Hehkutulppajärjestelmä

Hehkutulppajärjestelmä, often translated as glow plug system, is a crucial component in diesel engines. Its primary function is to preheat the combustion chamber before starting the engine, especially in cold weather conditions. Diesel engines rely on compression ignition, meaning the fuel ignites when exposed to sufficiently high temperatures. In cold environments, the engine block and cylinder walls absorb heat, making it difficult to reach the necessary ignition temperature through compression alone.

The hehkutulppajärjestelmä consists of several glow plugs, typically one for each cylinder, and a control unit. Each glow plug is a heating element that glows red hot when electricity is applied. This heat is transferred to the air within the combustion chamber, ensuring that when fuel is injected, it can ignite reliably. The control unit manages the activation and duration of the glow plugs based on factors like ambient temperature and engine coolant temperature.

The operation of the hehkutulppajärjestelmä usually begins with the driver turning the ignition key to the "on" position. The control unit then activates the glow plugs for a specific period, indicated by a warning light on the dashboard. Once the light goes out, the driver can crank the engine. In some modern systems, the glow plugs may also remain active for a short period after the engine has started to improve combustion stability and reduce emissions during the warm-up phase. Proper functioning of the hehkutulppajärjestelmä is essential for reliable cold-start performance and efficient operation of diesel engines.