Method for intelligently controlling dust collection time

Abstract

The application discloses a method for intelligently controlling ash collecting time, belongs to the technical field of coal chemical industry, and is improved on the basis of an existing fly ash gas stripping emission sequence control program. When the ash collecting sequence control goes to the ninth step, i.e. a lock hopper tank starts to discharge into a gas stripping storage tank, the gas stripping storage tank weighing weight W1 is recorded. When the sequence control goes to the tenth step, i.e. the discharging is completed, the gas stripping storage tank weighing weight W2 is recorded. If W2-W1 is greater than or equal to 8t, then the ash collecting time T1 is equal to 8T0 / (W2-W1). If W2-W1 is less than 8t, then T1 is equal to T0+600s. T0 is increased by 600s, which can prevent misjudgment caused by ash wall hanging. When the ash wall hanging is not completed, there is ash storage in the tank, and the tank is not easy to accept too much ash. When the ash collecting sequence control goes to the tenth step, a new T1 is assigned to replace the original T0, and T0 is a change value, which can automatically follow the coal type and save energy and resources. Through real-time calculation of the ash collecting amount, the ash collecting time is reasonably set, the nitrogen gas amount for ash collecting can be maximally saved, the filter damage is avoided, and the operation cost and maintenance cost can be saved.

Description

Technical Field

[0001] This invention belongs to the field of coal chemical technology, specifically relating to a method for intelligently controlling ash collection time. Background Technology

[0002] Dry ash removal systems are a crucial production process in coal gasification plants. During operation, these systems follow procedures for fly ash treatment and removal, gas stripping / cooling, fly ash discharge, and temporary dry ash storage. The dry ash removal system filters syngas through a filter and separates fly ash from the coal gas through a sieve. After filtration, the fly ash content in the crude coal gas is controlled at 20 mg / Nm³. 3 The following applies: Clean gas passes through the filter, while dust falls outside the filter holes. Over time, the accumulation of fly ash will cause the filter resistance to increase.

[0003] In coal gasification plants, the timing of the ash collection unit is particularly important. If the timing is set too short, a large amount of nitrogen is wasted, which contradicts energy conservation. If the timing is set too long, a large amount of ash will remain in the tank, which is not conducive to gas lifting and depressurization, and also poses a serious threat to the safety of the filter rods.

[0004] To address the technical problem of energy waste caused by unreasonable ash collection time in existing ash collection programs, there is an urgent need to find a method for intelligently controlling ash collection time, enabling real-time calculation of ash collection volume and reasonable setting of ash collection time to achieve both energy saving and safety. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for intelligently controlling the ash collection time, so as to solve the technical problem that the ash collection time of the existing ash collection program is unreasonable, resulting in energy waste.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for intelligently controlling ash collection time. The sequential control of fly ash gas stripping emission in the ash collection system includes the following steps:

[0008] 0) Confirm that there is no material remaining in the fly ash stripping storage tank and that it is not in the stripping state;

[0009] 1) Confirm that the fly ash stripping storage tank has been successfully received;

[0010] 2) The fly ash stripping storage tank is pressurized with nitrogen;

[0011] 3) Pressurize the fly ash stripping storage tank to the specified pressure and then stop pressurizing;

[0012] 4) The fly ash stripping storage tank is depressurized by stripping.

[0013] 5) The fly ash stripping storage tank has completed its first stripping operation;

[0014] 6) The fly ash stripping storage tank completes multiple stripping / cooling operations according to the procedure;

[0015] 7) Once multiple air lifts are completed, the counter is reset to zero;

[0016] 8) Confirm the material level in the downstream ash tank of the fly ash stripping storage tank to ensure that the fly ash stripping storage tank can discharge material;

[0017] 9) The fly ash stripping storage tank discharges material from the downstream ash tank and records the weight W1 of the ash tank before discharge.

[0018] 10) The fly ash stripping storage tank is discharged, and the weight of the ash tank W2 after discharge is recorded, and the control returns to step 0).

[0019] 11) Confirm that the fly ash stripping storage tank is empty, and then proceed with the shutdown procedure;

[0020] When W2-W1≥8t, the ash collection time T1=8T0 / (W2-W1); when W2-W1<8t, the time T1=T0+600s;

[0021] Where T0 is the initial ash accumulation time set in the sequential control of the ash collection system; T1 is the ash accumulation time that needs to be set in the optimized sequential control of the ash collection system.

[0022] When the ash collection sequence control completes step 10), the new T1 is assigned to replace the original T0.

[0023] Preferably, in step 1), the time for the fly ash stripping storage tank to complete receiving the material is not less than 900 seconds.

[0024] Preferably, in step 2), when nitrogen is pressurized, the fly ash gas stripping storage tank closes the pressure relief valve and opens the pressurization and fluidizing nitrogen valve.

[0025] Preferably, in step 3), pressurization is stopped when the fly ash stripping storage tank is pressurized to 0.20 MPa.

[0026] Preferably, in step 4), when performing gas lift and depressurization, the pressurization and fluidizing nitrogen valves are closed, and the depressurization valve is opened.

[0027] Preferably, in step 5), the first gas stripping is completed when the fly ash stripping storage tank is depressurized to 0.10 MPa.

[0028] Preferably, in step 6), the fly ash stripping storage tank completes at least two stripping / cooling operations.

[0029] Preferably, in step 8), it is confirmed that the material level in the downstream ash tank of the fly ash stripping storage tank is not higher than 24t.

[0030] Preferably, in step 9), the discharge time from the fly ash stripping storage tank to the downstream ash tank is 300s.

[0031] Preferably, T0 is adjusted according to the type of coal.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] This invention discloses a method for intelligently controlling fly ash collection time. The fly ash air stripping discharge sequence control includes: 0) confirming that there is no material remaining in the fly ash air stripping storage tank and that it is not in the air stripping state; 1) confirming that the fly ash air stripping storage tank has completed receiving material; 2) pressurizing the fly ash air stripping storage tank with nitrogen; 3) pressurizing the fly ash air stripping storage tank to the specified pressure and stopping pressurization; 4) depressurizing the fly ash air stripping storage tank; 5) completing the first air stripping in the fly ash air stripping storage tank; 6) completing multiple air stripping / cooling operations in the fly ash air stripping storage tank according to the program; 7) determining that multiple air stripping operations have been completed and resetting the counter to zero; 8) confirming the material level in the downstream ash tank of the fly ash air stripping storage tank to ensure that the fly ash air stripping storage tank can discharge material; 9) The fly ash stripping storage tank discharges material into the downstream ash tank and records the weight of the ash tank before discharge, W1; 10) The fly ash stripping storage tank completes the discharge and records the weight of the ash tank after discharge, W2, and the sequential control returns to step 0); 11) Confirm that the fly ash stripping storage tank is empty and the sequential control stops; When W2-W1≥8t, the ash collection time T1=8T0 / (W2-W1); When W2-W1<8t, T1=T0+600; T0 is increased by 600s to prevent ash from adhering to the wall, leading to misjudgment and affecting equipment safety; When ash is not completely discharged due to wall adhesion, there is ash remaining in the tank, and it is not easy to accept too much ash to avoid exceeding the equipment's capacity. Among them, T0 is the initial ash accumulation time set in the sequential control of the ash collection system; T1 is the ash accumulation time that needs to be set in the optimized sequential control of the ash collection system; When the ash collection sequential control completes step 10), the new T1 is assigned to replace the original T0. T0 is a variable value that automatically follows the coal type, achieving economic efficiency and energy saving. The intelligent control method for ash collection time disclosed in this invention involves the following steps: when the ash collection control reaches step 9, the lock hopper begins discharging material into the stripping storage tank, and the weight of the stripping storage tank is recorded as W1. When the control reaches step 10, discharging ends, and the weight of the stripping storage tank is recorded as W2. Upon completion of step 10, the new T1 value replaces the original T0. This invention achieves energy saving and safety by calculating the ash collection volume in real time and rationally setting the ash collection time. This design maximizes the saving of nitrogen used for ash collection while avoiding filter damage caused by excessive ash collection. It also saves operating costs and maintenance expenses. Attached Figure Description

[0034] Figure 1 This is a flowchart of a method for intelligently controlling ash collection time disclosed in this invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] The present invention will now be described in further detail with reference to the accompanying drawings:

[0038] Pulverized coal enters the pulverized coal lock hopper from the pulverized coal storage silo by gravity. After the pulverized coal lock hopper is full, it is isolated from all low-pressure equipment. High-pressure nitrogen is used to raise its pressure to balance with the coal feed tank. Then, the connecting valve of the balance pipeline between the pulverized coal lock hopper and the coal feed tank is opened. Once the coal feed tank reaches the low material level, the hopper discharge valve is opened to unload the coal. After unloading, the hopper is isolated from the coal feed tank, and the pressure is reduced to near atmospheric pressure in three stages. Then, the feed valve at the top of the hopper is opened to receive pulverized coal from the silo. After the hopper is fully filled, it is repressurized and awaits the next discharge signal. The pulverized coal in the coal feed tank, under the control of the coal circulation / feeding program, is metered and regulated before entering the burners. When the pulverized coal circulates, it is depressurized and returned to the silo through the pressure reducing pipe. The pressure in the coal feed pipe is controlled proportionally to the gasifier pressure through a range control system. When the pressure is low, nitrogen is added; when the pressure is high, it is vented to the small filter bag.

[0039] The ash removal process is as follows: The crude syngas exiting from the bottom of the syngas cooler passes through a high-temperature, high-pressure ceramic filter to remove fly ash. The clean syngas exits from the top of the filter and is split into two paths: one path goes to the wet scrubbing system for further washing and cooling, and the other, a small amount, goes to the quench compressor. Fly ash is collected in an ash collector at the bottom of the filter and discharged into an ash lock hopper. When the ash accumulation timer runs out or the hopper level is high, the program closes the ash collector's discharge valve and completely isolates the ash collector from the ash lock hopper, reducing the hopper pressure to near atmospheric pressure in three stages. Then, the hopper discharge valve is opened, and the fly ash is discharged into the air-lift tower cooler for air-lifting and cooling. After the ash lock hopper is discharged, its pressure is increased to match that of the ash collector using high-pressure nitrogen. Then, the connecting valve between them and the ash lock hopper feed valve are opened to begin collecting ash again.

[0040] See Figure 1This is a flowchart of a method for intelligently controlling ash collection time disclosed in this invention. As can be seen from the diagram, the sequential control steps of the ash collection system include: confirming that 35XV0101, 35XV0104, 35XV0026, 35XV0050, 35XV0106, 35XV0110, 35XV0111, 35XV0112 / 0012, and 35XV0113 are closed, and that 35XV0102, 35XV0103, 35XV0108, and 35XV0109 are opened, and that the fly ash collector V... -3501A is connected to fly ash discharge tank V-3502A. After ash accumulation timer reaches 60 (T0) minutes, 35KS-0001A is activated. When the fly ash discharge tank V-3502A has a high material level, 35XV0102 is closed; then 35XV0103, 35XV0108, and 35XV0109 are closed; 35XV0112 is opened for pressure reduction, with the first step of pressure reduction lasting 17 minutes; when 35PI0106 < 1.6 MPa and 35PDI0107 < 20 kPa, 35XV0112 is closed, and the process is repeated. First, the pressure relief timer is activated; 35XV0111 is turned on to reduce pressure, and the second step of pressure relief lasts for 7 minutes; when 35PI0106 < 0.4 MPa, 35XV0111 and 35XV0112 are activated, the second step pressure relief timer is reset, and the third step of pressure relief lasts for 6 minutes; when 35PI0106 < 0.3 MPa and 35US0014A is running, the third step pressure relief timer is reset; 35XV0015 and 35XV0112 are turned off; when 35PI0106 < 0.025 MPa, 35XV0101 is activated. 014 and 35XV0050; turn on 35XV0106; turn on 35XV0026, turn off after 20 seconds; turn on 35XV0104, put 35PC0105 into automatic mode, start the emission clock for 15 minutes, turn off 35XV0111 / 35XV0112; when 35PI0017 < 0.7MPa, turn on 35XV0104 and 35XV0106, and turn off 35XV0026; when V-3504A > 80 tons, turn off 35XV0106; turn off 35XV0050.Reset the discharge timer, reset 35US0014A, and send the signal to 35KS0002A in step one; when 35PI0106 > 0.5MPa, open 35XV0013 and 35XV0104, and switch 35PIC0105 to the maximum pressure control; when the pressure difference between valves V-3501A and V-3502A is high (report 35PDI0108 > 10KPa), open 35XV0113; close 35XV0104, 35XV0113, and 35PV0105, and open 35XV0110 and 35PIC01. 05. Switch to minimum pressure control; 35PD0108 / 0008 remains between 10Kpa and 20Kpa for 10 seconds, then 35XV0103 and 35XV0101 are opened, 35XV0110 is closed, and 35PV0109 is manually closed; 35XV0102 is opened, and 35XV0101 is closed after 10 seconds; 35XV0109 and 35XV0108 are opened; the evacuation timer is started for 10 minutes; when V-3501A reports a low level, the evacuation timer is reset; the process exits when V3501A shows a low level and there is no stop signal.The steps for controlling fly ash stripping emissions include: confirming that 35XV0022, 35XV0025, and 35FV0015 are closed; V-3504A reports a low level (35WI0001 < 0t) and 35TI0009 reports a low level (< 150℃), or overrides; triggering 35KS0001A in step 0 or starting by pressing "Start"; confirming that 35XV0015 / 0078 is closed and 35XV0014 is open, or that 35KS0001A has a stop command; and resetting 35US0014A; and closing 35XV0106 / 0050; and closing 35XV001 if 35WI0001 does not report a low level. 4. Turn on 35XV0022 and turn it off after one minute. After one minute, confirm that 35XV0022 is off, and turn on 35XV0025 after five minutes. After five minutes, turn on 35XV0025. After confirming that 35XV0025 is on, V-3504A will report a high pressure (35PSH0017>0.2Mpa). Turn off 35XV0025 and 35FV0015. Turn on 35XV0014. When 35PI0017<0.1Ppa, wait for one minute, turn on 35FIC0015 to switch to the purge setting SP value, and 35FV0015 will be cascaded. When 35QI0002>5... When 0 ppm or 35TI0009 > 150℃, 35FV0015 is manually shut down, and the stripping counter increments by 1; when 35TI0009 < 150℃ and the CO content in the S3503A exhaust gas is low (35QI0002 < 50ppm), and both signals persist for more than 15 seconds or an override signal is received, the stripping counter is reset; when 35WI0102 < 24t or an override command is received, 35XV0014 is shut down, and 35FV0015 is manually shut down; when 35FIC0015 / 65 is switched to the discharge setting SP value, 35XV0015 is turned on, 35XV0078 is turned on, and 35FV0015 is cascaded. Start the discharge timer for 15 minutes, turn on 35XV0015, 35XV0078, and 35FV0015 before cascading and record the V3504A weighing W1; confirm there is no stop command, and 35XV0015 is in the correct position with a 300-second delay or override, and 35FV0015 is manually turned off. Then start 35US0014A, turn on 35XV0014, turn off 35XV0078 / 15, reset the discharge timer, and record the V3504A weighing W2. The program loops. When there is a stop command, 35FV0015 is manually turned off, 34US0014A and the discharge timer are reset, the program stops, and the exit is displayed.

[0041] Table 1 Sequential Control of Ash Collection System

[0042]

[0043]

[0044] Table 2 Fly Ash Gas Stripping Emission Control

[0045]

[0046]

[0047] See Table 1 for the sequential control of the ash collection system; as can be seen from Table 1, the ash collection time is fixed and has no ability to adapt to changes in coal type. When the ash content of the coal used for gasification is low, it is easy to waste nitrogen. When the ash content of the coal used for gasification is high, excessive ash collection will cause the equipment to operate beyond its specifications and damage the filtration equipment.

[0048] See Table 2 for the fly ash gas stripping emission control. As can be seen from Table 2, through the improvement of the control system 35KS0002A and its linkage with control system 35KS0001A, the original control system has resolved the following issues: lack of adaptability to changes in coal type; when the ash content of the coal used for gasification is low, it easily leads to nitrogen waste; when the ash content of the coal used for gasification is high, excessive ash collection can cause equipment to operate beyond its specifications and damage the filtration equipment.

[0049] This invention discloses a method for intelligently controlling ash collection time, wherein the fly ash gas stripping emission control in the ash collection system includes the following steps:

[0050] 0) Confirm that there is no material remaining in the fly ash stripping storage tank and that it is not in the stripping state;

[0051] 1) Confirm that the fly ash stripping storage tank has completed receiving; the receiving time should not be less than 900 seconds.

[0052] 2) Nitrogen pressurization is performed on the fly ash stripping storage tank; during nitrogen pressurization, the pressure relief valve of the fly ash stripping storage tank is closed, and the pressurization and fluidizing nitrogen valves are opened;

[0053] 3) Pressurize the fly ash stripping storage tank to the specified pressure and then stop pressurizing; stop pressurizing the fly ash stripping storage tank when it reaches 0.20 MPa.

[0054] 4) Perform gas stripping and depressurization on the fly ash gas stripping storage tank; when performing gas stripping and depressurization, close the pressurization and fluidizing nitrogen valves and open the depressurization valve.

[0055] 5) The fly ash stripping storage tank completes the first stripping operation; the first stripping operation is completed when the fly ash stripping storage tank is depressurized to 0.10 MPa.

[0056] 6) The fly ash stripping storage tank shall complete multiple stripping / cooling operations according to the procedure; the fly ash stripping storage tank shall complete at least two stripping / cooling operations.

[0057] 7) Once multiple air lifts are completed, the counter is reset to zero;

[0058] 8) Confirm the material level in the downstream ash tank of the fly ash stripping storage tank to ensure that the fly ash stripping storage tank can discharge material; confirm that the material level in the downstream ash tank of the fly ash stripping storage tank is not higher than 24t.

[0059] 9) The fly ash stripping storage tank discharges material from the downstream ash tank and records the weight of the ash tank W1 before discharge; the discharge time from the fly ash stripping storage tank to the downstream ash tank is 300s.

[0060] 10) The fly ash stripping storage tank is discharged, and the weight of the ash tank W2 after discharge is recorded, and the control returns to step 0).

[0061] 11) Confirm that the fly ash stripping storage tank is empty, and then proceed with the shutdown procedure;

[0062] When W2-W1≥8t, the ash collection time T1=8T0 / (W2-W1); when W2-W1<8t, the time T1=T0+600s;

[0063] Where T0 is the initial ash accumulation time set in the sequential control of the ash collection system; T1 is the ash accumulation time that needs to be set in the optimized sequential control of the ash collection system.

[0064] When the ash collection control completes step 10), the new T1 value replaces the original T0; T0 is adjusted according to the type of coal; when the ash content of the coal is around 15% and the ash melting point is around 1260°, T0 corresponds to 6000s; when the ash content of the coal exceeds 22% and the ash melting point is around 1150°, T0 corresponds to 5000s.

[0065] In this invention, the ash collection sequence control refers to 35KS0002A, but T0 operates within 35KS0001A, with the default time being seconds. When the fly ash air stripping discharge sequence control reaches step 9, i.e., the lock hopper begins discharging material into the air stripping storage tank, the weight of the air stripping storage tank is recorded as W1. When the sequence control reaches step 10, i.e., the discharging ends, the weight of the air stripping storage tank is recorded as W2. When W2-W1≥8t, the ash collection time T1=8T0 / (W2-W1); when W2-W1<8t, T1=T0+600s. Increasing T0 by 600s is to prevent ash from adhering to the walls, leading to misjudgments and affecting equipment safety. When ash remains in the tank due to wall adhesion, it is difficult to accept excessive ash to avoid exceeding the equipment's capacity. When the ash collection sequence control completes step 10, the new T1 value replaces the original T0. In this invention, T0 is a variable value; this value can automatically follow the type of coal, thus achieving economic efficiency and energy saving.

[0066] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for intelligently controlling dusting time, characterized in that, The fly ash gas extraction emission sequence control in the fly ash collecting system comprises the following steps: 0) confirming that there is no material in the fly ash gas extraction tank and the fly ash gas extraction tank is not in the gas extraction state; 1) confirming that the fly ash gas extraction tank has completed material receiving; 2) the fly ash gas extraction tank is pressurized by nitrogen; 3) the fly ash gas extraction tank is pressurized to a specified pressure, and the pressurization is stopped; 4) the fly ash gas extraction tank is depressurized by gas extraction; 5) the fly ash gas extraction tank completes the first gas extraction; 6) the fly ash gas extraction tank completes multiple gas extractions / cooling according to the program; 7) determining that the multiple gas extractions are completed, and the counter is reset to zero; 8) confirming the material level of the downstream ash tank of the fly ash gas extraction tank to ensure that the fly ash gas extraction tank can discharge material; 9) the fly ash gas extraction tank discharges material to the downstream ash tank, and records the weight W1 of the ash tank before discharging material; 10) the fly ash gas extraction tank completes discharging material, records the weight W2 of the ash tank after discharging material, and returns to step 0) in sequence; 11) confirming that the fly ash gas extraction tank has no material, and the sequence control is stopped; When W2-W1≥8t, then the fly ash collecting time T1=8T0 / (W2-W1); when W2-W1<8t, then T1=T0+600s; Wherein, T0 is the initial setting of the fly ash collecting system sequence control; T1 is the fly ash collecting system sequence control that needs to be set after optimization; When step 10) of the fly ash sequence control is completed, the new T1 is assigned to replace the original T0.

2. The method of claim 1, wherein, In step 1), the time for the fly ash gas extraction tank to complete material receiving is not less than 900s.

3. The method of claim 1, wherein, In step 2), when the nitrogen pressurization is performed, the fly ash gas extraction tank closes the pressure relief valve, and opens the pressurization and fluidized nitrogen valve.

4. The method of claim 1, wherein, In step 3), the fly ash gas extraction tank stops pressurizing when the pressure reaches 0.20Mpa.

5. The method of claim 1, wherein, In step 4), when the gas extraction is performed, the pressurization and fluidized nitrogen valve is closed, and the pressure relief valve is opened.

6. The method of claim 1, wherein, In step 5), the fly ash gas extraction tank completes the first gas extraction when the pressure is reduced to 0.10Mpa.

7. The method of claim 1, wherein, In step 6), the fly ash gas extraction tank completes at least two gas extractions / cooling.

8. The method of claim 1, wherein, In step 8), the material level of the downstream ash tank of the fly ash gas extraction tank is not higher than 24t.

9. The method of claim 1, wherein, In step 9), the fly ash gas extraction tank discharges material to the downstream ash tank for 300s.

10. The method of claim 1, wherein, T0 is adjusted and set according to the type of coal.

Images