The fuel regulator is a mechanism that adjusts the fuel supply of the engine to reasonably match the working state of the engine. Composed of several independent regulator combinations, including height regulator, throttle regulator, acceleration regulator, idle controller, temperature regulator, and other auxiliary adjustment devices. The purpose is to ensure reliable fuel supply at different flight altitudes, speeds, atmospheric temperatures, and pressures, as well as at different engine speeds and any changes in engine operating conditions, in order to ensure stable combustion, no stalling, no surge in the intake duct and compressor, and no over speed, over temperature, and stable engine operation. The latest development adopts a fully functional digital control system, which uses electronic digital computers to comprehensively control the operating conditions of the engine.
Classification
Fuel regulators can be divided into spray and afterburner fuel regulators. To improve the takeoff, climb, and combat performance of an aircraft, increasing the engine thrust in a short period of time is called boosting. There are two methods for boosting power: water spraying and supplementary combustion.
Spray coolant into the engine to reduce air temperature, increase air density, and increase engine thrust. Generally, water, alcohol, methanol or a mixture of water/alcohol, water/methanol, etc. are injected into the engine intake duct, compressor inlet, and combustion chamber inlet.
Inject fuel into the space between the turbine and the tailpipe for supplementary combustion, utilizing the remaining oxygen in the gas to combust again, increasing the exhaust velocity, and obtaining significant additional thrust in a short period of time. For engines with supplementary combustion and boost, a boost regulator is specially installed to provide suitable fuel for the boost combustion chamber, and to work together with the nozzle to ensure that the engine's main engine state remains unchanged.
Working principle
The fuel regulator is a mechanical hydraulic regulator consisting of over 100 components. According to the schematic diagram of this type of fuel regulator, it consists of a starting controller, an acceleration controller, a deceleration controller, a steady-state controller, a temperature compensation device, and an emergency device. The working principles of each part are as follows:
1) Startup controller: During the startup process, the pilot pushes the throttle lever according to the engine status, driving the main throttle switch and the startup cam, so that the opening of the regulator metering oil needle is determined by the startup cam surface during the startup process. The start-up process ends (a>a0) and enters other working states. The opening of the fuel metering needle is controlled by other devices.
2) Acceleration controller: During the acceleration control process, the acceleration controller diaphragm box senses atmospheric pressure P. And the pressure difference of the outlet pressure P of the engine compressor, as well as the participation of the diaphragm top rod in controlling the opening of the fuel metering needle. After the engine reaches steady state, the steady-state controller takes over the acceleration controller and enters the steady-state control phase.
3) Deceleration controller: During the deceleration control process, the deceleration controller diaphragm module senses atmospheric pressure P. The pressure difference between the outlet pressure P of the engine compressor and the metering needle is controlled by the pressure balance spring through the reverse top rod to ensure that the fuel supply is supplied according to the deceleration fuel supply law determined by the deceleration controller during the deceleration process, so as not to cause the engine to run out due to fuel shortage caused by the fuel regulator reducing the fuel too quickly.
