The damage of center pipe in CCR reactor is one of the main reasons for unscheduled shutdown in CCR unit. This paper analyzes the design, fabrication and operation of center pipe based on the feedback from jobsite. It comes to the conclusion that the main reason for the damage is the deviation of the actual situation from the design assumption and exceeding the design safety range, thus resulting in the instability of the center pipe. Then the paper puts forward corresponding design revision and structure improvement measures, which extends the service life of the center tube effectively. Meanwhile, it also proposes the key parts of the center pipe to be inspected during the shutdown and maintenance period and the determination method for safety so as to ensure the safe, stable and long-cycle operation of the reactor.

The sealing surfaces of steel pipe flange at various positions in petrochemical production site are exposed to corrosive medium for a long time, so there will be erosion pits of varying degrees. In the process of equipment maintenance, disassembly and reassembly, the flange sealing surface will be damaged if not protected in time. Light knife repair technology for the sealing surface of steel pipe flange can solve the above problems and provide technical support for long-term safe and stable operation of petrochemical production equipment. Based on the overhaul experience of petrochemical production units over the years, seven types of light knife repair technology for the sealing surface of steel pipe flange are classified into two categories. Combining with practical operation, this paper introduces these technologies, which provides reference for the repair of flange sealing surface.

Aiming at the failure of the high temperature flue gas turbine of catalytic cracking energy recovery unit, new guide vane cyclone separation technology was adopted. This paper put forward the modification scheme of new vertical and multi-tube three-stage cyclone separators (three-stage cyclone for short) of high efficiency and low resistance. After modification, the catalyst concentration of flue gas by on-line testing from three-stage cyclone outlet was 92.5 mg/m3. The particle size of powder was less than 10 microns. This indicated that the performance of three-stage cyclone separation completely met the purification requirements of flue gas of flue gas turbine inlet. This can ensure the long-cycle and safe operation of the flue gas turbine.

A shutdown resulted from the failure caused by the bearing wear of the liquid propylene discharge pump in a polypropylene device occurred after startup. Through analysis on the site situation, pump’s internal structure and physical property of propylene under operating conditions, it is found that when the flow control of external flushing propylene is not stable, the axial thrust of the pump is increased, so that the friction between the internal components of the pump is intensified. Then heat is accumulated gradually, leading to dry-running of the pump and fragmentation of the pump bearing due to wear and tear. A small range flowmeter and needle valve are added on the flushing line to accurately control the flow rate of the external flushing propylene, which obtains good results. The pump has been running smoothly after the revamp. In addition, through analyzing the pump process conditions, suggestions for pump selection are proposed.

This paper analyzes the operating parameters of pumps in atmospheric and vacuum distillation unit after impeller cutting. According to the site conditions, the pump that needs frequency conversion modification is selected when the motors are reconfigured. Through increasing the capacity of 6300/690V transformer on the spot and making use of the reserved space for distributing rooms, the feasibility of frequency conversion modification is confirmed. Meanwhile, the paper analyzes the investment income and existing problems of the project and puts forward suggestions for the application prospects of speed regulation by 6 frequency conversion to 690 V motors.

This paper introduces the types of capacity regulation system in reciprocating compressor and their respective application. Meanwhile, it also introduces the related knowledge of compressor rotation unevenness and flywheel torque. The paper takes the commonly used models 2D and 4M in engineering as the research object and elaborates the impacts of the stepless capacity regulation system on the torque of reciprocating compressor. It is concluded that when a new stepless capacity regulation system is installed in the reciprocating compressor, it should be checked whether the compressor torque changes excessively, thus resulting in rotation unevenness exceeding the standard value. This is of certain guiding significance for the selection and check of the compressor and its operation and maintenance.

Fracture occurred during the operation of the reducer high speed shaft in certain power plant. Through macroscopic examination, chemical composition analysis, surface energy spectrum analysis, hardness testing, metallographic examination and mechanical performance test, this paper makes an analysis combining with the operating conditions of the reducer. The results show that the manufacturing quality of the reducer high speed shaft was unqualified. Since there are plenty of micro-cracks and acicular tissues in the surface of the nitriding layer, the micro-cracks spread during operation, which results in surface metal peeling and stress concentration. Finally, this leads to fatigue fracture of the high speed shaft. Aiming at the fracture causes, the paper presents some corresponding improvement suggestions.

Along with the development of large scale petrochemical equipment, reciprocating compressors tend to become larger with multiple throw types. In recent years, great progress has been made in the development and application of large reciprocating compressors in China. The maximum allowable continuous load on piston rod has been developed from 800kN, 1250kN up to 1500kN. But the maximum throws of domestic reciprocating compressors were still limited to 4 throw configuration in refineries. Based on the 600,000 t/a CCR unit of Sinopec Tahe Petrochemical Co., Ltd., 6M80 large reciprocating compressor was developed independently, thus realizing the localization of large 6 throw configuration reciprocating compressors. With the advanced computer aided design method and leading technology, the compressors have operated stably and reliably. The development of this model has produced products with independent intellectual property rights. Such compressors can replace the imported ones, therefore, the investment in equipment, delivery cycle and maintenance cost can be reduced, which has good economic and social benefits.

In the process of petroleum refining, hydrogenation technology has become an important means to improve the quality of petrochemical products. Most of the hydrogen required by hydrogenation plants is provided by hydrogenation conversion plants. In the production process, the operating load of hydrogen production converter will be adjusted according to the change of the capacity of hydrogenation unit. The change of hydrogen production converter load will lead to the change of temperature distribution inside the converter, and the change of temperature inside the converter will affect the operating life of the furnace tube directly. On the basis of the structure of the hydrogen production converter, operating parameters, the finite element model is established to simulate and calculate the internal temperature distribution of the converter under different load conditions, analyze the internal temperature change of each part in the converter under different load conditions and provide temperature parameters for the evaluation on the service life of furnace tube. Meanwhile, finite element model can provide guidance for the operation of the converter under different loads.

Aiming at the serious leakage and frequent overhaul of the mechanical seal in the liquid-ring vacuum pump, this paper puts forward the modification scheme of transforming the seal form into double-end dry gas seal through analyzing the existing problems of the mechanical seal. It introduces the basic structure and operation principles of the dry gas seal, points out the precautions for use. The transformed dry gas seal and auxiliary control system have been used in the liquid-ring vacuum pump successfully. After long-running verification, the problems of the original seal have been solved. The dry gas seal has no medium leakage and the maintenance is simple. Thus the overhaul times are greatly reduced and the service life of the seal is prolonged. The safety and stability of the equipment operation are greatly improved as well.

Adopting trough solar steam generator for heavy oil exploitation is the transformation of solar-thermal power generation technology, which can reduce energy consumption of conventional energy sources effectively and protect the environment. This paper takes the existing thermal process steam system of TK-921 single well in Xinjiang Tahe Oilfield as the object. Trough solar steam generator is introduced for system transformation, and the design of trough solar steam generator system is optimized. First, according to principles of energy saving and low cost, an optimized design method for the heat collection system using a steam generator assisted with the trough solar collector is proposed to meet the demand on heat loads in the all-weather thermal recovery process. Then a multi-objective optimization model for the system is established by constructing the annual cost model of the heat collection system using a steam generator assisted with the trough solar collector and together with the relationship among the annual cost model, the solar guarantee rate and the total cost of the system. Finally, the optimal target model is calculated by using MATLAB genetic algorithm, and the optimal collector area value is obtained by analyzing the Pareto non-inferior solution set of multi-objective function.

With the aid of ANSYS software, double point corrosion in pipelines is taken as the research object. Through establishing elliptical double point corrosion defects and square double point corrosion defects, this paper studies the maximum equivalent stress and the change law of residual intensity of the pipeline under different defect depths and defect spacing. It predicts the residual life as well. The results show that the equivalent stress distribution is uniform in the areas far from the defects and the maximum equivalent stress occurs in the edge area of the defect; the equivalent stress of the two kinds of double point corrosion defects increases with the increase of defect depth and with the increase of defect spacing, it decreases first and then remains unchanged and the threshold appears; the elliptical double point corrosion defect is more harmful. The conclusions can provide reliable data support for pipeline maintenance and replacement.

LNG tank is important equipment in receiving station. With the accumulation of running time and the change of operating state, the cooling effect of LNG tank will be reduced to varying degrees. This paper introduces the working principles, equipment selection, testing steps and evaluation criteria of infrared thermal imaging on-line detection. Combining with the example of infrared imaging inspection of LNG tank surface, it makes an overall assessment on the cooling effect of the storage tank and confirms the cooling state, which provides technical guarantee for the safe and stable operation of storage tank. Meanwhile, the paper provides scientific reference basis for the cold storage recovery operation of storage tank. It also provides better management ideas for the construction and integrity management of LNG storage tanks at other receiving stations.

In order to avoid the adverse impacts on operation quality caused by circumferential joint welding deformation for oil refining and chemical major reactors such as coking reactor, reformer, gas phase reactor and dehydrogenation reactor during the manufacturing process, this paper discusses various influencing factors and focuses on analyzing the main factor which is deformation caused by welding. A finite element model was established for a specific cylinder circumferential welding to carry out a simulation calculation of the plastic deformation. Then the results were compared with the test records to confirm the relevant analysis. On this basis, some technical countermeasures are proposed to prevent circumferential welding deformation in manufacturing. They are applied to the products and practical results are obtained.

This paper expounds the technological process of reciprocating compressor 2C470 system in polyethylene plant. It introduces the working principles of eddy current testing technology based on electromagnetic induction, testing equipment and testing standards of this technology, and the evaluation basis of eddy current testing technology for heat exchanger. This technology is applied to three heat exchangers in reciprocating compressor 2C470 system among which the wall thickness of the tubes of two heat exchangers (2E470A/C) are judged to be thinned seriously from two aspects covering macro inspection and eddy current atlas. Through practice, it is proven that eddy current testing technology is an effective means to detect the corrosion defects on the inner and outer walls of heat exchanger tube bundles. Meanwhile, precise and potent solutions are presented to ensure the long-term, safe and stable operation of polyethylene plant.