基于混沌分形理论的特征提取技术在气阀故障诊断中应用

气阀故障是往复压缩机的故障率最高的部件,如果气阀故障发现不及时很容易造成气阀串气,进而引起往复压缩机的压缩效率大大降低,如果阀片断裂脱落甚至会造成拉缸的恶性事故。针对目前往复压缩机气阀故障诊断无法评估损坏程度问题,本文结合混沌分形理论,提出了采用基于混沌分形理论的自动识别方法对气阀早期故障冲击变化信号进行特征提取,实现了气阀故障的早期预警。     

基于瞬时转速波动率的内燃机故障诊断方法研究

内燃机的瞬时转速包含着各个缸燃烧状态的重要信息,可以用于分析各个缸做功状态,诊断缸体点火相关故障,如燃料泄漏、气门泄漏和点火异常等故障。通过模型建立从理论上分析瞬时转速与气体压力扭矩、往复惯性力扭矩和阻力矩之间的关系,提出4个特征参数表征瞬时转速波动率波形及谐波特征,并通过仿真数据和实测故障数据证明瞬时转速波动率对于分析诊断内燃机点火故障的有效性,实现内燃机点火状态的早期预警。     

HCL冷凝装置压缩机气阀故障分析及改造

对HCL压缩机气阀故障的原因进行了分析,针对影响压缩机气阀安全平稳运行的瓶颈,对气阀进行了改造,降低了HcL冷凝装置压缩机气阀检修的频次,确保了装置安全平稳运行。     

往复式压缩机气阀可靠性分析

以往复式压缩机气阀工作原理为基础，结合压缩机的实际运行情况，对压缩机气阀的可靠性进行研究分析，并对气阀故障现象进行讨论，提出了提高气阀可靠性的途径。     

航空发动机转子早期裂纹故障振动特征的维谱分析

针对航空发动机转子早期裂纹故障难以检测的特点首先,根据转子裂纹扩展机理,建立早期裂纹转子振动分析理论模型,提出利用112维谱对早期裂纹振动信号进行分析。然后,利用112维谱分析法对早期裂纹转子理论模型和早期裂纹转子故障实验数据进行了具体分析。理论模型和实验数据分析结果都表明:应用112维谱对实际发动机转子早期裂纹故障信号进行分析,不仅能够得到一般频谱分析法难以获得的故障特征频率,还能对混叠噪声信号进行降噪。因此,112维谱能够有效的诊断航空发动机转子裂纹故障,在航空发动机故障诊断中具有一定的应用价值。     

往复压缩机连杆故障的特征提取方法

往复压缩机结构复杂,激励源众多,故障诊断较为困难.针对往复压缩机的连杆故障,本文根据连杆动力学特性,建立了连杆故障诊断的特征提取方法--基于小波和统计的故障特征提取方法.该方法已应用于2D12型往复压缩机的故障诊断.     

往复真空泵气阀的设计与计算

目前在役的往复式真空泵的固定环状阀设计大多沿用活塞式压缩机气阀设计的有关 方法和标准，但往复真空泵结构和活塞式压缩机并不完全相同，并明显具有进、排气压 力低的特点。由于气阀的阻力损失所增加的功耗在压缩机的功耗中占有一定的比例，本 文参照已试制成功的ＷＬ系列立式在复真空泵固定环状间结构。以降低功耗和提高气 阀寿命为目的，提出了确定气阀结构尺寸的有关设计方法。     

往复压缩机十字头销与连杆小头磨损过大故障机理研究

本文介绍了往复压缩机的十字头销与连杆小头磨损过大故障机理的研究。利用接触碰撞函数来表示十字头销和连杆小头之间的接触碰撞力,根据不同磨损程度下往复压缩机动力学行为来诊断故障程度,通过仿真实验建立往复压缩机故障状态信号与系统参数之间的关系。     

基于DSmT与小波网络的齿轮箱早期故障融合诊断

针对齿轮箱早期故障特征十分微弱难以有效辨识问题,提出基于DSmT理论与小波神经网络的齿轮箱早期故障融合诊断模型。利用多个振动传感器合理布置在齿轮箱的多个关键部位采集多源振动信息并进行特征提取;利用多个并联小波神经网络实现齿轮箱早期故障的初级诊断获得彼此独立的多个证据;利用DSmT理论对多个独立证据进行融合决策得出齿轮箱的最终诊断结论。DSmT理论克服了传统DST证据理论的局限性,小波神经网络实现多源证据信度分配的客观化。诊断实验结果表明,该方法能有效提高齿轮箱早期故障特征的辨识精度、降低诊断的不确定性。     

气柱共振对开洞结构内压风洞试验的影响

气柱共振对开洞结构内压风洞试验的影响不容忽视,尤其是连通的两空间或多空间结构。阐述了内压风洞试验相似律及体积补偿要求,即按原型与实验风速比的平方进行内部体积补偿,且体积补偿箱须遵守"深且窄"的原则。从往复压缩机管道系统引入了内压模型腔体的气柱共振频率计算公式。对两种补偿体积的开洞两空间结构进行内压风洞试验,试验结果证实了当体积补偿箱过于深长时,会出现气柱共振现象从而影响内压测量的精度。     

A Simulation Study on the Transient Motion of a Reciprocating Compressor Suction Valve Under Complicated Conditions

Stepless capacity control technology for reciprocating compressors is a key contributor to energy saving for the petroleum and petrochemical industries. Devices called “unloaders” are utilized to control the capacity of the compressor by forcibly holding the suction valves open during a variable portion of the compression stroke to control the compressor output. This approach can also lead to various faults of the suction valve. This paper describes the simulation and experimental studies of the transient motion of suction valves under stepless capacity control. Beginning with mathematical models for the normal cycle, improved models of a reciprocating compressor under stepless capacity control have been built. A simulation study of the working process of a double-acting reciprocating compressor has been completed. Theoretical formulas for the transient motion of the valve plate under complicated conditions and the dynamic pressure in the cylinder are compared with the experimental results. Based on the above simulations, a finite element analysis of the valve plate and valve seat has been completed. The experiment results showed that the vibration of the compressor cylinder under complicated conditions was consistent with numerical simulation results. Research presented in this paper is significant in providing tools for diagnosing faults in order to optimize the design of reciprocating compressors that utilize a stepless capacity control system.     

空压机冷却器冷却效果差引起排气压力超标的分析

由于活塞式空压机二级冷却器冷却效果不佳,二级排气压力超过设计压力,造成安全阀起跳。更换二级冷却器,解决了此故障。介绍了保证活塞式空压机冷却器冷却效果的操作方法。     

A preliminary evaluation of the Groll rotary vane compressor

The principles of operation and design of the prototype of a novel design of vane compressor with significant advantages over the conventional sliding vane type are described. Its performance is given and compared to that of equivalent commercially available sliding vane and reciprocating compressors used in refrigeration systems. Its volumetric efficiency on average was 3% greater than that of the sliding vane compressor and 23% more than that of the reciprocating machine. The adiabatic efficiency was on average 15% greater than that of the sliding vane and about equal to that of the reciprocating compressor. Owing to its high rotational speed it is more compact than the reciprocating compressor. Since the vanes are rigidly retained about their axis of rotation they cannot chatter as in a sliding vane compressor. It is therefore smooth and quiet in operation and no mechanical faults were encountered in 432 h of operation.     

Experimental study on stepless capacity regulation for reciprocating compressor based on novel rotary control valve

A capacity-regulation system based on a novel rotary control valve for reciprocating refrigeration compressor is proposed and designed for the first time. The regulation system is mainly composed of a rotary control valve and an adaptive regulation system. The structure and working principle of the rotary control valve is described in detail, and the control process of the adaptive regulation system for the valve is studied together with the program design. In addition, the parameters for the design and control of the rotary control valve are theoretically determined. To verify the feasibility and effectiveness of the proposed system, a three-cylinder reciprocating compressor was adopted as a test device. Experimental results showed that the technology was able to realize continuous stepless capacity regulation for the compressor within the range of (0)10–100%, and power consumption decreased correspondingly with the load reduction.     

平湖油气田往复式压缩机振动故障实例分析

针对海洋石油平台常见的往复式压缩机振动失效故障,运用振动分析方法,对其产生的振动故障类型进行总结,并针对平湖平台往复式压缩机的各种振动实例问题提出一系列的解决方法,为今后同类型设备的维护和运行提供一个整改范例,也为今后海洋石油平台的压缩机工程设计、成撬和安装及运行提出了改进方向。     

Design and Maintenance of Valves on a H_2 Reciprocating Compressor

Cylinder valves are the most important parts of a reciprocating compressor;their working condition affects the safety and operation of the reciprocating compressor directly.In initial design,it is dedicated to simulate the behaviour of a reciprocating compressor and performance of cylinder valves.For hydrogen application,it is considering carefully the real operating conditions both from the dynamic point of view and taking care of the effective conditions of the gas purity.The dynamic aspects of the design are related to the mechanical behaviour and to the consequent fatigue.The mathematical models are able to determine the ring displacement and the flow and pressure drop of the gas.Instruments are available for on-line monitoring of the reciprocating compressor.The various parts have to be repaired in time in case they have abrupt problems during the operating period.By detail design and maintenance,saving the quantities of spare parts,the reciprocating compressor of the plant can be running smoothly.Actually,the cylinder valves can be used nearly three years.     

Modeling of gas leakage through compressor valves

This paper describes a model developed to predict gas leakage in cases of incomplete sealing of the reed-type valves of small reciprocating compressors adopted for household refrigeration. The model assumes a one-dimensional formulation for the flow, considering the effects of viscous friction, slip-flow regime and compressibility. Reed bending into the port due to the pressure load is also taken into account to characterize the valve clearance. Computations are carried out during the compression cycle and the effect of leakage on both the isentropic and volumetric efficiencies is quantified for two operating conditions. It was found that leakage significantly reduces the compressor efficiency even for very small valve clearances and that leakage in the discharge valve is of greater importance than that in the suction valve.     

涡旋式压缩机在低温冷冻领域应用的实验研究

针对带HVE阀设计的半封闭卧式涡旋式压缩机,与当前冷冻市场上广泛使用的一款活塞式压缩机的性能进行对比测试。测试结果表明:由于喷气增焓的作用,随着系统压比的增大,涡旋式压缩机在制冷量方面表现出明显的优势。当蒸发温度为-25℃时,其制冷量与活塞式压缩机的比值,从25℃冷凝温度的约90%,提高到50℃冷凝温度的约130%。与活塞式压缩机相比,在上述运行工况下,涡旋式压缩机的性能也有所提升,当蒸发温度为-25℃时,R404A涡旋式压缩机的EER比活塞式压缩机的提高约2%~8%;R22涡旋式压缩机的EER比活塞式压缩机的提高2%~3%(冷凝温度为25℃时),冷凝温度为50℃时提高4%~5%。     

Efficiency analysis of power consumption in small hermetic refrigerant rotary compressorsAnalyse,du point de vue du rendement,de la consommation d'énergie dans les petits compresseurs frigorifiques rotatifs hermétiques

Theoretical and experimental studies of small hermetic rotary compressors for room air conditioners are reported. Comparing rotary and reciprocating compressors from the viewpoint of efficiency, the rotary compressor has a disadvantage of higher friction loss because the sliding surfaces in the compression chamber increase in number, however it has the following three significant features: volumetric efficiency is high; valve loss is low; since suction, compression and discharge are performed simultaneously, suction velocity and discharge velocity become approximately one half. Therefore the efficiency of the rotary compressor is higher than that of the reciprocating compressor.     

Efficiency analysis of power consumption in small hermetic refrigerant rotary compressors

Theoretical and experimental studies of small hermetic rotary compressors for room air conditioners are reported. Comparing rotary and reciprocating compressors from the viewpoint of efficiency, the rotary compressor has a disadvantage of higher friction loss because the sliding surfaces in the compression chamber increase in number, however it has the following three significant features: volumetric efficiency is high; valve loss is low; since suction, compression and discharge are performed simultaneously, suction velocity and discharge velocity become approximately one half. Therefore the efficiency of the rotary compressor is higher than that of the reciprocating compressor.