In the natural gas liquefaction process,the mixed refrigerant natural gas liquefaction process is widely used in LNG liquefaction plants because of its advantages of low energy consumption.This paper focuses on the in...In the natural gas liquefaction process,the mixed refrigerant natural gas liquefaction process is widely used in LNG liquefaction plants because of its advantages of low energy consumption.This paper focuses on the influences of important parameters in the C3/MRC liquefaction process,that is,the comparison between propane precooling temperature and the number of moles of methane in mixed refrigerant,power consumption and loss.In addition,the total process was optimized with the optimizer and manual adjustment in HYSYS software to minimize the total power consumption.The results show that with increasing propane precooling temperature,the propane flow rate is almost unchanged,while the mixed refrigerant flow rate decreases significantly,and the loss of the heat exchanger increases significantly.The power consumption of the propane precooling cycle and hybrid refrigeration cycle increases with increasing methane content in the refrigerant,so the power consumption of the whole process increases accordingly.The effect of the methane content in the mixed refrigerant on the process evaluation index is more significant than that of the propane precooling temperature.展开更多
The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(...The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor.展开更多
针对煤基天然气(SNG)设计了一种C3/MRC液化工艺,考察了丙烷制冷循环和混合冷剂制冷循环中各冷箱温度分布对液化功耗的影响,煤基天然气节流压力对液化率的影响,对比了不同组成原料气的液化比功耗。研究结果表明:C3/MRC液化工艺适用于煤...针对煤基天然气(SNG)设计了一种C3/MRC液化工艺,考察了丙烷制冷循环和混合冷剂制冷循环中各冷箱温度分布对液化功耗的影响,煤基天然气节流压力对液化率的影响,对比了不同组成原料气的液化比功耗。研究结果表明:C3/MRC液化工艺适用于煤基天然气,且冷箱热流体出口温度分布对液化功耗影响较大;BOG气体中H2含量随节流后压力增高而增大;液化煤基天然气的单位功耗高于气田天然气。优化后煤基天然气的液化率达到94.95%,比功耗为0.34 k W·h/kg LNG。展开更多
Persulfacte(PDS)activation by metal-free carbons is promising for water decontamination.Nevertheless,developing high-performance catalysts has been limited by the ambiguous understanding of the role of carbon structur...Persulfacte(PDS)activation by metal-free carbons is promising for water decontamination.Nevertheless,developing high-performance catalysts has been limited by the ambiguous understanding of the role of carbon structure in PDS activation behavior.In this study,the PDS activation using a series of sp2-sp3 carbon hybrids from modified activated carbon(AC)for Phenol(PE)removal.The activity of AC displays a volcano-type trend with sp3/(sp2+sp3)ratio,the catalyst with optimized ratio of 27% exhibited the best catalytic activity for PDS activation and PE removal.Defect sp3-C can modulate electron structure of sp2-sp3 C,which determines the PDS activation path.At the electron-rich sp2-sp3 C,PDS tend to reduce for generation the sp2-sp3 C-PDS*and induces a strong electron-transfer oxidation pathway.This study provides a guidance for designing of metal-free carbon catalysts for water purification.展开更多
To address challenges in feature extraction and real-time processing during traffic police pose estimation,this paper proposes an improved YOLOv11-pose network for traffic police gesture recognition.By replacing the C...To address challenges in feature extraction and real-time processing during traffic police pose estimation,this paper proposes an improved YOLOv11-pose network for traffic police gesture recognition.By replacing the C3K2 module in the backbone network with an enhanced C3K2-Star-CAA module,we achieve efficient extraction of traffic police posture features.A multi-branch star topology enables cross-level feature fusion and multi-scale information propagation,enhancing the model’s perception of minute posture details and complex background interference.Embedding the CAA attention mechanism at the key feature layer models critical locations and their spatial contextual relationships through contextual anchors,effectively enhancing key-point feature representation while suppressing complex background interference.Experimental results demonstrate that the improved model achieves 78.6%mAP on the self-built dataset with a detection speed of 186.9 fps,outperforming comparison models in both accuracy and real-time performance.The findings indicate that this approach provides a robust and highly real-time practical solution for traffic police gesture recognition.展开更多
By means of hydration heat,XRD and SEM,effect of phosphorus and fluorine(P205 and F-)in phosphorous slag on hydration process of tricalcium silicate(C3S)and tricalcium aluminate(C3A)was explored.The results indicated ...By means of hydration heat,XRD and SEM,effect of phosphorus and fluorine(P205 and F-)in phosphorous slag on hydration process of tricalcium silicate(C3S)and tricalcium aluminate(C3A)was explored.The results indicated that the early hydration exothermic rate of C3S and C3A was obviously lowered by P205 and F-in phosphorous slag,the second peak occurring time of C3A was delayed by 0.9 h,the exothermal output of C3S was reduced by 25.04%and the time of accelerating stage was postponed by 0.86 h.The early hydration degree of C3S and C3A was also decreased.Due to the influence of P205 and F,more pores and thinner crystals can be observed in the microstructure of hardened paste and the chance of cracks was reduced.展开更多
To meet the performance requirements of hot forging die heat resistant layer, the Ni60-SiC coating, Ni60-Cr3C2 coating, and Ni60-WC coating were prepared using W6Mo5Cr4V2 as substrate material with 30%SiC, 10%Cr3C2, 3...To meet the performance requirements of hot forging die heat resistant layer, the Ni60-SiC coating, Ni60-Cr3C2 coating, and Ni60-WC coating were prepared using W6Mo5Cr4V2 as substrate material with 30%SiC, 10%Cr3C2, 30%WC powder by means of plasma spraying and plasma spray re-melting and plasma spray welding, respectively. Microstructure of each carbide coating was analyzed, micro-hardness was tested, and mainly thermal parameters of coating were detected. The experimental results show that using plasma spray welding, the performance of 70%Ni60/30%SiC powder is the best, and its micro-hardness can achieved 1100HV, showing good thermal-physical property.展开更多
In our previous work, the reactive dividing wall column(RDWC) was proposed and proved to be effective for selective hydrogenation and separation of C3 stream. In the present paper, the dynamics and control of the prop...In our previous work, the reactive dividing wall column(RDWC) was proposed and proved to be effective for selective hydrogenation and separation of C3 stream. In the present paper, the dynamics and control of the proposed RDWC are investigated. Four control structures including composition and temperature controls are proposed. The feed forward controllers are employed in the four control strategies to shorten the dynamic response time, reduce the maximum deviations and offer an immediate adjustment. The control structures are compared by applying them into the RDWC system with 20% disturbances in both the feed flow rate and the feed compositions, and the results are discussed.展开更多
基金supported by the Research Project of Sinopec Shengli Oilfield Company“Research of Energy Flow Optimization Analysis and Application Technology of Oilfield Production System”.
摘要In the natural gas liquefaction process,the mixed refrigerant natural gas liquefaction process is widely used in LNG liquefaction plants because of its advantages of low energy consumption.This paper focuses on the influences of important parameters in the C3/MRC liquefaction process,that is,the comparison between propane precooling temperature and the number of moles of methane in mixed refrigerant,power consumption and loss.In addition,the total process was optimized with the optimizer and manual adjustment in HYSYS software to minimize the total power consumption.The results show that with increasing propane precooling temperature,the propane flow rate is almost unchanged,while the mixed refrigerant flow rate decreases significantly,and the loss of the heat exchanger increases significantly.The power consumption of the propane precooling cycle and hybrid refrigeration cycle increases with increasing methane content in the refrigerant,so the power consumption of the whole process increases accordingly.The effect of the methane content in the mixed refrigerant on the process evaluation index is more significant than that of the propane precooling temperature.
基金supported by the Science Development Funding Program of Dongying of China(Grant No.DJ2021006)Science Development Funding Program of Dongying of China(Grant No.DJ2021008).
摘要The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor.
摘要针对煤基天然气(SNG)设计了一种C3/MRC液化工艺,考察了丙烷制冷循环和混合冷剂制冷循环中各冷箱温度分布对液化功耗的影响,煤基天然气节流压力对液化率的影响,对比了不同组成原料气的液化比功耗。研究结果表明:C3/MRC液化工艺适用于煤基天然气,且冷箱热流体出口温度分布对液化功耗影响较大;BOG气体中H2含量随节流后压力增高而增大;液化煤基天然气的单位功耗高于气田天然气。优化后煤基天然气的液化率达到94.95%,比功耗为0.34 k W·h/kg LNG。
基金supported by the National Key Research and Development Program of China(2024YFC3907904)。
摘要Persulfacte(PDS)activation by metal-free carbons is promising for water decontamination.Nevertheless,developing high-performance catalysts has been limited by the ambiguous understanding of the role of carbon structure in PDS activation behavior.In this study,the PDS activation using a series of sp2-sp3 carbon hybrids from modified activated carbon(AC)for Phenol(PE)removal.The activity of AC displays a volcano-type trend with sp3/(sp2+sp3)ratio,the catalyst with optimized ratio of 27% exhibited the best catalytic activity for PDS activation and PE removal.Defect sp3-C can modulate electron structure of sp2-sp3 C,which determines the PDS activation path.At the electron-rich sp2-sp3 C,PDS tend to reduce for generation the sp2-sp3 C-PDS*and induces a strong electron-transfer oxidation pathway.This study provides a guidance for designing of metal-free carbon catalysts for water purification.
摘要To address challenges in feature extraction and real-time processing during traffic police pose estimation,this paper proposes an improved YOLOv11-pose network for traffic police gesture recognition.By replacing the C3K2 module in the backbone network with an enhanced C3K2-Star-CAA module,we achieve efficient extraction of traffic police posture features.A multi-branch star topology enables cross-level feature fusion and multi-scale information propagation,enhancing the model’s perception of minute posture details and complex background interference.Embedding the CAA attention mechanism at the key feature layer models critical locations and their spatial contextual relationships through contextual anchors,effectively enhancing key-point feature representation while suppressing complex background interference.Experimental results demonstrate that the improved model achieves 78.6%mAP on the self-built dataset with a detection speed of 186.9 fps,outperforming comparison models in both accuracy and real-time performance.The findings indicate that this approach provides a robust and highly real-time practical solution for traffic police gesture recognition.
基金Funded by the National Natural Science Foundation of China(No.50802067)
摘要By means of hydration heat,XRD and SEM,effect of phosphorus and fluorine(P205 and F-)in phosphorous slag on hydration process of tricalcium silicate(C3S)and tricalcium aluminate(C3A)was explored.The results indicated that the early hydration exothermic rate of C3S and C3A was obviously lowered by P205 and F-in phosphorous slag,the second peak occurring time of C3A was delayed by 0.9 h,the exothermal output of C3S was reduced by 25.04%and the time of accelerating stage was postponed by 0.86 h.The early hydration degree of C3S and C3A was also decreased.Due to the influence of P205 and F,more pores and thinner crystals can be observed in the microstructure of hardened paste and the chance of cracks was reduced.
摘要To meet the performance requirements of hot forging die heat resistant layer, the Ni60-SiC coating, Ni60-Cr3C2 coating, and Ni60-WC coating were prepared using W6Mo5Cr4V2 as substrate material with 30%SiC, 10%Cr3C2, 30%WC powder by means of plasma spraying and plasma spray re-melting and plasma spray welding, respectively. Microstructure of each carbide coating was analyzed, micro-hardness was tested, and mainly thermal parameters of coating were detected. The experimental results show that using plasma spray welding, the performance of 70%Ni60/30%SiC powder is the best, and its micro-hardness can achieved 1100HV, showing good thermal-physical property.
基金Supported by the National Basic Research Program of China(2012CB720500)the National Supporting Research Program of China(2013BAA03B01)+1 种基金the National Natural Science Foundation of China(21176178)China Scholarship Council(CSC[2015]3022)
摘要In our previous work, the reactive dividing wall column(RDWC) was proposed and proved to be effective for selective hydrogenation and separation of C3 stream. In the present paper, the dynamics and control of the proposed RDWC are investigated. Four control structures including composition and temperature controls are proposed. The feed forward controllers are employed in the four control strategies to shorten the dynamic response time, reduce the maximum deviations and offer an immediate adjustment. The control structures are compared by applying them into the RDWC system with 20% disturbances in both the feed flow rate and the feed compositions, and the results are discussed.