流动量热法测量超临界流体定压比热实验研究

Experimental study on isobaric specific heat capacity of supercritical fluid using flow calorimetry

中文关键词: 流动量热器  超临界  在线测量  比定压热容，

中文摘要:

      超临界流体的比定压热容数据的准确测量对于众多科学研究和工程应用至关重要。基于流动型量热法建立了一套适用于测量在25.00~80.00 ℃ 的温度、0.10~12.00 MPa 压力范围内的比定压热容在线测量实验系统，其测量的扩展相对不确定度为1.66%~2.46%（置信因子k=2）。在使用纯水（工况压力为7.00~12.00 MPa，温度25.00~60.00 ℃）、环己烷（工况压力为2.00~6.00 MPa，温度30.00~80.00 ℃）和CO2（工况压力为6.70~12.00 MPa，温度25.00~70.00 ℃）进行测量的基础上，得到平均绝对偏差分别为0.14%、0.99%和0.78%，最大绝对偏差分别为0.26%、1.32%和2.28%。验证了实验系统的实用性和可靠性，能够为科研和工程设计提供准确的数据测量支持。

英文摘要:

      Accurate measurement of isobaric specific heat capacity(cp) of supercritical fluids is essential for many scientific reasearches and engineering applications.Based on the flow-type calorimetry method,an experiment platform for measuring cp comprising the temperature range of 25-80 ° C and the pressure range of 0.1-12 MPa is constructed. The relative expanded uncertainty of cp was estimated to 1.66%-2.46%(coverage factor k=2).To verify the practicability and reliability of the flow calorimeter method, pure water(7.0-12.0 MPa,25.0-60.0 ℃),cyclohexane(2.0-6.0 MPa,30.0-80.0 ℃) and CO2(6.7-12.0 MPa,25-70 ℃) were tested respectively. The average absolute deviations are 0.14%, 0.99% and 0.78%, and the maximum absolute deviations are 0.26%, 1.32% and 2.28% respectively. The experiment platform can provide accurate data measurement support for future scientific researches and engineering designs.