Components.Partial.PartialStraightPipe
Partial base class for a 1-D staggered-grid straight-pipe refrigerant model.
Wires together the distributed-volume cells (from PartialDistributedVolume), a staggered SimpleStaggeredFlowModel for momentum, and the two FluidPorts, and provides the (p, h) ODE system in each cell. Extending components must declare model_structure (av_vb, av_b, a_vb, a_v_b — these control how port-side flow cells line up with volume cells), flow_model_mode (FromPressureDifference or FromMassFlow), and bind the geometry arrays (lengths, crossAreas, dimensions, roughnesses, dheights) plus the scalar **start values via initial equations from their own scalar geometry parameters. m_flow > 0 means refrigerant enters through port_a; medium*data must be a refrigerant medium (inherited).
This component extends from PartialDistributedVolume
Usage
HVACComponents.Components.Partial.PartialStraightPipe(medium_data, p_a_start, p_b_start, h_a_start, h_b_start, m_flow_start, ps_start=missing, hs_start=missing, fluidVolumes=missing, lengths=missing, crossAreas=missing, dimensions=missing, roughnesses=missing, dheights=missing, crossAreas_start=missing, dimensions_start=missing, roughnesses_start=missing, dheights_start=missing, diameters_start=missing, dp_nominal_start=missing, m_flow_nominal_start=missing, K_dp_start=missing, dp_exp_start=missing)
Parameters:
| Name | Description | Units | Default value |
|---|---|---|---|
N | Number of control volumes | – | |
N_Plus_1 | Number of cell faces (= N + 1) | – | N + 1 |
ph_distribution | Distribution mode for the initial pressure/enthalpy profile (Linear or Lumped) | – | |
initialization_mode | Initialisation mode: FixedInitial_ph sets initial equations on each mediums[i]; NoInit only seeds guesses | – | HVACComponents.FiniteVolumeInitializationMode.FixedInitial_ph() |
model_structure | Staggered-grid model structure controlling how flow cells line up with mass/energy cells | – | |
flow_model_mode | Flow formulation: FromPressureDifference computes m_flows from dps_f; FromMassFlow does the reverse | – | |
nFM | Number of momentum cells, derived from model_structure (av_vb: N-1, a_v_b: N+1, otherwise N) | – | ifelse(model_structure == HVACComponents.ModelStructure.av_vb(), N - 1, ifelse(model_structure == HVACComponents.ModelStructure.a_v_b(), N + 1, N)) |
nFM_Plus_1 | Number of momentum cells plus one (face count for flow-model arrays) | – | nFM + 1 |
medium_data | Refrigerant medium properties shared by all N control volumes | – | |
p_a_start | Initial pressure at port_a [Pa] | Pa | |
p_b_start | Initial pressure at port_b [Pa] | Pa | |
h_a_start | Initial specific enthalpy at port_a [J/kg] | J/kg | |
h_b_start | Initial specific enthalpy at port_b [J/kg] | J/kg | |
m_flow_start | Initial mass flow rate [kg/s] (solver guess on m_flows) | kg/s |
Connectors
Variables
| Name | Description | Units |
|---|---|---|
dms | Time derivative of fluid mass in each cell [kg/s] (length N) | – |
dUs | Time derivative of internal energy in each cell [W] (length N) | – |
m_flows | Mass flow rate at each cell face [kg/s] (length N+1) | kg/s |
H_flows | Enthalpy flow rate at each cell face [W] (length N+1); upwind-discretised on internal faces | – |
mb_flows | Net convective mass inflow per cell [kg/s] (length N; = m_flows[i] - m_flows[i+1]) | kg/s |
Hb_flows | Net convective enthalpy inflow per cell [W] (length N; = H_flows[i] - H_flows[i+1]) | – |
Qb_flows | Source/sink heat flow per cell [W] (length N); extender supplies | W |
Wb_flows | Source/sink mechanical power per cell [W] (length N); extender supplies | W |
Mtot | Total refrigerant mass inventory across all cells [kg] | – |
M_cv | Refrigerant mass in each cell [kg] (length N) | – |
vs | Mean refrigerant velocity in each cell [m/s] (length N) | – |
a | Top-left entry of the (mass, energy) 2x2 system in each cell [s] | – |
b | Top-right entry of the (mass, energy) 2x2 system in each cell [kg.m^3/J] | – |
c | Bottom-left entry of the (mass, energy) 2x2 system in each cell | – |
d | Bottom-right entry of the (mass, energy) 2x2 system in each cell [kg] | – |
det | Determinant of the (mass, energy) 2x2 system in each cell | – |