Rotary Engine Pilot and Main Fuel Injection Segmentation

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Solution Overview

Problem

Existing internal combustion engines, particularly rotary engines, have suboptimal combustion arrangements and characteristics due to complex configurations required for pilot and main fuel injection, which can be improved for better efficiency and performance.

Innovation Solution

The design incorporates a rotary internal combustion engine with multiple rotatable bodies and separate fuel injection systems for pilot and main fuel, utilizing distinct pressure regulating mechanisms to optimize fuel injection and combustion processes, allowing for efficient fuel distribution and ignition within the engine's combustion chambers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a common rail feeds both pilot and main fuel injection through a single injector with pressure intensification mechanism, then fuel injection functionality is achieved, but device complexity increases

Engineering Contradiction:
Improvefuel injection functionalityVSAvoidinjector configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The fuel injection system is segmented into two separate injectors: a pilot fuel injector and a main fuel injector. Each injector is dedicated to its specific function, eliminating the need for a complex single injector that must perform both pilot and main injection. The pilot injector has a smaller diameter nozzle optimized for pilot injection, while the main injector has a larger diameter nozzle for main fuel delivery, thereby reducing overall device complexity while maintaining full functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pressure intensification mechanism is extracted from the injector assembly and relocated to the common rail system. This allows both pilot and main injectors to be fed directly from the common rail at high pressure without requiring individual pressure intensification mechanisms at each injector, significantly simplifying the injector configuration while maintaining the required injection pressure.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If known combustion arrangements are used in rotary engines, then engine operation is achieved, but combustion efficiency is suboptimal

Engineering Contradiction:
Improveengine operationVSAvoidcombustion efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

A pilot fuel injection is performed before the main fuel injection to pre-ignite a small amount of fuel in the combustion chamber. This pilot combustion creates high-temperature zones that facilitate more complete and efficient combustion of the subsequent main fuel charge, thereby improving overall combustion efficiency and reducing energy losses.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pilot fuel injector is positioned to inject fuel at a specific location within the combustion chamber that creates optimal ignition zones. The separate positioning and sizing of the pilot injector nozzle provide localized high-temperature regions that enhance the combustion characteristics of the main fuel injection, improving overall combustion efficiency.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enhances combustion efficiency by allowing for precise control of fuel injection pressures and volumes, improving engine performance and reducing complexity in fuel injector design, leading to better fuel utilization and engine efficiency.

Implementation Method 1

a pilot fuel injector (45) in fluid communication with the secondary fuel conduit (204) to inject the pilot fuel into the pilot subchamber (72)

Methodology Applied
Scientific EffectFuel injection: Injector

Implementation Method 2

a main fuel injector (42) in fluid communication with the primary fuel conduit (202) to inject the main fuel into the combustion chamber (32)

Methodology Applied
Scientific EffectFuel injection: Injector

Implementation Method 3

The fuel is combusted by pressurizing the fuel in the primary and secondary conduits (202, 204)

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2778367B1Internal combustion engine with pilot and main injection
Publication Date: 2019.05.01 PRATT & WHITNEY CANADA CORP
  • EP2778367B1 patent drawingFigure 1
  • EP2778367B1 patent drawingFigure 2
  • EP2778367B1 patent drawingFigure 3

AI summary

An internal combustion engine with at least two rotatable bodies each defining at least one combustion chamber of variable volume and, for each rotatable body: a pilot subchamber, a pilot fuel injector (78) having a tip in communication with the pilot subchamber, an ignition element positioned to ignite fuel within the pilot subchamber, and a main fuel injector (42) spaced apart from the pilot fuel injector. The engine includes a common first fuel conduit (302) in fluid communication with each main fuel injector (42), and a common second fuel conduit (304) in fluid communication with each pilot fuel injector (78). First and second pressure regulating mechanisms (322,318) which are settable at different pressure values from one another respectively regulate a fuel pressure in the first and second conduits (302,304).