Counts as 25% of your grade
Due Monday, 17 December 2007
This project involves obtaining a baseline steady state of a PWR,
and demonstrating the ability
to automatically adjust the system to a second operating point with at
least 5% change in
thermal power. The project report should be written so that
someone with a nuclear engineering background, but no knowledge of this
class can understand what you did.
The first section of your final project will be a general
description of your power system. As a
minimum, this system must contain:
You will be able to obtain most information from an FSAR.
However, the FSAR's that I've been through neglect to give you piping
lengths for the coolant loops. Take those from PWR information provided by Dr. Hochreiter for
NucE 430. Remember that I'm not asking you to model a specific
plant. Your final product must be representative of a PWR, and
Give a complete description of the "as built" system geometry ,
including component lengths, volumes, and cross-sections. Include
sketches with dimensions
marked with specific attention to the appearance of the core region.
Reference your source (or sources) of information, and document
assumptions that you make due to inadequate system descriptions.
Describe how you choose to
divide this system into finite volumes for TRACE and include all
provide values of DX, FA, VOL, and HD for the input deck. Describe,
calculations for any area change
loss coefficients that you use (e.g. lower and upper core support
plates). Provide a table of key parameters, such
as: power; primary and
secondary pressures and mass flows; and core inlet and outlet
temperatures and pressures. Note
both your model's values and those for your chosen plant.
Provide information on the performance of the active components. Give the type of pump used, and its characteristics (rated head, rated flow, rated speed, rated torque). You may select one of the default head curves from the TRACE pump component. Give a full description of your chosen turbine performance model, including at least one reference to a text or journal article. Your model may be as simple as a constant efficiency turbine, but be careful to use standard definitions of turbine efficiency. For the steam line temperature at your chosen operating point, and a fixed turbine exhaust pressure, your hydraulic model of the turbine will provide the turbine mass flow rate through an appropriate loss coefficient at the steam line exit. One or more control blocks must provide an edit of the rated turbine power for any reasonable turbine inlet conditions. This can be implemented as a table of turbine power as a function of turbine inlet pressure, but the table must be fully documented and justified (show all calculations and equations) in your report. ( In practice you only need 2 points in this table to cover your baseline operating condition and 2nd power point). Clearly specify the chosen operating conditions at the turbine inlet.
Run one steady state calculation for your chosen power system at its standard operating conditions. Provide the input deck for this run and printed output of the last major edit. If the code does not declare a steady state provide a plot of turbine inlet temperature and pressure vs. time to justify your choice of a steady state dump.
The system must contain a means to obtain appropriate steam
generator feedwater flow for your second power state. One
simple possibility is an enthalpy balance
calculation. Provide full documentation of your control
system including the steps you used to determine the
gain and integration time scale of any PI controller.
Run a transient changing the thermal power to your chosen off-design value. Provide time history plots of :
If necessary provide two copies of these plots with different time
scales, so the details of the early transient are clear, as is the
approach to a second steady state. Also provide a file containing of
last major edit of the run. End time for the transient should be
long enough to see conditions close to a new
Attempt the same transient from the design point to off-design power
with twice and four times as many cells (fluid and wall) in
your steam generator tubes and corresponding section of the
boiler. Report the results in the same way as before, noting any
changes. Apply a Richardson extrapolation to the turbine inlet
mass flow (steam generator exit steam flow), and estimate the error in
the mass flow at a point in time where mass flow is
undergoing its largest rate of change. Document your choice of
this second point in time.
As an alternate you can do the mesh sensitivity study using an isolated steam generator model. Starting from your base steady state, initiate a transient by stepping the feedwater mass flow up or down by 5%. As with the base option, apply a Richardson extrapolation to the turbine inlet mass flow (steam generator exit steam flow), and estimate the error in the mass flow at a point in time where mass flow is undergoing its largest rate of change. Document your choice of this second point in time.
To prevent the inevitable attempts to do this project as an
all-nighter just before it is due, I am setting some intermediate
deadlines. You will get one of three marks on these assignments:
Remember the TRACE or SNAP may do strange things to you during this
Do not beat your head
against a brick wall too long. Contact me when troubles occur.
The project report must be submitted as a single word processor
document. Input models for the steady state and transient
should be submitted separately as either ASCII or SNAP project files.