Unit 1 Segment 1
Welcome to all our course participants!
course instructor: Margaret Wooldridge
Arthur F. Thurnau Professor Departments of Mechanical and Aerospace Engineering
University of Michigan, Ann Arbor, Michigan USA professional expertise in power, propulsion, energy systems,
combustion systems, fuel chemistry, advanced engine strategies, exhaust gas treatment, mobile and stationary sectors, etc.
What is thermodynamics all about???
This course will provide you with an introduction to the most powerful engineering principles you will ever learn: thermodynamics! Or the science of transferring energy from one place or form to another place or form. We will introduce the tools you need to analyze energy systems from solar panels, to engines, to insulated coffee mugs. More specifically, we will cover the topics of mass and energy conservation principles; first law analysis of control mass and control volume systems; properties and behavior of pure substances; and applications to thermodynamic systems operating at steady state conditions.
Course objectives: To make familiarize you with the basic concepts,
devices, and properties used in thermal science To teach the behavior of a simple pure substances
including solid, liquid, and gas phases To teach how to evaluate energy, work and heat
transfers processes To teach the conservation laws for mass and energy for
various physical systems To teach application of process knowledge to the
analysis of complete systems
Course Outcomes: Identify different subsystems, indicate where there is work, heat transfer
and the importance of temperature, pressure and density Given a set of properties, identify the correct phase and remaining
properties for a substance Given a physical setup, determine the associated work and heat transfers
that are the most reasonable approximations Given a physical device and process, compute the work and heat transfer Given a physical setup, formulate the ideal approximation to the
behavior and compute the corresponding work and heat transfer Given an actual device, analyze the corresponding ideal device Understanding how energy processes affect the environment
To help you understand the concepts, we will use freely available references and tools
1. U.S. Department of Energy Fundamentals Handbook Thermodynamics, Heat Transfer and Fluid Flow, Volume 1 of 3 (http://www.hss.doe.gov/nuclearsafety/techstds/docs/handbook/h1012v1.pdf)
2. Thermodynamics and Chemistry, 2nd Edition, by Howard DeVoe, Associate Professor Emeritus, University of Maryland (http://www2.chem.umd.edu/thermobook/)
3. Online calculator of steam (i.e. water), which includes links for carbon dioxide (CO2) and ammonia (NH3) properties: http://www.steamtablesonline.com/
The weekly reading assignments are listed in the course syllabus
Week Supportive Reading Material Topic 1 Devoe: Chapters 1-2.1 introduction, concepts, definitions, and
UNITS!! 2 Devoe: Chapter 2.1-2.3
DOE: Thermodynamic Properties , Temperature and Pressure Measurements, Property Diagrams and Steam Tables
thermodynamic properties, measuring temperature and pressure
3 Devoe: Chapter 2.4-2.5 describing the states of different systems, processes and pathways between states
4 Devoe: Chapter 2.6 DOE: Energy, Work, and Heat
the energy of a system
5 Devoe: Chapter 3.1-3.2 DOE: Energy, Work, and Heat, First Law of Thermodynamics
the 1st law of thermodynamics/the conservation of energy
6 Devoe: Chapter 3.3-3.10 DOE: Energy, Work, and Heat
heat and work transfer
7 DOE: Energy, Work, and Heat, Thermodynamic Systems and Processes, First Law of Thermodynamics
energy analysis of closed systems, internal energy, enthalpy, specific heats
8 DOE: Energy, Work, and Heat, Thermodynamic Systems and Processes, First Law of Thermodynamics
energy analysis of open systems, steady state systems
Course schedule: All reading material is from the reference texts Thermodynamics and Chemistry, 2nd Edition by Howard Devoe, and the U.S. Department of Energy Fundamentals Handbook Volume 1 Thermodynamics.
Frequently asked questions: What are the prerequisites for taking this course? An introductory background (high school or first year college level) in chemistry, physics, and calculus will help you be successful in this class. What will this class prepare me for in the academic world? Thermodynamics is required for many follow-on courses, like heat transfer, internal combustion engines, propulsion, and gas dynamics to name a few. What will this class prepare me for in the real world? Energy is one of the top challenges we face as a global society. Energy demands are deeply tied to the other major challenges of clean water, health, and poverty. Understanding how energy systems work is key to understanding how to meet all these needs around the world. Because energy demands are only increasing, this course also provides the foundation for many rewarding professional careers.
Based on what we just reviewed, look around you and identify 5 systems where energy transfer is important.
Unit 1 Segment 2
Based on what we just reviewed, look around you and identify 5 systems where energy transfer is important.
Now look again and identify 25 systems! Your laptop and desktop computers, cell phone,
car, train, bus, office heating/cooling, coffee mug, printer, scanner, lighting, clock, watch, television, bicycle, boiler, furnace
Energy transfer is everywhere in varying levels
of importance.
What are the drivers for changing the way we currently use energy?
Global energy demands are high! The night-time city lights of the world constructed from images taken by the U.S. Defense Meteorological Satellite Program's Operational Linescan System.
Source: Science@NASA, Lighting up the ecosphere
U-M Physics Professor Mark Newman http://www.umich.edu/news/research/story/networks.htm
Population cartogram
U-M Physics Professor Mark Newman http://www.umich.edu/news/research/story/networks.htm
Energy consumption cartogram
Between now and 2050 world population growth will be generated exclusively in developing countries Heilig, 1996. In the next 50 years, the world population is projected to grow by over 2 billion people. G.K. Heilig, IIASA LUC-Project, World Population Prospects:
Analyzing the 1996 UN Population Projections, WP-96-146, December 1996
Total Population by Region, 1950, 1995, 2025, and
2050 (in million) Energy demands are only going to get higher
Population growth is projected to grow by two billion people in the next 50 years. If each person uses one 50 Watt light bulb, how much new power will we need?
Unit 1 Segment 3
Population growth is projected to grow by two billion people in the next 50 years. If each person uses one 50 Watt light bulb, how much new power will we need?
50 W x 2,000,000,000 people = 100,000,000,000 W!!!!
How many nuclear power plants is that??? A lot. More on this later.
Renewables = net geothermal, solar, wind, and wood and waste electric power Based on U.S. Energy Information Administration data, 1980-2004
Global consumption of energy by source
UNITS ARE ABSOLUTELY CRITICAL FOR THERMODYNAMICS Common Units and Conversion Factors for Energy Analysis Pressure 1 Pa = 1 N/m2 = 1 kg/m/s2 = 1 kg/(m s2)=110-5 bar = 1.450410-4 psia = 9.869210-6 atm 1 bar = 105 Pa = 0.98692 atm = 14.504 psia = 2088.6 lbf/ft2 1 lbf/in2 (psia) = 144 lbf/ft2 = 6894.8 Pa = 6.894810-2 bar = 0.068046 atm 1 atm = 101.325 kPa = 14.696 psia = 1.0133 bar = 2116.2 lbf/ft2 Energy 1 J = 1 Nm = 1 kg m2/s2 = 1 Ws 1 kJ = 1 kWs = 0.94783 Btu = 0.23885 kcal = 737.56 ft lbf 1 Btu = 1.0550 kJ = 0.252 kcal = 778.16 ft lbf 1 kcal = 4.1868 kJ = 3.9684 Btu = 3088.0 ft lbf 1 kWh = 3.60103 kJ = 2655.2103 ft lbf = 3412.2 Btu 1 ft lbf = 1.285110-3 Btu = 1.355810-3 kJ 1 therm = 105 Btu = 29.3 kWh = 1.05506108 J 1 eV = 1.60210-19 J 1 MTOE = 1 million tonnes of oil equivalent = 0.041015 Btu = 6.9107 BOE 1 BOE = 1 barrel of oil equivalent = 5.8106 Btu 1 gallon of gasoline = 1.24105 Btu 1 cubic foot of natural gas = 1028 Btu
Common Units and Conversion Factors for Energy Analysis Energy Rate or Power 1 W = 1 J/s 1 W = 3.4122 Btu/h = 0.85987 kcal/h = 1.3410210-3 hp = 0.73756 ft lbf/s We = Watt of electric power Wt = Watt of thermal power 1 Btu/h = 0.29307 W = 0.252 kcal/h = 3.9310-4 hp = 0.21616 ft lbf/s 1 kcal/h = 1.163 W = 3.9683 Btu/h = 1.559510-3 hp = 0.85778 ft lbf/s 1 hp = 550 ft lbf/s = 2544.5 Btu/h = 745.7 W 1 ton (cooling capacity) = 12,000 Btu/h = 3.5168 kW Energy Density (Energy per Unit Mass or per Unit Mole or per Unit Area) (Mass) 1 kJ/kg = 0.42992 Btu/lbm = 0.23885 kcal/kg = 334.55 ft lbf/lbm (Mole) 1 kJ/kmol, 1 Btu/mol, etc. (Rate per Area) 1 W/m2 = 0.317 Btu/(h ft2) = 0.85986 kcal/(h m2) 1 Btu/(h ft2) = 3.1546 W/m2 = 2.7125 kcal/(h m2) 1 kcal/(h m2) = 1.163 W/m2 = 0.36867 Btu/(h ft2)
Prefixes and other assorted measurements 1 megawatt = 1MW = 1106 W 1 gigawatt = 1GW = 1109 W 1 terawatt = 1 TW= 11012 W 1 petawatt = 1 PW = 11015 W 1 exawatt = 1 EW = 11018 W 1 zettaawatt = 1 ZW = 11021 W 1 yottawatt = YW = 11024 W 1 Quad Btu = 1 quadrillion Btu = 11015 Btu 1 thousand Btu = 1 MBtu = 1000 Btu 1 million Btu = 1 MMBtu = 1106 Btu 1 short ton = 1 ton = 2000 lbs 1 metric ton = 1 tonne = 2200 lbs Btu = British thermal unit Hp = horsepower kWh = kilowatt hour
U.S. consumption of energy by source
Small improvements in combustion of fossil fuels can have huge impact on carbon reduction; compare to doubling the contributions of renewable resources in the global energy portfolio, yet renewables are vital to long term energy solutions
Source: DOE http://www.eia.doe.gov
Energy supply and demand by sector in the U.S.
Energy supply and demand in the U.S.
Source: DOE http://www.eia.doe.gov
Energy use by sector
Different energy sectors have dramatically different needs: transient propulsion systems, high heating rates for manufacturing, etc.
There is no silver bullet, no one-fuel, no one method solution.
What energy sector has the most demanding requirements for transient energy, i.e. energy demands that change as a function of time?
Unit 1 Segment 4
What energy sector has the most demanding requirements for transient energy, i.e. energy demands that change as a function of time?
You might think of seasonal changes for heating or cooling or even daily cycles, like changes in manufacturing production during the day and evening shifts. Now consider the power demands from a passenger vehicle!
Thermodynamics is the study of energy and the interaction of energy with matter.
Heat transfer is how energy is transferred when there is a temperature difference.
Fluid mechanics is the motion of fluids (which includes gases and liquids) and the
transformation of energy between mechanical and thermal forms.
Terminology and definitions: System - the object(s) under consideration A closed systems is also called a control mass.
Mass can not cross the system boundary. There is a fixed quantity of matter in the system.
An open systems is also called a control volume.
Mass can cross the system boundary. The amount of matter within the control volume can change.
Is the coffee in your thermos or mug best described as a control mass or control volume?
Is the CPU in your computer best described as a control mass or
control volume?
Unit 1 Segment 5
Is the coffee in your thermos or mug best described as a control mass or control volume?
That depends. Is the system the coffee or the cup? Is the coffee being poured into the cup?
Is the CPU in your computer best described as a control mass or control volume?
That depends. Is the system the CPU or the air used to cool the CPU?
Sometimes the system is obvious. Other times it can be more challenging to define.
Properties describe the characteristics of the system
Thermodynamic properties describe the thermal properties of the system
State the condition of the system as described by the system thermodynamic properties
Steady state means the system properties are not changing as a function of time
Extensive properties depend on the extent (or amount) of material in the system; these are properties that are additive, like mass
Intensive properties do NOT depend on the extent (or amount) of material in the system; these are properties which are NOT additive, like temperature
Equilibrium when the system is unchanging in terms of thermal, mechanical, phase and chemical characteristics
Process a path between two states
Introduction to some properties Density = mass per unit volume = = 1/v Specific volume = volume per unit mass = v = 1/ Pressure (absolute and relative) Temperature
You should have seen some of these properties before. What are the units of density, specific volume, pressure and temperature?
What category of properties are density, specific volume,
pressure and temperature? Intensive or extensive?
Unit 1 Segment 6
You should have seen some of these properties before. What are the units of density, specific volume, pressure and temperature?
The answers will vary based on which system of units you choose, SI or British. Here are some examples: density [kg/m3], specific volume [m3/kg], pressure [kPa] or [atm], temperature [oC ] or [K]
What category of properties are density, specific volume, pressure and temperature? Intensive or extensive?
Every one of these properties are intensive properties.
Units are critical to thermodynamics analysis and they are a HUGE asset.
Pressure 1 Pa = 1 N/m2 = 1 kg/m/s2 = 1 kg/(m s2)=110-5 bar = 1.450410-4 psia = 9.869210-6 atm 1 bar = 105 Pa = 0.98692 atm = 14.504 psia = 2088.6 lbf/ft2 1 lbf/in2 (psia) = 144 lbf/ft2 = 6894.8 Pa = 6.894810-2 bar = 0.068046 atm 1 atm = 101.325 kPa = 14.696 psia = 1.0133 bar = 2116.2 lbf/ft2 Energy 1 J = 1 Nm = 1 kg m2/s2 = 1 Ws 1 kJ = 1 kWs = 0.94783 Btu = 0.23885 kcal = 737.56 ft lbf 1 Btu = 1.0550 kJ = 0.252 kcal = 778.16 ft lbf 1 kcal = 4.1868 kJ = 3.9684 Btu = 3088.0 ft lbf 1 kWh = 3.60103 kJ = 2655.2103 ft lbf = 3412.2 Btu
Energy Rate or Power 1 W = 1 J/s 1 W = 3.4122 Btu/h = 0.85987 kcal/h = 1.3410210-3 hp = 0.73756 ft lbf/s 1 Btu/h = 0.29307 W = 0.252 kcal/h = 3.9310-4 hp = 0.21616 ft lbf/s 1 kcal/h = 1.163 W = 3.9683 Btu/h = 1.559510-3 hp = 0.85778 ft lbf/s 1 hp = 550 ft lbf/s = 2544.5 Btu/h = 745.7 W Energy Density (Energy per Unit Mass or per Unit Mole) Mass 1 kJ/kg = 0.42992 Btu/lbm = 0.23885 kcal/kg = 334.55 ft lbf/lbm Mole 1 kJ/kmol, 1 Btu/mol, etc.
Energy in closed systems: kinetic energy = K.E. potential energy = P.E.
Work energy transfer across the system boundary
Work transfer is not a system property. Work transfer depends on the process path. There are many types or forms of work tranfser.
What does a constant pressure compression process look like on a pressure-volume diagram?
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