Papers by Author: Xin Li Wei

Abstract: With the social progress and the development of the world economy, the contradiction between energy demand and supply is increasingly outstanding，so saving energy is the important task which the human are facing. Solar energy as a renewable clean energy is one of the potential energy applying on buildings. This article analyzes the geometric parameters of the solar air collector and summarizes the baffle types of the solar air collector and puts forward to methods improving the efficiency of solar air collector.

Abstract: The economic feasibility of solar wall system was assessed with RETScreen software for 15 widespread locations in northern China heating region. Several different economic and financial indicators were calculated, such as the internal rate of return, net present value, simple payback and benefit-cost ratio. Results showed that the solar wall system was only profitable for four sites according to the current domestic price of solar wall plate and its absorptivity. When the price was reduced or the absorptivity under the condition of invariable price was improved, there were more sites profitable for this system. So, only when the price of energy increases 95% or the price of solar wall plate falls 50%, the solar wall system will be profitable for all sites in northern China heating region.

Abstract: Oil tank is easily corroded by internal and external media in service. Corrosion types of gas spaces in oil tank were summarized, corrosion process was analyzed also. Through the research of corrosion mechanism of gas space of oil tank, author put forward that H2S corrosion was a dominant factor for gas space corrosion. H2S corrosion mechanism model at low temperature was obtained also. Metallic samples test showed that corrosion rate was decreased while the samples were placed in simulating atmosphere spaces of oil tank. Corrosion product iron sulfide has loose, porous, layered, and cracked structure. When ingredient of atmosphere varied with time，iron scale was produced, mixed with iron sulfide. Electrochemical test showed that the increase of acidity accelerated the cathode process and accelerated the corrosion rate of Q235-B steel.

Abstract: Pipe elbows are the most critical components in any piping system. However, the earlier experiments on cracked elbows were focused mainly on the determination of limit load of through wall cracked elbow. The experimental results of plastic collapse load of seven carbon steel 90⁰ elbows, subjected to in-plane opening bending moment, are reported in this work. Among the selected specimens, three were defect-free elbows and six had axial surface cracks at the intrados, crown or at extrados. Test arrangement and the collapse behavior with and without cracks were presented. The plastic collapse loads were then obtained on the basis of experimental results. Reasonably good matching between test results and existing estimation formulae has been observed.