Firstly this paper introduces the classification of dry gas seals in API 692. Taking the most commonly used series seal with interstage labyrinth seal as an example, it lists the system configuration schemes of dry gas seal in detail. API 692 divides the dry gas seal system into 6 parts and 38 subcategories. Under different circumstances, different subcategories are selected to form the dry gas seal system. Then, the differences between engineering design and specification requirements are compared with examples according to the authors' understanding. API 692, as a newly issued standard, provides a detailed basis for the design and manufacture of dry gas seals. At present, many projects have not fully implemented API 692 standard. In the future, if this standard is strictly implemented, all parties need to study it in detail and gradually adapt to it.which has achieved many successful applications in engineering practice. In this article, several solutions of naphtha hydrotreating feed heat exchanger have been analysed and compared. The optimization of solutions and recent application of heat transfer enhancement techniques have also been summarized.

In petrochemical projects, centrifugal hydraulic turbine can be used to recover and reuse the surplus liquid in the process of depressurization of high pressure fluid. Centrifugal hydraulic turbines are available in a variety of structures, depending on the differences in the working conditions of the recoverable surplus liquid energy. Along with the increasing technology readiness in the design and application of centrifugal hydraulic turbines, the demand for them continues to rise. Based on the theoretical support of practical needs for hydraulic turbine energy recovery and the application achievements in petrochemical plants, this paper focuses on introducing the advantages and disadvantages of different unit matching programs and considerations for selection, covering the application fields, product structure, technical difficulties, unit matching programs of hydraulic turbines. It is hoped that the owners (users) and the design institutes (designers) will know more about centrifugal hydraulic turbines, which will be helpful for those in need to select centrifugal hydraulic turbines in new projects or subsequent energy-saving revamps.

For the flexible thin tube sheet of one waste heat boiler, finite element analysis models including different arc radius of transition section are established. The temperature field distribution and the temperature change law at different paths of flexible thin tube sheet are analyzed. The results indicate that the temperature distribution of the flexible thin tube sheet is obviously different from that of the thick tube sheet. For the flexible thin tube sheet, the temperature along the axial direction is linearly distributed, but the temperature along the radial direction shows a gradient decreasing trend. In addition, different models of the flexible thin tube sheet with different corner radius are analyzed under P_s and P_s+ΔT calculation conditions. The results show that with the increase of corner radius, the stress conditions at the arc transition section and the nonpipe layout area are improved obviously, but under P_s+ΔT calculation conditions, the stress at the tube layout area and the axial stress of heat exchange tube is increased significantly.

Cold lining technology of small diameter stainless steel liner for pressure vessels is widely used on offshore platforms, so it is necessary to study it systematically. Firstly, the simplified mechanical model of cold lined composite pipe is established, and the calculation formula of the minimum interference under internal pressure is obtained according to the theory of elasticity. Then, aiming at the typical small-diameter nozzle, five different interference models are established by using the finite element analysis software ANSYS, and the distribution laws of contact pressure and stress intensity of the assembly joint surface of cold lined composite pipe under cold lining state and internal pressure state are obtained. Finally, in order to study the influence of internal pressure on the stress of cold lined composite pipe, four groups of different internal pressure are loaded according to the typical model, and the distribution law of stress intensity on the assembly joint surface of cold lined composite pipe under internal pressure is obtained.

According to the monitoring requirements of petrochemical fired heaters in the operation process, a two-dimensional temperature field acquisition device is installed on the combustion test heater of a company, and the collected temperature data and the thermal imaging map are analyzed and studied. Based on the dual attributes of temperature and image with two-dimensional temperature field information, this paper integrates the analysis means of both temperature and image dimensions, fully exploits the application value of furnace chamber temperature data, and realizes the functions of three-dimensional furnace chamber temperature field construction, flame combustion diagnosis, flame out alarm, furnace tube over-temperature hot spot and deformation monitoring, which provides more technical means to monitor the normal operation of heaters.

In the hydrogenation unit, feed reaction furnace and fractionation heating furnace are important heating equipment. With the upsizing of equipment, the heat load of fractionation heating furnace is also increasing. For the upsizing heating furnace, the furnace type selection is diversified. In order to choose the furnace type of heating furnace between box furnace and cylindrical furnace, designers have different considerations and focuses. In this paper, the furnace type of fractionation heating furnace in hydrogenation unit is discussed from different aspects such as process parameters, structure parameters, manufacturing and transportation so as to provide reference for the selection of furnace type.

For the S-Zorb regenerator, which has been in use for nearly 2 years and operating at over temperature, the deterioration of its main material 14Cr1MoR(H) is studied through mechanical property test, metallurgical structure analysis and simulated postweld heat treatment tests, and the welding repair process was developed. The results show that the yield strength and elongation after fracture of the base metal decreased by 40% and 15% respectively at normal temperature, and the impact toughness in the heataffected zone of the weld decreased by about 30%. There was a certain degree of material deterioration, but the metallographic structure of the material was normal and the ductilebrittle transition temperature was still far lower than the minimum metal design temperature of the equipment. After holding at (690±14) ℃ for 20 h and 4 h, the maximum decrease in the normal temperature tensile strength and high temperature yield strength of the base material was 15% and 21% respectively, and the impact toughness decreased by 55%. The maximum decrease in the normal temperature tensile strength and high temperature yield strength of the weld was 11% and 4.7% respectively, and the impact toughness decreased by 31%. In the metallographic structure, the carbide precipitates increased obviously and the particles became coarser. However, the yield strength and plasticity of the base metal at normal temperature were restored to a certain extent. The ductilebrittle transition temperature had little change. The material properties still met the technical requirements of the equipment. On this basis, the welding repair process was developed and applied to the regenerator. The equipment was put into operation for one cycle (3 years) and was in normal operation.

In order to effectively make up for the limitations of traditional corrosion monitoring technology such as probe monitoring, corrosion coupon monitoring and offline thickness monitoring, a petrochemical company introduced online ultrasonic thickness measurement and corrosion monitoring technology in the plant with more serious corrosion. The technology has the advantages of being applicable to high-temperature pipeline thickness measurement, flexible and convenient installation, cost savings and so forth. Application results show that the online thickness measurement and corrosion monitoring technology is stable and reliable with accurate data; the comparison error with offline thickness measurement data is no more than 6%. This technology can monitor the remaining wall thickness of the pipelines accurately, reflect the corrosion change trends truly, detect corrosion hazards timely and prevent corrosion events. Therefore, it will become a new technology widely used in corrosion monitoring in petrochemical plants in the future.

Styrene has the main physical and chemical characteristics of easy volatility and polymerization. Its VOCs will not only cause environmental pollution, but also bring harm to human body. It is suspected that long-term exposure to styrene is carcinogenic. Therefore, it is particularly important to have deeper analysis and understanding of the influencing factors of VOCs emission from styrene storage tanks so as to take corresponding and reasonable measures for treatment and do a good job in the cold insulation construction of storage tanks. In this paper, the influencing factors of tank design pressure, operating pressure, operating temperature, cold insulation thickness, solar radiant heat and ambient temperature are calculated, analyzed and compared respectively so as to have a deeper understanding of VOCs emission law of styrene storage tank and provide reference experience for VOCs emission in similar tank areas. It provides a design basis for the scientific treatment of VOCs in storage tanks. In addition, this paper puts forward the cold insulation construction and installation method of styrene storage tank combined with the thermal insulation method of storage tank, the cold insulation method of pipeline and equipment, and the structural characteristics of storage tank. This can provide some reference experience and guiding significance for the construction of similar projects and the preparation of relevant standards and specifications.

In order to solve the corrosion problem of the atmospheric pressure tower top and the corrosion problem of the top circulation system of the atmospheric and vacuum unit of a factory, the atmospheric pressure tower top was changed from a cold reflux process to a hot reflux process. After the revamp, the corroded parts have shifted significantly. Among them, the pressure pipeline behind the atmospheric tower top heat exchanger has severely corroded and thinned, and the air-cooled tube bundle has corroded and leaked, which affected the long-term stable operation of the device seriously. This paper analyzes the corrosion phenomena that occur under the constant-top cold reflux process and the constant-top hot reflux process respectively. Then it discusses the advantages and disadvantages of the two reflux processes based on the actual situation and proposes corrosion control recommendations.

The GH4033 bolt of the slide valve in an FCC unit was fractured after being in use for one year. In order to find out the fracture reason, macroscopic analysis, chemical composition, microstructure, fracture and microscopic analysis of the broken bolt were carried out. The results showed that the bolt was fractured by intergranular creep. Because the availability state did not meet the requirements of quality assurance, the austenitic grains were coarse and only a small amount of carbides precipitated along austenite grain boundary, so the fine grain strengthening and grain boundary strengthening were weakened; the high temperature creep performance of the bolt was reduced; under the action of high temperature and high stress, the micro cracks were formed due to the appearance of creep cavity, and the cracks expanded along the grain boundary, which led to the early rupture failure of the bolt.

The blockage of feed nozzle of FCC feedstock will limit the processing capacity of the unit and decrease the light oil yield. In serious cases, it will cause unplanned shutdown of the plant. Previously, there is no mature on-line treatment method for the complete blockage of the nozzle. Through comprehensive application of pressurized opening technology and high pressure cleaning technology, the special packing seal box was developed, and the reasonable working process was set up to realize the online dredging of FCC feed oil nozzle blockage, which can avoid economic loss and safety risks caused by unit shutdown. This technology can be used for reference to other equipment and pipeline online cleaning and dredging, and has a wide application prospect.

Flue gas turbine is the core equipment of waste heat recovery system of catalytic cracking unit. It is directly related to the smooth operation, safe production and energy saving and consumption reduction of the whole plant. Combined with the scale formation of flue gas turbine in the 2.2 million t/a heavy oil catalytic cracking unit of certain company, the causes for scale formation were analyzed. The results showed that the viscosity of catalyst, the concentration of fine powder and the centrifugal force caused by high-speed swirl were the key factors for scale formation. Aiming at the above-mentioned reasons, this paper put forward the preventive measures and suggestions to ensure the long-time stable operation of the flue gas turbine.

This paper analyzes the reasons for the high bearing temperature during the operation of the circulating pump in a petrochemical plant. It investigates the factors that may cause the fault one by one and determined that the fault was due to the thermal imbalance during the operation of the circulating pump. Under the premise of unchanged operating conditions and pump structure, the bearing box was improved to completely eliminate the operation fault of the circulating pump and ensure the stability and the optimal operation of the device.