SCR Catalyst Heating Avoidance for Ammonia Adsorption State
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exhaust gas control systems for internal combustion engines face inefficiencies in NOx removal due to wasteful energy use when heating selective catalytic reduction (SCR) catalysts, especially when ammonia cannot be adsorbed, leading to ineffective NOx reduction and energy wastage.
Innovation Solution
An exhaust gas control apparatus comprising a selective catalytic reduction catalyst, a heating device, a urea solution supply device, and a controller that determines the state of ammonia adsorption and avoids unnecessary heating of the SCR catalyst, reducing energy consumption by defrosting the urea solution and optimizing the supply and heating processes based on sensor data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the SCR catalyst is heated when ammonia cannot be adsorbed, then the catalyst temperature increases, but energy is wasted without achieving effective NOx removal
Solution Approach 1:
The controller determines whether ammonia can be adsorbed onto the SCR catalyst before initiating heating. This preliminary assessment prevents unnecessary heating when adsorption conditions are not met, thereby avoiding energy waste while ensuring heating only occurs when it will be effective for NOx removal
Solution Approach 2:
The system uses sensor data to continuously monitor the adsorption state of the SCR catalyst and provides feedback to the controller. Based on this feedback, the controller dynamically adjusts the heating operation, turning it on only when ammonia adsorption is feasible and turning it off when adsorption cannot occur, thus optimizing energy utilization
2Productivity
If the SCR catalyst is heated to increase NOx removal factor, then NOx removal efficiency improves, but energy consumption increases when ammonia is not available
Solution Approach 1:
The controller performs a preliminary determination of ammonia adsorption capability before activating the heating device. This ensures that heating energy is only consumed when it will directly contribute to improving NOx removal efficiency through effective ammonia-catalyst interaction
Solution Approach 2:
The system changes the operational parameter of the heating device based on the ammonia adsorption state. When adsorption is not possible, the heating parameter is set to zero or minimal level; when adsorption is feasible, the heating parameter is increased to optimize NOx removal, thus dynamically matching energy input to actual performance needs
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 suppresses wasteful energy use by ensuring that the SCR catalyst is only heated when ammonia can be effectively adsorbed, enhancing NOx removal efficiency and reducing energy expenditure in situations where NOx removal using a urea solution is difficult.
Implementation Method 1
NO x in exhaust gas and ammonia adsorbed on a selective catalytic reduction (SCR) catalyst react with each other on the SCR catalyst. Thus, NO x is reduced and converted into nitrogen.
Implementation Method 2
The heating device is configured to heat the selective catalytic reduction catalyst directly or indirectly.
Implementation Method 3
ammonia (NH 3 ) to be produced by hydrolyzing a urea solution
Implementation Method 4
ammonia adsorbed on a selective catalytic reduction (SCR) catalyst
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An exhaust gas control apparatus includes an SCR catalyst arranged in an exhaust passage, a heating device that heats the SCR catalyst, a urea solution supply device that supplies a urea solution to an upstream side of the SCR catalyst, a controller that operates the heating device and the urea solution supply device, and at least one sensor that acquires information related to a state of the exhaust gas control apparatus. The controller executes a state determination process (S1) for determining whether the exhaust gas control apparatus is currently in a predetermined state in which ammonia is not adsorbable on the SCR catalyst based on the information from the at least one sensor, and a heating avoidance process (S2) for avoiding heating the SCR catalyst with the heating device irrespective of an operating condition of the internal combustion engine when the exhaust gas control apparatus is currently in the predetermined state.