Diesel plant components and fuel supply

A diesel power plant uses a compression-ignition engine as prime mover to drive an alternator. Its main components are shown below.

 Air filter -> Intake    Exhaust -> Silencer -> Stack
                 |          ^
 Fuel system +---v----------+---+  coupling  +-----+
 ----------->| DIESEL ENGINE    |===========| Alt |->Bus
             +--+-----------+---+           +-----+
                |           |                  |
          Cooling system  Lube system       Exciter
       (pump, HX, tower)  (pump, filter, cooler)
     Starting system: compressed air / battery-motor
     Governor controls fuel to hold speed

Main components

1. Diesel engine: prime mover (2- or 4-stroke).
2. Alternator and exciter: convert mechanical power into electrical power.
3. Fuel supply system: stores, filters and injects fuel.
4. Air intake system: air filter, ducts, supercharger.
5. Exhaust system: manifold, silencer, chimney.
6. Cooling system: pumps, heat exchanger, cooling tower/radiator.
7. Lubrication system: oil pump, filter, cooler.
8. Starting system: compressed air or electric starter.
9. Governor and control panel.

Fuel supply system

 Storage tank -> transfer pump -> strainer -> Day tank
   -> fine filter -> booster pump -> injection pump
   -> injectors -> cylinders   (surplus back to day tank)

1. Storage tanks hold bulk fuel received from tankers through an unloading pump.
2. Transfer pump and strainer move fuel to the day tank, which holds a few hours' supply close to the engine.
3. Fine filters remove dirt and water to protect the injection pump and nozzles.
4. Booster pump feeds fuel at low pressure to the fuel injection pump.
5. The injection pump raises the pressure (about 100–200 bar) and meters the quantity set by the governor.
6. Injectors atomise the fuel into hot compressed air at the end of the compression stroke, where it self-ignites.

Injection arrangements: common rail (one pump, common high-pressure header), individual pump for each cylinder (most common), and distributor system.