Acoustic flow rate measurements
The thermodynamic efficiency measurement reaches its limits for low heads below 100 m. To determine an absolute efficiency for low head plants, we offer acoustic transit time flow rate measurement. For this method the propagation times of acoustic pulses crossing the flow field along an adequate number of acoustic paths are used for integration of discharge. Furthermore, for efficiency calculation accurate measurement an electric power and head measurement are needed.
etaeval possesses sensors and control units of Rittmeyer and Accusonic for measurements in closed conduits and open channels. We recommend to use for efficiency measurements at least 8 acoustic paths (16 sensors),. Our measurement installations are intended for temporary use. If required, we clarify a permanent installation for the customer.
Features of acoustic transit time flow measurement:
- determination of absolute efficiency
- suited for pumps and turbines
- no restrictions regarding head
- direkte Messung des Volumenstromes
Numerical flow simulations are recommended for flow rate measurement in short intakes to determine the weights of each acoustic path for the integration of discharge and for optimum positioning of sensors. Such simulations should be carried out in advance of measurements.