Design Of Control System For Saving Energy Of Dye And Dry Process

Energy cost of printing and dyeing in our country accounts for 2%~3% of the total cost in the 1950s and this percent has presently increased to 10%～15% or even higher. One important reason for energy waste in printing and dyeing is due to the fact that drying process is mainly guided by experience and lack of control management, resulting in over drying of cloth.Present paper analyzed the measurement of moisture and resistance method was brought forward as the measurement of sensor. According to the properties of resistance method, electro-circuits for sensor measurement and signal management were designed.Due to the special working environment of printing and dyeing industry such as high temperature, high humidity, high electromagnetism interference and high static electricity disturb, Simens S7-200 series PLC controller was chosen. System software was also designed according to the hardware of the control system.As about arithmetic of the control, it is difficult to obtain precise mathematic model due to the nonlinearity and uncertainty of the drying controlling system. What's more, a fixed PID parameter can't meet the need of ever changing model parameters. So, a good control effect can't be reached by using the method based on a regular PID parameter. Aim at the problems in drying process control, a fuzzy PID control project was advanced.The whole system works well in real application and PLC was replaced by ARM as main controller of the system, accompanied with ARM system hardware design and software design.Results of real application showed that this control system is proved to be good real-time performance, quick in response, stable during work, reliable and profitable in saving energy or using energy reasonably. It can also reduce energy consume and thus generate considerable profit, endowing it a wide market in the whole printing and dyeing industry.