Research On Energy Conservation Design Decision And Assessment Methodology Of Building Envelope Based On Exergy Cost Analysis

In our country, most buildings are energy-intensive, and in the new buildings, energy-intensive building scale also up to95%. The construction and operation of these energy-intensive building consumed vast amounts of energy and resources, and brings about many environmental impacts. Building energy consumption in general, building operation consumption possession of the most important influence, including heating, air conditioning and ventilation energy accounted for about2/3. According to the source of operating energy consumption, building energy-saving design can be divided into building energy-saving design, building equipment two parts. Our country building envelope insulation level will have long way to go compared with the developed country in the climate. Therefore, the designing of energy-efficient building envelope is a key step in reducing energy consumption.This paper first connection with life cycle theory, from the perspective of the whole life cycle of building envelope energy-saving design scheme in the environmental impact assessment, including building materials production energy consumption, building operation consumption and greenhouse gas emissions. Because the traditional architecture only from the quantitative relationship between energy saving effect is limited to looking at energy-using and energy-saving, ignoring energy quality. This paper adopted the method of exergy analysis, not only evaluate energy consumption of building materials production, but also building operation consumption, thus reflects the essence of energy activities. In this paper analysis the exergy flow of the energy-saving design buildings, and calculate the cost of the building envelope design scheme in the life cycle. By investigating the thermodynamics economics, established energy saving design of the building envelope with economic equilibrium equation of exergy, and describe that the probilty of economic and energy-saving when deem exergy of energy cost as a index to analysis the energy-saving design scheme. Energy-saving design is a diversified technological system, thus inferiority of design scheme cannot use single influence factors were analyzed often. This paper based on the lifecycle evaluation and exergy analysis basis, integrating the factors affecting energy-saving, established building envelope energy-saving design optimization evaluation model.Finally, taking a research building of Changsha of hot summer and cold winter zone for example, by using the method of this paper proposed, analysis and optimal retrofit scheme is obtained. This paper puts forward a new analysis method to evaluate the effects of building envelope design.This model deem the energy-saving effects in a life cycle, exergy-saving effect, environmental impacts, life cycle costs as the parameters, based on the optimization evaluation, In order to obtain the best comprehensive benefits for the target, searching for the overall balance of the benefit, supplying a new evaluation system of how to choose and evaluate a building envelope energy-saving design.