The naphtha hydrotreating unit is an important processing unit in petrochemical industry. With the treatment capacity of the units becoming larger in recent years, design and manufacture of large-scale equipment has gradually become the focus and difficulty of engineering practice. The naphtha hydrotreating feed heat exchanger is the key equipment for naphtha hydrotreating unit to reduce the feed heater load which can contribute to energy saving and emission reduction. Therefore, its design and optimization are also being updated constantly. The heat exchanger design has been changed from one pass shell with single series to two pass shells with double series and combination of other heat transfer enhancement techniques, 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.

Based on the analysis of chemical composition, microstructure, mechanical properties, fracture and energy spectrum, this paper analyzes the fracture causes of S30409 wing valve diversion cone in an FCC unit. The results showed that a large amount of σ phase was formed in the matrix structure and weld during the long-term high temperature operation of the wing valve; precipitation of σ phase led to decrease of the plasticity and toughness of the material; when the device was switched to the fan operation, the fluctuation of the working condition resulted in the vibration of the cyclone system, which impacted the wing valve; the accumulated damage at the weld seam of the guide cone with large stress concentration formed micro-cracks; the vibration cycle accelerated the crack expansion and finally led to the fracture and fall-off of the guide cone of the wing valve.

In order to explore the effects of different deposits sedimentation factors on crude oil sedimentation, a single variable method is used to control the factors such as different temperature ranges, shear rate, oil-displacing agent content and asphalt content. Indoor storage tanks are used to carry out deposits sedimentation comparison experiments. The results show that when the temperature difference of the oil wall is constant and the temperature interval increases gradually, the sedimentation of deposits decreases gradually; when the rotating speed is below 90 r/min, the sedimentation of deposits increases as the speed increases and when the rotating speed is higher than 90 r/min, the deposit sedimentation mass decreases gradually with the increase of the speed; the deposit mass increased by 13.9% in the range of 0.5% to 1.4% of the oil-displacing agent content. There is a nonlinear relationship between asphalt content and deposit mass, and when the asphalt content reaches 4% to 4.5% (w,%), the deposit mass decreases. The results of the analysis can provide reference for the sedimentation law of storage tank deposit in the future.

A company uses petroleum associated gas as raw materialin its associated gas treatment plant.With the gradual depletion of petroleum resources, the production of associated gas has been declining and the content of C3 and higher fractions has been decreasing as well. This resulted in the reduction of the amount of gas-liquid phase entering the column tray, and the decrease of the ratio of liquid phase to gas phase. The rectifying tower load has deviated far from the design value, which led to the decrease in separation efficiency and product yield of the rectifying tower. In view of this situation and through the hydraulic simulation calculation of the energy consumption and tray data of the unit, the opening rate was recalculated; the adaptive optimization of the rectifying tower was carried out and over 60% of the floating valve on the tray was blocked; a baffle was added to reduce the amount of liquid phase entering the blind zone, ensuring the mass transfer effect between the gas and liquid phases. After the revamp, the mass transfer performance of the tray in the rectifying tower was upgraded greatly, the product quality was improved and the energy consumption per unit product was reduced.

Aiming at the characteristics of high oil content and low sludge content in Xingzhong oil sludge, a new double-layer cyclone structure is proposed for the three-phase separation of oil-water-particles. Numerical simulation is used to study the separation effect of single-layer cyclone and three double-layer cyclones with different inlet type by selecting the hybrid model and k-e model, and analyze the effects of each cyclone structure on the pressure distribution, oil-water distribution and sludge particle distribution efficiency. The results show that: the cyclone separation effect is the best when the inlet flow rate is 40 m³/h, i.e., the inlet flow rate is 6 m/s; the pressure in the outer layer of the double-layer cyclone conforms to the pressure distribution characteristics of the cyclonic field, and the pressure difference distribution in the inner layer is not obvious, but the pressure is stable, which can further separate the fluid and oil sludge particles; the oil phase purity in the inner layer of the three types of double-layer cyclones is above 95%; and the oil phase purity in the overflow of the inner cyclone is more than 99%. The structure of double-layer cyclone can improve the three-phase separation effect of oil-water-particles effectively.

The weld cracking of expander inlet line of FCCU threatens the operation safety seriously. This paper lists the key factors and operation requirements from the aspects of design, welding materials, welding construction and operation. This is helpful for the operators and maintainers in the industry to understand the cracking mechanism, and then to find and solve the problems.

TP347 is widely used in high pressure pipelines of residue hydrogenation, wax oil hydrogenation and hydrocracking units in petrochemical industry. However, in recent years, reheat cracks have appeared in the stabilization heat treatment of thick wall TP347 pipelines in many projects. Therefore, combining with the actual engineering case, this paper formulated the research scheme aiming at the T347 reheat crack with the weldability of TP347 material as the starting point. Through the residual stress detection, four point bending, intergranular corrosion, micro metallography and other series of experimental research, the paper determined the main influencing factors of reheat crack after stabilization heat treatment. According to the research conclusions and construction site conditions, it put forward the specific preventive measures to avoid cracks of stainless steel pipe after TP347 stabilization heat treatment.

In recent years, with the rapid development of new energy such as photovoltaic power generation, the ambitious goal of "carbon peaking and carbon neutrality" was put forward in 2021, and it has become one of the important tasks of the central energy enterprises to develop and deploy new energy vigorously. Compared with traditional energy generation, photovoltaic power generation has the advantages of no risk of exhaustion of energy sources, safety, no noise and no pollution emissions, and has become an indispensable way to reduce carbon emission and achieve carbon neutrality. Taking the installation of photovoltaic devices in gas stations as an example, this paper introduces the design principles of photovoltaic energy storage control system, construction composition scheme, economic benefits and the impacts on the country's future energy pattern, which will help to inject new force of green environmental protection for a better life.

In order to meet the requirements of national environmental protection standards, petrochemical companies have carried out the transformation of low-nitrogen burners for heating furnaces with substandard emissions. Aiming at the existing problems after the transformation of xylene tower reboiler, the simulation analysis of a single low-nitrogen burner at the bottom was carried out; the existing problems of the original structure were found out and the corresponding improvement scheme of the burner structure was brought forward. According to the scheme, the numerical simulation verification of the whole furnace combustion was carried out and the internal flow field was analyzed emphatically. Through the verification, it was concluded that the structure improvement scheme of the burner was reasonable and suggestions for the structural design and production practice of the burner were proposed.

Aiming at the leakage problem of high pressure packing in the operation of high pressure and large displacement compressor in gas storage, investigation and analysis were carried out, and solutions were put forward. First of all, simulation analysis on the pressure seal of each ring in the packing box was carried out. It was demonstrated that the reason for the vulnerability to breakage of the three petal packing ring was the stress concentration. Asix petal packing ring was proposed to eliminate the stress concentration. The material form of the six petal packing ring was further improved, and the combination of PEEK + metal material was adopted to improve the strength and toughness of the outer ring. Then through dynamic load analysis of the packing ring, it was found that the bursting problem was caused by the viscosity of the lubricating oil. Finally, through analysis of spring binding force, the improvement of increasing spring binding force and adopting solid spring was put forward. After the above improvements, the sealing effect was good in the field test and the packing leakage problem was solved.

Fluid machinery is widely used in petroleum machinery industry, so the condition monitoring, diagnosis and maintenance of rotating machinery are of important practical value. Taking the typical fault characteristics of rotary fluid machinery as the object, a set of intelligent fault diagnosis system suitable for rotary fluid machinery is designed using LabVIEW software and MATLAB software. In addition to signal acquisition and processing and dynamic balance human-computer interaction system of common fault diagnosis of rotary fluid machinery, an intelligent fault identification system based on BP neural network optimized by genetic algorithm is designed in order to improve the intelligent level of the system. The test results based on the multi-functional rotor test-bed show that this diagnostic system has good fault recognition rate and accuracy rate in the fault diagnosis of rotary fluid machinery. The test system has the characteristics of high precision, complete functions, portability and expansibility, which can be better applied to the fault diagnosis of rotary fluid machinery.

Steam turbine is the key equipment which is most prone to fouling in FCC unit. During the operation of the steam turbine in the 1.2 Mt/a FCC of CNOOC Huizhou Petrochemical Co., Ltd., the pressure of the wheel chamber rises; the steam consumption increases; the speed regulating valve fully opens and the rotation speed decreases, which are judged to be the result of fouling of the flow parts of the steam turbine. The steam temperature of the turbine inlet is reduced and online high-speed cleaning of the turbine is implemented under the condition that the turbine unit is not shut down, the gas compressor torch does not need to be discharged, and the unit is in normal production at low load. After the on-line cleaning, the turbine wheel chamber pressure dropped from 3.4 MPa to 2.1 MPa, steam consumption dropped from 46 t/h to 40 t/h, and the speed regulation valve opening fell from 100% to 60%, which indicates that the online scale cleaning has achieved good results.

To cope with the increasingly severe challenge of management of special equipment posed by petrochemical processing equipment gradually developing towards large-scale, high parameters and long-term direction, the current situation of safety management of special equipment in the user unit is analyzed. On the basis of the analysis, the method of risk-based management (RBM) is adopted and specific solutions and risk control methods for the risk management of special equipment are proposed; the intelligent risk control system of special equipment is established based on risk assessment, intelligent operation control system, risk early warning system and intelligent management system platform. This is of positive practical significance for the users to improve the risk management of special equipment.