Lecture 1: Introductioncc.sjtu.edu.cn/Upload/20160222212126540.pdf · 2016-02-24 · include gas turbine engines. 3. Introductory treatment of thermodynamics for an expanded range

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Thermodynamics I Spring 2016

Lecture 1: Introduction

Yong Li Shanghai Jiao Tong University

Institute of Refrigeration and Cryogenics 800 Dong Chuan Road Shanghai, 200240, P. R. China

Email : [email protected] Phone: 86-21-34206056; Fax: 86-21-34206056

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Introduction

Introduction Yong Li » Phone: 3420-6056 » E-mail: [email protected] » Research Interest:

– Solar energy application, Solar heating, Solar cooling, Desiccant cooling, Thermal sciences as applied to advanced HVAC&R systems

» Teaching interest: – Thermodynamics (ME 200, ME 300) – Heat and Mass Transfer (ME 315) – Renewable Energy – Solar Energy application

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Continue Introduction

Continue Introduction Yong Li » Offices:

– Room ME Main Building 428 » Office hours:

– Mon, Wed from 3:30 to 5:00 p.m. – Send me an e-mail for other days and times

» Collect your email，take photo

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Course Policy--Objectives

Provide a thorough understanding of the basic concepts and laws of classical thermodynamics;

Apply the basic concepts and laws of to solve practical problems;

Develop the skills necessary for a systematic approach to engineering problem solving;

Cultivate a strong work ethic

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Course Policy-- Text book

M.J. Moran and H.N. Shapiro, Principles of Engineering Thermodynamics, Si Version, 7th edition, John Wiley & Sons, New York, 2012.

Prerequisite: » General Chemistry » University Physics » Calculus

Reading Assignments: » Indicated on syllabus » Read before coming to class

Software EES

Engineering Equation Solver

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Pay attention: Preface Conversion Factors, Units Objective of this Chapter Key Engineering Concepts Index Tables and Figures

Course Policy-- Text book

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Continue Course Policy

Homework Assignments: » Indicated on syllabus » Collected each week at the beginning of Wednesday’s

lecture (starting 29 February) – All assignments from previous Monday through previous Sunday

will be collected – Start new problems on new paper

» Solutions will be sent to my lecture website after the homework is collected

» Slides, HW answers, grades, reading material etc: http://cc.sjtu.edu.cn/xxx 课程资料

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Continue Course Policy

Exams: » Mid-term examinations » Two-hour comprehensive final exam

– Closed-book and closed notes – Equation sheet provided – Bring: pencils or pens, calculator, eraser, straight edge,

Grading: » Homework 20% » Quizzes and Mid-term examinations 35% » Experiments 5% » Open problems and discussion 5% » Final examination 35%

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Course Policy

Road to success: » Ask questions! » Read textbook assignments! » Do your homework regularly! » Join the discussion » EES http://www.fchart.com/ees/getting-started.php

Course Syllabus…… 3 Open Ended Problems or Essays

» Works in group or individual (3 person/group) » Presentation might be arranged

Experiments will be arranged.

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Engineering Design and Analysis

Engineering Design

Recognize (or create) a need and define all requirements and constraints associated with it. Select “best design,” -Engineering Analysis criteria: cost, efficiency, size, weight, life. Consider product life cycle reliability, manufacturability, maintenance, sustainability. -Engineering Analysis Customer and Business considerations: Aesthetics, appearance, color, customer appeal, first to market, capital.

Compatibility with other products, systems, policies.

Engineering Analysis

Apply fundamental principles to the functionality of the design. ---Modeling Conservation of mass, momentum species and energy must be followed.---Modeling Performance prediction, testing, and suggestion of improvements.

Limitations based on second law of thermodynamics.

Evaluate potential for scaling in terms of product size or product volume.

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Design

compromise must be sought among competing criteria:

Establish objectives synthesis analysis construction

testing evaluation

lowest cost, highest efficiency, smallest size, lightest weight, reliability, manufacturability,

maintainability, and marketplace considerations.

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Design

Engineering model

The objective in modeling is to obtain a simplified representation of system behavior that is sufficiently faithful for the purpose of the analysis, even if many aspects exhibited by the actual system are ignored.

Analysis Modeling

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Methodology for Solving Thermodynamics Problems

① Known: State briefly in your own words what is known. ② Find: State concisely what is to be determined. ③ Schematic and Given Data: Draw a sketch of the system to be

considered. Decide whether a closed system or control volume is appropriate for the analysis, and then carefully identify the boundary. Label the diagram with relevant information, locating key state points. processes executed by the system.

④ Assumptions: To form a record of how you model the problem, list all simplifying assumptions and idealizations

⑤ Analysis : Using your assumptions, reduce the appropriate governing equations and relationships to forms that will produce the desired results.

Modeling

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THERMODYNAMICS I

Course Objectives

1. Provide a thorough understanding of the basic concepts of thermodynamics, (i.e., 1st and 2nd law). 2. Apply the basic concepts of thermodynamics to the solution of practical problems. 3. Develop a systematic approach to problem-solving skills. 4. Cultivate a strong work ethic in students.

Definitions & Properties (10 hs)

1. State, Process, Equilibrium, Units, T, P, V 2. Problem Solving Techniques 3. p-v-T plots for pure substances 4. Internal energy and enthalpy 5. Incompressible liquid / ideal gas polytropic processes for ideal gases

Cycle Analysis (9 hs)

1. Vapor power cycles 2. Vapor compression cycles 3. Gas power cycles (Otto, Diesel, Brayton)

1st Law Open System (Control Volume) Analysis

(6 hs)

1. Conservation of mass 2. Conservation of energy 3. Applications: nozzles, diffusers, turbines, compressors, pumps, heat exchangers, and throttles

2nd Law Concepts (4 hs)

1. 2nd law statement 2. Irreversible（不可逆） and reversible processes 3. 2nd law limitations 4. Carnot cycle

Entropy Balance（熵平衡） (7 hs)

1. Entropy definitions / evaluations / changes 2. Entropy balance for closed and open systems 3. Isentropic processes and efficiency, reversible and steady-state, steady- flow processes

Small-Group Laboratory Demonstrations

1. Critical Point 2. Open System Energy Balance 3. Refrigeration Cycle

1st Law Closed System (Control Mass) Analysis

(6hs) 1. Mechanical forms of work 2. Quasi-static work 3. Boundary work 4. Modes of heat transfer 5. Energy balance for closed systems 6. Energy balance for cycles

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ME 300 THERMODYNAMICS II

Course Objectives

1. To provide a thorough understanding of the application of classical thermodynamics to practical problems. 2.Concepts new from ME 200 include transient energy analysis, exergy analysis, state and property relations, compressible flow and equilibrium analysis. Applications include gas turbine engines. 3. Introductory treatment of thermodynamics for an expanded range of materials including gas mixtures. 4.Systems involving chemical reactions, combustion is emphasized. Chemical equilibrium. 5. Limited design experience for systems requiring significant considerations of thermodynamics.

Review (5h)

1. Properties 2. First and Second Law

Gas Power Cycles (5h) 1. Air Standard Cycles 2. Brayton Cycle 3. Regeneration 5. Aircraft Gas Turbines

Compressible flow (3h)

1. 1-D steady flow in Nozzles and diffusers 2. Ideal gases flow in Nozzles and diffusers

First and Second Law Analyses (6h)

1. Transient Analysis 2. Exergy Analysis

Thermodynamic Relations (5h) 1. Using Equations of State 2. Important Mathematical Relations 3. Developing Property Relations 4. Evaluating Changes in Entropy,

Internal Energy, and Enthalpy

Mixture Properties (7h) 1. Ideal Gas Mixtures 2. Mixture Properties 3. Gas–Vapor Mixtures 4. Air Conditioning Processes

Combustion Analyses & Chemical Equilibrium (8 h)

1. Stoichiometry of Reactions 2. Energy Analysis for Reactions 3. Adiabatic Flame Temperature 4. Entropy for Reacting Systems 5. Chemical Equilibrium criteria 6.Equilibrium compositions 7. Equilibrium Flame Temperature

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What is Thermodynamics（热力学）?

Science to study how one energy changes from one to another

Energy exists in several forms, e.g., potential, kinetic, chemical, thermal, electrical, nuclear among many others Thermodynamics = Therme(heat) + dynamis(force) During interactions in nature, energy simply changes

from one form to another; but the total energy remains constant

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Basic Principles （基本原理）

First law of thermodynamics » A statement of conservation of energy principle » Energy is a thermodynamic property; quantifies energy

Second law of thermodynamics » Energy has quality as well as quantity. Actual processes

occur in direction of decreasing quality of energy » Establishes direction and possibility for process » Provides means for measuring the quality of energy » Determines theoretical limits regarding the performance of engineering devices

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Two Approaches

Classical Thermodynamics（经典热力学） does not require detailed knowledge of molecular structure to describe a system. » Macroscopic（宏观） (considers large scale behavior) » used almost exclusively in Thermodynamic I

Statistical Thermodynamics （统计热力学） considers quantum mechanical description and behavior of molecules » microscopic（微观） (considers molecular scale behavior) » occasionally used to enhance basic understanding in in

Thermodynamic I

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Applications

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Applications (contd.)

Solar Heating

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Applications (contd.)

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Dimensions and Units

Physical quantities characterized by dimensions Primary dimensions: mass (m), length (L), time (t), temperature (T), charge (C), etc. Secondary dimensions: velocity (m/sec), volume

(kg/m3) etc. Two important unit systems:

» “SI” (Metric) » “English” (USCS)

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Units

SI System (common in the industrialized world) » decimal basis, simple, logical » mass, length, time, temperature are primary with

base units of kg, m, sec, K, Coulomb » force derived using Newton’s Law » We must use

English System (common in USA) » No mathematical basis, arbitrary, confusing » force, mass, length, time, temperature are primary

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Ultimate objective

Carnot cycle remember 10 years (T-s diagram, processes)

Rankine cycle remember 5 years (T-s diagram, processes)

Otto cycle remember 5 years (T-s diagram, processes)

Second law of thermodynamics remember 50 years

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Thermodynamics can help to deal with Energy Challenge

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Statistical Communiqué of the People's Republic of China on the 2012 National Economic and Social Development

In 2012, the gross domestic product (GDP) of the year was 51,932.2 billion yuan, up by 7.8 percent over the previous year.

Preliminary estimation indicated that the total energy consumption in 2012 amounted to 3.62 billion tons of standard coal equivalent, up 3.9 percent over 2011. The consumption of coal grew by 2.5 percent; crude oil, up 6.0 percent; natural gas, up 10.2 percent; and electric power, up 5.5 percent. The national energy consumption per 10,000 yuan worth of GDP went down by 3.6 percent.

The death toll for producing one million tons of coal in coalmines was 0.374 person, down 33.7 percent

http://www.stats.gov.cn/english/newsandcomingevents/t20130222_402874607.htm

National Bureau of Statistics of China February 22, 2013

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Statistical Communiqué of the People's Republic of China on the 2013 National Economic and Social Development

In 2013, the gross domestic product (GDP) of the year was 56,884.5 billion yuan, up by 7.7 percent over the previous year.

Preliminary estimation indicated that the total energy consumption in 2013 amounted to 3.75 billion tons of standard coal equivalent, up 3.7 percent over 2012. The consumption of coal grew by 3.7 percent; crude oil, up 3.4 percent; natural gas, up 13.0 percent; and electric power, up 7.5 percent. The national energy consumption per 10,000 yuan worth of GDP went down by 3.7 percent.

The death toll for one million tons of coal produced in coalmines was 0.288 person, down 23.0 percent

http://www.stats.gov.cn/english/PressRelease/201402/t20140224_515103.html

National Bureau of Statistics of China February 24, 2014

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