Combustion stability and hetero-/homogeneous chemistry interactions for fuel-lean hydrogen/air mixtures in platinum-coated microchannels

Sui, Ran; Mantzaras, John

doi:10.1016/j.combustflame.2016.08.011

Cited by 41 publications

(15 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…48 An implicit discretisation scheme, featuring two-point backward differencing for the x-direction and central differencing for the cross-stream (y-) direction, was used. 46 The surface and gas phase chemistries are coupled according to Coltrin et al 49 by balancing the species flux at the gas-wall interface with the mass-weighted production rate at the 17,49,50 The resulting system of algebraic equations is highly nonlinear and a Newton linearisation, featuring an analytical evaluation of the derivatives, was utilised for the source term. 46 The resulting method is computationally stable and results in an efficient block tri-diagonal matrix structure.…”

Section: Methodsmentioning

confidence: 99%

“…). 17,49,50 The resulting system of algebraic equations is highly nonlinear and a Newton linearization, featuring an analytical evaluation of the derivatives, was utilized for the source term. 46 The resulting method is computationally stable and results in an efficient block tridiagonal matrix structure.…”

Section: Methodsmentioning

confidence: 99%

“…The surface and gas phase chemistries are coupled according to Coltrin et al by balancing the species flux at the gas–wall interface with the mass-weighted production rate at the catalytic wall J i + ρY i v s = R i M i , where v s is the Stephan velocity ( ). ,, The resulting system of algebraic equations is highly nonlinear and a Newton linearization, featuring an analytical evaluation of the derivatives, was utilized for the source term . The resulting method is computationally stable and results in an efficient block tridiagonal matrix structure.…”

Section: Computational Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Microkinetic Mechanisms for Partial Oxidation of Methane over Platinum and Rhodium

Kraus

Lindstedt

2017

J. Phys. Chem. C

View full text Add to dashboard Cite

A systematic approach for the development of heterogeneous mechanisms is applied and evaluated for the catalytic partial oxidation of methane over platinum (Pt) and rhodium (Rh). The derived mechanisms are self-consistent and based on a reaction class-based framework comprising variational transition state theory (VTST) and two-dimensional collision theory for the calculation of pre-exponential factors with barrier heights obtained using the unity bond index-quadratic exponential potential (UBI-QEP) method. The surface chemistry is combined with a detailed chemistry for the gas phase and the accuracy of the approach is evaluated over Pt for a wide range of stoichiometries (0.3 ≤ φ ≤ 4.0), pressures (2 ≤ P (bar) ≤ 16) and residence times. It is shown that the derived mechanism can reproduce experimental data with an accuracy comparable to the prevalent collision theory approach and without the reliance on experimental data for sticking coefficients. The derived mechanism for Rh shows encouraging agreement for a similar set of conditions and the robustness of the approach is further evaluated by incorporating partial updates via more accurate DFT determined barrier heights. Substantial differences are noted for some channels (e.g. where reaction progress is strongly influenced by early transition states) though the impact on the overall agreement with experimental data is moderate for the current systems. Remaining discrepancies are explored using sensitivity analyses to establish key parameters. The study suggests that the overall framework is well-suited for the efficient generation of heterogeneous reaction mechanisms, that it can serve to identify key parameters where high accuracy ab initio methods are required and that it permits the inclusion of such updates as part of a gradual refinement process.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Computational Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Microkinetic Mechanisms for Partial Oxidation of Methane over Platinum and Rhodium

Kraus

Lindstedt

2017

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…Later, Chen et al 9 compared the hetero−/homogeneous combustion of propane–air, and they found that the range of stable combustion of catalytic combustion is significantly larger than homogeneous combustion. Sui and Mantzaras 10 investigated the hetero‐/homogeneous combustion characteristics of hydrogen/air in a channel. The results indicated that the catalytic combustion could be sustained even the temperature range from 320 to 380 K, the homogeneous flame is extinct at the same time.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of combustion and radiation performances in a counterflow double‐channel combustor with pin fins for micro‐thermophotovoltaic system

Gao

Yan

Zhang

et al. 2021

Intl J of Energy Research

View full text Add to dashboard Cite

Summary As one vital role component of micro‐thermophotovoltaic (MTPV) system, the combustion characteristics of the micro‐combustor directly affect the wall temperature distribution and the MTPV system efficiency. Combined with the advantages of counterflow and pin rib arrangement, a counterflow double‐channel micro‐combustor with pin fins (combustor C) was built to enhance the heat transfer and improve the wall temperature. The combustion performances and radiation performances of single‐channel micro‐combustor (combustor A), counterflow double‐channel micro‐combustor (combustor B), and combustor C were investigated and compared under different mass flow rates (4~12 × 10−5 kg/s) and equivalence ratios (0.6~1.4). Results show that the pin fin is of positive significance for the fixation of flame root to improve the combustion stability, combustion efficiency, and radiation energy when the total mass flow rate is high, especially. When the mass flow rate is low, the combustion efficiency of combustor C is the lowest due to the limitation of combustion space. However, with the increase of the mass flow rate, the combustion characteristics of combustor C are the best due to the flame front area is larger among the three combustors and the flame root position is closer to the inlet area. The radiation energy, radiation efficiency, and mean temperature of the upper wall of the combustor C are significantly higher than other combustors under the same conditions. When the total mass flow rate is 12 × 10−5 kg/s, the radiation energy of combustor C is 0.51 times and 0.36 times that of combustor A and B, respectively. When the equivalence ratio is 1.0, the mean upper wall temperature of combustor C is 175.87 and 128.904 K higher than of combustor A and B, respectively. The counterflow double‐channels combustors have better wall temperature uniformity than single‐channel combustor under a wide range of working conditions.

show abstract

“…Chen et al 16 obtained that propane‐air flame is stable in the catalytic micro‐combustor with submillimeter gap, which is much more stable than the homogeneous counterparts. Sui et al 17 found that unbalanced diffusion of hydrogen would cause catalytically induced superadiabatic surface temperatures and the existence of gaseous chemistry would inhibit the superadiabaticity, which causes rich combustion phenomena. Mantzaras and Benz 18 firstly claimed Pt could delay homogeneous ignition.…”

Section: Introductionmentioning

confidence: 99%

Catalytic combustion characteristics of CH ₄ in the micro cavity‐combustor under different types of air inlet distribution

et al. 2020

View full text Add to dashboard Cite

There are combustion difficulties and combustion instability problems in micro-scale combustion due to the size effects. Focusing on the problem of combustion instability in micro-scale, on the basis of catalytic combustion, the recirculation zone (RZ) is constructed by cavity and the effect of RZ is enhanced by gas inlet at cavity wall to keep the stability of combustion. The total conversion of CH 4 in multi-inlets channel with cavity was higher compared with single inlet channel and single inlet channel with cavity. Numerical analysis was carried out to study the effects of total gas intake quantity (TGIQ), the excess air coefficient (EAC) and the air distribution mode, respectively. With the increase of TGIQ, the area of RZ increased gradually and a third RZ was gradually formed in the cavity. When the TGIQ gradually increased to 0.1828 mg/s, the combustor temperature increased significantly and as it continued to increase, the combustor temperature had little change. The highest temperature in combustor decreased gradually and the severe reaction zone moved from the back section of the combustor to the front with the increase of EAC. Moreover, the concentration of OH in cavity increased gradually and the mass flow rate of CH 4 in cavity decreased gradually. Increasing the air volume on the back cavity wall, the high-temperature zones and concentration of OH in cavity continuously improved when the TGIQ was same. The combustion process was enhanced and the catalytic reaction was stabled. The temperature of main channel first increased and then decreased.

show abstract

Combustion stability and hetero-/homogeneous chemistry interactions for fuel-lean hydrogen/air mixtures in platinum-coated microchannels

Cited by 41 publications

References 60 publications

Microkinetic Mechanisms for Partial Oxidation of Methane over Platinum and Rhodium

Microkinetic Mechanisms for Partial Oxidation of Methane over Platinum and Rhodium

Enhancement of combustion and radiation performances in a counterflow double‐channel combustor with pin fins for micro‐thermophotovoltaic system

Catalytic combustion characteristics of CH ₄ in the micro cavity‐combustor under different types of air inlet distribution

Contact Info

Product

Resources

About

Combustion stability and hetero-/homogeneous chemistry interactions for fuel-lean hydrogen/air mixtures in platinum-coated microchannels

Cited by 41 publications

References 60 publications

Microkinetic Mechanisms for Partial Oxidation of Methane over Platinum and Rhodium

Microkinetic Mechanisms for Partial Oxidation of Methane over Platinum and Rhodium

Enhancement of combustion and radiation performances in a counterflow double‐channel combustor with pin fins for micro‐thermophotovoltaic system

Catalytic combustion characteristics of CH 4 in the micro cavity‐combustor under different types of air inlet distribution

Contact Info

Product

Resources

About

Catalytic combustion characteristics of CH ₄ in the micro cavity‐combustor under different types of air inlet distribution