Continuous Stirred Tank Reactors (CSTR) are used ubiquitously in chemical process industry for mixing, reactions and crystallizations. The purpose of this research is to study the effect of solute concentration (sodiu...Continuous Stirred Tank Reactors (CSTR) are used ubiquitously in chemical process industry for mixing, reactions and crystallizations. The purpose of this research is to study the effect of solute concentration (sodium chloride) on the stirrer speed in a CSTR. The experimental method used in this research is the stop watch and beaker method. The behavior pattern of the fluid in a CSTR can be experimentally verified as an alternative to the mathematical model. The tracer experiments were carried out. The effect of different parameters such as stirring speed, concentration at a steady time interval was analyzed. Experimental data obtained at 0.6 M and 160 rpm gave a curve that is in close agreement to that of theoretical or mathematical model. In other words, the results obtained at a concentration of 0.6 M and 160 rpm are in close agreement with that of early researchers. The paper is divided into five main sections: the first section immediately after the abstract is the introductory section that is basically a review of literature;the second section takes care of the materials and methods;the third section is the experimental procedure and this section takes the shut-down procedure and data processing into consideration;the fourth section is the discussion of experimental results and the last section is the conclusion of the paper.展开更多
The continuous stirred tank reactor(CSTR)is one of the typical chemical processes.Aiming at its strong nonlinear characteristics,a quantized kernel least mean square(QKLMS)algorithm is proposed.The QKLMS algorithm is ...The continuous stirred tank reactor(CSTR)is one of the typical chemical processes.Aiming at its strong nonlinear characteristics,a quantized kernel least mean square(QKLMS)algorithm is proposed.The QKLMS algorithm is based on a simple online vector quantization technology instead of sparsification,which can compress the input or feature space and suppress the growth of the radial basis function(RBF)structure in the kernel learning algorithm.To verify the effectiveness of the algorithm,it is applied to the model identification of CSTR process to construct a nonlinear mapping relationship between coolant flow rate and product concentration.In additiion,the proposed algorithm is further compared with least squares support vector machine(LS-SVM),echo state network(ESN),extreme learning machine with kernels(KELM),etc.The experimental results show that the proposed algorithm has higher identification accuracy and better online learning ability under the same conditions.展开更多
CMAC(Cerebellar Model Articulation Controller或Cerebellar Model Arithmetic Computer)神经元网络是由Albus提出的一种表达复杂非线性函数的表格查询的自适应系统。本文将CMAC应用到具体的连续搅拌反应釜(CSTR)系统的学习控制研究中...CMAC(Cerebellar Model Articulation Controller或Cerebellar Model Arithmetic Computer)神经元网络是由Albus提出的一种表达复杂非线性函数的表格查询的自适应系统。本文将CMAC应用到具体的连续搅拌反应釜(CSTR)系统的学习控制研究中,仿真结果表明,该学习控制策略具有较强的自学习能力且容易实现,对于改善非线性控制的性能,不失为一种有益的尝试。展开更多
A new optimizing framework of process operation is proposed to deal with optimizing op- eration of continuous stirred tank reactor （CSTR）. The optimization framework includes two layers： the first layer, necessary ...A new optimizing framework of process operation is proposed to deal with optimizing op- eration of continuous stirred tank reactor （CSTR）. The optimization framework includes two layers： the first layer, necessary condition of optimally （NCO） tracking controller, calculates the optimal set-point of the process; and the second layer, output neighboring-extremal controller, calculates the input values of the controlled plant. The algorithm design and convergent analysis of output neighboring-extremal controller are discussed emphatically, and in the case of existing parametric uncertainty, the approach is shown to converge to the optimum atmost in two iterations. At last the approach is illustrated by simulation results for a dynamic CSTR.展开更多
秸秆厌氧发酵沼气工程中合理的沼液回流可减少沼液排放量,降低后续沼液处置利用成本。以稻秸为底物,采用完全混合搅拌反应器(CSTR)半连续发酵方式,研究沼液全量连续回流对稻秸厌氧发酵特性的影响,旨在为明确沼液全量回流对秸秆厌氧发酵...秸秆厌氧发酵沼气工程中合理的沼液回流可减少沼液排放量,降低后续沼液处置利用成本。以稻秸为底物,采用完全混合搅拌反应器(CSTR)半连续发酵方式,研究沼液全量连续回流对稻秸厌氧发酵特性的影响,旨在为明确沼液全量回流对秸秆厌氧发酵的影响机制、改进沼液全量回流技术提供科学依据。结果表明:在100%沼液回流条件下连续回流50 d时系统运行稳定,总固体(TS)产气率、挥发性固体(VS)产气率及容积产气率分别稳定在245 m L·g-1、300 m L·g-1及0.74 L·L-1·d-1。但随着运行时间延长,回流天数达85 d时,虽然发酵液pH值和沼气中φ(CH4)无明显变化,但系统产气效率明显受到抑制。产气受抑制阶段与产气稳定阶段相比,TS产气率、VS产气率及容积产气率分别下降到186 m L·g-1、226 m L·g-1及0.56 L·L-1·d-1,下降幅度达24%。进一步分析表明,沼液中ρ(NH4+-N)下降到185 mg·L-1,下降幅度为71%;主要金属离子总质量浓度增加到4.13 g·L-1,增加幅度为342%。初步判断沼液全量连续回用会因氮含量严重下降和盐分积累致系统产气量下降,但真实原因还有待进一步研究。展开更多
The similarities between life processes that exhibit oscillatory behavior and chemical oscillating systems impel people to think that the biological and abiological phenomena conform to the same law. Oscillating chemi...The similarities between life processes that exhibit oscillatory behavior and chemical oscillating systems impel people to think that the biological and abiological phenomena conform to the same law. Oscillating chemical systems have been the focus of much research in the area of theoretical and experimental chemical dynamics as well as analytical sciences in recent years, but the studies on the perturbation species are kept around the concentration level of 10 -7 mol/L. In our experiment, an amazed phenomenon was found. Ultra trace level (10 -20 mol/L) of H 2O 2 can cause so magnitude influence on the macro system (MnSO 4 KBrO 3 diacetone oscillating chemical system) that the effect can be observed by a macroscopical method. When the concentration of H 2O 2 is above 10 -13 mol/L , the oscillation can even be stopped. A further study on the mechanism will doubtlessly help to understand the mystery of life, such as the sudden cardiopathy and the metabolism failure.展开更多
文摘Continuous Stirred Tank Reactors (CSTR) are used ubiquitously in chemical process industry for mixing, reactions and crystallizations. The purpose of this research is to study the effect of solute concentration (sodium chloride) on the stirrer speed in a CSTR. The experimental method used in this research is the stop watch and beaker method. The behavior pattern of the fluid in a CSTR can be experimentally verified as an alternative to the mathematical model. The tracer experiments were carried out. The effect of different parameters such as stirring speed, concentration at a steady time interval was analyzed. Experimental data obtained at 0.6 M and 160 rpm gave a curve that is in close agreement to that of theoretical or mathematical model. In other words, the results obtained at a concentration of 0.6 M and 160 rpm are in close agreement with that of early researchers. The paper is divided into five main sections: the first section immediately after the abstract is the introductory section that is basically a review of literature;the second section takes care of the materials and methods;the third section is the experimental procedure and this section takes the shut-down procedure and data processing into consideration;the fourth section is the discussion of experimental results and the last section is the conclusion of the paper.
基金National Natural Science Foundation of China(No.51467008)Scientific Research Projects of Colleges and Universities in Gansu Province(Nos.2018C-10,2017D-09)。
文摘The continuous stirred tank reactor(CSTR)is one of the typical chemical processes.Aiming at its strong nonlinear characteristics,a quantized kernel least mean square(QKLMS)algorithm is proposed.The QKLMS algorithm is based on a simple online vector quantization technology instead of sparsification,which can compress the input or feature space and suppress the growth of the radial basis function(RBF)structure in the kernel learning algorithm.To verify the effectiveness of the algorithm,it is applied to the model identification of CSTR process to construct a nonlinear mapping relationship between coolant flow rate and product concentration.In additiion,the proposed algorithm is further compared with least squares support vector machine(LS-SVM),echo state network(ESN),extreme learning machine with kernels(KELM),etc.The experimental results show that the proposed algorithm has higher identification accuracy and better online learning ability under the same conditions.
文摘CMAC(Cerebellar Model Articulation Controller或Cerebellar Model Arithmetic Computer)神经元网络是由Albus提出的一种表达复杂非线性函数的表格查询的自适应系统。本文将CMAC应用到具体的连续搅拌反应釜(CSTR)系统的学习控制研究中,仿真结果表明,该学习控制策略具有较强的自学习能力且容易实现,对于改善非线性控制的性能,不失为一种有益的尝试。
文摘A new optimizing framework of process operation is proposed to deal with optimizing op- eration of continuous stirred tank reactor （CSTR）. The optimization framework includes two layers： the first layer, necessary condition of optimally （NCO） tracking controller, calculates the optimal set-point of the process; and the second layer, output neighboring-extremal controller, calculates the input values of the controlled plant. The algorithm design and convergent analysis of output neighboring-extremal controller are discussed emphatically, and in the case of existing parametric uncertainty, the approach is shown to converge to the optimum atmost in two iterations. At last the approach is illustrated by simulation results for a dynamic CSTR.
文摘秸秆厌氧发酵沼气工程中合理的沼液回流可减少沼液排放量,降低后续沼液处置利用成本。以稻秸为底物,采用完全混合搅拌反应器(CSTR)半连续发酵方式,研究沼液全量连续回流对稻秸厌氧发酵特性的影响,旨在为明确沼液全量回流对秸秆厌氧发酵的影响机制、改进沼液全量回流技术提供科学依据。结果表明:在100%沼液回流条件下连续回流50 d时系统运行稳定,总固体(TS)产气率、挥发性固体(VS)产气率及容积产气率分别稳定在245 m L·g-1、300 m L·g-1及0.74 L·L-1·d-1。但随着运行时间延长,回流天数达85 d时,虽然发酵液pH值和沼气中φ(CH4)无明显变化,但系统产气效率明显受到抑制。产气受抑制阶段与产气稳定阶段相比,TS产气率、VS产气率及容积产气率分别下降到186 m L·g-1、226 m L·g-1及0.56 L·L-1·d-1,下降幅度达24%。进一步分析表明,沼液中ρ(NH4+-N)下降到185 mg·L-1,下降幅度为71%;主要金属离子总质量浓度增加到4.13 g·L-1,增加幅度为342%。初步判断沼液全量连续回用会因氮含量严重下降和盐分积累致系统产气量下降,但真实原因还有待进一步研究。
文摘The similarities between life processes that exhibit oscillatory behavior and chemical oscillating systems impel people to think that the biological and abiological phenomena conform to the same law. Oscillating chemical systems have been the focus of much research in the area of theoretical and experimental chemical dynamics as well as analytical sciences in recent years, but the studies on the perturbation species are kept around the concentration level of 10 -7 mol/L. In our experiment, an amazed phenomenon was found. Ultra trace level (10 -20 mol/L) of H 2O 2 can cause so magnitude influence on the macro system (MnSO 4 KBrO 3 diacetone oscillating chemical system) that the effect can be observed by a macroscopical method. When the concentration of H 2O 2 is above 10 -13 mol/L , the oscillation can even be stopped. A further study on the mechanism will doubtlessly help to understand the mystery of life, such as the sudden cardiopathy and the metabolism failure.
