【作者】 高晓阳；

【导师】 刘荣堂；

【作者基本信息】 甘肃农业大学 ， 草业科学， 2010， 博士

【摘要】 甘肃省河西地区是我国重要的优质大麦产地之一,大麦麦芽质量是影响麦芽价格的重要因素,提高麦芽加工工艺技术和加工质量成为制麦企业发展的关键。本研究以甘肃省河西地区生产和种植的大麦主要品种甘啤4号,为干燥加工原料。研究沿用合作企业的热风型干燥方式,并以项目组实验研究确定的麦芽最佳干燥工艺,作为麦芽干燥温度控制研究的技术基础。本研究以大麦麦芽干燥加工系统为研究对象,针对甘肃大麦麦芽企业现有干燥工艺与装备,综合应用系统工程原理、自动控制和智能控制理论,集成运用流体数值模拟技术、传感技术、电子技术、单片机及接口技术、微机控制技术、模糊控制技术、神经网络技术、虚拟仪器技术和电机调速技术等多种技术手段,结合传热传质学与生态能值分析方法,进行了干燥控制的系统性研究,取得了以下主要研究成果：1以干燥室为研究对象,进行了干燥热能计算。结果表明,其圆柱型热风混合干燥室平均脱水量为1330kg/h,耗风量216384m3/h。另外,热量衡算结果表明,该干燥系统小时需热量为11.81×105kJ/h。利用ANSYS软件进行计算机模型模拟和数值仿真,流体动力分析结果为,在进入干燥热风混合室进风口后,风速逐渐下降,但接近排风口处时又有回升,在进风口处风速为最大；并在混合室的左右两侧形成两个大的旋涡。在整个区域风压分布变化明显,当风速较小时风压降低明显。此外,对风机叶片孤立翼型的升力和阻力进行流场模型模拟,结果分析表明,在孤立翼型的上表面即翼型的迎风面出现最大流速。模拟实验说明通过改变风机的翼型参数,可减小翼型阻力,提高风机通风效率。2本研究进行了干燥试验研究,建立了干燥炉热空气风速、麦层厚度和麦层空气阻力的数学模型为P=31.5He238v,P-麦层空气阻力(mmH2O),V-风速(m/s),H-麦层厚度(m)。3麦芽干燥工业生态系统的能值分析结果表明,中川麦芽厂能流循环指数(CREF)和有机能投入相对较低,说明该系统以无机投能为主,工业化程度高。能值投入率(EIR)值总体处于较低水平,在0.3-0.7间波动。表明中川麦芽厂的干燥麦芽生产成本低,市场竞争力较强。能值产出率(EYR)总体上处于波动上升态势,表明甘肃中川麦芽厂的能源利用效率在逐年提高,经济竞争力持续上升。中川麦芽厂环境负载率(ELR)由2005年的2.62×106增至2009年的3.94×106,总体也呈波动上升趋势,表明对环境的压力逐步增加,发展主要依靠输入能值和不可更新资源的消耗。4本研究设计了基于模糊控制的大麦麦芽干燥温湿度控制系统。设计了以AT89C51单片机为控制核心的系统硬件电路,选用AD590温度传感器和HS1101湿度传感器,设计了放大与调理电路,扩展了A/D转换电路和键盘与显示电路,研发了模糊控制算法、控制表和模糊控制器,实施了单片机变频控制鼓风机运行,和继电器控制排风机工作。配置了AT89C51内部RAM单元,设计了控制系统的汇编语言主程序和数据采集存储、数值滤波、模糊控制等6个子程序。MATLAB软件模拟和温湿度控制实验的运行结果表明,该系统控制稳定,控温范围0-99℃,温控精度达±0.25℃,平均误差≤±0.2℃,置信系数Kt=4.3(P=0.095),满足控制精度要求。实验结果表示,排潮热风平均湿度的标准偏差<±0.30%RH。5本研究适应企业微机化管理,设计了基于LabVIEW的麦芽干燥微机测控系统。设计了该虚拟仪器系统的硬件电路和系统软件,如数据采集程序、基于Lab VIEW的神经网络PID控制虚拟程序等。系统LabVIEW仿真实验表明,神经网络PID控制具有很好的动静态特性,控制器运行稳定。基于LabVIEW的麦芽干燥神经网络PID控制系统测试实验,结果表明,温度控制的平均误差≤±0.2℃,控制系统稳态精度高,系统超调较小。6设计的基于单片机和微机的干燥变频调速控制系统,3年试验运行表明,每生产1吨麦芽平均节水1.5吨、煤0.050吨,电50KWh。按公司年产麦芽2.0万吨计,每年仅干燥工段节电94.6万KWh,节能量(折算为电能)约232万KWh。麦芽生产每年可节约标煤1129吨。同时,麦芽干燥系统改造前后相比,综合节能14%因此,该研究提升了大麦麦芽干燥加工智能化和自动化水平,并具有节能和生态效益。更多还原

【Abstract】 The Hexi Corridor district of Gansu is one of the best barley bases in China. The quality of barley malt plays an important role on its price. Therefore, the key development factor of the barley malt plant relies on promoting drying process technology and drying malt quality.In this paper, Ganpi No.4 is selected as the drying raw material, because it is the main strain of barley planted in the Hexi Corridor. The hot wind drying method is used in the cooperative plant of the research project, and the optimum drying process is applied as the technological basis of study, which was sought for many experiments by another research team of our project.The project aims to set up barley malt drying system. Under the condition of the present drying process and the plant’s equipment, systematic control study and experiments were implemented with the emergy analysis method and heat transmission technology, based on the important principles of system engineering, automatic control and artificial intelligent control theory, and on the integrated technology of fluid numerical analogy, sensing and measurement, electronics, microcontroller and interface techniques, microcomputer control, fuzzy control, neural network control, virtual instrument, and motor speed control.The main results of this experimental study are as follows.1. While the drying room is chosen as a study object for the heating energy calculation, the results showed that the cylinder type of drying house has the dewatering capacity of 1330 kg/hr, and consumes 216384 m3 of wind volume every hour. The calculated results of energy balance showed that the drying system needs heat energy 11.81×105 kJ/h (kilojoules per hour).The computer modems analog and numeric simulations were completed by the software of ANSYS for the fluid dynamic analyses. The results showed that after drying winds enter the drying house, the velocity decreases gradually and has a little of increase where near the outlet, at the same time, two large vortexes are formed in the both left and right sides of the room. The maximum velocity occurs in the entrance. Therefore, it has been demonstrated that through altering the wing parameters of air blower, the resistant forces of wings will be reduced and also blowing efficiency will be improved.2. Barley malt drying experiments were carried out in a drying furnace, and a mathematical matrix, P=31.5He2.38V, was built up in relation to malt thickness (H, meter) and wind speed (V, m/s) as well as the air drag of malt (P, mmH2O).3. In the Zhongchuan Barley Malt Company, the emergy analyses conclusions of the drying ecological system follows. First, the circulation ratio of energy flow (CREF) and organic energy input are relatively lower, which shows the main input is inorganic energy and the industrialized level is high. Second, the emergy investment ratio (EIR) is generally lower, between 0.3 and 0.7, which means that the malt cost is lower and is strongly competitive. Third, the emergy yield ratio (EYR) trended upwards generally for these years, which shows the energy utilization efficiency is higher and economic competition power rises up continuously. Fourth, the environmental loading ratio(ELR) increases from 2.62×106 (in 2005) up to 3.94×106 (in 2009), which shows that pressure to the environment increases gradually and the plant development depends mainly on the energy input and consumption of unrenewable resources.4. A barley malt drying temperature and humidity control system design based on fuzzy logic control theory is introduced in this paper. The system hardware circuits with the AT89C51 controlling core were designed. The amplifying and regulating circuits were also designed attached with AD590 temperature sensors and HS1101 humidity sensors. A/D converter, keys and displaying circuit were expanded. Fuzzy algorithm, fuzzy control table and fuzzy controller were developed. Single-chip microcontroller controls frequency converter to drive air blower operation. In addition, inner RAM units of AT89C51 were distributed, and assembly language main program and 6 subprograms, such as data sampling and storing subprogram, digital filter subprogram, and fuzzy control subprogram etc., were developed accordingly.The results of the MATLAB analogue and control experiments showed that the control system has better stability and reliability, and has reached the accuracy requirements. The controlled temperature range is from 0 to 99℃, accuracy errors are between-0.25℃and +0.25℃, and average differences are less than±0.20℃in the confidence coefficient Kt of 4.3 (P=0.095). Additionally, the average relative humidity standard deviation (mean square error) is less than 0.30.5. To adapt to the microcomputer management of the plant, then a computer control drying system based on LabVIEW software of virtual instrument (VI) was designed. The hardware circuits and virtual instrument software, as data acquisition sub-VI and neural network PID control sub-VI etc., were developed. System simulation experiments showed that neural network PID control has good stationary and dynamic characteristics, and the system runs steadily.After the barley malt drying neural network PID control system based on LabVIEW experiments had been completed, the initial conclusions were that the average errors of the temperature control system are less than±0.20℃, and that the system has a highly stability and small overshoot.6. For three years of drying test operations on the microcontroller and microcomputer control system designed, with which the frequency converter is coupled with the driving motor, it has been shown that for each 1 tonne of barley malt production, an average of 1.5 tonne of water,0.05 tonne of coal, and 50 kW-hr of electricity are saved. Accounting for 20 ktonne of annual production of the barley malt plant, the drying process saves 946000 kW-hr of electricity and 2320000 kWh electric energy (all energy savings are converted to electricity quantities). Malt production saves 1129 tonne of standard coal per year. Compared to the former system, comprehensive energy saving is more than 14%.Therefore, this practical and experimental study improves the automation and intelligent levels of barley malt drying, and has the functions of energy saving and ecological efficiency.更多还原