Research on the experimental teaching of boiler principles
Paper abstract: Experimental teaching is an indispensable part of the teaching process of boiler principles. Strengthen and improve the boiler principles. Experimental teaching is one of the effective ways to cultivate the ability of undergraduate students majoring in thermal energy and power engineering. Based on the experience in the practice of boiler principle experimental teaching, the study discusses the reform of traditional educational concepts in the experimental teaching process, and the introduction of modern educational concepts in all aspects from teaching objectives, teaching content, teaching and assessment methods to cultivate innovation Specific measures for developing talents.
Thesis keywords: boiler principle; teaching research; experiment?
Boiler is one of the three main hosts of thermal power plants and one of the driving forces of industrial enterprises. resources, playing an extremely important role in the development of the national economy. "Boiler Principles" is one of the main professional courses for undergraduate students majoring in thermal energy and power engineering. The teaching goal of "Boiler Principles" is to enable students to comprehensively and systematically understand the structure of the boiler body and auxiliary devices, master the relevant knowledge of boiler working principles, and cultivate students' practical ability to analyze engineering problems, perform boiler design calculations, and boiler tests. This course is highly engineering, has a lot of content, and has many difficulties. It is difficult to achieve the teaching goals by relying solely on theoretical teaching. Practical links such as experiments, internships, and curriculum design that are closely integrated with engineering practice are an indispensable part of the teaching of boiler principles.
Universities’ laboratories are important places to combine theory and practice and cultivate college students’ engineering practice and innovation abilities. Strengthening and improving experimental teaching is one of the effective ways to cultivate the ability of college students. Experiments play an important role in the practical teaching of boiler principles. As a teacher engaged in experimental teaching of boiler principles, the author has reformed traditional educational concepts in the teaching process and introduced modern educational concepts in all aspects from teaching objectives, teaching content, teaching and assessment methods, which has significantly improved the teaching effect.
1. Teaching objectives of boiler principle experiments
The basic starting point of boiler principle experiment teaching is to help students better understand the course by providing a large number of devices and systems that simulate boiler-related phenomena. Content, master the basic principles, common test methods and operating techniques of boilers, and strengthen the practical capabilities of boiler design calculation and boiler testing. Traditional education takes the imparting of knowledge as the purpose of teaching. Teachers consider how to instill knowledge into students but ignore the cultivation of students' abilities. The development of modern society requires colleges and universities to cultivate a group of creative talents with high knowledge and ability. In order to meet this demand, colleges and universities should focus on cultivating students' abilities.
In the experimental teaching of boiler principle, teachers should play the leading role in teaching and the main role of students in learning, so that students can preview the experimental instructions, operate experimental equipment and instruments, and use their brains to think about experimental phenomena. , through teamwork to solve problems arising in the experiment, record and organize experimental data, write reports, and complete experimental thinking questions, their own learning ability, experimental skills, hands-on ability, independent thinking ability, teamwork spirit, organizational ability, The ability to analyze and solve practical engineering problems and the ability of independent innovation have been comprehensively trained and improved.
Utilize carefully designed experimental content to combine the knowledge points of the "Boiler Principles" course with the professional basic courses "Engineering Thermodynamics", "Heat Transfer", "Fluid Mechanics", and "Thermal Testing Technology", And the combination of professional courses "Air Pollution Monitoring Technology", "Air Pollution Control Engineering", and "Clean Coal Power Generation Technology", through the effective transfer and synthesis of multi-disciplinary knowledge, to achieve the teaching effect of drawing inferences from one instance and integrating it, which can not only consolidate It deepens students’ understanding of the early professional basic courses, deepens students’ understanding of the professional knowledge system they have learned, stimulates students’ interest and enthusiasm in learning subsequent courses, and cultivates students’ scientific thinking ability, thus providing a basis for subsequent course study and future Lay a solid foundation for engaging in engineering design and scientific research.
2. Teaching content of boiler principle experiment
The teaching content of the experimental course is related to the organization and implementation of experimental teaching. It is to standardize the experimental teaching process and inspect the experiment. Teaching quality and the basis for laboratory construction.
In view of the fact that the boiler principle involves a lot of content, is highly practical, and has many related courses, we separated the experimental part and set up a separate course. At the same time, we ensured that the design of the experimental teaching content is closely connected with the early professional basic courses and subsequent professional courses. In terms of teaching content, we strive to start from the reality of this course and seize the opportunity to penetrate and integrate it into other courses to create a systematic knowledge system platform for thermal energy and power engineering for students, changing the traditional teaching model of only imparting scattered knowledge from a single course.
The main line of teaching combined with the theoretical teaching of "Boiler Principles" is "Fuel - Combustion and Heat Balance Calculation - Heating Surface - Natural Circulation Boiler Hydrodynamics - Boiler Start-up, Stop and Operation - Boiler Pollutant Emission Monitoring and Control" , established five laboratories: "Coal Quality Analysis", "Flow Distribution of Parallel Pipe Groups", "Hydrodynamic Characteristics of Natural Circulation Boilers", "Combustion and Environmental Monitoring", and "Combustion Source Pollutant Emission Control".
The “Coal Quality Analysis” laboratory has opened two experiments: “Industrial Analysis of Coal” and “Calorific Value Determination of Coal” to enable students to master the principles and methods of coal quality analysis and calorific value determination. Understand the impact of coal quality on boiler performance.
The "Parallel Pipe Group Flow Distribution" and "Natural Circulation Boiler Hydrodynamic Characteristics" laboratories are each equipped with two sets of self-designed and built experimental systems. The former can enable students to have a clear perceptual understanding of the problem of uneven flow distribution caused by improper arrangement of the inlet and outlet headers of the superheater and reheater tube groups in power station boilers; the latter enables students to understand the natural circulation boiler Have a deeper understanding of hydrodynamic characteristics and measures to improve water cycle safety.
Based on the independently developed "Energy Island Cogeneration System", the "Combustion and Environmental Monitoring" laboratory has opened "Programmed Ignition and Flame Monitoring Display", "Combustion Adjustment and Combustion Efficiency Measurement", "Boiler Six experiments: "Thermal Balance", "Boiler Smoke Measurement", "Fume Composition Analysis", and "Gaseous Pollutant Emission Monitoring". The "Programmed Ignition and Flame Monitoring Display" experiment can enable students to understand the safe operating procedures and combustion process of the boiler; through the observation hole in the boiler, they can directly observe the flame shape and the influence of operating parameters on the flame shape, which greatly deepens the understanding of book knowledge. understand. The "Combustion Adjustment and Combustion Efficiency Determination" experiment enables students to have a direct perceptual understanding of the impact of various factors on combustion efficiency. At the same time, they learn the methods of measuring data related to boiler efficiency and calculating combustion efficiency. Through the "boiler heat balance" experiment, students can deepen their understanding of the principle of boiler heat balance, cultivate students' boiler heat balance experimental testing skills, enable students to analyze the causes of various heat losses, and learn to diagnose problems in boilers. The "Boiler Smoke and Dust Measurement" experiment enables students to become familiar with national standards and master the principles and methods of measuring the emission concentration, converted concentration and total emission of particulate matter in the exhaust from fixed pollution sources. The "Smoke Gas Component Analysis" experiment enables students to master the working principle and usage of the Osteni flue gas analyzer. The "Gaseous Pollutant Emission Monitoring" experiment enables students to master the principles of electrochemical methods for gaseous pollutant emission measurement and the use of EUROTRON MK2 8851 flue gas analyzer. This series of experiments lays a foundation for students to engage in boiler design, operation and research.
The "Combustion Source Pollutant Emission Control" laboratory is equipped with four dust removal devices (cyclone dust collector, bag dust collector, electrostatic precipitator, wet dust collector) and a jet bubbling flue gas A desulfurization device and a selective catalytic reduction flue gas denitrification device can be used for experimental teaching of two types and six projects of dust collector performance measurement and gas pollution purification, allowing students to systematically understand and master the basic knowledge and basic knowledge of pollution control. Principles, main equipment and typical processes, etc., to cultivate students' basic ability to analyze and solve the increasingly serious emission problems of combustion source pollutants, and to provide the necessary foundation for students to engage in related engineering design, technical management and other work.