Urea Crystallization Control in SCR Systems
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Solution Overview
Problem
Existing methods for controlling urea crystallization in SCR systems fail to prevent blockages and inefficiencies caused by urea crystallization, leading to increased consumption and reduced engine performance.
Innovation Solution
A method that determines a urea crystallization risk factor using crystallization energy factor-exhaust temperature pairs, activating an adaptive control strategy to raise engine exhaust temperature and trigger a diesel particulate filter when the risk exceeds a threshold, thereby preventing urea crystallization accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If urea water solution is injected into exhaust manifold for NOx reduction, then emission control efficiency is improved, but urea crystallization occurs in the injection system causing blockage and increased consumption
Solution Approach 1:
The patent applies preliminary action by predicting urea crystallization risk before it occurs. The system calculates a crystallization risk factor based on exhaust temperature, urea injection amount, and flow rate, and takes preventive measures (adjusting injection parameters or raising exhaust temperature) before crystallization actually happens, rather than waiting for blockage to occur and then purging it
Solution Approach 2:
The patent implements feedback control by continuously monitoring exhaust temperature, urea consumption, and flow rate, calculating the crystallization risk factor in real-time, and adjusting the urea injection system or exhaust temperature accordingly. This closed-loop feedback prevents crystallization accumulation that would otherwise lead to blockage
2Object-generated harmful factors
If electric purging or suck-back methods are used to eliminate urea crystallization, then existing crystal accumulation is reduced, but system complexity increases and prevention capability is lacking
Solution Approach 1:
Instead of using complex purging systems to remove crystals after formation, the patent applies preliminary action by predicting crystallization risk in advance and adjusting operating parameters to prevent crystal formation altogether, eliminating the need for complex purging infrastructure
Solution Approach 2:
The patent converts the harmful effect of low exhaust temperature (which causes crystallization) into a beneficial control parameter. By monitoring and adjusting exhaust temperature to stay above the crystallization threshold, the system uses temperature control as a preventive measure, turning a problem-causing factor into a solution-enabling parameter
3Ease of operation
If urea crystallization is allowed to accumulate before purging, then system operation is simpler, but urea consumption increases and conversion efficiency decreases
Solution Approach 1:
The patent uses feedback control to maintain optimal urea injection parameters based on real-time exhaust temperature and flow rate monitoring. This ensures urea is injected at the right amount and timing to achieve complete conversion without crystallization, maximizing productivity while keeping operation simple through automated control
Solution Approach 2:
The system performs self-adjustment by automatically calculating crystallization risk and modifying urea injection parameters or exhaust temperature control without external intervention. This self-service capability maintains high conversion efficiency and prevents blockage without requiring complex manual operation or frequent purging cycles
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 accurately predicts and actively controls urea crystallization, preventing blockages and improving exhaust treatment and operational stability of diesel vehicles.
Implementation Method 1
When an exhaust temperature is low, urea might be decomposed incompletely and crystallize in the injection system, on a wall of the exhaust manifold, or in a catalytic converter
Implementation Method 2
activating an adaptive control strategy to raise engine exhaust temperature
Data Source
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AI summary
The present application relates to a method and apparatus for controlling urea crystallization, a storage medium and an electronic device, by acquiring crystallization energy factors and exhaust temperatures of an operating area of an engine within a preset time period, and obtaining crystallization energy factor-exhaust temperature value pairs according to a preset sampling interval, and determining a urea crystallization risk factor within the preset time period according to the crystallization energy factor-exhaust temperature value pairs, then activating a urea crystallization adaptive control strategy to enable a urea selective catalytic reduction (SCR) system to enter a urea crystallization active removing mode upon determining that the crystallization risk factor is greater than the preset threshold, thereby achieving an active control of urea crystallization in the SCR system, avoiding a series of problems caused by an exhaust treatment and an operational stability of a vehicle.