Basic Principle of PT Oil Supply System for Diesel Generator Set

The fuel of diesel generator set flows through the filter from the oil tank and is sucked in by the gear pump. The fuel pressure discharged from the gear pump is about 980kPa, and then passes through the pressure regulator, governor, throttle valve (throttle) and shut-off valve (stop valve) inside the PT pump, leaving the PT pump assembly. Most of the fuel enters the fuel manifold of the left or right cylinder respectively through the oil supply pipe. Each cylinder head is equipped with a fuel channel, Allow fuel from the fuel manifold to enter the injector.

The diesel generator set fuel injector is controlled by the cam drive mechanism, which injects fuel into the cylinder regularly in sequence. The remaining fuel in the injector returns to the inlet side of PT pump through the fuel return manifold through another return channel drilled on the cylinder head parallel to the inlet channel.

The basic principle for PT type oil supply system to regulate oil supply is that the flow of liquid through a channel is proportional to the pressure of liquid, the time allowed to pass, and the resistance of the channel (section size of the channel). The flow is proportional to the pressure when the resistance of the passage time is constant; When the pressure and resistance are constant, the flow rate is proportional to the allowable passage time; If the pressure and time are constant, the flow is inversely proportional to the resistance. This is essentially an inevitable conclusion derived from Longgang's basic equation of fluid mechanics.

As a single injector, the cross section size of the gauge hole at the inlet is selected and unchanged. Then, the fuel quantity is only proportional to the pressure and injection time, so it can be called PT fuel supply system. In addition, the shape of the injection cam is unchanged. With the angle meter, the angle experienced is unchanged regardless of the speed change, but with the time meter, the fuel entering time is changed, and it becomes shorter with the speed increase, so that the fuel injection quantity is reduced. In this case, if the fuel delivery is to be kept unchanged, the PT fuel pump must be used to increase the fuel inlet pressure of the injector to compensate for the impact of time reduction on the fuel delivery.

Therefore, the fuel delivery pressure of PT fuel pump of diesel generator set changes with engine load and speed, which is the basic principle of using pressure and time to control circulating fuel delivery. Based on the above principles, the whole PT type oil supply system is formed. In this system, PT pump, fuel injector and smoke limiter are worth re discussing.

Jiangsu Starlight Power Generation Equipment Co., Ltd. is an early professional manufacturer of generators and diesel generator sets in China. The company has first-class national-level large-scale production and load testing equipment. Provide users with long-term diesel generator set sales, leasing, technical consultation, commissioning, maintenance, training services and generator set trusteeship business. If you would like to get more information welcome to contact us via sales@dieselgeneratortech.com.