A new approach for health-oriented ozone control strategy: adjoint-based optimization of NOx emission reductions using metaheuristic algorithms

2021 ◽  
pp. 127533
Author(s):  
Mengya Wang ◽  
Tao Huang ◽  
David C. Wong ◽  
Kin Fai Ho ◽  
Guanghui Dong ◽  
...  
Keyword(s):  
Control Strategy ◽  
Metaheuristic Algorithms ◽  
Nox Emission ◽  
Emission Reductions ◽  
New Approach ◽  
Ozone Control

scholarly journals Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City

2009 ◽  
Vol 9 (1) ◽  
pp. 39-55 ◽  
Author(s):  
M. Zavala ◽  
W. Lei ◽  
M. J. Molina ◽  
L. T. Molina
Keyword(s):  
Mexico City ◽  
Emission Control ◽  
Emission Factors ◽  
Nox Emission ◽  
Base Case ◽  
Mobile Source ◽  
Historical Trends ◽  
Emission Reductions ◽  
Control Policies ◽  
The Past

Abstract. The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

scholarly journals Measurement and model analyses of the ozone variation during 2006 to 2015 and its response to emission change in megacity Shanghai, China

2019 ◽  
Author(s):  
Jianming Xu ◽  
Xuexi Tie ◽  
Wei Gao ◽  
Yanfen Lin ◽  
Qingyan Fu
Keyword(s):  
Control Strategy ◽  
Fine Particles ◽  
Action Plan ◽  
Nox Reduction ◽  
Nox Emission ◽  
Transition Regime ◽  
Local Dispersion ◽  
Clean Air ◽  
Reduction Of Nox ◽  
Emission Change

Abstract. The fine particles (PM2.5) in China decrease significantly in recent years as a result of the implement of Chinese Clean Air Action Plan since 2013, while the O3 pollution is getting worse, especially in megacities such as Beijing and Shanghai. Better understanding the elevated O3 pollution in Chinese megacities and its response to emission change is important for developing an effective emission control strategy in future. In this study, we analyze the significant increasing trend of O3 concentration from 2006 to 2015 in the megacity Shanghai with the variability of 1–1.3 ppbv yr-1. It is likely attributed to the notable reduction of NOx concentration with the decreasing rate of 1.86–2.15 ppbv yr-1 accompanied with the little change of VOCs during the same period excluding the weak trends of meteorological impacts on local dispersion (wind speed), regional transport (wind direction) and O3 photolysis (solar radiation). It is further illustrated by using a state of the art regional chemical/dynamical model (WRF-Chem) to explore the O3 variation response to the reduction of NOx emission in Shanghai. The control experiment conducted in September of 2009 shows very excellent performance for O3 and NOx simulations including both the spatial distribution pattern, and the day by day variation by comparing with 6 in-situ measurements from MIRAGE-shanghai field campaign. Sensitive experiments with 30 % reduction of NOx emission from 2009 to 2015 in Shanghai estimated by Shanghai Environmental Monitoring Center shows that the calculated O3 concentrations exhibit obvious enhancement by 4–7 ppbv in urban zones with the increasing variability of 0.96–1.06 ppbv yr-1, which is well consistent with the observed O3 trend as a result of the strong VOC-limited condition for O3 production. The large reduction of NOx combined with less change of VOCs during the past ten years promotes the O3 production in Shanghai to move towards NOx-limited regime. Further analysis of WRF-Chem experiments and O3 isopleths diagram suggests that the O3 production in downtown is still under VOC-limited regime after 2015 despite of the remarkable NOx reduction, while moves to the transition regime between NOx-limited and VOC-limited in sub-urban zones. Supposing the insignificant VOCs variation persists, the O3 concentration in downtown would keep increasing till 2020 with the further 20 % reduction of NOx emission after 2015 estimated by Shanghai Clean Air Action Plan. While there are less O3 change in other regions where the O3 production is not under VOC-limited regime. The O3 production in Shanghai will switch from VOC-limited to NOx-limited regime after 2020 except downtown area which is likely close to the transition regime. As a result the O3 concentration will decrease by 2–3 ppbv in sub-urban zones, and more than 4 ppbv in suburb response to 20 % reduction of NOx emission after 2020, whereas is not sensitive to both NOx and VOCs changes in downtown. This result reveals that the control strategy of O3 pollution is a very complex process, and needs to be carefully studied.

Nonlinear Two Stage Control Strategy of a Wind Turbine for Mechanical Load and Extreme Moment Reduction

2011 ◽  
Author(s):  
Jonathan Chauvin ◽  
Yann Creff
Keyword(s):  
Control Strategy ◽  
Nonlinear Dynamic ◽  
Mechanical Load ◽  
Dynamic Feedback ◽  
Rotor Speed ◽  
Model Uncertainties ◽  
New Approach ◽  
Control Approach ◽  
Second Stage ◽  
Speed Regulation

This paper presents a new approach for the control of wind turbines. The proposed strategy can be decomposed in two part. In a first stage control strategy, we provide a nonlinear dynamic feedforward strategy for rotor speed regulation along with a nonlinear dynamic feedback to be robust to model uncertainties. It guarantees convergence of the rotor speed to its desired value. This first part only looks at the rotor dynamics and the aerodynamics. The tower dynamics is not taken into account. In a second stage control strategy, we provide a control action that minimize the tower fatigue. The strategy is largely validated for the onshore case. The proposed control approach can be extended to the offshore case and a first validation is proposed.

scholarly journals A new approach for visual identification of orange varieties using neural networks and metaheuristic algorithms

2018 ◽  
Vol 5 (1) ◽  
pp. 162-172 ◽  
Author(s):  
Sajad Sabzi ◽  
Yousef Abbaspour-Gilandeh ◽  
Ginés García-Mateos
Keyword(s):  
Neural Networks ◽  
Metaheuristic Algorithms ◽  
New Approach ◽  
Visual Identification

Control Strategy for NOx - Emission Reduction with SCR

2003 ◽  
Author(s):  
Dieter H. E. Seher ◽  
Michael Reichelt ◽  
Stefan Wickert
Keyword(s):  
Control Strategy ◽  
Emission Reduction ◽  
Nox Emission

Identification and Fractional Super-Twisting Robust Control of IPMC Actuators

2015 ◽  
Vol 18 (6) ◽  
Author(s):  
Riccardo Caponetto ◽  
Salvatore Graziani ◽  
Vincenzo Tomasello ◽  
Alessandro Pisano
Keyword(s):  
Control Strategy ◽  
Ad Hoc ◽  
Theoretical Aspect ◽  
Ionic Polymer Metal Composites ◽  
New Approach ◽  
Ionic Polymer ◽  
Pi Controllers ◽  
Polymer Metal ◽  
Twisting Control ◽  
Super Twisting Control

AbstractIn this paper Ionic Polymer-Metal Composites (IPMC) actuators motion control is addressed by using a new approach based on the modified fractional super twisting control strategy. We present the theoretical aspect of the proposed control strategy and then the performances of the controlling strategy are validated for an IPMC actuator by using an ad hoc developed experimental setup. The reported results show that the standard fractional super twisting control and the proposed modified fractional super twisting control over perform standard PI controllers.

A new approach for estimation of the effect of NOx emission reduction on roadside NO2 concentration in Tokyo

2013 ◽  
Vol 68 ◽  
pp. 92-102 ◽  
Author(s):  
Hideto Takekawa ◽  
Satoru Chatani ◽  
Akiyoshi Ito
Keyword(s):  
Emission Reduction ◽  
Nox Emission ◽  
New Approach

scholarly journals Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City

2008 ◽  
Vol 8 (4) ◽  
pp. 14991-15030 ◽  
Author(s):  
M. Zavala ◽  
W. F. Lei ◽  
M. J. Molina ◽  
L. T. Molina
Keyword(s):  
Mexico City ◽  
Emission Control ◽  
Emission Factors ◽  
Nox Emission ◽  
Base Case ◽  
Mobile Source ◽  
Historical Trends ◽  
Emission Reductions ◽  
Control Policies ◽  
The Past

Abstract. The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

scholarly journals A Study on the Ozone Control Strategy using the OZIPR in the Seoul Metropolitan Area

2012 ◽  
Vol 6 (2) ◽  
pp. 111-117 ◽  
Author(s):  
Lan Jin ◽  
Sun-Hwa Lee ◽  
Hye-Jung Shin ◽  
Yong Pyo Kim
Keyword(s):  
Metropolitan Area ◽  
Control Strategy ◽  
Seoul Metropolitan Area ◽  
Ozone Control

scholarly journals Non-linear response of PM2.5 to changes in NO<sub>x</sub> and NH<sub>3</sub> emissions in the Po basin (Italy): consequences for air quality plans

2021 ◽  
Author(s):  
Philippe Thunis ◽  
Alain Clappier ◽  
Matthias Beekmann ◽  
Jean Philippe Putaud ◽  
Cornelis Cuvelier ◽  
...  
Keyword(s):  
Air Quality ◽  
Emission Reduction ◽  
Oxidative Capacity ◽  
Nox Emission ◽  
Aerosol Formation ◽  
Linear Processes ◽  
Emission Reductions ◽  
Nh3 Emission ◽  
Non Linear ◽  
Pm2.5 Concentration

Abstract. Air pollution is one of the main causes of damages to human health in Europe with an estimate of about 380 000 premature deaths per year in the EU28, as the result of exposure to fine particulate matter (PM2.5) only. In this work, we focus on one specific region in Europe, the Po basin, a region where chemical regimes are the most complex, showing important non-linear processes, especially those related to interactions between NOx and NH3. We analyse the sensitivities of PM2.5 to NOx and NH3 emissions by means of a set of EMEP simulations performed with different levels of emission reductions, from 25 % up to a total switch-off of those emissions. Both single and combined precursor reduction scenarios are applied to determine the most efficient emission reduction strategies and quantify the interactions between NOx and NH3 emission reductions. The results confirmed the peculiarity of secondary PM2.5 formation in the Po basin, characterised by contrasting chemical regimes within distances of few (hundreds of) kilometres, as well as strong non-linear responses to emission reductions during wintertime. One of the striking results is the increase of the PM2.5 concentration levels when NOx emission reductions are applied in NOx-rich areas, such as the surroundings of Bergamo. The increased oxidative capacity of the atmosphere is the cause of the increase of PM2.5 induced by a reduction in NOx emission. This process can have contributed to the absence of significant PM2.5 concentration decrease during the COVID-19 lockdowns in many European cities. It is important to account for this process when designing air quality plans, since it could well lead to transitionary increases in PM2.5 at some locations in winter as NOx emission reduction measures are gradually implemented. While PM2.5 responses to NOx and NH3 emission reduction show large variations seasonally and spatially, these responses remain close to linear, i.e. proportional to the emission reduction levels, at least up to −50 % because secondary aerosol formation chemical regimes are not modified by those relatively moderate ranges.

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