.AixLib.Fluid.Movers.Compressors.Utilities.EngineEfficiency .AixLib.Fluid.Movers.Compressors.Utilities.EngineEfficiency
This package contains models describing calculations procedures of
engine efficiencies that are based on a literature review. However,
in this library the engine efficiency is implemented in such a way
that it fulfills
ηeng = Q̇ref / Pel.
For more information, please checkout
AixLib.Fluid.Movers.Compressors.BaseClasses.PartialCompression.
Calculation procedures presented in the litarture have some variables
in commen and these variables are presented below:
| Variable | Comment |
|---|---|
epsRef
|
Ratio of the real and the ideal displacement volume |
VDis
|
Displacement volume |
piPre
|
Pressure ratio |
rotSpe
|
Rotational speed |
staInl
|
Thermodynamic state at compressor's inlet conditions |
staOut
|
Thermodynamic state at compressor's out conditions |
TAmb
|
Ambient temperature |
Moreover, two approaches can be identified in general: A polynomial and a power approach. The characteristics of these approaches are presented below.
A generic polynomial approach is presented below:
ηeng = corFact * sum(a[i]*P[i]^b[i] for i in
1:nT)
Actually, four polynomial approaches are implemented in this
package.
A generic power approach is presented below:
ηeng = corFact * a * product(P[i]^b[i] for i in
1:nT)
Actually, one power approache is implemented in this package.
In the following, some general references are given for information about calculating efficiencies of compressors:
V. A. Cara Martin and R. Radermacher (2015): AHRI Project 8013: A Study of Methods to Represent Compressor Performance Data over an Operating Envelope Based on a Finite Set of Test Data. Publisher: Air-Conditioning, Heating, and Refrigeration Institute (AHRI)
| Name | Description |
|---|---|
 PartialEngineEfficiency | Based model used by all models describing engine efficiencies |
 PolynomialEngineEfficiency | Model describing engine efficiency based on polynomial approach |
 PowerEngineEfficiency | Model describing flow engine efficiency on power approach |
 SpecifiedEfficiencies | Package that engine efficiencies that are specifiied |