Water Injection Quality Detection for Engine Reliability

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Solution Overview

Problem

Internal combustion engines face challenges in optimizing fuel consumption due to knock and high exhaust gas temperatures, which can be exacerbated by poor water quality in water injection systems, leading to potential corrosion and combustion issues.

Innovation Solution

A water injection device equipped with a water quality and level detection system using electric sensors and ultrasonic sensors to ensure only sufficient quality water is used, comprising a capacitor for conductivity measurement and ultrasonic sensors for density assessment, integrated into a single component for precise detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If water injection is used to reduce knocking and exhaust gas temperatures, then fuel consumption is improved, but water quality deterioration leads to corrosion and system damage

Engineering Contradiction:
Improvefuel consumptionVSAvoidsystem durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by measuring water quality parameters (conductivity, density) before the water is injected into the engine. The detection device continuously monitors the water in the tank and detects quality deterioration in advance, allowing the system to prevent corrosion damage before it occurs by identifying poor quality water early in the storage phase rather than after damage has occurred.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using detection devices that continuously monitor water quality parameters and provide real-time information to the control system. The conductivity and density measurements feed back to the control unit, which can then adjust water injection operations or alert the driver to water quality issues, creating a closed-loop system that maintains reliability while enabling fuel consumption optimization.

Inventive Principle:
Principle #23Feedback

2Productivity

If separate water injection systems are implemented, then combustion performance is improved, but device complexity increases

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

Solution Approach 1:

The patent applies merging by integrating multiple detection functions (conductivity measurement, density measurement, and water level detection) into a single water quality detection device. The conductivity sensor and density sensor are combined in one unit that monitors the water tank, reducing the number of separate components needed and simplifying the overall system architecture while maintaining comprehensive water quality monitoring capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements universality by designing a water quality detection device that performs multiple functions simultaneously - measuring conductivity to detect mineral content, measuring density to detect water quality changes, and monitoring water level. This multi-functional device replaces what would otherwise require multiple separate sensors and measurement systems, reducing complexity while enabling comprehensive water quality assessment for optimal combustion performance.

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

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

Prevents damage to water-carrying components and ensures optimal combustion by regularly checking water quality and level, preventing the use of unsuitable water and maintaining engine performance and durability.

Implementation Method 1

one electrode being equipped with a capacitor. To detect the water quality, the conductivity of the water can be determined based on the charging and discharging of the capacitor. The electrodes and the capacitor form an RC circuit

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

The conductivity is defined as the reciprocal of the electrical resistance. The electrical conductivity of the water between the electrodes can be determined from the voltage measurement across the electrodes at a time point after the start of the discharge.

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 3

a first ultrasonic sensor, wherein the water's density can be determined by the ultrasonic sensor

Methodology Applied
Scientific EffectUltrasound: Ultrasound

Implementation Method 4

The transit time of an ultrasonic signal over a distance of known length is measured. From the determined transit time information, the density of the medium, and thus poor water quality, can be detected

Methodology Applied
Scientific EffectSpeed of Sound: Speed of Sound

Data Source

PatentEP3568584B1Water injection device, in particular of a combustion engine, and method for operating such a water injection device
Publication Date: 2021.04.21 ROBERT BOSCH GMBH
  • EP3568584B1 patent drawingFigure 1~2
  • EP3568584B1 patent drawingFigure 3
  • EP3568584B1 patent drawingFigure 4~5

AI summary

The present invention relates to a water injection device, in particular of an internal combustion engine (2), which comprises a water tank (5) for storing water; a conveying element (3) for conveying water, the conveying element (3) being connected to the water tank (5); at least one water injector (6), which is connected to the conveying element (3), for injecting water; and a water quality and water fill level detection device (18) for detecting a quality of the water in the water tank (5) and a fill level of the water tank (5). Further aspects of the invention relate to an internal combustion engine which comprises a water injection device (1) of this type and to a method for operating a water injection device (1) of this type.