MDE Unit 9 Q10 – Answer

Distillate Fuel Supply System for a Diesel Engine (Including Safety Devices)

A typical distillate fuel supply system for a diesel engine ensures a clean, steady flow of fuel to the engine while incorporating safety features to prevent fires, spills, and other hazards. Here’s a breakdown of the key components and safety devices:

Components:

  1. Fuel Tank: This sturdy container holds the main reserve of diesel fuel. It’s often made of metal to ensure strength and is vented to allow air intake as fuel is consumed.
  • Safety Devices:
    • Filler Cap: A secured cap with a seal prevents fuel spills during transport and storage.
    • Vent Line: This line allows air into the tank as fuel is used, preventing a vacuum that could hinder fuel flow. It may incorporate a flame arrester to prevent external ignition sources from reaching the fuel tank interior.
  1. Fuel Day Tank (Optional):  Some systems utilize a smaller day tank mounted closer to the engine. This tank serves as a buffer and provides a more consistent fuel supply to the engine.
  2. Fuel Lines:  Durable hoses or pipes carry fuel from the tank to the engine.
  • Safety Devices:
    • Material: Fuel lines are made of materials resistant to fuel degradation and able to withstand operating pressures.
    • Clamps and Connections: Secure clamps ensure tight connections at all points to prevent leaks.
  1. Fuel Filter (Primary):  This filter removes larger particles like dirt, rust, and debris from the fuel before it enters the engine.
  2. Fuel Transfer Pump (Optional):  Some systems, especially those with high fuel consumption or located higher than the engine, might utilize a pump to ensure a consistent flow of fuel to the engine.
  3. Fuel Shutoff Valve:  This manually operated valve allows for stopping fuel flow to the engine for maintenance or emergency shutdowns.
  • Safety Device: This valve serves as a critical safety measure to isolate the fuel system in case of emergencies.
  1. Secondary Fuel Filter (Optional):  Some systems might have an additional, finer filter located closer to the engine to remove any remaining microscopic contaminants.
  2. Fuel Injection Pump:  This pump pressurizes the fuel and delivers it to the engine’s injectors at high pressure.
  3. Fuel Injection System:  This system meters and injects the pressurized fuel directly into the engine cylinders at the appropriate time during the combustion cycle.

Additional Safety Considerations:

  • Fuel Line Routing: Fuel lines should be routed away from heat sources and protected from physical damage.
  • Spill Containment: A spill tray or pan can be placed under the fuel filter or other potential leak points to contain any spills.
  • Regular Maintenance: Regular inspection and replacement of fuel filters and other components are crucial to ensure proper system function and prevent issues.

By incorporating these components and safety devices, a distillate fuel supply system ensures a clean and reliable fuel source for the diesel engine while minimizing the risk of fires, leaks, and other hazards.