Automatic judgment and selection method for liquid level of dry quenching steam drum
By setting multiple liquid level measurement points in the dry quenching steam drum, and automatically calculating and feedbacking the measured values to the PID control system, the abnormal liquid level regulation problem caused by industrial instrument failure is solved, and higher liquid level regulation accuracy and stability are achieved.
Patent Information
- Application Number
- CN202411913373.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-24
- Publication Date
- 2025-03-25
AI Technical Summary
During the operation of the dry-quenching drum of the coking plant, an industrial instrument failure causes an abnormal current measurement value received in the PID control system, affecting the liquid level regulation of the drum, and it is difficult for the operator to detect and switch the measurement points in time, resulting in abnormal liquid level.
A method of automatic determination and selection of liquid level of dry quenching steam drum is adopted. By setting multiple liquid level measurement points, the measured value is automatically calculated and fed back to the PID control system. When any measurement point remains normal, the unique measurement value is output for regulation; if all measurement points fail, an emergency alarm will be issued waiting for manual intervention.
It reduces the abnormality of drum liquid level, improves the accuracy and stability of drum liquid level regulation, reduces the abnormal operation caused by the operator's delay in switching measurement points, and improves the stability of the normal operation of the dry-quenching drum in the coking plant.
Smart Images
Figure CN119690151A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of steam drums, and in particular to a method for automatically judging and selecting the liquid level of a dry coke quenching steam drum. Background Art
[0002] During the operation of the dry coke quenching drum in a coking plant, the liquid level of the drum needs to be regulated. If the liquid level of the drum is too high, it will affect the steam-water separation effect and cause steam to carry liquid; if the liquid level of the drum is too low, it will destroy the water circulation and shorten the life of the boiler.
[0003] In the process of PID control of the liquid level of the dry coke quenching drum in the coking plant, since the industrial instruments themselves have a life span and most of them are installed outdoors, they may fail or be damaged due to various reasons such as water ingress and aging, causing the current measurement value received in the PID control to be abnormal, thus affecting the regulation of the drum liquid level. In response to this situation, multiple measurement points are currently set on the drum, one is connected to the PID control system, and the others are used to check the actual liquid level of the drum. When the operator finds that the drum liquid level is abnormal, the measurement point is manually switched.
[0004] However, in actual control, the current measurement value in the PID control system can only select one of the measurement points for control. If the instrument point used for the current measurement value in the PID control system is damaged, the current measurement value will be inaccurate, and the liquid level adjusted by PID will be inaccurate in a short period of time, resulting in abnormal liquid level. Since the operator is concerned about too many production parameters, it is difficult to detect abnormal drum liquid level in time, resulting in too late manual intervention selection, affecting the normal operation of the dry coke quenching drum of the coking plant. Summary of the invention
[0005] In order to facilitate the adjustment of the dry coke quenching drum liquid level and improve the stability of the normal operation of the dry coke quenching drum in a coking plant, the present application provides a method for automatically judging and selecting the dry coke quenching drum liquid level.
[0006] The present application provides a method for automatically judging and selecting the liquid level of a dry coke quenching drum, which adopts the following technical solution: A method for automatically judging and selecting the liquid level of a dry coke quenching drum comprises the following steps: S1. Set standard parameters; S2, maintain the current measurement value P; collect liquid level data; S3. If all the measuring points are damaged, proceed to step S9; if not all the measuring points are damaged, proceed to step S4; S4, calculating the maximum liquid level difference A; S5, if the liquid level is stable, proceed to step S7; if the liquid level fluctuates slightly, proceed to step S6; if the liquid level fluctuates violently, proceed to step S8; S6, taking the maximum value Y1 among all effective values as the measured value P and inputting it into the PID control system, and proceeding to step S2; S7, taking the average value Y2 of all effective values as the measured value P and inputting it into the PID control system, and proceeding to step S2; S8, taking the minimum value Y3 among all effective values as the measured value P and inputting it into the PID control system, and proceeding to step S2; S9. Maintain the current measured value P, issue an emergency alarm, and conduct manual intervention.
[0007] Preferably, the step S1 includes the following steps: setting a first liquid level threshold H1; and setting a second liquid level threshold H2.
[0008] Preferably, step S5 includes the following steps: if 0<A≤H1, the liquid level is stable, and step S7 is performed; if H1<A≤H2, the liquid level fluctuates slightly, and step S6 is performed; if A>H2, the liquid level fluctuates violently, and step S8 is performed.
[0009] Preferably, step S2 comprises the following steps: S21, maintaining the current measurement value P; obtaining the liquid level of the first measurement point, the liquid level of the second measurement point, and the liquid level of the third measurement point at the same time; S22, the liquid level at the first measuring point is output as the first collected value; the liquid level at the second measuring point is output as the second collected value; the liquid level at the third measuring point is output as the third collected value; S23, if the first measuring point has a bad pixel, a first measuring point fault alarm is issued, the first effective value X1 is 0, and step S24 is performed; if the first measuring point has no bad pixel, the first effective value X1 is the first collection value, and step S24 is performed; S24, if the second measuring point has a bad pixel, a second measuring point fault alarm is issued, the second effective value X2 is 0, and step S25 is performed; if the second measuring point has no bad pixel, the second effective value X2 is the second collection value, and step S25 is performed; S25, if the third measuring point has a bad pixel, a third measuring point fault alarm is issued, the third effective value X3 is 0, and step S26 is performed; if the third measuring point has no bad pixel, the third effective value X3 is the third collection value, and step S26 is performed; S26. Output the first effective value X1, the second effective value X2 and the third effective value X3.
[0010] Preferably, step S3 includes the following steps: if X1=X2=X3=0, all the measuring points are damaged, and step S9 is performed; if X1>0 or X2>0 or X3>0, not all the measuring points are damaged, and step S4 is performed.
[0011] Preferably, step S4 comprises the following steps: S41, if X1>X2, proceed to step S42; if X1≤X2, proceed to step S44; S42, if X1≤X3, the maximum value Z1 is X3, the middle value Z2 is X1, the minimum value Z3 is X2, and the process goes to step S46; if X1>X3, the maximum value Z1 is X1, and the process goes to step S43; S43, if X2≤X3, the middle value Z2 is X3, the minimum value Z3 is X2, and the step S46 is performed; if X2>X3, the middle value Z2 is X2, the minimum value Z3 is X3, and the step S46 is performed; S44, if X2≤X3, the maximum value Z1 is X3, the middle value Z2 is X2, the minimum value Z3 is X1, and the process goes to step S46; if X2>X3, the maximum value Z1 is X2, and the process goes to step S45; S45, if X1≤X3, the middle value Z2 is X3, the minimum value Z3 is X1, and the process goes to step S46; if X1>X3, the middle value Z2 is X1, the minimum value Z3 is X3, and the process goes to step S46; S46, if Z1≤0, proceed to step S9; if Z1>0, proceed to step S47; S47, if Z2≤0, proceed to step S6; if Z2>0, proceed to step S48; S48. If Z3≤0, calculate the maximum effective value difference A, A=Z1-Z2, and proceed to step S5; if Z3>0, calculate the maximum effective value difference A, A=Z1-Z3, and proceed to step S5.
[0012] Preferably, step S6 comprises the following steps: S61, the maximum value Y1 among all valid values is the maximum value Z1; S62, output measurement value P, P=Y1; S63. Go to step S2.
[0013] Preferably, step S7 comprises the following steps: S71. If Z3≤0, then Y2=(Z1+Z2) / 2, and proceed to step S72; if Z3>0, then Y2=(Z1+Z2+Z3) / 3, and proceed to step S72; S72, output measurement value P, P=Y2; S73. Go to step S2.
[0014] Preferably, step S8 comprises the following steps: S81. If Z3≤0, then Y3=Z2, and proceed to step S82; if Z3>0, then Y3=Z3, and proceed to step S82; S82, output measurement value P, P=Y3; S83. Go to step S2.
[0015] In summary, the present application includes at least one of the following beneficial technical effects: 1. Three liquid level measurement points are set in the drum. According to the values of the liquid level measurement points, the measurement values are automatically calculated and fed back to the PID control system. As long as any one of the liquid level measurement points is in normal use, a unique measurement value can be output to the PID control system to regulate the drum liquid level, reduce the abnormal situation of the drum liquid level, and achieve the effect of facilitating the adjustment of the dry coke quenching drum liquid level; 2. The faulty liquid level measurement point will give an alarm feedback and wait for the operator to repair it. The other normal measurement points will calculate the data to obtain a unique measurement value, so that the measurement value can be continuously fed back to the PID control system, reducing the situation where the dry quenching drum of the coking plant operates abnormally due to the operator's untimely switching of the measurement point, and improving the stability of the normal operation of the dry quenching drum of the coking plant; 3. Obtain the fluctuation of the drum liquid level based on the data of the measuring point, so as to automatically select the most appropriate measurement value calculation mode to improve the accuracy and reliability of the measurement value; 4. According to the working conditions of the measuring points, the data of the faulty measuring points are automatically eliminated, and the data of the normal measuring points are used to obtain the measured values, thereby improving the accuracy and reliability of the measured values. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a flow chart of a method for automatically judging and selecting the liquid level of a dry coke quenching drum in an embodiment of the present application.
[0017] Figure 2 It is a flow chart of determining whether all measuring points are damaged in an embodiment of the present application.
[0018] Figure 3 It is a flow chart showing how to obtain the maximum value, the intermediate value and the minimum value in the embodiment of the present application.
[0019] Figure 4 It is a flow chart showing how to obtain the maximum liquid level difference in an embodiment of the present application. DETAILED DESCRIPTION
[0020] The following is combined with Figure 1-4 This application is described in further detail.
[0021] The present application embodiment discloses a method for automatically determining and selecting the liquid level of a dry coke quenching drum. Figures 1 to 4 , including the following steps.
[0022] S1, setting standard parameters, step S1 includes the following steps: setting the first liquid level threshold H1 to 15 mm; setting the second liquid level threshold H2 to 25 mm.
[0023] S2, maintaining the current measurement value P and collecting liquid level data. Step S2 includes the following steps.
[0024] S21, maintaining the current measurement value P; obtaining the liquid level at the first measurement point, the liquid level at the second measurement point, and the liquid level at the third measurement point at the same time.
[0025] S22, the liquid level at the first measuring point is output as a first collected value; the liquid level at the second measuring point is output as a second collected value; and the liquid level at the third measuring point is output as a third collected value.
[0026] S23. If the first measuring point has a bad pixel, a fault alarm of the first measuring point is issued, the first effective value X1 is 0, and step S24 is performed; if the first measuring point has no bad pixel, the first effective value X1 is the first collection value, and step S24 is performed.
[0027] S24. If the second measuring point has a bad pixel, a fault alarm of the second measuring point is issued, the second effective value X2 is 0, and step S25 is performed; if the second measuring point has no bad pixel, the second effective value X2 is the second collection value, and step S25 is performed.
[0028] S25. If the third measuring point has a bad pixel, a third measuring point fault alarm is issued, the third effective value X3 is 0, and step S26 is performed; if the third measuring point has no bad pixel, the third effective value X3 is the third collection value, and step S26 is performed.
[0029] S26. Output the first effective value X1, the second effective value X2 and the third effective value X3.
[0030] S3. If X1=X2=X3=0, all the measuring points are damaged, and the process goes to step S9; if X1>0 or X2>0 or X3>0, not all the measuring points are damaged, and the process goes to step S4.
[0031] S4, calculating the maximum liquid level difference A. Step S4 includes the following steps.
[0032] S41. If X1>X2, proceed to step S42; if X1≤X2, proceed to step S44.
[0033] S42. If X1≤X3, the maximum value Z1 is X3, the middle value Z2 is X1, the minimum value Z3 is X2, and the process goes to step S46; if X1>X3, the maximum value Z1 is X1, and the process goes to step S43.
[0034] S43. If X2≤X3, the middle value Z2 is X3, the minimum value Z3 is X2, and the step S46 is performed; if X2>X3, the middle value Z2 is X2, the minimum value Z3 is X3, and the step S46 is performed.
[0035] S44. If X2≤X3, the maximum value Z1 is X3, the middle value Z2 is X2, the minimum value Z3 is X1, and the process goes to step S46; if X2>X3, the maximum value Z1 is X2, and the process goes to step S45.
[0036] S45. If X1≤X3, the middle value Z2 is X3, the minimum value Z3 is X1, and the step S46 is performed; if X1>X3, the middle value Z2 is X1, the minimum value Z3 is X3, and the step S46 is performed.
[0037] S46. If Z1≤0, proceed to step S9; if Z1>0, proceed to step S47.
[0038] S47. If Z2≤0, proceed to step S6; if Z2>0, proceed to step S48.
[0039] S48. If Z3≤0, calculate the maximum effective value difference A, A=Z1-Z2, and proceed to step S5; if Z3>0, calculate the maximum effective value difference A, A=Z1-Z3, and proceed to step S5.
[0040] S5. If 0<A≤15mm, the liquid level is stable and the process goes to step S7; if 15mm<A≤25mm, the liquid level fluctuates slightly and the process goes to step S6; if A>25mm, the liquid level fluctuates violently and the process goes to step S8.
[0041] S6. Take the maximum value Y1 among all effective values as the measured value P and input it into the PID control system. Step S6 includes the following steps.
[0042] S61, the maximum value Y1 among all valid values is the maximum value Z1; S62, output measurement value P, P=Y1; S63. Go to step S2.
[0043] S7, taking the average value Y2 of all effective values as the measured value P and inputting it into the PID control system. Step S7 includes the following steps.
[0044] S71. If Z3≤0, then Y2=(Z1+Z2) / 2, and proceed to step S72; if Z3>0, then Y2=(Z1+Z2+Z3) / 3, and proceed to step S72; S72, output measurement value P, P=Y2; S73. Go to step S2.
[0045] S8, taking the minimum value Y3 among all effective values as the measured value P and inputting it into the PID control system. Step S8 includes the following steps.
[0046] S81. If Z3≤0, then Y3=Z2, and proceed to step S82; if Z3>0, then Y3=Z3, and proceed to step S82; S82, output measurement value P, P=Y3; S83. Go to step S2.
[0047] S9. Maintain the current measured value P, issue an emergency alarm, and conduct manual intervention.
[0048] The implementation principle of the automatic judgment and selection method of the dry coke quenching drum liquid level in the embodiment of the present application is: the first measuring point, the second measuring point and the third measuring point monitor the drum liquid level at the same time. When only one measuring point among the first measuring point, the second measuring point and the third measuring point can be used normally, the data of this measuring point is directly used as the measurement value of the PID control system. When the first measuring point, the second measuring point and the third measuring point all fail, an emergency alarm is issued and the operator intervenes quickly.
[0049] When the first, second and third measuring points are all in normal use, the drum level fluctuation is determined based on the data from the first, second and third measuring points. If the drum level is stable, the average value of the three measuring points is used as the measurement value of the PID control system; if the drum level fluctuation is small, the maximum value of the three measuring points is used as the measurement value of the PID control system; if the drum level fluctuation is large, the minimum value of the three measuring points is used as the measurement value of the PID control system.
[0050] When any of the first, second or third measuring points fails, the drum level fluctuation is determined based on the data from the other two normal measuring points. If the drum level is stable, the average value of the two normal measuring points is used as the measurement value of the PID control system; if the drum level fluctuation is small, the maximum value of the two normal measuring points is used as the measurement value of the PID control system; if the drum level fluctuation is large, the minimum value of the two normal measuring points is used as the measurement value of the PID control system.
[0051] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A method for automatically judging and selecting the liquid level of a dry coke quenching drum, characterized in that: The following steps are involved: S1. Set standard parameters; S2, maintain the current measurement value P; collect liquid level data; S3. If all the measuring points are damaged, proceed to step S9; if not all the measuring points are damaged, proceed to step S4; S4, calculating the maximum liquid level difference A; S5, if the liquid level is stable, proceed to step S7; if the liquid level fluctuates slightly, proceed to step S6; if the liquid level fluctuates violently, proceed to step S8; S6, taking the maximum value Y1 among all effective values as the measured value P and inputting it into the PID control system, and proceeding to step S2; S7, taking the average value Y2 of all effective values as the measured value P and inputting it into the PID control system, and proceeding to step S2; S8, taking the minimum value Y3 among all effective values as the measured value P and inputting it into the PID control system, and proceeding to step S2; S9. Maintain the current measured value P, issue an emergency alarm, and conduct manual intervention.
2. The method for automatically judging and selecting the liquid level of a dry coke quenching drum according to claim 1, characterized in that: The step S1 includes the following steps: setting a first liquid level threshold H1; and setting a second liquid level threshold H2.
3. The method for automatically judging and selecting the liquid level of a dry coke quenching drum according to claim 2, characterized in that: The step S5 includes the following steps: if 0<A≤H1, the liquid level is stable, and step S7 is performed; if H1<A≤H2, the liquid level fluctuates slightly, and step S6 is performed; if A>H2, the liquid level fluctuates violently, and step S8 is performed.
4. The method for automatically judging and selecting the liquid level of a CDQ drum according to claim 1, characterized in that: The step S2 comprises the following steps: S21, maintaining the current measurement value P; obtaining the liquid level of the first measurement point, the liquid level of the second measurement point, and the liquid level of the third measurement point at the same time; S22, the liquid level at the first measuring point is output as the first collected value; the liquid level at the second measuring point is output as the second collected value; the liquid level at the third measuring point is output as the third collected value; S23, if the first measuring point has a bad pixel, a first measuring point fault alarm is issued, the first effective value X1 is 0, and step S24 is performed; if the first measuring point has no bad pixel, the first effective value X1 is the first collection value, and step S24 is performed; S24, if the second measuring point has a bad pixel, a second measuring point fault alarm is issued, the second effective value X2 is 0, and step S25 is performed; if the second measuring point has no bad pixel, the second effective value X2 is the second collection value, and step S25 is performed; S25, if the third measuring point has a bad pixel, a third measuring point fault alarm is issued, the third effective value X3 is 0, and step S26 is performed; if the third measuring point has no bad pixel, the third effective value X3 is the third collection value, and step S26 is performed; S26. Output the first effective value X1, the second effective value X2 and the third effective value X3.
5. The method for automatically judging and selecting the liquid level of a CDQ drum according to claim 4, characterized in that: The step S3 includes the following steps: if X1=X2=X3=0, all the measuring points are damaged, and the step S9 is performed; if X1>0 or X2>0 or X3>0, not all the measuring points are damaged, and the step S4 is performed.
6. The method for automatically judging and selecting the liquid level of a CDQ drum according to claim 4, characterized in that: The step S4 comprises the following steps: S41, if X1>X2, proceed to step S42; if X1≤X2, proceed to step S44; S42, if X1≤X3, the maximum value Z1 is X3, the middle value Z2 is X1, the minimum value Z3 is X2, and the process goes to step S46; if X1>X3, the maximum value Z1 is X1, and the process goes to step S43; S43, if X2≤X3, the middle value Z2 is X3, the minimum value Z3 is X2, and the step S46 is performed; if X2>X3, the middle value Z2 is X2, the minimum value Z3 is X3, and the step S46 is performed; S44, if X2≤X3, the maximum value Z1 is X3, the middle value Z2 is X2, the minimum value Z3 is X1, and the process goes to step S46; if X2>X3, the maximum value Z1 is X2, and the process goes to step S45; S45, if X1≤X3, the middle value Z2 is X3, the minimum value Z3 is X1, and the process goes to step S46; if X1>X3, the middle value Z2 is X1, the minimum value Z3 is X3, and the process goes to step S46; S46, if Z1≤0, proceed to step S9; if Z1>0, proceed to step S47; S47, if Z2≤0, proceed to step S6; if Z2>0, proceed to step S48; S48. If Z3≤0, calculate the maximum effective value difference A, A=Z1-Z2, and proceed to step S5; if Z3>0, calculate the maximum effective value difference A, A=Z1-Z3, and proceed to step S5.
7. The method for automatically judging and selecting the liquid level of a CDQ drum according to claim 6, characterized in that: The step S6 comprises the following steps: S61, the maximum value Y1 among all valid values is the maximum value Z1; S62, output measurement value P, P=Y1; S63. Go to step S2.
8. The method for automatically judging and selecting the liquid level of a CDQ drum according to claim 6, characterized in that: The step S7 comprises the following steps: S71. If Z3≤0, then Y2=(Z1+Z2) / 2, and proceed to step S72; if Z3>0, then Y2=(Z1+Z2+Z3) / 3, and proceed to step S72; S72, output measurement value P, P=Y2; S73. Go to step S2.
9. The method for automatically judging and selecting the liquid level of a dry coke quenching drum according to claim 6, characterized in that: The step S8 comprises the following steps: S81. If Z3≤0, then Y3=Z2, and proceed to step S82; if Z3>0, then Y3=Z3, and proceed to step S82; S82, output measurement value P, P=Y3; S83. Go to step S2.