Combined with the commonly used process technology of expansion connection of heat exchange tube joint and using stainless steel S30403 as the material of tube and tube sheet, the mechanical expansion and hydraulic expansion of slotted structure are simulated numerically by the finite element method respectively. And the deformation mechanism and residual contact pressure distribution of the two processes are studied. The expansion depth and pullingout force are taken as the main evaluation indexes to analyze the effects of slotting size, set expansion on mechanical expansion and pressure on hydraulic. And comparative analysis is also conducted. These provide a basis for the preparation of heat exchanger standards and the parameters setting in expansion process.

The selfsupporting tower foundation includes two types: ground foundation and frame foundation. The seismic analysis of frame foundation is more complex, which is a difficult point in the seismic design. For the frame foundation, decoupled analysis is usually adopted for the frame supported tower and the supporting frame in the conventional method, and seismic analysis is carried out separately for the tower and frame foundation. The calculation model can't fully reflect the vibration characteristics of the combined structure of the tower and the frame, which is quite different from the actual engineering. In this paper, the overall combined structure model of tower and frame is established, and the distribution of mass and stiffness of the frame and tower along the height direction is taken into consideration. After comparative analysis, the seismic effect based on the overall model is less than that of the conventional simplified method, which is in line with the actual engineering. This can optimize the seismic design of frame and tower effectively.

Elliptical self-tight seal manhole with inside opening on steam drum is a common self-tight seal structure. However, there's no detailed description of the seal design of this structure in the existing standards and references, and there's a lack of instruction methods for reasonable gasket selection, and the problems of seal leakage and seal failure often occur in the practical application of engineering. In order to ensure the reliability of such seal from design calculations, the concept of gasket reliability factor was presented. According to structure analysis and summary of the application examples, this paper proposed four-step calculation method for the design of elliptical self-tight seal manhole with inside opening on steam drum including the formula to calculate and correct gasket effective sealing width and the formula to calculate the sealing performance.

In order to analyze the failure reasons of a steel single-layer spherical reticulated shell structure with fixedroof on one 20,000 m³ internal floating roof tank, the chemical composition and mechanical properties of the failure structure materials were analyzed. The results show that the sulfur content of the rod end castings of the hub joint, elongation after fracture and shrinkage after fracture of the test sample did not meet the requirements of relevant standards. Using the general finite element analysis software, the strength, stiffness and stability of the reticulated shells under design and failure conditions were analyzed respectively. And the analysis results indicate that the length to slenderness ratio of some members exceeded the design specification requirements, and the actual stress value of the member at the end of the rod exceeded the design value of the tensile strength of the material under failure conditions, which resulted in the strength failure of the structure.

At present, the price of light raw materials in the chemical raw material market remains high, and each ethylene plant has to face the situation of heavy cracking raw materials. The cracked gas produced by the cracking of heavy raw materials contains more gasoline components, and some of them enter the cracked gas compressor, causing the compressor to operate beyond the original design load. This greatly increases the burden on the compressor to drive the steam turbine. In order to maintain the high-load operation of the device, it is necessary to improve the capacity of the compressor in operation to drive the steam turbine. After comprehensive analysis, it is possible to improve the capacity of the compressor in operation to drive the steam turbine by improving the steam quality without replacing the main components of the steam turbine unit.

The ring tube axial flow pump is an important conveying equipment of polypropylene plant. Current fluctuations, power fluctuations, and inlet pumping-out often occur during pump operation, which affects the normal operation of the device. Two key test points Z1 at the pump drive end and Z2 at the pump inner bearing of a domestic axial flow pump are selected to test the actual operating parameters of the pump such as temperature, current and noise. The time domain and frequency spectrum are used to analyze the vibration data of the two key test points. The analysis results show that the effective value of vibration velocity in the Y-axis direction of the three-axis direction at the pump drive end Z1 is 3.940 mm/s which is the largest. The vibration energy in the Y-axis direction is high, and the pump body is slightly loose; there is no obvious impact feature in the test data of the two axial directions at the Z2 position in the pump inner bearing; the overall vibration amplitude is relatively small, and the internal liquid flow is relatively stable. The analysis results indicate that the vibration value of the pump is within the range specified in the relevant standards and will not affect the stable operation of the pump unit; the current power fluctuations and inlet pumping-out of the unit are mainly caused by sudden changes in medium density, speed and gas volume. According to the above phenomenon, this paper proposes corresponding solutions, which can provide reference for solving similar faults.

Vibration fault is a common fault of rotating equipment in petrochemical plants. From the perspective of field construction, this paper analyzes the types and causes of vibration faults of rotating equipment. Based on waveform and spectrum measurement results, the direct cause of vibration fault can be analyzed and judged scientifically during construction. And corresponding measures such as cladding welding repair process, bearing bush assembly process, laser alignment equipment, locking bolt, and internal seal installation methods and so on can be adopted to prevent and eliminate vibration faults, thus achieving a vibration fault rate of less than 0.5% during the general equipment maintenance cycle.

Steam turbine is the main prime mover driving centrifugal compressor, and its reliability is very important for long cycle operation of the device. This paper analyzes the failure case of the oil circuit control system of steam turbine and the optimization is carried out from the aspects of design, operation and maintenance. The scheme has been applied in the existing units and new units, and the reliability of the units has been improved greatly.

The good anti-corrosion work of the ethylene oxide/ethylene glycol plant can improve production efficiency and ensure the intrinsic safety of the plant. Taking the SD process as an example, this paper first summarizes the main damage mechanisms and proposes corresponding countermeasures. Second, a schematic corrosion process diagram is drawn to clarify the corrosion distribution and severity. Finally, corrosion control loops of typical corrosion regions are established to control the key process parameters. The research results show that organic acid corrosion and erosion are the main causes of failure, and the corrosion problems are mainly distributed in the stripper, multi-effect evaporator, EG reactor and drying tower. Corrosion can be alleviated by reducing the generation of acid and acid accumulation in the aqueous phase using corrosion control loop, which involves the process regulation of temperature, flow rate and pH value of the medium. This research aims to improve the integrity and reliability of the plant, and to provide reference for enterprises to accumulate anti-corrosion experience and improve anti-corrosion work.

Aiming at the failure of the girth welding in compressor inlet process piping, the analysis approaches such as the macro morphology, chemical composition, mechanical properties, metallographic structure and corrosion products were adopted to explore the failure reasons in combination with corrosive medium and corrosion acceleration test in order to improve the equipment integrity level in the compressor station. The results show that the corrosion rate of the weld is higher than that of the substrate in both gas and liquid phases, and the corrosion rate of the liquid phase is much higher than that of the gas phase. The failure site is located at 6 o 'clock direction at the bottom of the tube, and the failure develops from the inner wall to the outer wall. The external cause of girth welding failure is the welding quality defect, which forms turbulent cavitation zone locally in the weld, and the internal cause is the fluid containing corrosive gases such as CO₂ and H₂S. H₂S is the main corrosion type, and the looseness of corrosion scaling products creates conditions for the formation of block batteries. It is suggested to change the corrosion environment of pipeline by ungrading welding technology, improving welding quality, adding natural gas purification devices and dewatering devices. The results of this study can provide practical reference for failure analysis of the same type of process piping and for improving the management level of equipment integrity.

The reboiler of the dilution steam generation system in an ethylene plant has frequent leakage problems, which restricts the stable and long-term operation of the plant. By analyzing the corrosion morphology of the reboiler, the tube bundle material, the process medium and the overall condition of corrosion, this paper determines that the presence of corrosive medium in the process water system is the cause of the leakage. And the operation of the process anti-corrosion measures is not smooth, which causes the process water system to be an acidic or alkaline corrosive environment. And under certain temperature, pressure and flow rate, plus a superposition of cavitation effect, this results in serious local corrosion leakage in the reboiler tube bundle. Combining with the actual situation, this paper provides some suggestions for leakage prevention.

As an important medium affecting chemical reaction, catalyst is widely used in all walks of life around the world. The loading quality of catalyst directly affects the technical and economic indicators and the catalytic effect of production units. In recent years, fixed bed reactor has been widely used in gas-solid reaction and liquid-solid reaction process in petrochemical industry. The loading quality of catalyst directly affects the long-term and stable operation and the service life of catalyst. This paper summarizes and combs the methods of manual loading, dense phase loading, mechanical loading and intelligent loading used in fixed bed reactor catalyst loading. It analyzes the advantages and disadvantages of different methods. Then according to the analysis results and the current trend, the paper puts forward countermeasures and suggestions for improving catalyst loading equipment to improve catalyst loading quality so as to provide certain theoretical basis for realizing intelligent loading of fixed bed catalyst.