Home : Support : Online Help : MapleSim : MapleSim Component Library : Thermal and Thermal Fluids : Pipes and Valves : componentLibrary/thermal/pipesAndValves/valve

Valve

Simple valve

Description

The Valve component is a two-port thermal-fluid component that models a simple valve. A boolean parameter selects one of two characteristics: linear or exponential. The equations are

 $\frac{\mathrm{Δp}}{{\mathrm{Δp}}_{0}}=\frac{\mathrm{ρ}}{{\mathrm{ρ}}_{0}}\cdot \frac{{V}_{\mathrm{flow}}}{{K}_{v}}\cdot \left|\frac{{V}_{\mathrm{flow}}}{{K}_{v}}\right|$ ${Q}_{\mathrm{flow}}={f}_{L}\cdot \mathrm{Δp}\cdot {V}_{\mathrm{flow}}$ ${y}_{\mathrm{lim}}=\mathrm{max}\left(\mathrm{min}\left(y,{y}_{1}\right),0\right)$

Connections

 Name Description ${\mathrm{flowPort}}_{a}$ Thermal-fluid flow port ${\mathrm{flowPort}}_{b}$ Thermal-fluid flow port $y$ Real signal input that controls the valve

Variables

 Symbol Units Description Modelica ID $\mathrm{Δp}$ $\mathrm{Pa}$ Pressure drop from $a$ to $b$ dp ${Q}_{\mathrm{flow}}$ $W$ Heat addition to flow in pipe Q_flow ${V}_{\mathrm{flow}}$ $\frac{{m}^{3}}{s}$ Volume flow from $a$ to $b$ V_flow ${y}_{\mathrm{lim}}$ - Bounded signal that controls valve yLim

Parameters

 Symbol Default Units Description Modelica ID $\mathrm{medium}$ $\mathrm{fluidMedium}$ - medium $m$ 0 $\mathrm{kg}$ Mass of medium in component m ${T}_{0}$ 293.15 $K$ Initial temperature (parameter hidden when $m=0$) T0 true - Specifies whether component uses the linear or exponential equations LinearCharacteristic ${y}_{1}$ 1 - Maximum valve opening y1 ${K}_{\mathrm{v1}}$ 1 $\frac{{m}^{3}}{s}$ Maximum flow at $y={y}_{1}$ Kv1 ${k}_{\mathrm{v0}}$ 0.01 $-$ Leakage flow / max. flow, at  $0<{k}_{\mathrm{v0}}<1$ kv0 ${\mathrm{Δp}}_{0}$ 1 $\mathrm{Pa}$ Standard pressure drop dp0 ${\mathrm{ρ}}_{0}$ 10 $\frac{\mathrm{kg}}{{m}^{3}}$ Density of standard medium rho0 ${f}_{L}$ 0 - Friction loss factor frictionLoss

Initial Conditions

 Symbol Units Description Modelica ID ${\mathrm{Δp}}_{0}$ $\mathrm{Pa}$ Initial pressure across device dp ${Q}_{\mathrm{flow0}}$ $W$ Initial heat addition to flow Q_flow ${V}_{\mathrm{flow0}}$ $\frac{{m}^{3}}{s}$ Initial volumetric flow through device V_flow