Objective:The flexibility on a design maneuvering of building automation systems with the integration of organic solar cells is investigated.Methods:The energy demand load of the Engineering Lecture Theatre (ELT) at the University of Lagos is analyzed and parametric studies of the heat and charge transport within aMimosa pudicabased solar wafer are conducted, along with the modelling of a network of microchannels. A walk-through energy audit of all the devices that are installed or operated within the ELT and the thermophysical properties of the building envelope are considered, with the aim of satisfying the ASHRAE standard for thermal comfort and indoor air quality. A two-dimensional finite volume formulation of the heat and charge transfers within the boundaries of the flexible laminate and the organic extract is utilized.Result:Parametric analysis of the flow phenomenon and temperature distribution, especially across the wafer, at various operating conditions helps to determine significant design criteria, and assists in confirming the feasible power performance of the organic solar cell for building energy management.Conclusion:The results are anticipated for the design of reliable building automation systems for effective demand side monitoring, and for estimation of the economic viability of a proposed development of hybrid organic-inorganic based solar energy system for independent power generation within the Faculty of Engineering.
Objective:This research seeks to solve the problem of storing solar energy in small scale modules for domestic use.Method:The Solar Power Bank (SPB) was constructed with local materials based on their individual properties. The functionality of the SPB was tested in a convective environment. Davis automatic Weather Station (DWS) was used to get the weather parameters (like solar irradiance, solar energy and temperature) for each day the SPB was tested. The maximum solar irradiance for four days (during the experiment) were 220 W/m2, 208 W/m2, 450 W/m2and 900 W/m2. The maximum solar energy was 0.33 J, 03 J, 0.64 J and 1.33 J.Result:The maximum voltage and power obtained from the Solar Power Bank (SPB) was 0.18V and 0.065W respectively. The design showed tremendous heat energy entrapment during solar irradiance peak as the temperature in the SPB was about three times the DWS.Conclusion:It was specifically noted that the convection of the heat transfer that is triggered by the glass shield determines the functionality of the thermo-electric module. This is a clear indication that though the power output may be low to charge the batteries, the prospects of the SPB to operate in convective-rural communities (in tropic region) is very high.
In this paper, through introducing the design of real building at the north-east district, the paper mainly studies how to finish the combination on building and solar water heater in the design of residential building, by analyzing the cases about practical project and the climate characteristic, in order to provide references for the utility of solar energy in the resident building design, and promote the extensive apply of solar energy.
Possible interaction of volatilized As and S with CaO and Fe2O3 (creating solid product) could efficiently improve coal combustion flue gas cleaning. For this reason, S-CaO, As-CaO, S- Fe2O3 and As- Fe2O3 relationships were evaluated in bottom ash and fly ash fractions from fluidised-bed co-combustion of coal and wastes (and limestone as desulphurization additive) through calculation of correlation coefficients and composition of magnetic concentrates. It was concluded that S exhibited a dominant association with CaO while As exhibited affinity to both CaO and Fe2O3 - the significance differed a little in bottom ash and fly ash. In the bottom ash, the affinity of As to CaO was more significant, while in the fly ash the association to Fe2O3 slightly prevailed.
Objective: Thermal Dissolution (TD) and Co-thermal Dissolution (CTD) of Shenfu (SF) coal and lignin were studied. The effect of temperature on the TD and CTD of SF coal and lignin was discussed. Method: The synergistic effect of SF coal and lignin in CTD was probed with the characterization of thermal dissolution soluble fraction by elementary analysis, FTIR and TG determinations. Result: The results suggested that TD activity of lignin was higher than that of SF coal. Both SF coal and lignin gave their maximal thermal dissolution yield (TDY) of 57.6 and 82.5%, respectively at 360oC. In CTD of SF coal and lignin process, the experimental values (expressed by EXP) of TDY and Thermal Dissolution Soluble Yield (TSY) were both higher than the corresponding calculated weighted mean values (expressed by CAL) of TDY and TSY obtained from the individual TD of SF coal and lignin, suggesting that there existed a synergistic effect in the CTD of SF coal and lignin. Both TDY and TSY in CTD were enhanced to maximal values at 360oC with (EXP-CAL) values of 3.4 and 7.5%, respectively. Conclusion: There were interactions between SF coal and lignin in the CTD process. The pyrolysis of lignin at low temperature may form some intermediates such as phenoxy radicals, and these intermediates can further cause depolymerization of coal, thus promoting the TD of coal.
Background:The paper deals with a diesel common rail nozzle in which a novel orifice layout is implemented.Objective:Its influence on the nozzle mechanical-hydraulic behavior and on the spray shape transient development is experimentally investigated.Methods:In the research, a solenoid injector for light duty diesel engines is equipped with the novel nozzle prototype and tested. The prototype layout is described, pointing out the features of the nozzle orifices, in which a Slot cross-section is adopted; the investigation is accomplished extending the hydraulic tests and the spray visualizations to a reference nozzle with standard holes. The influence of the hole layout on the mechanical-hydraulic behavior of the nozzle is assessed by experimental analysis based on the rate of injection measurement, in comparison with the reference nozzle. Once the hydraulic behavior of the novel nozzle has been characterized in terms of mass flow rate, the slot influence on the spray shape is assessed analyzing the macroscopic features such as the penetration distance and the spray angle, in non evaporative conditions. The study is carried out under transient injection conditions, for different injection pressures, up to 1400 bar.Results:The results on spray characteristics also provide reference information to set up spray models suited to take the Slot orifice into account.
Background:District Energy (DE) is a technology capable of using renewable energy (e.g., solar thermal systems) and waste heat as energy sources efficiently. DE technology nonetheless has potential for improvement. Thermal Energy Storage (TES) can enhance DE performance significantly.Objective:An exergy analysis of a DE system which includes a solar thermal energy system and TES is performed, so as to improve understanding of its performance.Method:A case study based on the Friedrichshafen DE system in Germany is used to assess thermodynamically the role of solar energy and TES in a DE system. The system performance is separated into three modes: (1) fossil fuel is the only source of energy, (2) a discharging TES and fossil fuel provide heat for the DE system, and (3) solar energy and fossil fuels are the energy supplies. Exergy analyses are conducted for each performance mode and the overall DE system.Results:The results quantify the benefits of incorporating solar energy and TES on the performance of the Friedrichshafen DE system, and demonstrate that the overall exergy efficiency of the DE system increases from 23% to 27% with assistance of solar thermal collectors and TES, while the total energy efficiency increases from 83% to 87%.Conclusion:An increase of exergy efficiency is observed when TES is added to a DE system, due to a reduction in solar thermal energy loss by the TES, which allows more solar energy to be converted to useful energy to satisfy the DE system thermal energy demand.
Background: Additives affect the formation of different mercury speciation in coal-fired derived flue gas. Objective: In order to study the effect of the additive CaBr2 content, the Ontario Hydro Method (OHM) method has been applied to analyze the mercury speciation at the entrance and export of denitration (SCR). Method: Density Functional Theory (DFT) has been used to study the adsorption of mercury halide on unburned carbon surface. Result: The results show that along with the increasing amount of additive CaBr2, there is an increasing trend of the ratio of Hg2+ in flue gas. Conclusion: CaBr2 addition contributes to oxidize Hg 0 to Hg2+ and increase the mercury concentration through SCR. DFT results indicate that the adsorption of HgBr and HgBr2 on unburned carbon surface is chemisorption, and Br-C bond is stronger than Hg-C bond, both these bonds are covalent interaction.
The popularity of electric vehicles may lead to negative effects on the power system if the charging procedures of plug-in electric vehicles (PEVs) are uncoordinated. In order to solve the problem, the hierarchical and zonal dispatching architecture and a new bi-level optimization model are respectively presented for the charging/discharging schedules of the PEVs. The upper level model is devoted to minimizing the system load variance so as to implement peak load shifting by optimizing the dispatching plan of all periods for each electric vehicle aggregator (EVA), and the lower one is aimed at tracing the dispatching scheme determined by the upper decision-maker through presenting an optimal schedule of charging and discharging for electric vehicles in the charging areas. Two highly efficient commercial solvers, AMPL/IPOPT and AMPL/CPLEX respectively, are employed to solve the developed optimization problem. Finally, the testing IEEE system consisting of 5 agents and 30 nodes is adopted to illustrate the characteristics of the model and solving method presented in this paper.
Low carbon economy development undoubtedly becomes the main trend of social development in future under the background of the global climate change and the increasing international pressure to reduce emissions. However, the international trade, as part of the global economy, will be carried out in accordance with the rules of low carbon economy. Therefore, it has important significance to study the relation between the carbon emission and export trade and deeply excavate carbon reduction potential of Chinese industry production for finding way to reduce carbon emission in China and striving for the carbon emission reduction space from the international. This paper constructed the input-output model to calculate the CO2 emission density of Chinese export industry according to the input-output theory, and then basically analyzed the situation of carbon emission of export industry.
Objective:The rheological properties of oil severely affect the determination of percolation theory, development program, production technology and oil-gathering and transferring process, especially for super heavy oil reservoirs. This paper illustrated the basic seepage morphology of super heavy oil in micro pores based on its rheological characteristics.Methods:The non-linear flow law and start-up pressure gradient of super heavy oil under irreducible water saturation at different temperatures were performed with different permeable sand packs. Meanwhile, the empirical formulas between start-up pressure gradient, the parameters describing the velocity-pressure drop curve and the ratio of gas permeability of a core to fluid viscosity were established.Results:The results demonstrate that temperature and core permeability have significant effect on the non-linear flow characteristics of super heavy oil. The relationship between start-up pressure gradient of oil, the parameters representing the velocity-pressure drop curve and the ratio of core permeability to fluid viscosity could be described as a power function.Conclusion:Above all, the quantitative description of the seepage law of super heavy oil reservoir was proposed in this paper, and finally the empirical diagram for determining the minimum and maximum start-up pressure of heavy oil with different viscosity in different permeable formations was obtained.
For the bottleneck problem of the conversion efficiency in silicon-based solar cell, the Metallization Wrap– through (MWT) technology is one of the effective methods based on the analysis of factors affecting the solar cell conversion efficiency. The MWT technology is based on laser perforation and that the bus grid lines in the front surface of the solar cell are moved to the back surface. The effective area on the front surface increases and the conversion efficiency is improved. One of the most important processes in MWT technology is laser perforation and a new perforation scheme using two-dimensional laser array is designed. The high power laser is divided into a number of beams then those beams are arranged in a two-dimensional array. The silicon wafer is placed in a predetermined position by suction cup and is moved by stepper motor. The light barriers are opened by triggering switch and the silicon wafer is exposed. After a series of light, machine, and electric processes a rapid one-time two-dimensional array laser perforation on silicon wafer is formed. This patent is expected to be used in solar cell production department soon.
In order to take the reduction of pollution emissions as the target, this paper generates the model parameters based on the input-output relationship between material flow and energy flow of regional inter-industry, and builds the model of energy efficiency optimization of industrial park with the distribution of regional industry structure as the control variable. The modeling process is discussed in detail in model structure, elements and optimization objective and control variable etc. and the suggestions on further research are given.
Background:During last few years, the proton exchange membrane fuel cells (PEMFCs) underwent a huge development.Method:The different contributions to the design, the material of all components and the efficiencies are analyzed.Result:Many technical advances are introduced to increase the PEMFC fuel cell efficiency and lifetime for transportation, stationary and portable utilization.Conclusion:By the last years, the total cost of this system is decreasing. However, the remaining challenges that need to be overcome mean that it will be several years before full commercialization can take place.This paper gives an overview of the recent advancements in the development of Proton Exchange Membrane Fuel cells and remaining challenges of PEMFC.
Providing peaking auxiliary for wind power will affect the thermal power generation efficiency and reduce generation economic benefit. To realize the coordinated scheduling optimization of thermal power and wind power, the key problem is the economic compensation of thermal power peaking. In this paper, through the analysis of the influence of wind power on thermal power generation performance and thermal power peak load regulation on abandon wind, an economic compensation model based on objective optimization is established. The example analysis shows that cooperation of thermal power and wind power can improve the wind power accommodation level and unit efficiency, and the economic compensation mechanism can guarantee thermal power unit economic benefit effectively.
Background: The replacement of leaded high octane aviation gasoline with an unleaded renewable alternative would decrease the emissions of lead and fossil-derived carbon into the atmosphere. Replacement has been limited by the requirement of a very high octane number in many existing general aviation aircraft engines. Method: Two separate process pathways were developed that generate an unleaded octane fuel with a motor octane number >96 from triglyceride oils (TGs), such as crop oils and algae oil. A series of experiments coupled with process simulations was used to verify the feasibility of both pathways and to provide preliminary laboratory scale data that could form the basis for further development towards a commercial technology. In the first pathway, TG oil is catalytically cracked to produce a high concentration of simple aromatic hydrocarbons. These aromatic hydrocarbons are then alkylated using propylene to form a mixture, which after purification acquires fuel properties compliant with those in the ASTM specification for 100 octane low lead aviation gasoline (100LL AvGas). In the second process pathway, the aromatic hydrocarbons are isolated after cracking using a sulfolane solvent extraction process to increase alkylation efficiency and fuel quality. Result: The results demonstrate that it is technically feasible to produce a replacement for 100LL AvGas using either pathway, and thus these strategies may be attractive candidates for commercialization.
Background:Coal gasification is the promising technology for syngas routes to produce chemicals or transportation fuels. Additionally, it enables clean power generation from coal in Integrated Gasification Combined Cycles (IGCC). So far, coal fines with high ash contents could not be feasibly used in such routes.In this regard, the Internal Circulation gasifier (INCI) is designed to gasify high-ash coal fines efficiently. The staged system is combining a moving bed, a fluidized bed and a jetting fluidized bed in one reaction chamber.Method:The present paper substantially describes the laboratory-scale prototype development in the COORVED-project (“CO2-reduction by innovative gasifier design”) based on the INCI gasification principle of about 50-125 kW thermal input. Information about the gasifiers compounding, especially the reaction chamber, peripheral components and applied measurement systems are given.Results:Experimental results are presented, confirming the targeted, typical flow pattern inside the reaction chamber. Furthermore technical and operational limits of the COORVED prefiguration are discussed. Based on these results a major design change of the reaction chamber is required and explained in detail. Additionally, results of the feedstock variation from coke to lignite are shown.Conclusion:Finally, the operability of the INCI gasification principle is proven by a stationary operating system with controlled ash agglomeration.
Objective:Energy pricing in the international energy market is the key point for RMB internationalization, which can make the process further developed.Aim:Therefore it is of practical significance to study their co-integration relationship and causality, and though the impulse response to analyze their dynamic interaction relationship.Method:We take the Johansen co-integration and VAR model to explore the interaction between them.Results:Empirical results show that, firstly there is a long-term equilibrium between RMB internationalization and energy prices, and the change of short-term energy prices have a positive impact on the RMB internationalization index. Secondly, WTI oil price, domestic oil price and domestic coal price linearly Granger cause the RMB internationalization, but not vice versa. While RMB internationalization is only the Granger cause of the international coal price. Finally, the impulse response analysis shows that changes of energy prices play positive roles in promoting the internationalization of RMB.
To effectively formulate a scheme for the development of gas reservoirs, the distribution of formation water in the Shan 23 member of the Zizhou gas field of the Ordos basin in China was studied in depth, making full use of data covering formation water, logging and production. The study concluded that the types of formation water of the Shan 23 member in the Zizhou gas field are edge (bottom) water, lenticular water and formation water residue. The edge (bottom) water in the Shan 23 member is mainly distributed in three regions with low structures in the west, south and southeast of the area, respectively, to the well areas of Y47-Y29-Y43, Y64-Y40 and Y69. This layer is generally interpreted as a water layer by well logging and produces a large amount of water discharge in the processes of gas testing and production. The lenticular water in the Shan 23 member is mainly scattered in the middle and southern parts of the area and is generally interpreted as a water layer by well logging, mainly in small water bodies. The typical production characteristics of gas wells that produce formation water residue in a gas reservoir are as follows: With less water production, the gas saturation is high, and there is no obvious information about the water layer in the logging curves. However, during production, there is trace formation water, and as production continues, this part of the water is taken out. The edge (bottom) water is distributed in the lower structure of the area and is mainly distributed in the southwest part of the area. It is clearly controlled by the structure, especially the low-amplitude structure; thus, structure is more important for the control of edge (bottom) water. Structural characteristics have some influence on the lenticular water and the formation water residue in gas reservoirs. The position of the lower structure is the main area that enriches water. In a relatively independent region containing gas, the position of the lower micro structure is also a common distribution area of water. In addition, a larger water body often forms at the pinchout and the bend of a sand body.
This paper proposes a regenerative braking control strategy based on real-time dynamic loading (RTDL) of wheels. Based on the nonlinear relationship between a spring’s resilience and displacement, this paper establishes 7-degrees of freedom (DOF) full vehicle model with nonlinear suspension. Then, a method based on suspension deformation is devised to calculate the wheels’ dynamic load, and RTDL is used to calculate the braking force of the front and rear wheels. With the braking intensity and the battery state of charge (SOC) as input variables and the desired regenerative braking force as an output variable, we establish a regenerative braking control strategy based on RTDL and simulate it in ADVISOR software. Results show that the designed control strategy effectively improves the regenerative braking energy recovery efficiency by assuring braking stability, and verifies the rationality and feasibility of the proposed control strategy.
