Fluid flow measurement and control

摘要

In accordance with one embodiment, a controller in a fluid delivery system controls magnitudes of pressure in a first volume and a second volume. The first volume is of a known magnitude. The second volume is of an unknown magnitude and varies. The controller estimates a temperature of gas in the first volume and a temperature of gas in the second volume based on measurements of pressure in the first volume and measurements of pressure in the second volume. The controller then calculates a magnitude of the second volume based on measured pressures of the gases and estimated temperatures of gases in the first volume and the second volume.

主权项

1. A method comprising:
controlling magnitudes of pressure in a first volume and a second volume, the first volume being of a known magnitude, the second volume being of an unknown magnitude; estimating a temperature of gas in the first volume and a temperature of gas in the second volume based on measurements of pressure in the first volume and measurements of pressure in the second volume; and calculating a magnitude of the second volume based on measured pressures and estimated temperatures of the gases in the first volume and the second volume; wherein calculating the magnitude of the second volume includes:
utilizing estimated temperatures of the gas in the first volume and estimated temperatures of the gas in the second volume to account for adiabatic thermal variations of the gas in the first volume and the second volume, the adiabatic thermal variations occurring due to changes in the magnitudes of pressure in the first volume and the second volume.