Isobaric heat capacity of liquid 1,1,1,3,3-pentafluoropropane (R245fa) was measured. Since our group constructed a flow-calorimeter in 1985, specific isobaric heat capacity of liquid refrigerants have been measured for R32, R123, R125, R134a, R142b, and R152a. In 2014, the authors modified the apparatus of flow calorimetry with an improvement for achieving a stable mass-flow-rate by introducing plastic accumulators and two parallel needle valves. The apparatus is able to measure isobaric heat capacity with unmeasurable level small heat loss and good repeatability mostly within 0.4 % (80 % of the data) and the largest 1.5 % from the maximum scatter. The measurements were obtained at 15 points of state parameters, along two 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 value is predicted for each datum as being 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.
ASJC Scopus subject areas
- Chemical Engineering(all)