Generic Valve $—$ Basic model for generic valve

The Generic Valve component calculates the pressure loss for a given valve geometry (selected by the user). The calculation depends on the opening of the valve.

 Equations $\mathrm{\nu }=\mathrm{Modelica.Media.Air.MoistAir.Utilities.spliceFunction}\left(x=\mathrm{Δp},\mathrm{pos}={\mathrm{\nu }}_{\mathrm{oil}}\left(p={p}_{A\left(\mathrm{abs}\right)},T=T,{v}_{\mathrm{air}}={v}_{\mathrm{gas}\left(\mathrm{oil}\right)},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right),\mathrm{neg}={\mathrm{\nu }}_{\mathrm{oil}}\left(p={p}_{B\left(\mathrm{abs}\right)},T=T,{v}_{\mathrm{air}}={v}_{\mathrm{gas}\left(\mathrm{oil}\right)},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right),\mathrm{Δx}=100\right)$ $\mathrm{\rho }=\mathrm{Modelica.Media.Air.MoistAir.Utilities.spliceFunction}\left(x=\mathrm{Δp},\mathrm{pos}={\mathrm{\rho }}_{\mathrm{oil}}\left(p={p}_{A\left(\mathrm{abs}\right)},T=T,{v}_{\mathrm{air}}={v}_{\mathrm{gas}\left(\mathrm{oil}\right)},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right),\mathrm{neg}={\mathrm{\rho }}_{\mathrm{oil}}\left(p={p}_{B\left(\mathrm{abs}\right)},T=T,{v}_{\mathrm{air}}={v}_{\mathrm{gas}\left(\mathrm{oil}\right)},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right),\mathrm{Δx}=100\right)$ $T={T}_{0\left(\mathrm{oil}\right)}+{\mathrm{ΔT}}_{\mathrm{system}}$ $q=\frac{{m}_{\mathrm{flow}\left(A\right)}}{\mathrm{\rho }}$ $\mathrm{Δp}={p}_{A\left(\mathrm{limited}\right)}-{p}_{B\left(\mathrm{limited}\right)}$ ${m}_{\mathrm{flow}\left(A\right)}=\mathrm{Modelica.Fluid.Dissipation.PressureLoss.Valve.dp_severalGeometryOverall_MFLOW}\left(\mathrm{IN_con}=\mathrm{IN_con},\mathrm{IN_var}=\mathrm{IN_var},\mathrm{Δp}=\mathrm{Δp}\right)$ ${p}_{A\left(\mathrm{abs}\right)}={p}_{A}+{p}_{\mathrm{atm}\left(\mathrm{oil}\right)}$ ${p}_{A\left(\mathrm{limited}\right)}=\mathrm{max}\left({p}_{A},{p}_{\mathrm{vapour}\left(\mathrm{oil}\right)}-{p}_{\mathrm{atm}\left(\mathrm{oil}\right)}\right)$ ${p}_{B\left(\mathrm{abs}\right)}={p}_{B}+{p}_{\mathrm{atm}\left(\mathrm{oil}\right)}$ ${p}_{B\left(\mathrm{limited}\right)}=\mathrm{max}\left({p}_{B},{p}_{\mathrm{vapour}\left(\mathrm{oil}\right)}-{p}_{\mathrm{atm}\left(\mathrm{oil}\right)}\right)$ ${m}_{\mathrm{flow}\left(A\right)}+{m}_{\mathrm{flow}\left(B\right)}=0$

Variables

 Name Value Units Description Modelica ID $\mathrm{Δp}$ $\mathrm{Pa}$ Pressure drop dp $q$ $\frac{{m}^{3}}{s}$ Flow rate flowing into port_A q ${p}_{A\left(\mathrm{limited}\right)}$ $\mathrm{Pa}$ Limited gauge pressure pA_limited ${p}_{B\left(\mathrm{limited}\right)}$ $\mathrm{Pa}$ Limited gauge pressure pB_limited $\mathrm{\rho }$ $\frac{\mathrm{kg}}{{m}^{3}}$ Upstream density rho $\mathrm{\nu }$ $\frac{{m}^{2}}{s}$ Upstream kinematic viscosity nu ${p}_{A\left(\mathrm{abs}\right)}$ $\mathrm{Pa}$ Absolute pressure pA pA_abs ${p}_{B\left(\mathrm{abs}\right)}$ $\mathrm{Pa}$ Absolute pressure pB pB_abs $T$ $K$ Local temperature T ${p}_{A\left(\mathrm{summary}\right)}$ ${p}_{A}$ $\mathrm{Pa}$ Pressure at port A summary_pA ${p}_{B\left(\mathrm{summary}\right)}$ ${p}_{B}$ $\mathrm{Pa}$ Pressure at port B summary_pB ${\mathrm{Δp}}_{\mathrm{summary}}$ $\mathrm{Δp}$ $\mathrm{Pa}$ Pressure drop summary_dp ${q}_{\mathrm{summary}}$ $q$ $\frac{{m}^{3}}{s}$ Flow rate flowing into port_A summary_q ${P}_{\mathrm{hyd}\left(\mathrm{summary}\right)}$ $-\mathrm{Δp}q$ $W$ Hydraulic Power summary_HP ${p}_{\mathrm{sat}}$ [1] $\mathrm{Pa}$ Gas saturation pressure p_sat $\mathrm{\eta }$ [2] $\mathrm{Pa}s$ Upstream dynamic viscosity eta

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

[2] $\mathrm{Modelica.Media.Air.MoistAir.Utilities.spliceFunction}\left(x=\mathrm{Δp},\mathrm{pos}=\mathrm{oil.dynamicViscosity}\left(p={p}_{A\left(\mathrm{abs}\right)},T=T,{v}_{\mathrm{air}}={\mathrm{oil.v}}_{\mathrm{gas}},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right),\mathrm{neg}=\mathrm{oil.dynamicViscosity}\left(p={p}_{B\left(\mathrm{abs}\right)},T=T,{v}_{\mathrm{air}}={\mathrm{oil.v}}_{\mathrm{gas}},{p}_{\mathrm{sat}}={p}_{\mathrm{sat}}\right),\mathrm{Δx}=100\right)$

Connections

 Name Description Modelica ID ${\mathrm{port}}_{A}$ Layout of port where oil flows into an element ($0<{m}_{\mathrm{flow}}$, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_A ${\mathrm{port}}_{B}$ Hydraulic port where oil leaves the component (${m}_{\mathrm{flow}}<0$, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_B $\mathrm{oil}$ oil $\mathrm{opening}$ opening

Parameters

General Parameters

 Name Default Units Description Modelica ID ${\mathrm{ΔT}}_{\mathrm{system}}$ $0$ $K$ Temperature offset from system temperature dT_system

Hydraulic Resistance Parameters

 Name Default Units Description Modelica ID $\mathrm{geometry}$ [1] Choice of geometry for valve geometry valve coefficient [2] Choice of valve coefficient valveCoefficient $\mathrm{Av}$ [3] Av (metric) flow coefficient [Av]=m^2 Av $\mathrm{Kv}$ $\frac{10000000}{277}\mathrm{Av}$ Kv (metric) flow coefficient [Kv]=m^3/h Kv $\mathrm{Cv}$ $\frac{5000000}{123}\mathrm{Av}$ Cv (US) flow coefficient [Cv]=USG/min Cv ${\mathrm{Δp}}_{\mathrm{nominal}}$ $1000$ $\mathrm{Pa}$ Nominal pressure loss dp_nominal ${m}_{\mathrm{flow}\left(\mathrm{nom}\right)}$ [4] $\frac{\mathrm{kg}}{s}$ Nominal mass flow rate m_flow_nominal ${\mathrm{\rho }}_{\mathrm{nominal}}$ $1000$ $\frac{\mathrm{kg}}{{m}^{3}}$ Nominal inlet density rho_nominal ${\mathrm{opening}}_{\mathrm{nominal}}$ $\frac{1}{2}$ Nominal opening opening_nominal ${\mathrm{\zeta }}_{\mathrm{tot}\left(\mathrm{min}\right)}$ $0.001$ Minimal pressure loss coefficient at full opening zeta_TOT_min ${\mathrm{\zeta }}_{\mathrm{tot}\left(\mathrm{max}\right)}$ ${10}^{8}$ Maximum pressure loss coefficient at closed opening zeta_TOT_max ${\mathrm{Δp}}_{\mathrm{small}}$ $\frac{1}{100}{\mathrm{Δp}}_{\mathrm{nominal}}$ $\mathrm{Pa}$ Linearisation for a pressure loss smaller then dp_small dp_small

[1] $\mathrm{Modelica.Fluid.Dissipation.Utilities.Types.ValveGeometry.Ball}$

[2] $\mathrm{Modelica.Fluid.Dissipation.Utilities.Types.ValveCoefficient.AV}$

[3] $\frac{1}{400}\mathrm{\pi }$

[4] ${\mathrm{opening}}_{\mathrm{nominal}}\mathrm{Av}\sqrt{{\mathrm{\rho }}_{\mathrm{nominal}}{\mathrm{Δp}}_{\mathrm{nominal}}}$