Teaching Research and Practice of "Chemical Engineering Principles Optimization Design"

Awards, this article now introduces the main content of the results.

Combining modern knowledge and innovative design content, cultivating students' comprehensive use of knowledge and comprehensive decision-making capabilities With the continuous development of science and technology, engineers and technicians are required to have not only analytical capabilities, but also strong integrated application knowledge and comprehensive decision-making capabilities. Ability has become more and more important at present. It is true that this kind of comprehensive decision-making ability can not be achieved through the door course. However, as the main course of the door, the chemical engineering principle course, especially the course design of chemical engineering principle, will undoubtedly play an important role. Decision-making is usually based on optimization. Actually, it is actually applied to engineering and optimization operations. Therefore, the establishment of optimal design and optimization of operating concepts and putting them into practice are indispensable for developing comprehensive decision-making capabilities. The development of modern computer technology has made the chemical cell unit operation optimization design research field very active. Existing domestic chemical engineering and chemical engineering curriculum design textbooks do not reflect the content of optimized design. Therefore, traditional design methods are followed in the curriculum design. For example, distillation is widely used, but its energy consumption is very high. Therefore, a low-cost design must be selected for energy conservation and consumption reduction. While the previous textbook introduced the design of the distillation tower, according to experience, the reflux ratio was 1.12 times the minimum reflux ratio. This design is naturally impossible to obtain the optimal design. We have tried to change the design method, for example, let students calculate in several The flow rate is lower than the economic cost of the distillation column, and a comparison of multiple schemes is performed, and the scheme in which the total cost is relatively small is selected as the final design scheme. However, due to the multi-scheme comparative design method, which is still a traditional experience design method, the content is not updated, the method has no breakthrough, the method has not been improved, and the calculation workload is large and very cumbersome. Students use calculators. A lot of time is spent on duplicating boring calculations. It is difficult to complete multi-scheme comparison design tasks in a limited time. Often it is known that design results are not reasonable and they do not want to adjust the design parameters for multiple projects. Comparatively, in order to obtain reasonable results, the traditional chemical engineering curriculum design cannot train students' comprehensive decision-making ability, which is indispensable for high-quality talents in the new century. Therefore, it is necessary to reform traditional curriculum design. Since 1994, we have introduced new technologies and new technologies such as engineering engineering optimization technologies and computer-assisted computing technologies. We have changed the traditional curriculum design principle of chemical engineering, which focuses on imparting knowledge, into the transfer of knowledge and the development of student science. The quality and comprehensive ability not only cover the contents and methods of traditional experience design, but also has its goal. To establish the mathematical model of the objective function, we must contact production and scientific research, and include various design operations and prices that affect the design results in the objective function, and comprehensively apply the Ding-Ding principle, advanced mathematics, language engineering optimization technology and other courses. Knowledge programming, using a computer to solve. As long as the optimized design program is compiled and passed, the optimal design of different parameters under different working conditions can be quickly found. Flash this, optimizing the design can help students establish a process economy and comprehensive decision-making capabilities.

Strengthen the training from practice to theory, train and raise students' mathematics building chess and the ability to innovate innovative ability. It is the demand of the times that calls for the country. However, innovation can not be achieved, it is a product of thick and thin. Only by allowing students to accumulate in the talent training phase can it be possible for them to be able to create a proud performance in the future. Traditional curriculum design of chemical engineering only teaches the transfer of knowledge, training and training is the training of students to master the ready-made knowledge of books. Little consideration is given to changing this situation. We have changed the traditional curriculum design to the curriculum optimization design, and the teaching practice proves for many years. Optimized design is an effective way to cultivate and improve students' mathematical modeling and innovation capabilities.

Mathematical modeling is a training link from practice to theory. The establishment of a practical new mathematical model must have a solid foundation and sense of innovation. In the process of mathematical modeling, students must not stick to the rules and stick to the dogma and be separated from the reality. They must analyze the actual questions by themselves and understand what people have done to find out what is irrational in order to clearly identify the problems to be solved. The general simplification of the use of mathematical language abstraction into a mathematical model and the study of mathematical model solving methods. This kind of training from practice to theory is relatively lacking among current students. The curriculum optimization design can enable students to get useful exercise in this aspect. Taking the design of the multi-effect evaporation system as an example, the previous teaching materials introduced the empirical design method of various effects and areas without any pursuit goals. Therefore, the experience design cannot be very reasonable, and it will inevitably result in unnecessary waste of heat energy and equipment investment. . In the course of designing the curriculum, we introduced the viewpoint of engineering economy and the engineering optimization technology, and changed the experience design method of the traditional multi-effect evaporation system into an optimized design. The optimization design must establish a mathematical model. We guided the students to read many documents. The results showed that none of the models established by previous researchers considered the optimization of the steam condenser and the condensate flash, which must be improved. In the evaporation operation, the raw steam pressure and the condenser vacuum are the most sensitive and important conditions for the evaporation process, and they are also the most influential factors for the production cost of the evaporation operation. The art parameters and the flashing of condensed water are also sufficient for the mouth function. Measures should be considered when optimizing the design. Based on the above analysis, we have instructed students to establish a new mathematic model for the multi-effect evaporation system optimization design based on the raw steam pressure condenser vacuum degree and the effective effective heat transfer temperature difference as decision variables, taking into account the influencing factors such as condensed water flash. The new model is more in line with the actual situation of the project than the reported model.

After the mathematical model of the objective function is established, the solution method of the model should be studied. What we set up is a new mathematical model of multi-effect evaporation system optimization design. Our predecessor's algorithm is indefinitely suitable for solving our new model. We can't apply it rigorously. Instead, we should propose distinctive and innovative methods to solve the new model according to the characteristics of the new model. Ask for a solution. We guide students in the analysis of the predecessor algorithm based on the proposed multi-effect evaporation system optimization model of the new algorithm for a new algorithm complex nested Lagrangian multiplier method and matrix method. The complex method is used to deal with the inequality constraints. The Lagrangian multiplier method is used to deal with the equality constraints. The matrix method is used to quickly solve the equations of the equilibrium heat balance and the heat transfer rate of the phase equilibrium material. The matrix method is the new algorithm proposed by us for the first time, which is more efficient than the Newton iteration method and the 83160 method reported in the literature.

In summary, we have injected a sense of innovation in every aspect of the multi-effect evaporation optimization design process, from mathematical modeling to model solving, to guide students to explore new ideas and new solutions, give full play to the students' initiative, and motivate students to innovate. Awareness and innovation. For example, the new algorithm matrix method for solving the multi-effect evaporation system is 97 grade chemistry. Chen Wenbo, under the guidance of the teacher, proposed the cooperation and completed 8 papers, among which, the paper was published in the national-level publication of China Engineering Science, and two articles were published in the national level. The Journal of Chemical Engineering was issued, and two articles were published in the state-level publication on computer and applied chemistry. Another example is the 95 grade chemical once gave the classmate 95 grade chemical machine Zheng Yin classmate 96 class chemistry Chen Jizhi classmate 96 classify machine Huang Weifeng classmate 97 class chemistry Zheng Huidong classmate optimize the design in distillation tower plate tray structure size new design absorption tower optimization Design desiccator optimization design Batch distillation optimization design and other research areas proposed new solutions or algorithms, and the first author to complete academic research papers. In the traditional curriculum design of chemical engineering, students passively accept the existing knowledge of the teaching materials, and they are not trained in innovative thinking, let alone cultivate the ability to innovate. Therefore, they cannot propose new models and new algorithms to write and circulate papers; Principles In course optimization design, each unit operation optimization design model and algorithm are not new to the predecessors, thereby training students' innovative thinking, training and promoting students' mathematical modeling ability, stimulating student writing or writing papers with the author is The reform of the optimization design of the Principles of Chemical Engineering has proved to be a significant improvement in the quality of teaching.

Making full use of computer technology to solve engineering design problems and improve students' computer application ability Computer technology is an indispensable tool for contemporary engineering and technical personnel. The ability to skillfully use computers to solve practical engineering problems has become an important indicator of the quality of personnel training. The traditional chemical engineering curriculum design uses a calculator to calculate manually, but it is far from training students' computer application ability. Even if the content of traditional experience design is allowed to be solved by the students, because there is no goal to pursue, the mathematical model of the objective function should not be established, the solution is easy, the algorithm is simple, and the training of the student's programming ability is also limited. After the curriculum optimization design, the situation is very different. To optimize the design, a mathematical model of the objective function must be established. Because of the complexity of the project, the established objective functions are undifferentiated univariate or multivariate optimization problems. It is impossible to rely on manual calculations and must be programmed with a computer. . Taking the optimization design of the absorption tower as an example, we have guided students to consult a large number of papers on absorption tower design issued by domestic and foreign publications. After analyzing and summarizing the improvements, a more reasonable mathematical model of the objective function has been established. The algorithms involved in solving the objective function include the optimization algorithm, the numerical integration method, the least-multiplication nonlinear equation, the root-finding method, and so on. Although students other than the optimization algorithm's least-multiplication algorithm had previously learned more or less, but they learn, blood, or 7 ratios, the language deals with functions that are learned within days of the establishment of the Chemical Engineering Curriculum Optimization Design. It is difficult for them to use these algorithms to solve engineering design questions in a program. However, this new teaching content and method can greatly stimulate the students' morale. They are willing to accept this challenge. For this reason, they forget to eat and sleep, spend 10 hours in the engine room every day, and constantly modify and debug repeatedly until the program is passed. After such training, the students' computer programming skills produced quality. Of course, we also found that some students did not like to use their brains in the instructional curriculum optimization design teaching practice. When the program asked itself not to find a solution, but to want to copy Programs for other classmates or previous classmates in the class. After this situation was discovered, taking the absorber design as an example, the following method was adopted to immediately adjust the design goal. For example, the optimal design of the low-concentration gas absorption tower and the next-stage optimization design of the high-concentration gas absorption tower were carried out. In the next session, the optimal design of the absorption and desorption system was performed; this is the golden section method used for solving the problem, and the next method was solved using the Fibonacci method, and then the parabola method was used for the next solution. This combination of different design goals and different algorithms ensures that each classmate's design tasks and solving algorithms are different, prompting each classmate to independently program and debug to complete the design task, in order to improve students' ability to use computers.

Emphasizing the individual development of students, teaching students in accordance with their aptitude, cultivating good scientific quality, attaching importance to the development of students' personalities, teaching students in accordance with their aptitudes, cultivating students with diligent, questioning, meticulous, and practical thinking, etc. Good scientific quality is an important part of contemporary educational thinking. The traditional curriculum design of chemical engineering mainly focuses on imparting knowledge of books, teaching methods are rigid, and the mode of training is simple. It essentially determines that it takes the knowledge accumulated by previous generations as the main content, and this type of education leads to students’ innocence that they simply accept without thinking. Ignoring the cultivation of innovative consciousness and the development of student's personality influence students' initiative to carry out creative learning, and thus it is impossible to cultivate students' good scientific quality. The theoretical optimization of the Chemical Engineering Curriculum is solved through practical modeling, learning success, inspiring students' learning desires and innovative actions. Students will try to make the established mathematical model more consistent with the actual situation, and explore more effective solutions to formulate more efficient The program not only improves the comprehensive ability but also cultivates the scientific quality. The optimization design mathematical model is easy and difficult to distinguish between simple and complex, optimization algorithm is also inefficient and easy and difficult, design methods can be flexible and diverse. Students with good learning ability to do relatively difficult optimization of the design sequence to give high scores, and the students with high level of interest in programming absorbed into the extracurricular interest group, the teacher guide them to establish a new model to explore the development of new algorithms, 1 courseware For students who have difficulties in learning, they are only required to compile the main program of the optimization design objective function, and the subroutines of various optimization algorithms are provided by the teacher. This will not only encourage good students to take full advantage of their ability to show off their talents, but also ensure that poorly-learned students can also receive programming training and complete the task of optimizing curriculum design within the prescribed time to achieve the purpose of teaching students in accordance with their aptitude.