Search

With the rapid development of social economy, energy shortage and environmental pollution are becoming more and more serious, and clean energy power generation has become one of the measures to implement the sustainable development strategy. A large number of small and medium-sized hydropower stations in Southwest China have a large amount of surplus water due to light load and channel blockage. In response to this problem, a method of coupling the natural gas system and the power system using P2G and gas turbines is proposed to improve the absorption capacity of hydropower and reduce the amount of surplus water. In this article, a day-ahead economic dispatch model of electricity-gas coupling system(EGCS) is established with the goal of the lowest operating cost of the whole system, considering the output characteristics of run-off hydropower stations, natural gas system operation constraints, power system AC power flow and other constraints, and solve the model using the interior point method. The analysis of the calculation example shows that compared with the independent system, the EGCS can effectively reduce the amount of surplus water, improve the utilization rate of clean energy, and reduce the operating cost of the system. The rationality and effectiveness of the model are verified.

TA32 is a heat-resistant titanium alloy developed for superplastic forming in fabrication of near-space supersonic aerocraft. Clarification of superplastic deformation behavior is important to the optimization of forming parameters. Superplastic tensile test was conducted in vacuum to eliminate the effect of surface oxidation on experimental data, the test temperature and strain rate varied from 900oC to 960oC and 5.32×10-4 to 2.08×10-2s-1, respectively. It was observed that the size of equiaxed α grains exhibited a trend of coarsening with the increase of temperature and decrease of strain rate. Textures of deformed specimens exhibited random distribution with a decreased texture intensity compared with the as-received materials. The superplastic deformation mechanism of TA32 alloy was dominated by grain boundary sliding, which is accommodated by grain rotation and dynamic recrystallization.