Method and system for controlling opening degree of adjusting baffle of wind and smoke system of thermal power plant

Abstract

The invention discloses a method and system for controlling the opening degree of an adjusting baffle of a wind and smoke system of a thermal power plant. The control method comprises the steps that the position of an adjusting baffle electric head swing arm is positioned according to the full-opening and full-closing positions of an adjusting baffle; the method comprises the following steps of: opening and closing an adjusting baffle plate on a DCS (Distributed Control System) of a power plant in a full stroke, and respectively measuring dead zone opening degrees of the adjusting baffle plate in opening and closing directions and actual opening degrees and instruction opening degree deviation values under other different opening degree instructions; respectively fitting relation functions f1 (sigma) and f2 (sigma) of the deviation values of the opening direction and the closing direction of the adjusting baffle and the opening degree instruction according to the opening degree and the deviation value of the instruction; and establishing an instruction opening correction function f3 (sigma) and an adjusting baffle opening instruction correction module on the DCS control system of the power plant, correcting an adjusting baffle switching instruction of the DCS control system, and sending the corrected adjusting baffle switching instruction to the air and smoke baffle, thereby realizing accurate correspondence between the baffle switching instruction and an actual switching position.

Description

Technical Field

[0001] The invention belongs to the technical field of air and smoke systems of thermal power plants, and in particular to a method and system for controlling the opening of an adjusting damper of an air and smoke system of a thermal power plant. Background Art

[0002] There are many damper doors installed in the air and smoke system of thermal power plants. However, due to deviations in on-site installation, uneven quality, and unreasonable transmission mechanisms, the damper adjustment generally has large dead zones and hysteresis, which makes the actual opening of the damper inconsistent with the command opening, thereby reducing the automatic control effect of the air and smoke system, increasing the instability of the air and smoke system adjustment process, and may even cause unsafe accidents in the air and smoke system. On-site adjustment and installation, improvement of connecting rod transmission, etc. not only consume a lot of manpower, material resources, and financial resources, but also still cannot effectively solve the problem of accurate correspondence between the actual opening and the command opening. A solution that is easy to implement on-site, low-cost, and effective is urgently needed. Summary of the invention

[0003] In view of the problems of dead zone, hysteresis, etc. caused by the installation deviation of the regulating damper, the transmission clearance of the connecting rod and the like in the existing air and smoke system, the present invention provides a method and system for controlling the opening of the regulating damper in the air and smoke system of a thermal power plant. The method and system calculate and correct the opening command of the regulating damper based on the damper deviation characteristics tested on site and remotely by the DCS control system, and then send it to the DCS control system, thereby ensuring that the actual opening of the regulating damper is consistent with the command opening.

[0004] To this end, the present invention adopts the following technical solution.

[0005] In a first aspect, the present invention provides a method for controlling the opening of a damper of an air and smoke system of a thermal power plant, comprising:

[0006] Step 1: According to the fully closed and fully opened positions of the damper in the air and smoke duct, the positions of the swing arms of the damper electric heads are respectively positioned to correspond to the damper opening instructions in the DCS control system;

[0007] Step 2: remotely open and close the damper in the DCS control system and measure the maximum command σ of the damper dead zone in the opening direction. 开 and the deviation between the actual opening and the corresponding command opening under other opening commands; measure the minimum command σ for adjusting the dead zone opening of the damper in the closing direction 关 and the deviation between the actual opening under other opening instructions and the corresponding instruction opening;

[0008] Step 3: According to the maximum dead zone opening instruction σ 开The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f1(σ) between the deviation of the damper opening direction and the opening command; according to the minimum dead zone opening command σ 关 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f2(σ) between the deviation in the closing direction of the damper and the opening command;

[0009] Step 4, establishing an opening instruction correction function f3(σ) according to the switch direction of the regulating damper, the opening instruction of the regulating damper and the relationship functions f1(σ) and f2(σ), and establishing an regulating damper switch instruction correction module in the DCS control system according to the opening instruction correction function f3(σ); after the regulating damper opening instruction is input into the DCS control system, it is processed by the regulating damper switch instruction correction module and then sent to the regulating damper.

[0010] Furthermore, in step 1, the electric head of the adjusting baffle is controlled on-site, and when the adjusting baffle is in the fully closed position, the position of the swing arm of the electric head of the positioning adjusting baffle corresponds to the 0% opening in the closing direction of the adjusting baffle in the DCS control system; when the adjusting baffle is in the fully open position, the position of the swing arm of the electric head of the positioning adjusting baffle corresponds to the 100% opening in the opening direction of the adjusting baffle in the DCS control system.

[0011] Furthermore, in step 2, the damper electric head is remotely controlled to start from 0% opening in the DCS control system, and the opening is gradually increased by 2% each time until the damper is adjusted locally and starts to move. The opening command before the damper moves is the maximum command value of the damper dead zone in the opening direction σ 开 ; Then, two opening instructions are given in sequence within the remaining opening, and the actual opening of the damper is measured in turn inside the wind and smoke duct, and then the deviation value corresponding to the two openings is calculated; then, in the DCS control system, the opening is continuously reduced by 2% each time from 100% until the damper starts to move. The opening before the damper moves is the minimum instruction value of the damper dead zone in the closing direction σ 关 , and then give two opening instructions in turn within the remaining opening range, and measure the actual opening of the damper inside the wind and smoke duct in turn, and then calculate the deviation values ​​corresponding to the two openings.

[0012] Furthermore, in step 3, the relationship function f1(σ) is as follows:

[0013]

[0014] Wherein, the values ​​of a, b, and c are obtained by fitting a quadratic function through the maximum dead zone command of the closing direction, two opening commands, and the deviation between the actual opening and the command opening, and σ is the damper opening command.

[0015] Furthermore, in step 3, the relationship function f2(σ) is as follows:

[0016]

[0017] Wherein, the values ​​of m, n, and l are obtained by fitting a quadratic function through the minimum dead zone command of the opening direction, two opening commands, and the deviation between the actual opening and the command opening, and σ is the damper opening command.

[0018] Furthermore, in step 4, the opening instruction correction function f3(σ) is as follows:

[0019]

[0020] Where σ0 is the original opening instruction of the damper.

[0021] Furthermore, the content of the adjusting damper switch command correction module is as follows: according to the size of the input adjusting damper opening command σ and the damper original opening command σ0, the corresponding function formula in the function f3(σ) is selected to calculate and correct the adjusting damper opening command; then the corrected opening command is sent to the control module of the adjusting damper, and the control module sends the command to the adjusting damper for action.

[0022] In a second aspect, the present invention provides a control system for adjusting the damper opening of a wind and smoke system of a thermal power plant, comprising:

[0023] Electric head swing arm position positioning unit: according to the fully closed and fully opened positions of the damper in the air and smoke duct, the electric head swing arm position of the damper is positioned to correspond to the damper opening instruction in the DCS control system;

[0024] Deviation value measurement unit: remotely open and close the regulating damper in the DCS control system, and measure the maximum command σ of the dead zone opening of the regulating damper in the opening direction 开 and the deviation between the actual opening and the corresponding command opening under other opening commands; measure the minimum command σ for adjusting the dead zone opening of the damper in the closing direction 关 and the deviation between the actual opening under other opening instructions and the corresponding instruction opening;

[0025] Function fitting unit: based on the maximum dead zone opening instruction σ 开 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f1(σ) between the deviation of the damper opening direction and the opening command; according to the minimum dead zone opening command σ 关 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f2(σ) between the deviation in the closing direction of the damper and the opening command;

[0026] Correction module construction unit: establish an opening instruction correction function f3(σ) according to the switch direction of the regulating damper, the opening instruction of the regulating damper and the relationship functions f1(σ) and f2(σ), and establish an adjusting damper switch instruction correction module in the DCS control system according to the opening instruction correction function f3(σ); after the adjusting damper opening instruction is input into the DCS control system, it is processed by the adjusting damper switch instruction correction module and then sent to the adjusting damper.

[0027] The beneficial effects of the present invention are as follows: In view of the common problems of dead zone and large backlash in the current wind and smoke system regulating dampers, the present invention can obtain the deviation characteristics of the actual opening and command opening of the regulating damper on site without adjusting the installation position on site and improving the connecting rod transmission, establish a wind and smoke damper opening command correction function, and then correct the DCS control system damper opening command to eliminate the deviation problem between the command opening and the actual opening of the wind and smoke damper on site, thereby ensuring the control accuracy and stability of the wind and smoke system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in 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 work.

[0029] Figure 1 It is a flow chart of a method for controlling the damper opening of a wind and smoke system of a thermal power plant according to the present invention;

[0030] Figure 2 It is a structural diagram of a damper opening control system for an air and smoke system of a thermal power plant according to the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this specification more clear, the technical solutions of the present invention will be clearly and completely described below in combination with the specific embodiments of this specification and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments in the specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment is a method for controlling the damper opening of a thermal power plant air and smoke system. Figure 1 As shown, the steps are as follows:

[0034] Step 1: According to the fully closed and fully opened positions of the damper in the air and smoke duct, the positions of the swing arms of the damper electric heads are respectively positioned to correspond to the damper opening instructions in the DCS control system.

[0035] In step 1, the electric head of the adjusting baffle is controlled locally. When the adjusting baffle is in the fully closed position, the swing arm position of the electric head of the positioning adjusting baffle corresponds to the 0% opening in the closing direction of the adjusting baffle in the DCS control system; when the adjusting baffle is in the fully open position, the swing arm position of the electric head of the positioning adjusting baffle corresponds to the 100% opening in the opening direction of the adjusting baffle in the DCS control system.

[0036] Step 2: remotely open and close the damper in the DCS control system and measure the maximum command σ of the damper dead zone in the opening direction. 开 and the deviation between the actual opening and the corresponding command opening under other opening commands; measure the minimum command σ for adjusting the dead zone opening of the damper in the closing direction 关 And the deviation value between the actual opening under other opening instructions and the corresponding instruction opening.

[0037] In step 2, the damper electric head is remotely controlled and adjusted. In the DCS control system, the opening starts from 0% and increases by 2% each time until the damper is adjusted locally and starts to move. The opening command before the damper moves is the maximum command value of the damper dead zone in the opening direction σ 开 ; Then, two opening instructions are given in sequence within the remaining opening, and the actual opening of the damper is measured in turn inside the wind and smoke duct, and then the deviation value corresponding to the two openings is calculated; then, in the DCS control system, the opening is continuously reduced by 2% each time from 100% until the damper starts to move. The opening before the damper moves is the minimum instruction value of the damper dead zone in the closing direction σ 关 , and then give two opening instructions in turn within the remaining opening range, and measure the actual opening of the damper inside the wind and smoke duct in turn, and then calculate the deviation values ​​corresponding to the two openings.

[0038] Step 3: According to the maximum dead zone opening instruction σ 开 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f1(σ) between the deviation of the damper opening direction and the opening command; according to the minimum dead zone opening command σ 关 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f2(σ) between the deviation in the closing direction of the damper and the opening command.

[0039] In step 3, the relationship function f1(σ) is as follows:

[0040]

[0041] Wherein, the values ​​of a, b, and c are obtained by fitting a quadratic function through the minimum dead zone command of the closing direction, two opening commands, and the deviation between the actual opening and the command opening, and σ is the damper opening command.

[0042] In step 3, the relationship function f2(σ) is as follows:

[0043]

[0044] Wherein, the values ​​of m, n, and l are obtained by fitting a quadratic function through the maximum dead zone command of the opening direction, two opening commands, and the deviation between the actual opening and the command opening, and σ is the damper opening command.

[0045] Step 4, establishing an opening instruction correction function f3(σ) according to the switch direction of the regulating damper, the opening instruction of the regulating damper and the relationship functions f1(σ) and f2(σ), and establishing an regulating damper switch instruction correction module in the DCS control system according to the opening instruction correction function f3(σ); after the regulating damper opening instruction is input into the DCS control system, after being processed by the regulating damper switch instruction correction module, the corrected opening instruction is sent to the control module of the regulating damper, and the control module sends the instruction to the regulating damper for action.

[0046] In step 4, the opening instruction correction function f3(σ) is as follows:

[0047]

[0048] Where σ0 is the original opening instruction of the damper.

[0049] Specifically, the content of the damper switch command correction module is as follows: according to the size of the input damper opening command σ and the damper original opening command σ0, the corresponding function in the function f3 (σ) is selected to calculate and correct the damper opening command.

[0050] Example 2

[0051] This embodiment provides a control system for adjusting the damper opening of a thermal power plant air and smoke system. Figure 2 As shown, it consists of an electric head swing arm position positioning unit, a deviation value measurement unit, a function fitting unit and a correction module construction unit.

[0052] Electric head swing arm position positioning unit: according to the fully closed and fully open positions of the damper in the air and smoke duct, the electric head swing arm position of the damper is positioned to correspond to the damper opening instruction in the DCS control system.

[0053] Deviation value measurement unit: remotely open and close the regulating damper in the DCS control system, and measure the maximum command σ of the dead zone opening of the regulating damper in the opening direction 开and the deviation between the actual opening and the corresponding command opening under other opening commands; measure the minimum command σ for adjusting the dead zone opening of the damper in the closing direction 关 And the deviation value between the actual opening under other opening instructions and the corresponding instruction opening.

[0054] Function fitting unit: based on the maximum dead zone opening instruction σ 开 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f1(σ) between the deviation of the damper opening direction and the opening command; according to the minimum dead zone opening command σ 关 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f2(σ) between the deviation in the closing direction of the damper and the opening command.

[0055] Correction module construction unit: establish an opening instruction correction function f3(σ) according to the switch direction of the regulating damper, the opening instruction of the regulating damper and the relationship functions f1(σ) and f2(σ), and establish an adjusting damper switch instruction correction module in the DCS control system according to the opening instruction correction function f3(σ); after the adjusting damper opening instruction is input into the DCS control system, it is processed by the adjusting damper switch instruction correction module and then sent to the adjusting damper.

[0056] It should be noted that each unit in the above-mentioned control system for adjusting the damper opening of the wind and smoke system of a thermal power plant can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned units can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the corresponding operations of each of the above-mentioned units.

[0057] For the specific limitations of each unit of a control system for adjusting the damper opening of a thermal power plant's air and smoke system, please refer to the limitations of a method for controlling the damper opening of a thermal power plant's air and smoke system mentioned above. The two have the same functions and effects and will not be repeated here.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for controlling the damper opening of a wind and smoke system in a thermal power plant, characterized in that: include: Step 1: According to the fully closed and fully opened positions of the damper in the air and smoke duct, the positions of the swing arms of the damper electric heads are respectively positioned to correspond to the damper opening instructions in the DCS control system; Step 2: remotely open and close the damper in the DCS control system and measure the maximum command σ of the damper dead zone in the opening direction. 开 and the deviation between the actual opening and the corresponding command opening under other opening commands; measure the minimum command σ for adjusting the dead zone opening of the damper in the closing direction 关 and the deviation between the actual opening under other opening instructions and the corresponding instruction opening; Step 3: According to the maximum dead zone opening instruction σ 开 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f1(σ) between the deviation of the damper opening direction and the opening command; according to the minimum dead zone opening command σ 关 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f2(σ) between the deviation in the closing direction of the damper and the opening command; Step 4, establishing an opening instruction correction function f3(σ) according to the switch direction of the regulating damper, the opening instruction of the regulating damper and the relationship functions f1(σ) and f2(σ), and establishing an regulating damper switch instruction correction module in the DCS control system according to the opening instruction correction function f3(σ); after the regulating damper opening instruction is input into the DCS control system, it is processed by the regulating damper switch instruction correction module and then sent to the regulating damper.

2. The method for controlling the damper opening of the air and smoke system of a thermal power plant according to claim 1, characterized in that: In step 1, the electric head of the damper is controlled locally, and when the damper is in the fully closed position, the position of the swing arm of the electric head of the damper is positioned to correspond to the 0% opening of the damper in the closing direction in the DCS control system; When the regulating baffle is in the fully open position, the position of the swing arm of the electric head for positioning the regulating baffle corresponds to the 100% opening degree of the regulating baffle opening direction in the DCS control system.

3. The method for controlling the damper opening of the air and smoke system of a thermal power plant according to claim 1, characterized in that: In step 2, the damper electric head is remotely controlled and adjusted. In the DCS control system, the opening starts from 0% and increases by 2% each time until the damper is adjusted locally and starts to move. The opening command before the damper moves is the maximum command value of the damper dead zone in the opening direction σ 开 ; Then, two opening instructions are given in sequence within the remaining opening, and the actual opening of the damper is measured in turn inside the wind and smoke duct, and then the maximum dead zone opening in the opening direction and the deviation values ​​corresponding to the two openings are calculated; Then, in the DCS control system, the opening is continuously reduced by 2% each time from 100% until the damper starts to move on the spot. The opening before the damper is adjusted is the minimum command value of the damper dead zone in the closing direction σ 关 Then, two opening instructions are given in sequence within the remaining opening range, and the actual opening of the damper is measured inside the wind and smoke duct in sequence, and then the minimum dead zone opening in the closing direction and the deviation value corresponding to the two openings are calculated.

4. The method for controlling the damper opening of the air and smoke system of a thermal power plant according to claim 3 is characterized in that: In step 3, the relationship function f1(σ) is as follows: Wherein, the values ​​of a, b, and c are obtained by fitting a quadratic function through the maximum dead zone command of the opening direction, two opening commands, and the deviation between the actual opening and the command opening, and σ is the damper opening command.

5. The method for controlling the damper opening of the air and smoke system of a thermal power plant according to claim 4, characterized in that: In step 3, the relationship function f2(σ) is as follows: Wherein, the values ​​of m, n, and l are obtained by fitting a quadratic function through the minimum dead zone command of the closing direction, two opening commands, and the deviation between the actual opening and the command opening, and σ is the damper opening command.

6. The method for controlling the damper opening of the air and smoke system of a thermal power plant according to claim 5, characterized in that: In step 4, the opening instruction correction function f3(σ) is as follows: Where σ0 is the original opening instruction of the damper.

7. The method for controlling the damper opening of the air and smoke system of a thermal power plant according to claim 6, characterized in that: The contents of the damper switch command correction module are as follows: according to the size of the input damper opening command σ and the damper original opening command σ0, the corresponding function formula in the function f3(σ) is selected to calculate and correct the damper opening command; then the corrected opening command is sent to the control module of the damper, and the control module sends the command to the damper for action.

8. A control system for adjusting the damper opening of a thermal power plant air and smoke system, characterized in that: include: Electric head swing arm position positioning unit: according to the fully closed and fully opened positions of the damper in the air and smoke duct, the electric head swing arm position of the damper is positioned to correspond to the damper opening instruction in the DCS control system; Deviation value measurement unit: remotely open and close the regulating damper in the DCS control system, and measure the maximum command σ of the dead zone opening of the regulating damper in the opening direction 开 and the deviation between the actual opening and the corresponding command opening under other opening commands; measure the minimum command σ for adjusting the dead zone opening of the damper in the closing direction 关 and the deviation between the actual opening under other opening instructions and the corresponding instruction opening; Function fitting unit: based on the maximum dead zone opening instruction σ 开 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f1(σ) between the deviation of the damper opening direction and the opening command; according to the minimum dead zone opening command σ 关 The deviation between the actual opening and the corresponding command opening under other opening commands is used to fit the relationship function f2(σ) between the deviation in the closing direction of the damper and the opening command; Correction module construction unit: establish an opening instruction correction function f3(σ) according to the switch direction of the regulating damper, the opening instruction of the regulating damper and the relationship functions f1(σ) and f2(σ), and establish an adjusting damper switch instruction correction module in the DCS control system according to the opening instruction correction function f3(σ); after the adjusting damper opening instruction is input into the DCS control system, it is processed by the adjusting damper switch instruction correction module and then sent to the adjusting damper.

9. The damper opening control system for the air and smoke system of a thermal power plant according to claim 8, characterized in that: In the deviation value measurement unit, the remote control damper electric head starts from 0% opening in the DCS control system and gradually increases by 2% each time until the damper starts to move. The opening instruction before the damper moves is the maximum instruction value of the damper dead zone in the opening direction σ 开 ; Then, two opening instructions are given in sequence within the remaining opening, and the actual opening of the damper is measured in turn inside the wind and smoke duct, and then the deviation value corresponding to the two openings is calculated; then, in the DCS control system, the opening is continuously reduced by 2% each time from 100% until the damper starts to move. The opening before the damper moves is the minimum instruction value of the damper dead zone in the closing direction σ 关 , and then give two opening instructions in turn within the remaining opening range, and measure the actual opening of the damper inside the wind and smoke duct in turn, and then calculate the deviation values ​​corresponding to the two openings.

10. The damper opening control system for the air and smoke system of a thermal power plant according to claim 8, characterized in that: In the function fitting unit, the relationship function f1(σ) is as follows: In the formula, the values ​​of a, b, and c are obtained by fitting a quadratic function through the maximum dead zone command of the opening direction, two opening commands, and the deviation between the actual opening and the command opening. σ is the damper opening command. The relationship function f2(σ) is as follows: In the formula, the values ​​of m, n, and l are obtained by fitting a quadratic function through the minimum dead zone command of the closing direction, two opening commands, and the deviation between the actual opening and the command opening. σ is the damper opening command. In the correction module construction unit, the opening instruction correction function f3(σ) is as follows: Where σ0 is the original opening instruction of the damper.

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