modelGeneric_VarRef_VarDisVol_RotaryScroll
Generic overall engine efficiency based on literature review for
various compressors
Extends from PolynomialEngineEfficiency (Model describing engine efficiency based on polynomial approach).
Information
This model contains a calculation procedure for the engine efficiency
presented by Engelpracht (2017). However, this approach is just
fitted to various experimental data obtained by a literature review
and, therefore, to use with caution.
| Reference | Formula | Refrigerants |
Validity ncompressor
|
Validity Πpressure
|
|---|---|---|---|---|
| Engelpracht2017 |
ηeng = a1 + a2*π + a3*π^2 + a4*n*π + a5*n^2
+ a6*π^2*n + a7*π*n^2 + a8*n^3 + a9*π^2n^2 + a10*π*π^3 +
a11*n^4
|
Generic model |
0 - 120
|
1 - 10
|
References
Engelpracht, Mirko (2017): Development of modular and scalable simulation models for heat pumps and chillers considering various refrigerants. Master Thesis
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | useIseWor (from PartialEngineEfficiency) | false | = true, if isentropic work is used to compute compressor's power consumption |
| Modelling approach | |||
| Types.EnginePolynomialModels | polyMod (from PolynomialEngineEfficiency) | Types.EnginePolynomialModels.DurprezEtAl2007 | Chose predefined polynomial model for flow coefficient |
| Real[:] | a (from PolynomialEngineEfficiency) | Multiplication factors for each summand | |
| Real[:] | b (from PolynomialEngineEfficiency) | Exponents for each summand | |
| Integer | nT (from PolynomialEngineEfficiency) | size(a, 1) | Number of terms used for the calculation procedure |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Efficiency | epsRef (from PartialEfficiency) | Ratio of the real and the ideal displacement volume | |
| Modelica.Units.SI.Volume | VDis (from PartialEfficiency) | Displacement volume | |
| Real | piPre (from PartialEfficiency) | Ratio of compressor's outlet and inlet pressure | |
| Modelica.Units.SI.Frequency | rotSpe (from PartialEfficiency) | Compressor's current rotational speed | |
| Medium.ThermodynamicState | staInl (from PartialEfficiency) | Thermodynamic state at compressor's inlet | |
| Medium.ThermodynamicState | staOut (from PartialEfficiency) | Thermodynamic state at compressor's outlet | |
| Modelica.Units.SI.Temperature | TAmb (from PartialEfficiency) | Ambient temperature | |
| Modelica.Units.SI.Efficiency | etaEng (from PartialEngineEfficiency) | Overall engine efficiency | |
| Real[nT] | p (from PolynomialEngineEfficiency) | Array that contains all coefficients used for the calculation procedure | |
| Real[2] | corFac (from PolynomialEngineEfficiency) | Array of correction factors used if efficiency model proposed in literature differs from efficiency model defined in PartialCompressor model |
Revisions
- October 23, 2017, by Mirko Engelpracht:
First implementation (see issue 467).