Advanced process control method and device for entrained-flow bed coal water slurry gasification furnace

Abstract

The invention relates to the technical field of coal water slurry gasification furnaces, in particular to an advanced process control method, device and equipment for an entrained-flow bed coal water slurry gasification furnace and a computer storage medium. According to the advanced process control method of the entrained-flow bed coal water slurry gasification furnace, the maximization of effective gas yield is taken as a target, the coal is enabled to completely react as far as possible by adjusting the ratio of oxygen to coal, and meanwhile, the slag bonding of the gasification furnace is avoided by monitoring the pressure difference of a slag hole. Secondly, as black water in the chilling chamber contains a large amount of solid substances, the valves are easy to block, in order to ensure the usability of the valves, two black water angle valves are arranged, one black water angle valve is standby, and the other black water angle valve is used and switched regularly; and finally, adjusting a valve according to the combustion state to carry out temperature control on the liquid levels of the chilling chamber and the washing chamber so as to realize unattended operation. According to the invention, multivariable process control can be intelligently and automatically carried out, and real-time optimization of effective gas yield and reduction of energy consumption are realized.

Description

Technical Field

[0001] This invention relates to the field of coal-water slurry gasification furnace technology, and in particular to an advanced process control method, apparatus, equipment, and computer storage medium for a fluidized bed coal-water slurry gasification furnace. Background Technology

[0002] The gasification reaction in a coal-water slurry gasification unit is complex, with numerous side reactions, large fluctuations in coal quality, and lags in the measurement of key process variables, making it difficult to ensure the gasifier's optimal operating condition in a timely manner. Furthermore, coupling interference exists between control loops, forcing the oxygen-to-coal ratio control loop, coal slurry control loop, and oxygen control loop—which affect gasification performance—to operate manually. The high-temperature thermocouples in the gasifier struggle to accurately measure the reaction temperature in the furnace, making them unsuitable as control variables in conventional PID control, thus placing the gasifier under closed-loop control.

[0003] In summary, existing technologies lack intelligent and automated multivariate process control methods, making it impossible to optimize effective gas production and reduce energy consumption in real time. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the lack of intelligent and automated multivariate process control methods in the prior art, which makes it impossible to optimize effective gas production and reduce energy consumption in real time.

[0005] To address the aforementioned technical problems, this invention provides an advanced process control method for a fluidized bed coal-water slurry gasifier, comprising:

[0006] Adjust the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and predict the real-time syngas composition based on the real-time coal slurry flow rate and real-time oxygen flow rate.

[0007] With the goal of maximizing the effective gas production in the real-time syngas components, and constrained by the furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time, and the oxygen flow rate is adjusted in real time to control the combustion in the quench chamber.

[0008] Based on the current opening degree of the black water valve in use and the real-time black water flow, the switching control between the black water valve in use and the black water standby valve is triggered according to the preset shift time.

[0009] Predict the quench chamber liquid level change based on combustion status data, and maintain the quench chamber liquid level by adjusting the opening of the black water in-use valve;

[0010] The changes in the scrubbing tower liquid level are predicted based on combustion status data, and the liquid level in the scrubbing tower is maintained by adjusting the opening of the scrubbing tower drain valve.

[0011] Preferably, the step of adjusting the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and predicting the real-time syngas composition based on the real-time coal slurry flow rate and the real-time oxygen flow rate includes:

[0012] Obtain the target coal slurry flow rate setting value entered by the operator in the DCS interface;

[0013] The target coal slurry flow rate setpoint is read by the APC controller, the adjustment curve is calculated using the Lambda tuning method, and the coal slurry flow rate setpoint of the PID control loop is gradually adjusted according to the adjustment curve so that the actual coal slurry flow rate smoothly transitions to the target coal slurry flow rate.

[0014] Preferably, the step of maximizing the effective gas yield in the real-time syngas composition, constrained by furnace temperature threshold and slag outlet pressure difference threshold, determining the optimal oxygen-coal ratio in real time, and adjusting the oxygen flow rate in real time for quench chamber combustion control includes:

[0015] Based on the thermodynamic equilibrium model and the step test model, a dynamic relationship model between effective gas production and oxygen-coal ratio in syngas components is established.

[0016] With the goal of maximizing the effective gas production in the real-time syngas components and constrained by the furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time by using model predictive control rolling optimization.

[0017] The oxygen flow rate is adjusted in real time based on the optimal oxygen-to-coal ratio, and the oxygen valve opening is adjusted through a PID control loop.

[0018] Preferably, the furnace temperature threshold is determined based on the ash melting point.

[0019] Preferably, the step of triggering the switching control between the black water in-use valve and the black water standby valve based on the current black water valve opening degree and real-time black water flow rate, according to a preset shift schedule, includes:

[0020] When the shift change time is detected by the sequential control program, the switching logic is initiated.

[0021] Based on the current black water valve opening and flow characteristic curve, coarsely adjust the black water standby valve opening to be close to the current black water valve opening, and finely adjust the black water standby valve opening according to the real-time black water flow deviation until the black water flow returns to the original operating point. Completely close the current black water valve and update the operating variable in the APC controller to the black water standby valve opening.

[0022] Preferably, the step of predicting the quench chamber liquid level change based on combustion state data and maintaining the quench chamber liquid level by adjusting the opening of the black water in-use valve includes:

[0023] Predict the change in liquid level in the quench chamber based on combustion state data including black water evaporation rate and syngas flow rate;

[0024] If the liquid level in the quench chamber is lower than the set value, the opening of the currently used black water valve will be gradually increased through the PID control loop.

[0025] If the liquid level in the quench chamber is higher than the set value, the opening of the currently used black water valve will be gradually reduced through the PID control loop.

[0026] Preferably, the step of predicting the change in the scrubbing tower liquid level based on combustion state data and maintaining the scrubbing tower liquid level by adjusting the opening of the scrubbing tower drain valve includes:

[0027] Predict the change in scrubber level based on combustion status data, including syngas flow rate;

[0028] If the liquid level in the scrubbing tower is lower than the set value, the opening of the drain valve in the scrubbing tower will be gradually reduced through the PID control loop.

[0029] If the liquid level in the scrubbing tower is higher than the set value, the opening of the drain valve in the scrubbing tower will be gradually increased through the PID control loop.

[0030] The present invention also provides an advanced process control device for a fluidized bed coal-water slurry gasifier, comprising:

[0031] The load adjustment control module is used to adjust the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and to predict the real-time syngas composition based on the real-time coal slurry flow rate and the real-time oxygen flow rate.

[0032] The quench chamber combustion control module is used to determine the optimal oxygen-coal ratio in real time and adjust the oxygen flow rate in real time to control the quench chamber combustion, with the goal of maximizing the effective gas production in the real-time syngas composition and constrained by the furnace temperature threshold and slag outlet pressure difference threshold.

[0033] The black water valve switching control module is used to trigger the switching control between the black water valve in use and the black water standby valve based on the current opening degree of the black water valve in use and the real-time black water flow rate, according to the preset shift time.

[0034] The quench chamber liquid level control module is used to predict changes in the quench chamber liquid level based on combustion status data and maintain the quench chamber liquid level by adjusting the opening of the black water in-use valve.

[0035] The scrubbing tower level control module is used to predict changes in the scrubbing tower level based on combustion status data and maintain the scrubbing tower level by adjusting the opening of the scrubbing tower drain valve.

[0036] The present invention also provides an apparatus comprising:

[0037] Memory, used to store computer programs;

[0038] A processor is used to execute the computer program to implement the steps of the advanced process control method for a fluidized bed coal-water slurry gasifier described above.

[0039] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described advanced process control method for a fluidized bed coal-water slurry gasifier.

[0040] The technical solution of the present invention has the following advantages compared with the prior art:

[0041] The advanced process control method for the fluidized bed coal-water slurry gasifier described in this invention aims to maximize effective gas production. It ensures the coal reacts as completely as possible by adjusting the oxygen-to-coal ratio, while simultaneously monitoring the slag outlet pressure difference to prevent slagging in the gasifier. Secondly, because the black water in the quench chamber contains a large amount of solid matter, which can easily cause valve blockage, two black water angle valves are installed, one as a backup and the other in use, and switched periodically to ensure valve availability. Finally, the temperature of the liquid levels in the quench chamber and washing chamber is controlled by adjusting the valves according to the combustion status, achieving unattended operation. This invention enables intelligent and automated multi-variable process control, achieving real-time optimization of effective gas production and reduced energy consumption. Attached Figure Description

[0042] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0043] Figure 1 This is a flowchart illustrating the implementation of an advanced process control method for a fluidized bed coal-water slurry gasifier provided by the present invention. Detailed Implementation

[0044] The core of this invention is to provide an advanced process control method, device, equipment, and computer storage medium for a fluidized bed coal-water slurry gasifier, which can intelligently and automatically perform multi-variable process control, and realize real-time optimization of effective gas production and reduction of energy consumption.

[0045] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Please refer to Figure 1 , Figure 1 The flowchart illustrates the implementation of an advanced process control method for a fluidized bed coal-water slurry gasifier provided by this invention; the specific operation steps are as follows:

[0047] S101: Adjust the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and predict the real-time syngas composition based on the real-time coal slurry flow rate and real-time oxygen flow rate;

[0048] S102: With the goal of maximizing the effective gas production in the real-time syngas components, and constrained by the furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time, and the oxygen flow rate is adjusted in real time to control the combustion in the quench chamber.

[0049] S103: Based on the current opening degree of the black water valve in use and the real-time black water flow rate, trigger the switching control between the black water valve in use and the black water standby valve according to the preset shift time.

[0050] S104: Predict the quench chamber liquid level change based on combustion status data, and maintain the quench chamber liquid level by adjusting the opening of the black water in-use valve;

[0051] S105: Predict the change in the liquid level of the scrubbing tower based on the combustion status data, and maintain the liquid level of the scrubbing tower by adjusting the opening of the scrubbing tower drain valve.

[0052] For gasifiers, there are three control issues. First, combustion control needs to be addressed. This involves ensuring the coal reacts as completely as possible through proper oxygen-to-coal ratios, while simultaneously monitoring the slag outlet pressure differential to prevent slagging in the gasifier. Second, quench chamber level control needs to be addressed. The black water in the quench chamber contains a large amount of solid matter, which can easily cause valve blockage. To ensure valve availability, two black water angle valves are installed, one as a backup and one in use, and switched periodically. Combustion status also affects the quench chamber level. Finally, the scrubbing tower level needs to be stably controlled to achieve unattended operation. While ensuring a stable scrubbing tower level, the level in the condensate tank should be monitored.

[0053] Based on the above embodiments, this embodiment will provide a detailed description of step S101:

[0054] In some embodiments, adjusting the current coal slurry flow rate to a target coal slurry flow rate according to a load adjustment command, and predicting the real-time syngas composition based on the real-time coal slurry flow rate and the real-time oxygen flow rate include:

[0055] Obtain the target coal slurry flow rate setting value entered by the operator in the DCS interface;

[0056] The target coal slurry flow rate setpoint is read by the APC controller, the adjustment curve is calculated using the Lambda tuning method, and the coal slurry flow rate setpoint of the PID control loop is gradually adjusted according to the adjustment curve to ensure that the actual coal slurry flow rate smoothly transitions to the target coal slurry flow rate; in one specific embodiment:

[0057] Target coal slurry flow rate received:

[0058] Acquire the new coal slurry flow rate setting value (e.g., from 40m³) entered by the operator on the DCS interface.3 / h adjusted to 42m 3 / h).

[0059] The setting value is read through the APC controller, and dynamic optimization is initiated.

[0060] Dynamic adjustment of coal slurry flow rate:

[0061] The Lambda tuning method is used to calculate the adjustment curve to avoid system fluctuations caused by abrupt changes. The setpoint of the coal slurry flow rate in the PID control loop is gradually adjusted so that the actual coal slurry flow rate smoothly transitions to the target coal slurry flow rate.

[0062] Linked oxygen flow pre-adjustment:

[0063] Based on the current oxygen-to-coal ratio (R) O2,coal Based on the changes in coal slurry flow rate, the required oxygen flow rate adjustment can be predicted.

[0064] Adjust the oxygen flow rate in advance to avoid unstable combustion due to changes in the coal slurry.

[0065] After solving the control problem, a core optimization problem needs to be addressed: maximizing the effective gas components in the syngas while reducing coal consumption per unit of effective gas. The coal-water slurry gasification process is a partial oxidation reaction. However, due to heat losses in the gasifier and significant water evaporation during gasification, the actual oxygen-to-carbon ratio must be chosen higher than that calculated using the formula. (R O2,coal For the oxygen-to-coal ratio, m 3 / kg; R O2,carbon For the oxygen-to-carbon ratio, m 3 The theoretical calculated value ( / kg).

[0066] Thermodynamic equilibrium models, gasifier step test models, and industrial practice have demonstrated that the oxygen-to-carbon ratio (O-C ratio) significantly affects gasifier outlet temperature, effective gas production, specific coal consumption, and specific oxygen consumption. For every 0.01 increase in the O-C ratio, the gasifier outlet temperature increases by approximately 20°C. There is an optimal value for effective gas production with varying O-C ratios, ranging from 0.92 to 0.96 depending on the coal quality (our DCS display shows the oxygen-to-material ratio, which must be calculated based on the actual slurry concentration, slurry specific gravity, and carbon content in the coal). However, in actual operation, the selection of the O-C ratio must also consider the ash fusion point of the coal. The H2 content in the gas exiting the gasifier decreases with increasing oxygen-carbon ratio; the CO content increases with increasing oxygen-carbon ratio; the CO2 content first decreases and then increases with increasing oxygen-carbon ratio, and its minimum value is basically consistent with the oxygen-carbon ratio corresponding to the maximum effective gas output; the CH4 content first decreases with increasing oxygen-carbon ratio, and when the oxygen-carbon ratio exceeds 0.96, the CH4 content basically remains unchanged, which is an inevitable result of the reaction being affected by mixing at high temperature.

[0067] In summary, the optimal oxygen-to-carbon ratio, based on theoretical calculations, varies with coal quality fluctuations; both excessively high and low ratios significantly impact effective gas yield, output, coal consumption, and cost. Theoretical calculations and operator monitoring alone cannot guarantee optimal gasification. Therefore, a model is established after the gasifier's APC step test, employing a predictive control strategy. The central oxygen ratio (PV), coal slurry flow rate (PV), oxygen-to-coal ratio (PV), furnace temperature (calculated value, constraint variable), online CO2 content (PV), CH4 content (PV), gasifier outlet gas flow rate, and temperature (PV) are used as controlled variables. The central oxygen flow rate (SV), coal slurry flow rate (SV), and main oxygen flow rate (SV) are used as manipulated variables. This approach yields the optimal control strategy while incorporating feedback correction and online rolling optimization to address the challenges of large time delays and strong coupling in multivariate process control, achieving intelligent, automated, and edge-optimal operation.

[0068] Based on the above embodiments, this embodiment will provide a detailed description of step S102:

[0069] In some embodiments, with the goal of maximizing the effective gas yield in the real-time syngas composition, and constrained by furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time, and the oxygen flow rate is adjusted in real time for quench chamber combustion control, including:

[0070] Based on the thermodynamic equilibrium model and the step test model, a dynamic relationship model between effective gas production and oxygen-coal ratio in syngas components is established.

[0071] With the goal of maximizing the effective gas production in the real-time syngas components and constrained by the furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time by using model predictive control rolling optimization.

[0072] The oxygen flow rate is adjusted in real time based on the optimal oxygen-to-coal ratio, and the oxygen valve opening is adjusted through a PID control loop.

[0073] In some embodiments, the furnace temperature threshold is determined based on the ash melting point.

[0074] In one specific embodiment:

[0075] Syngas composition prediction:

[0076] Based on the thermodynamic equilibrium model and the step test model, the following relationship is established:

[0077] For every 0.01 increase in the oxygen-to-carbon ratio, the furnace temperature rises by approximately 20°C, the CO content increases, and the H2 content decreases.

[0078] Effective gas production (CO+H2) reaches its peak at an oxygen-to-carbon ratio of 0.92–0.96 (fluctuating with coal quality).

[0079] Optimize the oxygen-to-coal ratio:

[0080] Objective function: Maximize effective gas production (CO + H2).

[0081] Constraints:

[0082] The pressure difference at the slag outlet should be less than or equal to the safety threshold (to prevent slag formation).

[0083] Furnace temperature ≤ ash melting point + safety margin (to prevent slag blockage).

[0084] The optimal oxygen-coal ratio was calculated using rolling optimization with model predictive control (MPC).

[0085] Oxygen flow rate adjustment:

[0086] Based on the optimized oxygen-to-coal ratio, the oxygen flow rate setpoint is calculated backwards:

[0087] Oxygen flow rate = Coal slurry flow rate × Oxygen-to-coal ratio × Coal slurry carbon content correction factor

[0088] The oxygen valve opening is adjusted by a PID control loop to make the actual oxygen flow rate track the set value.

[0089] This embodiment adjusts the oxygen flow rate while closely monitoring the methane and carbon dioxide content in the syngas. Simultaneously, it correlates the oxygen flow rate with the effective gas yield, establishing a dynamic model between the two and maximizing the effective gas yield as the economic objective function. This achieves truly accurate and timely adjustment, bringing key parameters close to their optimal levels and avoiding careless adjustments or even misoperations by operators.

[0090] This embodiment sets up one black water angle valve in use and one on standby, switching between them once per shift. For this operation, a sequential control program is designed on the central control DCS. This program not only switches the valve position but also ensures stable water flow during the switching process. Due to differences in pipe scaling and valve characteristics, the same black water valve position may not correspond to the same water flow. Therefore, the switching program first performs a coarse adjustment, setting the opening of the standby valve to near that of the used valve. Then, based on the flow rate, it performs fine adjustments until the water flow returns to its original operating point.

[0091] Based on the above embodiments, this embodiment will provide a detailed description of step S103:

[0092] In some embodiments, triggering the switching control between the blackwater in-use valve and the blackwater standby valve based on the current blackwater valve opening and real-time blackwater flow rate according to a preset shift schedule includes:

[0093] When the shift change time is detected by the sequential control program, the switching logic is initiated.

[0094] Based on the current black water valve opening and flow characteristic curve, coarsely adjust the black water standby valve opening to be close to the current black water valve opening, and finely adjust the black water standby valve opening according to the real-time black water flow deviation until the black water flow returns to the original operating point. Completely close the current black water valve and update the operating variable in the APC controller to the black water standby valve opening.

[0095] In one specific embodiment:

[0096] Switch trigger:

[0097] The switching logic is initiated when the shift time is detected by the Sequential Operating Procedure (SOP).

[0098] Valve switching procedure:

[0099] Step 1: Based on the flow characteristic curve, adjust the opening of the standby valve to be close to the current opening of the valve in use (e.g., if the valve in use is 50% open, the standby valve will be opened to 45%).

[0100] Step 2: Fine-tune the opening of the backup valve (e.g., ±2%) based on the flow meter feedback until the flow rate returns to its original value.

[0101] Step 3: Completely close the valve in use and update the operating variable (MV) in the APC controller to the standby valve opening.

[0102] APC Collaboration:

[0103] After APC detects a change in the operating variable (MV), it automatically incorporates the new valve opening into the control range and continues to optimize the liquid level in the quench chamber.

[0104] Output:

[0105] The opening degree of the black water valve after switching (e.g., the opening degree of the standby valve is 48%).

[0106] This embodiment streamlines the operation standard operating procedure (SOP) and integrates the operation method into the sequential control program. It not only focuses on valve position switching but also on the stability of water flow after the switch. The black water valve opening is also a key performance indicator (MV) in the APC controller. After the valve switch is completed, the APC automatically detects the change in MV, automatically exits the original MV, and activates the new MV. This logic is implemented within the APC controller, truly achieving unattended black water valve switching.

[0107] Based on the above embodiments, this embodiment will provide a detailed description of step S104:

[0108] In some embodiments, predicting quench chamber liquid level changes based on combustion state data and maintaining quench chamber liquid level by adjusting the opening of the black water in-use valve includes:

[0109] Predict the change in liquid level in the quench chamber based on combustion state data including black water evaporation rate and syngas flow rate;

[0110] If the liquid level in the quench chamber is lower than the set value, the opening of the currently used black water valve will be gradually increased through the PID control loop.

[0111] If the liquid level in the quench chamber is higher than the set value, the opening of the currently used black water valve will be gradually reduced through the PID control loop.

[0112] In one specific embodiment:

[0113] Liquid level prediction model:

[0114] High-temperature combustion → increased black water evaporation → downward trend in liquid level.

[0115] Increased coal slurry flow rate leads to increased syngas flow rate, which intensifies liquid level fluctuations.

[0116] Dynamic adjustment of black water valve:

[0117] If the liquid level is lower than the set value, gradually increase the opening of the black water valve (e.g., increase by 5%).

[0118] If the liquid level is higher than the set value, the opening will be gradually reduced, and the scrubbing tower control will be activated.

[0119] Anti-congestion strategies:

[0120] Regularly switch the black water valve to prevent scale buildup from affecting control accuracy.

[0121] Based on the above embodiments, this embodiment will provide a detailed description of step S105:

[0122] In some embodiments, predicting changes in the scrubbing tower level based on combustion state data and maintaining the scrubbing tower level by adjusting the opening of the scrubbing tower drain valve includes:

[0123] Predict the change in scrubber level based on combustion status data, including syngas flow rate;

[0124] If the liquid level in the scrubbing tower is lower than the set value, the opening of the drain valve in the scrubbing tower will be gradually reduced through the PID control loop.

[0125] If the liquid level in the scrubbing tower is higher than the set value, the opening of the drain valve in the scrubbing tower will be gradually increased through the PID control loop.

[0126] In one specific embodiment:

[0127] Scrubber level control:

[0128] Predict liquid level changes based on syngas flow rate and adjust the opening of the drain valve.

[0129] If the liquid level is too high, increase the drainage rate; if it is too low, decrease the drainage rate.

[0130] condensate tank monitoring:

[0131] After the liquid level in the scrubbing tower stabilizes, check the liquid level in the condensate tank.

[0132] If the liquid level in the condensate tank is abnormal, adjust the upstream process parameters (such as the black water discharge rate from the quench chamber).

[0133] In this embodiment, the coal feed rate is treated as a controlled variable and set as a setpoint control. When load adjustments are needed, the operator modifies the setpoint. The APC controller adjusts the coal feed rate to smoothly transition to the new setpoint. During this process, the controller predicts changes in syngas composition based on coal feed rate changes and automatically adjusts the oxygen content accordingly. Simultaneously, it predicts the impact of combustion on the quench chamber liquid level and adjusts the black water valve position and quench water flow rate in a timely manner. In short, the interconnectedness of various variables ensures a smooth transition of the gasifier to the new load, during which the syngas composition is controlled and all liquid levels remain stable.

[0134] In PID tuning, this invention first understands the process control requirements, examines the condition of instruments and valves, and adjusts the filter coefficients on the DCS for variables requiring filtering. Then, using the Lambda method, an open-loop step test is performed on the loop. The lag time and settling time are identified from the response curve. One-quarter of the settling time is taken as the process time constant and Lambda. A dimensionless dynamic model between valve position and measured value is established, and the gain is determined. Then, the PID parameters are calculated using the lag time, time constant, and gain. After verification, these parameters are set in the DCS and configured as a closed loop. Fine-tuning is performed as needed, and observation is conducted over several cycles.

[0135] Based on the above embodiments, the water-coal slurry gasification furnace to which this invention can be applied includes the Jinhua furnace.

[0136] Based on the above embodiments, in one specific embodiment:

[0137] The gasifier A angle valve has four sets of eight angle valves in total: 13FIC1012A / B, 13FIC1004A / B, 14LIC1001A / B, and 14LIC1006A / B; the gasifier B angle valve has four sets of eight angle valves in total: 13FIC2012A / B, 13FIC2004A / B, 14LIC2001A / B, and 14LIC2006A / B.

[0138] The gasifier angle valves require timed opening and closing. Simultaneously, sequential control logic is implemented in the DCS, enabling automatic switching of 16 angle valves. Operators can customize the switching interval based on actual on-site operating conditions. By comparing the number of operations before and after implementation, the daily operation of the entire gasification unit significantly decreased after automatic valve switching. Before and after implementing this method, the average number of operations for these 16 angle valves decreased by 93.2%.

[0139] Table 1 below shows a comparison of the total number of operations and the average daily number of operations before and after the implementation of the method of this invention:

[0140] Table 1 Comparison of total operations and average daily operations before and after implementation of the method of the present invention.

[0141] project Not in use Put into use Reduce percentage Number of times the gasifier angle valve is operated (per day) 1818 123 93.23％ Number of operations for 13FIC1012A / B (times / day) 185 29 84.32％ Number of operations for 13FIC1004A / B (times / day) 212 13 93.87％ Number of operations for 14LIC1001A / B (times / day) 112 0.5 99.55％ Number of operations for 14LIC1006A / B (times / day) 122 0.5 99.59％ Number of operations in 13FIC2012A / B (times / day) 779 59 92.43％ 13FIC2004A / B Operation Count (times / day) 212 13.75 93.51％ Number of operations for 14LIC2001A / B (times / day) 64 1 98.44％ Number of operations for 14LIC2006A / B (times / day) 114 1 99.12％

[0142] As shown in Tables 2, 3, and 4, a comparison of the operating data of the gasifier A-angle valve reveals that the economic indicators of the gasifier A-angle valve have significantly improved after the implementation of the method of this invention. The effective gas content increased by 2.73%, the specific coal consumption decreased by 1.34%, and the by-product steam from the waste boiler increased by 9.47%. The standard deviation of the oxygen-to-coal ratio, a key indicator of the stability of the gasifier A-angle valve operation, decreased by 47.2%; the number of operations of the gasifier A-angle valve decreased by 100%, and the number of alarms decreased by 98.28%.

[0143] Table 2. Improvement rate of economic indicators before and after the implementation of the method of the present invention.

[0144]

[0145]

[0146] Table 3. Standard deviation reduction rate before and after implementation of the method of the present invention.

[0147]

[0148] Table 4. Reduction rate of alarm and operation frequency before and after the implementation of the method of the present invention.

[0149] project Before zero manual operation After zero manual operation is launched Reduction rate Number of operations 1000 times / day 0 times / day 100％ Number of alarms 697 times / day 12 times / day 98.28％

[0150] This invention also provides an advanced process control device for a fluidized bed coal-water slurry gasifier; the specific device may include:

[0151] The load adjustment control module is used to adjust the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and to predict the real-time syngas composition based on the real-time coal slurry flow rate and the real-time oxygen flow rate.

[0152] The quench chamber combustion control module is used to determine the optimal oxygen-coal ratio in real time and adjust the oxygen flow rate in real time to control the quench chamber combustion, with the goal of maximizing the effective gas production in the real-time syngas composition and constrained by the furnace temperature threshold and slag outlet pressure difference threshold.

[0153] The black water valve switching control module is used to trigger the switching control between the black water valve in use and the black water standby valve based on the current opening degree of the black water valve in use and the real-time black water flow rate, according to the preset shift time.

[0154] The quench chamber liquid level control module is used to predict changes in the quench chamber liquid level based on combustion status data and maintain the quench chamber liquid level by adjusting the opening of the black water in-use valve.

[0155] The scrubbing tower level control module is used to predict changes in the scrubbing tower level based on combustion status data and maintain the scrubbing tower level by adjusting the opening of the scrubbing tower drain valve.

[0156] The advanced process control device for the fluidized bed coal-water slurry gasifier in this embodiment is used to implement the aforementioned advanced process control method for the fluidized bed coal-water slurry gasifier. Therefore, the specific implementation of the advanced process control device for the fluidized bed coal-water slurry gasifier can be found in the embodiment section of the advanced process control method for the fluidized bed coal-water slurry gasifier above. For example, the load adjustment control module, the quench chamber combustion control module, the black water valve switching control module, the quench chamber liquid level control module, and the scrubbing tower liquid level control module are respectively used to implement steps S101, S102, S103, S104, and S105 in the aforementioned advanced process control method for the fluidized bed coal-water slurry gasifier. Therefore, its specific implementation can be referred to the description of the corresponding embodiments, and will not be repeated here.

[0157] A specific embodiment of the present invention also provides an advanced process control device for an entrained coal-water slurry gasifier, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of the aforementioned advanced process control method for an entrained coal-water slurry gasifier.

[0158] A specific embodiment of the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the aforementioned advanced process control method for an airflow bed coal-water slurry gasifier.

[0159] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0160] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0161] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0162] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0163] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An advanced process control method for a fluidized bed coal-water slurry gasifier, characterized in that, include: Adjust the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and predict the real-time syngas composition based on the real-time coal slurry flow rate and real-time oxygen flow rate. With the goal of maximizing the effective gas production in the real-time syngas components, and constrained by the furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time, and the oxygen flow rate is adjusted in real time to control the combustion in the quench chamber. Based on the current opening degree of the black water valve in use and the real-time black water flow, the switching control between the black water valve in use and the black water standby valve is triggered according to the preset shift time. Predict the quench chamber liquid level change based on combustion status data, and maintain the quench chamber liquid level by adjusting the opening of the black water in-use valve; The changes in the scrubbing tower liquid level are predicted based on combustion status data, and the liquid level in the scrubbing tower is maintained by adjusting the opening of the scrubbing tower drain valve.

2. The advanced process control method for a fluidized bed coal-water slurry gasifier according to claim 1, characterized in that, The step of adjusting the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and predicting the real-time syngas composition based on the real-time coal slurry flow rate and real-time oxygen flow rate includes: Obtain the target coal slurry flow rate setting value entered by the operator in the DCS interface; The target coal slurry flow rate setpoint is read by the APC controller, the adjustment curve is calculated using the Lambda tuning method, and the coal slurry flow rate setpoint of the PID control loop is gradually adjusted according to the adjustment curve so that the actual coal slurry flow rate smoothly transitions to the target coal slurry flow rate.

3. The advanced process control method for a fluidized bed coal-water slurry gasifier according to claim 1 or 2, characterized in that, The method of maximizing the effective gas yield in the real-time syngas composition, constrained by furnace temperature threshold and slag outlet pressure difference threshold, to determine the optimal oxygen-coal ratio in real time and to adjust the oxygen flow rate in real time for quench chamber combustion control includes: Based on the thermodynamic equilibrium model and the step test model, a dynamic relationship model between effective gas production and oxygen-coal ratio in syngas components is established. With the goal of maximizing the effective gas production in the real-time syngas components and constrained by the furnace temperature threshold and slag outlet pressure difference threshold, the optimal oxygen-coal ratio is determined in real time by using model predictive control rolling optimization. The oxygen flow rate is adjusted in real time based on the optimal oxygen-to-coal ratio, and the oxygen valve opening is adjusted through a PID control loop.

4. The advanced process control method for a fluidized bed coal-water slurry gasifier according to claim 3, characterized in that, The furnace temperature threshold is determined based on the ash melting point.

5. The advanced process control method for a fluidized bed coal-water slurry gasifier according to claim 1, characterized in that, The control method for switching between the black water in-use valve and the black water standby valve based on the current black water valve opening and real-time black water flow rate, according to a preset shift schedule, includes: When the shift time is detected by the sequential control program, the switching logic is initiated. Based on the current black water valve opening and flow characteristic curve, coarsely adjust the black water standby valve opening to be close to the current black water valve opening, and finely adjust the black water standby valve opening according to the real-time black water flow deviation until the black water flow returns to the original operating point. Completely close the current black water valve and update the operating variable in the APC controller to the black water standby valve opening.

6. The advanced process control method for a fluidized bed coal-water slurry gasifier according to claim 1 or 5, characterized in that, The step of predicting the quench chamber liquid level change based on combustion state data and maintaining the quench chamber liquid level by adjusting the opening of the black water in-use valve includes: Predict the change in liquid level in the quench chamber based on combustion state data including black water evaporation rate and syngas flow rate; If the liquid level in the quench chamber is lower than the set value, the opening of the currently used black water valve will be gradually increased through the PID control loop. If the liquid level in the quench chamber is higher than the set value, the opening of the currently used black water valve will be gradually reduced through the PID control loop.

7. The advanced process control method for a fluidized bed coal-water slurry gasifier according to claim 6, characterized in that, The step of predicting the change in the scrubbing tower liquid level based on combustion state data and maintaining the scrubbing tower liquid level by adjusting the opening of the scrubbing tower drain valve includes: Predict the change in scrubber level based on combustion status data, including syngas flow rate; If the liquid level in the scrubbing tower is lower than the set value, the opening of the drain valve in the scrubbing tower will be gradually reduced through the PID control loop. If the liquid level in the scrubbing tower is higher than the set value, the opening of the drain valve in the scrubbing tower will be gradually increased through the PID control loop.

8. An advanced process control device for a fluidized bed coal-water slurry gasifier, characterized in that, include: The load adjustment control module is used to adjust the current coal slurry flow rate to the target coal slurry flow rate according to the load adjustment command, and to predict the real-time syngas composition based on the real-time coal slurry flow rate and the real-time oxygen flow rate. The quench chamber combustion control module is used to determine the optimal oxygen-coal ratio in real time and adjust the oxygen flow rate in real time to control the quench chamber combustion, with the goal of maximizing the effective gas production in the real-time syngas composition and constrained by the furnace temperature threshold and slag outlet pressure difference threshold. The black water valve switching control module is used to trigger the switching control between the black water valve in use and the black water standby valve based on the current opening degree of the black water valve in use and the real-time black water flow rate, according to the preset shift time. The quench chamber liquid level control module is used to predict changes in the quench chamber liquid level based on combustion status data and maintain the quench chamber liquid level by adjusting the opening of the black water in-use valve. The scrubbing tower level control module is used to predict changes in the scrubbing tower level based on combustion status data and maintain the scrubbing tower level by adjusting the opening of the scrubbing tower drain valve.

9. A device, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of an advanced process control method for a fluidized bed coal-water slurry gasifier as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of an advanced process control method for a fluidized bed coal-water slurry gasifier as described in any one of claims 1 to 7.

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