阅读说明：本技术 一种造纸用dcs系统的优化节能降碳方法 (Optimized energy-saving carbon-reducing method of DCS (distributed control system) for papermaking ) 是由 罗佐帆 谢清若 黄一峰 彭小玉 农韦健 黄恩福 梁善宝 于 2019-10-09 设计创作，主要内容包括：本发明涉及一种造纸用DCS系统的优化节能降碳方法,采用DCS控制系统,首先根据原料种类、产品性能特点和纸机车速等,合理控制磨浆浓度、打浆电流、盘磨机开机最优磨浆浓度、芯层配比、面层和底层配比,然后用DCS控制不同的磨浆功率分配和盘磨串联方式；再对磨浆后结果进行综合分析,并得到相关数据；将数据反馈到DCS控制进行综合处理,得到优选数据；最后DCS按优选数据进行调整,控制不同的磨浆功率分配和盘磨串联方式,实现造纸用DCS系统的优化与节能降碳。与现有技术相比,本发明根据纸机原料相关特性参数与消耗数据,综合运用并优化DCS控制系统,以达到在最低能量消耗情况下纸张最佳的强度性能,实现了造纸系统优化节能降碳。(The invention relates to an optimized energy-saving carbon-reducing method of a DCS (distributed control System) for papermaking, which adopts a DCS control system, firstly reasonably controls the pulp grinding concentration, the pulping current, the optimal pulp grinding concentration when a disc grinder is started, the core layer ratio and the surface layer and bottom layer ratio according to the types of raw materials, the product performance characteristics, the speed of a paper machine and the like, and then controls different pulp grinding power distribution and disc grinder series connection modes by using the DCS; comprehensively analyzing the result after grinding to obtain related data; feeding back the data to DCS control for comprehensive treatment to obtain optimized data; and finally, the DCS is adjusted according to the optimized data, different pulp grinding power distribution and disc grinding series connection modes are controlled, and optimization, energy conservation and carbon reduction of the DCS for papermaking are realized. Compared with the prior art, the method comprehensively utilizes and optimizes the DCS control system according to the relevant characteristic parameters and consumption data of the paper machine raw materials so as to achieve the optimal strength performance of paper under the condition of lowest energy consumption and realize the optimization, energy conservation and carbon reduction of the paper making system.)

1. The invention relates to an optimized energy-saving carbon-reducing method of a DCS (distributed control system) for papermaking, which is characterized by comprising the following steps of:

reasonably controlling the pulping concentration, pulping current, optimal pulping concentration when the disc grinder is started, core layer proportion and surface layer and bottom layer proportion according to the types of raw materials, the performance characteristics of products, the speed of a paper machine and the like; controlling different pulp grinding power distribution and disc grinding series connection modes by the DCS, feeding back to the DCS for comprehensive treatment according to the obtained related data, and obtaining optimized data; and adjusting according to the optimized data, controlling different pulp grinding power distribution and disc grinding series connection modes, and realizing optimization, energy conservation and carbon reduction of the DCS for papermaking.

2. The method for optimizing energy conservation and carbon reduction of the DCS for papermaking according to claim 1, wherein the method comprises the following steps: the raw materials in the step (1) are needle wood fiber, eucalyptus fiber and bagasse fiber, and the product is characterized by 14-38g/m2 pure wood pulp or mixed pulp high-grade household paper, the paper machine speed is 1000-.

3. The method for optimizing energy conservation and carbon reduction of the DCS for papermaking according to claim 1, wherein the method comprises the following steps: the disc mill serial connection mode in the step (2) is that two disc mills are connected in series or three disc mills are connected in series, when the two disc mills are connected in series, the ratio of the number of the disc mills in the series is 8-10: 10-8, when three are connected in series, the ratio of 3-7: 4-7: 3-7, the energy-saving rate reaches 8-15%, and the carbon emission reduction rate reaches 10-20%.

Technical Field

The invention belongs to the technical field of papermaking, and particularly relates to an optimized energy-saving and carbon-reducing method for a DCS (distributed control system) for papermaking.

Background

The pulping and papermaking process is a complex industrial process and is a very technical work with high uncertainty, nonlinearity, correlation, large hysteresis and state incompleteness. The production process of the paper making enterprise is characterized by more process flows, more complex process procedures and process technologies; high temperature, strong corrosivity, serious electric energy pollution and serious damage to production equipment; the capacity of the papermaking electric equipment is large, and electric safety accidents are easy to happen. Therefore, according to the production process requirements of paper making enterprises, the paper making enterprises do scientific electricity utilization and power saving protection work, and the paper making enterprises are distinguished from different and more distinct characteristics of other industries. At present, the energy conservation and emission reduction task of enterprises is under heavy pressure, and in the low-carbon economic era, how to promote the development of the papermaking process to the direction of low energy consumption, low emission and low pollution by using an energy-saving technology is one of the main problems faced by the papermaking industry in China. With the great adjustment of the world economic pattern and the obvious acceleration of the transformation of the economic society in China, the restriction of resources, energy and environment for the development of the paper industry in China is increasingly prominent, and the rapid structure adjustment is urgently needed. The method saves energy, reduces electric energy pollution, leaves a new way of 'subtracting' energy consumption emission and 'adding' economic development, reduces energy consumption and carbon emission, is a strategic policy in two technical fields of energy conservation and carbon reduction, and is a long-term basic national policy in China.

At present, many paper mills in China still have the problems of high energy consumption, low electric energy utilization rate, serious electric energy pollution and the like, and the main reasons for causing the high energy consumption of the paper making industry in China are two: firstly, the technology and the equipment technology are relatively lagged behind; secondly, the optimization degree of energy use is low. At present, energy conservation and emission reduction tasks of enterprises are heavy and pressure is large, and most paper making enterprises are carrying out technical transformation on equipment and processes with low energy utilization efficiency so as to achieve the purposes of energy conservation and emission reduction. However, in the implementation process, due to lack of global analysis and judgment of the process energy system and no adoption of an advanced operation control system aiming at energy conservation and consumption reduction, the papermaking process energy system is difficult to realize optimized operation, and the most advanced electric energy-saving protection technology is lacked, so that a great deal of energy is wasted. The DCS control system can effectively solve the problem. Various data collected by the system are calculated and sorted in time, and corresponding measures are taken to realize guidance and production management, so that the stability of product quality is ensured, resource waste caused by frequent start and stop is avoided, and the production efficiency and the product quality are greatly improved.

In order to enhance the market competitiveness of products and improve the product quality and lead the production to develop towards the direction of large-scale, large-scale and high automation, enterprises need to use an advanced automatic control system to realize the rapid and accurate control of the whole production process. For a low-speed paper machine, the control of the pulping process can utilize disc mill equipment to perform good treatment on fibers due to low yield; but is very difficult for high speed paper machines. At present, the control of the pulping process has 30 years of history abroad, and because the high bat width and high vehicle speed paper machines are installed and produced in a large scale in China only in the last nine years, the method is still in the exploration process on how to solve the problems of good pulping sales, product quality and energy consumption. The comprehensive pulp grinding process includes three modes of specific energy control, freeness control and specific energy-specific tooth load control. Each control mode has advantages and disadvantages, and is respectively long. The DCS control system can well meet the production requirements, the purposes of optimizing production, improving enterprise benefits, saving energy and reducing carbon are achieved on the basis of DCS, and the optimization design operation success has important practical significance on the optimization, cost reduction and efficiency improvement and informatization level improvement of the DCS of domestic papermaking enterprises.

Disclosure of Invention

The invention aims to adopt a DCS control system to reasonably control the pulp grinding concentration, the pulping current, the optimal pulp grinding concentration when the disc grinder is started, the core layer proportion, the surface layer proportion and the bottom layer proportion, optimize different pulp grinding power distribution and disc grinder series connection modes, and feed data back to the DCS for comprehensive treatment to obtain optimal data; finally, the DCS is adjusted according to the optimized data, different pulp grinding power distribution and disc grinding series connection modes are controlled, and the optimization and energy saving rate of the DCS for papermaking are reduced by 8% -15% and the carbon emission rate is reduced by 10% -20%.

The method for optimizing energy conservation and carbon reduction by adopting the DCS comprises the following specific steps:

(1) according to the raw material variety, the product performance characteristics, the speed of the paper machine and the like, the pulping concentration, the pulping current, the optimal pulping concentration when the disc mill is started, the core layer proportion and the surface layer and bottom layer proportion are reasonably controlled.

(2) And controlling different pulp grinding power distribution and disc grinding serial modes by using the DCS, and feeding back to the DCS for comprehensive treatment according to the obtained related data to obtain optimal data.

(3) And adjusting according to the optimized data, controlling different pulp grinding power distribution and disc grinding series connection modes, and realizing optimization, energy conservation and carbon reduction of the DCS for papermaking.

The raw materials in the step (1) are needle wood fiber, eucalyptus fiber and bagasse fiber, and the product is characterized by 14-38g/m²Pure wood pulp or mixed pulp high-grade household paper, the speed of a paper machine is 1000-2000m/min, the pulp grinding concentration is 4-12%, the pulp grinding current is 195-200A, the optimal pulp grinding concentration is 6-10% when the disc grinder is started, the pulp amount occupied by the core layer is 65-75%, and the pulp amount occupied by the surface layer and the bottom layer is 25-35%.

The disc mills in the step (2) are connected in series in a manner that two disc mills are connected in series or three disc mills are connected in series.

And (3) distributing the refining power in the step (2), wherein when two disc mills are connected in series, the refining power is controlled by the following ratio of 8-10: 10-8 of proportion distribution; when three are connected in series, the refining power is controlled in a ratio of 3-7: 4-7: 3-7.

The priority data in the step (3) is carried out according to the steps (1) and (2), the energy saving rate reaches 8-15%, and the carbon emission reduction rate reaches 10-20%.

The above analyzed data show that the load is larger than the tooth toughness, the disc mill has high pulp strength, the disc mill has good effect, the energy consumption is low, and the carbon emission is reduced.

In the implementation process, the DCS system can be adopted to implement the pulping power distribution and series connection mode, the fiber structure, the paper forming characteristics, the energy consumption and the carbon reduction condition are analyzed, and the whole disc mill series connection mode, the pulping strength and the pulping power distribution mode are further implemented.

According to the characteristics of the used raw materials and the characteristics of products, the invention adopts a DCS control system, and realizes energy conservation and carbon reduction by optimizing control parameters in a disc mill series connection mode.

Compared with the prior art, the method comprehensively utilizes and optimizes the DCS control system according to the relevant characteristic parameters and consumption data of the paper machine raw materials so as to achieve the optimal strength performance of paper under the condition of lowest energy consumption and realize the optimization, energy conservation and carbon reduction of the paper making system.

Detailed Description

The following examples are presented to further illustrate the methods described herein, but are not intended to limit the invention.

Example 1: eucalyptus fiber double-disc mill 25g/m²Mixed pulp high-grade paper for daily use

(1) The raw material adopts eucalyptus fiber, and the product is 25g/m²The mixed pulp high-grade household paper has the paper machine speed of 1500m/min, the set total pulping power is kept to be 150kwh/t pulp, the pulping concentration is 10%, the pulping current is 198A, the optimal pulping concentration is 9% when the disc grinder is started, the core layer in the core layer pulp distribution system occupies 70% of the pulp amount, and the surface layer and the bottom layer in the surface layer and bottom layer pulp distribution system occupy 30% of the pulp amount.

(2) The total power of the input refining is set by DCS to keep 150kWh/t of pulp, and a refining mode of double-disc mill series connection is adopted, wherein the proportion of refining power is 9:10 and 10: 9.

(3) And (3) analyzing the fiber form, physical property, energy conservation and carbon reduction, and analyzing the fibers distributed at different rates by using an FQA fiber analyzer. The power distribution proportion is 9:10, the arithmetic average length is 0.554nm, the mass average length is 0.720nm, the number of fine fibers is 18.30 percent, the cohesive force and the breaking length of the formed paper are 5.0 and 1.3 respectively, the wet weight is 8.5g, the energy saving rate is reduced by 9 percent, and the carbon emission rate is reduced by 11 percent; the power distribution proportion is 10:9, the arithmetic mean length is 0.556nm, the mass mean length is 0.715nm, the number of fine fibers is 18.05 percent, the cohesive force and the breaking length of the formed paper are 5.35 and 1.54 respectively, the wet weight is 8.2g, the energy saving rate is reduced by 10 percent, and the carbon emission rate is reduced by 12 percent; the second power distribution mode is illustrated, the fiber length is longest, the content of fine fibers is lowest, and the energy consumption is low.

(4) From this, the DCS precise control parameters were determined for the refining power distribution using 10: 9. the refining power is 150kwh/t pulp.

(5) Under the condition that the set total power is 150kwh/t, the eucalyptus fiber is adopted, and the concentration is 25g/m²Mixed pulp high-grade household paper adopts 10:9, a heavy-end-to-light pulping mode and a double-disc grinding serial pulping mode are adopted for the eucalyptus fibers, the set total pulping power is kept to be 150kwh/t pulp, the consumed energy is the lowest, and the paper forming strength is the best.

Example 2: bagasse fiber three-disc mill 38g/m²Mixed pulp high-grade paper for daily use

(1) The raw material adopts bagasse fiber, and the product is 38g/m²The mixed pulp high-grade household paper has the paper machine speed of 1000m/min, the set total pulping power is kept to be 160kwh/t pulp, the pulping concentration is 12%, the pulping current is 200A, the optimum pulping concentration of the starting-up of a disc grinder is 10%, the core layer in the core layer pulp distribution system occupies 75% of the pulp amount, and the surface layer and the bottom layer in the surface layer and bottom layer pulp distribution system occupy 25% of the pulp amount.

(2) The total grinding power input through DCS is set to maintain 160kWh/t of pulp, a three-disc grinding series grinding mode is adopted, and the grinding power distribution ratio is 3: 5: 7 and 7: 5: 3.

(3) and (3) analyzing the fiber form, physical property, energy conservation and carbon reduction, and analyzing the fibers distributed at different rates by using an FQA fiber analyzer. The power distribution proportion is 3: 5: 7, the arithmetic average length is 0.550nm, the mass average length is 0.723nm, the number of fine fibers is 18.44%, the cohesive force and the breaking length of the finished paper are 4.8 and 1.26 respectively, the wet weight is 8.7g, the energy saving rate is reduced by 8 percent, and the carbon emission rate is reduced by 10 percent; the power distribution proportion is 7: 5: 3, the arithmetic average length is 0.554nm, the mass average length is 0.710nm, the number of the fine fibers is 18.18 percent, the cohesive force and the breaking length of the formed paper are 5.22 and 1.45 respectively, the wet weight is 8.4g, the energy saving rate is reduced by 9 percent, and the carbon emission rate is reduced by 11 percent; the second power distribution mode is illustrated, the fiber length is longest, the content of fine fibers is lowest, and the energy consumption is low.

(4) The accurate DCS control parameters are determined by adopting the following steps for distributing the refining power: 5: 3. the refining power was 160kwh/t pulp.

(5) Under the condition that the set total power is certain 160kwh/t, bagasse fiber and 38g/m2 mixed pulp high-grade household paper are adopted, and the following components are adopted: 5: 3, a power distribution mode, namely a mode of firstly grinding the wood fibers in a heavy mode and then grinding the wood fibers in a light mode, and a mode of grinding the wood fibers in series by three disc mills, wherein the set total grinding power is kept at a certain 160kwh/t pulp, the consumed energy is the lowest, and the paper forming strength is the best.

Example 3: double-disc grinding 14 g/m for softwood fiber²Pure wood pulp high-grade paper for daily use

(1) The raw material adopts softwood fiber, and the product is 14 g/m²The paper machine speed is 2000m/min, the set total pulping power is kept at 140kwh/t pulp, the pulping concentration is 4%, the pulping current is 195A, the optimum pulping concentration of the starting machine of the disc grinder is 6%, the core layer in the core layer pulp distribution system occupies 65% of the pulp amount, and the surface layer and the bottom layer in the surface layer and bottom layer pulp distribution system occupy 35% of the pulp amount.

(2) The total power of the input refining is set by DCS to keep 140kWh/t of pulp, and a refining mode of double-disc mill series connection is adopted, wherein the proportion of refining power is 7:9 and 9: 7.

(3) And (3) analyzing the fiber form, physical property, energy conservation and carbon reduction, and analyzing the fibers distributed at different rates by using an FQA fiber analyzer. The power distribution proportion is 7:9, the arithmetic average length is 0.555nm, the mass average length is 0.726nm, the number of fine fibers is 18.10 percent, the cohesive force and the breaking length of the formed paper are 5.26 and 1.5 respectively, the wet weight is 8.1g, the energy saving rate is reduced by 13 percent, and the carbon emission rate is reduced by 16 percent; the power distribution proportion is 9:7, the arithmetic average length is 0.562nm, the mass average length is 0.703nm, the number of fine fibers is 18.01 percent, the cohesion and the breaking length of the formed paper are 5.44 and 1.64 respectively, the wet weight is 8.05g, the energy saving rate is reduced by 15 percent, and the carbon emission rate is reduced by 20 percent; the second power distribution mode is illustrated, the fiber length is longest, the content of fine fibers is lowest, and the energy consumption is low.

(4) From this, the DCS precise control parameters were determined for the refining power distribution using 9: 7. the refining power was 140kwh/t pulp.

(5) Under the condition that the set total power is certain 140kwh/t, the needle wood fiber, 14 g/m, is adopted²Pure wood pulp high-grade domestic paper adopts 9:7, a power distribution mode, namely a mode of heavy-before-light pulping for the needle wood fibers and a mode of double-disc grinding in series, is adopted, the set total pulping power is kept at a certain 140kwh/t pulp, the consumed energy is the lowest, and the paper forming strength is the best.

Example 4: softwood fiber three-disc mill 25g/m²Mixed pulp high-grade paper for daily use

(1) The raw materials adopt softwood fibers, the product is 25g/m 2 mixed pulp high-grade household paper, the paper machine speed is 1800m/min, the set total pulping power is kept to be 150kwh/t pulp, the pulping concentration is 6%, the pulping current is 197A, the optimum pulping concentration is 8% when the disc grinder is started, the core layer in the core layer pulp distribution system occupies 70% of the pulp amount, and the surface layer and the bottom layer in the surface layer and bottom layer pulp distribution system occupy 30% of the pulp amount.

(2) The total power of the input refining is set by DCS to keep 150kWh/t of pulp, and a refining mode of three-disc mill series connection is adopted, wherein the proportion of refining power is 8:9:11 and 11:9: 8.

(3) And (3) analyzing the fiber form, physical property, energy conservation and carbon reduction, and analyzing the fibers distributed at different rates by using an FQA fiber analyzer. The power distribution ratio is 11:9:8, the arithmetic mean length is 0.558nm, the mass mean length is 0.715nm, the number of fine fibers is 18.23%, the paper cohesion and the breaking length are 5.2 and 1.25 respectively, the wet weight is 8.4g, the energy saving rate is reduced by 10 percent, and the carbon emission rate is reduced by 12 percent; the power distribution ratio is 11:9:8, the arithmetic average length is 0.542nm, the mass average length is 0.726nm, the number of fine fibers is 18.11 percent, the paper forming cohesion and the breaking length are 5.3 and 1.49 respectively, the wet weight is 8.15g, the energy saving rate is reduced by 11 percent, and the carbon emission rate is reduced by 13 percent; the second power distribution mode is illustrated, the fiber length is longest, the content of fine fibers is lowest, and the energy consumption is low.

(4) From this, the DCS precise control parameters were determined for the refining power distribution using 10: 9. the refining power is 150kwh/t pulp.

(5) Under the condition that the set total power is 150kwh/t, the needle wood fibers and 25g/m 2 mixed pulp high-grade household paper are adopted, and an 11:9:8 power distribution mode is adopted, namely, a heavy-first and light-second pulp grinding mode and a three-disc mill series pulp grinding mode are adopted for the needle wood fibers, the set total pulp grinding power is kept at 150kwh/t, the consumed energy is the lowest, and the paper forming strength is the best.