A method for building a desulfurization tower automatic slurry supply system based on a digital model

Abstract

The application discloses a method for building an automatic slurry supply system of a desulfurization tower based on a digital model, which comprises the following steps: recording actual operation data of an absorption tower, making a digital model according to the corresponding relationship between the real-time SO2 total amount of original flue gas of the absorption tower and the slurry supply amount of the absorption tower, establishing a slurry supply automation basic model according to the digital model, establishing a slurry supply correction digital model and a parameter protection threshold according to the real-time SO2 content of net flue gas of the absorption tower, and establishing an absorption tower processing capacity data model according to the real-time PH value of the absorption tower. The application adjusts the rotating speed of a slurry supply pump, stabilizes the pH value of slurry in the absorption tower, adjusts the rotating speed of a circulating pump to control the circulating amount of limestone slurry in the absorption tower, and achieves the purpose of controlling the desulfurization rate. According to the frequency conversion control of the rotating speed of the circulating pump according to the flue gas parameters, the circulating pump does not have to keep high-speed operation, the energy cost is greatly saved on the basis of meeting the stable desulfurization rate, the energy consumption is as low as possible, and the effect of saving electric energy is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of big data desulfurization fully mechanized mining technology, and particularly to a method for building an automatic slurry supply system of a desulfurization tower based on a digital model. BACKGROUND

[0002] In the traditional slurry supply process, there are mainly two ways:

[0003] One is manual control. In the domestic limestone-gypsum wet flue gas desulfurization process, the automatic adjustment control system of the desulfurization system cannot be built under the DCS framework. Even if there is an automatic slurry supply logic in the original logic, the control accuracy cannot meet the normal use standard.

[0004] Secondly, purchase external software. The automatic control system in the domestic limestone-gypsum wet flue gas desulfurization process generally adopts the way of purchasing control software to realize.

[0005] However, there are some problems in these two traditional ways. The manual adjustment accuracy is poor, the adjustment frequency is large, the consumption of limestone powder is large, and the parameters are easy to exceed the standard,

[0006] The purchased automatic control software is similar to the logic plug-in, which has a safety risk. At the same time, the software purchase cost of each automatic control system is about 500,000 yuan, and regular maintenance fees are also needed, which requires long-term software investment. SUMMARY

[0007] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0008] In view of the above and / or existing problems in the prior art, the present application is proposed.

[0009] Therefore, the problem to be solved by the present application is that the existing automatic slurry supply system has poor manual adjustment accuracy, large adjustment frequency, large consumption of limestone powder, and easy-to-exceed parameters.

[0010] To solve the above technical problems, the present application provides the following technical scheme: a method for building an automatic slurry supply system of a desulfurization tower based on a digital model, comprising,

[0011] record the actual operation data of the absorption tower;

[0012] make a digital model according to the corresponding relationship between the real-time SO2 total amount of the original flue gas of the absorption tower and the slurry supply amount of the absorption tower, and establish a slurry supply automation basic model according to the digital model;

[0013] The real-time SO2 content of the clean flue gas in the absorption tower is used to establish a slurry supply correction digital model and a parameter protection threshold;

[0014] According to the real-time PH value of the absorption tower, an absorption tower processing capacity data model is established.

[0015] As a preferred scheme of the method for building an automatic slurry supply system for a desulfurization tower based on a digital model, a main control loop for automatic slurry supply is established according to the slurry supply automation basic model, the slurry supply correction digital model, and the absorption tower processing capacity data model.

[0016] As a preferred scheme of the method for building an automatic slurry supply system for a desulfurization tower based on a digital model, the actual operation data of the absorption tower includes the real-time SO2 content of the clean flue gas in the absorption tower, the real-time PH value of the absorption tower, the slurry supply amount of the absorption tower, the total SO2 amount without using a desulfurization additive, and the total SO2 amount when using a desulfurization additive.

[0017] As a preferred scheme of the method for building an automatic slurry supply system for a desulfurization tower based on a digital model, the slurry supply automation basic model includes the total SO2 amount of the original flue gas without using a desulfurization additive and the absorption tower slurry circulating pump digital model, and the total SO2 amount of the original flue gas when using a desulfurization additive and the absorption tower slurry circulating pump digital model.

[0018] The measurement method of the original flue gas is that in the slurry preparation system, the original flue gas flow is measured according to the sensor installed in the flue, and the sulfur dioxide concentration of the original flue gas is analyzed by using related instruments.

[0019] The measurement method of the clean flue gas is that in the slurry preparation system, the clean flue gas flow is measured according to the sensor installed in the discharge port, and the sulfur dioxide concentration of the original flue gas is analyzed by using related instruments.

[0020] As a preferred scheme of the method for building an automatic slurry supply system for a desulfurization tower based on a digital model, the real-time SO2 content of the clean flue gas in the absorption tower is used to establish a slurry supply correction digital model and a parameter protection threshold;

[0021] The change in the slurry supply amount of the absorption tower is achieved by increasing the number of absorption towers, so the increase is a steep data relationship. The number of absorption towers increases from 0 to 1 absorption tower, 2 absorption towers, and 3 absorption towers, and the corresponding relationship is established by a digital model.

[0022] As a preferred scheme of the method for building an automatic slurry supply system for a desulfurization tower based on a digital model, the parameter protection threshold range is a given value of the limestone slurry flow calculated by proportioning and chemical equations.

[0023]

[0024] Then the limestone slurry flow actual value is measured, the difference between the given value and the actual value is calculated, the Ca / S value in the wet flue gas desulfurization is 1.1, so the calculation for the sulfur in the flue gas can be carried out according to the calcium molar number in the absorbent,

[0025] When the actual value is higher than the given value, the slurry pump rotating speed is reduced, and the limestone slurry feeding is reduced;

[0026] When the given value exceeds the actual value, the slurry pump rotating speed is increased, and the limestone slurry feeding is increased.

[0027] As a preferred scheme of the method for building the automatic slurry feeding system of the desulfurization tower based on the digital model, wherein: the absorption tower processing capacity data model is an upper and lower limit data model and a warning model of the desulfurization amount under different PH values under the condition that the number of absorption towers is unchanged;

[0028] The upper and lower limit data model of the absorption tower processing capacity under different PH values refers to the fact that the desulfurization amount under different PH values is embodied in the model under the condition that the number of absorption towers is unchanged;

[0029] The warning model refers to a model for controlling the PH value of the absorption tower, which alarms when the limit value is exceeded, so as to prevent the quality of the slurry from being deteriorated due to the over-supply of limestone slurry, thereby performing the warning;

[0030] The warning mode is a threshold value judgment of the PH value in the over-limit control model,

[0031] When the PH value in the over-limit control model is less than 5, a green light is displayed, that is, it is marked that there is no limestone slurry feeding reaction;

[0032] When the PH value in the over-limit control model is greater than 5 and less than 5.5, a blue light is displayed, that is, it is marked that there is a small amount of limestone slurry feeding reaction;

[0033] When the PH value in the over-limit control model is greater than 5.5 and less than 6, a yellow light is displayed, that is, it is marked that there is sufficient limestone slurry feeding reaction;

[0034] When the PH value in the over-limit control model is greater than 6, a red light is displayed, that is, it is marked that there is an excessive amount of limestone slurry feeding reaction.

[0035] As a preferred scheme of the method for building the automatic slurry feeding system of the desulfurization tower based on the digital model, wherein: the method for controlling the PH value of the absorption tower is to form a pH value control loop, which is a double closed loop control structure, two controllers are connected in series to control the rotating speed of the slurry feeding pump, so as to control the pH value of the slurry;

[0036] The outer ring pH controller in the two controllers is the main controller, and the limestone slurry flow controller is the secondary controller, and the controller generally adopts a PI controller, which can be obtained by setting the differential coefficient Td of the PID controller to 0.

[0037] A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method as described above when executing the computer program.

[0038] A computer-readable storage medium having a computer program stored thereon, characterized in that the computer program is executed by a processor to implement the steps of the method as described above.

[0039] The present application has the advantages of adjusting the rotation speed of the slurry supply pump to control the flow of newly injected limestone slurry, stabilizing the pH value of the slurry in the absorption tower, adjusting the rotation speed of the circulating pump to control the circulating amount of limestone slurry in the absorption tower, achieving the purpose of controlling the desulfurization rate, and performing frequency control on the rotation speed of the circulating pump according to the flue gas parameters, so that the circulating pump does not have to run at high speed all the time, greatly saving energy costs on the basis of meeting the stable desulfurization rate, maintaining as low energy consumption as possible, and achieving the effect of saving electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0041] Figure 1 The total SO2 amount without using desulfurization additives and the absorption tower slurry circulating pump digital model diagram for the method of building an automatic slurry supply system for a desulfurization tower based on a digital model in Example 2.

[0042] Figure 2 The total SO2 amount when using desulfurization additives and the absorption tower slurry circulating pump digital model diagram for the method of building an automatic slurry supply system for a desulfurization tower based on a digital model in Example 2.

[0043] Figure 3 The digital model diagram for correcting slurry supply according to the real-time SO2 content of the clean flue gas of the absorption tower for the method of building an automatic slurry supply system for a desulfurization tower based on a digital model in Example 2.

[0044] Figure 4 The absorption tower processing capacity upper and lower limit data model diagram at different pH values for the method of building an automatic slurry supply system for a desulfurization tower based on a digital model in Example 2.

[0045] Figure 5 The data model graph of the stone powder allowance and the PH value in the absorption tower based on the method of building the automatic slurry supply system of the desulfurization tower in Example 2.

[0046] Figure 6 The over-limit control model graph of the PH value in the absorption tower based on the method of building the automatic slurry supply system of the desulfurization tower in Example 2.

[0047] Figure 7 The flow chart of the method of building the automatic slurry supply system of the desulfurization tower based on the digital model in Example 2. DETAILED DESCRIPTION

[0048] In order to make the above objectives, characteristics and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0049] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0050] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent of or selected from other embodiments.

[0051] Example 1

[0052] The first embodiment of the present application provides a method of building an automatic slurry supply system of a desulfurization tower based on a digital model, which comprises

[0053] Recording the actual operation data of the absorption tower;

[0054] Making a digital model according to the corresponding relationship between the real-time SO2 total amount of the original flue gas of the absorption tower and the slurry supply amount of the absorption tower, and establishing a slurry supply automation basic model according to the digital model;

[0055] Establishing a slurry supply correction digital model and a parameter protection threshold according to the real-time SO2 content of the clean flue gas of the absorption tower;

[0056] Establishing an absorption tower processing capacity data model according to the real-time PH value of the absorption tower.

[0057] Establishing a main control loop of automatic slurry supply according to the slurry supply automation basic model, the slurry supply correction digital model and the absorption tower processing capacity data model.

[0058] The actual operation data of the absorption tower includes the real-time SO2 content of the absorption tower net flue gas, the real-time PH value of the absorption tower, the absorption tower slurry supply amount, the total SO2 amount without using the desulfurization additive, and the total SO2 amount when using the desulfurization additive.

[0059] The slurry supply automation basic model includes the original flue gas SO2 total amount without using the desulfurization additive and the absorption tower slurry circulating pump digital model, and the original flue gas SO2 total amount when using the desulfurization additive and the absorption tower slurry circulating pump digital model.

[0060] The measurement method of the original flue gas is that in the pulp preparation system, the original flue gas flow is measured according to the sensor installed in the flue, and then the related instrument is used to analyze the sulfur dioxide concentration of the original flue gas.

[0061] The measurement method of the net flue gas is that in the pulp preparation system, the net flue gas flow is measured according to the sensor installed in the discharge port, and then the related instrument is used to analyze the sulfur dioxide concentration of the original flue gas.

[0062] The real-time SO2 content of the absorption tower net flue gas establishes the digital model of the slurry supply correction and the parameter protection threshold value.

[0063] The change of the absorption tower slurry supply amount is realized by increasing the number of absorption towers, so the increase amount is a steep increase data relationship. The number of absorption towers is from 0 to 1 absorption tower, 2 absorption towers, 3 absorption towers, and the corresponding relationship is established through the digital model.

[0064] The parameter protection threshold value range is the given value of the limestone slurry flow calculated by matching and chemical equation,

[0065]

[0066] Then measure the actual value of the limestone slurry flow, and the difference between the given value and the actual value. The Ca / S value in the wet flue gas desulfurization is 1.1, so the calculation of sulfur in the flue gas can be carried out according to the number of moles of calcium in the absorbent,

[0067] When the actual value is higher than the given value, the slurry pump speed is reduced, and the limestone slurry feeding is reduced.

[0068] When the given value exceeds the actual value, the slurry pump speed is increased, and the limestone slurry feeding is increased.

[0069] The absorption tower processing capacity data model is to establish the upper and lower limit data model and the early warning model of the absorption tower processing capacity at different PH values.

[0070] Establishing the upper and lower limit data model of the absorption tower processing capacity at different PH values means that the desulfurization amount at different PH values is reflected in the model under the condition that the number of absorption towers remains unchanged.

[0071] The early warning model refers to establishing an over-limit control model based on the PH value of the absorption tower, and giving an alarm when the limit value is exceeded, so as to prevent the slurry quality from being deteriorated due to the over-supply of limestone slurry, thereby giving a pre-warning.

[0072] The early warning mode is a threshold judgment of the PH value in the over-limit control model,

[0073] When the PH value in the over-limit control model is less than 5, a green light is displayed, that is, it is marked that there is no limestone slurry supply reaction;

[0074] When the PH value in the over-limit control model is less than 5.5 and greater than 5, a blue light is displayed, that is, it is marked that there is a small amount of limestone slurry supply reaction;

[0075] When the PH value in the over-limit control model is greater than 5.5 and less than 6, a yellow light is displayed, that is, it is marked that there is sufficient limestone slurry supply reaction;

[0076] When the PH value in the over-limit control model is greater than 6, a red light is displayed, that is, it is marked that there is an excessive limestone slurry supply reaction.

[0077] The method for controlling the PH value of the absorption tower is to form a pH value control loop, which is a double closed loop control structure, and two controllers are connected in series to control the speed of the slurry supply pump, so as to control the pH value of the slurry;

[0078] The outer ring pH controller in the two controllers is the main controller, and the limestone slurry flow controller is the auxiliary controller, and the controller generally adopts a PI controller, which can be obtained by setting the differential coefficient Td of the PID controller to 0.

[0079] Embodiment 2

[0080] The second embodiment of the application is different from the first embodiment in that:

[0081] If the function is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product stored in a storage medium includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0082] The logic and / or steps represented in flow diagrams or otherwise described herein, for example, can be considered as a sequence of executable instructions for implementing logic functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

[0083] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can also be paper or other suitable material upon which the program is printed, as the program can be electronically captured, for example, via an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in a form that is then employable by a computer.

[0084] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, the various steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or combinations thereof, can be used: discrete logic circuitry having logic gates for implementing logic functions upon data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and so forth.

[0085] Example 3

[0086] Reference Figures 1-6 For the third embodiment of the present application, which differs from the first two embodiments, is:

[0087] First, a digital model is established for the relationship between the total amount of real-time SO2 in the original flue gas and the amount of slurry supplied to the absorption tower;

[0088] Second, a digital model is established for the relationship between the total amount of real-time SO2 in the original flue gas and the start-stop relationship of the slurry circulating pump of the absorption tower, including the total amount of SO2 without using desulfurization additives and the digital model of the slurry circulating pump of the absorption tower, such asFigure 1 As shown, the total amount of SO2 and the digital model of the circulating pump of the absorption tower slurry when using desulfurization additives, as shown in Figure 2 .

[0089] As can be clearly seen from the above two figures, when no desulfurization additives are added, the relationship between the real-time SO2 total amount of the original flue gas and the start-stop of the slurry circulating pump of the absorption tower is an intermittent positive relationship, and with the increase of the number of slurry circulating pumps, the total amount of SO2 removed also increases, but when desulfurization additives are added, the relationship between the real-time SO2 total amount of the original flue gas and the start-stop of the slurry circulating pump of the absorption tower is an uninterrupted positive relationship, and with the increase of the number of slurry circulating pumps, the total amount of SO2 removed also increases;

[0090] Next, the digital model of the total amount of SO2 in the original flue gas of the absorption tower and the slurry supply amount is established, as shown in Figure 3 , and finally the relationship between the total amount of SO2 in the original flue gas and the slurry supply amount is

[0091] y = 0.1228x 2 + 4.3526x + 1.389

[0092] According to the above digital model, the main control loop of automatic slurry supply is established.

[0093] According to the real-time SO2 content of the clean flue gas of the absorption tower, the digital model of the corrected slurry supply and the parameter protection threshold are established, as shown in Figure 3 .

[0094] Finally, the upper and lower limit data models of the absorption tower processing capacity at different PH values are established, as shown in Figure 4 , the data model of the stone powder allowance in the absorption tower and the PH value is established, as shown in Figure 5 , the over-limit control model based on the PH value of the absorption tower is established, as shown in Figure 6 , and finally the alarm is realized when the limit value is exceeded, to prevent the quality of the slurry from being deteriorated due to the over-supply of limestone slurry in the absorption tower.

[0095] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application 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 application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A method for constructing an automatic slurry supply system for a desulfurization tower based on a digital model, characterized in that: Record the actual operating data of the absorption tower; The actual operating data of the absorption tower includes the real-time SO2 content of the clean flue gas, the real-time pH value of the absorption tower, the slurry supply of the absorption tower, the total SO2 without the use of desulfurization additives, and the total SO2 with the use of desulfurization additives. A digital model is created based on the real-time total SO2 content of the raw flue gas in the absorption tower and the slurry supply to the absorption tower. A basic model for automated slurry supply is then established based on the digital model. The main control loop for automatic slurry supply is established based on the basic model of automated slurry supply, the digital model of slurry supply correction, and the data model of absorption tower processing capacity. The automated slurry supply basic model includes a digital model of the total SO2 content of the raw flue gas and the slurry circulation pump of the absorber tower when no desulfurization additives are used, and a digital model of the total SO2 content of the raw flue gas and the slurry circulation pump of the absorber tower when desulfurization additives are used. The method for measuring the raw flue gas is to measure the flow rate of the raw flue gas in the pulping system based on the sensor installed in the flue, and then analyze the sulfur dioxide concentration of the raw flue gas using relevant instruments. The method for measuring the clean flue gas is to measure the clean flue gas flow rate based on the sensor installed at the discharge port in the pulping system, and then analyze the sulfur dioxide concentration of the clean flue gas using relevant instruments. Establish a slurry supply correction digital model and parameter protection thresholds based on the real-time SO2 content of the clean flue gas from the absorption tower. The change in the slurry supply of the absorption tower is achieved by increasing the number of absorption towers. Therefore, the increase is a steep increase in data relationship. The number of absorption towers increases from 0 to 1, 2, and 3. The corresponding relationship is established through a digital model. The parameter protection threshold range is a given value of limestone slurry flow rate calculated through proportioning and chemical equations. The actual flow rate of the limestone slurry was measured, and the difference between the given value and the actual value was calculated. Since the Ca / S ratio in wet flue gas desulfurization is 1.1, the sulfur content in the flue gas was calculated based on the number of molar amounts of calcium in the absorbent. When the actual value is higher than the given value, reduce the speed of the slurry pump and reduce the limestone slurry feed. When the given value exceeds the actual value, increase the speed of the slurry pump and increase the limestone slurry feed. A data model of the absorption tower's processing capacity was established based on the real-time pH value of the absorption tower. The absorption tower processing capacity data model is used to establish upper and lower limit data models and early warning models for the absorption tower processing capacity at different pH values. The aforementioned data model for the upper and lower limits of the absorption tower's processing capacity at different pH values ​​refers to the model reflecting the desulfurization amount at different pH values ​​under the condition that the number of absorption towers remains unchanged. The aforementioned early warning model refers to the establishment of an over-limit control model based on the pH value of the absorption tower, which will issue an alarm when the limit value is exceeded to prevent the absorption tower slurry from deteriorating in quality due to excessive limestone slurry supply, thereby providing an early warning. The early warning method involves determining the pH threshold in the over-limit control model. A green light is displayed when the pH value in the over-limit control model is less than 5, indicating that there is no limestone slurry supplied for the reaction. When the pH value in the over-limit control model is less than 5.5 or greater than 5, a blue light will be displayed, indicating that a small amount of limestone slurry is supplied to the reaction. When the pH value in the over-limit control model is greater than 5.5 and less than 6, a yellow light will be displayed, indicating that there is sufficient limestone slurry supply for the reaction. A red light is displayed when the pH value in the over-limit control model is greater than 6, indicating that there is an excessive limestone slurry supply reaction. The method for pH control in the absorption tower is to form a pH control loop, which is a double closed-loop control structure consisting of two controllers connected in series to control and adjust the speed of the slurry pump, thereby controlling the pH value of the slurry. Of the two controllers, the outer loop pH controller serves as the main controller, and the limestone slurry flow controller serves as the secondary controller. The controllers are PID controllers, which can be obtained by setting the differential coefficient Td in the PID controller to 0.

2. 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, it implements the steps of the method described in claim 1.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method described in claim 1.

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