This paper introduces the process of reciprocating compressor thermal re-calculation through one example. It makes a qualitative analysis on the interstage pressure ratio change when the compressor inlet or outlet pressure changes and arrives at the conclusion that the final stage pressure ratio changes the most. Meanwhile, this paper makes a precise calculation of the interstage pressure ratio change and re-balance process using HYSYS. The above conclusion can provide reference for compressor operation, selection calculation and calibration calculation.

Aiming at the flexible thin tube plate of one waste heat boiler, finite element models with different tube plate thicknesses are established respectively for temperature field analysis and stress analysis. The results of temperature field analysis show that the change of tube sheet thickness mainly affects the temperature distribution on the pipe layout area. With the increase of the tube sheet thickness, the metal temperature rises continuously on the tube side of the pipe layout area and the metal temperature difference on both sides also continues to increase. This may cause the overheating on the metal surface of the pipe layout area. In addition, stress field analysis results under Ps and Ps+ΔT calculation conditions show that the increase of tube sheet thickness mainly affects the bending stress value on the non-pipe layout area of the tube sheet, and the influence on the stress level on the other parts of the tube sheet is relatively small, including the arc transition section. Under Ps calculation conditions, the increase of tube sheet thickness significantly reduces the bending stress on the non-pipe layout area of the tube sheet; under Ps+ΔT calculation conditions, the increase of tube sheet thickness also reduces the primary plus secondary stresses on the non-pipe layout area of the tube sheet. However, the degree of influence decreases with the increase of tube sheet thickness.

Finite element analysis software is adopted for fine numerical simulation in order to analyze the local stress at the connection between tower equipment and lug in the lifting environment and solve the problem of inapplicable calculation method for the local stress of plate hanging lug calculated by the traditional standard calculation method. This paper studies the influence of lifting load, lifting angle and sling angle, cylinder thickness, radius, lug thickness, width and rib thickness on local stress (membrane stress and surface stress) of cylinder. Meanwhile, orthogonal experiment and multivariate analysis of variance were used to determine the influence weight of different parameters on local stress. The main conclusions are as follows: in modeling and analysis, finite element cylinder can be simplified by semi-model symmetric boundary. Other excessive simplified models may reduce the local stress. Under load condition, the load size and local stress have positive linear relationship, but with the increase of lifting angle, the stress of membrane stress changes slowly and the surface stress increases rapidly. In the actual hoisting process, the local stress of the cylinder reaches the maximum value with the lifting angle reaching about 60° and the local stress of the cylinder is obviously affected by the change of sling angle The thickness and radius of the cylinder have significant influence on the local stress, while the local stress of the cylinder does not change obviously when the width of the lifting lug and the thickness of the rib plate change.

Vertical storage tanks are widely used in the petroleum and petrochemical industries, especially in the oilfield surface engineering and refining industries. With the wide application of storage tanks, higher requirements are put forward for the integrity of the storage tank design in engineering. The opening of storage tank has become the weak point of the storage tank due to the destruction of the structural integrity and continuity of the storage tank. The opening of the storage tank usually bears the external load from external system, and there is a risk of stress concentration and failure. Combining with engineering practice, this paper emphasizes the necessity of stress analysis on the opening of the storage tank bearing external load of piping, and systematically expounds the stress analysis method. It also summarizes the common methods for stress analysis of tank openings in engineering: the analysis method based on allowable external load, the analysis method based on WRC Bulletin 297/107/537 and the analysis method based on finite element numerical simulation. Then the paper describes in detail the application conditions, steps of application and limitations of these three methods.

Currently large NEN vertical heat exchangers are widely used in process units. This paper expounds several calculation points based on the development of the calculation of such heat exchangers. Firstly, loads that are easily ignored in heat exchanger standards such as weight load and pressure drop should be considered; secondly, several Ansys finite element models dealing with such devices are summarized, including solid models, multi-point constraint (MPC) method models, and simplified models such as tube plates simplified to equivalent solid plates; finally, the application of various models are discussed. Based on the conservative analysis and evaluation of the connection between the shell and the tube plate in the current JB/T 4732 standard, the plastic limit load method is recommended in addition to the simplified elastic-plastic method and the primary structure method in ASME, and sub-model structure can be combined with the analysis to improve efficiency. Finally, the calculation results are summarized with one NEN reactor as an example.

Through understanding the design conditions, operation and use of reboiler bundles at the bottom of the stabilizers in 20 sets of catalytic cracking units, it is summarized that the main failure forms of reboiler bundles at the bottom of the stabilizers in the application process are sulfide corrosion and vibration wear/fracture. The main factors affecting sulfide corrosion are the formation of gas phase space or scaling in the upper tube bundle, resulting in a significant increase in the temperature of the outer wall of the tube bundle and the increase in sulfide concentration, which produces serious corrosion problems; the main factors affecting the vibration of the tube bundle are the structural design, process conditions and operation control of the heat exchanger. Combined with the field application, standard specifications and design experience, the dual measures of corrosion prevention and vibration control are proposed to solve the leakage problem of reboiler tube bundles.

In order to obtain the influence laws of hydraulic testing on the corrosion in the pipeline, take good measures for corrosion protection and improve the safety of hydraulic testing, scanning electron microscope and XRD analysis methods are adopted to analyze the tube that has failed in the hydraulic testing. The microstructure, corrosion products and local corrosion cross sections of the pipe surface near the leakage point of hydraulic testing are analyzed and studied. The results show that the existence of more serious local corrosion on the surface of the pipe and axial cracks in the pipeline are the two causes for the failure of pressure stabilizing during the hydraulic testing; the corrosion products of the inner wall of the hydraulic test pipe are mainly stable γ-Fe₂O₃, α-Fe(OH)₂, and there is also a small amount of unstable corrosion intermediate product γ-Fe(OH)₂ with poor protection, causing the bottom of the pipeline to be still in active corrosion phase; the inner wall of the hydraulic testing pipeline corrodes the material film in the inner, middle, and outer layers; the outer layer is loose, unstable, and poorly protected; the middle layer is mostly a relatively stable α-Fe(OH)₂, and the inner layer has a higher oxygen content; the binding between the metal matrix is relatively close, and it is mostly very stable γ-Fe₂O₃; there's a gap between the outer layer, the middle layer and the inner layer, which is prone to crevice corrosion and leads to severe local corrosion.

This paper introduces the importance and the upgrading of the API 610 specification. It compares the differences between the 11th and 12th editions of API 610 in detail and interprets them in combination with engineering practice. After 10 years of summary and improvement, the 12th edition of API 610 better conforms to the actual engineering, and provides a better selection and design reference for the majority of practitioners. Meanwhile, some requirements in the new version have not yet been applied in actual projects. In the future, all parties need to negotiate with each other, study this specification in detail, and adapt to it gradually.

This paper briefly describes the manufacturing process of 2.25Cr-1Mo-0.25V heavy-wall forge welding hydrogenation reactor. By supervising the manufacturing process of 2.25Cr-1Mo-0.25V heavy-wall forge welding hydrogenation reactor in several large refining and chemical projects in recent years, the paper summarizes the typical quality problems such as unstable impact performance of cylinder forgings, unqualified ultrasonic detection, blind area of ultrasonic detection and other quality risks which should be controlled in manufacturing. Combining with the relevant test results, it focuses on analyzing the causes of the problems, and puts forward the corresponding quality management methods in order to provide reference for domestic manufacture and inspection of large forge welding hydrogenation reactors.

A high sulfur natural gas purification plant adopted the reduction and absorption process of hydrogenation reduction+amine absorption+tail gas incineration and the sulfur recovery rate exceeded 99.9%. The main function of tail gas incinerator in natural gas purification plant is to treat the residual tail gas after sulfur recovery and tail gas treatment by thermal incineration so as to make H2S and other sulfide, hydrocarbon, hydrogen, CO and other substances fully oxidized and meet the discharge standard. This can avoid environmental pollution. This paper introduces the basic control principles of tail gas incinerator in natural gas purification plant. Aiming at the problem of accident expansion caused by abnormal shutdown in the actual operation of tail gas treatment unit, the paper summarizes the key steps and principles of control and emergency disposal of tail gas incinerator which can reduce the number of accident expansion caused by abnormal shutdown. Moreover, aiming at the problems of nitrogen oxide exceeding the standard and the failure of the igniter head of the pilot lamp which often occur in the tail gas incinerator of the natural gas purification unit, separate solutions are given to ensure safe and smooth operation of the incinerator.

This paper conducts statistics about the equipment failures affecting unit production that occurred in 31 refining enterprises of a large petrochemical group company from 2019 to 2021. And the scope of the statistics covers more than 500 sets of refining units in 11 major categories. Big data analysis is conducted from multiple dimensions such as time, equipment, device, failure type, failure strength as well as management and technology through sorting out the faults. The paper summarizes the laws and causes for the equipment failures, and puts forward suggestions and measures to reduce equipment fault rate.

In order to fully ensure the effective operation of equipment and facility systems and eliminate the unsafe states of equipment and facilities in time, and further improve the safety and security of LNG receiving stations during production and operation, this paper thoroughly discusses and analyzes the integrity management process for equipment and facilities. It proposes the workflow of static equipment inspection based on risk. The paper outlines the steps of static equipment risk analysis such as risk calculation, failure possibility analysis, failure consequence analysis, and risk assessment. This can provide reference for practitioners.