Research On The Theory, Methods And Primary Application Of Circular Economy Design

Circular economy has been the focus of discussion for many fields. Scholars from both home and abroad, even people of various circles, have been clarifying and studying its concept, theory and relevant practice. From 1990s, however, the research of circular economy has been mainly on the macro-fields such as environment, mechanism etc, and therefore, the research on micro-fields, particularly quantitive analysis, is relatively insufficient. Hence the overall and synthetic research on circular economy of various lays is essential and necessary. Guided by the theory of systems engineering, the automation theory and the method of ecological engineering, the system model, system methods and its practical evaluation of circular economy are comprehensively and profoundly studied. It can be outlined as follows:(1)By conducting environmental systems dynamic models and simulating, conclusion is drawn as follow: the environmental load aggravates characteristically of positively feedback with the increase of pollution and decrease of environmental absorbing ability, thus circular economy is induced. Its concepts, principles and suggestions of development are introduced.(2)Static Input-output model is reviewed; By integrating production sectors and recycle sectors, dynamical circular economy models based on multi-sector, multi-period and maximal economical utility are put forward. Analyzing methods of various circular economy lays are gathered.(3)Various analyzing methods are summarized and improved. It mainly includes: ①Based on the analyse of chemical exergy and physical exergy, an improved method of exergy is put forward in which the exergy change of mixing is considered. ②Life cycle assessment model is analyzed from different points. First, weighs are induced to the reduced life cycle assessment. Second, for the environmental impact of products life cycle, four periods model and 2×3 matrix methods are induced. Third, economic analysis model of product life cycle based on the feedback process is put forward, in which the theory of operation management and automation are used. ③The linear analyzing method of material closed loop control system is improved and none-linear closed loop control graph and its solving method is put forward, which is based on the time-varying processes.(4)In the fourth chapter, the structure model integrating LCA and LP is given, and also in this chapter, the circular economy analyzing model is used to design the middle-water and sewage pipeline net systems in an uptown of Wuxi.(5)A practical evaluation method of large circular economy system is expounded, in which improved method of obtaining AHP weigh is proposed, and also fuzzy assessment and multi-layer gray assessment model is effectively combined.