CN1228159C - Accurate measuring method of casted blank surface temperature of continuous casting secondary cold region - Google Patents

Abstract

The invention relates to a method for accurately measuring the surface temperature of a slab in a secondary cooling zone during continuous casting of molten steel. This temperature measurement method consists of two parts, one is to continuously measure the temperature of the surface temperature of the single point or multiple points in the secondary cooling zone of the slab, and the other is to process the measured temperature data to find out The method of measuring the accurate temperature of the slab. The method for accurately measuring the surface temperature of the slab in the secondary cooling zone of continuous casting provided by the present invention is connected with a computer through a number of thermometers located in the secondary cooling zone of the continuous casting machine, and simultaneously and continuously transmits the temperature data to the computer and the computer will be in a time interval. The temperature data obtained by taking the maximum value can simultaneously and continuously reflect the real temperature of the surface of the continuous casting slab in the secondary cooling zone. Through this temperature, the casting speed of the continuous casting machine can be effectively adjusted, and the cooling water can be adjusted. The parameters such as the flow rate can improve the output and quality of the continuous casting slab.

Description

Accurate measurement method of slab surface temperature in the secondary cooling zone of continuous casting

technical field

The invention relates to the field of metallurgy, in particular to a method for accurately measuring the surface temperature of a slab in a secondary cooling zone during continuous casting of molten steel.

Background technique

At present, the continuous casting process is basically used in the production of modern iron and steel complexes, and the secondary cooling control is an important part of the continuous casting process. In the continuous casting process, the heat lost by the slab in the secondary cooling zone (referred to as the secondary cooling zone) accounts for 60% of the heat lost by the slab during solidification, which directly affects the output and quality of the slab. The surface temperature of the slab is an important parameter to adjust the cooling water flow, control the casting speed, and determine the depth of the liquid phase cavity. In order to understand the running state of the slab during the continuous casting process and implement automatic control, it is necessary to detect the surface temperature of the slab near the outlet of the mold, the segment and the straightening point.

In the prior art, the temperature measurement of the continuous casting slab generally adopts the method of point measurement, that is, the surface temperature of the slab is measured intermittently at a certain point in the secondary cooling zone with a non-contact thermometer. The temperature error of the slab surface measured by the temperature measurement method is very large, and it cannot reflect the entire temperature change of the slab in the secondary cooling zone of continuous casting. The reasons are:

As we all know, the temperature of the continuous casting slab is extremely high in the secondary cooling zone. During the cooling process, water film and iron oxide scale will be formed on the surface of the slab, and water vapor will be diffused on the surface of the slab. Water film, iron oxide scale, etc. make it difficult to accurately measure the surface temperature of the slab by point measurement.

In addition, in order to have a systematic understanding of the temperature of the slab at each key point in the secondary cooling zone, it is not possible to measure the temperature bit by bit by point measurement, because the temperature of the slab at every moment All are changing, and it is difficult to formulate the continuous casting process parameters suitable for the casting slab according to the temperature of each point of the slab in the secondary cooling zone measured by spot measurement.

Contents of the invention

The purpose of the present invention is to improve the deficiencies in the prior art and provide a method for continuously and accurately measuring the surface temperature of the slab in the secondary cooling zone of continuous casting.

To achieve the above object, the present invention takes the following design scheme:

This temperature measurement method consists of two parts, one is to continuously measure the temperature of the surface temperature of the single point or multiple points in the secondary cooling zone of the slab, and the other is to process the measured temperature data to find out The method of measuring the accurate temperature of the slab. The steps of this temperature measurement method are:

a The thermometer measures the temperature of the slab without contact,

b The temperature data signal is continuously transmitted to the computer,

c. The computer processes the temperature data according to a specific algorithm to obtain an accurate slab temperature, wherein:

The thermometer is arranged above the slab running track of the continuous casting machine;

The signal output end of the thermometer is connected to the communication port of the computer, so that the temperature data collected by the thermometer is transmitted to the computer; the temperature response time of the thermometer is 300 milliseconds to 2 Second;

The computer performs the following processing on the temperature data transmitted by the thermometer:

a The computer takes out a number of temperature data collected by the thermometer in the time interval of 30 seconds to 5 minutes;

b Compare several temperature data taken by the thermometer, and take out the largest temperature data;

c. Outputting the obtained maximum temperature data as a processing result. Such as saving to a disk file or printing out or displaying it through a monitor.

The way in which the signal output terminal of the thermometer is connected to the communication port of the computer can be serial or parallel.

In order to have a systematic and comprehensive reflection of the temperature of the continuous casting slab in the secondary cooling zone, the temperature measuring instrument can be respectively arranged in the crystallizer outlet area, fan section, straightening section and horizontal section of the continuous casting machine. Connect to said computer. Through such a temperature measuring system, the surface temperature of the slab at each point in the secondary cooling zone can be reflected continuously at the same time. The temperature detectors can also be arranged several at a certain distance in the transverse direction of the slab in the straightening section of the continuous casting machine. It is also possible to install thermometers in the mold outlet area, fan section area, straightening section area and horizontal section area in the longitudinal direction of the continuous casting machine, and at the same time set several a thermometer. The temperature data collected by each thermometer is transmitted to the computer, and the computer respectively performs the above-mentioned processing on the temperature data collected by each thermometer.

The temperature measurement method provided by the present invention accurately measures the mechanism of the temperature of the slab surface in the secondary cooling zone as follows: in the actual continuous casting process, the slab surface is often covered by water film, steam mist and iron oxide scale, etc., at this time When measuring the temperature on its surface, it is likely to measure the temperature of the water film or iron oxide scale attached to the surface of the casting slab, rather than the temperature of the actual surface of the casting slab, but the above-mentioned water film or vapor mist or iron oxide scale does not affect the temperature of the casting slab. Covering is not continuous. In the target range of the thermometer, the slab passing by within a certain period of time is not completely covered. Therefore, in the time interval mentioned, when the surface of the slab is not covered by the When the covered part appears in the temperature measurement target of the thermometer, the real surface temperature of the slab is quickly collected into the computer. This is the purpose of making the thermometer measure the continuous temperature of the continuous casting machine in the method of the present invention—that is, to capture the instantaneous real surface temperature of the uncovered surface of the slab. And because the temperature of the surface of the slab covered by water film, steam mist or iron oxide scale should be lower than that of the surface of the slab not covered, the real temperature of the surface of the slab must be within the time interval. The highest temperature value measured. Therefore, it is scientific to select the maximum value among several temperature data measured in a time interval as the real surface temperature of the slab.

From the above-mentioned temperature measurement principle, it can be seen that in order to obtain the real temperature of the surface of the slab, it is critical to set an appropriate time interval. Generally, the appropriate time interval can be 30 seconds to 5 minutes. Furthermore, 30 seconds to 2 minutes is the preferred choice, and the possibility of capturing the real temperature of the surface of the uncovered slab within such a time interval is very high. If the time interval is too small, there may be no uncovered slab surface passing through the temperature measurement target of the pyrometer, but if the time interval is too long, the temperature measurement efficiency will be reduced, and it is not conducive to passing the measurement results in a timely manner. Adjust the continuous casting process parameters accurately.

In addition, other factors that affect accurate temperature measurement include:

The response time of the temperature measurement system. The response time of the temperature measurement system is the time it takes for the thermometer to measure a temperature and then transmit it to the computer. Its size has a great impact on accurate temperature measurement. Generally, the response time of the temperature measurement system is required to be 300 milliseconds to 2 seconds.

The temperature measuring distance is the vertical distance between the temperature measuring head of the thermometer and the surface of the continuous casting slab. It can generally be between 0.5 and 5 meters.

The size of the target point of the thermometer, because the uncovered part on the slab may be small, if the target point is too large, it will be difficult to capture, and the accuracy of the measured temperature will be reduced. The diameter of the target point of the thermometer is generally preferably not greater than 5 mm.

In addition, the temperature measurement range of the thermometer used is within 600-2000°C, and its maximum error is preferably less than 1%.

The method for accurately measuring the surface temperature of the slab in the secondary cooling zone of continuous casting provided by the present invention is connected with a computer through a number of thermometers located in the secondary cooling zone of the continuous casting machine, and simultaneously and continuously transmits the temperature data to the computer and the computer will be in a time interval. The temperature data obtained by taking the maximum value can simultaneously and continuously reflect the real temperature of the surface of the continuous casting slab in the secondary cooling zone. Through this temperature, the casting speed of the continuous casting machine can be effectively adjusted, and the cooling water can be adjusted. flow to improve the yield and quality of continuous casting slabs.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing.

Fig. 1 is a structural schematic diagram of setting a thermometer in the longitudinal direction of the continuous casting machine and connecting the thermometer with a computer

Figure 2 is a structural schematic diagram of installing a thermometer on the row of the continuous casting machine and connecting the thermometer to the computer

Detailed ways

As shown in Figure 1, a temperature measuring instrument 2 is respectively provided in the mold outlet area A, the sector area B, the straightening area C and the horizontal area D of the continuous casting machine, and its signal output port is connected to the communication port of the computer 1 They are connected to form a temperature measuring system, so that the temperature signal of the billet 3 measured by the thermometer is continuously sent to the computer 1 . The thermometer 2 is arranged above the slab 3, and the distance from the surface of the slab is 1 meter. The response time of the above temperature measurement system is 400 milliseconds. The target spot of the pyrometer has a diameter of 2 mm.

The temperature is continuously measured through the above-mentioned temperature measurement system and the measured temperature data is transmitted to the computer. The computer compares several temperature data obtained in a time interval for each temperature measurement point, and takes out the largest temperature data; outputs the obtained largest temperature data as a processing result, such as storing in a disk file or printing out Or display it on the monitor. This time interval is 2 minutes.

As shown in Figure 2, several thermometers 2 can be set in the transverse direction of the straightening section of the continuous casting slab 3, for example, four are set: one temperature measuring instrument is set at A' at a distance from the edge of one side of the slab ≤ 10 mm Instrument 2, a thermometer 2 is installed at the midpoint C' of the entire slab and 1/4 of the slab width B' between A' and C'. A fourth thermometer is set at D' at a distance of 1/8 of the slab width from one edge.

The temperature measurement method and the processing method for the collected temperature data are as above. The interval is 4 minutes and the response time is 1 second. The temperature measurement distance is 3 meters.

A thermometer can be installed on the continuous casting machine in the vertical direction as shown in Figure 1, and in the horizontal direction as shown in Figure 2, so as to obtain more comprehensive system temperature data of the slab.

Claims (6)

1, a kind of accurate measuring method of casted blank surface temperature of continuous casting secondary cold region is characterized in that: its step is as follows:

The a temperature measurer is done the contactless type thermometric to strand,

The b temperature data signal is passed to computer continuously,

The described computer of c is handled described temperature data by special algorithm and is obtained strand temperature accurately, wherein:

Described temperature measurer is located at the strand orbit top of conticaster;

The signal output part of described temperature measurer is connected with the communication port of described computer, and the temperature data that temperature measurer is gathered is transferred in the described computer; The thermometric response time of described temperature measurer is 300 milliseconds～2 seconds;

Described computer carries out following processing to the temperature data that described temperature measurer transmission comes:

The a computer take out in 30 seconds～5 minute time interval temperature measurer adopt the plurality of temperature data;

The plurality of temperature data that b gets temperature measurer compare, and take out wherein maximum temperature data;

The temperature data of the described maximum that c will draw is exported as result.

2, assay method according to claim 1, it is characterized in that: described temperature measurer is a plurality of, crystallizer outlet area on conticaster, fan-shaped section district, aligning section district and horizontal segment district respectively are provided with a temperature measurer at least respectively, the temperature data that each temperature measurer is gathered all is transferred to described computer, and described computer carries out described processing to the temperature data that each temperature measurer is gathered respectively.

3, assay method according to claim 1 and 2 is characterized in that: at the aligning section district of described conticaster strand several described temperature measurers are set transversely.

4, assay method according to claim 3, it is characterized in that: four temperature measurers transversely are set: locate to be provided with a temperature measurer at distance strand one lateral edges≤10 millimeters A ' in the aligning section district of the strand of described conticaster, the midpoint C ' of whole strand and be in A ' and C ' between 1/4 B ' of strand width locate respectively to establish a temperature measurer, the distance at another edge on distance strand width is that 1/8 D ' of strand width locates to be provided with the 4th temperature measurer.

5, assay method according to claim 1 is characterized in that: the described time interval is 30 seconds～2 minutes.

6, assay method according to claim 1 is characterized in that: the thermometric target spot of described temperature measurer is for being not more than 5 millimeters.

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