COURSE DESCRIPTION This course provides an introduction to the most powerful engineering principles you will ever learn - Thermodynamics: 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 FORMAT The class consists of lecture videos, which average 8 to 12 minutes in length. The videos include integrated In-Video Quiz questions. There are also quizzes at the end of each section, which include problems to practice your analytical skills that are not part of video lectures. There are no exams. GRADING POLICY Each question is worth 1 point. A correct answer is worth +1 point. An incorrect answer is worth 0 points. There is no partial credit. You can attempt each quiz up to three times every 8 hours, with an unlimited number of total attempts. The number of questions that need to be answered correctly to pass are displayed at the beginning of each quiz. Following the Mastery Learning model, students must pass all 8 practice quizzes with a score of 80% or higher in order to complete the course. ESTIMATED WORKLOAD If you follow the suggested deadlines, lectures and quizzes will each take approximately ~3 hours per week each, for a total of ~6 hours per week. TARGET AUDIENCE Basic undergraduate engineering or science student. 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 a prerequisite 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, food resources, 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.
04.06 - Steam Tables Discussion
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Do curso por University of Michigan
Introduction to Thermodynamics: Transferring Energy from Here to There
548 classificações
University of Michigan
548 classificações
Na lição
Week 4
In this module we introduce the combined application of the Conservation of Mass and the Conservation of Energy for system analysis. We also review the common assumptions for typical energy transfer devices, like heat exchangers, pumps and turbines. Together these components will form the basis for all power plants used around the world.
Conheça os instrutores
Margaret Wooldridge, Ph.D.Arthur F. Thurnau Professor
Mechanical Engineering, Aerospace Engineering
This is a short tutorial on how to use the steam tables online.
We're only going to use the portion of the tables that are available for free.
You are, of course, more than welcome if you want to subscribe to the service to
get the full access to the steam tables. Through this, through this resource or
any other resource that you may have. There are other online calculators.
Again, you're more than welcome to try anything you want in terms of the online
calculators. The steam tables should be identical no
matter what resource that you use, so whether you use this online set of tables
or if you use tables that you might have. From your thermodynamics text book or
from any other resource, you should see values that are identical to six
significant figures. So, if you don't see good agreement
between different resources, then there's likely some problem with the way that
you're calculating or determining the information, okay?
So, let's go through the online steam tables here.
So, we're going to run the calculator here.
And that's going to open up this pane that shows you all these different tabs.
So, you have general properties for the steam tables, saturation properties,
steam turbine flash evaporator. And all these other tabs.
We are only going to use the general properties and the saturation properties.
And the general properties are just the superheat portion, the superheat region
of the steam tables. And here you have the input functions,
the way that you can input the data. And in this case, you have it set up as,
we have, the default is pressure and temperature.
And you can see the pressure is in bar and the temperature that you're looking
for is in degrees Celsius. So, if we were to go ahead and put in a
couple of parameters here to determine the information.
Let's say we want state information for 100 bar and let's say 585 degrees
Celsius, and then we hit Calculate. We see the information for the state is
populated in this first window here, the main thermodynamics property window.
And you can see pressure and temperature, those were our input parameters.
And then we have density, specific volume, enthalpy, entropy are all
provided. Exergy is a very advanced thermodynamic
property that we're not going to cover in this class.
Specific energy, energy we have covered. The constant pressure, specific heat.
That's the specific isobaric heat capacity, that CP is provided.
And CV is also provided in the speed of sound which of course we won't use.
Other good information they provide is the specific gas constant.
And, of course, this is for water. So, we know that the molar mass or the
molecular weight is 18 grams per mole. And if you add the universal gas constant
in a molecular weight, you can determine the specific gas constant.
So, all sorts of good information is provided in this window.
And then, yeah. So if we want the enthalpy, we can,
determine the enthalpy from this list. We can take, the enthalpy from this list.
I caution you about significant figures please, please do not use more than five
or six significant figures in this course.
This is, this is a wee bit more than I think we can state with any confidence
that is shown here in this table. and what we'll find is you use, if you
use the free version of this table is that of this online software.
Is that you can you can accidentally or maybe it's even on purpose, you can put
in state conditions that would actually not be in the super heat region.
So let's take 100 bar and 100 Celsius. And we use that to calculate.
And you see is that actually we did get information on this one.
Okay, so sorry, they did manage to give us the information.
I was trying to find a condition where they would run out of information for the
free software. So, often it'll tell you oh that's not
accessible. That's not a region where you have access
for the free version of this software. I know an example in the saturation
properties, so let's go there. So these, I've clicked on the tab, the
second tab here, so this is for properties that are within the saturation
region. And let's go ahead and choose one bar
which I know is outside the range of what they'll give us access to and a quality
of 50%. And so you see it says op, your free
pressure range, and free here they mean is access to the free version of their
software, is between 10 and 170 bar. So, of course, you can't get that
information here. So, let's go ahead and, and put in
something like a pressure of let's say 50 bar and a 50% quality.
And we calculate that. And we can see that we do get information
here in terms of the saturated liquid and the saturated vapor and then the 50%
value that's between those two. Now if we come down in this lower pane
here, the output pane, you're seeing you get a lot of this registration is
required. But the information we need is also
provided in this upper pane here, okay? So again, if we have 50% quality, the
saturated liquid is 1148 for the internal energy.
The saturated vapor is 2596 or let's say 2600, and you can see it makes sense 50%
between those two values is about 1872. So, the information we want is shown in
red, okay? So, there are also going to be other
functions if you look at the drop down menu here.
The saturation properties are shown for pressure and quality, which is the x.
But if you went to, let's say, temperature and enthalpy.
You may also run into challenges where that's not accessible for the free
version of the software. So I'll tell you this, is for any of the
homework problems and any of the examples that we do in this class we're, we make
sure that online steam tables will work for you.
That, that information is within the accessible, the freely accessible portion
of this calculator. Just make sure you look in this upper
plane, okay? so again, you're more than welcome to use
other resources, but we will use this. I will tell you if you have conditions
where we can't use this resource, and I will provide tables for you of the steam
data. And I expect you to be able to look at
those tables and to be able to determine what's the right values to use.
And you'll see that in some of the examples later on in the segments.
So, let's go back to the general properties here again.
if we delete out these previous calculations, and we come back up here.
And let's go ahead and try and get state conditions.
Let's go ahead and get state conditions for let's say 85 bar.
Whoops, not 185, 85 bar. And for let's say 690 degrees Celsius.
I'm just choosing some random values. And we do the calculation.
Again, look in this plane. Every now and then the software doesn't
like to put the output plane, pane here, the output registration.
Er, excuse me, the output pane. Doesn't always repeat the information
that's shown up here. And sometimes that's because it says, you
only get access to three states at a time.
So if we wanted to if we wanted to get more information in this output pane, so
that we could store, consecutive states, we'd have to delete.
And then, have no more than three in the output pane at any particular time.
But again, the information we want can always be found in this main window.
So, I hope that clears things up. Try not to get frustrated.
I know there's a lot of data that we don't have access to in this online
calculator. these are new tools that are just
recently being developed. If you decide to go out and buy yourself
a thermodynamics textbook, most of the new textbooks will provide electronic
access to steam tables and to a whole lot of other fluids.
Steam, air, carbon dioxide, a range of different refrigerants.
So, there are other tools that are becoming more and more accessable.
But, we're really in a transition now in a community from using these hard paper
copies of tables to these online versions of these tables.
So again, if you have any frustrations or if you're having questions, post those
online and we'll keep trying to answer them for you.
Thank you.
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