Diesel engine start-up method is divided into direct start and auxiliary system start. Direct start mainly for large diesel engines, such as the introduction of high-pressure air directly into the cylinder, the axis of the soul to produce a torque; for small or water-cooled diesel engine, with a rope or hand crank direct start mode has been phased out, and the use of auxiliary system to start . The starting of the auxiliary system is realized through the pinion gear meshing with the gearwheel on the diesel flywheel. The pinion gear is driven by the following methods: (1) Starting the motor The starting motor can adopt DC or AC motor, and the DC motor is usually used 6V, 12V, 24V, 32V motor, the voltage level and the diesel engine specifications, environmental conditions and the speed of the crankshaft. DC motors are usually powered by nickel-cadmium or lead-acid batteries. For fire pump requires two sets of batteries. Battery charging methods are: external AC charger, diesel-powered generator charging, a separate alternator or DC generator charging. In the case of conditions, the AC motor can be used as a starter, AC starter voltage can be: 110V, 220V, 380V. The advantage of this method is to start fast, starting torque. The disadvantage is high investment, high pressure is dangerous. (2) Pneumatic starting method Pneumatic start with air motor and compressed air (or hydrocarbon gas) directly into the cylinder in two ways. The use of compressed air pressure of 0.34 ~ 1.03MPa rotary vane or vane-type air motor, the drive motor to drive the diesel flywheel to drive the diesel engine. Pneumatic start-up mode requires a gas tank to provide the required gas stably, gas can come from the factory pipe network or a separate air compressor. (3) hydraulic motor Hydraulic motor needs a separate hydraulic system to drive the hydraulic system generally mounted on the diesel engine, the hydraulic system includes: fuel tank, hydraulic pump (driven by a diesel engine or a motor), hand pumps, accumulators and so on. When a diesel-driven hydraulic pump or a motor-driven hydraulic pump fails, a hand pump may be used to charge the system. Accumulator capacity can start 6 times considered, according to the need to set up one or more accumulators. (4) Auxiliary engine The diesel engine is started by a small air-cooled or water-cooled engine, and the main diesel engine can be started with a belt and a mounting method similar to other starting methods. The advantage of this method is that no external power source is needed. The disadvantage is the high cost and the need for periodic maintenance. This method of startup is not commonly used.