Control method and control system for cooling air system of dry deslagging unit of coal-fired power plant boiler

Abstract

The invention discloses a coal-fired power plant boiler dry slag discharging unit cooling air system control method and system. The control method comprises the steps that S1, real-time operation data of a dry slag discharging unit are obtained; the real-time operation data comprises the slag tapping temperature, the slag falling section conveying belt ash temperature, the slag falling section conveying belt ash amount, the slag falling section conveying belt ash thickness, the fan power / cooling air door opening degree, the in-furnace cooling air volume, the in-furnace cooling air temperature and the cooling air initial temperature; s2, according to the obtained real-time operation data of the dry deslagging unit, a fan power / cooling air door opening degree instruction is obtained; and S3, the fan power / cooling air door opening degree is automatically controlled according to the fan power / cooling air door opening degree instruction. According to the method, the fan power / cooling air door opening degree can be adjusted in real time according to the slag quantity and the slag temperature, the cooling air quantity and the outlet ash temperature are accurately controlled, the ash temperature is stabilized within the target range, the stability of the system is enhanced when the boiler load changes or the slag quantity fluctuates, and the ash cooling effect is guaranteed.

Description

Technical field:

[0001] The invention relates to the technical field of ash treatment in thermal power plants, and in particular to a control method, a control system and a device for a cooling air system of a dry slagging unit of a boiler in a coal-fired power plant. Background technology:

[0002] The dry slag discharge unit of a coal-fired power plant boiler undertakes important cooling and conveying tasks in the process of handling the bottom slag of the boiler. During the operation of the boiler, the high-temperature ash falls from the slag bucket to the stainless steel conveyor belt of the dry slag discharge unit. With the negative pressure of the boiler furnace or the use of a fan as the power, the external cooling air is introduced into the system through the head of the dry slag discharge shell and the adjustable air doors on both sides by suction, cooling the slag and recovering the heat energy into the furnace. After heat exchange between the cold air and the ash, the temperature rises to 300℃~400℃. The cooling air volume entering the furnace accounts for about 1% of the total air volume of the boiler, and the ash will gradually be cooled to about 150℃.

[0003] However, there are many problems in the actual operation of dry slag discharge units. Especially when the boiler load and water wall soot blowing operations change frequently, the amount of boiler slag will fluctuate greatly, and this fluctuation is highly random and unpredictable. Since the cooling air volume or fan power cannot flexibly adapt to the change of slag amount, the outlet slag temperature is often out of control, affecting the subsequent treatment of slag and the operation of the dry slag discharge unit. If the cooling air flow is too large, it may also cause unnecessary energy consumption of the fan system, resulting in an increase in the system operating cost, and may also cause excessive cooling air to enter the furnace, causing the center height of the boiler combustion flame to rise, causing the exhaust gas temperature to rise, and reducing the boiler efficiency; while the air flow is too small to achieve sufficient cooling effect, it may cause the slag temperature to rise rapidly, threatening the safe operation of the dry slag machine; the adjustable dampers on both sides of the dry slag shell have serious air leakage and low heat exchange efficiency, which often leads to a large amount of disordered cooling air entering the furnace, and the temperature of the cooling air entering the furnace is even less than 100℃, while the ash is not cooled to a safe temperature; in addition, if electric damper control is used to adjust the cooling air volume, the fluctuation of the boiler load will cause the change of the negative pressure at the bottom of the furnace, thereby affecting the stability of the cooling air volume. In actual engineering applications, the electric cooling dampers of most dry slag machines mainly rely on the experience and intuition of the operator to adjust the air volume. This method cannot achieve timely and stable control of the ash temperature, thereby adversely affecting the heat exchange efficiency and the overall performance of the boiler system.

[0004] At present, the control strategies for the cooling air system of the dry slag discharge unit mainly include: (CN118778733A) a control system and method for an intelligent air-cooled steel strip dry slag discharger, (CN118274332A) a monitoring control system and method for an air-cooled steel strip dry slag discharger, etc. The above methods mainly improve the control effect of the cooling air system of the dry slag discharger by studying and improving new intelligent algorithms, but there may be problems such as high algorithm complexity and large consumption of computing resources, especially in real-time monitoring and control scenarios, which may affect the response speed and stability of the system. (CN118517706A) A conveying control method for an air-cooled steel strip dry slag discharger mainly constructs an optimal parameter set by collecting historical temperature and historical conveying control parameters, and constructs an optimal conveying control model based on the optimal parameter set. This method relies on the accuracy and completeness of real-time operating data and lacks an effective feedback adjustment mechanism, which may lead to unsatisfactory control effects. (CN118746131A) The cooling method and device of the dry slag discharger mainly adjusts the preset cooling air distribution mode according to the collected slag volume, which limits its wide applicability in diversified industrial applications. At the same time, it lacks an automatic adjustment mechanism for feedback, and its ability to resist external disturbances (changes in furnace bottom negative pressure caused by boiler load changes, changes in external ambient temperature, and equipment air leakage) is difficult to evaluate. Therefore, how to accurately adjust the slag temperature and cooling air volume at the outlet of the dry slag discharger according to the real-time ash volume, reduce furnace bottom air leakage, and achieve accurate and orderly air control is a problem that technicians in this field urgently need to solve. Summary of the invention:

[0005] Technical problem: The present invention provides a control method, control system and device for the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, which solves the problems of inaccurate cooling air volume adjustment, furnace bottom air leakage and low heat exchange efficiency when the slag amount and slag temperature of the dry slag discharge unit change in the prior art. It can dynamically adjust the cooling air door size or fan power in real time according to the changes in slag amount and slag temperature, adjust the cooling air volume, realize precise and orderly air control, improve the heat exchange effect between ash and cooling air, reduce energy consumption, reduce furnace bottom air leakage, and enhance the response speed and stability of the system.

[0006] Technical solution:

[0007] The present invention first provides a method for controlling a cooling air system of a dry slagging unit of a coal-fired power plant boiler, comprising:

[0008] S1: Obtain the real-time operation data of the dry slag discharge unit; the real-time operation data includes the slag discharge temperature T S1 , Ash temperature T of conveyor belt in slag falling section S0 , Ash amount of conveyor belt in slag falling section M S 、The ash thickness of the conveyor belt in the slag falling section h S , fan power P / cooling air door opening D, cooling air volume into the furnace M a, Temperature of cooling air entering the furnace T a1 and cooling air initial temperature T a0 ;

[0009] S2: Obtain the fan power / cooling air door opening instruction F according to the real-time operation data of the dry slag discharge unit ff ;

[0010] S3: According to the fan power / cooling air door opening instruction F ff Automatically control the fan power / cooling damper opening.

[0011] Step S2 includes:

[0012] S21: Calculate the comprehensive feedforward control instruction F of the fan / cooling damper based on the real-time operation data f ;

[0013] S22: Set the slag discharge temperature to T set and slag temperature T S1 The deviation e S , input to the outer ring slag temperature controller for adjustment, and obtain the output value F of the outer ring slag temperature controller set ;

[0014] S23: The output value F of the outer ring slag temperature controller set The cooling air volume M a The deviation e a , input to the inner ring cooling air volume controller for adjustment, and obtain the output value G of the inner ring cooling air volume controller a ;

[0015] S24: The integrated feedforward output signal F f The output value G of the inner ring cooling air volume controller a Add them together to get the fan power / cooling air door opening instruction F ff .

[0016] Step S21 includes:

[0017] S211: Calculate the integral M1 of the change in the amount of ash in the conveyor belt of the slag falling section within the time τ, and compare M1 with the set threshold value K; if M1≤K, enter the control calculation process S212A; if M1>K, enter the iterative calculation process S212B;

[0018] The integral M1 calculation formula for calculating the change value of the ash amount in the conveyor belt of the dry slag discharge machine within the time τ is:

[0019]

[0020] ΔM S =M Sti-M St0

[0021] In the formula, ΔM S is the change in ash mass at each moment in the τ time period; M St0 M is the amount of ash in the conveyor belt of the dry slag discharger at the initial moment in the τ time period; Sti is the amount of ash in the conveyor belt of the dry slag discharger at the i-th moment within the τ time period;

[0022] Calculate the ash temperature T of the conveyor belt in the slag falling section within time τ S0 The integral of the change M2,M is calculated as:

[0023]

[0024] ΔT S0 =T S0ti -T S0t0

[0025] In the formula, ΔT S0 is the change of the initial temperature of the ash at each moment in the τ time period; T S0t0 T is the ash temperature of the conveyor belt in the slag falling section at the initial moment in the τ time period; S0ti is the ash temperature of the conveyor belt in the slag falling section at the i-th moment within the τ time period;

[0026] S212A: According to the control calculation process, the compensation value F of fan power / cooling air door opening is calculated by M1 and M2. f1 , as the integrated feedforward intermediate signal 1 output; compensation value F f1 The calculation formula is as follows:

[0027] F f1 =C·(exp(K1·M1)-1)+(exp(K2·M2)-1)

[0028] In the formula, C is the gain factor, K1 and K2 are proportional coefficients related to the ash thickness and temperature change, respectively, which are obtained according to the experimental fitting parameters;

[0029] S212B: According to the iterative calculation process, the compensation value F of the fan power / cooling air door opening is iteratively calculated based on the ash temperature of the conveyor belt in the slag falling section, the ash amount of the conveyor belt in the slag falling section, the initial temperature of the cooling air, the temperature of the cooling air entering the furnace, etc. f2 , as the integrated feedforward intermediate signal 2 output; compensation value F f2 The specific calculation process is as follows:

[0030] S212B1: The current ash temperature T of the conveyor belt of the dry slag discharge machine S0 , Ash thickness of conveyor belt in slag discharge section of dry slag discharger h S , cooling air initial temperature Ta0 , Temperature of cooling air entering the furnace T a1 , Cooling air volume into furnace M a , the dry slag conveyor belt speed v parameter is input into the mechanism modeling differential equation group;

[0031] The differential equations for the mechanism modeling are expressed as:

[0032]

[0033] Where, T Sout To calculate the estimated slag temperature; T a1 The temperature of the cooling air entering the furnace; M is the ash mass flow rate of the conveyor belt of the slag discharge section of the slag discharger at time t; a (t) is the cooling air volume entering the furnace at time t; c g is the specific heat capacity of ash; c a is the specific heat capacity of cooling air; T S0 T is the ash temperature of the conveyor belt of the current dry slag discharge machine; a0 is the initial temperature of cooling air; U is the comprehensive heat transfer coefficient between ash and cooling air, obtained by experimental test; A s is the heat exchange area between ash and cooling air; C g (t) is the total heat capacity of ash in the existing dry slag unit; C a (t) is the total heat capacity of the cooling air in the existing dry slag unit;

[0034] In the formula, C g (t) and C a (t) are calculated as follows:

[0035]

[0036] C g (t) = ρ g ·W belt ·h S (t)·c g ·L

[0037] C a (t) = M a (t)·c a

[0038] In the formula, ρ g is the ash density; v is the conveyor belt speed of the dry slag discharger; W belt h is the effective width of the conveyor belt of the dry slag discharger; S (t) is the ash thickness of the conveyor belt of the slag discharger at time t; L is the effective length of the conveyor belt of the dry slag discharger;

[0039] S212B2: Use the fourth-order and fifth-order Runge-Kutta numerical calculation method to iteratively solve the differential equations and obtain the estimated slag temperature T Sout ;

[0040] S212B3: Calculate and estimate the slag temperature T Sout and set slag temperature T set The temperature difference A;

[0041] A=T Sout -T set

[0042] S212B4: Determine the absolute value of the temperature difference A and the temperature difference limit N; the temperature difference limit N is set according to the actual control accuracy;

[0043] S212B5A: If |A|≤N, calculate the current cooling air output deviation M ae , and M ae As the integrated feedforward intermediate signal 2F f2 Output: M ae =M a0 -M ai ;

[0044] S212B5B: If |A|>N, change the cooling air volume M a Size; if the calculated temperature difference A>N, the cooling air volume is updated to M ai =M ai-1 +ΔM, if the calculated temperature difference A≤N, the cooling air volume is updated to M ai =M ai-1 -ΔM;

[0045] Where M ai is the current calculated cooling air volume, ΔM is the air volume update value, which is set according to the actual required accuracy;

[0046] S212B6: After the cooling air volume is updated, the updated cooling air volume is input into the differential equation and the differential equation group is iteratively solved, and the above steps are repeated;

[0047] S213: The integrated feedforward intermediate signals 1 and 2 do not appear at the same time at every moment. If the output at this moment is the integrated feedforward intermediate signal 1, the integrated feedforward intermediate signal 1 is first judged; if F f1 ≥0, the integrated feedforward intermediate signal 1 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax Compare and take the minimum value as the final comprehensive feedforward output signal F f If F f1 <0, then the integrated feedforward intermediate signal 1 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are eminCompare and take the maximum value as the final comprehensive feedforward output signal F f ; The formula is as follows:

[0048]

[0049] If the output at this time is the integrated feedforward intermediate signal 2, the integrated feedforward intermediate signal 2 is first judged; if F f2 ≥0, the integrated feedforward intermediate signal 2 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax Compare and take the minimum value as the final comprehensive feedforward output signal F f If F f2 <0, then the integrated feedforward intermediate signal 2 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are compared. emin Compare and take the maximum value as the final comprehensive feedforward output signal F f ; The formula is as follows:

[0050]

[0051] In step S22, the output value F of the outer ring slag temperature controller is obtained. set for:

[0052]

[0053] In the formula, e S T is the slag temperature setting value set and slag temperature T S1 The deviation, e S =T set -T S1 ; K p1 , K i1 and K d1 They are the PID proportional, integral and differential components of the outer loop slag temperature controller respectively.

[0054] In step S23, the output value G of the inner ring cooling air volume controller is obtained. a for:

[0055]

[0056] In the formula, e a is the output value F of the outer ring slag temperature controller set The cooling air volume M a The deviation, e a =F set -M a ; K p2 , K i2 and K d2 They are the PID proportional, integral and differential components of the inner loop cooling air volume controller respectively.

[0057] In step S24, the fan power / cooling air door opening instruction F is obtained. ff The calculation formula is:

[0058] F ff =F f +G a

[0059] In the formula, F f is the comprehensive feedforward output signal, G a is the output value of the inner ring cooling air volume controller, F ff It is the fan power / cooling air door opening instruction.

[0060] The present invention also provides a control system for a cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, comprising:

[0061] The real-time operation data collection module is used to obtain the real-time operation data of the dry slag discharge unit;

[0062] The cooling air command generation module adopts a feedforward-cascade-feedback control structure, which includes a feedforward control structure, a cascade control structure and a feedback control structure. The feedforward control structure is a comprehensive feedforward controller. The cascade control structure includes an outer-loop slag temperature controller with the slag discharge temperature as the adjustment variable and an inner-loop cooling air volume controller with the fan power / cooling air door opening as the adjustment variable. The feedforward-cascade-feedback control structure obtains the fan power / cooling air door opening instruction F according to the real-time operation data of the dry slag discharge unit. ff ;

[0063] Cooling air volume control module, used to convert fan power / cooling air door opening instruction F ff Automatically control the fan power / cooling damper opening.

[0064] The cooling air command generation module includes:

[0065] A comprehensive feedforward controller module, used for calculating feedforward control instructions according to the real-time operation data of the dry slag discharge unit acquired by the real-time operation data acquisition module;

[0066] The outer loop control command module is used to set the slag temperature setting value T set and slag temperature T Sf The deviation e S Input to the outer ring slag temperature controller for adjustment, and obtain the output value F of the outer ring slag temperature controller set ;

[0067] The inner loop control command module is used to convert the output value F of the outer loop slag temperature controller set The cooling air volume M a The deviation ea Input to the inner ring cooling air volume controller for adjustment, and obtain the output value G of the inner ring cooling air volume controller a ;

[0068] The command summing output module is used to convert the comprehensive feedforward output signal F f The output value G of the inner ring cooling air volume controller a Add them together to get the fan power / cooling air door opening instruction F ff .

[0069] The present invention also provides an electronic device, comprising:

[0070] one or more processors;

[0071] A memory for storing one or more programs;

[0072] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method for controlling the cooling air system of the dry slag discharge unit of a boiler in a coal-fired power plant.

[0073] The present invention also provides a storage medium having a computer program stored thereon, characterized in that when the program is executed by a processor, the above-mentioned method for controlling a cooling air system of a dry slag discharge unit of a boiler in a coal-fired power plant is implemented.

[0074] Advantages of the invention:

[0075] The present invention provides a control method, control system and device for the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, forming a cascade-feedback control structure composed of slag discharge temperature as the regulating variable and fan power / cooling air door opening as the regulated variable, and combining the designed comprehensive feedforward controller to form a control strategy design for the cooling air system of the dry slag discharge unit of a coal-fired power plant boiler with outstanding effect. Through the cascade-feedback control, the cooling air flow rate and the outlet ash temperature can be accurately controlled, so that the ash temperature is stabilized within the target range, the stability of the system is enhanced when the boiler load changes or the ash amount fluctuates, and the cooling effect of the ash is guaranteed. By using the comprehensive feedforward controller, the appropriate control process can be selected according to the change of the ash amount and the change of the ash temperature to adjust the compensation cooling air volume in advance, so that the system can quickly respond to the temperature fluctuation caused by the change of the slag amount and the slag temperature. By setting the upper and lower limits of the cooling air flow rate according to the boiler load, the unnecessary cooling air volume input caused by the change of the boiler load and the negative pressure in the furnace can be reduced, the energy consumption can be reduced, the boiler efficiency can be prevented from being reduced, and the economy and stability of the system can be improved. By blocking the cooling air doors on both sides of the dry slag discharge unit shell, the air leakage of the boiler can be reduced. The corresponding parts of the dry slag discharge unit are equipped with variable frequency fans / adjustable electric air doors, temperature sensors, visual slag amount monitoring sensors and ash temperature sensors, acoustic temperature sensors, air flow meters and other devices for data acquisition and implementation of the above control method. The control method, control system and device for the cooling air system of the dry slag discharge unit of a coal-fired power plant provided by the present invention have strong engineering application value and prospects. Description of the drawings:

[0076] Figure 1 A flow chart of a method for controlling a cooling system of a dry slagging unit of a coal-fired power plant boiler;

[0077] Figure 2 Flowchart of step S2;

[0078] Figure 3 Flowchart of step S21;

[0079] Figure 4 Flowchart of step S212B;

[0080] Figure 5 A structural block diagram of a control method for a cooling air system of a dry slagging unit of a coal-fired power plant boiler;

[0081] Figure 6 A schematic diagram of a control system for a cooling air system of a dry slagging unit of a coal-fired power plant boiler;

[0082] Figure 7 The structure diagram of the cooling air command generation module;

[0083] Figure 8 Block diagram of the integrated feedforward controller module;

[0084] Fig. 9 A schematic diagram of the cooling air system structure of a dry slagging unit of a coal-fired power plant boiler;

[0085] Fig.10 A structural diagram of an electronic device provided by an embodiment of the present invention;

[0086] Among them: 100- variable frequency fan / adjustable electric damper; 200- temperature sensor; 300- visual slag quantity monitoring sensor and ash temperature sensor; 400- air flow meter; 500- slag bucket; 600- dry slag discharge unit; 700- acoustic temperature sensor. Specific implementation method:

[0087] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0088] The invention provides a control method, a control system and a device for a cooling system of a dry slagging unit of a coal-fired power plant boiler.

[0089] like Figure 1 As shown, the present invention first provides a method for controlling a cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, and the specific steps are as follows:

[0090] S1: Obtain the real-time operation data of the dry slag discharge unit; the real-time operation data includes the slag discharge temperature T S1 , Ash temperature T of conveyor belt in slag falling section S0 , Ash amount of conveyor belt in slag falling section M S 、The ash thickness of the conveyor belt in the slag falling section h S , fan power P / cooling air door opening D, cooling air volume into the furnace M a , Temperature of cooling air entering the furnace T a1 and cooling air initial temperature T a0 ;

[0091] The real-time operation data may also include boiler load L and dry slag discharger conveyor belt speed v. By applying these real-time operation data for feedforward control, the system response speed is improved and the heat exchange process between cooling air and ash is accelerated.

[0092] S2: The slag temperature T S1 And the cooling air volume M aInput to the feedforward-cascade-feedback control structure for adjustment, and obtain the fan power P / cooling air door opening D instruction; the feedforward control structure is a comprehensive feedforward controller, and the cascade control structure includes an outer loop slag temperature controller (based on the slag temperature T S1 as the regulated quantity) and the inner ring cooling air volume controller (with the fan power P / cooling air door opening D as the regulated quantity);

[0093] Step S2 is as follows Figure 2 As shown, the specific steps include:

[0094] S21: Calculate the comprehensive feedforward control instructions of the fan / cooling damper according to the real-time operation data;

[0095] Step S21 is as follows Figure 3 As shown, including:

[0096] S211: Calculate the integral M1 of the change in the amount of ash on the conveyor belt in the slag falling section within the time τ, and compare M1 with the set threshold value K. If M1≤K, enter the control calculation process S212A; if M1>K, enter the iterative calculation process S212B; due to the low thermal conductivity of ash (<0.2W / m·℃), the heat exchange process between ash and cooling air is highly nonlinear; the main influencing factor of the cooling process is the amount of ash on the conveyor belt. Therefore, when the amount of ash changes too much, it is necessary to recalculate the required total air volume through the mechanism model for feedforward compensation.

[0097] The integral M1 calculation formula of the change value of the ash amount in the conveyor belt of the dry slag discharger in the slag section within the time τ is:

[0098]

[0099] ΔM S =M Sti -M St0

[0100] Where, ΔM S is the change in ash mass at each moment in the τ time period; M St0 M is the amount of ash in the conveyor belt of the dry slag discharger at the initial moment in the τ time period; Sti It is the amount of ash in the conveyor belt of the slag discharge section of the dry slag discharger at the i-th moment within the time period τ.

[0101] Ash temperature T of the conveyor belt in the slag falling section within τ time S0 The calculation formula for the integral M2 of the change is:

[0102]

[0103] ΔT S0 =T S0ti -T S0t0

[0104] Where, ΔT S0 is the change of the initial temperature of the ash at each moment in the τ time period; T S0t0 T is the ash temperature of the conveyor belt in the slag falling section at the initial moment in the τ time period; S0ti It is the ash temperature of the conveyor belt in the slag falling section at the i-th moment in the time period τ.

[0105] S212A: According to the control calculation process, the compensation value F of fan power / cooling air door opening is calculated by M1 and M2. f1 , which is output as the integrated feedforward intermediate signal 1. The calculation formula is as follows:

[0106] F f1 =C·(exp(K1·M1)-1)+(exp(K2·M2)-1)

[0107] Where C is the gain factor, K1 and K2 are proportional coefficients related to the ash thickness and temperature change, respectively, which are obtained based on the experimental fitting parameters.

[0108] S212B: According to the iterative calculation process, the compensation value of the fan power / cooling air door opening is iteratively calculated based on the parameters such as the ash temperature of the slag conveyor belt, the ash amount of the slag conveyor belt, the initial temperature of the cooling air, and the temperature of the cooling air entering the furnace, and is output as the comprehensive feedforward intermediate signal 2. The specific calculation process is as follows:

[0109] S212B1: The current ash temperature T of the conveyor belt of the dry slag discharge machine S0 , Ash thickness of conveyor belt in slag discharge section of dry slag discharger h S , cooling air initial temperature T a0 , Temperature of cooling air entering the furnace T a1 , Cooling air volume into furnace M a , the dry slag conveyor belt speed v parameter is input into the mechanism modeling differential equation group;

[0110] The differential equations for the mechanism modeling can be expressed as:

[0111]

[0112] Where, T Sout To calculate the estimated slag temperature; T a1 The temperature of the cooling air entering the furnace; M is the ash mass flow rate of the conveyor belt of the slag discharge section of the slag discharger at time t; a (t) is the cooling air volume entering the furnace at time t; c g is the specific heat capacity of ash; c a is the specific heat capacity of cooling air; T S0 T is the ash temperature of the conveyor belt of the current dry slag discharge machine;a0 is the initial temperature of cooling air; U is the comprehensive heat transfer coefficient between ash and cooling air, obtained by experimental test; A s is the heat exchange area between ash and cooling air; C g (t) is the total heat capacity of ash in the existing dry slag unit; C a (t) is the total heat capacity of the cooling air in the existing dry slag unit.

[0113] In the formula, C g (t) and C a (t) can be calculated as follows:

[0114]

[0115] C g (t) = ρ g ·W belt ·h S (t)·c g ·L

[0116] C a (t) = M a (t)·c a

[0117] In the formula, ρ g is the ash density; v is the conveyor belt speed of the dry slag discharger; W belt h is the effective width of the conveyor belt of the dry slag discharger; S (t) is the ash thickness of the conveyor belt of the slag discharger at time t; L is the effective length of the conveyor belt of the dry slag discharger.

[0118] S212B2: Use the fourth-order and fifth-order Runge-Kutta numerical calculation method to iteratively solve the differential equations and obtain the estimated slag temperature T Sout ;

[0119] S212B3: Calculate and estimate the slag temperature T Sout and set slag temperature T set The temperature difference A;

[0120] A=T Sout -T set

[0121] S212B4: Determine the absolute value of the temperature difference A and the temperature difference limit N; the temperature difference limit N is set according to the actual control accuracy. In this embodiment, N is 5 degrees Celsius.

[0122] S212B5A: If |A|≤N, calculate the current cooling air output deviation M ae (Initial cooling air volume M a0- Current calculated cooling air volume M ai ), and M ae As the integrated feedforward intermediate signal 2F f2 Output;

[0123] S212B5B: If |A|>N, change the cooling air volume M a Size; if the calculated temperature difference A>N, the cooling air volume is updated to M ai =M ai-1 +ΔM, if the calculated temperature difference A≤N, the cooling air volume is updated to M ai =M ai-1 -ΔM;

[0124] Where M ai is the current calculated cooling air volume, ΔM is the air volume update value, which can be set according to the actual required accuracy; in this embodiment, ΔM is 1% of the current maximum limit cooling air volume of the boiler load;

[0125] S212B6: After the cooling air volume is updated, the updated cooling air volume is input into the differential equation and the differential equation group is iteratively solved, and the above steps are repeated;

[0126] S213: The integrated feedforward intermediate signals 1 and 2 do not appear at the same time at every moment. If the output at this moment is the integrated feedforward intermediate signal 1, the integrated feedforward intermediate signal 1 is first judged; if F f1 ≥0, the integrated feedforward intermediate signal 1 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax (current boiler load maximum limit cooling air volume - current cooling air volume) is compared and the minimum value is taken as the final comprehensive feedforward output signal F f If F f1 <0, then the integrated feedforward intermediate signal 1 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are emin (the minimum cooling air volume of the dry slag discharge unit - the current cooling air volume) is compared and the maximum value is taken as the final comprehensive feedforward output signal F f ; The formula is as follows:

[0127]

[0128] If the output at this time is the integrated feedforward intermediate signal 2, the integrated feedforward intermediate signal 2 is first judged; if F f2 ≥0, the integrated feedforward intermediate signal 2 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax (current boiler load maximum limit cooling air volume - current cooling air volume) is compared and the minimum value is taken as the final comprehensive feedforward output signal F f If F f2<0, then the integrated feedforward intermediate signal 2 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are compared. emin (the minimum cooling air volume of the dry slag discharge unit - the current cooling air volume) is compared and the maximum value is taken as the final comprehensive feedforward output signal F f ; The formula is as follows:

[0129]

[0130] In the formula, F f is the comprehensive feedforward output signal, F f1 and F f2 They are the comprehensive feedforward intermediate signals 1 and 2, the maximum limit cooling air volume deviation of the current boiler load L (the maximum limit cooling air volume of the current boiler load - the current cooling air volume), F emin It is the deviation of the minimum cooling air volume limit for the operation of the dry slag discharge unit (the minimum cooling air volume limit for the operation of the dry slag discharge unit - the current cooling air volume).

[0131] S22: Set the slag discharge temperature to T set and slag temperature T S1 The deviation e S Input to the outer ring slag temperature controller for adjustment, and obtain the output value F of the outer ring slag temperature controller set ; The calculation formula is as follows:

[0132] e S =T set -T S1

[0133]

[0134] In the formula, e S T is the slag temperature setting value set and slag temperature T S1 Deviation, K p1 , K i1 and K d1 They are the PID proportional, integral and differential components of the outer loop slag temperature controller respectively.

[0135] S23: The output value F of the outer ring slag temperature controller set The cooling air volume M a The deviation e a Input to the inner ring cooling air volume controller for adjustment, and obtain the output value G of the inner ring cooling air volume controller a ; The calculation formula is as follows:

[0136] e a =F set -M a

[0137]

[0138] In the formula, e a is the output value F of the outer ring slag temperature controller set The cooling air volume M a Deviation, K p2 , K i2 and K d2 They are the PID proportional, integral and differential components of the inner loop cooling air volume controller respectively.

[0139] The outer ring slag temperature controller and the inner ring cooling air volume controller can both be proportional-integral-differential controller, sliding mode controller, ADRC active disturbance rejection controller, etc.

[0140] In this embodiment, the outer ring slag temperature controller and the inner ring cooling air volume controller are both proportional-integral-differential controllers;

[0141] S24: The integrated feedforward output signal F f The output value G of the inner ring cooling air volume controller a Add them together to get the fan power / cooling air door opening instruction F ff , and its calculation formula is as follows:

[0142] F ff =F f +G a

[0143] In the formula, F f is the comprehensive feedforward output signal, G a is the output value of the inner ring cooling air volume controller, F ff It is the fan power / cooling air door opening instruction.

[0144] S3: According to the fan power / cooling air door opening instruction F ff Automatically control the fan power / cooling damper opening.

[0145] In another specific implementation case, referring to Figure 6 Another technical solution of the present invention relates to a control system for a cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, specifically comprising:

[0146] The real-time operation data acquisition module 1 is used to obtain the real-time operation data of the dry slag discharge unit; the real-time operation data includes the slag discharge temperature T S1 , Ash temperature T of conveyor belt in slag falling section S0 , Ash amount of conveyor belt in slag falling section M S 、The ash thickness of the conveyor belt in the slag falling section h S , fan power P / cooling air door opening D, cooling air volume into the furnace M a , Temperature of cooling air entering the furnace Ta1 and cooling air initial temperature T a0 Specifically, the real-time operation data also includes the boiler load L and the dry slag discharger conveyor belt speed v. By applying these real-time operation data for feedforward control, the system response speed is improved and the heat exchange process between the cooling air and the ash is accelerated.

[0147] The cooling air command generation module 2 is used to input the slag discharge temperature and the cooling air volume into the furnace into the feedforward-cascade-feedback control structure for adjustment, and obtain the fan power / cooling air door opening instruction; the feedforward control structure is a comprehensive feedforward controller, and the cascade control structure includes an outer loop slag temperature controller (with the slag discharge temperature as the adjustment variable) and an inner loop cooling air volume controller (with the fan power / cooling air door opening as the adjusted variable);

[0148] In one embodiment, the cooling wind command generation module 2 is as follows: Figure 7 As shown, including:

[0149] The integrated feedforward controller module 21 is used to calculate the feedforward control instruction according to the real-time operation data of the dry slag discharge unit acquired by the real-time operation data acquisition module 1;

[0150] In one embodiment, the integrated feedforward controller module 21 is as follows Figure 8 As shown, including:

[0151] The slag amount change judgment module 211 calculates the integral M1 of the change in the slag amount of the conveyor belt in the slag falling section within the time τ, and compares M1 with the set threshold value K. If M1≤K, it enters the control calculation process S212A; if M1>K, it enters the iterative calculation process S212B; due to the low thermal conductivity of slag (<0.2W / m·℃), the heat exchange process between slag and cooling air is highly nonlinear; the main influencing factor of the cooling process is the amount of slag on the conveyor belt. Therefore, when the slag amount changes too much, it is necessary to recalculate the required total air volume through the mechanism model for feedforward compensation.

[0152] The integral M1 calculation formula of the change value of the ash amount in the conveyor belt of the dry slag discharger in the slag section within the time τ is:

[0153]

[0154] ΔM S =M Sti -M St0

[0155] Where, ΔM S is the change in ash mass at each moment in the τ time period; M St0 M is the amount of ash in the conveyor belt of the dry slag discharger at the initial moment in the τ time period; StiIt is the amount of ash in the conveyor belt of the slag discharge section of the dry slag discharger at the i-th moment within the time period τ.

[0156] A comprehensive feedforward intermediate signal generating module 212, including a control calculation process module 212A and an iterative calculation process module 212B;

[0157] In one embodiment, the control calculation process module 212A is based on the integral M1 of the change in the slag amount of the slag conveyor belt at time τ and the slag temperature T of the slag conveyor belt at time τ. S0 The integral of the change M2 is used to calculate the compensation value F of the fan power / cooling damper opening. f , as the comprehensive feedforward intermediate signal 1 output. The ash temperature T of the conveyor belt in the slag falling section at time τ S0 The calculation formula for the integral M2 of the change is as follows:

[0158]

[0159] ΔT S0 =T S0ti -T S0t0

[0160] In the formula, ΔT S0 is the change of the initial temperature of the ash at each moment in the τ time period; T S0t0 T is the ash temperature of the conveyor belt in the slag falling section at the initial moment in the τ time period; S0ti It is the ash temperature of the conveyor belt in the slag falling section at the i-th moment in the time period τ.

[0161] The compensation value F of fan power / cooling air door opening is calculated by M1 and M2. f1 The calculation formula is as follows:

[0162] F f1 =C·(exp(K1·M1)-1)+(exp(K2·M2)-1)

[0163] In the formula, C is the gain factor, K1 and K2 are proportional coefficients related to the ash thickness and temperature change, respectively, which need to be obtained based on experimental fitting parameters.

[0164] In one embodiment, the iterative calculation process module 212B iteratively calculates the compensation value of the fan power / cooling air door opening based on parameters such as the ash temperature of the slag conveyor belt in the slag falling section, the ash thickness of the slag conveyor belt in the slag falling section, the initial temperature of the cooling air, and the temperature of the cooling air entering the furnace, and outputs it as the comprehensive feedforward intermediate signal 2.

[0165] In one embodiment, the specific calculation process of the iterative calculation process module 212B is as follows:

[0166] Input the current dry slag machine conveyor belt ash temperature, dry slag machine conveyor belt ash volume, cooling air initial temperature, furnace cooling air temperature, furnace cooling air volume, dry slag machine conveyor belt speed parameters into the mechanism modeling differential equation group;

[0167] In one embodiment, the differential equations for mechanism modeling can be expressed as:

[0168]

[0169] Where, T Sout To calculate the estimated slag temperature; T a1 The temperature of the cooling air entering the furnace; M is the ash mass flow rate of the conveyor belt of the slag discharge section of the slag discharger at time t; a (t) is the cooling air volume entering the furnace at time t; c g is the specific heat capacity of ash; c a is the specific heat capacity of cooling air; T S0 T is the ash temperature of the conveyor belt of the current dry slag discharge machine; a0 is the initial temperature of cooling air; U is the comprehensive heat transfer coefficient between ash and cooling air, obtained by experimental test; A s is the heat exchange area between ash and cooling air; C g (t) is the total heat capacity of ash in the existing dry slag unit; C a (t) is the total heat capacity of the cooling air in the existing dry slag unit.

[0170] In the formula, C g (t) and C a (t) can be calculated as follows:

[0171]

[0172] C g (t) = ρ g ·W belt ·h S (t)·c g ·L

[0173] C a (t) = M a (t)·c a

[0174] In the formula, ρ g is the ash density; v is the conveyor belt speed of the dry slag discharger; W belt h is the effective width of the conveyor belt of the dry slag discharger; S (t) is the ash thickness of the conveyor belt of the slag discharger at time t; L is the effective length of the conveyor belt of the dry slag discharger.

[0175] The fourth-order and fifth-order Runge-Kutta numerical calculation method is used to iteratively solve the differential equations to obtain the estimated slag temperature T Sout ;

[0176] Calculate and estimate the slag temperature T Sout and set slag temperature T Sset The temperature difference A;

[0177] The absolute value of the temperature difference A and the temperature difference limit N are determined; the temperature difference limit N is set according to the actual control accuracy. In this embodiment, N is 5 degrees Celsius.

[0178] If |A|≤N, calculate the current cooling air output deviation M ae (Initial cooling air volume M a0 - Current calculated cooling air volume M ai ), and M ae As the integrated feedforward intermediate signal 2F f2 Output;

[0179] If |A|>N, change the cooling air volume M a Size; if the calculated temperature difference A>N, the cooling air volume is updated to M ai =M ai-1 +ΔM, if the calculated temperature difference A≤N, the cooling air volume is updated to M ai =M ai-1 -ΔM;

[0180] Where M ai is the current calculated cooling air volume, ΔM is the air volume update value, and ΔM can be set according to the actual required accuracy; in this embodiment, ΔM is 1% of the current maximum limit cooling air volume of the boiler load;

[0181] After the cooling air volume is updated, the updated cooling air volume is input into the differential equation and the differential equation group is iteratively solved, and the above steps are repeated;

[0182] The feedforward limit output module 213 makes a judgment based on the output signal of the integrated feedforward intermediate signal generation module 212; the integrated feedforward intermediate signals 1 and 2 do not appear at the same time at every moment. If the output at this time is the integrated feedforward intermediate signal 1, the integrated feedforward intermediate signal 1 is first judged; if F f1 ≥0, the integrated feedforward intermediate signal 1 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax (current boiler load maximum limit cooling air volume - current cooling air volume) is compared and the minimum value is taken as the final comprehensive feedforward output signal F f If F f1<0, then the integrated feedforward intermediate signal 1 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are emin (the minimum cooling air volume of the dry slag discharge unit - the current cooling air volume) is compared and the maximum value is taken as the final comprehensive feedforward output signal F f ; The specific formula is as follows:

[0183]

[0184] If the output at this time is the integrated feedforward intermediate signal 2, the integrated feedforward intermediate signal 2 is first judged; if F f2 ≥0, the integrated feedforward intermediate signal 2 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax (current boiler load maximum limit cooling air volume - current cooling air volume) is compared and the minimum value is taken as the final comprehensive feedforward output signal F f If F f2 <0, then the integrated feedforward intermediate signal 2 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are compared. emin (the minimum cooling air volume of the dry slag discharge unit - the current cooling air volume) is compared and the maximum value is taken as the final comprehensive feedforward output signal F f ; The specific formula is as follows:

[0185]

[0186] In the formula, F f is the comprehensive feedforward output signal, F f1 and F f2 They are the comprehensive feedforward intermediate signals 1 and 2, the maximum limit cooling air volume deviation of the current boiler load L (the maximum limit cooling air volume of the current boiler load - the current cooling air volume), F emin It is the deviation of the minimum cooling air volume limit for the operation of the dry slag discharge unit (the minimum cooling air volume limit for the operation of the dry slag discharge unit - the current cooling air volume).

[0187] The outer loop control command module 22 is used to set the slag temperature setting value T set and slag temperature T S1 The deviation e S Input to the outer ring slag temperature controller for adjustment, and obtain the output value F of the outer ring slag temperature controller set ; The calculation formula is as follows:

[0188] e S =T set -T S1

[0189]

[0190] In the formula, e ST is the slag temperature setting value set and slag temperature T S1 Deviation, K p1 , K i1 and K d1 They are the PID proportional, integral and differential components of the outer loop slag temperature controller respectively.

[0191] The inner loop control command module 23 is used to convert the output value F of the outer loop slag temperature controller set The cooling air volume M a The deviation e a Input to the inner ring cooling air volume controller for adjustment, and obtain the output value G of the inner ring cooling air volume controller a ; The calculation formula is as follows:

[0192] e a =F set -M a

[0193]

[0194] In the formula, e a is the output value F of the outer ring slag temperature controller set The cooling air volume M a Deviation, K p2 , K i2 and K d2 They are the PID proportional, integral and differential components of the inner loop cooling air volume controller respectively.

[0195] The outer ring slag temperature controller and the inner ring cooling air volume controller can both be a proportional-integral-differential controller, a sliding mode controller, an ADRC active disturbance rejection controller, etc.;

[0196] In one embodiment, the outer ring slag temperature controller and the inner ring cooling air volume controller are both proportional-integral-differential controllers;

[0197] The command summing output module 24 is used to convert the comprehensive feedforward output signal F f The output value G of the inner ring cooling air volume controller a Add them together to get the fan power / cooling air door opening instruction F ff , and its calculation formula is as follows:

[0198] F ff =F f +G a

[0199] In the formula, F f is the comprehensive feedforward output signal, G a is the output value of the inner ring cooling air volume controller, F ffIt is the fan power / cooling air door opening instruction.

[0200] Cooling air volume control module 3, used to convert fan power / cooling air door opening instruction F ff Automatically control the fan power / cooling damper opening.

[0201] It should be noted that the various units involved in the control system of the cooling air system of the dry slag discharge unit of a coal-fired power plant boiler described in the present invention can be implemented in whole or in part by software, hardware or a combination thereof. These units can be integrated into or independent of the central processing unit in the electronic device as hardware, or can be stored as software on a storage medium in the electronic device so that the central processing unit can access and execute corresponding functions.

[0202] The present invention also provides a device for a cooling air system of a dry slagging unit of a coal-fired power plant boiler;

[0203] like Fig. 9 As shown, the cooling air doors on both sides of the dry slag discharge unit 600 shell are all sealed and blocked, and a variable frequency fan / adjustable electric air door 100 is installed at the head of the dry slag discharge unit to adjust the cooling air volume entering the dry slag discharge unit 600; the variable frequency fan / adjustable electric air door 100 is connected to the cooling air volume control module to receive the fan power / cooling air door opening instruction; a temperature sensor 2 is installed on the slag outlet of the dry slag discharge machine head and the dry slag discharge machine conveyor belt shell near the boiler slag bucket 500. 00, 300, used to monitor the real-time temperature of the ash outlet and the real-time temperature of the ash at the slag drop point; a visual slag amount monitoring sensor 300 is installed on the outer shell of the dry slag discharger conveyor belt near the boiler slag hopper to monitor the slag thickness and slag amount changes on the conveyor belt; at the same time as the boiler slag hopper, two acoustic temperature sensors 700 are installed on the water-cooled wall of the boiler slag hopper 500 to monitor the temperature of the cooling air entering the furnace; an air flow meter 400 is installed at the lower section to monitor the air volume entering the boiler.

[0204] The present invention also provides an electronic device 800, including a storage device 810, a central processing unit 820, a communication module 830, a display 840, a power supply 850, and a bus 860;

[0205] In an optional specific embodiment, refer to Fig.10 The electronic device 800 includes: a storage device 810, a central processing unit 820, a communication module 830, a display 840, a power supply 850, and a bus 860. It should be emphasized that the electronic device 800 does not necessarily include Fig.10 All components shown; similarly, the electronic device 800 may also include Fig.10 Other components not shown may be based on existing technologies.

[0206] The storage device 810 may be a read-only memory (ROM) or other non-volatile storage device for storing static data and instructions, and a random access memory (RAM) or other volatile storage device for storing data and instructions. In addition, the storage medium may also be an electrically erasable read-only memory (EEPROM), a compact disc-read-only memory (CD-ROM), or other types of optical optical disc storage media, including but not limited to compact discs, laser discs, digital versatile discs, Blu-ray discs, etc., as well as magnetic disk storage media or other magnetic data storage devices. Or multiple combinations of the above suitable storage devices.

[0207] The central processing unit 820 may be a central processing unit (CPU), a general processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. The processing unit can implement or execute various exemplary logic processes and modules described in the present invention. The central processing unit 820 may also be an integrated implementation of computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0208] The storage device 810 is used to store the application code required to implement the solution of the present invention, and is executed under the control of the central processing unit 820. The central processing unit 820 is responsible for running the application code stored in the storage unit 810.

[0209] The communication module 830 has the functions of sending input signals and receiving output signals, which is the same as a conventional mobile communication terminal.

[0210] The display 840 is used to display objects such as graphic information, and the display can be an LCD display, an ink screen display, etc. but is not limited thereto.

[0211] The power supply 850 is used to provide power to the electronic device 800 .

[0212] The bus 860 is used to connect the storage device 810, the central processing unit 820, the communication module 830, the display 840, and the power supply 850; the bus 860 can be divided into an address bus, a data bus, a control bus, a power bus, etc. For convenience of representation, Fig.10 The fact that only one line is used in the diagram does not mean that there is only one bus or only one type of bus.

[0213] The present invention also provides a computer software product, which includes a series of computer instructions. When these instructions are executed on a central processing unit, each step of the above control method can be completed.

[0214] The present invention also provides a computer-readable storage medium, which stores a software program that can be executed by a computer to implement the above control method.

Claims

1. A method for controlling the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, characterized in that: include: S1: Obtain the real-time operation data of the dry slag discharge unit; the real-time operation data includes the slag discharge temperature T S1 , Ash temperature T of conveyor belt in slag falling section S0 , Ash amount of conveyor belt in slag falling section M S 、The ash thickness of the conveyor belt in the slag falling section h S , fan power P / cooling air door opening D, cooling air volume into the furnace M a , Temperature of cooling air entering the furnace T a1 and cooling air initial temperature T a0 ; S2: Obtain the fan power / cooling air door opening instruction F according to the real-time operation data of the dry slag discharge unit ff ; S3: According to the fan power / cooling air door opening instruction F ff Automatically control the fan power / cooling damper opening.

2. The method for controlling the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler according to claim 1, characterized in that: Step S2 includes: S21: Calculate the comprehensive feedforward control instruction F of the fan / cooling damper based on the real-time operation data f ; S22: Set the slag temperature to T set and slag temperature T S1 The deviation e S , input to the outer ring slag temperature controller for adjustment, and obtain the output value F of the outer ring slag temperature controller set ; S23: The output value F of the outer ring slag temperature controller set The cooling air volume M a The deviation e a , input to the inner ring cooling air volume controller for adjustment, and obtain the output value G of the inner ring cooling air volume controller a ; S24: The integrated feedforward output signal F f The output value G of the inner ring cooling air volume controller a Add them together to get the fan power / cooling air door opening instruction F ff .

3. The method for controlling the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler according to claim 2, characterized in that: Step S21 includes: S211: Calculate the integral M1 of the change in the amount of ash in the conveyor belt of the slag falling section within the time τ, and compare M1 with the set threshold value K; if M1≤K, enter the control calculation process S212A; if M1>K, enter the iterative calculation process S212B; The integral M1 calculation formula for calculating the change value of the ash amount in the conveyor belt of the dry slag discharge machine within the time τ is: M1=∫0 τ ΔM S dt ΔM S =M Sti -M St0 In the formula, ΔM S is the change in ash mass at each moment in the τ time period; M St0 M is the amount of ash in the conveyor belt of the dry slag discharger at the initial moment in the τ time period; Sti is the amount of ash in the conveyor belt of the dry slag discharger at the i-th moment within the τ time period; Calculate the ash temperature T of the conveyor belt in the slag falling section within time τ S0 The integral of the change M2,M is calculated as: M2=∫0 τ ΔT S0 dt ΔT S0 =T S0ti -T S0t0 Where, ΔT S0 is the change of the initial temperature of the ash at each moment in the τ time period; T S0t0 T is the ash temperature of the conveyor belt in the slag falling section at the initial moment in the τ time period; S0ti is the ash temperature of the conveyor belt in the slag falling section at the i-th moment within the τ time period; S212A: According to the control calculation process, the compensation value F of fan power / cooling air door opening is calculated by M1 and M2. f1 , as the integrated feedforward intermediate signal 1 output; compensation value F f1 The calculation formula is as follows: F f1 =C·(exp(K1·M1)-1)+(exp(K2·M2)-1) In the formula, C is the gain factor, K1 and K2 are proportional coefficients related to the ash thickness and temperature change, respectively, which are obtained according to the experimental fitting parameters; S212B: According to the iterative calculation process, the compensation value F of the fan power / cooling air door opening is iteratively calculated based on the parameters such as the ash temperature of the conveyor belt in the slag falling section, the ash amount of the conveyor belt in the slag falling section, the initial temperature of the cooling air, and the temperature of the cooling air entering the furnace. f2 , as the integrated feedforward intermediate signal 2 output; compensation value F f2 The specific calculation process is as follows: S212B1: The current ash temperature T of the conveyor belt of the dry slag discharge machine S0 , Ash thickness of conveyor belt in slag discharge section of dry slag discharger h S , cooling air initial temperature T a0 , Temperature of cooling air entering the furnace T a1 , Cooling air volume into furnace M a , the dry slag conveyor belt speed v parameter is input into the mechanism modeling differential equation group; The differential equations for the mechanism modeling are expressed as: Where, T Sout To calculate the estimated slag temperature; T a1 The temperature of the cooling air entering the furnace; M is the ash mass flow rate of the conveyor belt of the slag discharge section of the slag discharger at time t; a (t) is the cooling air volume entering the furnace at time t; c g is the specific heat capacity of ash; c a is the specific heat capacity of cooling air; T S0 T is the ash temperature of the conveyor belt of the current dry slag discharge machine; a0 is the initial temperature of cooling air; U is the comprehensive heat transfer coefficient between ash and cooling air, obtained by experimental test; A s is the heat exchange area between ash and cooling air; C g (t) is the total heat capacity of ash in the existing dry slag unit; C a (t) is the total heat capacity of the cooling air in the existing dry slag unit; In the formula, C g (t) and C a (t) are calculated as follows: C g (t)=ρ g ·W belt ·h S (t)·c g ·L C a (t)=M a (t)·c a In the formula, ρ g is the ash density; v is the conveyor belt speed of the dry slag discharger; W belt h is the effective width of the conveyor belt of the dry slag discharger; S (t) is the ash thickness of the conveyor belt of the slag discharger at time t; L is the effective length of the conveyor belt of the dry slag discharger; S212B2: Use the fourth-order and fifth-order Runge-Kutta numerical calculation method to iteratively solve the differential equations and obtain the estimated slag temperature T Sout ; S212B3: Calculate and estimate the slag temperature T Sout and set slag tapping temperature T set The temperature difference A; A=T Sout -T set S212B4: Determine the absolute value of the temperature difference A and the temperature difference limit N; the temperature difference limit N is set according to the actual control accuracy; S212B5A: If |A|≤N, calculate the current cooling air output deviation M ae , and M ae As the integrated feedforward intermediate signal 2F f2 Output: M ae =M a0 -M ai ; S212B5B: If |A|>N, change the cooling air volume M a Size; if the calculated temperature difference A>N, the cooling air volume is updated to M ai =M ai-1 +ΔM, if the calculated temperature difference A≤N, the cooling air volume is updated to M ai =M ai-1 -ΔM; Where M ai is the current calculated cooling air volume, ΔM is the air volume update value, which is set according to the actual required accuracy; S212B6: After the cooling air volume is updated, the updated cooling air volume is input into the differential equation and the differential equation group is iteratively solved, and the above steps are repeated; S213: The integrated feedforward intermediate signals 1 and 2 do not appear at the same time at every moment. If the output at this moment is the integrated feedforward intermediate signal 1, the integrated feedforward intermediate signal 1 is first judged; if F f1 ≥0, the integrated feedforward intermediate signal 1 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax Compare and take the minimum value as the final comprehensive feedforward output signal F f If F f1 <0, then the integrated feedforward intermediate signal 1 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are emin Compare and take the maximum value as the final comprehensive feedforward output signal F f ; The formula is as follows: If the output at this time is the integrated feedforward intermediate signal 2, the integrated feedforward intermediate signal 2 is first judged; if F f2 ≥0, the integrated feedforward intermediate signal 2 and the cooling air volume deviation F of the current boiler load maximum limit are calculated. emax Compare and take the minimum value as the final comprehensive feedforward output signal F f If F f2 <0, then the integrated feedforward intermediate signal 2 and the minimum limit cooling air volume deviation F of the dry slag discharge unit are compared. emin Compare and take the maximum value as the final comprehensive feedforward output signal F f ; The formula is as follows: In the formula, F f is the comprehensive feedforward output signal, F f1 and F f2 They are the integrated feedforward intermediate signals 1, 2, and F emax is the maximum limit cooling air volume deviation of the current boiler load L, F emin It is the minimum limit cooling air volume deviation for the operation of dry slag discharge unit.

4. The method for controlling the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler according to claim 2, characterized in that ,,The maximum limit cooling air volume deviation F of the current boiler load L emax = Current boiler load maximum limit cooling air volume - current cooling air volume, dry slag unit operation minimum limit cooling air volume deviation F emin = Minimum cooling air volume for dry slag discharge unit operation - current cooling air volume.

5. The method for controlling the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler according to claim 2, characterized in that: In step S22, the output value F of the outer ring slag temperature controller is obtained. set for; In the formula, e S T is the slag temperature setting value set and slag temperature T S1 The deviation, e S =T set -T S1 ; K p1 , K i1 and K d1 They are the PID proportional, integral and differential components of the outer loop slag temperature controller respectively.

6. The method for controlling the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler according to claim 2, characterized in that: In step S23, the output value G of the inner ring cooling air volume controller is obtained. a for: In the formula, e a is the output value F of the outer ring slag temperature controller set The cooling air volume M a The deviation e a =F set -M a ; K p2 , K i2 and K d2 They are the PID proportional, integral and differential components of the inner loop cooling air volume controller respectively.

7. A control system for the cooling air system of a dry slag discharge unit of a coal-fired power plant boiler, characterized in that: include: The real-time operation data collection module is used to obtain the real-time operation data of the dry slag discharge unit; The cooling air command generation module adopts a feedforward-cascade-feedback control structure, which includes a feedforward control structure, a cascade control structure and a feedback control structure. The feedforward control structure is a comprehensive feedforward controller. The cascade control structure includes an outer-loop slag temperature controller with the slag discharge temperature as the adjustment variable and an inner-loop cooling air volume controller with the fan power / cooling air door opening as the adjustment variable. The feedforward-cascade-feedback control structure obtains the fan power / cooling air door opening instruction F according to the real-time operation data of the dry slag discharge unit. ff ; Cooling air volume control module, used to convert fan power / cooling air door opening instruction F ff Automatically control the fan power / cooling damper opening.

8. A control system for cooling air system of dry slagging unit of coal-fired power plant boiler according to claim 7, characterized in that: The cooling air command generation module includes: A comprehensive feedforward controller module, used for calculating feedforward control instructions according to the real-time operation data of the dry slag discharge unit acquired by the real-time operation data acquisition module; The outer loop control command module is used to set the slag temperature setting value T set and slag temperature T S1 The deviation e S Input to the outer ring slag temperature controller for adjustment, and obtain the output value F of the outer ring slag temperature controller set ; The inner loop control command module is used to convert the output value F of the outer loop slag temperature controller set The cooling air volume M a The deviation e a Input to the inner ring cooling air volume controller for adjustment, and obtain the output value G of the inner ring cooling air volume controller a ; The command summing output module is used to convert the comprehensive feedforward output signal F f The output value G of the inner ring cooling air volume controller a Add them together to get the fan power / cooling air door opening instruction F ff .

9. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the cooling air system control method for a dry slag discharge unit of a coal-fired power plant boiler as described in any one of claims 1-7.

10. A storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the cooling air system control method of a dry slag discharge unit of a coal-fired power plant boiler as described in any one of claims 1 to 7 is implemented.

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