采用泡沫铜电极的热再生氨电池性能数值模拟

以采用泡沫铜电极的热再生氨电池（thermally regenerative ammonia-based battery，TRAB）为研究对象，建立了多孔介质内物质传输与电化学反应耦合的稳态模型，计算获得了电池性能及多孔电极内物质传输特性，并研究了电解质浓度和电极孔隙率对电池性能的影响。研究结果表明，从主流区界面到多孔电极内部，阳极氨和阴极铜离子浓度逐渐降低，存在一定的浓度梯度，而且随着反应电流的增大，浓度梯度明显增大。在一定的范围内分别增大阳极氨浓度和阴极铜离子浓度，从主流区向多孔电极内物质传输增强，电池性能均能不断提升；随着硫酸铵浓度的增大，电解质电导率增大，电池性能逐渐提升，但增幅逐渐减小。此外，多孔电极孔隙率也会影响电池性能，本研究中TRAB在电极孔隙率为0.6时获得最高的最大功率(15.3 mW)。     

Benchmark value determination of energy efficiency indexes for coal-fired power units based on data mining methods

The operational optimisation of coal-fired power units is important for saving energy and reducing losses in the electric power industry. One of the key issues is how to determine the benchmark values of the energy efficiency indexes of the units. Therefore, a new framework for determining these benchmark values is proposed, based on data mining methods. First, the energy efficiency key performance indicators (KPIs) associated with the net coal consumption rate (NCCR) were selected based on the domain knowledge. Second, the decision-making samples with minimal NCCR were acquired with the fuzzy C-means (FCM) clustering algorithm, and the corresponding clustering centres were employed as the benchmark values. Finally, based on the support vector regression (SVR) algorithm, the target values of the NCCR were obtained with the KPIs as input, and the energy saving potential was evaluated by comparing the target values with the historical values of the NCCR. An actual on-duty 1000 MW unit was taken as study unit, and the results show that the energy saving potential is remarkable when the operators adjust the KPIs based on the calculated benchmark values.     

枞树型核电轮槽精铣刀制造技术优化设计

以枞树型叶根精铣刀为例,阐述了可换硬质合金型线刀体和刀片精铣刀的优化设计、制造工艺、建模及优化设计,进行切削过程加工策略优化和加工过程模拟,设计制造了锥柄专用工装及检测环规、磨削刀片后角专用工装,采用NUMROTO软件编制刀片加工工步。该项目研制的可换刀片精铣刀型线精度完全能达到进口铣刀水平,能满足大部分轮槽与叶根加工对型线精度的要求,可以大幅度节约刀具费用。     

10MW级深冷液化空气储能发电系统自动启动控制方法研究

以10 MW级深冷液化空气储能发电系统为研究对象,简要介绍了技术原理、系统构成、主要设备及工艺流程,并从自动控制视角,分别设计了储、释能阶段的启动方法。基于该自动启动方法,可完成储能阶段空气净化及压缩、空气液化、储热和蓄冷子系统的联合运行以及释能阶段储热、蓄冷和膨胀发电子系统的联合运行,实现了储能阶段自动达到额定出液量及释能阶段自动满足额定发电量的需求,提高了能量型机械储能系统对电网负荷变化的响应速度。     

Achieving renewable energies utilization target in South-East Asia: Progress,challenges, and recommendations

The South-East Asian countries together have a target to increase the component of renewable energy in their primary energy supply to 23 % by 2025. However, there is a different starting point for the individual country members based on their natural conditions and specific political and regulatory frameworks. The Association of South-East Asia Nations (ASEAN), as the regional-cooperation organization, does not have the authority to intervene in the countries’ national policy for renewable energy. It can only provide inputs to develop renewable energy. However, that can also be challenging because it does not have a portal to access each member’s development of renewable energy utilization. This study aims to observe each ASEAN member’s progress by analyzing historical data. This study also reviews some academic papers to summarize the challenges and obstacles faced by each country. The result suggests that regionally, ASEAN members still rely highly on fossil fuels, especially the total primary supply. Moreover, the share of traditional biomass is also very high. Although, data shows that its use has started to reduce as countries gradually shift to other energy options, unfortunately, mostly to fossil fuel. However, power generation has developed in a positive direction. Historical data shows an increase in renewable energy use for power generation, mainly due to the higher utilization of hydropower. Furthermore, it is strongly recommended for ASEAN to build a monitoring portal of renewable energy to track the progress, so it can provide more precise policy recommendations to its members and establish better energy cooperation between each member in the future.     

Enhanced photoelectrochemical water splitting using gadolinium doped titanium dioxide nanorod array photoanodes

In this study highly oriented, rutile phase one dimensional Titania nanorod array (TiO₂ NRA) modified by gadolinium doping were synthesized on the conductive glass substrate (FTO) by the hydrothermal method. The effect of Gd doping on the photoelectrochemical performance of TiO₂ NRA was investigated. Crystal phase, structural, morphological and composition characteristics of these synthesized photoelectrodes were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM). FE-SEM images clearly show that some of the Gd dopant is uniformly distributed on the surface of TiO₂ NRA in the form Gadolinia (Gd₂O₃) microsphere. These gadolinia microsphere play an important role in reducing the surface recombination of electron and hole supported by photoluminescence's studies. Linear sweep voltammetry results show that Gd doping results in a two-fold increase in photocurrent density as compared to pristine TiO₂ NRA. UV–visible spectra, and Mott-Schotty measurements show that Gd doping shift the flat-band potential of TiO₂ NRA more toward negative potential that results in effective charge separation and transportation in the Gd doped TiO₂ NRA (Gd@TiO₂ NRA). Applied biased photon to current efficiency (ABPE) equation was used to find solar to hydrogen efficiency (STH). Gd@TiO₂ NRA show optimum conversion efficiency of ~0.64% at 0.03 V vs Ag/AgCl, while pristine TiO₂ NRA display ~0.33% at −0.21 V vs Ag/AgCl.     

汽爆秸秆对磷矿粉溶解作用及其溶解残渣对小麦生长的影响

为探究生物质对磷矿粉的溶解作用，以玉米秸秆为原料，利用蒸汽爆破（汽爆）技术释放有机酸，在高温水热条件下溶解磷矿粉并制备含磷腐殖酸。通过实验对汽爆秸秆溶解磷矿粉工艺进行了探究及优化，并利用傅里叶红外光谱（FT-IR）、扫描电子显微镜（SEM）和X射线荧光光谱（XRF）进行分析和表征。研究结果表明：15 g汽爆秸秆与1 g磷矿粉以及75 mL水在170℃、加入10% CaCl₂的条件下，反应3 h的溶磷量为1.46 mg/g（以秸秆质量计，下同）。加入与磷矿粉相同质量的NaHSO₄后可使体系pH值降低至2，pH值的降低是磷溶出的关键因素，溶磷量提高为13.10 mg/g。溶磷后的秸秆制备腐殖酸作为小麦盆栽肥料，用量0.2%时，小麦株高、根长、叶绿素含量和相对电导率均显著高于空白组。     

Power flow calculation for a distribution system with multi-port PETs: an improved AC-DC decoupling iterative method

Recently, power electronic transformers (PETs) have received widespread attention owing to their flexible networking, diverse operating modes, and abundant control objects. In this study, we established a steady-state model of PETs and applied it to the power flow calculation of AC–DC hybrid systems with PETs, considering the topology, power balance, loss, and control characteristics of multi-port PETs. To address new problems caused by the introduction of the PET port and control equations to the power flow calculation, this study proposes an iterative method of AC–DC mixed power flow decoupling based on step optimization, which can achieve AC–DC decoupling and effectively improve convergence. The results show that the proposed algorithm improves the iterative method and overcomes the overcorrection and initial value sensitivity problems of conventional iterative algorithms.     

Experimental investigation of power management and control of a PV/wind/fuel cell/battery hybrid energy system microgrid

This paper presents an experimental study of a standalone hybrid microgrid system. The latter is dedicated to remote area applications. The system is a compound that utilizes renewable sources that are Wind Generator (WG), Solar Array (SA), Fuel Cell (FC) and Energy Storage System (ESS) using a battery. The power electronic converters play a very important role in the system; they optimize the control and energy management techniques of the various sources. For wind and solar subsystem, the speed and Single Input Fuzzy Logic (SIFL) controllers are used respectively to harvest the maximum power point tracking (MPPT). To maintain a balance of energy in the hybrid system, an energy management strategy based on the battery state of charge (SOC) has been developed and implemented experimentally. The AC output voltage regulation was achieved using a Proportional Integral (PI) controller to supply a resistive load with constant amplitude and frequency. According to the obtained performances, it was concluded that the proposed system is very promising for potential applications in hybrid renewable energy management systems.