Thermodynamic property measurements of isopentane as a working fluid for high-temperature heat-pumps and ORCs

Abstract

As a working-fluid candidate for high-temperature heat pumps and organic Rankine-cycles (ORCs), isopentane is considered since its normal boiling-point temperature (300.96 K) is slightly lower than n-pentane. Although it is flammable, its negligible GWP (global warming potential) is important benefit to use large amount of the working fluid in industrial energy plants. The thermodynamic equation of state used for an estimation of the cycle performance was developed based on old experimental data especially in the gas-phase. In the present study, therefore, gas-phase PVT properties were newly obtained by using an apparatus with a magnetic levitation densimeter (MLD). The present authors measured 59 gas-phase PVT properties in a temperature range from (290 to 420) K and a pressure range up to 1.45 MPa.