A method for controlling ash removal emissions

Abstract

The present invention discloses a method for controlling ash removal emissions, including collecting historical optimal data of electrostatic precipitators, obtaining an electrostatic precipitator control optimization recommendation table, calculating the total ash amount of the unit entering the electrostatic precipitator according to the amount of coal burned corresponding to different loads, obtaining the recommended value I optimal for secondary current control through the electric field secondary current value curve derived by the formula, calculating the amount of compressed air, obtaining the required number of air compressors, and realizing fine adjustment of the electric precipitator power consumption and ash transportation power consumption according to the reference value. This method can reduce the hysteresis of manual adjustment, improve the adaptability of coal blending and combustion, further reduce the cost of power generation, improve economic benefits, make up for the shortcomings of operators adjusting the secondary current of the electrostatic precipitator according to information such as load, coal type, and operation experience, and successfully reduce the power consumption of the electrostatic precipitator.

Description

Technical Field

[0001] The invention relates to the field of electrostatic dust removal technology, and in particular to a dust removal emission control method. Background Art

[0002] Traditional power plants mainly rely on experience to adjust the secondary current of electrostatic precipitators, which lacks scientificity. Due to the high fuel costs, in order to improve the company's market competitiveness and ensure the company's profitability, the proportion of inferior coal blending has gradually increased. When burning coal with lower ash content, the system can play a greater role in timely targeted adjustment and optimization of boilers, reduce the lag of manual adjustment, improve the adaptability of coal blending, further reduce power generation costs, and improve economic benefits. The use of this control system makes up for the shortcomings of operators in adjusting the secondary current of electrostatic precipitators according to information such as load, coal type, and operating experience, and successfully reduces the power consumption of electrostatic precipitators. The average power consumption rate of the electrostatic precipitator plant has dropped from 0.15% to 0.12%.

[0003] Based on the analysis of the actual working characteristics of the electrostatic precipitator system, assisted by feedback control with reference to parameters such as boiler load and ash content of coal entering the furnace, the total ash amount of the unit entering the electrostatic precipitator is calculated according to the amount of coal burned corresponding to different loads, and the recommended value of the secondary current is deduced using the Doitch formula, accurately matching the relevant adjustment parameters, and internalizing and digitizing the good experience of manual adjustment, so as to achieve energy saving and consumption reduction and intelligent monitoring. The electrostatic precipitator system requires operators to adjust the secondary current of the electrostatic precipitator according to information such as load, coal type, and operating experience. The different cognition and different methods of operators lead to uneven adjustments of various teams. At present, Sutong Power Plant participates in the frequency regulation market, with large load fluctuations and large changes in coal types. The adjustment of related parameters relies on manual intervention and becomes lagging. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a method for controlling dust removal emissions, thereby achieving the goals of energy saving and consumption reduction and intelligent monitoring.

[0007] In order to solve the above technical problems, the present invention provides the following technical solution, a method for controlling dust removal emissions, comprising:

[0008] Collect the best historical data of electrostatic precipitator and obtain the recommended table for electrostatic precipitator control optimization;

[0009] Calculate the total ash volume entering the electrostatic precipitator according to the coal consumption corresponding to different loads;

[0010] The electric field secondary current value curve derived by the formula is used to obtain the recommended value I optimal for secondary current control;

[0011] By calculating the amount of compressed air, the required number of air compressors can be obtained, and based on the reference value, the power consumption of the electrostatic precipitator and the ash conveying can be finely adjusted.

[0012] As a preferred solution of the ash removal emission control method described in the present invention, the optimal historical data of electrostatic precipitator include electrostatic precipitator secondary current, coal type ash content, total coal volume of the unit, and power consumption rate parameters of the electrostatic precipitator plant.

[0013] As a preferred embodiment of the method for controlling dust removal emissions described in the present invention, the calculation of the total amount of dust entering the electrostatic precipitator includes the following calculation formula:

[0014] Gfh=B×A×η×α÷100

[0015] Among them, Gfh represents the total ash content of the electrostatic precipitator, B represents the amount of coal burned, A represents the total dust collecting electrode area, η represents the electrostatic precipitator efficiency, and α represents the proportion of ash in the coal that enters the electrostatic precipitator.

[0016] As a preferred embodiment of the method for controlling dust removal emissions described in the present invention, the formula derivation includes that the electrostatic precipitator efficiency formula is defined as:

[0017]

[0018] Among them, C0 represents the concentration of dust when it enters, C E It represents the concentration of dust when it leaves, Q' represents the flue gas flow rate, ω represents the particle driving speed, and f represents the specific dust collecting area, that is, the dust collecting area required to purify one cubic meter of flue gas in one second.

[0019] As a preferred scheme of the method for controlling dust removal emissions described in the present invention, the recommended value for secondary current control includes the optimal value Ioptimal of electrostatic precipitator secondary current, the critical value Ilin of electrostatic precipitator secondary current and the actual value Ireal of electrostatic precipitator secondary current. The actual value of the electric field secondary current is monitored regularly, the actual value Ireal of electrostatic precipitator secondary current is recorded, and the actual value Ireal of electrostatic precipitator secondary current is compared with Ilin. When Ireal is greater than Ilin and less than Ioptimal, the dynamic adjustment range is entered for dynamic adjustment to keep the secondary current value normal. When Ireal is greater than Ioptimal, an alarm is automatically issued to remind the operating personnel to manually adjust the secondary current of the electrostatic precipitator. When Ireal is less than Ilin, no intervention is made.

[0020] As a preferred solution of the ash removal emission control method described in the present invention, the corresponding compressed air demand includes the calculation formula:

[0021]

[0022] Among them, Q represents the compressed air demand, β represents the average ash-to-gas ratio. The minimum value in the design instructions is 13.9. Indicates the air density at standard state.

[0023] As a preferred scheme of the ash removal emission control method described in the present invention, the required number of air compressors includes the total required amount of compressed air, multiplied by the loss coefficient, i.e., the ash conveying unit efficiency and the loss along the way, divided by the rated flow of each conveying air compressor, to obtain the required number of air compressors. The number of air compressors of a single unit must be displayed to one decimal place. When two units are running at the same time, the demands of the single units are added together, and the rounded value is taken as the total number of air compressors required.

[0024] As a preferred embodiment of the method for controlling dust removal emissions described in the present invention, the fine adjustment of the electric precipitator power consumption includes calculating the driving speed of the dust particles, which is expressed as:

[0025]

[0026] Where q represents the charge, E represents the electric field strength, μ represents the smoke viscosity, and d p Indicates the dust particle diameter to obtain the appropriate field current value.

[0027] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the method described in a method for controlling dust removal emissions are implemented.

[0028] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of the method described in a method for controlling dust removal emissions are implemented.

[0029] Beneficial effects of the invention: The method system of the invention can bring into play a greater advantage to carry out targeted adjustment and optimization of the boiler in a timely manner, reduce the lag of manual adjustment, improve the adaptability of coal blending and combustion, further reduce the cost of power generation, and improve economic benefits. The use of this control system makes up for the shortcomings of the operating personnel in adjusting the secondary current of the electrostatic precipitator according to information such as load, coal type, and operating experience, and successfully reduces the power consumption of the electrostatic precipitator and the average power consumption rate of the electrostatic precipitator plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0031] Figure 1 A schematic flow chart of a method for controlling dust removal emissions provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0035] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0036] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Example 1

[0039] Reference Figure 1 , which is the first embodiment of the present invention, provides a method for controlling dust removal emissions, comprising:

[0040] S1: Collect the optimal historical data of electrostatic precipitator and obtain the recommended table for electrostatic precipitator control optimization.

[0041] Furthermore, by collecting the corresponding parameters of the electrostatic precipitator secondary current, coal type ash content, total coal volume of the unit, and power consumption rate of the electrostatic precipitator plant in the past three months, the corresponding coupling relationship is found out, and a recommended table for electrostatic precipitator control optimization is obtained.

[0042] S2: Calculate the total amount of ash entering the electrostatic precipitator based on the amount of coal burned at different loads.

[0043] Furthermore, the calculation of the total amount of ash entering the electrostatic precipitator of the unit includes the following calculation formula:

[0044] Gfh=B×A×η×α÷100

[0045] Among them, Gfh represents the total ash content of the electrostatic precipitator, B represents the amount of coal burned, A represents the total dust collecting electrode area, η represents the electrostatic precipitator efficiency, and α represents the proportion of ash in the coal that enters the electrostatic precipitator.

[0046] S3: The electric field secondary current value curve is derived through the formula to obtain the recommended value I of secondary current control.

[0047] Furthermore, the formula derivation includes that the electrostatic precipitator efficiency formula is defined as:

[0048]

[0049] Among them, C0 represents the concentration of dust when it enters, C E It represents the concentration of dust when it leaves, Q' represents the flue gas flow rate, ω represents the particle driving speed, and f represents the specific dust collecting area, that is, the dust collecting area required to purify one cubic meter of flue gas in one second.

[0050] It should be noted that, from the analysis of the Doitch formula, it can be seen that, except for the driving speed, the other three parameters in the formula can be determined, because the dust removal efficiency is a subjective requirement, which is obtained according to the dust concentration at the inlet and outlet of the dust collector. The processing air volume Q is known, and the A value can be calculated as long as the ω value is selected. Therefore, when applying the Doitch formula, as long as the driving speed ω value is correctly selected, it can be guaranteed that the electrostatic precipitator achieves the expected performance.

[0051] S4: The electric field secondary current value curve is derived through the formula to obtain the recommended value I of secondary current control.

[0052] It should be noted that the recommended value Ioptimum for the secondary current control includes that, since the driving speed is proportional to the square of the electric field strength, the required electric field strength can be obtained and this strength can be brought into the optimized secondary current value curve.

[0053] Furthermore, the recommended values ​​of secondary current control include the optimal value of electrostatic precipitator secondary current Ioptimal, the critical value of electrostatic precipitator secondary current Ilin and the actual value of electrostatic precipitator secondary current Iactual. The actual value of the electric field secondary current is monitored regularly, the actual value of the electrostatic precipitator secondary current Iactual is recorded, and the actual value of the electrostatic precipitator secondary current Iactual is compared with Ilin. When Iactual is greater than Ilin and less than Ioptimal, the dynamic adjustment range is entered for dynamic adjustment to keep the secondary current value normal. When Iactual is greater than Ioptimal, an alarm is automatically issued to remind the operating personnel to manually adjust the electrostatic precipitator secondary current. When Iactual is less than Ilin, no intervention is made.

[0054] S5: Calculate the amount of compressed air and find out the number of air compressors required.

[0055] Furthermore, the corresponding compressed air demand includes a calculation formula:

[0056]

[0057] Among them, Q represents the compressed air demand, β represents the average ash-to-gas ratio. The minimum value in the design instructions is 13.9. Indicates the air density at standard state.

[0058] It should also be noted that the total amount of compressed air required, multiplied by the loss coefficient (including the efficiency of the ash conveying unit and the loss along the way), divided by the rated flow of each conveying air compressor, can be obtained to obtain the number of air compressors required. The number of air compressors for a single unit must be displayed to one decimal place. When two units are running at the same time, the demands of the single units are added together and the value is rounded off as the total number of air compressors required.

[0059] S6: Based on the reference value, fine adjustment of the power consumption of electrostatic precipitator and ash conveying is achieved.

[0060] Furthermore, the fine adjustment of the electric power consumption of the electrostatic precipitator includes calculating the driving speed of the dust particles, which is expressed as:

[0061]

[0062] Where q represents the charge, E represents the electric field strength, μ represents the smoke viscosity, and d p Indicates the dust particle diameter to obtain the appropriate field current value.

[0063] Example 2

[0064] One embodiment of the present invention provides a method for controlling dust removal emissions. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0065] The above-mentioned optimal data of electrostatic precipitator history are collected, and the recommended data for electrostatic precipitator control optimization are shown in Table 1:

[0066]

[0067] The number of air compressors required calculated based on the ash-to-gas ratio in the early stage considers all the electric fields as a whole. However, in actual operation, the dust removal efficiency of the electric field with the largest output is 90%, and the compressed air volume transported only accounts for 60% of the total compressed air volume. Among them, the combined gas consumption of the second, third, and fourth electric fields and SCR ash transportation accounts for 40% of the total compressed air volume, and it is operated intermittently. In the later stage, short-term shutdown can be further considered under the premise that the ash content is controllable, so it needs to be multiplied by the empirical coefficient 1.65.

[0068] Currently, when operating in winter mode, there are losses in the on-site gas storage tanks, pipelines along the way, and various water discharge points for transporting compressed air, so the empirical coefficient needs to be increased to 1.75 (it can be considered to be removed in summer).

[0069] After liquid ammonia is converted to urea, the gas consumption of the urea station increases (intermittent use), so the empirical coefficient needs to be increased to 1.8.

[0070] In summary, the required compressed air volume is multiplied by 1.8 on the original basis. Since the two units cannot be connected logically, the number of air compressors of a single unit needs to be displayed to one decimal place. When the two units are running at the same time, the single unit demand is added and the rounded value is used as a reference for the total number of air compressors required. The company's single unit ash conveying air compressor demand calculation is shown in Table 2:

[0071] Table 2

[0072]

[0073] The holographic recording input interface is shown in Table 3:

[0074] Table 3

[0075]

[0076] When the operator receives an order to change the coal type, he / she inputs the characteristics of the newly replaced coal type 1 to 2 hours in advance. After calculating using the built-in formula and comparing it with the recommended value, an alarm is issued to remind the operator to make adjustments. The good experience of manual adjustment is internalized and digitized, thereby achieving the purpose of energy saving and consumption reduction and smart monitoring.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0078] Example 3

[0079] The third embodiment of the present invention is different from the first two embodiments in that:

[0080] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0081] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0082] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0083] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

Claims

1. A method for controlling ash removal emissions, characterized in that: include, Collect the best historical data of electrostatic precipitator and obtain the recommended table for electrostatic precipitator control optimization; Calculate the total ash volume entering the electrostatic precipitator according to the coal consumption corresponding to different loads; The recommended value of secondary current control is obtained by the electric field secondary current value curve derived from the formula; By calculating the amount of compressed air, the number of air compressors required can be obtained, and based on the reference value, the power consumption of electrostatic precipitator and ash conveying can be finely adjusted; The optimal historical data of electrostatic precipitator include parameters of electrostatic precipitator secondary current, coal type ash content, total coal quantity of the unit and power consumption rate of the electrostatic precipitator plant; The total amount of ash entering the electrostatic precipitator is calculated Including, the calculation formula for the total ash volume of electrostatic precipitator is: Gfh=B×A×η×α Among them, Gfh represents the total ash content of the electrostatic precipitator, B represents the amount of coal burned, A represents the total dust collecting electrode area, η represents the electrostatic precipitator efficiency, and α represents the proportion of ash in the coal that enters the electrostatic precipitator; The formula derivation includes that the electrostatic precipitator efficiency formula is defined as: Among them, C0 represents the concentration of dust when it enters, C E represents the concentration of dust when it leaves, Q' represents the flue gas flow rate, ω represents the particle driving speed, and f represents the specific dust collection area; The recommended value of the secondary current control includes the optimal value of the electrostatic precipitator secondary current I, the critical value of the electrostatic precipitator secondary current I and the actual value of the electrostatic precipitator secondary current I. The actual value of the electric field secondary current is regularly monitored, the actual value of the electrostatic precipitator secondary current I is recorded, and the actual value of the electrostatic precipitator secondary current I is compared with I. When I is greater than I but less than I, the dynamic adjustment range is entered for dynamic adjustment to keep the secondary current value normal. When I is greater than I, an alarm is automatically issued to remind the operator to manually adjust the electrostatic precipitator secondary current. When I is less than I, no intervention is performed. The corresponding compressed air demand includes the calculation formula: Where Q represents the compressed air demand, β represents the average ash-to-gas ratio, refer to the minimum value in the design instructions, Indicates the air density at standard state.

2. A method for controlling ash removal emissions as claimed in claim 1, characterized in that: The required number of air compressors includes the total required amount of compressed air, multiplied by the loss coefficient, i.e. the ash conveying unit efficiency and the loss along the way, divided by the rated flow of each conveying air compressor to obtain the required number of air compressors. The number of air compressors for a single unit must be displayed to one decimal place. When two units are running at the same time, the demands of the single units are added together and the value is rounded off as the total number of air compressors required.

3. A method for controlling ash removal emissions as claimed in claim 2, characterized in that: The fine adjustment of the electric power consumption of the electrostatic precipitator includes calculating the driving speed of the dust particles, which is expressed as: Where q represents the charge, E represents the electric field strength, μ represents the smoke viscosity, and d p Indicates the dust particle diameter to obtain the appropriate field current value.

4. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 3 are implemented.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 3 are implemented.

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