How Does Fuel Oil System Work In The Diesel Generator?

6 cylinder water cooled diesel engine generators are currently widely used power generation equipment in the market, mainly used as emergency equipment for chip semiconductors, data centers, finance, communications, hotels, medical, construction, municipal, mining, petrochemical, power plants, national defense and military.

The fuel oil system is the heart of the 6 cylinder high speed water cooled diesel engine. Before running the diesel generator set, everyone must have a certain understanding of the fuel oil system of the diesel generator set and master the method of checking the supply of the fuel oil system.

The fuel oil system needs to continuously supply clean fuel oil to the new stationary 227kw water cooled diesel engine. Most fuel oil supply systems have a daily fuel oil tank, a spare (storage) fuel oil tank and its related piping, etc. In order to simplify the fuel oil supply system, the location of the fuel oil tank should be as close to the generator room as possible. If local construction and fire regulations permit, the fuel oil tank can be installed next to the engine and its capacity should be increased as much as possible.

1. Auxiliary Fuel Oil Supply System

The auxiliary fuel oil supply system consists of a daily fuel oil tank, an auxiliary fuel oil pump, a primary fuel oil filter and its piping system. The primary fuel filter (or oil-water separator) is installed on the side of the auxiliary fuel oil pump inlet. The size of the daily fuel oil tank is determined by 8 times the fuel consumption per hour according to the rated load and speed of the 660kw high speed water cooled diesel engine. More importantly, the fuel oil tank should be large enough to ensure that the fuel temperature is below its evaporation point. The daily fuel oil tank should be as close to the engine as possible. Its main purpose is to maintain the minimum input resistance of the engine fuel delivery pump, the auxiliary fuel oil pump supplies fuel from the reserve fuel oil tank to the daily fuel tank, and the engine fuel oil pump delivers oil from the daily fuel oil tank to the engine fuel injection system, and returns excess oil back to the daily fuel oil tank.

2. Large Fuel Oil Storage System

In order to extend the running time of the unit, a separate spare fuel oil tank needs to be installed. Especially for those spare generators that do not have regular fuel oil supply, it is necessary to consider whether the fuel is sufficient during emergency start of the generator set. The height difference between the spare fuel oil tank and the daily fuel oil tank is very important, because the electric pumping pump has a vertical limit of 4m (13 feet), so the bottom of the large spare fuel oil tank should not be lower than the horizontal height of the daily fuel oil tank by more than 4m.

3. Considerations Factors of Installation

1) The fuel oil tank is usually made of welded steel plate or reinforced plastic, but never use electroplated steel plate (such as galvanized, lead, etc.), because there will be a chemical effect between the fuel and the electroplated layer, causing flaking, and eventually block the oil supply system.

2) Black iron steel pipe should be used for the delivery fuel oil pipe system, the minimum diameter of the fuel oil delivery pipe is 25mm.

3) The fuel oil supply pipe and the fuel oil return pipe should be installed separately to prevent the hot fuel from flowing back. The fuel oil suction pipe should be laid at the lowest point of the fuel oil tank at least 50mm, and away from the sewage valve. The height of the fuel oil return pipe to the fuel oil tank must be kept below 2.5 meters.

4) The lowest point of the oil tank must be equipped with a drain valve to regularly remove water or sediment in the oil tank, and the highest point of the oil tank must be provided with a vent hole;

5) The liquid level of the fuel oil tank should generally not be higher than the fuel oil injection nozzle of the 1800rpm 4 stroke water cooled diesel engine to prevent fuel oil from leaking into the cylinder. If installation at a high position is unavoidable, a 20Kpa differential check valve should be used on the fuel oil supply pipe.

6) If the fuel oil tank is far away from the unit, the temperature is low, or one tank simultaneously supplies oil to several units running in parallel, a larger pipe diameter should be used, or a fuel oil delivery pump should be installed to ensure smooth fuel oil flow.

7) All components of the fuel oil tank must be reliably grounded, and all flange connections must be effectively bridged to prevent the accumulation of static electricity.

8) The installation location should avoid heat sources.

9) A hose connection should be used between the oil pipe and the unit to prevent the vibration of the unit.

10) After the oil pipe is installed, check for oil leakage and exhaust.