Loading and Regeneration Analysis of a Diesel Particulate Filter with a Radio Frequency-Based Sensor

Sappok, Alexander; Bromberg, L.; Parks, James E.; Prikhodko, Vitaly Y.

doi:10.4271/2010-01-2126

Cited by 60 publications

(40 citation statements)

References 12 publications

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“…The new approach measures the transmission of microwaves in the lower GHz-range, which is strongly correlated with the soot mass trapped in the catalyst. It has been proven that the systems are basically suitable and very promising to measure the soot load precisely [5][6][7][8][9]. In the present study, it is examined, how temperature # and absolute humidity H influence this new soot load determination method.…”

Section: Introductionmentioning

confidence: 99%

Influencing Parameters on the Microwave-Based Soot Load Determination of Diesel Particulate Filters

et al. 2016

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Diesel Particulate Filters (DPF) are an essential part of today's diesel exhaust gas aftertreatment systems. For an effective filter regeneration strategy, the precise knowledge of the actual trapped soot mass is essential. Besides the state-of-the-art technology of determining the soot load via pressure drop and/or model-based, a microwave-based method enables direct and in situ soot load detection. Thereby, an electric field is impressed into the filter housing and the power transmission is measured, which correlates with the soot load. In this study, influencing parameters, especially temperature and humidity, are examined and compared to the sensitivity towards soot accumulation. Measurements were conducted in a laboratory test bench with a filter-core, which had been previously loaded with soot in an engine dynamometer. While humidity does not have a notable effect, the influence of temperature needs to be considered for real world application. Finally, a complete filter regeneration of the DPFcore in the laboratory test bench could be monitored with the microwave-based system. The carbon balance-derived burned soot mass coincides very well with the microwave derived transmission parameter.

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Section: Introductionmentioning

confidence: 99%

Influencing Parameters on the Microwave-Based Soot Load Determination of Diesel Particulate Filters

et al. 2016

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“…Even for novel exhaust catalyst systems, like NH3-SCR catalysts, where the amount of stored ammonia needs to be detected [13] or for diesel particulate filters, where the amount of stored soot is an important measurand [14], this microwave-based technique can be applied. A recent overview on this technique is given in [15].…”

Section: Introductionmentioning

confidence: 99%

In operando Detection of Three-Way Catalyst Aging by a Microwave-Based Method: Initial Studies

2015

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Initial studies on aging detection of three way catalysts with a microwave cavity perturbation method were conducted. Two physico-chemical effects correlate with the aging state. At high temperatures, the resonance frequencies for oxidized catalysts (λ = 1.02) are not influenced by aging, but are significantly affected by aging in the reduced case (λ = 0.98). The catalyst aging state can therefore potentially be inferred from the resonance frequency differences between reduced and oxidized states or from the resonance frequency amplitudes during lambda oscillations. Secondly, adsorbed water at low temperatures strongly affects the resonance frequencies. Light-off experiment studies showed that the resonance frequency depends on the aging state at temperatures below the oxygen storage light-off. These differences were attributed to different water sorption capabilities of differently aged samples due to a surface area decrease with proceeding aging. In addition to the aging state, the water content in the feed gas and the temperature affect the amount of adsorbed water, leading to different integral electrical material properties of the catalyst and changing the resonance properties of the catalyst-filled canning. The classical aging-related properties of the catalyst (oxygen storage capacity, oxygen storage light-off, surface area), agreed very well with data obtained by the microwave-based method. OPEN ACCESSAppl. Sci. 2015, 5 175

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“…Instead, they are intended to detect the status of full-sized exhaust gas aftertreatment devices during operation on the road. Typical applications are the determination of the oxygen loading of three-way catalytic converters (Moos et al, 2008Beulertz et al, 2013;Reiß et al, 2011a), or the soot loading (Sappok et al, 2010;Feulner et al, 2013) or ash loading (Kulkarni et al, 2013) of fullsized diesel particulate filters. The storage degree of NO in lean NO x traps (Fremerey et al, 2011;Moos et al, 2009) and the NH 3 loading on SCR catalyst devices have also been successfully monitored (Reiß et al, 2011b;Rauch et al, 2014Rauch et al, , 2015 using the cavity perturbation method.…”

Section: Introductionmentioning

confidence: 99%

Ammonia storage studies on H-ZSM-5 zeolites by microwave cavity perturbation: correlation of dielectric properties with ammonia storage

Dietrich

Rauch

Simon

et al. 2015

J. Sens. Sens. Syst.

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Abstract.To meet today's emission standards, the ammonia-based selective catalytic reduction (SCR) has become the major NO x control strategy for light and heavy diesel engines. Before NO x reduction can proceed, adsorption of ammonia on the acidic sites of the catalyst is necessary. For improvements in efficiency and control of the exhaust gas aftertreatment, a better understanding of the ammonia storage on the acidic sites of zeolite-based SCR catalysts is needed. Thereby, the correlation of dielectric properties of the catalyst material itself with the ammonia storage is a promising approach. Recently, a laboratory setup using microwave cavity perturbation to measure the dielectric properties of catalyst material has been described. This study shows the first experimental data on zeolite-based SCR materials in their H-form. The SCR powder samples are monitored by microwave cavity perturbation while storing and depleting ammonia, both with and without admixed NO x at different temperatures. Its complex dielectric permittivity is found to correlate closely with the stored mass of ammonia. The influence of the temperature and the Si / Al ratio of the zeolite to the ammonia storage behavior are also examined. These measurements disclose different temperature dependencies and differing sensitivities to ammonia storage for both real and imaginary parts of the complex permittivity. The apparent constant sensitivity of the real part can be related to the polarity of the adsorbed ammonia molecules, whereas the imaginary part depends on the Si / Al ratio and is related to the conductivity mechanisms of the zeolite material by proton hopping. It provides information about the zeolite structure and the number of (and the distance between) acidic storage sites, in addition to the stored ammonia mass.

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Loading and Regeneration Analysis of a Diesel Particulate Filter with a Radio Frequency-Based Sensor

Cited by 60 publications

References 12 publications

Influencing Parameters on the Microwave-Based Soot Load Determination of Diesel Particulate Filters

Influencing Parameters on the Microwave-Based Soot Load Determination of Diesel Particulate Filters

In operando Detection of Three-Way Catalyst Aging by a Microwave-Based Method: Initial Studies

Ammonia storage studies on H-ZSM-5 zeolites by microwave cavity perturbation: correlation of dielectric properties with ammonia storage

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