A Simple Core Model with TRACE
Finish Homework 9,
Start Homework 10
First be certain that given a basic geometric description of a core
or tube bundle, you can
calculate key quantities like available flow area and hydraulic
diameter. Given hydraulic diameter and rod
diameter, can you calculate an estimate of rod pitch? This later
exercise is a good sanity check
on input decks. Take a look at reactorCore.inp.
Based on the pitch and number of rods
associated with all heat structures (look
for "Surface Multiplier" in the model editor and sum the four values),
calculate the actual radial extent of the core
region. Also check to see
if the input deck's values for fraction of axial area available to flow
When designing power systems, or checking simulations, it is a very
good idea to do
simple side calculations on energy and mass balances. These can be done
by hand, with a simple
standalone program, or via control blocks in TRACE (or most other
simulation codes). Today I
want to look at a simple program (power.f
) for one such calculation, and use it to set a power (rpowi) in reactorCore.inp.
Copy power.exe to a directory
on your Udrive where you are already storing some programs.
Before you use it, you will need to inspect output from running reactorCore.inp to
determine the core inlet pressure, temperature, and TOTAL mass
flow rate. Once you've got these numbers, double click the
power.exe icon in your file space and respond to the requests for
data. For the core outlet, just give it the same pressure as the
inlet, and a temperature 50K higher than the inlet value. It will
give you the total power required to get that temperature change.
Enter that number as "rpowi" in the power component of
reactorCore.inp. Run TRACE with this revised input and compare
TRACE's prediction of the core outlet temperature to outlet temperature
that you gave to power.exe.
I recommend that you keep power.f in your personal set of analysis
tools. With minor modifications it can be used to generate
reasonable approximations to steam and water properties, or perform
other energy balance calculations.
Maintained by John Mahaffy : email@example.com