ABSTRACT Knowledge about the generalized operational efficiency of comminution machines and systems is of great interest when tailoring solid biofuel supply systems. The objectives were therefore to collect and compare data from the literature to those from machinery manufacturers on the performances of various forest biomass comminution systems, with the aim of identifying areas for further research. Our meta-analysis was based on data from 55 scientific publications and specification sheets from 566 machine models collected from manufacturer’s websites. A majority, 56%, of studies were carried out at the roadside and 54% of studies examined comminuted logging residues, which thus reflects the most common materials and environments of the forest fuel supply system studied in the literature. We conclude that: (1) Chipping is more productive and requires less energy than grinding for machinery with nominal power up to 300 kW. (2) Chipping small trees or residues lowers productivities and increases energy demand compared to logs; the comminution productivity is dependent on the type of machine, the nominal power, and the material handled. (3) The energy demand is a function of the variable type of machinery (chipper, grinder), and maximum particle size produced. (4) Productivities in operational studies are clearly lower than the ones reported by the manufacturers in idealized conditions. Further investigations of equipment such as large chippers and grinders operated in terminals under controlled conditions are needed, in order to gain a better understanding of the different factors affecting the efficiencies of large equipment.

中文翻译：

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审查粉碎森林燃料的效率

摘要 在定制固体生物燃料供应系统时，有关粉碎机器和系统的一般运行效率的知识非常重要。因此，目标是收集和比较文献中的数据与机械制造商提供的关于各种森林生物质粉碎系统性能的数据，目的是确定进一步研究的领域。我们的荟萃分析基于从制造商网站收集的 55 份科学出版物和 566 种机器型号的规格表中的数据。大多数（56%）的研究是在路边进行的，54% 的研究检查了粉碎的伐木残留物，因此反映了文献中研究的森林燃料供应系统中最常见的材料和环境。我们得出结论：(1) 与额定功率高达 300 kW 的机器的磨削相比，切削效率更高，所需能量更少。(2) 与原木相比，砍伐小树或残留物会降低生产力并增加能源需求；粉碎生产率取决于机器类型、额定功率和处理的材料。(3) 能量需求是可变类型机器（削片机、研磨机）和生产的最大粒度的函数。(4) 操作研究的生产率明显低于制造商在理想条件下报告的生产率。需要对在受控条件下在码头运行的大型削片机和研磨机等设备进行进一步调查，以便更好地了解影响大型设备效率的不同因素。