Residual oil, the remnant after crude oil distillation, presents significant challenges for processing and utilization due to its high density, high viscosity, and complex molecular structure. Hydrogenation of residual oil has become one of the key technologies for its deep processing owing to the environmental benefits and high yield of light oils it offers. This study primarily investigates the application of high-speed multi-stage Venturi-type purifier in puri-fying cold low pressure separator gases produced by residual oil hydrogenation. It uses fluid simulation methods to analyze the flow characteristics within the purifier and optimize the purifier design based on the simulation prediction. Fluid numerical calculations are based on models of the same dimensions as the actual device prototypes and the calculation results reveal the flow characteristics within the Venturi components and the atomization effects of liquid droplets under high-speed flow. On this basis, a comprehensive simulation of the purifier flow channels is conducted by further coupling with subsequent gas-liquid separation modules to explore the internal flow field characteristics and the droplet movement behavior within the system. The high-speed Venturi purifying equipment designed on the basis of the research results has been applied in the PSA feed gas purification process of a petrochemical plant's residue oil hydrogenation unit. After long-term operational testing at the industrial site, the efficient wa-shing performance of the high-speed Venturi-type purifier for impurity gases in hydrogen has been validated. This research can provide theoretical guidance and practical basis for gas purification technologies for industrial residual oil hydrogenation, and can be further optimized and applied in actual production.

For a PTA oxidation reactor, the shell material shall be SA-516 Gr.70/SB-265 Gr.1 clad plate and the procurement specification required that the thickness of internal agitated baffles shall not be less than 30 mm. Based on practical experience, the equipment manufacturer proposed an optimized baffle design featuring a three-section segmented configuration. The optimized design achieved a significant reduction in baffle thickness down to 16 mm by increasing the number of baffle supports and reducing the support spacing. This paper established a simplified analytical model of the baffle support structure to calculate its structural strength and deflection, while employing Finite Element Analysis (FEA) to evaluate stress intensity under fatigue loading. The assessment confirmed compliance with licensor specification requirements. Subsequent follow-up inspections and assessments of the agitator baffle demonstrated sound structural integrity after one year of operation with no defects identified. Practical application has shown that the optimized baffle design can improve support load distribution, reduce adverse impact on the clad plate of the vessel and achieve good operational performance.

Solid catalyst feeder is one of the core equipment in gas-phase polyethylene plant. In recent years, with the improvement of catalyst activity and the demand for high-grade polyethylene production represented by metallocene, new and higher requirements have been put forward for solid catalyst feed systems. Based on the engineering practice of a certain gas-phase polyethy-lene plant, this paper introduces the research and development process of skid-mounted solid catalyst feeder. It expounds the system composition, working principles, research and development points and application situation. During the R&D process, several key issues that restrict the performance of the equipment have been resolved and the localized production of the core equipment for polyethylene process has been achieved. This skid-mounted solid catalyst feeder has broad prospects for promotion and application, as well as good economic and social benefits.

In a large ethylene plant, the steam turbine used for the cracking gas compressor has experienced severe coking in thrust bearings du-ring operation and the axial displacement has remained in the alarm range for a long time, which eventually triggered high-high interlock and led to unplanned shutdown. The external manifestation of these issues are all characterized by excessive axial displacement in the compressor. When the axial displacement increases to the high-high interlock value, an unplanned shutdown will occur.The analysis has revealed that rotor axial force imbalance is the root cause of excessive axial displacement. Based on the actual operating conditions of the unit, this study tho-roughly resolved the aforementioned issues by expanding and relocating the balance pipe, as well as conducting domestically transformed thrust bearing modifications. These measures have yielded good results, while also pioneering the localization of critical spare parts for core units and accumulating valuable experience.

In order to further enhance the thermal efficiency of fired heaters and improve the scientific validity and rationality of waste heat recovery system design, this paper analyzes and studies the simulation calculation method for flue gas flow field of waste heat recovery system for fired heaters. Through boundary condition assumptions, calculation principles deduction, simulation calculation, and regression fitting based on on-site measured data, a technical route is summarized to form the simulation calculation method and flue design method for flue gas flow field in fired heaters. This provides a combined qualitative and quantitative analysis method for improving thermal efficiency and solving practical operation problems for fired heaters.

The petrochemical industry is not only a significant contributor to energy production, but also a key emission source of pollutants such as NO_x and CO₂. Low-oxygen combustion control technology serves as a primary technical approach for achieving energy conservation, emission reduction, and carbon mitigation in heating furnaces. It also constitutes a critical pathway to fulfilling the "Dual Carbon" goals in the petrochemical sector. In order to reduce the cost and improve the performance-price ratio and applicability of the retrofit of low-oxygen combustion control system, industrial tests were conducted to compare the monitoring and control perfor-mance of imported laser CO analyzers versus domestically produced dual-component zirconia O₂+CO_e analyzers. This initiative aimed to maximize the promotion and application of this energy-saving innovation and validate optimal analyzer selection for low-oxygen combustion control systems. The comparison results demonstrate that the dual-component zirconia O₂+CO_e analyzer can completely replace the imported laser CO analyzer in low-oxygen combustion control systems.

The medium stored in the hydrogen storage cylinder is high-pressure hydrogen, which will cause serious safety accidents once a leak occurs. The valve of hydrogen storage cylinders typically employ O-rings for sealing. Due to direct exposure to high-pressure hydrogen permeation and pressure, the sealing performance may change, thereby affecting the overall sealing effect of the valve. Therefore, with the goal of improving the sealing performance and service life of the valve groove structure of Type IV hydrogen storage cylinders, this paper adopts a self-developed hydrogen test device to simulate the influence of hydrogen on the O-ring under actual working conditions and uses the test results of the compressive properties of the O-ring to fit the constitutive equation of the material. In addition, the simulation analysis of the grooves of the bottle valve is also carried out to study the influence of varying groove bottom angles on the maximum equivalent stress. It is found that the maximum equivalent stress of the O-ring before and after the hydrogen test is the smallest when the groove bottom angle is 100°, and the maximum equivalent stress of the O-ring at this angle is reduced by 21.0% compared to that prior to the hydrogen test, whereas the stress reduction is only 14.3% when adopting the conventional groove design. Meanwhile, under the influence of hydrogen, the maximum equivalent stress of the O-ring is reduced by 6.6% when adopting a ramp groove structure with a bottom angle of 100°, compared to the conventional groove design of bottle valve. And the stress concentration distribution becomes more uniform.

The catalyst activity in acetylene hydrogenation reactors of ethylene plants is highly sensitive to temperature. Unstable temperature control may readily cause acetylene breakthrough or reactor runaway. Therefore, the accurate and stable control of reactor temperature is particularly important. The inlet temperature of the acetylene hydrogenation reactor is controlled by the control function block TIC30295, and the temperature element TE30295 is a K-type thermocouple equipped with E+H temperature transmitter. Temperature fluctuations in the reactor occurred multiple times during summer rainstorms and periods of significant temperature shifts, leading to corresponding emergence of acetylene content variations at the reactor outlet. A comprehensive multi-perspective analysis has been conducted on these fluctuation phenomena. Through simulated temperature measurement experiments, the root cause of aberrant fluctuations in the temperature control loop of the acetylene hydrogenation reactor due to ambient temperature variations was identified, enabling sustained stable operation of the reactor over extended periods. Concurrently, dynamic temperature measurement experiments revealed the inherent limitations of thermocouple cold-junction compensation in industrial applications. This led to the proposal of replacing thermocouples with Pt100 resistance temperature detectors (RTDs) as the solution.

The self-priming centrifugal pumps in petrochemical plants often fail to achieve self-priming during the commissioning phase. This paper analyses the causes of the above-mentioned fault based on the working principle of self-priming centrifugal pumps and actual cases. It identifies various factors that cause self-pri-ming faults and confirms that air leakage from the pump body and excessive pressure drop in the pipeline are the main factors leading to self-priming faults. Aiming at these causes, the paper puts forward suggestions for the equipment layout and pipeline design requirements of self-priming centrifugal pumps. These suggestions and requirements can improve the success rate of commissioning effectively and provide reference for future design work.

Currently, the increasing trend of crude oil deterioration poses greater challenges to corrosion control management, making it imperative to establish a scientific and standardized corrosion control workflow. A certain refinery has compiled a corrosion control manual for its crude distillation unit (CDU) based on identify-ing corrosion mechanisms and classifying corrosion circuits. This paper elaborates on the unit′s corrosion risk identification process for indivi-dual circuits using the corrosion control manual in conjunction with the operational process parameters, inspection of identified high-risk areas and subsequent internal examination verification during shutdown maintenance of the unit. It also expounds the critical significance of the corrosion control manual in corrosion management and formulates a PDCA closed-loop corrosion management workflow centered on this manual.

The technological complexity of the million-ton ethylene plants, characterized by intricate process flows, diverse equipment types, and overlapping effects of corrosion mechanisms, renders corrosion analyses of individual equipment during routine operations insufficient for fundamentally resolving corrosion challenges. This paper analyzes the corrosion mechanisms within the plant, investigates the typical corrosion issues and proposes anti-corrosion measures for both processes and equipment. It conducts systematic research and analysis of corrosion conditions in the entire ethylene plant during major overhaul shutdown to validate and optimize corrosion prevention and control measures. After comparing the similarities and differences in corrosion conditions over nearly two cycles, the key areas for corrosion prevention in the next operating cycle of the ethylene plant have been identified. This provides theoretical support for the long-term operation of the ethylene plant and ensures its reliable operation.