Experimental Analysis of Ammonia Generation Characteristics by Heated wall under low temperature exhaust gas conditions

Tetsu Ishii･Kengo Nakagawa･Eriko Matsumura (Doshisha univ.)

In SCR systems under low exhaust gas temperature conditions, the urea is not decomposed to ammonia completely and the NOx purification rate decreases. In this study, the effects of wall heating control on ammonia production under low exhaust gas temperature conditions through experimental analysis are reported.

Advanced Materials and Regeneration Control for Cost-Effective and Low-Backpressure DPF Systems in On-road and Off-road Heavy-Duty Applications

Ryoko Chijiiwa (Corning International)･Krishna Aravelli･Suhao He (Corning Inc.)

This study focuses on optimized control strategies for Diesel Particulate Filter (DPF) systems in on-road and off-road heavy-duty applications. It aims to leverage advanced materials to achieve cost-effective aftertreatment design with low-back pressure while complying with global emission regulations. The proposed approach integrates new DPF material designs and optimized regeneration control methods, maintaining filtration efficiency, minimizing pressure drop, and reducing overall system cost. Experimental validation and simulation analyses were conducted to evaluate trade-offs between filtration efficiency, pressure drop, and soot load capacity, providing insights for future emission control technologies in the heavy-duty segment.

Exhaust Gas Velocity Distribution Analysis Method Using Temperature Distribution and Heat Transfer Characteristics of Catalytic Converters

Jiho Cho･Hyungjun Kim･Sungmu Choi･Jaegyung Yoon･Changwan Hong･Sangmin Lee (Hyundai Motor)

This study proposes a method to measure exhaust gas velocity distribution at a catalytic converter inlet by analyzing transient temperature changes during warm-up. Unlike direct velocity measurements, this approach infers velocity profiles from temperature responses affected by thermal capacity. Experiments under various conditions validate its accuracy and feasibility. The method offers a novel way to assess flow uniformity, providing valuable insights to enhance catalyst design and performance.

Development of an Exhaust System Complying with Tier 4 PM Regulations through Study of PM Formation Mechanisms in the Exhaust System

Sungmu Choi･HyeongJun Kim･WonSoon Park (Hyundai Motor)

The U.S. Tier 4 regulation imposes a more stringent particulate mass (PM) limit of 0.5 mg/mile, with enforcement scheduled to commence in 2027. The experimental results revealed considerable variability in PM measurements obtained via filter paper, with occasional exceedances of the Tier 4 PM threshold. This phenomenon is hypothesized to result from the interaction between soluble exhaust gases, produced from the catalyst, and condensate water within the exhaust system, leading to PM formation. As exhaust temperatures rise, the evaporation of condensate water is believed to release the formed PM into the exhaust stream. The following strategies can be proposed to comply with Tier 4 particulate matter (PM) regulations: 1) implementation of high-efficiency GPF for PM reduction, 2) Utilization of additional catalyst to mitigate soluble exhaust gases, 3) elimination of semi-volatile compounds deposited in the exhaust system and measurement apparatus that may be converted to PM.

Study on the Degradation Mechanisms of North American Canisters

Seungyub Lee･Keunsoo Kim･Seunghwan Park (Hyundai Motor)

This study analyzes degradation in automotive fuel vapor canisters compliant with North American ORVR regulations. ORVR strictly limits refueling emissions and requires working capacity exceeding non-ORVR systems. Activated carbon drives vapor adsorption, so capacity loss risks noncompliance. We examine whether temperature swings during repeated adsorption-desorption cycles cause material deformation and thermal shock that accelerate degradation. Additional factors, including fuel intrusion and condensation, are assessed for effects on capacity and durability. Finally, we outline research needs to quantify degradation, refine materials and designs, and develop accelerated tests and models that ensure long-term performance, reliability, and regulatory conformity of fuel canisters overall.