基于多目标决策的建筑遗产节能改造寻优方法研究——以曼彻斯特大学图书馆为例

Developing an Optimization Method Based on Multi-Objective Decision Making for Energy Retrofit of Built Heritages:Taking Oddfellows Hall in Manchester as an Example

建筑遗产改造具备巨大的节能潜力,是当前中国建筑内涵式增长的关键。如何在最大化保留建筑原始风貌的基础上,提质环境性能,提升室内热舒适已成为建筑遗产改造领域的热点问题。选择英国曼彻斯特大学图书馆为研究对象,提出了一种由价值评估和热工模拟驱动,以多目标决策为核心的建筑遗产节能改造寻优方法,基于遗产价值、能源效率和热舒适的优化目标,以外保温、内保温、屋顶保温、窗户改造等改造措施及组合为决策自变量,通过评估和模拟结果的数学转化,进行节能改造措施的量化寻优。研究发现运用该方法得出的最优节能改造方案能降低37.4%的能耗,保留82%的遗产价值,室内热舒适达到ASHARE标准。研究表明该方法能在遗产节能改造中,提供满足不同目标侧重的多元化最优解集,得到各项决策自变量关联量化,为最终改造决策提供数据支持。研究旨在为建筑遗产的节能改造提供新的思路和方法。

Built heritage sites have witnessed the cultural inheritance of human history and urban development,and the retrofitting of these buildings has become a significant part of the connotative growth of Chinese cities and buildings.On the other hand,limited by the design and technology level at that time,most built heritages do not have the energy-saving property of thermal insulation,so it is necessary to retrofit the built heritage in terms of function,technology and energy,so as to adapt it to the needs of contemporary sustainable development.Three factors should be considered simultaneously:energy conservation and efficiency;thermal comfort and well-being;heritage value preservation,which is essentially a multi-objective decision making design optimization.Focusing on Oddfellows Hall in the Manchester University,an optimization method is proposed for the energysaving renovation of built heritages driven by value assessment and thermal simulation,with multiobjective decision-making as the core:1)finding viable energy-efficient reconstruction measures;2)evaluating the heritage value of each part of the building and the weight of the reconstruction measures on the heritage value of the building,and determine the combination of energy-efficient reconstruction measures at different depths;3)simulation analysis of energy consumption and PMV for a combination of renovation measures;4)applying mathematical transformation of the evaluation and simulation analysis results,and finally making a decision by optimizing the ranking.Due to the lack of material attributes of green technology and the restrictions of relevant protection regulations of built heritages,it is difficult for the latest and most modern retrofitting technologies and methods to be applied to the energy-saving retrofit of built heritages,so this paper mainly uses four types of enclosure structures of external insulation,internal insulation,roof insulation and window renovation as decision-making independent variables to carry out conventional energy-saving renovation research.First of all,the different“depth”of energy-saving renovation measures combination has been determined.Using the“Oddfellows Hall Historical Value Assessment Report”,the components are graded to quantify the impact of each retrofit on the building site and to determine the impact weight of the retrofit.Therefore,the relations between energy-saving transformation measures and heritage value is established,and on this basis,seven energy-saving transformation design schemes with different“depth”are derived,including single energy-saving measures and the combination of different energy-saving measures,which relate to three levels of full retrofit,heavy retrofit and light retrofit.Secondly,on the basis of referring to the selection of commonly used materials in the energysaving renovation of British built heritages,the types of materials and construction forms used in the renovation were determined.The IES VE software is used to assist modeling to simulate the environmental performance of different renovation plans,and the visualization results of energy consumption,PMV and other indicators are obtained by month.All retrofit plans have been compared with the original building by simulating results.Finally,the simulation results of the impact weight,daily average energy consumption and PMV of the seven retrofitting plans are summarized and sorted out,and the simulation results are digitally converted by using scatter plot and three-dimensional coordinate calculation.All plans are comprehensively compared,and the final ranking is scientifically formed.It was found that the exterior insulation renovation was the optimal solution under the multi-objective decision,which reduced energy consumption by 37.4%compared with the original building,retained 82%of the heritage value,and met the requirement of ASHARE standard for indoor thermal comfort.It should also be pointed out by this study that it is unacceptable to blindly sacrifice the value of architectural heritage in order to reduce energy consumption and improve comfort,because the destruction of architectural heritage value is irreversible,energy conservation and PMV are essentially secondary needs of built heritage renovation,and designers need to achieve low energy consumption and high comfort as much as possible on the basis of complying with relevant architectural heritage protection regulations and regulations.The optimization method proposed in this paper provide a diversified optimal solution set that meets different goals and focuses in the energy-saving renovation of heritage,obtain the correlation and quantification of various decision-making variables,provide data support for the final renovation decision,and provide new methods and ideas for the energy-saving renovation of built heritages.On the other hand,this paper mainly focuses on the exploration of optimization methods for energy-saving renovation of multi-objective built heritages,simplifying the setting of simulated physical environment variables and calculating the weight of the impact of energy-saving renovation measures,so there is some room for improvement in the research of this paper.The extent to which changes in these two factors affect the value of built heritages needs to be further analyzed and verified in subsequent study.