5 总结与展望。
（1） 制造系统能量效率的研究意义重大，已成为各国制造业可持续发展的一个重大战略课题，国际上研究非常活跃。其中，流程制造行业的能量效率研究起步早，已取得了大量研究成果；相对于流程制造业，离散制造业的能量效率研究起步较晚、过去重视不够。但从政府计划、国际组织和企业的措施以及高校和科研院所的研究内容可以发现，近年来关于离散制造业的能量效率研究非常活跃。
（2） 建立了制造系统能量效率研究内容的一种体系框架，该框架由三类研究对象（能耗行业、能耗系统以及能耗组件）、四类基础理论或技术（能效建模、能效特性、能效评价和能效监控）、两类功能技术（制造系统运行能效优化技术和高能效制造系统建设技术）以及一个根本目标（提高制造系统能量效率）组成。
（3） 考虑到离散制造系统能量消耗的复杂特性以及能量效率的研究现状，总结出了离散制造系统能量效率研究有待深化的几个难点问题，即离散制造系统能量效率建模、能量效率精细评价、产品能耗限额制定、高能效多目标优化和高能效机床设计问题。这些难点问题也是本文所建议的制造系统能量效率问题理论和技术研究的几个方向性问题。
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