Hexafluoropropylene (HFP) is used as an advanced fire extinguishing agent with high thermal stability, excellent fire suppression performance, and environmentally friendly characteristics. In this study, the inhibition mechanism of HFP during H₂ combustion was analyzed, focusing on its reaction behavior with H and OH radicals to verify its interruption of the combustion chain reaction by scavenging key reactive radicals. The unimolecular pyrolysis process of HFP was investigated to characterize the heat absorption effect when it dissociates into small molecular fragments. The gas-phase kinetic properties of the proposed reaction pathway were analyzed by combining high-level quantum chemical calculations with the RRKM/master equation. The results show that the unimolecular dissociation reaction of HFP has a significant rate difference at low temperatures, but this difference gradually decreases with increasing temperature. In the substitution reaction pathway, the reaction rates of HFP with H and OH were much higher than those of H-abstraction, suggesting that it has an important influence in inhibiting H₂ combustion. In addition, the addition reaction of HFP with H and OH also plays a key role in inhibiting combustion at low temperatures due to the presence of CC double bonds in the molecule. It is particularly noteworthy that the rate of the addition reaction of HFP with H increases significantly with increasing temperature, while the rate of the addition reaction with OH is lower than that of the former at high temperatures. The present study lays a data foundation for the establishment of a more accurate kinetic mechanism of combustion inhibition, which is of great significance for the design of new flame retardants.

With the development of new synthetic methods, 2-vinylfuran (V2F) has become a potential renewable biofuel. In this work, the potential energy surfaces for the V2F unimolecular dissociation reaction, the H-addition reaction, and the H-abstraction reaction were constructed at the G4 level. The temperature- and pressure-dependent rate constants for the relevant reactions on the potential energy surfaces were calculated by solving the master equation based on the transition state theory and Rice-Ramsperger-Kassel-Marcus theory. The results show that the rate constant for the intramolecular H-transfer reaction of V2F with H atoms from the C(5) site to the C(4) site to form 2-vinylfuran-3(2H)-carbene, followed by the decomposition to form h145te3o, is the highest. The rate constants for the H-abstraction reaction of V2F with H atoms were the largest at C(6) on the branched chain, followed by C(7), and the rate constants for the H-abstraction reaction at C(3), C(4), and C(5) on the furan ring were not competitive. Negative temperature coefficient effects are observed for the rate constants of the addition reactions of V2F with H atoms at low pressures, with the H-addition rate constant at the C(5) site being the largest. This work not only provides the necessary rate constants for the reaction mechanism of V2F combustion but also provides theoretical guidance for the practical application of furan-based fuels.

HFC-236fa (1,1,1,3,3,3-hexafluoropropane) is regarded as a potential fire extinguishing alternative to halon, and the present study delves into its mechanism in hydrogen combustion suppression. Based on the master equation solved by the transition state theory, the reaction kinetics of HFC-236fa were analyzed, revealing that it tends to undergo heat-absorbing reactions when dissociating into smaller species. The study focuses on the key roles of hydrogen atoms (H) and hydroxyl radicals (OH) in the radical scavenging reaction. The results show that the differences in the rate constant of the unimolecular dissociation and intramolecular elimination reactions of HFC-236fa are significant at low temperatures, and the differences gradually decrease with increasing temperatures. The reaction generating CF₃CHCF₂ and HF was the fastest rate reaction channel, suggesting that it plays an important role in combustion inhibition. Overall, the combustion inhibition mechanism of HFC-236fa is mainly dominated by the H-abstraction reaction of the OH in the carbon center, while the trifluoromethyl-related reaction contributes little to the inhibition. This study provides an important theoretical basis for the design and evaluation of fire extinguishing agents.

With the development of synthetic methods, 2-acetylfuran (AF2) has become a potential biomass fuel. The potential energy surfaces of AF2 and OH including OH-addition reactions and H-abstraction reactions were constructed by theoretical calculations at the CCSDT/CBS/M06-2x/cc-pVTZ level. The temperature- and pressure-dependent rate constants of the relevant reaction pathways were solved based on transition state theory and Rice-Ramsperger-Kassel-Marcus theory, as well as Eckart tunneling effect correction. The results showed that the H-abstraction reaction on CH₃ on the branched chain and the OH-addition reaction at the C (2) and C (5) sites on the furan ring were the main reaction channels in the reaction system. At low temperatures, the AF2 and OH-addition reactions dominate, and the percentage decreases gradually to zero with increasing temperature, and at high temperatures, the H-abstraction reactions on the branched chains become the most dominant reaction channel. The rate coefficients calculated in the current work improve the combustion mechanism of AF2 and provide theoretical guidance for the practical application of AF2.

This study combines an experimental semi-physical simulation model of an electric propulsion tugboat with four different neural networks to create a real-time simulation model for forecasting total power loads with small samples. The results of repeated experiments demonstrate that the BP neural network effectively forecasts the power load. Subsequently, addressing the limitations of traditional BP neural networks, an optimization approach employing an enhanced particle swarm algorithm and attention mechanism was developed, thereby improving the model’s prediction accuracy and robustness. The experiment shows that the improved prediction model achieves an R² value of 97.42%, demonstrating its effectiveness in forecasting changes in the short-term power load of ships as parameters change. In actual operation, ships can allocate power reasonably and in a timely manner according to the load forecast results, thereby improving the efficiency of the power grid.

With the advancement of new synthetic techniques, 5-Methyl-2-ethylfuran (5-MEF) has emerged as a promising renewable biofuel. In this study, the potential energy surfaces for the unimolecular dissociation reaction, H-addition reaction, and H-abstraction reaction of 5-MEF were mapped at the CBS-QB3 level. The temperature- and pressure-dependent rate constants for these reactions on the potential energy surfaces were determined by solving the master equation, using both transition state theory and Rice–Ramsperger–Kassel–Marcus theory. The results showed that the dissociation reaction of the C(6) site on the branched chain of 5-MEF has the largest rate constant and is the main decomposition pathway, while the dissociation reaction of the H atom on the furan ring has a lower rate constant and is not the main reaction pathway. In addition, the dissociation of H atoms on the branched chain and intramolecular H-transfer reactions also have high-rate constants and play an important role in the decomposition of 5-MEF. H-addition reactions mainly occur at the C(2) and C(5) sites, and the generation of the corresponding products through β-breakage becomes the main reaction pathway. With the increase in temperature, the H-addition reaction at the C(2) site gradually changes to a substitution reaction, dominating the formation of C₂H₅ and 2-methylfuran.