In order to apply plasma assisted combustion(PAC) into a reverse-flow aero-engine and verify the improvement of combustion performance, a feasible approach was proposed in this work. In this approach, based on the str...In order to apply plasma assisted combustion(PAC) into a reverse-flow aero-engine and verify the improvement of combustion performance, a feasible approach was proposed in this work. In this approach, based on the structure characteristics of the reverse-flow combustor, a parallel plate double dielectric barrier discharge(DBD) PAC actuator was designed to generate plasma. It was installed at the front of combustor. When the actuator is driven, the original air flow is not disturbed for the device’s structure and installation. Using aviation kerosene as fuel, the effects of plasma on ignition boundary and outlet temperature of the combustor were experimentally investigated at atmosphere pressures. Through the dual high voltage differential power supply, the large gap, large area and uniform plasma discharge was achieved. The results of PAC actuator discharge indicate that inlet air temperature has a small increase of 4–9 K. After PAC is applied, the combustion performances of reverse-flow combustor in an aero-engine are remarkably improved. Experimental results indicate that ignition boundary is widened by 3.7%–12.5% because of the impact of plasma. Outlet highest temperature of combustor is raised by 19–75 K;outlet temperature distribution coefficient is reduced by 11.1%–26.6%. This research provides an effective and practicable way to implement the application of PAC in aero-engine combustor and has some engineering application significance.展开更多
研究了双介质阻挡放电降解苯酚废水过程中不同因素对苯酚降解效果的影响,确定了最佳反应条件,并初步探讨其反应机理。采用自制双介质阻挡放电反应器,以模拟苯酚废水为研究对象,研究了苯酚废水浓度、输入电压、废水曝气量、反应时间等因...研究了双介质阻挡放电降解苯酚废水过程中不同因素对苯酚降解效果的影响,确定了最佳反应条件,并初步探讨其反应机理。采用自制双介质阻挡放电反应器,以模拟苯酚废水为研究对象,研究了苯酚废水浓度、输入电压、废水曝气量、反应时间等因素对苯酚降解效率的影响。结果表明:输入电压为5 k V,曝气气水比为40∶1,反应时间60 min,降解质量浓度为200 mg/L的模拟苯酚废水,苯酚最大去除率达到95.3%;其中苯酚废水浓度、输入电压、曝气气水比对试验结果影响较大。展开更多
Dielectric barrier discharge(DBD)has been extensively investigated in the fields of environment and energy,whereas its practical implementation is still limited due to its unsatisfactory energy efficiency.In order to ...Dielectric barrier discharge(DBD)has been extensively investigated in the fields of environment and energy,whereas its practical implementation is still limited due to its unsatisfactory energy efficiency.In order to improve the energy efficiency of DBD,a novel double dielectric barrier discharge(NDDBD)reactor with high field emission and secondary electron emission was developed and compared with traditional DDBD(TDDBD)configuration.Firstly,the discharge characteristics of the two DDBD reactors were analyzed.Compared to TDDBD,the NDDBD reactor exhibited much stronger discharge intensity,higher transferred charge,dissipated power and gas temperature due to the effective utilization of cathode field emission and secondary electron emission.Subsequently,toluene abatement performance of the two reactors was evaluated.The toluene decomposition efficiency and mineralization rate of NDDBD were much higher than that of TDDBD,which were 86.44%-100%versus 28.17%-80.48%and 17.16%-43.42%versus 7.17%-16.44%at 2.17-15.12 W and 1.24-4.90 W respectively.NDDBD also exhibited higher energy yield than TDDBD,whereas the overall energy constant k_(overall)of the two reactors were similar.Finally,plausible toluene decomposition pathway in TDDBD and NDDBD was suggested based on organic intermediates that generated from toluene degradation.The finding of this study is expected to provide reference for the design and optimization of DBD reactor for volatile organic compounds control and other applications.展开更多
The coal-fired flue gas spraying wastewater is a kind of refractory mixed wastewater with poor biodegradability.In this study,the degradation of model coal-fired flue gas spraying wastewater was studied by using disch...The coal-fired flue gas spraying wastewater is a kind of refractory mixed wastewater with poor biodegradability.In this study,the degradation of model coal-fired flue gas spraying wastewater was studied by using discharge free radicals produced by double-dielectric barrier discharge.The degradation rate of pollutants,chemical oxygen demand removal rate and other indicators were detected,and the influence of different conditions on the degradation effect was analyzed.The optimal parameters are as follows:residence time 120 min,input power 170.0 W,initial pH value 3.79,and aeration rate 1.8 mL/min.The initial concentrations of acetone,formaldehyde,chloroform,benzene and toluene were 100,100,100,and 100 mg/L,respectively.Furthermore,it is proved that the discharge area is independent of the degradation rate.Through the analysis of the mechanism,it is found that·OH is an important factor affecting the degradation rate of pollutants in model coal-fired flue gas spraying wastewater.展开更多
Wastewater from the spray absorption treatment of sludge drying gas is a kind of refractory wastewater with poor biodegradability.In this study,the free radicals generated from the double dielectric barrier were innov...Wastewater from the spray absorption treatment of sludge drying gas is a kind of refractory wastewater with poor biodegradability.In this study,the free radicals generated from the double dielectric barrier were innovatively used for the degradation of simulated spray wastewater.The effects of residence time,input power,initial pH,aeration rate,and discharge area on the degradation rate and COD(chemical oxygen demand)removal rate were investigated.The optimal conditions were as follows:residence time=120 min,input power=170.0 W,initial pH=5.54,aeration rate=0.9 mL/min,discharge area=10.8 cm^(2),and the initial concentrations of NH_(3),H_(2)S,methanethiol,trimethylamine,benzene and toluene were 250,250,50,50,50 and 100 mg/L,respectively.Meanwhile,it was also found that hydroxyl radical(⋅OH)played an important role in the degradation process.展开更多
Synthetic dyes are substances that are relatively stable and difficult to degrade in wastewater treatment plants using normal physical,chemical or / and biological treatment. The present work explored the synergistic ...Synthetic dyes are substances that are relatively stable and difficult to degrade in wastewater treatment plants using normal physical,chemical or / and biological treatment. The present work explored the synergistic effect of non-thermal plasma( NTP) and biological wastewater treatment technologies on practical dye wastewater degradation by establishing a double dielectric barrier discharge( DDBD) system combined with a sequencing batch reactor( SBR) system. The biodegradation and degradation efficiency of the DDBD-SBR system was investigated. The investigation results indicated that the DDBD technology was effective in treating the practical dye wastewater as a pre-treatment process. After a 10-min treatment,although the total organic carbon( TOC) removal efficiency was not so significant, the decolouration and the biodegradation were improved greatly. The microbial toxicity test revealed that the sample after degradation became less toxic than the original dye,which demonstrated the treatment had a significant effect on the reduction of toxicity. In addition,the SBR technology remedied the defects of DDBD treatment and improved TOC removal efficiency noticeably. The hybrid DDBD-SBR system made full use of the advantages of the individual technologies and exhibited an efficient capability for practical dye wastewater treatment.展开更多
基金supported by the National Natural Science Foundation of China (Funding Nos. 51436008, 91741112 and 51806245)
文摘In order to apply plasma assisted combustion(PAC) into a reverse-flow aero-engine and verify the improvement of combustion performance, a feasible approach was proposed in this work. In this approach, based on the structure characteristics of the reverse-flow combustor, a parallel plate double dielectric barrier discharge(DBD) PAC actuator was designed to generate plasma. It was installed at the front of combustor. When the actuator is driven, the original air flow is not disturbed for the device’s structure and installation. Using aviation kerosene as fuel, the effects of plasma on ignition boundary and outlet temperature of the combustor were experimentally investigated at atmosphere pressures. Through the dual high voltage differential power supply, the large gap, large area and uniform plasma discharge was achieved. The results of PAC actuator discharge indicate that inlet air temperature has a small increase of 4–9 K. After PAC is applied, the combustion performances of reverse-flow combustor in an aero-engine are remarkably improved. Experimental results indicate that ignition boundary is widened by 3.7%–12.5% because of the impact of plasma. Outlet highest temperature of combustor is raised by 19–75 K;outlet temperature distribution coefficient is reduced by 11.1%–26.6%. This research provides an effective and practicable way to implement the application of PAC in aero-engine combustor and has some engineering application significance.
文摘研究了双介质阻挡放电降解苯酚废水过程中不同因素对苯酚降解效果的影响,确定了最佳反应条件,并初步探讨其反应机理。采用自制双介质阻挡放电反应器,以模拟苯酚废水为研究对象,研究了苯酚废水浓度、输入电压、废水曝气量、反应时间等因素对苯酚降解效率的影响。结果表明:输入电压为5 k V,曝气气水比为40∶1,反应时间60 min,降解质量浓度为200 mg/L的模拟苯酚废水,苯酚最大去除率达到95.3%;其中苯酚废水浓度、输入电压、曝气气水比对试验结果影响较大。
基金financially supported by National Key R&D Program of China(No.2017YFC0212204)Key Research and Development Program of Shaanxi Province(No.2018ZDCXL-SF-02-04)。
文摘Dielectric barrier discharge(DBD)has been extensively investigated in the fields of environment and energy,whereas its practical implementation is still limited due to its unsatisfactory energy efficiency.In order to improve the energy efficiency of DBD,a novel double dielectric barrier discharge(NDDBD)reactor with high field emission and secondary electron emission was developed and compared with traditional DDBD(TDDBD)configuration.Firstly,the discharge characteristics of the two DDBD reactors were analyzed.Compared to TDDBD,the NDDBD reactor exhibited much stronger discharge intensity,higher transferred charge,dissipated power and gas temperature due to the effective utilization of cathode field emission and secondary electron emission.Subsequently,toluene abatement performance of the two reactors was evaluated.The toluene decomposition efficiency and mineralization rate of NDDBD were much higher than that of TDDBD,which were 86.44%-100%versus 28.17%-80.48%and 17.16%-43.42%versus 7.17%-16.44%at 2.17-15.12 W and 1.24-4.90 W respectively.NDDBD also exhibited higher energy yield than TDDBD,whereas the overall energy constant k_(overall)of the two reactors were similar.Finally,plausible toluene decomposition pathway in TDDBD and NDDBD was suggested based on organic intermediates that generated from toluene degradation.The finding of this study is expected to provide reference for the design and optimization of DBD reactor for volatile organic compounds control and other applications.
基金supported by enterprise projects(No.YT2017,No.YG1908).
文摘The coal-fired flue gas spraying wastewater is a kind of refractory mixed wastewater with poor biodegradability.In this study,the degradation of model coal-fired flue gas spraying wastewater was studied by using discharge free radicals produced by double-dielectric barrier discharge.The degradation rate of pollutants,chemical oxygen demand removal rate and other indicators were detected,and the influence of different conditions on the degradation effect was analyzed.The optimal parameters are as follows:residence time 120 min,input power 170.0 W,initial pH value 3.79,and aeration rate 1.8 mL/min.The initial concentrations of acetone,formaldehyde,chloroform,benzene and toluene were 100,100,100,and 100 mg/L,respectively.Furthermore,it is proved that the discharge area is independent of the degradation rate.Through the analysis of the mechanism,it is found that·OH is an important factor affecting the degradation rate of pollutants in model coal-fired flue gas spraying wastewater.
基金supported by the National Natural Science Foundation of China(No.61871409)Zhejiang Natural Science Foundation of China(No.LZ20F010001).
文摘Wastewater from the spray absorption treatment of sludge drying gas is a kind of refractory wastewater with poor biodegradability.In this study,the free radicals generated from the double dielectric barrier were innovatively used for the degradation of simulated spray wastewater.The effects of residence time,input power,initial pH,aeration rate,and discharge area on the degradation rate and COD(chemical oxygen demand)removal rate were investigated.The optimal conditions were as follows:residence time=120 min,input power=170.0 W,initial pH=5.54,aeration rate=0.9 mL/min,discharge area=10.8 cm^(2),and the initial concentrations of NH_(3),H_(2)S,methanethiol,trimethylamine,benzene and toluene were 250,250,50,50,50 and 100 mg/L,respectively.Meanwhile,it was also found that hydroxyl radical(⋅OH)played an important role in the degradation process.
基金Key Basic Research of Shanghai Science and Technology Committee,China(No.11JC1400100)National Natural Science Foundations of China(Nos.51108070,51178093)+2 种基金Shanghai Pujiang Programmethe Program for New Century Excellent Talents in University,China(No.NCET-12-0826)Fundamental Research Funds for Central Universities,China
文摘Synthetic dyes are substances that are relatively stable and difficult to degrade in wastewater treatment plants using normal physical,chemical or / and biological treatment. The present work explored the synergistic effect of non-thermal plasma( NTP) and biological wastewater treatment technologies on practical dye wastewater degradation by establishing a double dielectric barrier discharge( DDBD) system combined with a sequencing batch reactor( SBR) system. The biodegradation and degradation efficiency of the DDBD-SBR system was investigated. The investigation results indicated that the DDBD technology was effective in treating the practical dye wastewater as a pre-treatment process. After a 10-min treatment,although the total organic carbon( TOC) removal efficiency was not so significant, the decolouration and the biodegradation were improved greatly. The microbial toxicity test revealed that the sample after degradation became less toxic than the original dye,which demonstrated the treatment had a significant effect on the reduction of toxicity. In addition,the SBR technology remedied the defects of DDBD treatment and improved TOC removal efficiency noticeably. The hybrid DDBD-SBR system made full use of the advantages of the individual technologies and exhibited an efficient capability for practical dye wastewater treatment.
