Building on China's achievements in independent innovation of petrochemical equipment during the 14th Five-Year Plan (2021-2025) period, this paper systematically analyzes the current status and trends of innovation and development in petrochemical equipment under the requirements for industrial transformation and upgrading and new quality productive forces cultivation during the 15th Five-Year Plan (2026-2030) period. Through typical engineering cases such as aromatics and ethylene projects, it discusses the supporting role of strengthening the independent innovation of petrochemical equipment in industrial transformation and upgrading. The paper conducts an in-depth analysis of prominent issues including deficiencies in core technologies and key materials, insufficient industrial chain collaboration, weak innovation support and inadequate standard systems. It puts forward strategic and operable countermeasures and suggestions from four dimensions: achieving breakthroughs in core technologies, fostering collaborative ecosystems, strengthening innovation support and improving standard systems. This provides both theoretical and practical foundations for achieving independent innovation breakthroughs in petrochemical equipment and empowering the high-quality development of the petrochemical industry during the 15th Five-Year Plan period.

The flow channel structure and nozzle arrangement pattern have a significant impact on the mixing efficiency of multiphase media within a jet-stirred reactor. A jet-stirred reactor was selected as the research object in this study. Considering different flow channel structural features and layout configurations, a three-dimensional finite element model of the flow channel structure and the internal flow field within the reactor was developed. The concentration field distribution of the fluid in the confined space was then analyzed. The calculation results show that the swirling channel can enhance the fluid flow in confined spaces to a certain extent. Compared with the direct flow channel structure, the mixing uniformity of the medium in the long and wide directions in the reactor with the swirling channel structure has been improved by 46.4% and 60.4% respectively; the mixing uniformity of the medium in the length, width, and height directions in the reaction vessel with a mixed arrangement of straight swirling channels has been greatly improved by 95.9%, 98.1% and 36.2%; the structure of the swirling flow channel and the arrangement pattern of the surrounding mixed flow channel can improve the mixing uniformity of the medium in the reactor to some extent. The different internal flow channel structures and channel arrangement schemes established in this paper provide reference for the design and optimization of flow channels in jet-stirred reactors.

This paper discussed several issues in the design of leg supports for vertical vessels. It first conducted a detailed analysis of the forces acting on the leg supports and derived the calculation formula for the vertical load imposed by bending moments. Meanwhile, through rigorous geometric derivation, the precise solution formula for the bolt circle diame-ter D_b—a parameter essential for vertical load calculations in leg-type supports—has been obtained. Corresponding auxiliary calculation software was also developed using the Visual Basic.NET language. Additionally, it identified specific errors within the SW6—2011 v5.0 calculation software. This study can provide valuable references for designers to better understand leg support calculation methods and conduct non-standard leg support design.

In the original solvent recovery column reboiler of a benzene extraction unit, the heat exchanger tube bundle utilizes ordinary smooth tubes, resulting in low heat transfer efficiency and high energy consumption. This paper introduced a high-efficiency enhanced heat transfer tube with spiral grooves on both inner and outer surfaces. The heat transfer enhancement effects of the tube was validated through theoretical analysis and CFD simulation. Meanwhile, the design calculation results for smooth tubes and reinforced tubes were compared based on the process conditions of the reboiler. The results show that under the same thermal load, the total heat transfer coefficient of the enhanced tube reboiler was 38% higher than that of the original reboiler; after implementing enhanced heat transfer tubes in the recovery column reboiler, its steam consumption was reduced by 14.04% compared to the period prior to their deployment. The above results demonstrate that the high-efficiency enhanced tubes can achieve the objectives of both improving heat transfer efficiency and reducing energy consumption, providing a crucial theoretical basis for the retrofit of solvent recovery column reboilers.

To tackle the problems of heavy weight and high cost associated with large-diameter bolted flat head, this paper proposed the spherically dished cover with a bolting flange as an alternative structure. Taking the flat head of a DN1900 stirred reactor in a certain project as the research object, the finite element numerical calculation method was employed to investigate the influence patterns of design variables on the peak equivalent stress (S_eq), central displacement (Δy₁) and sealing surface displacement (Δy₂) in both the simplified bolted flat head and the simplified spherically dished cover with a bolting flange. The results indicated that the comprehensive mechanical properties of the spherically dished cover with a bolting flange were superior to those of the bolted flat head. Applying the findings of this research to the design of multi-opening flat head for stirred reactors, the mass of the optimized head is reduced by 55%. This demonstrates that the spherically dished cover with a bolting flange offers greater economic advantages over the bolted flat head while ensuring structural strength and stiffness and holds significant potential for widespread adoption.

This paper addresses the cleaning challenges of sticky material on the inner walls of enamel stirred reactors during catalyst production. It provides an in-depth analysis of the negative impacts of material residue on production efficiency and product quality. Based on practical production requirements, an optimized cleaning method was proposed and a self-cleaning system was designed. The research outcome has successfully resolved the challenge of clea-ning sticky material on the walls in enamel stirred reactors. This solution offers broad applicability to solid-liquid two-phase reactors and demonstrates high promotion value in the petrochemical industry.

In this paper, the numerical simulation of solid-liquid two-phase flow in a volute centrifugal pump was studied. Using CFD method, the entire flow passage of the pump was established. The unsteady calculation of varying flow rates, particle sizes and concentrations were carried out. Combined with traditional flow field analysis and vortex dynamics method, the internal flow field under different calculation conditions was analyzed and compared. The results showed that the increase of solid particle size and concentration will lead to the decrease of pump head, but under the design flow rate, the decrease proportion of pump head is smaller than that under the off-design conditions. Under the condition of certain concentration and flow rate, increasing or decreasing the particle size will reduce the pressure pulsation. When the particle size is constant, increasing the solid concentration will reduce the amplitude of the pressure pulsation of the unsteady flow in the volute. There is a high Q-value at the diaphragm tongue in the volute chamber, so the pressure pulsation amplitude at the diaphragm tongue is the largest under all working conditions. And there is a large range of vortex band around the volute chamber, which causes the uneven pressure pulsation in the volute chamber.

The internal sleeve of the expansion joint in the large flue gas pipeline at the inlet of a petrochemical catalytic cracking unit cracked and detached. Through macroscopic observation, metallographic structure and fracture analysis of the internal sleeve, it is determined that the fracture mechanism of the internal sleeve is fatigue cracking. Through flow field simulations of the upstream butterfly valve at various opening angles, it is confirmed that the cause of the cracking was the small opening butterfly valve and the structural discontinuity of the expansion joint internal sleeve, which caused turbulence in the flow field behind the butterfly valve. This resulted in the formation of large vortex regions, triggering vibrations in the expansion joint internal sleeve. Under alternating loads, fatigue cracking and detachment occurred to the internal sleeve. For the above reasons, clear requirements have been put forward for the design, manufacture, use and maintenance and inspection of expansion joint internal sleeve in the future.

A newly constructed alkylation unit design has selected shielded pumps and centrifugal pumps as the main mechanical pumps. Among them, the shielded pumps mainly follow the API 68—2011 standard (hereinafter referred to as API 685) and the centrifugal pumps mainly follow the API 610 11th Edition standard (hereinafter referred to as API 610). By comparing the overhaul situation of the pumps during the 48-month operation period, it was found that the maintenance rate of the shielded pumps was much higher than that of the centrifugal pumps. In order to identify the causes of high maintenance rates in shielded pumps, a comparative analysis was conducted on the differences between these two types of pumps during the design and trial operation phases. The study revealed that the API 685 standard exhibit multiple deficiencies in commercial viability and manufacturing details compared to the API 610 standard. Meanwhile, shielded pumps present certain challenges during trial operations due to their unique structural characteristics, which reduce the operational reliability. Aiming at the aforementioned deficiencies and combining with the comparative advantages of centrifugal pumps, optimization direction of shielded pumps is proposed.

A hydraulic turbine (HT-101) is employed as an energy-saving device for the lean solvent pump (P-101A) in a natural gas purification complex. However, due to fluctuations in raw gas pipeline pressure, solvent circulation rates and other influencing factors, HT-101 ope-rates under suboptimal conditions, resulting in low energy recovery efficiency and a significant deviation between actual and theoretical efficiency. Consequently, this causes variations in power consumption among P-101A pumps within the complex. This paper conducted a comprehensive analysis and study on the operational performance of the hydraulic turbine from both human and equipment perspectives. It has identified that the rich solvent flow entering and exiting the turbine, the P-101A outlet flow rate and the total dynamic head value (TDH) are the primary factors affecting its operating efficiency. Aiming at the above reasons, effective countermeasures and implementation plans were formulated from the perspectives of effectiveness, feasibility, and economic viability. As a result, the energy recovery efficiency of hydraulic turbine in the single combined unit has been improved by 13.40% compared to pre-optimization levels, achieving the expected targets and reducing the energy consumption of the complex effectively.

During the operation of a 1 million t/a ethylene plant in China, abnormal vibration fluctuations and gradual increase were observed at the high-pressure cylinder drive end of the cracking gas compressor, accompanied by an elevated leakage at the primary dry gas seal of the drive end. Through adjusting lube oil inlet pressure and temperature coupled with state monitoring and analysis, it was determined that the abnormal vibration at the drive end of the compressor's high-pressure cylinder was caused by the combined effects including the unstable condition of the bearing bushings on that side and disturbances caused by adjustment to the unit load. This abnormal phenomenon also indirectly affected the operation of the high-pressure cylinder drive-end dry gas seal, resulting in increased primary leakage flow. Aiming at the above reasons, online treatment measures such as increasing oil pressure, lowering oil temperature to improve oil film stiffness, and stabilizing compressor operating loads were taken to resolve the compressor abnormal vibration and meet the requirements for safe and stable production.

A natural gas purification plant commenced operations in 2014 and has undergone three rounds of major overhauls to date. Through conti-nuous refinement of its maintenance practices, the plant has developed seven key optimization technologies including amine solvent system regeneration, sulfur sweep, water filling and pressurization of de-sulfurization units, hydrotreating catalyst cooling, gas tightness testing in high-pressure sections, feed introduction, and flushing and water circulation runs. The implementation of these seven technologies can enhance inspection and maintenance technologies, streamline startup and shutdown procedures and establish clear acceptance criteria for critical steps. This contributes to achieving an effective integration of safety, efficiency and quality in the inspection and maintenance of high-sulfur natural gas purification units, while providing references for overhauls of similar facilities.