基于PID的饲料制粒调质温度控制系统设计与试验  

Design and test of the temperature control system for the feed pelleting and conditioning based on PID

作　　者：王红英[1] 范佳宇 王粮局[1] 吴俊华 王威 杨成才 WANG Hongying;FAN Jiayu;WANG Liangju;WU Junhua;WANG Wei;YANG Chengcai(National R&D Center for Agro-processing Equipment,College of Engineering,China Agricultural University,Beijing 100083,China)

机构地区：[1]中国农业大学工学院,国家农产品加工技术装备研发分中心,北京100083

出　　处：《农业工程学报》2023年第1期1-8,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2021YFD1300300)。

摘　　要：为解决颗粒饲料在制粒过程中调质温度依赖人工辅助控制问题,该研究设计了基于PID控制算法的调质温度控制系统。采用开环阶跃响应法建立电动比例调节阀与调质温度之间的控制模型。为了得到最优的PID控制参数(比例系数K_(p)、积分系数T_(i)、微分系数T_(d)),通过Simulink仿真试验对比了Ziegler-Nichols整定法、衰减曲线法和临界比例度法的PID响应曲线,确定PID最优控制参数为K_(p)=52.7,T_(i)=6.4,T_(d)=1.6。对小型制粒机调质温度控制系统进行试验,选用哺乳母猪配合粉料,调质温度分别设定为75、80和85℃,稳定后的调质温度均能维持在设定范围内;选取调质温度为80℃进行稳定性试验,每1 min记录调质温度,整个试验过程中调质温度基本稳定在(80±1)℃范围内,调质温度平均相对误差小于1%,调质温度变异系数小于0.5%,系统温度控制稳定,可自动采集制粒生产数据,实现了制粒过程中调质温度的快速响应和实时控制。研究结果可为颗粒饲料制粒机的自动化控制提供参考。Conditioning temperature is one of the key factors in the quality of feed pellets during feed processing.It is a high demand to maintain the constant conditioning temperature.Specifically,too high conditioning temperature can lead to the inactivation of heat-sensitive ingredients,such as probiotics,whereas,too low conditioning temperature can be found in the incomplete sterilization of the starch paste.In this study,a Proportion Integration Differentiation(PID)-based control system was developed to control the conditioning temperature of the feed pellets during processing.The whole unit consisted of a control system,steam piping,and a pelletizer.The control system with a Programmable Logic Controller(PLC)and a touch screen was utilized to control the start/stop of the pelletizer and the opening of the electric regulating valve.The process parameters of the pelletizer were also automatically collected,according to the given time interval.A temperature sensor was installed at the outlet of the pelletizer.The PT100 temperature sensor was used to collect the conditioning temperature of the material at the outlet of the temperature in real time.Subsequently,the collected data was fed back to the PLC.The PID closed-loop control algorithm was utilized to calculate the electric actuator again after the appropriate adjustment of the parameters.The stable control of tempering temperature was realized to change the steam flow into the temperature.A systematic analysis was made to obtain the convective heat exchange process between the mixed feed and steam at temperature.A theoretical model of heat transfer was established to obtain the specific parameters using the step response curve method.After that,the data curve was processed(R^(2)=0.976)to obtain a control model between the electric proportional control valve and the tempering temperature in the control system.As such,a large influence of special points was avoided on the experimental data after processing.Furthermore,the simulation analysis was carried out to determi

关 键 词：生产控制 品质 PID 调质温度 颗粒饲料 小型制粒机 

分 类 号：S816.8[农业科学—饲料科学]