Nano aerogel thermal insulation material is a new type of solid material with nano porous structure and the lowest thermal conductivity. The lack of basic heat transfer parameters results in large deviation in final thickness, restricting the promotion and application of this material. This paper uses the pipe insulation test device to simulate the working conditions, and uses nano aerogel thermal insulation material as the insulation layer. The surface heat flow is measured by the steady-state method, and the thermal conductivity of nano aerogel thermal insulation material at the temperature of tm is calculated by the Fourier law, so as to fit the heat transfer equation of nano aerogel thermal insulation material. And the thickness of each layer of the nano aerogel composite insulation structure is calculated by using Excel software combined with the trial and error method. The composite insulation structure formed by nano aerogel thermal insulation materials and traditional insulation materials is an optimal way. Among them, the "nano aerogel felt plus aluminum silicate needle felt" and the "nano aerogel felt plus calcium silicate" has the lowest comprehensive cost, and may be used as the preferred insulation structure for equipment and pipelines.

In this paper, a real time improvement algorithm based on sensitivity information for numerical optimization of chemical plants is developed based on the original receding horizon optimization algorithm to solve the problems in the large-scale and nonlinear operation optimization of chemical plants such as high complexity, difficult convergence and poor real-time performance. While overcoming the uncertainty of optimization, this algorithm uses the sensitivity information of nonlinear programming optimization result to predict on line the approximate optimal solution of operation optimization problem in the next optimization cycle. Meanwhile, the accuracy of the approximate optimal solution is further improved by background computation and off-line correction, so as to ensure that the optimal solution of operation optimization problem can be obtained quickly and accurately. Finally, a typical chemical plant is selected as the simulation case and the optimization computation time is reduced by 64.3% compared with that of the traditional method, which verifies the validity of the real time improvement algorithm.

Due to the influence of purchased naphtha, the aromatization unit of a company has been operated at a low load. In order to ensure the safe and efficient operation of the unit and improve the economic benefit of the company, a cutting system is to be installed downstream the stabilizer of gasoline hydrodesulfurization unit to cut the intermediate components of heavy gasoline at the bottom of stabilizer and sent them to the aromatization unit. This article focuses on the calibration data analysis and operation summary of the new fractionation column after it is put into use.

For some underground water tanks that adopt the overall anti floating design by covering the soil weight on the cantilever plate, the central partition wall is difficult to meet the local anti floating requirements from time to time. At this time, if the plane size of the water tank is narrow and long and the in-plane stiffness of the central longitudinal partition wall is weak, the adverse impact caused by the insufficient local anti floating will be amplified. This paper discusses such problems based on engineering examples, analyzes their adverse effects in detail, gives reference treatment methods, and demonstrates them through theoretical derivation.

The five compressor units of large chemical fertilizer plant are the core rotating equipment of chemical fertilizer production. It is important to carry out all weather monitoring of large compressor units to predict in advance the potential anomalies and hidden dangers of the compressor units. BH5000 condition monitoring and remote diagnosis system collects the vibration, shaft displacement, rotor key phase, bearing temperature and compressor unit speed in Bentley 3500. In the server, the spectrum analysis of the compressor unit state parameters is carried out through the condition monitoring and diagnosis software, the fault type, fault damage degree and fault location are judged, the unit faults are compared with database cases, the unit anomalies and hidden dangers are warned in advance, and remote precision diagnosis is realized by expert team using Internet technology, so as to change from breakdown maintenance to maintenance beforehand and from planned maintenance to predictive maintenance. The vibration of air compressor with water and the vibration caused by rotor imbalance of raw gas compressor turbine are found out quickly by using the spectrum analysis of condition monitoring. Eliminating the hidden dangers in the bud can fundamentally ensure the safe and long-term operation of compressor units.

The impurities in industrial butene such as H₂O, CO and O₂ have great influence on the activity of catalysts in polyolefin plants. Therefore, the butene raw material must be refined to remove the excessive H₂O, CO, O₂ and other impurities before participating in polymerization reaction. In this paper, the butane refining unit of a polyolefin plant is simulated by Aspen Plus, the refining process is discussed based on the stripper model established and the simulation results, and the characteristics and advantages of two butene refining schemes are introduced and discussed. Appropriate refining scheme may be selected according to the actual situations of a specific project.

In the design of supporting facilities in petrochemical industry, the design of rectangular reinforced concrete pool is essential. The internal force calculation of the pool includes the calculation of the pool wall and the bottom plate. This paper mainly discusses the internal force calculation of pool wall under different boundary conditions, presents the calculation results in combination with common rectangular reinforced concrete pool in the petrochemical industry, and optimizes the design of pool wall.

The extractive distillation process of n-hexane-acetone azeotrope was simulated by Aspen plus V11. Four common solvents including cyclohexanol, 2-methoxyethanol, dimethyl sulfoxide (DMSO) and N-methylpyrrolidone (NMP) were selected as the extractant. The operating parameters of continuous extractive distillation such as the number of theoretical plates, feed stage, solvent ratio and reflux ratio were optimized by means of sensitivity analysis tool. The results of simulation show that all the four solvents can separate the n-hexane-acetone azeotrope as the extractants. The total energy consumption of extractive distillation process is the lowest when 2-methoxyethanol is used as the extractant, and the bottom temperature of extractant recovery column is the lowest, so the grade of heat source required is the lowest.

The definition of reverse angle as well as its significance in reciprocating compressor design was introduced. Through engineering examples and theoretical calculation, the influence of design factors, process parameter factors, leakage failure factors and flow regulation factors on the reverse angle of reciprocating compressor was analyzed in detail. At last, some suggestions and measures were proposed for improving the reverse angle, providing guidance for the selection and fault diagnosis of reciprocating compressors.

Safety valve is a kind of pressure relief valve using the pressure of its own medium instead of any external force. Its calculation and type selection play a very important role in the safety of natural gas liquefaction equipment and pipeline system. For different process fluids and operating conditions, the traditional method is to use Excel according to the calculation formula stipulated in API 520, which takes time and has some errors in the calculation of some fluids. Based on the characteristics of natural gas, this paper adopts HYSYS process simulation software to simulate the fluid safety valve. By comparing the results of various methods in different cases with the results of manual calculation, the leakage volume and throat diameter are compared. The leakage volume of safety valve under most working conditions can be accurately calculated. Just a few types of parameters are to be filled in the HYSYS simulation software, and the calculation process is simple and easy to understand. It is especially suitable for the calculation of supercritical fluids and mixed fluids, providing references for engineers in related work, so as to improve work efficiency and accuracy. However, there may be a large difference between the results of multi-model method calculation, which requires engineers to make judgement.

From the perspective of environmental performance and resource utilization, water mist system is superior to other fire extinguishing systems and is gradually becoming the first-choice design scheme for newly-built large and medium-sized archives in China. However, there's a substantial divergence of opinion among major engineering design companies in China regarding the number of high pressure plunger pump group in water mist system and its protection range during the detailed engineering. This article takes the design of a real archive for example, analyzes in detail the concepts of enclosure and protection partition that influence the number of high pressure plunger pump group system, and puts forward a valuable viewpoint that the enclosure shall be defined as a limited space externally enclosed or partially enclosed and internally connected or separated by non firewalls and can meet the requirements of water mist fire extinguishing, providing guidance for the design of similar engineering projects in China.

 According to the design requirements of smoke control system stipulated in GB 50016-2018 Code for Fire Protection Design of Buildings and GB 51251-2017 Technical Standard for Smoke Management Systems in Buildings, this paper takes the blast resistant central control room of a project as an example, gives the basis for the division of smoke bay and the design ideas of smoke control system combined with the division of fire compartments and the functionality of the room, and studies the design requirements of smoke control systems in different fire compartments.