采用低温流体氘和氧的介电常数测量流体的密度

DENSITY MEASUREMENT OF CRYOGENIC FLUIDS D_2 AND O_2 BY DIELECTRIC CONSTANT METHOD

为测量低温流体在不同受控状态下的密度,设计了一套基于G-M低温制冷机的介电常数法低温流体密度测量实验装置,该实验装置适用温度测量范围为15~300 K,压力测量范围0.01~0.30 MPa。实验中的低温液体由常温气态流体经低温制冷机冷却液化得到,蓄流在装有平行板电容器的样品流体测试腔内。该测试腔上开有视窗,可用于观察冷却过程中低温液体的形成及其液位情况。对受控压力及温度下的液氘、液氧的密度进行了测量,所得数据与文献实验值及美国NIST标准数据吻合良好,液相区相对偏差小于±0.5%,满足高精度p-ρ-T热物性参数的需要。

In order to measure the density of cryogenic fluids in different states,an experimental setup for densitymeasurement of cryogenic fluids by dielectric constant method has been designed and fabricated to measure the ensity ofdeuterium and oxygen,with a two-stage G-M cryocooler as the cold source. The system is applicable for the temperaturerange of 15-300 K,and pressure range of 0.01-0.3 MPa. The experimental liquid is obtained through liquefaction of thegas by the cryocooler and then stored in the sample fluid test cell,in which the parallel plate capacitor is positioned. Thetest cell is embedded with an optical window,which can be used to observe the formation of liquid and its level during thecooling process. The densities of liquid deuterium and liquid oxygen under controlled pressure and temperature have beenmeasured. The liquid phase measurement agree with the experimental data in literature and the NIST reference data within± 0.5%,which meets the accuracy requirement of high quality p-ρ-Tproperty measurement.