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Study on Diesel Engine Selective Catalytic Reduction Performance at Different Atmospheric Pressures Using the
Yuhua Bi1, Jie Yan1, Shaohua Liu1
1Yunnan Laboratory of Internal Combustion Engines, Kunming University of Science and Technology, No. 727 Jingming South Road, Chenggong District, Kunming, 650500 Yunnan Province, China.
ACS Omega
|May 1, 2023
Summary
Lower atmospheric pressure reduces diesel engine selective catalytic reduction (SCR) performance, impacting nitrogen oxide (NOx) conversion and ammonia (NH3) slip. Optimal conditions were identified for efficient NOx reduction.
Area of Science:
- Environmental Science
- Mechanical Engineering
- Chemical Engineering
Background:
- Nitrogen oxides (NOx) are primary diesel engine emissions.
- Selective Catalytic Reduction (SCR) is crucial for mitigating NOx.
- SCR performance is evaluated by NOx conversion efficiency and ammonia (NH3) escape.
Purpose of the Study:
- To investigate the impact of atmospheric pressure, exhaust temperature, and mass flow rate on SCR performance.
- To analyze the interactions between these parameters using Response Surface Methodology (RSM).
- To determine optimal operating conditions for maximizing NOx conversion and minimizing NH3 escape.
Main Methods:
- Combined experimental and one-dimensional numerical simulation approach.
- Utilized Response Surface Methodology (RSM) for parameter interaction analysis.
- Varied atmospheric pressure, exhaust temperature, and exhaust mass flow rate.
Main Results:
- Reduced atmospheric pressure leads to lower NOx conversion efficiency and increased ammonia escape.
- At lower atmospheric pressures, exhaust mass flow rate has a diminished effect on NOx conversion efficiency.
- Optimal conditions identified: 100 kPa atmospheric pressure, 395 °C exhaust temperature, and 250 kg/h exhaust mass flow rate.
Conclusions:
- Atmospheric pressure significantly influences SCR system efficiency for diesel engines.
- Optimal operating parameters are essential for effective NOx reduction and emission control.
- Achieved 78.6% NOx conversion efficiency with minimal NH3 escape (1.7 g/cycle) under optimal conditions.
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