离心式冷水机组生命周期影响评价及关键影响因素分析

离心式冷水机组市场发展迅速,其生命周期中对环境产生的负面影响也日益受到关注。为了辨识离心式冷水机组全生命周期内环境影响的主要阶段和关键影响因素,为产品的优化设计提供依据,运用生命周期评价方法(LCA),选取CML 2002评价模型对离心式冷水机组的原材料获取、生产、运输、使用和回收再利用全生命周期过程的环境影响进行了定量评价,并对相关参数进行了敏感性分析。评价结果表明:机组整个生命周期环境影响主要体现在气候变暖和酸化,在同温层臭氧减少、富营养化、不可再生资源消耗等方面影响稍小;在造成的环境影响方面,使用和维护阶段的电能消耗是主要环节。敏感性分析结果表明,机组的制冷剂类型、能效水平和运行时间是机组环境影响的关键影响因素。     

Environmental life-cycle comparisons of two polychlorinated biphenyl remediation technologies: incineration and base catalyzed decomposition

Remediation action is critical for the management of polychlorinated biphenyl (PCB) contaminated sites. Dozens of remediation technologies developed internationally could be divided in two general categories incineration and non-incineration. In this paper, life cycle assessment (LCA) was carried out to study the environmental impacts of these two kinds of remediation technologies in selected PCB contaminated sites, where Infrared High Temperature Incineration (IHTI) and Base Catalyzed Decomposition (BCD) were selected as representatives of incineration and non-incineration. A combined midpoint/damage approach was adopted by using SimaPro 7.2 and IMPACTA2002+ to assess the human toxicity, ecotoxicity, climate change impact, and resource consumption from the five subsystems of IHTI and BCD technologies, respectively. It was found that the major environmental impacts through the whole lifecycle arose from energy consumption in both IHTI and BCD processes. For IHTI, primary and secondary combustion subsystem contributes more than 50% of midpoint impacts concerning with carcinogens, respiratory inorganics, respiratory organics, terrestrial ecotoxity, terrestrial acidification/eutrophication and global warming. In BCD process, the rotary kiln reactor subsystem presents the highest contribution to almost all the midpoint impacts including global warming, non-renewable energy, non-carcinogens, terrestrial ecotoxity and respiratory inorganics. In the view of midpoint impacts, the characterization values for global warming from IHTI and BCD were about 432.35 and 38.5 kg CO(2)-eq per ton PCB-containing soils, respectively. LCA results showed that the single score of BCD environmental impact was 1468.97 Pt while IHTI's score is 2785.15 Pt, which indicates BCD potentially has a lower environmental impact than IHTI technology in the PCB contaminated soil remediation process.     

Emissions and environmental impacts from air-conditioning and refrigeration systems

The impacts of air conditioning and refrigeration systems on stratospheric ozone are primarily linked to release of ozone-depleting refrigerants. Their contributions to global warming stem both from release of refrigerants and from emission of greenhouse gases (GHGs) for associated energy use. Because the energy-related component has a significantly higher warming impact, phaseout of hydrofluorocarbon (HFC) refrigerants with less efficient options will increase net GHG emissions. The same conclusion applies for perfluorocarbon (PFCs), though they are less commonly used as refrigerants. Integrated assessment of ozone depletion, global warming, and atmospheric lifetime provides essential indications in the absence of ideal refrigerants, namely those free of these problems as well as safety, stability, compatibility, cost, and similar burdens. This study examines the trend in refrigerant losses from chiller use. It documents both substantial progress in release reductions and the technical innovations to achieve them. It contrasts the impacts of current refrigerants with alternatives and with the chlorofluorocarbons (CFCs) they replaced. The study examines the sensitivity of efficiency to charge loss. It also summarizes thermodynamic and environmental comparisons of options to show that phaseout decisions based on chemical composition alone, without regard to attributes of individual substances, can result in greater environmental harm than benefit.     

Comparative life cycle assessment (LCA) of bio-modified binder and conventional asphalt binder

This study is a life cycle assessment (LCA) of conventional asphalt binder versus bio-modified binder that is produced by mixing asphalt binder with bio-binder obtained from swine manure. Both processes were evaluated and compared in terms of their contribution to global warming, using a global warming potential index and energy consumption. This LCA study uses a cradle-to-gate approach for the binder and includes a comparison between the environmental impacts of swine manure in lagoons and the production of bio-binder. The results show the energy consumption and global warming potential improvements after using bio-binder as a sustainable additive.     

风浪联合作用下海上风力涡轮机的碰撞阻尼减振控制

提出利用碰撞调谐质量阻尼器(Pounding Tuned Mass Damper,PTMD)控制近海单桩风力涡轮机塔身在风浪联合作用下的结构振动.为此,利用拉格朗日方程推导风浪联合作用下风机与PTMD 的耦合动力方程并据此分析了相关控制效果.具体而言,结构模型方面,以美国国家可再生能源实验室(NREL)的5 MW基准单...     

Sustainable manufacturing: a case study of the forklift painting process

Life cycle assessment (LCA) and design for environment (DFE) methods were applied to assess opportunities for reducing the environmental impacts of forklift manufacturing unit processes and to redesign those unit processes to increase overall sustainability. The unit processes of forklift manufacture generating the most environmental emissions were identified by applying LCA methodology. The results show that eco-toxicity and human toxicity were the most significant impacts of the forklift manufacturing process overall. Also, within the manufacturing unit processes, cutting, welding and painting had the highest impact values. In order to minimise environmental impacts, a new paint was created with increased solid content over the existing solvent paint used in the painting process. In addition, by applying DFE methodology and the high solid paint, overcoat and drying steps were eliminated from the forklift painting process. As a result, the environmental index of a follow-up LCA showed that environmental impacts could be reduced by 20%, while volatile organic compound (VOC) and paint usage could be decreased by 30% and 20%, respectively.     

A thermodynamic basis for evaluating environmental policy trade-offs

This paper introduces a novel thermodynamic measure of chemical change in the environment called pollution potential, which is defined as the change in exergy of mixing per mole of chemical species in the environment that may be attributed to pollutant releases – equivalent to the ideal exergy per mole required to remove a pollutant from the environment. Because all chemical pollutants may be measured in terms of pollution potential, the methodology described may provide a scientific basis for cross-comparison of disparate environmental impacts such as global warming potential (GWP) and ozone depletion potential (ODP) in a single measure. As an illustrative example, steady-state pollution potentials are calculated for several CFC replacements and a strong correlation between pollution potential and GWP is found for hydrofluorocarbons (HFCs). Although ozone depletion is found to be a significant factor in the pollution potential of CFC-11, for hydrochlorofluorocarbons (HCFCs) the contribution of ozone effects to total pollution potential is minimal. These findings suggest that policies that favor marginal reductions in ODP without regard for other environmental effects (e.g. climate change) may have unintended and detrimental consequences. Electronic Publication     

基础冲刷对海上风电场塔架支撑系统动力特性的影响分析

针对海上风力机塔柱支撑结构受到土基、海洋流体的复杂作用的特点,建立三维有限元数值模型,开展不同海床冲刷深度条件下支撑系统结构的动态特性,探讨其变化规律,为海上风力机支撑系统的动力稳定设计提供科学依据。     

风力机运行过程中气动载荷变化工程分析

为提高风力发电机组设计可靠性,需得到风力机在实际运行过程中叶片气动载荷的计算方法.从工程角度出发,对风力发电机使用的NACA专用翼型进行分析,结合薄翼理论推导出攻角变化特点,并依据风切变理论和塔影效应得到风力机实际运行时叶片在各个位置点的气动载荷.依据实际情况对风轮受力平面进行工程简化,得到风力机叶片气动载荷的计算方法.将此方法计算出的气动载荷与试验测量结果进行比对,吻合度较好.     

重新评价氨制冷剂在制冷空调领域的应用

臭氧消耗和全球变暖问题已成为制冷剂的重要制约因素之一。传统的氨制冷剂是一种性能优良的制冷剂,由于CFCs和HCFCs具有较高的臭氧破坏能力作用系数(ODP)和全球变暖潜能值(GWP),随着CFCs和HCFCs的逐步禁用,只要采取必要的安全措施,氨制冷剂作为一种自然工质将广泛应用于制冷和空调行业。     

Assessing the impact of marine wind farms on birds through movement modelling

Advances in technology and engineering, along with European Union renewable energy targets, have stimulated a rapid growth of the wind power sector. Wind farms contribute to carbon emission reductions, but there is a need to ensure that these structures do not adversely impact the populations that interact with them, particularly birds. We developed movement models based on observed avoidance responses of common eider Somateria mollissima to wind farms to predict, and identify potential measures to reduce, impacts. Flight trajectory data that were  collected post-construction of the Danish Nysted offshore wind farm were used to parameterize competing models of bird movements around turbines. The model most closely fitting the observed data incorporated individual variation in the minimum distance at which birds responded to the turbines. We show how such models can contribute to the spatial planning of wind farms by assessing their extent, turbine spacing and configurations on the probability of birds passing between the turbines. Avian movement models can make new contributions to environmental assessments of wind farm developments, and provide insights into how to reduce impacts that can be identified at the planning stage.     

Environmental impact assessment of the Egyptian cement industry based on a life-cycle assessment approach: a comparative study between Egyptian and Swiss plants

Egypt in 2015 announced the alteration of the fuels used in cement plants without the least regard to minimizing the environmental burden (EB) excesses. This study conducts a life-cycle assessment (LCA) of Egyptian cement-manufacturing unit, which is considered as the first one on LCA cement analysis to be conducted in Egypt. This study investigates the LCA of the cement industry in Egypt compared to the Swiss industry, using two methodologies. The first one has been done on-site, surveying the most common types of cement used in the construction industry in Egypt. Meanwhile, SimaPro software has been used to assess the environmental impacts, and three different cement plants were selected for this study: an Egyptian cement plant (ECP) which uses electricity, natural gas, and diesel as energy sources; a Swiss cement plant (SCP) which depends mainly on electricity, natural gas, and coal; and an Egyptian hypothetical plant (EHP) in which electricity and coal are assumed to be the main energy feeds, and comparisons of different strategies including midpoint and endpoint methods are outlined. Regarding the midpoint method, ETP recorded higher respiratory inorganics, aquatic acidification, global warming, and nonrenewable energy impacts than ECP, because of using coal, while for SCP, global warming and respiratory inorganics achieved the highest adverse impacts compared to ECP and EHP—due to the different manufacturing technology used. With regard to the endpoint method, the peak possibility of human health deterioration has been recorded due to the use of coal as fuel. This possibility was reduced by 46 % in the case of SCP as a result of the technology applied, which interestingly represents a reasonable reduction in terms of technological application.     

A computational procedure for prebending of wind turbine blades

Prebending of wind turbine blades constitutes a viable engineering solution to the problem of tower clearance, that is, ensuring that during wind turbine operation there is sufficient distance between the rotor blades and the tower to avoid collision. The prebent shape of the blade must be such that when the turbine rotor is subjected to wind and inertial loads, the blades are straightened into their design configuration. In this paper, we propose a method for accurate prediction of the prebent shape of wind turbine blades. The method relies on a stand‐alone aerodynamics simulation that provides the wind loads on a rigidly spinning rotor, followed by a series of structural mechanics simulations to determine the stress‐free prebent shape of the blade. This procedure involves only one‐way coupling between the fluid and structural mechanics, which avoids the challenges of solving the coupled fluid–structure interaction problem. The proposed methodology, which has no limitations on the blade geometry and structural modeling, is successfully applied to prebending of a 63‐m offshore wind turbine blade. Copyright © 2011 John Wiley & Sons, Ltd.     

长周期地面运动和SSI效应对风机动力响应的影响

针对建设在软土地基上的大功率风机结构,需要同时考虑长周期地面运动和土-结构相互作用(SSI)的影响。为了全面研究长周期地面运动和SSI效应对风机塔筒结构动力响应的影响,首先基于某1.25 MW变桨距风机结构建立了包含叶片、机舱、塔筒和基础的结构整体有限元模型,并进行了模态分析。其次在世界地震记录数据库中选择了1条普通波(EI-Cento波)和2条长周期波(HKD054波和CDAO波),并对两种波的时频特性进行对比分析,同时建立了考虑与不考虑SSI效应的对比模型。最后利用ANSYS软件并采用时程分析法对考虑与不考虑SSI效应的风机结构在两类地震波作用下的地震响应进行对比分析,并对叶片与塔筒的碰撞问题、门洞区域的应力集中、机舱内主轴在剪力作用下的破坏以及基础的失效问题进行了进一步的研究。结果表明:长周期地震作用下的风机结构位移、加速度、应力和内力响应值均大于普通波作用下的结果,在此基础上某些响应甚至会被SSI效应进一步放大。因此在风机结构的抗震设计中需要考虑长周期地震作用和SSI响应的影响,特别是在软土地基区域。另外,塔筒与门框连接区域、机舱内主轴和基础等薄弱区域需要适当加强。     

Multi-objective material selection for wind turbine blade and tower: Ashby’s approach

The world today is continuously striving towards carbon neutral clean energy technology. Hence, renewable energy sources like wind power system is increasingly receiving the attention of mankind. Energy production is now no more the sole criterion to be considered when installing new megawatt (MW) range of turbines. Rather some important design parameters like structural rigidity, cost effectiveness, life cycle impact, and, above all, reduced mass come into the scenario from new installation point of view. Accordingly, these issues are followed up in this article from wind turbine design perspective. The study, at the outset, aims to establish blade and tower material selection indices on the basis of inherent structural constraints and potential design objectives. Next, it highlights entire blade and tower material selection aspects for small and large scale horizontal axis wind turbines, both for onshore and offshore application. Finally, it distinguishes advanced blade and tower materials in agreement with multiple constraint, compound objective based design optimization procedure. Findings from the study can be deployed to harness massive scale wind energy from structurally more promising, economically more competitive and environmentally more clean and green turbines.     

Lightweight structure design for wind energy by integrating nanostructured materials

Wind power develops very fast nowadays with high expectation. Although at the mean time, the use of taller towers, however, smacks head-on into the issue of transportability. The engineering base and computational tools have to be developed to match machine size and volume. Consequently the research on the light weight structures of tower is carrying out in the main countries which are actively developing wind energy. This paper reports a new design scheme of light weight structure for wind turbine tower. This design scheme is based on the integration of the nanostructured materials produced by the Surface Mechanical Attrition Treatment (SMAT) process. The objective of this study is to accomplish the weight reduction by optimizing the wall thickness of the tapered tubular structure. The basic methods include the identification of the critical zones and the distribution of the high strength materials according to different necessities. The equivalent strength or stiffness design method and the high strength material properties after SMAT process are combined together. Bending and buckling are two main kinds of static loads concerned in consideration. The study results reveal that there is still enough margin for weight reduction in the traditional wind turbine tower design.     

Environmental and human health impact assessment of major interior wall decorative materials

Despite the growing interest in green products in the interior wall decorative material market, knowledge gaps exist because determining which product is more environmental and user friendly than the others is difficult. This work assesses the environmental and human health profiles of interior latex and wallpaper. Two interior latex products of different raw material ratios and one non-woven wallpaper product are considered. The environmental impact assessment follows life cycle assessment (LCA) methodology and applies Building Environmental Performance Analysis System (BEPAS). The human health impact is based on impact-pathway chain and is performed using Building Health Impact Analysis System (BHIAS). The assessment scope, associated emissions, and territorial scope of various emissions are defined to facilitate comparison study of interior wall decorative products. The impacts are classified into 15 categories belonging to three safeguard areas: ecological environment, natural resources, and human health. The impacts of categories are calculated and monetized using willingness to pay (WTP) and disability-adjusted life year (DALY) and summarized as an integrated external cost of environmental and human health impacts. Assessment results reveal that the integrated impact of interior latex is lower than that of non-woven wallpaper, and the interior latex of low quality causes low life cycle integrated impact. The most impacted categories are global warming, respiratory effects, and water consumption. Hotspots of product manufacturing are recognized to promote green product design.     

风电机组塔筒模态的环境脉动实测与数值模拟研究

摘 要：基于随机振动及系统识别理论,对内蒙古京能乌兰伊利更风电场中三座风电机组塔筒进行了环境脉动实测,提出了 “桨叶—轮毂—机舱—塔筒”耦合的整体建模的方法,数值模拟与实测结果表明,风电机组塔筒可以有效地避免共振,满足GL规范的设计要求;塔筒主要振动形式为侧向弯曲振动、前后弯曲振动和扭转振动;塔筒一阶平动阻尼比为1.78%左右,一阶扭转阻尼比为0.6%左右。采用整体建模方法建立的模型与实测结果有较好的一致性,可以指导风力发电塔系统的风致动力响应分析和振动控制分析。     

Life cycle assessment of oil palm empty fruit bunch delignification using natural malic acid-based low-transition-temperature mixtures: a gate-to-gate case study

In future biorefineries, the development of cheap and environmentally friendly solvents for biomass pretreatment is highly desirable. In this sense, low-transition-temperature mixtures (LTTMs) have high potential to serve as green solvents for replacing conventional pretreatment technologies. In this study, a life cycle assessment of LTTMs pretreatment was conducted to determine the environmental impacts caused by biomass delignification. A gate-to-gate analysis which started with harvested oil palm empty fruit bunch and ended with lignin was selected. The environmental impacts such as acidification potential, global warming potential, eutrophication potential, photochemical ozone creation potential, human toxicity potential and volatile organic compounds emission were evaluated. The comparable environmental balances of commercial l-malic acid and cactus malic acid-based LTTMs pretreatment processes verified the suitability of the process with natural malic acid as the source of proton donor. This study concludes that biomass delignification using natural cactus malic acid-based LTTMs had promising features such as high delignification efficiency and environmentally friendly compared to commercial l-malic acid-based LTTMs. Based on environmental point of view, the overall process of biomass delignification using sucrose-based LTTMs had lower CO₂ emissions compared to the monosodium glutamate- and choline chloride-based LTTMs. These findings are important for verifying the greenness and sustainability of LTTMs to be applied at industrial scale.     

瓦楞纸箱生产工艺生命周期评价案例研究

通过生命周期评价(LCA)技术框架,采用生命周期影响评价末端计量方法(LIME),对瓦楞纸箱生产过程的物耗、能耗及向环境排放的计算与特征化分析,对瓦楞纸箱生产工艺进行了环境影响评价。结果表明,其所导致的环境影响主要是化石能源消耗、全球变暖、酸化和富营养化。进一步对瓦楞纸箱生产过程中制板、印刷和成箱3工序的环境影响量化指标值做对比分析,指出了各工序导致环境影响的主要原因。并在瓦楞纸箱设计、生产工艺、废气和污水处理以及噪声治理等方面,为改善瓦楞纸箱生产工艺的环境性能提出了改进建议。