Sensitivity Analysis Of Indoor Environmental Construction Load In Office Building And Its Application In Optimization Design For Energy Saving

High-efficiency load optimization strategy can lay a solid foundation for office building energy conservation in the early design stage.In this paper,43 parameters,mainly including the thermal performance of the enclosure structure,were selected as independent variables,and the sensitivity of office building indoor environmental construction load(including heating,cooling,electrical loads)was studied.Based on the relevant content of ?Research on key technologies of low-cost adaptation and operation management of existing large public buildings?(2016YFC0700707),and after summarizing the influence of climate difference and building shape difference as well as construction difference on parameter sensitivity,the regional partitions of sensitivity characteristics,the estimation of sensitivity based on body shape index,and the load optimization based on sensitivity analysis were proposed respectively.The application performance of different sensitivity analysis methods in building load model was compared in the first step,and the results were evaluated by the result value and calculation cost.The sensitivity analysis methods included local,SRC based on Monte Carlo sampling,Morris,Sobol's and EFAST.The results showed that Morris method could show the importance of parameter by moderate calculation cost,and the correlationship coud present the correlative form between inputs and outputs which is valuable for the determination of optimal value of parameters.After the optimization of calculation cost in Morris method by uniformity sampling strategy,the sensitivity analysis was executed in the benchmark load model of office building in 72 regions of China's severe cold,cold,hot summer & cold winter thermal zones.After summarizing the commonness and difference in sensitivity and correlation in different regions,the regional partition of sensitivity characteristics was proposed.Within a certain partition,the high sensitivity parameters and high correlation parameters in the benchmark environmental construction load model can be basically determined.Subsequently,through comparing the sensitivity analysis results of building load models with different shapes,a sensitivity prediction method based on building shape index was proposed,which means that the sensitivity of corresponding parameter in a certain shape building can be estimated based on the pre-existing Morris sensitivity analysis result.In addition,the influence of thermal performance of envelop on high sensitivity parameters was also discussed.The results showed that such effect was weak under the restriction of ?Design standard for energy efficiency of public buildings?GB50189-2015.Based on the above analysis,it was possible to predict the high-sensitivity parameters and high-correlation parameters in the target building.The load optimization process based on sensitivity analysis was proposed after judging the optimal value of the window to wall ratio(WWR)and the solar heat gain coefficient of external Windows(SHGC)in each orientation.Both NSGA-II(100 generations/10 populations)and the optimization based on sensitivity analysis were executed in cases of Tang Shan,Lhasa,and An Kang,and the best solutions of heating and cooling load from two methods were nearly same.Compared with the mean value of heating and cooling loads in sensitivity analysis in each city,reductions of the best solution were about 21%,45%and 21.5% respectively.However the optimization method based on sensitivity analysis could control the calculation cost around 100 times in many cases.If the difference in orientation can be ignored,the calculation cost can be further reduced.Moreover,the application performance of this optimation process was nearly the same as the case study before in a real office building.