PPT《PowerPoint Template》

PowerPoint Template 工程热力学Engineering Thermodynamics 西安建筑科技大学环境与市政工程学院 School of Municipal &

Environmental Engineering Xi'

an University of Architecture &

Technology 主讲人:赵蕾Zhao Lei Email:zhaolei@xauat.

edu.cn 教师介绍 赵蕾, 博士,教授, 硕士生导师 环境与市政工程学院 Address:环境与市政工程学院实验教学楼206室热工流力教研室Tel:82202185E-mail: zhaolei@xauat.edu.cn 助教介绍 Name: Address:高层研究生公寓Tel: Introduction (绪论) Why do we need to learn Engineering Thermodynamics?Main Contents of Engineering ThermodynamicsSome Requirements for this course ?Why do we need to learn Engineering Thermodynamics? Thermodynamics is the branch of science which studies the rule that governs the transformation of thermal energy to other forms of energy. Also it focuses how to use thermal energy efficiently. 工程热力学主要关注的是如何有效利用热能.因而,主要研究热能和其它形式能量之间的转换规律.It includes all aspects of energy and energy transformations(能量转换), including power generation, refrigeration and relationships among the properties of matter. What does Engineering thermodynamics focus on? ( 热力学主要研究什么问题?) Thermodynamics can be defined as a branch of science of energy. heat Therme dynamis power (Greek words) 热能 Thermal Energy (1) Categories of energy resources in nature (自然能源的种类) A. Chemical energy(化学能): such as : coal(煤炭) crude oil(石油 ) natural gas (天然气) firedamp (沼气) , etc. 2. Why do we choose to learn the rules which govern transformation from thermal energy to mechanical energy? (为什么要研究热能与机械能之间的转换规律?) B. Mechanical energy(机械能) such as:wind resources(风力资源 ) water resources(水力资源 ) tidal energy(潮汐能), etc.C. Thermal energy (热能such as: solar energy(太阳能) geothermal energy(地热能),etc.D. Nuclear energy(原子能) Chemical energy Thermal energy Fusion or fission reaction Combustion(燃烧) directly used Mechanical energy can be used directly. (核聚变或和裂变) (2) How do we use the energy resources ? (能源的利用) Thermal energy Nuclear energy Thermal energy indirectly used Relationship between energy transformation and utilization(能源转换与利用的关系) 热能电能机械能风能 水能 化学能 核能 地热能 太阳能 一次能源(天然存在) 二次能源 光电转换 燃料电池 光热 聚变 裂变 燃烧 水车 水轮机 风车 热机 电动机 发电机 90% 转换 直接利用 利用 生物质 风能 温差发电 磁流体发电 90% of energy resources are transformed into thermal energy before it is used. Then, thermal energy is transformed into mechanical energy and used indirectly How can thermal energy be transformed into mechanical energy more efficiently? Thermal energy Mechanical energy(1) Universally (广泛性)Heartthe heating and air-conditioning systems, the refrigerator, humidifier, the pressure cooker, the water heater,the shower, the iron and even the computer.automotive engines,rockets, jet engines,and conventional and nuclear power plans, solar collector and the design of vehicles from ordinary cars to airplanes. transformed 3. What does Thermodynamics study?(热力学的研究对象) 热电厂(热能→机械能)Thermal Power Plant (Thermal Energy →Mechanical Energy 飞机(热能→机械能)Aeroplane (Thermal Energy →Mechanical Energy 汽车 (热能→机械能)Vehicle(Thermal Energy → Mechanical Energy) 冰箱 (机械能→热能)Refrigerator(Mechanical Energy → Thermal Energy Disorganized energy organized energy (无序能)有序能) transformed (2) Representatively (代表性 ) (3) Practicality(实用性) 4. Some examples of energy transformation application (能量转换的一些实例) (1)火力发电装置 (Steam power plant) Characteristics of energy conversion system in thermal power plant火力发电装置基本特点 锅炉 汽轮机 发电机 给水泵 凝汽器 过热器 heat source (热源)(2) working medium (工质) (水,蒸汽)(3) state change of the working medium (工质状态的变化) (加压、加热、膨胀做功、放热)(4) heat sink (冷源) Generalized Representation of Heat Engines(热机工作原理的示意) 热源(Heat source) 冷源(heat sink) How many W can be produced by absorbing QH? Is there any relationship between QH,QL and W? Is QL necessarily to be discharged to its surroundings, becoming waste energy? (2) Internal combustion engine 内燃机装置 Mixture of air and fuel(空气、油) Waste gases废气 吸气Charging stroke 压缩、点火Compress and Ignite 膨胀expand 排气Discharging stroke Characteristics of internal combustion engines内燃机装置基本特点 (1) heat source (热源)(2) working medium 工质(燃气)(3) State changes of the working medium (工质经历状态变化) (加压、加热、 膨胀做功、放热)(4) heat sink (冷源) 冰箱 (Refrigerator) (3)制冷空调装置 Refrigeration System Characteristics of Refrigeration System 制冷空调装置的特点 cold source 冷源(2) Working medium 工质(制冷剂)(3) State changes 工质的状态变化 (加压消耗外界的功量、放热、 膨胀、吸热)(4) Heat source热源 Heat source at high temperature (高温热源 hot reservoir)Working substance or working medium (工作介质)C. The change in state of working medium (工质的 状态变化)D. Heat sink at low temperature (低温冷源 cold reservoir)Thermal energy reservoirs: heat source heat sink (4) Main Factors in energy transformation (能量转换中的主要因素) ?What are the Main Contents of Engineering Thermodynamics? §0.2 Main Contents 主要内容 1. Basic Principles of Thermodynamics 能量转换的基本定律 (1) The first law of thermodynamics (conservation of energy principle)热力学第一定律 (能量守恒原理)For example: a rock falling off a cliff human body It asserts that energy is a kind of thermodynamic property of substance. 阐明能量是物质的一种热力学属性. It asserts that energy has quantity as well as quality and actual process occur in the direction of decreasing quality of energy. 阐明能量不仅有量的属性,而且也有质的属性,过程总是朝着能量贬值的方向进行.For example: a cup of hot water turns cold in room air (2) The second law of thermodynamics(热力学第二定律) 2. Properties of Working Medium工质的性质 (1) Properties of Ideal Gases 理想气体的性质 (2) Properties of Steam or Water Vapor 水蒸气的性质 (3) Moist Air 湿空气 3. Some applications in Engineering 一些工程应用 (1) Flow through Nozzles 喷管中的流动 (2) Power Cycles 动力循环(3) Refrigeration Cycles 制冷循环 (1) Classical Thermodynamics 经典热力学方法 连续体(continuum),用宏观物理量描述其状态, 其基本规律是无数经验的总结 特点:可靠,普遍,不能任意推广 经典 (宏观,平衡)热力学 classical (macroscopic, equilibrium) thermodynamics 4. Study Method (工程热力学研究方法) √ Microscopic approach is adopted based on the average behavior of large groups of individual particles 从微观粒子的运动及相互作用角度研究热现象及规律. 特点:揭示本质,模型近似 微观(统计)热力学 microscopic (statistical) thermodynamics (2) Statistical Thermodynamics (统计热力学方法) §0.3 Some Requirements for this course 教学要求1. Clearly understand and firmly grasp of the basic principles 弄清基本概念,注意每章后的思考题2. Finish the assignment independently and submit it a week after it is assigned. 独立完成作业,布置作业后的下周按时交

3、Explore your activeness, think hard, attend to discussion in class. 发挥主观能动性,勤于思考,积极课堂讨论

4、Solve problems as soon as it is discovered 有问题及时解决,不要拖至考试 Problem Solving Technique (解题方法) (1) Problem statement (问题陈述)(2) Schematic (示意图)(3) Assumptions (假设)(4) Physical Laws (物理定律)(5) Properties (物性参数)(6) Calculations (计算)(7) Reasoning, Verification, and Discussion (推理、证明和讨论) Neatness (整洁)Organization (有条理)Completeness (完整)Visual appearance (工整) Requirements for writing form of the assignments (对作业的书写要求) 请在布置了作业以后的一周内交作业. 作业得分在C及以下的同学可以重新做好之后请老师另阅. About the Exam 考试成绩评定

1、Assignment 10% (平时作业10%)

2、Exercise and discussion in class 10% (课堂练习及讨论参与情况 10%)

3、Experiment 10% (实验情况及报告10%)

3、Final Exam 70%( 期末考试70%) 热力学方面获诺贝尔奖的科学家(1) J.D.范.德瓦尔斯 Johannes van der Waals (1837-1923) 荷兰 气体和液体状态方程 1910年诺贝尔物理学奖 M.普朗克 Max Planck (1858-1947) 德国 发现能量子(量子理论) 热力学第二定律 1918年诺贝尔物理学奖 热力学方面获诺贝尔奖的科学家(3) W.H.能斯特 Walther Hermann Nernst (1864-1941) 德国 热化学,熵基准 1920年因发现热力学第三定律获诺贝尔化学奖.(1921年补发) 热力学方面获诺贝尔奖的科学家(4) L.昂萨格 Lars Onsager (1903-1976) 美国 不可逆过程热力学理论 1968-因创立多种热动力作用之间相互关系的理论获诺贝尔化学奖. 热力学方面获诺贝尔奖的科学家(5) I.普里高津 Ilya Prigogine (1917-) 比利时 热力学的耗散结构理论 1977年因提出热力学的耗散结构理论诺贝尔化学奖 热力学方面获诺贝尔奖的科学家(6) K.G.威尔逊 Kenneth G. Wilson (1936-) 美国 临界重整化群理论 1982年诺因提出关于相变的临界现象理论获贝尔物理奖 References 参考书1. 工程热力学 廉乐明 中国建筑工业出版社2. 工程热力学 沈维道等 高教出版社3. 工程热力学 曾丹苓等 高教出版社4. 工程热力学 刘桂玉等 高教出版社5. 工程热力学 何雅玲等6. Fundamentals of Classical Thermodynamics Gordon J. et al. Fifth ed7. Thermodynamics, Yunus A. Gengel et al. Fourth Edition 外文教材(每班至少每个宿舍有1本~2本) Thank you ........