diff --git a/IBPSA/Fluid/FixedResistances/CheckValve.mo b/IBPSA/Fluid/FixedResistances/CheckValve.mo index 6e5196f446..d4b33efb80 100644 --- a/IBPSA/Fluid/FixedResistances/CheckValve.mo +++ b/IBPSA/Fluid/FixedResistances/CheckValve.mo @@ -140,19 +140,17 @@ The basic flow function ṁ = sign(Δp) k √ Δp  ,

-with regularization near the origin, is used to compute the pressure drop. -The flow coefficient -

-

- k = ṁ ⁄ √ Δp   -

-

-is increased from l*KV_Si to KV_Si, -where KV_Si is equal to Kv but in SI units. -Therefore, the flow coefficient k is set to a value close to zero for negative pressure differences, thereby -restricting reverse flow to a small value. -The flow coefficient k saturates to its maximum value at the pressure dpValve_closing. -For larger pressure drops, the pressure drop is a quadratic function of the flow rate. +with regularization near the origin, is used to compute the mass flow rate +through the fully closed and fully open valve, respectively. +The valve is considered fully closed when subjected to a negative pressure drop, +and its flow coefficient k is then equal to l * Kv_SI +where Kv_SI is equal to Kv but in SI units. +The valve is considered fully open when the pressure drop exceeds +dpValve_closing, +and its flow coefficient k is then equal to Kv_SI. +For valve positions between these two extremes, a quintic spline interpolation +is applied to determine the mass flow rate as a function of +the pressure drop across the valve.

Typical use and important parameters

@@ -183,8 +181,13 @@ by default. ", revisions="