Speed Of Sound Measurement In Gaseous Carbon Dioxide At High Pressure And The Development Of Precise Measurement System For Speed Of Sound In Fluids

CO2 is the most important green-house gas. The accurate measurement of the properties of CO2 is needed during the development of the capture and storage technology(CCS). CO2 can be used in different industrial applications.Good understanding of thermophysical properties of carbon dioxide are also nessarsry for the system design and optimizition. Speed of sound is one of the foundamental thermophysical properties which can be measured very accurately, and it can also be used to calculate other themophysical properties. High accuracy measurement and precise characterization of speed of sound in seawater plays important role on ocean acoustical sensors. Developing a precise measurement system for sound of speed in fluids also plays an important role in the establishment the calibration device based on direct measurement of sound speed in seawater.The work did in this paper were showed as follows:(1) The existing experimental device for sound speed measurement using fiexed-length cylindrical resonator had been improved. The highest pressure which can be measured with high accuracy had been increased to 10 MPa. The speed of sound in CO2 had been measured accurately at temprature from 303 K to 353 K and at pressure from 1 MPa to 10 MPa. The precision experimental data of speed of sound in CO2 measured in this work showed a 0.01% to 0.03% discrepancy with the international standard equation of state for CO2 showed good agreement with the only precision published experimental data. The standard relative uncertainty of the measurement was 0.007% at the pressure below 5 MPa and 0.009%(k=1) at the pressure above 5 MPa.(2) An experimental system based on the differential time-of-flight method was built for the measurement of the speed of sound in liquids at high pressure. The double ultrasonic cavities were designed and assembled, the acoustic precision measurement system, liquid filling system with high pressure, pressure and temperature measurement system, and the data acquisition system were established.(3) The speed of sound in pure water was measured at temperature from 303 K to 353 K and at pressure from 2 MPa to 10 MPa.The results had verified the reliability of the experimental system built by this work. The precision experimental data of speed of sound in pure water measured in this work showed a-0.05% to 0.02% discrepancy with the international standard equation of state for pure water with a standard relative uncertainty of 0.018%(k=1), showed good agreement with other published experimental data. The results had verified the reliability of the experimental system built by this work. This system can be used in the measurement of speed of sound in other liquid such as sea water and new fuels in the next future.