Advanced Materials Research Vols. 608-609

Abstract: The electrolytes materials Ce_0.85Sm_0.15O_1.925-x at.% NiO (x=0, 0.5, 1, 2, 3) were synthesized by means of glycine-nitrate process (GNP). Their structures and ionic conductivities were characterized by X-ray diffraction, SEM and AC impedance spectroscopy. All the electrolytes were found to be ceria based solid solutions of fluorite type structures. Grain size increased with NiO. The grain boundary resistance could be decreased by small addition of NiO. Electrolyte-supported solid oxide fuel cells (SOFC) fabricated with Ni-doped Ce_0.85Sm_0.15O_1.925 electrolytes were studied and compared with other fuel cell with Ce_0.85Sm0.15O_1.925 (SDC) as electrolytes.

Abstract: A new approach of spontaneous deposition was carried out to prepare the Ru/Pt film electrocatalyst for direct methanol fuel cells. This deposition method just made Pt like a ‘skin’ covered Ru films, which reduced the load of Pt but obtained a higher activity. The Pt-modified Ru films electrode was studied with the cyclic voltammetries and in-situ ATR-SEITA spectra on methanol oxidation. Compare to bare Ru and Pt, the bands of the adsorbed CO and water observed in IR spectra can be assigned. The present results give a clue for designing new electrocatalysts for DMFCs.

Abstract: Hydrogen Fuel Cell Vehicles (HFCVs) represent a promising solution to reduce overall green house gas emissions and ensure sustainable mobility. The cost of the alternative production processes should be thought about in the frame of the whole infrastructure chain in HFCVs commercialization. This paper focuses on comparing three hydrogen production technologies to serve an emerging HFCVs market. The H2A model has provided the DOE Fuel Cell Technologies Program with a technology neutral cost calculator. Given the basic framework and the assumptions, the estimation outputs have been accomplished in H2A model. We conclude three points: Production costs and production capacity are closely linked; at the same scale of production, to adopt a different mode of production, the cost requirement is not the same; natural gas and electricity, especially electricity costs account for a large proportion of the cost in the hydrogen infrastructure construction.

Abstract: An improved particle swarm optimization algorithm is proposed for determining proton exchange membrane fuel cell (PEMFC) model parameters according to its V-I characteristics. In the algorithm, the weight update is adaptive with the change of objective function. The test results indicate that satisfying parameter accuracy can be achieved by the algorithm. Also, the V-I characteristics obtained by the improved particle swarm optimization algorithm are in good agreement with the simulated data.

Abstract: China is ranked as the world’s largest emitter of carbon dioxide (CO2). The CO2 emission from urban central heating (UCH) is responsible for 4.4% of China’s total CO2 emission. It is proposed that heat pump heating (HPH) could serve as a replacement for UCH to help realize energy-saving and emission-reduction goals to a greater extent. In northern China, 30% of urban building area is covered by urban decentralized heating (UDH). Replacing UDH with HPH is the current trend in China. In this paper we analyze the impact of replacing coal with heat pumps on the power generation sector in China. The results show that HPH has a positive impact on the power generation sector. By considering simultaneous replacement of UCH and UDH with HPH, the efficiency of power generation at the valley electricity time is increased by 0.512%; the ratio of peak–valley difference is decreased by 25.3%; the obtained reduction of CO2 emission cumulatively contributes to approximately 10.96% of this target.

Abstract: To recycle waste heat from circulating water, the model of the power plant heat pump regenerative thermal system is put forward, and the indexes of the system are analyzed. It is indicated in the specific case that the absorption heat pump has an advantage over the compression heat pump. Using the extraction steam of the low pressure cylinder as its driving heat source, economize on coal can be realized in the condition that the coefficient of performance(COP) of the heat pump is above the critical COP. For the case of the compression heat pump, the fuel efficiency is improved a little, but on the other hand, as the station service power is increased, the power supply coal consumption is increased too.

Abstract: A multiple energy assisted heat pump (MEAHP) system for radiant floor heating was proposed, which integrated a domestic air-assisted heat pump with a solar water heater. The system mainly employed a vacuum tube solar collector with a surface area of 7.44 m², an electrical rotary-type hermetic compressor, two capillary tubes and three heat exchangers. All operation modes have functioned successfully in Lanzhou city, China. The experimental data of air-source heat pump (Mode 2) and double-source heat pump (Mode 3) have been discussed. The results show that the coefficient of performance (COP) of the MEAHP system and the COP of the space heating system (COPs) are around 2.2 and 1.9 with the room air at 19 °C, respectively, and the temperature difference of the inlet and outlet of the radiant floor heating pipes is 2.8 °C. Some methods to improve the system performance are put forward.

Abstract: Based on the heating season testing of ground-source heat pump system (GSHP) in Wuhan, the article discussed the energy efficiency ratio of ground-source heat pump system under the heating conditions. By comparison with conventional chillers & coal-fired boiler system, the system energy savings, environmental benefits and incremental payback period are analysized. There comes to the conclusion that the energy saving rate of the heating season is about 19.74% higher than that of the cooling season, reducing 18.35 kg carbon dioxide emissions, 0.15kg of sulfur dioxide and 0.0743 kg of dust per unit construction area each year. Also this article concludes the annual energy saving rate of ground-source heat pump system equals to that of water-source heat pump, with the payback period 22% longer and the cost-effective ratio 32% higher.

Abstract: Set up the three dimension model of ground heat exchanger, consider the temperature variety between inlet and outlet, at the same make the zone into two parts. Use the fluent to slove it . The results prove that because of the temperature difference between inlet and outlet, the temperature approach inlet varies serious than that approach outlet. With the depth increasing, the temperature difference would be little, but the center temperature is high.

Abstract: This article based on a large-scale water source heat pump engineering in a city of China, according to the experiment and survey of pumping site as well as hydrogeological parameters combined with the building load requirements, the design scheme of cluster wells pumping and injection was given. A numerical simulation was also done in order to analyze and forecast the temperature changes in aquifer and thermal breakthrough, well group interference problems for the next 3 years. Moreover an experience equation about change of average temperature of water source heat pump wells was got which will provide reference for design and operation of GWHP for others.