.AixLib.Fluid.Actuators.Valves.ExpansionValves.UsersGuide.Approaches.PowerApproach .AixLib.Fluid.Actuators.Valves.ExpansionValves.UsersGuide.Approaches.PowerApproach
A generic power approach is presented below:
C = corFact * a * product(P[i]^b[i] for i in 1:nT)
All flow coefficient models presented in this library are based on a
literature review. Therefore, the variable corFact allows
a correction of the flow coefficient if the general modelling approach
presented in the litarature differs from ṁ =
C*Avalve*sqrt(2*ρinlet*dp).
Calculation procedures presented in the litarture have some variables
in commen and these variables are presented below:
| Variable | Comment |
|---|---|
A
|
Cross-sectional flow area |
dinlet
|
Diameter of the pipe at valve's inlet |
pinlet
|
Pressure at valve's inlet |
poutlet
|
Pressure at valve's outlet |
ρinlet
|
Density at valve's inlet |
ρoutlet
|
Density at valve's outlet |
Tinlet
|
Temperature at valve's inlet |
μinlet
|
Dynamic viscosity at valve's inlet |
σinlet
|
Surface tension at valve's inlet |
Coutlet
|
Specific heat capacity at valve's outlet |
hfg
|
Heat of vaparisation |
Actually, three power approaches are implemented in this package.
To add further calculation procedures, just add its name in
AixLib.Fluid.Actuators.Valves.ExpansionValves.Utilities.Choices
and expand the if-structure defined in
AixLib.Fluid.Actuators.Valves.ExpansionValves.Utilities.FlowCoefficient.PolynomialFlowCoefficient.
| Reference | Formula | Refrigerants |
Validity Tcondensing
|
Validity Tevaporating
|
Validity Tsubcooling
|
|---|---|---|---|---|---|
| ShanweiEtAl2005 |
C = a * a * (A/dclearance^2)^b1 *
((pinlet-poutlet)/pcrit)^b2
* (Tcrit/Tsubcooling)^b3 *
(rhoinlet/rhooutlet)^b4 *
(quality)^b5
|
R22, R407C, R410A
|
40 - 50 °C
|
0 - 10 °C
|
1.5 - 10 °C
|
| ZhifangAndOu2008 |
C = a * ((pinlet-poutlet) *
sqrt(A)/σinlet)^b1 *
(dinlet*sqrt(ρinlet *
pinlet)/μinlet)^b2
|
R134a
|
31 - 67.17 °C
|
no information
|
0 - 20 °C
|
| Li2013 |
C = a * (opening)^b1 *
(Tsubcooling/Tcrit)^b2
|
R22, R407C, R410A
|
30 - 50 °C
|
0 - 30 °C
|
1.5 - 15 °C
|