首先给出了以贮箱内气体为对象的一般热力学测量控制方程,完成气体及液体体积的计算;以贮箱系统为研究对象,建立了系统处于等温、绝热及非等温条件下的热力学模型,考虑了气体与液体、贮箱壁的传热传质等因素,得出了比较理想的测量模型。其次,对影响测量的系统误差进行了分析,建立了各种影响因素的误差模型,并提出了相应的修正措施。然后,给出了在现有技术水平下测量的最大误差,结果表明测量误差在贮箱总体积的1%以内。最后,对激励频率、体积改变量大小及测量设备等相关应用技术问题进行了分析讨论与合理设计。体积激励法是一种可满足测量精度和耗能要求的良好方法。
The measurement methods for liquid propellant residue was mainly discussed and the theory of compression mass gauge (CMG) was introduced. Firstly, thermodynamic models were established based on the gas in tank. According to the real thermodynamic process of the gas, the process exponential could be calculated, and the gas and liquid volume could be computed respectively. Then, the thermodynamic models for isothermal, adiabatic and normal conditions were deduced based on the tank system. Heat and mass transfer between gas and tank/liquid were considered. The compression adiabatic model was selected. Secondly, measurement errors were analyzed and the relevant modifications were put forward. Finally, the accuracy for liquid propellant residue volume reached 1% of the total tank volume. The problems were studied, such as the selection of the compression frequency, volume change and measurement equipment. With proper design, CMG is an available method for liquid propellant residue with high accuracy.