Check Valve $—$ Spring-loaded check valve with laminar/turbulent flow

The Check Valve component describes a spring-loaded check valve with laminar/turbulent flow. The resistance depends on the pressure differential, $\mathrm{Δp}={p}_{A}-{p}_{B}$:

 $\mathrm{Δp}<{p}_{\mathrm{closed}}$ Leakage from high pressure port to low pressure port only. $q=\mathrm{Δp}{G}_{\mathrm{leak}}$ ${p}_{\mathrm{closed}}<\mathrm{Δp}$ $<$ ${p}_{\mathrm{open}}$ Valve is partially open. ${p}_{\mathrm{open}}<\mathrm{Δp}$ Valve is wide open. Flow mode depends on Reynolds number. Resistance modeled as an orifice in parallel with laminar resistance.

In some cases it is either necessary or helpful to include the dynamics of a check valve: the poppet needs some time to close or open the flow path. This effect is modeled by a first order system. The parameter tau_ball (found in the General section under the Properties tab ( )) gives the time to open or close the valve 95%.

The mass and flow forces are not included. Use the modifier(s)

VolumeA(port_A(p(start=1e5,fixed=true)))

and/or

VolumeB(port_A(p(start=1e5,fixed=true)))

to set the initial condition(s) for the pressure of the lumped volume(s) $\left[\mathrm{Pa}\right]$.

Related Components

 Name Description Spring-loaded check valve with laminar/turbulent flow (different characteristic) Ideal spring-loaded check valve with laminar/turbulent flow, additional information

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

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 ${V}_{A}$ VolumeA ${V}_{B}$ VolumeB $\mathrm{ChVnSDyn}$ ChVnSDyn $\mathrm{ChVnS}$ ChVnS

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

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

Parameters

General Parameters

 Name Default Units Description Modelica ID ${\mathrm{ΔT}}_{\mathrm{system}}$ $0$ $K$ Temperature offset from system temperature dT_system use volume A $\mathrm{true}$ If true, a volume is present at port_A useVolumeA use volume B $\mathrm{true}$ If true, a volume is present at port_B useVolumeB ${V}_{A}$ ${10}^{-6}$ ${m}^{3}$ Geometric volume at port A volumeA ${V}_{B}$ ${10}^{-6}$ ${m}^{3}$ Geometric volume at port B volumeB ${p}_{\mathrm{closed}}$ ${10}^{5}$ $\mathrm{Pa}$ Pressure to start opening the valve pclosed ${G}_{\mathrm{leak}}$ ${10}^{-12}$ $\frac{{m}^{3}}{s\mathrm{Pa}}$ Conductance of leakage GLeak $\mathrm{orif}$ $1$ Orifice dimension orif $d$ $0.001$ $m$ Diameter of equivalent orifice diameter $\mathrm{area}$ $0.001$ ${m}^{2}$ Area of the equivalent orifice area ${p}_{\mathrm{nom}}$ ${10}^{6}$ $\mathrm{Pa}$ Nominal pressure drop pnom ${q}_{\mathrm{nom}}$ $1.89·{10}^{-5}$ $\frac{{m}^{3}}{s}$ Nominal volume flow rate qnom ${\mathrm{\rho }}_{\mathrm{nom}}$ $865$ $\frac{\mathrm{kg}}{{m}^{3}}$ Nominal density rhonom ${\mathrm{\tau }}_{\mathrm{ball}}$ $0$ $s$ Time to open or close check valve 95% tau_ball

Fully Open Parameters

 Name Default Units Description Modelica ID $\mathrm{Transition}$ $1$ Transition model Transition ${k}_{1}$ $10$ Laminar part of orifice model k1 ${k}_{2}$ $2$ Turbulent part of orifice model, ${k}_{2}=\frac{1}{{C}_{d}^{2}}$ k2 ${C}_{d}$ $0.707$ Max discharge coefficient C_d

Partially Open Parameters

 Name Default Units Description Modelica ID reg type $2$ Regularization type regtype $G$ $1.53·{10}^{-11}$ $\frac{{m}^{3}}{s\mathrm{Pa}}$ Hydraulic conductance $G=\frac{\mathrm{∂q}}{\mathrm{∂p}}$ G ${\Re }_{\mathrm{trans}}$ $100$ Transition Reynolds number Re_trans ${p}_{\mathrm{open}}$ $1.25·{10}^{5}$ $\mathrm{Pa}$ Pressure to open valve completely popen reg param $3$ Regularization parameter regparam