Modeling of Thermophoretic Soot Deposition and Stabilization on Cooled Surfaces

Mehravaran, Meisam; Brereton, G. J.

doi:10.4271/2011-01-2183

Cited by 12 publications

(4 citation statements)

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“…The models proposed by Teng and Regner [58,59], Teng [60], Mehravaran and Brereton [61], Reza Razmavar and Reza Malayeri [62], Sul et al [63], and Kuan et al [64] belong to this fourth category. These models compute the deterioration of the heat exchanger effectiveness caused by the fouling layer growth and calculate the increase in pressure drop along the device.…”

Section: Good Agreement Observedmentioning

confidence: 98%

“…Semiempirical model that predicts cooler effectiveness degradation and pressure drop over fouled EGR coolers Mehravaran and Brereton [61] • Thermophoresis • Thermophoresis hydrocarbon and water condensates. These simplified models are based on the assumption that thermophoretic effect is three to four orders of magnitude bigger than other deposition mechanisms, and during the first stages of the deposit growth, the removal of particles does not take place [54].…”

Section: Good Agreement Observedmentioning

confidence: 99%

“…On the one hand, with regard to the particle deposition process, thermophoresis is, in the majority of cases, the only referred deposition mechanism. Although some of these numerical approaches take into consideration the deposition of particulate matter due both to diffusion and thermophoretic effect, such as the model of Mehravaran and Brereton [61], the simulation of the deposition phenomenon of the remaining models is, on an exclusive basis, the calculation of the thermophoretic coefficient.…”

Section: Good Agreement Observedmentioning

confidence: 99%

See 2 more Smart Citations

Numerical Modelling of Fouling Process in EGR System: A Review

Paz¹,

Suárez²,

Vence³

et al. 2021

Environmental Issues and Sustainable Development

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In order to combat climate change, the new rigorous standards for pollutant reduction have shone a light on the use of exhaust gas recirculation system in order to minimize the NOx emissions of vehicles. For this reason, the fouling problem that appears on the exhaust gas recirculation line, caused by the deposition of soot particles and hydrocarbons that are part of the exhaust gas, has become particularly relevant in the last few years. In this field, researches have proposed numerical models in order to estimate and predict the deposit formation and growth. Using various numerical techniques, they intend to determine and reproduce the fouling layer buildup considering the different mechanisms that are involved in the deposit formation. This chapter provides a detailed and comprehensive account of the numerical approaches that have been proposed to analyze the fouling phenomenon that occurs inside the exhaust gas system. The main characteristics of each numerical model, as well as their main strengths and weaknesses, are exposed and evaluated, and their simulation capabilities are examined in detail.

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Section: Good Agreement Observedmentioning

confidence: 98%

Section: Good Agreement Observedmentioning

confidence: 99%

Section: Good Agreement Observedmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Modelling of Fouling Process in EGR System: A Review

Paz¹,

Suárez²,

Vence³

et al. 2021

Environmental Issues and Sustainable Development

View full text Add to dashboard Cite

show abstract

“…Although the fouling mechanism inside the EGR coolers is not fully understood, most argue that thermophoresis and hydrocarbon condensation are the dominant processes. Several investigators have attempted modeling these processes to predict the deposition velocity, soot layer thickness, and possible removal mechanisms [19][20][21][22][23]. However, the models are usually either ID or 2D, based on several assumptions, and cannot exactly match experimental results.…”

Section: Introductionmentioning

confidence: 99%

Effect of Engine Operating Conditions and Coolant Temperature on the Physical and Chemical Properties of Deposits From an Automotive Exhaust Gas Recirculation Cooler

Prabhakar

Boehman

2013

Journal of Engineering for Gas Turbines and Power

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The effect of engine operating conditions on exhaust gas recirculation (EGR) cooler fouling was studied using a 6.4 L V-8 common rail turbodiesel engine. An experimental setup, which included a custom-made shell and tube heat exchanger (EGR cooler) with six surrogate tubes, was designed to control flow variables independently. The engine was operated at 2150 rpm, 203 Nm and 1400 rpm, 81 Nm, representing medium and low load conditions, respectively, and the coolant to the heat exchanger was circulated at 85 °C and 40 °C. Heat exchanger effectiveness and pressure drop was monitored throughout the tests. Deposits from the EGR cooler were collected every 1.5 h for a total of9h, and their microstructure was analyzed using a scanning electron microscope while their chemical composition was analyzed using a pyrolysis GC-MS apparatus, and the elemental weight percentages were obtained using a CHN analyzer. The results of these analyses showed that the effectiveness of the EGR cooler drops rapidly initially and asymptotes in a few hours. The medium load condition had a higher effectiveness loss due to a greater accumulation of deposits inside the EGR cooler, mostly due to increased thermophoresis, and produced smaller and coarse particles. The low load condition had lower effiectiveness loss but produced bigger particles mostly due to excess hydrocarbons. Coolant temperature played a significant role in altering the deposit microstructure and in increasing the amount of condensed hydrocarbons. More deposits were produced for the cold coolant condition, indicating that lower coolant temperature promotes greater hydrocarbon condensation and thermophoresis. These results indicate the complex nature of folding in automotive heat exchangers.

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