CN114880790A - Variable working condition mechanism modeling method and system for steam-driven induced draft fan and storage medium - Google Patents

Abstract

The invention discloses a modeling method, system and storage medium for the mechanism of a steam-driven induced draft fan under variable working conditions. The method includes: obtaining a historical database generated by the operation of the steam-driven induced draft fan in a specific time period in the past; As the influencing factor, the historical database is used to fit the actual inlet flow change curve; the guide vane opening and the actual inlet flow are used as the influencing factors, the historical database is used to fit the actual specific pressure energy change curve; the guide vane opening and the actual specific pressure energy change curve is fitted; As the influencing factor, the historical database is used to fit the actual speed change curve; based on the similar principle followed when the induced draft fan operates at variable speed, the actual inlet flow change curve, the actual specific pressure energy change curve and the actual speed change curve are converted and fused to obtain the variable speed. Operating characteristic curve; extracting and fitting the design specific pressure energy mathematical model and operating efficiency mathematical model from the variable speed operating characteristic curve. The invention can improve the evaluation reliability of the operation efficiency of the steam-driven induced draft fan.

Description

A method, system and storage medium for modeling the variable working condition mechanism of a steam-driven induced draft fan

technical field

The invention relates to the technical field of control of a steam-driven induced draft fan in a power plant, in particular to a method, a system and a storage medium for modeling the mechanism of a variable working condition of a steam-driven induced draft fan.

Background technique

In order to reduce the power consumption rate of the plant, save the raw coal, and avoid the problems of large starting current and low power voltage caused by the motor drive of the induced draft fan of millions of units, the steam-driven induced draft fan has been put into practice in my country's large thermal power units. application. In order to make the steam-driven induced draft fan achieve the best operating efficiency, the technicians estimate the unit load, speed and guide vane opening configuration of the steam-driven induced draft fan at the optimal operating efficiency by collecting a large amount of operating data when the steam-driven induced draft fan is running. relation.

The operating efficiency of the steam-driven induced draft fan is actually closely related to its flue gas flow characteristics, flue pipe characteristics and the performance of the induced draft fan itself. The flue gas flow characteristics and flue pipe characteristics are affected by the coal quality, and the performance of the induced draft fan itself is affected by the unit However, at present, many scholars only rely on the unit load when evaluating the optimal operating efficiency of the steam-driven induced draft fan, and the evaluation model formula given at the same time covers too many unknown parameters, which is too ideal. , it is easy to cause large errors in the actual production process.

SUMMARY OF THE INVENTION

The present invention provides a method, system and storage medium for modeling the mechanism of a steam-driven induced draft fan under variable working conditions, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial choice or create conditions.

The embodiment of the present invention provides a method for modeling the mechanism of a steam-driven induced draft fan under variable working conditions, and the method includes:

Obtain the historical database generated by the operation of the steam-driven induced draft fan in a specific period of time in the past;

Taking coal quality and unit load as influencing factors, using the historical database to get the actual inlet flow change curve of the induced draft fan;

Taking the opening of the guide vane and the actual inlet flow as the influencing factors, the actual specific pressure energy variation curve of the induced draft fan is obtained by fitting the historical database;

Taking the opening of the guide vane and the actual specific pressure energy as the influencing factors, the actual speed variation curve of the induced draft fan is obtained by fitting the historical database;

Based on the similar principle followed during variable speed operation of the induced draft fan, the actual inlet flow rate variation curve, the actual specific pressure energy variation curve and the actual rotational speed variation curve are converted and fused to obtain the variable speed operation characteristic curve of the induced draft fan ;

The design specific pressure energy mathematical model and operational efficiency mathematical model of the induced draft fan are extracted and fitted from the variable speed operation characteristic curve.

Further, the acquisition of the historical database generated by the operation of the steam-driven induced draft fan in the past specific time period includes:

Invoke the initial historical database generated by the operation of the steam-driven induced draft fan within a specific time period in the past;

According to the predetermined normal value range of each index of the steam-driven induced draft fan during operation, the unqualified sample data contained in the initial historical database is eliminated, and an updated historical database is obtained.

Further, the actual inlet flow change curve of the induced draft fan is:

Q=0.00027894L ² -0.00013363C ² +0.00021404LC-0.65031L+0.94638C+1335.6

Among them, Q is the actual inlet flow, L is the unit load, and C is the coal quality.

Further, the actual specific pressure energy change curve of the induced draft fan is:

P=1.1664β ² +0.029919Q ² -0.261βQ+51.704β-17.82Q+4280.1

Among them, P is the actual specific pressure energy, β is the guide vane opening, and Q is the actual inlet flow.

Further, the actual speed change curve of the induced draft fan is:

n=α(0.7331β ² +0.000013658P ² -0.0123βP-58.853β+1.0013P+4316.1)

Among them, n is the actual speed, α is the load segment coefficient, P is the actual specific pressure energy, and β is the guide vane opening.

Further, the similar principle followed when the induced draft fan operates at variable speed satisfies the following formula:

Among them, Q is the actual inlet flow, Q ₀ is the design inlet flow, n is the actual speed, n ₀ is the design speed, P is the actual specific pressure energy, and P ₀ is the design specific pressure energy.

Further, the design specific pressure energy mathematical model of the induced draft fan is:

Among them, P ₀ is the design specific pressure energy, Q ₀ is the design inlet flow rate, and β is the guide vane opening.

Further, the operational efficiency mathematical model of the induced draft fan is:

Among them, η is the operating efficiency, Q ₀ is the design inlet flow rate, and P ₀ is the design specific pressure energy.

In addition, an embodiment of the present invention also provides a system for modeling the mechanism of a steam-driven induced draft fan under variable working conditions, the system comprising:

The acquisition module is used to acquire the historical database generated by the operation of the steam-driven induced draft fan within a specific time period in the past;

The first fitting module is used for taking coal quality and unit load as influencing factors, and using the historical database to obtain the actual inlet flow variation curve of the induced draft fan;

The second fitting module is used for taking the guide vane opening and the actual inlet flow as the influencing factors, and using the historical database to obtain the actual specific pressure energy variation curve of the induced draft fan;

The third fitting module is used for taking the guide vane opening and the actual specific pressure energy as influencing factors, and using the historical database to obtain the actual speed variation curve of the induced draft fan;

The fusion module is used to convert and fuse the actual inlet flow change curve, the actual specific pressure energy change curve and the actual rotational speed change curve based on the similar principle followed when the induced draft fan operates at variable speed to obtain the induced draft fan. Variable speed operation characteristic curve;

The extraction module is used for extracting and fitting the design specific pressure energy mathematical model and operation efficiency mathematical model of the induced draft fan from the variable speed operation characteristic curve.

In addition, an embodiment of the present invention further provides a computer-readable storage medium on which an application program is stored, and when the application program is executed by a processor, implements the above-mentioned method for modeling the variable working condition mechanism of a steam-driven induced draft fan.

The invention has at least the following beneficial effects: by introducing the two main factors of coal quality and unit load, the historical database generated by the operation of the steam-driven induced draft fan is used to carry out the fitting operation of the correlation curve, and then the following parameters are used when the induced draft fan operates at variable speed. The final operating efficiency evaluation model is obtained from the transformation of the similar principle, and it covers less unknown parameters, which can improve the evaluation reliability of the operating efficiency of the steam-driven induced draft fan.

Description of drawings

The accompanying drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the description. They are used to explain the technical solutions of the present invention together with the embodiments of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

Fig. 1 is a schematic flow chart of a method for modeling the variable working condition mechanism of a steam-driven induced draft fan in an embodiment of the present invention;

Fig. 2 is the variable speed operation characteristic curve diagram of the induced draft fan in the embodiment of the present invention;

FIG. 3 is a schematic diagram of the structure and composition of a mechanism modeling system for a steam-driven induced draft fan under variable working conditions in an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

It should be noted that although the functional modules are divided in the schematic diagram of the system and the logical sequence is shown in the flowchart, in some cases, the modules can be divided differently from the system, or executed in the order in the flowchart. steps shown or described. The terms "first", "second" and the like in the description and claims and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Please refer to FIG. 1 . FIG. 1 is a schematic flowchart of a method for modeling a variable working condition mechanism of a steam-driven induced draft fan according to an embodiment of the present invention. The method includes the following steps:

S101. Acquire a historical database generated by the operation of the steam-driven induced draft fan within a specific time period in the past.

In the implementation process, the initial historical database generated by the operation of the steam-driven induced draft fan in the past specific time period is firstly called; The unqualified sample data contained in the database are eliminated, and then the updated historical database is obtained, in which each index includes coal quality, unit load, actual inlet flow, guide vane opening, actual specific pressure energy and actual rotational speed.

Specifically, the process of eliminating unqualified sample data includes: firstly, time-correlated all sample data contained in the initial historical database; secondly, acquiring each index value at time t (t≥1), and after judging that there are at least When an index value does not fall within its corresponding normal value range, all index values at the time t are eliminated. On the contrary, when it is judged that each index value falls within its corresponding normal value range, All the index values at the time t are retained; then the index values at the time t+1 are obtained for the same judgment, and so on, until the data cleaning of the initial historical database is completed.

S102 , taking coal quality and unit load as influencing factors, and using the historical database to obtain a variation curve of the actual inlet flow rate of the induced draft fan.

Specifically, since the characteristics of flue gas flow and flue pipeline are related to the coal quality used in the power plant, and the performance of the induced draft fan is related to the unit load of the steam-driven induced draft fan, the embodiment of the present invention reduces the operating efficiency of the steam-driven induced draft fan For the purpose of estimating the deviation, the flue gas flow characteristics, flue pipeline characteristics and the performance of the induced draft fan are comprehensively considered. The coal quality and unit load are used as independent variables, and the historical database is used to construct the actual inlet flow change of the induced draft fan. curve.

In the implementation process, several groups of first data sets at different times are obtained from the historical database, wherein the first data sets include coal quality, unit load and actual inlet flow, and then the induced draft fan is fitted. The actual inlet flow curve is:

Q=0.00027894L ² -0.00013363C ² +0.00021404LC-0.65031L+0.94638C+1335.6

In the formula: Q is the actual inlet flow, L is the unit load, and C is the coal quality.

S103 , taking the guide vane opening and the actual inlet flow rate as influencing factors, and using the historical database to obtain the actual specific pressure energy variation curve of the induced draft fan.

In the implementation process, several groups of second data sets at different times are obtained from the historical database, wherein the second data sets include guide vane opening, actual inlet flow and actual specific pressure energy, and then fit the data The actual specific pressure energy change curve of the induced draft fan is:

P=1.1664β ² +0.029919Q ² -0.261βQ+51.704β-17.82Q+4280.1

In the formula: P is the actual specific pressure energy, β is the opening of the guide vane, and Q is the actual inlet flow.

It should be noted that, since the guide vane opening of the steam-driven induced draft fan ranges from 0 to 100%, several sets of second data sets selected in the embodiment of the present invention at least cover every guide vane within the guide vane opening range. Leaf opening and its associated actual inlet flow and actual specific pressure energy.

S104 , taking the guide vane opening and the actual specific pressure energy as influencing factors, and using the historical database to fit the actual rotational speed variation curve of the induced draft fan.

In the implementation process, several groups of third data sets at different times are obtained from the historical database, wherein the third data sets include guide vane opening, actual specific pressure energy and actual rotational speed, and then fit the The actual speed change curve of the induced draft fan is:

n=α(0.7331β ² +0.000013658P ² -0.0123βP-58.853β+1.0013P+4316.1)

In the formula: n is the actual speed, α is the load segment coefficient, P is the actual specific pressure energy, and β is the guide vane opening.

It should be noted that the value of the load segmentation coefficient α in the embodiment of the present invention is specified as follows: when the unit load generated by the steam-driven induced draft fan falls within the range of L≤450MW, the value of α is 1; When the unit load generated by the induced draft fan falls within the range of 450MW<L≤900MW, the value of α is 1.3167; when the unit load generated by the steam-driven induced draft fan falls within the range of L>900MW, the value of α is 1.5208 .

S105. Based on the similar principle followed during variable speed operation of the induced draft fan, convert and fuse the actual inlet flow rate variation curve, the actual specific pressure energy variation curve and the actual rotational speed variation curve to obtain the variable speed operation characteristics of the induced draft fan Graph.

In the embodiment of the present invention, the similar principle followed when the induced draft fan operates at variable speed satisfies the following formula:

Among them, Q is the actual inlet flow, Q ₀ is the design inlet flow, n is the actual speed, n ₀ is the design speed, P is the actual specific pressure energy, and P ₀ is the design specific pressure energy.

In the implementation process, according to the above similar principles, it can be seen that the variable speed operation of the induced draft fan will only affect the numerical changes of the rotational speed, the inlet flow rate and the specific pressure energy, but it is stipulated that the iso-opening line and iso-efficiency line before and after the variable speed of the induced draft fan remain unchanged. In this embodiment of the present invention, the actual rotational speed obtained from the actual rotational speed change curve under the current working condition of the steam-driven induced draft fan is used, and the actual inlet flow rate is calculated according to the ratio between the actual rotational speed and the proposed design rotational speed. Convert the change curve to obtain an initial inlet flow change curve, and convert the actual specific pressure energy change curve to obtain an initial specific pressure energy change curve, at this time based on the initial inlet flow change curve and the initial specific pressure energy change curve There is a cross relationship between independent variables, and then the above two change curves are fused into the same coordinate system, and then the inlet and outlet flow (m ³ /s), specific pressure energy (Nm/kg), operating efficiency (%) and The functional relationship between the guide vane opening degrees (°), that is, the variable speed operation characteristic curve of the induced draft fan is obtained by conversion, as shown in Figure 2.

S106 , extracting and fitting the design specific pressure energy mathematical model and the operational efficiency mathematical model of the induced draft fan from the variable speed operation characteristic curve.

In the implementation process, since the specific pressure energy is related to the guide vane opening and the inlet flow rate, several data points are extracted from the variable speed operating characteristic curve, and each data point corresponds to the guide vane opening and the inlet flow rate. and specific pressure energy, and then fit the mathematical model of the design specific pressure energy of the induced draft fan as:

Among them, P ₀ is the design specific pressure energy, Q ₀ is the design inlet flow rate, and β is the guide vane opening.

In the implementation process, since the operating efficiency is related to the inlet flow rate and specific pressure energy, several data points are extracted from the variable speed operating characteristic curve, and each data point corresponds to the inlet flow rate, specific pressure energy and operating efficiency , and then fit the mathematical model of the operating efficiency of the induced draft fan as:

Among them, η is the operating efficiency, Q ₀ is the design inlet flow rate, and P ₀ is the design specific pressure energy.

In the embodiment of the present invention, by introducing the two main factors of coal quality and unit load, the historical database generated by the operation of the steam-driven induced draft fan is used to perform the fitting operation of the correlation curve, and then the similarities that the induced draft fan follows during variable-speed operation are used. The final operating efficiency evaluation model is obtained by the principle conversion, and it covers less unknown parameters, which can improve the evaluation reliability of the operating efficiency of the steam-driven induced draft fan.

Please refer to FIG. 3. FIG. 3 is a schematic diagram of the structure of a system for modeling the mechanism of a steam-driven induced draft fan under variable working conditions provided by an embodiment of the present invention. The system includes the following:

The acquisition module 201 is used to acquire the historical database generated by the operation of the steam-driven induced draft fan in the past specific time period;

The first fitting module 202 is used for taking coal quality and unit load as influencing factors, and using the historical database to obtain the actual inlet flow variation curve of the induced draft fan;

The second fitting module 203 is used for taking the guide vane opening and the actual inlet flow as influencing factors, and using the historical database to obtain the actual specific pressure energy variation curve of the induced draft fan;

The third fitting module 204 is configured to use the guide vane opening and the actual specific pressure energy as influencing factors, and use the historical database to obtain the actual rotational speed variation curve of the induced draft fan;

The fusion module 205 is used to convert and fuse the actual inlet flow change curve, the actual specific pressure energy change curve and the actual rotational speed change curve based on the similar principle followed when the induced draft fan operates at variable speed, to obtain the induced draft fan The variable speed operation characteristic curve of ;

The extraction module 206 is configured to extract and fit the design specific pressure energy mathematical model and the operational efficiency mathematical model of the induced draft fan from the variable speed operation characteristic curve graph.

Regarding the specific limitation of each component module in a system for modeling the mechanism of a steam-driven induced draft fan under variable working conditions, reference may be made to the limitations of the method for modeling the mechanism of a variable operating condition of a steam-driven induced draft fan in the above-mentioned embodiments, and this is not the case here. Repeat.

In addition, an embodiment of the present invention also provides a computer-readable storage medium on which an application program is stored, and when the application program is executed by a processor, implements the above-mentioned method for modeling the variable working condition mechanism of a steam-driven induced draft fan.

Those of ordinary skill in the art can understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all of the physical components may be implemented as software executed by a central processing unit, digital signal processor or microprocessor, or as hardware, or as an integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is known to those of ordinary skill in the art, computer storage media includes both volatile and nonvolatile implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data , removable and non-removable media. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cartridges, magnetic tape, magnetic disk storage or other magnetic storage devices, or may Any other medium used to store desired information and which can be accessed by a computer. Furthermore, communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and can include any information delivery media, as is known to those of ordinary skill in the art .

The preferred implementation of the present invention is specifically described above, but the present invention is not limited to the above-mentioned embodiments. Those skilled in the art can also make various equivalent deformations or replacements without departing from the spirit of the present invention. Modifications or substitutions are all included within the scope defined by the claims of the present invention.

Claims (10)

1. a steam-driven induced draft fan variable working condition mechanism modeling method, is characterized in that, described method comprises: Obtain the historical database generated by the operation of the steam-driven induced draft fan in a specific period of time in the past; Taking coal quality and unit load as influencing factors, using the historical database to get the actual inlet flow change curve of the induced draft fan; Taking the opening of the guide vane and the actual inlet flow as the influencing factors, the actual specific pressure energy variation curve of the induced draft fan is obtained by fitting the historical database; Taking the opening of the guide vane and the actual specific pressure energy as the influencing factors, the actual speed variation curve of the induced draft fan is obtained by fitting the historical database; Based on the similar principle followed when the induced draft fan operates at variable speed, the actual inlet flow change curve, the actual specific pressure energy change curve and the actual rotational speed change curve are converted and fused to obtain the variable speed operation characteristic curve of the induced draft fan ; The design specific pressure energy mathematical model and operational efficiency mathematical model of the induced draft fan are extracted and fitted from the variable speed operation characteristic curve. 2. The method for modeling the variable working condition mechanism of the steam-driven induced draft fan according to claim 1, wherein the acquisition of the historical database generated by the operation of the steam-driven induced draft fan in the past specific time period comprises: Invoke the initial historical database generated by the operation of the steam-driven induced draft fan within a specific time period in the past; According to the predetermined normal value range of each index of the steam-driven induced draft fan during operation, the unqualified sample data contained in the initial historical database is eliminated, and an updated historical database is obtained. 3. The method for modeling the variable working condition mechanism of a steam-driven induced draft fan according to claim 1, wherein the actual inlet flow variation curve of the induced draft fan is: Q=0.00027894L ² -0.00013363C ² +0.00021404LC-0.65031L+0.94638C+1335.6 Among them, Q is the actual inlet flow, L is the unit load, and C is the coal quality. 4. The method for modeling the variable working condition mechanism of a steam-driven induced draft fan according to claim 1, wherein the actual specific pressure energy variation curve of the induced draft fan is: P=1.1664β ² +0.029919Q ² -0.261βQ+51.704β-17.82Q+4280.1 Among them, P is the actual specific pressure energy, β is the guide vane opening, and Q is the actual inlet flow. 5. The method for modeling the variable working condition mechanism of a steam-driven induced draft fan according to claim 1, wherein the actual rotational speed variation curve of the induced draft fan is: n=α(0.7331β ² +0.000013658P ² -0.0123βP-58.853β+1.0013P+4316.1) Among them, n is the actual speed, α is the load segment coefficient, P is the actual specific pressure energy, and β is the guide vane opening. 6. The method for modeling the variable working condition mechanism of a steam-driven induced draft fan according to claim 1, wherein the similar principle followed during the variable speed operation of the induced draft fan satisfies the following formula:

Among them, Q is the actual inlet flow, Q ₀ is the design inlet flow, n is the actual speed, n ₀ is the design speed, P is the actual specific pressure energy, and P ₀ is the design specific pressure energy. 7. The method for modeling the variable working condition mechanism of a steam-driven induced draft fan according to claim 1, wherein the design specific pressure energy mathematical model of the induced draft fan is:

Among them, P ₀ is the design specific pressure energy, Q ₀ is the design inlet flow rate, and β is the guide vane opening. 8. The method for modeling the variable working condition mechanism of a steam-driven induced draft fan according to claim 1, wherein the mathematical model of the operating efficiency of the induced draft fan is:

Among them, η is the operating efficiency, Q ₀ is the design inlet flow rate, and P ₀ is the design specific pressure energy. 9. A system for modeling the variable working condition mechanism of a steam-driven induced draft fan, wherein the system comprises: The acquisition module is used to acquire the historical database generated by the operation of the steam-driven induced draft fan within a specific time period in the past; The first fitting module is used for taking coal quality and unit load as influencing factors, and using the historical database to obtain the actual inlet flow variation curve of the induced draft fan; The second fitting module is used for taking the guide vane opening and the actual inlet flow as the influencing factors, and using the historical database to obtain the actual specific pressure energy variation curve of the induced draft fan; The third fitting module is used for taking the guide vane opening and the actual specific pressure energy as influencing factors, and using the historical database to obtain the actual speed variation curve of the induced draft fan; The fusion module is used to convert and fuse the actual inlet flow change curve, the actual specific pressure energy change curve and the actual speed change curve based on the similar principle followed when the induced draft fan operates at variable speed to obtain the induced draft fan. Variable speed operation characteristic curve; The extraction module is used for extracting and fitting the design specific pressure energy mathematical model and operation efficiency mathematical model of the induced draft fan from the variable speed operation characteristic curve. 10. A computer-readable storage medium having application program stored thereon, characterized in that, when the application program is executed by the processor, the steam-driven induced draft fan is converted into work as described in any one of claims 1-8. Mechanism modeling method.

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