空压机进气阀定位器故障引起空分设备工况波动分析及处理

介绍KDON-3200/7000型空分设备因空压机进气阀定位器故障发生的工况波动故障,分析故障原因,在空分设备不停车的情况下采取应急处理措施,降低故障对生产的影响,停机检修后消除故障,最后阐述了预防措施。     

Numerical modeling of startup and shutdown transients in reciprocating compressors

Several phenomena that affect energy consumption, noise level and reliability of compressors are associated with transient effects that occur during the compressor startup and shutdown. This paper presents a simulation methodology, experimentally validated, developed to analyze the compressor in such transients. Because the time scale associated with the compressor thermal behavior is much larger than that related to the mechanical physics, a thermal equilibrium condition has been considered herein for convenience. Results for valve displacement, piston motion, pressure in the compression chamber and resistive torques are provided to illustrate the application of the methodology and to assist an understanding of the physical aspects that affect the compressor performance throughout the startup and shutdown. It is observed that the dynamics of suction and discharge valves are greatly affected. Moreover, the model is employed to estimate the minimum voltage required for the compressor startup as a function of the equalized pressure and the auxiliary coil actuation time.     

冷箱壁冻裂事故原因分析及处理

介绍了神马尼龙 66盐公司空分装置一起由空压机油泵晃电而导致的系统停车 ,在紧急启动液氮汽化系统过程中由于液氮取出阀内漏所造成的冷箱壁冻裂事故。详细分析了事故的原因 ,并提出了防范对策。     

空压机油止回阀结构缺陷引起的设备事故分析

空压机油止回阀结构设计缺陷,引发了多起空压机设备事故,严重影响了空压机的正常运行。简介空压机设备事故现象和油路系统流程,详细分析了油止回阀存在的结构设计缺陷。通过改造油止回阀阀座结构,弥补了结构缺陷,使空压机正常运行。最后总结了空压机维护心得。     

液氧回灌阀燃爆事故分析及预防

介绍一起因液氧回灌阀反向使用造成阀门爆裂、导致空分设备停车的事故，分析了造成事故的原因及采取的防范措施。     

液氧回灌阀燃爆事故分析及预防

介绍一起因液氧回灌阀反向使用造成阀门爆裂、导致空分设备停车的事故,分析了造成事故的原因及采取的防范措施。     

Les hélico compresseurs ou compresseurs à visHelical or screw compressors

In the first part of the paper the patenting of the helical compressor at the end of the last century by a Swedish engineer as a type of air and gas blower, modified some 50 years later by another Swedish engineer as an air and gas compressor, is discussed. Decade by decade, the machine was developed by the Swedish firm SRM and by their licenced manufacturers machining the screw compressor in Sweden, Germany, France, Scotland, etc. At the present time this type of compressor seems to be fully developed and occupies a first class position in the range of positive displacement machines.Recently, a new type of screw compressor has been patented by a French engineer, this machine having only one main rotor and two small satellites, compared with the early type which had only two main rotors. These two types of compressors are now competing on the refrigeration market all over the world.In the second part of the paper, all the improvements made during the 50 yeats of development are examined in detail. In the beginning, the screw compressor was designed as an oil free compressor and was not very well adapted to the refrigerating plants, this type of oil free compressor still being used for the compression of pure gases. The first improvement was the oil injected screw compressor allowing the machine to support high compression ratios and large pressure differences and some time later, to be fitted with a sliding valve for the purpose of volume adaptation. One other modification to the profile of the rotors results in greater compressor efficiency allowing it to work with higher compression ratios; for example, in the case of low temperatures such as are used for the freezing of food products.This is not a good solution for saving energy, and the performance has been improved by creating a complementary orifice designed as a superfeed port. This increases the global efficiency of the whole circuit with a screw compressor.The same improvements were carried out on the mono rotor screw compressors and now the two types of compressors are competing with the same auxiliaries imposed by the special lubrication of this type of machine. Some comparisons are made with reciprocating and centrifugal compressors.     

氧压机水冷却器换热效果不佳的处理

60000m3/h空分设备配套氧压机多次出现因三级出口氧气温度过高报警而停车的现象,由于氧压机低压缸内所有的中间冷却器均整合在壳体内,不易拆卸清洗,于是在冷却水管上加装1个DN100mm的球阀,对各级冷却器进行反向冲洗。反向冲洗后效果明显,降低了氧压机的排气温度,保证其安全运行。     

空压机防喘振及联锁停车控制系统优化改造

由于仪表传输线路存在信号干扰,导致空分设备空压机联锁停车或防喘振阀全开的故障发生。通过对设备硬件及控制程序进行优化改进,将传输模拟信号电缆与传输逻辑信号电缆采取有效隔离,消除了控制系统上存在的安全隐患,保证了空压机正常运行。     

DH-90型空压机油泵互投逻辑控制的完善

2#14000m3/h空分设备DH-90型空压机在切换油泵操作中,因互投逻辑问题出现多次故障,致使空压机联锁停车,分析故障原因,逐步修改并完善油泵互投逻辑控制,实现空压机稳定运行。     

压缩机表面产生凝露的原因及其解决措施

变频多联机中距离室内机近的压缩机表面在运行中出现凝露现象,并伴随压缩机内油翻泡,油面下降。从理论方面分析该现象：在名义制冷、最大制冷工况下,制冷剂循环量没有控制好,导致过多的制冷剂进入压缩机后继续蒸发,温度降低到露点温度以下,从而出现压缩机表面凝露。为此,提出相应的控制措施,较好地解决了该问题,对保证多联机系统的稳定安全可靠运行具有一定的指导意义。     

Thermodynamic model for reciprocating compressors with the focus on fluid dependent efficiencies

Fluids with high global warming potential, which are used in existing refrigeration cycles and heat pumps, will have to be replaced soon by less harmful fluids, but the fluid selection is difficult especially due to the unknown compressor performance. In this work a differential compressor model for reciprocating compressors is introduced which predicts volumetric and isentropic efficiencies quickly and can be easily fitted with measured data at only one operation point of an existing compressor. In order to characterise the influence of different fluids two semi-physical correlations for the valve flows are fitted here, and a procedure of transferring them to different compressors is shown. The model is validated on, in total, 63 measured points based on numerous fluids from one semi-hermetic reciprocating compressor which is part of a heat pump cycle. The calculations lead to mean prediction errors of 3.0% for the isentropic and 2.3% for the volumetric efficiency.     

大唐多伦58000m~3/h空分设备空压机放空管道改造

大唐多伦58000 m3/h空分设备运行过程中,空压机防喘振放空阀反应迟缓,导致空压机卸载和空分设备紧急停车。防喘振放空阀移位并取消相应联锁后,问题解决。但随后出现了放空管道开裂破损现象,改造放空管道后此现象消失。简述空分设备配套空压机组的结构和主要技术参数,详细介绍空压机防喘振放空阀及放空管道出现的问题,阐述原因分析过程、处理措施及其效果。     

RIK90-4型空压机停机过程中喘振的原因分析

25000 m3/h空分设备配套的RIK90-4型空压机,由于放空阀及其管道的安装标高不合理,导致叶轮清洗水长期积聚在管道内,使放空阀的阀板与阀体生锈卡死,从而使空压机停机过程中的排气压力和排气量不匹配而发生喘振。简介喘振现象和经过,介绍原因分析过程,最后提出预防放空阀及其管道积水进而使放空阀卡死的措施。     

Theoretical study of a novel refrigeration compressor – Part II: Performance of a rotating discharge valve in the revolving vane (RV) compressor

A new refrigeration compressor, named ‘Revolving Vane (RV) compressor’, has been introduced in Part I of this paper series. For a first time in refrigeration compressors, a rotating discharge valve is employed in the RV compressor mainly due to the rotation of the entire cylinder. This paper presents a theoretical investigation on the dynamic behavior of a reed-type discharge valve undergoing rotatory motion, with the primary objective of elucidating the applicability of such valves in refrigeration compressors. Under the application of the Euler–Bernoulli beam theory, a mathematical model of the rotating valve is formulated and the transient response of the valve under centrifugal loads in addition to pressure forces is analyzed. Results have shown that under careful design considerations, the performance as well as the reliability of the rotating discharge valve can be enhanced as compared to a non-rotating valve that has been used in all refrigeration compressors currently.     

制冷剂-润滑油互溶混合物系流动沸腾特性测试装置的研制

在对已有相关测试装置设计技术的利弊分析基础上,提出了一种测试制冷剂-润滑油互溶混合流体管内流动沸腾特性的装置,其特征是通过与制冷剂流动沸腾换热测量回路并联接入一开式的润滑油回路,从而实现灵活控制和调节实验段内润滑油量的目的.通过在压缩机出口串连接入3个油分离器进行三级油分,从而实现压缩机出口的润滑油零排放.该装置具有连续在线注油、达到稳态时间短、操作灵活、控制简单等优点.     

主换热器效率下降导致空分设备被迫停车的分析与处理

介绍了永钢21000m3/h空分设备因主换热器换热效率下降而被迫停车故障的经过,分析后得出原因为:空压机泄漏的润滑油进入主换热器并冻结成油薄膜,使换热系数降低,最后阐述了处理过程。     

Current-induced spin-orbit torques

The ability to reverse the magnetization of nanomagnets by current injection has attracted increased attention ever since the spin-transfer torque mechanism was predicted in 1996. In this paper, we review the basic theoretical and experimental arguments supporting a novel current-induced spin torque mechanism taking place in ferromagnetic (FM) materials. This effect, hereafter named spin-orbit (SO) torque, is produced by the flow of an electric current in a crystalline structure lacking inversion symmetry, which transfers orbital angular momentum from the lattice to the spin system owing to the combined action of SO and exchange coupling. SO torques are found to be prominent in both FM metal and semiconducting systems, allowing for great flexibility in adjusting their orientation and magnitude by proper material engineering. Further directions of research in this field are briefly outlined.     

膨胀机润滑油温度偏高的故障排除

介绍6000 m3/h制氮设备正常运行时发生的膨胀机润滑油温度过高故障,从环境温度高、油冷却器结垢、油质变差和油泵出口温控阀失效等方面分析了故障原因。临时停运膨胀机,检查后发现是由于油冷却器被沉积物堵塞导致换热效果变差,清理沉积物后膨胀机恢复正常运行。     

30000m~3/h空分设备空压机漏油故障处理

30000m3/h空分设备配套EIZ100-4型空压机运行中出现油箱油位大幅度下降现象,在无法确定油是否泄漏到气侧和水侧的情况下,果断停车检修。通过检查低压端轴承箱、级间冷却器、油冷却器等可能出现内漏的环节,找准原因,采取适当的措施预以消除。简介空压机漏油现象,详细分析漏油故障的诊断过程和原因。