原料气压缩机轴封泄漏安全分析与策略应对调研

原料天然气压缩机属于石油天然气行业轻烃处理装置的核心设备。压缩机轴封泄漏点主要集中在曲轴箱部分,其包含静密封点和动密封点,而泄漏点就有3个,最高泄漏平均速度达到了24滴/min。原料天然气是一种含有大量丙烯、烷烃等多种成分的混合物,其伴有硫化氢有毒有害气体,污染周边环境和危害人员生命。根据对泄漏状况的分析,采用安全管理应用工具PDCA,找出问题的原因,改进现有的安全防护措施,本着减少泄漏、建设清洁生产和安全生产的要求来提升现场的安全环保管理水平。

苯乙烯压缩机填料密封泄漏原因及其改进

通过对苯乙烯压缩机运行检修情况的统计,针对压缩机填料密封泄漏量大的故障,从填料的材料、结构、配合工件、辅助措施等方面对泄漏原因进行分析,做出相应的改进措施,解决了填料泄漏问题,保障了压缩机正常运行。

煤制天然气装置低温甲醇洗系统运行问题及优化改造

某煤制天然气装置低温甲醇洗系统采用林德十一塔工艺,自原始开车以来,低温甲醇洗系统陆续出现了HHC倾析罐操作温度偏高、甲醇/水/HCN分离塔再沸器堵塞、循环气压缩机填料泄漏、氨预洗塔液泛等问题,对装置的长周期、安全、稳定运行造成了一定的影响。为此,查找与分析症结所在,实施相应的优化改造后,各类问题均得到了解决,有力地保障了煤制天然气装置的长周期、安全、稳定运行。

双加压法硝酸装置四合一机组常见问题分析及解决

重庆飞华环保科技有限责任公司270 kt/a稀硝酸装置采用西班牙TR公司开发的双加压法硝酸工艺,自2015年1月17日投运以来,稀硝酸装置的关键设备--四合一机组生产运行中出现了各类问题。分析与探究出现各类问题的原因,介绍针对各类问题飞华环保公司采取的相应解决(或处理)措施。并指出,总体而言四合一机组设计和制造质量是优异的,但由于飞华环保公司生产运行的特殊性--1 a中十几次的频繁开停车,做好四合一机组的维护和安全生产依然任重而道远。

Circumferential Propagation of Tip Leakage Flow Unsteadiness for a Low-Speed Axial Compressor

Full-annulus three-dimensional unsteady numerical simulations were conducted for a low-speed isolated axialcompressor rotor, intending to identify the behavior of self-induced unsteady tip leakage flow within multi-bladepassages. There is a critical mass flow rate near stall point, below it, the self-induced unsteadiness of tip leakageflow can propagate circumferentially and thus initiates two circumferential waves. Otherwise, the self-inducedunsteady tip leakage flow oscillates synchronously in each single blade passage. The major findings are: 1) whilethe self-induced unsteadiness of tip leakage flow is a single-passage phenomenon, there exist phase shifts amongblade passages in multi-passage environments then evolving into the first short length wave propagating at abouttwo times of rotor rotation speed after the transient period ends; and 2) the time traces of the pseudo sensors locatedon the rotor blade tips reveal another much longer length-scale wave modulated with the first wave due tophase shift propagating at about half of rotor rotation speed. Features of the short and long length-scale circumferentialwaves are similar to those of rotating instability and modal wave, respectively.

Experimental and Numerical Investigation on Compressor Cascade Flows with Tip Clearance at a Low Reynolds Number Condition

High flow rate aeroengines typically employ axial flow compressors, where aerodynamic loss is predominantly due to secondary flow features such as tip leakage and comer vortices. In very high altitude missions, turbo- machinery operates at low density ambient atmosphere, and the recent trend toward more compact engine core inevitably leads to the reduction of blade size, which in turn increases the relative height of the blade tip clearance. Low Reynolds number fiowfield as a result of these two factors amplifies the relative importance of secondary flow effects. This paper focuses on the behavior of tip leakage flow, investigating by use of both experimental and numerical approaches. In order to understand the complex secondary flow behavior, cascade tests are usually conducted using intrusive probes to determine the loss. However relatively few experimental studies are pub- lished on tip leakage flows which take into account the interaction between a rotating blade row and its casing wall. Hence a new linear cascade facility has been designed with a moving belt casing in order to reproduce more realistic flowfield as encountered by a rotating compressor row. Numerical simulations were also performed to aid in the understanding of the complex flow features. The experimental results indicate a significant difference in the flowfield when the moving belt casing is present. The numerical simulations reveal that the leakage vortex is pulled by the shearing motion of the endwall toward the pressure side of the adjacent blade. The results highlight the importance of casing wall relative motion in analyzing leakage flow effects.

Numerical Analysis of the Tip Leakage Flow Field in a Transonic Axial Compressor with Circumferential Casing Treatment

This paper reports on numerical investigations aimed at understanding the influence of circumferential casing grooves on the tip leakage flow and its resulting vortical structures.The results and conclusions are based on steady state 3D numerical simulations of the well-known transonic axial compressor NASA Rotor 37 near stall operating conditions.The calculations carried out on the casing treatment configuration reveal an important modification of the vortex topology at the rotor tip clearance.Circumferential grooves limit the expansion of the tip leakage vortex in the direction perpendicular to the blade chord,but generate a set of secondary tip leakage vortices due to the interaction with the leakage mass flow.Finally,a deeper investigation of the tip leakage flow is proposed.

Experimental and Numerical Investigation of the Unsteady Tip Leakage Flow in Axial Compressor Cascade

For convenience of both measurement and adjusting the clearance size and incidence, the current research is mainly conducted by experiments on an axial compressor linear cascade. The characteristics and the condition under which the unsteadiness of tip leakage flow would occur were investigated by dynamic measuring in different clearances, inlet velocities and incidences. From the experiment it is found that increasing tip clearance size or reducing rotor tip incidence can affect the strength of the tip clearance flow. Then the experimental results also indicate the tip leakage shows instability in certain conditions, and the frequency of unsteadiness is great influenced by inflow angle. The condition of occurrence of tip leakage flow unsteadiness is when the leakage flow is strong enough to reach the pressure side of the adjacent blade. The main cause of tip leakage flow unsteadiness is the tip blade loading.