Application of Siemens Simic control system in pap

2022-07-23
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Application of Siemens Simic control system in papermaking production line Fujian Quaker Paper Co., Ltd., located in Nan'an City, Quanzhou, Fujian Province, is a newly established paper company. The 2400/150 white board production line is the first production line it has invested in. From the perspective of production capacity and equipment level, the board production line is the first-class level among similar equipment in Fujian Province, and is also one of the few domestic equipment in the country. The mechanical equipment is manufactured by Hubei Shashi Light Industry Machinery Co., Ltd

as an OEM partner of Siemens, shashikete electric complete set Co., Ltd. has been committed to the development and application of Siemens industrial control products in the paper industry. We took part in the competition with the integrated control system scheme of Siemens products. Relying on the good reputation of Siemens products and the good performance of Kete company in the paper industry, with the strong support of Siemens, we won the bid in one fell swoop to undertake the control system and electrical drive of the production line

2 system introduction

(1) the main machine of the paperboard production line is composed of several processes, such as the section (four superimposed top), the pressing section (compound K press plus roll pressing), the drying section, the coating section, the finishing section, and the finishing section, to complete the whole process from pulp to high-quality finished paperboard. The total length of the machine is about 150 meters. The main control objects are the 38 main transmission points (variable frequency drive) of the production line and the auxiliary control (including hydraulic and pneumatic control) of the paper machine and coating machine

(2) according to the process requirements of the production line, our company has launched Siemens variable frequency drive and control system with PROFIBUS-DP communication as the core. The master station adopts S7-300 series cpu315-zdp, and the engineering frequency converter master driv-er is connected to DP bus through CBP communication board. The field operation and signal acquisition are realized through et200m remote i/o, and connected to DP bus through im153. The system is equipped with 38 CBP slave stations and 12 eth00m slave stations, with about 500 analog input/output and switching value input/output points

3 composition of control system

according to the requirements of users, we have designed the system into a three-level automatic control system structure integrating monitoring, control and drive based on the principles of advanced technology, safety and reliability, convenient operation, powerful function and scalability

3.1 monitoring layer: PC machine loads STEP7 and WinCC, and connects to the MPI communication port of CPU through MPI card

(1) carry out hardware configuration, communication setting, programming, testing and monitoring through step7v5.0

(2) monitor and manage the whole control system through WinCC:

a. animation display of the whole production line

b. system operation: operation of actuator and process parameter setting

c, display bar graph

d, display trend chart

e, alarm function

f, printing function

g, formula management

h, online help

3.2 the control layer

cpu315-2dp completes the coordinated control of the whole system. Its integrated DP communication port is connected to all DP slave stations through special cables. Profibus-DP Field bus runs through the whole control room and production line, making the system an organic whole

3.3 drive layer

(1) frequency converter: drives 38 main drive motors, each transmission point adopts encoder feedback and speed closed-loop control

(2) if MC wants to have a foothold in the new material market, C control cabinet: complete the control of all auxiliary drive motors

(3) solenoid valve, proportional valve, etc. are used to control the action of each actuator and various process variables. As for temperature 1, the intermediate value is taken as the goodness and flow

Jinan new era assay instrument Co., Ltd. has produced experimental machines for many years.

4 functions completed by the control system

4.1 logic control

conventional switching value i/o control

4.2 coordinated control of speed and torque

(1) the transmission system of the papermaking production line has high requirements for speed control. On the one hand, each transmission point is required to have a high speed stability accuracy, and on the other hand, a certain speed difference must be guaranteed between each transmission point according to the process requirements. Therefore, we guarantee the accuracy of the set value through 16 digit setting in the PLC program, After precise dynamic performance adjustment of the driver, it can meet the requirements of stable speed accuracy; In addition, a precise speed chain function is designed in the program. The proportional multiplication method is adopted. The speed chain can be connected in series or in parallel according to the technical requirements in the program. The proportional value is power-off memory, and the operator can accurately adjust the speed difference as required

(2) another feature of the production line is that the working modes of the transmission points are diversified. Some work in the speed mode, some in the torque mode, and some in the current mode. The conversion and control of all these working modes are completed through the PLC program

4.3 process quantity control

is mainly analog i/o control and has the functions of low cycle load cycle, deformation cycle and displacement cycle, such as temperature, pressure, flow, etc

4.4 whole machine coordination and interlocking control

the papermaking production line is an organic whole. In addition to the main machine, there are a large number of peripheral equipment, such as pulping, boiler, vacuum water absorption system, coating preparation, hydraulic pressure, compressed air system, etc. all processes and control equipment are interrelated and affect each other. The control system collects the on-site detection signals and interlocking signals in real time through et200, and sends them to the CPU through the bus for program processing, The output results are sent back to the field actuators from the bus to complete the coordination and interlocking control of the whole system

4.5 upper computer monitoring

the paper machine needs to change the product variety frequently in production. Changing the product variety once means a comprehensive adjustment of process parameters. This process often takes several hours. In order to solve this problem, in addition to the conventional monitoring function in the upper computer, we also designed a special formula function according to the characteristics of the paper production line, That is, when the paper machine is in normal operation under a production state (a certain speed, a certain paper grade, etc.), all the main process parameters and set values are recorded and stored. When this paper type needs to be produced next time, these parameters and set values are sent to the control system at one time. This can directly switch the paper machine from one working state to another, greatly reduce consumption and improve production efficiency

5 application experience

(1) in the early stage of commissioning, when downloading the hardware configuration, there was a phenomenon that the hardware configuration could not be downloaded. Later, under the guidance of relevant Siemens experts, this problem was solved by improving the system grounding, which made us realize the electrical control

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