A double-step Savonius rotor for local production of electricity: a design study

This paper presents a study, carried out with the help of the French Agency of Innovation (ANVAR). It deals with the conception of a small Savonius rotor (i.e. of low power) for local production of electricity. Our challenge was to design, develop and ultimately build a prototype of such a rotor, which was considered as a complete electromechanical system. An optimised configuration was chosen for the geometry of the present prototype. The building data were calculated on the basis of the nominal wind velocity V=10 m/s. Particular care was necessary to choose the appropriate generator, which was finally a rewound conventional car alternator. The whole design of the prototype has confirmed the high efficiency and the low technicality of the Savonius rotors for local production of electricity. The present prototype is to be tested in situ.     

向心式汽轮机在大型铜冶炼厂余热利用系统中的应用

介绍了向心式汽轮机的特点及大型铜冶炼厂余热利用系统,提出了饱和蒸汽发电系统方案,并将其与传统轴流式背压汽轮机系统方案进行经济技术比校．     

生物质能利用方式的分析比较

简要分析了几种生物质能利用方式的技术性、经济性和社会性特征。通过比较，认为通过热化学法或生化法将生物质转化为液态或气态燃料即可提升生物质能的能量品质，又可大大拓展生物质能的使用范围，是生物质能利用的主要方式。其中，生化法由于其近于零污染的特性而将成为生物质能利用的首选方式。     

车用替代能源综合评价与发展策略

本文从技术性与政策性角度分析了各种车用替代能源的技术优缺点以及政策支持力度。研究表明:首先,发展车用替代能源应该以新能源汽车及传统汽车的替代燃料两个方面为重点。其中,新能源汽车以燃气汽车、混合动力汽车与甲醇汽车为主要发展方向,使用替代能源为天然气或液化石油气、电与甲醇;传统汽车替代燃料以甲醇汽油、生物柴油与二甲醚为主要发展方向。其次,由于发展的多元性,车用替代能源发展策略应该同时注重区域性、技术性以及政策性。     

Hybrid operation of triboelectric nanogenerator for electricity generation by a low‐temperature differential heat engine

There are many types of triboelectric nanogenerators (TENGs) which differ in their operational modes (contact mode, sliding mode, etc.), converting mechanical energy into electrical energy. This paper introduces electricity generation from a small low‐temperature differential heat engine capable of utilizing low‐grade thermal energy. The engine is similar to the Gamma‐type Stirling engine and could run on temperature differentials ranging from 90 down to a few degrees Celsius. The work presented here gives technical details of how a small low‐temperature differential heat engine could be integrated with a TENG for electricity generation. Two different schemes were tested for the operation of TENG: one in non‐contact sliding mode and the other in vertical contact‐separation mode. For the temperature difference of 74.4 °C, the former delivered a maximum output voltage of 70 V whereas the latter resulted in 35 V. A maximum combined output voltage of 105 V was obtained capable of charging a 4.7 μF capacitor and discharged through LED lighting. Copyright © 2017 John Wiley & Sons, Ltd.     

The C.G.E. circulating zinc/air battery: A practical vehicle power source

The currently proposed electric vehicle power sources are briefly summarized, and compared with the circulating zinc/air system. Based on current laboratory test data, this system should be capable of 110 Wh/kg, 80 W/kg in a 1 tonne urban vehicle and up to 125 Wh/kg in heavy duty applications, with lifetimes up to twice those for lead—acid systems. Despite its comparatively low recharge efficiency (40%) it will be capable of overall per km costs comparable to those for gasoline powered vehicles at current U.S.A. or untaxed European gasoline prices.     

The sensitisation of thin films of nitroglycerine

High speed photography techniques have been used to study the sensitising effects of air bubbles volume a few mm³) within thin films of spark-ignited nitroglycerine. The collapse of the bubble is shown to lead to an increase in sensitivity of the liquid explosive, by (a) locally increasing the deflagration velocity and (b) generating a pressure pulse which is capable of producing hot spots at cavitation sites within the liquid. If several gas bubbles are included, cooperative effects are observed which lead to increased sensitiveness. The results support a distributed hot spot model for low velocity detonation.     

Development of a prototype low-temperature Rankine cycle electricity generation system

This paper describes the development of a small-scale system designed to generate electricity from low temperature heat (e.g., solar energy). The system operates on the Rankine cycle and uses n-pentane as the working fluid. A prototype system has been designed, constructed and tested. It is capable of delivering 1.5 kW of electricity with a thermal efficiency of 4.3%. Laboratory test results and a cost estimate for the prototype unit are presented in the paper.     

双效复叠吸附式制冷循环的研究

为克服吸附式制冷能量利用效率不高的缺点，采用硅胶－水、分子筛－水分别作为两级循环的工作对以及两级循环中都用分子筛－水为工作对，构造了两种双效复叠式制冷循环．该循环可有效利用第二级循环的吸附热、析出蒸汽的显热，能有效提高热力完善度。建立了计算机模型，对系统和影响性能的一些参数进行了分析讨论。     

为万匹马力柴油机改配拆旧增压器的成功一例

本文叙述用常规配机计算，探明拆旧VTR630型增压器在一定运行范围内可配用于国产6ESDZ76/160型低速柴油机，在该运行范围，其性能符合船主要求．6年多的运营实践证明该配机成功．从而，解决了用户燃眉之急，避免了由于停航和进口增压器所带来的经济损失，也为国内航运界拥有的几十条万吨级货轮所用同类主机改用该类旧增压器开创了先例·     

Optical characterisation of materials and systems for daylighting

The measurement of BRTF (Bi-directional reflectance and transmittance function) is described using a new instrument which is capable of supplying BRTF data and algorithms for use in computer simulations directly on diffuse materials and indirectly on large samples and sub-systems. A high sensitivity and dynamic range is needed to achieve low minimum observable BRTF and the role of angular resolution are discussed with examples. Forward scattering with extended tails is found to dominate pigmented polycarbonate. Slatted blinds are discussed as examples of systems where azimuth is important.     

附壁射流煤粉燃烧器试验研究

附壁射流煤粉燃烧器是根据燃烧空气动力学原理,利用壁面对射流的非接触式导流特性和射流组合特性而研制出的一种新型燃烧装置。本文科述了该燃烧器稳定煤粉火焰和不易结焦的原理及特性。试验室试验表明,它可在冷风条件下脱油稳燃V~(?)=10%的无烟煤,并有防焦功能,现在进行推广应用。     

双回流燃烧器实验研究与应用

本文针对国内电站锅炉燃用劣质煤所存在的着火困难、燃烧不稳定和燃烧效率低等问题,提出了能产生内回流区和外回流区的双回流新型结构直流燃烧器,分析讨论了它的实验室冷态试验和热态试验结果,介绍了这种燃烧器在工业应用中的情况。     

High-flux photovoltaic solar concentrators with kaleidoscope-based optical designs

We propose, analyze and offer sample designs and results for a high-flux photovoltaic concentrator comprised of a large-aperture paraboloidal-dish primary concentrator, and a second-stage kaleidoscope flux homogenizer. The following key design aims are all satisfied: (1) highly uniform irradiance on the solar cell absorber; (2) maximum collection efficiency; and (3) not exceeding the prescribed target flux level (for illustrative purposes here taken to be 500 suns), despite the dish being capable of much higher concentration. As a result of recent advances in the low cost and ease of production of large dish concentrators, the kaleidoscope-based design offers an intriguing alternative to other high-concentration optical designs developed to date. Admissible kaleidoscope geometries are identified. We generate quantitative results for a compact practical design that incurs low optical losses, and produces a highly homogeneous flux map.     

Mechanisms of film boiling heat transfer of normally impacting spray

The heat transfer mechanisms of horizontally impacting sprays were studied experimentally. An impulse-jet liquid spray system and a solid particle spray system were used. The liquid spray system is capable of producing uniform droplets with the independent variables of droplet size, velocity, liquid flow rate, and air velocity. The horizontally impacting sprays give a lower heat transfer at film boiling than the corresponding vertically impacting spray. The film boiling heat transfer is mainly controlled by the liquid mass flux. At low liquid mass flux and low droplet Weber number, the heat transfer increases with the droplet Weber number. At high droplet Weber number or high liquid mass flux, the heat transfer is not significantly affected by the droplet Weber number.     

Study of an indian biogas plant with a water pond

To overcome the problem of reduced biogas production, due to low ambient temperatures during the winter months of northern India, a novel concept of a shallow solar pond (SSP) water heater has been put forward and studied theoretically. The pond is proposed to be integrated with the dome of the conventional Indian (KVIC) biogas design. The results of the study show that system is capable of providing hot water upto a temperature of 40°C which, in turn, can be used for hot charging of the slurry besides reducing the heat losses from slurry to the ambient. Simultaneously, it helps in enhancing the slurry temperature from 20°C to 27°C.     

Numerical simulations of a low power microchannel thermal cycling reactor

A roadblock to the development of stand-alone microscale biomedical and chemical analysis systems is the relatively high heating power requirement of the microscale reactors, which typically exceeds the capability of low cost batteries. In this study, a microchannel thermal cycling reactor design using in-channel heating and passive cooling is proposed and a numerical model has been developed. Numerical simulations were conducted to determine the conditions under which efficient, rapid thermal cycling can be achieved with minimum heating power load. The simulations revealed that with a low thermal conductivity substrate and an optimized heater-channel configuration a microchannel reactor is capable of performing rapid thermal cycling to temperatures as high as 95 °C with as little as 20 mW/channel peak heating power.     

Analysis of a small horizontal axis wind turbine performance

A small‐scale horizontal axis wind turbine capable of producing 100 W of rated power has been designed and tested using a low‐speed wind tunnel. Power output from the wind turbine was calculated through measurements of the electrical current from a 12 V DC generator. Annual energy extraction from this wind turbine shows that a number of potential applications are possible especially in the remote areas where extension of power grid is not feasible. Copyright © 2001 John Wiley & Sons, Ltd.     

Solar water splitting for hydrogen production with monolithic reactors

The present work proposes the exploitation of solar energy for the dissociation of water and production of hydrogen via an integrated thermo-chemical reactor/receiver system. The basic idea is the use of multi-channelled honeycomb ceramic supports coated with active redox reagent powders, in a configuration similar to that encountered in automobile exhaust catalytic aftertreatment.Iron-oxide-based redox materials were synthesized, capable to operate under a complete redox cycle: they could take oxygen from water producing pure hydrogen at reasonably low temperatures (800 °C) and could be regenerated at temperatures below 1300 °C. Ceramic honeycombs capable of achieving temperatures in that range when heated by concentrated solar radiation were manufactured and incorporated in a dedicated solar receiver/reactor. The operating conditions of the solar reactor were optimised to achieve adjustable, uniform temperatures up to 1300 °C throughout the honeycomb, making thus feasible the operation of the complete cycle by a single solar energy converter.     

The performance of a low cost clay solar cooker

This paper reports the development of a low cost clay solar cooker. The main features of this cooker are that it is made from cheap, locally available materials, and needs no skilled labour. One of the new design features of the solar cooker is the replacement of the absorber plate with locally available black sontes. The effects of using the black stones instead of the abrosber plate resulted in solar cooker capable of storing solar energy, hence making late cooking possible.