Controlled Pressure Source $—$ Simple pressure controlled pump

The Controlled Pressure Source component describes a pressure-controlled pump with externally commanded pressure, limited flow rate, and internal leakage. The pressure at the outlet port of this component may differ from the commanded value because of the settings of the controller (gain k) and the time constant T of the pump delay. If the boundary pressure should exactly follow the reference pressure model, then Ideal Pressure Source should be used instead.

 Equations $T={T}_{0\left(\mathrm{oil}\right)}+{\mathrm{ΔT}}_{\mathrm{system}}$ ${p}_{\mathrm{abs}}={p}_{B}+{p}_{\mathrm{atm}\left(\mathrm{oil}\right)}$

Variables

 Name Value Units Description Modelica ID ${p}_{\mathrm{sat}}$ [1] $\mathrm{Pa}$ Gas saturation pressure p_sat $\mathrm{Vol}$ Vol $\mathrm{tank}$ tank ${p}_{\mathrm{abs}}$ $\mathrm{Pa}$ Absolute pressure, used for all property calls p_abs $T$ $K$ Local temperature T ${\mathrm{\rho }}_{\mathrm{summary}}$ [2] $\frac{\mathrm{kg}}{{m}^{3}}$ Density summary_rho ${p}_{B\left(\mathrm{summary}\right)}$ ${p}_{B}$ $\mathrm{Pa}$ Pressure at port B summary_pB $\mathrm{FlowSource}$ FlowSource ${\mathrm{PMeas}}_{1}$ PMeas1 ${\mathrm{Feedback}}_{1}$ Feedback1 ${\mathrm{Gain}}_{1}$ Gain1 ${\mathrm{Limiter}}_{1}$ Limiter1 ${\mathrm{FirstOrder}}_{1}$ FirstOrder1

[1] $\mathrm{oil.gasSaturationPressure}\left(T=T,{v}_{\mathrm{gas}}={\mathrm{oil.v}}_{\mathrm{gas}}\right)$

[2] $\mathrm{oil.density}\left(p={p}_{\mathrm{abs}},T=T,{v}_{\mathrm{air}}={\mathrm{oil.v}}_{\mathrm{gas}},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right)$

Connections

 Name Description Modelica ID $\mathrm{oil}$ oil ${\mathrm{port}}_{B}$ Port B, where oil leaves the component ($q<0$, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_B $\mathrm{commandSignal}$ Connector of input signal used as flow rate commandSignal ${p}_{\mathrm{set}}$ p_set

Parameters

General Parameters

 Name Default Units Description Modelica ID use input $\mathrm{true}$ If true, input port is present useInput $G$ $5.·{10}^{-12}$ $\frac{{m}^{3}}{s\mathrm{Pa}}$ Conductance of pump leakage G use volume B $\mathrm{true}$ If true, a volume is present at port B useVolumeB ${\mathrm{ΔT}}_{\mathrm{system}}$ $0$ $K$ Temperature offset from system temperature dT_system ${p}_{\mathrm{bias}}$ $5.·{10}^{6}$ $\mathrm{Pa}$ Bias of pressure pbias ${q}_{\mathrm{max}}$ $0.05$ $\frac{{m}^{3}}{s}$ Maximum pump flow rate qMax $t$ $0.05$ $s$ Time constant of pressure control system t $k$ ${10}^{-6}$ Gain of pressure controller k

Oil Parameters

 Name Default Units Description Modelica ID ${V}_{B}$ ${10}^{-6}$ ${m}^{3}$ Geometric volume at port B volumeB

Constant Parameters

 Name Default Units Description Modelica ID ${q}_{\mathrm{min}}$ $0$ $\frac{{m}^{3}}{s}$ Minimum pump flow rate qMin