Energy access and transition to cleaner cooking fuels and technologies in Sri Lanka: Issues and policy limitations

Easy energy access is a trigger for human, social, and economic development. A research project was undertaken in Sri Lanka to broaden the understanding of human dimension of energy access and technologies. A questionnaire survey, covering 2269 households, gathered data on socio-economic contexts and issues influencing a transition towards clean cooking facilities. The findings reveal that the transition is impeded by four factors: the lack of motivation and the pressure for switching over to cleaner facilities, the lack of modern energy technology options, the financial risks, and the lack of financing and other support. The paper describes the delicate two-way interrelation between women earning wages and the transitions to cleaner cooking fuels and technologies. The findings suggest the need for a policy framework involving the stakeholders, financing and standardised technologies. To make a change it is proposed to introduce a national, integrated policy incorporating financing and energy governance.     

CA6102汽油／LPG双燃料发动机动力性能的研究

为了解决解放CA6102发动机改装双燃料后动力性下降的问题,作者对LPG供气系统,点火系统,进气系统和燃烧系统进行了改进和优化,在不影响发动机经济性和排放的情况下,以实现发动机燃用LPG理动力性能下降不超过5％的目的。     

Communications on energy: Attitudes to fuel choice in UK industry: results of a survey

The results of a survey investigating attitudes to fuel choice among larger industrial consumers are described. The survey was conducted in two parts, the main part in the autumn of 1985, while a follow-up was undertaken following the fall in oil prices in early 1986. The issues covered include: perceived obstacles to fuel switching; attitudes to coal and gas; and responses to lower oil prices. The implications of the survey findings are briefly assessed.     

Effects of consumer subsidy on household fuel switching from coal to cleaner fuels: A case study for anthracites in Korea

The Korean coal industry is in a transition under low carbon policy through the steady reduction of coal production. Since consumer subsidy for the consumption of anthracites briquette in low-income households caused a distortion in domestic coal market, the so-called coupon program will be the first target in energy reform policy in order to induce fuel switching from anthracites to alternative clean energy. This paper tries to identify various factors that influence households' fuel switching decision. Disutility from briquette consumption is also considered as an important factor. Using the 2007 census data on briquette-consuming households, it is found that the coupon program provides an adverse effect to switching fuels to clean energy while the disutility of briquettes is positively associated with the probability of fuel switching. However, the empirical finding suggests that the policy alone attempting to remove coupon program may fail to switch fuels unless the cost of boiler changes is substantially reduced through the provision of accessible networks to alternative energy sources. It indicates that reform policy for consumer subsidy must be understood in line with more comprehensive regional energy plans to resolve energy poverty issue.     

电控喷射改善燃用LPG发动机动力性研究

燃用LPG的发动机的一个主要缺点是动力性下降，在分析其原因的基础上，提出利用电控喷射改善动力性的设想，并设计了系统，进行了实验研究验证，结果表明，电控喷射方式能提高发动机的动力性，其中液态喷射的动力性还优于原发动机。     

Effect of hydrogen and LPG addition on the efficiency and emissions of a dual fuel diesel engine

This paper presents some experimental investigations on dual fuel operation of a 4 cylinder (turbocharged and intercooled) 62.5 kW gen-set diesel engine with hydrogen, liquefied petroleum gas (LPG) and mixture of LPG and hydrogen as secondary fuels. Results on brake thermal efficiency and emissions, namely, un-burnt hydrocarbon (HC), carbon monoxide (CO), NO_x and smoke are presented here. The paper also includes vital information regarding performances of the engine at a wide range of load conditions with different gaseous fuel substitutions. When only hydrogen is used as secondary fuel, maximum enhancement in the brake thermal efficiency is 17% which is obtained with 30% of secondary fuel. When only LPG is used as secondary fuel, maximum enhancement in the brake thermal efficiency (of 6%) is obtained with 40% of secondary fuel. Compared to the pure diesel operation, proportion of un-burnt HC and CO increases, while, emission of NO_x and smoke reduces in both cases. On the other hand, when 40% of mixture of LPG and hydrogen is used (in the ratio 70:30) as secondary fuel, brake thermal efficiency enhances by 27% and HC emission reduces by 68%. Further, shortcoming of low efficiency at lower load condition in a dual fuel operation is removed when a mixture of hydrogen and LPG is used as the secondary fuel at higher than 10% load condition.     

Investigations on the combustion parameters of a dual fuel diesel engine with hydrogen and LPG as secondary fuels

This paper presents a detailed experimental investigations on the combustion parameters of a 4 cylinder (turbocharged and intercooled) 62.5 kW gen-set duel fuel diesel engine (with hydrogen and LPG as secondary fuels). A detailed account on maximum rate of pressure rise, peak cylinder pressure, heat release rate in first phase of combustion and combustion duration at a wide range of load conditions with different gaseous fuel substitutions has been presented in the paper. When 30% of hydrogen alone is used as secondary fuel, maximum rate of pressure rise increases by 0.82 bar/deg CA as compared to pure diesel operation, while, peak cylinder pressure and combustion duration increase by 8.44 bar and 5 deg CA respectively. When 30% of LPG alone is used as secondary fuel, the enhancements in maximum rate of pressure rise, peak cylinder pressure and combustion duration are found to be 1.37 bar/deg CA, 6.95 bar and 5 deg CA respectively. It is also found that heat release rate in first phase of combustion reduces at all load conditions as compared to the pure diesel operation in both types of fuel substitutions.One important finding of the present work is significant enhancement in performances of dual fuel engine when hydrogen-LPG mixture is used as the secondary fuel. The highlight of this case is that when the mixture of LPG and hydrogen (40% in the ratio LPG: hydrogen = 70:30) is used as secondary fuel, maximum rate of pressure rise (by 0.88 bar/deg CA) and combustion duration reduces (by 4 deg CA), while, peak cylinder pressure and heat release rate in first phase of combustion increase by 5.25 bar and 35.24 J/deg CA respectively.     

汽油/LPG双燃料汽车瞬态切换过程的数值模拟研究

应用发动机工作过程软件GT-POWER和化学动力学软件CHEMKIN建立了汽油/LPG双燃料汽车瞬态切换过程的计算模型,在此基础上对LPG/汽油双燃料汽车在切换过程中的燃烧情况进行研究。数值模拟结果表明：进行燃料切换后的第一个发动机工作循环的缸内压力升高率比较大,并且着火始点提前,发动机在切换过程中工作粗暴,因此采取了在切换之初减少LPG进气量的进气策略。通过采用优化后的LPG进气策略,达到了汽油和LPG在切换过程中快速平顺的效果。     

LPG／汽油双燃料汽车双达标低排放控制系统研究

作者针对市政府环境保护实事,根据国内现有技术基础。改装成本和市场的需求,在已开发的LPG汽车排放单达标的基础上,对LPG-汽油双燃料汽车排放双达标控制系统进行了研究,即开发了能够满足欧I标准要求的LPG-汽油双燃料汽车双达标低排放控制系统。     

Renewable energy benefits with conversion of woody residues to pellets

In the frame of an Interreg IIIC Network-Operation named RegEnergy, that unites 18 partners from 11 countries of Europe, the feasibility of using the woody by-products for heating purpose in a typical Mediterranean region was investigated. Focusing on the Abruzzo Region as representative sample area, it came out that a significant amount of the above mentioned renewable energetic material is annually available as a consequence of well-consolidated and economically significant agro-industrial activities, forest maintenance and industrial wood production and transformation. In particular, it was found that the total amount of woody residues, as dry substance, are more than 700 kt/a, with 30% resulting from pruning activities related to the cultivation of about 360 km² of vineyards and 450 km² of olive-groves; these residues are concentrated in the hilly part of the region close to the Adriatic sea coast. Starting by this pleasant situation, the feasibility of a properly localized wood pellets production plant was supported by both the economic and energetic analysis. Additional suggestions related to optimal plant localization and to the best use of the woody pellets as substitute of natural gas for heating purposes were reported along with the positive impact of the whole action on the quality of the environment and on the recovery of soil fertility.     

LPG／汽油两用燃料汽车加装电控补气三元催化器系统的匹配研究

本文对在LPG／汽油两用燃料汽车上加装三元催化器和电控补气装置的优化匹配过程进行了详细的介绍，加装该系统可以有效地降低尾气排放污染，使两用燃料车辆达到新的排放法规的严格要求。     

Impact of the superpowers' energy balances on world oil

The world has become so accustomed to looking at OPEC and the OECD consumers that it overlooks one of the largest oil and energy perspectives in the world. Half of all energy consumption and production on our planet is internal to the two superpowers, as is 45% of all oil consumption. The net energy imports of the USA are balanced by hydrocarbons exported by the USSR; but concern exists in both nations about their oil reserves, which support 22 million bbl of production every day. Will they continue to completent one another, or are there signs that suggest their oil balance in future will be less comportable for the rest of the world?     

缸内直接喷射应用于LPG发动机的研究

通过对LPG发动机技术与相关研究的分析,结合电控喷射技术,提出了与汽油缸内直接喷射相近的LPG发动机的缸内直接喷射技术。分析了LPG发动机缸内直接喷射的主要技术思路和研究内容。     

Maximum efficiency of direct energy conversion systems. Application to fuel cells

This work develops a methodology to calculate the maximum First Law efficiency of any power device. To do so external irreversibilities due to heat transfer are suppressed by means of Carnot engines which mechanical work is added up to the one resulting from the device under hypothetical internally reversible mode of operation. By applying the developed methodology comparisons between Direct Energy Conversion Systems (DECS) and power cycles can be properly set on balanced assumptions in each type of device. In this paper, the main equations of the methodology are presented and the specific equations for fuel cells are derived. The potential of this methodology is illustrated by comparing fuel cells and power cycles First Law efficiency as a function of temperature.     

LPG站集合管内空化现象分析

液化石油气(LPG)从集合管流入各个支管时由于局部压力的变化会产生空化现象,生成大量气泡。当气泡溃灭时将引发强烈的冲击波和高速微射流,形成气蚀极易对管线造成损害。针对液化石油气通过各个支管空化的影响因素进行数值计算,结果表明:入口压力越高,空化数越小,气含率越高,湍动能越大。当改变出口压力时发现,出口压力越高,空化数越大,气含率越低,湍动能就越小。随着管径的增大,空化强度越高,空化数越小,气含率越高,湍动能越大。     

Improving conversion efficiency of solar energy to electricity in cyanobacterial PEMFC by high levels of photo-H2 production

In this study, we described an efficient electrical power generating system containing cyanobacterial photo-H₂ production and custom-built proton exchange membrane fuel cell (PEMFC). The filamentous N₂-fixing cyanobacterium Anabaena cylindrica was used as the photo-H₂ producer. A photosynthesis inhibitor-diuron (DCMU) was used for the enhancement of photo-H₂ production in the culture under argon gas. For the first time, a total of 1.0 μM DCMU was found to be the most effective treatment, as this produced 3.6 fold higher levels of H₂ in microalgae. By measuring polarization curve, the gas mixture collected from the culture was proven to be an effective fuel for electrical generation through a custom-built PEMFC. When the PEMFC was directly combined with the culture tube, the cells generated as much as 843 mV during a 5-day incubation due to the efficient conversion of solar energy to H₂ by A. cylindrica. Light energy conversion efficiency (LCE) for both solar energy to H₂ and solar energy to electricity were also determined. The LCE for the cyanobacterial conversion of solar energy to H₂ reached a peak at four days with a maximal value of 2.05% and an average value of 1.70% ± 0.17. The corresponding LCE for the conversion of solar energy to electricity in this system was 1.13% at peak and 0.94% ± 0.09 on average.     

The rise and fall of oil generation in the USA: A study in institutional adaptability

After 1978, the US electric power industry more than halved oil generation of electricity. This reversed a rising trend that had accelerated with the liberalization of residual fuel oil import quotas in 1966. This paper uses detailed data on inter- utility sales filed with the US government and limited circulation statistical reports from electric utilities to appraise the changes. The changes reflect the capacity of a flexible, growing, integrated electric utility system to adapt to changing circumstances. Much of the reduction in oil use was effected by purchases of coal-generated electricity by oil-based companies on the east coast. Another major development was the introduction of new coal-fired plants to the west- south-central states. This allowed coal to take over from oil as the alternative to increasingly more expensive natural gas. In New York and California, however, gas became available to displace oil. A further more modest contribution was made by having plants that had shifted from coal to oil resume coal use.     

试论水电站调峰的节煤效益

本文主要论述水电厂调峰节煤的效益。水电节煤与替代电厂─—火电厂的运行特性有关，本文论述了火电机组的运行及煤耗特性，以数字实例说明了水电厂在日负荷曲线上担负不同的工作位置时，替代煤耗率是不同的。还论述水电调峰，还电、抽水蓄能电站的节煤机制。为水电调峰、水电与火电系统联网及抽水蓄能电站效益的正确评价提供了一种论证方法。     

Enhancing the operation of fuel cell-photovoltaic-battery-supercapacitor renewable system through a hybrid energy management strategy

It is necessary to have an energy management system based on one or more control strategies to sense, monitor, and control the behavior of the hybrid energy sources. In renewable hybrid power systems containing fuel cells and batteries, the hydrogen consumption reduction and battery state of charge (SOC) utilizing are the main objectives. These parameters are essential to get the maximum befits of cost reduction as well as battery and hydrogen storage lifetime increasing. In this paper, a novel hybrid energy management system (HEMS) was designed to achieve these objectives. A renewable hybrid power system combines: PV, PEMFC, SC, and Battery was designed to supply a predetermined load with its needed power. This (REHPS) depends on the PV power as a master source during the daylight. It uses the FC to support as a secondary source in the night or shading time. The battery is helping the FC when the load power is high. The supercapacitor (SC) is working at the load transient or load fast change. The proposed energy management system uses fuzzy logic and frequency decoupling and state machine control strategies working together as a hybrid strategy where the switching over between both strategies done automatically based on predetermined values to obtain the minimum value of hydrogen consumption and the maximum value of SOC at the same time. The proposed HEMS achieves 19.6% Hydrogen consumption saving and 5.4% increase in SOC value compared to the results of the same two strategies when working as a stand-alone. The load is designed to show a surplus power when the PV power is at its maximum value. This surplus power is used to charge the battery. To validate the system, the results were compared with the results of each strategy if working separately. The comparison confirms the achievement of the hybrid energy management system goal.     

Feasibility of an energy conversion system in Canada involving large-scale integrated hydrogen production using solid fuels

A large-scale hydrogen production system is proposed using solid fuels and designed to increase the sustainability of alternative energy forms in Canada, and the technical and economic aspects of the system within the Canadian energy market are examined. The work investigates the feasibility and constraints in implementing such a system within the energy infrastructure of Canada. The proposed multi-conversion and single-function system produces hydrogen in large quantities using energy from solid fuels such as coal, tar sands, biomass, municipal solid waste (MSW) and agricultural/forest/industrial residue. The proposed system involves significant technology integration, with various energy conversion processes (such as gasification, chemical looping combustion, anaerobic digestion, combustion power cycles-electrolysis and solar–thermal converters) interconnected to increase the utilization of solid fuels as much as feasible within cost, environmental and other constraints. The analysis involves quantitative and qualitative assessments based on (i) energy resources availability and demand for hydrogen, (ii) commercial viability of primary energy conversion technologies, (iii) academia, industry and government participation, (iv) sustainability and (v) economics. An illustrative example provides an initial road map for implementing such a system.