压缩机变频能量调节控制冷库温度的研究

研究了用压缩机变频能量调节控制冷库温度方法，建立了控制系统的数学模型，并实现了微机监测与控制。     

基于PLC控制的闭式循环柴油机系统实现

柴油机排出的废气被回收到混合箱与纯氧气混合，形成“人造大气”，由此作为柴油机的进气，实现柴油机闭式循环工作．闭式循环柴油机系统中，控制系统基于可编程控制器设计，利用INTOUCH7．0编制的监控界面，实现了系统工作参数实时显示、采集及故障报警．     

压缩机排气压力的串级控制

根据控制对象的实际情况,参照现有的类似控制系统,提出了一种适合于压缩机性能测试系统运行过程的控制方案．根据控制过程中对控制精度的不同要求,分阶段采用不同控制算法,并就本串级控制系统的硬件配置和软件设计提出了具体方案．     

二级倒立摆的TS型逐级模糊神经网络控制

提出了一种逐级模糊神经网络控制法．该控制法通过采用Takagi-Sugeno型模糊神经网络控制器和逐级模糊控制规则,实现了二级倒立摆系统的稳定控制．模糊神经网络控制器的参数采用遗传算法分4步进行优化．实验结果表明,采用逐级模糊神经网络控制法,用20条模糊规则就可以实现二级倒立摆系统的稳定控制,并且控制效果佳,系统鲁棒性强。     

水电站AGC中负荷调节策略的研究

在水电站 AGC中采用了一种新的负荷调节策略 .AGC的负荷设定值直接下达给调速器 ,避免了脉冲设定方式的不足 ;采用过渡分配方案 ,避免了大负荷调节时出现电站出力缺额和小负荷波动时机组频繁调节 .实际应用验证了算法的有效性 .     

无级气量调节系统在往复压缩机的应用

与传统往复压缩机负荷调节方式比较,无级气量调节系统具有气量调节稳定、操作简单和节能效果明显等特点;详细介绍了该系统在某柴油加氢装置新氢压缩机组上的应用情况,通过与备用机组运行数据对比,充分表现出该系统在日常操作和节能等方面的优势.     

Hydro Com气量无级调节系统在横河DCS中的实现

加氢裂化装置压缩机组K401C新增加一套贺尔碧格公司生产的Hydro Com无级气量调节系统,以实现对压缩机的排气量0～100%范围内的无级调节,在降低系统耗气量的同时,消耗的功率也大幅度降低,从而达到节能降耗、减亏增效的目的.该系统的控制部分在现场DCS(YOKOGAWA CS3000)实现.     

基于PLC的步进电机控制方法研究

以德国西门子公司小型可编程逻辑控制器S7-300为中央处理单元,以步进电机作为控制对象,在介绍步进电机控制特点的基础上,重点研究了步进电机的控制策略,设计了控制系统的硬件方案,并编写了相应的控制流程,测试了实际控制效果。     

虚拟可编程控制器的控制逻辑设计

本文深入研究了PLC的编程输入逻辑和运行监控功能,设计出具有很强针对性的键盘识别逻辑,并在此基础上自主开发了虚拟PLC软件系统。     

Methods for large reciprocating compressor capacity control: A review based on pulse signal concept

Large reciprocating compressors are important equipment used in a wide range of process industries. Most of these compressors have huge power requirements and their capacity often needs to be regulated. Advanced technologies in compressor capacity control are effective approaches for saving large amounts of energy in process industries. This paper reviews the basic theories and the state of the art of the capacity control technologies. In particular, a compressor working procedure is first presented using an analogy to the pulse signal concept. Compressor capacity control methods are classified into pulse frequency modulation and pulse amplitude modulation from a perspective of pulse signal processing. The mechanisms and feasibility of some important methods, including dead volume variable control, partial-stroke and full-stroke suction valve opening, are reviewed. Based on the pulse signal concept, a duty cycle regulation method for capacity control is introduced, and the performance and implementation of the new method are compared with those of the existing suction valve opening methods. The duty cycle regulation method has integrated advantages over the other methods in terms of regulating precision, pressure stability, energy saving and reliability. All the suction valve opening methods can cause gas reflux, resulting in the so-called breathing effect. The breathing effect has negative effects on regulation performance and compressor security, which needs further investigation in the future.     

A novel flow control scheme for reciprocating compressor based on adaptive predictive PID control

In the process of capacity regulation of reciprocating compressor, the frequent change of inlet temperature and pressure makes the control of exhaust flow unsta...     

Research on optimization design method of actuator parameters with stepless capacity control system for reciprocating compressor

Actuator and hydraulic system parameters have great influence on the performance, safety and reliability of the stepless capacity control system of reciprocating compressor. Due to the diversity and complex relationship of parameters, traditional parameters selected and calculated based on feasibility can't make the system run efficiently, have limitations, and may have adverse effects on the system or compressor. Therefore, taking the spring stiffness of the actuator and the impact velocity of ejection, the inlet oil pressure of the hydraulic system, and the indicated power deviation of the compressor as objective functions, the multi-parameter and multi-objective optimization research of the actuator and hydraulic system with the stepless capacity control system based on non-dominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) is carried out.Based on fuzzy analytic hierarchy process(FAHP), the optimal solution is selected from the Pareto front, and compared with the traditional design value, the result is better than that obtained by the traditional design method.     

基于LabVIEW的大型往复式氢气压缩机组在线监测系统开发

往复式氢气压缩机组在线监测系统的开发主要是针对机组运行特点和现场要求而设计的,通过对机组进行在线监测,可以实时掌握机组运行状态和变化趋势,为实现预知维修及机组的高效运行提供了可靠保障。该开发系统介绍了利用虚拟仪器(VI)技术的软件开发平台LabVIEW,对大型往复式氢气压缩机组实施在线监测的整体设计方案和软件设计。     

基于模糊模式原理的空气压缩机故障识别

运用模糊诊断技术,对进气阀故障、排气阀故障、气缸泄漏等压缩机最常见故障建立了模糊故障诊断模型,并对实际的压缩机故障进行了诊断试验.试验结果表明,诊断结果的准确率和可信度较高.     

基于混沌理论的往复式压缩机故障诊断

实测某往复压缩机气缸在正常、活塞体松动及拉缸工况下的振动信号,计算信号的关联维数、Kolmogorov熵及最大Lyapunov指数,并证明信号具有非线性。用奇异值分解(SVD)降噪法对信号进行降噪,通过奇异熵增量曲线选择降噪阶次,用互信息法求最佳延时,并用假近邻域法求最佳嵌入维数,同时用G-P算法、小数据量法求出关联维数、Kolmogorov熵及最大Lyapunov指数。计算结果表明,3种工况下的往复压缩机气缸振动信号均为非线性混沌信号,故障越严重,信号表现出的混沌特性越明显,可依据混沌指标对往复压缩机气缸的状态进行监测。     

基于改进G-P算法的往复式压缩机故障诊断技术

采用基于经验模态分解的G-P算法提取往复式压缩机振动信号关联维数,建立了小波降噪模型,利用自相关函数法和伪相图法结合起来确定延迟时间,并采用EMD法计算嵌入维数,通过洛仑兹系统的仿真研究,将此法应用在往复式压缩机模拟故障试验中,诊断效果较好。     

基于时频图像GLCM-HOG特征的往复压缩机故障诊断

往复压缩机的故障诊断技术能够为工业生产提供有效保障,针对传统方法诊断准确率不高的问题,提出了一种基于振动信号时频图像灰度共生矩阵-方向梯度直方图(GLCM-HOG)特征融合的往复压缩机故障诊断方法.首先,采用小波变换的方法处理往复压缩机的振动信号,生成时频图像;其次,利用灰度共生矩阵(GLCM)和方向梯度直方图(HOG...     

基于多分量奇异熵的往复式压缩机故障分类

由于往复式机械振动信号的强烈非线性,对其进行特征提取较为困难.针对上述现象提出了一种计算信号多分量奇异熵的特征提取方法.通过局域波法提取出振动信号的各基本模式分量. 利用非线性动力学相空间重构理论适当选择嵌入维数与延迟时间,计算出往复机振动信号各基本模式分量的奇异熵值,提取出故障信息,并经自适应神经模糊推理系统(ANFIS)对故障特征进行分类.结果表明全部分类正确,达到了故障诊断的目的.     

Study on effect analysis and parameter optimizing of stepless capacity control system on reciprocating compressors

An improved model of reciprocating compressor operation cycle with a stepless capacity control system is presented and influence of the key parameters of the system is evaluated. In the stepless capacity control system of a reciprocating compressor,mechanical unloaders are used to partially hold suction valves open for a certain time during the compression stroke. The typical working process of the reciprocating compressor is changed by capacity regulation apparatus. However,some critical parameters like the hydraulic force acting at the unloader have not been rigorously studied in previous researches. Here an improved numerical model of a double acting reciprocating compressor under the control stepless capacity is proposed and verified by experimental trials. Numerical simulations are carried out to select and evaluate the acting force which definitely has an influence on indicator diagrams of compressors. It is observed that the optimized range of 350 N to 380 N is preferable for the unloader force such that the intensity of opening and closing impacts are minimized.