A pulp and paper making DCS slurry proportioning control method

Abstract

The present application relates to papermaking technical field, specifically to a kind of pulping papermaking DCS slurry proportioning control method, S1: slurry liquid level PID control output obtains each slurry proportioning intermediate calculation value standby;S2: each slurry concentration value selection;S3: the absolute dry weight flow calculation of each slurry;S4: with absolute dry weight flow proportioning flow control value transmission to the flow PID loop set value of each slurry;S5: each slurry is provided with input cascade selection;S6: each slurry real-time absolute dry pulp calculation and summation;S7: because the "absolute dry proportioning flow control value" calculated with "flow proportioning control amount" is greater than the set value of flow PID;The flow real-time value in the absolute dry weight calculation in the S6 is not less than zero, and the divisor is not zero Limit or mathematical processing;S8: host computer slurry picture parameter setting and display.The present application can accurately control paper quality, stable production, avoid the fluctuation of concentration and affect production quality.

Description

Technical Field

[0001] This invention relates to a pulping and papermaking DCS pulp ratio control method, and particularly to a pulping and papermaking DCS pulp ratio control method, belonging to the field of papermaking technology. Background Technology

[0002] Modern papermaking machines are generally multi-layered paper machines consisting of face, core, and bottom layers. Each layer of pulp is made by mixing several different concentrations of pulp in a certain proportion, then pumping the pulp to the headbox for spraying, and finally dewatering and forming the paper in the wire and press sections. Pulp mixing is the beginning of papermaking, and the pulp includes short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet loss pulp, bamboo pulp, etc.

[0003] The current slurry mixing system consists of a mixing tank and multiple inlet pipes for different slurries. The mixing tank is equipped with a level transmitter, and each slurry comes from its own inlet pipe, which is equipped with a flow meter and a regulating valve, forming a flow rate PID control loop. The output of the hydraulic PID control loop in the mixing tank is multiplied by the mixing ratio and then sent to the setpoint (SP) of the flow rate PID control loop in each inlet pipe. The output of the flow rate PID control loop controls the opening of the regulating valve to change the flow rate, thus realizing cascade control of the level PID and the flow meter PID.

[0004] The above control does not take into account the concentration of each pulp in the calculation. If the pulp concentration of each section of the pulp inlet pipe is inaccurate or fluctuates, the control cannot make corresponding adjustments to the ratio according to the change of concentration. Or if the concentration values ​​are different, the pulp will not be controlled according to the set pulp ratio, making it difficult to achieve precise control of the ratio of each pulp. The physical properties of the paper will fluctuate, affecting the stability of production.

[0005] Therefore, it is urgent to improve the pulp ratio control method of DCS in pulp and paper making to solve the above-mentioned problems. Summary of the Invention

[0006] The purpose of this invention is to provide a pulping and papermaking DCS pulp ratio control method. Based on the original flow control of the equipment, it adds oven-dry volume flow ratio control. The control screen can switch between oven-dry volume flow ratio and flow ratio methods. It also adds control over whether each type of pulp can be added or not. Furthermore, if a concentration meter malfunctions, the control screen can use the laboratory value as the concentration detection value in the calculation.

[0007] To achieve the above objectives, the main technical solution adopted by the present invention includes: a pulping and papermaking DCS pulp ratio control method, comprising the following steps:

[0008] S1: The output LIC_CMD_REAL of the slurry level PID control is multiplied by the set ratio of each slurry and then multiplied by a coefficient of 1 to obtain the intermediate calculated value of each slurry ratio for later use.

[0009] S2: Selection of concentration values ​​for each slurry;

[0010] S3: Calculation of the absolute dry flow rate of each slurry;

[0011] S4: The flow rate PID loop setting value is transmitted to each slurry using the dry quantity flow rate ratio flow control value or the flow rate ratio control value.

[0012] S5: Each slurry has a cascade input selection option;

[0013] S6: Real-time calculation and summation of oven-dry slurry for each slurry component;

[0014] S7: Because the calculated "dry ratio flow control value" and "flow ratio control quantity" may be greater than the set value of the flow PID; the real-time flow value in the above-mentioned S6 dry quantity calculation is not less than zero, and the limit or mathematical processing of the divisor is not zero.

[0015] S8: Setting and displaying parameters for the upper computer's pulp mixing screen.

[0016] Preferably, the range of the PID control output for the slurry level in S1 is 0-100, and the set optimization value of the washing coefficient in S1 is 1=1.6.

[0017] Preferably, in step S1, the intermediate calculated values ​​of the proportions of short fiber pulp, long fiber pulp, medium-length fiber pulp, recycled pulp, wet-loss pulp, and bamboo pulp are obtained using the following formula:

[0018] Intermediate calculated value of short fiber pulp ratio: PJ3_M1=1.6*LIC_CMD_REAL[5]* SET_Percent1;

[0019] Intermediate calculated value of long fiber pulp ratio: PJ3_M2=1.6*LIC_CMD_REAL[5]* SET_Percent2;

[0020] Intermediate calculated value of medium fiber pulp ratio: PJ3_M3=1.6*LIC_CMD_REAL[5]* SET_Percent3;

[0021] Intermediate calculated value of recycled slurry ratio: PJ3_M4=1.6*LIC_CMD_REAL[5]* SET_Percent4;

[0022] Intermediate calculated value of wet loss slurry ratio: PJ3_M5=1.6*LIC_CMD_REAL[5]* SET_Percent5;

[0023] Intermediate calculated value of bamboo pulp ratio: PJ3_M6=1.6*LIC_CMD_REAL[5]* SET_Percent6;

[0024] PJ3_M1, PJ3_M2, PJ3_M3, PJ3_M4, PJ3_M5, and PJ3_M6 are reserved.

[0025] Preferably, in S2, the concentration process value or laboratory value of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet loss pulp, and bamboo pulp is selected as the concentration factor for calculating the oven-dry weight: PJ3_M

[11] , PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , PJ3_M

[16] are reserved; wherein the concentration process value is obtained by measuring the concentration of each type of pulp, and the laboratory value is input through the control screen after the test.

[0026] Preferably, in S3, the absolute dry flow rate ratio control values ​​PJ3_M1, PJ3_M2, PJ3_M3, PJ3_M4, PJ3_M5, and PJ3_M6 are obtained by dividing the above-mentioned intermediate calculated values ​​of each slurry ratio PJ3_M

[11] , PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , and PJ3_M

[16] by the above-mentioned concentration factors PJ3_M

[11] , PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , and PJ3_M

[16] by a coefficient 2 (coefficient 2 = 400 for debugging and optimization) and then using them for future reference.

[0027] Preferably, in S4, if the "dry weight ratio flow control value and flow ratio control value" selection bit is "1", the dry weight ratio control values ​​PJ3_M[6], PJ3_M[7], PJ3_M[8], PJ3_M[9], PJ3_M[1], and PJ3_M

[26] of each of the above three slurries are selected as the set values ​​of each slurry flow PID control loop; if it is "0", the original flow ratio control values ​​of each slurry are used as the set values ​​of each slurry flow PID control loop.

[0028] Preferably, in S5, each type of pulp has a separate "cascade input" selection. When the selection bit is "1", the pulp is set to the absolute dry weight ratio flow control value or the flow ratio control value. When the selection bit is "0", the internal setting value of the flow PID loop for that type of pulp is selected.

[0029] Preferably, in S6, the flow rate of each slurry is measured by the flow rate indicator of each slurry, and the real-time flow rate value of each slurry is obtained. Then, the concentration factor of each slurry in S2 is multiplied by the concentration factor of each slurry in S2: PJ3_M

[11] , PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , PJ3_M

[16] and divided by 100 to obtain the absolute dry weight of each slurry JGL_REAL[1], JGL_REAL[2], JGL_REAL[3], JGL_REAL[4], JGL_REAL[5], JGL_REAL[6] for later use. The above values ​​are summed to obtain the total absolute dry weight JGL_REAL[0] for later use and displayed on the control screen.

[0030] Preferably, the "dry ratio flow control value" and "flow ratio control quantity" calculated in S7 are greater than the set value of the flow PID. In the above-mentioned S6 dry quantity calculation, the real-time flow value is not less than zero, and the limit value or mathematical processing of the divisor is not zero, so that the set value of each slurry flow PID loop does not exceed the high range and is not less than the low range; the concentration factor is not less than "0".

[0031] Preferably, in S8, the upper computer pulp mixing screen parameter setting and display includes a concentration selection position, a "dry weight ratio flow control value and flow ratio control value" selection position, a separate "cascade input" selection position for each pulp, input of each pulp ratio, indication of each pulp flow rate and concentration, and display of dry weight.

[0032] This invention has at least the following beneficial effects:

[0033] 1. Based on flow control, the system adds oven-dry volume flow ratio control, allowing users to switch between oven-dry volume flow ratio and flow ratio methods via the control screen. It also provides improved control over whether each type of pulp can be added or not. Furthermore, if a concentration meter malfunctions, the control screen can use laboratory values ​​as the concentration detection value for calculation. After the upgrade, the commonly used oven-dry volume flow ratio control is put into use, resulting in more stable paper physical properties. In case of concentration meter malfunction, laboratory values ​​can be temporarily used for calculation, and the flow ratio control can be switched, providing better adaptability. This allows for precise control of paper quality, stable production, and avoidance of concentration fluctuations affecting production quality. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0035] Figure 1 This is a flowchart of the steps of the present invention;

[0036] Figure 2This is a schematic diagram illustrating the intermediate calculated values ​​of each slurry ratio in this invention;

[0037] Figure 3 This is a schematic diagram illustrating the selection of various slurry concentrations according to the present invention;

[0038] Figure 4 This is a schematic diagram illustrating the calculation of the control values ​​for the oven-dry weight ratio of each slurry according to the present invention.

[0039] Figure 5 This is a schematic diagram illustrating the calculation of the flow control values ​​for selecting the absolute dry weight ratio of each pulp according to the present invention.

[0040] Figure 6 This is a schematic diagram illustrating the calculation of the PID flow ratio control values ​​for each slurry flow rate according to the present invention;

[0041] Figure 7 This is a schematic diagram showing the selection of the setpoints for each slurry flow rate PID loop in this invention.

[0042] Figure 8 This is a schematic diagram illustrating the calculation and summarization of the real-time oven-dry weight of each slurry according to the present invention;

[0043] Figure 9 This is a schematic diagram illustrating the mathematical processing of the present invention, which stipulates that the range cannot be exceeded and the divisor cannot be zero.

[0044] Figure 10 This is a schematic diagram of the control screen for various pulp preparation methods according to the present invention. Detailed Implementation

[0045] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0046] like Figures 1-7 As shown in this embodiment, the pulp and paper DCS pulp ratio control method includes the following steps:

[0047] S1: The output of the PID control for slurry level, LIC_CMD_REAL, is multiplied by the set ratio of each slurry and then by a coefficient of 1 to obtain the intermediate calculated value of each slurry ratio for later use; the range of the PID control output for slurry level in S1 is 0-100, and the adjustment and optimization value of the set washing coefficient in S1 is 1=1.6.

[0048] In S1, the intermediate calculated values ​​for the proportions of short fiber pulp, long fiber pulp, medium-length fiber pulp, recycled pulp, wet-loss pulp, and bamboo pulp are obtained using the following formulas:

[0049] Intermediate calculated value of short fiber pulp ratio: PJ3_M1=1.6*LIC_CMD_REAL[5]* (PJ_DJ_SET_Percent[1]*100) / 100;

[0050] Intermediate calculated value of long fiber pulp ratio: PJ3_M2=1.6*LIC_CMD_REAL[5]* (PJ_DJ_SET_Percent[2]*100) / 100;

[0051] Intermediate calculated value of medium fiber pulp ratio: PJ3_M3=1.6*LIC_CMD_REAL[5]* (PJ_DJ_SET_Percent[3]*100) / 100;

[0052] Intermediate calculated value of recycled slurry ratio: PJ3_M4=1.6*LIC_CMD_REAL[5]* SET_Percent4(PJ_DJ_SET_Percent[4]*100) / 100;

[0053] Intermediate calculated value of wet loss slurry ratio: PJ3_M5=1.6*LIC_CMD_REAL[5]* (PJ_DJ_SET_Percent[5]*100) / 100;

[0054] Intermediate calculated value of bamboo pulp ratio: PJ3_M6=1.6*LIC_CMD_REAL[5]* (PJ_DJ_SET_Percent[6]*100) / 100;

[0055] PJ3_M1, PJ3_M2, PJ3_M3, PJ3_M4, PJ3_M5, and PJ3_M6 are reserved. Among them, LIC_CMD_REAL[5] is the PID output of the slurry level control in step one, which is a variable (range: 0-100). SET_Percent1……6 is the ratio of the slurry to the seed slurry, with a coefficient of 1 (coefficient 1=1.6, the value of the debugging and optimization).

[0056] LIC_CMD_REAL[5] is the output of the pulp mixing tank liquid level PID control loop (range 0 - 100). PJ_DJ_SET_Percent[1], PJ_DJ_SET_Percent[2], PJ_DJ_SET_Percent[3], PJ_DJ_SET_Percent[4], PJ_DJ_SET_Percent[6], PJ_DJ_SET_Percent[6], PJ_DJ_SET_Percent[7] are the mixing ratios of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet broken pulp, and bamboo pulp respectively, which can be set on the control screen. For more intuitiveness, in the range (0 - 100) of the screen, through the SCALE of the upper computer variable, it is configured to 100. Therefore, each formula is multiplied by 100 and then divided by 100 for easy understanding. 1.6 The amplification factor 1 of each pulp mixing ratio is mainly combined with the amplification factor 2 of each pulp mixing ratio in S3 (the debugging value is 400) to optimize the control process, ensure that the output value of the pulp mixing tank liquid level PID control loop is between 30 - 60, and the set value of the PID for each pulp flow control <PID high range, and the control requirements of the pulp mixing tank liquid level PID control loop;

[0057] S2: Selection of each pulp concentration value; In S2, through the selection of the concentrations of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet broken pulp, and bamboo pulp, the process value or laboratory value of the concentration is selected as the calculation factor of the absolute dry weight concentration: The control logics of the concentrations of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet broken pulp, and bamboo pulp are the same. Now, the control of the short fiber pulp at the bottom layer is selected for illustration. If PJ3_CPV_EN1 = "1", the process concentration CI_AI_REAL[4] of the short fiber pulp is transmitted to the short fiber pulp concentration factor PJ3_M

[11] through the MOV instruction. If PJ3_CPV_EN1 = "0", the laboratory value of the short fiber pulp is transmitted to the short fiber pulp concentration factor PJ3_M

[11] for standby. The purpose is that when the concentration meter fails, the laboratory value can be selected for calculation to ensure that the calculation of the absolute dry weight can still be used. Based on this logic, the concentration factors PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , PJ3_M

[16] of the long fiber pulp, medium-long fiber pulp, recycled pulp, wet broken pulp, and bamboo pulp can also be obtained for standby. Among them, the process value of the concentration is obtained through the concentration meter of each pulp, and the laboratory value is input through the control screen after testing;

[0058] S3: Calculation of the absolute dry flow rate of each slurry; In S3, the intermediate calculated values ​​of each slurry ratio PJ3_M1, PJ3_M2, PJ3_M3, PJ3_M4, PJ3_M5, and PJ3_M6 are divided by the concentration factors PJ3_M

[11] , PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , and PJ3_M

[16] , respectively. Multiply 3_M

[16] by coefficient 2 (coefficient 2=400 for debugging and optimization) to obtain the absolute dry flow rate ratio control values ​​PJ3_M[6], PJ3_M[7], PJ3_M[8], PJ3_M[9], PJ3_M[1], PJ3_M

[26] for use. Determine short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, and wet loss pulp. Calculate the absolute dry ratio control value of bamboo pulp. Since the calculation is the same, the calculation of the dry ratio control value PJ3_M[6] of the bottom short fiber pulp is selected for explanation. Through S1, the intermediate calculated value of the short fiber pulp ratio PJ3_M[1] is divided by the short fiber pulp concentration factor PJ3_M

[12] of S3, and then multiplied by the ratio amplification factor 2 (the adjustment value is 400) to obtain the dry ratio control value PJ3_M[6] of the short fiber pulp for later use, that is, PJ3_M[6]=400*PJ3_M[1] / PJ3_M

[11] . PJ3_M[6] is a dimensionless value and is the ratio of the dry value. Similarly, the dry ratio control values ​​PJ3_M[7], PJ3_M[8], PJ3_M[9], PJ3_M

[10] , and PJ3_M

[26] of long fiber pulp, medium long fiber pulp, recycled pulp, wet loss pulp, and bamboo pulp can be calculated for later use.

[0059] S4: The set value of the flow PID loop of each slurry is transmitted to the control value of the dry quantity flow ratio or the control value of the flow ratio. In S4, if the selection bit of "dry quantity flow ratio and flow ratio control value" is "1", the dry quantity flow ratio control values ​​PJ3_M[6], PJ3_M[7], PJ3_M[8], PJ3_M[9], PJ3_M[1], and PJ3_M

[26] of each slurry are selected as the set value of the flow PID control loop of each slurry. If it is "0", the original flow ratio control value of each slurry is used as the set value of the flow PID control loop of each slurry.

[0060] The "dry ratio flow control value and flow ratio control amount" selection control logic of short fiber pulp, long fiber pulp, medium and long fiber pulp, recycled pulp, wet loss pulp, and bamboo pulp is the same. Therefore, the "dry ratio flow control value and flow ratio control amount" selection of the bottom layer pulp short fiber pulp is selected for explanation. If PJ3_JG_EN1 = "1", the above step three short fiber pulp dry ratio control value PJ3_M[6] is transmitted to the short fiber pulp flow PID control loop setting value FIC_SP_SET

[12] by transmitting MOV instruction. If PJ3_JG_EN1 = "0", the original program flow control value PJ_DJ_SET_SP[1] is transmitted to the short fiber pulp flow PID control loop setting value FIC_SP_SET

[12] by transmitting another MOV instruction.

[0061] S5: Each slurry has a cascade input selection; S5 has a separate "cascade input" selection for each type of slurry. When the selection bit is "1", the absolute dry weight ratio flow control value or flow ratio control value of that slurry will be used as the set value. When the selection bit is "0", the internal set value of the flow PID loop of that slurry will be selected.

[0062] The set value of the PID control loop for the flow of short fiber pulp, long fiber pulp, medium-length fiber pulp, recycled pulp, and wet loss pulp is selected as either the "dry ratio flow control value" or the "flow ratio control quantity" or the internal set value of the PID. If PJ_DJ_EN1 = "1", the "dry ratio flow control value" or "flow ratio control quantity" selected by S4 is transmitted to the set value FIC_SP_SET

[12] of the short fiber pulp flow PID control loop by transmitting the MOV command. If PJ_DJ_EN1 = "0", it is not transmitted to FIC_SP_SET

[12] . The value of FIC_SP_SET

[12] is input through the PID control panel.

[0063] S6: Real-time calculation and summation of the oven-dry slurry of each slurry; In S6, the flow rate of each slurry is measured by the flow rate indicator of each slurry, and the real-time flow rate value of each slurry is obtained by multiplying it by the concentration factor of each slurry in S2 above: PJ3_M

[11] , PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , PJ3_M

[16] divided by 100 to obtain the oven-dry amount of each slurry JGL_REAL[1], JGL_REAL[2], JGL_REAL[3], JGL_REAL[4], JGL_REAL[5], JGL_REAL[6] for later use, and the above values ​​are summed to obtain the total oven-dry amount JGL_REAL[0] for later use, and displayed on the control screen;

[0064] By reading the real-time flow values ​​of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet loss pulp, and bamboo pulp from the original program and multiplying them by the concentration factor of each pulp in S2 and dividing by 100: the calculation methods for short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet loss pulp, and bamboo pulp are the same, so the calculation of the oven-dry pulp of short fiber pulp is selected for description. The real-time flow value of short fiber pulp in the original program is FIC_AI_REAL

[12] , in l / min, using the MOV transmission command: Send the intermediate variable PJ_DJ_FT_PV[1], multiply PJ_DJ_FT_PV[1] by the short fiber pulp concentration factor PJ3_M

[11] in S2 and divide by 100 to obtain the dry weight of short fiber pulp PJ_DJ_JGL_REAL[1] for later use, in Kg / min, i.e. PJ_DJ_JGL_REAL[1]=PJ_DJ_FT_PV[1]*PJ3_M

[11] / 100, and similarly calculate the following:

[0065] Oven-dry weight of long fiber pulp PJ_DJ_JGL_REAL[2] Reserved

[0066] Oven-dry weight of medium-length fiber pulp PJ_DJ_JGL_REAL[3] Reserved

[0067] The amount of recycled pulp at oven dry weight PJ_DJ_JGL_REAL[4] is reserved.

[0068] Absolute dry weight of wet-damaged pulp PJ_DJ_JGL_REAL[5] Reserved

[0069] Bamboo pulp oven-dry weight PJ_DJ_JGL_REAL[6] Reserved

[0070] PJ_DJ_JGL_REAL[1]+ PJ_DJ_JGL_REAL[2]+ PJ_DJ_JGL_REAL[3]+ PJ_DJ_JGL_REAL[4]+ PJ_DJ_JGL_REAL[5]+ PJ_DJ_JGL_REAL[6]=PJ_DJ_JGL_REAL[0], and sum the above values ​​to obtain the total dry weight PJ_DJ_JGL_REAL[0] for later use, and display it on the control screen;

[0071] S7: Because the calculated "dry ratio flow control value" and "flow ratio control quantity" may be greater than the set value of the flow PID; the real-time flow value in the above S6 dry quantity calculation cannot be less than zero, and the divisor cannot be zero, or mathematical processing is required; the "dry ratio flow control value" and "flow ratio control quantity" calculated in S7 are greater than the set value of the flow PID; the real-time flow value in the above S6 dry quantity calculation cannot be less than zero, and the divisor cannot be zero, or mathematical processing is required; the set value of each slurry flow PID loop should not exceed the high range and should not be less than the low range; the concentration factor should not be less than "0";

[0072] Because the "dry ratio flow control value" and "flow ratio control quantity" may be greater than the set value of the flow PID, it is less than the high range of the flow PID control loop; now take the set value of the flow PID loop of short fiber pulp to describe it, use the greater than instruction, if the greater than the set value FIC_SP_SET

[12] > the high range of the flow PID control loop FIC_AI_RH

[12] , execute the MOV instruction to transfer FIC_AI_RH

[12] to FIC_SP_SET

[12] , the above S6 dry quantity calculation flow real-time value cannot be less than zero, the divisor cannot be zero mathematical processing; use the less than instruction, if the transfer intermediate variable PJ_DJ_FT_PV[1] of S6 is less than 0, execute the MOV instruction to transfer "0" to PJ_DJ_FT_PV[1]; if the medium short fiber pulp concentration factor PJ3_M

[11] of S6 is less than 0 The MOV instruction is executed to pass “0.1” to PJ3_M

[11] . Other long fiber pulp, medium long fiber pulp, recycled pulp, wet loss pulp, bamboo pulp transfer intermediate variable PJ_DJ_FT_PV[2], transfer intermediate variable PJ_DJ_FT_PV[1], transfer intermediate variable PJ_DJ_FT_PV[2], PJ_DJ_FT_PV[3], PJ_DJ_FT_PV[4], PJ_DJ_FT_PV[5], PJ_DJ_FT_PV[6], concentration factor PJ3_M

[12] , PJ3_M

[13] , PJ3_M

[14] , PJ3_M

[15] , PJ3_M

[16] are processed in the same way.

[0073] S8: Upper computer pulp mixing screen parameter setting and display. In S8, the upper computer pulp mixing screen parameter setting and display includes concentration selection, "Oven dry quantity ratio flow control value and flow ratio control value" selection, "Cascade input" selection for each pulp, input of each pulp ratio, flow rate and concentration indication for each pulp, and display of oven dry quantity.

[0074] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0075] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes that element.

[0076] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for controlling pulp proportioning in a DCS (Distributed Control System) for pulping and papermaking, characterized in that: Includes the following steps: Step S1: Multiply the PID control output LIC_CMD_REAL of the pulp level by the set proportions of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet-damaged pulp, and bamboo pulp, respectively, and then multiply by a coefficient of 1 to obtain the intermediate calculated values ​​PJ3_M1, PJ3_M2, PJ3_M3, PJ3_M4, PJ3_M5, and PJ3_M6 of each pulp proportion for later use; Step S2: Select the concentration values ​​of each pulp. Select the concentration of short fiber pulp, long fiber pulp, medium and long fiber pulp, recycled pulp, wet loss pulp and bamboo pulp, and calculate the dry weight concentration factor by selecting the concentration process value or laboratory value: PJ3_M[11], PJ3_M[12], PJ3_M[13], PJ3_M[14], PJ3_M[15], PJ3_M[16] for later use; Step S3: Calculate the dry flow rate of each slurry. Divide the intermediate calculated value of each slurry ratio by the dry concentration factor of each slurry multiplied by the coefficient 2 to obtain the dry flow rate control values ​​of each slurry PJ3_M[6], PJ3_M[7], PJ3_M[8], PJ3_M[9], PJ3_M[1], PJ3_M[26] for later use. Step S4: Transmit the dry ratio flow control value or the flow ratio control value to the flow PID loop setting value of each slurry. When the selection bit is "1", the dry ratio flow control value of each slurry is selected as the setting value of the flow PID control loop of each slurry. When the selection bit is "0", the original flow ratio control value of each slurry is used as the setting value of the flow PID control loop of each slurry. Step S5: Each slurry has a cascade feeding selection. When the selection bit is "1", the slurry will use the dry ratio flow control value or the flow ratio control value as the set value. When the selection bit is "0", the internal set value of the slurry flow PID loop will be selected. Step S6: Calculate and sum the real-time dry weight of each slurry. In step S2, divide the dry weight concentration factor of each slurry by 100 to obtain the dry weights JGL_REAL[1], JGL_REAL[2], JGL_REAL[3], JGL_REAL[4], JGL_REAL[5], and JGL_REAL[6] of each slurry for later use. Sum them up to obtain the total dry weight JGL_REAL[0] for later use and display it on the control screen. Step S7: Because the calculated "dry ratio flow control value" and "flow ratio control value" may be greater than the set value of the flow PID; in step S6, the flow rate in the dry quantity calculation cannot be less than zero in real time, and the divisor cannot be zero, or mathematical processing is required. Step S8: Setting and displaying parameters on the upper computer's pulp mixing screen.

2. The pulp proportioning control method of DCS in pulping and papermaking according to claim 1, characterized in that: In step S1, the range of the PID control output for the slurry level is 0-100, and the set coefficient in step S1 is adjusted and optimized to a value of 1-1.

6.

3. The pulp proportioning control method of DCS in pulping and papermaking according to claim 1, characterized in that: In step S1, the intermediate calculated values ​​for the proportions of short fiber pulp, long fiber pulp, medium-long fiber pulp, recycled pulp, wet-damaged pulp, and bamboo pulp are obtained using the following formula: Intermediate calculated value of short fiber pulp ratio: PJ3_M1=1.6*LIC_CMD_REAL[5]* SET_Percent1; Intermediate calculated value of long fiber pulp ratio: PJ3_M2=1.6*LIC_CMD_REAL[5]* SET_Percent2; Intermediate calculated value of medium-length fiber pulp ratio: PJ3_M3=1.6*LIC_CMD_REAL[5]* SET_Percent3; Intermediate calculated value of recycled slurry ratio: PJ3_M4=1.6*LIC_CMD_REAL[5]* SET_Percent4; Intermediate calculated value of wet loss slurry ratio: PJ3_M5=1.6*LIC_CMD_REAL[5]* SET_Percent5; Intermediate calculated value of bamboo pulp ratio: PJ3_M6=1.6*LIC_CMD_REAL[5]* SET_Percent6.

4. The pulp proportioning control method of DCS in pulping and papermaking according to claim 1, characterized in that: The concentration process value is obtained by testing each type of pulp using a concentration meter, and the laboratory value is input through the control screen after testing.

5. The pulp proportioning control method of DCS in pulping and papermaking according to claim 1, characterized in that: The set coefficient in step S3 is set to an optimization value of 400.

6. The pulp proportioning control method of DCS in pulping and papermaking according to claim 1, characterized in that: Set the PID loop settings for each slurry flow rate to not exceed the high range and not be less than the low range; set the concentration factor not to be less than 0.

7. The pulp proportioning control method of DCS in pulping and papermaking according to claim 6, characterized in that: In step S8, the parameters of the upper computer slurry mixing screen are set and displayed, including the concentration selection position, the "dry ratio flow control value and flow ratio control value" selection position, the "cascade input" selection position for each slurry, the ratio input of each slurry, the flow rate and concentration indication of each slurry, and the display of the dry quantity.

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