海洋波浪能发电研究进展

海洋波浪能是一种清洁、无污染的可再生能源。首先根据波浪能发电装置的拾能原理和转换原理,按一次转换、中间转换及二次转换进行了分类,并对国内外已有波浪能发电装置的发展和特点进行了分析,总结了主要波浪能发电装置的优缺点,指出了波浪能发电的关键问题和发展趋势。     

Investigation on the decomposition of chemical compositions during hydrothermal conversion of dewatered sewage sludge

Hydrothermal conversion (HC) can be used to convert sewage sludge into fuel-like products. The investigation of biomass compositions conversion can facilitate the understanding of reaction pathways. HC of dewatered sewage sludge (DSS) is conducted in sub-/supercritical water with batch reactors. Hemicellulose has the highest conversion efficiency of 99.1 wt %, followed by crude protein, cellulose, lignin, and lipid/oil. The total gas and H₂ yields increase slowly from 200 to 300 °C, then sharply rise up from 350 to 450 °C. At 450 °C, the H₂ yield reaches to the maximum of 0.70 mol/kg organic matter. HC of DSS includes reactants degradation to intermediates and final products formation from intermediates. The water-soluble products (WSPs) are formed throughout the HC process, the oil-phase products (OPs) are mostly produced at low temperatures (250–350 °C), and char and gases are mainly generated at higher temperatures (above 350 °C).     

Experimental evaluation of electrode conversion efficiency of alkali metal thermal to electric converter

The alkali metal thermal to electric converter (AMTEC) system which utilizes the sodium ion conductivity of a beta″‐alumina solid electrolyte (BASE) is expected to have high conversion efficiency above 30% including practical heat losses. However, the achieved experimental efficiencies have been around 15%. In this paper, current–voltage characteristics and heat and mass transfer processes on a single cell have been examined experimentally and thermal electrode conversion efficiency has been discussed. Measured electrode conversion efficiency without thermal losses showed that it was about 40% at a power density of 0.3 W/cm². A theoretical analysis on the thermal losses has also been conducted and these losses are estimated to be 0.3 W/cm² in a practical tube type cell, so that an actual cell system efficiency of 30% is expected. © 2001 Scripta Technica, Heat Trans Asian Res, 30(3): 234–244, 2001     

三元催化反应器的作用原理及其检测

介绍排气后处理装置三元催化反应器的作用原理，对其转化要求及转化效率做了说明，指出三元催化反应器的检测方法。     

A solar thermophotovoltaic converter using Pbs photovoltaic cells

A solar thermophotovoltaic converter using PbS photovoltaic cells is proposed. The converter is in the form of a flat plate consisting of a heat mirror, a black absorber, a cell filter and PbS photovoltaic cells. Theoretical analysis shows that, ideally, the efficiency of such a system is about 30%.     

Hydrogen production from biomasses and wastes: A technological review

Biomass and organic solid waste are considered as very potential alternative energy sources in the future, leading to the realization of a clean and CO₂-free energy system. Therefore, the effective conversion of biomass and organic solid waste to a secondary energy source is urgently demanded. In addition, hydrogen is considered very promising among the secondary energy sources due to its advantages of cleanliness, wide range of conversion and utilization technologies, high energy efficiency, and high gravimetric energy density. This paper reviews several possible routes and key conversion technologies of biomass and organic solid waste to hydrogen. Recent progress related to biological and thermochemical conversion technologies is described. Thermochemical route includes gasification, pyrolysis, steam reforming, partial oxidation, and thermochemical cycle; while biological route covers fermentation (dark and photo), biophotolysis (direct and indirect), enzymatic, and microbial electrolysis. In addition, several challenges regarding the conversion and utilization of biomass and organic solid waste to hydrogen are also discussed in order to clarify the feasibility of biomass and the organic solid waste-based hydrogen economy.     

基于PLC的变频恒压变流量供水节能系统的研究与应用

针对传统供水系统能源浪费严重、自动化程度低等特点,设计开发了一种以PLC、变频器为核心构成的变频恒压变流量供水系统。介绍了该系统的节能原理、系统构成及工作原理、硬件、软件设计及系统优点,证明了变频恒压控制系统优越的技术性能和极其显著的经济效益,具有很好的推广应用价值和进一步的研究价值。     

SOLAR CONVERSION PARAMETERS OF GRADED BASE SILICON SOLAR CELLS

A simple model for the photovoltaic processes in a diffused base silicon solar cell is presented. The practical profiles of impurity concentration are taken into account by using the method of integration by piecewise exponential approximations. The realistic variation of mobility and built-in field are considered. Such parameters of solar conversion as short circuit current, open circuit voltage and conversion efficiency are computed. Results show that these parameters are are sensitive functions of the impurity distribution in the graded base and the recombination velocity at the surface of the diffused layer. The model holds promise of its application for parametric study and optimization of the solar cell configuration. © 1997 John Wiley & Sons, Ltd.     

A new approach to low cost large area selective surfaces for photothermal conversion

In the present study, selective black paint coatings have been prepared by coating reflective metal particles with a layer of selective black material. the coated particles were mixed in a binder and applied easily as a thin layer onto aluminium or galvanized iron (G.I.) sheet. Three selective black materials, namely CuO, CuS and PbS + CuS have been deposited on zinc metal powder, the solar absorptance of the coatings is ±0.95 and the emittance is ±0.4. the thickness of the coatings was about 20 to 30 μm. the emissivity decreases as the thickness increases, while the solar absorptivity does not change appreciably. the improvement in the collector efficiency, which is the ratio of the temperature increase above the temperature of the standard panel to the temperature increase of the standard panel above the ambient temperature, is estimated to be around 11 per cent. the process is potentially a low cost one for large scale application in solar photothermal conversion.     

Rational synthesis of one-dimensional carbon nitride-based nanofibers atomically doped with Au/Pd for efficient carbon monoxide oxidation

Controlled synthesis of carbon nitride nanostructures doped with noble metal-based catalysts is important in various catalytic applications. Herein, we developed a scalable, facile, and template-free approach for one-pot synthesis of one-dimensional gC₃N₄ nanofibers co-doped with Au and Pd donated as (Au/Pd/gC₃N₄NFs). The developed method tailored the high mass production of uniform gC₃N₄ nanofibers with a great surface area of (85 m² g⁻¹) and coherently co-doped with Au and Pd. Intriguingly, the complete CO oxidation temperature of Au/Pd/gC₃N₄NFs (144 °C) is significantly lower than that of Pd/gC₃N₄NFs (191 °C) and Au/gC₃N₄NFs (205 °C). The superior activity of Au/Pd/gC₃N₄NFs is attributed to the combination between outstanding inherent catalytic merits of Au/Pd and the unique physicochemical properties of gC₃N₄ nanofibers. Our newly designed simple approach may open the way for utilization of gC₃N₄ nanofibers in CO oxidation reaction.     

Optical properties of black nickel selective surface by conversion coating process

Optical properties of nickel black selective surfaces, prepared by a conversion coating process, on zincated aluminium alloy surfaces are studied in relation to the processing parameters. It is possible to obtain nickel black surfaces with solar absorptances ranging from 0.95 to 0.97 and thermal emittances ranging from 0.2 to 0.4. The coatings are stable up to 200°C but show degradation under humid conditions. Surface studies indicate that the optical properties may be explicable by the structure of these nickel films.     

Maximum efficiency of solar energy conversion

Owing to the energy scattered or absorbed by the constituents of earth's atmosphere and self‐absorption in the outer layers of the sun, the spectrum of solar flux at earth's surface is different from that of a blackbody. Consequently, the second law of thermodynamics for heat engine cycles operating between thermal reservoirs needs to be revised to determine the maximum conversion efficiency. A thermodynamic model similar to those for multi‐temperature plasmas and non‐isothermal particle‐exchange heat engines is proposed to estimate the maximum conversion efficiency of a mechanical or solid‐state heat engine subject to a radiation flux not having a blackbody spectrum. An example is given to illustrate the calculation of the maximum power that can be converted from a solar flux with considerable gas absorption. Copyright © 2011 John Wiley & Sons, Ltd.     

千瓦级小型液压式波浪能装置能量转换系统研究

针对小型海洋观测仪器用电需求,研究高效、可靠的小型液压式波浪能装置能量转换系统。在实验室建立一套3 kW的液压式波浪能能量转换系统,进行不同电阻负载、不同蓄能体积以及不同控制策略的液压系统试验,获得PTO效率曲线及各发电过程的特性曲线,详细分析不同控制策略的能量转换特性,得到PTO效率随阻值的增大趋于平稳、蓄能体积基本不影响PTO转换效率的结论,验证有蓄能器无控制器型直冲式能量转换系统的可行性。     

结合防波堤的振荡摇摆式波浪能装置试验研究

讨论一种结合防波堤的振荡摇摆式波浪能装置的结构和工作原理,并在河海大学河口航道综合试验厅进行物理模型试验。试验以重块和不锈钢板间的摩擦力作为波浪能转换装置的负载阻尼,通过测量不锈钢板两端的拉力及其位移计算波浪能转换输出功率。结果表明,当入射波的周期和浮体的固有周期接近时,浮体的运动接近共振状态,此时波浪能转换平均输出功率和转换效率最高,分别可达0.05 W和17.9%。入射波周期较大时,装置的波浪能转换输出功率较高,但此时其波浪能转换效率低于入射波周期较小时。水深对于浮体的姿态和运动特性起到关键作用,结果表明水深为60 cm时波浪能转换输出功率和转换效率最高。     

生物质能的转化和利用技术研究

能源短缺成为影响中国未来发展的主要问题之一。生物质能的应用有助于解决我国能源短缺的问题，同时能够减小化石燃料使用带来的负面影响。文章主要介绍了生物质能的概念、生物质能利用的意义及生物质能的转化和利用技术，而且还提出实际利用过程中需要解决的问题以及未来的发展方向——以生物质为核心的多联产系统。     

Flavin mononucleotide (FMN)-ethylenediaminetetraacetic acid (EDTA) photogalvanic cell

The photovoltages and photocurrent in a photogalvanic cell containing flavin mononucleotide (FMN) and a reducing agent, ethylenediaminetetraacetic acid (EDTA) have been determined and found to be appreciable. The efficiency of the cell has been estimated to be ～ 0-048 percent. The electrochemical behaviour of FMN in the presence of EDTA has been examined by cyclic voltametry.     

集中供热直供式热网存在的问题和建议

热电厂低真空运行直接向热网供热，效益最好，但随着热网负荷增大，会影响供热的稳定性。因此提出适时向间接供热的转换问题。     

生物质水热技术研究现状及发展

生物质水热转化技术作为一种新的生物质利用技术,在亚临界或超临界水下,将生物质直接转化为高品位气态、液态和固态产物。该技术具有原料适应性广、低成本和高转化率等特点,具有很好的应用前景。文章综述了近年来生物质水热技术研究的最新进展,分别对水热液化、水热气化和水热碳化3方面内容进行分析,对目前存在的问题提出了建设性的意见。     

Bio-oil production from hydrothermal liquefaction of waste Cyanophyta biomass: Influence of process variables and their interactions on the product distributions

Hydrothermal liquefaction (HTL) of waste Cyanophyta biomass at different temperatures (factor A, 260–420 °C), times (factor B, 5–75 min) and algae/water (a/w) ratios (factor C, 0.02–0.3) by single reaction condition and Response Surface Method (RSM) experiments was investigated. By single reaction condition runs, maximum total bio-oil yield (29.24%) was obtained at 350 °C, 60 min and 0.25 a/w ratio. Maximum bio-oil HHV of 40.04 MJ/kg and energy recovery of 51.09% was achieved at 350 °C, 30 min, 0.1 a/w ratio and 350 °C, 60 min, 0.25 a/w ratio, respectively. RSM results indicate that effect of AB interaction was significant on light bio-oil yield. Both AC and AB had more remarkable influence than BC on heavy bio-oil yield and aqueous total organic carbon (TOC) recovery whereas BC was noticeable on ammonia nitrogen (NH₃N) recovery in aqueous products. By model-based optimization of highest bio-oil yield, the highest bio-oil yield reached 31.79%, increasing by 8.72% after RSM optimization, and light and heavy bio-oil yield was 17.44% and 14.35%, respectively. Long-chain alkanes, alkenes, ketones, fatty acids, phenols, benzenes, amides, naphthalenes were the main components in light bio-oil. Some alcohols, phenols and aromatics were primarily found in heavy bio-oil. Solid residue after HTL consisted of numerous microparticles (～5 μm) observed by Scanning Electron Microscopy (SEM). Energy Dispersive Spectrometer (EDS) analysis shows these particles primarily contained C, O, Mg, P and microelements, derived from Cyanophyta cells.     

等离子体技术转化煤的应用

介绍等离子体的发生机理和等离子体技术在煤炭转化领域的应用,包括煤的热解、气化、液化、发电及煤的脱硫脱硝等,介绍该技术的应用研究现状、存在问题及发展前景,指出等离子煤转化是一种高效、洁净的技术,在煤化工等领域具有巨大的应用空间。