Junction2¶
Split valve without bypass: its inlets (port_1) mix, its outlets (port_2) leave at the mixed temperature
FastSmoothBuildings.Hydronics.Junction2, model (source)
Purpose
Junction without the second outlet: the
connections of the inlet port_1 mix, and every connection of the outlet port_2 leaves at
the mixed temperature T.
Equations
Mixed temperature, with δ = m_flow_small and T̄1 the mean of the
inlet temperatures:
T = (∑i wi T1,i + δ T̄1) / (∑i wi + δ),
where wi is the inlet flow with set flows and its positive part with pressure-driven flows.
Set flows and pressure-driven flows
With set flows, the junction conserves mass, ∑ port_1.m_flow + ∑ port_2.m_flow =
0. With pressure-driven flows, the inlet is a pressure node of small compliance and each outlet connection has the
linear conductance G = |m_flow_nominal[1]| / max(dp_nominal[1],
dpLink):
port_2[j].m_flow = −G (pin − p2,j),
τhyd G n2 dpin/dt =
∑ port_1.m_flow + ∑ port_2.m_flow.
Only dp_nominal[1] and m_flow_nominal[1] enter the equations, as in
Junction.
Parameters¶
| Parameter | Type | Unit | Default | Description |
|---|---|---|---|---|
| nPorts_1 | Integer | 1 | Number of connections of the inlet | |
| nPorts_2 | Integer | 1 | Number of connections of the outlet | |
| m_flow_small | Real | kg/s | 1e-6 | |
| pressureDriven | Boolean | false | true: flows from the pressures of the circuit | |
| tauHyd | Real | s | 5 | Time constant of the pressure of the inlet node |
| dp_nominal | Real | Pa | {5000, -1, -1} | Pressure drops of Buildings' Junction |
| m_flow_nominal | Real | kg/s | 0.15*{1, -1, -1} | Nominal flows of Buildings' Junction |
| dpLink | Real | Pa | 1000 | Pressure drop at the nominal flow when dp_nominal[1] is not positive |
| G | Real | kg/(s.Pa) | abs(m_flow_nominal[1])/max(dp_nominal[1], dpLink) | Conductance of each outlet (dp_nominal[1], at least dpLink) |
Revisions¶
- October 2026: moved from trano's
FastModel.Hydronics.