With the development of large-scale hydroprocessing units, two different forms of nozzle connection began to be applied in some special high pressure vessels, such as threaded ring lock heat exchangers. But the specific selection principles for nozzle connection forms are not mentioned in applicable pressure vessel codes and standards. This paper compares and analyses the merits and demerits of the two connection forms of tube and shell side inlet and outlet of the threaded ring lock heat exchanger in hydroprocessing unit from various perspectives and recommends a choice from the two forms, which can provide reference for the optimization design of nozzle connection of the threaded ring lock heat exchangers in hydroprocessing units.

This paper introduces the definition and requirements of digital delivery of petrochemical equipment. By analyzing the current situation and problems discovered in the practice of equipment digital delivery in projects, it summarizes the experience and effects in the exploration of digital delivery of petrochemical equipment, forms a relatively mature workflow and methodology, and expands application to find direction and breakthrough points for future digital work of petrochemical equipment, which could be used as good reference and has guidance value.

The rotary drum is a key component of the inverting filter centrifuge, and its design is developing towards high speed and high separation factor. Therefore, the accuracy of strength analysis of rotary drum is crucial. Based on the criteria in GB/T 28695—2012, this paper introduces the calculation methods of drum wall strength and circumferential stress inside the drum wall when the drum is rotating by taking the FWZ560 inverting filter centrifuge as an example. The allowable stress values of the material and the drum wall strength are calibrated, and the conclusion that the drum wall strength inspection is qualified is obtained, which proves that the method can meet the requirements of calculation accuracy. The calculation method described in this paper can provide reference for the development and design of this type of centrifuge.

In this paper, the computational fluid dynamics software ANSYS fluent is used to conduct numerical simulation research on a hydrogenation feed heating furnace. The surface thermal intensity of the radiation furnace tube, fuel combustion degree, radiation section furnace temperature, radiation section heat load, and NO_x generation under five conditions of excess air coefficient were compared and analyzed. Then the influence of excess air coefficient on the performance of the radiation section of the hydrogenation feed heating furnace was obtained. This can provide reference for the engineering design and operation of subsequent hydrogenation reaction feed heating furnaces.

The residual oil filter is a key equipment in the residual oil hydrogenation unit, and its accuracy and operating condition have great impact on the stable operation of the unit, the pressure drop of the reactor and the service life of the catalyst. The failures such as cracks, deformation and corrosion of the filter element during operation will directly affect the safe, stable and long period operation of the device. Aiming at the aforementioned problems, this paper brings forward the measures to improve the filters based on the tracking and analysis of the operation conditions about the residual oil filters in 14 sets of residual oil hydrogenation units from 13 enterprises.

This paper introduces the sources, emission standards, hazards, safety risks of industrial carbon monoxide (CO) waste gas and uses of CO gas. Combining with the basic structure and working principles of regenerative thermal oxidizer (RTO) and the application practice of CO exhaust gas treatment in a catalyst production plant, it elaborates the method of introducing CO exhaust gas into RTO as supplementary fuel gas to incinerate and treat organic waste gas from other plants, which provides a new idea for the treatment and discharge of CO waste gas up to standard. In addition, the paper also discusses the safety measures for treating CO waste gas by RTO equipment. The successful application of these safety measures can provide reference for the safe and stable operation of the RTO equipment and is worth popularizing in petrochemical industry. Finally, some suggestions are put forward for the development of CO waste gas treatment technology.

After the transformation of the closed decoking system using S-CCHS technology in the 1.2 million t/a delayed coking unit of one company, the problems of single petroleum coke products, high equipment failure rate which affects stable operation of the unit, and high operation and maintenance costs have gradually emerged. By developing special carbon materials for energy storage, establishing technical research team to reduce equipment failure rate, adopting new technologies, preventive maintenance strategies, small-scale technical upgrades, and other measures, the operation of the closed decoking system has been optimized. Through these measures, the objectives of enriching the structure of petroleum coke products, improving device stability, and reducing costs and improving efficiency have been achieved.

Reciprocating compressor has been widely used in refining units because of its advantages of wide coverage of working pressure and flow, high energy efficiency and strong air tightness. However, the reciprocating compressor has complex structure and many vulnerable parts, of which gas valve failure accounts for more than 60% of the total failure. And the unit shutdown caused by gas valve failure of booster of continuous reforming unit in a plant accounts for more than 85% of the total failure shutdown times in one petrochemical company. This paper describes the diagnosis of the failure of the booster valve of this device, and analyzes the causes of the failure and puts forward the corresponding solutions. The solution reduces the failure rate and extends the service life of the air valve by optimizing the operating environment of the valve, which is of great significance in ensuring the safe and stable operation of the unit over a long period of time.

The steam drum of cracking furnace is critical equipment of the ethylene plant, and its replacement construction quality has an important impact on the long term operation of the ethylene plant. This paper introduces the construction methods and precautions for the replacement of the steam drum of cracking furnace in the 1.1 million t/a ethylene plant of certain company. It expatiates on the key quality control points and quality control measures during the construction process and analyzes these in detail. The paper also summarizes the experience from the construction process. Standardized operating procedures have been developed. These can provide a basis for experience and reference for the replacement of cracking furnace steam drum of ethylene plant in future.

LNG unloading arm is an important connection channel between LNG carrier and receiving station pipeline, and is the core equipment of receiving station. The PHAST software was adopted to simulate the consequences of LNG leakage, natural gas diffusion, fire and explosion under the emergency detachment condition of the 16″ LNG unloading arm of one project. The results show that in general, the consequences of vertical downward leakage are more serious than those of vertical upward leakage; in the vertical downward leakage scenario, LNG may contact the lower deck and form a liquid pool; in all kinds of scenarios that may lead to serious consequences, the influence distance of jet fire is the furthest when the weather type is 1/F and the vertical downward leakage occurs; the influence range of the theoretical fatality rate 1 is 31.71 m downwind. Based on the analysis results, relevant suggestions are put forward for targeted and effective protection. Meanwhile, management of ship and dock personnel activity is strengthened to ensure the safe and reliable operation of the LNG unloading arm for a long period.

Computer recognition of defects in weld testing negative films of chemical equipment and pipelines is a difficult and hot topic in the testing industry in recent years. Due to the limitations of the professional fields, weld testing professionals and image recognition software engineers should learn from each other if they want to do a good job in automatic identification of negative film defects. Testing technicians should understand and master the preliminary theory of convolutional neural network, understand the complete process of convolutional neural network simulating human brain nerves, and conduct in-depth learning to finally identify the defects of weld testing negative films. Similarly, software engineers specializing in image recognition also need to understand and master the expertise of radiographic testing. This paper elaborates on the preliminary theory of convolutional neural network and the process of defect recognition using convolutional neural network. Meanwhile, aiming at the lack of data sources of typical defective images, the data source library is expanded from the perspective of actual radiographic testing based on the on-site practice and many years of experience in film evaluation. Practical verification proves that the above improvements have achieved better results.

Multiple cracks were found at the catalytic flue gas pipes and expansion joint during the maintenance period of a certain company. Due to the excellent high-temperature mechanical properties of nickel based alloys, they are widely used in the petrochemical industry. Therefore, this paper explores the feasibility of repairing cracks with nickel based welding material ENiCrFe-3 to address the above issues. To maintain consistency with the actual engineering, welding tests were conducted using 304H as the base material and NiCrFe-3 as the filler metal and a combination of argon arc welding and electrode arc welding was adopted. After the welding, high-temperature mechanical tests and metallographic structure inspections were conducted on the welded joints. The mechanical test results show that the high-temperature tensile and high-temperature impact properties of the welded joint are better than those of the base metal. The impact fracture morphology is mainly ductile dimples, and its overall hardness value is between 200 HV and 230 HV with little change. The metallographic examination results show that the fusion between the welding material and the base material is good, and there are no defects such as cracks or pores. The above results indicate that NiCrFe-3 can be used for welding catalytic flue gas pipes.

Aiming at the frequent corrosion leakage problem in the acidic gas system at the top of the regeneration tower of the solvent regeneration unit of one company, macroscopic inspection, wall thickness measurement, infrared thermal imaging detection, and corrosion energy spectrum analysis were carried out on the corrosion parts. The results showed that the acidic gas containing H₂S, CO₂, and water vapor at the top of the regeneration tower formed a gas-liquid mixture fluid containing droplets after the acid gas was cooled by a cooler. At the structural mutation site, severe turbulence occurred, resulting in increased flow rate and shear stress. Under the action of the superimposed effect of medium corrosion and fluid scouring, the protective film of corrosives formed on the metal surface is continuously scoured and peeled off and the wall thickness is continuously thinned, which ultimately leads to the leakage. Through such measures as expanding the diameter, upgrading the material, and optimizing the structure of the equipment and pipelines, corrosion has been suppressed effectively. This has ensured the safe and stable operation of the device.