scholarly journals Development of a point-kinetics model in OpenFOAM, integration in GeN-Foam, and validation against FFTF experimental data

2021 ◽  
pp. 108891
Author(s):  
Stefan Radman ◽  
Carlo Fiorina ◽  
Ping Song ◽  
Andreas Pautz
Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 516 ◽  
Author(s):  
Michela Lucian ◽  
Maurizio Volpe ◽  
Luca Fiori

Olive trimmings (OT) were used as feedstock for an in-depth experimental study on the reaction kinetics controlling hydrothermal carbonization (HTC). OT were hydrothermally carbonized for a residence time τ of up to 8 h at temperatures between 180 and 250 °C to systematically investigate the chemical and energy properties changes of hydrochars during HTC. Additional experiments at 120 and 150 °C at τ = 0 h were carried out to analyze the heat-up transient phase required to reach the HTC set-point temperature. Furthermore, an original HTC reaction kinetics model was developed. The HTC reaction pathway was described through a lumped model, in which biomass is converted into solid (distinguished between primary and secondary char), liquid, and gaseous products. The kinetics model, written in MATLABTM, was used in best fitting routines with HTC experimental data obtained using OT and two other agro-wastes previously tested: grape marc and Opuntia Ficus Indica. The HTC kinetics model effectively predicts carbon distribution among HTC products versus time with the thermal transient phase included; it represents an effective tool for R&D in the HTC field. Importantly, both modeling and experimental data suggest that already during the heat-up phase, biomass greatly carbonizes, in particular at the highest temperature tested of 250 °C.


2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.


2014 ◽  
Vol 77 ◽  
pp. 92-106 ◽  
Author(s):  
T. Zamacinski ◽  
C.M. Cooling ◽  
M.D. Eaton

2021 ◽  
Vol 247 ◽  
pp. 06030
Author(s):  
A. Laureau ◽  
E. Rosier ◽  
E. Merle ◽  
S. Beils ◽  
O. Bruneau ◽  
...  

Molten salt reactors as liquid-fuelled reactors are flexible in terms of operation or design choices, but they are very different in terms of design, operation and safety approach compared to solid-fuelled reactors. Such reactors call for a new definition of their operating procedures and safety approach. Dedicated developments and studies have been performed in the frame of the European SAMOFAR project of Horizon2020 and in parallel in France involving CNRS, CORYS and Framatome to develop a system code called LiCore adapted to such reactors, corresponding to a basic-principle power plant simulator. The neutronic model LiCore, at the centre of the simulator, corresponds to an improved point-kinetics model to take into account the specificities of a MSR, notably the circulation of the delayed neutron precursors out of the core. Coupled to a simple piston model for the fuel motion in the core, this code can perform calculations faster than real time to simulate the behaviour of the fuel circuit. Transient calculations performed with LiCore are presented, together with comparisons first to a simple point-kinetics model and then to 3D calculations with the TFM-OpenFOAM coupled code. Finally, the LiCore code has recently been integrated in the ALICES platform, the integrated simulation toolset designed by CORYS for the development, maintenance and operation of major simulator such as power plant simulators.


2020 ◽  
Vol 360 ◽  
pp. 110466 ◽  
Author(s):  
Rodrigo Costa Diniz ◽  
Alessandro da Cruz Gonçalves ◽  
Felipe Siqueira de Souza da Rosa

Sign in / Sign up

Export Citation Format

Share Document