NOx Emission Removal from a Parallel Diesel Engine Group by SCR System Based on Distributed Control Technology

Area of Science:

• Environmental Engineering
• Mechanical Engineering
• Control Systems

Background:

• Industrial diesel engine groups generate significant pollution, particularly nitrogen oxides (NOx), due to variable operating conditions and parallel engine configurations.
• Existing emission control methods may not adequately address the complexities of managing emissions from multiple, concurrently operating diesel engines.

Purpose of the Study:

• To propose and evaluate a distributed control system (DCS) for effectively managing NOx emissions from parallel diesel engine groups.
• To introduce a novel control strategy that optimizes the performance of selective catalytic reduction (SCR) devices across multiple engines.

Main Methods:

• A DCS architecture was developed, connecting individual diesel engines, each with an independent DCS unit and SCR device, to a central processing unit (CPU).
• A dimensionless parameter, the coefficient of difficulty (K), was introduced to quantify NOx conversion efficiency for each unit.
• A control algorithm was designed to minimize K, optimizing real-time NOx conversion efficiency distribution among the engines.

Main Results:

• The DCS deNOx technology was successfully applied to a 10-engine test bench operating in parallel.
• The system effectively controlled NOx emissions from the engine group, ensuring compliance with emission standards.
• The method demonstrated good economic performance through optimized NOx conversion efficiency distribution and economical urea injection.

Conclusions:

• The proposed DCS method provides an effective solution for controlling NOx emissions from multiple diesel engines operating in parallel.
• This approach is suitable for varied speeds and loads, offering both environmental compliance and economic benefits.
• The coefficient of difficulty (K) serves as a valuable metric for optimizing SCR performance in distributed engine systems.