Water Injection System for Internal Combustion Engine Load Optimization

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Solution Overview

Problem

Existing methods for water injection in internal combustion engines lack optimization across different load ranges and operating modes, leading to suboptimal performance and fuel consumption.

Innovation Solution

A method where water is injected exclusively into the combustion chamber and fuel is injected either directly into the combustion chamber or intake manifold, with varying timing and flow rates based on load ranges, allowing for optimized performance and fuel efficiency through a system with separate injectors and control valves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If water is injected into the combustion chamber at full load, then cooling effect is achieved and engine performance is increased, but fuel consumption increases and water usage increases

Engineering Contradiction:
Improveengine performanceVSAvoidfuel consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts water injection parameters (flow rate, timing, duration) based on engine load conditions. At full load, water injection is activated with optimized parameters to achieve cooling effect and improve performance. At partial loads, water injection is suspended or reduced, minimizing fuel consumption impact and water usage while maintaining acceptable performance levels.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If water is injected at all load ranges, then cooling effect is continuously achieved, but water consumption increases unnecessarily and fuel efficiency decreases

Engineering Contradiction:
Improvecombustion temperature controlVSAvoidwater consumption
Core Design Contradiction:
TemperatureVSLoss of substance

Solution Approach 1:

The water injection system operates dynamically based on real-time engine load conditions. The control unit activates water injection only when engine load exceeds a predetermined threshold (full load conditions). At partial loads, water injection is suspended, optimizing the balance between combustion temperature control and water consumption, thereby improving overall fuel efficiency without compromising necessary cooling when required.

Inventive Principle:
Principle #15Dynamics

3Productivity

If fuel is injected into both combustion chamber and intake manifold simultaneously, then combustion efficiency is improved, but system complexity increases and control difficulty increases

Engineering Contradiction:
Improvecombustion efficiencyVSAvoidinjection system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The injection system is segmented into two independent injection paths: one for fuel injection into the combustion chamber and another for fuel injection into the intake manifold. The control unit independently manages each injection path based on engine operating conditions, allowing flexible control of combustion efficiency without requiring complex integrated control, thereby maintaining system simplicity while achieving optimal combustion performance.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If water injection timing is synchronized with fuel injection timing, then combustion control is simplified, but cooling effectiveness is reduced

Engineering Contradiction:
Improveinjection control simplicityVSAvoidcooling effectiveness
Core Design Contradiction:
Ease of operationVSPower

Solution Approach 1:

The water injection timing is offset from fuel injection timing, with water injected slightly before the fuel injection event. This preliminary water injection allows the water to begin evaporating and absorbing heat before the fuel combustion occurs, maximizing the cooling effectiveness. The control unit independently manages the timing of water and fuel injection, achieving optimal cooling without requiring simplified synchronized control.

Inventive Principle:
Principle #10Preliminary action

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 approach enhances engine performance and reduces fuel consumption by providing a cooling effect and optimizing combustion in various operating conditions, while minimizing water usage and ensuring efficient engine operation across its entire range.

Implementation Method 1

an injection of water in addition to the actual fuel can have a favorable effect on the driving characteristics, for example by achieving a cooling effect

Methodology Applied
Scientific EffectEvaporative cooling: Evaporative Cooler

Data Source

PatentEP2789839B1System and method for water injection for an internal combustion engine
Publication Date: 2016.07.13 BAYERISCHE MOTOREN WERKE AG
  • EP2789839B1 patent drawingFigure 1
  • EP2789839B1 patent drawingFigure 2

AI summary

A water injection system for an internal combustion engine (12) has first injectors (16) that each inject a liquid directly into a combustion chamber (14) of the internal combustion engine (12) and second injectors (24) that each inject a liquid into an intake manifold (20) upstream of the combustion chamber (14). At least one fuel supply valve (40) is arranged between a fuel tank (38) and the first and second injectors (24), and a water supply valve (52) is arranged between a water reservoir (48) and the first injectors (16). The valves (40, 52) are switchable such that the first injectors (16) can be in flow communication with both the fuel tank (38) and the water reservoir (48), and the second injectors (24) can be in flow communication with the fuel tank (38). Water is injected into the combustion chambers (14) via the first injectors (16) only in certain load ranges.Depending on the load range, fuel is injected either directly into the combustion chambers (14) of the internal combustion engine (12) via the first injectors (16) or into the intake manifold (20) upstream of the combustion chambers (14) via second injectors (24).