Fuel System of Diesel Generator Set

Matters needing attention for fuel oil use of diesel generator set.

The diesel generator fuel system should supply clean fuel to the engine continuously. Most installations have a daily tank, a large tank and pump and associated systems.

The installation of separate fuel tanks for fixed generator sets should conform to local specifications.

No smoking, no sparks or flames in the vicinity of fuel. Volatile fuel and oil can explode.

Daily fuel tank

Daily fuel tanks directly feed the generator and should therefore be placed in the generator room. The steel chassis of the minicomputer is equipped with a steel or plastic cylinder with fuel pipe connection to the diesel engine. This kind of bottom tank can provide diesel engine with a minimum of 8 hours full load operation. Or if equipped with super large bottom tank can run for about 24 hours.

Large oil storage tank: in order to extend the running life of the genset, a split large cylinder is required, especially for those spare generator that does not have regular fuel supplies.

Large tanks should generally be placed outside where oil is convenient for refueling and should be easy to clean and inspect, but should not be exposed to areas where winter ice will freeze, as the flow of oil will slow down due to increased viscosity. Oil tank can be placed on the ground or underground.

Large tanks must have air holes to release the pressure caused by the filling tank or by volatilization and expansion. It is also necessary to prevent the production of vacuum due to oil consumption. The bottom of the tank should be round, with a 2-degree tilt to facilitate water and sediment accumulation. Oil tanks buried in the ground should often drain away the water.

The height difference between a large tank and a daily tank is important. Due to the reason that the maximum vertical distance of electric pumping pump is 4 meters. Therefore, the bottom of the large tank should not be below the daily tank level above 4 meter.

Oil delivery way: generator fuel pipes may use any fuel-compatible material such as steel pipes or hoses capable of adapting to any environmental factor.

Note: Fuel systems should not use lead-plated plumbing.

Fuel delivery and back-flow lines should beat least as thick as the openings in the engine, and spillage lines should be the same size. If the pipe is longer, or the ambient temperature is lower, these pipes should be enlarged to ensure smooth flow. Hose connections to diesel engines should be used to prevent damage or oil spills due to machine vibration.

Conveying tubing oil from the top end of the tank at the bottom of not less than 50mm and away from the discharge valve.

Clean oil is the most important for engine life and reliability. The first stage filter shall be installed between the conveying pump and the engine filter. Drain and sediment valves should be at the reverse end of the pump.

Fault diagnosis and analysis of diesel generator fuel system

Due to the reason that the fuel system of diesel generator set is working under the condition of high temperature and high pressure for a long time, it is inevitable that there will be various problem and faults.

Common fault and causes related to diesel generator fuel system are analyzed below.

1. Low pressure gas leakage (if the oil quality meets the requirement, the gas leakage in the low-pressure oil route should be checked.)

(1) Oil pump intake pipe

(2) Diesel oil filter (the first step to check diesel engine power shortage, first should be checked and then clean filter.)

(3) Firewood filter pipe

(4) Hand oil pump (most of the problems occurred there)

(5) Tank vent (to see if it is clogged)

(6) Fuel tank （The oil absorption pipe of the fuel tank is welded to the box body, and the crack or pinhole in the weld will cause the air to leak into the fuel system, which is often ignored.)

2. Governor fault (The manufacturer has adjusted it. No one can move.)

3. Smoke limiter Failure (It is a component that affects the performance of a diesel engine. The manufacturer has adjusted it well and no one can move it. Otherwise, it will affect the power and exhaust smoke of diesel oil generating set.)

The smoke limiter on the smoke limiter uses the air pressure in the intake pipe to adjust the air-fuel ratio to achieve the purpose of controlling smoke. Damage to the smoke limiter will result in insufficient power and increased exhaust smoke. If the air inlet of the intake pipe to the air nozzle of the smoke limitation device is leaked or blocked, it will also cause power loss and smoke exhaust increase.

If the vacuum tube on the smoke limiter breaks, the power of the diesel engine will decrease.

4. Diesel engine low idling adjustment screw can be adjusted. If the idle speed is too low, it will cause the engine to swim at idle speed.

Note: high idle adjustment screw should not be moved at will, otherwise it will cause engine over speed..

5. To determine which cylinder does not work, use the stopping cylinder one by one method to check. After determining which cylinder remove the faulty injector for debugging, and check whether the injector is overloaded with sealed copper gasket. At the same time, check the injector for failure, can be connected to the engine outside the test.

6. Oil return (check the fuel return of the diesel engine at rated speed to determine if there is a problem with the fuel flow.