A dual-flow choked nozzle based precise pressure controller for high-temperature gas systems

A novel dual-flow choked nozzle based pressure controller is developed to achieve high-precision pressure control. The primary air flow is mainly used for offering the required mass flow to the test section, and the secondary air flow is used for regulating the total mass flow through the choked nozzle to achieve required pressure levels. The test results show that the precision of the stabilization of the pressure can reach +/- 0.005 bar for cold-state environments with air flow at ambient temperature, and +/- 0.015 bar for hot-state environments with air flow temperature in the range of 797.1-931.5 degrees C. Besides, this pressure controller has fast response. A new pressure steady state can be reached within 23.1 s for air flow at ambient temperature and 70 s for hightemperature scenario. Since no moving component exposed to the high-temperature air flow, it is very suitable for the pressurized test rigs with extremely high-temperature gas flow.
QC 20211021