Converter is a power electronic equipment with weak resistance to voltage sag, which affects the operation of unit for many times. In this paper, the energy balance relationship of converter is studied, and the sag duration of converter under three-phase short circuit is deduced. Using the duration equation, the key factors affecting the immunity of converter are analyzed. The converter experimental platform is built to measure the sag immunity of converter under different sag depths and different load rates. The sag inflection point of converter is related to the load rate. The heavier the load, the shorter the sag duration. The sag depth of converter is related to the frequency. The lower the frequency, the stronger the voltage sag tolerance. According to the test conclusions, the application scope of different sag immunity means are analyzed. External power supply is suitable for key processes, and changing the control strategy is suitable for non-core processes. The conclusions can provide reference for the sag treatment of converters in petrochemical industry.

Petrochemical plant has continuous production lines, so proper lighting system is necessary to guarantee the normal operation, inspection and maintenance at night or in dark places and to support the safe production of petrochemical plants. This article discusses the principles for selection of illuminants and luminaires according to the lighting design requirements of petrochemical plants. From the perspective of engineering practice and considering both the illuminance standard value and illumination uniformity, this article summarizes the key points of luminaire arrangement through the light distribution curve of luminaire, providing reference for the lighting design of petrochemical plants.

 In view of the surplus low-pressure saturated steam in a newly-built aromatics complex, a steam compressor is used to solve the problem of poor utilization of low-pressure steam. By comparing the characteristics of low-pressure steam power generation, refrigeration, heat pump and compression, the steam compression technology is selected to recycle the low-pressure steam. With good economic benefits and short payback period, this technology is expected to be further promoted in the future. It also provides a new way of thinking for the steam balance optimization, energy saving and consumption reduction of refining and petrochemical enterprises.

This paper analyzes the stress distribution at the opening of a 60-meter-high self-supporting steel chimney under specific loads by using the finite element software ANSYS. The results show that the weak position simulated by the software is consistent with that calculated by the chimney design code. When the calculated stress-strain level at the chimney opening is low, the wall thickness at the opening can be appropriately reduced or the steel section can be reduced to improve the stress level. When the tube wall of the opening is plastic, the wall thickness at the opening or the section steel can be increased, and the wall thickness of the nozzle can be increased to reduce the stress level and make the tube wall of the opening within the yield strength.

As an important measure to ensure the safe operation of power system, relay protection has many functions. It is easy to realize the automation of power supply system by relying on relay protection. In view of the different operating status of the plant, in addition to mastering the basic relay protection setting method, it is also necessary to analyze, compare and select the appropriate working conditions. This paper analyzes the relay protection setting of 10kV power supply line in petrochemical plant with an example.

Anchor bolt is an important fastening member which connects the upper structure with the concrete foundation. At present, the domestic and foreign standards have different requirements for the uplift failure mechanism, bearing capacity calculation and anchorage length of anchor bolts, causing difficulties for engineers. In this paper, the related specifications are explained, the typical calculation formulas for determining the uplift bearing capacity of anchor bolts are discussed, and the results given by these typical formulas are compared with the test results.

The industrial exhaust gas from some units in coal gasification to methanol process has high CO and H₂ contents. Coal chemical enterprises can use such exhaust gas as fuel gas or extract H₂ as raw material for downstream units. By analyzing the composition of exhaust gas from methanol plants in coal chemical enterprises, this paper proposes three different exhaust gas utilization schemes and flow charts, and calculates the material balance and cost structure of these schemes. With a detailed comparison of the product output changes and economic efficiency of different schemes, the comprehensive utilization paths of heat energy, CO and H₂ components in the exhaust gas under different conditions are analyzed. The scheme of adjusting the gas phase distribution can recycle the industrial exhaust gas as fuel gas without adding new units and increase the production of H₂, achieving good economic benefits.

Taking the single-seat sleeve control valve as the research object, the numerical simulation calculation of the flow field of sleeve control valve before and after structural optimization was carried out, and the flow characteristic curve of the sleeve control valve before and after optimization at different openings was obtained by using the least squares fitting method. The research results show that the slope deviation of the flow characteristic curve of the sleeve control valve before optimization at different openings exceeds the standard and does not meet the equal percentage flow characteristic, the flow characteristic curve of the optimized sleeve control valve meets the equal percentage flow characteristic requirement, and CFD numerical simulation calculation method can be used as an important method for the development and design of sleeve control valves.

Quench heat exchanger in ethylene plant is used to quickly cool the high-temperature pyrolysis gas of cracking furnace in order to recover the heat and prevent secondary reactions. This paper studies the application of large quench heat exchangers in ethylene plant, simulates the distribution of cracked gas in large horizontal quench heat exchangers with the help of CFD, and obtains the influence of gas distributor and piping layout plan on the fluid distribution at the inlet, providing reference for the design of large quench heat exchanger of cracking furnace in ethylene plant.

With the continuous progress of information technology, the traditional management mode of audio-visual archives is difficult to meet the needs of the times. The information construction of engineering audio-visual archives is an important part of the management and development of archive resources in refining and petrochemical enterprises and also the inevitable trend of social development. Accelerating the pace of archive information construction and promoting the engineering audio-visual archives to give full play to their own role can provide reliable services for engineering design and project construction.

In order to continuously monitor the uniform corrosion, erosion and thinning of equipment and pipelines in refining and petrochemical plants, some monitoring points were reasonably arranged, the data transmission of wireless gateway was realized, the corrosion data monitoring platform was established and the corrosion rate and remaining life were calculated through the hardware design and software development of monitoring system, thus designing the online fixed-point automatic thickness measurement system. The actual application results prove that the online fixed-point automatic thickness measurement system can monitor the corrosion status of pipelines in real time. The thickness measurement data acquisition frequency is not less than 5 minutes. It can accurately display the wall thickness of pipelines and calculate the risk of corrosion based on the collected data, guiding enterprises to take correct treatment measures and providing technical support for the safe production of enterprises.

With the characteristics of long construction period, large capital investment, complex technology, remote construction site and poor surrounding support, coal to chemical projects are easily affected by various factors during construction. Combined with the characteristics of coal to chemical projects, this paper takes a project as an example to discuss how to establish a progress detection system for the project to achieve the goal of progress control.

Based on the introduction to cost-plus-fee contract mode, this paper analyzes the profit situation and cost risk of EPC contractors under cost-plus-fee mode by studying the contract terms and pricing methods of actual cost-plus-fee project cases, and attempts to put forward some suggestions on improving the profit margin of EPC contractors under such contract mode. This paper mainly discusses the project cost, and category II and III expenses are almost not involved.

The high concentration butadiene valve in butadiene extraction unit has problems of easy polymerization of medium and short operation cycle, seriously affecting the safe and stable operation of the unit. The polymerization mechanism and reasons of butadiene are briefly introduced, and the anti-polymerization measures for high concentration butadiene valve in butadiene extraction unit with acetonitrile method are introduced. Through technical analysis, the polymerization problem of valve is solved, a reasonable transformation scheme is put forward, and a type of anti-polymerization valve is developed to ensure the reliable operation of valve and prolong the operation cycle of unit in essence.

 Aiming at the problem that the sealing ring of triple-offset butterfly valve needs to be re-fitted due to the processing errors during manufacture, the calculation formula for the matching ring of triple-offset butterfly valve is proposed. The possible reasons for the valve failure are analyzed. The working conditions under which the sealing ring needs to be re-fitted are analyzed, and the corresponding calculation formula is obtained. It is verified through calculation examples and field applications. The results show that the calculation formula for the matching ring of triple-offset butterfly valve is accurate, reliable and feasible.

Butene-1 unit is used to produce high purity butene-1 products by cracking C₄. To solve the problem that the processing capacity and product recovery rate of a butane-1 unit can not meet the design requirements, this paper carries out cause analysis and simulation calculation, and puts forward some solutions. After reconstruction, the existing problem is solved, and the test run of the unit is successful.

As one of China's pillar industries, the construction industry is an important industry related to the national economy and people's life. However, at this stage, the traditional project management mode of China's construction industry has some problems such as simple, extensive and inefficient management. The transformation and upgrading of China’s construction industry is in urgent need. Blockchain and smart contracts have the characteristics of high openness, good confidentiality, high efficiency and good traceability, which are of great significance to the digital transformation and upgrading of the construction industry. Based on blockchain and smart contracts, this article mainly analyzes its application prospects in the construction industry.