Hydrocarbon Vapor Purge Control via Pump Temperature Estimation
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Solution Overview
Problem
In hybrid vehicles, the challenge lies in efficiently purging hydrocarbon vapors from an absorbent filter due to reduced vacuum in the purge circuit at high speeds, leading to potential atmospheric emissions, and existing methods for estimating vapor concentration are slow and imprecise, hindering real-time control of hydrocarbon vapor injection into engine cylinders.
Innovation Solution
A device comprising a radial pump, upstream and downstream pressure sensors, a temperature sensor, and a control module that calculates the pressure difference and temperature contributions to estimate gas flow temperature and vapor concentration, allowing precise control of the purge valve to maintain the stoichiometric air-fuel ratio, independent of latency in traditional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a radial pump is used to circulate hydrocarbon vapors in hybrid vehicles, then the purging capability is improved, but the device complexity increases
Solution Approach 1:
The system is divided into distinct functional modules: the radial pump for vapor circulation, pressure sensors for monitoring, temperature sensors for measurement, and a control module for coordination. This segmentation allows each component to be optimized independently while maintaining overall system functionality and reducing integration complexity.
Solution Approach 2:
The radial pump serves multiple functions: it circulates hydrocarbon vapors during purging operations, maintains pressure differentials for sensor measurements, and enables controlled vapor delivery to the engine. This multi-functionality reduces the need for additional dedicated components, thereby managing device complexity while improving purging capability.
2Measurement precision
If traditional temperature sensors are used, then the device complexity is reduced, but the measurement precision and response time are insufficient for real-time control
Solution Approach 1:
Traditional mechanical temperature sensors are replaced with a computational approach. The control module calculates temperature based on pressure differential measurements from upstream and downstream sensors, eliminating the need for separate temperature sensing hardware while achieving higher measurement precision and faster response times.
Solution Approach 2:
Pressure sensors serve as intermediary measurement devices. Instead of directly measuring temperature, the system measures pressure differentials across the pump and uses these intermediate measurements to derive temperature information through control module calculations, achieving indirect but more precise temperature monitoring.
3Productivity
If the purge valve is controlled to maintain stoichiometric ratio, then the combustion efficiency is improved, but the control complexity increases
Solution Approach 1:
The control module continuously monitors pressure differentials, vapor concentration, and engine parameters, then adjusts the purge valve position in real-time to maintain the stoichiometric air-fuel ratio. This closed-loop feedback control ensures optimal combustion efficiency while automating the complex coordination required between multiple sensors and actuators.
Solution Approach 2:
The system dynamically adjusts the purge valve opening degree based on calculated vapor concentration and real-time engine operating conditions. By continuously changing this control parameter in response to measured variables, the system maintains stoichiometric combustion without requiring complex manual intervention or additional control hardware.
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
Enables quick and precise estimation of hydrocarbon vapor concentration and control of the gas flow into engine cylinders, ensuring efficient combustion while reducing atmospheric emissions and extending pump lifespan by managing rotation speed during non-purge modes.
Implementation Method 1
determine a temperature of the gas flow circulating in the purge circuit... determine a contribution of an adiabatic compression of the gas flow to a temperature of the gas flow
Implementation Method 2
a carbon degassing filter, hereafter referred to as an 'absorbent filter' (commonly called a 'canister' by those skilled in the art), which absorbs hydrocarbon vapors from the tank
Data Source
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Figure 2
AI summary
The invention relates to a device (10) for purging the vapours of a fuel stored in a tank (30) of a combustion motor vehicle (1), comprising a control module (130) configured in particular to determine the contribution of the convection of the gas stream to the temperature of said gas stream on the basis of a received gas stream temperature measurement and a received internal pump temperature measurement, in order to determine the contribution of the conduction of the stream to the temperature of the gas stream on the basis of the mass flow rate of the stream, a received temperature of the gas stream and a received internal temperature measurement of the pump, in order to estimate the temperature of the gas stream circulating in a purge circuit (120) on the basis of the determined contributions of adiabatic compression, convection and conduction, so as to calculate the concentration of fuel vapours in the stream on the basis of the estimated temperature.