Stirling-type pulse tube refrigerator (PTR) with cold compression: Cold compressor,colder expander

This research paper focuses on the performance prediction and its validation via experimental investigation of a Stirling-type pulse tube refrigerator (PTR) equipped with a cold linear compressor. When the working gas is compressed at cryogenic temperature, the acoustic power (PV power) can be directly transmitted through the regenerator to the pulsating tube without experiencing unnecessary precooling process. The required PV power generated by the linear compressor, furthermore, can be significantly diminished due to the relatively small specific volume of the working gas at low temperature. The PTR can reach lower temperature efficiently with higher heat lift at the corresponding temperature than other typical single-stage Stirling-type PTRs. Utilizing a cryogenic reservoir as a warm end and regulating the entire operating temperature range of the PTR will enable a PTR to operate efficiently under space environment.In this research, the experimental validation as a proof of concept was carried out to demonstrate the capability of PTR operating between 80 K and 40 K. The linear compressor was submerged in a liquid nitrogen bath and the lowest temperature was measured as 38.5 K. The test results were analyzed to identify loss mechanisms with the simple numerical computation (linear model) which considers the dynamic characteristics of the cold linear compressor with thermo-hydraulic governing equations for each of sub components of the PTR. All the mass flows and pressure waves were assumed to be sinusoidal.     

Simulation of rotating stall in a whole stage of an axial compressor

Aerodynamic instabilities that naturally occur in compression systems, such as surge and rotating stall, largely reduce the life duration and performance of system components. The prediction of the compressor operating range is thus a key parameter for the design of gas turbines. This paper investigates the ability of an unsteady flow solver to simulate the rotating stall phenomenon in the full annulus of an axial compressor stage. A comparison with experimental data indicates that the simulation correctly estimates the stability limit. However the rotating stall flow patterns are different. While measurements show only one full span rotating stall cell (40 Hz), the simulation shows first a part span stall with 10 cells (790 Hz) that evolves then towards a full span stall with three cells (170 Hz). A spectral analysis based on numerical results underlines the role of rotor-stator interactions in the development of rotating stall. The effects of downstream volumes and inlet distortions are also discussed, showing the necessity to consider the whole geometry to correctly predict the rotating stall frequency.     

大型压缩机组设备群的故障预测与健康管理

介绍了压缩机组设备群—复杂系统的故障预示和健康状态管理技术和系统的研究。融合早期故障预示、综合故障诊断和远程专家诊断技术,研究设备群的健康状态管理技术,并研发了压缩机组设备群故障诊断和健康状态管理系统,实现主辅机故障诊断和健康状态管理一体化、监测控制信息利用共享化、生产企业和设备制造企业知识资源利用最大化,为石化生产企业和设备制造企业提供一套全生命周期的压缩机组设备群故障诊断和健康管理的系统解决方案。     

Solar or surplus heat-driven actuators using metal hydride alloys

A metal hydride (MH) actuator provides mechanical work by applying the hydrogen pressure transition that originates from the reversible reaction of the MH alloy as it absorbs and desorbs hydrogen gas. The MH actuators that have been reported employ a Peltier element or an electrical heating resistance wire as a heat source. This paper describes the design of an MH actuator that is driven by low-quality heat sources, such as solar heat or surplus heat. A certain composition of a LaNi₅-based alloy that produces desorbing and absorbing reactions through a low-temperature difference is specified. This alloy composition can provide a large amount of hydrogen desorption using solar heat or surplus heated water and a large amount of hydrogen absorption by natural air cooling in an adequate reaction time. To improve the moving speed and to control the performance, a reciprocating air compressor that applies this solar or surplus heat-driven MH actuator is proposed. These findings support the efficacy of an MH actuator operating without electric or fossil fuel energy consumption.     

基于虚拟仪器的压缩机性能测试系统的研究与实现

依据GB/T3853-1998《容积式压缩机验收试验》的国家标准,采用NI公司的LabVIEW虚拟仪器技术,对空气压缩机性能试验进行了自动测试研究;针对该测试系统中喷嘴系数选择具有强非线性,通过插值算法实现了喷嘴系数的自动选择.主要介绍了自动测试系统的构成及试验流程的计算方法,实际应用表明,该测控系统具有快速、开放性好...     

基于 NSGA-Ⅱ的无油涡旋空压机动定盘的选配

针对无油涡旋空压机零部件装配的特点和存在的问题,采用快速非支配排序遗传算法,根据动定盘选配问题的特点,对遗传基因进行十进制的编码,设计选择、交叉、变异等各个遗传算子,用C＃语言完成整个算法的编写,并以04 A型主机动定盘选配为实例,验证选配算法的可行性和有效性。     

505E调速器在U-GB151CO2压缩机上的应用

川化股份有限公司化肥厂二化尿素装置为日产2460T尿素的大型化肥装置,其CO2压缩机采用日本三菱3V-7B型两缸四段压缩机,由抽汽注汽冷凝式透平驱动.该透平的转速控制由505E控制器实现,并与ProTech 203相结合实现压缩机的两级超速保护.Woodward 505E数字控制器适用于具有一次可调整的纯抽汽、抽补结合或纯补汽型式透平的控制,可现场编程组态,使标准的设计能适用于各种不同的控制场合.文中介绍了505E控制器在UGB151 CO2压缩机上的调速应用,并例举调速系统出现的故障,进行分析排除.     

氧化氮压缩机铵盐的清除

分析了硝酸生产过程中铵盐形成的原因和对氧化氮压缩机的危害，对喷水、喷蒸汽2种清除铵盐的方法进行了分析比较．     

不同叶片安装角的轴流泵内部流动特性分析

结合浙江省某更新改造泵站,在三维湍流Navier-Stokes控制方程的基础上,采用标准k-ε模型和SIMPLEC算法,对不同叶片安装角的轴流泵内部全流道流场进行了数值模拟,分析讨论了不同安装角下的叶片静压分布图、叶片相对速度分布图,对轴流泵的扬程进行了预测,最后给出了该轴流泵合适的叶片安装角。     

关于泵和压缩机课程教学改革的思考

为了适应石油天然气工业的发展和宁波工程学院“知行合一,双核协同”的培养模式,泵和压缩机课程的教学也要不断地进行改革。本文针对泵和压缩机课程教学实际,探讨在教学目标、教学内容、教学方法和考核方式等方面的改革,以期提高课程教学质量。