Non-Uniform Combustion based Mode Switching Control for a Passive SCR System

2018 ◽  
Author(s):  
Qinghua Lin ◽  
Pingen Chen
Keyword(s):  
Switching Control ◽  
Mode Switching ◽  
Scr System ◽  
Passive Scr

Simultaneous Optimization of Configuration and Control for a Passive SCR System

2018 ◽  
Author(s):  
Pingen Chen ◽  
Qinghua Lin
Keyword(s):  
Catalytic Reduction ◽  
Simultaneous Optimization ◽  
Computationally Efficient ◽  
System Architectures ◽  
Aftertreatment System ◽  
In Series ◽  
System Configurations ◽  
Scr System ◽  
And Control ◽  
Passive Scr

The configuration and control of aftertreatment systems have a significant impact on their functionalities and emission control performance. The traditional aftertreatment system configurations, i.e., connections from one aftertreatment subsystem to another subsystem in series, are simple but generally do not yield the optimal aftertreatment system performance. New aftertreatment configurations, in conjunction with new engine and aftertreatment control, can significantly improve engine efficiency and emission reduction performance. However, new configuration design requires human intuition and in-depth knowledge of engine and aftertreatment system design and control. The purpose of this study is to develop a general systematic and computationally-efficient method which enables automated and simultaneous optimization of passive selective catalytic reduction (SCR) system architectures and the associated non-uniform cylinder-to-cylinder combustion (NUCCC) controls based on a newly proposed highly reconfigurable passive SCR model structure and integer partition theory. The proposed method is general enough to account for passive SCR systems with two or more TWC stages. We demonstrate through this case study that the optimized passive SCR configuration, in conjunction with the optimized NUCCC control, can reduce the NH3 specific fuel consumption by up to 21.90%.

Optimization of Mode Switching Timing Control for a Lean-Burn Gasoline Engine With a Prototype Passive SCR System

2018 ◽  
Author(s):  
Dakota Strange ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko ◽  
James E. Parks
Keyword(s):  
Gasoline Engine ◽  
Nox Reduction ◽  
Cost Effective ◽  
Nox Storage ◽  
Mode Switching ◽  
Timing Control ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Effective Manner ◽  
Passive Scr

Passive selective catalytic reduction (SCR) has emerged as a promising NOx reduction technology for highly-efficient lean-burn gasoline engines to meet stringent NOx emission regulation in a cost-effective manner. In this study, a prototype passive SCR which includes an upstream three-way catalyst (TWC) with added NOx storage component, and a downstream urealess SCR catalyst, was investigated. Engine experiments were conducted to investigate and quantify the dynamic NOx storage/release behaviors as well as dynamic NH3 generation behavior on the new TWC with added NOx storage component. Then, the lean/rich mode-switching timing control was optimized to minimize the fuel penalty associated with passive SCR operation. Simulation results show that, compared to the baseline mode-switching timing control, the optimized control can reduce the passive SCR-related fuel penalty by 6.7%. Such an optimized mode-switching timing control strategy is rather instrumental in realizing significant fuel efficiency benefits for lean-burn gasoline engines coupled with cost-effective passive SCR systems.

scholarly journals Direct Measurement of Ammonia Storage on Passive SCR Systems for Lean Gasoline NOx Reduction Using Radio Frequency Sensing

2019 ◽  
Author(s):  
Paul Ragaller ◽  
Josh Mandelbaum ◽  
Luc Lapenta ◽  
Alexander Sappok ◽  
Josh Pihl ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Real Time ◽  
Gasoline Engine ◽  
Nox Reduction ◽  
Practical Implementation ◽  
Engine Operation ◽  
Ammonia Storage ◽  
Scr System ◽  
Lean Gasoline ◽  
Passive Scr

Abstract Lean gasoline engine operation provides clear efficiency benefits relative to conventional stoichiometric combustion approaches. One of the key hurdles to the widespread, practical implementation of lean gasoline combustion remains the challenge of lean NOx control. One of the potential approaches for controlling NOx emission from lean gasoline engines is the so-called passive selective catalytic reduction (SCR) system. In such systems, periods of rich operation generate ammonia over a three-way catalyst (TWC), which is then adsorbed on the downstream SCR and consumed during lean operation. Brief periods of rich operation must occur in response to the depletion of stored ammonia on the SCR, which requires reliable measurements of the SCR ammonia inventory. Presently, lean exhaust system controls rely on a variety of gas sensors mounted up- and downstream of the catalysts, and which only provide an indirect inference of the operation state. In this study, a radio frequency (RF) sensor was used to provide a direction measurement of the amount of ammonia adsorbed on the SCR in real-time. The RF sensor was calibrated and deployed on a BMW N43B20 4-cylinder lean gasoline engine equipped with a passive SCR system. Brief periods of rich operation performed at lambda values between 0.98 and 0.99 generated the ammonia, subsequently stored on the SCR for consumption during periods of lean operation. The experiments compared real-time measurements of SCR ammonia inventory from the RF sensor with estimates of ammonia coverage derived from exhaust gas composition measurements upstream and downstream of the catalyst. The results showed a high degree of correlation between the RF measurements and SCR ammonia storage inventory, and demonstrated NOx conversion efficiencies above 98%, confirming the feasibility of the concept. Relative to stoichiometric operation, lean-gasoline operation resulted in fuel efficiency gains of up to 10%, which may be further improved through direct feedback control from the RF sensor to optimize lean–rich cycling based on actual, measured SCR ammonia levels.

scholarly journals Multi-mode switching control of hybrid electromagnetic suspension based on road conditions adaptation

2020 ◽  
Vol 58 (3) ◽  
pp. 697-710
Author(s):  
Xiangpeng Meng ◽  
Renkai Ding ◽  
Zeyu Sun ◽  
Ruochen Wang ◽  
Long Chen
Keyword(s):  
Switching Control ◽  
Mode Switching ◽  
Electromagnetic Suspension ◽  
Multi Mode

Mode-switching control and stability analysis of a hybrid electromagnetic actuator for the vehicle suspension

2020 ◽  
Vol 26 (19-20) ◽  
pp. 1804-1814
Author(s):  
Renkai Ding ◽  
Ruochen Wang ◽  
Xiangpeng Meng ◽  
Long Chen
Keyword(s):  
Energy Consumption ◽  
Performance Test ◽  
Control Method ◽  
Dynamic Performance ◽  
Electrical Energy ◽  
Switching Control ◽  
Mode Switching ◽  
Electromagnetic Actuator ◽  
Electrical Energy Consumption ◽  
Dynamic Performances

To coordinate the contradictory relationship between dynamic performances and electrical energy consumption of an electromagnetic active suspension, a hybrid electromagnetic actuator that integrates with a linear motor and a hydraulic damper is developed, which can achieve active control and energy regeneration compared with the linear electromagnetic actuator. A mode-switching control method is put forward based on the modified skyhook control. The stability of the switched controller with a specific switching rule is investigated based on the Lyapunov theorem. Then, the switching control system of a hybrid electromagnetic actuator is designed. Finally, a linear electromagnetic actuator and a passive damper are taken as comparison objects, and comparative bench tests, including a dynamic performance test and an energy consumption test, are conducted. The test results show that the hybrid electromagnetic actuator with mode-switching control can balance the dynamic performances and electrical energy consumption effectively.

scholarly journals Multi-Mode Switching Control of the EPS With Hybrid Power Supply

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 4329-4337 ◽  
Author(s):  
Bin Tang ◽  
Yingqiu Huang ◽  
Di Zhang ◽  
Haobin Jiang
Keyword(s):  
Power Supply ◽  
Switching Control ◽  
Mode Switching ◽  
Hybrid Power ◽  
Multi Mode

Improvement of settling response of disk drive head positioning servo using mode switching control with initial value compensation

1996 ◽  
Vol 32 (3) ◽  
pp. 1767-1772 ◽  
Author(s):  
T. Yamaguchi ◽  
Y. Soyama ◽  
H. Hosokawa ◽  
K. Tsuneta ◽  
H. Hirai
Keyword(s):  
Disk Drive ◽  
Switching Control ◽  
Mode Switching ◽  
Initial Value ◽  
Head Positioning
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