Intelligent control method and system for pressure of gas collecting pipe of coke oven

Abstract

The invention provides an intelligent control method and system for pressure of a gas collecting pipe of a coke oven, and particularly relates to the technical field of automatic control of the coking production process. According to the method, a coke oven gas collector pressure measured value and an air blower rear pressure value are obtained in real time, and the gas collector pressure change rate is calculated accordingly. When the pressure change rate exceeds a set threshold value, a feed-forward control amount for adjusting the blower speed or the backflow flap opening degree is generated based on the pressure change rate. Meanwhile, the front suction value of the primary cooler is obtained, and feedback control quantity is generated through a feedback control algorithm according to the deviation between the front suction value and the suction set value. And superposing the feedforward control quantity and the feedback control quantity to generate a final control instruction, and adjusting the rotating speed of an air blower or the opening degree of a backflow turning plate according to the final control instruction, so that the measured pressure value of the gas collecting pipe tends to a target pressure set value. According to the method, control delay caused by medium flowing is eliminated, instant and advanced adjustment is achieved, and the problem that control response is not timely is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic control of coking production process, in particular to an intelligent control method and system for coke oven gas collecting pipe pressure. BACKGROUND

[0002] In the coking industry, the coke oven gas generated in the production process needs to be collected and transported through the gas collecting pipe. The stable control of the coke oven gas collecting pipe pressure is directly related to environmental protection, safety production, equipment life and energy recovery efficiency. With the increasingly stringent environmental protection requirements and the promotion of intelligent production, it has become an urgent need in the industry to achieve precise, rapid and stable control of the gas collecting pipe pressure. However, due to the intermittent operation (such as coal charging) characteristics of coke oven production, it will cause a sharp fluctuation in the amount of generated gas. In addition, the gas transportation pipeline is long and the resistance changes are complex, which leads to rapid and large disturbance of the gas collecting pipe pressure. The traditional control method is difficult to effectively respond, resulting in environmental problems such as coke oven smoke and fire, which has become a technical bottleneck that has long plagued the industry.

[0003] To solve the above problems, the traditional and closest prior art usually adopts a "suction fixed value control" scheme, that is, a suction sensor is arranged at the inlet of the blower system (such as before the primary cooler), and the suction is maintained at a fixed value set by artificial experience. When the coke oven working condition changes (such as coal charging) and the amount of gas increases, and after several tens of seconds of transmission to the blower system to cause suction changes, the control system adjusts the blower speed or the backflow flap for compensation. The main defect of this scheme is that the control instruction lags far behind the process change: there is a time delay of tens of seconds from the pressure disturbance at the coke oven end to the detection of the suction change at the blower end and the start of the response, which leads to the inability to quickly suppress instantaneous impacts such as coal charging, resulting in poor control effect of the gas collecting pipe pressure and the need for frequent manual intervention to set the value.

[0004] In summary, how to solve the technical problem of the control instruction lagging behind the rapid change of the coke oven gas collecting pipe pressure due to the coal gas flow time, thereby causing the control response to be not timely is a problem that needs to be solved. SUMMARY

[0005] The main purpose of the present application is to provide an intelligent control method and system for coke oven gas collecting pipe pressure, to at least solve the technical problem of the control instruction lagging behind the rapid change of the coke oven gas collecting pipe pressure due to the coal gas flow time, thereby causing the control response to be not timely, thereby eliminating the control delay caused by the medium flow and achieving immediate and advance adjustment of the coke oven gas collecting pipe pressure.

[0006] In order to achieve the above purpose, the present application provides an intelligent control method and system for coke oven gas collecting pipe pressure.

[0007] In a first aspect, the present application provides an intelligent control method for coke oven gas collector pressure, comprising:

[0008] Real-time acquisition of pressure measured value of coke oven gas collector and pressure value after blower;

[0009] Calculation of pressure change rate according to the pressure measured value of the gas collector;

[0010] When the pressure change rate exceeds a set threshold, a feedforward control amount for adjusting the blower speed or the backflow flap opening degree is generated based on the pressure change rate;

[0011] Acquisition of pre-quenching suction value, and generation of feedback control amount through feedback control algorithm according to the deviation between the pre-quenching suction value and the suction set value;

[0012] Superposition of the feedforward control amount and the feedback control amount to generate a final control instruction, and adjustment of the blower speed or the backflow flap opening degree according to the final control instruction so that the pressure measured value of the gas collector tends to the target pressure set value.

[0013] Specifically, the real-time acquisition of the pressure measured value of the coke oven gas collector and the pressure value after the blower comprises:

[0014] The pressure measured value is collected by the pressure transmitter arranged on each coke oven gas collector;

[0015] The pressure value after the blower is collected by the pressure transmitter arranged on the gas main pipe after the blower;

[0016] The collected pressure measured value and the pressure value after the blower are transmitted to the programmable logic controller via the signal isolator.

[0017] Specifically, the calculation of the pressure change rate according to the pressure measured value of the gas collector comprises:

[0018] In a set control period, the pressure measured value at the current time and the historical pressure measured value at the last time are acquired;

[0019] The difference between the pressure measured value at the current time and the historical pressure measured value is calculated to obtain a pressure change amount;

[0020] The pressure change amount is divided by the length of the control period to obtain the pressure change rate.

[0021] Specifically, when the pressure change rate exceeds a set threshold, a feedforward control amount for adjusting the blower speed or the backflow flap opening degree is generated based on the pressure change rate, comprising:

[0022] When the pressure change rate exceeds a set threshold, the pressure change rate is multiplied by a feedforward proportional coefficient to obtain a feedforward control base value;

[0023] The pressure change rate is input into a fuzzy control rule base to obtain a feedforward control correction value through query;

[0024] The feedforward control base value and the feedforward control correction value are added to generate the feedforward control value.

[0025] Specifically, the pre-cooler suction value is obtained, and a feedback control value is generated through a feedback control algorithm according to a deviation between the pre-cooler suction value and a suction set value, including:

[0026] The pre-cooler suction value is collected by a suction transmitter arranged in front of the pre-cooler;

[0027] A difference between the pre-cooler suction value and a suction set value is calculated to obtain a suction deviation;

[0028] The suction deviation is input into a proportional-integral controller to output the feedback control value through operation.

[0029] Specifically, the feedforward control value and the feedback control value are superimposed to generate a final control instruction, including:

[0030] A feedforward weight coefficient is assigned to the feedforward control value, and a feedback weight coefficient is assigned to the feedback control value;

[0031] The feedforward control value with the feedforward weight coefficient and the feedback control value with the feedback weight coefficient are added to obtain a superimposed control value;

[0032] The superimposed control value is converted into a 4-20mA analog signal corresponding to a blower frequency converter or a flap actuator to generate the final control instruction.

[0033] Specifically, the blower speed or the backflow flap opening degree is adjusted according to the final control instruction, so that the measured value of the gas collector tends to the target pressure set value, including:

[0034] The 4-20mA analog signal corresponding to the final control instruction is sent to the blower frequency converter to adjust the blower speed, or to the backflow flap electro-hydraulic actuator to adjust the backflow flap opening degree;

[0035] The measured value of the gas collector after adjustment is monitored in real time, and a pressure deviation between the measured value of the gas collector and the target pressure set value is calculated;

[0036] When the absolute value of the pressure deviation is continuously within the allowable range, it is determined that the measured value of the pressure of the coke oven gas collector has tended to the target pressure set value.

[0037] In a second aspect, the present application provides an intelligent control system for the pressure of a coke oven gas collector, which applies the control method of the first aspect, and comprises:

[0038] a data acquisition and obtaining module, configured to obtain the measured value of the pressure of the coke oven gas collector and the pressure value after the blower in real time;

[0039] a pressure change rate calculation module, connected with the data acquisition and obtaining module, configured to calculate the pressure change rate of the coke oven gas collector according to the measured value of the pressure of the coke oven gas collector;

[0040] a feedforward control amount generation module, connected with the pressure change rate calculation module, configured to generate a feedforward control amount for adjusting the rotation speed of the blower or the opening degree of the backflow flap based on the pressure change rate when the pressure change rate exceeds a set threshold value;

[0041] a feedback control amount generation module, configured to obtain the suction value before the primary cooler, and generate a feedback control amount through a feedback control algorithm according to the deviation between the suction value before the primary cooler and a suction set value;

[0042] a control instruction synthesis and execution module, connected with the feedforward control amount generation module and the feedback control amount generation module, configured to superimpose the feedforward control amount and the feedback control amount to generate a final control instruction, and adjust the rotation speed of the blower or the opening degree of the backflow flap according to the final control instruction, so that the measured value of the pressure of the coke oven gas collector tends to the target pressure set value.

[0043] Specifically, the data acquisition and obtaining module comprises:

[0044] a first pressure measurement unit, realized by a pressure transmitter arranged on each coke oven gas collector, configured to acquire the measured value of the pressure;

[0045] a second pressure measurement unit, realized by a pressure transmitter arranged on the gas main pipe after the blower, configured to acquire the pressure value after the blower;

[0046] a signal transmission unit, connected with the first pressure measurement unit and the second pressure measurement unit, realized by a signal isolator and a programmable logic controller, configured to transmit the acquired measured value of the pressure and the pressure value after the blower to the programmable logic controller.

[0047] Specifically, the pressure change rate calculation module comprises:

[0048] a data buffer unit, configured to store the current pressure measured value and the historical pressure measured value in a set control period;

[0049] a difference calculation unit, connected with the data buffer unit, configured to calculate the difference between the current pressure measured value and the historical pressure measured value, and obtain a pressure change amount;

[0050] a change rate calculation unit, connected with the difference calculation unit, configured to divide the pressure change amount by the length of the control period, and obtain the pressure change rate.

[0051] The intelligent control method and system for coke oven collector pipe pressure provided by the application first acquire the coke oven collector pipe pressure measured value and the pressure value after the air blower, and calculate the collector pipe pressure change rate according to the two values. If the pressure change rate exceeds a set threshold value, the feedforward control amount for adjusting the air blower rotating speed or the backflow flap opening degree is generated based on the pressure change rate. Meanwhile, the suction value before the primary cooler is acquired, and the feedback control amount is generated by using the feedback control algorithm according to the deviation between the suction value and the suction set value. The feedforward control amount and the feedback control amount are superimposed to obtain the final control instruction, and the air blower rotating speed or the backflow flap opening degree is adjusted according to the instruction, so that the collector pipe pressure measured value approaches the target pressure set value. This method effectively solves the problem of control instruction lag and untimely control response caused by the coal gas flow time, eliminates the control delay caused by the medium flow, and realizes instant and advanced adjustment. BRIEF DESCRIPTION OF DRAWINGS

[0052] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0053] Figure 1 The flowchart of the intelligent control method for coke oven collector pipe pressure provided by the application is shown in the figure;

[0054] Figure 2 The connection diagram of the intelligent control system for coke oven collector pipe pressure provided by the application is shown in the figure.

[0055] The specific embodiments of the present application have been shown in the above drawings, and will be described in more detail hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application by any means, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0056] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0057] The terms "first", "second", "third", "fourth" and the like (if any) in the description, claims, and drawings of the present application, and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0058] In the present application, the words "exemplary" or "for example" are used to mean example, illustration, or illustration. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific manner.

[0059] The intelligent control method and system for coke oven collector pressure provided by the present application, the control method is aimed at coke oven collector pressure control, real-time acquisition of collector pressure measured value and blower rear pressure value, and the pressure change rate is calculated accordingly. When the pressure change rate exceeds the set threshold, the feedforward control amount for adjusting the blower speed or the backflow flap opening degree is generated based on it. At the same time, the suction value before the primary cooler is obtained, and the feedback control amount is generated by the feedback control algorithm according to the deviation of the suction value from the set value. The feedforward and feedback control amounts are superimposed to obtain the final control instruction, and the related equipment is adjusted according to the instruction to eliminate the medium flow delay and realize the instant and advance adjustment of the collector pressure.

[0060] The technical solutions of the present application and how the technical solutions of the present application solve the above-mentioned technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the present application will be described below in conjunction with the drawings.

[0061] Figure 1 The flowchart of the intelligent control method for coke oven collector pressure provided by the present application is shown in Figure 1 The intelligent control method for coke oven collector pressure provided by the present application is shown in

[0062] S101: Real-time acquisition of the pressure measured value of the coke oven collector and the blower rear pressure value.

[0063] Specifically, the real-time acquisition of the pressure measured value of the coke oven collector and the pressure value after the blower includes:

[0064] The pressure measured value is collected by the pressure transmitter arranged on each coke oven collector;

[0065] The pressure value after the blower is collected by the pressure transmitter arranged on the gas main after the blower;

[0066] The collected pressure measured value and the pressure value after the blower are transmitted to the programmable logic controller via the signal isolator.

[0067] The step S101 specifically includes:

[0068] The pressure measured value of the coke oven collector is collected by the pressure transmitter physically installed at the preset pressure measuring hole of each coke oven collector. These pressure transmitters are industrial pressure resistance type pressure transmitters, with a range of 0 to 500 pascals (Pa), and output a standard 4-20 milliampere (mA) analog current signal, which is linearly related to the measured pressure value.

[0069] The pressure value after the blower is collected by the pressure transmitter physically installed at the preset pressure measuring hole of the gas main after the blower. The pressure transmitter after the blower is an industrial pressure transmitter, with a range of 0 to 50 kilopascals (kPa), and also outputs a 4-20 mA analog current signal.

[0070] Then the 4-20 mA current signals from the coke oven collector pressure transmitter and the pressure transmitter after the blower are connected to the corresponding signal isolators. The signal isolator uses magneto-electric isolation or photoelectric isolation technology, which receives the 4-20 mA input signal from the field, performs electrical isolation and signal conditioning, and outputs a set of 4-20 mA signals that are completely isolated from the input signal and have a proportional relationship. This process aims to eliminate common-mode interference that may be introduced during signal transmission in the field, prevent ground loop current from damaging subsequent control equipment, and improve signal measurement accuracy and system reliability.

[0071] Finally, the two 4-20 mA signals representing the measured pressure value and the pressure value after the blower output by the signal isolator are connected to two analog input channels of the programmable logic controller through shielded cables. The analog input module built-in the programmable logic controller converts the received 4-20 mA current signal into digital value at a sampling frequency of 10 times per second. The conversion process is based on the formula P_actual= (I_mA - 4) * (P_max - P_min) / (20 - 4) +P_min, where P_actual is the calculated actual pressure value, I_mA is the measured current value (unit mA), P_max and P_min are the upper and lower limits of the pressure transmitter range respectively. The converted pressure measured value and the pressure value after the blower are stored in the specified data register of the programmable logic controller in engineering units (Pa or kPa) for subsequent step S102.

[0072] This step realizes accurate, stable, anti-interference real-time acquisition of key pressure parameters by deploying specific sensors and signal chain hardware and specifying signal processing procedures, providing a reliable data basis for the entire intelligent control system and being the prerequisite for subsequent fast feedforward control.

[0073] S102: Calculate the pressure change rate of the gas collector according to the measured pressure value.

[0074] Specifically, the calculation of the pressure change rate of the gas collector according to the measured pressure value includes:

[0075] Within a set control period, obtain the pressure measured value at the current time and the historical pressure measured value at the last time;

[0076] Calculate the difference between the pressure measured value at the current time and the historical pressure measured value to obtain the pressure change amount;

[0077] Divide the pressure change amount by the length of the control period to obtain the pressure change rate.

[0078] When step S102 is implemented, it specifically includes:

[0079] The control period is set to 1.5 seconds, which is synchronized with the program scanning period of the programmable logic controller. At the beginning of each control period, the current time collected gas collector pressure measured value is read from the data register address DB1.DBD0 of the programmable logic controller, recorded as the current pressure value P_current, unit is Pascal (Pa). At the same time, the pressure measured value stored at the end of the last control period is read from the data register address DB1.DBD4 of the programmable logic controller, recorded as the historical pressure value P_previous, the unit is also Pascal (Pa). Calculate the pressure change ΔP, the pressure change ΔP is equal to the current pressure value P_current minus the historical pressure value P_previous, that is, ΔP = P_current - P_previous. Then, calculate the pressure change rate dP_dt, the pressure change rate dP_dt is equal to the pressure change ΔP divided by the control period T, that is, dP_dt = ΔP / T, where T is 1.5 seconds, the unit of pressure change rate dP_dt is Pascal per second (Pa / s). Finally, the calculated pressure change rate dP_dt is written into the data register address DB1.DBD8 of the programmable logic controller for subsequent step S103 calling.

[0080] This step converts the absolute pressure value into the rate of change of pressure with time through fixed period data sampling and differential calculation, quantifies the trend and speed of pressure change, provides a direct mathematical basis for system identification of sudden pressure impact (such as coal loading operation), and is a key preprocessing link to realize fast response of feedforward control.

[0081] S103: When the pressure change rate exceeds a set threshold, generating a feedforward control amount for adjusting the speed of the blower or the opening of the backflow flap based on the pressure change rate.

[0082] Specifically, when the pressure change rate exceeds a set threshold, generating a feedforward control amount for adjusting the speed of the blower or the opening of the backflow flap based on the pressure change rate, comprising:

[0083] When the pressure change rate exceeds a set threshold, multiplying the pressure change rate by a feedforward proportional coefficient to obtain a feedforward control basic amount;

[0084] Input the pressure change rate into a fuzzy control rule base to query a feedforward control correction amount;

[0085] Add the feedforward control basic amount and the feedforward control correction amount to generate the feedforward control amount.

[0086] When implementing, step S103 specifically comprises:

[0087] The pressure rate of change dP dt calculated in step S102 is read from the data register address DB1.DBD8 of the programmable logic controller, and the unit is Pascal per second (Pa / s). The pressure rate of change threshold is set to 10 Pa / s, which is based on the typical pressure impact experience value of the coke oven charging operation. Compare the pressure rate of change dP dt with the threshold 10 Pa / s, if the absolute value of dP dt is greater than 10 Pa / s, trigger the feedforward control amount calculation process.

[0088] Feedforward control base quantity calculation: multiply the pressure rate of change dP dt by the feedforward proportional coefficient Kp ff, to get the feedforward control base quantity U base, the calculation formula is U base = dP dt × Kp ff. The feedforward proportional coefficient Kp ff is set to 0.5, the unit is second per Pascal (s / Pa), so that U base is a dimensionless quantity, representing the linear control component based on the pressure rate of change.

[0089] Fuzzy control correction quantity query: the pressure rate of change dP dt is used as the input variable of the fuzzy control rule base. The fuzzy control rule base uses the Mamdani type fuzzy reasoning system, the domain of the input variable dP dt is defined as-20 Pa / s to 20 Pa / s, and the domain of the output variable feedforward control correction quantity U correction is defined as-1 to 1. The fuzzy subsets of dP dt include negative big (NB), negative small (NS), zero (ZE), positive small (PS), and positive big (PB), using a triangular membership function. The fuzzy subsets of U correction are defined the same. The fuzzy rule base contains five rules: if dP dt is NB, then U correction is NB; if dP dt is NS, then U correction is NS; if dP dt is ZE, then U correction is ZE; if dP dt is PS, then U correction is PS; if dP dt is PB, then U correction is PB. The minimum value method is used for fuzzy reasoning, and the center of gravity method is used for defuzzification, to convert the fuzzy output to an accurate value U correction.

[0090] Feedforward control quantity generation: the feedforward control base quantity U base and the feedforward control correction quantity U correction obtained by fuzzy control query are algebraically added to generate the feedforward control quantity U ff, the calculation formula is U ff = U base + U correction. The feedforward control quantity U ff is a dimensionless quantity, representing the feedforward control instruction reference value for adjusting the speed of the blower or the opening degree of the backflow flap. Store U ff to the data register address DB1.DBD12 of the programmable logic controller, for subsequent step S105 to call.

[0091] The step converts the pressure change rate into a feedforward control amount by combining proportional calculation and fuzzy logic, utilizes the linear response of the proportional coefficient to ensure rapidity, and through the fuzzy rule base, adapts to the nonlinearity and uncertainty of the coke oven pressure change, significantly improves the prediction accuracy and response adaptability of the system to sudden impacts such as coal charging, and provides a core instruction basis for the feedforward-feedback composite control.

[0092] S104: Obtain the pre-rougher suction value, and generate a feedback control amount through a feedback control algorithm according to the deviation of the pre-rougher suction value from a suction set value.

[0093] Specifically, the pre-rougher suction value is obtained, and a feedback control amount is generated through a feedback control algorithm according to the deviation of the pre-rougher suction value from a suction set value, including:

[0094] The pre-rougher suction value is collected by a suction transmitter arranged in front of the rougher;

[0095] A difference between the pre-rougher suction value and a suction set value is calculated to obtain a suction deviation;

[0096] The suction deviation is input into a proportional-integral controller, and the feedback control amount is output through operation.

[0097] In implementation, step S104 specifically includes:

[0098] The pre-rougher suction value is collected by an industrial-grade differential pressure transmitter arranged on a gas pipeline in front of the rougher. The transmitter has a range of -5 kilo-Pascal to 0 kilo-Pascal and outputs a 4-20 milliampere analog signal, and the corresponding suction range is -5000 Pa to 0 Pa. The programmable logic controller reads the current signal through an analog input module, converts the actual suction value S_actual into Pascal (Pa) according to the formula S_actual = (I_mA - 4) * (0 - (-5000)) / (20 - 4) + (0), and stores S_actual in the data register address DB2.DBD0.

[0099] The suction set value S_set is set by an operator on the human-machine interface of the programmable logic controller according to process requirements, and a typical value is -1000 Pa. The value is stored in the data register address DB2.DBD4. The suction deviation e_s is calculated, and the suction deviation e_s is equal to the pre-rougher suction measured value S_actual minus the suction set value S_set, i.e., e_s = S_actual - S_set. The suction deviation e_s is stored in the data register address DB2.DBD8.

[0100] The suction deviation e s is input into a proportional-integral controller. The proportional-integral controller adopts a positional PID algorithm, and its discretization formula is U_fb(k) = Kp * e_s(k) + Ki * Σ[e_s(j)] + U0, wherein only the proportional term and the integral term are enabled. The specific parameter settings are: proportional gain Kp = 0.8, integral time constant Ti = 15 seconds, integral gain Ki = Kp / Ti, the sampling sequence number k represents the current control period, U0 is the initial value of the controller output, and is set to 0. The proportional-integral controller calculates the feedback control quantity U_fb according to the current and historical suction deviations e s(k) in each control period (1.5 seconds). The feedback control quantity U_fb is a dimensionless quantity, representing a feedback control instruction reference value for adjusting the blower speed or the backflow flap opening degree. The summation symbol Σ in Σ[e_s(j)] (usually subscript j = 0, superscript j = k) represents the accumulation of all historical suction deviation values e s(j) from the 0th period to the current kth period. U_fb is stored in the data register address DB2.DBD12 of the programmable logic controller for subsequent step S105.

[0101] This step continuously corrects the deviation of the suction before the primary cooler from the set value through the proportional-integral controller, generates a feedback control quantity, which can effectively overcome slow disturbances such as changes in gas pipeline resistance, ensure that the suction is maintained stable, and provide reliable steady-state precision guarantee for the feedforward-feedback composite control, and together with the feedforward control, constitutes a complete control strategy.

[0102] S105: superimpose the feedforward control quantity and the feedback control quantity to generate a final control instruction, and adjust the blower speed or the backflow flap opening degree according to the final control instruction, so that the measured value of the pressure of the gas collector tends to the target pressure set value.

[0103] Specifically, the superimposition of the feedforward control quantity and the feedback control quantity to generate a final control instruction comprises:

[0104] a feedforward weight coefficient is assigned to the feedforward control quantity, and a feedback weight coefficient is assigned to the feedback control quantity;

[0105] the feedforward control quantity with the feedforward weight coefficient is added to the feedback control quantity with the feedback weight coefficient to obtain a superimposed control quantity;

[0106] the superimposed control quantity is converted into a 4-20mA analog signal corresponding to the blower frequency converter or the flap actuator to generate the final control instruction.

[0107] Specifically, the air blower speed or the backflow flap opening degree is adjusted according to the final control instruction, so that the measured value of the pressure of the gas collecting pipe tends to the target pressure set value, comprising:

[0108] The 4-20mA analog signal corresponding to the final control instruction is sent to the air blower frequency converter to adjust the air blower speed, or to the backflow flap electro-hydraulic actuator to adjust the backflow flap opening degree.

[0109] The measured value of the pressure of the gas collecting pipe after adjustment is monitored in real time, and the pressure deviation between the measured value of the pressure of the gas collecting pipe and the target pressure set value is calculated.

[0110] When the absolute value of the pressure deviation is continuously within the allowed range, it is determined that the measured value of the pressure of the gas collecting pipe has tended to the target pressure set value.

[0111] When implementing step S105, it specifically comprises:

[0112] The feedforward control quantity U_ff is read from the programmable logic controller data register address DB1.DBD12, and the feedback control quantity U_fb is read from the address DB2.DBD12. The feedforward weight coefficient a is set to 0.6, and the feedback weight coefficient β is set to 0.4, satisfying a+ β = 1.0. The weighted summation method is used for superposition, and the superimposed control quantity U_combined is calculated, and the calculation formula is U_combined = a × U_ff + β × U_fb.

[0113] The superimposed control quantity U_combined is converted into a 4-20mA analog signal. The effective output range of U_combined is set to -5.0 to 0. The conversion formula is I_out = (U_combined - (-5.0)) × (20 - 4) / (0 - (-5.0)) + 4, wherein I_out is the output current value, unit: milliampere. Through the analog output module of the programmable logic controller, the calculated I_out value is output to the corresponding physical channel.

[0114] The generated 4-20mA final control instruction signal is sent to the frequency given input end of the air blower frequency converter through the shielded cable to linearly adjust the air blower speed, or the signal is sent to the control signal input end of the backflow flap electro-hydraulic actuator to adjust the backflow flap opening degree.

[0115] The adjusted header pressure measured value is monitored in real time, which is continuously read from the data register address DB1.DBD0. The target pressure set value is set as 140 Pa. The pressure deviation ΔP_control is calculated, which is equal to the header pressure measured value minus the target pressure set value 140 Pa. The allowed range is set as ±20 Pa. When the absolute value of the pressure deviation ΔP_control is less than or equal to 20 Pa in 5 consecutive control cycles, it is determined that the header pressure measured value has tended to the target pressure set value, and the system enters a stable state.

[0116] In this step, the final control instruction is generated by weighted fusion of the feedforward control amount and the feedback control amount, and the actuator is driven to act, and a closed-loop monitoring mechanism is constructed to ensure that the header pressure is quickly and stably in the target range, and finally the rapid suppression and long-term stable control of the pressure disturbance are realized, and the complete control closed loop from intelligent decision to physical execution is completed.

[0117] The embodiment provides an intelligent control method for coke oven header pressure. The coke oven header pressure measured value and the pressure value after the air blower are acquired in real time, and then the header pressure change rate is calculated. If the pressure change rate exceeds a set threshold, a feedforward control amount for adjusting the air blower rotating speed or the backflow flap opening degree is generated according to the change rate. Meanwhile, the suction value before the primary cooler is acquired, and a feedback control amount is generated by using a feedback control algorithm according to the deviation of the suction value from the suction set value. The feedforward control amount and the feedback control amount are superimposed to form a final control instruction, and the air blower rotating speed or the backflow flap opening degree is adjusted according to the instruction, so that the coke oven header pressure measured value tends to the target pressure set value. The method effectively solves the technical problems of control instruction lag and untimely control response caused by coal gas flow time, eliminates the control delay caused by medium flow, and achieves instant and advanced precise adjustment of the coke oven header pressure.

[0118] Figure 2 A connection diagram of the intelligent control system for coke oven header pressure provided in the application is shown in Figure 2 The intelligent control system for coke oven header pressure provided in the embodiment is shown in Figure 1 The control system comprises the following modules.

[0119] A data acquisition and acquisition module is configured to acquire the pressure measured value of the coke oven header and the pressure value after the air blower in real time.

[0120] A pressure change rate calculation module is connected with the data acquisition and acquisition module and configured to calculate the pressure change rate of the coke oven header according to the pressure measured value of the coke oven header.

[0121] A feedforward control quantity generation module, connected with the pressure change rate calculation module, configured to generate a feedforward control quantity for adjusting the speed of the air blower or the opening degree of the backflow flap based on the pressure change rate when the pressure change rate exceeds a set threshold value;

[0122] A feedback control quantity generation module configured to obtain a suction value before the primary cooler and generate a feedback control quantity based on the deviation between the suction value before the primary cooler and a suction set value through a feedback control algorithm;

[0123] A control instruction synthesis and execution module, connected with the feedforward control quantity generation module and the feedback control quantity generation module, configured to superimpose the feedforward control quantity and the feedback control quantity to generate a final control instruction, and adjust the speed of the air blower or the opening degree of the backflow flap according to the final control instruction so that the measured value of the pressure of the gas collecting pipe tends to the target pressure set value.

[0124] Specifically, the data acquisition and obtaining module comprises:

[0125] A first pressure measurement unit, realized by a pressure transmitter arranged on each coke oven gas collecting pipe, configured to acquire the measured value of the pressure;

[0126] A second pressure measurement unit, realized by a pressure transmitter arranged on the gas main pipe after the air blower, configured to acquire the pressure value after the air blower;

[0127] A signal transmission unit, connected with the first pressure measurement unit and the second pressure measurement unit, realized by a signal isolator and a programmable logic controller, configured to transmit the acquired measured value of the pressure and the pressure value after the air blower to the programmable logic controller.

[0128] Specifically, the pressure change rate calculation module comprises:

[0129] A data buffering unit, configured to store the measured value of the pressure at the current time and the historical measured value of the pressure at the last time within a set control period;

[0130] A difference calculation unit, connected with the data buffering unit, configured to calculate the difference between the measured value of the pressure at the current time and the historical measured value of the pressure to obtain a pressure change amount;

[0131] A change rate calculation unit, connected with the difference calculation unit, configured to divide the pressure change amount by the length of the control period to obtain the pressure change rate.

[0132] The intelligent control system for the pressure of the coke oven gas collecting pipe provided in the embodiment specifically comprises:

[0133] The data acquisition and acquisition module includes a first pressure measurement unit, a second pressure measurement unit and a signal transmission unit. The first pressure measurement unit is realized by physically installing an industrial pressure resistance pressure transmitter at the preset pressure measuring hole of each coke oven gas collector, the transmitter range is 0 to 500 pascal, output 4-20 milliamperes analog current signal, used for collecting the pressure measured value of coke oven gas collector. The second pressure measurement unit is realized by physically installing an industrial pressure transmitter at the preset pressure measuring hole of the gas main pipe after the blower, the transmitter range is 0 to 50 kilopascal, output 4-20 milliamperes analog current signal, used for collecting the pressure value after the blower. The signal transmission unit includes a signal isolator and a programmable logic controller, the signal isolator uses magneto-isolation technology, receives 4-20 milliamperes input signal from the first pressure measurement unit and the second pressure measurement unit and carries out electrical isolation and signal conditioning, outputs the isolated 4-20 milliamperes signal to the analog input module of the programmable logic controller, realizes the anti-interference transmission and acquisition of the pressure signal, and provides reliable raw data basis for the system.

[0134] The pressure change rate calculation module includes a data buffer unit, a difference calculation unit and a change rate calculation unit. The data buffer unit is realized by using the data storage area of the programmable logic controller, in the set 1.5 second control period, the current collected pressure measured value is stored in address DB1.DBD0, and the pressure measured value of the last period is transferred to address DB1.DBD4 as the historical pressure measured value. The difference calculation unit is realized by arithmetic operation instruction of programmable logic controller, reads the current pressure value P_current of DB1.DBD0 and the historical pressure value P_previous of DB1.DBD4, calculates the pressure change ΔP = P_current - P_previous. The change rate calculation unit continues to divide the pressure change ΔP by the control period T = 1.5 seconds by arithmetic operation instruction, gets the pressure change rate dP_dt = ΔP / T, and stores the result in address DB1.DBD8, completes the quantization of pressure change trend, and provides input basis for feedforward control.

[0135] The feedforward control quantity generation module is connected with the pressure rate of change calculation module through data register addresses DB1.DBD8 to read the pressure rate of change dP_dt. The module includes comparison logic, a proportional operation unit and a fuzzy inference unit. The comparison logic compares the absolute value of dP_dt with a set threshold of 10 pascal per second, and triggers control quantity calculation when the threshold is exceeded. The proportional operation unit multiplies dP_dt by a feedforward proportional coefficient Kp_ff=0.5 to obtain a feedforward control base quantity U_base = dP_dt x Kp_ff. The fuzzy inference unit uses a Mamdani type fuzzy logic system, takes dP_dt as input, and after fuzzy processing, rule base query (including five rules such as outputting negative large if dP_dt is negative large) and de-fuzzy processing, outputs a feedforward control correction quantity U_correction. Finally, the U_base and U_correction are added by an adder to generate a feedforward control quantity U_ff and store it in addresses DB1.DBD12, realizing nonlinear feedforward compensation based on the pressure rate of change.

[0136] The feedback control quantity generation module operates independently, including a suction force acquisition unit, a deviation calculation unit and a proportional integral control unit. The suction force acquisition unit is realized by a differential pressure transmitter installed before the primary cooler. The transmitter has a range of -5 to 0 kilopascal and outputs a 4-20 milliamp signal, which is converted by a programmable logic controller into an actual suction force value S_actual stored in addresses DB2.DBD0. The deviation calculation unit reads S_actual and an operator set suction force set value S_set=-1000 pascal (stored in DB2.DBD4), calculates a suction force deviation e_s = S_actual - S_set and stores it in DB2.DBD8. The proportional integral control unit uses a positional PI control algorithm, reads e_s and performs operation U_fb(k) = Kp * e_s(k) + Ki * Σ[e_s(j)], where the proportional gain Kp=0.8 and the integral gain Ki=Kp / Ti (integral time constant Ti=15 seconds), outputs a feedback control quantity U_fb and stores it in addresses DB2.DBD12, realizing continuous correction of the steady state deviation.

[0137] The control instruction synthesis and execution module is connected with address DB1.DBD12 and DB2.DBD12 through data bus respectively to read feedforward control quantity U_ff and feedback control quantity U_fb. The module contains weight distribution unit, adder and signal conversion unit. The weight distribution unit distributes feedforward weight coefficient a = 0.6 for U_ff and feedback weight coefficient β = 0.4 for U_fb. The adder performs weighted superposition operation U_combined = a × U_ff + β × U_fb. The signal conversion unit converts U_combined into 4-20 milliamperes analog signal through formula I_out = (U_combined - (-5.0)) × (20 - 4) / (0 - (-5.0)) + 4. The final control instruction is sent to frequency given input end of the blower frequency converter or control input end of the backflow flap electro-hydraulic actuator through the analog output module of the programmable logic controller, to drive the actuator to act, and complete the closed-loop control of pressure.

[0138] The system realizes full-process automation of data acquisition, change rate calculation, feedforward and feedback control quantity generation and instruction synthesis through modular design. The modules are connected through data register address, ensuring the coherence and feasibility of the system logic.

[0139] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0140] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is limited only by the appended claims.

Claims

1. A method for intelligent control of coke oven gas collecting pipe pressure, characterized in that, The method includes: Real-time acquisition of the measured pressure values ​​of the coke oven gas collecting pipe and the pressure values ​​after the blower; Calculate the pressure change rate based on the measured pressure value of the gas collecting pipe; When the pressure change rate exceeds a set threshold, a feedforward control quantity is generated based on the pressure change rate to adjust the blower speed or the opening of the return flap. The suction force value in front of the precooler is obtained, and a feedback control quantity is generated through a feedback control algorithm based on the deviation between the suction force value in front of the precooler and the suction force set value. The feedforward control quantity and the feedback control quantity are superimposed to generate the final control command. The blower speed or the opening of the return flap is adjusted according to the final control command so that the measured pressure value of the gas collecting pipe tends to the target pressure set value.

2. The intelligent control method for coke oven gas collecting pipe pressure according to claim 1, characterized in that, The real-time acquisition of the measured pressure values ​​of the coke oven gas collecting pipe and the pressure values ​​after the blower includes: The measured pressure values ​​are collected by pressure transmitters installed on the gas collecting pipes of each coke oven. The pressure value after the blower is collected by a pressure transmitter installed on the main gas pipe after the blower. The collected measured pressure value and the pressure value after the blower are transmitted to the programmable logic controller via a signal isolator.

3. The intelligent control method for coke oven gas collecting pipe pressure according to claim 1, characterized in that, The calculation of the pressure change rate based on the measured pressure value of the gas collecting pipe includes: Within the set control cycle, obtain the current measured pressure value and the previous historical measured pressure value; The pressure change is obtained by calculating the difference between the current measured pressure value and the historical measured pressure value. The pressure change rate is obtained by dividing the pressure change by the duration of the control cycle.

4. The intelligent control method for coke oven gas collecting pipe pressure according to claim 1, characterized in that, When the pressure change rate exceeds a set threshold, a feedforward control quantity is generated based on the pressure change rate to adjust the blower speed or the opening of the return flap, including: When the pressure change rate exceeds the set threshold, the pressure change rate is multiplied by a feedforward proportional coefficient to obtain the feedforward control base quantity. The pressure change rate is input into a fuzzy control rule base, and a feedforward control correction value is obtained by querying it. The feedforward control base quantity is added to the feedforward control correction quantity to generate the feedforward control quantity.

5. The intelligent control method for coke oven gas collecting pipe pressure according to claim 1, characterized in that, The process of obtaining the suction force value before the precooler and generating a feedback control quantity through a feedback control algorithm based on the deviation between the precooler suction force value and the suction set value includes: The suction value in front of the precooler is collected by a suction transmitter installed in front of the precooler; The suction deviation is obtained by calculating the difference between the suction value before the primary cooler and a suction set value. The suction deviation is input into a proportional-integral controller, which then calculates and outputs the feedback control quantity.

6. The intelligent control method for coke oven gas collecting pipe pressure according to claim 1, characterized in that, The step of superimposing the feedforward control quantity and the feedback control quantity to generate the final control command includes: Assign a feedforward weight coefficient to the feedforward control quantity and a feedback weight coefficient to the feedback control quantity; The feedforward control quantity with the feedforward weight coefficient and the feedback control quantity with the feedback weight coefficient are added together to obtain the superimposed control quantity. The superimposed control quantity is converted into a 4-20mA analog signal corresponding to the blower frequency converter or the flap actuator to generate the final control command.

7. The intelligent control method for coke oven gas collecting pipe pressure according to claim 1, characterized in that, The step of adjusting the blower speed or the opening of the return flap according to the final control command, so that the measured pressure value of the air collecting pipe tends to the target pressure set value, includes: The 4-20mA analog signal corresponding to the final control command is sent to the blower frequency converter to adjust the blower speed; or sent to the return flap electro-hydraulic actuator to adjust the return flap opening. The measured pressure value of the gas collecting pipe after adjustment is monitored in real time, and the pressure deviation between the measured pressure value of the gas collecting pipe and the target pressure setting value is calculated. When the absolute value of the pressure deviation remains within the allowable range, it is determined that the measured pressure value of the gas collection pipe has approached the target pressure setting value.

8. An intelligent control system for the pressure of a coke oven gas collecting pipe, characterized in that, The control system employs the control method according to any one of claims 1-7, and the control system comprises: The data acquisition module is used to acquire the measured pressure values ​​of the coke oven gas collecting pipe and the pressure values ​​after the blower in real time. The pressure change rate calculation module is connected to the data acquisition and acquisition module and is used to calculate the pressure change rate based on the measured pressure value of the gas collection pipe. A feedforward control quantity generation module is connected to the pressure change rate calculation module. When the pressure change rate exceeds a set threshold, it generates a feedforward control quantity based on the pressure change rate to adjust the blower speed or the opening of the return flap. The feedback control quantity generation module is used to obtain the suction force value in front of the precooler, and generate a feedback control quantity through a feedback control algorithm based on the deviation between the suction force value in front of the precooler and the suction force set value. The control command synthesis and execution module is connected to the feedforward control quantity generation module and the feedback control quantity generation module. It is used to superimpose the feedforward control quantity and the feedback control quantity to generate the final control command, and adjust the blower speed or the opening of the return flap according to the final control command so that the measured pressure value of the gas collection pipe tends to the target pressure set value.

9. The intelligent control system for coke oven gas collecting pipe pressure according to claim 8, characterized in that, The data acquisition module includes: The first pressure measurement unit is implemented by a pressure transmitter installed on the gas collecting pipe of each coke oven, and is used to collect the actual pressure value. The second pressure measurement unit is implemented by a pressure transmitter installed on the gas main pipe after the blower, and is used to collect the pressure value after the blower. A signal transmission unit, connected to the first pressure measurement unit and the second pressure measurement unit, and implemented with a programmable logic controller via a signal isolator, is used to transmit the collected measured pressure value and the pressure value after the blower to the programmable logic controller.

10. The intelligent control system for coke oven gas collecting pipe pressure according to claim 8, characterized in that, The pressure change rate calculation module includes: The data caching unit is used to store the measured pressure value at the current moment and the historical measured pressure value at the previous moment within a set control period. The difference calculation unit, connected to the data cache unit, is used to calculate the difference between the current measured pressure value and the historical measured pressure value to obtain the pressure change. A rate of change calculation unit, connected to the difference calculation unit, is used to divide the pressure change by the duration of the control cycle to obtain the pressure change rate.

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