modelPowerFlowCoefficient
Extends from BaseClasses.PartialFlowCoefficient (Partial model describing base flow coefficient).
Information
This model contains calculation procedures for flow coefficients (for more information, please check out AixLib.Fluid.Actuators.Valves.ExpansionValves.BaseClasses.PartialExpansionValve). The calculation procedures based on a power approach and are presented below.
Implemented approaches
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.
| 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
|
References
M. Shanwei, Z. Chuan, C. Jiangping and C. Zhiujiu. (2005): Experimental research on refrigerant mass flow coefficient of electronic expansion valve. In: Applied Thermal Engineering 25(14), S. 2351–2366
X. Zhifang, S. Lin and O. Hongfei. (2008): Refrigerant flow characteristics of electronic expansion valve based on thermodynamic analysis and experiment. In: Applied Thermal Engineering 28(2), S. 2381–243
Li, W. (2013): Simplified modeling analysis ofmass flow characteristics in electronic expansion valve. In: Applied Thermal Engineering 53(1), S. 8–12
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelling approach | |||
| Types.PowerModels | powMod | Types.PowerModels.ShanweiEtAl2005 | Chose predefined power model for flow coefficient |
| Real | a | Multiplication factor for generic power approach | |
| Real[:] | b | Exponents for each multiplier | |
| Integer | nT | size(b, 1) | Number of terms used for the calculation procedure |
| Further geometry data | |||
| Modelica.Units.SI.Diameter | dCle | 0.02e-3 | Clearance diameter dCle = d_inner - d_needle |
| Real | pDifRat | 0.84 | Pressure differential ratio factor depending on valve moddeld |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | opening (from PartialFlowCoefficient) | Current valve's opening | |
| Modelica.Units.SI.Area | AVal (from PartialFlowCoefficient) | Cross-sectional area of the expansion valve | |
| Modelica.Units.SI.Diameter | dInlPip (from PartialFlowCoefficient) | Diameter of the pipe at valve's inlet | |
| Medium.ThermodynamicState | staInl (from PartialFlowCoefficient) | Thermodynamic state at valve's inlet conditions | |
| Medium.ThermodynamicState | staOut (from PartialFlowCoefficient) | Thermodynamic state at valve's outlet conditions | |
| Modelica.Units.SI.AbsolutePressure | pInl (from PartialFlowCoefficient) | Pressure at valves's inlet conditions | |
| Modelica.Units.SI.AbsolutePressure | pOut (from PartialFlowCoefficient) | Pressure at valves's outlet conditions | |
| Real | C (from PartialFlowCoefficient) | Mass flow coefficient used for expansion valves | |
| Real[nT] | P | Array that contains all coefficients used for the calculation procedure | |
| Real | corFact | Corraction factor used to correct flow coefficient |
Revisions
- October 16, 2017, by Mirko Engelpracht, Christian Vering:
First implementation (see issue 457).