Urea direct injection denitration system based on gas injection

Abstract

The invention discloses a urea direct injection denitration system based on gas injection. The urea direct injection denitration system comprises a urea solution storage module, a compressed air supply module, a urea solution distribution module, a flue, a spray gun, a detection module and a controller. According to the system, the content of nitrogen oxide in the flue and ammonia escape data are obtained in real time through the detection module, the controller adjusts the opening degree of the air pressure adjusting valve and the opening degree of the air flow adjusting valve according to the data, accurate control over the urea injection amount is achieved, and nitrogen oxide emission can reach the stricter environmental protection standard more easily. The problem of ammonia escape caused by excessive urea injection can be avoided by accurately controlling the urea injection amount, the ammonia escape is reduced, resources can be saved, and the environmental problems such as secondary pollution caused by the ammonia escape can be prevented. According to the invention, based on a gas injection mode, the conveying and injection amount control of the urea solution is realized, and the use of a large number of traditional instruments is avoided, so that the complexity and the construction investment cost of the system are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flue gas denitration, in particular to a urea direct injection denitration system based on gas induction. BACKGROUND

[0002] As a denitration method applied to selective catalytic reduction (SCR) or non-selective catalytic reduction (SNCR), urea direct injection denitration technology has been widely used. The principle is to inject urea solution into high-temperature flue gas, and under the action of high temperature, urea is decomposed into NH3, which then reacts with nitrogen oxides to achieve the purpose of denitration.

[0003] However, with the continuous improvement of environmental protection requirements, the demand for ultra-low emission of nitrogen oxides and intelligent denitration is increasing. The existing urea direct injection system has certain limitations and cannot accurately control the urea injection amount according to the actual situation. On the one hand, it is difficult to achieve efficient denitration, resulting in nitrogen oxides emissions that are difficult to meet more stringent standards; on the other hand, it is easy to cause ammonia escape, which not only wastes resources but also may cause secondary pollution and other problems.

[0004] To solve the above problems, it is inevitable to precisely control the urea injection amount by partitioning and flexibly modifying the urea direct injection system. However, the traditional modification method often requires a large number of delivery pumps and electric regulating valves and other instruments, which not only increases the complexity of the system but also significantly increases the construction investment cost of the system. SUMMARY

[0005] The present application aims to at least partially solve one of the technical problems in the related art.

[0006] To this end, an embodiment of the present application proposes a urea direct injection denitration system based on gas induction.

[0007] The urea direct injection denitration system based on gas induction of the present application comprises a urea solution storage module, a compressed air supply module, a urea solution distribution module, a flue, a spray gun, a detection module and a controller. The urea solution distribution module comprises an inducer, a liquid delivery pipe, a gas delivery pipe, an air pressure regulating valve and an air flow regulating valve. The two ends of the liquid delivery pipe are respectively in communication with the urea solution storage module and the inducer. The two ends of the gas delivery pipe are respectively in communication with the compressed air supply module and the inducer. The inducer is used to mix and atomize the urea solution with compressed air. The air pressure regulating valve and the air flow regulating valve are both provided on the gas delivery pipe to adjust the pressure and flow of the compressed air.

[0008] The spray gun is provided in the flue and is in communication with the inducer to spray the atomized urea solution into the flue.

[0009] The detection module is arranged in the flue for detecting the content of nitrogen oxides and ammonia escape data in the flue, and the controller is in control connection with the air pressure regulating valve, the air flow regulating valve and the detection module respectively, so as to adjust the opening degree of the air pressure regulating valve and the air flow regulating valve according to the detection data of the detection module.

[0010] In some embodiments, the urea solution distribution module further comprises an air pressure gauge and an air flow gauge, both of which are arranged on the air pipe, the air pressure gauge is used for monitoring the pressure of compressed air, and the air flow gauge is used for monitoring the flow of compressed air, and the air pressure gauge and the air flow gauge are in control connection with the controller.

[0011] In some embodiments, the urea solution distribution module further comprises a first manual on-off valve, which is arranged on the liquid pipe.

[0012] In some embodiments, the urea solution distribution module further comprises a second manual on-off valve, which is arranged between the ejector and the lance.

[0013] In some embodiments, the urea solution distribution module further comprises a urea solution flow meter, which is arranged on the liquid pipe.

[0014] In some embodiments, the urea solution storage module comprises a liquid storage tank, the liquid storage tank is provided with a liquid outlet pipeline, the liquid outlet pipeline is in communication with the liquid pipe, and the liquid outlet pipeline is provided with an opening and closing valve.

[0015] In some embodiments, a plurality of partitions are arranged in the flue along the flow direction of flue gas, and the number of the lances is equal to the number of the partitions.

[0016] In some embodiments, the number of the urea solution distribution modules is equal to the number of the lances and is connected in one-to-one correspondence.

[0017] In some embodiments, a plurality of the urea solution distribution modules are connected in parallel with the urea solution storage module, and a plurality of the urea solution distribution modules are connected in parallel with the compressed air supply module.

[0018] In some embodiments, the detection module is used for monitoring the content of nitrogen oxides and ammonia escape data in each partition, and adjusting the opening degree of the air pressure regulating valve and the air flow regulating valve in the urea solution distribution module corresponding to each partition according to the detection data of each partition.

[0019] The present application is based on a gas-induced urea direct injection denitration system that acquires real-time flue gas NOx content and ammonia slip data through a detection module. The controller adjusts the opening of the air pressure regulating valve and the air flow regulating valve based on these data, achieving precise control of urea injection amount. This helps improve denitration efficiency and makes it easier for NOx emissions to meet more stringent environmental standards. Precise control of urea injection amount can avoid the problem of ammonia slip caused by excessive urea injection. Reducing ammonia slip not only saves resources, but also prevents secondary pollution and other environmental problems caused by ammonia slip. The present application is based on a gas-induced method that uses an ejector, air pressure regulating valve, and air flow regulating valve to control the delivery and injection amount of urea solution, avoiding the use of a large number of traditional instruments, thereby reducing system complexity and construction investment costs. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of a gas-induced urea direct injection denitration system according to an embodiment of the present application.

[0021] REFERENCE NUMERALS

[0022] 100, urea direct injection denitration system; 1, urea solution storage module; 101, liquid storage tank; 102, liquid outlet pipeline; 103, on-off valve; 2, compressed air supply module; 3, urea solution distribution module; 301, ejector; 302, liquid delivery pipe; 303, gas delivery pipe; 304, air pressure regulating valve; 305, air flow regulating valve; 306, air pressure gauge; 307, air flow meter; 308, first manual on-off valve; 309, second manual on-off valve; 310, urea solution flow meter; 4, flue; 5, lance. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below, with examples shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application.

[0024] As Figure 1As shown, the gas injection based urea direct injection denitration system 100 of the embodiment of the present application comprises a urea solution storage module 1, a compressed air supply module 2, a urea solution distribution module 3, a flue 4, a spray gun 5, a detection module (not shown in the figure) and a controller (not shown in the figure). The urea solution distribution module 3 comprises an ejector 301, a liquid delivery pipe 302, a gas delivery pipe 303, an air pressure regulating valve 304 and an air flow regulating valve 305, both ends of the liquid delivery pipe 302 are in communication with the urea solution storage module 1 and the ejector 301 respectively, and both ends of the gas delivery pipe 303 are in communication with the compressed air supply module 2 and the ejector 301 respectively. The ejector 301 is used to mix and atomize the urea solution by using compressed air, and the air pressure regulating valve 304 and the air flow regulating valve 305 are both arranged on the gas delivery pipe 303 for adjusting the pressure and flow of the compressed air.

[0025] The spray gun 5 is arranged in the flue 4 and is in communication with the ejector 301 to spray the atomized urea solution into the flue 4. The detection module is arranged in the flue 4 for detecting the content of nitrogen oxides and ammonia escape data in the flue 4, and the controller is in control connection with the air pressure regulating valve 304, the air flow regulating valve 305 and the detection module respectively, for adjusting the opening degree of the air pressure regulating valve 304 and the air flow regulating valve 305 according to the detection data of the detection module.

[0026] In use, the urea solution storage module 1 is responsible for storing urea solution, and the compressed air supply module 2 provides compressed air. The urea solution is delivered to the ejector 301 through the liquid delivery pipe 302, and the compressed air is delivered to the ejector 301 through the gas delivery pipe 303. The ejector 301 mixes and atomizes the urea solution by using compressed air. In this process, the air pressure regulating valve 304 and the air flow regulating valve 305 adjust the pressure and flow of the compressed air in the gas delivery pipe 303 to ensure that the urea solution can achieve the appropriate atomization effect. The atomized urea solution is sprayed into the flue 4 through the spray gun 5. Under the action of high-temperature flue gas, the urea is decomposed into NH3, and the NH3 reacts with the nitrogen oxides in the flue 4, thereby achieving the purpose of denitration.

[0027] The detection module detects the content of nitrogen oxides and ammonia escape data in the flue 4 in real time and transmits these data to the controller. The controller adjusts the opening degree of the air pressure regulating valve 304 and the air flow regulating valve 305 according to the detection data, so as to accurately control the pressure and flow of the compressed air, and further accurately control the injection amount of the urea solution.

[0028] The present application is based on a gas-induced urea direct injection denitration system 100 that obtains the nitrogen oxide content and ammonia escape data in the flue 4 in real time through a detection module. The controller adjusts the opening of the air pressure regulating valve 304 and the air flow regulating valve 305 according to these data, achieving precise control of the urea injection amount. This helps to improve the denitration efficiency and make it easier for nitrogen oxide emissions to meet more stringent environmental standards. Precise control of the urea injection amount can avoid the problem of ammonia escape caused by excessive urea injection. Reducing ammonia escape not only saves resources, but also prevents environmental problems such as secondary pollution caused by ammonia escape. The present application is based on a gas-induced method, which realizes the transportation and injection amount control of urea solution through the ejector 301, air pressure regulating valve 304 and air flow regulating valve 305, avoiding the use of a large number of traditional instruments, thereby reducing the complexity and construction investment cost of the system.

[0029] In some embodiments, the urea solution distribution module 3 further comprises an air pressure gauge 306 and an air flow meter 307, both of which are provided on the air conveying pipe 303. The air pressure gauge 306 is used to monitor the pressure of compressed air, and the air flow meter 307 is used to monitor the flow of compressed air. The air pressure gauge 306 and the air flow meter 307 are in control connection with the controller.

[0030] The air pressure gauge 306 and the air flow meter 307 monitor the pressure and flow of compressed air in the air conveying pipe 303 in real time and transmit these data to the controller. The controller not only adjusts according to the nitrogen oxide content and ammonia escape data in the flue 4 transmitted by the detection module, but also combines the compressed air pressure and flow data provided by the air pressure gauge 306 and the air flow meter 307 to comprehensively judge and accurately adjust the opening of the air pressure regulating valve 304 and the air flow regulating valve 305. This can more accurately control the parameters of compressed air, thereby further accurately controlling the injection amount of urea solution.

[0031] In some embodiments, the urea solution distribution module 3 further comprises a first manual on-off valve 308 provided on the liquid conveying pipe 302.

[0032] During normal operation, the first manual on-off valve 308 is in an open state, ensuring that the urea solution is smoothly transported from the urea solution storage module 1 to the ejector 301 through the liquid conveying pipe 302. When the system needs to be maintained, repaired or encounters an emergency, the operator can manually close the first manual on-off valve 308 to cut off the transportation of urea solution, thereby stopping the injection of urea solution into the flue 4.

[0033] The first manual switch valve 308 provides a means of manual intervention for the system. In the event of a failure of the automatic control or the need for temporary stoppage of urea solution supply, the operator can quickly respond by manually operating the first manual switch valve 308 to ensure the safe and stable operation of the system. For example, when the eductor 301 or the lance 5 fails and needs to be repaired, closing the first manual switch valve 308 can prevent unnecessary waste and damage to the equipment caused by the continuous flow of urea solution.

[0034] In some embodiments, the urea solution distribution module 3 further comprises a second manual switch valve 309, which is arranged between the eductor 301 and the lance 5.

[0035] When the system is operating normally, the second manual switch valve 309 is in an open state, and the urea solution mixed and atomized by the eductor 301 can smoothly pass through the valve and then be injected into the flue 4 by the lance 5 for denitration reaction. However, when special circumstances arise, such as the need for individual repair or replacement of the lance 5, or the need for temporary stoppage of injection by a certain lance 5, the operator can manually close the second manual switch valve 309 to block the delivery of urea solution to that lance 5, without affecting the normal operation of other parts of the system.

[0036] In some embodiments, the urea solution distribution module 3 further comprises a urea solution flow meter 310, which is arranged on the liquid delivery pipe 302.

[0037] The urea solution flows out of the urea solution storage module 1, is delivered through the liquid delivery pipe 302, and the urea solution flow meter 310 accurately measures its flow rate and transmits the measurement data to the controller. The controller combines the data of nitrogen oxide content and ammonia slip in the flue 4 provided by the detection module, as well as the compressed air data provided by the air pressure gauge 306 and the air flow meter 307, and comprehensively analyzes the actual flow rate of the urea solution to more accurately adjust the opening of the air pressure regulating valve 304 and the air flow regulating valve 305, in order to achieve precise control of the injection amount of urea solution.

[0038] The urea solution flow meter 310 provides direct data of the urea solution flow rate, allowing the controller to have a more intuitive and accurate understanding of the delivery of urea solution. Based on this data, the injection amount of urea solution can be more accurately matched with the content of nitrogen oxides in the flue 4, thereby significantly improving the denitration efficiency and ensuring that the nitrogen oxide emissions meet the ultra-low emission standard.

[0039] In some embodiments, the urea solution storage module 1 comprises a liquid storage tank 101, an outlet pipe 102 is arranged on the liquid storage tank 101, the outlet pipe 102 is in communication with the liquid delivery pipe 302, and an on-off valve 103 is arranged on the outlet pipe 102.

[0040] When the system is running, if it is necessary to transport the urea solution in the storage tank 101 to the subsequent process, the operator will open the on-off valve 103 on the liquid outlet pipeline 102. At this time, the urea solution in the storage tank 101 will flow into the liquid inlet pipeline 302 under the action of gravity or other transport power through the liquid outlet pipeline 102, and then be transported to the ejector 301 for subsequent mixing and atomization operation. When the system stops running, needs to be maintained and repaired, or temporarily does not need to transport the urea solution, the on-off valve 103 is closed to prevent the urea solution from continuing to flow out and cut off the passage of the urea solution from the storage tank 101 to the liquid inlet pipeline 302.

[0041] The on-off valve 103 is provided to enable the operator to conveniently control the output of the urea solution in the storage tank 101. When the system starts, the valve can be opened in time to supply the urea solution to the position; when the system stops, the valve is quickly closed to avoid unnecessary leakage and waste of the urea solution, thereby improving the flexibility and controllability of the system operation.

[0042] In some embodiments, a plurality of sub-zones are provided in the flue 4 along the flow direction of the flue gas, and the number of the injection lances 5 is equal to the number of the sub-zones.

[0043] Since a plurality of sub-zones are provided in the flue 4 along the flow direction of the flue gas, and each sub-zone corresponds to an injection lance 5, the system can perform targeted denitration operation according to the actual situation in each sub-zone. The detection module detects the content of nitrogen oxides and the ammonia escape data in each sub-zone respectively, and transmits these data to the controller. The controller adjusts the opening degree of the air pressure regulating valve 304 and the air flow regulating valve 305 connected to the corresponding injection lance 5 according to the specific data of each sub-zone, so as to accurately control the injection amount of the urea solution in each sub-zone. For example, when the content of nitrogen oxides in a sub-zone is high, the controller increases the injection amount of the urea solution of the injection lance 5 corresponding to the sub-zone; when the content of nitrogen oxides in a sub-zone is low, the controller reduces the injection amount of the urea solution of the corresponding injection lance 5.

[0044] The flue gas conditions in different sub-zones may be different, such as uneven distribution of nitrogen oxides concentration, etc. By dividing the flue 4 into sub-zones and providing an independent injection lance 5 for each sub-zone, accurate denitration can be performed according to the actual situation of each sub-zone. In this way, the problem of insufficient local denitration or excessive injection of urea caused by uniformly injecting urea solution in the entire flue 4 can be avoided, thereby significantly improving the denitration efficiency and better meeting the requirement of ultra-low emission of nitrogen oxides.

[0045] Precise control of the urea injection amount of each partition can effectively reduce the phenomenon of ammonia escape. Because the urea solution injection amount of each partition is precisely adjusted according to the nitrogen oxide content of the partition, there is no situation that the overall injection amount cannot adapt to the local situation, resulting in excessive decomposition of urea in a certain area to produce a large amount of ammonia escape. Reducing ammonia escape not only saves resources, but also reduces the problem of secondary pollution that may be caused by ammonia emission.

[0046] The flue gas conditions in the flue 4 may change with the change of production conditions. The partitioned spray gun 5 enables the system to better adapt to these changes and make flexible adjustments according to the real-time conditions of different partitions. For example, when a process link in the production process changes and causes the nitrogen oxide content in a certain area of the flue 4 to suddenly increase, the system can quickly increase the urea injection amount of the corresponding spray gun 5 in that area to ensure the stability of the denitration effect of the entire flue 4.

[0047] In some embodiments, the number of urea solution distribution modules 3 is multiple and connected one-to-one with multiple spray guns 5.

[0048] In embodiments where multiple urea solution distribution modules 3 are connected one-to-one with multiple spray guns 5, each urea solution distribution module 3 is independently responsible for providing the corresponding spray gun 5 with mixed and atomized urea solution. The ejector 301 of each urea solution distribution module 3 uses compressed air to mix and atomize the urea solution from the urea solution storage module 1, and the air pressure regulating valve 304 and the air flow regulating valve 305 adjust the pressure and flow of the compressed air according to the instructions of the controller, thereby controlling the atomization effect and injection amount of the urea solution.

[0049] The detection module detects the nitrogen oxide content and ammonia escape data in each partition respectively and transmits them to the controller, which sends adjustment instructions to the air pressure regulating valve 304 and the air flow regulating valve 305 in the corresponding urea solution distribution module 3 for each partition. That is, the urea solution injection amount of each spray gun 5 can be independently and precisely controlled according to the actual denitration demand of the partition it belongs to.

[0050] Each spray gun 5 has an independent urea solution distribution module 3, which can be adjusted individually according to the nitrogen oxide content and ammonia escape situation of the corresponding partition. This precise control method can maximize the denitration efficiency of each partition and make the nitrogen oxide emission in the entire flue 4 more evenly and stably reach the ultra-low emission standard. For example, in the case where the nitrogen oxide concentration in different partitions differs greatly, each distribution module can accurately adjust the urea injection amount to avoid the problem of incomplete denitration in some areas and excessive urea in some areas.

[0051] When the working condition of a certain sub-zone in the flue 4 changes, such as a sudden increase or decrease in the concentration of nitrogen oxides, only the urea solution distribution module 3 corresponding to the lance 5 of the sub-zone needs to be adjusted, without affecting the normal operation of other sub-zones. This enables the system to quickly adapt to various complex and variable production conditions and flue gas conditions, enhancing the overall flexibility and adaptability of the system.

[0052] In some embodiments, multiple urea solution distribution modules 3 are connected in parallel with the urea solution storage module 1, and multiple urea solution distribution modules 3 are connected in parallel with the compressed air supply module 2.

[0053] When the system is running, the urea solution in the urea solution storage module 1 can be simultaneously delivered to each parallel urea solution distribution module 3, and the process of each distribution module obtaining the solution does not interfere with each other. The compressed air supply module 2 simultaneously provides compressed air to each urea solution distribution module 3. Each distribution module can independently receive compressed air and can adjust the pressure and flow of the compressed air according to its own control needs.

[0054] When the system is working, the detection module transmits the nitrogen oxide content and ammonia escape data of each sub-zone to the controller, and the controller issues adjustment instructions to the air pressure regulating valve 304 and the air flow regulating valve 305 in each urea solution distribution module 3 according to these data. Each distribution module adjusts the parameters of the compressed air according to the instructions to realize the mixing and atomization of the urea solution, and sprays the atomized urea solution through the corresponding lance 5 into the corresponding sub-zone of the flue 4, completing the denitration operation.

[0055] Parallel connection makes each urea solution distribution module 3 relatively independent. If one of the distribution modules fails, it will not affect the normal operation of other distribution modules, ensuring the continuous operation of the entire denitration system. For example, when the regulating valve of a certain distribution module fails, other distribution modules can still spray urea solution according to the needs of each sub-zone, avoiding the situation that the entire system is paralyzed due to local failure.

[0056] When more sub-zones need to be set in the flue 4 or the number of lances 5 needs to be increased, new urea solution distribution modules 3 can be added in parallel on the basis of the existing ones. This scalability enables the system to easily adapt to flues 4 of different sizes and different denitration requirements, with strong versatility and flexibility.

[0057] Each urea solution distribution module 3 can independently receive the solution from the urea solution storage module 1 and the compressed air from the compressed air supply module 2, and accurately adjust according to the actual situation of the corresponding sub-zone. This further improves the denitration accuracy of each sub-zone, better handles the complex and variable distribution of nitrogen oxides in the flue 4, and ensures that the denitration effect of the entire flue 4 reaches the best.

[0058] In some embodiments, the detection module is used to monitor the content of nitrogen oxides and ammonia escape data in each partition, and adjust the opening degree of the air pressure regulating valve 304 and the air flow regulating valve 305 in the urea solution distribution module 3 of the corresponding partition according to the detection data of each partition.

[0059] The detection module is distributed in each partition of the flue 4, and the content of nitrogen oxides and ammonia escape data in each partition are monitored in real time. The flue gas composition and working condition of different partitions may be different, and by independently setting the monitoring in each partition, the actual situation of each region can be accurately obtained. The detection module transmits the collected nitrogen oxide content and ammonia escape data of each partition to the controller. After receiving these data, the controller analyzes and judges the data of each partition according to the preset denitration control strategy and algorithm.

[0060] According to the analysis result, the controller sends adjustment instructions to the air pressure regulating valve 304 and the air flow regulating valve 305 in the urea solution distribution module 3 of the corresponding partition according to the specific situation of each partition. If the content of nitrogen oxides in a certain partition is high, the controller will increase the opening degree of the air pressure regulating valve 304 and the air flow regulating valve 305 in the partition, so that more compressed air enters the ejector 301, thereby increasing the injection amount of urea solution to improve the denitration effect; on the contrary, if the content of nitrogen oxides in a certain partition is low or the ammonia escape data is abnormal, the controller will accordingly reduce the valve opening degree to reduce the injection amount of urea solution.

[0061] Because the flue gas conditions of each partition are different, a unified urea injection amount cannot meet the actual needs of each region. By independently adjusting the detection data of each partition, it can ensure that the nitrogen oxides in each partition can be effectively treated, greatly improving the overall denitration efficiency, and making the nitrogen oxide emission more stably reach the ultra-low emission standard. Precise control of the urea injection amount of each partition can effectively avoid the problem of ammonia escape caused by excessive urea injection. According to the real-time adjustment of the ammonia escape data of each partition, the reaction of urea and nitrogen oxides can reach the optimal stoichiometric ratio, reducing the leakage of ammonia, reducing resource waste and secondary pollution risk.

[0062] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0063] Furthermore, the terms "first", "second", or the like are used merely to describe corresponding features, and do not imply or connote relative importance or a quantity of the specified features. Thus, a feature defined with "first" or "second" can include at least one of the feature. In the description of the present application, the meaning of "a plurality" is at least two, for example, two, three, etc., unless explicitly specified and limited otherwise.

[0064] In the present application, unless explicitly specified and limited otherwise, the terms "mounting", "connecting", "connecting", "fixing" and the like should be interpreted broadly, for example, can be fixed connection, or detachable connection, or integrated; can be mechanical connection, or electrical connection or communication with each other; can be directly connected, or indirectly connected through intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless explicitly defined otherwise. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0065] In the present application, unless explicitly specified and limited otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0066] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description 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 appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples, without contradiction.

[0067] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A gas-ejection-based urea direct injection denitration system (100), characterized in that, The application relates to a urea solution distribution device for a flue gas denitrification system. The device comprises: a urea solution storage module (1) and a compressed air supply module (2); a urea solution distribution module (3) comprising an ejector (301), a liquid delivery pipe (302), a gas delivery pipe (303), an air pressure regulating valve (304) and an air flow regulating valve (305), two ends of the liquid delivery pipe (302) being respectively connected with the urea solution storage module (1) and the ejector (301), two ends of the gas delivery pipe (303) being respectively connected with the compressed air supply module (2) and the ejector (301), the ejector (301) being used for mixing and atomizing urea solution by using compressed air, the air pressure regulating valve (304) and the air flow regulating valve (305) being arranged on the gas delivery pipe (303) and used for regulating the pressure and flow of compressed air; a flue (4) and a spray gun (5) arranged in the flue (4) and connected with the ejector (301) so as to spray the atomized urea solution into the flue (4); 2. The gas-ejection-based urea direct injection denitration system (100) according to claim 1, characterized in that, a detection module arranged in the flue (4) and used for detecting the content of nitrogen oxides and ammonia escape data in the flue (4), and a controller connected with the air pressure regulating valve (304), the air flow regulating valve (305) and the detection module respectively and used for adjusting the opening degree of the air pressure regulating valve (304) and the air flow regulating valve (305) according to the detection data of the detection module.

3. The gas-ejection-based urea direct injection denitration system (100) according to claim 1, characterized in that, The urea solution distribution module (3) further comprises an air pressure gauge (306) and an air flow gauge (307), the air pressure gauge (306) and the air flow gauge (307) being arranged on the gas delivery pipe (303), the air pressure gauge (306) being used for monitoring the pressure of compressed air, the air flow gauge (307) being used for monitoring the flow of compressed air, and the air pressure gauge (306) and the air flow gauge (307) being connected with the controller.

4. The gas-ejection-based urea direct injection denitration system (100) according to claim 1, characterized in that, The urea solution distribution module (3) further comprises a first manual on-off valve (308) arranged on the liquid delivery pipe (302).

5. The gas-ejection-based urea direct injection denitration system (100) according to claim 1, characterized in that, The urea solution distribution module (3) further comprises a second manual on-off valve (309) arranged between the ejector (301) and the spray gun (5).

6. The gas-ejection-based urea direct injection denitration system (100) according to claim 1, characterized in that, The urea solution distribution module (3) further comprises a urea solution flow gauge (310) arranged on the liquid delivery pipe (302).

7. The gas-ejection-based urea direct injection denitration system (100) according to claim 1, characterized in that, The urea solution storage module (1) comprises a liquid storage tank (101), the liquid storage tank (101) being provided with a liquid outlet pipeline (102), the liquid outlet pipeline (102) being connected with the liquid delivery pipe (302), and the liquid outlet pipeline (102) being provided with an on-off valve (103). The flue (4) is provided with a plurality of sub-zones along the flue gas flow direction, and the number of the spray guns (5) is equal to the number of the sub-zones.

8. The gas-ejection-based urea direct injection denitration system (100) according to claim 7, characterized in that, The number of the urea solution distribution modules (3) is multiple and each of them is connected to one of the multiple spray guns (5) one by one.

9. The gas-ejection-based urea direct injection denitration system (100) according to claim 8, characterized in that, The multiple urea solution distribution modules (3) are connected to the urea solution storage module (1) in parallel, and the multiple urea solution distribution modules (3) are connected to the compressed air supply module (2) in parallel.

10. The gas-ejection-based urea direct injection denitration system (100) according to claim 9, characterized in that, The detection module is used for monitoring the content of nitrogen oxides and ammonia escape data in each of the partitions, and adjusting the opening degree of the air pressure regulating valve (304) and the air flow regulating valve (305) in the urea solution distribution module (3) corresponding to each of the partitions according to the detection data of each of the partitions.

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