Development of an Open Loop Fuzzy Logic Urea Dosage Controller for Use With an SCR Equipped HDD Engine

2009 ◽  
Author(s):  
Raffaello Ardanese ◽  
Michelangelo Ardanese ◽  
Marc C. Besch ◽  
Theodore Adams ◽  
Arvind Thiruvengadam ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Catalytic Reduction ◽  
Control Strategies ◽  
Open Loop ◽  
Particulate Filter ◽  
Oxides Of Nitrogen ◽  
Heavy Duty ◽  
Ammonia Slip ◽  
Fuzzy Logic Approach ◽  
Heavy Duty Diesel

Selective Catalytic Reduction (SCR) systems have been shown to be the most promising exhaust aftertreatment system for near term in-use applications to meet the stringent US 2010 oxides of nitrogen (NOx) emissions regulations of 0.2 g/bhp-hr for on-highway heavy duty diesel engines. SCR systems use the ammonia-containing compound urea, as a reducing agent. In order to control the urea dosage during transient operation of the engine, sophisticated control strategies are needed. This study discusses the development of an open loop, non-sensor based fuzzy logic urea dosage controller. The goal of the fuzzy logic based control was to achieve maximum NOx emission reduction, while limiting the amount of ammonia slip. The open loop controller was implemented on a heavy duty diesel engine equipped with a catalyzed diesel particulate filter (DPF) and a SCR system. The control system was quantified by operating the engine over different test cycles on an engine dynamometer. This study shows that the fuzzy logic approach is a simple and effective way to control NOx, as well as ammonia slip.

In-Use Emissions from 2010-Technology Heavy-Duty Trucks: Impact on Air Quality Planning in California

2017 ◽  
Vol 2627 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Seungju Yoon ◽  
John F. Collins ◽  
Chandan Misra ◽  
Jorn D. Herner ◽  
Michael W. Carter ◽  
...  
Keyword(s):  
Air Quality ◽  
Catalytic Reduction ◽  
Substantial Contribution ◽  
Oxides Of Nitrogen ◽  
Heavy Duty ◽  
Low Speed ◽  
Testing Procedures ◽  
Certification Standard ◽  
Heavy Duty Diesel ◽  
Control Technologies

Introduction of a selective catalytic reduction system for heavy-duty diesel trucks (HDDTs) has substantially reduced emissions of oxides of nitrogen (NOx). However, it was found that in-use NOx emissions measured from three 2010-technology HDDTs were higher than the certification standard and higher than the levels measured during engine certification. In-use NOx emissions from three HDDTs tested over chassis dynamometer cycles were 1.7 to 9 times higher than the NOx certification standard of 0.20 grams per brake horsepower-hour, and the emissions measured with a portable emissions measurement system over highway test routes were up to five times higher than the certification standard. Such high in-use NOx emissions occurred primarily during low-speed operations (25 mph or less). This is a concern in California because more than 50% of running-exhaust NOx emissions from HDDTs will occur during low-speed operations that constitute only 11% of total vehicle miles traveled by 2025. This substantial contribution of NOx emissions during low-speed operations should be addressed carefully in the process of developing regulations and strategies to improve air quality in California. For better understanding and control of high in-use NOx emissions, there is a strong need for investigation of NOx control technologies effective at low-speed operation, differences between engine testing and whole vehicle testing procedures, and the roles of both engine certification requirements and in-use compliance requirements in reducing real-world NOx emissions.

Urea injection control strategy in urea-selective catalytic reduction for heavy-duty diesel engine under transient process

2019 ◽  
pp. 146808741986063
Author(s):  
Binyang Wu ◽  
Longfei Deng ◽  
Yize Liu ◽  
Dezeng Sun ◽  
Wanhua Su
Keyword(s):  
Selective Catalytic Reduction ◽  
Transient Process ◽  
Catalytic Reduction ◽  
Heavy Duty ◽  
Ammonia Slip ◽  
Ammonia Storage ◽  
Heavy Duty Diesel Engine ◽  
Injection Control ◽  
Storage Area ◽  
Heavy Duty Diesel

A urea injection control strategy for urea-selective catalytic reduction under a transient process is investigated on a heavy-duty diesel engine test bench in this study. The aim is to improve NO x conversion efficiency and reduce ammonia slip. With the selective catalytic reduction system as the research object, an open thermodynamic conservation system is established. The conservation relationship in the process of urea injection, NO x reduction reaction, ammonia storage, and ammonia slip is investigated. The ideal target ammonia storage area and the ammonia storage characteristics during the transient process are studied. The ammonia storage area and boundary, which change with the transient temperature, are established. Correction of real-time ammonia injection is further deduced from the boundary of the area. The world harmonized transient cycle test cycle result showed that compared to feed-forward control, the NO x conversion efficiency increased by 16% and the NH3 slip decreased by 75% when using the proposed real-time ammonia storage-management control method.

scholarly journals Investigation of Urea Uniformity with Different Types of Urea Injectors in an SCR System

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1269
Author(s):  
Muhammad Khristamto Aditya Wardana ◽  
Kwangchul Oh ◽  
Ocktaeck Lim
Keyword(s):  
Diesel Engine ◽  
Catalytic Reduction ◽  
Nox Reduction ◽  
Heavy Duty ◽  
Ammonia Gas ◽  
Experimental Parameters ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel ◽  
Scr System

Heavy-duty diesel engines in highway use account for more than 40% of total particulate and nitrogen oxide (NOx) emissions around the world. Selective catalytic reduction (SCR) is a method with effective results to reduce this problem. This research deals with problems in the urea evaporation process and ammonia gas distribution in an SCR system. The studied system used two types of urea injectors to elucidate the quality of ammonia uniformity in the SCR system, and a 12,000-cc heavy-duty diesel engine was used for experimentation to reduce NOx in the system. The uniformity of the generated quantities of ammonia was sampled at the catalyst inlet using a gas sensor. The ammonia samples from the two types of urea injectors were compared in experimental and simulation results, where the simulation conditions were based on experimental parameters and were performed using the commercial CFD (computational fluid dynamics) code of STAR-CCM+. This study produces temperatures of 371 to 374 °C to assist the vaporization phenomena of two injectors, the gas pattern informs the distributions of ammonia in the system, and the high ammonia quantity from the I-type urea injector and high quality of ammonia uniformity from the L-type urea injector can produce different results for NOx reduction efficiency quality after the catalyst process. The investigations showed the performance of two types of injectors and catalysts in the SCR system in a heavy-duty diesel engine.

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