東京大学 · 環境科学
Wei教授の研究室では、建物内の熱環境とエネルギー消費の予測・最適化を目的とした数値流体力学(CFD)と深層学習の融合研究を推進しています。特に、非定常な室内温度分布の高速予測を目的に、ポincare-PODと深層ニューラルネットワーク(DNN)を組み合わせたPOD-DNN手法の開発や、学習データ量に左右されにくい構造の最適化を実現する「ネストドPOD-DNN」の提案を行っています。また、スーパーマーケットにおける冷蔵・冷凍ショーケースの熱漏れや換気条件がエネルギー消費に与える影響をCFDモデルを用いて定量的に評価し、省エネと快適性向上のための実用的戦略の提案も行っています。
Figures are computed from collected data and may differ slightly.
Abstract Computational fluid dynamics (CFD) is widely used to predict the indoor thermal environment; however, large time cost represents a significant disadvantage. Several deep learning approaches have been introduced to reduce prediction time in steady‐state predictions, though their feasibility under unsteady ones has yet to be investigated. Considering the flexibility of the multilayer perceptron (MLP) input–output format, this study compared the performance of two MLP input–output formats,
The purpose of this study is evaluating energy consumption and the indoor thermal environment of grocery stores, which using frozen and refrigerated display cases, by taking temperature distribution into consideration. In this report, store CFD models which can evaluate the indoor temperature distribution were adopted to study the influence, made by temperature or ventilation flux altering, on energy consumption of grocery stores. The results indicate that the mixture of indoor air, no matter af
In this study, to predict unsteady temperature distributions, POD-DNN was utilized, where DNN was trained to predicted coefficients of POMs. Two strategies, flatten POD-DNN and nested POD-DNN were compared. The flatten POD-DNN provided high accuracy if training data is sufficient, but otherwise very inaccurate. The nested POD-DNN roughly predicted the development of temperature fields even training data was small. The results showed their different sensitivities to the training data size.
Supermarkets and grocery stores represent an important energy-intensive role in the commercial sector. In Japan, grocery stores occupy 8% of energy consumption in the commercial sector. Refrigerated and frozen display cases are widely used in grocery stores and those occupation of energy consumption in a store range from 50% to 67%. In addition, plenty of research illustrated that alterations in humidity and temperature affect the cooling load of display cases. Also, cold air leaking from displa
In this report, some energy-saving and thermal comfort improving strategies adopted in a grocery store were estimated by using the store environment analysis CFD model. As results, by replacing the frozen multi-deck display cases with frozen reach-in cases, total energy consumption of cases and air conditioners decreased to 3/4 both in summer and winter, meanwhile it led to a more comfortable thermal environment. In winter, exhausting from the lower part of display cases resulted in 3% decreasin
For Bayesian network structure learning with continuous data, traditional methods typically require data discretization or assume that the data follows a Gaussian distribution. However, the processing method can result in information loss, and real-world data often deviates from the Gaussian assumption, leading to biased outcomes. To address these issues, we propose using the k-nearest neighbor (k-NN) algorithm to estimate mutual information and conditional mutual information for Bayesian networ
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