Device for improving calcium-based dry desulfurization efficiency by dynamically spraying nanofluid

Abstract

The utility model belongs to the technical field of flue gas purification, and relates to a device for improving calcium-based dry desulfurization efficiency by dynamically jetting nanofluid, which comprises a nanofluid supply facility, a nanofluid ejector and a control system, the nanofluid supply facility comprises a nanofluid generator, a nanofluid conveying switch valve, a fluid pump, a nanofluid spraying time control electromagnetic valve, a nanofluid spraying flow control regulating valve and a nanofluid spraying site switch valve which are sequentially connected in the flowing direction of nanofluid. An outlet of the nanofluid injection site switch valve is connected with the nanofluid injector; the nano-fluid generator, the nano-fluid conveying switch valve, the nano-fluid spraying time control electromagnetic valve, the nano-fluid spraying flow control regulating valve and the nano-fluid spraying site switch valve are all connected with a control system; the nano-fluid ejector is arranged in a flue gas pipeline, is a multi-fluid ejector and is at least provided with more than two groups of forward-spraying / reverse-spraying injection heads.

Description

Technical Field

[0001] This utility model belongs to the field of flue gas purification technology and relates to a device for improving the efficiency of calcium-based dry desulfurization by dynamic injection of nanofluids. Background Technology

[0002] To meet the national requirement for ultra-low SO2 emissions (<35mg / Nm³) 3 To meet the requirements of [unspecified requirements], calcium-based dry desulfurization technology is currently widely used. However, due to factors such as the low activity of Ca(OH)2 in the dry state, the slow diffusion rate of SO2 within the desulfurizing agent, the fact that calcium sulfate, a product of the desulfurization reaction, hinders the exposure of active sites within the desulfurizing agent, and the low activity of single calcium-based desulfurizing agents, the efficiency of calcium-based dry desulfurization is only about 70%, with an actual Ca / S molar ratio of around 4, resulting in a significant waste of Ca(OH)2. Currently, the industry mainly focuses on the preparation of highly active, multifunctional calcium-based desulfurizing agents, with limited research on how to enhance the reaction process between Ca(OH)2 and SO2, and how to in-situ enhance the efficiency of Ca(OH)2 desulfurizing agents during the reaction. Analysis of the calcium-based desulfurization process revealed that: (1) After the reaction of Ca(OH)2 with SO2, calcium sulfate, which is insoluble in water, is generated on the surface of the desulfurizing agent, which hinders the further reaction of the internal desulfurizing agent with SO2 and greatly wastes the desulfurizing agent; (2) The single Ca(OH)2 desulfurizing agent itself has low activity and the reaction process with SO2 is slow; (3) The reaction between Ca(OH)2 and SO2 is an exothermic reaction, and an appropriate reduction in flue gas temperature is beneficial to the desulfurization reaction; (4) Ca(OH)2 has low activity in the dry state. Appropriately increasing the relative humidity of the flue gas can form a liquid film on the surface of the desulfurizing agent, so that the diffusion of SO2 gas molecules in the pores and product layer of the desulfurizing agent is transformed into ion diffusion in the liquid phase, reducing the diffusion path and resistance. At the same time, the water absorbs the dissolved SO2 and forms new reaction components. These factors are beneficial for the desulfurization reaction.

[0003] In existing dry desulfurization technologies, the production of highly active Ca(OH)₂ desulfurizing agents is commonly used to address the low activity of the single Ca(OH)₂ desulfurizing agent itself. However, as the reaction proceeds, insoluble calcium sulfate forms on the surface of the desulfurizing agent, hindering further reaction between the internal desulfurizing agent and SO₂. Therefore, simply using highly active Ca(OH)₂ desulfurizing agents is insufficient to achieve satisfactory results. Furthermore, some technologies employ continuous water spraying or misting to humidify the desulfurizing agent during the reaction process. However, this still fails to address the problem of insoluble calcium sulfate forming on the surface of the desulfurizing agent clogging the reactive sites. Excessive humidity can also cause desulfurizing agent flaking, material caking, bed pressure fluctuations, and even bed collapse, and it is impossible to dynamically control the humidification process to adapt to flue gas fluctuations. Therefore, addressing the issues of calcium sulfate clogging the catalytic active sites on the surface of the desulfurizing agent, the low activity of a single Ca(OH)₂ desulfurizing agent in the dry state, and the impact of high flue gas temperature on desulfurization reaction efficiency is crucial for improving the efficiency of calcium-based dry desulfurization. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a device for improving the efficiency of calcium-based dry desulfurization by dynamic injection of nanofluids. The device uses a nano-injector to dynamically inject nanofluids into the desulfurization reactor and / or flue gas pipeline through a control system, so as to achieve the purpose of improving the efficiency of calcium-based dry desulfurization by dynamic injection of nanofluids.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A device for improving the efficiency of calcium-based dry desulfurization by dynamic injection of nanofluids includes a flue gas duct, a dry dust collector, a flue gas pump and a chimney arranged sequentially along the flue gas flow direction, and a desulfurizing agent storage tank for injecting desulfurizing agent into the flue gas duct is provided on the flue gas duct. It also includes a nanofluid supply facility for providing nanofluids, a nanofluid injector for injecting nanofluids into the flue gas duct and a control system for controlling the dynamic injection of nanofluids.

[0007] The nanofluid supply facility includes a nanofluid generator, a nanofluid delivery switch valve, a fluid pump, a nanofluid jet time control solenoid valve, a nanofluid jet flow control regulating valve, and a nanofluid jet point switch valve connected in sequence along the nanofluid flow direction. The outlet of the nanofluid jet point switch valve is connected to the nanofluid ejector to realize the supply of nanofluid to the nanofluid ejector.

[0008] The nanofluid generator, nanofluid delivery switch valve, nanofluid injection time control solenoid valve, nanofluid injection flow control regulating valve, and nanofluid injection point switch valve are all connected to the control system to realize the dynamic injection control of the nanofluid by the control system.

[0009] The nanofluid injector is arranged in the flue gas duct and is a multi-fluid injector with at least two sets of forward / reverse spray nozzles.

[0010] Furthermore, the nanofluid injection point switching valve is connected to each group of injection heads to control the injection point position of the nanofluid injector.

[0011] Furthermore, each group of injection heads includes an injector nozzle, an injector annular distribution ring, and an annular distribution ring support tube. Multiple injector nozzles are evenly distributed on the injector annular distribution ring along the circumferential direction. The annular distribution ring support tube is used to fix the injector annular distribution ring inside the flue gas duct.

[0012] Furthermore, automatic flue gas monitoring systems connected to the control system are installed at both the inlet of the flue gas duct and the outlet of the chimney.

[0013] Furthermore, a temperature and pressure detector and a relative humidity detector connected to the control system are installed on the flue gas duct at the outlet side of the desulfurization reaction zone.

[0014] Furthermore, the nanofluid is a fluid containing a solute for dissolving the desulfurization reaction products on the desulfurizing agent, nanoparticles for improving desulfurization efficiency, and a solvent.

[0015] Alternatively, it may be a fluid containing a solute and a solvent for dissolving the desulfurization reaction products on the desulfurizing agent, or a fluid containing nanoparticles and a solvent for improving desulfurization efficiency.

[0016] Alternatively, it may be a fluid containing a solute and a solvent for dissolving the desulfurization reaction products on the desulfurizing agent, a fluid containing nanoparticles and a solvent for improving desulfurization efficiency, or a fluid containing a solvent but not a solute or nanoparticles.

[0017] A device for improving the efficiency of calcium-based dry desulfurization by dynamic injection of nanofluids includes a flue gas duct, a desulfurization reactor, a dry dust collector, a flue gas pump, and a chimney arranged sequentially along the flue gas flow direction. A desulfurizing agent storage tank for injecting desulfurizing agent into the flue gas duct and / or the desulfurization reactor is provided on the flue gas duct. The device also includes a nanofluid supply facility for providing nanofluids, a nanofluid injector for injecting nanofluids into the flue gas duct and / or the desulfurization reactor, and a control system for controlling the dynamic injection of nanofluids.

[0018] The nanofluid supply facility includes a nanofluid generator, a nanofluid delivery switch valve, a fluid pump, a nanofluid jet time control solenoid valve, a nanofluid jet flow control regulating valve, and a nanofluid jet point switch valve connected in sequence along the nanofluid flow direction. The outlet of the nanofluid jet point switch valve is connected to the nanofluid ejector to realize the supply of nanofluid to the nanofluid ejector.

[0019] The nanofluid generator, nanofluid delivery switch valve, nanofluid injection time control solenoid valve, nanofluid injection flow control regulating valve, and nanofluid injection point switch valve are all connected to the control system to realize the dynamic injection control of the nanofluid by the control system.

[0020] The nanofluid injector is arranged in the flue gas duct. The nanofluid injector is a multi-fluid injector and has at least two sets of forward / reverse spray nozzles.

[0021] The beneficial effects of this utility model are as follows:

[0022] This invention provides a device for improving the efficiency of calcium-based dry desulfurization through dynamic nanofluid injection, and its beneficial effects are mainly reflected in the following three aspects:

[0023] First, this device innovatively utilizes a nano-injector to dynamically inject nanofluid into the desulfurization reactor and / or flue gas duct. This design not only solves the problem of low activity of Ca(OH)2 in the dry state, but also effectively dissolves the water-insoluble calcium sulfate generated on the surface of the desulfurizing agent through the special properties of nanofluid, thereby exposing more active sites and enabling the internal desulfurizing agent to further react with SO2, significantly improving desulfurization efficiency.

[0024] Secondly, the device achieves dynamic injection control of the nanofluid through a control system that integrates a nanofluid generator, nanofluid delivery switching valves, nanofluid injection time control solenoid valves, nanofluid injection flow control regulating valves, and nanofluid injection point switching valves. It also dynamically adjusts the injection control based on the monitoring structure of the automatic flue gas monitoring system, temperature and pressure detectors, and relative humidity detectors. This intelligent control function automatically adjusts the injection time, flow rate, and injection point of the nanofluid according to flue gas fluctuations, avoiding problems such as desulfurizer caking and material compaction caused by excessive humidity, while ensuring the continuous and efficient desulfurization reaction. This dynamic regulation capability greatly enhances the adaptability and stability of the device.

[0025] Finally, the device employs a multi-fluid injector design with at least two sets of forward / reverse spray nozzles, enabling more uniform spraying of the nanofluid and ensuring more thorough wetting and activation of the desulfurizing agent. Simultaneously, the nanoparticles in the nanofluid further enhance desulfurization efficiency, while the solute dissolves the desulfurization reaction products, promoting the continued progress of the reaction. This comprehensive design gives the device significant technical advantages and practical value in the field of calcium-based dry desulfurization.

[0026] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic diagram of the structure of a device for improving the efficiency of calcium-based dry desulfurization through dynamic nanofluid injection, as shown in Example 1. Figure 1 ;

[0029] Figure 2 This is a schematic diagram of the structure of a device for improving the efficiency of calcium-based dry desulfurization through dynamic nanofluid injection, as shown in Example 1. Figure 2 ;

[0030] Figure 3 This is a schematic diagram of the microstructure of the desulfurizing agent in Example 1;

[0031] Figure 4 This is a schematic diagram of the microstructure of nanoparticles fixed in situ on the desulfurizing agent in Example 1;

[0032] Figure 5 This is a partial structural schematic diagram of the nanofluid ejector in Example 1;

[0033] Figure 6 This is a schematic diagram of the structure of a device for improving the efficiency of calcium-based dry desulfurization by dynamic nanofluid injection in Example 2.

[0034] Figure reference numerals: 1- Flue gas to be treated; 2- Desulfurizing agent storage bin; 3- Flue gas duct; 4- Desulfurizing agent; 5- Nanofluid ejector; 6- Control system; 7- Nanofluid generator; 8- Nanofluid delivery switch valve; 9- Fluid pump; 10- Desulfurized flue gas; 11- Bag filter; 12- Flue gas pump; 13- Chimney; 14- Automatic flue gas monitoring system; 15- Nanofluid injection time control solenoid valve; 16- Nanofluid injection flow control regulating valve; 17- Nanofluid injection point switch valve; 18- Temperature and pressure detector; 19- Relative humidity detector; 20- Desulfurization reactor; 41- Calcium hydroxide particles; 42- Calcium sulfate particles; 43- Nanoparticles; 44- Pores left after calcium sulfate particles dissolve; 51- Nanofluid ejector nozzle; 52- Nanofluid ejector annular distribution ring; 53- Annular distribution ring support pipe. Detailed Implementation

[0035] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0037] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0038] Example 1

[0039] like Figure 1 and Figure 2 As shown, this is a device for improving the efficiency of calcium-based dry desulfurization by nanofluid dynamic injection. It includes a flue gas duct 3, a bag filter 11, a flue gas pump 12 and a chimney 13 arranged sequentially along the flue gas flow direction. A desulfurizing agent storage chamber 2 for injecting desulfurizing agent 4 into the flue gas duct is provided on the flue gas duct 3.

[0040] The key feature of this embodiment is that it also includes a nanofluid supply facility for providing nanofluid, a nanofluid injector 5 for injecting nanofluid into the flue gas duct, and a control system 6 for controlling the dynamic injection of nanofluid. The nanofluid supply facility includes a nanofluid generator 7, a nanofluid delivery switch valve 8, a fluid pump 9, a nanofluid injection time control solenoid valve 15, a nanofluid injection flow control regulating valve 16, and a nanofluid injection point switch valve 17 connected in sequence along the nanofluid flow direction. The outlet of the nanofluid injection point switch valve 17 is connected to the nanofluid injector 5 to realize the supply of nanofluid to the nanofluid injector 5 and control the start and stop, injection point, injection flow rate, injection duration, and injection interval of the nanofluid injector 5.

[0041] Furthermore, the nanofluid generator 7, the nanofluid delivery switch valve 8, the nanofluid injection time control solenoid valve 15, the nanofluid injection flow control regulating valve 16, and the nanofluid injection point switch valve 17 are all connected to the control system to realize the dynamic injection control of the nanofluid by the control system 6.

[0042] The nanofluid injector 5 is arranged in the flue gas duct 3. The nanofluid injector is a multi-fluid injector and has at least two sets of forward / reverse spray nozzles. Each set of nozzles is arranged in a ring. The diameter of the droplets ejected by the multi-fluid injector is no greater than 50 micrometers. The angle between the nanofluid outlet direction of the nozzle and the flue gas inflow velocity direction is between -180° and 180°.

[0043] Furthermore, an automatic flue gas monitoring system 14 connected to the control system 6 is installed at the inlet of the flue gas duct and the outlet of the chimney, and a temperature and pressure detector 18 connected to the control system is installed on the outlet side of the desulfurization reaction zone on the flue gas duct and / or the desulfurization reactor.

[0044] like Figure 1 and 5As shown, the nanofluid injector 5 has two sets of forward-spraying nozzles arranged at intervals along the flue gas flow direction. Each set of nozzles includes an injector nozzle 51, an injector annular distribution ring 52, and an annular distribution ring support tube 53. The plurality of injector nozzles 51 are evenly distributed on the injector annular distribution ring 52 along the circumferential direction. The annular distribution ring support tube 53 is used to fix the injector annular distribution ring 52 inside the flue gas duct 3.

[0045] The nanofluid injection point switching valve 17 is connected to two sets of injection heads respectively, thereby controlling the injection point of the nanofluid injector 5. In another embodiment, the nanofluid injector 5 has one set of forward-spraying injection heads and one set of reverse-spraying injection heads arranged at intervals along the flue gas flow direction, or a combination of multiple sets of reverse-spraying injection heads and forward-spraying injection heads.

[0046] The automatic flue gas monitoring system 14 is respectively arranged at the inlet of the flue gas duct 3 and the outlet of the chimney 13 to obtain parameters of the flue gas zone m1 to be treated before the desulfurization reaction, such as SO2 concentration, temperature T1, pressure P2, and relative humidity W1, and parameters of the clean flue gas after desulfurization and dust removal treatment at the outlet of the chimney 13, such as SO2 concentration. The temperature and pressure detectors 18 and the relative humidity detectors 19 are arranged in the desulfurization reaction zone m2 in the flue gas duct 3 and the mixed flue gas zone m3 before entering the dry dust collector after passing through the desulfurization reaction zone, to obtain the temperature T2, pressure P2, and relative humidity W2 of the desulfurization reaction zone m2, and the temperature T3, pressure P3, and relative humidity W3 of the mixed flue gas zone m3. The desulfurizing agent storage tank 2, the automatic flue gas monitoring system 14, the temperature and pressure detectors 18 and the relative humidity detectors 19 are all connected to the control system 6 to realize the dynamic injection of nanofluid and the dynamic adjustment of the desulfurizing agent injection amount.

[0047] The method of using the device for improving the efficiency of calcium-based dry desulfurization through nanofluid dynamic injection is as follows:

[0048] The flue gas to be treated 1 is sent to the desulfurization reactor through the flue gas duct 3. The desulfurizing agent 4 is injected from the desulfurizing agent storage bin 2 into the flue gas duct 3. The nanofluid generated by the nanofluid generator 7 is sequentially transported to the nanofluid injector 5 through the nanofluid delivery switch valve 8 and the fluid pump 9, and then injected into the flue gas duct 3 through the nanofluid injector 5, so that it mixes with the desulfurizing agent 4 in the flue gas duct 3 to form a highly efficient desulfurization reaction zone m2.

[0049] After desulfurization treatment in the desulfurization reaction zone, the desulfurized flue gas 10 enters the dry dust collector (bag dust collector 11) to remove dust, and then is transported to the chimney 13 by the flue gas pump 12 and discharged into the atmosphere.

[0050] Specifically, the flue gas to be treated, 1, is SO2-containing flue gas, which is introduced into the flue gas duct 3 and mixed with desulfurizing agent powder injected from the desulfurizing agent storage bin 2. After the desulfurization reaction, it enters the bag filter 11 to obtain clean flue gas, which is then pumped to the chimney 13 by the flue gas pump 12 and discharged into the atmosphere. To improve the reactivity of the desulfurizing agent and enhance the contact between the desulfurizing agent and the SO2-containing flue gas, a nanofluid injector 5 placed in the flue gas duct 3 injects nanofluid in a direction 180° to the flue gas flow direction to enhance the contact between the flue gas and the desulfurizing agent.

[0051] like Figure 3 and Figure 4 As shown, after the nanofluid is sprayed into the desulfurization reaction zone, the solute (ammonia water) contained in the nanofluid, which is used to dissolve the desulfurization reaction product (calcium sulfate) on the desulfurizing agent, dissolves the calcium sulfate 42 generated by the reaction of the desulfurizing agent 41 with SO2, thereby leaving a number of pores 44 left after the calcium sulfate particles are dissolved, so that the desulfurizing agent 41 can expose the surface reaction active sites in time.

[0052] Meanwhile, the nanofluid contains nanoparticles 43 (iron oxide nanoparticles) that enhance the desulfurization reaction. Under the action of the nanofluid injector 5, reactive sites can be added in situ on the surface of the powdered desulfurizing agent 41 in the desulfurization reaction zone.

[0053] Meanwhile, the solvent (water) in the nanofluid can increase the relative humidity of the powdered desulfurizer 41 and the SO2-containing flue gas, forming a liquid film on the surface of the desulfurizer 41, so that SO2 and the desulfurizer can quickly undergo desulfurization reaction in an ionic state.

[0054] The method in this embodiment further includes: the control system acquiring the relative humidity W1 of the flue gas zone m1 before the desulfurization reaction through the automatic flue gas monitoring system 14; acquiring the relative humidity W2 of the flue gas after the desulfurization reaction zone m2 and / or the relative humidity W3 of the mixed flue gas zone m3 before entering the dry dust collector after the desulfurization reaction; and simultaneously acquiring the SO2 concentration value of the flue gas at the chimney. The maximum value among the relative humidities W1, W2, and / or W3 is taken, and in conjunction with the feedback of the SO2 concentration value of the flue gas at the chimney, the injection point γ1, injection flow rate Q1, injection direction α1, injection duration t1, and injection interval φ1 of the nanofluid are dynamically adjusted to control the change in flue gas humidity after the nanofluid is injected, ensuring that the relative humidity of the flue gas does not reach the flue gas saturation humidity due to the increase of the fluid injection, guaranteeing that the flue gas has a certain relative humidity without condensation, maintaining the efficiency of high-efficiency desulfurization, and ensuring that the SO2 concentration of the outlet flue gas meets the emission standard requirements.

[0055] Generally, when the temperature T5 is between 50℃ and 100℃, the relative humidity W2 of the desulfurization reaction zone is between 0% and 50%, preferably between 5% and 20%; when the temperature T5 is above 100℃, the relative humidity W2 of the desulfurization reaction zone is between 0% and 1%, so as to ensure high desulfurization efficiency while preventing condensation of flue gas and avoiding situations such as desulfurizing agent clumping, material caking, bed pressure fluctuations, or even bed collapse.

[0056] The principle of synergistic control of SO2 concentration and relative humidity in flue gas is as follows: For example, if the relative humidity W1 of the flue gas zone m1 to be treated is 10%, the relative humidity W2 of the desulfurization reaction zone m2 and the relative humidity W3 of the mixed flue gas zone m3 after desulfurization reaction are detected. The SO2 concentration value at the outlet is controlled by synergistic control (the injection volume is increased when the concentration increases), and the amount of injected nanofluid is dynamically adjusted to ensure that the maximum humidity value falls within the range of 10% to 20%, while maintaining the efficiency of high-efficiency desulfurization, so that the SO2 concentration in the outlet flue gas meets the emission standard requirements.

[0057] Specifically, the solvent in the nanofluid is preferably water, and the solute used to dissolve the desulfurization reaction products on the desulfurizing agent is ammonia, ammonium salts (ammonium chloride, ammonium nitrate, ammonium chloride, ammonium acetate, carbon carbonate, ammonium bicarbonate), etc., preferably ammonia; the solute can be one, two, or a combination of multiple solutes; the mass concentration of the combined solute is 1-5%, preferably 1-3%, and the ratio of the minimum mass concentration to the maximum mass concentration among the multiple solutes is 0-0.5:1; the nanoparticles used to improve desulfurization efficiency are vanadium oxide, iron oxide, ferric hydroxide, magnesium sulfate, calcium oxide, aluminum oxide, silicon dioxide, etc., preferably iron oxide and ferric hydroxide. The single Ca(OH)2 desulfurizing agent itself has low activity and the reaction process with SO2 is slow. The main reason is that the oxidation reaction of SO2 to SO3 or CaSO3 to CaSO4 is the key to restricting the reaction rate of Ca(OH)2 fixing SO2, and the catalytic oxidation reaction, therefore, adding nanoparticles such as iron oxide or ferric hydroxide can improve the calcium-based desulfurization efficiency;

[0058] The nanoparticles are one, two, or a combination of multiple nanoparticles; the mass concentration of the combined nanoparticles is 0.5-5%, preferably 1-3%, and the ratio of the minimum mass concentration to the maximum mass concentration of the multiple nanoparticles is 0-0.5:1.

[0059] Furthermore, the temperature of the desulfurization reaction zone is controlled between 50°C and 350°C.

[0060] Furthermore, the implementation content and effects of this invention are explained. A representative flue gas desulfurization experiment under typical operating conditions was conducted using the nanofluid dynamic injection method described in this embodiment to improve the efficiency of calcium-based dry desulfurization. The initial experimental conditions are as follows:

[0061] 1) Inlet conditions of the flue gas to be treated: flue gas temperature 72℃, relative humidity W1 of the flue gas zone m1 to be treated is 1%, SO2 concentration is 132mg / Nm 3 ;

[0062] 2) Calcium-based desulfurizer is sprayed separately to adjust the Ca / S molar ratio at the flue gas inlet (~4.0) and control the SO2 concentration at the outlet to 35 mg / Nm³. 3 .

[0063] Experimental conditions and results for nanofluids:

[0064] 1) The preferred solvent is water, with 5% ammonia added and diluted to 1%; add an appropriate amount of combined iron oxide and aluminum oxide nanoparticles in a ratio of 2:1, so that the total mass concentration of nanoparticles in the solvent is 3%, and the nanofluid is prepared.

[0065] 2) Turn on the nanofluid supply system and atomize it into particles smaller than 40μm through the atomizing spray gun, and spray it into the desulfurization reaction zone m2; at the same time, detect the SO2 concentration and relative humidity W3 in the mixed flue gas zone m3.

[0066] 3) Gradually increase the injection rate of nanofluid and decrease the injection rate of calcium-based desulfurizer to maintain the SO2 concentration in the flue gas at the chimney outlet at 35 mg / Nm³. 3 The following records show the detected relative humidity W3 and the following data: When W3 increases from 1% to 5%, the Ca / S ratio decreases from 4.0 to 3.6, and the SO2 concentration in the flue gas at the chimney outlet decreases from 35 mg / Nm³. 3 Reduced to 30 mg / Nm 3 When W3 increases to 10.2%, the Ca / S ratio decreases to 3.1, and the SO2 concentration in the flue gas at the chimney outlet is 23 mg / Nm³. 3 When W3 increases to 19.8%, the Ca / S ratio decreases to 2.5, and the SO2 concentration in the flue gas at the chimney outlet is 9.8 mg / Nm³. 3 .

[0067] The method and apparatus for improving the efficiency of calcium-based dry desulfurization using nanofluid dynamic injection, as described in this embodiment, were successfully applied to flue gas desulfurization, increasing the efficiency from 70% to 90%, a feat difficult to achieve with traditional dry desulfurization technologies. Furthermore, this method significantly improves the utilization efficiency of the desulfurizing agent, reducing the SO2 concentration in the flue gas from 132 mg / Nm³. 3 Reduced to 10 mg / Nm 3 The following levels meet the national standard of 35 mg / Nm 3The ultra-low emission standard has made a positive contribution to environmental protection. Finally, through the implementation of this invention, the actual Ca / S ratio of the calcium-based dry desulfurizing agent is reduced from 4 to below 3, which greatly improves the utilization rate of the desulfurizing agent, reduces the cost of flue gas desulfurization, and has significant economic benefits.

[0068] Example 2

[0069] like Figure 6 As shown, the difference between this embodiment and embodiment 1 is that a desulfurization reactor 20 is also provided between the flue gas duct 3 and the bag filter 11, and the nanofluid ejector 5 is installed in the desulfurization reactor.

[0070] The method of use involves directly injecting the nanofluid into the desulfurization reactor connected to the flue gas duct 3 via a nanofluid injector 5, thereby forming a highly efficient desulfurization reaction zone m1 within the reactor. The nanofluid supplied by the nanofluid supply facility has a solvent of water and ethanol, a solute of 10% ammonia, nanoparticles of 0.5% iron oxide and 1% aluminum oxide, and a temperature of 90°C. The nanofluid injector 5 injects the nanofluid into the desulfurization reactor at a 160° angle to the flue gas flow direction. After the nanofluid is injected into the desulfurization reaction zone m1, the ammonia water solute in the nanofluid, which is used to dissolve the calcium sulfate product of the desulfurization reaction, dissolves the calcium sulfate 42 generated by the reaction of the desulfurizing agent 41 with SO2, so that the desulfurizing agent 41 exposes the surface reactive sites in time. At the same time, the nanofluid contains nanoparticles of iron oxide and aluminum oxide 43 to enhance the desulfurization reaction. Under the action of the injector, reactive sites can be added in situ on the surface of the powdered desulfurizing agent 41 in the desulfurization reaction zone. Meanwhile, the solvent in the nanofluid can increase the relative humidity of the powdered desulfurizing agent 41 and the SO2-containing flue gas, forming a liquid film on the surface of the desulfurizing agent, so that SO2 and the desulfurizing agent can quickly carry out the desulfurization reaction in an ionic state, thereby improving the efficiency of calcium-based dry desulfurization.

[0071] Correspondingly, in this embodiment, the temperature and pressure detector 18 and the relative humidity detector 19 are arranged after the desulfurization reaction zone m2 in the desulfurization reactor 20 to obtain the relative humidity W3 of the mixed flue gas m3 after the desulfurization reaction.

[0072] The method in this embodiment further includes: obtaining the relative humidity W1 of the flue gas zone m1 before the desulfurization reaction; obtaining the relative humidity W3 of the mixed flue gas zone m3 before entering the dry dust collector after the desulfurization reaction; and simultaneously obtaining the SO2 concentration value of the flue gas at the chimney. The maximum value of the relative humidity W1 and W3 is taken, and in conjunction with the feedback of the SO2 concentration value of the flue gas at the chimney, the injection point γ1, injection flow rate Q1, injection direction α1, injection duration t1, and injection interval φ1 of the nanofluid are dynamically controlled to control the change in flue gas humidity after the nanofluid injection, ensuring that the relative humidity of the flue gas does not reach the flue gas saturation humidity due to the increase of the fluid injection, guaranteeing that the flue gas has a certain relative humidity without condensation, maintaining the efficiency of high-efficiency desulfurization, and ensuring that the SO2 concentration of the outlet flue gas meets the emission standard requirements.

[0073] Example 3

[0074] The difference between this embodiment and Embodiment 1 lies in the method of application. The nanofluid is injected through the nanofluid injector 5 onto the desulfurizing agent 4; or the nanofluid is directly injected upstream of the desulfurizing agent 4; or the nanofluid is directly injected into the desulfurizing agent injection pipe, first forming a mixture of nanofluid and desulfurizing agent, and then injected into the desulfurization reactor and / or flue gas duct to form a highly efficient desulfurization reaction zone m2. Correspondingly, the nanofluid injector 5 needs to be positioned at the location used for injecting the nanofluid. This also achieves the goal of improving the efficiency of calcium-based dry desulfurization through dynamic nanofluid injection.

[0075] Example 4

[0076] The difference between this embodiment and embodiment 1 is that the method involves simultaneously injecting nanofluid into the desulfurization reactor and the flue gas duct 3 connected to the flue gas duct 3 through a nanofluid injector 5, thereby simultaneously forming a desulfurization reaction zone m2 in the desulfurization reactor 20 and the flue gas duct 3. That is, nanofluid injectors 5 are arranged on both the desulfurization reactor and the flue gas duct.

[0077] Example 5

[0078] This embodiment differs from the previous embodiments in that its method of use involves a control system that dynamically sprays a combination of solvent, solute for dissolving desulfurization reaction products, and nanoparticles to improve the desulfurization efficiency of the desulfurizing agent. First, a solvent containing a solute free of easily soluble calcium sulfate (a reaction product) and nanoparticles is sprayed for duration t2 to increase the humidity of the desulfurizing agent. Then, a mixed solution containing a solvent and a solute for dissolving calcium sulfate (a reaction product) is sprayed for duration t3 to expose the reactive sites on the surface of the desulfurizing agent. Finally, a nanofluid is sprayed for duration t4. Alternatively, the spray sequence can be randomly combined with the actual operating parameters of the desulfurization reaction zone, such as temperature and pressure. Through this combination, using a dynamic humidification and gas mixing approach, the efficiency of SDS-based calcium-based dry desulfurization is further improved.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A device for improving the efficiency of calcium-based dry desulfurization through nanofluid dynamic injection, comprising a flue gas duct, a dry dust collector, a flue gas pump, and a chimney arranged sequentially along the flue gas flow direction, and a desulfurizing agent storage chamber for injecting desulfurizing agent into the flue gas duct, characterized in that: It also includes a nanofluid supply facility for providing nanofluids, a nanofluid injector for injecting nanofluids into flue gas ducts, and a control system for controlling the dynamic injection of nanofluids; The nanofluid supply facility includes a nanofluid generator, a nanofluid delivery switch valve, a fluid pump, a nanofluid jet time control solenoid valve, a nanofluid jet flow control regulating valve, and a nanofluid jet point switch valve connected in sequence along the nanofluid flow direction. The outlet of the nanofluid jet point switch valve is connected to the nanofluid ejector to realize the supply of nanofluid to the nanofluid ejector. The nanofluid generator, nanofluid delivery switch valve, nanofluid injection time control solenoid valve, nanofluid injection flow control regulating valve, and nanofluid injection point switch valve are all connected to the control system to realize the dynamic injection control of the nanofluid by the control system. The nanofluid injector is arranged in the flue gas duct and is a multi-fluid injector with at least two sets of forward / reverse spray nozzles.

2. The device for improving the efficiency of calcium-based dry desulfurization by dynamic nanofluid injection according to claim 1, characterized in that: The nanofluid injection point switching valves are connected to each group of injection heads to control the injection point of the nanofluid injector.

3. The device for improving the efficiency of calcium-based dry desulfurization by dynamic nanofluid injection according to claim 2, characterized in that: Each set of injection heads includes an injector nozzle, an annular distribution ring of the injector, and an annular distribution ring support tube. Multiple injector nozzles are evenly distributed on the annular distribution ring of the injector along the circumferential direction. The annular distribution ring support tube is used to fix the annular distribution ring of the injector inside the flue gas duct.

4. The device for improving the efficiency of calcium-based dry desulfurization by dynamic nanofluid injection according to claim 1, characterized in that: Automatic flue gas monitoring systems connected to the control system are installed at the inlet of the flue gas duct and the outlet of the chimney.

5. The device for improving the efficiency of calcium-based dry desulfurization by nanofluid dynamic injection according to claim 4, characterized in that: Temperature and pressure detectors and relative humidity detectors, which are connected to the control system, are installed on the flue gas duct at the outlet side of the desulfurization reaction zone.

6. The apparatus for improving the efficiency of calcium-based dry desulfurization by dynamic nanofluid injection according to any one of claims 1 to 5, characterized in that: The nanofluid is a fluid containing a solute for dissolving the desulfurization reaction products on the desulfurizing agent, nanoparticles for improving desulfurization efficiency, and a solvent. Alternatively, it may be a fluid containing a solute and a solvent for dissolving the desulfurization reaction products on the desulfurizing agent, or a fluid containing nanoparticles and a solvent for improving desulfurization efficiency. Alternatively, it may be a fluid containing a solute and a solvent for dissolving the desulfurization reaction products on the desulfurizing agent, a fluid containing nanoparticles and a solvent for improving desulfurization efficiency, or a fluid containing a solvent but not a solute or nanoparticles.

7. A device for improving the efficiency of calcium-based dry desulfurization through nanofluid dynamic injection, comprising a flue gas duct, a desulfurization reactor, a dry dust collector, a flue gas pump, and a chimney arranged sequentially along the flue gas flow direction, and a desulfurizing agent storage chamber for injecting desulfurizing agent into the flue gas duct and / or the desulfurization reactor, characterized in that: It also includes a nanofluid supply facility for providing nanofluids, a nanofluid injector for injecting nanofluids into flue gas ducts and / or desulfurization reactors, and a control system for controlling the dynamic injection of nanofluids; The nanofluid supply facility includes a nanofluid generator, a nanofluid delivery switch valve, a fluid pump, a nanofluid jet time control solenoid valve, a nanofluid jet flow control regulating valve, and a nanofluid jet point switch valve connected in sequence along the nanofluid flow direction. The outlet of the nanofluid jet point switch valve is connected to the nanofluid ejector to realize the supply of nanofluid to the nanofluid ejector. The nanofluid generator, nanofluid delivery switch valve, nanofluid injection time control solenoid valve, nanofluid injection flow control regulating valve, and nanofluid injection point switch valve are all connected to the control system to realize the dynamic injection control of the nanofluid by the control system. The nanofluid injector is arranged in the flue gas duct. The nanofluid injector is a multi-fluid injector and has at least two sets of forward / reverse spray nozzles.

Images