Advanced Materials Research Vols. 1092-1093

Abstract: Groundwater source pumps are popular recently in worldwide. More and more pumps have been built in city. It is well known that the heat recharged to ground aquifer from refrigeration and air-conditioning in summer will migrate along with groundwater flow. So it is worthy to study the problem such as whether it impact on the safety of oil station. This paper presents a model which use simulation the heat of groundwater pump migrate process to study the impact on oil station downstream. Through simulation the heat field diffusion procedure and temperature change are obtained. Results show that the recharged heat issued from summer groundwater source pump will spread for a long distance to oil-station with downstream flow, the temperature around oil-station rise significant. The heat may influence the safety of storage tank and oil station.

Abstract: A reasonable and effective control strategy for HEV (Hybrid Electric Vehicle) with HESS (Hybrid Energy Storage System) can improve the system efficiency and battery service life. A dynamic programming-based global optimal control strategy which fully considered the efficiency of each component in HEV is presented. To compare with the nonlinear proportion factor dynamic coordination strategy, the fuel consumption is not increased. The cycle numbers of battery are further decreased which benefits its cycle life improvement. The regenerative energy callback ratio improves 3% under the shanghai drive cycle as an example. Since this optimization algorithm considers efficiency of each subsystem, the efficiency optimum under the selected driving cycle was realized. It can also provide a reference for the non-linear scaling factor allocation strategies to determine the scale factors.

Abstract: Since imported LNG is increasing gradually in China, the research of LNG cold energy utilization becomes quite urgent. A novel air liquefaction process with LNG cold energy utilization is proposed in this paper. With the Aspen plus software, this paper builds the simulation model of the air liquefaction process by using LNG cold exergy and analyzes the effects of the key parameters on the performance of the process. The results show that the power requirement to produce liquid air with LNG cold energy utilization is 142.9kWh/t, lower by 67.4％than that for the conventional air liquefaction process, and the specific exergy consumption of liquid air production is 310.3kWh/t. With LNG cold energy utilization, the energy cost of liquid air production in this proposed process is 48.7% lower than that of conventional process. The optimal conditions are reached through the analysis of economic effectiveness.

Abstract: Fuel cell based micro combined heat and power (micro-CHP) systems are residential scale clean energy conversion unit. It employs fuel cells in a compact system that converts natural gas, propane or other fuels into both electricity and heat, which increases efficiency by simultaneously generating power and heat for one unit, on-site within a home. A prototype system consisting of a natural gas steam reforming unit, CO cleaning unit, PEM fuel cell stack, waste heat recovery unit and auxiliary unit is integrated. Test results of the prototype show that it can start within an hour and the syngas produced can meet the fuel cell’s requirements. The prototype’s electric power and thermal power are 200W and 530W respectively, while the electric and thermal efficiency are 15.4% and 40.9% respectively.

Abstract: In this study, effects of different working conditions on a organic flow battery performance were investigated. The organic redox flow battery was assembled based on AQS as positive material and Br₂/HBr as negative material. So there were no metal ions in the new battery. When the electrolyte flow rates or the currents were changed, the battery performance changed apparently. Higher flow rate can improve battery performance, while higher current can reduce the battery discharge capacity and discharge voltage. As the improvements are limited, we need choose the appropriate working conditions to get the best battery performance in practical applications.

Abstract: Dopamine was used as the carbon precursor to prepare SiO/C composite. Dopamine achieved self-polymerization and covered on the surface of the SiO particles in Tris-buffer, and the SiO/C composites were gained after heat-treating in the tube furnace under Argon. X-ray diffraction ( XRD ) , scanning electron microscope ( SEM ) were used to determine the phases obtained and to observe the morphologies of the composite. The galvanostatic discharge/charge test was carried out to characterize the electrochemical properties of the composite. When the sample of the mixed SiO and dopamine at a weight ratio of 1 : 3, the composite showed the best cycle ability with the discharge capacity of 1362 mAh g⁻¹ in the first cycle, and the initial coulombic efficiency is 55.6%, after 50 cycles, the discharge capacity is 442 mAh g⁻¹. The improved stability of the composite is attributed to carbon-coating forming during heat-treatment process.

Abstract: Qualified gasoline additive could improve the vehicle emission, fuel economy and deposits in engine. However, some people consider that additive plays a little role in the gasoline, for the quality of additives is still quite uneven on the market. This paper researched the influence of additives on complete-vehicle emission by adding 10 different market additives into gasoline, respectivly. Then one qualified additive was chosen and blended into base oil to do road running test with driving 1.2 × 104 km on a light-duty vehicle. The results show that vehicle emissions could decreased 15% averagely and deposits in engine can be cleaned obviously with qualified additive.

Abstract: A two-dimensional steady state numerical model for high temperature polymer exchange membrane fuel cells based on Nafion212/SiO₂ composite membrane was developed. Finite element method was used to solve electrochemical kinetics coupled with flow, multi-component transport, charge balance and energy conservation. The model-predicted fuel cell polarization curve was compared with the published experimental result and a good agreement was found. The effects of the structure parameters of the catalyst layer including Pt/Carbon ratio and Pt loading on the performance of high temperature polymer exchange membrane fuel cells were evaluated.

Abstract: The tar decomposition of low-pressure ejection type burner was researched. The burner used software to simulate and analyse impact of the nozzle diameter d, the gas flow rate V and the distance of the nozzle to the wall L on tar cracking. The orthogonal test were used for design parameters d, V and L, the optimization values of these three parameters were carried out, and experimental method was used for test the numerical simulation results. Numerical simulation and experimental results showed that the greatest impact on tar cracking is the nozzle diameter d, the minor effect is the distance of the nozzle to the wall L and the weakest effect is the gas flow rate V, and when the nozzle diameter d=4 mm, the distance L=18 mm and the gas flow rate V=0.10 m³/h, the tar cracking is the most efficiency.

Abstract: A series of sulfonated poly(arylene ether sulfone) (SPAES) membranes were prepared for microbial fuel cell (MFC) application. The performance of the MFCs equipped with SPAES membranes was researched in details. The results showed that the output power density of the MFCs with different SPAES membranes increased with the increase of the IEC at the first few days. The performances were close after long-term operation. The influence of inoculum amount, the load and the concentration of K3Fe(CN)6 on the MFC performance was also investigated.