Tag Archives: напряженно-деформированное состояние
DEVELOPMENT OF RECOMMENDATIONS ON THE APPLICATION OF LOCALLY STRENGTHENED VESSEL’S CONNECTING PIPES WITH ENFORCEMENT RIBS
The operational safety of oil and gas chemical facilities depends on the resource of each particular component part of the equipment, that are used in technological process. One of the most urgent tasks for today is to identify potentially dangerous places in the facility and work on forecasting the resource of safe operation and reducing the probability of sudden destruction.
One of these places is welded vessel’s connecting pipes, which, due to different deformation capacity of its parts, causes a concentration of additional stresses and requires special attention in the design and manufacture of apparatus.
In this paper authors consider on the main way to reinforce the hole – the using of reinforcing rings, the advantages and disadvantages of using reinforcing rings are also indicated. The analysis of frequently used pressure vessels hole reinforcing methods showed, that complexities in the design and installation of reinforcing rings are in assembly technology, discovery of weld defects and detection of the defects location.
The possibility of using of locally strengthened vessel’s connecting pipes with enforcement rib is shown in this work, also this units in some cases may be used as an alternative to reinforcing rings, as they are more processible in the manufacture, repair and inspection. The calculations showed that the using of two enforcement ribs oriented along vessel’s generating line for hole reinforcing allows to reduce the level of stresses in the area of welded vessel’s connecting pipes. But the experiments showed that in conditions of cyclic loading the using of locally strengthened vessel’s connecting pipes with enforcement ribs, which are oriented along vessel’s generating line, is not recommended.
At present, special attention is paid to the issues of industrial safety in oil refineries. This is due to the growing number of accidents in recent years. The most likely are the emergency situations associated with the process pipelines depressurization due to their corrosive wear, the normal process conditions violations, planned preventive maintenance insufficient quality, etc. Process units’ incomplete loading, caused by a change in the raw materials consumption structure at enterprises, leads to a change in the equipment loading regimes and the increase in its stops. To a greater extent, this refers to the process pipelines linking the reactor equipment, which has a no stationary change in the stress state. In this connection, it became necessary to develop a method for determining the process piping movement when the reactor axis misaligns from the vertical.
The process piping deformation calculating results verification in the reactor axis misalignment from the vertical obtained in the SOLID WORKS software package and their comparison with the results of the reactor prototype mock-up with process piping were performed in this work. Ultimately, this allows creating a unified approach to the various factors influence study on the reactor pipeline systems, which is an important task that contributes to improving reliability and trouble-free operation. The estimation of deformation displacement piping axis deviation from the vertical reactor standard, numerical and observational methods, the comparative analysis of the results obtained.
Currently, there are a huge number of packers type of tool for conducting geological and technical measures in open hole. But despite the great diversity of types of packers, all united by the presence of common deficiencies, namely:
– not reliable sealing packer;
– the destruction of the sealing element in rubber re-planting packer in the wellbore;
– inadvertent operation of the packer during tripping operations (SPO)
– the probability of sticking packer in the wellbore.
The above disadvantages packers may cause complications in the wells that increases the downtime or loss of the well and consequently leads to high cost oil and gas companies.
To address the identified shortcomings in the packer, packer radically new design for the open hole was developed. Special attention was given to the design of sliding bearings to prevent leaking of the sealing rubber member due to occurrence of the pressure difference, and provide further breakdown reliable packer. Increasing the number of cycles stall rubber sealing element is achieved by adding a rubber composition belting cord, leading to increasing its stiffness, with slightly decreased rubber elasticity. Specially designed landing node allowed to exclude spontaneous land packer during tripping, thereby eliminating the possibility of complications during tripping. As a result of constructive upgrades for openhole packer column significantly decreased the percentage of no packer leakage, as was improved sealing rubber elements and node responsible for the safety of these elements.
Thus, to the ins developed packer designs include the preservation of the performance of the sealing rubber member by applying belting cord in the rubber and the mechanism of sliding bearings, which allows multiple re-planting packer in open hole. Just packer design allows exclusion of unauthorized operation during tripping. Another advantage of the upgraded design is to improve the packer tightness when working in wells with a large pressure drop.
In article the attention to a problem of slow subcritical development the crack-like defects resulting from influence mechanical (static and cyclic) loadings in the pipeline is paid.
Creation of model of destruction of the main pipeline in the presence in it the crack-like defects, static loadings, corrosion processes, cyclic damages of metal and dynamic effects represents very complex problem. Besides, it is almost impossible to develop the unified model realizing all variety of mechanisms and processes of destruction of metal owing to features of work of metal in the main pipelines.
In this work this problem is solved by definition of the characteristic considering consequences of processes of accumulation of damages and mechanisms of destruction.
The purpose of this work determination of the actual values of such parameter and research of its influence on the intense deformed state. In work the coefficient of linear temperature expansion as it is present at determination of temperature tension was chosen. Its actual values are defined by a dilatometric method. It was offered to solve researches of influence of coefficient of linear temperature expansion on the intense deformed state by means of the program ANSYS complex. The choice of numerical methods of calculation is caused by that it is possible to solve multiple calculations only by means of the COMPUTER, besides the ANSYS program gives out evident dependences of distribution of equivalent tension on length.
On the basis of the obtained data the dependences defining influence of factors at change of properties of material are constructed, on the intense deformed condition of metal.
It is as a result established that the temperature factor has most of all impact on the intense deformed state at change of coefficient of linear temperature expansion.