SCR System Urea Consumption Optimization via Engine Parameter Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for treating diesel engine exhaust gases, particularly those using selective catalytic reduction (SCR) systems, face challenges in optimizing the consumption of the NOx reducing agent, leading to excessive reservoir filling and inefficient emission control.
Innovation Solution
A process that determines the actual NOx quantity in exhaust gases, calculates a dimensionless number based on urea injection volume and distance traveled, and adjusts engine operating parameters to reduce NOx production when consumption exceeds limits, optimizing urea use and extending refill intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the flow rate of reducing agent is increased to eliminate more NOx, then the quantity of NOx treated is improved, but the consumption of reducing agent increases excessively
Solution Approach 1:
The patent implements dynamic adjustment of engine operating parameters (load, speed, injection timing) based on real-time monitoring of reducing agent consumption and NOx production. This allows the system to adaptively optimize the balance between treating NOx and preserving reducing agent, rather than using fixed injection rates
Solution Approach 2:
The system continuously monitors reducing agent consumption levels and NOx emissions, using this feedback to adjust both the reducing agent injection rate and engine operating parameters. This closed-loop control prevents excessive consumption while ensuring adequate NOx treatment
2Quantity of substance
If engine operating parameters are modified to reduce NOx production, then the quantity of NOx produced is reduced, but fuel consumption increases
Solution Approach 1:
The system applies partial modifications to engine parameters only when necessary to meet NOx emission targets, rather than continuously operating in high-efficiency-low-NOx mode. This selective adjustment minimizes the impact on fuel consumption while achieving compliance
Solution Approach 2:
The patent dynamically changes engine operating parameters (such as injection timing, load distribution, and speed) to optimize the trade-off between NOx production and fuel consumption, using real-time data to determine the optimal parameter set
3Quantity of substance
If the reducing agent reservoir is filled more frequently to ensure adequate supply, then the availability of reducing agent is improved, but the user convenience deteriorates due to increased service constraints
Solution Approach 1:
The system performs preliminary calculations of reducing agent consumption based on current engine operation and historical data, allowing it to predict when the reservoir will be depleted and plan refilling operations in advance, minimizing disruptions to user operation
Solution Approach 2:
The system automatically monitors reducing agent levels and manages refilling schedules without requiring user intervention or awareness, making the service constraint transparent and minimizing its impact on user convenience
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 effectively treats exhaust gases while minimizing reducing agent consumption, ensuring the SCR system operates within specified limits, reducing emissions and prolonging urea reservoir refill intervals.
Implementation Method 1
selective catalytic reduction (SCR) and inject a NOx reducing solution
Implementation Method 2
eliminate the quantity of NOx to be treated
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A process for treating exhaust gases from an internal combustion engine (2) in a motor vehicle (1) comprising an exhaust line (3) equipped with a selective catalytic reducer, hereinafter referred to as SCR (5), and a tank (6) containing a nitrogen oxide (NOx) reducing agent, this process comprises the following steps: - determination of the actual quantity (12) of NOx present in the exhaust gases, - determination of a quantity of NOx to be treated as a function of a predetermined limit quantity (13) of NOx to be released into the atmosphere, - determination of a flow rate (14) of reducing agent to be injected into the SCR (5) to remove the quantity of NOx to be treated, - injection of the flow rate (14) of reducing agent previously determined into the SCR (5), from the tank (6), - modification of operating parameters of the engine (2) in order to vary the quantity of NOx produced by the engine.The modification of the operating parameters of the engine (2) is carried out on the basis of a dimensionless number (24) calculated according to the following steps: - calculation of the volume (18) of reducing agent injected into the SCR between two consecutive fillings of the tank (6), - measurement of the distance (20) traveled by the vehicle (1) between two consecutive fillings of the tank (6), - calculation of a flow rate (21) discretized by dividing the volume (18) of reducing agent injected by the distance (20) traveled, - calculation of the dimensionless number (24) by dividing the discretized flow rate (21) by a predetermined consumption limit (23) of reducing agent, if the dimensionless number (24) is greater than 1, the modification of the engine parameters is carried out to reduce the quantity of NOx produced by the engine (2).