A method for controlling dust discharge in dry coke quenching without a material level meter

Abstract

The present invention relates to a method for controlling ash discharge during primary dust removal in dry coke quenching (CDQ) without a material level meter, and belongs to the technical field of CDQ dust removal methods. The technical solution of the present invention is to integrate circulating gas flow rate, furnace loading frequency, secondary dust removal frequency, and boiler inlet circulating gas temperature data, combined with hopper temperature, to develop an algorithm to calculate the ash discharge interval, and then coordinate ash discharge with temperature-linked ash removal. The beneficial effects of the present invention include achieving automatic ash discharge without a material level meter and improving the stability of primary dust removal operations.

Description

Technical Field

[0001] The invention relates to a dry coke quenching one-step dust removal and ash discharge control method without a material level meter, belonging to the technical field of dry coke quenching dust removal methods. Background Art

[0002] The CDQ process utilizes inert gas (nitrogen) for direct heat exchange with the red-hot coke in the CDQ furnace. After cooling the coke, the inert gas reaches a temperature of approximately 900-980°C. After passing through a primary dust collector, it enters the CDQ waste heat boiler for heat exchange. The cold circulating gas from the boiler is cooled to 160-180°C. After dust removal in a secondary CDQ dust collector, it is pressurized by a circulating fan and cooled to approximately 130°C via a heat pipe exchanger before recirculating into the CDQ furnace. The primary dust collector is a gravity dust collector with a significantly reduced airflow velocity in the settling chamber. This removes coarse coke fines from the circulating gas, minimizing wear on the CDQ waste heat boiler tubes. The dust stored in the primary dust hopper is hot, large, and highly abrasive. This often causes damage to the primary dust level meter, leading to false alarms of red ash discharge or prolonged periods of no dust accumulation, impacting the stability of the CDQ system. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for controlling ash discharge in a dry coke quenching primary dust removal process without a material level meter. By integrating other production data and combining the ash hopper temperature, an algorithm is written to calculate the ash discharge interval time, and the ash discharge is linked to the temperature. This method realizes automatic ash discharge without a material level meter, improves the stability of the primary dust removal operation, and effectively solves the above-mentioned problems existing in the background technology.

[0004] The technical solution of the present invention is: a method for controlling ash discharge of dry coke quenching with one-step dust removal and without a material level meter, comprising the following steps:

[0005] (1) Four parameters, namely, circulating gas flow rate, furnace loading frequency, secondary dust removal and ash removal frequency, and boiler inlet circulating gas temperature, were selected as the basis for judgment;

[0006] (2) Determine the standard reference data for average circulating gas flow rate, furnace loading frequency, secondary dust removal and ash discharge frequency, boiler inlet circulating gas temperature and ash discharge time;

[0007] (3) Setting the ash discharge interval time, which is obtained by multiplying the ash discharge time affected by the average flow rate of circulating gas, the frequency of loading, the frequency of secondary dust removal and the temperature of circulating gas at the boiler inlet by the corresponding proportional coefficient;

[0008] (4) Set the ash hopper temperature to chain ash discharge. When the set temperature is reached, the chain ash discharge will be started regardless of the ash discharge interval time. This will avoid problems such as blockage caused by the ash hopper cooling too low and the ash accumulation time too long, which will affect the stability of the dry quenching system.

[0009] In step (2), the standard reference data of the average flow rate of circulating gas, the frequency of furnace loading, the frequency of secondary dust removal and ash discharge, the circulating gas temperature at the boiler inlet and the ash discharge time can be obtained by calculating the average value based on historical data, or can be directly determined based on job experience.

[0010] In step (3), T is the standard reference data for dust removal time.

[0011] The ash discharge time t1 affected solely by the average flow rate of circulating gas is calculated as follows: t1 = T × (l / L), where l is the average flow rate of circulating gas since the last ash discharge, and L is the standard reference data for the average flow rate of circulating gas;

[0012] The ash discharge time t2 affected by the charging frequency alone is calculated as follows: t2 = T × (f1 / F1), where f1 is the charging frequency since the last ash discharge, and F1 is the standard reference data for the charging frequency.

[0013] The dust removal time t3 affected by the secondary dust removal frequency alone is calculated as follows: t3 = T × (f2 / F2), where f2 is the secondary dust removal frequency since the last dust removal, and F2 is the standard reference data for the secondary dust removal frequency.

[0014] The ash removal time affected solely by the circulating gas temperature at the boiler inlet is t4, and the calculation formula is: Where c is the circulating gas temperature at the boiler inlet since the last ash discharge, and C is the standard reference data for the circulating gas temperature at the boiler inlet;

[0015] The calculation formula for the dust removal interval time t is: t=a1t1+a2t2+a3t3+a4t4

[0016] Among them, a1, a2, a3 and a4 are the influence coefficients of circulating gas flow rate, furnace loading frequency, secondary dust removal and ash discharge frequency and boiler inlet circulating gas temperature respectively. The sum of a1, a2, a3 and a4 is equal to 1. The values ​​of these coefficients are continuously adjusted according to actual conditions.

[0017] In the step (4), when the ash hopper temperature drops below 90°C and remains at that level for 5 minutes, the ash discharge is started in a chain manner, ignoring the ash discharge interval, and the ash is discharged until the ash hopper temperature rises above 120°C or the ash discharge continues for 15 minutes.

[0018] The beneficial effects of the present invention are: by integrating other production data and combining the ash hopper temperature, an algorithm is written to calculate the ash discharge interval time, and the ash discharge is linked with the temperature, thereby realizing automatic ash discharge without a level meter and improving the stability of the primary dust removal operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a control panel diagram of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the invention implementation cases will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] A method for controlling ash discharge by dry quenching with one-step dust removal and without a material level meter comprises the following steps:

[0022] (1) Four parameters, namely, circulating gas flow rate, furnace loading frequency, secondary dust removal and ash removal frequency, and boiler inlet circulating gas temperature, were selected as the basis for judgment;

[0023] (2) Determine the standard reference data for average circulating gas flow rate, furnace loading frequency, secondary dust removal and ash discharge frequency, boiler inlet circulating gas temperature and ash discharge time;

[0024] (3) Setting the ash discharge interval time, which is obtained by multiplying the ash discharge time affected by the average flow rate of circulating gas, the frequency of loading, the frequency of secondary dust removal and the temperature of circulating gas at the boiler inlet by the corresponding proportional coefficient;

[0025] (4) Set the ash hopper temperature to chain ash discharge. When the set temperature is reached, the chain ash discharge will be started regardless of the ash discharge interval time. This will avoid problems such as blockage caused by the ash hopper cooling too low and the ash accumulation time too long, which will affect the stability of the dry quenching system.

[0026] In step (2), the standard reference data of the average flow rate of circulating gas, the frequency of furnace loading, the frequency of secondary dust removal and ash discharge, the circulating gas temperature at the boiler inlet and the ash discharge time can be obtained by calculating the average value based on historical data, or can be directly determined based on job experience.

[0027] In step (3), T is the standard reference data for dust removal time.

[0028] The ash discharge time t1 affected solely by the average flow rate of circulating gas is calculated as follows: t1 = T × (l / L), where l is the average flow rate of circulating gas since the last ash discharge, and L is the standard reference data for the average flow rate of circulating gas;

[0029] The ash discharge time t2 affected by the charging frequency alone is calculated as follows: t2 = T × (f1 / F1), where f1 is the charging frequency since the last ash discharge, and F1 is the standard reference data for the charging frequency.

[0030] The dust removal time t3 affected by the secondary dust removal frequency alone is calculated as follows: t3 = T × (f2 / F2), where f2 is the secondary dust removal frequency since the last dust removal, and F2 is the standard reference data for the secondary dust removal frequency.

[0031] The ash removal time affected solely by the circulating gas temperature at the boiler inlet is t4, and the calculation formula is: Where c is the circulating gas temperature at the boiler inlet since the last ash discharge, and C is the standard reference data for the circulating gas temperature at the boiler inlet;

[0032] The calculation formula for the dust removal interval time t is: t=a1t1+a2t2+a3t3+a4t4

[0033] Among them, a1, a2, a3 and a4 are the influence coefficients of circulating gas flow rate, furnace loading frequency, secondary dust removal and ash discharge frequency and boiler inlet circulating gas temperature respectively. The sum of a1, a2, a3 and a4 is equal to 1. The values ​​of these coefficients are continuously adjusted according to actual conditions.

[0034] In the step (4), when the ash hopper temperature drops below 90°C and remains at that level for 5 minutes, the ash discharge is started in a chain manner, ignoring the ash discharge interval, and the ash is discharged until the ash hopper temperature rises above 120°C or the ash discharge continues for 15 minutes.

[0035] Example:

[0036] In the embodiment, the CDQ primary level meter has been damaged due to wear and tear, and the cost of applying for a spare part is high, so the automatic ash discharge of the present invention is used instead. Specifically, the following steps are included:

[0037] ① Write a program to calculate the average value of the circulating gas flow rate, take the real-time value of the total circulating gas flow rate, accumulate it in a timing program with a cycle time of 1s, and calculate the time since the last ash discharge in seconds. The accumulated value of the circulating gas flow rate is divided by the accumulated time to obtain the average flow rate, and then according to the formula described above, calculate the ash discharge time t1 affected by the circulating gas flow rate alone.

[0038] ② Write a program to calculate the frequency of furnace loading. The basis for judging the furnace loading is the furnace bottom door opening signal and the lifting weight is greater than 48 tons. The cumulative number of furnace loadings and the number of hours since the last ash discharge are divided by the number of hours and then multiplied by 12 to get the furnace loading frequency. The unit is "furnace / 12 hours". Then, according to the formula described above, calculate the ash discharge time t2 affected by the furnace loading frequency alone.

[0039] ③ Write a program to calculate the frequency of secondary dust removal and ash discharge. The secondary dust discharge is triggered by the high material level signal delay of the ash bin. Use this point in the program to determine whether the secondary dust removal has been discharged. Accumulate the number of secondary dust discharges since the last ash discharge, divide the number of discharges by the number of hours and multiply by 12 to get the frequency of secondary dust removal and ash discharge. Then, according to the formula described above, calculate the ash discharge time t3 affected by the secondary dust removal and ash discharge frequency alone.

[0040] ④ Write a program to calculate the average temperature of the circulating gas at the boiler inlet. Take the real-time value of the circulating gas temperature at the boiler inlet, accumulate it in a timing program with a cycle time of 1s, and calculate the time since the last ash discharge in seconds. Divide the accumulated value by the accumulated time to obtain the average temperature. Then, according to the formula described previously, calculate the ash discharge time t4 affected by the circulating gas temperature at the boiler inlet alone.

[0041] ⑤Write the ash hopper temperature interlocking ash discharge program. When the ash hopper temperature is continuously lower than 90℃, after a delay of 10 minutes,

[0042] Start discharging ash when the ash hopper temperature rises to above 120℃ or when ash discharging continues for 15 minutes.

[0043] ⑥Draw the operation panel, such as Figure 1 As shown in the figure, various standard reference data and their corresponding influence coefficients can be set. The dust removal interval time is displayed at the bottom of the panel, and there is a "Start / Release" button at the bottom left of the panel.

[0044] Button, the status in the figure indicates that automatic ash discharge is in use. A single click can switch the automatic ash discharge function into use. The button will also display "Release", and the program will not automatically discharge ash according to the calculated time, but the ash hopper temperature chain discharge is still valid.

[0045] ⑦Debugging parameters, set standard reference data based on historical data: ash discharge time 16h, circulating gas flow 50000m 3 / h, furnace loading frequency 15 furnaces / 12 hours, secondary dust removal and ash removal frequency 1.5 times / 12 hours, average temperature of circulating gas at boiler inlet 780℃, a1, a2, a3, a4 are set to 0.3, 0.3, 0.2, 0.2. After a period of use, the standard reference data of secondary dust removal and ash removal frequency is adjusted to 1 time / 12 hours, and a1, a2, a3, a4 are readjusted to 0.45, 0.30, 0.05, 0.20,

[0046] The ash removal time basically fluctuates between 13 and 17 hours.

[0047] The present invention realizes automatic ash discharge without a material level meter by combining other production data, and improves the stability of primary dust removal operation by combining ash hopper temperature interlocking control.

Claims

1. A method for controlling ash discharge in a single-stage dust removal process without a material level meter for dry coke quenching, characterized in that The following steps are involved: (1) Four parameters, namely, average circulating gas flow rate, furnace loading frequency, secondary dust removal and ash removal frequency, and boiler inlet circulating gas temperature, are selected as the basis for judgment; (2) Determine the standard reference data for the average flow rate of circulating gas, furnace loading frequency, secondary dust removal and ash discharge frequency, boiler inlet circulating gas temperature and ash discharge time; the standard reference data for the average flow rate of circulating gas, furnace loading frequency, secondary dust removal and ash discharge frequency, boiler inlet circulating gas temperature and ash discharge time are calculated based on historical data or directly determined based on job experience; (3) Set the ash discharge interval time. The ash discharge interval time is obtained by multiplying the ash discharge time affected by the average circulation gas flow rate, furnace loading frequency, secondary dust removal and ash discharge frequency, and boiler inlet circulation gas temperature by the corresponding proportional coefficients. T is the standard reference data for ash discharge time. The ash discharge time t1 affected by the average circulation gas flow rate alone is calculated as follows: t1 = T × (l / L), where l is the average circulation gas flow rate since the last ash discharge, and L is the standard reference data for the average circulation gas flow rate. The ash discharge time t2 affected by the charging frequency alone is calculated as follows: t2 = T × (f1 / F1), where f1 is the charging frequency since the last ash discharge, and F1 is the standard reference data for the charging frequency. The dust removal time t3 affected by the secondary dust removal frequency alone is calculated as follows: t3 = T × (f2 / F2), where f2 is the secondary dust removal frequency since the last dust removal, and F2 is the standard reference data for the secondary dust removal frequency. The ash removal time affected solely by the circulating gas temperature at the boiler inlet is t4, and the calculation formula is: , where c is the circulating gas temperature at the boiler inlet since the last ash discharge, and C is the standard reference data for the circulating gas temperature at the boiler inlet; The calculation formula for the dust removal interval time t is: t = a1t1+a2t2+a3t3+a4t4 Among them, a1, a2, a3 and a4 are the influence coefficients of circulating gas flow rate, furnace loading frequency, secondary dust removal and ash removal frequency and boiler inlet circulating gas temperature respectively. The sum of a1, a2, a3 and a4 is equal to 1. The values ​​of these coefficients are constantly adjusted according to actual conditions. (4) Set the ash hopper temperature to chain ash discharge. When the set temperature is reached, the chain ash discharge will be started regardless of the ash discharge interval time. This will avoid the ash hopper temperature cooling too low and the ash accumulation time too long, which will cause the ash to become lumped and block, affecting the stability of the dry quenching system.

2. The method for controlling ash discharge of dry coke with one-step dust removal and no material level meter according to claim 1, characterized in that: In the step (4), when the ash hopper temperature drops below 90°C and remains at that level for 5 minutes, the ash discharge is started in a chain manner, ignoring the ash discharge interval, and the ash is discharged until the ash hopper temperature rises above 120°C or the ash discharge continues for 15 minutes.

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