Applied Mechanics and Materials Vols. 291-294

Abstract: Hydrogen production by electrolysis of water is necessary to provide huge amounts of cheap or surplus electricity. So currently is produced by electrolysis of water only 4% of hydrogen. Due to the need to save primary energy resources and environmental problems of thermo-chemical hydrogen production mainly related to the production of CO2 can be assumed that the production of hydrogen by electrolysis of water using renewable energy sources will increasingly expand. The paper deals with possibility of hydrogen production by electrolysis of water using photovoltaic energy.

Abstract: Cu-Ce-La mixed oxide catalysts were prepared by co-precipitation methods with a series of precipitator concentration and characterized using X-ray diffraction, BET, TPR, and catalytic reaction for the water-gas shift. The Cu-Ce-La mixed oxide prepared by 4.0 mol/L NaOH concentration presented the highest activity and thermal stability. the precipitator concentration influence the activity of catalyst via the stability of crystal structure and mesoporous structure. La³⁺ or Ce⁴⁺ substituted copper ion of CeO₂ framework during reaction process. The concentration of precipitator can control pore diameter of catalyst in synthetical process. The raising of precipitator concentration, from 0.5 to 2.0 mol/L, lead to enhancing of synergistic effects between CuO and CeO₂.

Abstract: In this study we investigated the use of a microbial fuel cell (MFC) to abioticlly cathodic decolorization of a model azo dye, Methyl Orange (MO). Experimental results showed that electricity could be continuously generated the MO-fed MFC and MO was successfully decolorized in the cathode. The decolorization rate was highly dependent on the catholyte pH. When pH was varied from 3.0 to 9.0, the k value in relation to MO degradation decreased from 0.298 to 0.016 μmol min^-1, and the maximum power density decreased from 34.77 to 1.51 mW m^-2. Sulfanilic acid and N,N-dimethyl-p-phenylenediamine were identified as the decolorization products of MO by HPLC-MS.

Abstract: When the oscillating buoy wave power device installed on the ocean buoy, the floater and the ocean buoy move up and down under the action of the waves. Therefore, whether there is a vertical relative displacement between the floater and the ocean buoy becomes a crucial problem of the wave power generation. Based on the wave theory, taking the vertical cylinder floater for example, introduced the wave force and the moving displacement of the floater，the relative displacement between the floater and three different sizes of ocean buoys under four different oceanic conditions was analyzed by MATLAB. The result indicates that the greater wave height, the greater relative displacement; the shorter wave period, the greater relative displacement; and the larger size of the ocean buoy, the greater relative displacement. So the electric power can be generated and the scheme is feasible.

Abstract: A two-phase fermentation process that combined H2 and CH4 production with supernatant liquid recirculation to adjust the pH, was suggested in this study. It was found that with the suitable recirculation, the phase separation performance was improved in the hydrogen production reactor. The highest average H2 and CH4 yield were 2.02, 7.30 L / kg TS • d, respectively, when the RRs were 45 L/2d, 30 L/3d, respectively. The main degradation pathway of organic matter was propionic acid and butyric acid mixed fermentation types. The change of RR affected the fermentation pathway and gas production rate slightly.

Abstract: Tremendous efforts are being made to produce polymer electrolyte membrane (PEM) for fuel cell using advanced materials in order to replace Nafion due to the high costs and its complicated synthesis procedures. One of the efforts include an extensive research on natural polymer to produce biopolymer based electrolyte membranes with desirable properties such as high proton conductivity, as well as good chemical and thermal stabilities. The examples of biopolymer that have been used are polysaccharide (e.g. cellulose, starch and glycogen), chitin and chitosan. This paper presents an overview of the types of biopolymer used to produce a PEM, comprised also their chemical and physical properties, and its performances in fuel cell applications.

Abstract: This research work investigates the heat transfer characteristics of a direct contact heat exchanger. A cold two phase refrigerant R134a is injected into water stored in an evaporator to exchange directly heat with the water and form clathrates during the charging mode of the operation. The clathrate is used later for obtaining chilled water for air-conditioning purposes. It was found that the performance of the system depends on the refrigerant, its ratio to water, compressor speed and the mass flow rate of the refrigerant.

Abstract: Lithium-ion battery energy storage technology has recently made great development, which can play a significant role in power system. Take grid load shifting for example, lithium-ion battery energy storage technology can alleviate the problem of the growing difference between peak and valley, and reduce power system equipment investment, etc. While the high cost of lithium-ion battery energy storage technology limits its large-scale application at present stage. Hence, during early stage of energy storage project investment planning, it is necessary to analyze the economic problems of its investment. Based on the technical level of the lithium-ion battery at present, lithium-ion battery energy storage system capacity configuration strategy is proposed and economic analysis model is established. Finally, economic issues of investment in lithium-ion battery energy storage system for grid load shifting are studied, and the capacity configuration recommendations are given.

Abstract: Because of phase change materials (PCMs)’ composition, machining error, measuring error and other factors, the PCMs’ thermal physical properties, geometric properties, etc are usually uncertain. Phase change heat transfer process is an uncertainty heat transfer process. In this paper, it is considered factors’ uncertainty influencing phase change thermal storage heat transfer process. Heat transfer model of phase change thermal storage is established. And the uncertainty phase change heat transfer process is analysis based on Monte Carlo method. The experiment shows that the temperature of PCMs varied between the upper bound and lower bound of calculations. Comparison between simulation results of the model and experimental data implies that it is necessary to consider influencing factor’s uncertainty in phase change thermal storage heat transfer analysis.

Abstract: Rational configuration of energy storage system is an effective means to improve power system energy utilization and solve the bottleneck problem of wind power. To energy saving and emission reduction as study object, analyse energy storage system energy saving and emission reduction benefit evaluation index. Establish the wind/storage system benefit evaluation model to calculate wind/storage optimum matching capacity used nested genetic algorithm. The calculated results show that the wind/storage system with reasonable configuration can improve the social benefits of energy saving and emission reduction.