Advanced Materials Research Vols. 1092-1093

Abstract: In this work, six asymmetric compound parabolic concentrators (ACPC) were designed for concentrating radiation on all-glass evacuated solar tubes (EST). The ACPCs are required to be horizontally oriented in the east-west direction and to collect direct sunlight for at least 6 hrs in any day of a year. The angular dependence of optical efficiency of six ACPCs, identical in the height of both reflectors after the higher reflector being truncated, was investigated by ray-tracing method, and the annual radiation on EST concentrated by ACPCs was estimated based on solar geometry and monthly horizontally radiation. Results shows that the ACPC designed based on “hat shaped” virtual absorber with a V-groove at the bottom of reflectors is the best in terms of the optical efficiency averaged over the acceptance angle, followed by the one designed based on “hat-shaped” absorber without a V-groove at the bottom, and the one designed based on the cover tube of EST is the worst. However, from the point of annual radiation on EST, the ACPC designed based on the cover tube is the best solution, followed by the one designed based on “ice-cream shaped” absorber and the one designed based on “hat shaped” absorber is the worst due to the smallest geometric concentration factor.

Abstract: Energy shortage and environmental pollution, has become the primary topic in today's social development to be solved. Remote parts of the animal husbandry and water problems tend to have also been regional restrictions. In view of the above problems, photovoltaic water pump arises at the historic moment. This paper the basic principle and composition of photovoltaic pump system were summarized, and research progress on light volt pump and the status quo, explore photovoltaic water pump for the next research direction was analyzed,By photovoltaic water pumps in the world market demand and operation cost, economic benefit and social benefit of photovoltaic water pump products were analyzed, and the validation of the advantage and feasibility of photovoltaic water pump, prospects the application prospect of photovoltaic pump system.

Abstract: In order to improve working efficiency of photovoltaic (PV) system and decrease outputs fluctuation. A method of maximum power point tracking (MPPT) based on self-tuning fuzzy PID control is proposed. Based on analysis of typical PV cell characteristics, a combination of PID control and fuzzy control is proposed according to the shortage of perturbation and observation (P&O) method. The model of PV grid-connected system was established and simulated in Matlab. Results show that the method tracks changes of external solar intensity rapidly and accurately, and it makes PV system work with good dynamic and static performance. Besides, viewpoint that the higher of solar intensity, the more instability in the output parameters of PV cell is proposed.

Abstract: In order to make a further promotion and development of photovoltaic power generation project, this paper brings the extension theory in photovoltaic power generation project quality evaluation and builds the photovoltaic power generation project extension evaluation index system and model on the basis of matter-element theory and extension analysis. Ranking the evaluating projects by calculating the indicators compared with the correlation of evaluation degrees. The paper takes three photovoltaic power generation project in Shaanxi in 2012 as an example, expounding the model is reasonable and reliable. The empirical results give a best reflection on the quality of the photovoltaic power generation project, which provide a scientific basis for project decision. The paper results provide a new thought for quality assessment of photovoltaic power generation project, enriching the photovoltaic power generation project evaluation method.

Abstract: The mechanism of biomass pyrolysis carbonization technology was introduced. Then the stage and characteristic of pyrolysis carbonization technology were expounded. The research status of the biomass pyrolysis carbonization and biomass pyrolysis carbonization equipment were reviewed. Finally, these people point out that the fixed bed pyrolysis carbonization equipment and new heating technology shall be the main focus for future research and development.

Abstract: Shallow geothermal energy is a new renewable high-quality clean energy that has aroused great interest of man for its renewability, huge stock, cleanness and high availability. Encouraged by the favorable policies of the government, shallow geothermal energy exploitation in geologically suitable areas has become a great priority. In this paper, principal rock-soil physical parameters are derived from field thermal response test set in the context of Qing’an, Suihua City, and subsurface temperature field is modeled to further establish the heat exchange performance parameters with a view to providing reference for the planning and proper deployment of GSHP-based shallow geothermal energy exploitation in this area.

Abstract: Advantage of solid adsorption refrigeration is environmental protection, energy saving, simple structure, no noise and the advantages of stable and reliable operation, the use of solar energy driven refrigeration is an energy-saving environmental protection technology, it can effectively reduce the huge energy consumption and environmental pollution due to the burning of fossil energy resources. This article introduces the general situation of development of solar adsorption refrigeration, puts forward the research progress and application prospect of the solar energy air conditioning system.

Abstract: Effects of solar panels must be taken into account by the light intensity of its output characteristics in practical application, especially solar panels placed outdoor. So the light intensity coefficient is an important parameter to be considered. In this paper,we took the light intensity characteristics of single crystal silicon solar cell as the research object. Also,through transforming the illumination intensity which are 777.60W/m²,996.97 W/m² and 1224.88 W/m², we would finish researching the characteristics of the cell sheet, which included battery plate volt ampere characteristic, open circuit voltage, short circuit current and maximum output power. Also, we’ve got the relationship of U_oc-T, I_sc-T and P_m-T, respectively and Put forward the better intensity theory. It would lay a solid foundation of practice for the further study on how to improve the rate of light conversion.

Abstract: This paper uses Z source inverter in switched reluctance wind power generation (SRWPG) to connect to power grid. According to operation of switched reluctance generator (SRG), requirements of grid-connection and the unique single stage buck boost feature of Z source inverter, Z source inverter with space vector pulse with modulation (SVPWM) is adopted to satisfy the voltage level of grid-connection. A control method of grid-connection inverter is developed to keep the capacitor voltage of Z source inverter stable and regulate the active and reactive power. Simulation of SRG and Z source inverter are constructed based on MATLAB/Simulink platform. Simulation results reveal that Z source inverter is feasible and valuable in wind power generation on SRG system.

Abstract: It can clear the various economic factors in the process of the implementation of the small towns heating to establish small town heating economic model. It comes down to the total economic cost of small towns heating under the condition of different fuel types to analyze the parameters in the mode with different fuels according to the heating process. When some kind of fuel is used, by calculating we can conclude that the lowest heating cost contributes to use of economical fuels in the region.