The effects of different parameters on oxidation rate are non-linear, interactive and diversified in which the change of adequacy of O2 supply is an important indicator. The influence of microstructure on oxidation rate became stronger worsening the fitting linearity to calculate the activation energy based on present method with the decreased adequacy of O2 supply due to the increase of temperature, the decrease of gas flow rate, etc. Here, we proposed a method to characterize thermal-oxidation behaviors of nuclear graphite by combining O2 supply and micro surface area of graphite. The proposed method improved the linearity and reduced the standard error of Arrhenius plots of oxidized graphite IG-110 (10 L/min reactant gas) and ET-10 (0.2 L/min reactant gas). The value of activation energy of graphite IG-110 oxidized under ASTM D7542 condition is calculated as 220 kJ/mol by this method echoing the results of previous studies with sufficient O2 supply. For the conditions with less O2 supply at low gas flow rate and/or high temperature, the change of microstructure of oxidized graphite should be obtained as an important factor influencing oxidation rate of graphite.

This study gives emphasis to the economic analysis of hybrid Energy systems which are gradually paid attention by researchers worldwide as a new way to cope with climate change and sustainable development. The economic cost is an important feature that restricts the development of hybrid energy system. The purpose of this study is to verify the economic characteristics of hybrid energy system with HOMER Pro software. Firstly, the economic characteristics of different single energy sources are investigated. Secondly, the economic performances of different hybrid energy systems are analyzed and compared. The research results show that our simulations based on HOMER Pro software have good agreement with those in reference cases. In the future, a unified economy evaluation will be carried out for these hybrid energy utilizations.