探究我国能源动力工程及能源可持续发展

随着自然环境日益恶化,人们逐渐意识到环保措施的重要性,并且在居民日常生活中以及工业生产中,从企业到政府、从个人到团体都积极响应国家的号召,对生活方式以及生产工艺进行升级改造,实现可持续发展。对于我国能源动力工程来说,未来的发展方向应该是怎样的,将形成怎样的能源结构,是需要我们深入探讨的。     

生命周期评价方法及应用于我国可再生能源领域研究进展

近年来我国风力发电、太阳能发电的装机并网规模迅速增加。如何科学、准确、全面地评估可再生能源发展所带来的生态环境影响也成为政府、学界和公众普遍关注的问题。在众多的评估方法中,生命周期评价是一种常见和有代表性的方法。该方法起源于西方并逐渐引入我国,已经在我国可再生能源领域的研究中有所应用。本文综述了生命周期评价的生产流程分析法、环境扩展的投入产出法以及混合分析方法等方法学研究进展,然后综述了基于上述方法学的我国可再生能源领域的有关研究进展,包括生命周期方法的应用、本土数据库的发展以及影响评价方法的进展。认为研究高技术单元分辨率的混合生命周期研究方法、拓展建立本土化生命周期评价数据库和开发标准化的生命周期评价指标体系是我国可再生能源生命周期评价研究发展中应注意的问题。     

大中型沼气工程生命周期能效评价

基于生命周期评价理论,对山东某沼气工程进行了能效评价。研究得出,该沼气工程生命周期总能耗(折合标准煤)为561 471.47 kg/a(11.54 kg/GJ),其中,化石能耗占96.62%;节能量为1 100 271.42 kg/a;生命周期综合能源利用率为61.82%;生命周期新水耗量为26 552.56 m3/a。利用Sima Pro 8.0.2软件,采用生态指数法分析得出,该沼气工程生命周期产生的环境影响为364.303 3 k Pt/a(7.480 5 Pt/GJ);通过情景分析得出,沼气工程的环境损害减弱能力为191.805 2 k Pt/a(34.49%)。针对该沼气工程存在的一些问题,提出了开发沼液综合利用技术等建议,为提高沼气工程能效、减少环境损害提供理论参考。     

基于LCA的风力发电、光伏发电及燃煤发电的环境负荷分析

基于生命周期评价理论,建立风力发电、光伏发电及燃煤发电的生命周期评价体系,研究生命周期各阶段的环境负荷并进行对比分析.结果表明:在电厂建设阶段,燃煤发电碳足迹最低,为1.94g/(kW·h),风力发电碳足迹最高,为9.42g/(kW·h).在发电运营阶段,光伏发电碳足迹几乎为零,风力发电碳足迹为0.2g/(kW·h),燃煤发电机组碳足迹最高,为83.3g/(kW·h).风力发电和光伏发电在电厂建设阶段碳足迹占比较高,分别为99.4%和99.78%;燃煤发电在发电运营阶段碳足迹占比最高,为96.13%.在整个生命周期中对全球变暖影响最大的是燃煤发电,为3.63×10~(-5)标准当量,影响最小的是风力发电,为7.9×10~(-7)标准当量;对环境酸化影响最大的是光伏发电,为6.7×10~(-6)标准当量,影响最小的是风力发电,为1.6×10~(-7)标准当量;风力发电和光伏发电的固体废弃物排放几乎为零.     

中国农业沼气工程生命周期评价

文章系统回顾了中国农业沼气工程的生命周期评估（LCA）研究,以生产利用1 MJ沼气为统一功能单位,对其环境影响进行了定量的对比分析。研究结果表明：受系统边界和参考系统选择等因素的影响,中国农业沼气工程LCA研究的结果差别很大,但大都能显著减少化石能源消耗和温室气体（GHG）排放;中国农业沼气工程生命周期能耗为0.01～0.76 MJ/MJ,节能收益最高可达2.27 MJ/MJ,利用煤炭加热保温是高能耗的最主要因素;中国农业沼气工程生命周期的GHG排放为9～219 g/MJ,GHG减排收益为33～787 g/MJ,其在环境酸化、富营养化和光化学氧化等环境影响方面的效益有待更多的研究确认。     

我国生物质燃料乙醇示范工程的全生命周期评价

目前,我国甜高粱、木薯等非粮燃料乙醇正处于规模化推广的前期论证阶段,亟需对其进行全面深入的可行性分析.文章基于生命周期评价原理,结合国内4家燃料乙醇生产企业的示范工程,对其全生命周期过程的能源消耗、环境影响和经济成本提供定量的评价结果,为评价、对比非粮乙醇和粮食基乙醇提供科学、权威的数据,填补了这一方面国内研究领域的空白.评价结果表明,发展甜高粱和木薯等非粮乙醇是可行的,与玉米乙醇相比具有较强的优势.     

资源节约与环境保护重大示范工程重点领域和重点技术

一、节水1.以循环冷却水高浓缩、浓浆输灰、干除灰、干除渣、海水利用等为主要内容的火力发电工业节水技术。2 .以逆流漂洗、印染废水深度处理回用、溴化锂冷却等为主要内容的纺织工业节水技术。3.以制浆封闭筛选、中浓操作、多圆盘过滤机白水回收等为主要内容的造纸工业节水技术。4 .以高炉煤气干法除尘、污水处理及回用等为主要内容的钢铁工业节水技术。5 .以循环冷却水高浓缩、稠油污水处理回用、污水深度处理回用等为主要内容的石油石化工业节水技术。6 .以实现工业废水“零”排放为主要内容的节水工艺和技术。7.高效、低成本节水产品与…     

基于可再生能源的分布式发电技术的应用及前景

对以可再生能源为基础的分布式发电技术进行介绍,分析分布式发电的优势和推广应用的必要性,介绍国内外分布式发电系统的应用状况以及我国分布式发电的前景和发展目标,讨论我国可再生能源分布式发电存在的问题.     

Life cycle assessment (LCA) and life cycle cost (LCC) analysis model for a stand-alone hybrid renewable energy system

Nowadays the biggest challenge for most organizations is a real and substantial application of sustainability through the measurement and comparability of results in order to satisfy the principles of sustainability of all the stakeholders. Definitively, it is necessary to pursue sustainability through the measurements of specific indicators and control the variables that influence the state of the economic, social and environmental issues. The aim of this paper is to contribute to the development of a comprehensive, yet practical and reliable tool for a systematic sustainability assessment, based on the Life Cycle Assessment (LCA) and the Analytic Hierarchy Process (AHP) to support decision makers in complex decision problems in the field of environmental sustainability. The results are applied to a novel compressed air energy storage system proposed as a suitable technology for the energy storage in a small scale stand-alone renewable energy power plant (photovoltaic power plant) that is designed to satisfy the energy demand of a radio base station for mobile telecommunications. The outcome is a dynamic analysis and iterative integrated sustainability assessment of corporate performance.     

某热电厂实施冷热电联产的节能分析

通过对热电联产冷分产及冷热电联产能源消耗的计算分析比较,进一步论述在热电厂热电联产基础上发展冷热电联产的可行性和合理性,结合实例说明发展冷热电联产所产生的经济性、节能性和环保性,并为其他热电厂的节能改造提出建议,     

A comprehensive life cycle analysis of cofiring algae in a coal power plant as a solution for achieving sustainable energy

Algae cofiring scenarios in a 360 MW coal power plant were studied utilizing an ecologically based hybrid life cycle assessment methodology. The impacts on the ecological system were calculated in terms of cumulative mass, energy, industrial exergy, and ecological exergy. The environmental performance metrics, including efficiency, loading, and renewability ratios were also quantified to assess the sustainability of cofiring scenarios from a holistic perspective. The analysis results revealed that cumulative mass and ecological exergy consumption were higher for algae cofiring compared to single coal firing due to high material and energy inputs for the algae cultivation. On the contrary, total energy and industrial exergy utilization were reduced with an increasing share of algae cofiring where algae is dried with solar energy. Additionally, natural gas dried algae cofiring scenarios had a lower renewability ratio in comparison with single coal firing. The results of this study are vital for the policy makers to decide on more environmentally friendly algae cofiring options by considering the potential impacts on ecological system.     

A life cycle energy assessment for biogas energy in Serbia

The aim of this paper was to present the energy flows in the life cycle of biogas utilization systems (cogeneration and transportation), as well as their mutual relations, starting from providing the feedstock for digestion through to end-of-life management of biogas system as fertilizer on agricultural land. This study was carried out through the energy analysis of two scenarios (biogas in cogeneration and biogas in transportation) using performance of Mirotin biogas plant (1 MW) in Serbia. Results obtained in this study have shown that the analyzed scenario (biogas in cogeneration and biogas in transportation) have positive energy balances (52,114 and 53,585 GJ) and these scenarios are sustainable from energetic point of view.     

Operational energy in the life cycle of residential dwellings: The experience of Spain and Colombia

Life Cycle Assessment (LCA) has been applied within the residential building sector of two buildings, one in each a developed (Spain) and a developing (Colombia) country. The main goal of this paper involves the environmental loads and also brings together the operational energy for activities during the operation phase such as HVAC, domestic hot water, electrical appliances, cooking and illumination. The present research compares two real scenarios: Situation 1, where 100% of the dwelling’s energy is supplied with electricity only and Situation 2, where dwellings can be operated with natural gas plus electricity.     

Energy and exergy analysis of a micro-compressed air energy storage and air cycle heating and cooling system

Energy storage systems are becoming more important for load leveling, especially for widespread use of intermittent renewable energy. Compressed air energy storage (CAES) is a promising method for energy storage, but large scale CAES is dependent on suitable underground geology. Micro-CAES with man-made air vessels is a more adaptable solution for distributed future power networks. In this paper, energy and exergy analyses of a micro-CAES system are performed, and, to improve the efficiency of the system, some innovative ideas are introduced. The results show that a micro-CAES system could be a very effective system for distributed power networks as a combination that provides energy storage, generation with various heat sources, and an air-cycle heating and cooling system, with a energy density feasible for distributed energy storage and a good efficiency due to the multipurpose system. Especially, quasi-isothermal compression and expansion concepts result in the best exergy efficiencies.     

A comparative life cycle analysis of hydrogen production via thermochemical water splitting using a Cu-Cl cycle

In this paper, a comparative environmental study is reported of the Cu-Cl water-splitting cycle with various other hydrogen production methods: the sulphur-iodine (S-I) water-splitting cycle, high temperature water electrolysis, conventional steam reforming of natural gas and hydrogen production from renewable resources. The investigation uses life cycle assessment (LCA), which is an analytical tool to identify and quantify environmentally critical phases during the life cycle of a system or a product and/or to evaluate and decrease the overall environmental impact of the system or product. The LCA results for the hydrogen production processes indicate that the thermochemical cycles have lower environmental impacts while steam reforming of natural gas has the highest.     

On the exergy analysis of power plants

The thermal performance of power generating and consuming devices can be improved significantly, both during design and operation. This is especially important in eastern and central European countries during their transition to a market environment. A solution can be sought by combining exergy and economic analyses. The performances of conventional power plants and nuclear power plants are discussed, based on the exergy concept. It is proposed to define the entire nuclear plant efficiency by the system coefficient of performance.     

Dynamic life cycle assessment (LCA) of renewable energy technologies

Before new technologies enter the market, their environmental superiority over competing options must be asserted based on a life cycle approach. However, when applying the prevailing status-quo Life Cycle Assessment (LCA) approach to future renewable energy systems, one does not distinguish between impacts which are ‘imported’ into the system due to the ‘background system’ (e.g. due to supply of materials or final energy for the production of the energy system), and what is the improvement potential of these technologies compared to competitors (e.g. due to process and system innovations or diffusion effects). This paper investigates a dynamic approach towards the LCA of renewable energy technologies and proves that for all renewable energy chains, the inputs of finite energy resources and emissions of greenhouse gases are extremely low compared with the conventional system. With regard to the other environmental impacts the findings do not reveal any clear verdict for or against renewable energies.Future development will enable a further reduction of environmental impacts of renewable energy systems. Different factors are responsible for this development, such as progress with respect to technical parameters of energy converters, in particular, improved efficiency; emissions characteristics; increased lifetime, etc.; advances with regard to the production process of energy converters and fuels; and advances with regard to ‘external’ services originating from conventional energy and transport systems, for instance, improved electricity or process heat supply for system production and ecologically optimized transport systems for fuel transportation.The application of renewable energy sources might modify not only the background system, but also further downstream aspects, such as consumer behavior. This effect is, however, strongly context and technology dependent.