Diesel Emissions Test Stand to Improve Selective Catalytic ReductionEPA Grant Number: SU835980
Title: Diesel Emissions Test Stand to Improve Selective Catalytic Reduction
Investigators: Compere, Marc
Institution: Embry - Riddle Aeronautical University
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: October 1, 2015 through September 30, 2017
Project Amount: $74,984
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2015) Recipients Lists
Research Category: Sustainability , P3 Awards , Pollution Prevention/Sustainable Development , P3 Challenge Area - Energy
Our research objective is to design and develop advanced emission controls for future Diesel hybrid vehicles. Recently adopted Corporate Average Fuel Economy (CAFE) standards mandate 54mpg by 2025. One smart strategy auto manufacturers will use to achieve this high fuel economy is a new generation of light duty Diesel hybrids. Engines in hybrid vehicles experience more starts and stops than typical Diesels on heavy duty trucks. Some of the worst emissions occur in Diesels during cold starts and even some warm starts. Our goal is to design the next generation of smart emission controls to account for the numerous starts and stops a Diesel hybrid engine will experience in a light-duty hybrid vehicle.
We will improve our Diesel emission testing facility and test advanced control strategies on live Diesel exhaust. Our Diesel engine will include a Diesel Particulate Filter (DPF), Diesel Oxidation Catalyst (DOC), and a Selective Catalytic Reduction (SCR) system. The SCR is the primary system under study and required active control. We will design and test custom SCR control laws implemented in hardware to reduce NOx emissions. Model validation will precede real time control law generation and testing. The EPA phase ii award will provide simultaneous upstream and downstream emissions measurements to characterize our emissions components and determine effectiveness of the new controls approaches. Controls approaches will focus on nonlinear observer development using variable structure, or sliding mode control theory. We will use automotive grade sensors and ensure the control laws can be implemented in cost effective automotive-grade computing hardware. The hardware in the loop and controller in the loop experiments will develop our student’s skill and experience at both the undergraduate and graduate levels.
Our expected results include validated models and control laws that generate very low tailpipe NOx emissions. From a controls standpoint, the challenge is to inject enough Diesel exhaust fluid to reduce NOx to nearly zero without injecting too much and saturating the catalyst. Catalyst operating temperature is critical for proper chemical operation. The nonlinear observer will be fault tolerant for power loss over a wide catalyst temperature range. The observer and controller should be able to ‘wake up’ and converge very quickly to estimate the real hardware’s internal operating conditions. We will also explore the possibility of a novel heat storage design to maintain catalyst temperature. If a heat storage device using phase change material is warranted we will explore such a design to achieve significantly improved emissions for hybrid vehicles. The result would allow a typical Diesel hybrid automobile to start up and emit very low emissions under warm or cold start conditions. We will document our findings in peer reviewed conferences and journals.