Investigation of Solid Deposit Inside L-Type Urea Injector and NOx Conversion in a Heavy-Duty Diesel Engine

Muhammad Khristamto Aditya Wardana,Ocktaeck Lim

doi:10.3390/catal11050595

Muhammad Khristamto Aditya Wardana, Ocktaeck Lim

Open Access

https://doi.org/10.3390/catal11050595

Copy DOI

Abstract

The heavy-duty diesel engine is used in the main transportation vehicles in Korea to deliver products from various companies; however, diesel engines produce enormous quantities of nitrogen oxide (NOx), which harms human health. The selective catalytic reduction (SCR) system is a common solution to reduce NOx emissions from diesel engines; however, heavy-duty diesel engines produce more NOx than can be dealt with using an SCR and thus require investigations into effective NOx reduction solutions. This study investigated 12,000 cc heavy-duty diesel engines from Hyundai using the 1000 rpm engine operation to produce 1330 ppm of NOx emission. The ammonia generation process was assessed by the amount of ammonia produced; the amount of ammonia gas was identified by 19 gas sensors on the catalyst surface; the effectiveness of the mixing process between the ammonia and the NOx in the system was determined by the NOx conversion values from a gas analyzer. Comparison between the experiment and simulation results shows the ammonia and NOx values and elucidates the temperature results for vaporization and saturation quantity, ammonia distribution, and NOx conversion in the system. The NOx conversion investigations also provide the chemical reaction and numerical equation relevant to the ammonia and NOx distribution.

Highlights

Since the increasing individual mobility of on-road and off-road transportation in the 20th century, human-made vehicles, such as cars, trucks, buses, etc., produce significant emissions, which can damage the human body from the inside
The selective catalytic reduction (SCR) process to reduce nitrogen oxide (NOx) emissions from an engine is as follows: (1) a urea–water solution (UWS; AdBlue) is injected into the SCR system as small droplet particles; (2) the urea droplet will breakup after hitting the wall system; (3) the small urea droplets evaporate, becoming ammonia gas due to the hot gas temperature; (4) the ammonia gas mixes with the NOx emission gas, which produces nitrogen (N2) and steam (H2O) in the system
The results show that the suggested urea injector for the Hyundai D6CC produced more ammonia than the original urea injector from Hyundai D6CC; more ammonia in an SCR system is indicative of higher NOx conversion

Summary

Introduction

Since the increasing individual mobility of on-road and off-road transportation in the 20th century, human-made vehicles, such as cars, trucks, buses, etc., produce significant emissions, which can damage the human body from the inside. The SCR process to reduce NOx emissions from an engine is as follows: (1) a urea–water solution (UWS; AdBlue) is injected into the SCR system as small droplet particles; (2) the urea droplet will breakup after hitting the wall system; (3) the small urea droplets evaporate, becoming ammonia gas due to the hot gas temperature; (4) the ammonia gas mixes with the NOx emission gas, which produces nitrogen (N2) and steam (H2O) in the system. This process and reaction can reduce NOx emissions from diesel engines. Khristamto [2] showed the differences in ammonia quantity between the original urea injector of the Hyundai D6CC and the suggested urea injector

UWS Saturation and Vaporization Processes

The Ammonia Distribution and NOx Conversion Value

The CFD Model and the Parameter Condition

The Experimental Model and the Parameter Conditions

Conclusions