Infrared temperature measuring device and method of use thereof

Abstract

The present application relates to temperature measuring device technical field, specifically, a kind of infrared temperature measuring device and its use method, including field of view adjusting module, automatic focusing module, angle of view adjusting module, temperature measuring module, main control module and auxiliary module, drive unit and scanning unit, lens unit and lens control unit, adjustable diaphragm and diaphragm control assembly, sensitive unit and data acquisition unit, main control unit is made of high-speed processing unit, auxiliary unit includes cooling unit and field of view purging unit, compared with prior art, through the components of field of view adjusting module, automatic focusing module, angle of view adjusting module, temperature measuring module, main control module and auxiliary module, automatic focusing and molten steel signal capture algorithm, realize the influence of eliminating molten steel liquid level change in ladle and steel slag splashing during smelting, through the device and the characteristic operation process of unique design realize high-efficiency target alignment, improve measurement accuracy, realize the technical effect of accurate continuous monitoring of molten steel temperature in steelmaking process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature measuring devices, in particular to an infrared temperature measuring device and a method for using the same. BACKGROUND

[0002] The steel industry is the foundation industry of a country, and the automation level of steel smelting is a symbol of industrialization of a country. Accurate and real-time acquisition of molten steel temperature is the premise of improving the control precision of molten steel temperature in each process link, and is the key to ensuring steel quality, improving efficiency and reducing energy consumption.

[0003] The current molten steel temperature measurement methods mainly include three types: consumable fast intermittent temperature measurement, platinum-rhodium thermocouple with protective tube continuous temperature measurement and thermal radiation continuous temperature measurement. Although the consumable fast intermittent temperature measurement can directly obtain the temperature of molten steel, the thermal shock of high-temperature molten steel and the corrosiveness of steel slag make the thermocouple only be used once, and the change of molten steel temperature cannot be continuously monitored, which directly restricts the process control in the production process. Although the platinum-rhodium thermocouple with protective tube continuous temperature measurement realizes short-term continuous measurement of molten steel temperature, the temperature measurement response is seriously lagged after the protective tube is added, and it is difficult to meet the requirement of refining on the response speed of temperature measurement. The thermal radiation continuous temperature measurement has attracted widespread attention in the industry because it does not directly contact with molten steel, and can greatly reduce the risk of high-temperature corrosion damage.

[0004] However, the molten steel continuous temperature measurement instrument based on thermal radiation needs to solve the following problems:

[0005] (1) In the steelmaking process, the steel slag on the surface of molten steel is different from the thermal radiation coefficient of molten steel. Therefore, the temperature measurement point must be accurately located in the bubbling area (about several tens of centimeters in diameter) in the steel furnace, and the surface of the molten steel in this area is not covered with steel slag, so as to avoid the influence of the steel slag on the surface of the molten steel on the measurement result. This involves the problem of accurate positioning of measurement. Since the bubbling position of the steel furnace is relatively fixed, the angle of the temperature measurement probe installed on the top cover of the steel furnace can be preliminarily adjusted, which facilitates subsequent fine adjustment.

[0006] (2) Although the bubbling position and area size in the steel furnace are relatively fixed, the inner wall of the ladle becomes thin after being used for several times, which causes the height of the molten steel liquid surface to have a floating of tens of centimeters up and down when the ladle of the same weight of raw materials is added in different smelting batches, resulting in a large change in the distance from the temperature measurement instrument to the molten steel liquid surface during smelting of different ladles, so that the temperature measurement point may deviate from the bubbling area, resulting in a large measurement deviation. The temperature measurement point needs to be dynamically adjusted in time during the steelmaking process. However, manual adjustment device is not suitable in the harsh environment of the molten steel smelting process, and the auxiliary laser alignment device is also not suitable in this environment.

[0007] (3) In the smelting process, there are a large amount of smoke and steel slag splashing, which will seriously affect the stability and accuracy of the measurement signal in the measurement light path. In addition, if the steel slag splashes and solidifies on the lens, it will block the light path. In order to reduce the influence, high-pressure gas is needed to flush the steel slag and smoke in the light path along the measurement light path on the measurement probe, which on the one hand ensures that the steel slag will not block the lens, and on the other hand improves the stability of the measurement signal. The design of the high-pressure gas device is not within the protection scope of the present application, but how to extract accurate signals from unstable signals in the steelmaking measurement process is one of the problems to be solved by the present application.

[0008] The present application designs an infrared temperature measuring device and its use method, which accurately finds the target temperature point, is beneficial to eliminate the influence of different ladle sizes and steel slag in molten steel, improves the measurement accuracy, and through the automatic focusing and molten steel signal grabbing algorithm, it is beneficial to eliminate the influence of the change of molten steel liquid level in the ladle and the splashing of steel slag during smelting, improve the measurement accuracy, and realize the accurate continuous monitoring of the temperature of molten steel in the steelmaking process. SUMMARY

[0009] The present application overcomes the shortcomings of the prior art and provides an infrared temperature measuring device and its use method, which accurately finds the target temperature point, is beneficial to eliminate the influence of different ladle sizes and steel slag in molten steel, improves the measurement accuracy, and through the automatic focusing and molten steel signal grabbing algorithm, it is beneficial to eliminate the influence of the change of molten steel liquid level in the ladle and the splashing of steel slag during smelting, improve the measurement accuracy, and realize the accurate continuous monitoring of the temperature of molten steel in the steelmaking process.

[0010] In order to achieve the above-mentioned purpose, the present application provides an infrared temperature measuring device, characterized in that it comprises a field of view adjusting module, an automatic focusing module, a viewing angle adjusting module, a temperature measuring module, a main control module and an auxiliary module, the field of view adjusting module comprises a driving unit and a scanning unit, the automatic focusing module comprises a lens unit and a lens control unit, the viewing angle adjusting module comprises an adjustable diaphragm and a diaphragm control assembly, the temperature measuring module comprises a sensitive unit and a data acquisition unit, the main control unit is composed of a high-speed processing unit, and the auxiliary unit comprises a cooling unit and a field of view blowing unit.

[0011] The aperture of the adjustable diaphragm comprises a target identification file, a target scanning file and a target measurement file.

[0012] The aperture of the target identification file is larger than that of the target scanning file, and the aperture of the target scanning file is larger than that of the target measurement file.

[0013] The sensitive unit of the temperature measuring module is provided with at least one reference channel and at least one measurement channel, and the data after signal normalization of the reference channel and the measurement channel is used as the signal for target temperature calculation.

[0014] A use method of an infrared temperature measuring device, comprising the following steps:

[0015] S1: System state automatic adjustment: check and adjust the data acquisition unit, cooling unit, purging unit work to meet the required work normal;

[0016] S1-1, data acquisition unit state check:

[0017] Check if the signal-to-noise ratio meets the requirements;

[0018] S1-2, cooling unit state check and adjustment:

[0019] The cooling unit is interconnected with the temperature measurement module, and the temperature and cooling water flow are adjusted in real time to ensure that the temperature measurement module is controlled at a constant temperature.

[0020] S1-3, purging unit state check and adjustment, select the best data acquisition frequency and data extraction time window:

[0021] S1-3-1: Select the sampling frequency and signal extraction time window range (0.1-600s) in the range of (0.1-1000Hz);

[0022] The selected sampling frequency and signal extraction time window in S1-3-1 meet the requirements of statistical data analysis, which means that the proportion of data in the time window is greater than 10% and the relative deviation is less than 1%. If the purging effect meets the requirements, the measurement conditions are considered to be met, and the measured data can be used as the original measurement signal for subsequent signal processing.

[0023]

[0024] S1-3-2: Collect all data in the time window and sort them, and take the average value of the largest proportion of data as the effective measurement value;

[0025] S1-3-3: Select different time windows and repeat S1-3-1-S1-3-2 to obtain all effective measurement values.

[0026] S2, target recognition and preliminary temperature measurement range positioning:

[0027] After the infrared temperature measurement device is initialized, it enters the target recognition mode, the main control module sends instructions to adjust the adjustable diaphragm to the first target recognition gear, starts collecting and comparing the data uploaded by the temperature measurement module, and scans the two-dimensional plane temperature data in the specified range, then selects the measurement area according to the target area determination standard algorithm.

[0028] S2-1, the scanning method is: ​

[0029] There are two angle adjusting devices on the device, corresponding to the X-axis dimension and Y-axis dimension of the measuring plane respectively, and when scanning, the full scanning can be performed, the x dimension is from 0 to θxmax, the minimum step of adjustment is dθx, the y dimension is from 0 to θymax, the minimum step of adjustment is dθy, and the scanning includes the "several" shape, the "8" shape, the spiral shape and the four-leaf clover shape.

[0030] S2-2: the target area determination standard algorithm is:

[0031] S2-2-1: the target measurement area measurement value is higher than the steel slag area temperature;

[0032] S2-2-2: the target measurement area temperature is relatively uniform, the angle change has little effect on the measurement value, and dS / dθ tends to 0, S is a measurement signal, and θ is a viewing angle;

[0033] S2-2-3: at the boundary of the target measurement area, the steel slag and molten steel radiation coefficients are different, and the range boundary dS / dθ of the target measurement area is large;

[0034] The measurement range is determined by using the algorithm of S2-2, the angle scanning is adjusted through the X-axis and Y-axis dimensions, and the measurement range is preliminarily selected only by using the measurement signal;

[0035] S3, accurate positioning of the temperature measuring point:

[0036] The main control module sends a command to adjust the adjustable diaphragm to the target scanning file, and sends a command to the field of view adjusting module, performs field of view scanning in the measurement area range selected in S2, obtains two-dimensional plane temperature data, determines the measurement range according to the target area determination standard algorithm, and selects a point in the measurement range as a temperature measuring point;

[0037] S4, automatic focusing and target measurement:

[0038] After the target measurement point is determined, the main control module sends a focusing instruction to the automatic focusing module to realize fine adjustment of the focal length, at this time, the measurement signal is maximum and the measurement value is not sensitive to the change of the focusing distance, the data of the temperature measuring module is collected at this time, and then the temperature measuring information is processed according to the predetermined algorithm, and the accurate measurement of the target temperature is completed.

[0039] The present application solves the problem of reliable measurement of molten steel temperature in the process of blast furnace steelmaking, and has the following characteristics compared with the prior art:

[0040] The system can automatically judge and adjust the measurement parameters to meet the requirements of molten steel temperature measurement in complex environment (strong electromagnetic interference, high temperature environment, steel slag splashing, etc.), and ensure the reliability of measurement.

[0041] The best measuring point is quickly selected by the obtained measuring signal characteristic analysis and two-stage regulation mode, the measuring device is simplified, and the convenience, reliability and accuracy of the device in application under harsh conditions are improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1 It is a working flowchart of the infrared temperature measuring device of the present application.

[0043] Fig. 2 It is a composition schematic diagram of the infrared temperature measuring device of the present application. DETAILED DESCRIPTION

[0044] The present application will be further described in combination with the drawings.

[0045] Reference Figs. 1-2 The present application provides an infrared temperature measuring device, which comprises a field of view adjustment module, an automatic focusing module, a view angle adjustment module, a temperature measuring module, a main control module and an auxiliary module. The field of view adjustment module comprises a driving unit and a scanning unit. The automatic focusing module comprises a lens unit and a lens control unit. The view angle adjustment module comprises an adjustable diaphragm and a diaphragm control assembly. The temperature measuring module comprises a sensitive unit and a data acquisition unit. The main control unit is composed of a high-speed processing unit. The auxiliary unit comprises a cooling unit and a field of view blowing unit.

[0046] The aperture of the adjustable diaphragm comprises a target identification file, a target scanning file and a target measuring file.

[0047] The aperture of the target identification file is larger than that of the target scanning file, and the aperture of the target scanning file is larger than that of the target measuring file.

[0048] The sensitive unit of the temperature measuring module is provided with at least one reference channel and at least one measuring channel. The data of the reference channel and the measuring channel after signal normalization is used as the signal for target temperature calculation.

[0049] A use method of an infrared temperature measuring device, comprising the following steps:

[0050] S1: automatic adjustment of system state: the working conditions of the data acquisition unit, the cooling unit and the blowing unit are checked and adjusted to meet the required normal working conditions.

[0051] S1-1: data acquisition unit state check:

[0052] Since the environment of the blast furnace steelmaking is very complex and harsh, the electric arc heating can also cause very serious electromagnetic interference, and the anti-interference design and electromagnetic shielding design are very important. In the system preparation stage, it should be checked whether the unit part is working normally and whether the data quality meets the requirements of the later data analysis.

[0053] Check whether the signal-to-noise ratio meets the requirements.

[0054] S1-2, cooling unit state check and adjustment:

[0055] The temperature of molten steel in steelmaking process is generally about 1600 degrees, and the infrared temperature measurement module is usually fixed near the observation hole of the steel furnace cover. It must be cooled by water or other means to reduce its working temperature to below 100 degrees and maintain a constant temperature, so as to maximize the accuracy of measurement. The cooling unit is connected with the temperature measurement module. Through real-time feedback of temperature and cooling water flow adjustment, the temperature measurement module is controlled in the set constant temperature state;

[0056] S1-3, purge unit state check and adjustment, select the best data acquisition frequency and data extraction time window. In addition to electromagnetic interference affecting the measurement signal, the splashing of steel slag and smoke will also affect the stability of the measurement signal. Therefore, the device sets a purge unit on the temperature measurement probe, which blows away the steel slag and smoke along the measurement light path to reduce the influence of this factor;

[0057] Considering that the degree and size of steel slag splashing have certain randomness and the influence on the measurement signal is relatively low frequency, but within a certain time window, it is subject to statistical distribution (normal distribution), so within a certain sampling frequency, it can be processed by statistical methods, such as selecting a fixed proportion of data in the entire data in the time window according to its distribution law (such as the 10% data with the highest frequency or the 10% data with the highest measurement value).

[0058] The appropriate sampling frequency and signal extraction time window have a great influence on the data quality. The appropriate sampling frequency ensures the independence of the data, and the appropriate time window ensures that the obtained data meet the statistical rules. These two parameters can be selected by experiment.

[0059] One of the preferred ideas is that the influence of light path obstruction on the signal is unidirectional reduction. When the air pressure and air flow are large enough, the steel slag or mist on the measurement light path can be completely blown away, and there is no obstruction on the entire measurement light path. At this time, the detection signal obtained is the largest. Within a suitable measurement time window, statistically speaking, the signal without obstruction can always be obtained. The measurement value should be closest to the actual molten steel temperature.

[0060] S1-3-1: Select the sampling frequency and signal extraction time window range (0.1-600s) within the range of (0.1-1000Hz);

[0061] The selected sampling frequency and signal extraction time window in S1-3-1 can meet the requirements of statistical data analysis. The requirements of statistical data analysis are that the proportion of data in the time window is greater than 10%, and the relative deviation is less than 1%. If the purge unit meets the requirements, the purge effect is considered to meet the requirements, otherwise the purge flow is adjusted until it meets the requirements;

[0062] When the purge effect meets the requirements, it is considered that the measurement conditions are met, and the measured data can be used as the original measurement signal for subsequent signal processing;

[0063] S1-3-2: Collect all data in the time window and sort them, and take the average value of the largest proportion of data as the effective measurement value;

[0064] S1-3-3: Select different time windows, repeat S1-3-1-S1-3-2, and obtain the effective measurement value of all time windows:

[0065] a) Define the sampling frequency (e.g. 1 Hz) and signal extraction time window (e.g. 60 seconds)

[0066] b) Collect all data in the first time window (e.g. 1-60 seconds), and extract the average value of the largest 20% data in the time window as the effective measurement value of the first time window.

[0067] c) Collect all data in the second time window (e.g. 2-61 seconds), and extract the average value of the largest 20% data in the time window as the effective measurement value of the second time window.

[0068] d) Obtain the effective measurement data of all time points in turn.

[0069] S2, target recognition and preliminary temperature measurement range positioning:

[0070] After the infrared temperature measurement device is initialized, it enters the target recognition mode, the main control module sends a command to adjust the adjustable diaphragm to the first target recognition gear, starts collecting and comparing the data uploaded by the temperature measurement module, and scans the two-dimensional plane temperature data in the specified range, and then preliminarily selects the measurement area according to the target area determination standard algorithm;

[0071] S2-1, the scanning method is:

[0072] There are two angle adjustment devices on the device, corresponding to the X-axis dimension and Y-axis dimension of the measurement plane. When scanning, it can be fully scanned, x dimension from 0 to θxmax, the minimum step is dθx, y dimension from 0 to θymax, the minimum step is dθy. The scanning includes "few" shape, "8" shape, spiral shape and four-leaf clover shape;

[0073] S2-2: The target area determination criterion algorithm is:

[0074] S2-2-1: The target measurement area measurement value is higher than the steel slag area temperature;

[0075] S2-2-2: In the target measurement area, the temperature is relatively uniform, the angle change has little effect on the measurement value, and dS / dθ tends to 0, S is the measurement signal, and θ is the viewing angle;

[0076] S2-2-3: At the boundary of the target measurement area, the steel slag and molten steel radiation coefficients are different, the range boundary dS / dθ of the target measurement area is large; the measurement spot (such as 1 cm in diameter) is generally smaller than the measurement area (such as 30 cm in diameter), the temperature in the measurement area is uniform, and the measurement spot drift (corresponding to θ change) has little effect on the measured temperature;

[0077] The measurement range is determined by using the algorithm of S2-2, the angle scanning is adjusted by X-axis and Y-axis dimensions, and the range measurement can be preliminarily selected only by using the measurement signal, compared with the traditional method of using additional devices (such as visual or laser spot) for auxiliary positioning, the application directly uses the characteristics of the measurement data signal for positioning, without additional devices.

[0078] S3, precise positioning of temperature measurement point:

[0079] The main control module sends a command to adjust the adjustable diaphragm to the target scanning file, and sends a command to the field of view adjustment module to scan the field of view in the measurement area range selected in S2, to obtain two-dimensional plane temperature data, determine the measurement range according to the target area determination criterion algorithm, and select a point therein as a temperature measurement point;

[0080] S4, automatic focusing and target measurement:

[0081] After the target measurement point is determined, the main control module sends a focusing command to the automatic focusing module to realize fine adjustment of the focal length, at this time the measurement signal is maximum and the measurement value is not sensitive to the change of the focusing distance, at this time the data of the temperature measurement module is collected, then the temperature measurement information is processed according to the predetermined algorithm, and the accurate measurement of the target temperature is completed.

[0082] The above is only a preferred embodiment of the application, which is only used to help understand the method and its core idea of the application, and the protection scope of the application is not limited to the above-mentioned embodiments, any technical solution belonging to the idea of the application shall be within the protection scope of the application. It should be noted that for ordinary skilled persons in the art, some improvements and decorations without departing from the principle of the application shall also be considered as the protection scope of the application.

[0083] The present application solves the technical problem of the prior art that the molten steel continuous temperature measuring instrument based on thermal radiation influences the temperature measuring accuracy and has a large deviation. Through the unique design of the infrared temperature measuring device, the target temperature measuring point is accurately found, which is beneficial to eliminate the influence of different ladle sizes and steel slag in the molten steel and improve the measurement accuracy. Through the automatic focusing and molten steel signal grabbing algorithm, the influence of the change of the molten steel liquid level in the ladle and the splashing of the steel slag during the smelting is eliminated, the measurement accuracy is improved, and the accurate continuous monitoring of the molten steel temperature during the steelmaking process is realized.

Claims

1. An infrared temperature measuring device, characterized in that The infrared temperature measuring device comprises a field of view adjusting module, an automatic focusing module, a viewing angle adjusting module, a temperature measuring module, a main control module and an auxiliary module, the field of view adjusting module comprises a driving unit and a scanning unit, the automatic focusing module comprises a lens unit and a lens control unit, the viewing angle adjusting module comprises an adjustable diaphragm and a diaphragm control assembly, the temperature measuring module comprises a sensitive unit and a data acquisition unit, the main control module is composed of a high-speed processing unit, and the auxiliary module comprises a cooling unit and a field of view blowing unit. The use method of the infrared temperature measuring device comprises the following steps: S1: automatically adjusting the system state: checking and adjusting the working conditions of the data acquisition unit, the cooling unit and the blowing unit to meet the required normal working conditions; S1-1: checking the state of the data acquisition unit: checking whether the signal-to-noise ratio meets the requirements; S1-2: checking and adjusting the state of the cooling unit: the cooling unit is connected with the temperature measuring module, and the temperature and the cooling water flow are adjusted in real time to ensure that the temperature measuring module is controlled in a constant temperature state; S1-3: checking and adjusting the state of the blowing unit, and selecting the best data acquisition frequency and data extraction time window: S1-3-1: selecting the sampling frequency and the signal extraction time window in the range of (0.1-1000 Hz) and (0.1-600 s); the selected sampling frequency and signal extraction time window in the range of S1-3-1 can meet the requirements of statistical data analysis, and the requirements of statistical data analysis are that the proportion of data in the time window is greater than 10%, and the relative deviation is less than 1%, so that the blowing effect of the blowing unit meets the requirements, otherwise the blowing flow is adjusted until it meets the requirements; when the blowing effect meets the requirements, it is considered that the measurement requirements are met, and the measured data can be used as the original measurement signal for subsequent signal processing; S1-3-2: collecting all data in the time window and sorting, and taking the average value of the largest proportion of data as the effective measurement value; S1-3-3: selecting different time windows, repeating the operations of S1-3-1 to S1-3-2, and obtaining the effective measurement values of all time windows; S2: target recognition and preliminary temperature measurement range positioning: after the infrared temperature measuring device is initialized, the target recognition mode is entered, the main control module sends an instruction to adjust the adjustable diaphragm to the first target recognition gear, starts to collect and compare the data uploaded by the temperature measuring module, scans in the specified range to obtain two-dimensional plane temperature data in the range, and then preliminarily selects the measurement area according to the target area determination standard algorithm; S2-1: the scanning mode is: there are two angle adjusting devices on the device, which correspond to the X-axis dimension and Y-axis dimension of the measurement plane respectively, full scanning is performed when scanning, the x dimension is from 0 to θxmax, the minimum step is dθx, the y dimension is from 0 to θymax, the minimum step is dθy, and the scanning includes "few” shape, "8” shape, spiral shape and four-leaf clover shape; S2-2: the target area determination standard algorithm is: S2-2-1: the target measurement area has a higher temperature than the steel slag area; S2-2-2: In the target measurement area, the temperature is relatively uniform, the angle change has little effect on the measurement value, dS / dθ tends to 0, S is the measurement signal, and θ is the viewing angle; S2-2-3: At the boundary of the target measurement area, the radiation coefficients of the steel slag and the molten steel are different, and the range boundary dS / dθ of the target measurement area is large; The S2-2 algorithm is used to determine the measurement range, the angle scanning is adjusted through the X-axis and Y-axis dimensions, and only the measurement signal is used to preliminarily select the range measurement; S3, accurate positioning of the temperature measurement point: The main control module sends a command to adjust the adjustable diaphragm to the target scanning file, and sends a command to the field of view adjustment module to perform field of view scanning in the measurement range selected in S2 to obtain two-dimensional plane temperature data, determine the measurement range according to the target area determination standard algorithm, and select a point in the measurement range as the temperature measurement point; S4, automatic focusing and target measurement: After the target measurement point is determined, the main control module sends a focusing command to the automatic focusing module to realize fine adjustment of the focal length. At this time, the measurement signal is maximum and the measurement value is not sensitive to the change of the focal length. At this time, the data of the temperature measurement module is collected, and then the temperature information is processed according to the predetermined algorithm to complete the accurate measurement of the target temperature.

2. The infrared temperature measurement device of claim 1, wherein The aperture of the adjustable diaphragm includes a target recognition file, a target scanning file and a target measurement file.

3. The infrared temperature measurement device of claim 2, wherein, The aperture of the target recognition file is larger than that of the target scanning file, and the aperture of the target scanning file is larger than that of the target measurement file.

4. The infrared temperature measurement device of claim 1, wherein, The sensitive unit of the temperature measurement module is provided with at least one reference channel and at least one measurement channel, and the normalized data of the reference channel and the measurement channel signals are used as the signals for calculating the target temperature.

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