CN116880591A - Stable pressure equalizing control system and method for pressure equalizing regulating valve of blast furnace hot blast stove - Google Patents
Stable pressure equalizing control system and method for pressure equalizing regulating valve of blast furnace hot blast stove Download PDFInfo
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D16/00—Control of fluid pressure
- G05D16/20—Control of fluid pressure characterised by the use of electric means
- G05D16/2006—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means
- G05D16/2013—Control of fluid pressure characterised by the use of electric means with direct action of electric energy on controlling means using throttling means as controlling means
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B9/00—Stoves for heating the blast in blast furnaces
- C21B9/10—Other details, e.g. blast mains
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2300/00—Process aspects
- C21B2300/04—Modeling of the process, e.g. for control purposes; CII
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Abstract
The application belongs to the technical field of pressure equalizing control of blast furnace hot blast stoves, and particularly provides a stable pressure equalizing control system and method for a pressure equalizing regulating valve of a blast furnace hot blast stove, wherein the method comprises the following steps: when the furnace needs to be replaced, opening the equalizing regulating valve according to the initial opening value; the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened; calculating the actual pressure rise rate by adopting a curve fitting algorithm; adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate; after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed. The front-back pressure difference of the valve is consistent when the pressure equalizing regulating valve is regulated, the action resistance of the pressure equalizing regulating valve is reduced, the faults of the regulating valve are reduced, and the service life of the regulating valve is prolonged; the fluctuation of the blast furnace air supply pressure in the pressure equalizing process of the hot blast furnace is eliminated, and the problem of fluctuation of the blast furnace air supply pressure caused by unstable pressure equalizing is solved.
Description
Technical Field
The application relates to the technical field of pressure equalizing control of blast furnace hot blast stoves, in particular to a stable pressure equalizing control system and method for a pressure equalizing regulating valve of a blast furnace hot blast stove.
Background
Each blast furnace is provided with 2-4 hot blast furnaces, and the working principle of the hot blast furnaces is that coal gas is combusted firstly to heat a heat accumulator, cold air is subjected to heat exchange through the hot heat accumulator, and then the hot blast furnaces are alternately combusted and blown alternately to continuously obtain high-temperature hot air for the blast furnaces. There are two main modes of operation of the stove: the furnace burning and air supply are that a plurality of hot blast stoves work intermittently, and the pre-air supply hot blast stove needs to be pressurized in advance when the air supply is switched, and the stamping process is equivalent to blast furnace air reduction, so that the furnace changing can cause pressure fluctuation until the pressurization is completed.
The hot blast furnace is subjected to pressure equalizing before the hot blast furnace is replaced, the small blast furnace is usually realized by a pressure equalizing switch valve, the opening of the pressure equalizing switch valve is uncontrollable, and after a given switch action of a system, the stable pressure equalizing control difficulty is high, so that the large blast furnace is the blast furnace air supply pressure when the hot blast furnace is replaced stably; and the pressure equalizing control is simply to increase the opening of the valve according to the equal proportion of the interval time, so that constant flow is inflated in the pressure equalizing process, and the air supply pressure of the blast furnace is fluctuated in the pressure equalizing process.
Disclosure of Invention
Aiming at the control by the regulating valve, particularly when the valve is just opened, the pressure difference before and after the regulating valve is large, the resistance is large in the process of opening the valve, and the current is large, so that the service life of the valve is shortened; the pressure equalizing control is simply to increase the opening of the valve according to the equal proportion of the interval time, and the constant flow is not ensured to be inflated in the pressure equalizing process, so that the pressure of the blast furnace air supply is fluctuated in the pressure equalizing process.
In a first aspect, the technical scheme of the application provides a stable pressure equalizing control system of a pressure equalizing regulating valve of a blast furnace hot blast stove, which comprises a hot blast stove, wherein the hot blast stove is provided with a cold blast inlet connected with a cold blast pipeline, a pressure regulating inlet connected with a pressure regulating pipeline and a hot blast outlet connected with a hot blast pipeline;
a cold air valve is arranged at a position, close to the cold air inlet, of the cold air pipeline, a pressure equalizing switch valve is arranged at a position, close to the cold air inlet, of the pressure regulating pipeline, and a pressure equalizing regulating valve is arranged at the front end of the pressure equalizing switch valve along the cold air inlet direction of the pressure regulating pipeline; a hot air valve is arranged on the hot air pipeline at a position close to the hot air outlet, and the hot air outlet is connected to the blast furnace through a hot air pipeline;
each hot blast stove is provided with a first pressure sensor for collecting the pressure of the hot blast stove;
the system also comprises a control module, wherein the cold air valve, the pressure equalizing switch valve, the pressure equalizing regulating valve, the hot air valve and the first pressure sensor are respectively connected with the control module;
the control module is used for controlling the pressure equalizing regulating valve to be opened according to the initial opening value when the furnace needs to be replaced; the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened; calculating the actual pressure rise rate by adopting a curve fitting algorithm according to the data acquired by the first pressure sensor; adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate; after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed.
As the optimization of the technical scheme of the application, one end of the hot air pipeline, which is close to the blast furnace, is provided with a second pressure sensor for collecting the blast furnace air supply pressure;
the second pressure sensor is connected with the control module, and the control module is used for acquiring the blast furnace air supply pressure according to the data acquired by the second pressure sensor and the pressure in the hot blast stove acquired by the first pressure sensor, and calculating the pressure deviation between the blast furnace air supply pressure and the pressure in the pre-air supply hot blast stove; and when the pressure deviation is smaller than a first threshold value or the opening of the pressure equalizing regulating valve is larger than a second threshold value, judging that pressure equalizing is completed.
As the optimization of the technical scheme of the application, the control module is also used for acquiring the discrete data of the hot blast stove pressure acquired at regular time by the first pressure sensor, adopting a curve fitting algorithm to acquire a time pressure curve equation, and deriving at the latest time point to acquire the actual pressure rise rate at the current moment.
In a second aspect, the technical scheme of the application also provides a stable pressure equalizing control method for the pressure equalizing regulating valve of the blast furnace hot blast stove, which comprises the following steps:
when the furnace needs to be replaced, opening the equalizing regulating valve according to the initial opening value;
the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened;
calculating the actual pressure rise rate by adopting a curve fitting algorithm;
adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate;
after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed.
As a preferred aspect of the present application, the step of controlling the opening of the regulator valve by using a PID control algorithm according to the deviation of the set pressure rise rate from the actual pressure rise rate includes:
respectively obtaining the blast furnace air supply pressure, the pressure in the pre-air supply hot blast stove and the opening of a pressure equalizing regulating valve;
calculating the pressure deviation between the blast furnace air supply pressure and the pressure in the pre-air supply hot blast stove;
and when the pressure deviation is smaller than a first threshold value or the opening of the pressure equalizing regulating valve is larger than a second threshold value, judging that pressure equalizing is completed.
Preferably, when the pressure deviation is smaller than a first threshold value or the opening of the equalizing regulating valve is larger than a second threshold value, the step of judging that equalizing is completed includes:
judging whether the pressure deviation is smaller than a first threshold value or whether the opening degree of the pressure equalizing regulating valve is larger than a second threshold value;
if yes, judging that the pressure equalizing is finished, and executing the following steps: the cold air valve of the hot air furnace is sequentially controlled to be opened, the hot air valve of the hot air furnace is opened, the pressure equalizing switch valve is closed, and the pressure equalizing regulating valve is closed;
if not, executing the steps of: and calculating the actual pressure rise rate by adopting a curve fitting algorithm.
Preferably, the step of determining whether the pressure deviation is smaller than a first threshold value or whether the opening of the pressure equalizing regulating valve is larger than a second threshold value further includes:
when the pressure deviation is not smaller than a first threshold value or the opening of the equalizing regulating valve is not larger than a second threshold value, judging whether the time interval for regulating the opening of the regulating valve is reached or not;
if yes, resetting the time interval timing;
the method comprises the following steps: calculating the actual pressure rise rate by adopting a curve fitting algorithm;
if not, executing the steps of: and respectively obtaining the blast furnace air supply pressure, the pressure in the pre-air supply hot blast stove and the opening of the pressure equalizing regulating valve.
As the preferable mode of the technical scheme, the step of calculating the actual pressure rise rate by adopting a curve fitting algorithm comprises the following steps:
and obtaining a time pressure curve equation by adopting a curve fitting algorithm to the discrete data of the hot blast stove pressure acquired at fixed time, and deriving at the latest time point to obtain the actual pressure rise rate at the current moment.
As the optimization of the technical scheme of the application, when the furnace needs to be replaced, the step of controlling the pressure equalizing regulating valve to be opened according to the initial opening value comprises the following steps:
and setting the pressure rise rate of the hot blast stove according to the historical data.
From the above technical scheme, the application has the following advantages: the front-back pressure difference of the valves in the regulating action of the pressure equalizing regulating valve is consistent by adjusting the control sequence of the valves in the whole pressure equalizing process, so that the action resistance of the pressure equalizing regulating valve is reduced, the faults of the regulating valve are reduced, and the service life of the regulating valve is prolonged; the stable pressure equalizing control algorithm adopts a curve fitting algorithm to control the constant pressure rising rate of the hot blast stove, realizes constant-speed flow inflation pressure equalizing of the hot blast stove, eliminates fluctuation of the hot blast stove on the blast furnace air supply pressure in the pressure equalizing process, and solves the problem of fluctuation of the blast furnace air supply pressure caused by unstable pressure equalizing.
In addition, the application has reliable design principle, simple structure and very wide application prospect.
It can be seen that the present application has outstanding substantial features and significant advances over the prior art, as well as its practical advantages.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.
FIG. 1 is a process connection block diagram of a system according to one embodiment of the application.
Fig. 2 is a schematic flow chart of a method of one embodiment of the application.
FIG. 3 is a schematic diagram of PID control according to an embodiment of the application.
Detailed Description
The equalizing valve of large blast furnace is added with a total regulating valve, and only 1 common regulating valve is needed because equalizing pressure is needed to be carried out on the pre-blowing hot blast stove before changing the furnace. The pressure equalizing process diagram is shown in figure 1. The conventional control method comprises the following steps: when the furnace is replaced, the pressure equalizing control is required to be carried out on the pre-air supply blast furnace, firstly, the pressure equalizing switch valve of the hot blast furnace is opened, then the regulating valve is slowly opened to carry out the pressure equalizing control, the opening of the regulating valve is increased by a fixed value according to the interval time, the stability of the charging flow in the pressure equalizing process of the hot blast furnace cannot be ensured, and the air supply pressure of the blast furnace is fluctuated in the pressure equalizing process. Because the hot blast stove is required to be pressurized in advance when changing the stove, the pressurizing process is equivalent to blast furnace wind reduction, which necessarily leads to blast furnace wind supply pressure fluctuation, and if stable speed and pressure equalizing of the hot blast stove cannot be ensured, the blast furnace wind supply pressure fluctuation is aggravated. The control algorithm can control the blast furnace air supply pressure by controlling the constant flow rate and the constant speed pressure equalizing and charging during furnace changing, and reduce the fluctuation of the blast furnace air supply pressure to the allowable range. In order to make the technical solution of the present application better understood by those skilled in the art, the technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.
The embodiment of the application provides a stable pressure equalizing control system of a pressure equalizing regulating valve of a blast furnace hot blast stove, which comprises a hot blast stove, as shown in figure 1, wherein the hot blast stove is provided with a cold air inlet connected with a cold air pipeline 100, a pressure regulating inlet connected with a pressure regulating pipeline 200 and a hot air outlet connected with a hot air pipeline 300; the hot blast stove in the embodiment of the application comprises a No. 1 stove, a No. 2 stove and a No. 3 stove.
A cold air valve 101 is arranged on the cold air pipeline 100 at a position close to the cold air inlet, a pressure equalizing switch valve 202 is arranged on the pressure regulating pipeline 200 at a position for opening the inlet and regulating the pressure, and a pressure equalizing regulating valve 201 is arranged at the front end of the pressure equalizing switch valve along the cold air inlet direction on the pressure regulating pipeline 200; a hot air valve 301 is arranged on the hot air pipeline 300 at a position close to a hot air outlet, and the hot air outlet is connected to a blast furnace through the hot air pipeline 300;
each stove is provided with a first pressure sensor 401 for acquiring the stove pressure;
the system further comprises a control module, wherein the cold air valve 101, the pressure equalizing switch valve 202, the pressure equalizing regulating valve 201, the hot air valve 301 and the first pressure sensor 401 are respectively connected with the control module;
the control module is used for controlling the pressure equalizing regulating valve to be opened according to the initial opening value when the furnace needs to be replaced; the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened; calculating the actual pressure rise rate by adopting a curve fitting algorithm according to the data acquired by the first pressure sensor; adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate; after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed.
A second pressure sensor 402 for collecting the air supply pressure of the blast furnace is arranged at one end, close to the blast furnace, of the hot air pipe; the second pressure sensor 402 is connected with a control module, and the control module is used for acquiring the blast furnace air supply pressure according to the data acquired by the second pressure sensor and the pressure in the hot blast stove acquired by the first pressure sensor, and calculating the pressure deviation between the blast furnace air supply pressure and the pressure in the pre-air supply hot blast stove; and when the pressure deviation is smaller than a first threshold value or the opening of the pressure equalizing regulating valve is larger than a second threshold value, judging that pressure equalizing is completed. And the system is also used for acquiring the discrete data of the hot blast stove pressure acquired at fixed time by the first pressure sensor, adopting a curve fitting algorithm to acquire a time pressure curve equation, and deriving at the latest time point to acquire the actual pressure rise rate at the current moment.
The embodiment of the application also provides a stable pressure equalizing control method for the pressure equalizing regulating valve of the blast furnace hot blast stove, which comprises the following steps:
step 1: when the furnace needs to be replaced, opening the equalizing regulating valve according to the initial opening value;
step 2: the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened;
step 3: calculating the actual pressure rise rate by adopting a curve fitting algorithm;
step 4: adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate;
step 5: after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed.
When the furnace needs to be replaced, the pressure equalizing regulating valve and all the hot blast stove pressure equalizing switch valves are in a closed state, the pressure difference between the front and the back of the regulating valve is small, the resistance of the action of the regulating valve is small, the initial opening value V0 of the regulating valve is firstly opened, the V0 value is the pressure equalizing initial opening, and in order to reduce the fluctuation of the blast furnace air supply when the pressure equalizing is started, the V0 value is generally 2-5%; then the equalizing switch valve of the pre-air supply hot blast stove is opened, and the hot blast stove starts to charge air and equalize pressure; and then adjusting the opening of the regulating valve according to a stable pressure equalizing control algorithm, and carrying out constant-speed air supply until pressure equalizing is completed. After the pressure equalization is finished, the cold air valve of the hot air furnace is opened, the hot air furnace valve is opened again, the hot air furnace starts to supply air, the pressure equalization process of the hot air furnace is finished, then the pressure equalization switch valve is closed, the hot air furnace enters the air supply stage, and finally the original air supply hot air furnace is controlled to enter the furnace burning stage. After the equalizing valves are completely closed, all the equalizing switch valves of the hot blast stoves are in a closed state (only equalizing one hot blast stove at a time), and then the regulating valve is closed, so that the pressure difference between the front and the rear of the regulating valve is small and even 0.
As shown in fig. 2, the embodiment of the application also provides a stable pressure equalizing control method for the pressure equalizing regulating valve of the blast furnace hot blast stove, which comprises the following steps:
s1: when the furnace needs to be replaced, opening the equalizing regulating valve according to the initial opening value;
s2: the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened;
s3: respectively obtaining the blast furnace air supply pressure, the pressure in the pre-air supply hot blast stove and the opening of a pressure equalizing regulating valve;
s4: calculating the pressure deviation between the blast furnace air supply pressure and the pressure in the pre-air supply hot blast stove;
s5: judging whether the pressure deviation is smaller than a first threshold value or whether the opening degree of the pressure equalizing regulating valve is larger than a second threshold value;
if yes, judging that the pressure equalizing is finished, and executing the step S10;
if not, executing the step S6;
s6: judging whether a time interval for adjusting the opening of the adjusting valve is reached or not;
if yes, executing step S7; if not, executing the step S3;
s7: resetting the time interval timing; executing step S8;
s8: calculating the actual pressure rise rate by adopting a curve fitting algorithm;
s9: adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate; executing the step S3;
s10: and the cold air valve of the hot air furnace is sequentially controlled to be opened, the hot air valve of the hot air furnace is opened, the pressure equalizing switch valve is closed, and the pressure equalizing regulating valve is closed.
The method provided by the embodiment of the application is a specific implementation method based on the system provided by the embodiment, and it is to be noted that, according to an ideal gas state equation pv=nrt, in the process of pressure equalizing and inflating the hot blast stove, if a constant flow is to be maintained, the pressure rise rate (the pressure rise amount in the hot blast stove in unit time) in the hot blast stove is ensured to be constant, namely, the pressure in the pre-supply hot blast stove is controlled to be increased at a constant speed: dP/dt=ks; wherein dP/dt is a tangent line of a time pressure curve in the hot blast stove, ks is a pressure rise rate of the hot blast stove, and the value range is set by an operator: 0.5 to 2.
In the pressure equalizing process of the hot blast stove, the hot blast stove pressure is gradually increased, if the variable quantity in fixed interval time is adopted for pressure rising rate calculation, the value fluctuation is large, the actual pressure change of the hot blast stove cannot be truly fed back, the pressurizing speed is controlled by adopting the value, and the system is extremely unstable.
The system adopts a curve fitting algorithm to obtain a pressure curve equation, and derives at the nearest point to obtain the pressure rise rate Kv at the current moment.
The curve fitting method is to fit a plurality of discrete data to obtain a continuous function (namely a curve), wherein the fitted function is generally a primary or secondary equation (determined by observing a curve change pattern on site) according to the pressure change trend characteristics of the hot blast stove, and if the fitted function is the primary equation, the fitted function is simplified into a least square method.
The number of discrete data and the time interval of each discrete point need to be considered. The time interval is generally 1-5 s, and the data number is 10-30.
The valve control algorithm is controlled according to the deviation between the set pressure rise rate Ks and the actual pressure rise rate Kv, and a PID control algorithm is adopted, and the controller schematic diagram is shown in figure 3.
Because the feedback of the valve output and the pressure rise rate has certain hysteresis, after one control algorithm, the system needs a hysteresis time to feed back the effect, so after each output of the PID control algorithm, the system needs a time delay, which is also called an execution period of the algorithm, and the execution period of the algorithm is generally 5-10 s.
With the increase of the pressure in the hot blast stove, for example, the opening degree of the regulating valve is kept unchanged, the cold air flow to the hot blast stove is necessarily reduced, so that the opening degree of the regulating valve is required to be gradually increased to realize the constant-speed increase of the pressure in the hot blast stove. In order to reduce the back and forth adjustment of the adjusting valve, the PID control algorithm limits the increment of each time, so as to prevent the excessive opening of the primary valve adjustment, which leads to the fluctuation of the blast furnace air supply pressure, and limit the valve opening control to be only increased and not decreased, prevent the back and forth adjustment of the valve opening, and reduce the fluctuation of the blast furnace air supply pressure.
When the furnace needs to be replaced, the pressure equalizing regulating valve and all the hot blast stove pressure equalizing switch valves are in a closed state, the pressure difference between the front and the back of the regulating valve is small, the resistance of the action of the regulating valve is small, the initial opening value V0 of the regulating valve is firstly opened, the V0 value is the pressure equalizing initial opening, and in order to reduce the fluctuation of the blast furnace air supply when the pressure equalizing is started, the V0 value is generally 2-5%; then the equalizing switch valve of the pre-air supply hot blast stove is opened, and the hot blast stove starts to charge air and equalize pressure; and then adjusting the opening of the regulating valve according to a stable pressure equalizing control algorithm, and carrying out constant-speed air supply until pressure equalizing is completed.
When the pressure equalization is finished, the pressure of the hot blast stove approaches the supply pressure of the blast furnace, which means that the pressure equalization of the pre-supply hot blast stove is finished. One of the following conditions is satisfied, indicating that the pressure equalization control is completed.
(1) When the deviation Pb between the pressure of the blast furnace air supply and the pressure in the pre-air supply hot blast stove is smaller than P0, the value of P0 is 10-30 kPa;
(2) The opening of the valve is regulated to be more than 90% in a pressure equalizing way.
After the pressure equalization is finished, the cold air valve of the hot air furnace is opened, the hot air furnace valve is opened again, the hot air furnace starts to supply air, the pressure equalization process of the hot air furnace is finished, then the pressure equalization switch valve is closed, the hot air furnace enters the air supply stage, and finally the original air supply hot air furnace is controlled to enter the furnace burning stage. After the equalizing valves are completely closed, all the equalizing switch valves of the hot blast stoves are in a closed state (only equalizing one hot blast stove at a time), and then the regulating valve is closed, so that the pressure difference between the front and the rear of the regulating valve is small and even 0.
The action sequence of each valve in the equalizing control is changed, so that the front pressure and the back pressure are consistent when the regulating valve acts, the action resistance of the regulating valve is reduced, and the service life of the regulating valve is prolonged; controlling the constant-speed pressure increase in the pressurizing process of the hot blast stove, equalizing the constant-speed flow and eliminating the fluctuation of the blast furnace air supply pressure in the equalizing process; and calculating the pressure rise rate of the hot blast stove, and obtaining the pressure rise rate by deriving the nearest point of the curve through a curve fitting method of the pressure value, thereby ensuring the stable control of the pressure acceleration. In practice, the step of calculating the actual pressure rise rate using a curve fitting algorithm includes: and obtaining a time pressure curve equation by adopting a curve fitting algorithm to the discrete data of the hot blast stove pressure acquired at fixed time, and deriving at the latest time point to obtain the actual pressure rise rate at the current moment.
Although the present application has been described in detail by way of preferred embodiments with reference to the accompanying drawings, the present application is not limited thereto. Various equivalent modifications and substitutions may be made in the embodiments of the present application by those skilled in the art without departing from the spirit and scope of the present application, and it is intended that all such modifications and substitutions be within the scope of the present application/be within the scope of the present application as defined by the appended claims. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (9)
1. The stable pressure equalizing control system of the pressure equalizing regulating valve of the blast furnace hot blast stove is characterized by comprising the hot blast stove, wherein the hot blast stove is provided with a cold blast inlet connected with a cold blast pipeline, a pressure regulating inlet connected with a pressure regulating pipeline and a hot blast outlet connected with a hot blast pipeline;
a cold air valve is arranged at a position, close to the cold air inlet, of the cold air pipeline, a pressure equalizing switch valve is arranged at a position, close to the cold air inlet, of the pressure regulating pipeline, and a pressure equalizing regulating valve is arranged at the front end of the pressure equalizing switch valve along the cold air inlet direction of the pressure regulating pipeline; a hot air valve is arranged on the hot air pipeline at a position close to the hot air outlet, and the hot air outlet is connected to the blast furnace through a hot air pipeline;
each hot blast stove is provided with a first pressure sensor for collecting the pressure of the hot blast stove;
the system also comprises a control module, wherein the cold air valve, the pressure equalizing switch valve, the pressure equalizing regulating valve, the hot air valve and the first pressure sensor are respectively connected with the control module;
the control module is used for controlling the pressure equalizing regulating valve to be opened according to the initial opening value when the furnace needs to be replaced; the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened; calculating the actual pressure rise rate by adopting a curve fitting algorithm according to the data acquired by the first pressure sensor; adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate; after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed.
2. The stable pressure equalizing control system of the pressure equalizing regulating valve of the blast furnace hot blast stove according to claim 1, wherein a second pressure sensor for collecting the blast furnace air supply pressure is arranged at one end of the hot blast pipeline close to the blast furnace;
the second pressure sensor is connected with the control module, and the control module is used for acquiring the blast furnace air supply pressure according to the data acquired by the second pressure sensor and the pressure in the hot blast stove acquired by the first pressure sensor, and calculating the pressure deviation between the blast furnace air supply pressure and the pressure in the pre-air supply hot blast stove; and when the pressure deviation is smaller than a first threshold value or the opening of the pressure equalizing regulating valve is larger than a second threshold value, judging that pressure equalizing is completed.
3. The blast furnace hot blast stove pressure equalizing regulating valve stabilizing and equalizing control system according to claim 2, wherein the control module is further used for obtaining a time pressure curve equation from the discrete data of the hot blast stove pressure acquired at regular time by the first pressure sensor by adopting a curve fitting algorithm, and obtaining the actual pressure rise rate at the current moment by deriving at the latest time point.
4. The stable pressure equalizing control method for the pressure equalizing regulating valve of the blast furnace hot blast stove is characterized by comprising the following steps of:
when the furnace needs to be replaced, opening the equalizing regulating valve according to the initial opening value;
the equalizing switch valve of the pre-air supply hot blast stove is controlled to be opened;
calculating the actual pressure rise rate by adopting a curve fitting algorithm;
adopting a PID control algorithm to control the opening of the regulating valve according to the deviation of the set pressure rise rate and the actual pressure rise rate;
after the pressure equalization is finished, the cold air valve of the hot air furnace is controlled to be opened, the hot air valve of the hot air furnace is controlled to be opened, the pressure equalization switch valve is closed, and the pressure equalization regulating valve is closed.
5. The method for stabilizing and equalizing control of equalizing control valve of blast furnace hot blast stove according to claim 4, wherein the step of controlling the opening of the control valve by PID control algorithm according to the deviation of the set pressure increasing rate and the actual pressure increasing rate comprises:
respectively obtaining the blast furnace air supply pressure, the pressure in the pre-air supply hot blast stove and the opening of a pressure equalizing regulating valve;
calculating the pressure deviation between the blast furnace air supply pressure and the pressure in the pre-air supply hot blast stove;
and when the pressure deviation is smaller than a first threshold value or the opening of the pressure equalizing regulating valve is larger than a second threshold value, judging that pressure equalizing is completed.
6. The method for stabilizing and equalizing control of equalizing control valve in blast furnace hot blast stove according to claim 5, wherein the step of judging that equalizing is completed when the pressure deviation is smaller than a first threshold value or the equalizing control valve opening is larger than a second threshold value comprises:
judging whether the pressure deviation is smaller than a first threshold value or whether the opening degree of the pressure equalizing regulating valve is larger than a second threshold value;
if yes, judging that the pressure equalizing is finished, and executing the following steps: the cold air valve of the hot air furnace is sequentially controlled to be opened, the hot air valve of the hot air furnace is opened, the pressure equalizing switch valve is closed, and the pressure equalizing regulating valve is closed;
if not, executing the steps of: and calculating the actual pressure rise rate by adopting a curve fitting algorithm.
7. The method for stabilizing and equalizing control of equalizing control valve in blast furnace hot blast stove according to claim 6, wherein the step of judging whether said pressure deviation is smaller than a first threshold value or whether the equalizing control valve opening is larger than a second threshold value further comprises:
when the pressure deviation is not smaller than a first threshold value or the opening of the equalizing regulating valve is not larger than a second threshold value, judging whether the time interval for regulating the opening of the regulating valve is reached or not;
if yes, resetting the time interval timing;
the method comprises the following steps: calculating the actual pressure rise rate by adopting a curve fitting algorithm;
if not, executing the steps of: and respectively obtaining the blast furnace air supply pressure, the pressure in the pre-air supply hot blast stove and the opening of the pressure equalizing regulating valve.
8. The method for stabilizing and equalizing control of equalizing regulating valve in hot blast stove according to claim 7, wherein the step of calculating the actual pressure rise rate by using curve fitting algorithm comprises:
and obtaining a time pressure curve equation by adopting a curve fitting algorithm to the discrete data of the hot blast stove pressure acquired at fixed time, and deriving at the latest time point to obtain the actual pressure rise rate at the current moment.
9. The method for stabilizing and equalizing control of equalizing control valve for blast furnace hot blast stove according to claim 8, wherein, when the furnace change is required, before the step of controlling to open equalizing control valve according to the initial opening value, comprising:
and setting the pressure rise rate of the hot blast stove according to the historical data.
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