.AixLib.Fluid.Movers.Compressors.UsersGuide.Approaches.VolumetricEfficiency .AixLib.Fluid.Movers.Compressors.UsersGuide.Approaches.VolumetricEfficiencyGenerally, two kinds of calculation approaches can be
identified: A polynomial and a power approach. A generic polynomial
approach is presented below:
ηvol = corFact * sum(a[i]*P[i]^b[i] for i in
1:nT)
A generic power approach is presented below:
ηvol = corFact * a * product(P[i]^b[i] for i in
1:nT)
All volumetric efficiency models presented in this library are
based on a literature review. Therefore, the variable
corFact allows a correction of the volumetric
efficiency if the general modelling approach presented in the
litarature differs from ηvol = V̇ide /
V̇rea.
Calculation procedures presented in the litarture have some
variables in commen and these variables are presented
below:
| Type | Name | Comment |
|---|---|---|
| input | epsRef |
Ratio of the real and the ideal displacement volume |
| input | VDis |
Displacement volume |
| input | piPre |
Pressure ratio |
| input | rotSpe |
Rotational speed |
| input | staInl |
Thermodynamic state at compressor's inlet conditions |
| input | staOut |
Thermodynamic state at compressor's out conditions |
| input | TAmb |
Ambient temperature |
Actually, four polynomial approaches are implemented in this
package. To add further calculation procedures, just add its name
in AixLib.Fluid.Movers.Compressors.Utilities.Types
and expand the if-structure defined in
AixLib.Fluid.Movers.Compressors.Utilities.VolumetricEfficiency.PolynomialVolumetricEfficiency.
| Reference | Formula | Refrigerants | Validity ncompressor |
Validity Πpressure |
|---|---|---|---|---|
| DarrAndCrawford1992 | ηvol = a1 + a2*n -
a3*epsRef*(ρinlIse/ρinl-1) -
a4*n*(ρinlIse/ρinl-1) |
R134a | 40 - 75 |
3 - 10 |
| Karlsson2007 | ηvol = a1*Tinl*π + a2*π + a3 +
a4*Tinl + a5*n + a6*n^2 |
R407c | No information |
No information |
| KinarbEtAl2010 | ηvol = a1 + a2*π |
Generic model | Generic model |
Generic model |
| ZhouEtAl2010 | ηvol = 1 + a1 - a2*π^(1/κ) |
Generic model | Generic model |
Generic model |
| Li2013 | ηvol = ηvolRef * (a1 +
a2*(n/nref) + a3*(n/nref)^2) |
R22,R134a | 30 - 120 |
4 - 12 |
| HongtaoLaughmannEtAl2017 | ηvol = a1 + a2*(n/nref) +
a3*(n/nref)^2 + a4*π + a5*(n/nref)*π +
a6*(n/nref)^2*π + a7*π^2 + a8*(n/nref)*π^2 +
a9*(n/nref)^2*π^2 + a10*pout +
a11*(n/nref)*pout +
a12*(n/nref)^2*pout - a13*pinl -
a14*(n/nref)*pinl -
a15*(n/nref)^2*pinl +
a16*pinl*pout +
a17*(n/nref)*pinl*pout +
a18*(n/nref)^2*pinl*pout +
a19*(n/nref)^3*pinl*pout +
a20*(n/nref)^4*pinl*pout -
a21*pinl^2 - a22*(n/nref)*pinl^2 -
a23*(n/nref)^2*pinl^2 -
a24*(n/nref)^3*pinl^2 -
a25*(n/nref)^4*pinl^2 |
Generic model | Generic model |
Generic model |
| Koerner2017 | ηvol = a1*π^b1 |
R410a | 50 - 120 |
1 - 10 |
| Engelpracht2017 | ηvol = a1 + a2*((π-c1)/c2) +
a3*((Tinl-c3)/c4)*((π-c1)/c2) +
a4*((Tinl-c3)/c4) + a5*((n-c5)/c6) +
a6*((n-c5)/c6)^2 |
Generic model | 0 - 120 |
1 - 10 |
Actually, one power approache is implemented in this package. To
add further calculation procedures, just add its name in AixLib.Fluid.Movers.Compressors.Utilities.Types
and expand the if-structure defined in
AixLib.Fluid.Movers.Compressors.Utilities.VolumetricEfficiency.PowerVolumetricEfficiency.
| Reference | Formula | Refrigerants | Validity ncompressor |
Validity Πpressure |
|---|---|---|---|---|
| MendozaMirandaEtAl2016 | ηvol = a1 * π^b1 *
(π^1.5*n^3*Vdis)^b2 * (Mref/M)^b3 |
R134a,R450a,R1324yf,R1234ze(E) | 0 - 50 |
1 - 6 |