Life cycle sustainability assessment (LCSA) is one of the most relevant tools delving in sustainability science, based currently on the triple bottom line idea that is defined as the contemporary implementation of the three tools of life cycle assessment (LCA), life cycle costing (LCC) and social life cycle assessment (S-LCA). The methodology is currently being applied to a wide set of products and systems. However, as per in the large interest towards energy-related products, the sustainability assessment of energy systems—in particular those where fluid streams are used—could be more effective if some further stages could be included in the analysis, i.e. a process level analysis with regard to energy quality and exergy, and a more thorough energy analysis of the fluid flows available to achieve an optimal design of the system. This paper proposes an extended framework for LCSA introducing two additional stages to the methodology: Constructal law (CL) inspired analysis of the energy design of the system and exergy analysis (EA) of the system and its life cycle. A fully developed case study (a biomass boiler) is proposed, described the extended life cycle energy and sustainability assessment (LCESA: LCA, LCC, S-LCA, CL, EA), highlighting both the quantitative results related to each section together with the strengths and limits of the methodology, while stressing the potential applications as, e.g., decision support tool and support to the design of energy system. The results highlight different and optimized designs for the boiler through a constructal law–based analysis and several hot-spots throughout different stages of the life cycle, ranging from the production stage of steel for most environmental indicators in LCA to the cooking stage for the exergy analysis. Relevant positive impacts are traced also in the S-LCA point of view during both the use and production step. The methodology could represent a potential advancement towards the LCSA application to energy technologies as it highlights some limits and proposes specific advancements.

中文翻译：

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结构规律、火用分析和生命周期能源可持续性评估：应用于锅炉的扩展框架

生命周期可持续性评估 (LCSA) 是研究可持续性科学的最相关工具之一，目前基于三重底线理念，即生命周期评估 (LCA)、生命周期成本计算 (LCA) 三个工具的当代实施。 LCC) 和社会生命周期评估 (S-LCA)。该方法论目前正应用于广泛的产品和系统。然而，根据对能源相关产品的巨大兴趣，如果分析中可以包括一些进一步的阶段，即过程级分析，能源系统的可持续性评估 - 特别是那些使用流体流的系统 - 可能会更有效关于能量质量和火用，以及对可用的流体流动进行更彻底的能量分析，以实现系统的优化设计。本文为 LCSA 提出了一个扩展框架，为该方法引入了两个额外的阶段：构造律 (CL) 启发式系统能量设计分析和系统及其生命周期的火用分析 (EA)。提出了一个完整的案例研究（生物质锅炉），描述了延长生命周期能源和可持续性评估（LCESA：LCA、LCC、S-LCA、CL、EA），突出了与每个部分相关的定量结果以及该方法的优势和局限性，同时强调潜在的应用，例如决策支持工具和对能源系统设计的支持。结果通过基于构造律的分析和生命周期不同阶段的几个热点突出显示了锅炉的不同和优化设计，从 LCA 中大多数环境指标的钢铁生产阶段到火用分析的蒸煮阶段。在使用和生产步骤期间，S-LCA 的观点也追踪了相关的积极影响。该方法可以代表 LCSA 应用于能源技术的潜在进步，因为它突出了一些限制并提出了具体的进步。