Automatic detection method for leakage fault in valve in blast furnace injection process

Abstract

The invention discloses an automatic detection method for a leakage fault in a valve in a blast furnace injection process. The leakage of the valve is divided into two directions of leakage towards the inside of a system and leakage towards the outside of the system; when the pressure in the injection tank is not pressurized or fluidized, the injection tank is in a pressure maintaining state; if the pressure of the injection tank is continuously reduced under the condition that the injection tank is not pressurized or fluidized, and the reduction rate continuously reaches 3Kpa per minute, it is judged that the valve leaks outwards, and the system gives an alarm of'injection tank leakage '; and if the pressure of the injection tank is continuously increased under the condition that the injection tank is not pressurized or fluidized, and the rising speed continuously reaches 3Kpa per minute, it is judged that the valve leaks into the system, and the system gives an alarm that the pressure of the injection tank is increased. The internal leakage of the injection tank is automatically detected through the system, the leakage to the inside of the system and the leakage to the outside of the system are distinguished, an alarm is given in time, and a post processes a leaked equipment valve to eliminate the influence on production.

Description

Technical Field

[0001] The invention relates to the field of blast furnaces, and in particular to a method for autonomously detecting internal leakage faults of valves in a blast furnace injection process. Background Art

[0002] At present, the domestic blast furnace coal injection system design is gradually using fully automatic control coal injection, using programs to control the equipment in the entire process system to achieve the coal injection process under automatic control. Due to the reduction of manual intervention after automatic control, when the equipment has obvious faults such as being unable to open and close, the alarm control can be used to operate in a safe direction. However, it cannot be directly discovered when the valve leaks into and out of the system. The reason is that during automatic control, the system detects that the valve switch signal is normal and will not alarm. When the valve leaks inside, it will cause the pressure in the system to rise or fall, thereby affecting the stable operation of the system and directly affecting the stability of the injection rate and the accuracy of the hourly injection volume, which has a direct impact on the precise control of the system.

[0003] Therefore, it is necessary to develop new detection methods to effectively judge valve leakage in the automatic control process. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings and defects of the prior art, the present invention provides an autonomous detection method for internal leakage faults in valves during the blast furnace injection process. The system automatically detects internal leakage in the injection tank, and distinguishes between leakage into the system and leakage out of the system. It promptly issues an alarm and handles the leaking equipment valves at the post to eliminate the impact on production.

[0005] Technical solution: The present invention provides a method for autonomously detecting internal leakage faults of valves during blast furnace injection, which is characterized by comprising the following steps:

[0006] 1) Add a detection and judgment program for valve internal leakage in the blast furnace automatic control coal injection system;

[0007] 2) According to the characteristics of the injection system, the leakage of the valve is divided into two directions: leakage into the system and leakage out of the system;

[0008] 3) When the pressure in the spray tank is not in the state of charging and fluidization, it is in the state of maintaining pressure;

[0009] 4) If the pressure of the spray tank continues to drop without pressurization or fluidization, and the drop rate continues to reach 3Kpa per minute, it is judged that there is a valve leaking out of the system, and the system will alarm "spray tank leakage";

[0010] 5) If the pressure of the spray tank continues to rise without pressurization or fluidization, and the rising rate reaches 3Kpa per minute, it is judged that there is a valve leaking into the system, and the system will alarm "the pressure of the spray tank rises".

[0011] Among them, for the step 4), when the alarm information is "spray tank leakage", check the corresponding dome valve, small pressure relief valve and large pressure relief valve of the spray tank.

[0012] Among them, for the step 5), when the alarm information is "the pressure of the spray tank rises", according to the different process forms used, the following can be checked: the bottom fluidization cut-off valve, the cone fluidization cut-off valve, the small charging valve, and the large charging valve.

[0013] Among them, check and confirm the leaking equipment valves and carry out subsequent processing.

[0014] Wherein, when the pressure is maintained in step 3), the pressure is stable with a small fluctuation range and will not trigger an alarm.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention automatically detects the internal leakage of the spray tank through the system, and distinguishes whether it is leakage into the system or leakage out of the system, and promptly alarms and handles the leaking equipment valve by the post to eliminate the impact on production. In the present invention, when the spray tank leaks into the system, the medium filled in causes the pressure in the tank to rise, affecting the system's control of pressure stability. When the pressure is higher than the set value and production is carried out, it causes the spray system rate to be unstable and fluctuate greatly, affecting the uniformity of the spray.

[0016] The fluctuation of the injection rate of the present invention will cause the accuracy of the hourly injection volume to decrease, and the final result is that the amount of coal powder injected into the blast furnace is unstable, which directly affects the stable and smooth operation of the blast furnace and is extremely harmful. In the present invention, when the injection tank leaks out of the system, the pressure in the injection tank drops, and the system needs to be filled with more medium to reach the target pressure, resulting in an increase in nitrogen usage, an increase in gas consumption per ton of coal, and a decrease in production indicators. The coal powder and coke powder in the leaked medium will flush the valves and pipelines of the equipment, accelerate wear and cause secondary damage to the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the use status of an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0019] The method for autonomously detecting internal leakage fault of valve in blast furnace injection process of the present invention comprises the following steps:

[0020] 1) Add a detection and judgment procedure for valve internal leakage in the blast furnace automatic control coal injection system.

[0021] 2) According to the characteristics of the injection system, valve leakage is divided into two directions: leakage into the system and leakage out of the system.

[0022] 3) When the pressure in the spray tank is not pressurized or fluidized, it is in a pressure-maintaining state; when in the pressure-maintaining state, the pressure is stable with a small fluctuation range and will not trigger an alarm.

[0023] 4) If the pressure of the spray tank continues to drop without pressurization or fluidization, and the drop rate continues to reach 3Kpa per minute, it is judged that there is a valve leaking out of the system, and the system will alarm "spray tank leakage";

[0024] 5) If the pressure of the spray tank continues to rise without pressurization or fluidization, and the rising rate reaches 3Kpa per minute, it is judged that there is a valve leaking into the system, and the system will alarm "the pressure of the spray tank rises".

[0025] 6) With respect to the step 4), when the alarm message is "spray tank leakage", check the corresponding dome valve, small pressure relief valve and large pressure relief valve of the spray tank.

[0026] 7) For the above step 5), when the alarm message is "pressure rise in the spray tank", the following can be checked according to the process used: bottom fluidization cut-off valve, cone fluidization cut-off valve, small charging valve, and large charging valve.

[0027] 8) According to the above information, the leakage of the spray tank can be discovered at the first time during the production process, the system will automatically alarm, and it can also propose which equipment valves to check according to the process adopted for subsequent processing.

[0028] The present invention automatically detects the internal leakage of the spray tank through the system, and distinguishes whether it is leakage into the system or leakage out of the system, and promptly alarms and processes the leaking equipment valve by the post to eliminate the impact on production. In the present invention, when the spray tank leaks inward, the medium filled in causes the pressure in the tank to rise, affecting the system's control of pressure stability. When the pressure is higher than the set value and production is carried out, it causes the spray system rate to be unstable and fluctuate greatly, affecting the uniformity of the spray.

[0029] The fluctuation of the injection rate of the present invention will cause the accuracy of the hourly injection volume to decrease, and the final result is that the amount of coal powder injected into the blast furnace is unstable, which directly affects the stable and smooth operation of the blast furnace and is extremely harmful. When the injection tank of the present invention leaks outward, the pressure in the injection tank drops, and the system needs to be filled with more medium to reach the target pressure, resulting in an increase in nitrogen usage, an increase in gas consumption per ton of coal, and a decrease in production indicators. The coal powder in the leaked medium washes the valves and pipelines of the equipment, accelerates wear and causes secondary damage to the equipment.

[0030] Example:

[0031] As shown in the figure, the 3# spray tank is pressurized after the powder is filled, and then enters the waiting state. When the large and small stamping valves and the bottom fluidizing valve are not opened, the pressure in the tank is set to 0.859MPa, and the actual tank pressure is 0.845MPa. The drop rate continues to reach (0.859-0.845)*1000=14KPa per minute, which is greater than the judgment value of 3KPa, so it is judged to be a leakage in the spray tank. An alarm pop-up window appears, and it is necessary to check the large and small row valves or dome valves, etc.

Claims

1. A method for autonomously detecting internal leakage faults of valves during blast furnace injection, characterized in that: The steps include: 1) Add a detection and judgment program for valve internal leakage in the blast furnace automatic control coal injection system; 2) According to the characteristics of the injection system, the leakage of the valve is divided into two directions: leakage into the system and leakage out of the system; 3) When the pressure in the spray tank is not in the state of charging and fluidization, it is in the state of maintaining pressure; 4) If the pressure of the spray tank continues to drop without pressurization or fluidization, and the drop rate continues to reach 3Kpa per minute, it is judged that there is a valve leaking out of the system, and the system will alarm "spray tank leakage"; 5) If the pressure of the spray tank continues to rise without pressurization or fluidization, and the rising rate reaches 3Kpa per minute, it is judged that there is a valve leaking into the system, and the system will alarm "spray tank pressure rise".

2. The method for autonomously detecting internal leakage faults of valves during blast furnace injection according to claim 1, characterized in that: Regarding the step 4), when the alarm information is "spray tank leakage", check the corresponding dome valve, small pressure relief valve and large pressure relief valve of the spray tank.

3. The method for autonomously detecting internal leakage faults of valves during blast furnace injection according to claim 1, characterized in that: Regarding step 5), when the alarm message is "pressure rise in the spray tank", the following can be checked according to the process used: bottom fluidization cut-off valve, cone fluidization cut-off valve, small charging valve, and large charging valve.

4. The method for autonomously detecting internal leakage fault of valves during blast furnace injection according to claim 3 or 4, characterized in that: Check and confirm the leaking equipment valve and carry out subsequent treatment.

5. The method for autonomously detecting internal leakage faults of valves during blast furnace injection according to claim 1, characterized in that: When the pressure is maintained in step 3), the pressure is stable with a small fluctuation range and will not trigger an alarm.

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