Hi Guanyu,
The plug-in should come with some help. If not, I copy below the text.
Cheers
Carlos
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OPENLOOP 1.5
FUNCTIONALITY
HEAT TRANSPORT
The OpenLoop plugin is designed for applying a time-varying temperature
differential between groups of abstraction and injection boreholes for open-loop
geothermal systems.
It is capable of handling more than one group of extraction/injection pairs
simultaneously, using separate temperature differentials for each group. Within
each group, extraction as well as injection can take place in an unlimited
number of mesh nodes. The module can also deal with systems where extraction and
injection nodes are inverted during the simulation time.
Furthermore, the application of the module for any group can start at any time
during the simulation run. Before that time, temperature conditions from the
model setup are used for the infiltration bore(s). This might be useful for
representing observation data (real injection temperatures) in the first phase,
while using calculated injection temperatures for the prediction phase.
MASS TRANSPORT
The OpenLoop plug-in can also be used for applying a concentration differential
in mg/l. The module support thermohaline (heat and mass transport) simulations
and multi-species mass transport..
DATA PREPARATION
1. All time-varying temperature and concentration differentials are defined
as time-varying power functions in FEFLOW. For each system of
injection/extraction nodes and each process variable (temperature, each species
concentration) a separate time-varying power function has to be prepared, even
if differentials in different systems or for different chemical species are
identical.
2. A nodal reference distribution with the name 'OpenLoop' is created to
identify participating nodes for a temperature differential. For single-species
mass transport, the distribution is called 'OpenLoop Mass', for multi-species
transport 'OpenLoop Mass 1' for species 1, 'OpenLoop Mass 2' for species 2,
etc..In these reference distributions, all nodes belonging to a specific group
(injection and extraction nodes) are assigned a value equal to the number of the
time-varying power function containing the corresponding temperature or
concentration differential. All other nodes need to be given values less than or
equal to 0 (default in FEFLOW is -99999 = nodata). Be careful with mesh
refinement: In case of refining the mesh after assigning the power function
number, the data interpolation will lead to a number of nodes with non-zero
values around the wells, too.
3. A nodal reference distribution with the name 'OpenLoop AutoOn' may be created
to postpone the automatic boundary condition setting / removal on certain nodes.
All nodes with a later start should be assigned the start time [d] for automatic
temperature calculation. All other nodes in the distribution shall have zero or
negative values. This option can be useful for simulations whose first part is
based on observation data for injection wells, while the second predictive part
is to be run based on a temperature or concentration differential.
SIMULATION RUN
In each time step, the module will calculate the average abstraction temperature
or concentration. The calculation is done separately for each group, and
averaging is done based on the contribution to total energy or contaminant mass
abstraction by pumping from each extraction node.
The temperature or concentration differential derived from the time-varying
power function associated to the group is added (+) to the average
temperature/concentration, and the result is used to set a fixed
temperature/concentration (1st kind) boundary condition at the injection nodes.
The temperature/concentration boundary condition is adapted to the current
extraction temperature/concentration and temperature/concentration differential
before each time step of the simulation.
A time-stepping control scheme integrated in the plug-in ensures that all time
steps in the temperature differential functions are met exactly if the model is
run based on automatic time stepping.
