Water Injection Device Pressure Maintenance for Rapid Engine Readiness

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Solution Overview

Problem

Internal combustion engines face challenges in maintaining optimal fuel consumption due to knock and high exhaust gas temperatures, particularly at high altitudes where water injection systems experience delayed operational readiness due to steam formation, leading to functional impairments and temperature peaks.

Innovation Solution

A water injection device with a shut-off element, such as an electric shut-off valve or non-return valve, is used to maintain system pressure above water vapor pressure when inactive, preventing evaporation and ensuring rapid pressure build-up and injection release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the water pump is switched off between operating points, then energy consumption is reduced, but water stands in the injectors and lines, heats up, and evaporates causing delayed operational readiness

Engineering Contradiction:
Improveenergy consumptionVSAvoidoperational readiness
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent replaces the mechanical pump system with a pressure maintenance system using a shut-off valve. Instead of actively pumping water, the system uses a shut-off valve to maintain pressure in the water line, preventing evaporation without continuous energy input from a pump.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the pressure parameter in the water injection system by introducing a shut-off valve that maintains a minimum pressure level. This pressure maintenance prevents water evaporation during inactive phases, ensuring rapid operational readiness when water injection is needed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If water is injected to reduce knock and exhaust gas temperatures, then combustion performance is improved, but system complexity increases due to separate water injection systems

Engineering Contradiction:
Improvecombustion performanceVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the shut-off valve serve multiple functions: it maintains system pressure to prevent evaporation, enables rapid pressure build-up when needed, and can be integrated with existing fuel injection control systems. This multi-functionality reduces overall system complexity despite adding water injection capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Temperature

If water injection is activated for rapid load jumps, then temperature peaks are prevented, but pressure build-up time increases due to steam formation

Engineering Contradiction:
Improveexhaust gas temperatureVSAvoidpressure build-up time
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

The patent applies preliminary action by maintaining system pressure continuously through the shut-off valve, even when water injection is not actively needed. This pre-maintained pressure ensures that when rapid load jumps occur, the system can respond immediately without delay for pressure build-up, preventing temperature peaks effectively.

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 solution prevents steam formation and ensures quick operational readiness of the water injection system, reducing knocking tendencies and temperature peaks, even during rapid load jumps.

Implementation Method 1

maintain the system pressure in a region of the water injection device... at a level in order to avoid evaporation of the water in the area

Methodology Applied
Scientific EffectVapor pressure: Vapour Pressure

Implementation Method 2

conveying element for conveying water from the water tank into the water injector

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3292297B1Water injection device of an internal combustion engine
Publication Date: 2023.02.22 ROBERT BOSCH GMBH
  • EP3292297B1 patent drawingFigure 1~2
  • EP3292297B1 patent drawingFigure 3

AI summary

The invention relates to a water injection device (1) of an internal combustion engine, comprising a water tank (5) for storing water, at least one water injector (6), a pump element (3) for pumping water out of the water tank (5) into the water injector (6), and a blocking element (11) which is arranged in a region (8a) between the pump element (3) and the water injector (6) and which is designed to keep a system pressure between the blocking element (11) and the water injector (6) at a level such that the water located in the region (8a) is prevented from evaporating. The invention further relates to an internal combustion engine which comprises a water injection device (1) according to the invention.