117371 20231006143307.0 doi 10.3390/su132313424 sideral 127015 ART-2021-127015 eng Fernández E. (orcid)0000-0001-6765-4218 A new approach for static NOx measurement in PTI 2021 Access copy available to the general public Unrestricted NOx emissions in vehicles are currently only controlled through the homologation process. There is a lack of knowledge to assess and control real NOx emissions of vehicles reliably. Even if vehicles in EU-27 are subject to Periodical Technical Inspection (PTI), NOx are not among the pollutants currently being controlled. For PTIs, tests need to be simple, quick, inexpensive, representative, and accurate. Ideally, tests need to be carried out under static conditions, without the need for a power bench or complex equipment. In this paper, a new approach for measuring NOx in PTI is proposed. The method has been developed and validated at a PTI Spanish station to ensure feasibility and repeatability. This method is based on the relationship between the “% engine load” value and exhaust NOx concentration at idle engine speed. Starting from the state of minimum possible power demand in a vehicle (idling and without any consumption), a load state with an average 98% increase in engine power demand is generated by connecting elements of the vehicle’s equipment. The relationship between power demand (through the “% engine load” value) and NOx concentration is then analyzed. The quality and representativity of this relationship have been checked with a p-value lower than 0.01. The method has been compared with a different NOx measurement technique, based on the simulation on a test bench and the ASM 2050 cycle, showing better performance in terms of repeatability and representativeness. The “% engine load” dispersion with the new approach is 7%, which ensures the reliability and repeatability of the method. The results show that the proposed method could be a valuable tool in PTI to detect high NOx emitting vehicles and to obtain information from the diesel vehicles fleet. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 3.889 2021 ENVIRONMENTAL STUDIES 57 / 128 = 0.445 2021 Q2 T2 ENVIRONMENTAL SCIENCES 133 / 279 = 0.477 2021 Q2 T2 GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY 35 / 47 = 0.745 2021 Q3 T3 GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY 7 / 9 = 0.778 2021 Q4 T3 0.664 2021 Energy Engineering and Power Technology 2021 Q1 Renewable Energy, Sustainability and the Environment 2021 Q1 Management, Monitoring, Policy and Law 2021 Q1 Geography, Planning and Development 2021 Q1 5.0 2021 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Valero A. Universidad de Zaragoza (orcid)0000-0003-3330-1793 Alba J.J. Universidad de Zaragoza (orcid)0000-0003-4440-830X Ortego A. Universidad de Zaragoza (orcid)0000-0002-6148-1253 5004 530 Universidad de Zaragoza Dpto. Ingeniería Mecánica Área Ingen.e Infraestr.Transp. 5004 590 Universidad de Zaragoza Dpto. Ingeniería Mecánica Área Máquinas y Motores Térmi. 13, 23 (2021), 13424 [34 pp] Sustainability (Basel) Sustainability (Switzerland) 2071-1050 2543925 http://zaguan.unizar.es/record/117371/files/texto_completo.pdf Versión publicada 2762139 http://zaguan.unizar.es/record/117371/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:117371 articulos driver 2023-10-06-14:08:53 ARTICLE