Diesel Fuel Systems

The fuel system on a diesel engine is a highly specialized set of components which must deliver the correct amount of fuel to the cylinder at the precise moment it is needed. A well-designed fuel system enables the engine to produce maximum power at maximum efficiency with a minimum of exhaust emissions.

Today’s diesel injectors must develop very high injection pressures to function with modern high compression ratio engine designs. They must also control the start and duration of injection within milliseconds to perform at the level demanded by engine customers. These precision injectors require an adequate supply of clean, stable fuel for proper operation. This requirement in turn demands careful attention to the fuel storage and handling systems specified for each installation.

This section discusses the various fuel systems available on current Caterpillar diesel engines, details the numerous fuel storage and handling system options available for diesel fuels, and outlines the advantages, disadvantages, and special considerations which accompany each system.

Diesel Engine Fuel System Descriptions/Components

Caterpillar diesel engines are all furnished with a fuel system based on a conventional design, utilizing unit injectors, but with differing means of injector actuation and control.

The following sections briefly describe the basic fuel system and the three types of injector control systems currently in use.

SECTION CONTENTS

Basic Fuel System................8

• MUI Fuel System • MEUI Fuel System • HEUI Fuel System • Common Rail Fuel System • ACERT Technology

Design Considerations.........12

• Fuel Storage Systems • Fuel Tank Design

Considerations • Fuel Transfer Systems • Fuel Piping Design

Considerations • Fuel Filtration Systems

Miscellaneous Considerations...................30

• Fuel Temperature • Fuel Coolers • Fuel Heaters • Burning Used Crankcase Oil

Fuel Consumption Practices...........................36