This example models a borehole heat exchanger with two pipes that are
symmetrically spaced.
The simulation period is 5 years.
From the 4th to the 10th months, the mass flow source switches on the
flow rate through the borehole. The leaving
water of the mass flow source is 25°C,
and the water that returns from the borehole is between
20.5°C
and
21.5°C.
model UTube
"Model that tests the borehole model"
extends Modelica.Icons.Example;
package Medium =
Buildings.Media.ConstantPropertyLiquidWater;
Buildings.Fluid.HeatExchangers.Boreholes.UTube borHol(
redeclare each package Medium = Medium,
hBor=150,
dp_nominal=10000,
dT_dz=0.0015,
samplePeriod=604800,
m_flow_nominal=0.3,
redeclare each parameter Buildings.HeatTransfer.Data.BoreholeFillings.Bentonite
matFil,
redeclare parameter Buildings.HeatTransfer.Data.Soil.Sandstone matSoi,
TExt0_start=283.15,
TFil0_start=283.15)
"Borehole heat exchanger";
inner Modelica.Fluid.System system;
Sources.Boundary_ph sin(nPorts=1,
redeclare package Medium = Medium)
"Sink";
Sources.MassFlowSource_T sou(
nPorts=1,
redeclare package Medium = Medium,
use_m_flow_in=true,
T=298.15)
"Source";
Modelica.Blocks.Sources.Pulse pulse(
amplitude=0.3,
period=365*86400,
startTime=365*86400/4);
equation
connect(sou.ports[1], borHol.port_a);
connect(borHol.port_b, sin.ports[1]);
connect(pulse.y, sou.m_flow_in);
end UTube;