NEW ENTHALPY INCREMENT FLOW CALORIMETER AND MEASUREMENTS ON A MIXTURE OF 68-PERCENT METHANE AND 32-PERCENT PROPANE

A new flow calorimeter for measuring isobaric enthalphy increment and Joule-Thomson effect was built and tested during the period 1987-1993. The calorimeter has several features that reduce the heat leakage better than previous designs; this includes thermal shields cooled by propane, a heat sink, and superinsulation on all piping. The temperature and pressure range covered by the calorimeter is 133 to 343 K and 0.17 to 14 MPa. Measurements on a mixture of 68.32% methane and 31.68% propane are presented. The enthalpy increment measurements have an average standard uncertainty of 0.08 kJ . kg(-1), or 0.22% of the enthalpy increment.