Engine Intake Condensed Water Estimation Using Thermodynamic Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the amount of condensed water in an engine system's intake passage are limited by memory capacity and the number of operating states that can be accounted for, leading to inaccuracies in estimating this critical parameter.
Innovation Solution
An apparatus that calculates the amount of condensed water by estimating the first amount of moisture in the intake air and the second amount of moisture in the EGR gas, then subtracting the amount of saturated water vapor to arrive at an accurate estimation of condensed water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a map indicating the relationship between intake air flow rate and condensed water amount is used, then the estimation can be performed, but the accuracy is limited due to memory capacity constraints and the number of operating states that can be accounted for
Solution Approach 1:
The patent transforms the estimation approach from using a pre-stored map with discrete operating states to calculating condensed water amount dynamically using physical parameters (intake air flow rate, water vapor concentration, humidity, temperature, atmospheric pressure) through mathematical expressions. This parameter-based calculation eliminates memory constraints and provides continuous accuracy across all operating conditions.
Solution Approach 2:
The patent replaces the mechanical lookup system (map-based estimation requiring memory storage and discrete steps) with a computational system using mathematical calculations based on thermodynamic principles. This substitution allows real-time continuous estimation without the limitations of discrete map data points.
2Measurement precision
If the number of operating states in the map is increased to improve accuracy, then more precise estimation is achieved, but the memory capacity requirement and system complexity increase
Solution Approach 1:
Instead of increasing the quantity of stored map data points to cover more operating states, the patent changes the approach to using fundamental physical parameters that can be continuously measured. The estimation is performed through calculations using intake air flow rate, water vapor concentration, humidity, temperature, and atmospheric pressure, eliminating the need for extensive memory storage while maintaining accuracy across all operating conditions.
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 allows for highly accurate estimation of condensed water in the intake passage, improving the accuracy of corrosion prevention and operational control within the engine system.
Implementation Method 1
In an engine system in an initial stage of warming-up when an intake passage is lower in temperature than a dew point, moisture included in a gaseous matter passing through the intake passage may condense and condensed water may thus be produced in the intake passage
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A controller executes a process including: calculating a first amount of moisture included in intake air using an estimating expression (S 100); calculating a second amount of moisture included in exhaust gas and produced by combustion of fuel using an estimating expression (S 102); calculating an amount of saturated water vapor (S104); calculating an amount of condensed water (S106); setting a correction coefficient (S 108); and calculating a cumulative volume of condensed water (S110).