A Study Of Constant Flow Valve With Overpressure Protection Function

Aircraft pressure refueling system is an important part of ensuring the aircraft turnout. Itdecides the frequency of use and effectiveness of the work. Automatic system and valvepiping is used to control the refueling process by the fueling with pressure, in order to makethe refueling process fast and stable. Foreign related refueling equipment had applicationhistory. At present, the constant flow function and overpressure protection function ofdomestic constant flow valve used in aircraft refueling system can not be good to have both.The related research is rather unsatisfactory. Domestic related research was blockaded byforeign technology in this area. Therefore, it is necessary to design a constant flow valve withrelevant function. Based on the content of the task, the paper did many works:Firstly, this paper presents analysis and compares several existing aircraft groundpressure refueling program and the constant flow valve. Then a new solution for itsshortcomings was presented. The constant flow control valve which based on the selfpressure feedback for aircraft refueling system was designed, in order to make the refuelingprocess efficient, fast, safe and convenient. It utilizes the full machinery structure, and takesadvantage of fluid pressure created by itself to control means. It was affected weakly by oilpressure, in order to achieve the purpose of constant flow refueling. In addition, it has thefunction of overpressure protection.Secondly, the structure, operating principle and working process for the valve waselaborated in detail. The math model of the constant flow control valve was established andthe surface equation of the valve core was designed.Thirdly, dynamics modeling for the valve core was established. Vibration of the valvecore and its impact on flow was also analyzed. Furthermore, the stability of motion of thevalve core was proved. Simulation results shows that the valve core of the constant flowcontrol valve will not appear divergent oscillation when the pressure of oil vibrates. It has alow frequency oscillation within a small range and it is still able to maintain the stability ofthe output flow.In the end, with the help of simulation software AMEsim and MATLAB, the sensitivityof some critical parameters was analyzed and the performance of the constant flow controlvalve was verified. The computing output was showed that the constant flow control valve isnot sensitive about some critical parameter such as viscous damping force and the mass of thevalve core, while is comparatively sensitive about spring rate and film tension. The constant flow control valve can maintain a constant output flow perfectly within a given input range.The valve has corking constant flow performance. If the Imported oil pressure or exportoil pressure is too high, the valve will be shut down automatically. The program caneffectively make constant flow function and overpressure protection function of the constantflow fuel valve can be good to have both. Efficiency of aircraft ground pressure refueling canbe improved. The program is easier to control the amount of fuel, and can raise a certainamount of oil in the limited time, contributing to improving the turnout of aircraft.