目的 分析川渝某净化厂换热器的腐蚀原因及影响因素,探讨解决措施.方法 通过微观分析换热管束泄漏的原因,采用旋转挂片法室内考察了换热器内循环水中的Ca2+、HCO-3、Cl-、SO2-4对腐蚀的影响.结果 换热管束泄漏是由腐蚀导致的,腐蚀从管束的内表面开始,逐渐形成腐蚀孔,最后导致换热管出现腐蚀泄漏.循环水中Ca2+、HCO-3对水质的腐蚀性影响较大,当循环水中的ρ(Ca2+)低至44 mg/L时,系统中碳钢的腐蚀速率高达1.05 mm/a.结论 为了防止管束发生腐蚀失效,需要加强水质控制,提高系统的Ca2+含量、碱度,或者更换耐蚀性更高的材质.

对P110钢在490℃下进行了4 h的盐浴渗氮,通过光学显微镜、X射线衍射仪、扫描电镜研究了渗氮对P110钢组织的影响.利用4种不同的硫腐蚀介质,研究了元素硫对渗氮及未渗氮试样腐蚀行为的影响.结果显示:P110钢经渗氮处理后,渗层组织由表及里依次为氧化物层、化合物层、扩散层,化合物层主要由Fe2 C、Fe2 N和Mn组成;化合物层结构致密,能对钢基体起到良好的保护作用,显著提高了P110钢耐硫腐蚀性能.

Due to complicated operating conditions and various corrosion environments, different forms of material failure may appear in service gas pipelines and other equipment, such as pipeline rupture, downhole tubing perforation and valve leakage.In order to solve these problems, the reasons of pipeline and equipment material failure were analyzed and the measures were proposed accordingly, which can provide technical support for corrosion control on the scene.This paper focuses on the evaluation methods on material failure in sour gas field, and researches the different typical cases of material failure on pipelines and equipment.In the end, the assessment technique of material failure of gas pipelines and irrelevant equipment is formed.

Flow field for gas pipeline gas flowing through the valve is input into the CFD(Computational Fluid Dynamics) for three-dimensional simulation,so as to build the generation model of gas pipeline valve flow noise.Steady-state simulation and transient simulation are carried out for the flow field of gas flowing through the valve.Results show that the pulsating flow in the turbulence(such as pressure and velocity fluctuation) is the root cause for flow noise generation.Valve flow field distribution from the analog simulation is transformed by the Lighthill wave equation to get a dipole sound source so as to obtain generation,transmission and attenuation law of the valve flow noise through valve pipe section flow noise analysis.A test is carried out to verify the valve sound field from the analog simulation,indicating the feasibility of using Fluent software for analog simulation of flow field and sound field of gas flowing through the valve.Research results can provide technical support to the acoustic method leak detection of gas pipeline and theoretical basis to the development of gas pipeline valve noise control methods.

A gas chromatography method for the quantitative analysis of isooctyl acid was introduced in this paper.Analytical condition were as follows,column :10 % modified polyethylene glycol 20M on acid washed 201,2 m column with 3 mm i.d.,FID as detector,phe-nylmethyl ketone as internal standard compound.Experimental results showed that this method was accurate,easy to operate and can be applied to quantitative analysis.The relative weight correction factor of isooctyl was 1.036,and its relative error was less than 2.0 %.