Topic Under This Units
      Introduction.
      Requirements of a diesel injection system.
      Classification of injection system.
      Diesel injection systems(jerk pump injectors).
      Nozzles of different types.
      Electronic fuel infection system.
    INTRODUCTION:
     The fuel-injection system is the most vital component in the
     working of CI engine.
     The engine performance, power o/p , economy etc is greatly
     dependent on the effectiveness of the fuel-injection system.
     Basically the purpose of carburetion & fuel-injection is the
     same i.e. preparation of the combustible charge. But in case
     of carburetion fuel is atomized by processes relying on the air
     speed greater than fuel speed at the fuel nozzle , whereas in
     fuel-injection the fuel speed at the point of delivery is greater
     than the air speed to atomize the fuel.
          Requirements of a diesel injection 
          system
          The functional requirements of an injection system are listed 
             below;
            1.  Introduction of the fuel into the combustion chamber
                should take place within a precisely defined period of the
                cycle.
            2.  The metering of amount of fuel injected per cycle should
                done very accurately.
            3.  The quantities of fuel metered should vary to meet the
                changing load & speed requirements.
            4.  The injection rate should be such that it results           in the
                desired heat-release pattern.
            5.  Theinjected fuel must be broken into very fine droplets.