A method and system for calculating parameters of a water-based ink sheet intaglio printing machine pre-register oven

Abstract

The application discloses a kind of water-based ink paper gravure press pre-fitting alignment oven parameter calculation method and system, belong to paper gravure press electronic shaft control system technical field.This calculation method includes the following steps: collecting printing process parameters and environmental parameters, calculating the evaporation rate of moisture in paper and the evaporation rate of moisture in ink;Combined with the evaporation rate of moisture in ink, according to the evaporation rate of moisture in ink equation, constant-speed drying stage energy conservation equation, obtain oven temperature and front oven air speed;Combined with the evaporation rate of moisture in paper, according to the evaporation rate of moisture in paper equation, constant-speed drying stage energy conservation equation, calculate back oven air speed;Oven temperature, front oven air speed and back oven air speed are assigned to corresponding pre-fitting alignment oven parameter variable.To solve the problem of large error caused by dependence on worker experience in pre-fitting alignment oven parameter setting process, long time-consuming adjustment, can improve pre-fitting alignment oven parameter setting efficiency and accuracy, reduce pre-fitting alignment paper substrate waste, with the characteristics of simple calculation, high accuracy, high efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of paper gravure press electronic shaft control system, and particularly relates to a water-based ink paper gravure press pre-registration oven parameter calculation method and system. BACKGROUND

[0002] As the core equipment of packaging printing equipment, the water-based ink paper gravure press is widely used in the industrial fields of food, beverage, cigarette, medicine, cosmetics, clothing and decorative paper. The pre-registration link is the core step for the paper gravure press to realize high-efficiency start-up printing production, and the accurate setting of the pre-registration parameters of the oven is also the basis for realizing high-precision control of the horizontal expansion and contraction registration error.

[0003] However, in the actual engineering printing, the pre-registration parameter setting of the oven depends on the experience of the operator and the printing formula parameters, is affected by many factors such as ink-paper printing adaptability, hot air evaporation drying, paper deformation expansion and contraction, and has a complex coupling mechanism, resulting in a complex and low-efficiency oven parameter setting process, and a large error with the actual oven parameter setting, which seriously hinders the development of the paper gravure press towards high speed and high efficiency and intelligence. SUMMARY

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a water-based ink paper gravure press pre-registration oven parameter calculation method and system, which can solve the problems of large error and long time consumption caused by the dependence on the experience of workers in the pre-registration oven parameter setting process, improve the pre-registration oven parameter setting efficiency and accuracy, reduce the waste of paper base materials in the pre-registration link, and has the characteristics of simple calculation, high accuracy and high efficiency.

[0005] In order to achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0006] The present application provides a water-based ink paper gravure press pre-registration oven parameter calculation method, which comprises the following steps:

[0007] Collecting printing process parameters and environmental parameters, calculating the water evaporation rate in the paper and the water evaporation rate in the ink;

[0008] Combining the water evaporation rate in the ink, the oven temperature and the front oven air speed are obtained according to the water evaporation rate equation of the ink and the energy conservation equation in the constant speed drying stage;

[0009] Combining the water evaporation rate in the paper, the back oven air speed is calculated according to the water evaporation rate equation of the paper and the energy conservation equation in the constant speed drying stage;

[0010] The oven temperature, the front oven air speed and the back oven air speed are assigned to the corresponding pre-registration oven parameter variables.

[0011] In an embodiment, the printing process parameters include printing speed, ink-up amount, water content in ink, paper water absorption rate; the environmental parameters include environmental humidity and environmental temperature.

[0012] In an embodiment, the process of calculating the water evaporation rate in paper and the water evaporation rate in ink is as follows:

[0013] Obtaining the mass of water absorbed by paper from ink, the length of paper in oven and the printing speed, and calculating the water evaporation rate in paper;

[0014] Obtaining the mass of water in ink after printing, the length of paper in oven and the printing speed, and calculating the water evaporation rate in ink.

[0015] In an embodiment, the formula for calculating the water evaporation rate in paper is as follows:

[0016] ;

[0017] In the formula, is the water evaporation rate in paper, m p is the mass of water absorbed by paper from ink, L is the length of paper in oven, v is the printing speed;

[0018] The formula for calculating the water evaporation rate in ink is as follows:

[0019] ;

[0020] In the formula, is the water evaporation rate in ink, m s is the mass of water in initial state of ink, m p is the mass of water absorbed by paper from ink, L is the length of paper in oven, v is the printing speed.

[0021] In an embodiment, the specific expression for calculating the oven temperature is as follows:

[0022] ;

[0023] In the formula, T A is the oven temperature, is the water evaporation rate in ink, h fg is the latent heat of vaporization of water evaporation, p A is the hot air density, cA Cp,air T s Tf k c h Le Le

[0024] In one embodiment, the convective mass transfer coefficient of the face oven is calculated as k c The specific expression is as follows:

[0025] ;

[0026] wherein k c h is the convective mass transfer coefficient of the face oven, R u R is the universal gas constant, A s A is the printing area of the ink, M s Mw is the molar mass of water in the ink, P s Psat is the saturated vapor pressure of the ink, m is the evaporation rate of water in the ink, T s Tf is the ink temperature at the end of drying.

[0027] In one embodiment, the specific expression for calculating the face oven air speed is as follows:

[0028] ;

[0029] wherein V 1 is the face oven air speed, L c L is the characteristic length, p A p is the hot air density, u is the air dynamic viscosity at the oven temperature T A Re is the Reynolds number. Re

[0030] In one embodiment, the specific expression for calculating the back oven air speed is as follows:

[0031] ;

[0032] wherein V 2 is the back oven air speed, α , β and δ ​is an empirical parameter, and the value range is [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, K ct is the convective mass transfer coefficient of the reverse oven, B is the nozzle diameter, p A is the hot air density, c A is the specific heat capacity of the hot air, Le is the Lewis number, λ A is the thermal conductivity of the hot air, u is the oven temperature T A is the air dynamic viscosity, L c is the characteristic length.

[0033] In an embodiment, the convective mass transfer coefficient of the reverse oven K ct is calculated as follows:

[0034]

[0035] wherein, K ct is the convective mass transfer coefficient of the reverse oven, A is the paper area, M w is the molar mass of water, ΔH v is the water vapor enthalpy value evaporated from the paper, ΔH s is the adsorption heat of water in the paper, is the water evaporation rate in the paper, R u is the universal gas constant, T A is the oven temperature, P p is the saturated vapor pressure in the paper, P tot is the saturated vapor pressure in the environment, p A is the hot air density, c A is the specific heat capacity of the hot air, Le is the Lewis number.

[0036] The present application also provides a water-based ink paper gravure printing machine pre-registration oven parameter calculation system, comprising:

[0037] a water evaporation rate acquisition module for collecting printing process parameters and environmental parameters, and calculating the water evaporation rate in the paper and the water evaporation rate in the ink;​

[0038] an oven temperature and front oven air speed obtaining module, which is used for obtaining the oven temperature and the front oven air speed according to the water evaporation rate equation of the ink and the energy conservation equation of the constant speed drying stage in combination with the water evaporation rate of the ink;

[0039] a back oven air speed obtaining module, which is used for calculating the back oven air speed according to the water evaporation rate equation of the paper and the energy conservation equation of the constant speed drying stage in combination with the water evaporation rate of the paper;

[0040] a parameter assignment module, which is used for assigning the oven temperature, the front oven air speed and the back oven air speed to corresponding pre-registration oven parameter variables.

[0041] Compared with the prior art, the method has the following beneficial effects:

[0042] The method for calculating the pre-registration oven parameters of the water-based ink paper gravure press provided by the application divides the printing and drying process into two links of water evaporation in the paper absorbed ink and water evaporation in the ink, and evaporates the water in the water-based ink in the front oven and evaporates the water in the paper absorbed ink in the back oven. Based on the water evaporation rates of the paper and the water-based ink, the theoretical oven temperature and the front and back oven air speeds required for complete evaporation of the water in the paper absorbed ink and the water in the ink are calculated according to the water drying rate equations and the energy balance equations of the paper and the water-based ink, and finally, the calculated oven temperature, front and back oven air speeds are assigned to corresponding pre-registration oven parameter variables. The method provided by the application avoids the setting mode which seriously depends on the experience of the operator and the printing formula, realizes accurate calculation of the pre-registration oven parameters of the paper gravure press, and solves the problems of long time consumption and low precision in setting the oven parameters in the pre-registration printing process of the water-based ink paper gravure press. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a calculation flowchart of the method for calculating the pre-registration oven parameters of the water-based ink paper gravure press provided by the application;

[0044] Figure 2 is a calculation flowchart of the method for calculating the pre-registration oven parameters of the water-based ink paper gravure press provided by an embodiment;

[0045] Figure 3 is a water drying principle diagram of the water-based ink paper printing in the application;

[0046] Figure 4 is an oven structure diagram of the water-based ink paper gravure press in the application;

[0047] Figure 5 is a schematic diagram of the pre-registration oven parameter calculation system of the water-based ink paper gravure press in the application. DETAILED DESCRIPTION

[0048] In order to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts should fall within the protection scope of the present application.

[0049] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0050] The present application will be described in further detail below in conjunction with the accompanying drawings:

[0051] The present application aims at the technical problem of large error and long time consumption caused by worker experience in the pre-setting process of oven parameters, and through collecting physical parameters such as printing speed, ink, and paper, according to the water evaporation rate equation of ink and paper and the energy conservation equation of constant speed drying stage, the oven temperature and the front and back oven air speed are calculated, a pre-setting oven parameter calculation method in the key technical field of electronic shaft control system of water-based ink and paper gravure press is proposed, which improves the pre-setting parameter calculation speed of the oven while ensuring the accuracy, reduces the waste of paper base material in the pre-setting link, and provides key technical support for the one-key start and pre-setting system development of packaging and printing equipment.

[0052] The above-mentioned water-based ink and paper gravure press pre-setting oven parameter calculation method comprises the following steps: collecting printing speed, ink amount, and paper ink physical parameters, and calculating the water evaporation rate of ink and paper; according to the water evaporation rate equation of water-based ink and the energy conservation equation of constant speed drying stage, the oven temperature and the front oven air speed are calculated; according to the water evaporation rate equation of paper and the energy conservation equation of constant speed drying stage, the back oven air speed is calculated; the calculated oven temperature, front oven air speed, and back oven air speed are assigned to the corresponding pre-setting oven parameter variables.

[0053] As Figure 1As shown, the water-based ink paper gravure printing machine pre-registration oven parameter calculation method provided by the present application realizes accurate calculation of the oven parameters of the paper gravure printing machine pre-registration, and solves the problems of long time consumption and low precision in setting the oven parameters in the pre-registration process of the water-based ink paper gravure printing machine.

[0054] Specifically, as shown in the figure, the water-based ink paper gravure printing machine pre-registration oven parameter calculation method comprises the following steps: Figure 1

[0055] S1: Collect printing process parameters and environmental parameters, and calculate the water evaporation rate in the paper and the water evaporation rate in the ink;

[0056] Among them, the printing process parameters include printing speed, ink amount, water content in ink, and paper water absorption rate, and the environmental parameters include environmental humidity and environmental temperature.

[0057] Among them, the process of calculating the water evaporation rate in the paper and the water evaporation rate in the ink is as follows:

[0058] S01: Obtain the water mass absorbed by the paper in the ink, the paper length in the oven, and the printing speed, and calculate the water evaporation rate in the paper;

[0059] S02: Obtain the water mass in the ink after printing, the paper length in the oven, and the printing speed, and calculate the water evaporation rate in the ink.

[0060] Specifically, the calculation formula of the water evaporation rate in the paper is as follows:

[0061] ;

[0062] In the formula, is the water evaporation rate in the paper, m p is the water mass absorbed by the paper in the ink, L is the paper length in the oven, v is the printing speed.

[0063] Specifically, the calculation formula of the water evaporation rate in the ink is as follows:

[0064] ;

[0065] In the formula, is the water evaporation rate in the ink, m s is the water mass in the initial state of the ink, m p is the water mass absorbed by the paper in the ink, L is the paper length in the oven, v is the printing speed. ​

[0066] S2: Combining the water evaporation rate in the ink, according to the water evaporation rate equation in the ink and the energy conservation equation in the constant drying stage, the oven temperature and the front oven air speed are obtained;

[0067] The specific expression for calculating the oven temperature is:

[0068] ;

[0069] In the formula, T A T is the oven temperature, m is the water evaporation rate in the ink, h fg L is the latent heat of water evaporation, p A r is the hot air density, c A c is the specific heat capacity of the hot air, T s Tf is the ink temperature when drying is completed, k c K is the convective mass transfer coefficient of the front oven, Le Le is the Lewis number.

[0070] The specific expression for calculating the convective mass transfer coefficient K of the front oven is as follows: k c

[0071] ;

[0072] In the formula, k c K is the convective mass transfer coefficient of the front oven, R u R is the universal gas constant, A s A is the ink printing area, M s M is the molar mass of water in the ink, P s P is the saturated vapor pressure of the ink, m is the water evaporation rate in the ink, T s Tf is the ink temperature when drying is completed.

[0073] The specific expression for calculating the front oven air speed is as follows:

[0074] ;

[0075] In the formula, V 1 is the front oven air speed, L c L is the characteristic length, p A ​the hot air density, u the oven temperature T A the air dynamic viscosity, Re the Reynolds number.

[0076] S3: Combining the water evaporation rate in the paper, the water evaporation rate equation in the paper and the energy conservation equation in the constant drying stage, the air velocity of the back oven is calculated;

[0077] The specific expression for calculating the air velocity of the back oven is:

[0078]

[0079] In the formula, V 2 is the air velocity of the back oven, α , β and δ are empirical parameters, and the value ranges are [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, K ct is the convective mass transfer coefficient of the back oven, B is the nozzle diameter, p A is the hot air density, c A is the specific heat capacity of the hot air, Le is the Lewis number, λ A is the thermal conductivity of the hot air, u is the oven temperature T A is the air dynamic viscosity, L c is the characteristic length.

[0080] The calculation method of the convective mass transfer coefficient of the back oven K ct is as follows:

[0081]

[0082] In the formula, K ct is the convective mass transfer coefficient of the back oven, A is the paper area, M w is the molar mass of water, ΔH v is the water vapor enthalpy value evaporated from the paper, ΔH s is the adsorption heat of water in the paper, is the water evaporation rate in the paper, R u is the universal gas constant,​​T A Tbox is the oven temperature, P p Pbox is the saturated vapor pressure in the paper, P tot Penv is the saturated vapor pressure in the environment, p A Dbox is the hot air density, c A Cbox is the hot air specific heat capacity, Le Lebox is the Lewis number.

[0083] S4: Assign the oven temperature, the front oven air speed, and the back oven air speed to the corresponding pre-calibrated oven parameter variables.

[0084] Referring to Figure 2 In another embodiment, a water-based ink sheet offset press pre-calibrated oven parameter calculation method includes the following steps:

[0085] Step 1: Collect the printing speed, ink-up amount, ink and paper physical parameters, and environmental humidity and temperature;

[0086] Step 2: Calculate the water evaporation rate in the paper and ink:

[0087] Compared with film printing, during the drying process of the paper after printing by the oven hot air, not only the evaporation of the water in the ink, but also the evaporation of the water in the paper absorbed by the ink, as shown in FIG. 1. In order to simplify the modeling of the drying mechanism of the ink and the paper, it is assumed that the paper enters the drying process in the oven, the front oven dries the ink, the back oven dries the water in the paper, and the front and back ovens are separated by the paper, and the drying of the ink and the paper does not affect each other, as shown in FIG. 2. Figure 3 Figure 4

[0088] During the hot air drying process, the water evaporation stage in the paper and the ink mainly includes the constant speed drying and the falling speed drying stages. Most of the water in the paper and the ink is evaporated in the constant speed drying stage, and the water in the falling speed stage is negligible. Therefore, the water evaporation rate in the paper is:

[0089] (1)

[0090] In the formula, m is the water evaporation rate in the paper, m p m is the mass of the water in the ink absorbed by the paper, L Lbox is the length of the paper in the oven, v V is the printing speed.

[0091] The water evaporation rate in the ink is:

[0092] (2)​​​

[0093] where, is the water evaporation rate in the ink, m s is the water mass in the initial state of the ink, m p is the water mass absorbed by the paper in the ink, L is the length of the paper in the oven, v is the printing speed.

[0094] Step 3: According to the water evaporation rate equation of the ink and the energy conservation equation of the constant speed drying stage, the oven temperature T A is calculated, the front oven speed V 1, the specific expression is:

[0095] (3)

[0096] where, T A is the oven temperature, is the water evaporation rate in the ink, h fg is the latent heat of vaporization of water evaporation, p A is the hot air density, c A is the specific heat capacity of hot air, T s is the ink temperature when drying is completed, the value range is [100℃, 120℃], k c is the convective mass transfer coefficient of the front oven, Le is the Lewis number, the specific expression is as follows:

[0097] (4)

[0098] where, k c is the convective mass transfer coefficient of the front oven, R u is the universal gas constant, A s is the ink printing area, M s is the molar mass of water in the ink, P s is the saturated vapor pressure of the ink, is the water evaporation rate in the ink, T s is the ink temperature when drying is completed.

[0099] where, Le is the Lewis number, the specific calculation expression is as follows:

[0100] (5)

[0101] where, λ A is the hot air thermal conductivity, p A is the hot air density, c A is the hot air specific heat capacity, D A is the water vapor diffusion coefficient in hot air.

[0102] Further, according to the convective heat transfer coefficient, the front oven speed V 1, the specific expression is:

[0103] (6)

[0104] where, V 1 is the front oven air speed, L c is the characteristic length, u is the aerodynamic viscosity of the air at the oven temperature T A , and Re is the Reynolds number, the specific calculation method is:

[0105] (7)

[0106] where, α , β and δ are empirical parameters, the value ranges are [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, B is the nozzle diameter, is the Nusselt number, the calculation method is as follows:

[0107] (8)

[0108] where, is the convective heat transfer coefficient, the relationship between the convective heat transfer coefficient and the convective mass transfer coefficient is as follows:

[0109] (9)

[0110] Step 4: According to the water evaporation rate equation in the paper and the energy conservation equation in the constant speed drying stage, the back oven air speed V 2, the specific expression is:

[0111] (10)

[0112] where,V 2 is the backside oven air velocity, α , β and δ are empirical parameters, with the value ranges of [0.20, 0.40], [0.50, 0.60] and [0.20, 0.30] respectively, B is the nozzle diameter, p A is the hot air density, c A is the hot air specific heat capacity, Le is the Lewis number, λ A is the hot air thermal conductivity, u is the oven temperature T A is the air dynamic viscosity at the oven temperature, L c is the characteristic length, K ct is the backside oven convective mass transfer coefficient, which is calculated as follows:

[0113] (11)

[0114] where, K ct is the backside oven convective mass transfer coefficient, A is the paper area, M w is the molar mass of water, ΔH v is the water vapor enthalpy value evaporated from the paper, ΔH s is the water adsorption heat in the paper, is the water evaporation rate in the paper, R u is the universal gas constant, T A is the oven temperature, P p is the saturated vapor pressure in the paper, P tot is the saturated vapor pressure in the environment, p A is the hot air density, c A is the hot air specific heat capacity, Le is the Lewis number.

[0115] Step 5: Assign the calculated oven temperature T A , the frontside oven air velocity V 1, and the backside oven air velocity V 2 to the corresponding pre-fitted oven parameter variables.

[0116] In a specific embodiment, the water-based ink paper gravure printing machine pre-registration oven parameter calculation method comprises the following steps:

[0117] Step 1: Collect printing process parameters and environmental parameters, specifically:

[0118] Printing speed: 300 m / min, ink supply amount: 3 g / m 2 , water content in water-based ink: 33%, paper: 220 g white card paper, water absorption rate 10%, environmental temperature: 20℃, environmental humidity is 30%, the length of the paper in the oven L=5m,

[0119] Step 2: Based on the above collected printing speed, ink supply amount and material parameters, calculate the water evaporation rate in paper and ink; the water evaporation rate calculation expression of paper and ink is shown in formula (1) and formula (2);

[0120] From formula (1), the water evaporation rate in paper is: ;

[0121] From formula (2), the water evaporation rate in ink is: ;

[0122] Step 3: According to the ink water evaporation rate equation and the energy conservation equation in the constant speed drying stage, the oven temperature T A , the front oven air speed V 1, the calculation results are as follows:

[0123] Oven temperature:

[0124] Front oven air speed:

[0125] Step 4: According to the water evaporation rate equation in paper and the energy conservation equation in the constant speed drying stage, the back oven air speed V 2, the calculation results are as follows:

[0126] Back oven parameters

[0127] Step 5: Assign the calculated oven temperature T A , front oven air speed V 1, back oven air speed V 2 to the corresponding pre-registration oven parameter variables.

[0128] In an embodiment, as Figure 5As shown, the water-based ink sheet gravure printing machine pre-registration oven parameter calculation system is provided, comprising a moisture evaporation rate acquisition module, an oven temperature and front oven air speed acquisition module, a back oven air speed acquisition module, and a parameter adjustment assignment module;

[0129] The moisture evaporation rate acquisition module is used to collect printing process parameters and environmental parameters, and calculate the moisture evaporation rate in the paper and the moisture evaporation rate in the ink.

[0130] The oven temperature and front oven air speed acquisition module is used to obtain the oven temperature and front oven air speed in combination with the moisture evaporation rate in the ink, according to the ink moisture evaporation rate equation and the energy conservation equation in the constant speed drying stage.

[0131] The back oven air speed acquisition module is used to calculate the back oven air speed in combination with the moisture evaporation rate in the paper, according to the moisture evaporation rate equation in the paper and the energy conservation equation in the constant speed drying stage.

[0132] The parameter adjustment assignment module is used to assign the oven temperature, front oven air speed and back oven air speed to corresponding pre-registration oven parameter variables.

[0133] The above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. A method for calculating parameters of a pre-registration oven for a water-based ink gravure printing press, characterized in that, Includes the following steps: Collect printing process parameters and environmental parameters, and calculate the evaporation rate of moisture in paper and ink; Based on the evaporation rate of moisture in the ink, and according to the ink moisture evaporation rate equation and the energy conservation equation for the constant-rate drying stage, the oven temperature and the front oven wind speed are obtained. Based on the evaporation rate of moisture in the paper, and according to the equation for the evaporation rate of moisture in the paper and the energy conservation equation for the constant-rate drying stage, the air velocity in the reverse drying oven is calculated. Assign values ​​to the corresponding pre-fitted oven parameter variables for the oven temperature, front oven wind speed, and back oven wind speed. The specific expression for calculating the air velocity in the reverse drying oven is as follows: ； In the formula, V 2 represents the airflow speed of the reverse side of the oven. α , β and δ These are empirical parameters, with values ​​ranging from [0.20, 0.40], [0.50, 0.60], and [0.20, 0.30], respectively. K ct The convective mass transfer coefficient of the reverse oven. B Nozzle diameter, ρ A For hot air density, c A For the specific heat capacity of hot air, Le For Lewis's number, λ A For hot air thermal conductivity, u Oven temperature T A The aerodynamic viscosity at that point, L c The characteristic length; The convective mass transfer coefficient of the reverse oven K ct The calculation method is as follows: ； In the formula, K ct The convective mass transfer coefficient of the reverse oven. A For the area of ​​the paper, M w The molar mass of water, ΔH v The enthalpy of water vapor evaporating from the paper. ΔH s This is the heat of adsorption of moisture in the paper. R is the rate of moisture evaporation in the paper. u This is the universal gas constant. T A This refers to the oven temperature. P p This is the saturated vapor pressure in paper. P tot The saturated vapor pressure in the environment. ρ A For hot air density, c A For the specific heat capacity of hot air, Le For Lewis.

2. The method for calculating the parameters of the pre-registration oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that, The printing process parameters include printing speed, ink application amount, ink moisture content, and paper water absorption rate; the environmental parameters include ambient humidity and ambient temperature.

3. The method for calculating the parameters of the pre-registration oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that, The process of calculating the evaporation rate of moisture in paper and the evaporation rate of moisture in ink is as follows: Obtain the mass of water absorbed by the ink in the paper, the length of the paper in the oven, and the printing speed, and calculate the rate of water evaporation from the paper. Obtain the moisture content of the ink after printing, the paper length in the oven, and the printing speed, and calculate the moisture evaporation rate of the ink.

4. The method for calculating the parameters of the pre-registration oven for a water-based ink paper gravure printing machine according to claim 3, characterized in that, The formula for calculating the moisture evaporation rate in the paper is as follows: ； In the formula, This represents the rate of moisture evaporation from the paper. m p The amount of moisture absorbed by the paper from the ink. L The length of the paper in the drying oven. v For printing speed; The formula for calculating the evaporation rate of moisture in the ink is as follows: ； In the formula, This represents the rate of moisture evaporation in the ink. m s This represents the moisture content of the ink in its initial state. m p The amount of moisture absorbed by the paper from the ink. L The length of the paper in the drying oven. v For printing speed.

5. The method for calculating the parameters of the pre-registration oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that, The specific expression for calculating the oven temperature is as follows: ； In the formula, T A This refers to the oven temperature. This represents the rate of moisture evaporation in the ink. h fg The latent heat of vaporization for water evaporation. ρ A For hot air density, c A For the specific heat capacity of hot air, T s The ink temperature at which drying is complete. k c The convective mass transfer coefficient of the front-side oven. Le For Lewis.

6. The method for calculating the parameters of the pre-registration oven for a water-based ink paper gravure printing machine according to claim 5, characterized in that, Calculate the convective mass transfer coefficient of the front oven. k c The specific expression is as follows: ； In the formula, k c R is the convective mass transfer coefficient of the front-side oven. u This is the universal gas constant. A s For the area of ​​ink printing, M s This represents the molar mass of water in the ink. P s The saturated vapor pressure of the ink. This represents the rate of moisture evaporation in the ink. T s This refers to the ink temperature when drying is complete.

7. The method for calculating the parameters of the pre-registration oven for a water-based ink paper gravure printing machine according to claim 1, characterized in that, The specific expression for calculating the air velocity of the front oven is as follows: ； In the formula, V 1 represents the airflow speed of the front oven. L c For characteristic length, ρ A For hot air density, u Oven temperature T A The aerodynamic viscosity at that point, Re It is the Reynolds number.

8. A parameter calculation system for a pre-registration oven for a water-based ink gravure printing press, characterized in that, include: The moisture evaporation rate acquisition module is used to collect printing process parameters and environmental parameters, and to calculate the moisture evaporation rate in paper and the moisture evaporation rate in ink. The oven temperature and front oven air velocity acquisition module is used to obtain the oven temperature and front oven air velocity by combining the evaporation rate of moisture in the ink and based on the ink moisture evaporation rate equation and the energy conservation equation of the constant rate drying stage. The reverse drying oven wind speed acquisition module is used to calculate the reverse drying oven wind speed by combining the moisture evaporation rate in the paper and the energy conservation equation for the constant rate drying stage. The parameter adjustment and assignment module is used to assign the oven temperature, front oven wind speed and back oven wind speed to the corresponding pre-fitted oven parameter variables; The specific expression for calculating the air velocity in the reverse drying oven is as follows: ； In the formula, V 2 represents the airflow speed of the reverse side of the oven. α , β and δ These are empirical parameters, with values ​​ranging from [0.20, 0.40], [0.50, 0.60], and [0.20, 0.30], respectively. K ct The convective mass transfer coefficient of the reverse oven. B Nozzle diameter, ρ A For hot air density, c A For the specific heat capacity of hot air, Le For Lewis's number, λ A For hot air thermal conductivity, u Oven temperature T A The aerodynamic viscosity at that point, L c The characteristic length; The convective mass transfer coefficient of the reverse oven K ct The calculation method is as follows: ； In the formula, K ct The convective mass transfer coefficient of the reverse oven. A For the area of ​​the paper, M w The molar mass of water, ΔH v The enthalpy of water vapor evaporating from the paper. ΔH s This is the heat of adsorption of moisture in the paper. R is the rate of moisture evaporation in the paper. u This is the universal gas constant. T A This refers to the oven temperature. P p This is the saturated vapor pressure in paper. P tot The saturated vapor pressure in the environment. ρ A For hot air density, c A For the specific heat capacity of hot air, Le For Lewis.

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