Traditional physical simulation method of hydraulic fracturing has certain limitations in quantitatively studying fracture morphology and dynamically monitoring fracture propagation paths. It is challenging to quantitatively evaluate the dynamic processes of fracture initiation and propagation. Therefore, there is an urgent need to develop digital and intelligent technologies to enhance the accuracy of hydraulic fracturing physical simulation methods. Systematically investigated the method principle, research status and development direction of digital core reconstruction, acoustic emission positioning and distributed optical fiber monitoring, explored the data acquisition, fracture reconstruction and data interpretation in the process of multi?method joint monitoring experiment, and clarified the sample preparation, method combination and application scope in hydraulic fracturing physical simulation. The characteristics of non?plane, asymmetrical and unbalanced initiation and propagation of true triaxial hydraulic fracturing physical simulation are pointed out and outlooks are presented with the aim of helping researchers deeply understand the dynamic process of complex fracture expansion. Digital and intelligent hydraulic fracturing physical simulation methods are the future research trend. The research results can be used as reference for the development of hydraulic fracturing physical simulation technology, experimental scheme design.
The influence of curing temperature on catalytic desulfurization, nitrogen and acid removal of NiW/Al2O3 hydrotreating catalyst during the curing tprocess was studied. The catalyst with incomplete curing was re?cured and its hydrogenation performance was studied. The structure of the vulcanized catalyst was characterized by physical adsorption (BET), X?ray diffraction (XRD) and X?ray photoelectron spectroscopy (XPS). The results showed that the sulfur content and degree of vulcanization on the catalyst increased with the increase of vulcanization temperature, and the carbon accumulation also increased, which led to the decrease of the specific surface area, pore volume and average pore size of the catalyst. After vulcanization, the active phase of the catalyst changed from low active W6+ and Ni2+ to high active W4+ and Ni-W-S phases. After revulcanization, the pore volume and average pore size of the catalyst decreased, while the specific surface area, sulfur and carbon contents increased. The increase in carbon deposition covered part of the active center and reduced the atomic ratio of W and Al on the catalyst surface, resulting in the aggregation of active metals in the vulcanized state and reduced the activity of the catalyst, indicating that the revulcanized catalyst was difficult to achieve complete vulcanized catalyst activity.
ZSM?5 has been widely used in the field of petrochemical industry. The extensive use of organic templates in its conventional synthesis process has caused serious problems on environmental and cost. In this paper, the hydrothermal synthesis of ZSM?5 with tetraethyl orthosilicate, aluminum sulfate octadecahydrate and alkaline hydrolysis product of HZSM?5 as silica source, alumina source and structural directing agent, respectively, has been investigated, which aims at developing of new process for green synthesis of zeolites. The synthesized samples were characterized by a series of techniques, such as XRD, TEM, SEM, N2 physical adsorption and TG analysis. It has been shown that successful synthesis of ZSM?5 can be achieved by induction of alkaline hydrolysis product of HZSM?5 in organic template?free system. The prepared sample possesses a relative low crystallinity and specific surface area than ones from conventional process. The study in this paper has provided the chance for combination of green synthesis of zeolites and post?treatment route for synthesis of hierarchical zeolites.
Fuel cells have attracted widespread attention owing to the merits of high efficiency, high safety and wide application, etc. Therefore, fuel cells can meet the increasing requirement for clean energy in human society. Among them, anion exchange membrane fuel cells have shown broad application prospects due to the environmental friendliness, the use of non?precious metal catalysts, high safety and stability, etc. As the core component of anion exchange membrane fuel cells, anion exchange membranes can isolate the anode from the cathode and conduct hydroxide ions. Thus, the property of anion exchange membranes plays a crucial role in the performance of anion exchange membrane fuel cells. In the development process of anion exchange membranes, the low conductivity and poor hydroxide ions conductivity stability have become the key technical challenge. The development of flexible anion exchange membranes can play a positive role in promoting the further commercialization of anion exchange membrane fuel cells. Based on this, this article reviews the recent research progress on flexible anion exchange membranes from three aspects: polymer molecular chain design, structural optimization design, and new material synthesis and the composites.
Silver?doped powders with n（Ag+）/n（Ti4+） of 0.001、0.003、0.005、0.010、0.030 and 0.050 and ceramic hollow microspheres loaded with titanium dioxide photocatalyst were prepared by sol?gel method. The prepared catalysts were characterized by SEM, XRD and Uv?Vis DRS, and their photocatalytic properties were tested under xenon lamp light source. The doping mechanism was analyzed using first?principles calculations.The results show that the degradation rate of 0.005Ag?TiO2 powder after photocatalytic degradation of 10 mg/L methylene blue for 90 min is 76%. It is concluded that n（Ag+）/n（Ti4+）=0.005 is the best doping amount, and the degradation rate of ceramic hollow microsphere supported catalyst for 90 min is 97%. Ag doping can introduce impurity energy levels in the TiO2 system, so that the valence band electrons can reach the conduction band by hierarchical transition. The calculation results are consistent with the experimental results.
The low?permeability reservoir in Qiuling Oilfield of Tuha shows that the characteristics of early water discovery and rapid rise of water cut in some wells during water injection development, and dynamic analysis shows that there are dominant channels or the possibility of fractures in the reservoir. In order to further improve the development effect and enhance oil recovery, it is necessary to verify and determine the development of micro?fractures in the reservoir at the later stage of reservoir development. In this paper, based on the description of the core of a water washing inspection well, the development and distribution of reservoir fractures are studied, and a method of identifying the fracture development horizon based on logging curves are proposed. Through the analysis of logging data of two wells and the comparison of water absorption profiles, the method is proved to be feasible and reliable, and the study provides theoretical support for improving the development effect of water drive, effective utilization and recovery of remaining oil in Qiuling Oilfield of Tuha.
During the extraction and transportation of waxy crude oil, paraffin will deposit on the wall, forming wax deposition. In recent years, microbial wax removal and prevention technology has been widely studied for its economic and environmental advantages. Five strains of bacteria were screened from crude oil sludge, and through the determination of their paraffin degradation rate and surface hydrophobicity, the bacterium B3 was selected and identified as Bruella intermedia. The experimental results showed that bacterial B3 had the best growth activity at a temperature of 40 ℃, an initial pH of 6, and a shaking table speed of 160 r/min, and had the best degradation effect on paraffin at this time. When bacteria B3 grows and metabolizes with paraffin as a carbon source, they can produce lipopeptide biosurfactants, with an emulsification coefficient of 52.5% for liquid paraffin. After 7 days of interaction between bacteria B3 and crude oil, the wax prevention rate reached 77.2%, and the viscosity reduction rate reached 50.2% at 41 ℃. Bacterial B3 can degrade paraffin, improve crude oil fluidity, and reduce wax deposition.
The vertical adsorption tower is crucial for carbon dioxide removal from flue gas, but its complex and variable adsorption process poses challenges for optimal production. Achieving uniform gas distribution is essential, prompting the evaluation of various gas distributors via computational fluid dynamics (CFD). Four types were compared: no distributor, conical, truncated cone, and a combination of sieve plate with baffle. Results were assessed based on velocity vector smoothness and curve uniformity. A single sieve plate resulted in non?uniform airflow concentrated at the tower center. Types Ⅰ and Ⅱ improved flow but with uneven distribution. Type Ⅲ, featuring a sieve plate and baffle, significantly enhanced uniformity. Optimal parameters identified were a baffle diameter (d) of 100 mm and a distance (h) of 150 mm from sieve plate to air inlet. This configuration achieved the most uniform airflow distribution, demonstrating superior effectiveness in carbon dioxide adsorption processes.
The solidification and splash phenomena of Ni during plasma spray deposition were simulated by VOF model. The Navier?Stokes equations are solved in combination with the volume?of?fluid technique to track the free surface of the particles. In addition, the heat transfer including phase change is modeled using the enthalpy method. The coating formation process of nickel droplets at high speed was simulated by setting three different experimental conditions. The formation mechanism of nickel coating was analyzed deeply. During the spraying process of different speeds, the diffusion coefficient of higher droplet speed is greater than that of slower speed and there will be splash. In the case of different substrate temperatures, the higher the substrate temperature, the farther the molten particle tiling distance is. In addition, the diameter of the molten droplet is changed. Under the same other simulation conditions, the larger the particle diameter, the larger the spread distance, but it is not linearly related, and the larger the particle, the greater the thickness of the solidified sheet.
The kinetic properties of single?bubble ultrasonic cavitation are simulated using the finite element analysis software COMSOL Multiphysics. The motion process of a single cavitation bubble driven by ultrasonic sinusoidal, square and triangular waves when vibrating in water is simulated by solving the Rayleigh?Plesset model which takes into account the energy viscous loss and the radiation damping caused by the vibration of the spherical bubble, and the curves of the changes of bubble radius, motion velocity and kinetic energy of the bubble wall and pressure within the bubble wall are analyzed.The results show that under the same conditions, the stability of sine wave drive is the strongest; square wave drive has the best cavitation effect but the longest cavitation time; triangular wave shows the weakest cavitation effect. Driven by three types of waves, the kinetic energy of motion of the bubble wall is the largest during the first collapse, and the maximum pressure inside the bubble occurs when the bubble collapses to its minimum radius. The maximum pressure inside the bubble is the greatest when driven by sinusoidal wave compared to square wave and triangular wave.
As a high?risk area, the fire safety has always attracted much attention. Although smoke and flame alarm have been widely used, there are still problems such as single ?point detection and easy environmental impact. In response to such problems, a multi?way flame smart video monitoring system based on the B/S architecture is designed and implemented, and it is presented in the form of a web system. In the system, an improved YOLOV5 flame detection algorithm is integrated. The Ghost convolution is used to replace in conventional convolution to achieve the lightweight of the network, and the improved attention mechanism modules and small target detection anchor frame is added to enhance small target detection ability. Finally, the flame movement information extracted from the Optical flow network and the original flame data is sent into the improved YOLOV5 flame detection algorithm to further improve the detection accuracy of the flame. A large number of on?site test proves that the system can identify and locate the flames in the plant in real time. The detecting frame rate can reach 15 ms/frame, and the detection rate reaches 100%, which has high stability. An efficient and reliable fire monitoring solution is provided for the chemical industry.
Aiming at the problems of low positioning accuracy and poor stability in multi?effect and non?line?of?sight conditions, a new indoor positioning system Chan?Taylor?Unscented Kalman Filter (C?T?UKF) combined positioning algorithm is designed based on the time of flight positioning algorithm, combined with the Chan?Taylor (C?T) cooperative positioning algorithm, and fused with the Unscented Kalman Filter (UKF) algorithm. The system mainly consists of positioning base stations, positioning tags, wireless communication systems and upper computers, etc. The Chan algorithm is adopted to calculate the distance measured by the time of flight method, and the calculated coordinates are used as the initial value of the Taylor algorithm for iterative calculation. The iterative results are smoothed by the Unscented Kalman algorithm. The results show that the positioning system based on this algorithm has the characteristics of high accuracy, strong stability and low cost. The average positioning errors in line?of?sight and non?line?of?sight conditions are less than 0.17 m and 0.20 m respectively, and it can be applied to high?precision positioning scenarios.
Website Copyright © Editorial Department of Journal of Liaoning Petrochemical University
Address: No. 1, west section of Dandong Road, Wanghua District, Fushun City, Liaoning Province Tel:024-56865105 E-mail:lnxuebao@126.com Zip Code:113001
The system is designed and developed by Beijing magtec Technology Development Co., Ltd.
