The concept and risks of medium blow-by in hydrogenation unit are introduced. According to the operating pressure, the hydrogenation unit is divided into high pressure, medium pressure and low pressure systems, and medium blow-by occurs in the connection parts of systems with different pressure levels. Typical medium blow-by is divided into five categories, i.e., medium blow-by in high-pressure pumps, compressors, high-pressure vessels/columns, multi-branch systems and special parts. The prevention and control philosophy for medium blow-by is put forward, that is to carry out the prevention and control step by step in the sequence of anomaly discovery and alarm, software prevention and control measures, hardware prevention and control measures, and final prevention and control measures. The multi-level combined prevention and control measures are given against the five categories of medium blow-by risks in hydrogenation unit. These philosophy and measures can be applied in various refining and petrochemical plants for reference.

In order to recover propane from oil and gas fields, two improved propane recovery processes are proposed based on the existing patented DHX process, and the three processes are simulated and analyzed by HYSYS. The results show that all the three processes can meet the requirements of propane recovery rate higher than 98% and ethane to propane ratio at the bottom of deethanizer no higher than 1.6%. The patented DHX process is complex. It uses propane refrigeration system and has high equipment investment cost. The improved DHX process Ⅰ and Ⅱ eliminate the propane refrigeration system, simplify the process flow and reduce the equipment investment. The energy consumption of dry gas outlet compressor in the improved DHX process Ⅱ is 47% higher than that of the improved DHX process I. That is to say, the improved DHX process I is superior to both the patented DHX process and the improved DHX process Ⅱ in terms of energy consumption and operability. Therefore, the improved DHX process I is recommended for propane recovery unit for higher propane yield and lower energy consumption.

In order to prepare high purity isobutane product from C4 fractions, a new process that combines extractive distillation, hydrogenation and product separation systems was designed. The best process flow scheme and operation parameters were determined by simulation, providing guidance for on-site operation of the plant. By optimizing the heat exchange network, the steam consumption was reduced by 20%, the cooling water consumption was saved by 2000 t/h, and an accumulative economic benefit of 50 million RMB was created annually. This route has become a new way for the rational utilization of C4 resources in China.

This paper introduces the concept and definition of inherent safety design and emphasizes its important role in the engineering design of petrochemical plants. The safety protection layers in industrial processes and the position of instrumentation control in the layers are discussed. BPCS and SIS have different functions for their different realization modes and response time. According to the characteristics of BPCS and SIS, the fail-safe principle and separate setting principle for instrumentation control in inherent safety design are presented. Based on engineering design experiences, the typical practice of instrumentation control in inherent safety design is put forward to reduce the material reserves, prevent the further leakage of chemicals and maximize the application of SIS system.

This paper focuses on the corrosion of vacuum pump in the deoctanizer of a megaton ethylene plant. It was found that the main causes of the corrosion in vacuum pump system were under-deposit corrosion and dissolved oxygen corrosion. At the same time, the corrosion of the vacuum pump was aggravated by the insufficient injection of preservatives and the high temperature working environment. Finally, the corrosion in the vacuum pump system was effectively alleviated by intensifying the flushing of desalted water tank, eliminating the leakage and removing the oxygen in the system, increasing the injection amount of preservatives, dredging the process flow and reducing the working temperature, thus ensuring the long-term and stable operation of the vacuum pump system

This paper introduces in detail the key points in the selection of anti-surge valve for centrifugal compressor from the aspects of the type selection of anti-surge valve, the calculation and selection of CV value, and the quick opening time and flow characteristics of anti-surge valve. Based on practical engineering, inappropriate CV valve and long quick opening time may cause surging problems. Some feasible solutions are put forward, providing guidance for the rational selection of anti-surge valve for centrifugal compressors.

By using systematic analysis tools, Electrical System Robustness Study (ESRS) finds out the potential weakness in power supply and distribution system early in the engineering stage, and puts forward corresponding solutions to eliminate them in the engineering stage, so as to ensure the system robustness and the normal operation and maintenance of the plant. The application of ESRS in an oversea refinery project is introduced from the aspects of research objectives, research scope, focus and items to be noted to provide some help for domestic and oversea projects in the future. It is hoped that effective ESRS can be conducted in future domestic projects.

Faced with the construction of large-scale petrochemical plants, a large number of engineers adopt high and large concrete frame equipment foundation matched with the construction scheme of high-support formwork. Based on the construction experience of high-support formwork of blending silo foundation in PP plant, the high-support formwork of blending silo foundation in SINOPEC-SK’s 300 kt/a PP plant is taken as an example to discuss the calculation methods and construction points of high-support formwork.

The numerical simulation of the flow field in vane gas-liquid separator was carried out by Computational Fluid Dynamics, and the influences of gas velocity and swirling blade angle on the pressure drop and droplet removal efficiency of gas-liquid separator were studied. The results showed that the pressure drop of gas-liquid separator was proportional to the square of gas inlet velocity. The droplets with relatively large diameter showed a “V” shape distribution in gas-liquid separator and was significantly influenced by gas velocity and swirling blade angle. High demisting efficiency was achieved. The small diameter droplets showed a more uniform distribution in gas-liquid separator. Compared to gas velocity, the 15°swirling blade angle had a more significant effect on the removal efficiency.

The deep vacuum pumping system of the atmospheric and vacuum distillation unit III at SINOPEC Jinling Company consisted of third stages of steam vacuum pumping, in which wet air cooling and ordinary water cooling were used for the cooler downstream the vacuum extractor. However, the corrosion fouling was serious, the cooling effect was not good, and fluctuation vacuum was observed in the deep vacuum tower system. So it was necessary to revamp the system with a scheme using secondary steam pumping, high efficiency water cooling and liquid ring pump unit. After the revamping, the steam consumption and sulfur-containing sewage was significantly reduced, the energy consumption of the plant was reduced, and the economic benefit was remarkable. This paper discusses the comparison and selection of process schemes for the revamping and the design and application effect of process flow, layout and piping installation.

This paper introduces the process flow and features of DSWAS technology for the 18 kt/a spent acid regeneration unit at PetroChina Jinzhou Petrochemical Company. The actual operation shows that the economic and technological indexes of the unit are good, and the flue gas emission index meets the special emission limit of atmospheric pollutants stipulated in the Emission Standard of Pollutants for Petroleum Refining Industry (GB31570-2015). And the problems in the operation of the unit and the countermeasures are briefly discussed.

In order to eliminate the security risk of DCS network in Chongqing Natural Gas Purification Plant (hereinafter referred to as the purification plant), the network structure, security status and security risks of 10 sets of DCS system in the purification plant were analyzed, so as to find out the network security status and the security risks of DCS system in the purification plant. Combined with cause analysis and the requirements of relevant laws, regulations and standards, some improvement measures and configuration rectification suggestions on DCS network security in the purification plant were put forward according to the information of DCS network security products introduced by many DCS manufacturers. The research showed that there were three problems in DCS network security in the purification plant, i.e., few network security protection facilities, function failure of the existing protection facilities, and lack of DCS network security management system. It was concluded that the security risk of DCS network in the purification plant is increasing day by day, and it is necessary for the purification plant to further strengthen the DCS network security configuration and establish a DCS network security management system, so as to ensure the safe operation of DCS system.

Large scale equipment not only brings difficulties for transportation and hoisting, but also brings greater challenges to equipment manufacturing. Great attention should be paid to the quality control in the manufacturing process of large towers. The roundness, straightness, perpendicularity after installation and the levelness of tray support ring will directly affect the installation of internals and the process performance guarantee of the tower. The causes of roundness outlier of large tower, a common problem in the manufacturing, are analyzed based on engineering design examples. A whole tower model is established by ANSYS based on the measured roundness, and qualitative and quantitative analysis are carried out for the influence of roundness outlier on the strength of tower as well as the deformation of tower section and the overall trend, not only providing guidance for the intrinsic safety risk assessment of tower and the site installation of internals, but also providing ideas for dealing with similar problems.

Based on the two failed start-up of a steam turbine in a domestic project, the reasons for the problems were analyzed from many aspects, the construction, engineering design and start-up plans were correspondingly adjusted and modified according to the final analysis conclusions, and the steam turbine was started up successfully at the third try. This paper points out the items to be noted during the design of steam turbine inlet pipe, the installation of pipe support and prior to the start-up of steam turbine.

The vertical equipment of petrochemical plant is arranged in framework. Due to the influence of thermal expansion during the operation of equipment, the head of the equipment and the pipes connected with the equipment often collide with the steel structure. Combined with the problems emerged during construction, this article expounds the basic requirements and matters needing attention for the platforms and openings at different positions of vertical equipment in the framework of petrochemical plant, classifies and analyzes the influence of thermal expansion of equipment on the platforms and openings at special positions such as the reducing section of equipment, the inclined pipeline and the top of equipment, compares and discusses in detail the three different design forms of top platform, and summarizes the key points and precautions of platform settings under different circumstances for better application in other designs.

This paper introduces the outline features of equipment, the plane layout and the key points of connecting pipeline planning for the reformer drum of the 40000 Nm3/h hydrogen plant in a refinery. The reformer drum is connected with two waste heat boilers at the same time. The riser from the outlet of the two waste heat boilers to the inlet of the drum can be considered as belonging to the same drum riser piping system. The stress analysis software CAESARII is used to calculate and optimize the design of the steam drum piping system of the reformer. The problems in the design are discussed in this paper, which can provide reference for the design of similar units in the future.

By analyzing the process and methods of manually calculating and selecting large pipe support of towers, it was concluded that various parameters, large amount of manual calculation and repeated checking were the main reasons for the difficult and time-consuming calculation and selection. A calculation program was written to change the current calculation and selection of large pipe support of towers, and its application effect was tested with an example. Practice has proved that by writing the calculation program, the calculation and selection time of large pipe support of towers was shortened, and the problems of low manual calculation efficiency and error-proneness were solved, providing a fast and effective calculation tool for the calculation and selection of large pipe support of towers.

This paper introduces the development, structure characteristics and application scope of cracking furnace steel frame with wall panel, and briefly introduces the structural design key points and experience of cracking furnace steel frame with wall panel, including the influence of large-scale modularized cracking furnace on the structure, the design difficulties of bottom column and cross-section hearth-passing column, and the inter-module column splicing, the calculation of wind load and the rational design of top-level equipment. Some design ideas and design difficulties to be noted are provided for the design of cracking furnace steel frame with wall panel.