaning device according to claim 1, characterized in that: The spray brushing device (41) includes two types: a type I blowing brushing device and a type II blowing brushing device; wherein the type I blowing brushing device is used to blow brush single-layer heat exchange tubes, that is, each blowing air main pipe (410) corresponds to one heat exchange tube; the type II blowing brushing device is used to blow brush double-layer heat exchange tubes at the same time, that is, only one blowing air main pipe (410) is set between the two heat exchange tubes.

3. The dust cleaning device according to claim 1, characterized in that: The injection gas delivery system also includes an injection gas classification valve (46), an injection gas hose (47), and an injection gas header pipe (44); Wherein, the injection gas header pipe (44) is connected to a plurality of injection gas main pipes (410); The injection gas classification valve (46) and the injection gas header pipe (44) are connected by an injection gas hose (47).

4. The dust cleaning device according to claim 1, characterized in that: A sealing member is provided between the injection gas pipeline passing through the waste heat boiler shell and the shell (49), and the sealing member includes a telescopic sealing member (43) and a fixed sealing member (42); wherein the fixed sealing member (42) connects the shell (49) and the injection gas pipeline; and the telescopic sealing member (43) connects the fixed sealing member (42) and the injection gas pipeline, wherein the telescopic sealing member can be telescoped along with the movement of the transmission device (45) and the injection gas pipeline.

5. The dust cleaning device according to claim 1, characterized in that: An inlet gas temperature measuring point (491) is set at the inlet of the heat exchange tube, and an outlet flue gas temperature measuring point (493) is set at the outlet; a pressure inlet measuring point (492) is set at the inlet of the heat exchange tube, and a pressure outlet measuring point (494) is set at the outlet of the heat exchange tube.

6. A smart waste heat boiler ash cleaning method, which is implemented based on the device provided in claim 3; characterized in that: The method comprises: The monitoring and control module performs real-time monitoring to monitor the flue gas temperature drop and resistance drop of the waste heat boiler; When the flue gas temperature drop and resistance drop are within the set normal threshold range, the dust cleaning work is carried out periodically at a fixed frequency, and at the same time, it is determined whether there is dust accumulation in the heat exchange tube bundle; Once ash accumulation occurs, start cleaning until the flue gas temperature drop and resistance drop return to normal thresholds; If any value of the flue gas temperature drop or resistance drop of a certain stage of heat exchange tube exceeds 15% of the normal threshold, it is considered that there is dust accumulation; If dust accumulation is determined to exist, the spray gas classification valve (46) and the transmission device (45) are controlled to open for dust removal: the corresponding spray gas classification valve (46) is opened, the spray gas enters the spray brush device (41), and is sprayed outward through the nozzle (414); the transmission device (45) drives the spray gas main pipe (410) to move horizontally, thereby driving the brush sweeping device (413) to move horizontally; Periodically blow off dust, or perform group cleaning during the overall cleaning process. The group cleaning process includes: The spray air classification valve of the first stage on the top layer is opened first, and the brushing device (413) is moved horizontally under the drive of the transmission device. After reaching the set number of reciprocating times, the spray air classification valve of the second stage is opened and sprayed; and so on, until all heat exchangers are cleaned.

7. The method according to claim 6, characterized in that When the dust accumulation is serious, a bottom-up group cleaning method is adopted. First, the injection air classification valve at the bottom layer is opened, and the brushing device (413) is moved horizontally under the drive of the transmission device. After reaching the set reciprocating number, it moves upward step by step until all the heat exchangers with serious dust accumulation are cleaned, and then the dust is cleaned from top to bottom.

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