Printing paper powder / VOCs two-phase mixed explosion pressure prediction method

Abstract

The invention discloses a printing paper powder / VOCs two-phase mixed explosion pressure prediction method, and belongs to the technical field of dust / gas two-phase explosion research, and the method comprises the steps: obtaining explosion pressure data under different combinations of paper powder concentration and VOCs concentration through a paper powder / VOCs two-phase mixed explosion pressure test experiment, and determining the concentration of VOCs based on the explosion pressure data; extracting explosion pressure characteristic parameters; constructing a paper powder / VOCs two-phase mixed explosion pressure prediction model based on the explosion pressure data and the explosion pressure characteristic parameters under different paper powder concentration and VOCs concentration combinations; and predicting the printing paper powder / VOCs two-phase mixed explosion pressure by using the model. By means of the printing paper powder / VOCs two-phase mixed explosion pressure prediction method, the paper powder / VOCs two-phase mixed explosion pressure can be rapidly and accurately predicted, and the most effective and most economical powder-gas two-phase explosion-proof condition is found for production of printing enterprises.

Description

Technical Field

[0001] This invention relates to the field of dust / gas two-phase explosion research technology, and in particular to a method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs. Background Technology

[0002] The vast majority of materials used in printing companies are flammable, making them highly susceptible to fires and explosions. As the printing industry continues to expand, fires and explosions involving printing companies occur frequently. The flammability and explosion risks of printing materials such as paper, ink, and organic solvents cannot be ignored. Furthermore, printing waste remains flammable and can easily cause fires when near high-temperature heat sources or open flames, posing a significant risk. Simultaneously, due to the production processes in printing companies, flammable paper dust and flammable VOCs gases often coexist and co-exist in the same areas. In some cases, paper dust and VOCs gases share a dust collection system. After prolonged strong suction from the dust collection system, a uniform two-phase mixture of paper dust and VOCs gas remains within the system, posing a significant explosion risk. Additionally, static electricity generated by machinery during high-speed operation or encountering other ignition sources can potentially trigger a fire or explosion of the gas mixture within the dust collection system.

[0003] The explosion pressure of a two-phase mixture is a crucial indicator of its severity. Measuring this pressure is of significant practical importance for the safety design, risk assessment, and effective selection of accident prevention and control measures for such powder-gas two-phase mixture systems. However, current technologies lack systematic experimental methods and predictive models to accurately predict the explosion pressure of two-phase mixtures. Summary of the Invention

[0004] This invention provides a method for predicting the explosion pressure of a two-phase mixture of printing paper powder and VOCs, in order to solve the technical problem that existing technologies cannot accurately predict the explosion pressure of two-phase mixtures.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs includes: The explosion pressure test experiment of paper powder / VOCs two-phase mixture was conducted to obtain explosion pressure data under different combinations of paper powder concentration and VOCs concentration, and the explosion pressure characteristic parameters were extracted based on the explosion pressure data. Based on the explosion pressure data and explosion pressure characteristic parameters under different combinations of paper dust concentration and VOCs concentration, a prediction model for the explosion pressure of a two-phase mixture of paper dust and VOCs is constructed. The model is used to predict the explosion pressure of a two-phase mixture of printing paper dust and VOCs.

[0006] Furthermore, the explosion pressure test experiment of the paper powder / VOCs two-phase mixture to obtain explosion pressure data under different combinations of paper powder concentration and VOCs concentration includes: Based on a preset paper dust concentration gradient, multiple different paper dust concentration data are set; simultaneously, based on a preset VOCs concentration gradient, multiple different VOCs concentration data are set; wherein the number of paper dust concentration data matches the number of VOCs concentration data. Multiple different paper dust concentration data and multiple different VOCs concentration data are combined in pairs. Each combination includes one paper dust concentration data and one VOCs concentration data, thus obtaining all possible combinations of paper dust concentration data and VOCs concentration data. Each combination is recorded as a concentration condition. For each concentration condition, paper powder and VOCs are configured according to their paper powder concentration data and VOCs concentration data, and a two-phase mixture explosion pressure test of paper powder / VOCs is conducted based on the configured paper powder and VOCs.

[0007] Furthermore, the number of paper dust concentration data and the number of VOCs concentration data are both 5.

[0008] Furthermore, the paper dust concentration data is set to: 250 g / m³ 3 375g / m 3 500g / m 3 625g / m 3 750g / m 3 .

[0009] Furthermore, the VOCs concentration data are set to: 0%, 1%, 2%, 3%, 4%.

[0010] Furthermore, the experimental apparatus used in the explosion pressure test was a 12L cylindrical explosion test apparatus; the experimental parameters set during the experiment included dust spray pressure, ignition delay time, and ignition energy.

[0011] Furthermore, the explosion pressure data under different combinations of paper dust concentration and VOCs concentration represent the explosion pressure at different times corresponding to different VOCs concentrations under the same paper dust concentration.

[0012] Furthermore, the explosion pressure characteristic parameters are the maximum explosion pressure, maximum pressure rise rate, and explosion index corresponding to different paper powder concentrations under the same VOCs concentration.

[0013] Furthermore, the construction of a two-phase explosion pressure prediction model for paper dust / VOCs mixtures based on explosion pressure data and explosion pressure characteristic parameters under different combinations of paper dust concentration and VOCs concentration includes: Based on the explosion pressure data under different combinations of paper dust concentration and VOCs concentration, a curve was plotted showing the change of explosion pressure over time for the same paper dust concentration and different VOCs concentrations. Based on the aforementioned explosion pressure characteristic parameters, a line graph showing the change of explosion pressure characteristic parameters with paper dust concentration under the same VOCs concentration was plotted. Based on the curve and the line graph, a three-dimensional surface graph is established with paper dust concentration and VOCs concentration as variables and two-phase mixing explosion pressure as the dependent variable. A predictive model for the explosion pressure of a two-phase mixture of paper dust and VOCs was derived by fitting nonlinear surfaces.

[0014] Furthermore, the prediction model for the explosion pressure of the paper powder / VOCs two-phase mixture is expressed as follows:

[0015] Where z represents the two-phase mixed explosion pressure; x represents the paper dust concentration; and y represents the VOCs concentration.

[0016] The beneficial effects of the technical solution provided by this invention include at least the following: Based on experimental test data and parameter variation analysis, this invention can quickly and accurately predict the explosion pressure of paper dust / VOCs two-phase mixtures by using characteristic parameters such as maximum explosion pressure, pressure rise rate, and explosion index. It also establishes an explosion pressure prediction model under different combinations of paper dust concentration and VOCs concentration, providing a basis for determining the most effective and economical two-phase explosion-proof conditions for printing enterprises in their production processes. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the execution flow of the method for predicting the explosion pressure of a two-phase mixture of printing paper powder and VOCs provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a 12L cylindrical explosion experimental apparatus; Figure 3 These are the effect curves of VOCs on explosion pressure at different paper dust concentrations provided in the embodiments of the present invention; wherein, (a) is 250 g / m³. 3 Concentration of paper dust; (b) is 375 g / m 3 Concentration of paper dust; (c) is 500 g / m3 Concentration of paper dust; (d) is 625 g / m 3 Concentration of paper dust; (e) is 750 g / m 3 Concentration of paper dust; Figure 4 This is a line graph showing the effect of paper dust on explosion pressure characteristic parameters under different VOC concentrations provided in the embodiments of the present invention; wherein, (a) is 0% VOC concentration; (b) is 0.5% VOC concentration; (c) is 1% VOC concentration; (d) is 1.5% VOC concentration; and (e) is 2% VOC concentration. Figure 5 This is a three-dimensional bar chart showing the change of maximum explosion pressure with two-phase concentration provided in an embodiment of the present invention; Figure 6 This is a three-dimensional surface plot showing the variation of maximum explosion pressure with two-phase concentration, provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0020] First, it should be noted that in the embodiments of the present invention, the words "exemplarily," "for example," etc., are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplarily" is intended to present the concept in a specific manner. Furthermore, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either one or the other.

[0021] This embodiment provides a method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs. Through system experimental design and experimental data testing and analysis, it solves the problem of the lack of quantitative assessment and prediction methods for the explosion pressure of two-phase mixtures in existing technologies. The execution flow of this method is as follows: Figure 1 As shown, it includes the following steps: S1. Through the explosion pressure test experiment of paper powder / VOCs two-phase mixture, the explosion pressure data under different combinations of paper powder concentration and VOCs concentration were obtained, and the explosion pressure characteristic parameters were extracted based on the explosion pressure data. Specifically, in this embodiment, the implementation process of S1 is as follows: S11, Based on the preset paper dust concentration gradient, set multiple different paper dust concentration data; at the same time, based on the preset VOCs concentration gradient, set multiple different VOCs concentration data. In this embodiment, the paper dust concentration is set to 250 g / m³. 3 375g / m3 500g / m 3 625g / m 3 750g / m 3 VOCs concentration data were set to: 0%, 1%, 2%, 3%, 4%.

[0022] Based on the above, this embodiment obtained 25 combinations of different paper dust concentrations and VOCs volume concentrations to form experimental groups. The specific data combinations are shown in Table 1. Each experiment was repeated 3 times and the average value was taken to obtain the explosion pressure data of the paper dust / VOCs two-phase mixture under different operating conditions.

[0023] Table 1 Experimental Scheme

[0024] S12, combine multiple different paper dust concentration data with multiple different VOCs concentration data in pairs. Each combination includes one paper dust concentration data and one VOCs concentration data, thereby obtaining all possible combinations of paper dust concentration data and VOCs concentration data. Each combination is recorded as a concentration condition.

[0025] S13, for each concentration condition, configure the paper dust and VOCs according to its paper dust concentration data and VOCs concentration data, and perform a 24-hour drying treatment on the paper dust. Add the configured paper dust and VOCs to... Figure 2 The 12L cylindrical explosion experimental apparatus shown (which includes a pressure sensor, ignition electrode, dust spraying system, and data acquisition module) forms a two-phase mixture. The dust spraying system is activated, and ignition is performed after the dust cloud is uniformly distributed. Explosion pressure data is collected by the pressure sensor at a sampling frequency of 10kHz. This allows for the acquisition of explosion pressure characteristic parameters of the mixture under different concentration conditions. The explosion pressure characteristic parameters refer to the maximum explosion pressure, maximum pressure rise rate, and explosion index of the paper dust / VOCs two-phase mixture. The experimental parameters set during the experiment include a dust spraying pressure of 200kPa, an ignition energy of 500mJ, and an ignition delay time adjusted to 60ms based on the dust cloud formation state. The particle size of the paper dust is 50μm.

[0026] S14. Based on the explosion pressure data and explosion pressure characteristic parameters of the paper powder / VOCs two-phase mixture, the explosion pressure variation law with time corresponding to different VOCs concentrations under the same paper powder concentration, and the explosion pressure characteristic parameters corresponding to different paper powder concentrations under the same VOCs concentration are obtained.

[0027] S2. Based on the explosion pressure data and explosion pressure characteristic parameters under different combinations of paper dust concentration and VOCs concentration, a prediction model for the explosion pressure of a two-phase mixture of paper dust and VOCs is constructed. Specifically, in this embodiment, the implementation process of S2 is as follows: S21. Based on the variation of explosion pressure over time corresponding to different VOC concentrations at the same paper dust concentration, plot the curves of explosion pressure over time corresponding to different VOC concentrations at the same paper dust concentration; based on these curves, analyze the variation of explosion pressure of the two-phase mixture of paper dust and VOCs at different VOC concentrations, including: analyzing the influence of VOC concentration on the explosion pressure of the two-phase mixture at different paper dust concentrations; wherein, the higher the explosion pressure, the more obvious the promoting effect of VOCs on the explosion pressure of the two-phase mixture.

[0028] Taking a paper dust concentration of 500 g / m³ as an example, the curve of explosion pressure versus time is plotted as follows: Figure 3 As shown.

[0029] The results showed that as the VOCs concentration increased, the peak explosion pressure gradually increased. When the VOCs concentration was 2%, the peak pressure reached its maximum value, and the rate of increase slowed down after exceeding 2%.

[0030] S22, Based on the explosion pressure characteristic parameters corresponding to different paper dust concentrations under the same VOCs concentration, plot a line graph showing the change of explosion pressure characteristic parameters with paper dust concentration under the same VOCs concentration; based on the line graph, analyze the influence of paper dust concentration on the explosion pressure characteristic parameters of the two-phase mixture explosion of paper dust / VOCs under different VOCs concentrations, including: based on the line graph showing the change of the two-phase mixture explosion pressure characteristic parameters under the same inerting ratio, the same VOCs concentration, and different paper dust concentrations, analyze the influence of paper dust concentration on the two-phase mixture explosion pressure characteristic parameters under different VOCs concentrations.

[0031] Taking a VOCs concentration of 2% as an example, the line graph of the explosion pressure characteristic parameters is shown in Figure 4. The results show that when the paper dust concentration is 625 g / m³, the maximum explosion pressure (Pmax), the maximum pressure rise rate (dP / dt), and the explosion index (Kst) all reach their maximum values, indicating that the two-phase mixture explosion is most violent at this time.

[0032] S23, based on 25 sets of experimental data, using paper dust concentration (x-axis data) and VOCs concentration (y-axis data) as variables, and two-phase mixing explosion pressure (z-axis data) as the dependent variable, a three-dimensional bar chart and a three-dimensional surface plot were constructed; among them, the three-dimensional bar chart is as follows: Figure 5 As shown, the three-dimensional surface plot is as follows Figure 6 As shown.

[0033] S24, through nonlinear surface fitting, a prediction model for the explosion pressure of the two-phase mixture of paper dust and VOCs is obtained:

[0034] Where z represents the two-phase mixed explosion pressure; x represents the paper dust concentration; and y represents the VOCs concentration.

[0035] The model has a fitting error of less than 5% and can effectively predict the explosion pressure under different concentrations. Quantifying the explosion pressure under different concentration combinations provides data support for printing companies to optimize explosion-proof measures such as dust concentration control and ventilation. Based on this, it can be concluded that paper dust concentration and VOCs concentration have a synergistic effect on the explosion pressure of the two-phase mixture; the explosion risk is highest when the paper dust concentration is 625 g / m³ and the VOCs concentration is 2%.

[0036] S3, using the model to predict the explosion pressure of the two-phase mixture of printing paper dust and VOCs.

[0037] In summary, this embodiment, through experimental testing and data analysis, derives a method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs. This method evaluates the explosion pressure using parameters such as the explosion pressure over time curve, the maximum explosion pressure value, the pressure rise rate, and the explosion index. A decrease in the peak explosion pressure, a slower pressure rise rate, and a smaller explosion index indicates that the method effectively suppresses the explosion of the two-phase mixture. Furthermore, the explosion risk is lowest when the concentrations of both paper dust and VOCs are controlled at low levels and their concentrations are reasonably matched.

[0038] It should also be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0039] Furthermore, the term "and / or" merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. Additionally, the character " / " in this text generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship; please refer to the context for specific interpretations. "At least one" refers to one or more, while "more" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0040] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention. It should be pointed out that although preferred embodiments of the present invention have been described, those skilled in the art, once they understand the basic inventive concept of the present invention, can make several improvements and modifications without departing from the principles described herein. These improvements and modifications should also be considered within the scope of protection of the present invention. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

Claims

1. A method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs, characterized in that, include: The explosion pressure test experiment of paper powder / VOCs two-phase mixture was conducted to obtain explosion pressure data under different combinations of paper powder concentration and VOCs concentration, and the explosion pressure characteristic parameters were extracted based on the explosion pressure data. Based on the explosion pressure data and explosion pressure characteristic parameters under different combinations of paper dust concentration and VOCs concentration, a prediction model for the explosion pressure of a two-phase mixture of paper dust and VOCs is constructed. The model is used to predict the explosion pressure of a two-phase mixture of printing paper dust and VOCs.

2. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 1, characterized in that, The explosion pressure test experiment using a two-phase mixture of paper powder and VOCs obtained explosion pressure data under different combinations of paper powder concentration and VOCs concentration, including: Based on a preset paper dust concentration gradient, multiple different paper dust concentration data are set; simultaneously, based on a preset VOCs concentration gradient, multiple different VOCs concentration data are set; wherein the number of paper dust concentration data matches the number of VOCs concentration data. Multiple different paper dust concentration data and multiple different VOCs concentration data are combined in pairs. Each combination includes one paper dust concentration data and one VOCs concentration data, thus obtaining all possible combinations of paper dust concentration data and VOCs concentration data. Each combination is recorded as a concentration condition. For each concentration condition, paper powder and VOCs are configured according to their paper powder concentration data and VOCs concentration data, and a two-phase mixture explosion pressure test of paper powder / VOCs is conducted based on the configured paper powder and VOCs.

3. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 2, characterized in that, The number of paper dust concentration data and the number of VOCs concentration data are both 5.

4. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 3, characterized in that, The paper dust concentration was set to 250 g / m³. 3 375g / m 3 500g / m 3 625g / m 3 750g / m 3 .

5. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 3, characterized in that, The VOCs concentration data were set to: 0%, 1%, 2%, 3%, and 4%.

6. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 1, characterized in that, The experimental apparatus used for the explosion pressure test was a 12L cylindrical explosion test apparatus; the experimental parameters set during the experiment included dust spray pressure, ignition delay time, and ignition energy.

7. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 1, characterized in that, The explosion pressure data for different combinations of paper dust concentration and VOCs concentration represent the explosion pressure at different times corresponding to different VOCs concentrations under the same paper dust concentration.

8. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 7, characterized in that, The explosion pressure characteristic parameters are the maximum explosion pressure, maximum pressure rise rate, and explosion index corresponding to different paper powder concentrations under the same VOCs concentration.

9. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 8, characterized in that, The explosion pressure prediction model for a two-phase mixture of paper dust and VOCs is constructed based on explosion pressure data and explosion pressure characteristic parameters under different combinations of paper dust and VOCs concentrations, including: Based on the explosion pressure data under different combinations of paper dust concentration and VOCs concentration, a curve was plotted showing the change of explosion pressure over time for the same paper dust concentration and different VOCs concentrations. Based on the aforementioned explosion pressure characteristic parameters, a line graph showing the change of explosion pressure characteristic parameters with paper dust concentration under the same VOCs concentration was plotted. Based on the curve and the line graph, a three-dimensional surface graph is established with paper dust concentration and VOCs concentration as variables and two-phase mixing explosion pressure as the dependent variable. A predictive model for the explosion pressure of a two-phase mixture of paper dust and VOCs was derived by fitting nonlinear surfaces.

10. The method for predicting the explosion pressure of a two-phase mixture of printing paper dust and VOCs as described in claim 9, characterized in that, The prediction model for the explosion pressure of the paper powder / VOCs two-phase mixture is expressed as follows: Where z represents the two-phase mixed explosion pressure; x represents the paper dust concentration; and y represents the VOCs concentration.

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