Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

CALIBRATION AND SIMULATION OF A CAPACITIVE SENSOR FOR VOID FRACTION MEASUREMENTS

Get access (open in a dialog) DOI: 10.1615/IHTC16.mpf.023561
pages 6339-6346

Abstrakt

New experimental data are necessary for developing new heat transfer and pressure drop correlations for designing evaporators for Organic Rankine cycle (ORC) applications. Void fraction measurements are crucial for developing flow-pattern based heat transfer and pressure drop models. For this reason, an accurate calibration procedure is performed on an in-house designed capacitive sensor having a 21 mm inner diameter. For a given experimental condition and working fluid, the flow regime map is created. The sensor is calibrated via a finite element method that includes the flow regime geometries that are expected to be observed. The simulation results are compared with the existing void fraction models from the literature. The considered working fluid is Solkatherm® SES36, which is commercially being used in low-temperature waste heat recovery ORCs (WHR-ORC). The saturation temperature is 120 °C (corresponds to a saturation pressure of 9.83 bar). The mass flux is considered to be between 200-400 kg/m²/s and the heat flux as 20 kW/m². It is found that the simulated capacitance signals are in line with the existing prediction models. Moreover it is observed that the proposed capacitance sensor design is able to detect the flow pattern (due to the capability of detecting the spatial distribution of phases) when combined with the proposed calibration method.