alarm device
4.The importance of monitoring hydrogen leakage of the water tank for water-hydrogen-hydrogen cooled generator stators is illuminated, and issues about the alarm device for generator water leakage, leakage of the cooling water system for stator winding, and hydrogen leakage detecting by using the air flow meter are discussed.
5.On the bridge main engine instrument board, there is main engine cooling water thermometer, lub oil pressure gauge, main engine revolution indicator, main engine emergency shutdown pushbutton, and there is audible and visual alarm device for main engine lub oil low pressure, cooling water high temperature , gear box lub oil low working pressure.
6.At last, the active and passive methods to prevent helicopter from vortex-ring accident are put forward, and it is pointed that the vortex-ring alarm device is the effective routine to reduce helicopter vortex-ring state flight accident and assure flight safety, and it is suggested to form the system of helicopter vortex-ring prevention.
