Evaluation method, storage medium and application of steam quality stability of thin-plate tofu drying machine

Abstract

The present invention discloses an evaluation method, storage medium and application of the stability of steam quality of a thin plate wire drying machine, comprising the following steps: (1) obtaining multiple groups of cylinder wall temperatures and condensed water temperatures at the thin plate outlet during the production process of the wire drying machine at certain time intervals; (2) calculating the stability coefficient ε of the steam quality during the production process of the thin plate wire drying machine based on the cylinder wall temperature and the condensed water temperature at the thin plate outlet; (3) evaluating the stability of the steam quality during the production process of the thin plate wire drying machine according to the value of the stability coefficient ε. The evaluation method of the present invention can quantitatively evaluate the stability of the steam quality during the production process of the thin plate wire drying machine, provide a reliable basis for quickly discovering steam quality problems during the production process of the thin plate wire drying machine and taking effective emergency control measures in a timely manner to ensure product production quality, and at the same time provide indirect method support for the cause investigation and locking of abnormal problems in the production process, problem solving ideas and verification of improvement effects.

Description

Technical Field

[0001] The invention relates to an evaluation method and application, and specifically to an evaluation method, storage medium and application of steam quality stability of a thin-plate tobacco drying machine, and belongs to the technical field of cigarette processing. Background Art

[0002] Thin plate drying is a crucial processing step in the tobacco making process. This process uses steam to heat the thin plate. When the tobacco enters the thin plate drying machine, it is in full contact with the hot thin plate body. Through heat conduction, the moisture in the tobacco is evaporated from the inside to the outside, so as to achieve rapid drying and shaping of the tobacco. The stability of the processing directly affects the stability of the sensory quality of the cigarette product.

[0003] Steam is the key heating medium for sheet-type tobacco drying. The stability of steam quality directly affects the stability of sheet-type temperature, and plays a very important role in the stability of moisture control during tobacco production and processing. The quality of sheet-type tobacco drying steam here refers to the amount of condensed water in the steam, that is, the degree of pure steam. Excessive condensed water in the steam will cause the actual heat content of the steam to be low, thereby causing the temperature on the tube wall of the sheet-type heating surface to be low. If the amount of condensed water in the steam fluctuates, the temperature on the tube wall of the sheet-type heating surface will fluctuate, thereby causing the moisture content of the tobacco at the outlet of the drying to fluctuate.

[0004] There is no direct detection or effective evaluation method for the stability of steam quality. In actual production, the tube wall temperature (i.e., the sheet temperature) of the wire drying machine is converted from the steam pressure, which is difficult to detect directly. It is greatly affected by the steam quality and has a large uncertainty. If the condensed water content in the supplied steam is too high, there will be a large deviation between the actual value and the displayed value of the tube wall temperature. Since there is currently no quick and effective method to evaluate the stability of steam quality in the production process of the plate wire drying machine, these abnormal production conditions are highly concealed and difficult to detect in time. If there is an abnormal fluctuation in the moisture content at the outlet of the wire drying machine during the production process, it is also difficult to effectively and quickly identify the problem and make targeted improvements, which has caused a serious restriction on achieving a high level of homogenized production in the wire drying process. Summary of the invention

[0005] In view of the many defects and deficiencies in the background technology, the present invention provides an evaluation method for the stability of steam quality in the production process of a thin-plate wire drying machine. On the one hand, the stability of the steam quality in the production process of the thin-plate wire drying machine is evaluated according to the quantitative detection results. On the other hand, the content of condensed water in the steam is mapped by the evaluation of the steam quality and requirements are put forward for the maintenance of the condensation drainage system of the steam supply pipeline. The detection method of the present invention is to first obtain the cylinder wall temperature and condensed water temperature in the production process of the thin-plate wire drying machine, obtain the stability coefficient of the steam quality in the production process of the thin-plate wire drying machine by a statistical method, and evaluate the stability of the steam quality in the production process of the thin-plate wire drying machine by the coefficient. The present invention has the characteristics of clear characterization significance and high discrimination of the detection results, because the stability of the steam quality of the wire drying machine is highly correlated with the stability of the cylinder wall temperature of the wire drying machine and the corresponding condensed water temperature response. The determination method of the present invention can quantitatively evaluate the stability of the steam quality in the production process of the thin-plate wire drying machine, provide a reliable basis for quickly discovering the steam quality problems in the production process of the thin-plate wire drying machine and taking effective emergency control measures in time to ensure the quality of product production, and at the same time provide indirect method support for the cause investigation and locking of abnormal problems in the production process, problem solving ideas and improvement effect verification.

[0006] A method for evaluating the stability of steam quality in a production process of a thin-plate tofu drying machine comprises the following steps:

[0007] (1) Obtain multiple groups of cylinder wall temperatures and condensed water temperatures at the sheet outlet during the production process of the fiber drying machine at certain time intervals;

[0008] (2) The stability coefficient ε of the steam quality in the production process of the thin-plate drying machine is calculated based on the cylinder wall temperature and the condensed water temperature at the thin-plate outlet;

[0009] (3) The stability of the steam quality in the production process of the thin-plate tofu drying machine is evaluated according to the value of the stability coefficient ε. The closer the value of the stability coefficient ε is to 0, the better the stability of the steam quality is, and vice versa.

[0010] Preferably, the value of the barrel wall temperature and the value of the condensed water temperature at the thin plate outlet in step (1) are both obtained through the data detection and collection system corresponding to each cigarette manufacturing enterprise.

[0011] Preferably, the value of the cylinder wall temperature and the value of the condensed water temperature at the thin plate outlet are consistent in terms of the interval of data sampling time and the synchronization of data sampling time.

[0012] Preferably, the statistical stability coefficient ε of the steam quality in the production process of the thin plate wire drying machine includes: determining the stability coefficient ε based on the instantaneous value of the drum wall temperature obtained by converting the steam pressure at the thin plate steam inlet through the control system of the wire drying machine in the production process and the instantaneous value of the actual detected temperature of the condensed water in the thin plate steam outlet pipeline of the wire drying machine in the production process.

[0013] Preferably, determining the stability coefficient ε based on the instantaneous value of the drum wall temperature obtained by converting the steam pressure at the thin plate steam inlet of the production process wire drying machine control system and the instantaneous value of the actual detected temperature of the condensed water at the thin plate steam outlet pipeline of the wire drying machine in the production process includes: calculating the stability coefficient ε of the steam quality in the production process of the thin plate wire drying machine by the following formula:

[0014]

[0015] Where ε is the steam quality stability evaluation coefficient, H i It is the instantaneous value of the tube wall temperature obtained by converting the steam pressure at the steam inlet of the thin plate through the control system of the production process of the tofu drying machine, that is, the value collected by the post industrial control computer, L i is the instantaneous value of the actual detected temperature of the condensed water in the steam outlet pipe of the tofu drying machine during the production process, i is the instantaneous sampling point in the production process, and i is a natural number, and n is the cumulative sampling point of a batch of production; It means that the difference between the instantaneous cylinder wall temperature and the instantaneous condensate water temperature is subtracted from the average value of the difference to obtain the offset of the instantaneous difference, and then the square of the offset of the instantaneous difference is summed; H i -L i It is the difference between the cylinder wall temperature and the condensate water temperature.

[0016] Prior to this, the stability of steam quality in the production process of the thin-plate drying machine is evaluated based on the value of ε, including:

[0017] Comparing the value of ε with a first preset threshold and a second threshold; and

[0018] Based on the comparison results, the stability of steam quality in the production process of the thin-plate tofu drying machine is evaluated.

[0019] Preferably, evaluating the stability of steam quality in the production process of the thin-plate tofu drying machine based on the comparison results includes:

[0020] a) When the value of ε is less than the first preset threshold value, the evaluation result of the stability of the steam quality in the production process of the thin plate drying machine is good stability;

[0021] b) when the second preset threshold value>ε value≥the first preset threshold value, the evaluation result of the stability of the steam quality in the production process of the thin plate drying machine is average;

[0022] c) When the value of ε is ≥ the second preset threshold value, the evaluation result of the stability of the steam quality in the production process of the thin plate tofu drying machine is poor.

[0023] Preferably, the first preset threshold is 0.17, and the second preset threshold is 0.23.

[0024] Preferably, a computer-readable storage medium stores a computer program, which, when executed by one or more processors, implements the steps of the method according to any one of claims 1 to 8.

[0025] Preferably, a method for evaluating the stability of steam quality in a thin-plate tofu drying machine production process is used to warn of the need to overhaul a condensate drain system of a steam supply pipeline.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention has the characteristics of clear characterization significance and high differentiation of detection results, and can quantitatively evaluate the stability of steam quality in the production process of thin-plate tofu drying machine;

[0028] 2. The evaluation method of the present invention can quantitatively evaluate the stability of the steam quality in the production process of the thin plate wire drying machine, so as to quickly discover the steam quality problems in the production process of the thin plate wire drying machine, and provide method support for the cause investigation and locking of abnormal problems in the production process, problem solving ideas and improvement effect verification. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and beneficial effects of the present invention clearer, a detailed description will be given below in conjunction with embodiments to facilitate understanding by technicians.

[0030] Example 1

[0031] Evaluation of steam quality stability during production of a batch of tobacco cuts by sheet drying.

[0032] Here are the steps:

[0033] (1) Obtain the condensed water temperature at the outlet of the thin plate under the wall temperature time during the production process of the tofu drying machine. Specifically, from the beginning of production, the corresponding data values ​​are synchronously collected every 6 seconds. Due to the large amount of data, the data is partially displayed, as shown in Table 1 below:

[0034]

[0035] (2) If the wall temperature of the drying machine during production and the condensed water temperature at the outlet of the sheet at the corresponding time are known, then according to the formula The stability coefficient ε of the steam quality in the production process of the thin-plate drying machine was obtained, which was 0.12.

[0036] Among them, ε is the steam quality stability evaluation coefficient, H i It is the instantaneous value of the tube wall temperature obtained by converting the steam pressure at the steam inlet of the thin plate through the control system of the production process of the tofu drying machine, that is, the value collected by the post industrial control computer, L iIt is the instantaneous value of the actual detected temperature of the condensed water in the steam outlet pipe of the thin plate of the tofu drying machine during the production process, where i is the instantaneous sampling point number in the production process (i is a natural number), and n is the cumulative sampling point number for a batch of production. It means that the difference between the instantaneous cylinder wall temperature and the instantaneous condensate water temperature is subtracted from the average value of the difference to obtain the offset of the instantaneous difference, and then the square of the offset of the instantaneous difference is summed.

[0037] Among them, H i -L i The model is established by combining the mathematical statistical meaning of standard deviation in stability evaluation with the difference between the barrel wall temperature and the corresponding condensate temperature. Under normal production conditions, the barrel wall temperature and the corresponding condensate temperature have a very stable corresponding equilibrium relationship. When the quality of steam entering the thin-plate wire drying machine fluctuates, the equilibrium relationship is also broken. The model is established by long-term tracking of the production database of thin-plate wire drying and has a high degree of applicability. Specifically: During the production process of a batch of thin-plate wire drying, the barrel wall temperature and the condensate temperature will automatically collect about 1100-1400 groups of corresponding data. After analyzing more than 1,000 batches of production data, it was found that although the difference between the barrel wall temperature and the corresponding condensate temperature of the thin-plate wire drying machine in different line segments is different, under normal circumstances, the difference between the barrel wall temperature and the corresponding condensate temperature of the thin-plate wire drying machine in each line segment is relatively stable, that is, the difference is a relatively stable constant. When the difference fluctuates greatly, it will appear in the production process. When the key indicators and parameters such as the incoming moisture, cylinder wall temperature, hot air temperature, and hot air speed are relatively stable, the outlet moisture will suddenly increase for unknown reasons, which indirectly indicates that the displayed cylinder wall temperature is lower than the actual value, and the steam entering the thin plate of the wire drying machine contains a certain degree of condensed water. Because the incoming moisture is stable and other processing parameters are relatively stable, only when the actual cylinder wall temperature of the wire drying machine is low can its dehydration capacity be low, that is, the outlet moisture increases, and the cylinder wall temperature is converted from the steam pressure. Only when a certain degree of condensed water replaces the steam and enters the thin plate, can the pressure entering the cylinder wall be consistent, that is, the displayed cylinder wall temperature is relatively consistent, but the actual value is low. Therefore, the formula of standard deviation is used to evaluate the difference between the cylinder wall temperature and the condensed water temperature, which has reliable practical application value to characterize the stability of the steam quality in the production process of the thin plate wire drying machine; finally, the stability of the steam quality in the production process of the thin plate wire drying machine is evaluated according to the value of ε.

[0038] In the above implementation process, the closer the value of ε is to 0, the better the stability of the steam quality in the production process of the thin-plate tobacco drying machine. Each cigarette production enterprise can formulate a specific evaluation value of ε based on its own quality management requirements.

[0039] At the same time, the value of ε can be determined by establishing an evaluation mathematical model in the PLC control system to achieve statistical analysis after a batch of tobacco is fully produced, and the relevant data can be transmitted to the production management system platform for storage.

[0040] That is, the evaluation model is established on the industrial control system for calculation, and the calculated data is transmitted to the production management system (or quality data center) for storage, historical query or comparative analysis of the data.

[0041] Each factory can establish a corresponding quality control evaluation method (see the table below) according to this invention in combination with its own internal quality management requirements, and timely evaluate the stability of steam quality during the production process of the thin plate drying machine.

[0042] Steam stability evaluation Corresponding to ε Good stability ε<0.17 generally 0.23>ε≥0.17 Poor ε≥0.23

[0043] (3) Since the value of ε is small, it meets the factory's quality evaluation requirement of <0.17, which means that the steam quality stability of the thin-plate drying process in the production of this batch of tobacco is good.

[0044] Example 2

[0045] This embodiment is a practical application of the evaluation model constructed based on Embodiment 1.

[0046] (1) After the production of a batch of tobacco shreds was completed, the stability coefficient ε of the steam quality in the production process of the thin-plate drying machine was obtained, and ε was 0.20;

[0047] (2) Since the value of ε is relatively large, according to the corresponding quality control requirements of the factory, it means that the steam quality stability of the thin plate drying process in the production of this batch of tobacco is general, that is, there is a slight fluctuation in the steam quality during the thin plate drying process.

[0048] (3) After the production was completed, the equipment personnel checked the condensate discharge system and quickly identified the cause as the blockage of the valve core of the automatic drain pump for steam condensate entering the thin plate body. After maintenance and adjustment, the single machine test was normal.

[0049] (4) The first batch after maintenance was tracked and the stability coefficient ε of the steam quality in the production process of the thin plate tofu drying machine was obtained. ε was 0.13, indicating that the maintenance was effective, that is, the stability of the steam quality in the production process of the thin plate tofu drying machine was good.

[0050] (5) After the implementation of the present invention, the stability problem of steam quality in the production process of the thin-plate tofu drying machine can be discovered and dealt with in a timely manner, and the effect of solving the problem can be quantitatively evaluated.

[0051] Example 3

[0052] This embodiment is a practical application of the evaluation model constructed based on Embodiment 1.

[0053] (1) During the period from July to November 2021, the moisture content at the outlet of the thin plate drying machine in the silk-making workshop fluctuated greatly, with a standard deviation between 0.22% and 0.28%, which was far below the factory's quality control requirement of <0.17%, and also far below the control level of 0.13% to 0.15% maintained in the previous period;

[0054] (2) The equipment technicians in the silk-making workshop first checked the condensate discharge pipeline and valves and found no abnormalities, confirming that the problem of poor condensate discharge in the production process was eliminated;

[0055] (3) Since the outlet moisture of the thin-plate drying machine is controlled by automatically adjusting the wall temperature value according to the feedback of the outlet moisture, the equipment technicians in the silk-making workshop have been adjusting the PID parameters of the automatic control of the wall temperature, but the standard deviation is still controlled between 0.19% and 0.24%. Although there has been some improvement, it still does not meet the factory's quality control requirements.

[0056] (4) After applying this evaluation method, it was found that the stability coefficient ε of the steam quality in the production process of the thin-plate silk drying machine was maintained between 0.27 and 0.31 for multiple batches in a row, indicating that the steam quality stability of the thin-plate silk drying machine was poor. The equipment technicians in the silk-making workshop checked the condensate discharge pipeline and valves again and confirmed that there was no abnormality. They then contacted the power support workshop for assistance in the investigation. After the investigation, the power workshop found that the condensate drain system of its main steam supply pipeline was faulty, and the amount of condensate contained in the main steam was sometimes more and sometimes less.

[0057] (5) After the power workshop completed the equipment maintenance, the stability coefficient ε of the steam quality in the production process of the thin-plate wire drying machine remained between 0.08% and 0.14, indicating that the steam quality stability of the thin-plate wire drying machine production process was good. At the same time, the standard deviation of the moisture content at the wire drying outlet was maintained between 0.08% and 0.11%, indicating that the improvement effect was obvious.

[0058] (6) After the implementation of the present invention, the abnormality of the thin-plate tofu drying machine production process can be assisted in accurately identifying the problem, which plays an important role in optimizing the quality control mode and improving the product quality processing effect.

[0059] In summary, the advantages of the present invention in the specific implementation mode are:

[0060] 1. The evaluation method of the present invention can quantitatively evaluate the stability of the steam quality in the production process of the thin-plate tofu drying machine, solving the problem that the stability of the steam quality of the traditional thin-plate tofu drying machine is difficult to evaluate;

[0061] 2. The present invention can quickly improve the efficiency of troubleshooting a series of quality problems caused by fluctuations in steam quality in thin-plate tofu drying machines, and provide a basis for operators to take emergency control measures. It solves a series of problems in traditional thin-plate tofu drying machines, such as scattered troubleshooting points, long troubleshooting cycles, and difficulty in accurately assessing subsequent production quality, due to the relatively hidden nature of fluctuations in steam quality;

[0062] 3. The present invention can improve the problem of steam quality fluctuation of the thin-plate wire drying machine, identify key improvement elements, provide auxiliary solutions, and provide an effective verification and evaluation method for the improvement effect.

[0063] Finally, it should be noted that the above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine, characterized in that: The steps include: (1) Obtain multiple groups of cylinder wall temperatures and condensed water temperatures at the sheet outlet during the production process of the fiber drying machine at certain time intervals; (2) The stability coefficient ε of the steam quality in the production process of the thin-plate drying machine is calculated based on the cylinder wall temperature and the condensed water temperature at the thin-plate outlet; (3) The stability of the steam quality in the production process of the thin-plate tofu drying machine is evaluated according to the value of the stability coefficient ε. The closer the value of the stability coefficient ε is to 0, the better the stability of the steam quality is, and vice versa. Wherein: The statistical stability coefficient ε of the steam quality in the production process of the thin plate drying machine includes: the stability coefficient ε is determined based on the instantaneous value of the drum wall temperature obtained by converting the steam pressure at the thin plate steam inlet of the drying machine control system in the production process and the instantaneous value of the actual detected temperature of the condensed water in the thin plate steam outlet pipeline of the drying machine in the production process; Based on the instantaneous value of the drum wall temperature obtained by converting the steam pressure at the steam inlet of the thin plate through the control system of the production process of the wire drying machine and the instantaneous value of the actual detected temperature of the condensed water at the steam outlet pipe of the thin plate of the wire drying machine in the production process, the stability coefficient ε is determined, including: the stability coefficient ε of the steam quality of the thin plate wire drying machine production process is calculated by the following formula: Where ε is the steam quality stability evaluation coefficient, H i It is the instantaneous value of the tube wall temperature obtained by converting the steam pressure at the steam inlet of the thin plate through the control system of the production process of the tofu drying machine, that is, the value collected by the post industrial control computer, L i is the instantaneous value of the actual detected temperature of the condensed water in the steam outlet pipe of the tofu drying machine during the production process, i is the instantaneous sampling point in the production process, and i is a natural number, and n is the cumulative sampling point of a batch of production; It means that the difference between the instantaneous cylinder wall temperature and the instantaneous condensate water temperature is subtracted from the average value of the difference to obtain the offset of the instantaneous difference, and then the square of the offset of the instantaneous difference is summed; H i -L i It is the difference between the cylinder wall temperature and the condensate water temperature.

2. The method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine according to claim 1, characterized in that: The value of the barrel wall temperature and the value of the condensed water temperature at the thin plate outlet in the step (1) are both obtained through the data detection and collection system corresponding to each cigarette manufacturing enterprise.

3. The method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine according to claim 2, characterized in that: The value of the cylinder wall temperature and the value of the condensed water temperature at the thin plate outlet are consistent in terms of the interval of data sampling time and the synchronization of data sampling time.

4. The method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine according to claim 1, characterized in that: The stability of steam quality in the production process of the thin-plate drying machine is evaluated according to the value of ε, including: comparing the value of ε with a first preset threshold and a second preset threshold; and Based on the comparison results, the stability of steam quality in the production process of the thin-plate tofu drying machine is evaluated.

5. The method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine according to claim 4, characterized in that: The stability of steam quality in the production process of the thin-plate tofu drying machine is evaluated based on the comparison results, including: a) When the value of ε is less than the first preset threshold value, the evaluation result of the stability of the steam quality in the production process of the thin plate drying machine is good stability; b) when the second preset threshold value>ε value≥the first preset threshold value, the evaluation result of the stability of the steam quality in the production process of the thin plate drying machine is average; c) When the value of ε is ≥ the second preset threshold value, the evaluation result of the stability of the steam quality in the production process of the thin plate tofu drying machine is poor.

6. The method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine according to claim 5, characterized in that: The first preset threshold is 0.17, and the second preset threshold is 0.

23.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by one or more processors, the steps of the method according to any one of claims 1 to 6 are implemented.

8. Application of the method for evaluating the stability of steam quality in the production process of a thin-plate tofu drying machine as described in any one of claims 1 to 6 in warning the need to overhaul the condensate drain system of the steam supply pipeline.

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