| DaQu is an essential raw material for Chinese Baijiu production in Chinese Baijiu enterprises.For a long time,the production of DaQu is mainly manual operation.Workers rely on many years of production experience to ensure the temperature and humidity of the whole DaQu workshop through turning DaQu,stacking DaQu and switching windows,which not only increases the labor intensity of workers,but also reduces the production efficiency.In addition,the temperature and humidity parameters of DaQu workshop environment are different in different fermentation periods,and the accurate measurement can not be guaranteed.Finally,affected by seasonal factors,DaQu can only be produced in spring and autumn.Therefore,based on the DaQu making process of a Chinese Baijiu enterprise,the structure of the DaQu workshop is optimized by simulation analysis,and the control system of the DaQu workshop is designed.and finally meets the requirements of DaQu workshop temperature at the target temperature of ± 0.5 ℃,realizes the transformation of DaQu workshop from traditional production to intelligent information production,and also improves the quality and production efficiency of finished DaQu.The main contents of this paper are as follows:(1)Simulation of temperature field in DaQu workshop:Firstly,physical and chemical parameters such as density,heat capacity and thermal conductivity are calculated through the production manual of DaQu and the literature;then the complex door and window structure in experimental DaQu workshop is simplified,the three-dimensional model of DaQu workshop is constructed,and the grid division of DaQu workshop structure model is completed;Next,the steady state simulation of inlet and outlet and DaQu with or without gap is carried out by using DaQu as heat source,By analyzing the velocity field and temperature field of simulation results,the scheme of outlet air gap above the bottom inlet is selected as the final DaQu workshop structure;Finally,by comparing the unsteady simulation results of different initial DaQu workshop temperature and different inlet wind speed,it is determined that 2 m/s is the best speed of inlet wind.(2)Control system design: through the analysis of the production data of the traditional DaQu workshop,the accuracy of the single DaQu workshop target curve is improved by realizing the piecewise fitting of the single DaQu workshop target curve;then the temperature and humidity weight calculation algorithm is proposed to improve the accuracy of the temperature and humidity data;The optimization algorithm of the curve is designed,which effectively uses the historical production data and reduces the deviation between the control curve and the ideal DaQu workshop curve;Next,the flexibility and robustness of the control system are improved by introducing the grade value into the fuzzy PID control;Finally,the human-computer interaction function module is designed to optimize the control process.(3)Engineering implementation and testing of the control system:optimizing the structure of the DaQu workshop and implementing its construction according to the simulation results of the temperature field;designing a sensor network to collect the temperature and humidity data of the DaQu workshop through Modbus RTU mode;realizing the real-time data acquisition and the precise control of the equipment by programming such programs as polling data acquisition,database interaction and fine-tuning fuzzy PID control;realizing the effective display,operation and critical condition alarm of the production data through the touch screen function interface and the design of the alarm program,thus improving the man-machine interaction ability of the system;The results of the final control system show that the temperature control in the DaQu workshop meets the requirements of ±0.5℃,and the finished product DaQu color and rich flavor,and meets the requirements of the Chinese Baijiu enterprises for the color and quality of the DaQu. |
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