Buildings.Fluid.FixedResistances.Validation.PlugFlowPipes.Data.BaseClasses

BaseClasses for data records

Information

This package contains base classes that are used to construct the models in Buildings.Fluid.FixedResistances.Validation.PlugFlowPipes.Data.

Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).

Package Content

Name	Description
PipeDataBaseDefinition	BaseClass for experimental data from the pipe test bench
PipeDataULg	Base class for ULg experimental data

Buildings.Fluid.FixedResistances.Validation.PlugFlowPipes.Data.BaseClasses.PipeDataBaseDefinition

BaseClass for experimental data from the pipe test bench

Information

Defines basic record of experimental data with n measured points. The first column corresponds to time, further columns to measured data.

Extends from Modelica.Icons.Record (Icon for records).

Parameters

Type	Name	Default	Description
Integer	nCol		Number of columns in the data file
String	filNam		Name of data file

Modelica definition

partial record PipeDataBaseDefinition "BaseClass for experimental data from the pipe test bench" extends Modelica.Icons.Record; parameter Integer nCol "Number of columns in the data file"; parameter String filNam "Name of data file"; end PipeDataBaseDefinition;

Buildings.Fluid.FixedResistances.Validation.PlugFlowPipes.Data.BaseClasses.PipeDataULg

Base class for ULg experimental data

Information

This record contains information of an aproximately 15 minutes long test bench carried out at the University of Liège.

Data structure

Column 1: Time in s

Column 2: Mass flow rate in kg/s

Column 3: Outlet pipe temperature in °C

Column 4: Outlet water temperature in °C

Column 5: Inlet pipe temperature in °C

Column 6: Inlet water temperature in °C

Test procedure

Before to perform a test, the water city network is pushed inside the approximately 39 meter long studied pipe during about 10 minutes to be sure that it is at the same temperature. During this time period, valves V3 and V1 are opened, the boiler is off and the valve V2 is closed.

Then, the valve V1 is closed and the valve V2 and V3 are opened. The boiler is started to reach the setpoint hot water temperature. When the temperature setpoint is achieved, data starts to be recorded, the valve V1 is opened and the valve V2 is closed at the same time to supply the studied pipe in hot water. After the outlet pipe temperature is stabilized, the boiler is shut off.

During the test, the ambient temperature is equal to 18°C and the mass flow rate is set to 1.245 kg/s.

Test bench schematic

Schematic of test rig at ULg

Notice: length are approximate

Pipe characteristics

Metal density about 7800 kg/m³
Specific heat capacity about 480 J/kg/K
Thickness 3.91 mm (Outer diameter 0.0603 m)
Inner diameter: 0.05248 m
Roughness is currently neglected
Initial temperature of the pipe is considered equal to the initial temperature of the water (cooling before test)
Heat transfer coefficient between the pipe and the ambient is assumed at 5 W/m²K (from internal model) due to insulation. The pipe is insulated by Tubolit 60/13 (13mm of thickness) whose nominal thermal coefficient is inferior 0.04. Notice the insulation is quite aged therefore the nominal thermal coefficient could be higher
Heat transfer coefficient between water and pipe is a function of the fluid temperature (determined by EES software).

Extends from PipeDataBaseDefinition (BaseClass for experimental data from the pipe test bench).

Parameters

Type	Name	Default	Description
Integer	nCol		Number of columns in the data file
String	filNam		Name of data file
Temperature_degC	T_start_in	20	Initial temperature at inlet [degC]
Temperature_degC	T_start_out	20	Initial temperature at outlet [degC]
MassFlowRate	m_flowIni	0	Mass flow initialization [kg/s]

Modelica definition

partial record PipeDataULg "Base class for ULg experimental data" extends PipeDataBaseDefinition; parameter Modelica.Units.NonSI.Temperature_degC T_start_in=20 "Initial temperature at inlet"; parameter Modelica.Units.NonSI.Temperature_degC T_start_out=20 "Initial temperature at outlet"; parameter Modelica.Units.SI.MassFlowRate m_flowIni=0 "Mass flow initialization"; end PipeDataULg;