Abstract: The energy property of products is considered as the research object, and the energy function model is put forward based on the product life-cycle energy consumption model. The product life-cycle energy consumption is analyzed. The resource/energy flow framework of product system and the product life-cycle energy consumption model is set up. The relationship between the product structure and the energy consumption in the each life-cycle stage is analyzed. The energy relation in several aspects are analyzed and quantized, such as the materials compatibility, the assembly and disassembly, the energy transmission in use stage, the part life and EOL. By considering energy optimization and function realization, the rules of structure design are discussed. The algorithm of relation degree among the product elements is given. Then, the model of combination design of product structure for energy optimization are presented by applying modular theory and the fuzzy clustering algorithm. The result of the refrigerator structure optimization and the improved suggest are proposed, which is demonstrated that the method is applicable and effective.

Key words: Energy model, Modular design, Relation degree, Structure design, Structure elements