ABSTRACT
In this study, a hydrogen fuel jet-stabilized combustor is proposed, the combustion flow characteristics are numerically investigated under the conditions of three equivalence ratios (1, 0.37, and 0.22), and the effects of hydrogen flow rate assignment on the combustion flow are also analyzed. The results show that it is easier for the multijet scheme to form a full and stable vortex structure pair in the recirculation zone under lean conditions than the single-jet scheme, and it has a uniform reaction rate to form larger combustion zones, which makes it easier to achieve flame stabilization. The combustion efficiency of two fuel jet schemes is less than 65% when the equivalence ratio is 1, and complete combustion can be achieved under lean conditions; however, the outlet temperature distribution factor (OTDF) is basically the same. For the multijet scheme with an equivalence ratio of 0.22, as the flow rate assigned to the central jet decreases, a stable and full vortex pair is formed in the recirculation zone, and a high-temperature region can be formed under each working condition, but its area decreases with the central jet flow rate. The combustion efficiency in the recirculation zone increases first and then decreases as the central jet flow decreases, and the OTDF decreases with it.
ABSTRACT
OBJECTIVE: To analyze the volatile oil in Piper hongkongense from five different habitats. METHODS: The volatile oil was analyzed by GC-MS. RESULT: The volatile components oil of each sample varied significantly. Caryophyllene, α-caryophyllene and nerolidol 2 were common constituents of five samples. The volatile oil and chemical constituent contents of fresh sample were higher than that of the old sample. CONCLUSION: The volatile oil and chemical constituent contents of Piper hongkongense from different habitats have sig- nificant differences, which are affected by habitats, harvest season, storage time and so on.
