Method for preventing blockage of a spray system of a flue gas absorption tower

Abstract

The application discloses a method for preventing blockage of a flue gas absorption tower spraying system, comprising the following steps: obtaining the desulfurization efficiency of the flue gas absorption tower spraying system; when the desulfurization efficiency reduction is not less than a first preset value and less than a second preset value, and lasts for a first preset time length, performing a first action for a preset number of times, the first action being used for online cleaning of nozzle blockage; after performing the first action for the preset number of times, detecting the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system within a second preset time length, if the growth rate is not greater than a first preset growth rate, returning to step S10; when the desulfurization efficiency reduction is not less than the second preset value and less than a third preset value, and lasts for a third preset time length, it is determined that the nozzle blockage foreign matter is high-level crystalline foreign matter; when the desulfurization efficiency reduction is not less than the third preset value, and lasts for a fourth preset time length, a shutdown maintenance warning is sent, through the above method, on the one hand, the blockage of the nozzle can be determined in time, and on the other hand, frequent shutdown caused by blockage can be reduced, thereby guaranteeing the longest operation time length of the unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flue gas absorption tower spraying technology, in particular to a method for preventing blockage of a flue gas absorption tower spraying system. BACKGROUND

[0002] In the flue gas desulfurization process of coal-fired power plants, nozzle blockage is a common problem that seriously affects the desulfurization efficiency and the stable operation of the unit. The traditional nozzle blockage detection method mainly relies on manual inspection and regular maintenance, which has the following disadvantages: manual inspection is low in efficiency and cannot realize real-time monitoring, resulting in that the nozzle blockage problem cannot be discovered and handled in time; regular maintenance is high in cost and needs frequent shutdown inspection, affecting the continuous operation of the unit; there is a lack of effective blockage identification means, which cannot accurately determine the blockage cause, resulting in inaccurate treatment measures; and the control accuracy is low. SUMMARY

[0003] The present application aims to provide a method for preventing blockage of a flue gas absorption tower spraying system to solve the problems raised in the background.

[0004] The first aspect of the present application proposes a method for preventing blockage of a flue gas absorption tower spraying system, characterized in that it comprises the following steps:

[0005] Step S10: obtaining the desulfurization efficiency of the flue gas absorption tower spraying system;

[0006] Step S20: when the desulfurization efficiency decrease is not less than a first preset value and less than a second preset value, and lasts for a first preset time length, performing a first action for a preset number of times, the first action being used for online cleaning of nozzle blockage;

[0007] Step S30: after performing the first action for a preset number of times, detecting the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system within a second preset time length, if the growth rate is not greater than a first preset growth rate, returning to step S10;

[0008] Step S40: when the desulfurization efficiency decrease is not less than a second preset value and less than a third preset value, and lasts for a third preset time length, it is determined that the nozzle blockage foreign matter is high-level crystalline foreign matter;

[0009] Step S50: when the desulfurization efficiency decrease is not less than a third preset value, and lasts for a fourth preset time length, a shutdown maintenance warning is issued.

[0010] According to one embodiment of the present application, the step S30 further comprises: if the growth rate is greater than the first preset growth rate, determining that the nozzle blockage is a primary crystallization foreign matter, and controlling to perform a second action, the second action being used for online mitigation of the blockage process; after performing the second action, continuously monitoring the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system within a third preset time length, if the growth rate is not greater than the first preset growth rate, returning to step S10; if the growth rate is greater than the first preset growth rate, determining that the nozzle blockage foreign matter is a medium-level crystallization foreign matter, and then no longer performing any online action of removing and mitigating the nozzle blockage.

[0011] According to one embodiment of the present application, the first preset time length is greater than the third preset time length and the fourth preset time length, and the third preset time length is greater than the fourth preset time length.

[0012] According to one embodiment of the present application, the first action comprises: online high-pressure water flushing.

[0013] According to one embodiment of the present application, the second action comprises: controlling the pH value of the slurry, and adjusting the slurry water to softened water.

[0014] According to one embodiment of the present application, if the growth rate is greater than the first preset growth rate, determining that the nozzle blockage foreign matter is a medium-level crystallization foreign matter, and then no longer performing any online action of removing and mitigating the nozzle blockage, further comprises: real-time desulfurization efficiency of the flue gas absorption tower spray system.

[0015] According to one embodiment of the present application, after determining that the nozzle blockage foreign matter is a high-level crystallization foreign matter, further comprising: issuing a “sulfur dioxide index close to standard limit value, temporary shutdown for maintenance” to the user, and giving a nozzle blockage cleaning strategy.

[0016] According to one embodiment of the present application, the nozzle blockage cleaning strategy comprises: using a chemical cleaning agent for descaling.

[0017] According to one embodiment of the present application, further comprising: detecting the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system, and if the current sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system is less than the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system at the previous time minus 3σ, wherein σ represents the standard deviation of the sequence of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system from the initial time to the current time under the current working condition, and the difference between the current sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system and the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system at the next time is less than a first preset difference, then determining that the nozzle blockage is a sudden foreign matter, and issuing a temporary shutdown for maintenance suggestion to the user.

[0018] According to one embodiment of the present application, issuing a temporary shutdown for maintenance suggestion to the user comprises: adjusting the installation angle of the nozzle which is severely eroded by the tower wall of the absorption tower, and covering the support beam of the spray layer with a stainless steel plate.

[0019] Compared with the prior art, the beneficial effects of the technical scheme are as follows:

[0020] 1. Improve the accuracy of nozzle blockage diagnosis: by monitoring the desulfurization efficiency of the flue gas absorption tower spraying system and excluding sensor abnormalities, the technical scheme can determine the blockage of the nozzle blockage in a timely manner, thereby improving the accuracy of the nozzle blockage diagnosis.

[0021] 2. Reduce the number of shutdowns: the technical scheme reduces the frequent shutdowns caused by blockage by cleaning the nozzle blockage online, thereby ensuring the longest running time of the unit.

[0022] 3. Improve the efficiency of the unit: by presetting the action and detecting the growth rate of sulfur dioxide concentration, the technical scheme can timely handle the nozzle blockage problem, avoid the decrease of desulfurization efficiency caused by blockage, and improve the efficiency of the unit.

[0023] 4. Reduce maintenance costs: the technical scheme reduces the workload of manual inspection and maintenance by intelligently diagnosing and handling the nozzle blockage problem, thereby reducing the maintenance costs.

[0024] 5. Improve the adaptability and reliability of the system: the technical scheme can intelligently judge the type of nozzle blockage foreign matter according to different preset values and time lengths, and issue corresponding processing instructions, thereby improving the adaptability and reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A flowchart of a method for preventing blockage of a flue gas absorption tower spraying system according to the present application; DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the present application are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0028] It should be understood that the term "and / or" as used herein merely describes an associated relationship among associated objects, and can represent three relationships, for example, A and / or B can represent three cases of A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0029] Depending on the context, the word "if" as used herein can be interpreted as meaning "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if it is determined" or "if (a stated condition or event) is detected" can be interpreted as meaning "when it is determined" or "in response to determining" or "when (a stated condition or event) is detected" or "in response to detecting (a stated condition or event)".

[0030] It should also be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that a product or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such product or device. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the product or device comprising the element.

[0031] The optional embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0032] Figure 1 , a flow chart of a method for preventing blockage of a flue gas absorption tower spraying system according to the present application, as shown in Figure 1 The present application provides a method for preventing blockage of a flue gas absorption tower spraying system.

[0033] The method for preventing blockage of the flue gas absorption tower spraying system comprises the following steps:

[0034] Step S10, obtaining a desulfurization efficiency of the flue gas absorption tower spraying system;

[0035] Step S20, when the desulfurization efficiency decrease is not less than a first preset value and less than a second preset value, and lasts for a first preset time length, performing a first action for a preset number of times, the first action being used for online cleaning of nozzle blockage;

[0036] Step S30, after performing the first action for a preset number of times, detecting a growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system within a second preset time length, and if the growth rate is not greater than a first preset growth rate, returning to step S10;

[0037] Step S40, when the desulfurization efficiency reduction amount is not less than the second preset value and less than the third preset value, and lasts for a third preset time length, it is determined that the nozzle blockage foreign matter is high-level crystallization foreign matter;

[0038] Step S50, when the desulfurization efficiency reduction amount is not less than the third preset value, and lasts for a fourth preset time length, a shutdown maintenance warning is issued.

[0039] In the embodiment, by acquiring the sulfur dioxide concentration at the inlet of the flue gas absorption tower spraying system and the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system, the desulfurization efficiency of the flue gas absorption tower spraying system is determined, desulfurization efficiency = (sulfur dioxide concentration at the inlet - sulfur dioxide concentration at the outlet) / sulfur dioxide concentration at the inlet x 100%. The common blockage positions of the flue gas absorption tower spraying system mainly include nozzle blockage, filler blockage, branch pipe blockage and main pipe blockage. The desulfurization efficiency and the outlet sulfur dioxide concentration growth rate are the key factors to determine the degree of nozzle blockage. Therefore, the degree of nozzle blockage can be determined by the desulfurization efficiency reduction amount and the outlet sulfur dioxide concentration growth rate. Common foreign matters mainly include soft scale such as calcium sulfite, primary crystallization foreign matter composed of calcium sulfate or calcium fluoride, intermediate crystallization foreign matter composed of calcium sulfate or calcium fluoride, and high-level crystallization foreign matter composed of calcium sulfate or calcium fluoride. Among them, the primary crystallization foreign matter indicates that the calcium sulfate or calcium fluoride is relatively thin, which belongs to the thickness that can be removed by the second action to online alleviate the blockage process; the intermediate crystallization foreign matter indicates that the calcium sulfate or calcium fluoride is relatively thick, which is the thickness that cannot be alleviated or removed by the first action and the second action; the high-level crystallization foreign matter indicates that the calcium sulfate or calcium fluoride is very thick, reaching the thickness of the critical point of sulfur dioxide emission standard.

[0040] In the embodiment, when the desulfurization efficiency reduction is not less than the first preset value and less than the second preset value and lasts for the first preset time length, it is indicated that the nozzle is blocked and has a preliminary influence on the desulfurization efficiency, but the influence is small. In order to prevent the accumulation of foreign matters and prevent frequent shutdown of the unit, the first action needs to be performed for a preset number of times. The first action is used for online cleaning of the nozzle blockage. Through the first action, if the foreign matters are soft scale such as calcium sulfite, the nozzle foreign matters can be quickly cleaned, and the hidden danger can be eliminated. After the first action is performed for a preset number of times, the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system in the second preset time length is detected. If the growth rate is not greater than the first preset growth rate, it is indicated that the foreign matters blocking the nozzle are mainly soft scale such as calcium sulfite, and a good cleaning effect can be achieved through the first action. If the growth rate is greater than the first preset growth rate, it is determined that the nozzle blockage still exists, and after the first action, the remaining nozzle blockage foreign matters are mainly hard scale such as calcium sulfate or calcium fluoride. However, the thickness of the hard scale such as calcium sulfate or calcium fluoride is thin, and the hard scale does not obviously affect the desulfurization efficiency. However, since the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system in the second preset time length is rapidly increasing, it is indicated that the scaling accumulation rate of the hard scale such as calcium sulfate or calcium fluoride is continuously increasing. At this time, the second action can be performed to slow down or eliminate the scaling rate of the hard scale such as calcium sulfate or calcium fluoride, and the running time length of the unit without shutdown is improved. After the second action is performed, the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system in the third preset time length is continuously monitored. If the growth rate is not greater than the first preset growth rate, it is indicated that the crisis of rapid scaling of the hard scale such as calcium sulfate or calcium fluoride has been eliminated through the second action. If the growth rate is greater than the first preset growth rate, it is determined that the hard scale such as calcium sulfate or calcium fluoride has reached a relatively thick thickness, and the second action cannot achieve the effect of online alleviation of the blockage. However, at this time, the desulfurization efficiency reduction is low, and the environmental protection has not been affected. Therefore, in order to ensure the safe operation of the unit, no online action of removing and alleviating the nozzle blockage is performed, and the operation parameters such as the sulfur dioxide concentration at the inlet of the flue gas absorption tower spraying system, the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system, and the desulfurization efficiency are monitored in real time. When the desulfurization efficiency reduction is not less than the second preset value and less than the third preset value and lasts for the third preset time length, it is determined that the nozzle blockage foreign matters are relatively thick blockage matters, and the current nozzle blockage degree has reached a critical point of sulfur dioxide emission. At this time, a temporary shutdown suggestion is given, and the user can selectively perform the operation of temporary shutdown or not according to the necessity of the current unit operation. When the desulfurization efficiency reduction is not less than the third preset value and lasts for the fourth preset time length, a shutdown for maintenance warning is given. At this time, the user needs to be urgently warned to prevent more dangerous events from occurring.By the method, on the one hand, different anti-blocking strategies can be adopted for different blockage conditions, and the type of foreign matter blockage can be determined in time, so as to accurately predict the nozzle blockage for the user; on the other hand, frequent shutdown and maintenance can be prevented, and thus the stable operation time of the unit is improved.

[0041] Further, the first preset length is greater than the third preset time length and the fourth preset time length, and the third preset time length is greater than the fourth preset time length.

[0042] The first preset length is greater than the third preset time length and the fourth preset time length, and the third preset time length is greater than the fourth preset time length, so that the timeliness of the elimination or mitigation strategy can be selectively executed according to different blockage severity, the efficiency of eliminating hidden dangers is improved, and the safe operation of the unit is improved.

[0043] According to system operation experience and historical data, the first, second and third preset values of the desulfurization efficiency and the corresponding first, second, third and fourth preset time lengths are set.

[0044] Further, the sulfur dioxide concentration at the inlet of the flue gas absorption tower spraying system and the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system are detected by a sulfur dioxide concentration sensor.

[0045] Further, when the unit is started again, the sulfur dioxide concentration sensor is excluded from the abnormality, and the improved LeNet-5 network is used to exclude the sulfur dioxide concentration sensor from the abnormality.

[0046] Through the abnormality exclusion, the detection error caused by the abnormality of the sulfur dioxide concentration sensor is excluded, and thus the accuracy of the desulfurization efficiency is improved, and finally the accuracy of the control of the present application is improved.

[0047] Further, the improved LeNet-5 network is used to exclude the sulfur dioxide concentration sensor from the abnormality, which comprises:

[0048] The LeNet-5 network is improved: the ReLU function is used to replace the Sigmoid function as the activation function of the LeNet-5 network; and the Droupout mechanism is introduced in the training process of the LeNet-5 network, and a certain proportion of network units and connections are randomly deleted to reduce the over-reliance between units and improve the generalization ability of the network.

[0049] The labeled sulfur dioxide concentration sensor data is used as a training sample to train the improved LeNet-5 network, and a trained model is obtained;

[0050] The trained improved LeNet-5 network is used to exclude the abnormality of the to-be-detected signal of the sulfur dioxide concentration sensor.

[0051] Further, the step S30 further comprises: if the growth rate is greater than the first preset growth rate, determining that the nozzle clogging object is a primary crystallization foreign matter, and controlling to perform a second action, the second action being used for online mitigation of the clogging process; after performing the second action, continuously monitoring the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system within a third preset time length, if the growth rate is not greater than the first preset growth rate, returning to the step S10; if the growth rate is greater than the first preset growth rate, determining that the nozzle clogging foreign matter is a medium-level crystallization foreign matter, and then not performing any online action of removing and mitigating the nozzle clogging.

[0052] Further, the second preset time length is equal to the third preset time length.

[0053] Further, the first action comprises: online high-pressure water flushing.

[0054] Through the online high-pressure water flushing, soft dirt such as calcium sulfite or other impurities can be removed in time to prevent calcium sulfite from being oxidized into hard dirt such as calcium sulfate later.

[0055] Further, the second action comprises: controlling the pH value of the slurry and adjusting the slurry water to softened water.

[0056] Specifically, the pH value of the slurry is controlled to be between 6.0 and 7.0, which on the one hand guarantees the desulfurization efficiency and mitigates the continuous deterioration of hard dirt such as calcium sulfate or calcium fluoride, and on the other hand reduces the corrosion of the weak acid slurry to the absorption tower.

[0057] Preferably, the pH value is 6.5.

[0058] Adjusting the slurry water to softened water can reduce the deposition of calcium salt in the system and delay the scaling period of hard dirt such as calcium sulfate or calcium fluoride.

[0059] Further, if the growth rate is greater than the first preset growth rate, determining that the nozzle clogging foreign matter is a medium-level crystallization foreign matter, and then not performing any online action of removing and mitigating the nozzle clogging, further comprises: real-time desulfurization efficiency of the flue gas absorption tower spray system.

[0060] Further, after determining that the nozzle clogging foreign matter is a high-level crystallization foreign matter, further comprises: issuing a "sulfur dioxide index close to standard limit value, temporary shutdown for maintenance" to the user, and giving a nozzle clogging cleaning strategy.

[0061] When the nozzle clogging foreign matter is a high-level crystallization foreign matter, the desulfurization efficiency is sharply reduced, and the treatment capacity for sulfur dioxide is reduced. At this time, the treatment capacity of the flue gas absorption tower spray system for sulfur dioxide has decreased to near the environmental protection standard limit value.

[0062] Further, the nozzle clogging cleaning strategy comprises: using a chemical cleaning agent for descaling.

[0063] For the plug containing both calcium sulfate and calcium fluoride, a comprehensive cleaning method can be adopted. For example, part of the calcium sulfate scale can be removed by using alkali cleaning method first, and then the calcium fluoride scale and the remaining calcium sulfate scale can be removed by using acid cleaning method. During the cleaning process, physical cleaning methods such as high-pressure water jet, ultrasonic cleaning, etc. can also be combined to improve the cleaning effect.

[0064] Among them, the acid cleaning method includes that although the calcium sulfate has high resistance to acid, strong acids such as hydrochloric acid can still remove part of the calcium sulfate scale to a certain extent. Pure soda (sodium carbonate) can be used to react with calcium sulfate to generate calcium carbonate, and then the formed calcium carbonate can be removed by using acid cleaning solution. In addition, it can also be tried to use organic acids such as citric acid for cleaning.

[0065] The alkali cleaning method includes that calcium sulfate scale is removed by using sodium hydroxide to react with calcium sulfate to generate calcium hydroxide and sodium sulfate. In industry, 20% sodium hydroxide is generally used for soaking, and the soaking time is related to the thickness of the calcium sulfate scale layer.

[0066] The desulfurization efficiency of the real-time flue gas absorption tower spraying system also includes: detecting the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system, and the current sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system is less than the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system at the previous time - 3σ, wherein σ represents the standard deviation of the sequence of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system from the initial time to the current time under the current working condition, and the difference between the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system at the next time is less than the first preset difference, then it is determined that the nozzle blockage is caused by sudden foreign matter, and a temporary shutdown for maintenance suggestion is sent to the user.

[0067] When the current sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system is far lower than the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system at the previous time, and the difference between the sulfur dioxide concentration at the outlet of the flue gas absorption tower spraying system at the next time is less than the first preset difference, it indicates that the current nozzle has a sudden large-area blockage, and the current outlet sulfur dioxide concentration is a mutation point. The sudden foreign matter is usually caused by the falling of anti-corrosion scales or gypsum scale pieces, rather than the accumulation of calcium sulfate or calcium fluoride. Therefore, the user can be timely informed of the falling of anti-corrosion scales or gypsum scale pieces, the reason for the nozzle blockage, and a temporary shutdown for maintenance suggestion is given.

[0068] Further, the temporary shutdown for maintenance suggestion sent to the user includes: adjusting the installation angle of the nozzle with serious erosion of the absorption tower wall, and covering the stainless steel plate on the spraying layer support beam.

[0069] Specifically, according to the falling of the anticorrosion material of the tower wall around the nozzle of the spray layer, the installation angle of the nozzle which is seriously eroded by the tower wall of the absorption tower is adjusted to reduce the erosion of the anticorrosion layer of the tower wall. Meanwhile, the support beam of the spray layer is covered with a 3mm thick stainless steel plate, and a square ring hoop made of the same material is used to fix the PP plate of the support beam of the spray layer and the stainless steel plate at the top, effectively preventing the falling of the anticorrosion material of the support beam of the spray layer.

[0070] Further, a shutdown maintenance alarm is sent, including: sending a "shutdown maintenance alarm" prompt information to the user through the intelligent terminal.

[0071] The intelligent terminal includes at least one of a smart phone, a tablet computer, a smart speaker, a smart bracelet, and a smart watch; for example, sending a prompt information to an APP on a smart phone.

[0072] The present application sends a prompt information to the user, so that the user can know the blocking situation in time, so that the user can take measures more timely, and ensure that the unit meets the environmental protection requirements and runs stably.

[0073] Corresponding to the above-mentioned several embodiments of the method for preventing the smoke absorption tower spray system from being blocked, an embodiment of the present application also provides a device for preventing the smoke absorption tower spray system from being blocked. Since the device for preventing the smoke absorption tower spray system from being blocked provided by the embodiment of the present application corresponds to the method for preventing the smoke absorption tower spray system from being blocked provided by the above-mentioned several embodiments, the implementation modes of the above-mentioned method for preventing the smoke absorption tower spray system from being blocked are also applicable to the device for preventing the smoke absorption tower spray system from being blocked provided by the present embodiment, which will not be described in detail in the present embodiment.

[0074] A device for preventing the smoke absorption tower spray system from being blocked, comprising:

[0075] An acquisition module acquires the desulfurization efficiency of the smoke absorption tower spray system;

[0076] A processing module includes, when the desulfurization efficiency decrease is not less than the first preset value and less than the second preset value, and lasts for the first preset time length, performing a first action for a preset number of times, the first action being used for online cleaning of nozzle blockage;

[0077] After the first action is performed for a preset number of times, the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system within a second preset time period is detected. If the growth rate is not greater than a first preset growth rate, the desulfurization efficiency of the flue gas absorption tower spray system is obtained. If the growth rate is greater than the first preset growth rate, it is determined that the nozzle clogging object is a primary crystallization foreign matter, and a second action is controlled to be performed, the second action being used to online alleviate the clogging process. After the second action is performed, the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system within a third preset time period is continuously monitored. If the growth rate is not greater than the first preset growth rate, the desulfurization efficiency of the flue gas absorption tower spray system is obtained. If the growth rate is greater than the first preset growth rate, it is determined that the nozzle clogging foreign matter is a medium crystallization foreign matter, and no online action of removing and alleviating the nozzle clogging is performed any more.

[0078] When the desulfurization efficiency drop is not lower than the second preset value and lower than the third preset value, and lasts for the third preset time period, it is determined that the nozzle clogging foreign matter is a high-level crystallization foreign matter.

[0079] When the desulfurization efficiency drop is not lower than the third preset value, and lasts for a fourth preset time period, a shutdown maintenance warning is issued.

[0080] The first preset time period is greater than the third preset time period and the fourth preset time period, and the third preset time period is greater than the fourth preset time period.

[0081] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means 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, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0082] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0083] Any processes or methods described in the flowcharts or otherwise described herein can be understood as representing code modules, segments, or portions of code which include one or more executable instructions for implementing specific logic functions (or steps) of the application, and alternate implementations are possible. In this description and the following claims, the terms "code module", "code segment", or "portion of code" can collectively refer to one or more sections of code, which can be stored in and / or executed by a computer, a processor, or other logic device.

[0084] Logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be embodied in computer-readable instructions, which can be used to cause a general-purpose computing device, special-purpose computing device, or other computerized device to perform operations described herein. As used in this description and the following claims, the term "computer-readable medium" can refer to any media capable of storing, communicating, propagating, or transporting software, including non-transitory media. Such computer- readable media can include, but are not limited to, solid-state memories, optical media, hard drives, floppy disks, magnetic tape, or other magnetic media, punch cards, paper tape, or other physical medium that stores computer- readable instructions or other computer- readable data. For example, a computer-readable medium can include a solid-state memory, which can be removable, built-in, or integral to a computing device. The term "computer- readable medium" can also include communication media, including carrier waves that can be employed to communicate computer- readable instructions between computing devices, including wireless media such as radio frequency (RF) waves, infrared waves, wireless media such as Bluetooth, or others.

[0085] It should be understood that aspects of the application can be implemented in hardware, software, firmware, or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. As well, if desired, such hardware or software can be implemented as one or more computer programs, running on a computer or other suitable computing device, which can be embodied on a computer readable medium. For example, computer readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired computer program code in the form of computer- executable instructions or data structures and that can be accessed by a general purpose or special purpose computer. Also, it should be understood that any of the above-described devices can be used in a distributed computing environment, where tasks are performed by local and remote processing devices that can be in communication through a computer network.

[0086] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiment method can be instructed by a program to complete the relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0087] In addition, each functional unit in each embodiment of the present application can be integrated in one processing control module, or each unit can exist physically alone, or two or more units can be integrated in one control module. The integrated control module can be realized in the form of hardware or in the form of a software function control module. The integrated control module, if realized in the form of a software function control module and sold or used as an independent product, can also be stored in a computer readable storage medium.

[0088] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. A method for preventing clogging of a spray system of a flue gas absorption tower, characterized in that, The method comprises the following steps: Step S10, obtaining the desulfurization efficiency of the flue gas absorption tower spray system; Step S20, when the desulfurization efficiency decrease is not less than the first preset value and less than the second preset value, and lasts for the first preset time length, performing the first action for a preset number of times, the first action being used for online cleaning of nozzle blockage; Step S30, after performing the first action for a preset number of times, detecting the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system within the second preset time length, if the growth rate is not greater than the first preset growth rate, returning to step S10; Step S40, when the desulfurization efficiency decrease is not less than the second preset value and less than the third preset value, and lasts for the third preset time length, determining that the nozzle blockage foreign matter is high-level crystallization foreign matter; Step S50, when the desulfurization efficiency decrease is not less than the third preset value, and lasts for the fourth preset time length, issuing a shutdown maintenance warning.

2. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 1, characterized in that: The step S30 further comprises, if the growth rate is greater than the first preset growth rate, determining that the nozzle blockage matter is primary crystallization foreign matter, and controlling the second action to be performed, the second action being used for online mitigation of the blockage process; after performing the second action, continuously monitoring the growth rate of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system within the third preset time length, if the growth rate is not greater than the first preset growth rate, returning to step S10; if the growth rate is greater than the first preset growth rate, determining that the nozzle blockage foreign matter is medium-level crystallization foreign matter, and then no longer performing any online action of cleaning and mitigating nozzle blockage.

3. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 2, characterized in that: The first preset time length is greater than the third preset time length and the fourth preset time length, and the third preset time length is greater than the fourth preset time length.

4. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 1, characterized in that: The first action comprises online high-pressure water flushing.

5. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 2, characterized in that: The second action comprises controlling the pH value of the slurry and adjusting the slurry water to softened water.

6. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 3, characterized in that: If the growth rate is greater than the first preset growth rate, determining that the nozzle blockage foreign matter is medium-level crystallization foreign matter, and then no longer performing any online action of cleaning and mitigating nozzle blockage, further comprises: real-time monitoring the desulfurization efficiency of the flue gas absorption tower spray system.

7. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 3, characterized in that: After determining that the nozzle blockage foreign matter is high-level crystallization foreign matter, further comprising: issuing a "sulfur dioxide index close to the standard limit value, temporary shutdown for maintenance" to the user, and giving a nozzle blockage cleaning strategy.

8. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 7, characterized in that: The nozzle blockage cleaning strategy comprises using a chemical cleaning agent for descaling.

9. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 3, characterized in that: Further comprising: Detecting the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system, if the current sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system is less than the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system at the previous time minus 3σ, wherein σ represents the standard deviation of the sequence of the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system from the initial time to the current time under the current working condition, and the difference between the current sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system and the sulfur dioxide concentration at the outlet of the flue gas absorption tower spray system at the next time is less than a first preset difference, then determining that the nozzle blockage is sudden foreign matter, and issuing a temporary shutdown for maintenance suggestion to the user.

10. The method for preventing the blockage of the spray system of the flue gas absorption tower according to claim 9, characterized in that: Issuing a temporary shutdown for maintenance suggestion to the user comprises: adjusting the installation angle of the nozzles that are severely washed by the tower wall of the absorption tower, and covering the support beam of the spray layer with a stainless steel plate.

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