阅读说明：本技术 四喷嘴水煤浆气化炉控制系统以及控制方法 (Control system and control method for four-nozzle coal water slurry gasification furnace ) 是由 周琨 张成学 周雪花 徐瑞哲 于 2019-12-17 设计创作，主要内容包括：本发明提供一种四喷嘴水煤浆气化炉控制系统以及控制方法,四喷嘴水煤浆气化炉控制系统包括：称重给料机系统、磨煤机、第一煤浆储槽、低压煤浆泵、第二煤浆储槽、高压煤浆泵、气化炉和DCS系统；称重给料机系统包括称重给料机、下料口、给料机电机和给料机转速探头；称重给料机的进料端上方安装下料口。本发明提供的四喷嘴水煤浆气化炉控制系统,能够全面对煤浆浓度、气化炉氧气和煤浆的配比进行调节,从而实现水煤浆气化炉的自动化控制,提高水煤浆气化效率,使水煤浆安全稳定调节,降低煤耗,使得产量最大化。(The invention provides a control system and a control method for a four-nozzle coal water slurry gasification furnace, wherein the control system for the four-nozzle coal water slurry gasification furnace comprises the following components: the system comprises a weighing feeder system, a coal mill, a first coal slurry storage tank, a low-pressure coal slurry pump, a second coal slurry storage tank, a high-pressure coal slurry pump, a gasification furnace and a DCS; the weighing feeder system comprises a weighing feeder, a feed opening, a feeder motor and a feeder rotating speed probe; and a feed opening is arranged above the feed end of the weighing feeder. The control system of the four-nozzle coal water slurry gasification furnace provided by the invention can adjust the coal slurry concentration and the proportion of the gasification furnace oxygen and the coal slurry, thereby realizing the automatic control of the coal water slurry gasification furnace, improving the coal water slurry gasification efficiency, ensuring the safe and stable adjustment of the coal water slurry, reducing the coal consumption and maximizing the yield.)

1. The utility model provides a four nozzle coal slurry gasification stove control system which characterized in that includes: the system comprises a weighing feeder system (1), a coal mill (2), a first coal slurry storage tank (3), a low-pressure coal slurry pump (4), a second coal slurry storage tank (5), a high-pressure coal slurry pump (6), a gasification furnace (7) and a DCS system;

the weighing feeder system (1) comprises a weighing feeder (1-1), a feed opening (1-2), a feeder motor (1-3) and a feeder rotating speed probe (1-4); the feed opening (1-2) is arranged above the feed end of the weighing feeder (1-1);

the feed end of the coal mill (2) is communicated with a process water pipeline and an additive pipeline; wherein the process water pipeline is provided with a process water flow meter (2-1) and a process water regulating valve (2-2); the additive pipeline is provided with an additive flow meter (2-3) and an additive regulating valve (2-4); the process water pipeline is communicated with the discharge end of the weighing feeder (1-1) through a coal feeding pipeline (1-5);

the feeding end of the first coal slurry storage tank (3) is communicated with the discharging end of the coal mill (2) through a pipeline;

the feed end of the low-pressure coal slurry pump (4) is communicated with the first coal slurry storage tank (3); the discharge end of the low-pressure coal slurry pump (4) is communicated with the discharge end of the second coal slurry storage tank (5) through a first coal slurry conveying pipeline (G1); wherein a slurry concentration meter (8) is installed on the first slurry transport line (G1);

the gasification furnace (7) is provided with four opposite nozzles which are positioned on the same horizontal plane;

the feed end of the high-pressure coal slurry pump (6) is communicated with the second coal slurry storage tank (5); the discharge end of the high-pressure coal slurry pump (6) is respectively communicated with the outer ring feed inlet of each nozzle of the gasification furnace (7) through a second coal slurry conveying pipeline (G2); each nozzle of the gasification furnace (7) is also communicated with a central oxygen pipeline and a main oxygen pipeline; wherein the central oxygen pipeline is provided with a central oxygen flow meter (7-1) and a central oxygen flow regulating valve (7-2); the main oxygen pipeline is provided with a main oxygen flow meter (7-3) and a main oxygen flow regulating valve (7-4); a high-temperature thermocouple (7-5) is arranged on the inner furnace wall of the gasification furnace (7);

the input end of the DCS is respectively connected with the feeder rotating speed probe (1-4), the process water flow meter (2-1), the additive flow meter (2-3), the coal slurry concentration meter (8), the central oxygen flow meter (7-1), the main oxygen flow meter (7-3) and the high-temperature thermocouple (7-5);

the output end of the DCS is respectively connected with the feeder motor (1-3), the process water regulating valve (2-2), the additive regulating valve (2-4), the central oxygen flow regulating valve (7-2) and the main oxygen flow regulating valve (7-4).

2. The control system of the four-nozzle coal-water slurry gasification furnace according to claim 1, wherein the feeder rotating speed probe (1-4) adopts a coaxial speed sensor.

3. The control system of the four-nozzle coal-water slurry gasifier according to claim 2, wherein the speed sensor employs a carbon-free brush type ac pulser.

4. The control system of the four-nozzle coal-water slurry gasification furnace according to claim 2, wherein the process water flow meter (2-1) and the additive flow meter (2-3) adopt electromagnetic flow meters.

5. The control method of the control system of the four-nozzle coal-water slurry gasification furnace of any one of claims 1 to 4, characterized by comprising the following steps:

step 1, the coal water slurry gasification process comprises the following steps:

step 1.1, weighing raw material coal by a weighing feeder system (1), and mixing the raw material coal with process water conveyed by a process water pipeline and an additive conveyed by an additive pipeline to obtain mixed coal liquid;

step 1.2, conveying the mixed coal liquid to a coal mill (2), and grinding by the coal mill (2) to obtain first coal slurry;

step 1.3, the first coal slurry is sent to a second coal slurry storage tank (5) through a low-pressure coal slurry pump (4) to be stored;

step 1.4, pressurizing the coal water slurry stored in the second coal slurry storage tank (5) to 7.88MPa by a high-pressure coal slurry pump (6), and then, calculating according to the oxygen-coal ratio, and entering an outer ring channel of each process burner of the gasification furnace (7);

pure oxygen conveyed by the air separation device is divided into four paths by a stop valve, each path of pure oxygen is divided into two branches, the first branch is central oxygen, and the second branch is main oxygen; the central oxygen enters a central channel of the process burner after passing through a central oxygen flow meter (7-1) and a central oxygen flow regulating valve (7-2); the main oxygen enters an outer ring channel of the process burner after passing through a main oxygen flow meter (7-3) and a main oxygen flow regulating valve (7-4);

the pressurized coal water slurry, central oxygen and main oxygen enter a gasification furnace through four process burners symmetrically arranged on the same horizontal plane in a coaxial jet manner, and the gasification reaction conditions are 6.5MPa and 1350 ℃; detecting the inner wall temperature of the gasifier by a high temperature thermocouple (7-5) to generate a crude synthesis gas with the component of CO₂、H₂、CO、CH₄And a water vapor mixture, wherein the unconverted components in the coal water slurry and the coal ash form ash;

step 2, the coal water slurry gasification control process comprises two parts of automatic control of coal slurry concentration and gasification process control of a gasification furnace;

step 2.1, in the coal water slurry gasification process of the step 1, a feeder rotating speed probe (1-4) measures the real-time rotating speed of a feeder in real time, a process water flowmeter (2-1) measures the real-time flow of process water in real time, an additive flowmeter (2-3) measures the real-time flow of an additive in real time, a coal slurry concentration meter (8) measures the real-time flow of coal slurry in real time, a central oxygen flowmeter (7-1) measures the real-time flow of central oxygen in real time, a main oxygen flowmeter (7-3) measures the real-time flow of main oxygen in real time, and a high-temperature thermocouple (7-5) measures the real-time temperature;

step 2.2, transmitting the real-time rotating speed of the feeder, the real-time flow of the process water, the real-time flow of the additive, the real-time flow of the coal slurry, the real-time flow of the central oxygen, the real-time flow of the main oxygen and the real-time temperature of the inner wall of the gasification furnace to an APC system through a DCS system in real time;

step 2.3, pre-establishing a regulation mathematical model by the APC system, and obtaining optimal control values of the rotating speed of a feeder motor (1-3), the process water supply flow, the additive supply flow, the central oxygen supply flow and the main oxygen supply flow through the regulation mathematical model; then respectively controlling the rotating speed of a feeder motor (1-3), a process water regulating valve (2-2), an additive regulating valve (2-4), a central oxygen flow regulating valve (7-2) and a main oxygen flow regulating valve (7-4) through optimal control values, so that the four-nozzle coal water slurry gasification furnace device automatically, safely and stably operates;

the step 2.3 specifically comprises the following steps:

step 2.3.1, pre-establishing a control model:

wherein:

y(s) is the control variable MV;

u(s) is the controlled variable CV;

k is a gain coefficient and represents the condition of the response speed between the controlled variable and the controlled variable;

τ_n、τ₁、τ₂respectively a first time coefficient, a second time coefficient and a third time coefficient which are required by the control model to reach the steady state of the controlled variable when the control variable changes;

d is a time coefficient required by the controlled variable to respond to the controlled variable;

s is a time variable;

step 2.3.2, respectively obtaining k and tau corresponding to different control variables and controlled variables by adopting a step test method_n、τ₁、τ₂And the value of d; thereby obtaining a specific control variable and a control model corresponding to the specific controlled variable;

the method specifically comprises the following steps:

the coal slurry preparation APC controller variable and control relationship comprises:

step 2.3.2.1, the mathematical model for adjusting the concentration of the coal water slurry by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₁(s) is the coal water slurry concentration;

y₁(s) A coal feeding amount set value is set for the weighing feeder;

step 2.3.2.2, the mathematical model for adjusting the concentration of the coal water slurry by the set value of the water supply quantity of the process water is as follows:

wherein:

u₁(s) is the coal water slurry concentration;

y₂(s) is a set value of the water supply quantity of the process water;

step 2.3.2.3, the mathematical model for adjusting the coal slurry tank liquid level by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₂(s) is the liquid level of the coal slurry tank;

y₁(s) is a coal feeding amount set value of the weighing feeder;

step 2.3.2.4, the mathematical model for adjusting the slurry tank liquid level by the process water feed amount set value is as follows:

wherein:

u₂(s) is the liquid level of the coal slurry tank;

y₂(s) is a set value of the water supply quantity of the process water;

step 2.3.2.5, the mathematical model for adjusting the instantaneous coal feeding amount of the weighing feeder by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₃(s) the instantaneous coal feeding amount of the weighing feeder;

y₁(s) feeding for weighingA machine coal feeding amount set value;

step 2.3.2.6, the mathematical model for adjusting the instantaneous water supply of the process water by the set value of the water supply of the process water is as follows:

wherein:

u₄(s) is the instantaneous feed rate of the process water;

y₂(s) is a set value of the water supply quantity of the process water;

the gasifier APC controller variables and control relationships include:

the gasification furnace is provided with four high-temperature thermocouples which are respectively a first high-temperature thermocouple, a second high-temperature thermocouple, a third high-temperature thermocouple and a fourth high-temperature thermocouple; the first high-temperature thermocouple is used for measuring the temperature of the vault of the gasification furnace; the second high-temperature thermocouple is used for measuring the temperature of the burner chamber of the gasification furnace; the third high-temperature thermocouple is used for measuring the temperature of the lower part of the gasification furnace; the fourth high-temperature thermocouple is used for measuring the temperature of the bottom of the gasification furnace;

the gasification furnace is provided with four burners, namely a burner A, a burner B, a burner C and a burner D; the four burners are arranged at the same horizontal position at the upper part of the gasification furnace in an opposed manner at an included angle of 90 degrees, wherein the burner A is arranged opposite to the burner B, the burner C is arranged opposite to the burner D, the burner A, the burner D, the burner B and the burner C are arranged clockwise, and each burner is connected with a coal slurry branch pipe, a main oxygen branch pipe and a central oxygen branch pipe;

step 2.3.2.7, the mathematical model for adjusting the methane content of the raw gas by the main oxygen flow set values of the four burners is as follows:

wherein:

u₅(s) is the methane content of the raw gas;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.8, the mathematical model for adjusting the carbon dioxide content of the raw gas by the main oxygen flow set values of the four burners is as follows:

wherein:

u₆(s) is the carbon dioxide content of the raw gas;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.9, the mathematical model for adjusting the temperature of the vault of the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₇(s) is the temperature of the vault of the gasifier;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.10, the mathematical model for adjusting the gasifier burner chamber temperature by the main oxygen flow set value of each burner is as follows:

wherein:

u₈(s) gasifier burner chamber temperature;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.11, the mathematical model for adjusting the lower temperature in the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₉(s) is the lower temperature in the gasifier;

y₃(s) for each burnThe main oxygen flow set value of the nozzle;

step 2.3.2.12, the mathematical model for adjusting the bottom temperature of the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₀(s) is the gasifier bottom temperature;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.13, the mathematical model for adjusting the oxygen-coal ratio of the burner A by the set value of the main oxygen flow of each burner is as follows:

wherein:

u₁₁(s) the oxygen-coal ratio of the burner A;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.14, the mathematical model for adjusting the oxygen-coal ratio of the burner B by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₂(s) is the oxygen-coal ratio of the burner B;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.15, the mathematical model for adjusting the oxygen-coal ratio of the burner C by the set value of the main oxygen flow of each burner is as follows:

wherein:

u₁₃(s) is the oxygen-coal ratio of the burner C;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.16, the mathematical model for adjusting the oxygen-coal ratio of the burner D by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₄(s) the oxygen-coal ratio of the burner D;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.17, the mathematical model for adjusting the central oxygen proportion of the burner A by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₅(s) is the central oxygen proportion of the burner A, namely: the ratio of the central oxygen flow of the burner A to the main oxygen flow of the burner A;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.18, the mathematical model for adjusting the central oxygen proportion of the burner B by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₆(s) is the central oxygen proportion of the B burner, namely: the ratio of the central oxygen flow of the burner B to the main oxygen flow of the burner B;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.19, the mathematical model for adjusting the central oxygen proportion of the burner C by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₇(s) is the central oxygen proportion of the C burner, namely: the ratio of the central oxygen flow of the burner C to the main oxygen flow of the burner C;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.20, the mathematical model for adjusting the central oxygen proportion of the burner D by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₈(s) is the central oxygen proportion of the D burner, namely: the ratio of the central oxygen flow of the burner D to the main oxygen flow of the burner D;

y₄(s) setting the central oxygen flow rate of each burner;

in step 2.3.2.21, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner A and the burner B by the main oxygen flow rate set value of the burner A is as follows:

wherein:

u₁₉(s) the main oxygen flow difference of the burner A and the burner B;

y₅(s) is a main oxygen flow set value of the burner A;

in step 2.3.2.22, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner A and the burner B by the main oxygen flow rate set value of the burner B is as follows:

wherein:

u₁₉(s) the main oxygen flow difference of the burner A and the burner B;

y₆(s) is a main oxygen flow set value of the burner B;

step 2.3.2.23, the mathematical model for adjusting the difference between the main oxygen flow of the burner C and the main oxygen flow of the burner D by the main oxygen flow set value of the burner C is as follows:

wherein:

u₂₀(s) the main oxygen flow difference of the burner C and the burner D;

y₇(s) is a main oxygen flow set value of the burner C;

step 2.3.2.24, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner C and the burner D by the main oxygen flow rate set value of the burner D is as follows:

wherein:

u₂₀(s) the main oxygen flow difference of the burner C and the burner D;

y₈(s) is a main oxygen flow set value of the burner D;

step 2.3.2.25, adjusting the primary oxygen flow set point for burner A (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₅(s) is a main oxygen flow set value of the burner A;

step 2.3.2.26, adjusting the primary oxygen flow set point for burner B (L)_A+L_B)-(L_C+L_D) Mathematical model ofThe type is as follows:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₆(s) is a main oxygen flow set value of the burner B;

step 2.3.2.27, adjusting the primary oxygen flow set point for burner C (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₇(s) is a main oxygen flow set value of the burner C;

step 2.3.2.28, adjusting the primary oxygen flow set point for burner D (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₈(s) setting the main oxygen flow for the D burnerA value;

and 2.3.3, inputting target values of the controlled variables according to the specific control variables and the control models corresponding to the specific controlled variables to obtain target values of the controlled variables, subtracting the target values of the controlled variables from the set values of the controlled variables to obtain adjustment values of the controlled variables, and acting on corresponding execution mechanisms according to the adjustment values of the controlled variables to realize adjustment of the controlled variables, so that the real-time values of the controlled variables of the adjusted system are equal to the target values of the controlled variables, and the control and adjustment of the four-nozzle coal water slurry gasification furnace are realized.

Technical Field

The invention belongs to the technical field of instrument automation, and particularly relates to a control system and a control method for a four-nozzle coal water slurry gasification furnace.

Background

At present, the coal chemical industry field uses a large amount of coal water slurry gasification technology as a coal gas preparation process technology, and the technology provides a powerful support for realizing the autonomy of the coal gasification technology and promoting the rapid development of the coal chemical industry.

However, the existing coal water slurry gasification technology mainly has the following problems: the concentration of the coal water slurry injected into the coal water slurry gasification furnace, the proportion of oxygen and the coal slurry are important parameters influencing the coal gasification process, and the effective gas content at the outlet of the coal water slurry gasification furnace is directly influenced. However, the existing coal water slurry gasification system cannot accurately adjust the concentration of the coal water slurry and the proportion of oxygen and the coal slurry, so that the coal water slurry gasification efficiency is low.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a control system and a control method of a four-nozzle coal water slurry gasification furnace, which can effectively solve the problems.

The technical scheme adopted by the invention is as follows:

the invention provides a control system of a four-nozzle coal water slurry gasification furnace, which comprises: the system comprises a weighing feeder system (1), a coal mill (2), a first coal slurry storage tank (3), a low-pressure coal slurry pump (4), a second coal slurry storage tank (5), a high-pressure coal slurry pump (6), a gasification furnace (7) and a DCS system;

the weighing feeder system (1) comprises a weighing feeder (1-1), a feed opening (1-2), a feeder motor (1-3) and a feeder rotating speed probe (1-4); the feed opening (1-2) is arranged above the feed end of the weighing feeder (1-1);

the feed end of the coal mill (2) is communicated with a process water pipeline and an additive pipeline; wherein the process water pipeline is provided with a process water flow meter (2-1) and a process water regulating valve (2-2); the additive pipeline is provided with an additive flow meter (2-3) and an additive regulating valve (2-4); the process water pipeline is communicated with the discharge end of the weighing feeder (1-1) through a coal feeding pipeline (1-5);

the feeding end of the first coal slurry storage tank (3) is communicated with the discharging end of the coal mill (2) through a pipeline;

the feed end of the low-pressure coal slurry pump (4) is communicated with the first coal slurry storage tank (3); the discharge end of the low-pressure coal slurry pump (4) is communicated with the discharge end of the second coal slurry storage tank (5) through a first coal slurry conveying pipeline (G1); wherein a slurry concentration meter (8) is installed on the first slurry transport line (G1);

the gasification furnace (7) is provided with four opposite nozzles which are positioned on the same horizontal plane;

the feed end of the high-pressure coal slurry pump (6) is communicated with the second coal slurry storage tank (5); the discharge end of the high-pressure coal slurry pump (6) is respectively communicated with the outer ring feed inlet of each nozzle of the gasification furnace (7) through a second coal slurry conveying pipeline (G2); each nozzle of the gasification furnace (7) is also communicated with a central oxygen pipeline and a main oxygen pipeline; wherein the central oxygen pipeline is provided with a central oxygen flow meter (7-1) and a central oxygen flow regulating valve (7-2); the main oxygen pipeline is provided with a main oxygen flow meter (7-3) and a main oxygen flow regulating valve (7-4); a high-temperature thermocouple (7-5) is arranged on the inner furnace wall of the gasification furnace (7);

the input end of the DCS is respectively connected with the feeder rotating speed probe (1-4), the process water flow meter (2-1), the additive flow meter (2-3), the coal slurry concentration meter (8), the central oxygen flow meter (7-1), the main oxygen flow meter (7-3) and the high-temperature thermocouple (7-5);

the output end of the DCS is respectively connected with the feeder motor (1-3), the process water regulating valve (2-2), the additive regulating valve (2-4), the central oxygen flow regulating valve (7-2) and the main oxygen flow regulating valve (7-4).

Preferably, the feeder rotating speed probe (1-4) adopts a coaxial speed sensor.

Preferably, the speed sensor is a carbon-free brush type alternating current pulse generator.

Preferably, the process water flow meter (2-1) and the additive flow meter (2-3) adopt electromagnetic flow meters.

The invention also provides a control method of the control system of the four-nozzle coal water slurry gasification furnace, which comprises the following steps:

step 1, the coal water slurry gasification process comprises the following steps:

step 1.1, weighing raw material coal by a weighing feeder system (1), and mixing the raw material coal with process water conveyed by a process water pipeline and an additive conveyed by an additive pipeline to obtain mixed coal liquid;

step 1.2, conveying the mixed coal liquid to a coal mill (2), and grinding by the coal mill (2) to obtain first coal slurry;

step 1.3, the first coal slurry is sent to a second coal slurry storage tank (5) through a low-pressure coal slurry pump (4) to be stored;

step 1.4, pressurizing the coal water slurry stored in the second coal slurry storage tank (5) to 7.88MPa by a high-pressure coal slurry pump (6), and then, calculating according to the oxygen-coal ratio, and entering an outer ring channel of each process burner of the gasification furnace (7);

pure oxygen conveyed by the air separation device is divided into four paths by a stop valve, each path of pure oxygen is divided into two branches, the first branch is central oxygen, and the second branch is main oxygen; the central oxygen enters a central channel of the process burner after passing through a central oxygen flow meter (7-1) and a central oxygen flow regulating valve (7-2); the main oxygen enters an outer ring channel of the process burner after passing through a main oxygen flow meter (7-3) and a main oxygen flow regulating valve (7-4);

the pressurized coal water slurry, central oxygen and main oxygen enter a gasification furnace through four process burners symmetrically arranged on the same horizontal plane in a coaxial jet manner, and the gasification reaction conditions are 6.5MPa and 1350 ℃; detecting the inner wall temperature of the gasifier by a high temperature thermocouple (7-5) to generate a crude synthesis gas with the component of CO₂、H₂、CO、CH₄And a water vapor mixture, wherein the unconverted components in the coal water slurry and the coal ash form ash;

step 2, the coal water slurry gasification control process comprises two parts of automatic control of coal slurry concentration and gasification process control of a gasification furnace;

step 2.1, in the coal water slurry gasification process of the step 1, a feeder rotating speed probe (1-4) measures the real-time rotating speed of a feeder in real time, a process water flowmeter (2-1) measures the real-time flow of process water in real time, an additive flowmeter (2-3) measures the real-time flow of an additive in real time, a coal slurry concentration meter (8) measures the real-time flow of coal slurry in real time, a central oxygen flowmeter (7-1) measures the real-time flow of central oxygen in real time, a main oxygen flowmeter (7-3) measures the real-time flow of main oxygen in real time, and a high-temperature thermocouple (7-5) measures the real-time temperature;

step 2.2, transmitting the real-time rotating speed of the feeder, the real-time flow of the process water, the real-time flow of the additive, the real-time flow of the coal slurry, the real-time flow of the central oxygen, the real-time flow of the main oxygen and the real-time temperature of the inner wall of the gasification furnace to an APC system through a DCS system in real time;

step 2.3, pre-establishing a regulation mathematical model by the APC system, and obtaining optimal control values of the rotating speed of a feeder motor (1-3), the process water supply flow, the additive supply flow, the central oxygen supply flow and the main oxygen supply flow through the regulation mathematical model; then respectively controlling the rotating speed of a feeder motor (1-3), a process water regulating valve (2-2), an additive regulating valve (2-4), a central oxygen flow regulating valve (7-2) and a main oxygen flow regulating valve (7-4) through optimal control values, so that the four-nozzle coal water slurry gasification furnace device automatically, safely and stably operates;

the step 2.3 specifically comprises the following steps:

step 2.3.1, pre-establishing a control model:

wherein:

y(s) is the control variable MV;

u(s) is the controlled variable CV;

k is a gain coefficient and represents the condition of the response speed between the controlled variable and the controlled variable;

τ_n、τ₁、τ₂respectively a first time coefficient, a second time coefficient and a third time coefficient which are required by the control model to reach the steady state of the controlled variable when the control variable changes;

d is a time coefficient required by the controlled variable to respond to the controlled variable;

s is a time variable;

step 2.3.2, respectively obtaining k and tau corresponding to different control variables and controlled variables by adopting a step test method_n、τ₁、τ₂And the value of d; thereby obtaining a specific control variable and a control model corresponding to the specific controlled variable;

the method specifically comprises the following steps:

the coal slurry preparation APC controller variable and control relationship comprises:

step 2.3.2.1, the mathematical model for adjusting the concentration of the coal water slurry by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₁(s) is the coal water slurry concentration;

y₁(s) is a coal feeding amount set value of the weighing feeder;

step 2.3.2.2, the mathematical model for adjusting the concentration of the coal water slurry by the set value of the water supply quantity of the process water is as follows:

wherein:

u₁(s) is the coal water slurry concentration;

y₂(s) is a set value of the water supply quantity of the process water;

step 2.3.2.3, the mathematical model for adjusting the coal slurry tank liquid level by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₂(s) is the liquid level of the coal slurry tank;

y₁(s) is a coal feeding amount set value of the weighing feeder;

step 2.3.2.4, the mathematical model for adjusting the slurry tank liquid level by the process water feed amount set value is as follows:

wherein:

u₂(s) is the liquid level of the coal slurry tank;

y₂(s) isA process water supply amount set value;

step 2.3.2.5, the mathematical model for adjusting the instantaneous coal feeding amount of the weighing feeder by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₃(s) the instantaneous coal feeding amount of the weighing feeder;

y₁(s) is a coal feeding amount set value of the weighing feeder;

step 2.3.2.6, the mathematical model for adjusting the instantaneous water supply of the process water by the set value of the water supply of the process water is as follows:

wherein:

u₄(s) is the instantaneous feed rate of the process water;

y₂(s) is a set value of the water supply quantity of the process water;

the gasifier APC controller variables and control relationships include:

the gasification furnace is provided with four high-temperature thermocouples which are respectively a first high-temperature thermocouple, a second high-temperature thermocouple, a third high-temperature thermocouple and a fourth high-temperature thermocouple; the first high-temperature thermocouple is used for measuring the temperature of the vault of the gasification furnace; the second high-temperature thermocouple is used for measuring the temperature of the burner chamber of the gasification furnace; the third high-temperature thermocouple is used for measuring the temperature of the lower part of the gasification furnace; the fourth high-temperature thermocouple is used for measuring the temperature of the bottom of the gasification furnace;

the gasification furnace is provided with four burners, namely a burner A, a burner B, a burner C and a burner D; the four burners are arranged at the same horizontal position at the upper part of the gasification furnace in an opposed manner at an included angle of 90 degrees, wherein the burner A is arranged opposite to the burner B, the burner C is arranged opposite to the burner D, the burner A, the burner D, the burner B and the burner C are arranged clockwise, and each burner is connected with a coal slurry branch pipe, a main oxygen branch pipe and a central oxygen branch pipe;

step 2.3.2.7, the mathematical model for adjusting the methane content of the raw gas by the main oxygen flow set values of the four burners is as follows:

wherein:

u₅(s) is the methane content of the raw gas;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.8, the mathematical model for adjusting the carbon dioxide content of the raw gas by the main oxygen flow set values of the four burners is as follows:

wherein:

u₆(s) is the carbon dioxide content of the raw gas;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.9, the mathematical model for adjusting the temperature of the vault of the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₇(s) is the temperature of the vault of the gasifier;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.10, the mathematical model for adjusting the gasifier burner chamber temperature by the main oxygen flow set value of each burner is as follows:

wherein:

u₈(s) gasifier burner chamber temperature;

y₃(s) for each burnerA primary oxygen flow set value;

step 2.3.2.11, the mathematical model for adjusting the lower temperature in the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₉(s) is the lower temperature in the gasifier;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.12, the mathematical model for adjusting the bottom temperature of the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₀(s) is the gasifier bottom temperature;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.13, the mathematical model for adjusting the oxygen-coal ratio of the burner A by the set value of the main oxygen flow of each burner is as follows:

wherein:

u₁₁(s) the oxygen-coal ratio of the burner A;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.14, the mathematical model for adjusting the oxygen-coal ratio of the burner B by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₂(s) is the oxygen-coal ratio of the burner B;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.15, the mathematical model for adjusting the oxygen-coal ratio of the burner C by the set value of the main oxygen flow of each burner is as follows:

wherein:

u₁₃(s) is the oxygen-coal ratio of the burner C;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.16, the mathematical model for adjusting the oxygen-coal ratio of the burner D by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₄(s) the oxygen-coal ratio of the burner D;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.17, the mathematical model for adjusting the central oxygen proportion of the burner A by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₅(s) is the central oxygen proportion of the burner A, namely: the ratio of the central oxygen flow of the burner A to the main oxygen flow of the burner A;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.18, the mathematical model for adjusting the central oxygen proportion of the burner B by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₆(s) is the central oxygen proportion of the B burner, namely: the ratio of the central oxygen flow of the burner B to the main oxygen flow of the burner B;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.19, the mathematical model for adjusting the central oxygen proportion of the burner C by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₇(s) is the central oxygen proportion of the C burner, namely: the ratio of the central oxygen flow of the burner C to the main oxygen flow of the burner C;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.20, the mathematical model for adjusting the central oxygen proportion of the burner D by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₈(s) is the central oxygen proportion of the D burner, namely: the ratio of the central oxygen flow of the burner D to the main oxygen flow of the burner D;

y₄(s) setting the central oxygen flow rate of each burner;

in step 2.3.2.21, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner A and the burner B by the main oxygen flow rate set value of the burner A is as follows:

wherein:

u₁₉(s) the main oxygen flow difference of the burner A and the burner B;

y₅(s) is a main oxygen flow set value of the burner A;

in step 2.3.2.22, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner A and the burner B by the main oxygen flow rate set value of the burner B is as follows:

wherein:

u₁₉(s) the main oxygen flow difference of the burner A and the burner B;

y₆(s) is a main oxygen flow set value of the burner B;

step 2.3.2.23, the mathematical model for adjusting the difference between the main oxygen flow of the burner C and the main oxygen flow of the burner D by the main oxygen flow set value of the burner C is as follows:

wherein:

u₂₀(s) the main oxygen flow difference of the burner C and the burner D;

y₇(s) is a main oxygen flow set value of the burner C;

step 2.3.2.24, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner C and the burner D by the main oxygen flow rate set value of the burner D is as follows:

wherein:

u₂₀(s) the main oxygen flow difference of the burner C and the burner D;

y₈(s) is a main oxygen flow set value of the burner D;

step 2.3.2.25, adjusting the primary oxygen flow set point for burner A (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₅(s) is a main oxygen flow set value of the burner A;

step 2.3.2.26, adjusting the primary oxygen flow set point for burner B (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₆(s) is a main oxygen flow set value of the burner B;

step 2.3.2.27, adjusting the primary oxygen flow set point for burner C (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₇(s) is a main oxygen flow set value of the burner C;

step 2.3.2.28, adjusting the primary oxygen flow set point for burner D (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₈(s) is a main oxygen flow set value of the burner D;

and 2.3.3, inputting target values of the controlled variables according to the specific control variables and the control models corresponding to the specific controlled variables to obtain target values of the controlled variables, subtracting the target values of the controlled variables from the set values of the controlled variables to obtain adjustment values of the controlled variables, and acting on corresponding execution mechanisms according to the adjustment values of the controlled variables to realize adjustment of the controlled variables, so that the real-time values of the controlled variables of the adjusted system are equal to the target values of the controlled variables, and the control and adjustment of the four-nozzle coal water slurry gasification furnace are realized.

The control system and the control method of the four-nozzle coal water slurry gasification furnace provided by the invention have the following advantages:

the control system of the four-nozzle coal water slurry gasification furnace provided by the invention can be used for adjusting the coal slurry concentration and the proportion of the oxygen and the coal slurry of the gasification furnace, so that the automatic control of the coal water slurry gasification furnace is realized, the coal water slurry gasification efficiency is improved, the coal water slurry is safely and stably adjusted, the labor intensity of workers is greatly reduced, the operation error of the workers is reduced, the coal consumption is reduced, and the yield is maximized.

Drawings

FIG. 1 is a schematic structural diagram of a control system of a four-nozzle coal-water slurry gasification furnace provided by the invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a control system of a four-nozzle coal water slurry gasification furnace, which refers to a figure 1 and comprises: the system comprises a weighing feeder system 1, a coal mill 2, a first coal slurry storage tank 3, a low-pressure coal slurry pump 4, a second coal slurry storage tank 5, a high-pressure coal slurry pump 6, a gasification furnace 7 and a DCS system;

the weighing feeder system 1 comprises a weighing feeder 1-1, a feed opening 1-2, a feeder motor 1-3 and a feeder rotating speed probe 1-4; a feed opening 1-2 is arranged above the feed end of the weighing feeder 1-1;

the feed end of the coal mill 2 is communicated with a process water pipeline and an additive pipeline; wherein, the process water pipeline is provided with a process water flow meter 2-1 and a process water regulating valve 2-2; an additive pipeline is provided with an additive flowmeter 2-3 and an additive regulating valve 2-4; in addition, the process water pipeline is communicated with the discharge end of the weighing feeder 1-1 through a coal feeding pipeline 1-5;

the feeding end of the first coal slurry storage tank 3 is communicated with the discharging end of the coal mill 2 through a pipeline;

the feed end of the low-pressure coal slurry pump 4 is communicated with the first coal slurry storage tank 3; the discharge end of the low-pressure coal slurry pump 4 is communicated with the discharge end of the second coal slurry storage tank 5 through a first coal slurry conveying pipeline G1; wherein, a coal slurry concentration meter 8 is arranged on the first coal slurry conveying pipeline G1;

the gasification furnace 7 is provided with four opposed nozzles which are positioned on the same horizontal plane;

the feed end of the high-pressure coal slurry pump 6 is communicated with the second coal slurry storage tank 5; the discharge end of the high-pressure slurry pump 6 is respectively communicated with the outer ring feed inlet of each nozzle of the gasification furnace 7 through a second slurry conveying pipeline G2; each nozzle of the gasification furnace 7 is also communicated with a central oxygen pipeline and an outer oxygen pipeline; wherein, the central oxygen pipeline is provided with a central oxygen flowmeter 7-1 and a central oxygen flow regulating valve 7-2; the outer ring oxygen pipeline is provided with an outer ring oxygen flow meter 7-3 and an outer ring oxygen flow regulating valve 7-4; a high-temperature thermocouple 7-5 is arranged on the inner furnace wall of the gasification furnace 7;

the input end of the DCS is respectively connected with a feeder rotating speed probe 1-4, a process water flowmeter 2-1, an additive flowmeter 2-3, a coal slurry concentration meter 8, a central oxygen flowmeter 7-1, an outer ring oxygen flowmeter 7-3 and a high-temperature thermocouple 7-5;

the output end of the DCS is respectively connected with a feeder motor 1-3, a process water regulating valve 2-2, an additive regulating valve 2-4, a central oxygen flow regulating valve 7-2 and an outer ring oxygen flow regulating valve 7-4.

The gasification process of the coal water slurry comprises the following steps:

step 1, weighing raw material coal by a weighing feeder system 1, and mixing the raw material coal with process water conveyed by a process water pipeline and an additive conveyed by an additive pipeline to obtain mixed coal liquid;

step 2, conveying the mixed coal liquid to a coal mill 2, and grinding the mixed coal liquid by the coal mill 2 to obtain first coal slurry;

step 3, the first coal slurry is sent to a second coal slurry storage tank 5 for storage through a low-pressure coal slurry pump 4;

step 4, pressurizing the coal water slurry stored in the second coal slurry storage tank 5 to 7.88MPa by a high-pressure coal slurry pump 6, and then, calculating according to the oxygen-coal ratio, and entering an outer ring channel of each process burner of the gasification furnace 7;

pure oxygen conveyed by the air separation device is divided into four paths by a stop valve, each path of pure oxygen is divided into two branches, the first branch is central oxygen, and the second branch is external epoxy; the central oxygen enters a central channel of the process burner after passing through a central oxygen flow meter 7-1 and a central oxygen flow regulating valve 7-2; the outer epoxy enters an outer ring channel of the process burner after passing through an outer ring oxygen flow meter 7-3 and an outer ring oxygen flow regulating valve 7-4;

the pressurized coal water slurry, central oxygen and external epoxy enter a gasification furnace through four process burners symmetrically arranged on the same horizontal plane in a coaxial jet manner, and the gasification reaction conditions are 6.5MPa and 1350 ℃; detecting the inner wall temperature of the gasifier by a high-temperature thermocouple 7-5 to generate crude synthesis gas with the component of CO₂、H₂、CO、CH₄And the water vapor mixture, wherein the unconverted components in the coal water slurry and the coal ash form ash.

Description of key components in the figures:

1. a feeding machine rotating speed probe:

a coaxial speed sensor is adopted and is a carbon-free brush type alternating current pulse generator. The rotating speed probe of the feeder converts the rotating speed of the motor of the feeder into an electric signal and outputs the electric signal to the DCS for monitoring.

2. Flow meter

The process water flowmeter and the additive flowmeter adopt electromagnetic flowmeters, and the electromagnetic flowmeters perform flow measurement according to Faraday's law of electromagnetic induction. The electromagnetic flowmeter has the advantages of extremely small pressure loss and large measurable flow range. The output signal and the measured flow are linear, the accuracy is high, and the flow of acid, alkali, salt solution, water, sewage, corrosive liquid, slurry, pulp and other fluids with the conductivity more than or equal to 5 mu s/cm can be measured.

The electromagnetic flowmeter converts the measured process water flow and additive flow and sends the converted signals to a DCS system for monitoring.

3. Coal slurry concentration meter

The coal slurry concentration meter is an important monitoring meter for controlling the concentration of the coal slurry. And the coal slurry concentration meter transmits the measured coal slurry concentration signal to the DCS.

The working principle of the coal slurry concentration meter is as follows:

the concentration is measured by using the principle that ultrasonic signals are transmitted in a medium containing suspended matters to generate amplitude attenuation. The system structure based on the microprocessor and the integrated multiple detection technologies ensures that the measurement is not influenced by medium states and environmental factors, and ensures the accuracy, stability and reliability of the coal slurry concentration meter. The concentration meter comprises an ultrasonic sensor, a concentration measurement circuit board, a signal output circuit board, a microprocessor circuit board, a display, a keyboard assembly, a transmitter shell, an installation assembly and the like.

4. High-temperature thermocouple

The high-temperature thermocouple is used for measuring the temperature of the inner furnace wall of the gasification furnace and monitoring the temperature of the gasification furnace, and transmits a measurement signal to the DCS for monitoring.

The working principle of the high-temperature thermocouple is as follows:

the basic principle of the high-temperature thermocouple temperature measurement is as follows: the two material conductors with different components form a closed loop, when temperature gradients exist at two ends, current can pass through the loop, and electromotive force, namely thermoelectric force, exists between the two ends. The homogeneous conductors of the two different compositions are hot electrodes, the end with the higher temperature being the working end and the end with the lower temperature being the free end, which is usually at some constant temperature. When the thermocouple is used for measuring temperature, a measuring instrument can be connected, and the temperature of the measured medium can be measured after the thermoelectromotive force is measured. Thermocouples for gasifiers typically measure temperatures from 1100 ℃ to 1300 ℃, and typically employ type B thermocouples which employ sheathed protective sleeves.

DCS System

The DCS system is used for collecting signals of measuring elements of the gasification device and automatically controlling the valves. Meanwhile, the measurement signal is transmitted to the APC system through the OPC protocol interface, and the control signal of the APC system is received, and then the on-site valve is regulated.

The DCS system comprises a controller, an I/O control clamping piece, a safety barrier, a cabinet, a switch, an operation station and the like.

APC System

The APC system is used for carrying out complex model operation on multivariable measurement signals transmitted by the DCS system to obtain an optimized control value, and the control value is transmitted to the DCS system through the OPC interface for control.

The APC system is composed of a server, a gateway, a switch, a display, a mouse and a keyboard.

The APC system mainly carries out automatic operation on the coal slurry preparation and the gasification furnace through a mathematical model, thereby obtaining an optimal control value to carry out automatic control on a field system.

The coal slurry preparation unit comprises a weighing feeder, a coal mill, a coal slurry discharge chute and a coal slurry pump. The system of the invention controls the coal slurry preparation unit mainly to realize the automatic control of the coal slurry concentration, the coal slurry concentration measured by a coal slurry concentration meter is compared with the set value of an APC system in a DCS system, if the deviation exists, the concentration is adjusted by adjusting the coal feeding flow of a weighing coal feeder or the water inlet flow of process water, the weighing coal feeder mainly adjusts the speed through the rotating speed, the flow of the process water is adjusted through the opening of an adjusting valve, the higher the coal feeding flow is, the higher the concentration is, the larger the opening of the process water adjusting valve is, the larger the process water flow is, and the lower the coal slurry concentration is.

The gasification furnace system mainly controls the components of the produced crude synthesis gas, the temperature of the gasification furnace and the proportion of oxygen and coal slurry. The value of the synthesis gas analyzer, the value of the high-temperature thermocouple, the value of the oxygen and coal slurry flow rate of the device collected by the DCS are compared with the value calculated by the APC model, and the adjustment is carried out by adjusting an oxygen flow valve FV 1203. And the oxygen flow regulating amplitudes of the four burners are consistent as much as possible to avoid the nozzles from spraying eccentrically.

The implementation range of the APC system of the gasification device comprises: preparing coal slurry and gasifying the coal slurry. According to functional design, the APC control system has 1 main controller and 2 sub-controllers, and the system has 21 CVs and 10 MVs.

The invention provides a control system of a four-nozzle coal water slurry gasification furnace, which can respectively adjust the concentration of the coal water slurry, the proportion of oxygen and the coal slurry, and specifically comprises the following steps:

(1) adjusting the coal slurry concentration:

the DCS detects the real-time coal slurry concentration of the second coal slurry storage tank 5 through a coal slurry concentration meter; then, adjusting the rotating speed of a motor of the feeder so as to adjust the coal feeding flow; or adjusting the process water adjusting valve 2-2 so as to adjust the water inflow of the process water, and adjusting the concentration of the coal slurry by adjusting the coal feeding flow or the water inflow of the process water; specifically, the speed of the weighing feeder is adjusted mainly through the rotating speed, the flow of process water is adjusted through the opening degree of a process water adjusting valve 2-2, and the concentration of the weighing feeder is high when the rotating speed of the weighing feeder is higher and the coal feeding flow is higher; the larger the opening of the process water regulating valve is, the larger the process water flow is, and the lower the coal slurry concentration is.

(2) Adjusting the ratio of oxygen to coal slurry:

DCS collects the numerical values of the components of the produced crude synthesis gas transmitted by the synthesis gas analyzer, and then adjusts the central oxygen flow adjusting valve 7-2 and the outer ring oxygen flow adjusting valve 7-4 so as to adjust the central oxygen flow and the outer ring oxygen flow, thereby adjusting and controlling the crude synthesis gasCH in coal gas₄Content, CO₂Content, temperature in the gasification furnace, oxygen-coal ratio; the control of the center oxygen percentage is realized by controlling the flow of the center oxygen, so that the material atomization effect and the flame length of the burner can be adjusted, and a good reaction effect is achieved. In addition, the oxygen flow regulating amplitudes of the four burners are consistent as much as possible so as to avoid the nozzles from spraying unevenly.

The invention specifically provides a control method of a four-nozzle coal water slurry gasification furnace control system, which comprises the steps of monitoring and controlling the concentration of coal slurry, analyzing and monitoring the flow rate and the oxygen amount flow rate of the coal slurry of the gasification furnace, realizing automatic control, safe and stable adjustment of the coal water slurry gasification furnace by utilizing a control technology, and realizing edge clamping operation, so that the labor intensity of staff is greatly reduced, the operation error of people is reduced, the coal consumption is reduced, and the yield is maximized.

The method specifically comprises the following steps:

step 1, the coal water slurry gasification process comprises the following steps:

step 1.1, weighing raw material coal by a weighing feeder system 1, and mixing the raw material coal with process water conveyed by a process water pipeline and an additive conveyed by an additive pipeline to obtain mixed coal liquid;

step 1.2, conveying the mixed coal liquid to a coal mill 2, and grinding by the coal mill 2 to obtain first coal slurry;

step 1.3, the first coal slurry is sent to a second coal slurry storage tank 5 for storage through a low-pressure coal slurry pump 4;

step 1.4, pressurizing the coal water slurry stored in the second coal slurry storage tank 5 to 7.88MPa by a high-pressure coal slurry pump 6, and then, calculating according to the oxygen-coal ratio, and entering an outer annular channel of each process burner of the gasification furnace 7; (single burner 22m3/h, 4 burners 88m 3/h).

Pure oxygen conveyed by the air separation device is divided into four paths by a cut-off valve (41000Nm3/h, 8.4MPa and 32 ℃), each path of pure oxygen is divided into two branches, the first branch is central oxygen, and the second branch is main oxygen; the central oxygen enters a central channel of the process burner after passing through a central oxygen flow meter 7-1 and a central oxygen flow regulating valve 7-2; the main oxygen enters an outer ring channel of the process burner after passing through a main oxygen flow meter 7-3 and a main oxygen flow regulating valve 7-4; (Single burner: 10252Nm3/h.8.4MPa, 32 ℃ C.).

The pressurized coal water slurry, central oxygen and main oxygen enter a gasification furnace through four process burners symmetrically arranged on the same horizontal plane in a coaxial jet manner, and the gasification reaction conditions are 6.5MPa and 1350 ℃; the firebrick is lined in the combustion chamber, the temperature of the outer wall of the gasification furnace can be kept less than 280 ℃, the temperature of the inner wall of the gasification furnace is detected by a high-temperature thermocouple 7-5, thereby generating crude synthesis gas, the component of which is CO₂、H₂、CO、CH₄And a water vapor mixture, wherein the unconverted components in the coal water slurry and the coal ash form ash;

step 2, the coal water slurry gasification control process comprises two parts of automatic control of coal slurry concentration and gasification process control of a gasification furnace;

specifically, the control system is used for measuring the coal slurry concentration, the coal feeding amount, the water feeding flow, the additive flow, the oxygen flow and the gasifier temperature on the basis of a weighing feeder, a coal mill and a gasifier, outputting a control result to a DCS (distributed control system) through APC (automatic Power control) controller model operation, and controlling the rotating speed of the on-site weighing coal feeder, a water feeding flow adjusting valve, an additive flow adjusting valve and an oxygen flow adjusting valve through the DCS to realize the automatic control of the gasifier, so that the aim of automatic safe and stable operation of the four-nozzle coal-water-slurry gasifier device is fulfilled.

Step 2.1, in the coal water slurry gasification process of the step 1, a feeding machine rotating speed probe 1-4 measures the real-time rotating speed of a feeding machine in real time, a process water flowmeter 2-1 measures the real-time flow of process water in real time, an additive flowmeter 2-3 measures the real-time flow of an additive in real time, a coal slurry concentration meter 8 measures the real-time flow of coal slurry in real time, a central oxygen flowmeter 7-1 measures the real-time flow of central oxygen in real time, a main oxygen flowmeter 7-3 measures the real-time flow of main oxygen in real time, and a high-temperature thermocouple 7-5 measures the real-;

step 2.2, transmitting the real-time rotating speed of the feeder, the real-time flow of the process water, the real-time flow of the additive, the real-time flow of the coal slurry, the real-time flow of the central oxygen, the real-time flow of the main oxygen and the real-time temperature of the inner wall of the gasification furnace to an APC system through a DCS system in real time;

step 2.3, pre-establishing a regulation mathematical model by the APC system, and obtaining optimal control values of the rotating speed of the feeder motor 1-3, the process water supply flow, the additive supply flow, the central oxygen supply flow and the main oxygen supply flow through the regulation mathematical model; then respectively controlling the rotating speed of a feeder motor 1-3, a process water regulating valve 2-2, an additive regulating valve 2-4, a central oxygen flow regulating valve 7-2 and a main oxygen flow regulating valve 7-4 through optimal control values, so that the four-nozzle coal water slurry gasification furnace device automatically, safely and stably operates;

the step 2.3 specifically comprises the following steps:

step 2.3.1, pre-establishing a control model:

wherein:

y(s) is the control variable MV;

u(s) is the controlled variable CV;

k is a gain coefficient and represents the condition of the response speed between the controlled variable and the controlled variable;

τ_n、τ₁、τ₂respectively a first time coefficient, a second time coefficient and a third time coefficient which are required by the control model to reach the steady state of the controlled variable when the control variable changes;

d is a time coefficient required by the controlled variable to respond to the controlled variable;

s is a time variable;

the above model is obtained by:

taking the control variable as the given flow of the weighing feeder; the controlled variables are coal slurry concentration as an example:

the method for controlling the coal slurry concentration adopts the method of adjusting the given flow of the weighing feeder or adjusting the process water inflow, two mathematical models are required to be established to form a group, and the coal slurry concentration can be controlled under the combined action.

The relationship between the given flow rate y(s) of the weighing feeder and the coal slurry concentration u(s) can be simply expressed as:

y(s)＝A*u(s)……………………………………………………………1.1

wherein

y(s) is the control variable (given flow rate of the gravimetric feeder);

u(s) is the controlled variable (slurry concentration);

a is two variable relation models.

The simple expression represents the relation between the concentration change of the coal slurry and the given coal amount of the weighing feeder. The relationship between the two variables and the meaning of the pre-estimated model are expressed by adopting a detailed model as follows:

the model adopts an FIR model and adopts position modeling, and the estimation model can be expressed as follows:

y(t)＝b₀u(t)+b₁u(t-1)+b₂u(t-2)+…+b_nbu(t-n_b)……………1.2

wherein b is₀、b₁、b₂、….b_nbThe coefficient of the relationship between the MV and the CV is an infinite number, such as: and the values of y can be deduced by knowing the values of u at different time points, so that the target value of the MV at the next time is solved when the control CV value is a preset value, the regulating quantity of the MV is obtained according to the difference between the current MV value and the target value of the MV, and then the regulating quantity of the MV is sent to a DCS (distributed control system), so that the regulation of the field weighing feeder can be realized.

In practical application items, because the solution of 1.2 is very complex, in order to more conveniently obtain a relational model, the expression 1.2 is transformed by using laplace to obtain a simplified relational expression:

1.3 the expression shows that the value S of CV (coal slurry concentration) to be controlled is u (S) at a certain future time, the value MV (coal feeding flow of the weighing feeder) at the future time S is y (S) can be obtained through the relational expression, the value of the current MV is y₀(s), i.e. the set value of MV is y₀(s) calculatingDeriving the deviation of the MV value as Δ Y ═ Y(s) -Y₀And(s) the deviation value of the MV value is sent to a DCS, and the DCS controls the MV to change through the deviation value delta Y, so that the future CV control is satisfied and the required value is satisfied.

Of course, the coefficients k, τ in the model_n、τ₁、τ₂And d, solving through historical data, adopting a step test method to ensure that when the MV (given flow of the weighing feeder) changes as required, the CV (coal slurry concentration) also changes correspondingly, and substituting the obtained historical data into the 1.3-type transfer function model to obtain 5 coefficients. Thereby obtaining the control model corresponding to the specific control variable and the specific controlled variable which are introduced later.

Step 2.3.2, respectively obtaining k and tau corresponding to different control variables and controlled variables by adopting a step test method_n、τ₁、τ₂And the value of d; thereby obtaining a specific control variable and a control model corresponding to the specific controlled variable;

the method specifically comprises the following steps:

the main control functions of the coal slurry preparation APC controller are as follows: on the premise of ensuring the coal slurry supply quantity and the coal slurry concentration, a multivariable predictive control model is adopted, and the coal water ratio is stably controlled by adjusting the coal supply quantity and the process water flow, so that the accurate and stable control of the coal slurry concentration is realized. Specifically, six mathematical models including steps 2.3.2.1-2.3.2.6 are established.

Step 2.3.2.1, the mathematical model for adjusting the concentration of the coal water slurry by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₁(s) is the coal water slurry concentration;

y₁(s) is a coal feeding amount set value of the weighing feeder;

the coal slurry concentration is adjusted by the coal feeding quantity set value of the weighing feeder, the control delay is realized, and the delay of 14 minutes is set through a step test.

Step 2.3.2.2, the mathematical model for adjusting the concentration of the coal water slurry by the set value of the water supply quantity of the process water is as follows:

wherein:

u₁(s) is the coal water slurry concentration;

y₂(s) is a set value of the water supply quantity of the process water;

wherein the feedwater flow setting and the coal slurry concentration adjustment are in a reaction relation, and the delay of 6 minutes is set through a step test.

Step 2.3.2.3, the mathematical model for adjusting the coal slurry tank liquid level by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₂(s) is the liquid level of the coal slurry tank;

y₁(s) is a coal feeding amount set value of the weighing feeder;

wherein a 15 minute delay is set through the step test.

Step 2.3.2.4, the mathematical model for adjusting the slurry tank liquid level by the process water feed amount set value is as follows:

wherein:

u₂(s) is the liquid level of the coal slurry tank;

y₂(s) is a set value of the water supply quantity of the process water;

wherein, the 15-minute delay is set through a step test, and the water supply flow is similar to the action model of the weighing feeder on the liquid level of the coal slurry tank.

Step 2.3.2.5, the mathematical model for adjusting the instantaneous coal feeding amount of the weighing feeder by the coal feeding amount set value of the weighing feeder is as follows:

wherein:

u₃(s) the instantaneous coal feeding amount of the weighing feeder;

y₁(s) is a coal feeding amount set value of the weighing feeder;

the action effect between the two variables is obvious and has no time delay.

Step 2.3.2.6, the mathematical model for adjusting the instantaneous water supply of the process water by the set value of the water supply of the process water is as follows:

wherein:

u₄(s) is the instantaneous feed rate of the process water;

y₂(s) is a set value of the water supply quantity of the process water;

the two variables have obvious effect and no time delay.

An APC system needs to be configured with a coal slurry preparation APC controller model, a DCS system is configured with a gasification furnace data interaction program, a loop control switching program, a variable assignment program and the like, and a DCS system is configured with a man-machine interaction control interface, so that an operator can conveniently realize the commissioning and cutting-off and variable display of the APC system in the DCS system. After the APC system is used, data in the DCS system is read through the OPC interface, a control value is calculated through a model and is given to the DCS system, a program of the DCS system gives the control value to a control variable of a control loop for control, and a control result is fed back to the APC system through the change of a controlled variable to form closed-loop control.

TABLE 1 APC controller variables and control relationships for coal slurry preparation

The gasifier APC controller variables and control relationships include:

the gasification furnace APC controller has the main control functions: on the premise of ensuring the safe operation of the gasification furnace and the product quality, a multivariable predictive control model is adopted to stably control the components of the raw gas, the temperature of a hearth of the gasification furnace, the oxygen-coal ratio and the central oxygen ratio by adjusting the flow of the main oxygen and the central oxygen, thereby realizing the efficient and stable long-period operation of the gasification furnace.

The determination of the gasification furnace APC control scheme is based on the gasification reaction principle, and under the condition of ensuring the flow stability of the coal water slurry entering the furnace, the following control is realized by means of controlling the flow of the main oxygen:

the gasification furnace is provided with four high-temperature thermocouples which are respectively a first high-temperature thermocouple, a second high-temperature thermocouple, a third high-temperature thermocouple and a fourth high-temperature thermocouple; the first high-temperature thermocouple is used for measuring the temperature of the vault of the gasification furnace; the second high-temperature thermocouple is used for measuring the temperature of the burner chamber of the gasification furnace; the third high-temperature thermocouple is used for measuring the temperature of the lower part of the gasification furnace; the fourth high-temperature thermocouple is used for measuring the temperature of the bottom of the gasification furnace;

the gasification furnace is provided with four burners, namely a burner A, a burner B, a burner C and a burner D; the four burners are arranged at the same horizontal position at the upper part of the gasification furnace in an opposed manner at an included angle of 90 degrees, wherein the burner A is arranged opposite to the burner B, the burner C is arranged opposite to the burner D, the burner A, the burner D, the burner B and the burner C are arranged clockwise, and each burner is connected with a coal slurry branch pipe, a main oxygen branch pipe and a central oxygen branch pipe;

step 2.3.2.7, controlling the content (500-1200 PPM) of CH4 in the raw gas to reflect the reaction temperature in the combustion chamber of the gasification furnace, ensuring the normal flow of molten slag and preventing the slag hole of the gasification furnace from being blocked; the mathematical model for regulating the methane content of the raw gas by the main oxygen flow set value of each burner is as follows:

wherein:

u₅(s) is the methane content of the raw gas;

y₃(s) setting a main oxygen flow rate value of each burner;

the control model of four regulating valves is theoretically the same, but because of the small difference in actual use, for example, the small deviation of valve flow control can slightly adjust the coefficient of the model, the regulation of methane and oxygen is in reaction, and 18-minute delay is set through a step test.

Step 2.3.2.8, controlling CO in the raw gas₂The content (14-17%) reflects that the carbon fed into the furnace can fully react to generate effective gas components; the mathematical model for regulating the carbon dioxide content of the raw gas by the main oxygen flow set values of the four burners is as follows:

wherein:

u₆(s) is the carbon dioxide content of the raw gas;

y₃(s) setting a main oxygen flow rate value of each burner;

a delay of 18 minutes was set by the step test.

2.3.2.9, controlling the temperature in the combustion chamber of the gasification furnace, slowing down the ablation of the refractory bricks and prolonging the service life of the refractory bricks; the gasifier is provided with four high-temperature thermocouples for measuring the temperature of the gasifier, and respectively measuring the vault temperature of the gasifier, the burner chamber temperature of the gasifier, the lower part temperature of the gasifier and the bottom temperature of the gasifier, and the installation position is from top to bottom. The oxygen amount controlled by each oxygen branch pipe regulating valve is related to the temperature in the furnace, so the four temperature points and the set value of the opening degree of the oxygen branch pipe regulating valve need to be modeled for control.

The mathematical model for adjusting the temperature of the vault of the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₇(s) is the temperature of the vault of the gasifier;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.10, the mathematical model for adjusting the gasifier burner chamber temperature by the main oxygen flow set value of each burner is as follows:

wherein:

u₈(s) gasifier burner chamber temperature;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.11, the mathematical model for adjusting the lower temperature in the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₉(s) is the lower temperature in the gasifier;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.12, the mathematical model for adjusting the bottom temperature of the gasification furnace by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₀(s) is the gasifier bottom temperature;

y₃(s) setting a main oxygen flow rate value of each burner;

and 2.3.2.13, controlling a proper oxygen-coal ratio to improve the effective gas content and reduce the specific oxygen consumption to improve the economy.

The gasification furnace is provided with four burners A \ B \ C \ D, the four burners are arranged at the same horizontal position on the upper part of the gasification furnace in an opposite mode with an included angle of 90 degrees, the burners A are opposite to the burners B, the burners C are opposite to the burners D, A, D, B, C are arranged clockwise, each burner is connected with a coal slurry branch pipe and an oxygen branch pipe, in order to control the proportion of oxygen and coal slurry, the ratio of the flow of the oxygen branch pipe to the flow of the coal slurry branch pipe is measured to be used as an oxygen-coal ratio, because of the four burners, four oxygen-coal ratios can be calculated, the size of the oxygen-coal ratio is related to the opening of an oxygen branch pipe adjusting valve, under the condition that the coal slurry amount is not changed, the larger the setting value of the oxygen branch pipe adjusting valve is, the larger the opening. In order to control the proportion of the aerobic coal and prevent safety accidents caused by excessive oxygen, the effective gas components can be effectively improved by controlling the proportion of the aerobic coal, and the economic target is achieved.

The mathematical model for adjusting the oxygen-coal ratio of the burner A by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₁(s) the oxygen-coal ratio of the burner A;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.14, the mathematical model for adjusting the oxygen-coal ratio of the burner B by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₂(s) is the oxygen-coal ratio of the burner B;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.15, the mathematical model for adjusting the oxygen-coal ratio of the burner C by the set value of the main oxygen flow of each burner is as follows:

wherein:

u₁₃(s) is the oxygen-coal ratio of the burner C;

y₃(s) setting a main oxygen flow rate value of each burner;

step 2.3.2.16, the mathematical model for adjusting the oxygen-coal ratio of the burner D by the main oxygen flow set value of each burner is as follows:

wherein:

u₁₄(s) the oxygen-coal ratio of the burner D;

y₃(s) setting a main oxygen flow rate value of each burner;

and 2.3.2.17, controlling the central oxygen percentage by controlling the central oxygen flow, and adjusting the material atomization effect and the flame length of the burner nozzle to achieve a good reaction effect.

The mathematical model for regulating the central oxygen proportion of the burner A by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₅(s) is the central oxygen proportion of the burner A, namely: the ratio of the central oxygen flow of the burner A to the main oxygen flow of the burner A;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.18, the mathematical model for adjusting the central oxygen proportion of the burner B by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₆(s) is the central oxygen proportion of the B burner, namely: the ratio of the central oxygen flow of the burner B to the main oxygen flow of the burner B;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.19, the mathematical model for adjusting the central oxygen proportion of the burner C by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₇(s) is the central oxygen proportion of the C burner, namely: the ratio of the central oxygen flow of the burner C to the main oxygen flow of the burner C;

y₄(s) setting the central oxygen flow rate of each burner;

step 2.3.2.20, the mathematical model for adjusting the central oxygen proportion of the burner D by the central oxygen flow set value of each burner is as follows:

wherein:

u₁₈(s) is the central oxygen proportion of the D burner, namely: the ratio of the central oxygen flow of the burner D to the main oxygen flow of the burner D;

y₄(s) setting the central oxygen flow rate of each burner;

and step 2.3.2.21, in order to prevent the phenomenon of the partial spraying of the four burners, the oxygen content of the four burners is restrained from generating larger deviation by newly adding a calculation module oxygen flow difference in the DCS. One of the key points of the control model for establishing the four-nozzle coal water slurry is to balance the oxygen amount fed into the four burners and prevent the partial spraying, so that a step test is actually carried out to establish a strict constraint model.

The mathematical model for adjusting the difference between the main oxygen flow of the burner A and the main oxygen flow of the burner B by the main oxygen flow set value of the burner A is as follows:

wherein:

u₁₉(s) the main oxygen flow difference of the burner A and the burner B;

y₅(s) is a main oxygen flow set value of the burner A;

in step 2.3.2.22, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner A and the burner B by the main oxygen flow rate set value of the burner B is as follows:

wherein:

u₁₉(s) the main oxygen flow difference of the burner A and the burner B;

y₆(s) is a main oxygen flow set value of the burner B;

step 2.3.2.23, the mathematical model for adjusting the difference between the main oxygen flow of the burner C and the main oxygen flow of the burner D by the main oxygen flow set value of the burner C is as follows:

wherein:

u₂₀(s) the main oxygen flow difference of the burner C and the burner D;

y₇(s) is a main oxygen flow set value of the burner C;

step 2.3.2.24, the mathematical model for adjusting the difference between the main oxygen flow rates of the burner C and the burner D by the main oxygen flow rate set value of the burner D is as follows:

wherein:

u₂₀(s) the main oxygen flow difference of the burner C and the burner D;

y₈(s) is a main oxygen flow set value of the burner D;

step 2.3.2.25, adjusting the primary oxygen flow set point for burner A (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a It is composed ofThe method comprises the following steps: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₅(s) is a main oxygen flow set value of the burner A;

step 2.3.2.26, adjusting the primary oxygen flow set point for burner B (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₆(s) is a main oxygen flow set value of the burner B;

step 2.3.2.27, adjusting the primary oxygen flow set point for burner C (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₇(s) is a main oxygen flow set value of the burner C;

step 2.3.2.28, adjusting the primary oxygen flow set point for burner D (L)_A+L_B)-(L_C+L_D) The mathematical model of (a) is:

wherein:

u₂₁(s) is (L)_A+L_B)-(L_C+L_D) (ii) a Wherein: l is_A、L_B、L_C、L_DRespectively representing the main oxygen flow of the burner A, the burner B, the burner C and the burner D;

y₈(s) is a main oxygen flow set value of the burner D;

an APC controller model of the configuration gasification furnace is needed in the APC system, a data interaction program, a loop control switching program, a variable assignment program and the like of the configuration gasification furnace in the DCS system are configured, a man-machine interaction control interface is configured in the DCS system, and therefore operating personnel can conveniently achieve commissioning and cutting-off and variable display of the APC system in the DCS system. After the APC system is used, data in the DCS system is read through the OPC interface, a control value is calculated through a model and is given to the DCS system, a program of the DCS system gives the control value to a control variable of a control loop for control, and a control result is fed back to the APC system through the change of a controlled variable to form closed-loop control.

TABLE 2 gasifier APC controller variables and control relationships

And 2.3.3, inputting target values of the controlled variables according to the specific control variables and the control models corresponding to the specific controlled variables to obtain target values of the controlled variables, subtracting the target values of the controlled variables from the set values of the controlled variables to obtain adjustment values of the controlled variables, and acting on corresponding execution mechanisms according to the adjustment values of the controlled variables to realize adjustment of the controlled variables, so that the real-time values of the controlled variables of the adjusted system are equal to the target values of the controlled variables, and the control and adjustment of the four-nozzle coal water slurry gasification furnace are realized.

The control system and the control method of the four-nozzle coal water slurry gasification furnace provided by the invention have the following advantages:

(1) the inventor of the invention has found the following relationships among the variables through a great deal of research and trial and error: the coal feeding quantity and the coal slurry concentration of a weighing feeder, the process water feeding quantity and the coal slurry concentration, the coal feeding quantity and the coal slurry tank liquid level of the weighing feeder, the process water feeding quantity and the coal slurry tank liquid level of the weighing feeder, the coal feeding quantity and the instantaneous coal feeding quantity of the weighing feeder, the instantaneous water feeding quantity and the instantaneous water feeding quantity of the process water, the main oxygen flow and the methane content of the raw gas of a burner, the main oxygen flow and the carbon dioxide content of the raw gas of the burner, the main oxygen flow and the vault temperature of a gasifier, the main oxygen flow and the burner chamber temperature of the burner, the main oxygen flow and the middle-lower temperature of the gasifier, the main oxygen flow and the bottom temperature of the gasifier, the main oxygen flow and the oxygen-coal ratio of the burner, the central oxygen flow and the central oxygen ratio of the burner, the main oxygen flow and the main oxygen flow difference of two burners, and the relationship between the main oxygen flow and the main oxygen flow difference of two, an accurate mathematical model is established, so that the process parameters of the gasification furnace can be finely controlled;

(2) the invention is suitable for the large-scale coal chemical industry, has a cross-over type lifting for the automatic lifting of the four-nozzle coal water slurry gasification furnace, solves the problem of automatic control of the coal water slurry gasification furnace which generally troubles enterprises in the industry by constructing a whole set of system, effectively improves the production safety and the stable operation, reduces the production cost, reduces the labor intensity of personnel, maximizes the yield, and has good market popularization value.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements should also be considered within the scope of the present invention.