Device for simulating boiler flue gas generation in laboratory and use method thereof

Abstract

The invention belongs to the technical field of simulation devices, and discloses a device for simulating boiler flue gas generation in a laboratory and a using method thereof.The device comprises an electromagnetic vibrator, a feeding groove is fixed to the electromagnetic vibrator, a stock bin is fixed to the position over the end, close to the electromagnetic vibrator, of the feeding groove, and a filter screen is fixed to the bottom of the stock bin; a funnel-shaped container is flexibly connected under the other end of the feeding groove; an air inlet pipe is fixed on the side wall of the funnel-shaped container; a heat preservation cover is fixed to the upper end of the inner tank body, a flow equalizing chamber is fixed to the lower end of the inner tank body, an air inlet is formed in the lower end of the flow equalizing chamber, a heating resistance wire is fixed to the inner wall of the inner tank body, a variable-diameter sleeve is arranged at the upper end in the inner tank body, the upper end of the variable-diameter sleeve is fixed to the heat preservation cover, and the lower end of the funnel-shaped container penetrates through the heat preservation cover and extends into the variable-diameter sleeve. A discharging opening is formed in the heat preservation cover, and the lower end of the interior of the inner tank body is filled with high-alumina ceramic beads; uniform and stable feeding of various trace amounts can be achieved, and meanwhile the coal ash can well achieve the preheating effect.

Description

Technical Field

[0001] The invention belongs to the technical field of simulation devices, and in particular relates to a device for simulating boiler smoke generation in a laboratory and a method for using the device. Background Art

[0002] As the main primary energy source in my country, coal accounts for a large proportion of energy consumption in power station boilers, industrial boilers, power equipment in various related industrial fields, and residents' daily life. During the combustion process of coal in the boiler, it will undergo complex physical and chemical changes, which will lead to the generation of various gases and solid coal ash, such as CO2, NOx and other gases, as well as coal ash that can be suspended in the air for a long time, that is, flue gas, which will cause dust accumulation and slagging on the heating surface of the boiler.

[0003] Therefore, when studying the problem of coal ash deposition on the boiler heating surface, a specific device is needed to simulate the generation of boiler flue gas, which is crucial for a deep understanding of the behavior of coal ash on the boiler heating surface. At this time, a flue gas generator is usually required. However, through research, it is found that the structure and function of existing flue gas generators are uneven. The following introduces several typical simulated flue gas generators:

[0004] For example, publication number CN210496322U discloses a dust aerosol generator, which includes a powder feeding mechanism, a powder transmission mechanism, and a powder injection mechanism. The powder is transported to the conveyor belt of the powder transmission mechanism by the powder feeding mechanism, and then transported to the brush roller box by the conveyor belt, so that the brush roller brushes up the powder on the conveyor belt and carries it to the powder outlet opened on the brush roller box when rolling, and then compressed air is introduced into the brush roller box to flush the powder carried by the brush roller from the powder outlet to the powder injection mechanism. In the above scheme, the amount of powder transported to the outlet is greatly affected by the adhesion characteristics between the brush and the coal ash, that is, when the adhesion is large, the amount of powder is large, and when the adhesion is small, the amount of powder is small. Since the adhesion characteristics between the brush and the coal ash are uncontrollable, the amount of powder transported to the outlet cannot be accurately controlled, which can easily cause uneven feeding and unstable feeding, which will make the concentration difficult to control during aerosol production, resulting in uneven concentration of the generated aerosol. Secondly, since the amount of powder transported to the outlet is affected by the adhesion characteristics between the brush and the coal ash, when the adhesion is small, the powder adhered to the brush becomes less, which can easily cause accumulation of powder in the brush roller box, or even blockage.

[0005] For another example, publication number CN115624892A discloses a device for simulating the generation of boiler flue gas aerosol, including a heating furnace body, a peristaltic pump is arranged at the upper end of the heating furnace body, a liquid delivery pipeline is installed on the peristaltic pump, one end of the liquid delivery pipeline extends into the heating furnace body, and the other end extends into a liquid storage tank containing a suspension. In the above scheme, the suspension is transported into the heating furnace body by means of a peristaltic pump using a liquid delivery pipeline, although uniform feeding can be ensured. In the process of simulating the generation of high-concentration flue gas, in order to increase the content of coal ash in the suspension, we have to significantly increase its concentration. However, this approach will cause the viscosity of the suspension to increase, and then when it is transported by a peristaltic pump, the risk of pipeline blockage will also increase accordingly.

[0006] For another example, publication number CN102390720A discloses a fluidized bed micro-feeder. The main feature of the invented device is to use airflow to fluidize and carry the material to achieve continuous micro-feeding. In order to achieve continuous and stable output, when the working conditions change, the distance between the discharge pipe and the material can be adjusted. This feeding method makes full use of the fluidization characteristics of the fluidized bed, but in actual operation, the fluidization state of the coal ash is very complicated. When the fluidization wind speed changes, its fluidization state will also change, and the corresponding coal ash discharge amount will also change accordingly. How to accurately adjust the discharge amount and keep it stable is still a big problem.

[0007] In addition, in addition to considering the reliability of the flue gas concentration, the dust-containing flue gas needs to be heated to a predetermined temperature. For example, under laboratory conditions, the simulated flue gas is usually required to reach a temperature of more than 600°C. For the current heating method, regenerative heating is a common heating method. This regenerative furnace has a resistance wire arranged on the outside to generate a heat source, and a certain amount of heat storage elements, such as high-temperature resistant ceramic beads, are placed inside. At this time, the ceramic beads are arranged in the heating chamber of the regenerative furnace in a filling manner, and the gas is heated by the high-temperature ceramic beads. However, this regenerative furnace has high requirements for flow. If the designed heating power is extremely mismatched with the flow, the following situations will occur: when the heated flow is too high, the heating furnace will be overloaded, causing the heating element to exceed the allowable temperature and burn out; when the heated gas flow is too low, the heat inside the heating furnace cannot be conducted out in time, and dry burning occurs, which will also cause the heating element of the heating furnace to exceed the allowable temperature and burn out. Moreover, this regenerative furnace is usually used for gas heating, and is rarely considered for heating dust-containing flue gas.

[0008] For example, publication number CN112503763A discloses a small-flow air ultra-high temperature electric heating device. The high-temperature resistant silicon-molybdenum rod is used as the heat exchange element, and a multi-return structure is adopted to extend the heating time of the gas. This device can heat the temperature of a certain flow of gas to above 1000K. However, this device is only designed for gas and is not suitable for dusty gas. Because under this design, the particles will come into direct contact with the heating element, which will not only damage the heating element, but also cause the loss of particles.

[0009] In summary, the existing flue gas generation simulation device still has some key problems to be solved. The main manifestations are: 1) uneven feeding, which will eventually lead to uneven concentration of generated flue gas; 2) how to heat the flue gas containing fine coal ash to a predetermined temperature under limited conditions.

[0010] In summary, in the process of simulating boiler flue gas generation, ensuring the uniform distribution of coal ash and achieving efficient preheating of the flue gas containing coal ash under limited conditions are the key issues that the present invention aims to solve. Summary of the invention

[0011] In view of the deficiencies in the prior art, an object of the present invention is to provide a device for simulating boiler flue gas generation in a laboratory and a method of using the same, so as to solve the problems mentioned in the background technology.

[0012] The purpose of the present invention can be achieved through the following technical solutions:

[0013] A device for simulating boiler flue gas generation in a laboratory, comprising:

[0014] An electromagnetic vibrator, the electromagnetic vibrator is fixedly connected to the side wall of the feeding trough, a silo is fixedly connected to the upper part of one end of the feeding trough close to the electromagnetic vibrator, a filter screen is fixedly connected to the bottom of the silo, a funnel-shaped container is flexibly connected to the lower part of the other end of the feeding trough, and an air inlet pipe connected to the interior of the funnel-shaped container is fixedly connected to the side wall of the funnel-shaped container;

[0015] An outer shell, wherein the inner tank body is fixedly connected to the interior of the outer shell, an insulation cover is fixedly connected to the upper end of the outer shell, an equalizing chamber is fixedly connected to the lower end of the outer shell, an air inlet communicating with the interior of the equalizing chamber is provided at the lower end of the equalizing chamber, a heating resistor is fixedly connected to the inner wall of the inner tank body, a reducing sleeve is provided at the inner upper end of the inner tank body, the upper and lower ends of the reducing sleeve are open structures, the upper end of the reducing sleeve is fixedly connected to the insulation cover, the lower end of the funnel-shaped container passes through the insulation cover and extends into the reducing sleeve, a discharge port is provided on the insulation cover, the discharge port is communicated with the interior of the reducing sleeve, and the lower end of the inner tank body is filled with high-aluminum porcelain beads;

[0016] An air compressor, wherein the air outlet of the air compressor is connected to two pipes, one pipe is connected to the air inlet at the lower end of the flow equalizing chamber, and the other pipe is connected to the air inlet pipe.

[0017] Furthermore, it also includes a digital frequency modulation controller, which is electrically connected to the electromagnetic vibrator.

[0018] Furthermore, a cavity is provided inside the flow equalizing chamber, the air inlet is connected to the cavity, and a plurality of evenly distributed air outlets are provided on the upper end surface of the flow equalizing chamber, and the air outlets are connected to the cavity.

[0019] Furthermore, a cover plate is fixedly connected to the upper end of the feeding trough, and the cover plate is made of a transparent material.

[0020] Furthermore, the cross-sectional shape of the feeding trough is a V-shaped structure.

[0021] Furthermore, a bracket is fixedly connected to the bottom of the outer shell.

[0022] Furthermore, it also includes a temperature-controlled thermocouple, which is fixedly connected to the outer shell, and a detection end of the temperature-controlled thermocouple passes through the outer shell and the inner tank body and extends to the inner side of the inner tank body.

[0023] Furthermore, a first mass flow meter is installed on the pipeline connecting the air compressor and the air inlet, and a second mass flow meter is installed on the pipeline connecting the air compressor and the air inlet pipe.

[0024] Furthermore, the reducing sleeve includes a straight tube arranged at the upper end and a flared tube arranged at the lower end, the diameter of the straight tube is the same as the diameter of the upper end of the flared tube, the diameter of the flared tube increases successively from top to bottom, and the lower end edge of the flared tube is in close contact with the inner wall of the inner tank body.

[0025] A method for using a device for simulating boiler flue gas generation in a laboratory, comprising the following steps:

[0026] Determine the feeding speed: Start the electromagnetic vibrator to drive the silo and the feeding trough to vibrate together, and control the vibration frequency of the electromagnetic vibrator through a digital frequency modulation controller. The coal ash evenly falls from the silo through the filter screen into the feeding trough and starts timing. The accumulated ash within a specified time is collected and weighed, and then the coal ash feeding speed is calculated. Repeat this process several times, take the average value, and finally determine the feeding speed, and then determine the vibration frequency of the electromagnetic vibrator;

[0027] Feeding: Start the electromagnetic vibrator again and set the vibration frequency through the digital frequency modulation controller. The fly ash in the silo falls evenly into the feeding trough through the filter screen through vibration. The fly ash particles show a uniform and linear motion state at the bottom of the feeding trough for feeding;

[0028] Anti-blocking: The fly ash falls evenly into the funnel-shaped container from the feeding trough. At the same time, the air compressor is started to generate airflow. Part of the airflow enters from the side of the funnel-shaped container to form a cyclone, which mixes with the fly ash to form a certain concentration of smoke and enters the reducer sleeve to avoid blockage;

[0029] Preheating: At the same time, the thermal resistor wire is energized to generate heat, so that the fly ash and high-aluminum porcelain beads in the inner tank are heated. Another part of the airflow generated by the air compressor enters the flow equalization chamber and is evenly dispersed before passing through the high-aluminum porcelain beads, causing the airflow to continue to heat up until it mixes with the fly ash. The hot gas further preheats the fly ash. By controlling the gas flow, the fly ash undergoes deceleration and acceleration in the reducing sleeve and then goes out from the discharge port. The fly ash can stay in the inner tank for a long enough time to be fully preheated.

[0030] The nouns, conjunctions or adjectives involved in the above technical solution are explained as follows:

[0031] Fixed connection refers to a connection in which parts or components are fixed without any relative movement. There are two types of connection: detachable and non-detachable.

[0032] (1) A removable connection is a connection that uses screws, splines, wedge pins, etc. to hold parts together. This type of connection can be disassembled for maintenance without damaging the parts. However, the specifications of the connectors used must be correct (such as the length of the bolts, keys, and wedge pins) and they must be properly tightened.

[0033] (2) Non-detachable connections mainly refer to welding, riveting and tenoning. Since they need to be disassembled by forging, sawing or oxygen cutting for maintenance or replacement, spare parts generally cannot be reused. At the same time, when making connections, attention should be paid to process quality, technical inspection and remedial measures (such as calibration, polishing, etc.).

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. In the device of the present invention, the vibrating output end of the vibrating feeder is fixed together with the feeding trough, the silo is fixed above the feeding trough, and the filter screen is fixed at the bottom of the silo. When the vibrating feeder is started to vibrate, the silo and the feeding trough are driven to vibrate together, and the coal ash in the silo is uniformly dropped into the feeding trough through the filter screen by the vibration. The coal ash is uniformly and linearly transported at the bottom of the feeding trough. At the same time, in this process, since the vibration frequency remains unchanged, the coal ash is always uniformly and stably transported, and the final flue gas concentration is relatively uniform.

[0036] 2. In the device of the present invention, by controlling the air intake amount of the air compressor into the funnel-shaped container, the air flow enters from the side of the funnel-shaped container to generate a cyclone, so that the coal ash and air are mixed to form a certain concentration of flue gas and then enter the inner tank body, which, to a certain extent, plays a role in preventing blockage.

[0037] 3. In the device of the present invention, a thermal resistor wire is arranged on the inner wall of the inner tank body, a reducing sleeve is arranged at the upper end of the inner tank body, high-aluminum porcelain beads are filled at the lower end of the inner tank body, and a flow equalization chamber is arranged at the bottom of the inner tank body. When the coal ash enters the reducing sleeve from the upper end, the coal ash is preheated by the heat of the thermal resistor wire. At the same time, the air flow enters the flow equalization chamber from the lower end and is evenly dispersed and then passes through the high-aluminum porcelain beads, so that the gas is continuously heated until it is mixed with the coal ash. The hot gas further preheats the coal ash. By controlling the flow rate of the gas, the coal ash undergoes deceleration and acceleration in the reducing sleeve and then goes out from the discharge port. The coal ash can have a sufficiently long residence time in the inner tank body and be fully preheated. This method can prevent the coal ash from falling into the bottom of the furnace in the low-speed zone and failing to escape in time, and can also ensure that the coal ash has a longer residence time.

[0038] 4. In the device of the present invention, the feeding amount is controlled by adjusting the frequency of electromagnetic vibration, the mesh size of the screen, and the stacking height, and the flow rate and particle concentration of the flue gas are simulated by adjusting the gas flow control within a certain range; the convenience of operation and the accuracy of control are fully considered, so that the user can quickly adjust the parameters according to the needs of the experiment or production, and realize reliable control of the feeding amount and flue gas characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of the structure of a reducer sleeve according to an embodiment of the present invention;

[0042] Figure 3 is a schematic diagram of the structure of the flow equalizing chamber according to an embodiment of the present invention;

[0043] Figure 4 is a front view of a feed trough according to an embodiment of the present invention;

[0044] Figure 5 2. It is a schematic diagram of the three-dimensional structure of the feeding trough according to an embodiment of the present invention;

[0045] Figure 6 It is a schematic diagram of the internal structure of the feeding trough according to an embodiment of the present invention.

[0046] In the figure: 1. electromagnetic vibrator; 2. digital frequency modulation controller; 3. silo; 4. filter screen; 5. feeding trough; 51. conveying part; 510. horizontal conveying channel; 511. smoothing part; 512. gathering part; 52. blanking part; 520. vertical conveying channel; 6. funnel-shaped container; 7. air inlet pipe; 8. discharge port; 9. insulation cover; 10. inner tank body; 11. reducing sleeve; 111. straight pipe; 112. flared pipe, 12. high-aluminum porcelain beads; 13. heating resistance wire; 14. flow equalizing chamber; 141. cavity; 142. air outlet; 15. bracket; 16. air inlet; 17. first mass flow meter; 18. air compressor; 19. second mass flow meter; 20. temperature-controlled thermocouple; 21. outer shell; 22. discharge port; 23. preheating chamber. DETAILED DESCRIPTION

[0047] 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.

[0048] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0049] like Figure 1-Figure 6 As shown, a device for simulating boiler flue gas generation in a laboratory comprises:

[0050] An electromagnetic vibrator 1 is fixedly connected to the side wall of a feeding trough 5. A silo 3 is fixedly connected to the upper part of the feeding trough 5 near one end of the electromagnetic vibrator 1. A filter screen 4 is fixedly connected to the bottom of the silo 3. A funnel-shaped container 6 is flexibly connected to the lower part of the other end of the feeding trough 5. An air inlet pipe 7 connected to the interior of the funnel-shaped container 6 is fixedly connected to the side wall of the funnel-shaped container 6.

[0051] An outer shell 21, the inner tank body 10 is fixedly connected to the inner part of the outer shell 21, the upper end of the outer shell 21 is fixedly connected to the heat preservation cover 9, the lower end of the outer shell 21 is fixedly connected to the flow equalizing chamber 14, the lower end of the flow equalizing chamber 14 is provided with an air inlet 16 connected to the inner part thereof, the inner wall of the inner tank body 10 is fixedly connected with a heating resistance wire 13, a reducing sleeve 11 is provided at the inner upper end of the inner tank body 10, the upper and lower ends of the reducing sleeve 11 are open structures, the upper end of the reducing sleeve 11 is fixedly connected to the heat preservation cover 9, the lower end of the funnel-shaped container 6 passes through the heat preservation cover 9 and extends into the reducing sleeve 11, a discharge port 8 is provided on the heat preservation cover 9, the discharge port 8 is connected to the inside of the reducing sleeve 11, and the lower end of the inner tank body 10 is filled with high-aluminum porcelain beads 12;

[0052] The air compressor 18 has two pipes connected to its air outlet end, one pipe is connected to the air inlet 16 at the lower end of the flow equalizing chamber 14 , and the other pipe is connected to the air inlet pipe 7 .

[0053] When in use, the electromagnetic vibrator 1 is started to generate vibration, which drives the silo 3 and the feeding trough 5 to vibrate together. The coal ash in the silo 3 falls evenly into the feeding trough 5 through the filter screen 4 through vibration. The coal ash shows a uniform and linear motion state at the bottom of the feeding trough 5 until it falls into the funnel-shaped container 6, and then enters the reducing sleeve 11 through the funnel-shaped container 6; at the same time, the thermal resistor 13 is controlled to generate heat so that the coal ash and high-aluminum porcelain beads 12 in the inner tank body 10 are heated; at the same time, the air compressor 18 is started to generate airflow, and a part of the airflow enters from the side of the funnel-shaped container 6. The airflow will blow up the coal ash that falls from the feeding trough 5 to the funnel-shaped container 6. For example, in some occasions, the airflow entering from the side of the funnel-shaped container 6 generates a cyclone, so that the coal ash is mixed with air to form a certain concentration of flue gas, and then enters the reducing sleeve 11, so as to avoid blockage of the coal ash during transportation. The other part of the airflow enters the flow equalization chamber 14 and is evenly dispersed and flows upward. During the heating process, it passes over the surface of the high-aluminum porcelain beads 12, effectively increasing the heat exchange area of ​​the gas. As the airflow temperature rises, it accelerates upward and meets the coal ash moving downward. Since the relative velocity of the gas and solid phases is high, it has a high heat transfer coefficient, which is conducive to the rapid heating of the coal ash. After the coal ash decelerates, it accelerates again under the action of the airflow and finally flows out of the discharge port 8.

[0054] Of course, regarding the description of the fixed connection between the feeding trough 5 and the silo 3, in actual operation, the feeding trough 5 can be directly welded to the silo 3, or the feeding trough 5 can be fixed to the silo 3 through a connecting piece; or in some cases, the feeding trough 5 can be in a detachable manner with the silo 3, such as by bolts, etc., to fix the two together, so that the feeding trough 5 can be integrated with the silo 3.

[0055] Of course, the electromagnetic vibrator 1 is a device that uses electromagnetic force to generate mechanical vibration. It consists of a coil and a magnet. When the current passing through the coil changes, a magnetic field is generated, which exerts a force on the magnet, causing the magnet and the coil to move relative to each other, thereby generating vibration; by adjusting the voltage and frequency of the electromagnetic vibrator 1, the output voltage and output frequency ranges are 0-260V and 40-400HZ respectively, achieving different vibration effects, thereby controlling the feed rate of coal ash.

[0056] To adjust the voltage and frequency of the electromagnetic vibrator 1, an embodiment of the present invention further includes a digital frequency modulation controller 2, which is electrically connected to the electromagnetic vibrator 1. The digital frequency modulation controller 2 is used to control the vibration frequency of the electromagnetic vibrator 1. In the experiment of feeding fly ash using electromagnetic vibration feeding, in order to ensure the accuracy and controllability of the experiment, the voltage and frequency are controlled on the digital frequency modulation controller 2, and the ranges of the output voltage and the output frequency are 0-260V and 40-400HZ, respectively, to achieve different vibration effects, thereby controlling the feeding rate of the fly ash.

[0057] like Figure 4-Figure 6 As shown, for the description of the feed trough 5, as in one embodiment of the present invention, the cross-sectional shape of the feed trough 5 is preferably a V-shaped structure. The V-shaped structure is selected to make the coal ash more concentrated at the bottom of the feed trough 5, and the coal ash movement is uniform and linear; wherein the feed trough 5 includes a conveying part 51 that is fixedly connected between the silo 3 and the silo 3 directly below, and a horizontal conveying channel 510 is formed above the conveying part 51, and the conveying part 51 is arranged horizontally, and the cross-section of the conveying part 51 includes a smooth part 511 at the bottom, and a gathering part 512 that is fixedly connected on both sides of the smooth part 511 for gathering the incoming coal ash; a blanking part 52 is fixedly connected below one end of the conveying part 51 away from the silo 3, and the blanking part 52 is arranged vertically, and a vertical conveying channel 520 is provided in the blanking part 52, and the upper end of the vertical conveying channel 520 is connected to the horizontal conveying channel 510, and the lower end of the vertical conveying channel 520 is connected to the funnel-shaped container 6.

[0058] During implementation, the coal ash falling from the filter screen 4 falls onto the smooth part 511 of the horizontal conveying channel 510. Since the feeding trough 5 is in a vibrating state as a whole, the coal ash on the horizontal conveying channel 510 is uniform. The uniform coal ash falls from the horizontal conveying channel 510 into the vertical conveying channel 520, and then falls from the vertical conveying channel 520 into the funnel-shaped container 6.

[0059] Regarding the description of the filter screen 4, the filter screen 4 can be selected as a metal screen, and the mesh number of the screen needs to be adjusted according to the particle size of the coal ash; for example, in the present application, the particle size of the coal ash needs to be controlled at 10-100 μm, that is, the filter screen 4 can be adjusted to 120 mesh at this time; at the same time, in some occasions, in order to increase the falling speed or amount of the coal ash above the filter screen 4, the filter screen 4 can also be adjusted, such as increasing the sieve aperture of the filter screen 4, thereby increasing the falling speed or amount of the coal ash above the filter screen 4, thereby affecting the feeding amount of the coal ash, such as the sieve aperture of the filter screen 4 can be adjusted to 100 mesh for the feeding amount of the coal ash adapted to the demand of the present application; of course, the stacking height of the coal ash above the filter screen 4 will also affect the falling speed or amount of the coal ash from above the filter screen 4, such as for the present application, such as for the feeding amount of the coal ash adapted to the demand of the present application, the stacking height of the coal ash above the filter screen 4 can be adjusted to 5 cm.

[0060] It should be noted that, in the present application, the outer shell 21, the inner tank 10, the heat-insulating cover 9, the flow-equalizing chamber 14 and the thermal resistance wire 13 together constitute a preheating furnace for preheating the coal ash.

[0061] In one embodiment of the present invention, reference Figure 3 The flow equalizing chamber 14 has a cavity 141 formed inside, the air inlet 16 is connected to the cavity 141, and the upper end surface of the flow equalizing chamber 14 has a plurality of evenly distributed air outlets 142 formed therein, the air outlets 142 are connected to the cavity 141. After the airflow enters the cavity 141 inside the flow equalizing chamber 14 from the air inlet 16 and converges, it is dispersed and evenly flows out from the plurality of air outlets 142. The purpose is to disperse the airflow and improve the preheating efficiency of the airflow when passing through the high-aluminum ceramic beads 12.

[0062] In one embodiment of the present invention, a cover plate is fixedly connected to the upper end of the feed trough 5, and the cover plate is made of a transparent material. Such a design facilitates the operator to observe the movement state of the coal ash in the feed trough 5 through the transparent cover plate. At the same time, it is also convenient for the operator to adjust the vibration frequency of the electromagnetic vibrator 1 according to the movement state of the coal ash. Among them, the cover plate and the feed trough 5 can be fixed by bolt connection. When coal ash accumulates in the feed trough 5, the cover plate can be disassembled for combing.

[0063] In one embodiment of the present invention, a bracket 15 is fixedly connected to the bottom of the outer shell 21. The bracket 15 is provided to support the entire preheating furnace and stabilize the preheating furnace.

[0064] In one embodiment of the present invention, a temperature-controlled thermocouple 20 is further included, and the temperature-controlled thermocouple 20 is fixedly connected to the outer shell 21, and the detection end of the temperature-controlled thermocouple 20 passes through the outer shell 21 and the inner tank body 10 and extends to the inner side of the inner tank body 10. The temperature-controlled thermocouple 20 is configured to detect the real-time temperature inside the inner tank body 10, and is also convenient for subsequent temperature control as needed.

[0065] In one embodiment of the present invention, a first mass flow meter 17 is installed on the pipeline connecting the air compressor 18 and the air inlet 16, and a second mass flow meter 19 is installed on the pipeline connecting the air compressor 18 and the air inlet pipe 7. The first mass flow meter 17 and the second mass flow meter 19 are used to accurately control the gas flow in the pipelines connected to each other.

[0066] In one embodiment of the present invention, reference Figure 2 The reducing sleeve 11 includes a straight tube 111 arranged at the upper end and a flared tube 112 arranged at the lower end. The diameter of the straight tube 111 is the same as the diameter of the upper end of the flared tube 112. The diameter of the flared tube 112 increases from top to bottom. The lower end edge of the flared tube 112 is in close contact with the inner wall of the inner tank body 10.

[0067] The setting of the reducing sleeve 11 is crucial, as it controls the movement state of the coal ash particles by adjusting the gas flow rate. In the bottom of the preheating chamber 23 above the high-aluminum porcelain beads 12 in the inner tank body 10, in order to prevent the preheating furnace from burning out due to excessive power, the flow rate is usually designed to be small, which may be lower than the minimum fluidization wind speed required for the suspension of the coal ash particles. Therefore, once coal ash particles fall into this area, it is difficult to suspend them, which will cause the concentration of coal ash particles at the discharge port 8 to become difficult to control; therefore, in order to prevent the coal ash particles from falling into the bottom of the preheating furnace, it is necessary to properly control their speed. For this application, the airflow passing over the high-aluminum porcelain beads 12 accelerates upward and meets the coal ash particles moving downward, which is used to slow down the falling speed of the coal ash particles. At the same time, the airflow of the high-aluminum porcelain beads 12 accelerates upward. After the deceleration movement, the coal ash particles are accelerated upward again under the action of the airflow carried by the high-aluminum porcelain beads 12, so as to prevent the coal ash particles from falling into the bottom of the preheating furnace;

[0068] At the same time, the coal ash particles coming out of the discharge port 22 of the funnel-shaped container 6 will experience a process of first deceleration and then acceleration inside the reducing sleeve 11, which helps to heat the coal ash particles and increase the residence time in the inner tank 10, thereby achieving more sufficient preheating. This design not only optimizes the preheating effect of the coal ash particles, but also ensures the discharge quality and efficiency of the entire system. Preferably, for the size of the reducing sleeve 11 to be known, the gas velocity change and particle concentration calculation method in the reducing sleeve 11 are as follows:

[0069] The speed at the discharge port 22 is:

[0070]

[0071] The velocity at the straight pipe 111 is:

[0072]

[0073] The velocity at the expanded tube 112 is:

[0074]

[0075] The particle concentration is:

[0076] Among them, Q1 and Q2 represent the gas flow at the feed port 22, the straight pipe 111 and the expanded pipe 112 respectively, in units of m 3 / h, A1, A2 and A3 represent the cross-sectional area of ​​the gas flowing through the feed port 22, the straight pipe 111 and the expanded pipe 112, respectively, in m 2 , M represents the particle mass in g.

[0077] like Figure 2 As shown, the pipe diameter 22 at the feed port is set to 10 mm, the inner diameter of the straight pipe 111 sleeve is 30 mm, the maximum inner diameter of the expanded pipe 112 sleeve is 100 mm, and the gas flow rate at the feed port 22 is selected to be 0.72 m 3 / h, gas flow rate at straight pipe 111 and expanded pipe 112 is 6m 3 / h, and verified that the velocity of the feed port 22 is 2.57m / s, the gas velocity at the bottom of the straight tube 111 is 2.36m / s, the gas velocity at the maximum expansion of the expansion tube 112 is 0.21m / s, and the particle concentration is 6g / m 3 When the particles flow into the area with increased diameter as the gas flows, the gas flow rate decreases relatively due to the increase in cross-sectional area, resulting in a decrease in the carrying force on the particles, so the particles will experience deceleration. This deceleration helps the particles stay in the sleeve for a longer time, so that they can absorb heat more fully and achieve the purpose of preheating. On the contrary, when the particles flow to the area with reduced diameter, the reduction in cross-sectional area causes the gas flow rate to increase, and the carrying force on the particles increases accordingly, so the particles will experience accelerated motion. This acceleration helps the particles continue to move forward in the sleeve, and also helps to maintain the fluidized state of the particles and prevent deposition. Then, the particles go out from the discharge port 8, and can have a sufficiently long residence time in the inner tank body 10 to be fully preheated.

[0078] For example, in one embodiment of the present application, in order to ensure that the coal ash particles are fully preheated and can be discharged from the discharge port 8, the speed of the discharge port and the speed of the straight pipe 111 can be set to 2.57m / s and 2.36m / s respectively; by setting in this way, the effect of first decelerating and then accelerating the coal ash particles can be achieved; of course, for the setting of the speed of the discharge port 22 and the speed of the straight pipe 111, the air flow rate of the discharge port and the air flow rate of the straight pipe 111 can be adjusted, and the inner diameter of the sleeve of the straight pipe 111 and the maximum inner diameter of the sleeve of the expanded pipe 112 can be adjusted at the same time. For example, in practice, the air flow rate of the discharge port 22 is 0.72m 3 / h, and the air flow rate of the straight pipe 111 is 6m 3 / h, and at the same time adjust the inner diameter of the straight tube 111 casing to 30mm and the maximum inner diameter of the expanded tube 112 casing to 100mm.

[0079] A method for using a device for simulating boiler flue gas generation in a laboratory, comprising the following steps:

[0080] Determine the feeding speed: start the electromagnetic vibrator 1 to drive the silo 3 and the feeding trough 5 to vibrate together, control the vibration frequency of the electromagnetic vibrator 1 through the digital frequency modulation controller 2, start timing from the movement of the silo 3 evenly falling into the feeding trough 5 through the filter screen 4, collect the accumulated ash within the specified time, weigh it, and then calculate the coal ash feeding speed, repeat it several times, take the average value, and finally determine the feeding speed, and then determine the vibration frequency of the electromagnetic vibrator 1;

[0081] Feeding: Start the electromagnetic vibrator 1 again and set a certain vibration frequency through the digital frequency modulation controller 2. The coal ash in the silo 3 falls evenly into the feeding trough 5 through the filter screen 4 through vibration. The coal ash shows a uniform and linear motion state at the bottom of the feeding trough 5, and the feeding is carried out;

[0082] Anti-blocking: The coal ash falls evenly from the feeding trough 5 into the funnel-shaped container 6. At the same time, the air compressor 18 is started to generate airflow. A part of the airflow enters from the side of the funnel-shaped container 6 to form a cyclone, which is mixed with the coal ash to form a certain concentration of smoke and enters the reducing sleeve 11 to avoid blockage;

[0083] Preheating: At the same time, the thermal resistor 13 is energized to generate heat, so that the fly ash and high-aluminum porcelain beads 12 in the inner tank body 10 are heated. Another part of the airflow generated by the air compressor 18 enters the flow equalization chamber 14 and is evenly dispersed before passing through the high-aluminum porcelain beads 12, so that the airflow continues to heat up until it is mixed with the fly ash. The hot gas further preheats the fly ash. By controlling the gas flow rate, the fly ash undergoes deceleration and acceleration motion in the reducing sleeve 11, and then goes out from the discharge port 8. The fly ash can have a sufficiently long residence time in the inner tank body 10 and is fully preheated.

[0084] 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.

[0085] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A device for simulating boiler flue gas generation in a laboratory, characterized in that: include: An electromagnetic vibrator (1), the electromagnetic vibrator (1) being fixedly connected to the side wall of a feeding trough (5), a silo (3) being fixedly connected to the upper part of the feeding trough (5) near one end of the electromagnetic vibrator (1), a filter screen (4) being fixedly connected to the bottom of the silo (3), a funnel-shaped container (6) being flexibly connected to the lower part of the other end of the feeding trough (5), an air inlet pipe (7) being fixedly connected to the side wall of the funnel-shaped container (6) and communicating with the interior thereof; An outer shell (21), the inner shell (21) is fixedly connected to an inner tank (10), the upper end of the outer shell (21) is fixedly connected to a heat preservation cover (9), the lower end of the outer shell (21) is fixedly connected to a flow equalization chamber (14), the lower end of the flow equalization chamber (14) is provided with an air inlet (16) communicating with the interior thereof, the inner wall of the inner tank (10) is fixedly connected to a heating resistor (13), and the upper end of the inner shell (10) is provided with a A reducing sleeve (11), wherein the upper and lower ends of the reducing sleeve (11) are open structures, the upper end of the reducing sleeve (11) is fixedly connected to the heat-insulating cover (9), the lower end of the funnel-shaped container (6) passes through the heat-insulating cover (9) and extends into the reducing sleeve (11), the heat-insulating cover (9) is provided with a discharge port (8), the discharge port (8) is communicated with the inside of the reducing sleeve (11), and the lower end of the inner tank body (10) is filled with high-aluminum porcelain beads (12); An air compressor (18), wherein the air outlet end of the air compressor (18) is connected to two pipes, one pipe is connected to the air inlet (16) at the lower end of the flow equalizing chamber (14), and the other pipe is connected to the air inlet pipe (7).

2. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: It also includes a digital frequency modulation controller (2), and the digital frequency modulation controller (2) is electrically connected to the electromagnetic vibrator (1).

3. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: The flow equalizing chamber (14) has a cavity (141) formed inside, the air inlet (16) is connected to the cavity (141), and the upper end surface of the flow equalizing chamber (14) has a plurality of evenly distributed air outlets (142) formed thereon, the air outlets (142) are connected to the cavity (141).

4. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: The upper end of the feeding trough (5) is fixedly connected with a cover plate, which is made of a transparent material.

5. The device for simulating boiler smoke generation in a laboratory according to claim 4, characterized in that: The cross-sectional shape of the feeding trough (5) is a V-shaped structure.

6. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: A bracket (15) is fixedly connected to the bottom of the outer shell (21).

7. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: It also includes a temperature-controlling thermocouple (20), which is fixedly connected to the outer shell (21), and a detection end of the temperature-controlling thermocouple (20) passes through the outer shell (21) and the inner tank body (10) and extends toward the inner side of the inner tank body (10).

8. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: A first mass flow meter (17) is installed on the pipeline connecting the air compressor (18) and the air inlet (16), and a second mass flow meter (19) is installed on the pipeline connecting the air compressor (18) and the air inlet pipe (7).

9. The device for simulating boiler smoke generation in a laboratory according to claim 1, characterized in that: The reducing sleeve (11) comprises a straight tube (111) arranged at the upper end and a flared tube (112) arranged at the lower end, the diameter of the straight tube (111) being the same as the diameter of the upper end of the flared tube (112), the diameter of the flared tube (112) increasing from top to bottom, and the lower end edge of the flared tube (112) being in close contact with the inner wall of the inner tank body (10).

10. A method for using a device for simulating boiler smoke generation in a laboratory, using the device for simulating boiler smoke generation in a laboratory as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Determine the feeding speed: start the electromagnetic vibrator (1) to drive the silo (3) and the feeding trough (5) to vibrate together, control the vibration frequency of the electromagnetic vibrator (1) through the digital frequency modulation controller (2), and start timing when the coal ash evenly falls from the silo (3) through the filter screen (4) into the feeding trough (5). Collect the accumulated ash within a specified time and weigh it, and then calculate the coal ash feeding speed. Repeat this process multiple times, take the average value, and finally determine the feeding speed, and then determine the vibration frequency of the electromagnetic vibrator (1); Feeding: The electromagnetic vibrator (1) is started again and a certain vibration frequency is set through the digital frequency modulation controller (2). The coal ash in the silo (3) falls evenly into the feeding trough (5) through the filter screen (4) by vibration. The coal ash presents an even and linear motion state at the bottom of the feeding trough (5), and feeding is performed; Anti-blocking: The coal ash falls evenly from the feeding trough (5) into the funnel-shaped container (6). At the same time, the air compressor (18) is started to generate airflow. A part of the airflow enters from the side of the funnel-shaped container (6) to form a cyclone, which is mixed with the coal ash to form a certain concentration of smoke and enters the reducing sleeve (11) to avoid blockage. Preheating: At the same time, the thermal resistor (13) is energized to generate heat, so that the coal ash and high-aluminum porcelain beads (12) in the inner tank body (10) are heated. Another part of the airflow generated by the air compressor (18) enters the flow equalization chamber (14) and is evenly dispersed before passing through the high-aluminum porcelain beads (12), so that the airflow continues to heat up until it is mixed with the coal ash. The hot gas further preheats the coal ash. By controlling the flow rate of the gas, the coal ash undergoes deceleration and acceleration in the reducing sleeve (11) and then goes out from the discharge port (8). The coal ash can stay in the inner tank body (10) for a sufficiently long time to be fully preheated.

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