阅读说明：本技术 钢包烘烤压力控制系统及方法 (Steel ladle baking pressure control system and method ) 是由 肖利 曾冠武 朱凤湘 于 2020-11-26 设计创作，主要内容包括：本发明涉及钢包控制领域,具体涉及一种钢包烘烤压力控制系统及方法,实现了通过钢包压力变化对钢包排烟管道上变频风机进行自动控制,进而实现自动调节钢包压力,避免了钢包压力过大或过小的情况出现,降低了钢包烘烤能耗。本发明钢包烘烤压力控制系统,包括控制模块,钢包盖上设置有压力检测装置,钢包排烟管道上设置有变频风机,所述压力检测装置及变频风机分别与控制模块连接,所述控制模块用于根据钢包压力自动调节变频风机的频率。本发明适用于钢包烘烤压力控制。(The invention relates to the field of ladle control, in particular to a ladle baking pressure control system and method, which realize automatic control of an up-conversion fan on a ladle exhaust pipeline through ladle pressure change, further realize automatic regulation of ladle pressure, avoid the condition of overlarge or undersize ladle pressure and reduce ladle baking energy consumption. The steel ladle baking pressure control system comprises a control module, wherein a pressure detection device is arranged on a steel ladle cover, a variable frequency fan is arranged on a steel ladle smoke exhaust pipeline, the pressure detection device and the variable frequency fan are respectively connected with the control module, and the control module is used for automatically adjusting the frequency of the variable frequency fan according to the steel ladle pressure. The invention is suitable for controlling the baking pressure of the ladle.)

1. The steel ladle baking pressure control system comprises a control module and is characterized in that a pressure detection device is arranged on a steel ladle cover, a variable frequency fan is arranged on a steel ladle smoke exhaust pipeline, the pressure detection device and the variable frequency fan are respectively connected with the control module, and the control module is used for automatically adjusting the frequency of the variable frequency fan according to the steel ladle pressure.

2. The ladle baking pressure control system according to claim 1, wherein the variable frequency fan comprises a frequency converter and a fan, and the frequency converter is respectively connected with the control module and the fan.

3. The ladle baking pressure control system according to claim 1 or 2, wherein the pressure detection device is a micro differential pressure transmitter.

4. The ladle baking pressure control system of claim 3, wherein the micro differential pressure transmitter comprises a pressure transmitting metal tube mounted at the very center of the ladle lid.

5. The ladle baking pressure control system according to claim 4, wherein the micro differential pressure transmitter is installed remotely, and the pressure transmission metal pipe is installed at the midpoint of the ladle cover through an extension pipe.

6. The ladle baking pressure control system of claim 5, wherein the micro differential pressure transmitter is mounted in an external remote operating room.

7. The ladle baking pressure control method is applied to the ladle baking pressure control system of any one of claims 1 to 6, and is characterized by comprising the following steps:

step (1), a pressure detection device detects pressure data of a steel ladle in real time and sends the steel ladle pressure data to a control module;

step (2), the control module processes the pressure data to obtain a pressure detection value;

step (3), judging a pressure detection value, and if the pressure detection value is larger than a set first threshold value, increasing the frequency of the variable frequency fan; and if the pressure detection value is smaller than a set second threshold value, reducing the frequency of the variable frequency fan, wherein the first threshold value is larger than the second threshold value.

8. The ladle baking pressure control method according to claim 7, wherein in the step (2), the specific method for obtaining the pressure detection value comprises:

step 201, setting a furnace pressure detection period and starting to detect the ladle furnace pressure;

step 202, detecting a plurality of pressure values according to the detection period, then removing the highest and lowest pressure values, and taking the arithmetic mean value of the remaining plurality of pressure values as the pressure detection value of the current round.

9. The ladle baking pressure control method according to claim 7 or 8, wherein in step (3), the method of increasing the frequency of the variable frequency fan comprises: the fan frequency is adjusted with the same set adjustment amount each time.

10. The ladle baking pressure control method according to claim 7 or 8, wherein in step (3), the method of reducing the frequency of the variable frequency fan comprises: the fan frequency is adjusted with the same set adjustment amount for each reduction.

Technical Field

The invention relates to the field of ladle control, in particular to a ladle baking pressure control system and method.

Background

Along with the enhancement of the demand of users on high-quality steel products, the refinement of a smelting process and the aggravation of market competition, how to realize the accurate temperature control and energy conservation in a ladle baking process is gradually emphasized by steel enterprises, the pressure control in the ladle baking process is greatly related to the ladle baking flaming and cold air suction, and the traditional baking process does not control the ladle pressure or adopts a manual mode to adjust, so that the pressure in the baking process is uncontrollable, the response speed is slow, and the control accuracy is low; thus, two situations occur during the baking process: the pressure is too large, the ladle edge is fired, fuel escapes from the ladle edge, the related equipment on the ladle cover is roasted, the service life is shortened, the control precision is reduced, the pressure is too small, the ladle edge absorbs cold air, meanwhile, the incompletely combusted fuel is absorbed into a smoke exhaust system, the energy consumption is large, and meanwhile, the operation safety is threatened. Therefore, how to ensure complete fuel combustion and controllable pressure is an important technology for realizing ladle baking, and is a method for reducing energy consumption of ladle baking.

Disclosure of Invention

The invention aims to provide a steel ladle baking pressure control system and method, which can be used for automatically controlling an up-conversion fan of a steel ladle smoke exhaust pipeline through steel ladle pressure change, further automatically adjusting steel ladle pressure, avoiding the condition that the steel ladle pressure is too large or too small, and reducing steel ladle baking energy consumption.

The invention adopts the following technical scheme to realize the aim, and the steel ladle baking pressure control system comprises a control module, wherein a pressure detection device is arranged on a steel ladle cover, a variable frequency fan is arranged on a steel ladle smoke exhaust pipeline, the pressure detection device and the variable frequency fan are respectively connected with the control module, and the control module is used for automatically adjusting the frequency of the variable frequency fan according to the steel ladle pressure.

Further, in order to facilitate installation and use, the variable frequency fan comprises a frequency converter and a fan, wherein the frequency converter is respectively connected with the control module and the fan.

Furthermore, in order to improve the pressure measurement accuracy and stability, the pressure detection device is a micro differential pressure transmitter.

Further, in order to improve the accuracy of measuring the ladle pressure, the micro differential pressure transmitter includes a pressure transmitting metal pipe installed at the midpoint of the ladle cover.

Further, in order to avoid errors caused by vibration, the micro differential pressure transmitter is installed remotely, and the pressure transmission metal pipe is installed at the midpoint of the steel ladle cover through an extension pipe.

Further, the micro differential pressure transmitter is installed in an external remote operation room.

The ladle baking pressure control method is applied to the ladle baking pressure control system and comprises the following steps:

step (1), a pressure detection device detects pressure data of a steel ladle in real time and sends the steel ladle pressure data to a control module;

step (2), the control module processes the pressure data to obtain a pressure detection value;

step (3), judging a pressure detection value, and if the pressure detection value is larger than a set first threshold value, increasing the frequency of the variable frequency fan; and if the pressure detection value is smaller than a set second threshold value, reducing the frequency of the variable frequency fan, wherein the first threshold value is larger than the second threshold value.

Further, in step (2), the specific method for obtaining the pressure detection value includes:

step 201, setting a furnace pressure detection period and starting to detect the ladle furnace pressure;

step 202, detecting a plurality of pressure values according to the detection period, then removing the highest and lowest pressure values, and taking the arithmetic mean value of the remaining plurality of pressure values as the pressure detection value of the current round.

Further, in step (3), the method for increasing the frequency of the variable frequency fan comprises: the fan frequency is adjusted with the same set adjustment amount each time.

Further, in step (3), the method for reducing the frequency of the variable frequency fan comprises the following steps: the fan frequency is adjusted with the same set adjustment amount for each reduction.

The frequency conversion control system detects the pressure data of the steel ladle in real time through the pressure detection device, sends the pressure data to the control module, and the control module automatically adjusts the frequency of the frequency conversion fan according to the pressure data of the steel ladle; if the ladle pressure is too small, the frequency of the variable frequency fan is reduced, so that the ladle pressure cannot be too large or too small and is kept in a normal range, automatic control over the variable frequency fan on the ladle smoke exhaust pipeline through ladle pressure change is realized, then the ladle pressure is automatically adjusted, the condition that the ladle pressure is too large or too small is avoided, and the ladle baking energy consumption is reduced.

Drawings

Fig. 1 is a block diagram of a ladle baking pressure control system according to the present invention.

Detailed Description

The steel ladle baking pressure control system comprises a control module, wherein a pressure detection device is arranged on a steel ladle cover, a variable frequency fan is arranged on a steel ladle smoke exhaust pipeline, the pressure detection device and the variable frequency fan are respectively connected with the control module, and the control module is used for automatically adjusting the frequency of the variable frequency fan according to the steel ladle pressure.

In order to facilitate installation and use, the frequency conversion fan comprises a frequency converter and a fan, wherein the frequency converter is respectively connected with the control module and the fan. The frequency converter can be selected according to the rated current of the fan, and the selection principle of the frequency converter is as follows: the current of the frequency converter is equal to the rated current of the fan plus the rated current of the fan (15-25%); the frequency converter can adopt a local installation mode, and a special cabinet is arranged for protecting the frequency converter.

In order to improve the pressure measurement precision and stability, the pressure detection device is a micro differential pressure transmitter. Range of micro differential pressure sensor: +/-100 Pa;

in order to improve the accuracy of measuring the ladle pressure, the micro differential pressure transmitter includes a pressure transmitting metal pipe installed at the midpoint of a ladle cover.

In order to avoid errors caused by vibration, the micro differential pressure transmitter is installed remotely, and the pressure transmission metal pipe is installed at the center of the steel ladle cover through an extension pipe.

The micro differential pressure transmitter is installed in an external remote operation room.

The ladle baking pressure control method is applied to the ladle baking pressure control system and comprises the following steps:

step (1), a pressure detection device detects pressure data of a steel ladle in real time and sends the steel ladle pressure data to a control module;

step (2), the control module processes the pressure data to obtain a pressure detection value;

step (3), judging a pressure detection value, and if the pressure detection value is larger than a set first threshold value, increasing the frequency of the variable frequency fan; and if the pressure detection value is smaller than a set second threshold value, reducing the frequency of the variable frequency fan, wherein the first threshold value is larger than the second threshold value.

Further, in step (2), the specific method for obtaining the pressure detection value includes:

step 201, setting a furnace pressure detection period and starting to detect the ladle furnace pressure;

step 202, detecting a plurality of pressure values according to the detection period, then removing the highest and lowest pressure values, and taking the arithmetic mean value of the remaining plurality of pressure values as the pressure detection value of the current round.

For example, the furnace pressure detection period may be set to 100ms, 10 pressure values (y1, y2, y3 … y10) are detected, the highest y10 and the lowest y1 pressure values are removed, and the arithmetic average value is taken as the pressure detection value of the current round, so that the ladle pressure detection value:

in step (3), the method for increasing the frequency of the variable frequency fan comprises the following steps: the fan frequency is adjusted with the same set adjustment amount each time.

In step (3), the method for reducing the frequency of the variable frequency fan comprises the following steps: the fan frequency is adjusted with the same set adjustment amount for each reduction.

Wherein, the fan adjusting frequency range can be set to be 0-50Hz (the protection frequency is 10 Hz); the pressure control range is set to be +/-5 Pa; when the adjustment is carried out, the frequency of the fan can be adjusted by continuously adding or subtracting the same set adjustment quantity; for example, if the current pressure of the ladle is set to P and the frequency of the fan is set to K, then:

the pressure of the steel ladle is higher than 5Pa, and the frequency of the fan is adjusted: k is K + 1;

the pressure of the steel ladle is lower than-5 Pa, and the frequency of the fan is adjusted: k-1.

The structural block diagram of the steel ladle baking pressure control system comprises a PLC cabinet, a frequency converter, a fan, a steel ladle and a micro differential pressure transmitter, wherein the frequency converter is respectively connected with the PLC cabinet and the fan, the fan is arranged on a steel ladle smoke exhaust pipeline (not shown in the figure), the micro differential pressure transmitter is respectively connected with the PLC cabinet and the steel ladle, a pressure transmission metal pipe of the micro differential pressure transmitter is arranged at the center of a steel ladle cover (not shown in the figure), and if remote installation is adopted, the pressure transmission metal pipe is arranged at the center of the steel ladle cover through an extension pipe.

According to one embodiment of the invention, a certain steel mill is provided with 20 ladle roasters, coke oven gas is used as fuel, a pressure control system is not provided, the phenomena of fire and cold air suction often occur to ladles, the average hour energy consumption is 353m3/h, and the ladle operation rate is 80%.

The invention is adopted to carry out the addition and the reconstruction of the ladle pressure control system, and the specific implementation steps are as follows:

(1) in the existing single ladle system, a motor is Y160m-2, and the rated current is 12A;

(2) rated current of further frequency converter: the converter current is 12+12 × 20% ═ 14.4A;

(3) according to the step (2), selecting a frequency converter as PTI-G470075, wherein the specific parameters are shown in the following table:

(4) selecting a micro differential pressure sensor;

(5) further, the range of the micro differential pressure sensor: +/-100 Pa;

(6) the differential pressure transmitter is remotely installed, a metal pipe for pressure transmission is directly installed in the center of a steel ladle cover and then is connected to the micro differential pressure transmitter through an extension pipe;

(7) furthermore, the micro differential pressure transmitter is arranged in the operation chamber to avoid the influence of other factors such as vibration and the like;

(8) the type selection of the micro differential pressure transmitter is as follows:

model number	Measuring range	Output signal	Accuracy of measurement	Power supply
					PY301	±100Pa	4-20mA	0.1％FS	24VDC

(9) Introducing a frequency signal of fan operation and a ladle pressure signal into a ladle baking system PLC;

(10) the process system of ladle pressure control comprises the following steps:

after reversing for 5s each time, beginning to detect the furnace pressure, wherein the furnace pressure detection period is 100ms, detecting 10 pressure values (y1, y2 and y3 … y10), removing the highest y10 and the lowest y1 pressure values, taking the arithmetic mean value as the pressure detection value of the current round, and then detecting the ladle pressure:the adjusting frequency range of the fan is 0-50Hz (the protection frequency is 10 Hz); the pressure control range is +/-5 Pa; the pressure adjustment adopts continuous plus-minus adjustment, and ladle current pressure is P, and fan frequency is K, then has:

ladle pressure is higher than 5Pa (P-Y >5), fan frequency: k is K + 1;

ladle pressure is lower than-5 Pa (P-Y < -5), fan frequency: k-1.

By implementing the method, the hourly energy consumption of the steel ladles of the enterprise is reduced to 312m3/h, the average exhaust gas temperature is 118 ℃, and the method has the advantages of annual benefit:

reduced fuel hour energy consumption 365 24 operating rate roaster stages fuel unit price

＝(353-312)*365*24*0.8*20*0.6

334.8 ten thousand yuan

In conclusion, the invention realizes the optimization of the hot working process by researching the parameters and the performance change of the light high-strength steel in the hot working process, and greatly improves the hot working process level of the light high-strength steel.