The Research Of The Veneer Drying Energy-saving Monitoring System Based On PLC

The research content of the thesis comes from the science and technology support project "energy saving and environmental protection of artificial board manufacturing technology research and demonstration"(20BAD24B0304) of The 12 th Five Year Plan, and completing the work with the project funding. This system adopts PLC and touch screen control technology, not only improve the automation level of veneer dry production, but also to achieve the monitoring of energy consumption of the veneer dry, innovative and improve the economic benefit of enterprise production, so it has good practical value.At present, with the rapid development of wood industry, the average annual total production of plywood keeps high tendency, veneer is the intermediate product in the production process of plywood, so the supply and demand of veneer remained at a high level in the production process of plywood. As the substantial increase in plywood production improving the economic benefits, the energy consumption of the production process is increasing day by day,most of the energy consumption in the wood industry was used for drying wood. Veneer drying,a necessary plywood production process of plywood production, most of the energy consumption of the whole plywood production process was used for it, in the western developed countries veneer drying consumed 60%~70% of the total energy consumption of plywood production process, while in China accounted for about 80%. In response to the national call of the green production and low carbon environmental protection, aiming at the increasingly serious energy crisis, enterprises pay more and more attention to how to improve the efficiency of energy-using and reduce the waste of energy.Aiming at the situation of high energy consumption and lag in technology, this paper analyzes the present situation of domestic production of veneer drying, energy saving technology status at home and abroad of veneer drying, putting forward the waste heat recovery system and the steam cascade utilization, in order to improve the situation of large energy waste of the production process, and on the basis of the analysis the research group developed a set of energy-saving monitoring system of veneer drying based on PLC. This system uses OMRON’s C200 HE PLC as the main control device, using temperature and humidity sensor, a gas flow sensor, the on-line detection device of steam temperature and pressure sensor, to achieve the real-time detection of the process parameters. By the A/D 、 D/A conversion module of PLC to realize the information data processing of analog and digital, with a combination of touch screen technology to achieve real-time display of the parameters and good human-computer interaction.The part of software design, including manual/automatic control program and touch screen man-machine interface design. Through the man-machine interface can choose the control mode of the system, the real-time adjustment of process initial parameters, real time calculation and display the relevant technical indicators, clear and intuitive to reflect the situation of energy consumption and energy efficiency. In addition, the use of touch screen technology can also alarm and record the possible accidents, providing convenience for the staff to monitor the production process.