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Investigation on the urea deposit formation and thermal decomposition characteristics in the SCR aftertreatment system of a diesel engine

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Journal of Environmental Sciences 2021年第5期33卷 157-171页

作者： Menghan Li Yao Zhang jiancheng yang Xiaori Liu Zhenguo Li Qiang Zhang Tianjin Key Laboratory of Clean Energy and Pollution Control School of Energy and Environmental EngineeringHebei University of TechnologyTianjin 300401China School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China National Engineering Laboratory for Mobile Source Emission Control Technology China Automotive Technology&Research Center Co.Ltd.Tianjin 300300China State Key Laboratory of Engines Tianjin UniversityTianjin 300072China School of Energy and Power Engineering Shandong UniversityJinanShandong 250061China

Selective catalytic reduction is the most efficient and reliable equipment for NOx control in current diesel engines. However, the issue of urea crystallization becomes increasingly serious with the implement of the new emissions standards. In this paper, urea deposit samples collected from engine test bed and tube furnace were characterized by thermogravimetric analysis and Fourier transform-infrared analysis to aid the comprehension of urea deposit formation. Moreover, thermogravimetric tests were conducted to disclose the effects of catalyst on the thermal decomposition processes of urea deposit. The results indicated that less temperature resistant species are formed in the engine test bed than in the tube furnace at conditions with the same temperatures. The main compositions in the World Harmonized Transient Cycle(WHTC) urea deposits are urea, cyanuric acid(CYA) and ammelide, implying that accelerating the decomposition of these species could prevent the accumulation of urea deposit. CuWTi, Cu β and CuZSM catalysts could lead to increased yield of CYA during pure urea thermolysis. Cu β, CuWTi and VWTi catalysts tend to promote the thermolysis of CYA while VWTi has the most significant catalytic effects on the thermal decomposition of ammelide and ammeline.

关键词： Urea deposit Decomposition characteristics Selective catalytic reduction Catalyst Thermolysis

Hydrothermal pretreatment of protein-rich substrate:Modified physicochemical properties and consequent responses in its anaerobic digestion

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Carbon Resources Conversion 2023年第1期6卷 1-10页

作者： Fa Qiao Guangyi Zhang Jie Fan Hang Zhang Bowen Shi jiancheng yang Jianling Zhang Zhennan Han Shenyang University of Chemical Technology Shenyang 110142Liaoning ProvinceChina School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Urban Construction Wuhan University of Science and TechnologyWuhan 430081Hubei ProvinceChina China Power Engineering Consulting Group Co. LtdBeijing 100120China

Wasted tofu rich in protein was subject to hydrothermal pretreatment(HTPT)under different conditions(at 120,140,160 and 180℃;for 0,30,60 and 90 min)followed by biochemical methane potential(BMP)tests,and 140℃and 0 min were found to be respectively the best temperature and duration for HTPT of tofu in terms of its biogas *** the under the optimal conditions(140℃,0 min)the accumulative methane yield reached up to 510.9 mL⋅(gVS)-1,which was 26.98%higher than that without HTPT(402.3 mL⋅(gVS)-1).The start-up process of continuous anerobic digestion(AD)of the tofu before and after hydrothermal treated(HT)at the optimal HTPT conditions(140℃,0 min)was examined,to investigate and compare how their consequent AD responded to *** was found that,for start-up of continuous AD,the HT tofu delivered more balanced nutrients and thus led to more stable AD and quicker biogas ***,HTPT generated products refractory to biodegradation,to slightly decrease the total biogas *** AD of HT tofu some weak ammonia-tolerant microbes,such as methylotrophic methanogens,survived and played indispensable *** of living microbial community structure indicated that,some hydrolytic acidification bacteria intolerant to ammonia nitrogen(such as Proteobacteria)were always active and appeared at high *** viable methylotrophic methanogens,*** M2,took obvious responsibilities in start-up of the AD for HT tofu.

关键词： Hydrothermal pretreatment(HTPT) Protein-rich substrate Anaerobic digestion(AD) Biogas Microbial community structure

Fluidized bed combustion of high water content alcohol extracted herb residue and the impacts of blending wasted activated coke

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Carbon Resources Conversion 2023年第1期6卷 11-19页

作者： Xuan Liu Xinyu Zhu Wenyan Wang Bowen Shi Guangyi Zhang Jianling Zhang jiancheng yang Yanming Shen School of Chemical Engineering Shenyang University of Chemical TechnologyShenyang 110142LiaoningChina School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China China Power Engineering Consulting Group Co. LtdBeijing 100120China

Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue *** alcohol extracted herb residue(AEHR),one special type of HRs,was chosen as the object and was subjected to immediate combustion in a fluidized bed reactor to investigate the characteristics of its resulting NOx *** results showed that,most of the NOx in the flue gas was produced from the char nitrogen(C-N);as the fuel water content increased,the NOx emission concentration exhibited a trend of first decreasing and then increasing;and a properly low combustion temperature inhibited the NOx emission upon the premise of ensuring full *** staging combustion was adopted to effectively control NOx:the NOx emission concentration in the flue gas was reduced to 296 mg⋅m􀀀3 and the NOx emission reduction rate reached 46.51%compared to conventional ***-combustion by blending wasted activated coke(WAC)into the AEHR helped both stabilize the combustion state and reduce further the NOx *** the blending ratio of WAC fell within a proper range of 20-30%,the NOx emission concentration in the flue gas was as low as 231.4 mg⋅m􀀀*** addition to the dilution effect of the combustion flue gas of the blended WAC,the local reducing atmosphere caused by its incomplete combustion as well as its strong absorbability and catalytical effect was accountable for the further decrease of the NOx emission concentration.

关键词： Alcohol extracted herb residue Wasted activated coke Fluidized bed combustion NOx Air staging combustion

Linear Coupling Resonance Stop-bands Compensation at Booster Ring of HIAF

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IMP & HIRFL Annual Report 2017年第1期 229-230页

作者： Li Jie yang jiancheng 不详

The High Intensity heavy-ion Accelerator Facility(HIAF)is a new heavy ion accelerator complex under detailed design by institute of modern physics[1].Two typical particles of ^(238)U^(35+) and proton is *** ^(34)Tm booster ring(BRing)is designed to stack 1.0×10^(11) ^(238)U^(35+) ions at low injection energy of 17 MeV/*** space charge effect of intensive highly charged particle beam creates depressed tune spread[2].This effect gets serious especially when RF starts capture and at early stage of ***,the designed nominal working point(9.45,9.47)seats next to linear coupling resonance of νx-νy=*** of quadruples,high order field component and longitudinal magnetic field contribute to stop-band of this resonance.

关键词： bands nominal acceleration

Analysis and mitigation of bump magnetic field tracking errors in a multiturn injection system

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Radiation Detection Technology and Methods 2023年第4期7卷 531-544页

作者： Shuaishuai Zhang Guodong Shen Weiping Chai Jingjing Zhang Hongliang Guo Lingxiao Hou Liping Yao Shuang Ruan jiancheng yang Institute of Modern Physics Chinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Beijing100049China

Purpose The Space Environment Simulation and Research Infrastructure(SESRI)is a cluster of accelerators designed to simulate the cosmic radiation environment by generating particles of various types and *** these accelerators,a synchrotron in the 300 MeV proton and heavy ion accelerator complex utilizes a multiturn injection scheme with four bump magnets to accumulate proton and heavy ion beams ***,the bump magnetic field experiences a rapid drop rate of up to 1000 T/s,inevitably leading to a deviation(field tracking error)from the ideal magnetic *** injection efficiency and particle distribution are significantly affected by this field tracking error,as evaluated by the ACCSIM *** During the device testing stage,the sources of field tracking errors were identified by analysis of the bump power supplies and the field of the *** techniques were then implemented to reduce the field tracking error from[Math Processing Error]to[Math Processing Error]throughout the entire power supply,transmission cable,and magnet *** Moreover,the successful injection and accumulation of beams during the operational phase of the synchrotron confirmed the effectiveness of the proposed mitigation ***,a magnetic field measurement system was developed to monitor the magnetic field tracking error *** The combination of the field tracking error mitigation methods and the measurement system provides valuable guidance for optimizing the magnetic fields with rapid drop rates.

关键词： SESRI Multiturn injection Bump magnet Field tracking error mitigation

基于支持向量回归机的空调逐时负荷滚动预测算法

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中南大学学报（自然科学版） 2014年第3期45卷 952-957页

作者：周璇杨建成华南理工大学机械与汽车工程学院广东广州510640 广东省城市空调节能与控制工程技术研究开发中心广东广州510640

针对当前空调负荷预测算法精度不高难以满足空调系统节能优化控制的问题,提出基于支持向量回归机(Support Vector Regression,SVR)的空调逐时负荷滚动预测算法,建立SVR滚动预测模型,模型参数采用网格搜索遍历算法进行寻优。为简化模型... 详细信息

针对当前空调负荷预测算法精度不高难以满足空调系统节能优化控制的问题,提出基于支持向量回归机(Support Vector Regression,SVR)的空调逐时负荷滚动预测算法,建立SVR滚动预测模型,模型参数采用网格搜索遍历算法进行寻优。为简化模型的复杂性,还对影响空调负荷的主要因素进行了相关性分析。此外,算法利用当日前1 h的滚动信息,不断对模型进行修正以提高负荷预测精度。最后探讨以期望误差为预测精度评价指标时,不同训练样本长度对神经网络和SVR算法预测精度的影响。预测结果表明:基于支持向量回归机的空调逐时负荷滚动预测算法较BP神经网络算法的预测精度提高10.3%,比常规支持向量回归机算法预测精度提高23.9%,训练样本较小时,算法预测性能更为优越。

关键词：空调逐时负荷滚动预测算法支持向量回归机网格搜索遍历算法期望误差

6 - 2 Beam Loss Distribution and Collimation Efficiency Calculation of CSRm

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IMP & HIRFL Annual Report 2013年第1期 228-229页

作者： Li Peng Yuan Youjin yang jiancheng yang Xiaodong ZhengWenheng

Simulation research on cable-laying scheme of HIAF dipole power supply

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Radiation Detection Technology and Methods 2023年第1期7卷 149-158页

作者： Runzu Zhang Anhui Feng Ye Liu Zhongzu Zhou Yongbo Zhang Pengfei Liu jiancheng yang Daqing Gao Shuang Ruan Guodong Shen Hengmin Liu Institute of Modern Physics Chinese Academy of SciencesLanzhou730000China Tianshui Electric Drive Research Institute Group Co. LtdTianshui741020China

Background A strong electromagnetic force is the major cause of vibration in dipole power supply ***,the long-term operation of cables under vibration conditions leads to structural fatigue *** and methods To investigate the cable-laying scheme of a dipole power supply,a finite element model for the electromagnetic–structural coupling between cables and cleats was *** electrodynamic forces were simulated for fixed-length cables in the horizontal,vertical,and bent models under pulse-current ***,based on the optimized arrangement mode,the deformation of the cables and the stresses of the cleats were *** A small cable electrodynamic force was observed in the positive–negative interlace arrangement,and the cable deformation was caused by electrodynamic *** maximum cleat deformation occurred at the position with the largest electrodynamic force,where the cleats were ***,the mechanical characteristics of the cables and cleats under pulse-current excitation are described intuitively and quantitatively,providing theoretical support for the cable-laying scheme of the dipole power supply.

关键词： Cable Pulse current Laying scheme Electrodynamic force Vibration

Study on the longitudinal capture efficiency of a CW heavy-ion Linac

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Radiation Detection Technology and Methods 2022年第3期6卷 391-400页

作者： Qiyu Kong Xuejun Yin Zhongshan Li Peng Jin Heng Du Xiaoni Li Zheng Liu Youjin Yuan Jiawen Xia jiancheng yang Weiqing yang Zhe Xu Junxia Wu Yong Zhang Long Jing Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Huizhou Research Center of Ion Science Huizhou 516003China Lanzhou University Lanzhou 730000China

Purpose The continuous-wave(CW)linear accelerator,SSC-Linac,has been put into operation successfully as the new injector of Separate Sector Cyclotron(SSC)for Heavy Ion Research Facility in Lanzhou(HIRFL).The SSC-Linac is operated at the frequency of 53.667 MHz,which is the four times of the SSC operating *** order to improve the longitudinal capture efﬁciency and increase the beam current extracted from the SSC,an independent multi-harmonics buncher(MHB)operating at a fundamental frequency of 13.417 MHz had been designed and *** This buncher adopts the dual-gap structure and sawtooth waveform is generated by multi-harmonics synthetized *** dynamics simulation with MHB was carried out and discussed in this ***,the beam commissioning using 84Kr14+had been performed on *** and conclusion The measured maximum capture efﬁciency 86.5%was obtained,which was well agreed with the simulation *** to the successful commissioning of MHB and the outstanding-performance of SSC-Linac,the extracted beam current from SSC has been improved one order of magnitude higher than before.

关键词： Heavy ion Linear accelerator Multi-harmonics buncher Capture efﬁciency