.AixLib.Fluid.Movers.Compressors.UsersGuide.Approaches.VolumetricEfficiency .AixLib.Fluid.Movers.Compressors.UsersGuide.Approaches.VolumetricEfficiency
Generally, 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
|