抄録
Isobaric heat capacity of liquid R245fa was measured. Our group constructed a flow-calorimeter in 1985 for measuring specific isobaric heat capacity of HFC liquid refrigerants. In 2014, the authors modified the apparatus of a flow calorimetry with an improvement for achieving a stable mass-flow-rate by introducing plastic accumulators and two parallel needle valves. We confirmed that the apparatus is able to measure isobaric heat capacity with unmeasurable level heat loss and repeatability within the uncertainty. The measurements were obtained at fifteen points of state parameters along pressures of 500 kPa and 800 kPa in a temperature range from 278 K to 343 K. The expanded uncertainty (coverage factor of k=2) for the heat capacity values is predicted to be between 0.36 and 1.12 %. The purity of the sample liquid R245fa is analyzed as being better than 99.99 % in mass fraction by the manufacture.
