Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
DIELETRIC CONSTANT OF A NEAR-AZEOTROPIC HFC BLEND (R410A) IN LIQUID AND GAS PHASE
Submission Author:
Ricardo Augusto Mazza , SP
Co-Authors:
Ricardo Augusto Mazza
Presenter: Ricardo Augusto Mazza
doi://10.26678/ABCM.ENCIT2016.CIT2016-0146
Abstract
The dielectric constant or relative permittivity of one environmentally acceptable near-azeotropic HFC blend (R410a) was evaluated experimentally. The temperatures and pressure spans from 279 to 323 K and 1 to 22 MPa to cover the liquid and gaseous states. A pressure-tight concentric cylinders cell was designed and manufactured taking account the standards and literature recommendations. The gas and liquid capacitance measurement was performed by a commercial LCR bridge meter. The electrical connection was made according to the recommendations of LCR manufacturer. Two well know substance was tested to calibrate the cell and validate the experimental procedure. The results of the dielectric constant measurement of R410a liquid phase were in agreement with the results given in literature. The liquid phase dielectric constant decreases with increasing temperature and is 30% higher at the lowest tested temperature than at the highest. The dielectric constant for the gas phase remains almost constant and it is at least 7.6 times lower than for the liquid phase. The results show that it is possible to identify the R410a liquid and gas phases using their electrical properties, which it is very useful in many two-phase flow studies like in flow pattern recognition.
Keywords
Dielectric properties, relative permittivity, dielectric measurements, R410a refrigerants
