Posted Thu, 07 Sep 2023 14:54:02 GMT by Guanyu Yuan Martin Luther University Halle-Wittenberg
I want to model a doublet ATES system. How to use the OpenLoop Plug-in to realize the fixed injection temperature? (For example,I would like to inject water with 14℃ in summer and inject water with 6℃ in witer. The extraction and injection well be inverted with the season change)
Posted Tue, 26 Sep 2023 11:53:03 GMT by Carlos Andres Rivera Villarreyes Global Product Specialist - FEFLOW
Hi Guanyu, The plug-in should come with some help. If not, I copy below the text. Cheers Carlos ###### 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.
Posted Fri, 03 Nov 2023 15:19:03 GMT by Guanyu Yuan Martin Luther University Halle-Wittenberg
Hello, Thanks for your answer. I found that there are 2 plug-ins, OpenLoop and Open-Loop Design. Would you please tell me the difference between these 2 plug-ins? Also, I wonder how to use Open-Loop Design. I checked the Help document but I cannot understand following expression: 4. A second nodal distribution in User Data with the name 'OpenLoopPortion' is to be created to define the portions of injection/extraction on the nodes belonging to a system. The integer reference value represents the number of the time-series to be used as the portion function for the well at this location. The same time-series ID may be used for more than one well. The values in the time series are expected to be between 0 and 1, and typically would add up to 1 when summing over all extraction or injection nodes of a system (unless water is discharged elsewhere). All other nodes are to be given zero or negative values. Is OpenLoopPortion a mandatory setting when using Open-Loop Design? If so, how to arrange the value of nodes? Thanks, Guanyu
Posted Fri, 01 Dec 2023 08:06:15 GMT by Carlos Andres Rivera Villarreyes Global Product Specialist - FEFLOW
With the release of FEFLOW 8.1, the Open-Loop plugin, where you fix the temperature difference becomes obsolute. You can do now everything within the graphical interface without the plug-in. Please watch the video tour below: MIKE 2024 | FEFLOW | Geothermal Modelling Without Limits [] Best regards Carlos Rivera  

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