model FixedResistance extends Modelica.Icons.Example; package Medium = Buildings.Media.ConstantPropertyLiquidWater; Modelica.Blocks.Sources.Constant PAtm(k=101325); Modelica.Blocks.Sources.Ramp P( duration=1, height=20, offset=101315); Buildings.Fluid.FixedResistances.FixedResistanceDpM res1( redeclare package Medium = Medium, from_dp=true, m_flow_nominal=5, dp_nominal=10); Buildings.Fluid.Sources.Boundary_pT sou1( redeclare package Medium = Medium, use_p_in=true, T=293.15, nPorts=3); Buildings.Fluid.Sources.Boundary_pT sin1( redeclare package Medium = Medium, T=283.15, use_p_in=true, nPorts=3); Buildings.Fluid.FixedResistances.FixedResistanceDpM res2( redeclare package Medium = Medium, from_dp=true, m_flow_nominal=5, dp_nominal=10, use_dh=true); Buildings.Fluid.FixedResistances.FixedResistanceDpM res3( redeclare package Medium = Medium, from_dp=true, m_flow_nominal=5, dp_nominal=10, use_dh=true); FixedResistances.LosslessPipe pipCon(redeclare package Medium = Medium, m_flow_nominal=5) "Lossless pipe connection"; Buildings.Fluid.Sensors.MassFlowRate masFlo2(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Fluid.Sensors.MassFlowRate masFlo3(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Utilities.Diagnostics.AssertEquality assEqu(threShold=1E-4, message= "Inputs differ, check that lossless pipe is correctly implemented.") "Assert equality of the two mass flow rates"; inner Modelica.Fluid.System system; equation connect(res2.port_b, masFlo2.port_a); connect(res3.port_b, masFlo3.port_a); connect(masFlo3.port_b, pipCon.port_a); connect(P.y, sou1.p_in); connect(sou1.ports[1], res1.port_a); connect(sin1.ports[1], res1.port_b); connect(masFlo3.m_flow, assEqu.u1); connect(masFlo2.m_flow, assEqu.u2); connect(PAtm.y, sin1.p_in); connect(sou1.ports[2], res2.port_a); connect(sou1.ports[3], res3.port_a); connect(sin1.ports[2], masFlo2.port_b); connect(sin1.ports[3], pipCon.port_b); end FixedResistance;

model FixedResistancesExplicit "Test of multiple resistances in series" extends Modelica.Icons.Example; package Medium = Buildings.Media.IdealGases.SimpleAir; Buildings.Fluid.Sources.Boundary_ph sou( redeclare package Medium = Medium, nPorts=1, p(displayUnit="Pa") = 101335, use_p_in=true); Buildings.Fluid.Sources.Boundary_ph sin( redeclare package Medium = Medium, nPorts=1, use_p_in=false, p=101325); Buildings.Fluid.FixedResistances.FixedResistanceDpM res11( redeclare package Medium = Medium, from_dp=false, m_flow_nominal=2, dp_nominal=5); inner Modelica.Fluid.System system(p_ambient=101325); Buildings.Fluid.FixedResistances.FixedResistanceDpM res12( redeclare package Medium = Medium, from_dp=false, m_flow_nominal=2, dp_nominal=5); Buildings.Fluid.FixedResistances.FixedResistanceDpM res22( redeclare package Medium = Medium, m_flow_nominal=2, dp_nominal=5, from_dp=true); Buildings.Fluid.FixedResistances.FixedResistanceDpM res21( redeclare package Medium = Medium, m_flow_nominal=2, dp_nominal=5, from_dp=true); Buildings.Fluid.FixedResistances.FixedResistanceDpM res31( redeclare package Medium = Medium, from_dp=false, m_flow_nominal=2, dp_nominal=5); Buildings.Fluid.FixedResistances.FixedResistanceDpM res32( redeclare package Medium = Medium, from_dp=false, m_flow_nominal=2, dp_nominal=5); Buildings.Fluid.FixedResistances.FixedResistanceDpM res42( redeclare package Medium = Medium, m_flow_nominal=2, dp_nominal=5, from_dp=true); Buildings.Fluid.FixedResistances.FixedResistanceDpM res41( redeclare package Medium = Medium, m_flow_nominal=2, dp_nominal=5, from_dp=true); Buildings.Fluid.Sources.MassFlowSource_h bou( redeclare package Medium = Medium, m_flow=1, nPorts=1); Buildings.Fluid.Sources.MassFlowSource_h bou1( redeclare package Medium = Medium, m_flow=1, nPorts=1); Buildings.Fluid.Sources.Boundary_pT sin1( redeclare package Medium = Medium, T=273.15 + 10, nPorts=2, use_p_in=false, p=101325); Buildings.Fluid.Sources.Boundary_ph sin2( redeclare package Medium = Medium, nPorts=1, use_p_in=false, p=101325); Buildings.Fluid.Sources.Boundary_ph sou1( redeclare package Medium = Medium, nPorts=1, p(displayUnit="Pa") = 101335, use_p_in=true); Modelica.Blocks.Sources.Ramp P( duration=1, height=20, offset=101315); Buildings.Fluid.Sensors.MassFlowRate senMasFlo1(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Fluid.Sensors.MassFlowRate senMasFlo2(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Fluid.Sensors.MassFlowRate senMasFlo3(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Fluid.Sensors.MassFlowRate senMasFlo4(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Utilities.Diagnostics.AssertEquality assertEquality; Buildings.Utilities.Diagnostics.AssertEquality assertEquality1; equation connect(res11.port_b, res12.port_a); connect(res21.port_b, res22.port_a); connect(res31.port_b, res32.port_a); connect(res41.port_b, res42.port_a); connect(sou.ports[1], res11.port_a); connect(bou.ports[1], res31.port_a); connect(bou1.ports[1], res41.port_a); connect(sou1.ports[1], res21.port_a); connect(P.y, sou.p_in); connect(P.y, sou1.p_in); connect(res12.port_b, senMasFlo1.port_a); connect(res22.port_b, senMasFlo2.port_a); connect(res32.port_b, senMasFlo3.port_a); connect(res42.port_b, senMasFlo4.port_a); connect(senMasFlo3.port_b, sin1.ports[1]); connect(senMasFlo4.port_b, sin1.ports[2]); connect(senMasFlo1.port_b, sin.ports[1]); connect(senMasFlo2.port_b, sin2.ports[1]); connect(senMasFlo3.m_flow, assertEquality1.u1); connect(senMasFlo4.m_flow, assertEquality1.u2); connect(senMasFlo1.m_flow, assertEquality.u1); connect(senMasFlo2.m_flow, assertEquality.u2); end FixedResistancesExplicit;

model FixedResistancesParallel extends Modelica.Icons.Example; package Medium = Buildings.Media.ConstantPropertyLiquidWater; Modelica.Blocks.Sources.Constant PAtm(k=101325); Modelica.Blocks.Sources.Ramp P( duration=1, height=20, offset=101315); Buildings.Fluid.FixedResistances.FixedResistanceDpM res1( redeclare package Medium = Medium, m_flow_nominal=5, dp_nominal=10, deltaM=0.3, linearized=false, from_dp=false); Buildings.Fluid.Sources.Boundary_pT sou1( redeclare package Medium = Medium, T=293.15, nPorts=2, use_p_in=true); Buildings.Fluid.Sources.Boundary_pT sin1( redeclare package Medium = Medium, T=283.15, nPorts=2, use_p_in=true); Buildings.Fluid.FixedResistances.FixedResistanceDpM res2( redeclare package Medium = Medium, m_flow_nominal=5, dp_nominal=10, deltaM=0.3, linearized=false, from_dp=false); Buildings.Fluid.Sensors.MassFlowRate masFlo2(redeclare package Medium = Medium) "Mass flow rate sensor"; Buildings.Utilities.Diagnostics.AssertEquality assEqu(threShold=1E-4, message= "Inputs differ, check that lossless pipe is correctly implemented.") "Assert equality of the two mass flow rates"; Buildings.Fluid.Sensors.MassFlowRate masFlo1(redeclare package Medium = Medium) "Mass flow rate sensor"; inner Modelica.Fluid.System system(p_ambient=101325); equation connect(PAtm.y, sin1.p_in); connect(P.y, sou1.p_in); connect(res2.port_b, masFlo2.port_a); connect(res1.port_b, masFlo1.port_a); connect(sou1.ports[1], res1.port_a); connect(sou1.ports[2], res2.port_a); connect(sin1.ports[1], masFlo1.port_b); connect(sin1.ports[2], masFlo2.port_b); connect(masFlo2.m_flow, assEqu.u1); connect(masFlo1.m_flow, assEqu.u2); end FixedResistancesParallel;

model FixedResistancesSeries "Test of multiple resistances in series" extends Modelica.Icons.Example; package Medium = Buildings.Media.IdealGases.SimpleAir; Modelica.Blocks.Sources.Constant PAtm(k=101325); parameter Modelica.SIunits.Pressure dp_nominal = 5 "Nominal pressure drop for each resistance"; Modelica.Blocks.Sources.Ramp P( duration=1, height=2*dp_nominal*nRes, offset=101325 - dp_nominal*nRes); Buildings.Fluid.Sources.Boundary_pT sou( redeclare package Medium = Medium, T=273.15 + 20, use_p_in=true, nPorts=1); Buildings.Fluid.Sources.Boundary_pT sin( redeclare package Medium = Medium, T=273.15 + 10, use_p_in=true, nPorts=1); parameter Integer nRes( min=2) = 10 "Number of resistances"; Buildings.Fluid.FixedResistances.FixedResistanceDpM[ nRes] res( redeclare each package Medium = Medium, each dp_nominal=dp_nominal, each from_dp = false, each m_flow_nominal=2); inner Modelica.Fluid.System system(p_ambient=101325); equation for i in 1:nRes-1 loop connect(res[i].port_b, res[i+1].port_a); end for; connect(PAtm.y, sin.p_in); connect(P.y, sou.p_in); connect(sin.ports[1], res[nRes].port_b); connect(sou.ports[1], res[1].port_a); end FixedResistancesSeries;

model Pipe "Test of a pipe with multiple segments" extends Modelica.Icons.Example; replaceable package Medium = Buildings.Media.ConstantPropertyLiquidWater; Modelica.Blocks.Sources.Ramp P( duration=1, height=2*pip.dp_nominal, offset=101325 - pip.dp_nominal); Buildings.Fluid.Sources.Boundary_pT sou( redeclare package Medium = Medium, use_p_in=true, T=273.15 + 50, nPorts=2); Buildings.Fluid.Sources.Boundary_pT sin( redeclare package Medium = Medium, T=273.15 + 10, nPorts=2, use_p_in=false, p(displayUnit="Pa") = 101325); inner Modelica.Fluid.System system(p_ambient=101325); HeatTransfer.Sources.FixedTemperature TEnv(T=263.15); Buildings.Fluid.FixedResistances.Pipe pip( thicknessIns=0.01, lambdaIns=0.01, m_flow_nominal=10, redeclare package Medium = Medium, length=10, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial); HeatTransfer.Sources.FixedTemperature TEnv1[10](each T=263.15); Buildings.Fluid.FixedResistances.Pipe pip1( thicknessIns=0.01, lambdaIns=0.01, m_flow_nominal=10, redeclare package Medium = Medium, length=10, useMultipleHeatPorts=true, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial); Buildings.Fluid.Sensors.TemperatureTwoPort senTem(redeclare package Medium = Medium, m_flow_nominal=pip.m_flow_nominal) "Temperature sensor"; Buildings.Fluid.Sensors.TemperatureTwoPort senTem1(redeclare package Medium = Medium, m_flow_nominal=pip.m_flow_nominal) "Temperature sensor"; Buildings.Utilities.Diagnostics.AssertEquality assEqu; equation connect(P.y, sou.p_in); connect(sou.ports[1], pip.port_a); connect(TEnv.port, pip.heatPort); connect(sou.ports[2], pip1.port_a); connect(TEnv1.port, pip1.heatPorts); connect(pip.port_b, senTem.port_a); connect(senTem.port_b, sin.ports[1]); connect(pip1.port_b, senTem1.port_a); connect(senTem1.port_b, sin.ports[2]); connect(assEqu.u1, senTem.T); connect(senTem1.T, assEqu.u2); end Pipe;

model SplitterFixedResistanceDpM extends Modelica.Icons.Example; package Medium = Buildings.Media.IdealGases.SimpleAir; Buildings.Fluid.FixedResistances.SplitterFixedResistanceDpM spl( m_flow_nominal={1,2,3}, dh={1,2,3}, redeclare package Medium = Medium, dp_nominal(displayUnit="Pa") = {5,10,15}) "Splitter"; Buildings.Fluid.Sources.Boundary_pT bou1( redeclare package Medium = Medium, T=273.15 + 10, use_p_in=true, nPorts=1); Buildings.Fluid.Sources.Boundary_pT bou2( redeclare package Medium = Medium, T=273.15 + 20, use_p_in=true, nPorts=1); Buildings.Fluid.Sources.Boundary_pT bou3( redeclare package Medium = Medium, T=273.15 + 30, use_p_in=true, nPorts=1); Modelica.Blocks.Sources.Constant P2(k=101325); Modelica.Blocks.Sources.Ramp P1( offset=101320, height=10, duration=0.5); Modelica.Blocks.Sources.Ramp P3( offset=101320, height=10, duration=0.5, startTime=0.5); inner Modelica.Fluid.System system(p_ambient=101325); equation connect(P1.y, bou1.p_in); connect(P2.y, bou2.p_in); connect(bou3.p_in, P3.y); connect(bou1.ports[1], spl.port_1); connect(bou3.ports[1], spl.port_3); connect(spl.port_2, bou2.ports[1]); end SplitterFixedResistanceDpM;