Hydrocarbon Trap Reaction-Rate Modeling for Catalyst Warm-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydrocarbon traps release hydrocarbons before the catalyst reaches sufficient temperature during cold starts, leading to inefficient hydrocarbon oxidation.
Innovation Solution
An exhaust gas treatment system with a hydrocarbon trap, air injection, and exhaust heating unit, controlled by a model determining hydrocarbon storage levels and reaction rates, adjusts operations to delay hydrocarbon release and enhance catalyst heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydrocarbon trap is used to store hydrocarbons during cold start, then hydrocarbon emissions can be controlled, but the hydrocarbon trap may reach desorption temperature before the catalyst reaches sufficient temperature for effective oxidation
Solution Approach 1:
The system performs preliminary heating of the catalyst using an exhaust heating unit before the hydrocarbon trap reaches desorption temperature. This preliminary action ensures the catalyst is ready to immediately oxidize hydrocarbons when they are released from the trap, preventing premature emission of unoxidized hydrocarbons.
Solution Approach 2:
The control system continuously monitors temperatures of both the hydrocarbon trap and catalyst, and adjusts the heating strategy based on real-time temperature feedback. When the trap approaches desorption temperature but the catalyst is still below optimal oxidation temperature, the system intensifies heating to bridge the temperature gap.
2Duration of action of moving object
If the hydrocarbon trap releases hydrocarbons early to reduce storage time, then the system responds faster, but hydrocarbon oxidation efficiency decreases due to insufficient catalyst temperature
Solution Approach 1:
The system changes the temperature parameter of the catalyst by applying external heating before hydrocarbon release. This parameter change ensures the catalyst reaches the critical temperature threshold for efficient oxidation, allowing the system to maintain both short storage duration and high oxidation efficiency.
Solution Approach 2:
The catalyst is pre-heated to optimal oxidation temperature before the hydrocarbon trap releases stored hydrocarbons. This preliminary preparation of the catalyst ensures immediate and efficient oxidation conversion when hydrocarbons enter the catalytic converter, maximizing productivity.
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
Enhances hydrocarbon oxidation efficiency by delaying hydrocarbon release until the catalyst reaches optimal temperature, improving the conversion of hydrocarbons into carbon dioxide and water.
Implementation Method 1
determining a first reaction rate representing a rate of hydrocarbon adsorption at non-acidic sites of the hydrocarbon trap, determining a third reaction rate representing a rate of hydrocarbon adsorption at acidic sites of the hydrocarbon trap
Implementation Method 2
determining a second reaction rate representing a rate of hydrocarbon desorption at non-acidic sites of the hydrocarbon trap, determining a fourth reaction rate representing a rate of hydrocarbon desorption at acidic sites of the hydrocarbon trap
Implementation Method 3
An exhaust heating unit is downstream of the hydrocarbon trap, wherein the exhaust heating unit receives an exhaust output from the hydrocarbon trap
Implementation Method 4
The objective of a catalyst such as a TWC is to convert the primary emissions from the engine into carbon dioxide, water, and nitrogen
Data Source
AI summary
An exhaust gas treatment system including a hydrocarbon storage model; and a controller operably connected to the hydrocarbon storage model, the controller configured to execute a method for determining a hydrocarbon storage level of a hydrocarbon trap, the method comprising determining a first reaction rate representing a rate of hydrocarbon adsorption at non-acidic sites of the hydrocarbon trap; determining a second reaction rate representing a rate of hydrocarbon desorption at non-acidic sites of the hydrocarbon trap; determining a third reaction rate representing a rate of hydrocarbon adsorption at acidic sites of the hydrocarbon trap; determining a fourth reaction rate representing a rate of hydrocarbon desorption at acidic sites of the hydrocarbon trap; and determining the hydrocarbon storage level in the hydrocarbon trap based on the first reaction rate, the second reaction rate, the third reaction rate, and the fourth reaction rate.