Turbulence, Coherent Structures, Dynamical Systems and SymmetryP. Holmes, J. L. Lumley, G. Berkooz, and C. W. Rowley, 2nd ed., Cambridge University Press, Cambridge, England, U.K., 2012, 386 pp., $90

A review of energy systems models in the UK: Prevalent usage and categorisation

NOx emissions have always been a main concern in the development of diesel engines. This paper summarizes the studies about NOx emission reduction in diesel engines. The need for meeting the stringent requirements with regard to NOx emissions in a diesel engine has led to the development of a range of after treatment techniques. After treatment methods are required to reduce NOx emissions that cannot be controlled by fuel composition and combustion phenomena. Current after treatment techniques that are being employed are Selective Catalytic Reduction (SCR), Lean NOx Trap (LNT) and SCR Filter (SCRF). The benefits and constraints of different types of SCR are discussed. Urea SCR is a prominent well proven technology. Urea SCR produces 96–99% conversion efficiency with the help of a reductant NH 3 . The operating parameters such as nature of catalyst, temperature range of catalyst, flow of DEF (Diesel Exhaust fluid) to injector and mixing of NH 3 and NOx are discussed. Hybrid SCR such as Cu-SCR + Fe-SCR, SCR + LNT moderates fuel consumption and augments the catalytic activity at low temperature. SCRF has low cell density (200–300 csi vs 400–600 csi for SCR), and also has lower deNOx efficiency for a number of reasons. Pre-stored NH 3 and Preheating helps in low temperature reaction of SCRF. Technical problems in aqueous urea systems have led to the evolution of solid SCR system (SSCR). This review incorporates the study of solid ammonium salts decomposition, temperature range of the salts and infrastructure required for SSCR.

A review on various after treatment techniques to reduce NOx emissions in a CI engine

Predictive Control Strategies based on Weather Forecast in Buildings with Energy Storage System: A Review of the State-of-the Art

https://heemels.tue.nl/content/papers/RicHee_AUT11a.pdf

Reconfigurable control of piecewise affine systems with actuator and sensor faults: Stability and tracking

Introduction to Control Reconfiguration.- Literature Overview.- Part I. Reconfiguration Problem.- Running Example: the 2-Tank System.- General Reconfiguration Problem.- Part II. Linear Solution Approaches.- Direct Reconfiguration Using a Static Block.- Reconfiguration Using a Virtual Sensor.- Reconfiguration Using a Virtual Actuator.- Reconfiguration with Set-Point Tracking.- Reconfiguration by Disturbance Decoupling.- Part III. Structural Tests for Control Reconfiguration.- Structural Models.- Basic Structural Properties.- Solvability of Disturbance Decoupling.- Structural Solutions to Disturbance Decoupling.- A Structural Reconfiguration Algorithm for Actuator Faults.- Part IV. Application Examples.- Reconfiguration of the 3-Tank System.- Reconfiguration of a Helicopter Model.- Conclusion.

Control Reconfiguration of Dynamical Systems: Linear Approaches and Structural Tests

This paper addresses the control of a system after an actuator has failed: A reconfiguration of the control structure is sought which keeps the system operational. The goal is to find a different set of actuators for controlling the plant and to use them in such a way that the plant output is identical to the output of the nominal closed-loop system. It is further required that the nominal controller remains part of the reconfigured control loop. This paper shows that this reconfiguration problem is equivalent to a disturbance decoupling problem which is solved by means of the geometric approach. The resulting solution is a reconfiguration block, which generates suitable inputs for the faulty plant based on the output of the nominal controller. The feasibility of this approach is demonstrated by a physical experiment with a helicopter model

Control Reconfiguration After Actuator Failures Using Disturbance Decoupling Methods

Selective Catalytic Reduction (SCR) is a leading after treatment technology for the removal of nitrogen oxide (NOx) from exhaust gases (DeNOx). It presents an interesting control challenge, especially at high conversion, because both reagents (NOx and ammonia) are toxic, and therefore an excess of either is highly undesirable. Numerous system layouts and control methods have been developed for SCR systems, driven by the need to meet future emission standards. This paper summarizes the current state-of-the-art control methods for the SCR aftertreatment systems, and provides a structured and comprehensive overview of the research on SCR control. The existing control techniques fall into three main categories: traditional SCR control methods, model-based SCR control methods, and advanced SCR control methods. For each category, the basic control technique is defined. Further techniques in the same category are then explained and appreciated for their relative advantages and disadvantages. Thus this paper presents a snapshot of the current state of the art for the research area of SCR control. This is a very active field, and it is hoped that by providing a better understanding of the different control strategies already developed for SCR control, future areas of interest will be identified and developed with the ultimate aim of satisfying the increasingly stringent emissions legislation. Copyright © 2014 SAE International.

/pdf/the-state-of-the-art-in-selective-catalytic-reduction-j27ks8i09k.pdf

Thomas Steffen

Papers

Control Reconfiguration of Dynamical Systems: Linear Approaches and Structural Tests

Control Reconfiguration After Actuator Failures Using Disturbance Decoupling Methods

The State of the Art in Selective Catalytic Reduction Control

Investigating the performance of a combined solar system with heat pump for houses

Characterisation, control, and energy management of electrified turbocharged diesel engines