Statistically supported real driving emission calibration: Using cycle generation to provide vehicle-specific and statistically representative test scenarios for Euro 7

The progression of emission legislation has intensified the efforts of the automotive industry to develop improved exhaust gas after-treatment systems. The requirement to fulfill Euro 6d-TEMP in real-world driving scenarios, the already significant calibration effort for Euro 6d and the Euro 7 emission standards in discussion have significantly increased the work load for calibration engineers and the requirements for testing resources. Many original equipment manufacturers are implementing taskforces in order not to have to discard the planned start of production for their products, and some are even already forced to reduce their product portfolio. This is due to the diverse testing matrix required to cover all possible real driving emissions test scenarios. One big challenge is the extension and possible variation of boundary conditions regarding ambient temperatures, traffic conditions, road gradients and other varying driving resistances. Moreover, the test duration can cause considerable differences in the measured emissions, even if the same route is driven repeatedly. Addressing these challenges makes the application of a dedicated, event-targeted emission calibration mandatory. Since only a few sequences of the time-consuming road tests are relevant for improving the emission calibration, the methodology presented in this article focuses on the exact reproduction of these emission events on an emission chassis dynamometer with the aim of implementing calibratable solutions for these events. This is done using a real driving emission-cycle-generator which creates real driving emission compliant severe test scenarios and which focuses on the statistical relevance related to the typical product specific operation. The underlying generation process accesses a large database with real driving emission measurement results focusing on vehicle- or vehicle-group-specific challenges, using statistical approaches. It will be demonstrated how this procedure reduces test time and how it helps to tackle the substantial real driving emission work-load, while providing a dependable base to achieve real driving emission legislation compliance.

THE ADVANTAGES OF USING DUAL-FUEL ENGINE COMPARED TO THE CONVENTIONAL ENGINE

Flexible dual-fuel power technology is becoming increasingly important in a marine market where fuel oil prices are fluctuating and emission legislation is becoming ever more stringent.The advantage of the dual-fuel technology is, without doubt, fuel flexibility. This technology makes it possible to utilise the economic and environmental superiority of gas fuel. The benefits of natural gas are low price and good environmental compatibility, thanks to its clean combustion.The main objective of the present work is to provide a more comprehensive view of the advantages of choosing a dual fuel engine instead of the conventional engine. For this analysis will be considered two ships and will also be taken into account the Energy Efficiency Operational Indicator (EEOI).

Marine science within a net-zero emission statutory framework

Inspired by the growing cries from young climate crisis activists, and noting that net-zero emission legislation is growing in frequency across Europe and globally, this paper briefly discuses some ways in which marine science might respond. Marine science can provide governments support and advice for emission-reducing policies and actions, as well as tackling our own emissions. Supporting government actions will require new and innovative science. While implementing this science, as a community, we can lead by example in bringing about change in the way professionals do business and hence reducing business’s overall carbon footprint. After all, if environmental science cannot change, why should the rest of society?

Charging-Based PN Sensing of Automotive Exhaust Particles

Mobile measurement of particle number concentration (PN) in the exhaust of motor vehicles has recently become an integral part of emission legislation. Charge-based sensing techniques for the examination of PN, like Diffusion Charging (DC), represent a promising alternative to condensational particle counters (CPCs) as established PN sensors, because they enable to build robust, compact and energy efficient systems. However, due to the charging process, particle properties like size and morphology have a big impact on the sensor’s PN response. For particles of different size and shape we experimentally investigated those impacts using own-built charging-based sensors. The PN response of the DC sensor showed desired behavior for compact NaCl particles, but less satisfying behavior for combustion aerosol standard (CAST) particles, which is a widely used test aerosol for automotive applications. With a photoelectric charger, the PN response of CAST particles was significantly better.