In this study, we investigated the drag reduction property of a premixed slurry drag reducer in a millimeter-scale pipe. The aim of this study is to establish the correlation between Darcy friction factor and drag reducer concentration (C) and volume flow (Q). First, the experimental plan was designed by using the response surface method (RSM), and then the experimental data were processed to establish the quadratic correlation between the response variable and the description variable. After that, ANOVA analysis of variance was used to verify the accuracy of the experimental data and the correlation. Finally, the prediction model is extended to a larger concentration and volume flow range, and it is found that the accuracy between the predicted value of friction coefficient and the experimental value is ± 30%, thus verifying that the correlation is suitable for the small-scale fully turbulent region. Compared with traditional experimental design and correlation methods, the implementation of Response Surface Methodology (RSM) in this study not only reduces the experimental time but also yields a more robust correlation for predicting the friction coefficient.

The utilization of drag-reducing polymers has long been hindered by their irritancy, corrosiveness, and toxicity across various domains. In this investigation, we explored sodium alginate, a natural drag reducer, for its efficacy in reducing drag and its resilience to shear in millimeter-scale pipelines. Initially, an experimental setup was devised to assess the drag reduction capabilities of sodium alginate at varying concentrations and flow rates using Response Surface Methodology (RSM). The relationship between drag reduction (DR), concentration (C), and flow rate (Q) was established by analyzing the experimental data. Subsequently, variance analysis was employed to validate the data accuracy, with a comparison between predicted and experimental DR values revealing an error margin within ± 20%. Analysis of cyclic shear testing of sodium alginate solution in tubes demonstrated its effectiveness as a shear flow drag reducer. Furthermore, results from laser particle size analysis indicated minimal molecular breakage of sodium alginate during cyclic shear.

Since the discovery of the turbulence drag reduction phenomenon over 70 years ago, it has been recognized that the addition of small quantities of drag-reducing agents to fluids can significantly decrease wall shear stress, thereby enhancing fluid pumpability. In many applications, the fluids often contain salts, such as those used in fracturing processes within the petroleum sector. The aim of this study is to experimentally investigate the effects of salinity, flow rate, and polymer concentration on the drag reduction performance of sodium alginate in circular pipes. The experimental process was designed using Response Surface Methodology (RSM), and a predictive regression model for the drag reduction rate (DR) was developed. By comparing the predicted results with the experimental outcomes, we found that the accuracy of the predictive model is high, with the error controlled within ± 20%. To provide a more intuitive understanding of the effect of salinity on the drag reduction performance of sodium alginate, this paper introduces the innovative concept of Drag Reduction Inhibition Rate (ε). The results indicate that the drag reduction rate in saline solutions is generally lower than that in salt-free solutions. However, during the initial stage of turbulence, a small amount of salt facilitates the unfolding of sodium alginate molecules, thereby enhancing the drag reduction effect (ε > 100%). Following this initial turbulent phase, the inhibitory effect of salinity on the polymer becomes pronounced, causing the drag reduction inhibition rate to decrease from 115 to 20%. We propose that high concentrations of salt may restrict the extent of polymer unfolding, resulting in concentrated solutions degrading into dilute solutions.

The Architectural Environment and Energy Application Engineering program aims to cultivate versatile engineering technology professionals, and internship education plays a crucial role in bridging theory and practice. Taking the Architectural Environment and Energy Application Engineering program at Shandong University of Petroleum and Chemical Technology as a case study, this paper analyzes the issues encountered in internship training. In response to these challenges, three improvement measures are proposed. First, virtual simulation scenarios are integrated with BIM (Building Information Modeling) software training, reinforcing overall system understanding through the combination of "training reports + BIM models." Second, a card model-making project is introduced to enhance students' hands-on skills and teamwork through group collaboration, with a comprehensive assessment approach combining "model evaluation + defense." Third, external internship bases are expanded, with the addition of the Shengli Oilfield New Energy Center, covering seven major projects, including photovoltaic and waste heat recovery. By constructing a dual-track training system of "traditional HVAC + new energy low-carbon" in parallel, the fragmentation of practical training and the disconnect between theory and practice are effectively addressed.

In this study, we investigated the drag reduction property of a premixed slurry drag reducer in a millimeter-scale pipe. The aim of this study is to establish the correlation between Fanning friction factor and drag reducer concentration (C) and volume flow (Q). First, the experimental plan was designed by using the response surface method (RSM), and then the experimental data were processed to establish the quadratic correlation between the response variable and the description variable. After that, ANOVA analysis of variance was used to verify the accuracy of the experimental data and the correlation. Finally, the prediction model is extended to a larger concentration and volume flow range, and it is found that the accuracy between the predicted value of friction coefficient and the experimental value is ±30%, thus verifying that the correlation is suitable for the small-scale fully turbulent region.