Study Of A Proportional Flow Rate Control Valve For High Temperature Gaseous Fuel

The real time regulation of the fuel supply for ramjet engine is important for the improving of the engine's performance and efficiency. The cold liquid fuel is circulated across the engine surface before going into the combustion chamber to decrease the surface temperature of the engine, therefore the temperature of the fuel supply through the flow rate control valve is raised up to be as high as 400~500°C, and most of the liquid fuel becomes gas because of the gasification and decomposition. If a flow rate control valve made of ordinary materials is used to regulate the high temperature medium, because of the different thermal expansion of the valve body and spool, there will be larger leakage or friction force between the valve body and the spool. Therefore the valve may fail to work or the proportional characteristics may be destroyed. So, it's important to analyze and test the static and dynamic characteristics of the high temperature flow rate control valve.In this paper, the mathematical model of the high temperature flow rate control valve is given. The simulation is done using Matlab. The static and dynamic characteristics of the valve are analyzed. The proportional characteristic curve, flowrate-pressure drop characteristic curve and step response characteristic curve are obtained at room and high temperature under different working conditions. Then the results are compared. The AMESim model of the high temperature flow rate control valve is given, and the simulation results are compared with the Matlab's. A flow rate control valve is designed and made of GH783 alloy. The experimental system is set up and the experiment is carried out at two different temperatures. The proportional characteristic curve and step response characteristic curve are obtained and compared with the simulation results.