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MEASUR-Tools-Suite v1.2.4
The MEASUR Tools Suite is a collection of industrial efficiency calculations written in C++ and with bindings for compilation to WebAssembly.
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MEASUR-Tools-Suite v1.2.4
The MEASUR Tools Suite is a collection of industrial efficiency calculations written in C++ and with bindings for compilation to WebAssembly.
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The compressor assessment modules estimate compressor package power and airflow for centrifugal, modulation, start/stop, load/unload, and variable-frequency-drive compressor controls. The public results are intentionally reported first: calculated package power \([\unit{\kilo\watt}]\), calculated airflow \([\unit{\acfm}]\), power fraction \([\unit{\unitless}]\), and airflow fraction \([\unit{\unitless}]\).
These models are part of a larger compressed-air assessment workflow. They preserve the legacy numerical behavior while exposing namespaced C++ modules, one WebAssembly binding per logical calculator, passive value-object results, and TypeScript declarations with explicit units.
Common result reconstruction from fractions.
Each control model first determines the power and airflow fractions for the requested input basis. The final reported power and airflow are then reconstructed from the full-load reference values.
\begin{equation}\label{eq:compressor-assessment-result-power} P_{calc} = f_P \cdot P_{FL} \end{equation}
\begin{equation}\label{eq:compressor-assessment-result-airflow} Q_{calc} = f_Q \cdot Q_{FL} \end{equation}
| \(P_{calc}\) | Calculated compressor package power \([\unit{ \kilo\watt}]\) |
| \(Q_{calc}\) | Calculated compressor airflow \([\unit{ \acfm}]\) |
| \(f_P\) | Fraction of full-load package power \([\unit{ \unitless}]\) |
| \(f_Q\) | Fraction of full-load airflow \([\unit{ \unitless}]\) |
| \(P_{FL}\) | Full-load package power \([\unit{ \kilo\watt}]\) |
| \(Q_{FL}\) | Full-load airflow \([\unit{ \acfm}]\) |
Three-phase electrical input conversion used by measured electrical methods.
Methods named calculateFromElectrical convert voltage, current, and power factor to measured package power before applying the same model-specific measured-power path. The constant 1.732 is the square root of three rounded to the legacy value.
\begin{equation}\label{eq:compressor-assessment-electrical-power} P_{meas} = \frac{V \cdot I \cdot PF \cdot 1.732}{1000} \end{equation}
| \(P_{meas}\) | Measured three-phase package power \([\unit{ \kilo\watt}]\) |
| \(V\) | Line voltage \([\unit{ \volt}]\) |
| \(I\) | Current \([\unit{ \ampere}]\) |
| \(PF\) | Power factor \([\unit{ \unitless}]\) |
| \(1.732\) | Legacy square-root-of-three constant \([\unit{ \unitless}]\) |
| \(1000\) | Watt-to-kilowatt conversion \([\unit{ \watt\per\kilo\watt}]\) |
Shared pressure and inlet correction for non-centrifugal models.
The pressure/inlet correction updates full-load and maximum power/airflow before model evaluation. Centrifugal compressor models use their discharge-pressure curve adjustment instead. For screw compressors the rated inlet pressure is used as the pressure-ratio base; otherwise atmospheric pressure is used.
\begin{equation}\label{eq:compressor-assessment-pressure-power} P_{adj} = F_P \cdot \frac{P_{atm}}{P_{in}} \cdot BHP_{FL} \cdot \frac{0.746}{\eta} \cdot R_P \end{equation}
\begin{equation}\label{eq:compressor-assessment-pressure-flow} Q_{adj} = F_Q \cdot Q_{rated} \cdot \left(1 - 0.00075(P_d - P_{rated})\right) \end{equation}
\begin{equation}\label{eq:compressor-assessment-pressure-ratio} R_P = \frac{\left(\frac{P_d + P_b}{P_b}\right)^{(n-1)/n} - 1} {\left(\frac{P_{rated} + P_{in,rated}}{P_{in,rated}}\right)^{(n-1)/n} - 1} \end{equation}
When pressure adjustment is enabled, the empirical atmospheric correction factors are:
\begin{equation}\label{eq:compressor-assessment-pressure-factor-power} F_P = -0.0000577P_{atm}^3 + 0.000251P_{atm}^2 + 0.0466P_{atm} + 0.4442 \end{equation}
\begin{equation}\label{eq:compressor-assessment-pressure-factor-flow} F_Q = 0.000258P_{atm}^3 - 0.0116P_{atm}^2 + 0.176P_{atm} + 0.09992 \end{equation}
| \(P_{adj}\) | Adjusted package power \([\unit{ \kilo\watt}]\) |
| \(Q_{adj}\) | Adjusted airflow \([\unit{ \acfm}]\) |
| \(F_P\) | Atmospheric pressure correction for power \([\unit{ \unitless}]\) |
| \(F_Q\) | Atmospheric pressure correction for airflow \([\unit{ \unitless}]\) |
| \(P_{atm}\) | Atmospheric pressure \([\unit{ \psia}]\) |
| \(P_{in}\) | Measured inlet pressure \([\unit{ \psia}]\) |
| \(BHP_{FL}\) | Full-load brake horsepower \([\unit{ \horsepower}]\) |
| \(0.746\) | Horsepower-to-kilowatt conversion \([\unit{ \kilo\watt\per\horsepower}]\) |
| \(\eta\) | Motor efficiency \([\unit{ \unitless}]\) |
| \(R_P\) | Polytropic pressure-ratio correction \([\unit{ \unitless}]\) |
| \(Q_{rated}\) | Rated airflow capacity \([\unit{ \acfm}]\) |
| \(P_d\) | Operating discharge pressure \([\unit{ \psig}]\) |
| \(P_{rated}\) | Rated discharge pressure \([\unit{ \psig}]\) |
| \(P_b\) | Pressure-ratio base pressure \([\unit{ \psia}]\) |
| \(P_{in,rated}\) | Rated inlet pressure \([\unit{ \psia}]\) |
| \(n\) | Polytropic exponent \([\unit{ \unitless}]\) |
Modules | |
| Compressor Assessment Result Formula | |
| Common result reconstruction from fractions. | |
| Compressor Assessment Electrical Formula | |
| Three-phase electrical input conversion used by measured electrical methods. | |
| Compressor Assessment Pressure Inlet Correction | |
| Shared pressure and inlet correction for non-centrifugal models. | |
Files | |
| file | compressor.h |
| Shared compressor assessment enums, result objects, and base utilities. | |
Namespaces | |
| namespace | compressed_air::assessment |
| Compressor assessment performance models and supporting calculations. | |
1.9.8