Correcting method for measuring temperature of flowing tobacco shreds in tobacco shred drying cavity

Abstract

The invention provides a correction method for measuring temperature of flowing tobacco shreds in a tobacco shred drying cavity, which comprises the following steps of: S1, measuring the surface temperature of the flowing tobacco shreds in the tobacco shred drying cavity by using an infrared temperature measuring device to obtain initial temperature data of the measured tobacco shreds; s2, determining the emissivity of the measured tobacco shreds, and correcting the initial temperature data according to the emissivity; s3, calculating the ratio of the measurement distance to the tobacco shred thickness as a distance coefficient, and correcting the temperature data obtained in the previous step according to the distance coefficient; s4, correcting the temperature data obtained in the previous step according to the reflectivity of the surface of the cut tobacco; s5, correcting the temperature data obtained in the previous step by using an environment temperature compensation algorithm; and S6, outputting the corrected tobacco shred temperature data. According to the method, the obtained tobacco shred temperature can be accurate, and the temperature measurement requirement of the flowing tobacco shred in a complex environment can be well met.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco manufacturing, and in particular relates to a correction method for measuring the temperature of flowing shredded tobacco in a shred drying chamber. Background Art

[0002] In the tobacco processing, tobacco drying is one of the most important steps. Its main purpose is to ensure the quality and flavor of tobacco by uniformly heating and drying the tobacco. In this process, the temperature control of tobacco has a direct impact on the final quality of the product. However, due to the continuous flow of tobacco in the drying chamber and the uneven temperature distribution in the drying chamber, it has become a challenge to accurately measure and control the temperature of tobacco in real time.

[0003] At present, the commonly used methods for measuring tobacco temperature include contact and non-contact methods. The contact temperature measurement method usually uses sensors such as thermocouples, but due to the high-speed flow of tobacco in the drying chamber, the contact sensor is easily worn or damaged, and cannot accurately capture the dynamic temperature changes of tobacco in real time. Therefore, non-contact infrared temperature measurement technology has gradually become the main temperature measurement method in the drying process.

[0004] Infrared temperature measurement technology indirectly calculates the temperature by detecting the infrared radiation intensity on the surface of an object. It has the advantages of being fast and non-contact, and is suitable for objects moving at high speed. However, when infrared temperature measurement technology is applied to tobacco flowing in the drying chamber, it still faces the following technical difficulties: emissivity uncertainty: the surface emissivity of tobacco is affected by factors such as its material, color, and surface roughness. Changes in emissivity will lead to inaccurate infrared temperature measurement results; the influence of measurement distance on temperature measurement: the infrared radiation energy decays with the increase of measurement distance. If it is not corrected, the change in measurement distance will lead to errors in temperature measurement results; environmental radiation interference: the high temperature environment and other heat sources in the drying chamber may produce environmental radiation or reflection interference, affecting the accuracy of temperature measurement results; dynamic fluidity influence: because tobacco is flowing in the drying chamber and the temperature field is uneven, the temperature measurement device only measures the surface temperature of tobacco and cannot reflect the overall temperature change; at the same time, the fluctuation of ambient temperature will further affect the measurement results. The existing tobacco temperature measurement methods are often based on static or single factor considerations, which cannot fully reflect the complex changes in process conditions, resulting in inaccurate measurement of tobacco temperature. Therefore, how to design a correction method for measuring the temperature of flowing tobacco in a drying chamber so that the obtained tobacco temperature is more accurate and better meets the temperature measurement requirements of flowing tobacco in a complex environment has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] The object of the present invention is to provide a method for correcting the measured temperature of flowing tobacco in a drying chamber, so as to solve the above-mentioned technical problems in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for correcting the measured temperature of flowing tobacco in a drying chamber comprises the following steps:

[0008] Step S1, using an infrared temperature measuring device to measure the surface temperature of the flowing tobacco in the drying chamber to obtain initial temperature data of the measured tobacco;

[0009] Step S2, determining the emissivity of the tested tobacco, and correcting the initial temperature data according to the emissivity;

[0010] Step S3, calculating the ratio of the measured distance to the thickness of the tobacco as a distance coefficient, and correcting the temperature data obtained in the previous step according to the distance coefficient;

[0011] Step S4, correcting the temperature data obtained in the previous step according to the reflectivity of the tobacco surface;

[0012] Step S5, applying an ambient temperature compensation algorithm to correct the temperature data obtained in the previous step;

[0013] Step S6: output the corrected tobacco temperature data.

[0014] Preferably, the specific content of correcting the initial temperature data according to the emissivity is:

[0015] According to the material, surface texture, and color characteristics of the tobacco, select or calibrate the appropriate emissivity value, and use the following formula to correct the initial temperature data: ;

[0016] Where: T measured is the corrected temperature; E is the measured infrared radiation energy; τ is the transmittance of the air medium; is the emissivity of the object being measured; σ is the Stefan-Boltzmann constant.

[0017] Preferably, the specific content of correcting the temperature data obtained in the previous step according to the distance coefficient is:

[0018] Use the following formula to correct the temperature data obtained in the previous step: ;

[0019] Where: T correctedis the temperature after distance correction; α is a correction coefficient related to the attenuation rate of infrared radiation energy; K0 is the ratio of the measurement distance to the thickness of tobacco under calibration conditions; K value when measuring the tobacco temperature at the standard distance.

[0020] Preferably, the distance coefficient K is calculated as follows: ;

[0021] Among them, d measure is the distance between the infrared temperature measuring device and the measured tobacco, d smoke The thickness of the tobacco.

[0022] Preferably, the specific method for obtaining the correction coefficient α is:

[0023] At different distances d measured Under the condition of 100°, measure the surface temperature T of the tobacco being tested. measured ; Compare the reference temperature at the standard distance and analyze the temperature attenuation trend at different distances; Fit the value of α based on these experimental data.

[0024] Preferably, the specific contents of correcting the initial temperature data according to the reflectivity of the tobacco surface are:

[0025] Use the following formula for correction: ;

[0026] Where: T final is the corrected temperature; T b is the temperature before correction.

[0027] Preferably, the specific content of applying the ambient temperature compensation algorithm to correct the temperature data obtained in the previous step is:

[0028] Collect the ambient temperature data in the drying chamber, calculate the difference between the ambient temperature and the temperature data obtained in the previous step, and use the following formula for correction: ;

[0029] Where: T compensated is the temperature corrected for the ambient temperature; T env is the ambient temperature; T smoke is the initial temperature data of the tobacco obtained by measurement; k is the compensation coefficient.

[0030] Preferably, the compensation coefficient is obtained through multiple experiments and historical data calibration.

[0031] Preferably, it also includes a multi-point temperature measurement method, and the multi-point temperature measurement method includes:

[0032] Arrange multiple infrared temperature measuring devices in the tobacco drying chamber to obtain the temperature data of tobacco at different positions;

[0033] Based on the temperature data of tobacco at different positions, the three-dimensional temperature field in the tobacco drying chamber is reconstructed to evaluate the heat flow distribution of tobacco.

[0034] Preferably, the reconstruction of the three-dimensional temperature field is modeled using finite element analysis or computational fluid dynamics techniques.

[0035] The beneficial effects of the present invention are:

[0036] The correction method for measuring the temperature of flowing tobacco in a drying chamber of the present invention comprehensively considers the influence of emissivity, measurement distance, reflectivity and ambient temperature on the measured temperature of tobacco, and dynamically adjusts the measured temperature of tobacco, so that the obtained tobacco temperature is more accurate, and can better meet the temperature measurement requirements of flowing tobacco in a complex environment. At the same time, the present invention can not only improve the accuracy of tobacco temperature measurement, but also provide reliable technical support for the optimization of tobacco drying process and the improvement of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments, and further describe the specific embodiments of the present invention in detail in conjunction with the drawings, wherein

[0038] Figure 1 A flow chart of a method for correcting the measured temperature of flowing tobacco in a drying chamber provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0040] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0041] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0042] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0043] like Figure 1As shown, an embodiment of the present invention provides a method for correcting the measured temperature of flowing tobacco in a drying chamber, which comprises the following steps:

[0044] Step S1, using an infrared temperature measuring device to measure the surface temperature of the flowing tobacco in the drying chamber to obtain initial temperature data of the measured tobacco;

[0045] Step S2, determining the emissivity of the tested tobacco, and correcting the initial temperature data according to the emissivity;

[0046] Step S3, calculating the ratio of the measured distance to the thickness of the tobacco as a distance coefficient, and correcting the temperature data obtained in step S2 according to the distance coefficient;

[0047] Step S4, correcting the temperature data obtained in step S3 according to the reflectivity of the tobacco surface to reduce the influence of environmental radiation and other reflection interference;

[0048] Step S5, applying an ambient temperature compensation algorithm to correct the temperature data obtained in step S4 to correct the influence of nearby high temperature objects and ambient temperature changes on the measurement results;

[0049] Step S6, outputting the corrected tobacco temperature data, i.e., the temperature data obtained in step S5.

[0050] In infrared temperature measurement, the emissivity of the object surface is one of the key factors affecting the measurement accuracy. The emissivity of tobacco will vary depending on the material, color and surface texture. In order to accurately obtain the temperature of tobacco, it is first necessary to calibrate it according to the characteristics of the tobacco.

[0051] Furthermore, the specific content of correcting the initial temperature data according to the emissivity is:

[0052] According to the material, surface texture, and color characteristics of the tobacco, select or calibrate the appropriate emissivity value, and use the following formula to correct the initial temperature data: ;

[0053] Where: T measured is the temperature after emissivity correction; E is the measured infrared radiation energy, which is also the initial temperature data; τ is the transmittance of the air medium; is the emissivity of the object being measured; σ is the Stefan-Boltzmann constant. The emissivity can be calibrated by experiment or obtained from a known database.

[0054] The distance between the infrared temperature measuring device and the object to be measured will affect the measurement result. The infrared radiation energy on the object to be measured decays as the distance increases. In order to reduce the influence of this decay on the temperature measurement, the present invention introduces a distance coefficient K for correction.

[0055] Furthermore, the specific contents of correcting the temperature data obtained in step S2 according to the distance coefficient are as follows:

[0056] The temperature data obtained in step S2 is corrected using the following formula: ;

[0057] Where: T corrected is the temperature after distance correction; α is a correction coefficient related to the attenuation rate of infrared radiation energy; K0 is the ratio of the measurement distance to the thickness of tobacco under calibration conditions; K value when measuring the tobacco temperature at the standard distance.

[0058] Specifically, the calculation formula of the distance coefficient K is: ;

[0059] Among them, d measure is the distance between the infrared temperature measuring device and the measured tobacco, d smoke The thickness of the tobacco.

[0060] Specifically, the specific method for obtaining the correction coefficient α is:

[0061] At different distances d measured Under this condition, the surface temperature T of the tobacco cut to be tested is obtained. measured ; Compare the reference temperature at the standard distance and analyze the temperature attenuation trend at different distances; Fit the value of α based on these experimental data.

[0062] Since the reflectivity of the tobacco surface may cause measurement errors due to light or mirror effects, in order to reduce the influence of reflection interference on the temperature measurement results, the present invention corrects the measurement errors caused by light or mirror effects by adjusting the reflectivity compensation setting of the infrared temperature measuring device, and uses the corresponding formula to correct the errors caused by reflection.

[0063] Furthermore, the specific contents of correcting the temperature data obtained in step S3 according to the reflectivity of the tobacco surface are as follows:

[0064] According to the reflective characteristics of the tobacco surface, adjust the reflectivity compensation setting of the infrared temperature measuring device;

[0065] The temperature data obtained in step S3 is corrected using the following formula:

[0066] ;

[0067] Where: T final is the temperature after reflectivity correction; T b is the background temperature, that is, the temperature before correction, which is also the temperature data obtained in step S3.

[0068] In order to further improve the accuracy of measurement, the present invention also takes into account the influence of ambient temperature and corrects the measured temperature of the tobacco by using an ambient temperature compensation algorithm.

[0069] Furthermore, the specific content of applying the ambient temperature compensation algorithm to correct the temperature data obtained in step 4 is:

[0070] The sensor collects the ambient temperature data in the drying chamber in real time, calculates the difference between the ambient temperature and the initial temperature data of the tobacco, and uses the following formula for correction: ;

[0071] Where: T compensated is the temperature after correction by ambient temperature; T env is the ambient temperature; T smoke is the initial temperature data of the tobacco obtained by measurement; k is the compensation coefficient. It can be understood that the final output T compensated The value is taken as the measured temperature of the tobacco.

[0072] Specifically, the compensation coefficient is obtained through multiple experiments or historical data calibration.

[0073] In order to more comprehensively monitor the temperature distribution in the drying chamber, a multi-point temperature measurement method can also be provided, and the three-dimensional temperature field can be reconstructed based on the multi-point temperature data.

[0074] Furthermore, the correction method for measuring the temperature of flowing tobacco in the drying chamber also includes a multi-point temperature measurement method, which includes:

[0075] Arrange multiple infrared temperature measuring devices in the tobacco drying chamber to obtain the temperature data of tobacco at different positions;

[0076] Based on the temperature data of tobacco at different positions, a three-dimensional temperature field distribution model in the tobacco drying chamber is constructed to evaluate the heat flow distribution of tobacco. This model can fully reflect the temperature changes of tobacco in the chamber and help optimize the heating process.

[0077] Specifically, the reconstruction of the three-dimensional temperature field is modeled using finite element analysis or computational fluid dynamics techniques.

[0078] In order to verify the effect of the correction method of the present invention on the temperature measurement of flowing tobacco in the drying chamber, a comparative experiment was conducted to test the temperature data without correction and after the multiple correction processing of the present invention, and analyze its effect through experimental data. The experiment mainly measured the temperature of tobacco under different conditions by infrared temperature measuring device, covering the steps of emissivity correction, distance coefficient correction, reflectivity correction, ambient temperature compensation, etc.

[0079] 1. Experimental subjects:

[0080] The temperature of the flowing tobacco in the drying chamber was measured, and the temperature of the tobacco fluctuated between 28°C and 31.58°C.

[0081] 2. Measuring tools:

[0082] Infrared temperature measuring device.

[0083] 3. Variables:

[0084] Emissivity: The emissivity of tobacco varies between 0.85 and 0.95 depending on the material properties.

[0085] Measuring distance: The measuring distance between the infrared temperature measuring device and the tobacco is within the range of 1 meter to 2 meters.

[0086] Ambient temperature: The ambient temperature in the chamber is maintained between 25°C and 27°C.

[0087] Reflectivity: Adjusted according to the surface characteristics of tobacco.

[0088] 4. Experimental groups:

[0089] Uncorrected group: The tobacco temperature was directly measured using an infrared temperature measuring device without any correction.

[0090] Correction group: Use the emissivity correction, distance coefficient correction, reflectivity correction and ambient temperature compensation algorithms of the present invention to process the measurement results.

[0091] 5. Measurement points:

[0092] Multiple measuring points are selected in the cavity to monitor the temperature changes of the flowing tobacco at different positions.

[0093] 6. Experimental data:

[0094] Table 1 shows the temperature data without correction and after correction by the present invention. The real temperature of the tobacco is calibrated by a high-precision measuring device.

[0095] Table 1 Temperature data without correction and after correction by the present invention

[0096] 7. Data Analysis:

[0097] Uncorrected group:

[0098] The uncorrected temperature measurement results have large errors, with an average error of about 2.75°C. This is mainly because infrared temperature measurement technology is affected by emissivity, distance, ambient temperature and reflectivity, resulting in low measurement values ​​and unable to accurately reflect the actual tobacco temperature.

[0099] Correction Group:

[0100] After correction by the method of the present invention, the error between the measured temperature and the true temperature is significantly reduced, the average error is less than 0.05°C, and the maximum error is 0.05°C, which significantly improves the accuracy of the temperature measurement result.

[0101] The corrected temperature is very close to the true temperature, which shows the accuracy of the correction method with multiple corrections of the present invention in the low temperature range, especially suitable for the temperature range of 28°C to 31.58°C.

[0102] 8. Conclusion:

[0103] The experimental results show that when the tobacco temperature ranges from 28°C to 31.58°C, the uncorrected temperature measurement has a large error, with an average error of 2.75°C. After the emissivity correction, distance coefficient correction, reflectivity correction and ambient temperature compensation of the present invention, the average error is significantly reduced to 0.05°C, indicating that the correction method of the present invention effectively improves the measurement accuracy in the low temperature range and can be well applied to the tobacco drying process in industrial production.

[0104] The present invention comprehensively considers the multiple influences of emissivity, measurement distance, reflectivity and ambient temperature, and dynamically adjusts the measurement parameters through multi-point temperature measurement, spectral analysis and intelligent adaptive compensation algorithm to ensure more accurate tobacco temperature data. The method can not only improve the accuracy of temperature measurement results, but also provide reliable technical support for the optimization of tobacco drying process and the improvement of product quality. Its main technical effects are as follows: Improved temperature measurement accuracy: Through multiple corrections of emissivity, distance, reflectivity and ambient temperature, the measurement error is reduced to ensure more accurate temperature data; Adaptation to dynamic working conditions: The method can respond to the temperature changes of flowing tobacco in the drying chamber in real time, dynamically adjust compensation parameters, and adapt to complex processing environments; Reduce environmental interference: By introducing reflectivity correction and ambient temperature compensation, the interference of ambient radiation and other heat sources on temperature measurement can be effectively reduced; Comprehensive monitoring: Combined with multi-point temperature measurement and temperature field reconstruction, the temperature distribution in the entire drying chamber can be comprehensively monitored to help optimize the process; Improved production quality: Accurate temperature control helps to maintain the quality stability of tobacco, thereby improving the quality and consistency of the final product.

[0105] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for correcting the measured temperature of flowing tobacco in a drying chamber, characterized in that: It includes the following steps: Step S1, using an infrared temperature measuring device to measure the surface temperature of the flowing tobacco in the drying chamber to obtain initial temperature data of the measured tobacco; Step S2, determining the emissivity of the tested tobacco, and correcting the initial temperature data according to the emissivity; Step S3, calculating the ratio of the measured distance to the thickness of the tobacco as a distance coefficient, and correcting the temperature data obtained in the previous step according to the distance coefficient; Step S4, correcting the temperature data obtained in the previous step according to the reflectivity of the tobacco surface; Step S5, applying an ambient temperature compensation algorithm to correct the temperature data obtained in the previous step; Step S6: output the corrected tobacco temperature data.

2. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 1, characterized in that: The specific contents of correcting the initial temperature data according to the emissivity are as follows: According to the material, surface texture, and color characteristics of the tobacco, select or calibrate the appropriate emissivity value, and use the following formula to correct the initial temperature data: ； Where: T measured is the corrected temperature; E is the measured infrared radiation energy; τ is the transmittance of the air medium; is the emissivity of the object being measured; σ is the Stefan-Boltzmann constant.

3. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 1, characterized in that: The specific contents of correcting the temperature data obtained in the previous step according to the distance coefficient are as follows: Use the following formula to correct the temperature data obtained in the previous step: ； Where: T corrected is the temperature after distance correction; α is a correction coefficient related to the attenuation rate of infrared radiation energy; K0 is the ratio of the measurement distance to the thickness of tobacco under calibration conditions; K value when measuring the tobacco temperature at the standard distance.

4. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 3, characterized in that: The calculation formula of distance coefficient K is: ； Among them, d measure is the distance between the infrared temperature measuring device and the measured tobacco, d smoke The thickness of the tobacco.

5. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 4, characterized in that: The specific method for obtaining the correction coefficient α is: At different distances d measured Under the condition of measured ; Compare the reference temperature at the standard distance and analyze the temperature attenuation trend at different distances; Fit the value of α based on these experimental data.

6. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 1, characterized in that: The specific contents of correcting the temperature data obtained in the previous step according to the reflectivity of the tobacco surface are as follows: Use the following formula for correction: ； Where: T final is the corrected temperature; T b is the temperature before correction.

7. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 1, characterized in that: The specific contents of applying the ambient temperature compensation algorithm to correct the temperature data obtained in the previous step are as follows: Collect the ambient temperature data in the drying chamber, and calculate the difference between the ambient temperature and the temperature data obtained in the previous step; Use the following formula for correction: ； Where: T compensated is the temperature corrected for the ambient temperature; T env is the ambient temperature; T smoke is the initial temperature data of the tobacco obtained by measurement; k is the compensation coefficient.

8. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 7, characterized in that: The compensation coefficient is obtained through multiple experiments and historical data calibration.

9. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to any one of claims 1 to 8, characterized in that: It also includes a multi-point temperature measurement method, which includes: Arrange multiple infrared temperature measuring devices in the tobacco drying chamber to obtain the temperature data of tobacco at different positions; Based on the temperature data of tobacco at different positions, the three-dimensional temperature field in the tobacco drying chamber is reconstructed to evaluate the heat flow distribution of tobacco.

10. The method for correcting the measured temperature of flowing tobacco in a drying chamber according to claim 9, characterized in that: The reconstruction of the three-dimensional temperature field is modeled using finite element analysis or computational fluid dynamics techniques.

Images