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氨氧化反应制取一氧化氮过程中,稳定氧化炉操作的关键因素是控制反应温度,本文主要讲述采用浙大中控的JX-300XP DCS图形化编程软件,实现氧化炉温度与氨空比串级变比值控制。系统形象直观,易于理解,控制效果良好,较好地体现了DCS在自动控制方面的优势。 相似文献
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《化工自动化及仪表》1977,(2)
(Ⅴ)高压液位自控由前述研制的液位计、调节器和调节阀组成高压液位自控系统,实现合成氨分离器的自动放氨和铜洗塔液位自动调节。一、自动放氨 1970年与吴淞化肥厂结合搞一氨分自动放氨,共同研究制订控制方案时,曾进行过比例积分(PI)连续调节和控制上下限的位式调节两种方案的比较试验。在连续调节时,Ti=∞,实际是一个比例调节系统,比 相似文献
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氨氧化炉是硝酸生产中的关键设备,保证制造过程中的工艺质量对其安全稳定运行具有重要意义。本文根据氨氧化炉的结构特点和图样要求,对氨氧化炉的制造工艺和质量控制提出方案。 相似文献
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DCS实现了浮法玻璃熔窑的自动控制,特别是对分区熔化温度自控和分小炉空/燃比双交叉控制,稳定作业,节能降耗,提高生产线自动化水平。 相似文献
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氨氧化炉是硝酸生产中的关键设备,保证其主要部件的制造质量,对氨氧化炉安全稳定运行具有重要意义。在对氨氧化炉主要部件制造时,根据结构特点和组装要求,进行胎具设计、弯制工艺试验、组焊和质量控制,制造的氨氧化炉在运行中氨的氧化率高,炉温实时检测稳定,各项工艺指标平稳。 相似文献
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氨氧化炉是硝酸生产中的关键设备,保证其主要部件的制造质量,对氨氧化炉安全稳定运行具有重要意义。在对氨氧化炉主要部件制造时,根据结构特点和组装要求,进行胎具设计、弯制工艺试验、组焊和质量控制,制造的氨氧化炉在运行中氨的氧化率高,炉温实时检测稳定,各项工艺指标平稳。 相似文献
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《硫酸工业》1960,(6)
沸腾炉内反应温度的自动控制,由于比手动控制更及时更精确,从而有效地稳定炉温,减少炉子结疤次数,提高了硫酸产量,改善了劳动条件。喷水冷却炉子是用适当调节喷水量来达到保持炉内反应温度恒定的目的。国内某些研究机关和工厂则多采用气动方案来使这种适当调节成为自动。这种方案的优点,在于高度可靠和可以将温度波动缩到最小。但由于结构复杂,价格昂贵(装一套至少4500元),安装调整维护都很困难,且所用的一些仪表设备,目前我国还远远不能满足需要。因之试制一种结构简单、价格便宜的自动调节喷水量的设备就非常必要了。由于沸腾炉的热容量较大,采用一种两位电动控制的方案是可以期望得到完全满意的效果的。 相似文献
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由于常规PID控制方式对非线性、大滞后对象难以进行有效的控制,模糊控制具有很好的动态特性,所以结合常规PID和模糊控制的优势设计了参数自调整Fuzzy-PID复合控制器。通过模糊推理实现参数自调整,以使控制器能够适应不同对象和对象的不同状态。采用模糊推理的方法完成两种控制方式的平稳过渡。对某制药厂连消温度的控制表明,该控制器可以大幅度提高控制精度和缩短系统响应时间,从而避免了染菌事故的发生,提高了发酵单位。 相似文献
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ADAPTIVE FUZZY MODEL BASED PREDICTIVE CONTROL OF AN EXOTHERMIC BATCH CHEMICAL REACTOR* 总被引:1,自引:0,他引:1
An adaptive fuzzy model based predictive control (AFMBPC) approach is presented to track the desired temperature trajectories in an exothermic batch chemical reactor. The AFMBPC incorporates an adaptive fuzzy modeling framework into a model based predictive control scheme to derive analytical controller output. This approach has the flexibility to cope with different fuzzy model structures whose choice also lead to improve the controller performance. In this approach, adaptation of fuzzy models using dynamic process information is carried out to build a predictive controller, thus eliminating the determination of a predefined fixed fuzzy model based on various sets of known input-output relations. The performance of the AFMBPC is evaluated by comparing to a fixed fuzzy model based predictive controller (FFMBPC) and a conventional PID controller. The results show the better suitability of AFMBPC for the control of highly nonlinear and time varying batch chemical reactors. 相似文献
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以螺杆挤出机温控系统的扰动多、非线性、时变以及大滞后的特性,研究得到了智能化的控制算法,对于现场无法充分预料的情况,这种温度控制系统能够发挥重要的作用。使用Zig Bee无线传感技术可实现温度监控的远程操作,提升检测效率和水平。对远程无线温度控制系统的硬件系统进行了设计,对CC2430射频主控芯片的外围电路、温度传感电路以及温度控制电路进行设计。针对螺杆挤出机温度控制系统进行实例分析,研究结果表明:使用常规PID控制器,在阶跃信号和脉冲干扰信号作用下,系统超调量和稳定时间不能够满足螺杆挤出机温度控制的要求。使用模糊PID控制器,相比常规PID控制器的超调量和稳定时间要明显增强。以尼龙6/Ca Cl2复合材料挤出为例,分别使用常规PID控制算法和模糊控制算法进行对比分析,研究温度控制精度对产品成型质量的影响。在模糊控制算法下,三种产品(温度设置分别为240,260,280℃)的缺口冲击强度合格率比较使用常规PID控制算法时提高了6.87%,弯曲应力合格率、断裂伸长率合格率、拉伸强度合格率分别提高了8.67%,9.33%,8.77%。 相似文献
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针对被控对象惯性延迟大、被调节信号反馈慢的特点,笔者采用恒流量温度控制方案对原聚合釜温度控制系统的单回路控制方案进行了改造,应用模糊-PID控制使聚合釜夹套水温与聚合反应温度保持较小的温差,将调节温度的过程变得更加平缓,经过实际应用取得了令人满意的效果. 相似文献
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模糊自整定PID控制器的设计与仿真 总被引:7,自引:2,他引:5
制浆碱回收蒸发工段第一步就是通过蒸汽将黑液进行浓缩,蒸汽的温度控制效果对后续燃烧工段和苛化工段起着举足轻重的作用。主管道蒸汽温度控制通常具有大惯性、大延迟、时变等特性,采用常规的PID控制难以获得满意的控制效果。为此,提出一种模糊自整定PID控制器的串级控制算法,该算法很大程度上提高了主蒸汽温度的控制品质。针对隶属度函数对模糊推理模型的精度影响和控制算法的特点编写了模糊规则,并且根据动态性要求的不同,分两种情况进行比较。仿真表明,模糊自整定PID串级控制算法在整体性能上要优于传统PID串级控制。 相似文献
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Temperature difference control (TDC) schemes can clearly suppress the adverse influence of pressure variations on product quality control of various distillation columns (DCs) by employing temperature differences (TDs) between the sensitive stage temperature (TS) and reference stage temperature (TR), i.e., TS-TR, to infer the controlled product qualities. However, because the TDC scheme has failed to specially take the corresponding relationship between the TD employed in each control loop and the controlled product quality into account, it may suffer from relatively large steady-state errors in the controlled product qualities. To address this problem, an enhanced TDC (ETDC) scheme is proposed in the current article, in which an enhanced TD (ETD), i.e., TS-α×TR, is employed to replace the conventional TD for each control loop. While the locations of the sensitive and reference stages of the ETD are respectively determined according to sensitivity analysis and SVD analysis, the adjusted coefficient α is set to be the ratio between the averaged absolute variation magnitudes (AAVMs) of the TS and TR so that the relationship between the TS and TR can be appropriately coordinated. With reference to the operations of three different distillation systems, i.e., one conventional DC distilling an ethanol (E)/butanol (B) binary mixture, one conventional DC distilling an E/propanol (P)/B ternary mixture, and one dividing-wall distillation column distilling an E/P/B ternary mixture, the performance of the ETDC scheme is assessed by compared with the conventional TDC scheme and the double TD control (DTDC) scheme. The dynamic simulation results show that the ETDC scheme is better than the conventional TDC scheme with reduced steady-state errors in the controlled product qualities and improved dynamic responses, and is comparable with the DTDC scheme despite the less temperature measurements are employed. 相似文献
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S. Kanagalakshmi D. Manamalli M. Mohamedrafiq 《Chemical Engineering Communications》2016,203(4):452-462
The proposed real-time multimodel for the injection molding process mainly contributes to the barrel temperature control. Good control of the plastic melt temperature is very important for injection molding in reducing the operator setup time, ensuring product quality, and preventing thermal degradation of the melt. The controllability and set points of the barrel temperature also depend on the precise monitoring and control of the plastic melt temperature. Motivated by the practical temperature control of injection molding, this article proposes a multimodel-based proportional integral derivative (PID) control scheme in real-time and the simulation studies of the PID, fuzzy, and adaptive neuro fuzzy inference system (ANFIS) control schemes. The injection molding process consists of three zones, and the mathematical model for each zone is different. The control output for each zone controller is assigned a weight, based on the computed probability of each model, and the resulting action is the weighted average of the control moves of the individual zone controller. 相似文献