Hydrogen unit is usually used as a supporting unit to provide hydrogen for all kinds of hydrogenation units in refinery. With the development of hydrogenation process, the demand for hydrogen is increasing, and the technology of hydrogen production is developing rapidly. As the core equipment of hydrogen unit, hydrocarbon steam reformer undertakes the dual tasks of heating and reaction. The development of hydrogen technology is mainly reflected in the developing trend of various types steam reformers. This paper studies the technical features, reformer type characteristics, heat transfer effect, internal and external structure, and pipe system differences of various types of hydrocarbon steam reformers by comparative analysis. Combined with the current status of industrial furnace modularization, the paper forecasts the breakthrough direction and modularized engineering trend of steam reformer, so as to provide guidance for the research and development of hydrocarbon steam reformer technology.

Thermal efficiency of cracking furnace in ethylene plant is an important parameter to measure the operation of cracking furnace. It is directly related to the energy consumption of ethylene plant. This paper introduces the present situation and influencing factors of thermal efficiency of cracking furnace in Tianjin 0.2 MTA ethylene plant. It proposes that the main way to improve the thermal efficiency is the effective utilization of heat in radiation and convection section of the cracking furnace. The paper expounds the methods and countermeasures for improving thermal efficiency of the cracking furnace from such aspects as improving fuel utilization rate, lowering exhaust gas temperature, optimizing operation and management. Meanwhile, it explicates the measures that need to be improved in future.

This paper introduces the basic concepts of fluid mixing and a new gas-gas mixer with a cone-shaped distribution section researched and developed according to the mixing requirements of flue gas and purified flue gas during the development of activated coke dry flue gas desulfurization technology. Compared with the existing tee-type mixer, the speed and temperature distribution in the new gas-gas mixer is more uniform, which can effectively prevent the low temperature zone and avoid dew point corrosion during the gas mixing process. Meanwhile, this can also improve the mixing efficiency, but the pressure drop may increase slightly.

Aiming at the problem that the penultimate free-stand blade fractured frequently in two 50MW steam turbo-generators of a power plant after five years of operation, this paper makes an in-depth analysis on the causes of the accidents and searches for the root cause of the problem. Through analyzing the blade material and fracture, checking the blade frequency, calculating the strength of the blade and the blade root by means of mathematical modeling and finite element analysis, understanding the stress distribution and defects of the blade, comparing the requirements of design standards, the paper revealed the root cause of the blade root fracture and based on this, it presented several sugges tions for improvement. This provides a theoretical basis for the set revamp at the following stage.

This paper introduces the first industrial application and effects of a new compound vertical sieve tray (Compound VST). After replacing the F1 floating valve tray of the existing EO purification column with this tray, the capacity more than doubled and the tray efficiency increased by 25%. The capacity expansion and energy conservation effects were significant. This provides reference for the revamp of similar plants in the future.

This article introduces the general principles and specific points of the alarm and interlock settings of the large unit of the refining and chemical plant.The settings of the alarm interlock of the main unit, the drive unit, the auxiliary system and the public conditions are included.

Based on the analysis of the frequent large vibration failures of screw compressors, it is concluded that gear damage, rotor bending and dynamic imbalance are the main causes for the large vibration of the unit. Such methods as replacing the old gears with new ones, surfacing welding and turning of rotor bending parts and weight-removing to remove dynamic imbalance are adopted to eliminate the failure completely. This case also provides reference for the failure treatment of the same type of equipment.

By comparing the corrosion of operating crude gas preheaters of the shift units matching different coal gasification processes, this paper analyzes the process conditions and material selection of various crude gas preheaters based on such factors as the medium characteristics and material selection requirements of different crude gas preheaters. It is finally concluded that the direct corrosion cause of the crude gas preheaters of the shift units matching different coal gasification processes is that the operating temperature of the crude gas is lower than the dew point temperature of the superheated high-temperature transform gas with which it is exchanged. As a result, the high-temperature transform gas is instantly chilled below the dew point temperature at the wall of the heat exchange tube, and thus dew point corrosion occurs.

Leakage occurs frequently at the dilution steam pipe elbow of the cracking furnace of certain ethylene plant. Through fracture analysis, it was found that the wall thickness of the elbow was reduced seriously and the leakage point was in the heat affected zone of the weld. This paper adopts macroscopic inspection and metallographic analysis methods to analyze the reasons for the leakage of dilution steam pipe elbow. It is found that the leakage is caused by the thinning of pipe elbow resulting from gas-liquid scour on the elbow by the dilution steam and the alkali stress corrosion at the weld resulting from the concentration of Na+in the process medium in the heat-affected zone of the weld. Aiming at the above problems, the paper proposes optimization suggestions and preventive measures.

Most domestic pipeline natural gas compressors adopt imported units and their core components dry gas seals have the features of large shaft diameter, high pressure and harsh operating conditions. All of the units adopt imported products. Thus the high price, long maintenance time and untimely after-sale service have become potential risks of long-distance pipeline operation. This paper introduces the process of domestication development of dry gas seal for PCL800 model of GE units in West Pipeline Company. Firstly, the design conditions of dry gas seal were determined through the operating conditions of the units. Then, according to the design conditions and the sealing chamber size of the units, the type of dry gas seal, the structure design, the configuration of sealing materials and the selection of groove shape were determined. Through professional dry gas seal software, the performance parameters and leakage of the seal under design conditions were calculated and analyzed. Finally, the factory test of the developed domestic dry gas seal prototype was conducted. And the test results indicated that the dry gas seal of the pipeline natural gas centrifugal compressor met the design technical requirements. This domestication development work can provide reference for the domestication of dry gas seals for other pipeline compressors.

This paper proposes the necessity of hazard and operability study (HAZOP) and safety integrity level (SIL) assessment in safety design for complete sets of equipment in petrochemical plants. It sorts out and summarizes the work process, methods and key points of HAZOP and SIL for complete sets of equipment. The work sequence is to conduct HAZOP and then SIL assessment followed by SIL verification. The purpose of HAZOP and SIL assessment for complete sets of equipment is to control the accident risk to acceptable level through design work. But it does not mean that accidents can be avoided completely. HAZOP and SIL assessment are analysis activities through brainstorming. The completeness of documents, the involvement and professional and knowledge levels of the team members and the sufficient preparation and analysis time will affect the quality and effects of the analysis directly.

In order to ascertain the reasons for the cracking failure of the bearing of a thermoregulation water pump in a plastic production unit of a petrochemical company, the inner ring of the failed bearing of the water pump was tested and analyzed by means of scanning electron microscope, Rockwell hardness tester and metallographic microscope. The test results showed that the cracking failure of the bearing inner ring was mechanical fatigue. The main reason for the bearing inner ring cracking was that there were too many non-metallic inclusions in the inner ring material. The same batch of imported bearing spare parts were checked and tested, and communication with the bearing supplier was done so as to avoid similar material defects.

Aiming at the problem of large amount of ice hanging on the outside of the silencer upper wall caused by the steam discharge in ethylene plant in winter, the silencer upper wall is optimized. This paper introduces the structure of silencer and analyzes the causes of ice accumulation. Based on the analysis, it takes such measures as adding auxiliary ears to the upper wall of silencer. This effectively solves the problem of ice hanging on the wall of silencer caused by steam discharge in ethylene plant in winter, eliminates the risk of personal injury caused by ice falling from high places, reduces the probability of production fluctuation caused by abnormal faults of instrument and electrical equipment, and ensures the long-term safe and stable operation of the ethylene plant.

Since the startup of the FCC II of certain company after overhaul, vibration of the flue gas turbine has been continuously rising. The vibration couldn't be improved obviously after operation adjustment and optimization. Online descaling of flue gas machine couldn't eliminate the abnormal vibration effectively. Finally, after repair and replacement of inlet deflection cone, the fault was eliminated and vibration restored to normal. Combining with the online condition monitoring of large units, this paper analyzes the impacts of operating condition adjustment on the vibration of the flue gas turbine. It discusses the problem of abnormal vibration of the flue gas turbine caused by high temperature creep deformation of the deflection cone. This provides reference for the disposal of similar problems in flue gas turbines.

As important equipment of condensate stabilization unit, condensate stabilization tower is mainly used to remove the light components of condensate by plate tower and reduce the vapor pressure of condensate so as to achieve the goal of condensate stabilization. During the operation process of the condensate stabilization tower, salt deposition appeared in the tower plate and tube bundle of the reboiler at the bottom of the tower. This reduced the plate flux and heat transfer effect of the reboiler in the stabilization tower, resulting in liquid flooding in the stabilization tower and difficulty in maintaining the bottom temperature of the tower. This paper analyzes the causes of salt deposition in the stabilization tower in detail, and finds out the corresponding treatment measures to solve the problem of salt blockage in the stabilization tower.