When the turbine releases the throttle, there is a loud deflation sound. Why?

When the turbine loosens the throttle, there is a loud deflation sound, which is the working sound of the pressure relief valve. Introduce the following reasons: 1. Working principle of the turbine: When the fuel filling valve starts to work, the turbine compresses a large amount of air and pushes it into the engine combustion chamber through the throttle. When the driver releases the accelerator pedal, the throttle valve closes. However, the blades of the turbine will not stop working immediately. At this time, there is still residual compressed air in the intake pipe between the turbine and the throttle. If the air is not exhausted in time, the strong pressure will damage the throttle and turbine blades. 2. Function of the pressure reducing valve: When the valve of the pressure reducing valve detects that the air pressure in the air inlet pipeline is too high, it will release the residual compressed air in the air inlet pipeline in time, thus protecting the throttle and turbine blades. It also reduces the occurrence of turbine delay and makes the engine work more smoothly. Air noise is the "noise" produced when the pressure reducing valve discharges compressed air. "