 <OpenGeoSysProject>

   <mesh>BHE_1P.vtu</mesh>

   <geometry>BHE_1P.gml</geometry>

   <processes>

     <process>

       <name>HeatTransportBHE</name>

       <type>HEAT_TRANSPORT_BHE</type>

       <integration_order>2</integration_order>

       <process_variables>

         <process_variable>temperature_soil</process_variable>

         <process_variable>temperature_BHE1</process_variable>

       </process_variables>

       <borehole_heat_exchangers>

         <borehole_heat_exchanger>

           <type>1P</type>

           <flow_and_temperature_control>

             <type>TemperatureCurveConstantFlow</type>

             <flow_rate>0.0002</flow_rate>

             <temperature_curve>inflow_temperature</temperature_curve>

           </flow_and_temperature_control>

           <borehole>

             <length>30.0</length>

             <diameter>0.28</diameter>

           </borehole>

           <grout>

             <density>2190.0</density>

             <porosity>0.0</porosity>

             <specific_heat_capacity>1735.160</specific_heat_capacity>

             <thermal_conductivity>0.73</thermal_conductivity>

           </grout>

           <pipes>

             <inlet>

               <diameter>0.25826</diameter>

               <wall_thickness>0.00587</wall_thickness>

               <wall_thermal_conductivity>1.3</wall_thermal_conductivity>

             </inlet>

             <longitudinal_dispersion_length>0.001</longitudinal_dispersion_length>

           </pipes>

           <refrigerant>

             <density>1000.0</density>

             <viscosity>0.00114</viscosity>

             <specific_heat_capacity>4190</specific_heat_capacity>

             <thermal_conductivity>0.59</thermal_conductivity>

             <reference_temperature>25</reference_temperature>

           </refrigerant>

         </borehole_heat_exchanger>

       </borehole_heat_exchangers>

     </process>

   </processes>

   <media>

     <medium id="0">

       <phases>

         <phase>

           <type>AqueousLiquid</type>

           <properties>

             <property>

               <name>phase_velocity</name>

               <type>Constant</type>

               <value>0 0 0</value>

             </property>

             <property>

               <name>specific_heat_capacity</name>

               <type>Constant</type>

               <value>4068</value>

             </property>

             <property>

               <name>density</name>

               <type>Constant</type>

               <value>992.92</value>

             </property>

           </properties>

         </phase>

         <phase>

           <type>Solid</type>

           <properties>

             <property>

               <name>specific_heat_capacity</name>

               <type>Constant</type>

               <value>1778</value>

             </property>

             <property>

               <name>density</name>

               <type>Constant</type>

               <value>1800</value>

             </property>

           </properties>

         </phase>

         <phase>

           <type>Gas</type>

           <properties>

             <property>

               <name>specific_heat_capacity</name>

               <type>Constant</type>

               <value>1000</value>

             </property>

             <property>

               <name>density</name>

               <type>Constant</type>

               <value>2500</value>

             </property>

           </properties>

         </phase>

       </phases>

       <properties>

         <property>

           <name>porosity</name>

           <type>Constant</type>

           <value>0</value>

         </property>

         <property>

           <name>thermal_conductivity</name>

           <type>Constant</type>

           <value>2.78018</value>

         </property>

         <property>

           <name>thermal_longitudinal_dispersivity</name>

           <type>Constant</type>

           <value>0</value>

         </property>

         <property>

           <name>thermal_transversal_dispersivity</name>

           <type>Constant</type>

           <value>0</value>

         </property>

       </properties>

     </medium>

   </media>

   <time_loop>

     <processes>

       <process ref="HeatTransportBHE">

         <nonlinear_solver>basic_picard</nonlinear_solver>

         <convergence_criterion>

           <type>DeltaX</type>

           <norm_type>NORM2</norm_type>

           <reltol>1e-6</reltol>

         </convergence_criterion>

         <time_discretization>

           <type>BackwardEuler</type>

         </time_discretization>

         <time_stepping>

           <type>FixedTimeStepping</type>

           <t_initial>0.0</t_initial>

           <t_end>600</t_end>

           <timesteps>

             <pair>

               <repeat>10</repeat>

               <delta_t>60</delta_t>

             </pair>

           </timesteps>

         </time_stepping>

       </process>

     </processes>

     <output>

       <type>VTK</type>

       <prefix>BHE_1P</prefix>

       <timesteps>

         <pair>

           <repeat>1</repeat>

           <each_steps>1</each_steps>

         </pair>

       </timesteps>

       <variables>

         <variable>temperature_soil</variable>

         <variable>temperature_BHE1</variable>

       </variables>

       <suffix>ts{:timestep}_t_{:time}</suffix>

     </output>

   </time_loop>

   <parameters>

     <parameter>

       <name>T0</name>

       <type>Constant</type>

       <value>55</value>

     </parameter>

     <parameter>

       <name>T0_BHE1</name>

       <type>Constant</type>

       <values>20 20</values>

     </parameter>

   </parameters>

   <process_variables>

     <process_variable>

       <name>temperature_soil</name>

       <components>1</components>

       <order>1</order>

       <initial_condition>T0</initial_condition>

       <boundary_conditions />

     </process_variable>

     <process_variable>

       <name>temperature_BHE1</name>

       <components>2</components>

       <order>1</order>

       <initial_condition>T0_BHE1</initial_condition>

     </process_variable>

   </process_variables>

   <nonlinear_solvers>

     <nonlinear_solver>

       <name>basic_picard</name>

       <type>Picard</type>

       <max_iter>200</max_iter>

       <linear_solver>general_linear_solver</linear_solver>

     </nonlinear_solver>

   </nonlinear_solvers>

   <linear_solvers>

     <linear_solver>

       <name>general_linear_solver</name>

       <lis>-i cg -p jacobi -tol 1e-16 -maxiter 10000</lis>

       <eigen>

         <solver_type>BiCGSTAB</solver_type>

         <precon_type>ILUT</precon_type>

         <max_iteration_step>1000</max_iteration_step>

         <error_tolerance>1e-16</error_tolerance>

       </eigen>

       <petsc>

         <prefix>gw</prefix>

         <parameters>-gw_ksp_type cg -gw_pc_type bjacobi -gw_ksp_rtol 1e-16 -gw_ksp_max_it 10000</parameters>

       </petsc>

     </linear_solver>

   </linear_solvers>

   <curves>

     <curve>

       <name>inflow_temperature</name>

       <coords>0 864000</coords>

       <values>20 20</values>

     </curve>

   </curves>

 </OpenGeoSysProject>