整体往复式压缩机曲轴力学性能研究与安全评价

发布时间：2018-07-05 19:54

本文选题：整体往复式压缩机 + 安全评价　；参考：《西南石油大学》2014年博士论文

【摘要】：整体往复式压缩机是石油天然气行业增压集输的重要动力设备,压缩机安全运行是天然气增产的重要保证,目前天然气压缩机的管理仍是采取基于传统的计划性维修和事故后处理的模式。随着机组使用年限的增加事故率也随之上升,机组安全运行是油气田管理者十分关注的问题,特别是老、旧机组及超期服役机组的安全运行状况令人担忧。压缩机整体安全性评价正是为满足这种需求而提出的,本文基于整体往复式压缩机安全评价思想出发,提出压缩机系统评价和部件评价相结合的方法,并根据部件安全性和经济性权重不同,依据专家评分与层次分析法计算得出部件权重系数,建立整体安全性评价方法。整体往复式压缩机的燃气发动机和压缩机撬装在一个底座上,共用一根曲轴,承担着动力传递枢纽的作用。作为压缩机关键核心部件的曲轴在机组运行过程中承受着随时间周期性变化的冲击、振动等交变载荷。正是这些交变载荷的存在,使得曲轴产生弯曲、扭转及弯扭等复杂变形,曲轴力学特性不仅影响着曲轴的使用寿命,而且直接关系到机组整体的安全性和稳定性,在此基础上开展对曲轴力学性能研究和安全评价。本文针对ZTY470型整体往复式压缩机曲轴结构,对其进行力学分析和评价研究,通过对曲轴结构运动动力分析、热力分析及各轴颈载荷研究确定曲轴承受的交变载荷,获得作用在各曲柄销上的切向力、法向力及扭矩等外部载荷。根据实际结构简化力学分析模型,建立超静定方程。并结合有限元软件对整体往复式压缩机曲轴进行静力学分析、模态分析,在轴系模态分析的基础上,施加时间历程载荷对轴系进行瞬态响应分析,根据分析结果对曲轴分别进行了静强度和疲劳强度校核。然后,根据曲轴无损检测结果是否含有裂纹缺陷分别建立安全评价模型。对无裂纹缺陷曲轴结构根据材料S-N曲线、疲劳寿命累积准则,以及现场历史载荷统计建立块状载荷谱,建立压缩机曲轴疲劳寿命评价模型；对于检出含有裂纹缺陷的曲轴结构,对裂纹缺陷进行工程化处理成为有效的裂纹尺寸,通过对裂纹尖端应力应变等场强分析、表面半椭圆裂纹应力强度因子计算等,结合Paris裂纹扩展速率公式,建立含裂纹缺陷曲轴的剩余寿命评价模型。这样,便建立了压缩机曲轴无裂纹缺陷和含裂纹缺陷两种模式下的安全评价和剩余寿命预测模型。为修正和完善对曲轴的评价,针对性的开展了曲轴材料拉伸试验(屈服强度、抗拉强度)、疲劳强度(疲劳极限、S-N曲线)及断裂测试(断裂韧性、裂纹扩展门槛值及裂纹稳定扩展阶段扩展速率),获得曲轴材料安全评价的力学性能参数和结构参数,以修正和完善评价结果的可靠性。在此基础上,为方便对压缩机的安全运行进行评价及曲轴等部件的受力分析和评价,编制了天然气压缩机安全使用评价CSA Versionl.0评价软件。因此,本文提出整体往复式压缩机安全评价方法、曲轴力学性能研究和安全评价方法,为油气田单位压缩机安全管理提出一种有效的评价措施,也为目前仍在使用的老、旧机组乃至超期服役机组的报废标准提供一种合理的理论依据。
[Abstract]:The overall reciprocating compressor is an important power equipment for the turbocharging and transporting in the oil and gas industry. The safe operation of the compressor is an important guarantee for the increase of gas production. At present, the management of the gas compressor is still based on the traditional planned maintenance and post accident treatment mode. The safe operation of the unit is a concern of the oil and gas field managers, especially the old, the safety operation of the old unit and the overdue service unit is worrying. The overall safety evaluation of the compressor is put forward to meet this demand. Based on the overall evaluation idea of the integral reciprocating compressor, this paper puts forward the evaluation of the compressor system and the evaluation of the compressor system. The method of component evaluation is combined. According to the safety and economic weight of components, the weight coefficient of components is calculated according to the expert score and the analytic hierarchy process, and the overall safety evaluation method is established.
The gas engine and compressor of the whole reciprocating compressor are pry mounted on a base and shared a crankshaft to bear the function of the power transfer hub. The crankshaft, as the key core component of the compressor, bears the impact of periodic changes during the operation of the unit, such as the alternating load of vibration and so on. It is the existence of these alternating loads. The crankshaft has complicated deformation such as bending, torsion and bending. The mechanical characteristics of crankshaft not only affect the life of crankshaft, but also directly relate to the safety and stability of the whole unit. On this basis, the mechanical properties of crankshaft are studied and safety evaluation is carried out.
In this paper, the mechanical analysis and evaluation of the crankshaft structure of the ZTY470 type integral reciprocating compressor are carried out. Through the dynamic analysis of the crankshaft structure, the thermodynamic analysis and the study of the journal load, the alternating load on the crankshaft is determined, and the external loads, such as the tangential force, the normal force and the torque on the crankshaft, are obtained. The structure simplifies the mechanical analysis model and establishes the hyper static equation. Combined with the finite element software, the static analysis and modal analysis of the crankshaft of the whole reciprocating compressor are carried out. On the basis of the modal analysis of the shaft system, the transient response analysis of the shaft system is carried out by applying the time history load, and the static strength and fatigue of the crankshaft are carried out respectively according to the analysis results. Then, a safety evaluation model is established for the crankshaft nondestructive testing results to contain crack defects. The fatigue life evaluation model of the compressor crankshaft is set up based on the material S-N curve, the cumulative fatigue life cumulative criterion, and the statistics of the field historical load, and the fatigue life evaluation model of the compressor crankshaft is established. With the crack defect of the crankshaft structure, the crack defect is engineered to be an effective crack size. Through the analysis of the stress and strain of the crack tip, the stress intensity factor calculation of the semi elliptical crack on the surface and the formula of the Paris crack propagation rate, the residual life evaluation model of the crackle defect crankshaft is established. The safety evaluation and residual life prediction model under two modes of crackle defect and crack defect in compressor crankshaft are established. In order to correct and improve the evaluation of crankshaft, the tensile test of crankshaft material (yield strength, tensile strength), fatigue strength (fatigue limit, S-N curve) and fracture testing (fracture toughness, crack propagation) are carried out. The mechanical performance parameters and structural parameters of the crankshaft material safety evaluation are obtained to correct and improve the reliability of the evaluation results. On this basis, the natural gas compressor safety is compiled to evaluate the safety of the compressor and to analyze and evaluate the force of the crankshaft. Full use evaluation CSA Versionl.0 evaluation software.
Therefore, this paper puts forward the safety evaluation method of the integral reciprocating compressor, the research on the mechanical properties of the crankshaft and the method of safety evaluation, and puts forward an effective evaluation measure for the safety management of the unit compressor in oil and gas field, and provides a reasonable theoretical basis for the old, old unit and even the overdue service unit, which is still in use.
【学位授予单位】：西南石油大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH45

【参考文献】