- Tytuł:
- Simulation of start-up behaviour of a passive autocatalytic hydrogen recombiner
- Autorzy:
- Rożeń, A.
- Powiązania:
- https://bibliotekanauki.pl/articles/146233.pdf
- Data publikacji:
- 2018
- Wydawca:
- Instytut Chemii i Techniki Jądrowej
- Tematy:
-
catalytic recombination
computational fluid dynamics
hydrogen safety
natural convection
rekombinacja katalityczna
obliczeniowa dynamika płynów
naturalna konwekcja - Opis:
- Heterogeneous catalytic recombination of hydrogen with oxygen is one of the methods used to remove hydrogen from the containment of a light-water nuclear reactor (LWR). Inside a passive autocatalytic recombiner (PAR), hydrogen and oxygen molecules are adsorbed at catalyst active spots and they recombine to yield water. Heat released in this exothermic reaction creates natural convection of gas in the spaces between the elements supporting a catalyst. Hot and humid gas fl ows upwards into the PAR chimney, while fresh, hydrogen-rich gas enters the PAR from below. Catalytic recombination should start spontaneously at room temperature and low hydrogen concentration. Computational fl uid dynamics (CFD) has been used to study the dynamic behaviour of a plate-type Areva FR-380 recombiner in a quiescent environment for several test scenarios, including different rates of increase in hydrogen concentration and temporary catalyst deactivation. A method for the determination of pressure boundary conditions at the PAR exits was proposed and implemented into a CFD code. In this way, transient operation of PAR could be simulated without the need to model gas circulation outside the device. It was found that fi rst a slow downward fl ow of gas is developed, which may persist until the temperature of the catalyst foils rises. As soon as the gas inside the PAR absorbs enough heat to become lighter than the gas outside the PAR, it starts to fl ow upwards. Criteria for determining the start-up time of PAR were proposed. Model predictions were also compared with experimental data obtained in tests conducted at the THAI facility.
- Źródło:
-
Nukleonika; 2018, 63, 2; 27-41
0029-5922
1508-5791 - Pojawia się w:
- Nukleonika
- Dostawca treści:
- Biblioteka Nauki
Artykuł