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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.
|
Centrifugal models return the same standard power and airflow outputs as the shared assessment result. Blow-off control also returns blow-off airflow and blow-off fraction. Discharge-pressure adjustment is curve based: a second-order curve is fitted from catalog capacity and pressure points, then evaluated at the requested full-load and optional maximum pressure.
Linear relationship between no-load and full-load power.
The load/unload model anchors the curve at no-load power and full-load power.
\begin{equation}\label{eq:centrifugal-load-unload-airflow-from-power} f_Q = (f_P - f_{P,NL})\frac{1}{1 - f_{P,NL}} \end{equation}
\begin{equation}\label{eq:centrifugal-load-unload-power-from-airflow} f_P = (1 - f_{P,NL})f_Q + f_{P,NL} \end{equation}
| \(f_P\) | Fraction of full-load power \([\unit{ \unitless}]\) |
| \(f_Q\) | Fraction of full-load airflow \([\unit{ \unitless}]\) |
| \(f_{P,NL}\) | No-load power divided by full-load power \([\unit{ \unitless}]\) |
Piecewise model through no-load, unload, full-load, and maximum-flow points.
Power-to-airflow calculations interpolate linearly between no-load and unload until unload power is reached, then interpolate to the maximum-flow point.
\begin{equation}\label{eq:centrifugal-mod-unload-low} f_Q = (f_P - f_{P,NL})\frac{f_{Q,UL}}{f_{P,UL} - f_{P,NL}} \quad \text{for } f_P < f_{P,UL} \end{equation}
\begin{equation}\label{eq:centrifugal-mod-unload-high} f_Q = f_P\frac{1 - f_{Q,base}}{1 - f_{P,UL}} + 1 - \frac{1 - f_{Q,base}}{1 - f_{P,UL}} \quad \text{for } f_P \ge f_{P,UL} \end{equation}
| \(f_{P,NL}\) | No-load power fraction \([\unit{ \unitless}]\) |
| \(f_{P,UL}\) | Unload power fraction \([\unit{ \unitless}]\) |
| \(f_{Q,UL}\) | Unload airflow divided by full-load airflow \([\unit{ \unitless}]\) |
| \(f_{Q,base}\) | Unload airflow divided by maximum airflow \([\unit{ \unitless}]\) |
Useful airflow and blow-off airflow for centrifugal blow-off control.
Below the blow-off power point, useful airflow is the blow-off airflow fraction minus the specified blow-off fraction. Above that point, useful airflow follows a linear segment from the blow-off point to full load.
\begin{equation}\label{eq:centrifugal-blowoff-low} f_Q = f_{Q,BO} - f_{BO} \quad \text{for } f_P \le f_{P,BO} \end{equation}
\begin{equation}\label{eq:centrifugal-blowoff-high} f_Q = \frac{1 - f_{Q,BO}}{1 - f_{P,BO}} \left(f_P - 1 + \frac{1 - f_{P,BO}}{1 - f_{Q,BO}}\right) \quad \text{for } f_P > f_{P,BO} \end{equation}
\begin{equation}\label{eq:centrifugal-blowoff-airflow} Q_{BO} = (f_{Q,BO} - f_Q)Q_{FL} \end{equation}
| \(f_{P,BO}\) | Blow-off package power divided by full-load power \([\unit{ \unitless}]\) |
| \(f_{Q,BO}\) | Blow-off airflow divided by full-load airflow \([\unit{ \unitless}]\) |
| \(f_{BO}\) | User-specified blow-off fraction \([\unit{ \unitless}]\) |
| \(Q_{BO}\) | Calculated blow-off airflow \([\unit{ \acfm}]\) |
| \(Q_{FL}\) | Full-load airflow \([\unit{ \acfm}]\) |
Modules | |
| Centrifugal Load/Unload Formula | |
| Linear relationship between no-load and full-load power. | |
| Centrifugal Modulation/Unload Formula | |
| Piecewise model through no-load, unload, full-load, and maximum-flow points. | |
| Centrifugal Blow-Off Formula | |
| Useful airflow and blow-off airflow for centrifugal blow-off control. | |
Files | |
| file | centrifugal_compressor.h |
| Centrifugal compressor assessment model declarations. | |
1.9.8