modelpipe_parameters
Model to communicate starting conditions and pipe geometry
Information
1. Purpose of model
Collector for pipe specific parameters
2. Level of detail, physical effects considered, and physical insight
(no remarks)
3. Limits of validity
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4. Interfaces
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5. Nomenclature
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6. Governing Equations
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7. Remarks for Usage
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8. Validation
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9. References
10. Version History
Model created by Philipp Huismann (huismann@gwi-essen.de) on 10.10.2018
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Pressure | p_start | 10e5 | Pressure at start of simulation |
| SI.Temperature | T_start | 20 + 273.15 | Temperature at start of simulation |
| SI.Temperature | T_start_out | (T_start - simCenter.T_ground)*exp(-R/(diameter_i^2*Modelica.Constants.pi/4*v_nom*rho*cp_w)) + simCenter.T_ground | Calculates the expected outlet Temperature for a given velocity and pipe dimensions |
| SI.MassFlowRate | m_flow_start | 1 | Mass flow at start of simulation |
| SI.SpecificEnthalpy | h_start | TILMedia.VLEFluidFunctions.specificEnthalpy_pTxi(simCenter.fluid1, p_start, T_start, {1, 0, 0}) | Enthalpy at start of simulation |
| SI.SpecificEnthalpy | h_start_out | if calc_initial_dstrb then TILMedia.VLEFluidFunctions.specificEnthalpy_pTxi(simCenter.fluid1, p_start, T_start_out, {1, 0, 0}) else h_start | Starting Enthalpy at the end of the pipe |
| SI.Density | rho | TILMedia.VLEFluidFunctions.density_pTxi(simCenter.fluid1, p_start, T_start, {1, 0, 0}) | |
| SI.DynamicViscosity | dyn_vis | TILMedia.VLEFluidFunctions.dynamicViscosity_pTxi(simCenter.fluid1, p_start, T_start, {1, 0, 0}) | |
| SI.SpecificHeatCapacity | cp_w | TILMedia.VLEFluidFunctions.specificIsobaricHeatCapacity_pTxi(simCenter.fluid1, p_start, T_start, {1, 0, 0}) | |
| Real | R | (log(diameter_o/(diameter_i + pipe_wall_thickness*2))/(2*Modelica.Constants.pi*lambda_insulation) + log(2*1/(diameter_o))/(2*Modelica.Constants.pi*simCenter.lambda_ground)) | |
| SI.Length | length | 1 | Length of the pipe |
| SI.Height | depth | 1.5 | Deptsh of the pipe |
| SI.Length | diameter_i | 0.3 | Inner Diameter of the pipe |
| SI.Length | diameter_o | 0.4 | Outer Diameter of the pipe |
| SI.Height | z_in | 1 | Inlet Height of the pipe |
| SI.Height | z_out | 1 | Outlet Height of the pipe |
| SI.Length | pipe_wall_thickness | 0.005 | Pipe Wall Thickness |
| SI.Length | K | 0.000045 | average height of surface asperities |
| SI.Velocity | v_nom | simCenter.v_nom | Design Velocity of the pipe. Typically smaller than 2 m/s |
| SI.ThermalConductivity | lambda_insulation | 0.024 | HeatTransferCoefficient of the insulation |
| SI.SpecificHeatCapacity | pipe_wall_capacity | 450 | HeatCapacity of the pipe wall material |
| SI.Density | pipe_wall_d | 7850 | Density of the pipe wall material |
| SI.Area | carrier_pipe_area | Modelica.Constants.pi/4*((diameter_i + 2*pipe_wall_thickness)^2 - diameter_i^2) | Area of the carrier pipe |
| SI.HeatCapacity | carrier_pipe_capacity | carrier_pipe_area*length*pipe_wall_capacity*pipe_wall_d | |
| HeatTransfer | |||
| Boolean | calc_initial_dstrb | simCenter.calc_initial_dstrb | Activates the calculation of a initial temperature distribution inside the pipes |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.SimCenter | simCenter |